Advances in Physical Ergonomics and Human Factors: Proceedings of the AHFE 2019 International Conference on Physical Ergonomics and Human Factors, July 24-28, 2019, Washington D.C., USA [1st ed.] 978-3-030-20141-8;978-3-030-20142-5

This book reports on the state of the art in physical ergonomics and addresses the design of products, processes, servic

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Advances in Physical Ergonomics and Human Factors: Proceedings of the AHFE 2019 International Conference on Physical Ergonomics and Human Factors, July 24-28, 2019, Washington D.C., USA [1st ed.]
 978-3-030-20141-8;978-3-030-20142-5

Table of contents :
Front Matter ....Pages i-xiii
Front Matter ....Pages 1-1
Deep Learning Model to Recognize the Different Progression Condition Patterns of Manual Wheelchair Users for Prevention of Shoulder Pain (Jen-Yung Tsai, Yih-Kuen Jan, Ben-Yi Liau, Chien-Liang Chen, Peng-Je Chen, Chih-Yang Lin et al.)....Pages 3-13
Physical Workload Analysis in Processing Operations: Metal Processing Manufacturing (Zenija Roja, Henrijs Kalkis, Sandis Babris, Inara Roja, Kristine Bokse, Ansis Ventins)....Pages 14-21
The Role of Stakeholders in E-Occupational Health and Safety System in Estonia (Inese Vilcane, Tarmo Koppel, Henrijs Kalkis, Olga Tsenter, Piia Tint)....Pages 22-33
Influence of the Upper Limb Position on the Forearm EMG Activity – Preliminary Results (Ilona Kačerová, Marek Bureš, Martin Kába, Tomáš Görner)....Pages 34-43
Preschool Children’s Product Design Based on Heart Flow Theory (Wei Wang, Fangyu Li)....Pages 44-56
Ergonomic Risk Evaluation of the Manual Handling Task of Bovine Quarters in a Brazilian Slaughterhouse (Adriana Seára Tirloni, Diogo Cunha dos Reis, Natália Fonseca Dias, Antônio Renato Pereira Moro)....Pages 57-69
Influence of Location and Frequency Variations of Binaural Electrostimulation on Heart Rate Variability (Jing-Shia Tang, Nan-Ying Yu, Fang-Hsin Lee, Chi-Wen Lung, Liang-Cheng Lee, Ben-Yi Liau et al.)....Pages 70-79
A Study of the Correlation Between Payload and Whole-Body Vibration of a Scooter Rider (Shih-Yi Lu, Yen-Hui Lin)....Pages 80-85
Physiological Indicators of Mental Workload in Visual Display Terminal Work (Yi Ding, Yaqin Cao, Yi Wang)....Pages 86-94
Study on the Changes of Physical Status Under the Condition of Lacking Food and Water on Oxygen-Deficient Plateau (Xingwei Wang, Lue Deng, Hailiang Zhou, Qin Yao, Heqing Liu, Weiping Bu et al.)....Pages 95-105
An Evaluation of Work Posture by REBA: A Case Study in Maintenance Department (Nanthawan Am-Eam, Patompong Jankaew, Kunthara Ninthappho, Thaweeuk Noosom)....Pages 106-114
Front Matter ....Pages 115-115
Can the Use of Well-Adjusted School Furniture Improve Students’ Performance? (Agostinho Fernandes, Nélson Costa, Paula Carneiro, Ana Cristina Braga)....Pages 117-123
Influence of Lumbar Support Prominence for a Car Seat in the Seating Pressure and Discomfort Perception (Luis Ortiz, Fernanda Maradei, Laura Guerrero, Paula Galvis)....Pages 124-134
Analysis of Work-Related Musculoskeletal Disorders on Office Workers at the Industrial University of Santander (Fernanda Maradei, Jenny Rodriguez, Javier Castellanos)....Pages 135-145
The Understanding and Influence of the Connotation of Semantics on the Figurative Product (Ching-Yi Wang, Peng-Jyun Liu)....Pages 146-156
Human Sweating Measurements (Xiaoli Fan, Chaoyi Zhao, Hong Luo, Wei Zhang)....Pages 157-164
Review of the Evaluation Methods of Mental Workload (Xiaoli Fan, Chaoyi Zhao, Huimin Hu, Yuwei Jiang)....Pages 165-172
Experts and Novices on the Recognition and Cognitive Differences of Brand Color (Ching-Yi Wang, Peng-Jyun Liu, Yu-Hsuan Chung, Yu-Ting Chen)....Pages 173-186
Ergonomic Requirements in the Design of High Performance Sports Suits: BMX Clothing (Fausto Zuleta Montoya, Gustavo Sevilla Cadavid, Blanca Echavarria-Bustamante, Johana Hoyos-Ruiz)....Pages 187-196
A Study on the Correlation of Foot Data with Body Height and Weight of Chinese Adults (Linghua Ran, Hong Luo, Chaoyi Zhao, Xin Zhang, Huimin Hu, Zhongting Wang)....Pages 197-203
Front Matter ....Pages 205-205
The Influence of the Transformation Between Standing and Cycling Position on Upper Body Dimensions (Thomas Peeters, Jochen Vleugels, Stijn Verwulgen, Guido De Bruyne)....Pages 207-212
Ergonomic Improvements in Heavy-Duty Four-Wheel Cart with Pelvis Support (Jaimin Patel, Nader Madkour, Jay Jani, Guru Prasadh Rao, Pawan Sharma, Yueqing Li)....Pages 213-221
Incidence and Postural Risk Factors for Low Back Pain Among Informal Garment Female Workers (Sunisa Chaiklieng, Thanyawat Homsombat)....Pages 222-230
Comparative Assessment of Classroom Desk Dimensions with Respect to Students Anthropometry for Females Middle Schools (Ahamed Altaboli, Aisha Akrim, Entsar Omar, Fatima Hamad, Sarah Ahmed)....Pages 231-241
Design and Research of Outdoor Rescue Products Based on Vital Signs and Cognitive Orientation (Wenjing Wang)....Pages 242-251
Design Research on Storage Space Product Service System for Automobile Passenger Transport (Wanqiang Li, Hong Hu, Jie Zhou)....Pages 252-263
Front Matter ....Pages 265-265
Risk-Based Thinking Methodology and Its Influence on Occupational Health and Safety Process (Hana Pacaiova, Anna Nagyova, Milan Oravec)....Pages 267-276
Effective Tools to Eliminate Dangerous Practices in the Performance of Work (Karol Habina, Jan Trcka)....Pages 277-286
Lift as Subject of Risk Analysis in the Context of Smart Buildings (Juraj Glatz, Juraj Sinay, Marianna Tomašková, Marta Vargová)....Pages 287-295
Study of Forklift Cab Shape Design Based on Behavior Analysis (Jing Ou, Yun-shuang Zheng, Jun Yi, Bing Guo)....Pages 296-308
Risk Assessment Software Tools (Jan Donič)....Pages 309-314
The Lean Solution of Hospice Service Design in the “Internet+” Era (Yang Zhao, Chengcheng Liu)....Pages 315-326
Compliance Supervision or Self-regulation: A New Research Perspective Based on Game Theory (Yuan Gao, Yunxiao Fan)....Pages 327-336
Front Matter ....Pages 337-337
Observing or Experiencing – The Effect of Age Simulation on the Sensitivity to Age-Related Impairment in Elderly Care (Danny Rueffert, Angelika C. Bullinger)....Pages 339-347
Strength and Motor Function in an Aging Population in Dependence to Work Position (Marek Bures, Vera Cadkova)....Pages 348-359
The Evaluation of Mechanical Properties of Soft Tissue on Pressure Ulcers Among Bedridden Elderly Patients (Chi-Wen Lung, Yih-Kuen Jan, Jin-Huei Lu, Chien-Liang Chen, Fang-Chuan Kuo, Ben-Yi Liau)....Pages 360-368
The Application of Lifecycle Design Strategies in the Interaction Design (Chengcheng Liu, Yang Zhao)....Pages 369-376
Ergonomics in Automotive Glass Manufacturing: Workers’ Perceptions of Strain (John Smallwood, Claire Deacon)....Pages 377-387
Enhancing the Life of the Elderly - An Application of Design Thinking (Ravindra S. Goonetilleke, Emily Yim Lee Au)....Pages 388-396
Human Listener’s Misperception Between Signal Comprehension in Noise and Noise Acceptability (Bankole K. Fasanya)....Pages 397-404
Front Matter ....Pages 405-405
Exploring the Balance Between Utilitarian and Hedonic Values of Wearable Products (Hassan Iftikhar, Parth Shah, Yan Luximon)....Pages 407-416
A Comparison of Traditional and 3D Scanning Measurement in Ear Anthropometry (Fang Fu, Ameersing Luximon, Yan Luximon)....Pages 417-423
A Novel Hybrid Personal Cooling System Incorporated with Dry Ice and Ventilation Fans to Mitigate the Heat Strain of Mascot Actors in a Hot and Humid Environment (Cathy Sin-Wei Chow, Faming Wang)....Pages 424-435
Modern Textile-Based Compression Device for Improving Venous Haemodynamics of Lower Extremities (Xinbo Wu, Rong Liu)....Pages 436-442
Back Matter ....Pages 443-445

Citation preview

Advances in Intelligent Systems and Computing 967

Ravindra S. Goonetilleke Waldemar Karwowski Editors

Advances in Physical Ergonomics and Human Factors Proceedings of the AHFE 2019 International Conference on Physical Ergonomics and Human Factors, July 24–28, 2019, Washington D.C., USA

Advances in Intelligent Systems and Computing Volume 967

Series Editor Janusz Kacprzyk, Systems Research Institute, Polish Academy of Sciences, Warsaw, Poland Advisory Editors Nikhil R. Pal, Indian Statistical Institute, Kolkata, India Rafael Bello Perez, Faculty of Mathematics, Physics and Computing, Universidad Central de Las Villas, Santa Clara, Cuba Emilio S. Corchado, University of Salamanca, Salamanca, Spain Hani Hagras, School of Computer Science & Electronic Engineering, University of Essex, Colchester, UK László T. Kóczy, Department of Automation, Széchenyi István University, Gyor, Hungary Vladik Kreinovich, Department of Computer Science, University of Texas at El Paso, El Paso, TX, USA Chin-Teng Lin, Department of Electrical Engineering, National Chiao Tung University, Hsinchu, Taiwan Jie Lu, Faculty of Engineering and Information Technology, University of Technology Sydney, Sydney, NSW, Australia Patricia Melin, Graduate Program of Computer Science, Tijuana Institute of Technology, Tijuana, Mexico Nadia Nedjah, Department of Electronics Engineering, University of Rio de Janeiro, Rio de Janeiro, Brazil Ngoc Thanh Nguyen, Faculty of Computer Science and Management, Wrocław University of Technology, Wrocław, Poland Jun Wang, Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin, Hong Kong

The series “Advances in Intelligent Systems and Computing” contains publications on theory, applications, and design methods of Intelligent Systems and Intelligent Computing. Virtually all disciplines such as engineering, natural sciences, computer and information science, ICT, economics, business, e-commerce, environment, healthcare, life science are covered. The list of topics spans all the areas of modern intelligent systems and computing such as: computational intelligence, soft computing including neural networks, fuzzy systems, evolutionary computing and the fusion of these paradigms, social intelligence, ambient intelligence, computational neuroscience, artificial life, virtual worlds and society, cognitive science and systems, Perception and Vision, DNA and immune based systems, self-organizing and adaptive systems, e-Learning and teaching, human-centered and human-centric computing, recommender systems, intelligent control, robotics and mechatronics including human-machine teaming, knowledge-based paradigms, learning paradigms, machine ethics, intelligent data analysis, knowledge management, intelligent agents, intelligent decision making and support, intelligent network security, trust management, interactive entertainment, Web intelligence and multimedia. The publications within “Advances in Intelligent Systems and Computing” are primarily proceedings of important conferences, symposia and congresses. They cover significant recent developments in the field, both of a foundational and applicable character. An important characteristic feature of the series is the short publication time and world-wide distribution. This permits a rapid and broad dissemination of research results. ** Indexing: The books of this series are submitted to ISI Proceedings, EI-Compendex, DBLP, SCOPUS, Google Scholar and Springerlink ** More information about this series at http://www.springer.com/series/11156

Ravindra S. Goonetilleke Waldemar Karwowski



Editors

Advances in Physical Ergonomics and Human Factors Proceedings of the AHFE 2019 International Conference on Physical Ergonomics and Human Factors, July 24–28, 2019, Washington D.C., USA

123

Editors Ravindra S. Goonetilleke Department of IELM Hong Kong University of Science and Technology Kowloon, Hong Kong

Waldemar Karwowski University of Central Florida Winter Park, FL, USA

ISSN 2194-5357 ISSN 2194-5365 (electronic) Advances in Intelligent Systems and Computing ISBN 978-3-030-20141-8 ISBN 978-3-030-20142-5 (eBook) https://doi.org/10.1007/978-3-030-20142-5 © Springer Nature Switzerland AG 2020 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, expressed or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. This Springer imprint is published by the registered company Springer Nature Switzerland AG The registered company address is: Gewerbestrasse 11, 6330 Cham, Switzerland

Advances in Human Factors and Ergonomics 2019

AHFE 2019 Series Editors Tareq Ahram, Florida, USA Waldemar Karwowski, Florida, USA

10th International Conference on Applied Human Factors and Ergonomics and the Affiliated Conferences Proceedings of the AHFE 2019 International Conference on Physical Ergonomics and Human Factors, held on July 24–28, 2019, in Washington D.C., USA

Advances in Affective and Pleasurable Design Advances in Neuroergonomics and Cognitive Engineering Advances in Design for Inclusion Advances in Ergonomics in Design Advances in Human Error, Reliability, Resilience, and Performance Advances in Human Factors and Ergonomics in Healthcare and Medical Devices Advances in Human Factors and Simulation Advances in Human Factors and Systems Interaction Advances in Human Factors in Cybersecurity Advances in Human Factors, Business Management and Leadership Advances in Human Factors in Robots and Unmanned Systems Advances in Human Factors in Training, Education, and Learning Sciences Advances in Human Factors of Transportation

Shuichi Fukuda Hasan Ayaz Giuseppe Di Bucchianico Francisco Rebelo and Marcelo M. Soares Ronald L. Boring Nancy J. Lightner and Jay Kalra Daniel N. Cassenti Isabel L. Nunes Tareq Ahram and Waldemar Karwowski Jussi Ilari Kantola and Salman Nazir Jessie Chen Waldemar Karwowski, Tareq Ahram and Salman Nazir Neville Stanton (continued)

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Advances in Human Factors and Ergonomics 2019

(continued) Advances in Artificial Intelligence, Software and Systems Engineering Advances in Human Factors in Architecture, Sustainable Urban Planning and Infrastructure Advances in Physical Ergonomics and Human Factors Advances in Interdisciplinary Practice in Industrial Design Advances in Safety Management and Human Factors Advances in Social and Occupational Ergonomics Advances in Manufacturing, Production Management and Process Control Advances in Usability and User Experience Advances in Human Factors in Wearable Technologies and Game Design Advances in Human Factors in Communication of Design Advances in Additive Manufacturing, Modeling Systems and 3D Prototyping

Tareq Ahram Jerzy Charytonowicz and Christianne Falcão Ravindra S. Goonetilleke and Waldemar Karwowski Cliff Sungsoo Shin Pedro M. Arezes Richard H. M. Goossens and Atsuo Murata Waldemar Karwowski, Stefan Trzcielinski and Beata Mrugalska Tareq Ahram and Christianne Falcão Tareq Ahram Amic G. Ho Massimo Di Nicolantonio, Emilio Rossi and Thomas Alexander

Preface

The discipline of human factors and ergonomics (HF/E) is concerned with the design of products, process, services and work systems to assure their productive, safe and satisfying use by people. Physical ergonomics involves the design of working environments to fit human physical abilities. By understanding the constraints and capabilities of the human body and mind, we can design products, services and environments that are effective, reliable, safe and comfortable for everyday use. A thorough understanding of the physical characteristics of a wide range of people is essential in the development of consumer products and systems. Human performance data serve as valuable information to designers and help ensure that the final products will fit the targeted population of end users. Mastering physical ergonomics and safety engineering concepts is fundamental to the creation of products and systems that people can use, avoidance of stresses and minimization of the risk for accidents. This book focuses on the advances in the physical HF/E, which are a critical aspect in the design of any human-centered technological system. The ideas and practical solutions described in this book are the outcomes of dedicated research by academics and practitioners aiming to advance theory and practice in this dynamic and all-encompassing discipline. A total of six sections are presented in this book: Section Section Section Section

1 2 3 4

Section 5 Section 6

Physical ergonomics and work-related musculoskeletal disorders Physical ergonomics and comfort Design, anthropometry and posture New trends of development and application of risk analyses methods in the strategy of Industry 4.0 Design for people Ergonomics design of wearables

Each section contains research papers that have been reviewed by the members of the international editorial board. Our sincere thanks and appreciation to Board Members as listed below: Sandra Alemany, Spain Mark Boocock, New Zealand

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Preface

Emilio Cadavid, Colombia Jack Callaghan, Canada Wen-Ruey Chang, USA Patrick Dempsey, USA Robert Feyen, USA Jerzy Grobelny, Poland Thomas Hofmann, Germany Jon James, South Africa Henrijs Kalkis, Latvia Kentaro Kotani, Japan Y. Kwon, Korea Mark Lehto, USA Chi-Wen Lung, Taiwan Ameersing Luximon, Hong Kong Liang Ma, China S. Maly, Czech Republic Mahiyar Nasarwanji, USA J. Niu, China Enrico Occhipinti, Italy Y. Okada, Japan H. Pacaiova, Slovak Republic Gunther Paul, Australia P. K. Ray, India Uwe Reischl, USA Zenjia Roja, Latvia Luz Saenz, Colombia Luo Shijan, China Juraj Sinay, Slovak Republic Shamsul Bahri Hj Mohd Tamrin, Malaysia Shuping Xiong, Korea James Yang, USA We hope that this book, which is the international state of the art in the physical domain of human factors, will be a valuable source of theoretical and applied knowledge enabling the human-centered design of a variety of products, services and systems for global markets. July 2019

Ravindra S. Goonetilleke Waldemar Karwowski

Contents

Physical Ergonomics and Work-Related Musculoskeletal Disorders Deep Learning Model to Recognize the Different Progression Condition Patterns of Manual Wheelchair Users for Prevention of Shoulder Pain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Jen-Yung Tsai, Yih-Kuen Jan, Ben-Yi Liau, Chien-Liang Chen, Peng-Je Chen, Chih-Yang Lin, Yi-Chun Liu, and Chi-Wen Lung Physical Workload Analysis in Processing Operations: Metal Processing Manufacturing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Zenija Roja, Henrijs Kalkis, Sandis Babris, Inara Roja, Kristine Bokse, and Ansis Ventins

3

14

The Role of Stakeholders in E-Occupational Health and Safety System in Estonia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Inese Vilcane, Tarmo Koppel, Henrijs Kalkis, Olga Tsenter, and Piia Tint

22

Influence of the Upper Limb Position on the Forearm EMG Activity – Preliminary Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ilona Kačerová, Marek Bureš, Martin Kába, and Tomáš Görner

34

Preschool Children’s Product Design Based on Heart Flow Theory . . . . Wei Wang and Fangyu Li Ergonomic Risk Evaluation of the Manual Handling Task of Bovine Quarters in a Brazilian Slaughterhouse . . . . . . . . . . . . . . . . . Adriana Seára Tirloni, Diogo Cunha dos Reis, Natália Fonseca Dias, and Antônio Renato Pereira Moro Influence of Location and Frequency Variations of Binaural Electrostimulation on Heart Rate Variability . . . . . . . . . . . . . . . . . . . . . Jing-Shia Tang, Nan-Ying Yu, Fang-Hsin Lee, Chi-Wen Lung, Liang-Cheng Lee, Ben-Yi Liau, and Chien-Liang Chen

44

57

70

ix

x

Contents

A Study of the Correlation Between Payload and Whole-Body Vibration of a Scooter Rider . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Shih-Yi Lu and Yen-Hui Lin

80

Physiological Indicators of Mental Workload in Visual Display Terminal Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Yi Ding, Yaqin Cao, and Yi Wang

86

Study on the Changes of Physical Status Under the Condition of Lacking Food and Water on Oxygen-Deficient Plateau . . . . . . . . . . . Xingwei Wang, Lue Deng, Hailiang Zhou, Qin Yao, Heqing Liu, Weiping Bu, and Yongchang Luo

95

An Evaluation of Work Posture by REBA: A Case Study in Maintenance Department . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 Nanthawan Am-Eam, Patompong Jankaew, Kunthara Ninthappho, and Thaweeuk Noosom Physical Ergonomics and Comfort Can the Use of Well-Adjusted School Furniture Improve Students’ Performance? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117 Agostinho Fernandes, Nélson Costa, Paula Carneiro, and Ana Cristina Braga Influence of Lumbar Support Prominence for a Car Seat in the Seating Pressure and Discomfort Perception . . . . . . . . . . . . . . . . 124 Luis Ortiz, Fernanda Maradei, Laura Guerrero, and Paula Galvis Analysis of Work-Related Musculoskeletal Disorders on Office Workers at the Industrial University of Santander . . . . . . . . . . . . . . . . 135 Fernanda Maradei, Jenny Rodriguez, and Javier Castellanos The Understanding and Influence of the Connotation of Semantics on the Figurative Product . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 Ching-Yi Wang and Peng-Jyun Liu Human Sweating Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 Xiaoli Fan, Chaoyi Zhao, Hong Luo, and Wei Zhang Review of the Evaluation Methods of Mental Workload . . . . . . . . . . . . 165 Xiaoli Fan, Chaoyi Zhao, Huimin Hu, and Yuwei Jiang Experts and Novices on the Recognition and Cognitive Differences of Brand Color . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173 Ching-Yi Wang, Peng-Jyun Liu, Yu-Hsuan Chung, and Yu-Ting Chen

Contents

xi

Ergonomic Requirements in the Design of High Performance Sports Suits: BMX Clothing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187 Fausto Zuleta Montoya, Gustavo Sevilla Cadavid, Blanca Echavarria-Bustamante, and Johana Hoyos-Ruiz A Study on the Correlation of Foot Data with Body Height and Weight of Chinese Adults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197 Linghua Ran, Hong Luo, Chaoyi Zhao, Xin Zhang, Huimin Hu, and Zhongting Wang Design, Anthropometry and Posture The Influence of the Transformation Between Standing and Cycling Position on Upper Body Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . 207 Thomas Peeters, Jochen Vleugels, Stijn Verwulgen, and Guido De Bruyne Ergonomic Improvements in Heavy-Duty Four-Wheel Cart with Pelvis Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 Jaimin Patel, Nader Madkour, Jay Jani, Guru Prasadh Rao, Pawan Sharma, and Yueqing Li Incidence and Postural Risk Factors for Low Back Pain Among Informal Garment Female Workers . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222 Sunisa Chaiklieng and Thanyawat Homsombat Comparative Assessment of Classroom Desk Dimensions with Respect to Students Anthropometry for Females Middle Schools . . . . . . . . . . . . 231 Ahamed Altaboli, Aisha Akrim, Entsar Omar, Fatima Hamad, and Sarah Ahmed Design and Research of Outdoor Rescue Products Based on Vital Signs and Cognitive Orientation . . . . . . . . . . . . . . . . . . . 242 Wenjing Wang Design Research on Storage Space Product Service System for Automobile Passenger Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . 252 Wanqiang Li, Hong Hu, and Jie Zhou New Trends of Development and Application of Risk Analyses Methods in the Strategy of Industry 4.0 Risk-Based Thinking Methodology and Its Influence on Occupational Health and Safety Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267 Hana Pacaiova, Anna Nagyova, and Milan Oravec Effective Tools to Eliminate Dangerous Practices in the Performance of Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277 Karol Habina and Jan Trcka

xii

Contents

Lift as Subject of Risk Analysis in the Context of Smart Buildings . . . . 287 Juraj Glatz, Juraj Sinay, Marianna Tomašková, and Marta Vargová Study of Forklift Cab Shape Design Based on Behavior Analysis . . . . . 296 Jing Ou, Yun-shuang Zheng, Jun Yi, and Bing Guo Risk Assessment Software Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309 Jan Donič The Lean Solution of Hospice Service Design in the “Internet+” Era . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315 Yang Zhao and Chengcheng Liu Compliance Supervision or Self-regulation: A New Research Perspective Based on Game Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327 Yuan Gao and Yunxiao Fan Design for People Observing or Experiencing – The Effect of Age Simulation on the Sensitivity to Age-Related Impairment in Elderly Care . . . . . . . . 339 Danny Rueffert and Angelika C. Bullinger Strength and Motor Function in an Aging Population in Dependence to Work Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348 Marek Bures and Vera Cadkova The Evaluation of Mechanical Properties of Soft Tissue on Pressure Ulcers Among Bedridden Elderly Patients . . . . . . . . . . . . . 360 Chi-Wen Lung, Yih-Kuen Jan, Jin-Huei Lu, Chien-Liang Chen, Fang-Chuan Kuo, and Ben-Yi Liau The Application of Lifecycle Design Strategies in the Interaction Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 369 Chengcheng Liu and Yang Zhao Ergonomics in Automotive Glass Manufacturing: Workers’ Perceptions of Strain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 377 John Smallwood and Claire Deacon Enhancing the Life of the Elderly - An Application of Design Thinking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 388 Ravindra S. Goonetilleke and Emily Yim Lee Au Human Listener’s Misperception Between Signal Comprehension in Noise and Noise Acceptability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 397 Bankole K. Fasanya

Contents

xiii

Ergonomics Design of Wearables Exploring the Balance Between Utilitarian and Hedonic Values of Wearable Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 407 Hassan Iftikhar, Parth Shah, and Yan Luximon A Comparison of Traditional and 3D Scanning Measurement in Ear Anthropometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 417 Fang Fu, Ameersing Luximon, and Yan Luximon A Novel Hybrid Personal Cooling System Incorporated with Dry Ice and Ventilation Fans to Mitigate the Heat Strain of Mascot Actors in a Hot and Humid Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 424 Cathy Sin-Wei Chow and Faming Wang Modern Textile-Based Compression Device for Improving Venous Haemodynamics of Lower Extremities . . . . . . . . . . . . . . . . . . . . . . . . . . 436 Xinbo Wu and Rong Liu Author Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 443

Physical Ergonomics and Work-Related Musculoskeletal Disorders

Deep Learning Model to Recognize the Different Progression Condition Patterns of Manual Wheelchair Users for Prevention of Shoulder Pain Jen-Yung Tsai1, Yih-Kuen Jan2,3,4, Ben-Yi Liau5, Chien-Liang Chen6, Peng-Je Chen7, Chih-Yang Lin8, Yi-Chun Liu9, and Chi-Wen Lung2,9(&) 1

2

7

9

Department of Digital Media Design, Asia University, Taichung, Taiwan [email protected] Rehabilitation Engineering Lab, University of Illinois at Urbana-Champaign, Champaign, IL, USA 3 Kinesiology & Community Health, University of Illinois at Urbana-Champaign, Champaign, IL, USA 4 Computational Science and Engineering, University of Illinois at Urbana-Champaign, Champaign, IL, USA 5 Department of Biomedical Engineering, Hungkuang University, Taichung, Taiwan 6 Department of Physical Therapy, I-Shou University, Kaohsiung, Taiwan Health Industry Development Working Committee of China, Beijing, China 8 Electrical Engineering, Yuan Ze University, Chung-Li, Taiwan Department of Creative Product Design, Asia University, Taichung, Taiwan [email protected]

Abstract. Wheelchair user will use different propulsion strategies to control in a variety of progression conditions that may induce the shoulder pain. The hypothesis of this study is that wheelchair user in different progression conditions has different ways to control the wheelchair. The purpose of this study is to use the accelerometer to recognize the movement of the wheelchair. It can be easily used to define the different progression condition in order to know the cause of the inducement of shoulder pain. The researchers collected acceleration data during the wheelchair progression in rough and smooth distinguishing surfaces: (1) outdoor grassland and; (2) indoor flatland. Researchers transformed the acceleration data into spectrogram files and training convolutional neural network (CNN) deep learning model to accurately recognize and predict wheelchair user’s wheelchair location. As the results, the wheelchair user’s medial-lateral direction of acceleration is expected to present more significant features than the front-back motion when being related to progression condition. At the same time, the vertical direction of acceleration also reflected the wheelchair vibration during different surface of progression condition. Keywords: Propulsion strategy Convolutional neural network

 Acceleration  Spectrogram 

© Springer Nature Switzerland AG 2020 R. S. Goonetilleke and W. Karwowski (Eds.): AHFE 2019, AISC 967, pp. 3–13, 2020. https://doi.org/10.1007/978-3-030-20142-5_1

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1 Introduction Wheelchair users rely on the manual wheelchair to restore daily mobility. Shoulder pain in manual wheelchair users with paraplegia is very common. Their shoulders unavoidably overuse both arms to propel and control the wheelchair. During the previous report, there are around 50% to 70% of patients who use manual wheelchairs and experienced upper limb pain [1]. The wheelchair user shoulder joint carry more pressure related to the resistance force of the propulsion over the rough pathway. These users may often feel that they have too much weight on their shoulders and this leads them to having shoulder pain. Shoulder pain could bring more complicated problems in the shoulder joint. The shoulders could bear the weights by receiving too much pressure across the subacromial area during the manual control of the wheelchair [2]. It also shows that wheelchair user’s shoulder pressure significantly relates to increasing the crisis of acromioclavicular joint edema or coracoacromial ligament thickening [3]. While the other report shows that over usage of the shoulder could increase the damage at high compression forces on the glenohumeral joint heavy loading on rotator cuff muscles, the subacromial bursa, and tendinopathy [1, 4]. It is more important to understand that manual wheelchair users propel and control in their living environment. It could be in any way and progression surface that they run over with the wheelchair, either on the bumps, ramps, and rough surface of the pathway. The related studies report that wearable sensors have been used to detect and collect the data of human or mobility behavior then processed by the programmable classification [5, 6]. The accelerometer records the velocity change rate of the wheelchair that is separated by x-y-z axial vector quantity. As previously mentioned on the report, it has been said that they collected human activity data by attaching the accelerometer on the external limbs [6]. The extracted and obtained features from each of the axis signals of accelerometer are turning into acceleration-magnitude signal, and it is usually being expressed in time-domain signal. Furthermore, the coordinate acceleration expresses the object movement with vibration, rotation, and falling. The time-domain signal is not directly referring to the specific movement or position [7]. They use time-domain signal data of accelerometer to train convolutional neural network (CNN) and recognize the human activity pattern. In deep learning, CNN is a class of deep neural networks, most commonly applies to analyze visual imagery. However, it is difficult to provide suitable graphic features to satisfy training CNN for time-domain signal. In the end, a spectrogram may use for CNN to gather visual representation of the spectrum of frequencies of a signal as it varies with time. The hypothesis of this study is that training model may have high accuracy to classify the different progression condition for a variety of propulsion strategy. The purpose of this study is to understand how the propulsion strategy affects the shoulder pain in relation to the acceleration.

Deep Learning Model to Recognize

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2 Methods To implement the researchers’ study and verify the hypothesis, researchers expect to build a novel method for predicting propulsion strategy by dynamic data. There were two distinguishing features of wheelchair progression condition that were used in this study. First is indoor flatland to feature smooth surface while the other is outdoor grassland to feature the rough surface. They were used to collect acceleration of dynamic data and process deep learning for classification of the two distinguishing features. It could capture and induce each axis of acceleration data to process visual recognition to find out which axis that is most related to wheelchair user’s propulsion strategy. At the end of the study, the spectrogram has been used for clearer visual representation. The result summarizes the different propulsion strategies to influence shoulder pain (Fig. 1).

Measurement & Collection of Dynamic Data

>

Time Domain Signal Data Induce Spectrogram

>

CNN Training Model & Prediction

>

Reflect Human Strategies

Fig. 1. Methodology diagram for the CNN model in preventing shoulder pain.

2.1

Subject of the Study

The researchers recruited a normal subject (male, 49 years old, 176 cm, 77 kg, no shoulder pain or upper limbs injury history) to understand X, Y and Z axis of accelerometer data about manual wheelchair user’s propulsion strategy. The researchers also described the purpose of the experiment to the subject and informed him to use both hands to propel a manual wheelchair. For collecting data in propulsion wheelchair, two distinguishing features have been used for progression condition. Researchers set up two locations which both size is 1350 x 550 cm. The subject propelled the wheelchair along the rectangular area moving non-stop with counter-clockwise direction until 20 min (Fig. 2).

(A) Indoor flatland

(B) Outdoor grassland

1350 cm

550 cm

1350 cm

550 cm

Fig. 2. Distinguishing features for progression condition in this study. (A) Indoor flatland and; (B) Outdoor grassland.

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Device Setting and Data Collection

To easily utilize the convenience trend, researchers used the smartphone with an accelerometer that contains the microchip (Bosch BMI120, LGA package 2.5  3.0  0.8 mm3) to measure different axial acceleration. Then, researchers also set the smartphone horizontally attached on the left armrest of manual wheelchair for acceleration data collection (Fig. 3). The smartphone position refers to the accelerometer direction including medial-lateral (x-axis), front-back (y-axis), vertical (z-axis) with unit timestamp. The accelerometer set the acquisition rate at 40 Hz.

Fig. 3. Smartphone horizontal attached on left armrest of manual wheelchair to collect accelerometer data. The wheelchair front direction is y-axis of the accelerometer.

2.3

Data Augmentation

These time domain signal data are the raw data of acceleration. They have to undergo visual processing before researchers recognize training CNN as a model [6]. The wheelchair accelerometer data were separated and extracted to single x-axis, y-axis and z-axis data into two distinguishing features of “outdoor grassland” and “indoor flatland” (Fig. 4). Then researchers extracted and separated the 5 and 10-s as a process from each group accelerometer data as a single graphic for the wheelchair propulsion feature. The spectrogram is a visual file for providing more features to the CNN training model. Although, researchers got these spectrogram files and the file quantities are not enough to train CNN model. For solving this situation, researchers resized the spectrogram images and added them to increase the number of images into the small dataset [8]. 2.4

CNN Classification and Recognition

The study’s CNN model follows the architecture of AlexNet to build classification model of manual wheelchair progression condition. Researchers used five convolution layers (Activation function: ReLU) with max pooling layers and two fully-connected layers under Tensorflow structure by Python. One advantage of using Tensorflow and Python is that the model could use both central processing unit (CPU) and graphics

Deep Learning Model to Recognize

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(A) Indoor flatland

(B) Outdoor grassland

Fig. 4. The X, Y, and Z axis 10-s data transform into the single spectrogram. Each spectrogram is a visual data for CNN training. (A) Indoor flatland and; (B) Outdoor grassland.

processing unit (GPU) to feed the training data of minibatch into convolution layers and distributed into GPU to speed up training time for processing large number calculation of visual recognition [9] (Fig. 5). This model runs 100-epoch to train with minibatch size 128 of the dataset. Researchers set the function of dropout rate at 80% increase training speed. It could use the one-hot function to encode and convert the images for calculating cross-entropy. After that, researchers used the Adam optimizer to make the learning rate more stable and efficient [10].

J.-Y. Tsai et al. Blue layer Green layer Red layer

Frequency

8

Time

Time

Time-domain signal

Spectrogram

Max Pool

Max Pool

5 x 5 x 32

ReLU

conv4

conv5

conv3

conv2

conv1

ReLU

Max Pool

5 x 5 x 64

5 x 5 x 128

Dense

Max Pool

5 x 5 x 256

5 x 5 x 256

………………

ReLU

ReLU

ReLU

224 x 224 x 3

Feature 1 Feature 2 SoŌmax

2048 2048

Fig. 5. The study follows AlexNet architecture to build convolutional neural network (CNN) model to classify the images.

3 Results It transforms each of the X, Y, and Z axis accelerometer data into a single spectrogram. There are 1,440 files of 5-s and 720 files of 10-s acceleration data that have been generated to the spectrogram then have been resized for data augmentation. The spectrogram contains visual data to increase the recognition features. The researchers trained the CNN model to recognize the spectrogram of “outdoor grassland” and “indoor flatland” in each dataset of x-axis, y-axis, z-axis, and x-y-z axis. The model runs entire epoch to learn these spectrogram features. Furthermore, researchers observed the loss function value in every training epoch. The model training also loss function in approaching to zero that presents a good learning rate (Fig. 6). CNN Training Loss

0.7

x-y-z axis x axis y axis z axis

0.6

Total Loss

0.5 0.4 0.3

0.2 0.1 0 1

11

21

31

41

51

61

71

81

91

101

111

121

Epochs

Fig. 6. The diagram shows the loss function value in approach to zero in each dataset of the axes.

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The results of training CNN model have been generated to recognize wheelchair progression condition. After training and validation, the model could learn to classify the spectrogram into “outdoor grassland” or “indoor flatland”. The validation accuracy of x-axis, y-axis, z-axis, and x-y-z axis are 83.3%, 70.2%, 85.8% and 78.1%, separately (Table 1). These results matched our hypothesis that training model can classify the different progression condition for a variety of propulsion strategy. Therefore, the feature of x-axis (medial-lateral direction) is more distinguished than y-axis (front-back direction). Table 1. The results of CNN training model Flatland/Grass Axis x y Loss 0.000005 0.000049 Validate accuracy 83.3% 70.2% Note: accelerometer direction including front-back (y-axis), vertical (z-axis).

z x-y-z 0.000005 0.000042 85.8% 78.1% medial-lateral (x-axis),

4 Discussion The experiment shows that manual wheelchair really caused shoulder pain to the users. However, as the hypothesis stated, CNN training model can classify the different progression condition for a variety of propulsion strategy to help wheelchair users lessen the joint pain. At the end, the medial-lateral direction (x-axis, 83.3%) provides more accurate results than front-back direction (y-axis, 70.2%). The “outdoor grassland” wave peaks’ number are obviously more than the “indoor flatland.” Researchers examined the acceleration diagram that showed the wheelchair progression condition. The medial-lateral acceleration does not just show the dramatic vibration but is also related to the propulsion with left-right force on a certain period of time (Fig. 7).

(B) Outdoor grassland

AcceleraƟon (G)

AcceleraƟon (G)

(A) Indoor flatland

Time (Frame, 40Hz)

Time (Frame, 40Hz)

Fig. 7. A representative of the medial-lateral direction 10-s results. There are three wave peaks over acceleration at “outdoor grassland” while only one for “indoor flatland.”

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The medial-lateral acceleration might reflect shoulder pain crisis that refers to wheelchair user’s keeping of the correct direction for the propulsion on different progression condition. It could also refer to the wheelchair user’s having to use extra power in the balance of both arms. The balance is important for the wheelchair progression. The user exerts more effort in his shoulder for a careful control progression in rough surface like grassland. This causes the user to control the wheelchair moving forward in a balanced state (Fig. 8).

LeŌ

Right

Fig. 8. The wheelchair user uses both arms to propel the wheelchair to control the wheelchair moving forward in a balanced state.

The wheelchair user exposed a situation of the shoulder pain risk that causes shoulder joint to wear and tear as stated in the previous study [11]. The peak acceleration of front-back direction (y-axis) showed the wheelchair forward propulsion. Researchers have seen the different waveform diagrams between “outdoor grassland” and “indoor flatland.” These front-back direction diagrams could also represent the wheelchair progression condition. When the wheelchair has been propelled at “outdoor grassland,” user may use more time to roll forward in the push rim (Fig. 9). Wheelchair user may use different propulsion strategy to move forward in different distinguishing feature of progression condition. The status of vertical acceleration (z-axis) refers to wheelchair vibration in different progression condition. When the wheelchair propelled at “outdoor grassland,” it may have more vibrations than “indoor flatland” (Fig. 10). The deep learning of CNN has a higher accuracy in vertical acceleration, that means it may recognize rough or smooth surface by the magnitude vibration of wheelchair in progression. In the different locations, the wheelchair user’s propulsion strategy refers to carefully controlling of the wheelchair in forward direction with the use of upper limbs. The limitation of this study is that researchers only included a normal subject. As this is a preliminary study, researchers focused on using a wearable smart device for building the method. In the future work, researchers will recruit wheelchair user with shoulder pain for advanced study. These methods can be used in the future for clinical field study to profile the wheelchair user’s propulsion strategy in relation with Wheelchair User’s Shoulder Pain Index (WUSPI) or Brief Pain Inventory (BPI) [12]. Using the

Deep Learning Model to Recognize

(B) Outdoor grassland

AcceleraƟon (G)

(A) Indoor flatland

11

gentle propel hard

gentle

gentle propel hard

propel hard

gentle

propel hard propel hard

Time (Frame, 40Hz)

Fig. 9. A representative of the front-back direction 10-s results. There are four repeated times of hard propulsion over acceleration at “outdoor grassland” while two only for “indoor flatland.”

(A) Indoor flatland

(B) Outdoor grassland Z

AcceleraƟon (G)

AcceleraƟon (G)

Z

Time (Frame, 40Hz)

Time (Frame, 40Hz)

Fig. 10. A representative of the vertical direction 10-s results. There is more vibration over the acceleration at “outdoor grassland” than “indoor flatland.”

mobile or wearable smart device, more studies and applications would be developed on human activity recognition including health control, aging monitoring and preventive medicine.

5 Conclusion Although this is a preliminary study, researchers have trained CNN model to recognize the untrained spectrogram of wheelchair progression condition and predict the location as well. It has been found out that each axis could represent different characteristics.

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This study does not only intend to develop a method to use a smartphone with the accelerometer to collect wheelchair user’s dynamic data. This study also discovered that the medial-lateral direction of acceleration is more accurate than front-back direction in the CNN model to recognize the feature. The vertical direction of acceleration can get the vibration of the wheelchair in distinguishing surface. In conclusion, the propulsion strategy in wheelchair users may focus on the mediallateral direction to carefully control the wheelchair in different progression condition. Acknowledgments. The authors would like to thank Mr. Fityanul Akhyar, M.Sc. and Miss Claudine Roque, B.Sc. for their assistance. This study was supported by the Ministry of Science and Technology of the Republic of China (MOST-106-2218-E-468-001, MOST-107-2813-C468-007-E, MOST-107-2813-C-468-096-E, MOST-107-2813-C-468-097-E,), and Asia University Hospital and China Medical University Hospital (ASIA-105-CMUH-19 and ASIA-106CMUH-06).

References 1. Alm, M., Saraste, H., Norrbrink, C.: Shoulder pain in persons with thoracic spinal cord injury: prevalence and characteristics. J. Rehabil. Med. 40, 277–283 (2008) 2. Patel, R.M., Gelber, J.D., Schickendantz, M.S.: The weight-bearing shoulder. J. Am. Acad. Orthop. Surg. 26, 3–13 (2018) 3. Mercer, J.L., Boninger, M., Koontz, A., Ren, D., Dyson-Hudson, T., Cooper, R.: Shoulder joint kinetics and pathology in manual wheelchair users. Clin. Biomech. (Bristol, Avon) 21, 781–789 (2006) 4. Sie, I.H., Waters, R.L., Adkins, R.H., Gellman, H.J.A.: Upper extremity pain in the postrehabilitation spinal cord injured patient. Arch. Phys. Med. Rehabil. 73, 44–48 (1992) 5. Rawashdeh, S.A., Rafeldt, D.A., Uhl, T.L.: Wearable IMU for shoulder injury prevention in overhead sports. Sensors 16, 1847 (2016) 6. Munoz-Organero, M., Powell, L., Heller, B., Harpin, V., Parker, J.: Automatic extraction and detection of characteristic movement patterns in children with ADHD based on a convolutional neural network (CNN) and acceleration images. Sensors (Basel) 18, 3924 (2018) 7. Vanrell, S.R., Milone, D.H., Rufiner, H.L., Vanrell, S.R., Milone, D.H., Rufiner, H.L.: Assessment of homomorphic analysis for human activity recognition from acceleration signals. IEEE J. Biomed. Health Inform. 22, 1001–1010 (2018) 8. Lotter, W., Sorensen, G., Cox, D.: A multi-scale cnn and curriculum learning strategy for mammogram classification. In: Deep Learning in Medical Image Analysis and Multimodal Learning for Clinical Decision Support, pp. 169–177. Springer (2017) 9. Krizhevsky, A., Sutskever, I., Hinton, G.E.: ImageNet classification with deep convolutional neural networks. In: Advances in Neural Information Processing Systems, pp. 1097–1105 (2012) 10. Tomori, S., Kadoya, N., Takayama, Y., Kajikawa, T., Shima, K., Narazaki, K., Jingu, K.: A deep learning-based prediction model for gamma evaluation in patient-specific quality assurance. Med. Phys. 45, 4055–4065 (2018)

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11. Van Straaten, M.G., Cloud, B.A., Zhao, K.D., Fortune, E., Morrow, M.M.B.: Maintaining shoulder health after spinal cord injury: a guide to understanding treatments for shoulder pain. Arch. Phys. Med. Rehabil. 98, 1061–1063 (2017) 12. Sawatzky, B.J., Slobogean, G.P., Reilly, C.W., Chambers, C.T., Hol, A.T.: Prevalence of shoulder pain in adult- versus childhood-onset wheelchair users: a pilot study. J. Rehabil. Res. Dev. 42, 1–8 (2005)

Physical Workload Analysis in Processing Operations: Metal Processing Manufacturing Zenija Roja1(&), Henrijs Kalkis1,2, Sandis Babris3, Inara Roja4, Kristine Bokse1,2, and Ansis Ventins2 1

3

University of Latvia, Raina blvd.19, Riga, Latvia {zenija.roja,henrijs.kalkis}@lu.lv 2 Riga Stradins University, Riga, Latvia [email protected] BA School of Business and Finance, K. Valdemara street 161, Riga, Latvia [email protected] 4 Riga 1st Hospital, Bruninieku 5, Riga LV-1001, Latvia [email protected]

Abstract. The aim of this study is to perform physical workload analysis in metal processing industry operations (assembly operators, packaging operators and inspection staff) using objective ergonomics research methods based on the heart rate monitoring and muscle fatigue. The study was carried out in a medium sized metal manufacturing enterprise in Latvia in the department of manufacturing of ironing boards. Assembly, packaging operators and inspection staff agreed to take part in the objective heart rate monitoring and muscle myotonometry measurements. Results show that workers are at high risk of developing WMSDs, since they are subjected to heavy manual work and load on muscles during work. Accordingly to the heart rate analysis the assembly operators and packing operators can be subdivided into heavy work category, but inspection staff- in moderately heavy category. Myotonometry investigation results confirm muscle fatigue and heaviness of physical workload. Keywords: Production

 Operators  Heart rate  Miotonometry

1 Introduction Processing industry is one of the leading industries of Latvian economy. The number of WRMSDs in manufacturing of finished metal products has been growing since the recent years. Great influence is on physical ergonomics that analyses work-related musculoskeletal disorders in various economics sectors as well as in industrial manufacturing. The manufacturing operations requires a many manual handling activities, awkward postures, lifting and moving big, heavy and inconvenient products [1]. It can result in very serious problems on worker’s health [2]. Heavy manual work affects not only the system of muscles, skeleton and connective tissues, but also cardiovascular system. In scientific research it is pointed out that to ensure optimal physiological results in the work process it is necessary to choose such work tasks that do not cause threat to body physiology. Usually physiologic reaction of the body to heavy manual © Springer Nature Switzerland AG 2020 R. S. Goonetilleke and W. Karwowski (Eds.): AHFE 2019, AISC 967, pp. 14–21, 2020. https://doi.org/10.1007/978-3-030-20142-5_2

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work is general tiredness, more rarely – local muscular fatigue. The most commonly used physiological criterion for evaluation of the physical load is energy consumption during physical load and consumption of oxygen [3]. During such analysis usually the work content is divided into smaller tasks and physiological impact can be measured by the expenditure of the energy in these individual tasks [4]. In several researches the oxygen consumption is used to analyze the workload severity [3, 5] have developed regression equations to predict oxygen consumption using personal, task, and workplace variables. In scientific research for comparative analysis of objective measurements Rating of Perceived Exertion (RPE) scale is used, worked out by Swedish scientist Gunnar Borg in 1982. This instrument is used for evaluation of effort and fatigue of the individual, for instance, during intensive physical work. Work intensity, in its turn, determines the load of individual functional systems (muscular, skeleton and connective tissues, cardiovascular, etc.) during the work process. It is a subjective opinion on physical feelings (heart function, breathing frequency, increased sweating, blood pressure changes, muscular fatigue, etc.) in the work process. The research was to perform physical workload analysis in metal processing industry operations (assembly operators, packaging operators and inspection staff) using objective ergonomics research methods. The study was carried out in a medium sized metal manufacturing enterprise in Latvia in the department of manufacturing of ironing boards. The study was approved by the Human Ethics and Institutional Review Board at the University of Latvia in 2018.

2 Materials and Methods 2.1

Research Design

30 assembly operators, 30 packaging operators and 15 members of the inspection staff with chronic pain (for four months or more) in the neck, shoulders, arms, hands and legs agreed to take part in the objective (heart rate monitoring, muscle myotonometry) measurements. The inclusion criteria were: age, length of service, presence of chronic pain in certain body parts, incl. neck and shoulder area, the back, arms and legs (medical examination data); full consent to participate in the research, no physical activities (exercises during the work breaks and after the work). The exclusion criteria were: acute pain in shoulders and neck area, arms, legs and back; non-work related disorders, and having not mandatory medical examinations. The investigation endured for one year period. Demographic information of the assembly, packaging and inspection operators are shown in Table 1. 2.2

Research Methods

A questionnaire was used to find out the opinion of employees on existing physical workload in the department of ironing board manufacturing. Seventy-five employees were included in the survey.

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Table 1. Demographic factors of the assembly, packaging and inspection operators, including length of service, mean age and range, mean height, mean weight, mean body mass index (BMI), mean rest heart rate (RHR) and standard deviation (SD) Population (length of service)

n

Mean age ± SD

Range Mean height, Mean cm ± SD weight, kg ± SD

Assembly operators 0–7 years 8–15 years >15 years Packaging operators 0–7 years 8–15 years >15 years Inspection staff 0–7 years 8–15 years >15 years

30 47.8 ± 13.6 22–72 172.6 ± 8.0

79.9 ± 7.5

Mean BMI, Mean RHR, kg/m2 ± SD beats/min ± SD 27.0 ± 3.7

76.5 ± 7.3

10 15 5 30

36.9 51.3 59.0 41.2

± ± ± ±

14.9 7.8 11.1 19.2

22–59 34–67 49–72 22–65

168.9 174.3 175.4 167.5

± ± ± ±

7.3 8.6 5.6 18.7

83.0 79.4 75.4 71.4

± ± ± ±

8.9 6.7 5.0 10.2

29.2 26.4 24.5 26.4

± ± ± ±

3.3 3.8 1.9 4.1

58.7 72.3 77.0 71.7

± ± ± ±

9.6 8.2 8.6 7.6

12 10 8 15

27.8 30.6 56.9 48.6

± ± ± ±

6.6 6.4 7.6 11.8

22–40 30–48 42–65 38–70

170.6 168.6 166.6 172.8

± ± ± ±

14.8 12.4 11.9 5.3

69.5 71.5 73.5 76.3

± ± ± ±

9.8 9.7 11.3 8.7

25.8 26.7 27.2 25.6

± ± ± ±

3.3 3.7 3.8 2.8

55.7 60.3 63.8 57.3

± ± ± ±

8.8 8.7 7.8 4.2

7 47.6 ± 11.3 38–66 172.9 ± 5.4 8 49.6 ± 13.0 34–70 172.8 ± 5.6 0

75.3 ± 8.6 77.1 ± 9.4

25.2 ± 3.2 25.8 ± 2.7

74.2 ± 7.5 63.1 ± 6.8

In order to analyze work strain and work heaviness category (WHC) the Borg Scale of Ratings of Perceived Exertion (RPE) was used [6] with the scale from 6 to 20, where 6 means - no intensity (strain) at all, and 20 is maximum intensity. The RPE measurements were carried out in the work process. Heart Rate Monitoring (HRM) was used to determine physical workload by setting the work heaviness degree [7]. To measure the heart rate the device POLAR S810iTM and data processing software Polar Precision Performance was used which allowed to transform HR data into metabolic energy consumption (kcal/min) [8]. NIOSH (USA) standard ISO 28996 energy expenditure classification was used to express the work heaviness degree (see Table 2). Table 2. Work heaviness classification in terms of energy expenditure Workload categories NIOSH (USA) standard ISO 28996 [9] Light work Moderate work Hard work Very hard work Ultimate work

Energy expenditure Male, kcal/min Female, kcal/min

I II III IV V

2.0–4.9 5.0–7.4 7.5–9.9 10.0–12.4 more 12.5

1.5–3.4 3.5–5.4 5.5–7.4 7.5–9.4 more 9.5

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MYOTON-3 device was used in order to carry out analysis of muscle’s functional state and fatigue levels [10]. Moyotonometry with Myoton-3 device allows to measure viscoelastic parameters of various muscles groups and provide functionality analysis for diagnostics [11]. Measurements were carried out with relaxed muscles before the beginning of the work cycle during one week cycle for such muscles: m. extensor digitorum; m. flexor carpi radialis; m. gastrocnemius (caput mediale); m. tibialis anterior and m. trapezius (upper part). All involved persons were in a similar sitting position during the measurements. Statistical analysis with descriptive statistics was provided with computer software SPSS.20.0 [12]. The reliability was calculated with the confidence interval (95% CI) [13] and reliability interval was determined using Cohen’s Kappa (j) coefficient [14].

3 Results and Discussion The study involved metal manufacturing organization with the department of metal boards. This department employed 75 workers, males only. All of them participated in the survey. Survey results revealed that 36.7% of assembly operators complained generally of having pain in their neck region, 42.5% - in the shoulders, 22.6% - in the palm and 11.7% - in the lower back. It has to be noted that the most complaints regarding the pain in the mentioned bodily parts were uttered by assembly operators aged 34–67 with the length of service 8–15 years (CI = 1.56–2.62): 52.3% - the neck region, 51.0% the shoulders, 33.2% - the palm and 20.0% - the lower back. Packing operators noted the pain after work as follows: 55% - in the neck region, 70% - in the upper back, 48% - in the arms and lower legs. The greatest discomfort is felt by employees who have been working in the profession for 8–15 years and more, which is the same as aforementioned data (CI = 0.53–5.70). Of the inspection staff, 78% with the length of service from 8 to 15 years marked in the survey that during the work they feel discomfort in the upper back and more in the arms and legs (CI = 0.54–4.97). The survey data showed that all participants noted exposure to high physical overload at work: they lift and move ironing boards with weight of 10–15 kg, but packaging operators marked that sometimes they lift and move up to 25 kg. The hands, legs and lower back are the most stressed body parts in the work process. Applying the Borg Scale to determine physical load intensity it was found out that assemblers of ironing boards and packers of ironing boards recognized that their work corresponds to heavy work category (15– 16 points), but inspection staff–somewhat heavy (13–14 points). Data shows that almost all metal boards’ workers (87%) have forced and awkward work postures. Mainly assembly and packing operators aged 18 to 35 years indicates that work is not intensive. It should be noted that 78% of younger employees aged 22–35 smoke during rest breaks and after work, they also often use alcohol. Physical activities in their leisure time are done by 34% only. HRM was performed for 6 h long work process including rest breaks. Research results of heart rate monitoring for assembly operators, packing operators, and inspection staff are shown up in Table 3.

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Table 3. Heart rate monitoring results of assembly, packing, and inspection operators, heart rate (HR), Pearson’s correlation (r), Cohen’s Kappa (k), percentage of the heart rate range (%HRR), energy expenditure (E), the rate of perceived exertion (RPE, scale 6–20), and work heaviness category (WHC). Occupation

Assembly operators (n = 30) Packing operators (n = 30) Inspection staff (n = 15)

Mean E ± Mean SD, RPE kcal/min ± SD (range)

WHC

HRM Mean HR ± SD, beats/min 125 ± 14

Mean % HRR ± Range r k SD HR, beats/min 108–160 0.95 0.68 52 ± 8

120 ± 13

89–165

0.92 0.59 42 ± 6

7.6 ± 1.1 16 ± 2 Hard work (14–19)

113 ± 8

80–120

0.91 0.55 42 ± 6

6.4 ± 1.3 12 ± 2 Mode-rate (11–13) work

8.1 ± 1.5 15 ± 2 Hard work (13–17)

Results showed that assembly operators and packing operators are subjected to heavy work, but inspection staff – to medium heavy work, which corresponds to the subjective evaluation with Borg scale. Moyotonometry research results are shown in Table 4. Table 4. Moyotonometry research results of assembly operators (n = 30), packing operators (n = 30), inspection staff (n = 15) with various moyotonometry categories, Cohen’s Kappa (j) Moyotonometry category Assembly operators I - muscle is able to relax 0% 70% II - muscle is able to adapt to the workload and to partly relax III - muscle is not able to 30% relax

Cohen’s Kappa (j) 0.41 0.78

0.65

Packing Cohen’s operators Kappa (j) 0% 0.76 73.3% 0.88

26.7%

0.65

Inspection staff 74% 24%

0%

Cohen’s Kappa (j) 0.81 0.62

0.42

Moyotonometry results proves that muscle tone of the assembly operators has increased in the muscle of the shoulder region and in both of the measured forearm muscles at the end of the work week. But for packing operators’ muscle tone has increased in all measured muscle groups. Muscle tone of the inspection staff increases in shoulders region, arms and legs. It was found out that work experience impact the muscle tone and fatigue levels (see Table 5).

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Table 5. The number of assembly operators (n = 30), packing operators (n = 30), inspection staff (n = 15), length of service in the occupation, Moyotonometry category Work experience, years

A (0–7)

B (8–15)

C (>15)

• • • • • • • • •

Assembly operators Packing operators Inspection staff Assembly operators Packing operators Inspection staff Assembly operators Packing operators Inspection staff

Moyotonometry category I II 0 6 0 7 3 4 0 6 0 4 2 6 0 1 0 2 0 0

III 4 4 0 9 6 0 4 6 0

Muscle groups of the youngest and middle-aged assembly operators and packing operators (length of service: 0–15 years) during the working week cycle are able to adapt to the workload and relax, partly belonging to II Moyotonometry category. Assembly operators and packing operators with the work experience over 15 years corresponds to III Moyotonometry Category hence main muscle groups are not able to relax. It was found out that at the end of the week work cycle, muscle tone in 80% of assembly operators and in 75% of packing operators, having the work experience in the profession more than 15 years, met the III Moyotonometry category. It shows that muscles are not able to adjust to workload in the working cycle and the employees work with overload. It similarly refers to the employees whose length of service in the profession is 8–15 years: 60% of assembly operators and 60% of packing operators correspond to Category III, while inspection staff corresponds to Category I and II. Acquired results in myotonometry confirm the results acquired in the heart rate monitoring: the mean energy consumption in assembly operators and packing operators was from 7.6 ± 1.1 to 8.1 ± 1.5, which suggests heavy physical work, while the mean energy consumption in inspection staff was 6.4 ± 1.3, which suggests medium heavy manual work. It corresponds to other authors’ conclusions that physical fatigue can be measured calculating energy consumption [15]. Scientists have proved that in people with big body mass heart rate increases [16]. Thus results on BMI, acquired in our study, coincide with the aforementioned, since BMI of assembly operators and packing operators was increased: from 26.4 ± 4.1 to 27.0 ± 3.7, but among the inspection staff it was nearly normal (25.6 ± 2.8). It could suggest physical effort during the work. In a number of the employees, involved in the study, the physical overload might be related to psychosocial risks as well, which was proved by other authors’ studies on chronic pain in the area of neck and shoulders [17].

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4 Conclusions Workers in metal manufacturing enterprise are at high risk of developing WMSDs, since they are subjected to heavy manual work and load on muscles during work. Accordingly to the results of heart rate monitoring the assembly operators and packing operators can be subdivided into heavy work category, but inspection staff- in moderately heavy category. Our conclusion is that assembly operators, packing operators, and inspection staff falls into three myotonometry categories. The study will be proceeded expanding the survey, including in it psychosocial risks and electromyography investigations in order to evaluate fatigue of deep muscle groups in the studied employees.

References 1. Lind, C.: Assessment and design of industrial manual handling to reduce physical ergonomics hazards – use and development of assessment tools. Doctoral Thesis (No. 2017:7) KTH Royal Institute of Technology. Technology and Health Unit of Ergonomics (2017) 2. Hoogendoorn, W.E., Bongers, P.M., De Vet, H.C.W., Douwes, M., Koes, B.W., Miedema, M.C., Ariëns, G.A.M., Bouter, L.M.: Flexion and rotation of the trunk and lifting at work are risk factors for low back pain: results of a prospective cohort study. Spine (Phila Pa 1976) 25(23), 3087–3092 (2000) 3. Dempsey, P.D.: A critical review of biomechanical, epidemiological, physiological and psychophysical criteria for designing manual materials handling tasks. Ergonomics 41(1), 73–78 (1998) 4. Li, K.W., Yu, R., Gao, Y., Maikala, R.V., Tsai, H.: Physiological and perceptual responses in male Chinese workers performing combined manual materials handling tasks. Int. J. Ind. Ergon. 1–6 (2008). https://doi.org/10.1016/j.ergon.2008.08.004 5. Garg, A., Chaffin, D.B., Herrin, G.D.: Prediction of metabolic rates for manual materials handling jobs. Am. Ind. Hyg. Assoc. J. 39(8), 661–674 (1978) 6. Borg, G.A.: Psychophysical bases of perceived exertion. Med. Sci. Sports Exerc. 14, 377–381 (1982) 7. Jackson, A.S., Blair, S.N., Mahar, M.T., Wier, L.T., Ross, R.M., Stuteville, J.E.: Prediction of functional aerobic capacity without exercise testing. Med. Sci. Sports Exerc. 22(6), 863–870 (1990) 8. Karvonen, M., Kentala, E., Mustala, O.: The effects of training on heart rate: a longitudinal study. Annales Medicinae Experimentalis et Biologiae Fenniac 35, 307–315 (1957) 9. Mantoe, H.I., Kemper, W.M., Saris, M., Wasshburn, R.A.: Measuring Physical Activity and Energy Expenditure. Human Kinetics Publishers, Champaign (1996) 10. Vain, A.: Estimation of the functional state of skeletal muscle. In: Veltink P.H., Boom H.B.K. (eds.) Control of Ambulation Using Functional Neuromuscular Stimulation, pp. 51– 55. University of Twente Press, Enschede (1995) 11. Korhonen, R.K., Vain, A., Vanninen, E., Viir, R., Jurvelin, J.S.: Can mechanical myotonometry or electromyography be used for the prediction of intramuscular pressure? Physiol. Meas. 26, 951–963 (2005) 12. IBM Corp. Released 2011. IBM SPSS Statistics for Windows, Version 20.0. Armonk, NY: IBM Corp. (2011)

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13. Thompson, M.L., Myers, J.E., Kriebel, D.: Prevalence odds ratio or prevalence ratio in the analysis of cross sectional data: what is to be done? Occup. Environ. Med. 55, 272–277 (1998) 14. Landis, J.R., Koch, G.G.: The measurement of observer agreement for categorical data. Biometrics 33, 59–174 (1977) 15. Visentin, V., Sgarbossa, F., Calzavara, M., Persona, A.: Fatigue accumulation in the assignment of manual material handling activities to operators. IFAC-PapersOnLine 51(11), 826–831 (2018) 16. Baba, R., Koketsu, M., Nagashima, M., Inasaka, H., Yoshinaga, M., Yokota, M.: Adolescent obesity adversely affects blood pressure and resting heart rate. Circ. J. 71(5), 722–726 (2007) 17. Fava, G.A., Sonino, N.: The clinical domains of psychosomatic medicine. J. Clin. Psychiatry 66, 849–858 (2005)

The Role of Stakeholders in E-Occupational Health and Safety System in Estonia Inese Vilcane1(&), Tarmo Koppel1, Henrijs Kalkis2, Olga Tsenter1, and Piia Tint1 1

Department of Business Administration, Tallinn University of Technology, Akadeemia street 3, Tallinn 12618, Estonia {Inese.Vilcane,Tarmo.Koppel,Piia.Tint}@taltech.ee, [email protected] 2 Faculty of European Studies, Riga Stradins University, Dzirciema street 16, Riga 1007, Latvia [email protected]

Abstract. In the present study occupational health and safety system and basis of the E-Health were analysed. The E-Occupational health and safety means transforming E-Health basic principles into E-Occupational health and safety context. The E-Occupational health and safety system differentiates from EHealth system as the stakeholders are different, including their interactions, hierarchy and tasks. Thus, the necessity of creating E-Occupational health and safety system is based not only on the scientific literature, but also on the level of the European and national development priorities. Estonia has a welldeveloped E-Health system, but not yet in the form of E-Occupational health and safety. Authors of the present paper investigated Estonian occupational health structure systematically and, based on the research results, developed the framework of E-Occupational health and safety, where stakeholders’ functions are taken into account. As a result of the study are described by stakeholders’ main activities obtained from the legislation, scientific literature and risk assessment cases. Stakeholders’ activities are arranged into the system enabling to create IT-solutions. Keywords: E-Occupational health and safety

 E-OSH  Stakeholders

1 Introduction Development of the technology leads to a variety of benefits for the society; wider availability of data, new knowledge and increased productivity are among them. At the same time, these benefits constitute a challenge to increasing complexity of the advanced technology, personal privacy and over-rated expectations. Smart services are able to create new interfaces between service providers and service users, whereas service users create social value due to participation in co-producing activities. Thereby, digital solutions undoubtedly strengthen service production processes and, thus, service economy, as well as expand the knowledge to support the decisionmaking [1]. © Springer Nature Switzerland AG 2020 R. S. Goonetilleke and W. Karwowski (Eds.): AHFE 2019, AISC 967, pp. 22–33, 2020. https://doi.org/10.1007/978-3-030-20142-5_3

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Information and communication technology (ICT) has recently become one of the leading tools for increasing competitiveness in almost every area of expertise in economics in particular and in the Western society in general. For this reason, any national strategy or action plan should take into account the opportunities offered and challenges posed by means of modern ICT. Nevertheless, the Digital Agenda 2020 for Estonia (hereafter Digital Agenda 2020) does not cover the application of ICT in various fields, including different aspects of health care and business sectors [2]. In this research, authors discussed the very first recommendations for the development of E-OSH system based on the principles and context of the Estonian E-Health system. E-Health refers to the application of ICT to meet the needs of patients, healthcare providers and policy makers; and to use of digital data for clinical, educational and administrative purposes, both at local sites and at a distance [3]. At the heart of both systems are care of human health, in one case, human-patient treatment (EHealth), in the second case, the health of the employee and taking preventive measures at the workplace, before an employee has a health problem (E-OHS). Occupational health and safety system includes monitoring of the work environment, risk assessment, training of employees on safe working practices and introduction of preventive measures to eliminate health-threatening conditions. Based on the aforementioned, following research questions were presented: What components (stakeholders) are needed to be involved to create a well-functioning EOHS system in Estonia, and what are the main activities in this direction? The aim of this study was to find E-OHS development possibilities by understanding and using well-functioning components of the E-Health system, based on the theoretical and practical research material.

2 The Benefits of Developing ICT Solutions in the E-Health and E-Occupational Health and Safety Context The use of ICT and digitalisation in Europe began to develop very rapidly when Member States (MS) of the European Union approved the E-Europe 2002 initiative [4], which aimed to exploit the advantages offered by the World Wide Web and started the very first structured European policy on ICT for MS’ governments. One of the main objectives of the initiative was to encourage the use of the Internet and, in relation to it, the two following key actions were defined: Government on-line and Health on-line, which refer to the application of newly developed technologies to enable electronic access to public services, and to make health information as accessible as possible [5]. Al-Shorbaji [6] believes that, the rapid growth of ICT is altering the healthcare sector in a way never witnessed before, since it helps to improve the quality of healthcare services, simplifies the access to these services and reduce costs. The potential of this field is huge; investments in E-Health initiatives are being made. Moreover, there is a need for a multidisciplinary approach to the research in this area of expertise [6]. Research on E-OHS creation opportunities is a multidisciplinary approach, where occupational health and safety are interdisciplinary science.

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In Priorities for occupational safety and health research in Europe: 2013–2020 it is widely spoken about the impact of ICT on occupational safety and the implementation of ICT solutions [7]. The ICT revolution has several attributes that distinguish its effects on labor markets from those of earlier periods of technological change. The modular architecture of the Internet and the key role of software in advancing innovation make ICTs highly flexible and plastic technologies [8]. At the same time, the diffusion of ICTs has boosted the mobility of capital, labor and knowledge, with jobs migrating more easily within and across nations [9]. Sophisticated tasks, once perceived as requiring uniquely human skills, can increasingly be replaced by ICTs [10, 11]. ICT change human behaviour in all aspects, starting from digital economy, health and education services, traveling, working life, personal and group communication, etc. On this way, ICT has impact on happiness and well-being on individual and macro level, sustainable development and mutual impact of all previous entities on quality of life [12]. Variety of studies prove that the effectiveness of any organization is closely related to a performer of the work, whose skills and activities affect results of the organization’s activity [13]. An essential role here is played by ensuring of wellbeing of an employee in a work environment. Wellbeing at work promotes employee’s feeling of belonging and trust to the enterprise. Strengthening this feeling and mutual trust significantly increases financial state of the enterprise [14]. Furthermore Arsovski et al. [15], Castellacci [16] and Valenduc and Vendramin [31] in their studies look how ICT impacts on the quality of work life and that ICT solutions are related to concepts such as well-being and happiness [15–17]; Ramendran et al. [18] point as well to the improvements of the employees’ lifestyle [18]. Currently, the biggest part of OHS records and data are collected for enterprises’ internal needs, as well as reported in the case of the State Labor Inspection. Very often companies’ OHS records are only paper-based, which is particularly common for small and medium-sized enterprises. Lin et al. [19] consider that the safety inspection process suffers from several drawbacks that hinder the effectiveness and analytical learning capacity of the process; lacks a comprehensive and structured procedure. Dedicated ICT tools could significantly improve the day-to-day practices and management of safety inspections [19]. The implementation of ICT has the potential to change the nature of how the work is carried out and affect the working environment [7]. Goodrum and Haas [20] stated, that a lot of research on the industry has been done about how technology influences on productivity. These studies have led to significant gains in productivity and profit margins [20]. “Advances in technology have many benefits. Among the most often cited are improved quality and productivity” [21]. ICT tools also provide benefits to workforce safety and well-being. For instance, ICT innovations allowing the industrialization and automation of work tasks were considered to be one of the main factors preventing a significant increase of injury rate in the US construction industry during the 1990s [22]. Authors of the present study assume that OHS ICT tools could be integrated into the E-OHS system, for example risk assessment E-tools. European Agency for Safety and Health at Work explains that E-tools are ‘interactive’. They require some input of

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information by the user, whether in the form of knowledge (e.g. through completion of a checkbox or data field) or measurement of the environment (e.g. smartphone measurement of noise or light levels). Based on this input, the tool produces tailored information for the user (e.g. by guiding the user through a decision-making process) [23]. With regard to the E-Health, World Health Organisation expresses an opinion that inclusion of stakeholders and the community into common activities is an important quality factor, as it helps to establish long term cooperation contacts, develop learning processes and meet client needs and expectations, although it is not the only factor affecting success of E-Health projects [24]. Vedluga and Mikulskien [25] finds that a considerable number of E-Health development failures may be attributed to the poor cooperation between the stakeholders. The fact that stakeholders may achieve results acceptable to all parties and successfully implement projects cannot be neglected and therefore it is essential for E-Health measurements to include a broad range of stakeholders [25].

3 Methods Following components of occupational health and E-Health were investigated: health and safety system and its knowledge management; the principles of the creation of well-functioning E-Health system in Estonia. The research is based on a secondary data analysis of scientific papers in this field. Authors also investigated occupational health and safety legislation in Estonia and in the European Union, as it is very important part in the creation of the E-OHS system. Data collection relied on performing of a search of literature for relevant studies using combinations of keywords that reflected E-Health and governance, ICT in occupational health and safety related topics. Inclusion and exclusion criteria were applied to identify the relevant papers. Analyzing firstly the existing E-Health system and secondly the current occupational and health system, stakeholders and their corresponding tasks were derived into the framework of the EOHS system. Therefore, the principles of E-Health are applied into organizing the occupational health and safety.

4 Role of the Stakeholders in E-OHS in Estonia In order to evaluate the stakeholders in the E-OHS System, the authors studied the infrastructure of the Estonian OHS system, which is presented on Fig. 1. OHS stakeholders involved in the Estonian OHS system and their activities provide as follows: participating institutions and organizations stakeholders, as well as responsibility hierarchy, areas of competence, interactions, roles and responsibilities. These are aspects to be understood in detail, which form the basis for creation of an E-OHS system. Figure 1 outlines the main keywords that explain specific activities and responsibilities of the institution.

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Fig. 1. The OSH infrastructure in Estonia, modified [27].

In the Estonian OHS system, the Ministry of Social Affairs is the executive body, regulating the entire area of expertise, whereas two of its structural units, the Working Life Development Department and the Health Department, are directly involved in occupational health and safety-related policy making process [26]. In the field of OHS, the role of the Health Board is following: to participate in the preparation of occupational health programmes and organize their implementation; analyze information concerning occupational diseases; organize refresher courses for occupational safety specialists; and register occupational health service providers. The Health Board could provide stakeholders’ training for the implementation of the EOHS system. Generally speaking, the Labour Inspectorate is a governmental agency operating under the jurisdiction of the Estonian Ministry of Social Affairs, some of the main functions of which, according to Estonian OSH Act, are provision of the state supervision over working environments with the aim to ascertain compliance with prescribed legal norms; over investigations of occupational incidents, accidents and illnesses; implementation of preventive measures; collect and analyse statistical data, regarding the issue [28]. Based on the Estonian OHS system and the parties involved, four main E-OHS stakeholder groups were nominated [28], as outlined below on Fig. 2: Labour Inspection; Company (OHS specialist); Workers and Occupational Health Doctors. Main E-OSH stakeholders and their role in the system are illustrated on the Fig. 2 (compiled by the authors of the present paper). The key roles and responsibilities of stakeholders in OHS and E-OHS remain unchanged; the only difference is that in EOHS almost all activities are carried out in the E-environment. Until now, the majority of all documents necessary for occupational health and safety were produced in paper format.

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E-OSH STAKEHOLDERS AND ROLE

27

LABOUR INSPECTION. To supervise the observance and implementation of OHS legal norms in enterprises. COMPANY (OHS specialist).To provide a healthy work environment for the employee. WORKERS. To support the employer in implementing the OHS system in the company. OH DOCTORS. Workers' hetlh monitoring and mandatory check up.

Fig. 2. E-OHS stakeholders and their role in the OSH system (created by the authors).

Each stakeholder group has specific activities and tasks which include activities with different documents and responsibilities at a different levels, as illustrated below on Fig. 3.

Labour Inspection

Company OHS specialist

Workers

OH doktor

• Main tasks: • Company OHS electronic data management of inspections, • Company OHS risk level assessment, • Online control of working conditions. • Main tasks: • Electronic OHS data management, • Online OHS risk management, • OHS risk agent determination, health risk analysis, • Identification of highly exposed, • Risk agents real-time monitoring, • Individual risk assessment. • Main tasks: • Wearable monitoring device, • Digital tools - devices for selfmanagement, • Access to risk analysis results. • Main tasks: • Risk group identification, • Workers' health examination, • Health risk determination, • Telehealth coaching.

Fig. 3. Stakeholders’ main tasks in the E-OHS system (created by the authors).

Labour Inspectorate plays an important role and has relevant tasks in the occupational health and safety system. The Labour Inspectorate as a stakeholder is directly involved in the implementation and maintenance of the E-OHS system, and activities of which are outlined on the Fig. 3. As mentioned above, the Labor Inspectorate is a supervisory authority that checks the compliance of companies’ work environment with legal norms. OHS documents are available for the Labor Inspectorate in the E-OHS system, which are being regularly checked. The Labor Inspectorate also has the opportunity to check the employers’s risk assessment of the work environment in the E-OHS system and the data entered in the system for each workplace.

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The most significant changes and the biggest challenge for switching to E-OHS system would be for the employers and health and safety professionals. Currently enterprises produce paper-based documentation for OHS; and the employer would have to enter all the occupational health and safety related data in the E-OHS system: workplace measurement data protocols; work environment risk assessment; E-tools used for risk assessment; a risk mitigation plan; job listings; and mandatory medical examinations. Switching to E-OHS will require additional resources to be allocated for training personnel, and additional time for entering all the relevant information into the system and maintenance of the system. Table 1. E-OSH components integration levels (created by the authors). Components Stakeholders (vertical OH doctors integration level) Electronic • Worker’s data records keeping management (level 1) • Workers’ health Internet based monitoring. technologies and services (level 2) • Health risks control. • Tele – occupational health coaching mHealth and real-time monitoring (level 3)



Decision support tools, smart algorithms (level 4)

• Health risks determination. • Risk group identification

Worker

Company

Authority

• Individual risk assessment and management • Worker access to risk analysis results. • Collecting and processing worker complaints. • Online tools for selfmanagement • Mobile health monitoring devices. • Wearable monitoring devices for risk agents. E.g. Smart workwear • Online test, if suitable for the specific work

• Risk management documentation storage

• Inspected companies’ data management

• Online risk management. • Inspected companies’ • Transparent risk data management management

• Risk agents’ real-time monitoring



• Smart algorithms for risk • Companies’ risk level assessment – which agents determination and companies to inspect health risk analysis. • Risk groups’ identification and management. • Identifying highly exposed workers. • Identifying workers who require medical examination

An important group of stakeholders is occupational health doctors and their patients - employees. This group is one of the connecting elements between E-Health and EOHS, since it is the employer’s obligation to conduct medical examinations of employees as stated in the OHS Act (1999, lastly revised in 2019): the employer is obliged to organise the provision of the medical examinations for employees whose health may be affected during working processes by occupational hazards or the nature of the work itself, as well as to bear the costs of such examinations [28].

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In E-OHS system the parties involved, including workers, would have many newly introduced opportunities to follow the safety processes and monitor work place risk at any time. The employee will also have access to e-tools to individually assess the risks and the opportunity to inform the occupational health and safety specialist about potential problems. Employees will have permanent access to information about the workplace they work in. Authors have grouped stakeholder activities and data processing according to the level of IT solution (as highlighted below on the Table 1). The first level of integration is the collection and acquisition of various data and documents into electronic environment, data grouping and organization. The second level involves the exchange of information, documents and data between the stakeholders. At the third level, various mobile applications are used to monitor employee work environment risk factors. At the fourth level - smart data processing, analysis, and decisions. 4.1

Level. ‘Electronic Records Keeping’ (Illustrated on Table 1)

At this level, basic data entry, collection, storage, and systemization is carried out. Each of the stakeholders participates according to their roles and access opportunity. At this level, the occupational doctor carries out ‘Worker’s data management’, also receives first-time health data for the employee. These include the employer’s order to the occupational health doctor, which contains data on the risk factors of the worker’s job. Additionally, there is information on occupational disease history or accidents at work, digital prescription history, digital images, etc. Employees at this level have the opportunity to take ‘Individual risk assessment and management’ and can assess various risk factors in an enterprise; levels of risk, workplaces exposed to high exposures, risk reduction measures, and personal protective equipment. The company’s activity at this level is ‘Risk management document storage’. This includes assessment of work environment risks and results; development of preventive action plan and work environment risk reduction plan; work safety regulations and briefing for employees; lists of personal protective equipment; and orders for compulsory medical examinations. The State Labour Inspectorate makes ‘Inspected companies’ data management’. Data is available from companies’ work environment risk assessment sources. 4.2

Level. ‘Internet Based Technologies and Services’ (Illustrated on Table 1)

At the second level, the occupational health doctor carries out the processing of the employee-patient data, compliance, and verification, collection of data or additional information or exchange of communicative information in the E-OHS between the employee and the employer. If necessary, they will assign the additional health check, prescribe the treatment, or take necessary measures in the work environment, as well as advise employees and employers on a healthy working environment. In the second level, E-OHS system employees have the following options: ‘Give the access to worker on risk analysis results’, ‘Collect and process worker`s complaints’, ‘Utilize online tools for self-management’. Using such tools, worker can evaluate and control various risk factors; to assess the risk factors, it is necessary to enter various data about the conditions of the workplace. If the employee receives unsatisfactory results, then there

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exists opportunity to submit a complaint to the occupational safety officer about working conditions or consult the occupational health doctors. First of all, the occupational safety officer must carry out inspection of the workplaces, including all necessary measurements of risk factors parameters in the work environment, such as noise, vibration, microclimate, electromagnetic fields, the concentration of chemicals in the air or other occupational hazards. The second step is to check the ergonomics (workload, cognitive overload and organizational issues) parameters of the work environment. The technical specifications of different equipment should be evaluated as well. When all of these data are collected in the system, then ‘Online risk management’ and ‘Transparent risk management’ can be performed. 4.3

Level. “mHealth and Real-Time Monitoring” (Illustrated on Table 1)

This level monitors health in real-time, which could be accomplished by smartphones or stand-alone wearable monitoring devices. At this level, the occupational therapist does not manage the data. However, the employees can download mHealth data into their E-OHS account, where the occupational doctor will be able to see the results if the employee has given the permission. The employee has several options from here: ‘Mobile health monitoring devices’ and ‘Wearable monitoring devices for risk agents’. At this level, the Occupational Safety Specialist can monitor various risk factors, such as noise, vibration, dust and chemicals, etc. That helps to determine the risk factor for daily exposure, as well as to record load, physical or cognitive fatigue indicators. This data is neither inaccessible, nor connected with authority institutions. 4.4

Level. ‘Decision Support Tools, Smart Algorithms’ (Illustrated on Table 1)

This level consists of decision support tools, smart algorithms, in which a computer or artificial intelligence processes data, performs data analysis, correlation, and gives recommendations. The employer obtains: ‘Smart algorithms for risk agents determination and health risk analysis’, ‘Risk groups identification and management’, ‘Identifying highly exposed workers’, ‘Identifying workers who require medical examination’. Such data allows not only smart planning of a healthy work environment, but also integrates this data into the company’s economic performance and business development strategy to optimize and improve company’s operations and sustainability. This approach corresponds with various European Union development strategies.

5 Discussion In a typical organization, workers’ health, safety and well-being are managed in a fragmented way, often in separated departments and by separate unconnected functions. Precursor for E-OHS can be found from Total Worker Health concept, which is to integrate separate components to assure systematic functioning of these functions throughout the organization – protecting and promoting health, safety and well-being

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of workers [30]. In this article developed E-OHS system framework and the main stakeholders groups are based on the occupational safety and health system existing in Estonia, using the E-Health system approach, which is regarded as the first step to improve Estonian E-OHS. Such E-OHS system fits into Estonian E-System and it is in accordance with the Estonian and European Union development strategies. Several studies, such as Arsovski et al. [15], Castellacci [16], Valenduc and Vendramin [31], and Ramendran et al. [18], have mentioned that there is notable impact of ICT on quality of working life, and that ICT solutions are related to concept well-being. Introducing E-OHS will improve the quality of the working environment as it will make occupational protection measures transparent, comprehensive and structured procedure, and will involve employees in their implementation. Employee involvement in the decision-making process facilitates, increases their workability and job satisfaction [15, 16, 18, 31]. In the near future E-OHS is predicted to be included in the organization’s work system, because it brings a lot of benefits [1, 32], and it is in accordance with the priorities OSH and Estonia Digital Agenda 2020 [2, 7]. The EOHS solutions are important to the personnel who organize and harmonize the elements of the organization as an integrated management system. The technological development in the IT-applications has made it possible to integrate the occupational technological applications and personnel safety sub-systems on an individual level. The successful implementation and integration of E-OHS into the companies’ management systems would emerge an optimum socio-technical system, which increases safety at work, creates psychosocial comfort, improves work life quality and motivation for work. It should not be forgotten that the cost-benefit analysis of introducing such system is a very topical issue, which has always been an economic justification for any employer; the studies emphasize that the new system for access to ICT solutions reduces costs and the IT complexity and, at the same time, optimizes the work-load and delivery of the services [32]. This points to the need for E-OHS system to be implemented also from an economic point of view. Issues of occupational safety are closely related to the healthcare sector, since in various occupations employees tend to suffer from work-related diseases and injuries obtained at workplace. In this regard, authors of the present paper suggest allocating E-OHS as a separate section in the overall EHealth system. The next step necessary to conduct would be questionnaires for the stakeholders in order to collect their viewpoints and needs regarding the development of E-OHS system. In the case of the successful implementation of the E-OHS system in Estonia, it will be possible to integrate it into other countries as well, adapting it accordingly and integrating it into countries’ local occupational safety and health systems.

6 Conclusions Contemporary scientific literature shows publications in which the authors positively evaluate ICT solutions in the work environment, including OSH. Hence there is a research gap to create an E-OSH system. For example, the safety inspection process suffers from several drawbacks that hinder the efficiency, effectiveness, and analytical

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learning capacity of the process, lack the comprehensive and structured procedure. Hence the ICT tools could significantly improve the day-to-day practices and management of safety inspections [19]. Based on the study, authors put forward four E-OSH stakeholder groups: Labour Inspection; Company (OHS specialist); Workers and OH doctors. Each stakeholder group has specific activities and tasks, which include activities with different documents and responsibilities at different levels. These stakeholder groups have a key role to play in providing the basic functionality of the E-OSH system. This would ensure an efficient flow of data within the E-OSH system between stakeholders. In such way it will help to create transparent processes with consistent activities and continuously improve the performance of the system.

References 1. Kaivooja, J., Virtanen, P., Jalonen, H., Stenvall, J.: The effects of the internet of things and big data to organizations and their knowledge management practices. In: Knowledge Management in Organizations, KMO 2015. Lecture Notes in Business Information Processing, vol. 224, pp. 495–513. Springer, Cham (2015) 2. Ministry of Economic Affairs and Communications: Digital Agenda 2020 for Estonia. https://www.mkm.ee/sites/default/files/digital_agenda_2020_estonia_engf.pdf 3. Kalvet, T., Aaviksoo, A.: The Development of eServices in an Enlarged EU: eGovernment and eHealth in Estonia. European Communities. JRC Scientific and Technical Reports, p. 120. Office for Official Publications of the European Communities, Luxembourg (2008) 4. European Commission. eEurope: An Information Society For All, 28.5.2002, COM 263 final, Brussels. https://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=COM:2002:0263: FIN:EN:PDF 5. Domenichiello, M.: State of the art in adoption of e-health services in Italy in the context of European Union e-government strategies. Procedia Econ. Financ. 23, 1110–1118 (2015) 6. Al-Shorbaji, N.: Is there and do we need evidence on eHealth interventions? IRBM Digit. Technol. Healthc. 34(1), 24–27 (2013) 7. European Agency for Safety and Health at Work (EU-OSHA): Priorities for occupational safety and health research in Europe for the years 2013–2010. Publication Office of the European Union. https://osha.europa.eu/en/tools-and-publications/publications/reports/ priorities-for-occupational-safety-and-health-research-in-europe-2013-2020 8. Garcia-Murillo, M., MacInnes, I., Bauer, M.J.: Techno-unemployment: a framework for assessing the effects of information and communication technologies on work. Telemat. Inform. 35(7), 1863–1876 (2018) 9. Baldwin, R.: The Great Convergence: Information Technology and the New Globalization. The Belknap Press of Harvard University Press, Cambridge (2016) 10. Brynjolfsson, E., McAfee, A.: The Second Machine Age: Work, Progress, and Prosperity in a Time of Brilliant Technologies. W. W. Norton & Company, New York (2014) 11. McAfee, A., Brynjolfsson, E.: Machine, Platform, Crowd: Harnessing our Digital Future. W. W. Norton & Company, New York (2017) 12. Korunka, C., Hoonakker, P.: Impact of ICT in Quality of Working Life, pp. 1–9. Springer, New York (2014) 13. Sperry, L. Effective Leadership: Strategies for Maximizing Executive Productivity and Health, p. 237. Brunner-Routledge, New York (2002)

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14. Roja, Z., Kalkis, H., Reinholds, I., Cekuls, A.: Ergonomics risk analysis in construction operations. Agron. Res. 14(1), 211–219 (2016) 15. Arsovski, Z., Lula, P., Dordevi, A.: Impact of ICT of life. In: 1st International Conference on Quality of Life, Conference Manual, pp. 225–232. Center for Quality, University of Kragujevac (2016) 16. Castellacci, F.: Innovation and happiness: the missing link. In: NUPI Workshop (2013) 17. Vendramin, P., Valenduc, G.: ICT, flexible working and quality of life. In: Proceedings of Unity and Diversity: The Contribution of the Social Sciences and the Humanities to the European Research Area, European Commission (EUR 20484), Brussels, pp. 186–191 (2002) 18. Ramendran, C., Raman, G., Mohamed, R.K.M.H., Beleya, P., Nodeson, S.: Organizational flexibility and its implications on employee’s productivity. Interdiscip. J. Contemp. Res. Bus. 4(10), 298–316 (2013) 19. Lin, K.-Y., Tsai, M.-H., Gatti, C.U., Lin, J.-C.J., Lee, C.-H., Kang, S.-C.: A user-centered information and communication technology (ICT) tool to improve safety inspections. Autom. Constr. 48, 53–63 (2014) 20. Goodrum, P.M., Haas, C.T.: Partial factor productivity and equipment technology change at activity level in U.S. construction industry. J. Constr. Eng. Manag. 128(6), 463–472 (2002) 21. Construction Industry Institute.: Leveraging Technology to Improve Construction Productivity. https://www.construction-institute.org/resources/knowledgebase/knowledge-areas/ construction-technology/topics/rt-240 22. Teizer, J.: 3D range imaging camera sensing for active safety in construction. J. Inf. Technol. Constr. 13, 103–117 (2008) 23. European Agency for and Health at Work.: OSH E-tools. https://osha.europa.eu/lv/toolsand-publications/tools-osh-management 24. World Health Organization.: From innovation to implementation. eHealth in the WHO European region WHO Regional Office for Europe, Copenhagen. http://www.euro.who.int/ __data/assets/pdf_file/0012/302331/From-Innovation-to-Implementation-eHealth-ReportEU.pdf?ua=1 25. Vedluga, T., Mikulskien, B.: Stakeholder driven indicators for eHealth performance management. Eval. Program Plan. 63, 82–92 (2017) 26. Estonian Ministry of Social Affairs, Labour. http://www.sm.ee/en/labour-1 27. Northern Dimension Partnership in Public Health and Social Well-being. Country Reports on Occupational Safety and Health in the Northern Dimension Area. NDPHS Series 1/2008 (2008) 28. Parliament of Estonia: Occupational health and safety (OSH) act, Passed 16 June 1999 (lastly revised 20.01.2019) (RT I 1999, 60, 616). https://www.riigiteataja.ee/en/eli/ 511112013007/consolide 29. Parliament of Estonia: Occupational health and safety act. RT, I (24, 10.01.2019). https:// www.riigiteataja.ee/en/eli/524012019005/consolide 30. Schill, A.L., Chosewood, L.C.: The NIOSH Total Worker Health™ program (2013) 31. Valenduc, G., Vendramin, P.: ICT, flexible working and quality of life. In: European Conference, Unity and Diversity, Social and Cultural Changes: The Impact on Wellbeing Bruges (2001) 32. Izvercian, M., Ivascu, L., Radu, A.: Using cloud computing in occupational risks. In: International Symposium on Occupational Safety and Hygiene, Proceedings of SHO 2013, Guimaraes, Portugalia, pp. 491–495 (2013)

Influence of the Upper Limb Position on the Forearm EMG Activity – Preliminary Results Ilona Kačerová(&), Marek Bureš, Martin Kába, and Tomáš Görner University of West Bohemia, Univerzitní 2732/8, 301 00 Pilsen 3, Czech Republic {ikacerov,kaba,tgorner}@kpv.zcu.cz, [email protected]

Abstract. The paper is focused on influence of the upper limb position on the forearm EMG activity. This paper briefly reviews proposed methodology and measuring process. Those results are just preliminary which served for evaluation of proposed methodology. The research is focused on the issue of local muscular stress in the area of the hand and forearms. The lateral muscular stress is evaluated by integrated electromyography. The paper presents preliminary results of male group (20–45 years). The research will continue and will be extended to other groups and also to female population. Keywords: Occupational disease  Local muscular stress Integrated electromyography  EMG



Work position



1 Introduction Many people and also companies are facing the problem of occupational disease. It can be caused by many reasons, whether biological, chemical or physical influences. Occupational disease may be permanent or temporary, but it is clear that the worker will be indisposed for some time, which is not a pleasant situation for him or for company he works for. In the Czech Republic were reported 1 370 occupational diseases by 1 117 workers (551 women and 566 men) in 2017 [1]. Compared to year 2016, the total number of reported occupational diseases increased by 73 (i.e. 5,6%) [2]. In 2017, workers in the “manufacture of motor vehicles, trailers and semitrailers”, the “welfare and social care” and “mining and quarrying” sectors were the most affected. Workers in motor vehicle manufacturing were predominantly suffering from limb overload (155 cases) and professional dermatoses (16 cases). The carpal tunnel syndrome which is the most common diagnosis of the reported cases of occupational diseases is caused by limb overload (over 320 reported cases) or from vibration (over 140 reported cases) [1]. The research is focused on the issue of local muscular stress in the area of the hand and forearms. The lateral muscular stress can be evaluated in several ways - by integrated electromyography (surface Electro-Myo-Graphy) or by tensometric and computational method. In the research was used the method of integrated electromyography, which belongs to the experimental investigation methods that allow © Springer Nature Switzerland AG 2020 R. S. Goonetilleke and W. Karwowski (Eds.): AHFE 2019, AISC 967, pp. 34–43, 2020. https://doi.org/10.1007/978-3-030-20142-5_4

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objective evaluation of neuromuscular activity by the registration of bioelectric potentials. The method of integrated electromyography is the only legally permitted method for measuring in the Czech Republic and is also the most accurate available method of measuring local muscle load. This is a non-invasive method which uses surface electrodes to capture signals. Signal sources are action potentials arising from the gradual recruitment of motor units during the contractile activity of skeletal muscles during movement. These action potentials pass through muscle tissue, fat and skin to the electrodes. The resulting EMG record – an electromyogram, takes the form of an interference pattern, which is formed from the over planning summation potentials of plurality of motor units below the spot of the electrodes. Frequency captures the frequency of occurrence of action potentials per time unit. And examines the assessment of the impact of the shoulder positions on the local muscular load in the area of the hand and forearm. This measurement is focused on the burden of small muscle groups in labouring limbs [3]. The number of movements of assessed motion structures and working positions are determined and evaluated, depending on the extent of the static and dynamic components of the work. This is an initial design of an experiment to confirm that the experiment is correct.

2 Methodology 2.1

Subjects

As a first sample one male group were selected to perform the pilot measurement. The group was in the age range 20 to 45 years. There were 7 men almost all completely healthy without any movement disorder, health problems or hand surgery. The vast majority was university students or administrative workers who have sedentary job and spend most of theirs time working with the computer. One of the man undergo surgical procedures in the wrist. If the health problem has been more serious and obvious during measurement, the result was not included in the statistical evaluation. Men had a different physiological body structure and a different physique. All of those men were right-handed. 2.2

Process of the Measurement

A group of men from the Czech population aged 20 to 45 were measured by integrated electromyography and evaluated. Measuring of each subject was performed in the same way. First the personal data were filled in the measurement protocol (age, weight, height, dominant hand, health problems) and then the actual measurement started. As the first flexors and extensors must be found on volunteer’s hand. The muscles are searched for by the touch, during the palpation, the worker performs certain movements that will help to find a suitable spot for sticking the electrodes. Moves and searches must be done standing, the worker’s elbow should be at an angle of 90°. After that the electrodes are stick to the selected locations. There are 3 colours of electrodes – red,

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yellow and green. The red electrodes were stick on flexors, the yellow one on extensors and the green one must be attached outside the muscle (usually stick on the elbow). After that electrodes are attached by a flexible bandage to avoid electrodes release. After that electrodes are connected to EMG Holter and to PC. It is important to register volunteer´s records. Next the curves are displayed and the maximum freeing forces are measured and the sensitivity of the electrodes is adjusted. During this test muscles were warmed up. The curves must be 2/3 of the graph then the real measurement can start. Before the EMG measurement maximum free forces (Fmax) must be detected. It is measured by the Jamar Plus+ dynamometer, whose handle was set to the second position which is according to the [4, 5]. Firstly, the maximal free force of the right hand was measured, then the free force of the left hand. Those maximal forces must be corresponding to workers age and gender which is compared to [6]. Finally, measurements of the assessment of the impact of the shoulder positions on the local muscular load in the area of the hand and forearm were performed. This proposed experiment is according to government regulations [7, 8] in the Czech Republic. Those regulations determine whether the worker’s position is acceptable, conditionally acceptable and non-acceptable. The government regulation also determines the angles of human body (e.g. shoulder, wrist, elbow etc.) in which a worker can work. Those angles determined the measurement range (for shoulder it is 40°, 60° and 80°). Our research was focused on dynamic activity when volunteer raised his hand from 0 to 40°, from 0 to 60° and from 0 to 80° (flexion and abduction) with weight (2 kg, 4 kg, 6 kg, 8 kg, 10 kg). And also with no weight. Those angles were measured by standard goniometers. The methodology for measurement was developed according to the literature review of previous research papers in order to be able to perform comparison. Firstly, the flexion was measured, abduction later. Hands were measured alternately, firstly the right hand which was lifted from 0° to 40° with zero weight. Then right hand was lifted from 0° to 40° with 2 kg weight, then right hand from 0° to 40° with 4 kg weight and so on. During the measurement there were an effort to perform the act for 3 s. Hands were replaced after reaching the required levels with all weights and had one minute between each round for the rest and muscle regeneration. It was important to let the muscles relax to keep the curve down to a minimum.

3 Results The results of the measurements are the relative values of the exerted muscle forces - % Fmax. The results were varied depending on the physical condition of the volunteers. Volunteers who are accustomed to using the muscles of their hands and forearms (for example by work out in fitness centre) have had better results than volunteers who have more passive lifestyle. Results of measurements were also affected by the place where the electrodes are stacked, amount of hairs on forearm etc.

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Comparison of Arm Flexion 0°–40°

The following tables contain average Fmax and standard deviations. The tables are divided for flexors and extensors of the right and left hand (Tables 1, 2, 3, and 4). Table 1. Differences by flexion 0°–40° extensors right hand Flexion 0°–40° Average Fmax [%] Standard deviation 0 kg 0,5075 0,245 2 kg 8,516 2,152 4 kg 11,201 4,373 6 kg 16,243 2,498 8 kg 19,523 3,557 10 kg 21,856 3,557

Table 2. Differences by flexion 0°–40° flexors right hand Flexion 0°–40° Average Fmax [%] Standard deviation 0 kg 0,467 0,492 2 kg 3,11 1,484 4 kg 4,981 2,253 6 kg 8,048 4,002 8 kg 10,246 3,882 10 kg 13,632 6,627 Table 3. Differences by flexion 0°–40° extensors left hand Flexion 0°–40° Average Fmax [%] Standard deviation 0 kg 1,011 0,620 2 kg 9,843 3,370 4 kg 13,215 5,138 6 kg 15,388 5,239 8 kg 20,052 11,403 10 kg 25,643 12,967

Table 4. Differences by flexion 0°–40° flexors left hand Flexion 0°–40° Average Fmax [%] Standard deviation 0 kg 0,661 0,954 2 kg 4,068 1,238 4 kg 8,523 4,166 6 kg 10,908 3,730 8 kg 13,518 8,039 10 kg 15,278 5,812

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Comparison of Arm Flexion 0°–60°

Tables 5, 6, 7, and 8. Table 5. Differences by flexion 0°–60° extensors right hand Flexion 0°–60° Average Fmax [%] Standard deviation 0 kg 0,725 0,326 2 kg 13,497 3,989 4 kg 14,228 2,212 6 kg 18,681 5,619 8 kg 22,529 3,143 10 kg 27,753 4,022

Table 6. Differences by flexion 0°–60° flexors right hand Flexion 0°–60° Average Fmax [%] Standard deviation 0 kg 0,736 0,605 2 kg 4,007 1,195 4 kg 4,963 1,658 6 kg 7,292 1,868 8 kg 9,353 2,824 10 kg 12,382 3,848

Table 7. Differences by flexion 0°–60° extensors left hand Flexion 0°–60° Average Fmax [%] Standard deviation 0 kg 1,027 0,571 2 kg 9,768 3,358 4 kg 10,615 3,026 6 kg 17,68 6,157 8 kg 21,832 10,166 10 kg 24,300 8,972

Table 8. Differences by flexion 0°–60° flexors left hand Flexion 0°–60° Average Fmax [%] Standard deviation 0 kg 0,476 0,146 2 kg 5,667 3,277 4 kg 7,585 2,564 6 kg 9,53 2,684 8 kg 12,585 4,360 10 kg 15,783 5,366

Influence of the Upper Limb Position on the Forearm EMG Activity

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Comparison of Arm Flexion 0°–80°

Tables 9, 10, 11, and 12. Table 9. Differences by flexion 0°–80° extensors right hand Flexion 0°–80° Average Fmax [%] Standard deviation 0 kg 1,358 0,850 2 kg 14,051 3,491 4 kg 13,895 3,331 6 kg 18,852 2,454 8 kg 24,413 3,572 10 kg 31,200 5,333

Table 10. Differences by flexion 0°–80° flexors right hand Flexion 0°–80° Average Fmax [%] Standard deviation 0 kg 0,701 0,364 2 kg 5,305 1,378 4 kg 6,326 2,193 6 kg 7,665 2,006 8 kg 9,39 1,623 10 kg 12,342 2,950

Table 11. Differences by flexion 0°–80° extensors left hand Flexion 0°–80° Average Fmax [%] Standard deviation 0 kg 1,58 1,364 2 kg 11,551 4,230 4 kg 14,061 2,687 6 kg 20,845 6,797 8 kg 26,703 9,632 10 kg 30,199 7,650

Table 12. Differences by flexion 0°–80° flexors left hand Flexion 0°–80° Average Fmax [%] Standard deviation 0 kg 0,858 0,890 2 kg 6,338 4,094 4 kg 8,663 5,101 6 kg 11,077 7,052 8 kg 15,867 10,701 10 kg 21,820 7,762

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Comparison of Arm Abduction 0°–40°

Tables 13, 14, 15, and 16. Table 13. Differences by abduction 0°–40° extensors right hand Flexion 0°–40° Average Fmax [%] Standard deviation 0 kg 0,735 0,868 2 kg 10,047 3,411 4 kg 12,728 4,118 6 kg 14,15 3,532 8 kg 18,728 3,338 10 kg 22,829 2,854

Table 14. Differences by abduction 0°–40° flexors right hand Flexion 0°–40° Average Fmax [%] Standard deviation 0 kg 0,44 0,457 2 kg 2,717 0,657 4 kg 5,378 2,550 6 kg 5,667 1,381 8 kg 7,267 1,842 10 kg 10,017 2,310

Table 15. Differences by abduction 0°–40° extensors left hand Flexion 0°–40° Average Fmax [%] Standard deviation 0 kg 0,48 0,238 2 kg 12,442 4,228 4 kg 13,186 5,133 6 kg 14,68 5,143 8 kg 19,502 5,527 10 kg 25,542 8,350

Table 16. Differences by abduction 0°–40° flexors left hand Flexion 0°–40° Average Fmax [%] Standard deviation 0 kg 0,181 0,223 2 kg 3,193 0,971 4 kg 6,877 3,478 6 kg 8,662 3,758 8 kg 12,642 3,962 10 kg 14,916 4,277

Influence of the Upper Limb Position on the Forearm EMG Activity

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Comparison of Arm Abduction 0°–60°

Tables 17, 18, 19, and 20. Table 17. Differences by abduction 0°–60° extensors right hand Flexion 0°–60° Average Fmax [%] Standard deviation 0 kg 0,605 0,382 2 kg 9,39 2,856 4 kg 14,911 3,165 6 kg 18,555 4,460 8 kg 22,07 4,634 10 kg 27,616 3,216

Table 18. Differences by abduction 0°–60° flexors right hand Flexion 0°–60° Average Fmax [%] Standard deviation 0 kg 0,35 0,337 2 kg 2,333 0,774 4 kg 5,461 1,690 6 kg 6,337 1,190 8 kg 8,972 1,938 10 kg 12,463 1,461

Table 19. Differences by abduction 0°–60° extensors left hand Flexion 0°–60° Average Fmax [%] Standard deviation 0 kg 0,703 0,573 2 kg 11,327 3,976 4 kg 13,63 5,345 6 kg 19,816 7,228 8 kg 27,046 8,915 10 kg 30,316 12,369

Table 20. Differences by abduction 0°–60° flexors left hand Flexion 0°–60° Average Fmax [%] Standard deviation 0 kg 0,795 0,684 2 kg 2,833 0,925 4 kg 6,87 3,249 6 kg 10,731 4,498 8 kg 14,398 5,586 10 kg 18,746 6,138

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Comparison of Arm Abduction 0°–80°

Tables 21, 22, 23, and 24. Table 21. Differences by abduction 0°–80° extensors right hand Flexion 0°–80° Average Fmax [%] Standard deviation 0 kg 1,145 0,918 2 kg 11,126 2,089 4 kg 15,562 1,927 6 kg 21,062 3,770 8 kg 25,662 2,473 10 kg 29,601 6,854

Table 22. Differences by abduction 0°–80° flexors right hand Flexion 0°–80° Average Fmax [%] Standard deviation 0 kg 0,348 0,298 2 kg 2,968 0,886 4 kg 5,38 1,099 6 kg 6,573 1,812 8 kg 9,076 2,132 10 kg 12,811 3,228

Table 23. Differences by abduction 0°–80° extensors left hand Flexion 0°–80° Average Fmax [%] Standard deviation 0 kg 0,587 0,295 2 kg 8,212 1,879 4 kg 14,263 4,771 6 kg 19,753 5,434 8 kg 26,033 9,647 10 kg 32,314 12,789

Table 24. Differences by abduction 0°–80° flexors left hand Flexion 0°–80° Average Fmax [%] Standard deviation 0 kg 0,48 0,422 2 kg 4,316 2,696 4 kg 7,39 2,687 6 kg 10,156 3,707 8 kg 15,313 4,764 10 kg 21,590 6,612

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All experiments were performed with an overhand grip which is the reason why extensors show higher results. If the measurement would be made by an underhand grip, flexors would be more stressed. Due to the different physical constitution it can be seen that with the rising weight the standard deviation increases which caused greater variability of results. Flexors have lower values than extensors. Average % Fmax values are gradually rising on both hand. Right hand (dominant hand) has lower average scores than the left hand. The greatest growth is between 0 kg and 2 kg. The results of the right hand (dominant hand) are lower than the results of the left hand.

4 Conclusion The paper is focused on specific changes in EMG results which emerge with the shoulder angle. The presented results are only preliminary. Those results helped for evaluation of the measuring methodology and brought important knowledge on which areas to pay more attention. The research is continuing. More groups will be measured as well as female population. But female population will be probably measured with the different weights (from 0 kg to 6 kg only). In the final phase our research will bring new information and more detailed outputs on interconnections between shoulder angle, lifting weights and % Fmax. Acknowledgments. This paper was created with the subsidy of the project SGS-2018-031 – “Optimizing sustainable production system parameters” in the framework of the internal grant agency of the University of West Bohemia in Pilsen.

References 1. Occupational disease in the Czech Republic (2017). http://www.szu.cz/uploads/NZP/Hlaseni_ NzP_2017.pdf 2. Occupational disease in the Czech Republic (2016). http://www.szu.cz/uploads/NRNP/ aktual_Hlaseni_NzP_2016.pdf 3. Kumar, S., Mital, A.: Electromyography in Ergonomics. Taylor & Francis Group, London (1996) 4. Firrell, J.C., Crain, G.M.: Which setting of the dynamometer provides maximal grip strength? J. Hand Surg. 21(3), 397–401 (1996) 5. Blackwell, J.R., Kornatz, K.W., Heath, E.M.: Effect of grip span on maximal grip force and fatigue of flexor digitorum superficialis. Appl. Ergon. 30(5), 401–405 (1999) 6. Mathiowetz, V., Kashman, N., Volland, G., Weber, K., Dowe, M., Rogers, S.: Grip and pinch strength: normative data for adults. Arch. Phys. Med. Rehabil. 66, 69–72 (1985) 7. Government Regulation n. 361/2007 Coll. https://www.zakonyprolidi.cz/cs/2007-361 8. Government Regulation n. 68/2010 Coll. https://www.zakonyprolidi.cz/cs/2010-68

Preschool Children’s Product Design Based on Heart Flow Theory Wei Wang and Fangyu Li(&) School of Architecture and Design, Southwest Jiaotong University, Chengdu 611756, China [email protected], [email protected]

Abstract. Through the study of the theory and results of flow, this paper puts forward the method suitable for preschool children’s product design, and seeks for a new way of development and research for preschool children’s product design. Based on the flow theory, through on-the-spot investigation, put forward on the premise of preschool children’s needs and behavior characteristics, combined with the use of environment and the function of product features, establish a preschool children product innovation design method, including a specific goal, timely and accurate feedback, the unity of behavior and consciousness, potential thinking guide, subjective emotional experience and other elements, and is verified through a case. Based on the innovative design concept of flow theory, this paper deeply understands the needs of preschool children, so as to provide preschool children with emotional experience and psychological space of entertaining through lively education through design, promote the healthy development of children’s body and mind, and provide new ideas for the design of children’s furniture. The innovative design concept based on flow theory is a new design method from unilateral functional needs to spiritual needs. Keywords: Heart flow  Entertaining and learning User characteristics and experience



1 Research Background The International Convention on the Rights of the Child defines children as anyone under the age of 18. The total number of data for the sixth census in 2010 [1] shows that China has a population base of 1.376 billion, of which the population of children aged 0–17 accounts for 20.93%. According to the National Bureau of Statistics, since the low number of children in China in 2010, the following year has shown an upward trend, because children have special status in the family and society. According to the survey, since the country introduced the “comprehensive second child” policy, urban child spending accounts for about 40% of total household consumption [2]. At the same time that children are getting more and more attention, children’s products are getting more and more people’s attention. Therefore, Chinese children’s products have a large potential market and have realistic economic significance.

© Springer Nature Switzerland AG 2020 R. S. Goonetilleke and W. Karwowski (Eds.): AHFE 2019, AISC 967, pp. 44–56, 2020. https://doi.org/10.1007/978-3-030-20142-5_5

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2 Develop New Opportunities and Meanings China’s family structure is becoming more and more miniaturized. Children are the core members of modern urban families. Children’s products are also diverse. According to their functions, they can be divided into three categories: rest, study and games. In recent years, children’s entertainment products have become an emerging market, growing rapidly between traditional games and learning products. Educating and educating technology refers to the theory and practice of integrating the fun of learning and the means of education by means of creating, using and managing appropriate technical processes and resources based on respecting the current life values of learners. It is an educational idea that promotes life experience and learning effects. For children, because their minds are not mature enough, it is difficult to focus on the boring learning, children’s entertainment products that integrate knowledge, health, fun and entertainment, so that children can play and entertain., subtly stimulate interest in learning, improve inquiry ability, cultivate creative thinking, and have realistic educational significance [3].

3 Preschool Children’s Attributes 3.1

Analysis of User Characteristics of Preschool Children

The International Convention on the Rights of the Child defines a child as anyone under the age of 18, but in the medical world, the age of a child is defined between 0 and 14 years of age [4]. However, children can be divided into the following four stages: birth, early childhood, preschool, and school age. Preschool children refer to children in the pre-primary age group, ages 3–6, and children in this period are at the most rapid psychological and physiological development. Physical functions, behavioral habits, ways of thinking, brain intelligence, and emotional cognition are increasing with the growth of different ages. Children at this stage have a great sense of novelty about things, like to imitate the people and things they touch, and have a strong ability to accept new things. However; pre-age children do not form their own values. Only by instinctual cognition can sense external things and cannot accurately define the right and wrong signals conveyed by external things [5]. Therefore, only the analysis of the psychological and physiological characteristics of preschool children can build the emotional experience and psychological space of fun, care and collaboration, promote the healthy development of children’s mind and body, and provide new ideas for children’s product design below. In this paper, the age of preschool children can be divided into three parts, namely, 3–4 years old in the early preschool period, 4–5 years old in the middle stage and 5–6 years old in the late stage. Table 1 shows the development of user characteristics of preschool children at different ages.

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W. Wang and F. Li Table 1. Development of user characteristics of preschool children at all ages

User characteristics Physiological Body function characteristics

Language skills

Psychological Way of characteristics thinking

Behavioral habit

Age stage 3–4 years old The body’s weight gain is fast, the balance is enhanced, and the incomplete development of the nerve leads to some uncoordinated limbs, which has a preliminary understanding of the space A conscious, simple conversation with unclear articulations The curiosity of the outside world is enhanced, it is susceptible to external influences, and it begins to express one’s own thinking, with poor memory and inattention Basic actions can be realized: running, jumping, playing ball, etc., the hand movements are not fine enough, and parents need to accompany them to complete the task

4–5 years old The development of the brain is close to that of the adult, the nervous system is gradually developed, the control of the movement is enhanced, and the space is deeply understood

Simple communication, like to imitate adults to speak

5–6 years old The various parts of the body grow rapidly, the nervous system develops more maturely, the body is flexibly controlled, and the space is accurately judged, and the gender characteristics are significantly different Free to communicate

I like to imitate the people and things that come into contact, and they are plastic and start to generate their own interests and hobbies

Rich in imagination, more independent ideas, independent thinking ability, ability to understand and appreciate others, gender preferences gradually formed

The basic action is more accurate, you can do some simple and fine actions, and move

You can complete basic and fine actions, complete some simple tasks independently, like games, and have gender differences in behaviors

(continued)

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Table 1. (continued) User characteristics Other features Emotional cognition

Environmental development

Age stage 3–4 years old The level of cognition is low, it can distinguish simple shapes and colors, and emotions are violent

4–5 years old Can clearly distinguish things, improve the control of emotions, good at observation, express emotion through language and action Kindergarten small Begin to accept classes: Go out of collective life, sharing and the family to collective contact the new awareness circle of communication, sharing awareness is not high

5–6 years old Observing power is getting stronger and stronger, creativity is strong, things are more curious, emotions are more stable, and you can adjust your emotions Begin to learn to coordinate interpersonal relationships, improve selfdiscipline and have a sense of responsibility

Physiological Characteristics of Preschool Children. 3 to 6 years old is a stage in which children are rapidly developing in terms of physiology, and they are more prominent in terms of physical function and language ability. Preschool children grow rapidly from the initial body weight to various parts of the body. With the increase of age, the brain develops closer to adults, the limbs operate gradually and flexibly, and the space has an accurate understanding. But at the age of 3–6, children are immature, and they tend to be obsessed with maintaining their “order”. We need to have more patience, understanding and communication. Children at this stage have a great sense of novelty to things, are more responsive to the outside world, and are often fascinated by the heights and paintings. They are lively and active, and often climb up and down. At the beginning of their growth, their body tissues have not yet fully developed, their bones are not so strong, and they are prone to fracture dislocation [6]. Psychological Characteristics of Preschool Children. The psychological characteristics of preschool children change rapidly, and the way of thinking and behavioral habits increase with age, gradually forming self-personality, and gradually differentiated into gender preferences. Through research and analysis, it is found that preschool children are extremely curious about external things. However, due to poor adaptability, imitation is often used as a way of learning [6]. Their attention is difficult to concentrate for a long time. Children at this stage are more “selfish” and possessive. They often prove their sense of existence by possessing one thing. At the same time, children aged 3–6 have a variety of items: clothing, toys, books, etc., and they are beginning to become interested in quantity and classification. In the early stage of

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children’s cognition, family environment and parental behavior have a profound impact on children’s living habits and personality development. 3.2

Analysis of the Development Environment of Preschool Children

Due to the special status of children in the family and society, according to the survey, since the introduction of the “comprehensive second child” policy, urban children’s expenditures account for about 40% of total household consumption expenditure [2]. At the same time that children are getting more and more attention, children’s products are getting more and more attention. After busy work, most parents lack companionship to their children and are addicted to electronics. According to the survey report, only 50% of parents will play with children in toys. It can be seen that although the children’s material needs are met, their mental needs are lacking in large gaps [7]. With the development of the economy and the improvement of family conditions, children have become the subject of much attention in the family and have a special status in the family and society. People pay more attention to children’s clothing, food and shelter, and the children’s product market is promoted. Some places have begun to set up separate children’s places. Promote children’s interactions with the outside world, enhance children’s sociality, and become an important direction for children’s product design.

4 Preschool Children’s Product Design Method Based on Heart Flow Theory 4.1

Experience of the Theory of Flow Theory Design

The design of children’s products is based on the needs of users. The “human-machineenvironment” system is the basic object of research. Combining the relationship between users, product use feelings and product use situations, and building the flow of ideas by enhancing the use value of products. Experience the situation, so that children users can find the ultimate gaming experience and integrate emotions in the process of using products. Not only can children learn skills through gamification learning, but also benefit children’s interest cultivation, physical and mental health, and help to cultivate children’s positive. Mentality and good habits, through the heart of the product experience, better accompany children’s growth. Traditional children’s products have a single function, mainly for the independent needs of parents. Children’s own experience of products is not high, and children’s active emotional interaction and continuous psychological experience cannot be realized. Children’s product design based on heart flow theory has unique advantages in children’s product experience, emotional experience and situational experience based on children’s main needs: Product Experience Design. Based on children’s understanding and human care, through the realization of the perceptual elements such as shape, color and function, the product’s physical fit and emotional care will be enhanced, and children’s active recognition of products and deep joyful product experience will be realized.

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Emotional Experience Design. Based on the diversity and leaps of the children’s emotional world, through the product’s sense of story and entertainment, the product gives positive emotions and emotional stimuli, stimulates children’s curiosity and imagination, and realizes children’s interest, exploration, self-affirmation and emotional resonance. The emotional experience rises. Situational Experience Design. Based on the formation process and mental model of children’s emotional thoughts, through the multi-dimensional interaction and multisynergy of products, children can experience the continuous deep situational experience of “thinking observation-abstract simulation-subjective reinforcement-active participation-emotional improvement” to enable children to achieve their goals. Selfmatching, generating the internal motivation to pursue knowledge, forgetting the sense of time, and achieving the state of mind that consciousness and activity are united. 4.2

Explanation Based on the Design Method of Heart Flow Theory

Mihaly Cskszentmihalyi believes that the heart flow experience consists of six parts: action and consciousness, high concentration, loss of self-awareness, control, feedback Table 2. Children’s product design method based on heart flow theory Experience factor Heart flow condition

Experience stage Product experience

Heart flow experience

Emotional experience

Heart flow result

Situational experience

Heart flow characteristics • Clear and clear goals • Accurate and immediate feedback • Balance of skills and skills • Action and consciousness • High concentration of attention • Potential sense of control

Performance method Shape, color, function, function: (1) Precisely locate the child’s mental model (2) Safe materials and appearance (3) Reasonable size and man-machine (4) Diverse and interesting features (5) A simple and easy to use combination

Multi-sensory immersive performance: (1) Ease of use: The operation process is in line with children’s usage habits, and the operation is easy Smooth children’s self-affirmation (2) Interacting and enriching the sense of companion to develop children’s social skills (3) Entertaining: Inspire children’s curiosity and imagination: to achieve ultimate immersion (1) Enhance the story of the situation and • Loss of selfresonate with the child awareness • Illusion of time (2) Diverse functions trigger children’s exploration and attract children to participate distortion actively • Intrinsic (3) Educate and entertain, and develop children’s purpose hobbies by playing games participation (4) The superiority and honor after completing the task (5) Implement an effective reward mechanism

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and behavioral harmony and internal purpose. In 1996, Jackson & Marsh conducted a more in-depth analysis of the theory of heart flow in sports, and split the feedback and behavior in the original six parts into two goals: clear goals and accurate feedback, while increasing time. Twisted experience and challenge-skill balance are two features that make up nine heartflow features [8]. Chen, Wigand and NilanNovak et al. attributed the nine characteristics of the flow of thought to three experience factors: condition, experience, and result. Chen et al. divided it into three stages of experience: experience, experience and effect [9]. After further research, the characteristics of children’s product design flow theory are summarized, as shown in Table 2. This paper uses this as a theoretical basis to propose an objective design method for the design of the heart flow model for preschool children’s product design.

5 Overview of Preschool Children’s Product Design Practices The online version of the volume will be available in LNCS Online. Members of institutes subscribing to the Lecture Notes in Computer Science series have access to all the pdfs of all the online publications. Non-subscribers can only read as far as the abstracts. If they try to go beyond this point, they are automatically asked, whether they would like to order the pdf, and are given instructions as to how to do so. Please note that, if your email address is given in your paper, it will also be included in the meta data of the online version. 5.1

Analysis of Traditional Children’s Furniture Design

According to relevant data, there are currently more than 300 million children under the age of 16 in China, accounting for about a quarter of the country’s population, and now 74% of urban children have their own rooms [10]. It can be seen that children’s furniture has a broad market. More and more parents are paying attention to children’s furniture. Therefore, this article chooses children’s furniture as the object of design practice. Nowadays, the development of children’s furniture is gradually mature and there are many categories. Children’s furniture is classified into four categories (rest, learning, games, and storage), as shown in Fig. 1. At present, China’s children’s furniture is in the initial stage of development. The design theory research mainly focuses on surface design. The safety and functional standards have not yet formed a perfect system. The “Children’s Home Design Technical Conditions” implemented in 2013 established children in China. The national standard of furniture provides a certain technical specification for the design of children’s furniture in China. Since the 1990s, foreign countries have paid attention to children’s furniture design. The design advocates the principle of people-oriented, pays attention to the user’s psychological appeal and health protection, pays attention to the versatility, safety and re-creation of furniture, and forms a universal security system, such as Nordic in 1994. The first green furniture standard was enacted and 13 furniture safety directives were enacted. The United States established 48 standards for children’s furniture materials. Japan began research on furniture design standards in 1946

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Fig. 1. Classification of children’s furniture. Table 3. Domestic and foreign design status of children’s furniture. Design focus

Technical standard

Surface design

2003 national standard

Nordic

Research phase Development of Mature

People oriented

Japan

Mature

United States

Mature

Redesign and re-creation Multi-functional learning

1994 standard + 13 safety instructions 1973 law + 12 technical specifications 48 material standards

Domestic

and developed 12 technical specifications for children’s furniture [10] is shown in Fig. 1 (Table 3). 5.2

Problems in Children’s Furniture Design

In the cycle of using children’s products, children often have low usage rate and simple design. The specific performance is as follows: Table 2 shows the problems in children’s furniture design [11] (Table 4). 5.3

User Analysis and Research

The applicable population is mainly preschool children. The age of 3–6 is the key moment for children to learn from the ignorance to the concept of “order”. At this stage, children have a great sense of novelty to things, and they begin to feel space and familiarity. Games, leisure and learning took up most of their time, and they began to

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Functional aspect Failure to meet the two-way needs of children and parents Single function, lack of fun Operation is too complicated

Unreasonable product structure distribution

Safety aspect

Man-machine aspect Pursue growth and ignore the physiological characteristics of children

Overhangs

Use rigid materials High concentration of harmful substances Lack of quality inspection standards

Light weight, product stability is weak

Appearance The use of color is too complicated, does not meet the reasonable color matching, affecting children’s mood and vision development Counterfeit foreign models, products are more similar

Brand aspect Lack of market cultivation process Brand price is not reasonable Marketing methods, after-sales service behind

have a wide variety of personal items such as toys and books. They began to learn to share, and the family environment will also affect children’s habits and personality. In the early stage, through field visits to kindergartens, children’s parks, secondchild families and other places, as well as observation records of users, Table 1 is the preliminary field visit investigation and analysis content. The purpose of the survey is to obtain user characteristics and common behavioral habits to analyze the user needs and product market needs of children’s furniture design (Table 5). Table 5. Font sizes of headings. Table captions should always be positioned above the tables. Place

User

kindergarten

3–4 years old children (jingle)

Character introduction The youngest child in the class Poor autonomy

Second child family

3 years, 6 years old child (six six)

Smart, tempered, naughty

Event characteristics

Problem

Choose a simple toy: a snowflake piece

Furniture occupies a large area and is cumbersome to arrange

Commonly used rice spoons and brushes to beat the table Sprinkle the tabletop snowflakes while playing Mothers use small animals to draw small animals as rewards Linyi paintings are basically scribbled I don’t like to play with my brother, I am more lonely

Toys are not easy to store Storage basket color is single The desktop is messy Toys are free to be placed, which is inconvenient to find Second child family, space restrictions

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Innovation of Heart Flow Theory in Children’s Product Design

Experience stage Product experience

Emotional experience

Situational experience

Performance method Shape, color, function, function: (1) Preschool children aged 3–6 years old (2) The material uses pine and birch, and the appearance is wood color (3) Market Positioning: Mid-market function positioning: Recreation table: chute rack, projection image, (shrink) pen holder drying easel, rotating rack, game board (storage basket) Learning As a reading table, Remove the Children’s Recreation the portion carried desktop panel for storage table table: table by the middle 1, the game children to play sand table can be desktop games table (sand used as a storage a. Open the organ tray), area by moving the left 2, painting and right sides of table the desktop: it has the functions of drying and storing brushes; projection image: b. Project the pattern on the drawing paper, and the children can copy it Part of the space Book Shelf Autonomous The rack is under the shelf distribution divided into four storage can accommodate “compartments”, books and children can allocate “compartments” according to their storage needs (1) versatile, can be used as a dual function of learning and games (2) By moving or removing the rack, it can be used by single or double person, which is convenient for second-child families or parents to accompany (3) Select the storage needs according to the children’s own needs, let the children integrate into them, and develop good habits of self-management (4) After completing the task, it is convenient to display and satisfy the child’s inner superiority and honor

According to the analysis of previous research, user characteristics and development environment, the design of children’s furniture products should comprehensively analyze children’s heart flow experience, ergonomics and safety protection, and

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formulate reasonable design plans from appearance, function and materials: 1. Appearance: Children are the simplest and simplest group, and they are happy to discover something unknown. From the appearance, the simplest shape is adopted, and the interesting part is presented in the form of organ design, so that children have a sense of desire to explore. 2. Structure: The structure is inserted into the structure of the chute, and the plates are interspersed together and fixed by screws. In order to facilitate transportation, each part of the design can be easily disassembled and taken away. This children’s furniture not only has the design attributes of traditional children’s furniture, but also the innovative design of children’s furniture products based on the theory of flow, starting from three experience stages, see Table x. (1) Material selection: Children’s furniture uses pine wood and birch. It is cheap and green, and uses safe chemical ingredients. The paints and coatings use national standards of green products. (2) Structural safety: The structure of the furniture is subjected to strength, ensuring stability, avoiding looseness and causing safety accidents, and avoiding sharp shapes and sharp corners as much as possible. (3) Ergonomics: The design that meets the size and behavior requirements of children aged 3–6 years, and the visual feeling of simple childlike fun. As an important product in the process of children’s growth and development, children’s furniture has the functions of thinking guidance, emotional communication and security protection. Its design concept and function are of great significance to children’s IQ and EQ training. It does not stop there: (4) Sustainability: Fully consider the problem of children’s rapid growth, and the function needs to meet the progressive development of children’s thinking. When children are 3–5 years old, their minds are immature. Games and leisure account for most of the time. Just having bright colors and novel features is enough to attract them. The demand for furniture is weakened, but because of their many “personal” items. storage will be one of its needs, let them establish the concept of “classification” and “distribution”. When children are 5–6 years old, they begin to have their own ideas. The interest cultivation gradually takes up part of the children’s life. The design of children’s furniture needs to have reasonable layout and various functions to meet the children’s games, leisure and learning. (5) Interpersonal emotional environment: Children’s home is not only an educational and counseling product for intellectual enlightenment, but also a growth companion for children’s emotional cultivation. Children aged 3–6 are generally “selfish” and possessive. While pursuing children’s independent space, we should pay more attention to the emotional interaction between parents’ accompanying and peer-to-peer collaboration.

6 Conclusion The application of heart flow theory in children’s furniture design is an innovative design concept. Children’s furniture is an important product with both thinking guidance, emotional communication and security protection. Its design concept and function realize the children’s IQ and EQ training. Significance in the design process, using the child flow design method based on the flow theory, starting from the nine flow characteristics and three experience stages, fully consider the user’s senses and

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emotional experience, so that the product interaction and use methods meet the needs of users. And apply it to design practice. The emotional experience and psychological space of fun, caring and collaboration are constructed, which promotes the healthy development of children’s body and mind, and also provides new ideas for the design of children’s furniture. Acknowledgements. We grearly thank these funds. The paper is supported by Science&Technology Department of Sichuan Province Soft Science Fund (2017ZR0187). The paper is supported by Science&Technology Department of Chenddu Soft Science Fund (2017RK00-00368-ZF). The paper is supported by Innovation Environment Upgrading Plan for International Science and Technology Cooperation Projects of Science&Technology Department of Chenddu (2017-GH02-00091-HZ, 2017-GH02-00093-HZ). The paper is supported by China Scholarship Fund (201707005050). The paper is supported by Humanities and Social Sciences of Ministry of Education Planning Fund (18YJAZH123).

References 1. Sixth Census Commission: Main Data Bulletin of the Sixth National Population Census in 2010 (No. 1). Sixth Census Commission, Beijing (2010) 2. Liang, B., Zhu, J.: Children’s product design ideas and examples. Manag. Manag. 10, 128– 129 (2012) 3. Papastergiou, M.: Digital Game-Based Learning in high school Computer Science education: impact on educational effectiveness and student motivation. Comput. Educ. 52, 1–12 (2009) 4. Ji, X.: Toy design and research for the creativity of preschool children (2018) 5. Tang, Y.: Application of interesting design in electronic reading books for preschool children. Jiangnan University 6. Shi, Y., Luo, Q.: Research on furniture design adapting to psychological and physiological characteristics of preschool children. Popular Literature (24) 2017 7. Peng, L.: Research on the design of educational products for preschool children. Beijing Institute of Technology (2015) 8. Li, C.: A review of the study of heart flow experience. J. Kaifeng Coll. Educ. (3) (2017) 9. Ou, F., Hao, T.: Research on internet product design based on heart flow theory. Packag. Eng. 4, 70–74 (2016) 10. Shi, S., Yan, J., Guo, P.: Research on the market status and design of growing children’s furniture. Exam. Wkly. 15, 193–194 (2015) 11. Cheng, T.: Research on Children’s Furniture Design. Xi’an Engineering University (2014) 12. Song, H.: Research and application of children’s furniture design methods. Northwestern Polytechnical University (2007) 13. Shi, Y., Luo, Q.: Research on furniture design adapting to psychological and physiological characteristics of preschool children. Popular Literature (24) 2017 14. Hofs, D., Theune, M., Akker, R.: Natural interaction with a virtual guide in a virtual environment. J. Multimodal User Interfaces 3(1–2), 141–153 (2010) 15. Valli, A.: The design of nayural interaction. Multimedia Tools Appl. 38(3), 29–305 (2008) 16. Kistler, F., Endrass, B., Damian, I., Dang, C., André, E.: Natural interaction with culturally adaptive virtual characters. J. Multimodal User Interfaces 6(1–2), 39–47 (2012) 17. Godfrey, M., Johnson, O.: Digital circles of support Meeting the information needs of older people. Comput. Hum. Behav. 25(3), 633–642 (2009)

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18. Jiang, W.: A new perspective in college physical education: the theory of heart flow. Tsinghua University (2010) 19. Jin, W.: Research on user experience design of internet shopping platform based on heart flow theory (2016) 20. Wang, Z.: Design and development of network video courseware based on heart flow theory

Ergonomic Risk Evaluation of the Manual Handling Task of Bovine Quarters in a Brazilian Slaughterhouse Adriana Seára Tirloni1(&), Diogo Cunha dos Reis1,2, Natália Fonseca Dias1, and Antônio Renato Pereira Moro1,2 1

Technological Center, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil [email protected] 2 Biomechanics Laboratory, CDS, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil

Abstract. In 2017, Brazil was the largest exporter and the second largest producer of beef in the world, besides the sixth sector that causes most occupational diseases in this country. Thus, this study aimed to analyze the ergonomic risk of the manual handling task of bovine quarters in a slaughterhouse. The riskassessment model presented in ISO11228-1 was employed. However, the five steps were unfulfilled. Conforming to monthly production data, each one of the seven workers registered handled 282 pieces per day (33.8 ± 22.8 kg/piece). Some inappropriate work conditions can be highlighted: handled weights were high per worker, per day; floors were uneven and slippery; handling with one hand and standing posture was restricted. All the interviewed workers (n = 6) perceived the exertion to accomplish the task as 8 (very hard+), along with feeling back pain. The manual handling task of bovine quarters was unacceptable and needs adaptation, as there were many ergonomics risk factors. Keywords: Slaughterhouse Muscle strength

 Risk assessment  Ergonomics  Discomfort 

1 Introduction Manual handling is any activity that requires the use of human force to lift, lower, carry or otherwise move or restrain an object [1]. Tasks in the meat processing industry are both technically and physically demanding, in which workers perform manual handling of substantial loads (whole carcasses), at high frequency, including lifting, moving, turning and twisting heavy carcasses among the workstations [2]. According to Berkowitz [3], some cattle cuts are delivered as front- or hind- quarters without significant processing, and can weigh from 75 to 125 kg. The demand of muscular strength, work posture and time requirement (repetitive and static work) are basic variables that cause musculoskeletal exigency, so they should be taken as a priority in the work design process, in order to eliminate the risks of work-related musculoskeletal disorders (WMSDs) [4]. Disorders of the musculoskeletal system are common worldwide and one of the most frequent disorders in © Springer Nature Switzerland AG 2020 R. S. Goonetilleke and W. Karwowski (Eds.): AHFE 2019, AISC 967, pp. 57–69, 2020. https://doi.org/10.1007/978-3-030-20142-5_6

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occupational health [1]. In cattle slaughterhouses, three potential factors often prevalent: repetitive motions, awkward postures or work positions, and/or exertions of significant force, cause and most likely account for the majority of WMSDs [5]. Heneweer et al. [6] verified that heavy workload and the load accumulation or lift frequency were moderate to strong risk factors for low back pain (LBP) in workers. Kaka et al. [7] evaluated 102 male cattle butchers and identified that lower back complaints (66.7%) were the most commonly reported WMSDs. The same thing happened to cattle slaughterhouse workers (90% felt bodily discomfort), however, the shoulder was the region most affected [8]. In Brazil, in 2017, statistical data showed that 10.7% of all records for occupational diseases were related to back pain and other disorders in intervertebral discs [9]. Considerable costs are associated with LBP, due to lost productivity and income, medical expenses, rehabilitation and surgical interventions as well as the costs of disabling pain and limited daily function [6]. In order to guarantee safety, health and quality of life in slaughterhouses, Regulatory Standard 36 (NR-36) establishes requirements for the manual transportation and lifting of products and loads [10]. Therefore, this standard is a tool that assists the health and safety managers of the workers, since Brazil was the largest exporter and the second largest producer of beef in the world [11], besides the sixth sector that causes most occupational diseases in Brazil [9]. Although NR-36 does not define any specific method for analyzing the risk of manual handling tasks, another international standard, ISO-11228 - Ergonomics Manual handling - Part 1: Lifting and carrying, recommends a risk-assessment model associated with manual material-handling tasks [1]. The method takes into consideration the hazards (unfavorable conditions) related to the manual lifting, and examines variables such as object mass and grip, the positions of the object relative to the positions of the body (distances and trunk postures), the lifting frequency and duration, in addition to the cumulative mass manipulated by each worker per day [1]. This research is justified, as few studies specifically investigated the handling of products and loads in slaughterhouses. Andersen et al. [12] verified the factors that influenced perceived physical exertion during manual lifting in blue-collar workers (slaughterhouse workers were included). In a pig slaughterhouse, Botti et al. [2] observed the positive effects of the semi-automation ham deboning line in relation to the manual process using the NIOSH lifting index method. Despite the manual load handling is common in slaughterhouses, no studies were found that evaluated the risk of handling and lifting loads in cattle slaughterhouses using the ISO 11228-1 method [1]. Thus, the objective of this study was to analyze the ergonomic risk of the manual handling task (lifting and carrying) of bovine quarters in a Brazilian slaughterhouse.

2 Method This case study was approved by the Committee of Ethics in Research with Human Beings, of the Federal University of Santa Catarina – Brazil, protocol nº 2098/2011, in accordance with the Declaration of Helsinki. This research was conducted in a cattle

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slaughterhouse in North Brazil, in which 438 workers slaughtered 450 animals daily in one work shift. The organizational characteristics of work in the cattle slaughterhouse are describes in Table 1. Table 1. Organizational characteristics of work in the cattle slaughterhouse. Organizational characteristics of work Work shift duration 500 min Repetitive daily work hours 425 min Rest breaks 3  20 min Meala 60 min Uniform change 15 min a Not included in work shift duration

As mentioned by the document - “Environmental Risk Prevention Program” provided by the slaughterhouse, the room temperature in the dispatch sector was 14 °C and the meat temperature was approximately 7 °C. Workers used Personal Protective Equipment with a Certificate of Approval (CA) by the Brazilian Ministry of Labor (clothing, gloves, socks, and boots) provided by the slaughterhouse. 2.1

Participants

The work task selection of the dispatch sector was intentional since workers handled bovine quarters individually and frequently, indicating the need for an ergonomic risk analysis. In the bovine quarters dispatch, there were 7 male registered employees, however, only 6 workers performed this task at data collection. They were invited to participate in this study and after their consent, all workers were interviewed in the sector. Workers were between 26 to 41 years old (33.4 ± 5.5) and had 4.0 ± 2.7 years working in the company. 2.2

Manual Handling Task of Bovine Quarters

The manual handling task of bovine quarters was initiated when a worker on a metal platform (0.40 m tall) (Fig. 1A) positioned a packed bovine quarter, which came from an overhead conveyor, on the shoulder of another worker (Fig. 1B). Bovine pieces were transported from the dispatch sector to a truck that was on one of the two docks in that sector (Fig. 1C). The worker entering the truck should pass over a metal ramp (Fig. 1D) located in the doorway of the dock. The passage height (doorway with the ramp) was 2 m. Workers walked about 3 to 15 m from the point of the meat pickup in the dispatch sector to the point where the meat piece was hung inside the truck (Fig. 1C). The worker carrying the meat should hang it by hooks on the truck’s roof rail at two different heights (2.1 m and 1.3 m) (Fig. 1E). This meat layout was intended to make

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better use of the space inside the truck and to transport a greater number of pieces to the customers. In the highest position, the worker attached a hook to the meat, later hanging it in the truck (Fig. 1E). For this action, the worker climbed on a 0.20 m high platform. In order to deposit the meat at an intermediate height, the worker would take a nylon cord when leaving the truck (Fig. 1F). During the transport of a piece, the worker passed the cord between the bone and the muscle of the meat and tied a simple knot. The cord was positioned on the hook to later be attached to the meat that was higher. 2.3

Risk-Assessment Model

In the present study, the single-task manual lifting was analyzed, Waters et al. [13] define this task as one that does not vary significantly from lift to lift or only one lift is of interest. For the estimation of the risk associated with a manual material-handling task, the risk-assessment model was employed in the origin and destination manual lifting conditions as presented in the International Organization for Standardization (ISO) 11228 - Ergonomics — Manual handling — Part 1: Lifting and carrying [1]. An initial screening of manual handling was carried out to evaluate the health risks of the task. The risk screening consists of five steps and an evaluation of the ideal conditions for manual handling, in order to verify if it is acceptable. In relation to the steps, if one step is not fulfilled, it means that the task needs adaptation (in such a way that all questions in the step model are satisfied), there are high health risks and the assessment should not proceed. The step model describes the following procedures for addressing the interrelated aspects of manual lifting and carrying [1]: – Step 1 – mass of object to be lifted  reference mass (for population group evaluated) and ideal condition? – Step 2 – mass and frequency < limits? – Step 3 – mass of object < limits derived by the Equation (Table 2)? – Step 4 – cumulative mass < 10000 kg? – Step 5 – cumulative mass and distance of carrying < limits? The evaluation of ideal conditions for manual handling: ideal posture, a firm grip on the object in the neutral wrist posture, and favorable environmental condition were also performed [1] (Table 3). In this study, the reference mass of 25 kg was adopted because the analyzed population was composed of male adults [1]. 2.4

Instruments

Documents about work organization, monthly production and environmental condition were provided by management personnel: ergonomic analysis of work, production control worksheets and report of work environmental conditions. For the filming of the manual handling task of bovine quarters and recording of the handled mass weights, a Sony HDR-XR160 digital camcorder was used.

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A

B

C

D

E

F

Fig. 1. Process description of manual handling of bovine quarters.

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The workers were interviewed about exertion perception when handling a bovine quarter, and for this, the Borg scale 0–10 adapted by the authors was used [14]. Workers visualized the verbal and numerical scales and indicated their perceived exertion (Fig. 2). In addition, the workers were asked about feeling bodily discomfort and in which regions. 0 0.5 Missing Extrem ely light

1 Very light

2 3 4 5 6 Light Modera Modera Hard Hard + te te + (heavy)

7 Very hard

8 9 10 Very Very Extremely hard + hard ++ hard (almost max.)

Fig. 2. Exertion perception evaluation by Borg scale [14].

2.5

Statistical Analysis

The statistical analysis was descriptive, images were analyzed and the data was annotated on a spreadsheet.

3 Results In compliance to monthly production data, each one of the seven registered workers handled 282 pieces per day (33.8 ± 22.8 kg per piece; 11.9–66.9 kg,). Additionally, during data collection, the 27 pieces of bovine weighed 65.4 ± 7.8 kg (50.3–76.0 kg). The screening of the manual handling of bovine quarter task showed that this single-task was unacceptable, since reference and cumulative mass were higher than recommended. Likewise, the mean mass of the object to be lifted (bovine quarter) was greater than the limit mass resulting in the lifting equation at the origin (11.85 kg). In addition, lifting at the destination, the vertical location multiplier (vm) was not fulfilled (meat deposition - 2.1 m tall) resulting in a multiplier factor equal to zero (inappropriate) (Table 2). Based on production data and data collection, step 1 showed the inadequacy of the task because the mass handled was >25 kg, i.e. larger than the mass constant for the adult-male working population (25 kg). Although it is unnecessary to complete the analysis of the manual handling, step 1 already inhibits the continuity of evaluation, so it verified that the following 4 steps were also unmet (Table 2). Steps 2 and 3 were unfulfilled, due to the recommended mass being smaller than the lifted mass and several handling conditions were unfavorable (Table 3). Steps 4 and 5 were not satisfied, since the average cumulative mass handled per worker was greater than 10 tons (10,447 kg) per day and workers carried each bovine quarter more than 10 m. The standard [1] recommends 12 criteria described in Table 3 as ideal conditions of manual material handling, 10 were unfulfilled and inappropriate.

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Table 2. Description of multiplier factors that comprise the risk-assessment and step fulfillments of the method. Multiplier factors/steps mref - Reference mass (factor multiplier and steps 1 and 2) mcum - Cumulative mass (steps 4 and 5) hm - Horizontal distance multiplier, distance between the center mass of the object and the worker

Referencesa Men; Age: 18–45 years mref = 25 kg 10,000 kg/day Distance  10 m h  0.63 cm

vm - Vertical location multiplier, object handle height (step 3)

0 < v < 1.75 m

dm - Vertical-displacement multiplier

d  1.75 m

am - Asymmetry multiplier (trunk rotation angle) fm - Frequency multiplier of the lifting task (per min). Considering the vertical location (floor – hands  0.75 cm)

a  135° Long duration 2 h < repetitive lifting task  8 h fm > 0 Poor; cm = 0.90

Study data 33.8 ± 22.8 kg1 65.4 ± 7.8 kg2

Met No

10,4447 kg/day Distance 3 – 15 m Origin – 0.25 m; hm = 1 Destination – 0.30 m; hm = 0.83 Origin – 1.5 m; vm = 0.78 Destination – 2.10 m; vm = 0 d = 0.60 m; dm = 0.90 0°; am = 1

No

0.66 lift/min; fm = 0.75

Yes

Yes Yes

Yes No

Yes Yes

Poor; cm = 0.90 Yes# cm - Coupling multiplier for the quality of gripping a Allows application of method [1]; 1production data; 2data collection; #decrease the object limit mass; The limit for the object mass is derived by the equation: m  mref x hm x vm x dm x am x fm x cm [1]; When the origin and destinations factors were not cited, the same factor to analyze both conditions of manual handling was applied.

All the workers classified the exertion perception to accomplish the task as 8 (very hard+), along with feeling bodily discomfort in the low back. Half of the workers felt discomfort in their knees (n = 3).

4 Discussion In the present research, workers handling cattle cuts that weighed on average 11.9 kg to 66.9 kg, corroborating that the tasks in the cattle processing industry are physically demanding [2], with application of significant force [5] and require handling of heavy weights by workers [3]. In Brazil, the Statistical Yearbook of Labor Accidents of 2017 revealed that 10.7% of all recorded occupational diseases were related to back pain and other disorders in

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intervertebral discs [9]. Low back pain is a complex condition with multiple contributors to both the pain and associated disability, including psychological, social and biophysical factors, along with comorbidities, and pain-processing mechanisms [16]. The European Agency for Safety and Health at Work [17] cited the following work-related physical risk factors that increase the risk of low back disorders: heavy manual labor, manual material handling, awkward postures, static work, whole-bodyvibration, and slipping and falling. However, it is based on multiple high quality studies, this agency mentioned that manual material handling and whole-bodyvibration are the factors with strong evidence of exposure–response relationship.

Table 3. Criteria for analyzing ideal conditions of manual material handling.

2

Ideal conditions [1] Moderate ambient thermal environment (20–26 °C) [15] Two-handed operation only

3

Unrestricted standing posture

4 5 6

Handling by one person only Smooth lifting Good coupling between the hands and the objects handled

7

11

Good coupling between the feet and the floor Manual handling activities, other than lifting, are minimal The objects to be lifted are not cold, hot or contaminated Vertical displacement of the load is  0.25 m and does not occur below knuckle or above shoulder height The trunk is upright and not rotated

12

The load is kept close to the body

1

8 9 10

Real conditions 14 °C

Met No

One hand held the meat and the other manipulated the hook and the cord Workers needed to crouch down to enter the truck, when crossing the ramp handling a bovine quarter One person Smooth Quality of gripping was poor since the bovine quarters were large, pliable, asymmetrical and difficult to grasp; workers used gloves; as well as workers had to simultaneously manipulate a metal hook and a cord to help hang the pieces Floors were uneven and slippery

No No

Yes Yes No

No

Workers did not performed job rotations Cold meat temperature = 25 kg), the norm recommends that the package should be reduced, or manual handling should be eliminated by mechanization and automation. It can provide conditions to reduce workers’ exposure to the risks of manually transporting loads, optimize work, as well as prevent injuries and diseases. Nevertheless, Battevi et al. [31] cited that despite high automation levels in today’s factories, manual lifting should still be considered a widespread risk factor. Thus, the occupational health and safety team shall maintain the monitoring of the manipulated object mass limits (conforming to the age of the working population), lifting frequency, cumulative mass transported per day by a worker (10 tons), not exceeding that suggested by ISO 11228-1 [1]. Furthermore, avoiding awkward postures required during the lifting process (such as twisted or bent trunks or far reaches). Under unfavorable environmental conditions, or when lifting from/to unsuitable levels, e.g. arms above shoulder height, the recommended limits for cumulative mass for carrying should be substantially reduced (at least by one-third) [1]. These ergonomic recommendations aiming to reduce the exposure of workers to the risk of manually handling loads and decrease stress levels of the back. In order to avoid hazardous handling activities, the floors and passages where manual handling are performed must be in well-maintained and clear passages [1, 10]. In addition to these guidelines, ISO 11228-1 [1] requires that floor or ground surfaces should be level, not slippery and clear of obstacles to prevent potential slipping or tripping accidents. It also mentions that the presence of steps, steep slopes and ladders can increase the risk of injury by adding to the complexity of movement when handling objects. Accordingly, preventive measures should be taken as effective training of the workers and necessary adaptations of the work conditions to assist in reducing manualhandling injuries [1]. Moreover, The American Meat Institute [5] and NR-36 [10] assert that several administrative controls can be used to reduce the duration, frequency and severity of ergonomic stressors (hazard). Besides that, measures must be taken to adjust the load weight and size, the numbers of movements to be carried out, and the distances with loads to be moved that may compromise the safety and health of workers [10]. Additionally, rest breaks and job rotations can relieve fatigued muscles; must combine two or more tasks to reduce repetition and utilize varying work patterns [5]. The NR-36 recommends alternating with other tasks or appropriate breaks between periods not exceeding two hours [10]. This is sound advice, but sometimes, workers could not perform other tasks (restrictions of employment contract) and, in the present research, workers already took 3 x 20 min breaks, in addition to the meal (conforming to NR-36). Thus, it is suggested to follow OSHA’s indications [32], train employees on use of proper lifting techniques and lifting devices, seeing that pushing or sliding loads eliminates lifting and carrying that can be strenuous to the hands, arms, and back. However, it should not be assumed that the provision of information and training of workers alone will ensure safe manual handling [1].

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4.1

67

Strengths and Limitations

One study limitation was the small number of participants, nevertheless, almost all the slaughterhouse workers who performed this task were interviewed. Additionally, this sample was not representative of the population in Brazilian slaughterhouses. In this way, it is suggested to perform data collection in other slaughterhouses in Brazil. As a strength, this research was exploratory and the first to investigate work conditions, bodily discomfort and perceived physical exertion to perform the manual handling task of bovine quarters.

5 Conclusion It is concluded that in the studied condition, the manual handling task of bovine quarters was unacceptable and needs adaptation, as the risk-assessment model was impossible to apply in the first step (handled mass > 25 kg). Besides the first step, the four other model steps were unfulfilled, showing that the task had high health risks. There were many ergonomics risk factors in this task: handled weights were high per worker, per day; work environment temperature was not moderate; object handled by ramps and with one hand; quality of gripping was poor; floors were slippery; workers did not perform job rotations; objects were cold, were hung above the shoulder height and were not kept close to the body; trunk was tilted laterally; and finally, meat handling caused restriction of standing posture. In addition, all workers felt bodily discomfort in the low back and performed high exertion. It is suggested that this manual handling should be eliminated by mechanization and automation, in order to reduce the risks of back pain and injury.

References 1. International Organization for Standardization (ISO): Ergonomics – Manual Handling – Part 1: Lifting and Carrying. Geneva: ISO; 2003. Standard Nº. 11228–1:2003 2. Botti, L., Mora, C., Regattieri, A.: Improving ergonomics in the meat industry: a case study of an Italian ham processing company. In: IFAC Symposium on Information Control in Manufacturing INCOM, vol. 48, no. 3, pp. 598–603. Elsevier, Amsterdam (2015) 3. Berkowitz, D.E.: Industria Alimentaria. In: Stellman, J.M. (ed.). Enciclopedia de salud y seguridad en el trabajo. Chapter 67; vol III, parte X: Sectores basados en recursos biológicos, pp. 67.16–67.20. Ministerio de Trabajo y Asuntos Sociales, Madrid (2001) 4. Laurig, W., Vedder, J.: Ergonomía. In: Stellman, J.M. (ed.). Enciclopedia de salud y seguridad en el trabajo. Chapter 29; vol I, parte IV: Herramientas y Enfoques, pp. 29.61– 29.66. Ministerio de Trabajo y Asuntos Sociales, Madrid (2001) 5. American Meat Institute: Worker Safety in the Meat and Poultry Industry. AMI, Washington (DC) (2013). https://www.meatinstitute.org/index.php?ht=a/GetDocumentAction/i/83419/ 6. Heneweer, H., Staes, F., Aufdemkampe, G., van Rijn, M., Vanhees, L.: Physical activity and low back pain: a systematic review of recent literature. Eur. Spine J. 20, 826–845 (2011) 7. Kaka, B., Idowu, O.A., Fawole, H.O., Adeniyi, A.F., Ogwumike, O.O., Toryila, M.T.: An analysis of work-related musculoskeletal disorders among butchers in Kano metropolis. Nigeria. Saf. Health Work. 7, 218–224 (2016)

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8. Martins, R.S., Gonçalves Amaral, F., Pereira da Silva, M.: The influence of physiological breaks and work organization on musculoskeletal pain index of slaughterhouse workers. In: 20th Congress of the International Ergonomics Association (IEA 2018), vol. 820, pp. 159– 168. Springer, Chan (2019) 9. Anuário Estatístico de Acidentes do Trabalho: AEAT 2017. Ministério da Fazenda, Brasília (2017) 10. Brasil. Ministério do Trabalho. Norma Regulamentadora NR 36 - Segurança e saúde no trabalho em empresas de abate e processamento de carnes e derivados. Portaria MTE nº 555, de 18 de abril de 2013. Brasília – DF (2013) 11. Associação Brasileira da Industria Exportadoras de Carnes: Perfil da Pecuária no Brasil, Relatório anual. ABIEC (2018). http://www.abiec.com.br 12. Andersen, L.L., Sundstrup, E., Brandt, M., Dastjerdi, E.L., Persson, R., Jakobsen, M.D.: Factors associated with high physical exertion during manual lifting: cross-sectional study among 200 blue-collar workers. Work 59 (Suppl. 1), 59–66 (2018) 13. Waters, T., Occhipinti, E., Colombini, D., Alvarez, E., Hernandez, A.: The variable lifting index (VLI): a new method for evaluating variable lifting tasks using the revised NIOSH lifting equation. In: Proceedings of 17th IEA World Conference, Beijing, China (2009) 14. Colombini, D., Occhipinti, E.: Risk Analysis and Management of Repetitive Actions. CRC Press, Boca Raton (2017) 15. International Organization for Standardization (ISO): Ergonomics of the thermal environment – analytical determination and interpretation of thermal comfort using calculation of the PMV and PPD indices and local thermal comfort criteria. Switzerland: ISO; 2005. Standard Nº. 7730:2005(E) 16. Hartvigsen, J., Hancock, M.J., Kongsted, A., Louw, Q., Ferreira, M.L., Genevay, S., et al.: What low back pain is and why we need to pay attention. Lancet 391(10137), 2356–2367 (2018) 17. Beeck, L.R.O., Hermans, V.: Research on work-related low back disorders. Inst. Occup Saf. Health, Brussels, Belgium (2000) 18. Jordan, C., Luttmann, A., Theilmeier, A., Kuhn, S., Wortmann, N., Jäger, M.: Characteristic values of the lumbar load of manual patient handling for the application in workers’ compensation procedures. J. Occup. Med. Toxicol. 6, 17 (2011) 19. Coenen, P., Gouttebarge, V., van der Burght, A.S., van Dieën, J.H., Frings-Dresen, M.H., van der Beek, A.J., Burdorf, A.: The effect of lifting during work on low back pain: a health impact assessment based on a meta-analysis. Occup. Environ. Med. 71(12), 871–877 (2014) 20. Ahsan, M.K., Matin, T., Ali, M.I., Ali, M.Y., Awwal, M.A., Sakeb, N.: Relationship between physical work load and lumbar disc herniation. Mymensingh Med. J. 22(3), 533– 540 (2013) 21. Tirloni, A.S., Reis, D.C., Ramos, E., Moro, A.R.P.: Association of bodily discomfort with occupational risk factors in poultry slaughterhouse workers. DYNA 84(202), 49–54 (2017) 22. Tirloni, A.S., Reis, D.C.D., Dias, N.F., Moro, A.R.P.: The use of personal protective equipment: finger temperatures and thermal sensation of workers’ exposure to cold environment. Int. J. Environ. Res. Public Health 15, 2583 (2018) 23. Tirloni, A.S., dos Reis, D.C., Dias, N.F., Moro, A.R.P.: Evaluation of worker satisfaction with the use of hand tools in a poultry slaughterhouse. In: Proceedings of the AHFE 2018 International Conference on Safety Management and Human Factors, vol. 789, pp. 476–488. Springer, Cham (2019) 24. Vergara, L.G.L., Pansera, T.R.: Ergonomics analysis of the activity of boning shoulder in a pig slaughter-house in the city of Ipiranga-SC. Work 41, 703–709 (2012)

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25. Tirloni, A.S., Reis, D.C.D., Ramos, E., Moro, A.R.P.: Thermographic evaluation of the hands of pig slaughterhouse workers exposed to cold temperatures. Int. J. Environ. Res. Public Health 14, 838 (2017) 26. Tirloni, A.S., Reis, D.C., Ramos, E., Moro, A.R.P.: Evaluation of bodily discomfort of employees in a slaughterhouse. In: Proceedings of the AHFE 2017 International Conference on Physical Ergonomics and Human Factors, vol. 602, pp. 153–162. Springer, Cham (2018) 27. Krishnamurthy, I., Othman, R., Baxter, G.D., Mani, R.: Risk factors for the development of low back pain: an overview of systematic reviews of longitudinal studies. J. Phys. Ther. Rev. 23(3), 162–177 (2018) 28. Jakobsen, M.D., Sundstrup, E., Persson, R., Andersen, C.H., Andersen, L.L.: Is Borg’s perceived exertion scale a useful indicator of muscular and cardiovascular load in blue-collar workers with lifting tasks? A cross-sectional workplace study. Eur. J. Appl. Physiol. 114(2), 425–434 (2014) 29. Anema, J.R., Schellart, A.J., Cassidy, J.D., Loisel, P., Veerman, T.J., van der Beek, A.J.: Can cross country differences in return-to-work after chronic occupational back pain be explained? An exploratory analysis on disability policies in a six country cohort study. J. Occup. Rehabil. 19(4), 419–426 (2009) 30. Brasil. Consolidação das leis do trabalho (CLT). Aprova a Consolidação das Leis do Trabalho. Diário Oficial [dos] Estados Unidos do Brasil, Poder Executivo, Rio de Janeiro, DF, 9 ago. 1943. Secção 1, pp. 11937–11984 (1943) 31. Battevi, N., Pandolfi, M., Cortinovis, I.: Variable lifting index for manual-lifting risk assessment: a preliminary validation study. Hum. Factors 58(5), 712–725 (2016) 32. OSHA. Occupational Safety and Health Administration. Prevention of musculoskeletal injuries in poultry processing (2013). https://www.osha.gov/Publications/OSHA3213.pdf

Influence of Location and Frequency Variations of Binaural Electrostimulation on Heart Rate Variability Jing-Shia Tang1,2, Nan-Ying Yu3, Fang-Hsin Lee1, Chi-Wen Lung4, Liang-Cheng Lee5, Ben-Yi Liau6, and Chien-Liang Chen3(&) 1

4

Department of Nursing, Chung-Hwa University of Medical Technology, Tainan, Taiwan [email protected] 2 International Doctoral Program in Nursing, College of Medicine, National Cheng Kung University, Tainan, Taiwan 3 Department of Physical Therapy, I-Shou University, Kaohsiung, Taiwan [email protected] Department of Creative Product Design, Asia University, Taichung, Taiwan 5 Department of Finance, I-Shou University, Kaohsiung, Taiwan 6 Biomedical Engineering, Hungkuang University, Taichung, Taiwan

Abstract. The aim of this study was to determine an appropriate frequency and location of binaural electrostimulation to ensure the treatment effect. Twentythree healthy participants were recruited to receive 15 min of electrostimulation at two different frequencies (i.e., 1 vs. 25 Hz), and the same procedure was performed at two locations (tragus vs. earlobe). This study observed fluctuations in heart rate variability to reflect the autonomic activity. Repeated measures ANOVA was carried out to determine the differences. Results showed that the activities of parasympathetic and total power increased after stimulation in both tragus and earlobe trials. However, the effect of 25 Hz stimulation to increase total power was significantly higher than that of 1 Hz. No significant difference in stimulating the earlobes or tragus was observed. Therefore, binaural electrostimulation might be cardioprotective and useful as a complement to medical treatment. Keywords: Transcutaneous Auricular Nerve Stimulation  Non-invasive Cranial Electrostimulation  Autonomic activity

1 Introduction Heart rate variability (HRV) is a relevant marker reflecting cardiac modulation by sympathetic and parasympathetic components of the autonomic nervous system (ANS). HRV is a popular noninvasive research tool in cardiology. The clinical application of HRV is mainly associated with assessing cardiovascular and metabolic illness progression. In general, low HRV has been found to be a significant predictor of cardiac mortality and morbidity, indicating that a high HRV is more desirable than a low HRV [1]. In recent years, investigators have hypothesized that adequate vagus activity can © Springer Nature Switzerland AG 2020 R. S. Goonetilleke and W. Karwowski (Eds.): AHFE 2019, AISC 967, pp. 70–79, 2020. https://doi.org/10.1007/978-3-030-20142-5_7

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reduce the risk of metabolic syndromes such as obesity, elevated glucose level, and blood pressure. Therefore, metabolic syndromes can be prevented by direct stimulation to increase the activity of the vagus nerve [2]. Transcutaneous (noninvasive) vagus nerve stimulation (tVNS) has recently been proposed as an alternative to traditional VNS requiring surgery. The tVNS is targeted to the auricular branch of the vagus nerve instead of the cervical branch in the neck in invasive VNS. Tragus stimulation is most successful in evoking vagus-evoked somatosensory potential [3, 4]. However, the earlobe is free of cutaneous vagal innervation [5]. The tVNS stimulates the afferent auricular branches of the vagus nerve that project to the solitary nucleus. Neurons in the solitary nucleus further project to the limbic and ANS structures [6]. Fibers from the solitary nucleus project to the locus coeruleus and dorsal raphe nucleus, which are major nuclei related to noradrenergic and serotonergic innervations of the entire brain cortex, respectively. Serotonin and norepinephrine are involved in the pathophysiology of depression and mechanisms of action of antidepressant treatments [7]. Consequently, direct stimulation of the afferent nerve fibers on the ear should alleviate depressive symptoms [8]. Given that the right vagal nerve projects efferent fibers to the heart, investigators have suggested that VNS on the neck to the cervical vagus nerve is safer on the left side of the body than on the right side of the body [9, 10]. Given that no direct fibers connect the ear vagus nerve to the heart, both left and right ears should be safe for applying tVNS [11]. Nonetheless, a previous study showed that the immediate effect of 10 min of tVNS on HRV is limited, and the effect of right tVNS stimulation on HRV is greater than that of left tVNS stimulation [12]. Therefore, we believe that the immediate effect of increasing vagal activity by binaural electrostimulation (BES) should be pronounced. In this study, the negative pole (anode) was placed in the right ear, and the positive pole (cathode) was placed in the left ear. Anodal stimulation has depolarizing effects, which lead to excitation of neural activity, while the cathode is the return electrode [13, 14]. This method of placing positive and negative electrodes is similar to recent transcranial direct current stimulation (tDCS) [15]. TDCS delivers a weak direct current via electrodes placed on the earlobes and creates a constant electric field in the brain, which can lead to acute alterations in the excitability of cortical areas by its subthreshold depolarizing or hyperpolarizing effects on neuronal resting membrane potentials [16]. However, whether the stimulation of the earlobes with BES will have similar effects on ANS activity as stimulating the tragus remains unclear. Notably, different stimulation frequencies have various effects on serotonergic and noradrenergic systems. The dorsal raphe nucleus/serotonergic system preferably responds to high-frequency stimulation (10–100 Hz) [17, 18], and the locus coeruleus/ noradrenergic neurons can react to low-frequency stimulation (0.1–4 Hz) [18]. Previous studies suggested that a frequency between 1 and 30 Hz and intensity of 4–6 mA are sufficient to elicit a therapeutic effect on changes in ANS activity [8, 11]. Therefore, our study compared the difference in HRV response caused by stimulation between 1 and 25 Hz during BES treatment. The purpose of this study was to investigate the HRV responses caused by BES at different locations and frequencies in a healthy population. We expected to identify an appropriate location and frequency of electrical stimulation to ensure the treatment effect.

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2 Methods 2.1

Participants

A total of 23 healthy college students (10 men and 13 women) participated in this study. Their mean age, height, weight, and body mass index were 20.4 ± 0.9 years, 165.6 ± 7.0 cm, 57.8 ± 12.0 kg, and 20.8 ± 2.9 kg/m2, respectively. Participants were eligible if they did not have cardiovascular illnesses, severe diabetes, major mental conditions, and outer ear problems; were not pregnant; and were not taking any medication possibly influencing the ANS. Participants were asked not to smoke and consume alcohol or caffeine 3 h before participation. The participants were fully informed about the study protocol and gave their informed written consent to participate in the experimental procedure. All applicable institutional and governmental regulations concerning the ethical use of human volunteers were followed during the course of this research. 2.2

BES Device

We used the Ginming Low-Frequency Electric Therapy Apparatus (EAR-3, Pokam Corp., Ltd., Taiwan) for the experiment. BES was performed via electrical stimulation of the auricular branch of the vagus nerve in both ears. BES consists of a portable battery-driven electrical stimulator connected to the ear electrodes placed in contact with the bilateral earlobes or tragus (Fig. 1). When using this instrument, the ear contact area is moistened with water, and the ear wire is clipped. The instrument output’s electrical stimulation has a pulse width of 4 ms, pulse frequency that can be adjusted between 1 and 25 Hz, and output voltage of 0–30 V ( 0.05). Time did not significantly affect blood pressure, heart rate, and HRV (p > 0.05), except for HF% (p = 0.033). In addition, there was no significant different trial-by-time interaction (p > 0.30). The above results showed that simple ear clipping without power supply did not obviously change the blood pressure, heart rate, and HRV activity (Table 1).

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Table 1. Effects of clipping on a pair of ear electrode on blood pressure and heart rate variability (n = 23) Parameters Location Baseline at 10 min with P value P value P value of ear clip rest ear clips (trial) (time) (trial*time) SBP Earlobes 107.8 ± 2.9 106.9 ± 2.6 0.667 0.180 0.461 (mmHg) Tragus 107.9 ± 2.7 105.7 ± 2.7 DBP Earlobes 65.00 ± 2.12 64.70 ± 1.56 0.068 0.491 0.811 (mmHg) Tragus 62.70 ± 1.56 61.96 ± 1.50 Heart rate Earlobes 74.09 ± 2.10 74.04 ± 2.29 0.891 0.582 0.565 (bpm) Tragus 73.35 ± 2.38 74.26 ± 2.31 TP Earlobes 7.60 ± 0.14 7.49 ± 0.14 0.508 0.163 0.627 [ln(ms2)] Tragus 7.63 ± 0.11 7.58 ± 0.13 LF Earlobes 6.89 ± 0.13 6.80 ± 0.14 0.879 0.789 0.433 [ln(ms2)] Tragus 6.84 ± 0.19 6.88 ± 0.12 HF Earlobes 5.68 ± 0.22 5.69 ± 0.23 0.357 0.692 0.773 [ln(ms2)] Tragus 5.79 ± 0.17 5.83 ± 0.20 LF/HF Earlobes 1.20 ± 0.14 1.11 ± 0.15 0.350 0.203 0.316 (ln ratio) Tragus 1.91 ± 0.69 1.05 ± 0.17 LF (%) Earlobes 73.90 ± 2.10 72.48 ± 2.48 0.415 0.101 0.458 Tragus 73.49 ± 2.23 70.36 ± 3.04 HF (%) Earlobes 19.21 ± 1.98 21.47 ± 1.97 0.665 0.033 0.884 Tragus 19.63 ± 1.88 22.20 ± 2.69 SBP = systolic blood pressure; DBP = diastolic blood pressure. TP, LF, HF, LF/HF, LF%, and HF% are all parameters of heart rate variability (HRV). The values are expressed as means ± SEM. TP: total power is the marker of autonomic nervous activity, LF: low-frequency power reflects both sympathetic and parasympathetic modulations, HF: high frequency reflects parasympathetic activity, LF/HF (In ratio): the ratio of LF to HF reflects sympathovagal balance, LF%: LF in normalized unit reflects sympathetic activity, HF%: HF in normalized unit reflects sympathetic inhibition.

3.2

Effect of BES on HRV Activity, Blood Pressure, and Heart Rate

We analyzed the effects of BES on HRV, blood pressure, and heart rate and compared the difference between the clip electrodes attached to the earlobes and tragus. Time significantly affected the HRV variables of TP (p < 0.001), LF (p < 0.001), and HF (p = 0.012) after receiving 15 min of BES (Table 2). Thus, the ANS activities after BES were significantly higher than those before BES, but no significant change in blood pressure and heart rate was observed. However, all the measures of HRV showed neither a significant between-trial difference nor interaction of time and trial (p > 0.20). A comparison of BES effects with clip electrodes attached on the tragus and earlobes was conducted; although the afferent auricular branch of the vagus nerve was located medial of the tragus [24], direct electrostimulation here did not increase effects on HRV activity compared with the earlobes. The microcurrent generated by BES was also

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transmitted through the earlobes, which activated the vagus nerve branches at the entry of the acoustic meatus. In addition, BES with appropriate intensity was sufficient to affect the activity of HRV, and its main effect was to increase the TP of ANS activity (both TP and LF, p < 0.001), especially parasympathetic (HF, p = 0.012) activities. Table 2. Effect of different locations of binaural electrostimulation (BES) on blood pressure and heart rate variability (n = 23) Parameters Location of BES

Before BES

SBP (mmHg)

106.9 105.7 64.70 61.96 74.04 74.26 7.49 7.58 6.80 6.88 5.69 5.83 1.11 1.05 72.48 70.36 21.47 22.20

Earlobes Tragus DBP Earlobes (mmHg) Tragus HR (bpm) Earlobes Tragus TP Earlobes [ln(ms2)] Tragus Earlobes LF [ln(ms2)] Tragus Earlobes HF [ln(ms2)] Tragus LF/HF Earlobes (ln ratio) Tragus LF (%) Earlobes Tragus HF (%) Earlobes Tragus

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

2.6 2.7 1.58 1.50 2.29 2.31 0.14 0.13 0.14 0.12 0.23 0.20 0.15 0.17 2.48 3.04 1.97 2.69

1 Hz BES 106.4 105.9 64.26 63.48 72.57 72.39 7.66 7.71 6.91 6.94 5.87 5.83 1.04 1.10 71.03 70.77 21.04 20.46

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

2.4 2.8 1.59 1.70 2.35 1.76 0.15 0.11 0.13 0.10 0.21 0.19 0.14 0.17 2.50 3.09 1.78 2.49

25 Hz BES 107.0 105.3 64.52 64.70 73.04 72.52 7.80 7.80 7.14 7.09 5.92 5.94 1.22 1.16 74.48 72.32 19.05 20.52

± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ±

2.7 2.5 1.45 1.82 2.00 1.67 0.16 0.10 0.17 0.09 0.22 0.19 0.13 0.15 2.33 2.69 1.77 2.39

P value (trial)

P value (time)

P value (trial*time)

0.359

0.975

0.766

0.375

0.248

0.017

0.918

0.234

0.898

0.684

T0). A statistical difference was found between the effect of 25 Hz BES and 1 Hz BES on increasing LF and TP activity (T2 > T1, Table 3). This result indicated that both 1 Hz and 25 Hz BES improved the TP of HRV, but the effect of 25 Hz was more pronounced than that of 1 Hz. In addition, the effect of 25 Hz BES on improving parasympathetic activity was not observed at 1 Hz.

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Table 3. Effects of different frequencies of binaural electrostimulation (BES) on blood pressure parameters and heart rate Variability (n = 23) Parameters

Before BES (T0)

SBP (mmHg) 106.3 ± 2.5 DBP (mmHg) 63.33 ± 1.40 HR (bpm) 74.15 ± 2.08 7.54 ± 0.12 TP [ln(ms2)] LF [ln(ms2)] HF [ln(ms2)] LF/HF (ln ratio) LF (%) HF (%)

6.84 ± 0.12 5.76 ± 0.20 1.08 ± 0.15 71.42 ± 2.59 21.84 ± 2.20

1Hz BES (T1) 106.2 63.87 72.48 7.68

± ± ± ±

25 Hz BES (T2)

2.5 106.1 ± 2.5 1.49 64.61 ± 1.50 1.94 72.78 ± 1.59 0.11 7.80 ± 0.12

6.92 ± 0.10 5.85 ± 0.19 1.07 ± 0.14

7.12 ± 0.11 5.93 ± 0.19 1.19 ± 0.13

70.90 ± 2.57 73.40 ± 2.25 20.75 ± 1.93 19.79 ± 1.90

P value Bonferroni test 0.975 0.248 0.234

> >

T0**; T1 > T0*; T1# T0**; T2 > T1* T0*

0.239 0.182

SBP = systolic blood pressure; DBP=diastolic blood pressure. TP, LF, HF, LF/HF, LF%, and HF% are all parameters of heart rate variability. The values of HRV are expressed as means ± SEM. #p = 0.053; *p < 0.05; **p  0.001 in Bonferroni test.

4 Limitations This study involved some experimental limitations. (1) This study explored autonomic activity, which needed to be measured at the same time of the day, and the number of experiments should not be excessive to avoid cumulative therapeutic effects. The time course of the experiment should not be too long (>1 h) to avoid affecting the mood and patience of the participants. Moreover, the number of experiments that participants could cooperate with was limited. Thus, we only arranged two experimental trials (tragus vs. earlobe) and used a design that accumulated stimulation frequency. A disadvantage of this method was that high-frequency stimulation effects may contain some effects of low-frequency stimulation. A limited experimental time did not allow for complete recovery of low-frequency stimulation. However, the effects of these two stimulation frequencies were consistent, and there was no phenomenon of canceling or reversing the effect. (2) Although this study confirmed that BES could stimulate ANS activity via the afferent auricular branch of the vagus nerve at the entry of the acoustic meatus, our neurostimulating device did not only perform local stimulation on the unilateral tragus area but also applied microcurrent levels of electrical stimulation across the head via transcutaneous electrodes placed on both ears. Our neurostimulating device may also affect the activity of other nerves in the brain [25, 26]. Therefore, whether the physiological response is purely the effect of autonomic activation remains to be further clarified.

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5 Conclusions The use of BES to improve ANS activity, especially parasympathetic activity, required an appropriate stimulation frequency, and 25 Hz was more effective than 1 Hz. However, there was no significant difference in stimulating the earlobes or tragus. Therefore, the use of appropriate BES might be cardioprotective and useful as a complement to medical treatment. Acknowledgments. We are grateful for the Ministry of Science and Technology of the Republic of China for financially supporting this research under contract MOST 107-2314-B-214-002.

References 1. Stein, P., Kleiger, R.: Insights from the study of heart rate variability. Annu. Rev. Med. 50, 249 (1999) 2. De Couck, M., Mravec, B., Gidron, Y.: You may need the vagus nerve to understand pathophysiology and to treat diseases. Clin. Sci. 122(7), 323–328 (2012) 3. Fallgatter, A., Neuhauser, B., Herrmann, M., Ehlis, A.-C., Wagener, A., Scheuerpflug, P., Reiners, K., Riederer, P.: Far field potentials from the brain stem after transcutaneous vagus nerve stimulation. J. Neural Transm. 110(12), 1437–1443 (2003) 4. Polak, T., Markulin, F., Ehlis, A.-C., Langer, J.B., Ringel, T.M., Fallgatter, A.J.: Far field potentials from brain stem after transcutaneous vagus nerve stimulation: optimization of stimulation and recording parameters. J. Neural Transm. 116(10), 1237–1242 (2009) 5. Peuker, E.T., Filler, T.J.: The nerve supply of the human auricle. Clin. Anat. 15(1), 35–37 (2002) 6. Liu, R.-P., Fang, J.-L., Rong, P.-J., Zhao, Y., Meng, H., Ben, H., Li, L., Huang, Z.-X., Li, X., Ma, Y.-G.: Effects of electroacupuncture at auricular concha region on the depressive status of unpredictable chronic mild stress rat models. Evid. Based Compl. Alt. Med. (2013) 7. Dorr, A.E., Debonnel, G.: Effect of vagus nerve stimulation on serotonergic and noradrenergic transmission. J. Pharmacol. Exp. Ther. 318(2), 890–898 (2006) 8. Rong, P., Liu, J., Wang, L., Liu, R., Fang, J., Zhao, J., Zhao, Y., Wang, H., Vangel, M., Sun, S., et al.: Effect of transcutaneous auricular vagus nerve stimulation on major depressive disorder: a nonrandomized controlled pilot study. J. Affect. Disord. 195, 172–179 (2016) 9. Sperling, W., Reulbach, U., Bleich, S., Padberg, F., Kornhuber, J., Mueck-Weymann, M.: Cardiac effects of vagus nerve stimulation in patients with major depression. Pharmacopsychiatry 43(01), 7–11 (2010) 10. Kreuzer, P., Landgrebe, M., Husser, O., Resch, M., Schecklmann, M., Geisreiter, F., Poeppl, T., Prasser, S., Hajak, G., Langguth, B.: Transcutaneous vagus nerve stimulation: retrospective assessment of cardiac safety in a pilot study. Front. Psychiatry 3, 70 (2012) 11. Jin, Y., Kong, J.: Transcutaneous vagus nerve stimulation: a promising method for treatment of autism spectrum disorders. Front. Psychiatry 10, 609 (2016) 12. De Couck, M., Cserjesi, R., Caers, R., Zijlstra, W.P., Widjaja, D., Wolf, N., Luminet, O., Ellrich, J., Gidron, Y.: Effects of short and prolonged transcutaneous vagus nerve stimulation on heart rate variability in healthy subjects. Auton. Neurosci. Basic Clin. 203, 88–96 (2017) 13. Nitsche, M.A., Liebetanz, D., Lang, N., Antal, A., Tergau, F., Paulus, W.: Safety criteria for transcranial direct current stimulation (tDCS) in humans. Clin. Neurophysiol. Off. J. Int. Fed. Clin. Neurophysiol. 114(11), 2220–2222 (2003)

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14. Nitsche, M.A., Cohen, L.G., Wassermann, E.M., Priori, A., Lang, N., Antal, A., Paulus, W., Hummel, F., Boggio, P.S., Fregni, F., et al.: Transcranial direct current stimulation: State of the art 2008. Brain Stimul. 1(3), 206–223 (2008) 15. Antal, A., Paulus, W.: Transcranial direct current stimulation and visual perception. Perception 37(3), 367–374 (2008) 16. Nasseri, P., Nitsche, M.A., Ekhtiari, H.: A framework for categorizing electrode montages in transcranial direct current stimulation. Front. Hum. Neurosci. 9, 54 (2015) 17. Hajós-Korcsok, É., Sharp, T.: Electrical stimulation of the dorsal and median raphe nuclei increases extracellular noradrenaline in rat hippocampus: evidence for a 5-HT-independent mechanism. Pharmacol. Biochem. Behav. 71(4), 807–813 (2002) 18. Kwon, Y.-b, Kang, M.-s, Ahn, C.-j, Han, H.-j, Ahn, B.-c, Lee, J.-h: Effect of high or low frequency electroacupuncture on the cellular activity of catecholaminergic neurons in the brain stem. Acupunct. Electrother. Res. 25(1), 27–36 (2000) 19. Kuo, T.B., Lin, T., Yang, C.C., Li, C.-L., Chen, C.-F., Chou, P.: Effect of aging on gender differences in neural control of heart rate. Am. J. Physiol. Heart Circ. Physiol. 277(6), H2233–H2239 (1999) 20. Chen, C.L., Tang, J.S., Li, P.C., Chou, P.L.: Immediate effects of smoking on cardiorespiratory responses during dynamic exercise: arm vs. leg ergometry. Front. Physiol. 6, 376 (2015) 21. Chen, C.-L., Lung, C.-W., Jan, Y.-K., Liau, B.-Y., Tang, J.-S.: The effects of cupping therapy on reducing fatigue of upper extremity muscles—a pilot study. In: International Conference on Applied Human Factors and Ergonomics, 2017, pp. 73–83. Springer (2017) 22. Tang, J.-S., Lung, C.-W., Lee, F.-H., Chuang, C.-C., Liau, B.-Y., Chen, C.-L.: The influence of dry cupping of differing intensities on heart rate variability. In: International Conference on Applied Human Factors and Ergonomics, 2018, pp. 309–317. Springer (2018) 23. Cardiology TFotESo: Heart rate variability standards of measurement, physiological interpretation, and clinical use. Eur. Heart J. 17, 354–381 (1996) 24. Kreuzer, P.M., Landgrebe, M., Husser, O., Resch, M., Schecklmann, M., Geisreiter, F., Poeppl, T.B., Prasser, S.J., Hajak, G., Langguth, B.: Transcutaneous vagus nerve stimulation: retrospective assessment of cardiac safety in a pilot study. Front. Psychiatry 3, 70 (2012) 25. Scherder, E., Knol, D., van Someren, E., Deijen, J.B., Binnekade, R., Tilders, F., Sergeant, J.: Effects of low-frequency cranial electrostimulation on the rest-activity rhythm and salivary cortisol in Alzheimer’s disease. Neurorehabilitation Neural Repair 17(2), 101–108 (2003) 26. Scherder, E.J., van Tol, M.J., Swaab, D.F.: High-frequency cranial electrostimulation (CES) in patients with probable Alzheimer’s disease. Am. J. Phys. Med. Rehabil. 85(7), 614–618 (2006)

A Study of the Correlation Between Payload and Whole-Body Vibration of a Scooter Rider Shih-Yi Lu(&) and Yen-Hui Lin Chung Shan Medical University, Taichung 40201, Taiwan, ROC [email protected]

Abstract. Long-term exposure to whole-body vibrations increases the risk of different pathological changes to the body and neural system. Although most scooter riders use it only for short-distance transportation, some people, such as postmen and deliverymen, utilize it as a tool for making a living in Taiwan. We recruited nine participants to take part in the experiment. The experiment included three levels of rider weight and three levels of payload to evaluate the whole-body vibration under nine (=3  3) operating conditions. The 8-h estimated vibration dose value (VDV) was determined from the collected data in accordance with the ISO 2631-1 standard. The study results indicate that the heavier the rider weight is or the heavier the payload is, the greater is the vibration exposure. Both rider weight and payload have a significant effect on vibration exposure. The design of the shock absorber has a greater impact on vibration exposure. Keywords: Whole-body vibration Deliveryman

 Occupational health  Scooter rider 

1 Introduction Workers often expose to a WBV environment in various industries such as transportation, agriculture, construction, and manufacturing. The WBV could influence many human responses physiologically and pathologically (Griffin 1990). Mani et al. (2010) stated that occupational WBV in sitting could be linked to low back pain, altered peripheral nervous system function, visual and vestibular disturbances, as well as prostate and gastrointestinal problems. Bernard (1997) and Bovenzi et al. (2017) stated that there is strong evidence of a positive association between exposure to WBV and back disorder in their overview studies. Exposure to WBV may delay neural system operation and thus causes mechanical damage or injuries to the spine (Lis et al. 2007; Seidel 1988; Seroussi et al. 1989a, b; Zimmermann et al. 1993). The human performance, comfort and health could usually be affected with constant exposure to WBV (Desai et al. 2018). When workers are exposed to an intensive vibration environment, their spine and organ system resonates with the vibration. The ISO 2631-1 (1997) informative annexes provide guidance on the possible effects of vibration on health, comfort and perception, and motion sickness with a wider frequency range between 0.1 and 80 Hz (ISO 2631-1 1997; Sezgin and Arslan 2012). © Springer Nature Switzerland AG 2020 R. S. Goonetilleke and W. Karwowski (Eds.): AHFE 2019, AISC 967, pp. 80–85, 2020. https://doi.org/10.1007/978-3-030-20142-5_8

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Although most scooter riders use it only for short-distance transportation, some people, such as postmen and deliverymen, utilize it as a tool for making a living in Taiwan. The purpose of this experiment is to understand the situation in which the domestic delivery personnel use the scooter to deliver items on a daily basis when exposed to the whole body vibration. The vibration dose value generated by the different payload on rear seat is used to evaluate the maximum daily allowable value of the deliveryman. It is discussed whether the rider weight and rear seat payload of the scooter will affect the vibration exposure of the deliveryman.

2 Materials and Methods In this experiment, a scooter was selected as the main vehicle to be tested, and nine senior university students with different weights were recruited for riding test. The nine participants were divided into three groups according to their body weight, with 2–4 people in each group. Each scooter rider had at least 1-year experience of riding, and was familiar with the test route adopted in this study. Each participant self-reported riding his motorcycle in an upright sitting position without leaning forward or backward by more than 100. A tri-axial ICP seat pad accelerometer (model 356B40, Larson Davis Inc., USA) was employed to measure vibrations transmitted to the seated human body as a whole through the supporting surface of the buttock. The accelerometer had a frequency sensitivity range of 0.5–5000 Hz, and was pre-calibrated for excitation of 1 g RMS/159.2 Hz with a hand-held calibrator (model 394C06, PCB Piezotronics Inc., USA). Seat pad outputs were connected to a 3-channel amplifier (model 480B21, PCB Piezotronics Inc., USA) with a signal conditioning gain of 10. The outputs of the amplified signals were recorded on a portable data logger. This data logger was a modified version of that used by Liu et al. (2006); it can acquire three analog signals each at a rate of 5000 samples per second, and store collected data on a 2 GB compact flash (CF) memory card. The logged data were downloaded onto a personal computer using a card reader for further data processing. The participants rode the preset scooter (Fig. 1) and give different weights (0 kg, 20 kg, 40 kg) in the back seat, simulating the items placed in the back seat when the deliveryman delivers. Then, ride the scooter at the average speed of 30*40 km/h. The driving route of the experiment is about 20.3 km, and it takes about 1 h and 10 min to ride. The route started from the university, followed the main road to the Huanzhong Road and Xiangshang Road, and then back to the university. We undertook each test on weekdays between 9:30 a.m. and 11:30 a.m., or between 1:30 p.m. and 4:30 p.m., or after 7:00 in the evening. The standard testing procedure of the riding/driving test and detailed instructions was explained to all participants before the test. For each riding task, a seat pad accelerometer was placed on the seat beneath the participant’s buttocks in accordance with the ISO 2631-1 standard (1997); the positive x and z directions were anterior and upward, respectively. Thus, acceleration in the positive z direction generates a compressive loading on the subject’s spine. A packsack was placed in the front of the scooter to carry the signal amplifier, the data logger and a rechargeable battery set. The overall weight of the packsack was 1.5 kg.

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Analysis software - ‘Viewlog’ software programmed with LabVIEW 7.0 (National Instruments, USA) was applied to download the logged data from the CF card. ‘Viewlog’ consists of calibration, vibration analysis, script interpretation and batch processing modules to facilitate analysis and processing of data in bulk (Chen et al. 2006). The vibration analysis module, developed under a research contract of Taiwan IOSH (2007), evaluates the exposure level of WBV in terms of ISO 2631-1 (1997). The module was specifically designed to perform batch computing and export the results to a user-defined MS Excel template. The measurement duration for each task was counted from the time the participant drove out of the parking lot to the time that he returned to the point of departure. Sub-periods of riding on the rural, provincial and urban roadway for all participants and tasks in each measurement period were determined from the logged data provided by an experimenter. The Excel report employed an embedded macro program to compute the total VDV of each axis by combining data of all 30-s exposure periods using Eqs. (1) given below, VDV ¼

hXVDV i1=4 4 i

ð1Þ

where VDVi denotes the acceleration dose of the ith exposure period (30 s). The estimated 8-h VDV (VDV(8)) was thus derived from the axis with the greatest total VDV using Eq. (1), and compared with the upper boundary of Health Guidance Caution Zone defined in ISO 2631-1 (1997), which is 17 m/s1.75. VDV8 ¼ VDV 

T8 Tm

ð2Þ

In Eq. (2), T8 denotes the 8-h time period, and VDV and Tm denote the total VDV and the measurement duration, respectively.

Fig. 1. Photos of scooter, vibration seat pad, and rider

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3 Results The 8-h vibration dose values (VDV) of the nine experimental participants are shown in Table 1. The subject’s weights are divided into three levels, 40 kg to 50 kg, 69 kg to 78 kg, and 91 kg or more for subsequent analysis. Table 1. VDV of 9 participants (m/s1.75) No Rider weights 1 2 3 4 5 6 7 8 9

Payloads 0 kg 20 kg 40 kg 40 kg Light 5.20 5.12 5.34 47 kg 5.11 5.78 6.57 50 kg 5.11 8.05 9.57 69 kg Medium 6.47 6.83 6.85 70 kg 7.76 8.62 8.91 76 kg 6.94 8.24 9.12 78 kg 7.07 7.26 8.42 91 kg Heavy 20.47 20.92 23.33 95 kg 20.49 22.87 23.13

We compare the front seat weight (body weight), rear seat weight (payload) with VDV data, and use EXCEL for analysis to see if there is a significant difference. Table 2 shows the VDV with different payloads by rider weights, and both payloads and rider weights leads to significant difference (p < 0.05). Table 2. The results of two-way ANOVA Source of variation Rows (payloads) Columns (weights) Error Total

SS 448.1574 6.093531 0.561447 454.8123

df 2 2 4 8

MS F p-value F crit 224.0787 1596.437 1.57E−06 6.944272 3.046766 21.70652 0.007117 6.944272 0.140362

4 Discussion The participants found that the route tested in this study was not significantly different from the roadway conditions that they generally encountered, such that it can represent a typical roadway for most motorcycle riders. Long-term exposure to WBV is associated with early spinal degeneration. Experimental results showed that the VDV of the scooter riders was between 5.2–23.3 m/s1.75, and some of them had VDV exceeding the upper boundary of the health guidance caution zone (17 m/s1.75) as recommended by ISO 2631-1. Most motorcycle riders do not expose themselves to WBV for extended periods. However, the large population and gradually aging society means

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that many motorcycle riders require special attention for potential health problems resulting from WBV exposure. To assess the health effects of systemic vibration on motorcyclists, both ISO 2631-1 and ISO 2631-5 specifications might be consulted. In the past, it was pointed out that ISO 2631-1 would underestimate the harm of impact vibration to human body, and ISO 2631-5 was issued in 2004, mainly for the specification of multiple impact body vibrations. The research on the 2631-5 specification is still quite small, but the recent reference to ISO 2631-5 almost unanimously recommends that when assessing systemic vibration, both ISO 2631-1 and ISO 2631-5 should be considered to avoid the use of a single specification in result of underestimation of the health hazard of vibration (Marjanen 2005; Alem 2005).

5 Conclusions The study results indicate that the heavier the rider weight is or the heavier the payload is, the greater is the vibration exposure. Rider weight has a significant effect on vibration exposure, while there is significant difference in rear seat payload as well. The total load of the scooter has a significant effect on the amount of vibration exposure, especially for rider weight and payload. In the future, scooters of different brands can be included in the study, as perhaps the design of the shock absorber has a greater impact on vibration exposure.

References Griffin, M.J.: Handbook of Human Vibration. Academic Press, London (1990) Mani, R., Milosavljevic, S., Sullivan, S.J.: The effect of occupational whole-body vibration on standing balance: a systematic review. Int. J. Ind. Ergon. 40(6), 698–709 (2010) Bernard, B.P.: Musculoskeletal disorders and workplace factors: a critical review of epidemiologic evidence for work-related disorders of the neck, upper extremities, and low back. DHHS (NIOSH) Publication No. 97B141 (1997) Bovenzi, M., Schust, M., Mauro, M.: An overview of low back pain and occupational exposures to whole-body vibration and mechanical shocks. Med. Lav. 108(6), 419–433 (2017) Lis, A.M., Black, K.M., Korn, H., Nordin, M.: Association between sitting and occupational LBP. Eur. Spine J. 16(2), 283–298 (2007) Seidel, H.: Myoelectric reactions to ultra-low frequency and low-frequency whole body vibration. Eur. J. Appl. Physiol. 57(5), 558–562 (1988) Seroussi, R.E., Krag, M.H., Mullez, D.L., Pope, M.H.: Internal deformations of intact and denucleated human lumbar discs subjected to compression, flexion, and extension loads. J. Orthop. Res. 7(1), 122–131 (1989a) Seroussi, R.E., Wilder, D.G., Pope, M.H.: Trunk muscle electromyography and whole body vibration. J. Biomech. 22(3), 219–229 (1989b) Zimmermann, C.L., Cook, T.M., Goel, V.K.: Effects of seated posture on Erector Spinae EMG activity during whole body vibration. Ergonomics 36(6), 667–675 (1993) Desai, R., Guha, A., Seshu, P.: Multibody biomechanical modelling of human body response to direct and cross axis vibration. Procedia Comput. Sci. 133, 494–501 (2018)

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International Organization for Standardization: Mechanical Vibration and Shock—Evaluation of Human Exposure to Whole-body Vibration—Part 1: General requirements, ISO 2631-1. Geneva, International Organization for Standardization (1997) Sezgin, A., Arslan, Y.Z.: Analysis of the vertical vibration effects on ride comfort of vehicle driver. J. VibroEng. 14(2), 559–571 (2012) Liu, Y.P., Chen, H.C., Chen, C.Y.: Multi-transducer data logger for worksite measurement of physical workload. J. Med. Biol. Eng. 26, 21–28 (2006) Chen, H.C., Chen, C.Y., Lee, C.L., Wu, H.C., Lou, S.Z.: Data logging and analysis tools for worksite measurement of physical workload. In: Proceedings of 16th World Congress of the IEA, Maastricht, Netherlands (2006) Marjanen, Y.: Using ISO 2631-5 as an additional whole body vibration evaluation method with ISO 2631-1 to include also transient shocks to the analysis. In: Proceeding of 12th International Congress on Sound and Vibration, Lisbon, Portugal (2005) Alem, N.: Application of the new ISO 2631-5 to health hazard assessment of repeated shocks in U.S. army vehicles. Ind. Health 43, 403–412 (2005)

Physiological Indicators of Mental Workload in Visual Display Terminal Work Yi Ding, Yaqin Cao(&), and Yi Wang Department of Industrial Engineering, School of Management Engineering, Anhui Polytechnic University, Wuhu, People’s Republic of China [email protected], [email protected], [email protected]

Abstract. The aim of the present study was to examine the relationship between experienced mental workload and physiological response by multimodal data. The participants were required to perform a test simulation task that imposed varying level of mental resource demand. At the same time physiological parameters (heart interbeat intervals, electromyography, and galvanic skin response) were recorded by non-invasive wearable sensors. The subjective ratings of mental workload were also collected after the experiment. Results shown that LF/HF was significantly larger in difficult level of task than middle and easy levels but between middle and easy levels of tasks. Moreover, the average of SC was significantly larger in difficult and middle levels of tasks than the easy level but between difficult and middle levels of tasks. There were significantly positive correlations between the subjective evaluation of mental workload and LF/HF and between the subjective evaluation and behavioral performance. Keywords: VDT operation  Mental workload  Physiological measurement  NASA-TLX scale

1 Introduction Computer-based systems utilizing VDT (visual display terminal) have been widespread in many workplaces began in the middle seventies, with the emerging of “Industry 4.0”, “Internet+”, “Intelligent Manufacturing”, VDT work is bound to be further developed in near industrial revolution. Concerns about adverse health problems occurring among VDT users have been voiced since the date of its birth, especially high prevalence and incidence of musculoskeletal disorders and visual fatigue [1]. Lots of work have been done to explore the visual fatigue and musculoskeletal problems caused by VDT work. However, the nature of work has changed dramatically from working with physical to working with the cognitive demands as the VDT works have become more widespread [2, 3], hence how human cognitive systems interact with computer interfaces has been concerned. Mental workload remains an important variable with which to investigate user performance of VDT work [3–5]. The current consensus being that both excessively high and excessively low levels of mental workload influence work performance negatively. Mental workload is a subjective © Springer Nature Switzerland AG 2020 R. S. Goonetilleke and W. Karwowski (Eds.): AHFE 2019, AISC 967, pp. 86–94, 2020. https://doi.org/10.1007/978-3-030-20142-5_9

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experience in response to a task load and cannot be measured directly. In order to fully understand the role of mental workload in human computer interactions, we need to explore the method for measuring it. As one of the most widely used concept in ergonomics and human factors, mental workload is also one of the most nebulous concepts with no universally accepted definition [2, 6, 7]. The definitions of mental workload mainly promoted from the complexity of task, utilization of working memory capacity, or perceptual and cognitive resources demands [2, 7, 8] However, the concept of mental workload is still controversial [2, 9]. With the characteristics of subjective, task-dependent, dynamic and multidimensional, how to measure and define mental workload are difficult [2, 5]. Hence, there are many researchers trying to measure and model mental workload before the real-world application of it. The nature of mental workload is reflected in the variety of measurement methods [2, 10]. There are three categories of workload metrics: operator’s performance, subjective experience, and physiological consequences [2, 3, 9, 11]. Subjective methods, such as SWAT and NASA-TLX, are inexpensive and easy to conduct. But these methods require the participant to recall their experience during tasks, can not provide real-time data, and often require large of samples [12, 13]. Moreover, subjective methods contain so many items that participants may be confused and need to pay enough attention to understand the items, which will gain their mental workload or negatively affect performance [14]. Research [2] pointed out that physiological measures are a natural type of workload metric for physiological activity required in tasks. Accompany with advances in noninvasive sensors and physiological signals processing, objective methods are paid more attention recent years. In paper [5], mental workload is regard as a subjective experience in response to a task load and can be modified by a variety of performance shaping factors. As noninvasive and objective feedback of people’s current mental workload level, multiple physiological measures of mental workload may be more suitible. There are two reviews of multiple physiological measures of mental workload conducted by [5] and [6]. They divided physiological measures of mental workload into six key measures: brain activity, cardiac activity, electrodermal activity, eye movement, respiration activity, and blood pressure. The main disadvantages of physiological measures conclude high cost than traditional methods (i.e. primary, secondary or subjective measures), requiring technical skills for interpreting the physiological signals, difficult to discrimination between signals and noise [6]. But with the advances in physiological sensors and signal processing techniques, multiple physiological measures are now realistic candidates for noninvasive capture of mental workload without interruption [15]. Electrocardiography (ECG) technique is the most commonly used physiological method in mental workload measurement. In study [16], they found a significant decrease in the LF band (0.02–0.06 Hz) during high task difficulty. Heart rate increases with the task difficulty increase or in multi task condition [17, 18]. In study [19], NN (normal normal) interval and HRV (heart rate variability) increase during rest but decrease during the parts of the task rated as more effortful in simulated flight task. GSR (Galvanic Skin Response) was regarded as an indicator of mental workload [20]. Study [21] investigated driver’s cognition load with ECG and GSR measures. The GSR analysis showed that mean GSR was higher in difficult task. Other studies indicate that

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GSR is sensitive to sudden stress, but not gradual changes in mental workload [22, 23]. More indicators of mental workload were reviewed in [5] and [6]. Though lots of researches investigate the gauging of mental workload by physiological parameters, the conclusions about where and what changes occur still remain unclear, such as how does the physiological activity change with the tasks continued? Mental workload is treated as a subjective experience in response to a task load [5]. Physical load to some extent will also affect the participant’s subjective feeling, while the attached load is rarely considered in previous researches. Therefore, the aim of the present study was to examine the relationship between experienced mental workload and physiological response by multi-modal data. We measured the changes in physiological activity as the level of task difficulty varies and examines the validation of indicators for estimating mental workload. Muscle activity is also recorded in the tasks to guarantee the same level of physical load in different tasks.

2 Research Method 2.1

Participants

The experiment is aimed to investigate the gauging of mental workload in computer work with non-invasive wearable sensors. Fourteen right-hand, healthy and with normal or correction vision, with no history of nerve or mental illness and no history of mental illness or organic disease were recruited as participants. All of them rested well and did not drink coffee in the night before (7 females and 7 males, aging from 18 to 23 years, Mage = 20 years, SDage = 1.27). They all signed written consent forms before the experiment and received a gift as compensation. They had no preexisting heartrelated condition and skin condition or were allergic to electrodes. 2.2

Apparatus

ErgoLAB man-machine environment synchronization platform (Beijing Kingfar technology co. LTD, China) was used for measuring heart, sEMG (superficial EMG), and EDA activity. The photoplethysmography (PPG) raw data was recorded to transform to heart data. sEMG signals were collected by non-invasive wearable sensors from finger extensor muscle. GSR was also collected from index and middle fingers of left hand. Skin was prepared to reduce impedance by using scrubbing cream and cotton swab. Three Kangren® pre-gelled disposable AgCl electrodes with an active area of 6.15 mm2 (Type: CH3236TD) were replaced on muscle belly and top and down of finger extensor muscles of right hand. The sample rate of EMG was 1024 Hz, with a band-pass filter of 5–500 Hz and noise level of 1.6 lV. The root mean square (RMS) of the signal was determined using a time constant of 120 ms. The sample rate of GSR was 32 Hz and the sample rate of PPG was 256 Hz with a noise level of 1.6 lV. All electrode impedances were maintained below 5 kX during the experiment.

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Procedure

Participants sat in a quiet room with soft light (170LX ± 3LX) to eliminate the impact of light on work performance. The laboratory temperature was set at 21 ± 1 °C and the relative humidity remained at 60% ± 2%. The process of experiment was introduced to subjects and signed written consent forms before the experiment. Three tasks with different levels of difficulty were designed. Each participants should complete the three tasks with a random sequence. The participants had a rest (10 min) after the completion of one task. In the easy level of task, participant was required to finish a test about word operation in 30 min. In the middle level of task, participant was required to finish a test about word and excel operation and type 250 words in 30 min. In addition, in the difficult level of task, participant was required to finish a test about word, excel and PowerPoint operation and type 250 words in 30 min. During the experiment, physiological signals and behavioral performance of participants were recorded. The subjective of mental workload was measured by NASA-TLX questionnaire [11]. 2.4

Statistical Analysis

The time to complete the tasks and all physiological activations were analyzed. The data analysis was carried out by using SPSS ver. 20.0 (IBM Corporation, USA). Firstly, physiological signals were processed through ErgoLAB (Beijing Kingfar technology co. LTD, China). Then all responses variables were compared using Single factor repeated measurement ANOVA. Pearson’s correlation was calculated to identify the relationship between physiological signals of participants with subjective measurement. Statistically significance for all tests was set at p < 0.05. Outliers of the data were deleted via boxplot [24].

3 Results 3.1

Subjective Evaluation of Mental Workload

The NASA Task Load Index [11] including six dimensions to assess mental workload was used to collect participant’s subjective responses. The averages of subjective evaluations on easy, middle and difficult levels of task are 39.8 (SD = 17.00), 53.1 (SD = 15.50), and 69.5 (SD = 16.95). The one-way analysis of variance showed that there was significant effect of task levels on subjective evaluation (F = (2, 39) = 11.39, p < 0.001). Post hoc analysis showed that there was significant difference between each two pairs (ps < 0.05). 3.2

Behavioral Performance

Behavioral responses are the express of people’s cognition and physiology responses, and data related with behavior and performances are easily to obtain [25]. In the experiment, participants are required to complete every task in 30 min. The average finishing time of easy, middle and difficult tasks are 15.5 min (SD = 5.37), 26.7 min (SD = 3.49) and 28.2 min (SD = 3.06). Moreover, the Friedman test showed that there

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was significant difference (p < 0.001). Post hoc analysis showed that there was significant difference between easy task and middle (p < 0.001), between easy task and difficult (p < 0.001) but between middle task and difficult (p = 0.56). 3.3

Physiological Results

Three kinds of physiological signals were recorded and analyzed. The indexes are shown in Table 1. Table 2 gives the single factor repeated measurement ANOVA. The tasks have significant effect on LF/HF and SC signal mean but AVHR and EMG. Twosample paired t-test shown that LF/HFs evoked in middle and difficult tasks were significant higher than easy task (t(13) = −2.78, p = 0.016 and t(13) = −3.38, p = 0.005), but there was no significant difference between middle and difficult tasks(t (13) = −0.3, p = 0.77). Two-sample paired t-test shown that mean of EDA evoked in middle and difficult tasks were significant higher than easy task (t(13) = −3.54, p = 0.004 and t(13) = −3.23, p = 0.007), but there was no significant difference

Table 1. Physiological indexes measured in the experiment Indexes AVHR LF/HF YRMS MF SC Mean

Unit bpm lV % lS

Description The average of heart beats per minute The ratio of low frequency power and high frequency The root mean square of EMG amplitude The median frequency of EMG The average of skin conductance

Table 2. The comparison of physiological results elicited during three tasks Indexes AVHR

Easy Middle Difficult LF/HF Easy Middle Difficult YRMS Easy Middle Difficult MF Easy Middle Difficult SC mean Easy Middle Difficult Note: * p < 0.05

Mean (SD) F 75.5 (5.8) 72.6 (9.5) 69.4 (11.5) 2.3 (1.3) 2.7 (2.0) 3.6 (2.5) 30.7 (8.8) 40.8 (16.0) 40.3 (16.1) 20.2 (3.3) 22.4 (5.2) 22.9 (8.0) 15.1 (9.3) 17.0 (10.3) 16.2 (8.9)

p

F(2,26) = 2.346 0.116

η2 0.153

F(2,26) = 4.764 0.017* 0.268

F(2,26) = 2.132 0.139

0.141

F(2,26) = 0.694 0.439

0.051

F(2,26) = 3.725 0.038* 0.223

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between middle and difficult tasks (t(13) = −0.18, p = 0.86). The results shown that there was no significant difference between different levels of tasks for EMG results. This implies that the physical load caused by different tasks has no effect on mental workload. 3.4

Correlation Analysis Between Physiological Responses and Other Results

The correlations between the physiological activations evoked by each level of task and other results were also analyzed. There were significantly positive correlations between the subjective evaluation of mental workload and LF/HF(r = 0.377, p = 0.014) and between the subjective evaluation and behavioral performance (r = 0.422, p = 0.005). There was no significant correlation between the subjective evaluations of mental workload and other physiological indexes.

4 Discussion This study explored the multimodal measurement of mental workload during computer work combined subjective evaluation, behavioral performance and physiological signals. The main value of this study lies in that whether multimodal methods can reflect people’s mental workload during general computer work. We found different results for heart rate variability and EDA activations but no significant difference for heart rate. EMG was also recorded at the same time and the results shown no significant difference between tasks, which implies same effect of physical load during tasks. Moreover, in a real-office environment we found correlations between physiological activations and other results. For heart rate, there are many researches pointed out higher heart rate with task difficulty increase [17, 18]. However, in our study, similar results were not obtained. A slight decrease of heart rate was found with task difficulty increase but there no significant difference. Larger discrete degree of heart rate was found in middle and difficult level of tasks. Heart rate can be both influenced by workload and emotion/arousal [26]. Participants might feel boring or tired during the tasks, which elicited reduced heart rate [27]. Paper [26] pointed out that short-term psychological stress could cause slightly decreased heart rate. For HRV, consistent directions are shown in our study. Paper [28] explored the mental workload levels in everyday life scenarios by ECG. LF/HF ratio showed a statistically significant increase with increased workload in their study. However, in the study [29], opposite results were found for marine pilots. Different tasks could contribute to these results. The results in this study show that HRV is more sensitive than heart rate for general computer work. For SC signal, higher SC indicates mental workload increased [5, 21]. Similar results were obtained in our study. Paper [30] promoted that SC is a reliable measure of mental workload. While, in our study, there was no significant difference between middle and difficult tasks for SC. There was no sudden stress but gradual change in difficult task, which might cause this result.

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We also analyzed the correlations between subjective evaluation results, behavioral performance and physiological activation. There were significantly positive correlations between the subjective evaluation of mental workload and LF/HF and between the subjective evaluation and behavioral performance. In addition, there are some limitations in our work. Participants were all from university students. They might have different feeling on the tasks. Some individuals maybe happy when type a lot and are productive, others may feel nervous or boring. In addition, different kinds of real-world workload should be investigated in the future, and other information from posture or eye movement can be helpful.

5 Conclusion Mental workload remains an important variable with which to investigate user performance of VDT work. Although existing many techniques to measure mental workload, but there is no consistent in the results. Mental workload is treated as a subjective experience in response to a task load. Physical load will also affect the participant’s subjective feeling to some extent. While the attached load is rarely considered in previous researches. So multi-modal methods was used in this study to explore a thorough and precise measurement of mental workload. The results presented in this paper demonstrate that physiological parameters, especially HRV and EDA, can be used for noninvasive real-time measurement of workload. This study offers the possibility of being applied to office workers and provides preliminary data support and theoretical exploration for follow-up smart office design. Acknowledgments. This work is supported by the National Natural Science Foundation of China (No. 71801002, 71701003), the Humanities and Social Sciences Foundation of the Ministry of Education in China (No. 18YJC630023), the Anhui Natural Science Foundation Project (No. 1808085QG228), the Key Project for Natural Science Fund of Colleges in Anhui Province (No. KJ2017A108). We thank the research support plan from Beijing Kingfar technology CO., LTD (China) for providing related equipment and scientific and technological support. We thank all the participants for carrying out the experiments.

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6. Kramer, A.F.: Physiological metrics of mental workload: a review of recent progress. In: Damos, D.L. (ed.) Multiple-Task Performance, pp. 279–328. Taylor and Francis Press, London (1991) 7. Maior, H.A., Wilson, M.L., Sharples, S.: Workload alerts—using physiological measures of mental workload to provide feedback during tasks. ACM Trans. Comput. Hum. Interact. 25 (2), 1–30 (2018) 8. Wickens, C.D.: Mental workload: assessment, prediction and consequences. In: Longo, L., Leva, M.C. (eds.) Human Mental Workload: Models and Applications. Communications in Computer and Information Science, pp. 251–263. Springer Press, Dublin (2017) 9. Kostenko, A., Rauffet, P., Chauvin, C., Coppin, G.: A dynamic closed-looped and multidimensional model for mental workload evaluation. IFAC-PapersOnLine 49(19), 549–554 (2016) 10. Gawron, V.J.: Human Performance, Workload, and Situational Awareness Measures Handbook, 2nd edn. CRC Press, Boca Raton (2008) 11. Hart, S.G., Staveland, L.E.: Development of NASA-TLX. In: Hancock, P.A., Meshkati, N. (eds.) Human Mental Workload, pp. 139–183. Elsevier Science, Amsterdam (1988) 12. Lean, Y., Shan, F.: Brief review on physiological and biochemical evaluations of human mental workload. Hum. Factor. Ergon. Man. 22(3), 177–187 (2012) 13. Fallahi, M., Motamedzade, M., Heidarimoghadam, R., Soltanian, A.R., Farhadian, M., Miyake, S.: Analysis of the mental workload of city traffic control operators while monitoring traffic density: a field study. Int. J. Ind. Ergon. 54, 170–177 (2016) 14. Tattersall, A.J., Foord, P.S.: An experimental evaluation of instantaneous self-assessment as a measure of workload. Ergonomics 39(5), 740–748 (1996) 15. Marinescu, A.C., Sharples, S., Ritchie, A.C., Sánchez, T., McDowell, L.M., Morvan, H.P.: Physiological parameter response to variation of mental workload. Hum. Factors 60(1), 31–56 (2018) 16. Splawn, J.M., Miller, M.E.: Prediction of perceived workload from task performance and heart rate measures. In: Proceedings of the Human Factors and Ergonomics Society 57th Annual Meeting, vol. 57, no. 1, pp. 778–782. Sage Publication, Francisco (2013) 17. Fournier, L.R., Wilson, G.F., Swain, C.R.: Electrophysiological, behavioral, and subjective indexes of workload when performing multiple tasks: manipulations of task difficulty and training. Int. J. Psychophysiol. 31, 129–145 (1999) 18. De Rivecourt, M., Kuperus, M.N., Post, W.J., Mulder, L.J.M.: Cardiovascular and eye activity measures as indices for momentary changes in mental effort during simulated flight. Ergonomics 51(9), 1295–1319 (2008) 19. Veltman, J.A., Gaillard, A.W.K.: Physiological workload reactions to increasing levels of task difficulty. Ergonomics 41(5), 656–669 (1998) 20. Xu, X.: Analysis on Mental Stress/Workload Using Heart Rate Variability and Galvanic Skin Response During Design. Concordia University, Montreal (2014) 21. Engström, J., Johansson, E., Östlund, J.: Effects of visual and cognitive load in real and simulated motorway driving. Transport. Res. F Traffic Psychol. Behav. 8(2), 97–120 (2005) 22. Fairclough, S.H., Venables, L.: Prediction of subjective states from psychophysiology: a multivariate approach. Biol. Psychol. 71, 100–110 (2006) 23. Collet, C., Salvia, E., Petit-Boulanger, C.: Measuring workload with electrodermal activity during common braking actions. Ergonomics 57(6), 886–896 (2014) 24. Cao, Y., Qu, Q., Duffy, V.G., Ding, Y.: Attention for web directory advertisements: a topdown or bottom-up process? Int. J. Hum. Comput. Int. 35(1), 89–98 (2019) 25. Norman, D.A.: Emotional Design: Why We Love (Or Hate) Everyday Things. Basic Books, New York (2007)

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Study on the Changes of Physical Status Under the Condition of Lacking Food and Water on Oxygen-Deficient Plateau Xingwei Wang(&), Lue Deng, Hailiang Zhou, Qin Yao, Heqing Liu, Weiping Bu, and Yongchang Luo Institute of Aviation Medicine, Beijing 100036, China [email protected]

Abstract. Objective to study the changes of physical status under the condition of lacking food and water on oxygen-deficient plateau. Methods 2 volunteers survived for 72 h with little water, pilot biscuit and emergency oxygen supply on the high altitude plateau by themselves, using sleeping bags and chemical heating bags to keep out the cold at night. The volunteers were asked not to eat biscuit, drink water and use oxygen unless extremely needed, and the amount of biscuit and water the volunteer took were recorded. The volunteers survived at 5237 m altitude for 18 h first, and then walked down to 4742 m altitude and survived for 54 h continuously. The body composition indexes and physiological parameters were monitored. Results Under the condition of lacking food and water on oxygen-deficient plateau for 72 h, the physical status of the 2 volunteers changed to be feeble, but they could walk and do some light work normally. Their lips were dry and cracked, but no serious changes occurred except fever. The total amounts of biscuit and water were 60 g and 650 ml for one volunteer, and 94 g and 950 ml for the other. For both volunteers, the fat percentage declined, while the muscle percentage rose in the whole survival time. Their body temperatures rose in the second day, and the heart rates and blood pressures did the same in the second and the third days. The oxygen saturations declined significantly after 6 h and recovered after 2 days for one volunteer, while declined slightly in the all 3 days for the other. Conclusion The human physical status would decline under the condition of lacking food and water on oxygen-deficient plateau which was higher than 4700 m. With a little emergency oxygen supply and not much more activities, young people could still sustain for 72 h without serious states. Keywords: Physical

 State  Survival  Plateau  Oxygen-deficient

1 Introduction The plateau area is characterized by low oxygen, cold, lack of drinking water and food and other special climatic environment characteristics. Moreover, it is often mountainous and gully with inconvenient transportation, and the distress signal is easily blocked. When people survive on the plateau, they will face many special difficulties that are more severe than those in the plains. People in danger must make the best use © Springer Nature Switzerland AG 2020 R. S. Goonetilleke and W. Karwowski (Eds.): AHFE 2019, AISC 967, pp. 95–105, 2020. https://doi.org/10.1007/978-3-030-20142-5_10

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of the limited living conditions to try to maintain physical condition, and try to seek help and wait for rescue. Due to the lack of plateau geographical characteristics in the world’s advanced countries, the study of plateau survival in distress is rare. China’s Qinghai-Tibet Plateau covers an area of about 2.5 million square kilometers, with an average altitude of 4000 m [1]. It is the world’s largest plateau with the highest average altitude. In order to explore the changes of human body constitution under the condition of water and food shortage in the environment of the low oxygen plateau, this paper carried out a simulated survival experiment of airborne personnel in distress, successfully completed the 72 h survival experiment in the mountainous area of the plateau above 4700 m, and preliminarily grasped the changes of human body constitution under the harsh conditions of the plateau.

2 Subjects and Methods 2.1

Subject

Two healthy volunteers, aged 22 and 26, were selected as subjects to simulate the personnel landing on the plateau in distress. Their heights were 175 cm and 170 cm respectively, and their weights were 63.4 kg and 66.1 kg. Before entering the plateau, anoxic preconditioning training was carried out in the constant pressure oxygen chamber for 5 consecutive days and 3 h per day. After entering the plateau, they stayed at an altitude of 3700 m for about 24 h, and then entered the experimental area.

3 Material 2 leather jackets, 2 pairs of leather boots, 2 long johns, 2 sets of certain type parachute. Two subjects wore and used them separately. Wear underwear according to actual ambient temperature requirements. Each subject was provided with a survival kit, including: a new type of anti-cold sleeping bag, a new type of solid chemical oxygen generator (portable), a survival knife, an insulation bag, two chemical heat production bags, a new type of aviation food 500 g, drinking water 1000 ml. The new type of anti-cold sleeping bag was developed for the needs of plateau survival. The new thermal insulation material coffee bean carbon fiber was used as the filling material to replace the current material, which greatly increases the thermal insulation. According to the inspection by the National Special Protective Clothing Quality Supervision and Inspection Center, the thermal insulation amount of the sleeping bag with winter wear was 7.23clo. The new type of plateau solid chemical oxygen generator was developed to meet the demand of emergency oxygen for activities such as lowering the survival height of people in danger at the plateau. The detection results of the components of the generated gas were shown in Table 1. The new aviation food is developed for the metabolic characteristics of people in distress in the plateau under the condition of hypoxia and water shortage and in the

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Table 1. Components of oxygen gas of the new plateau solid chemical oxygen generator Component O2 (%) CO2 (ppm) CO (ppm) Cl2 (ppm) Fiber size (lm) Content 99.8% 400 12 0.05), the lumbar support prominence influences discomfort (p-value < 0.05). The 30 mm support has the best relationship between the pressure exerted by the body, force, and discomfort perception. On the contrary, the 50 mm support had the worst performance among all. Keywords: Car driver seat Pressure distribution

 Lumbar support prominence  Discomfort 

1 Introduction One usually adopts a sustained and prolonged posture during the driving activity due to the physical restrictions of the place, the time in a seated position and the constant alert state with high visual demands [1]. This position is among the main causes of discomfort presented during car driving [2] and is one of the reasons for increased lower back ailments [3]. Low back pain is the main cause of performance disturbance and absenteeism in professional public transport drivers with 14 years of experience on average, where a prolonged sitting posture is one of the most predominant factors [4]. In drivers, the prevalence of low back pain in two weeks is 20.5% [5], in a month of 50.3% [6], and in a year it is 72% [3]. Therefore, low back pain is a constant in this population. In comparison with a standing posture, sitting reduces lumbar lordosis, increases muscle activity in the lower back, intradiscal pressure and pressure on the ischium. A lumbar support device that reduces the spinal load and lower back muscle activities can help to increase sitting comfort and reduce the risk of low back pain [7]. © Springer Nature Switzerland AG 2020 R. S. Goonetilleke and W. Karwowski (Eds.): AHFE 2019, AISC 967, pp. 124–134, 2020. https://doi.org/10.1007/978-3-030-20142-5_13

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Likewise, it has been demonstrated that the use of a lumbar support preserves the degree of lumbar lordosis, related to a lower intradiscal pressure [8]. Besides, in the case of a lumbar support with a variable prominence in drivers’ prolonged sessions, this lumbar support has represented a reduction in terms of numbness in the buttocks [9]. Studies have determined different prominences of lumbar support as the most favourable. In a first case, values of 0 cm, 2 cm and 4 cm were used, finding by means of radiographs that the values of 2 and 4 cm are the ones that achieve neutral lumbar lordosis, which is associated with a lower risk of injury [10]. Additionally, a value of 1 cm is determined as the best prominence by means of a virtual model and finite element analysis in the human body-seat interface [11], as well as the use of a 4 or 5 cm adjustable lumbar support that will facilitate forward rotation of the pelvis and increase the lumbar lordosis [12]. The pressure distribution, especially in the buttocks and lower back areas, is an objective measure associated with subjective measures such as localized discomfort, particularly in car seats [13]. Likewise, the maximum pressure of the seat pan tray together with the distribution of pressure, seem to play an important role in quantifying comfort or discomfort [14]. Furthermore, a medical experiment has demonstrated that the pressure distribution between the seat pan and the human body is related to the intradiscal pressure at the L4-L5 level, where an ideal pressure distribution of 60% of the participant’s weight achieved by tilting the seat pan is associated with a lower intradiscal pressure [15]. Therefore, the aim of this study is to determine the influence of the prominence change of a lumbar support in the contact area and the average pressure exerted by the human body on the seat pan in a simulated environment, as well as to determine discomfort perception for each of the lumbar support prominence levels.

2 Method The study required 30 male individuals aged between 18 and 33 with an average weight of 65.5 kg and average height of 170 cm. A driver’s car seat (Fig. 1) was implemented. The seat had a backrest provided with a 10 mm lumbar manufacturing curvature of adjusted backward inclinations in the seat pan at 10°, its backrest with an inclination of 110° (Fig. 2) and a footrest with an angle of 45°, all the previous angles measured with respect to the horizontal line and were based on the recommended angles for an optimal driving position [12]. The footrest allowed a horizontal movement to generate an internal angle of 136° in the knee and thus ensure contact of the lower part of the legs with the seat. There were implemented 4 lumbar supports made of rigid foam D-30 of 30 kg/m3 which is normally used for seats and mattresses. The supports were covered in textile canvas and had a 16  30 cm rectangular contact area with the backrest and a semioval section of 10, 20, 30, 40 mm of prominence, respectively (Fig. 3). The contact area record, the average pressure and the maximum pressure exerted by the body on the seat was made by means of a mat BodiTrak sensor (Fig. 4) and the Smart seat FSA version 1 software.

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Fig. 1. Simulated driving posture, knee angle conservation.

Fig. 2. Angles of the seat pan (10°) and backrest (110°).

Fig. 3. Lumbar support prominence. 10, 20, 30, 40 mm respectively.

The most pronounced area of the lumbar curvature was located on each standing participant’s back by means of palpation following the iliac crests level. Later, a reference mark was made on the skin part where the lumbar support should be placed at vertebrae L4 and L3 level (Fig. 5) [16].

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Fig. 4. Bodytrack mat and location of lumbar support.

Fig. 5. Location and marking of the apex of lumbar curvature on L3-L4

Fig. 6. Location of the support according to the mark in lumbar curvature.

Once the participant was sitting down and the lumbar support was located with a random prominence level, the support apex height from the seat surface was measured (Fig. 6). Subsequently, it took 1 min to achieve the person’s positioning, then the pressure was recorded for 3 min with one measurement per second and finally, the

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participant stood up to change the lumbar support, relax the body and assess perceived discomfort by means of a 100 mm Visual Analogue Scale (VAS) where the value of 0 usually indicates that there is no discomfort perception due to pain and 100 indicates the maximum perceived discomfort. A Minitab 18 statistical software was implemented in order to analyze the obtained data. The ANOVA analysis was used for mean comparison with a confidence level of 95%, finding significant differences for values less than 0.05. Likewise, in terms of quantitative response variables an analysis was carried out by means of the Pearson correlation with an alpha significance level of 0.05.

3 Results The sensing area, the average pressure, the maximum pressure, the force and the body weight percentage exerted on the car seat pan do not show a significant correlation with the perceived discomfort variable for prominence levels of the lumbar support, as shown in (Table 1) for an alpha value of 0.05. The ANOVA analysis shows that there are no significance differences for lumbar support prominence levels in the response variables of average pressure, contact area and force, with a p > 0.05 value. However, the differences in discomfort levels are significant with a p < 0.05 value (Table 2). A descriptive analysis evidences that the average area of contact is reduced as the prominence of the lumbar support increases (Fig. 7). The lowest average pressures are found with a prominence of 10 and 30 mm and a prominence of 50 mm that evidently represents the highest pressure value (KPa) (Fig. 8). The calculated force (N) has the lowest value with 30 mm of prominence and the values of 10 and 50 mm indicate the highest forces (Fig. 9). Table 1. Pearson correlation Discomfort prominence (mm) 10 corr p-value 20 corr p-value 30 corr p-value 40 corr p-value 50 corr p-value

Maximum pressure (kPa)

Average pressure (kPa)

Sensing area (cm2)

% of body weight on the seat

0,079 0,679 −0,186 0,324 −0,274 0,142 −0,093 0,624 0,036 0,849

−0,022 0,91 −0,16 0,398 −0,045 0,814 −0,08 0,675 0,246 0,19

−0,229 0,224 0,009 0,962 −0,259 0,166 0,09 0,637 0,156 0,412

−0,06 0,754 −0,143 0,451 −0,101 0,597 −0,124 0,513 0,181 0,339

Influence of Lumbar Support Prominence for a Car Seat Table 2. ANOVA for prominence factor levels. Value 1,9 Average pressure (kPa) Value 0,47 Maximum pressure (kPa) Value 0,501 Force (N) Value 0,1 Percentage of body weight on the seat Value 0,098 Discomfort Value 3,2

Sensing area (cm2)

F Value 0,113 F Value 0,761 F Value 0,735 F Value 0,981 F Value 0,983 F Value 0,015

p p p p p p

Fig. 7. Sensing area according to lumbar support prominence levels.

Fig. 8. Average pressure according to the lumbar support prominence.

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Fig. 9. Applied force vs. lumbar support prominence

The least and greatest discomfort occurs in the values of 30 and 50 mm, respectively (Fig. 10). The maximum pressure values are shown in the default support of 10 mm, and the value with the lowest maximum pressure is evidenced by the prominence of 30 and 50 mm (Fig. 11). Finally, the body weight percentage recorded on the lowest value seat is presented with the 30 mm support, followed by the 40 mm support. The 10 and 50 mm prominences are the ones with the highest percentage (Fig. 12). Within the results, it was also identified that the support location height measured from the seat pan is between 15 and 20 cm with a 17.7 cm average.

Fig. 10. Perceived discomfort according to lumbar support prominence.

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Fig. 11. Maximum pressure according to lumbar support prominence.

Fig. 12. % of body weight applied according to lumbar support prominence.

Fig. 13. Pressure distribution according to lumbar support prominence (mm). It shows the reduction of the contact area and the increase of pressure.

4 Discussion The literature review is not consistent with some of the prominence values already studied. Harrison et al. [12], proposes a 50 mm value in order to maintain the correct lumbar curvature in the driving position, but in our results, it is perceived as the most

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uncomfortable one. This difference may arise since the biomechanically favourable value is not necessarily perceived as a more comfortable one [17]. On the other hand, in terms of finite element analysis studies for driving position, the optimum size to achieve the seat comfort is a 10 mm value [11], this prominence coincides with lower discomfort values and average pressure found in our study, however, the results show high percentages (49.7%) of the body weight on the seat and a higher maximum pressure, so it could be said that it is not the most favourable support in all the aspects studied. The 30 mm lumbar support is within the prominence range of 20–50 mm. This support was identified in De Carvalho’s study in order to maintain adequate lumbar lordosis [10], and coincides with the minor discomfort prominence for a lumbar pad in sitting posture [18]. This study evidences in a descriptive way that this kind of support has the best behaviour with the lowest values of average pressure, force and discomfort. In addition, this prominence is identified as the most appropriate one to achieve a lower percentage of body weight on the seat pan, which would allow the achievement of a position that favours the reduction of intradiscal pressure, and lower back ailments. The study also found out that there is a similar behaviour between average pressure and discomfort, where the smallest 10, 20, 30 mm prominences are the most favourable, unlike 40 and 50 mm prominences, which have the least favourable values. This suggests to understand that discomfort could be evaluated by means of the average pressure [13], however, our findings show that these two variables do not have a significant correlation for any of their prominence levels (p > 0.05). As the support prominence increases, the contact area (Fig. 7) has a descending behaviour and the average pressure tends to increase (Fig. 8), this can be related to the participant’s forward displacement away from the backrest, which was found in some images of the pressure distribution in the mat (Fig. 13). It should be noted that no pattern that allows this result to be generalized was found in the images; only, in some images, the areas of force concentration grow as the support prominence increases. Due to this, it is convenient to extend these findings in future research in order to determine what the seat pan forward adjustment should be like, to therefore provide better support to the area of contact with the legs. Finally, the average value of the body weight percentage applied to the seat varies between 47.9 and 50.1%. The literature shows ideal distribution average values of 60.4%, therefore the maximum value found is below this value [15]. According to the above, the 30 and 40 mm protrusions can reduce the force applied to the seat, so that the remaining weight is transferred to other parts of the seat such as the backrest; this represents a reduction in the force that supports the lumbar spine and its intervertebral discs. However, it should be mentioned that the pressure distribution between the legs and buttocks plays an important role, since the lower part of the thighs helps to support weight and avoid the pressure concentration in the ischial tuberosities area.

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5 Conclusions The results of this study show that there is not enough evidence to prove that the change in prominence in a lumbar support has a influence on the average pressure, contact area, force and distribution of body weight in the human body-seat pan (p-value > 0.05). On the other hand, the perceived discomfort evidences significant differences (p-value < 0.05) and it is influenced by the change in prominence where the values of 30 and 50 mm are the ones with the least and greatest discomfort respectively. For this research, it was considered that 30 mm is the optimal prominence of the lumbar support for a driving seat in all the variables descriptively analysed. Finally, although the pressure distribution in the human-seat pan interface has been identified as playing an important role in understanding discomfort perception, this study did not demonstrate enough significant evidence to assess discomfort by means of the area, the pressure or the force registered on the seat pan.

References 1. Villanueva, M.B.G., Takeuchi, Y., Sotoyama, M., Jonai, H., Saito, S.: Adjustments of posture and viewing parameters of the eye to changes in the screen height of the visual display terminal. Ergonomics 39(7), 933–945 (1996) 2. Rhimi, A.: Concepts for the reduction of the discomfort generated by the prolonged static posture during the driving task, part II: experiments and validations. Int. J. Ind. Ergon. 57, 55–62 (2017) 3. Lis, A.M., Black, K.M., Korn, H., Nordin, M.: Association between sitting and occupational LBP. Eur. Spine J. 16(2), 283–298 (2007) 4. Kresal, F., Roblek, V., Jerman, A., Meško, M.: Lower back pain and absenteeism among professional public transport drivers. Int. J. Occup. Saf. Ergon. 21(2), 16–172 (2015) 5. Miyamoto, M., Konno, S., Gembun, Y., Liu, X., Minami, K., Ito, H.: Epidemiological study of low back pain and occupational risk factors among taxi drivers. Ind. Health 46(2), 112–117 (2008) 6. Miyamoto, M., Shirai, Y., Nakayama, Y., Gembun, Y., Kaneda, K.: An epidemiologic study of occupational low back pain in truck drivers. J. Nippon. Med. School = Nippon Ika Daigaku zasshi 67(3), 186–190 (2000) 7. Makhsous, M., Lin, F., Bankard, J., Hendrix, R.W., Hepler, M., Press, J.: Biomechanical effects of sitting with adjustable ischial and lumbar support on occupational low back pain: evaluation of sitting load and back muscle activity. BMC Musculoskelet. Disord. 10, 1–11 (2009) 8. Chen, J.C., Dennerlein, J.T., Chang, C.C., Chang, W.R., Christiani, D.C.: Seat inclination, use of lumbar support and low-back pain of taxi drivers. Scand. J. Work. Environ. Heal. 31(4), 258–265 (2005) 9. Aota, Y., et al.: Effectiveness of a lumbar support continuous passive motion device in the prevention of low back pain during prolonged sitting. Spine (Phila. Pa. 1976) 32(23), 674– 677 (2007) 10. De Carvalho, D.E., Callaghan, J.P.: Influence of automobile seat lumbar support prominence on spine and pelvic postures: a radiological investigation. Appl. Ergon. 43(5), 876–882 (2012)

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11. Guo, L.X., Dong, R.C., Zhang, M.: Effect of lumbar support on seating comfort predicted by a whole human body-seat model. Int. J. Ind. Ergon. 53, 319–327 (2016) 12. Harrison, D.D., Harrison, S.O., Croft, A.C., Harrison, D.E., Troyanovich, S.J.: Sitting biomechanics, part II: optimal car driver’s seat and optimal driver’s spinal model. J. Manipulative Physiol. Ther. 23(1), 37–47 (2000) 13. Looze, D., Michiel, P., Kuijt-Evers, Lotiie, F.M., Van Dieën.: Sitting comfort and discomfort and relationships whit objective measures. Ergonomics 46(10), 985–997 (2003) 14. Zemp, R., Taylor, W.R., Lorenzetti, S.: Are pressure measurements effective in the assessment of office chair comfort/discomfort? A review. Appl. Ergon. 48, 273–282 (2015) 15. Zenk, R., Franz, M., Bubb, H., Vink, P.: Technical note: spine loading in automotive seating. Appl. Ergon. 43(2), 290–295 (2012) 16. Coleman, N., Hull, B.P., Ellitt, G.: An empirical study of preferred settings for lumbar support on adjustable office chairs. Ergonomics 41(4), 401–419 (1998) 17. Maradei, M.F., Quintana, L., Castellanos-Olarte, J.M.: Assessment of biomechanical demands and discomfort in drivers to stablish design criteria for truck seats. Int. J. Interact. Des. Manuf. 10(4), 431–437 (2016) 18. Carcone, S.M., Keir, P.J.: Effects of backrest design on biomechanics and comfort during seated work. Appl. Ergon. 38(6), 755–764 (2007)

Analysis of Work-Related Musculoskeletal Disorders on Office Workers at the Industrial University of Santander Fernanda Maradei1(&), Jenny Rodriguez1, and Javier Castellanos2 1 Grupo de Investigación Ergonomía, Producto Y Significado GEPS, Universidad Industrial de Santander, Ciudad Universitaria Carrera 27 # 9 Escuela de Diseño Industrial Oficina 322, Bucaramanga, Colombia [email protected], [email protected] 2 Universidad Pontificia Bolivariana, Campus UPB Km 7 Vía Piedecuesta, Bucaramanga, Colombia [email protected]

Abstract. Office work has caused pain presence and development of musculoskeletal diseases related to work and repetitive task all over the world. This study looked forward to identifying and analyzing the occurrence of self-reported musculoskeletal symptoms among workers at the Industrial University of Santander, Colombia. The Nordic questionnaire with evaluation in neck, shoulders, low back, elbows and wrists/hands was used, since it is a very powerful tool to study the occupational factors, as well as to identifying their nature in order to generate proposals for changes that reduce musculoskeletal demands into work activities. This questionnaire was completed by 121 workers, including teachers and administrative employees, from October to November 2016. Results showed that the highest prevalence of musculoskeletal symptoms during the last 12 months and 7 days was in the neck and lower back. Additionally, they indicated that workstations in offices should be laid out following ergonomics standards, guidelines and recommendations. Keywords: Musculoskeletal symptoms  Office work  Nordic questionnaire Prevalence



1 Introduction Office work as an economic activity has been transformed in last decades. Currently, tasks in the office work are fundamentally affected by pressure of time, the required engagement to successfully finish them and the prolonged time for their execution. The simultaneous occurrence of these three situations can affect workers productivity [1]. This kind of work requires an intense cognitive activity in problems solving, data management, communications and information; which force workers to remain continuously in their workplace, promoting a prolonged static seated posture [2]. Besides, since computer workstations have become essential and necessary tools for organizations and workers, the most common posture adopted to use them is seated. According to scientific literature, this is the most common position not only at work, but also on © Springer Nature Switzerland AG 2020 R. S. Goonetilleke and W. Karwowski (Eds.): AHFE 2019, AISC 967, pp. 135–145, 2020. https://doi.org/10.1007/978-3-030-20142-5_14

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transportations systems and in leisure time [3]. It has been associated this intensive use of computers at work and the execution of repetitive tasks with pain, different pathologies and injuries. Among the later, lumbar pain is one of the most common and it is defined by the International Code of Diseases as the pain perception in the lower back [4]. This pathology affects a quarter of the world population with a prevalence higher than 60% in 12 months, and therefore it has been identified as a public health problem [5, 6]. On the other hand, risk factors associated with musculoskeletal disorders (MSD) in work office activities with Visual Display Units (VDU) can be divided into three categories. First one, individual factors such as age, gender, obesity, physical activity, smoking habits, use of vision correction and inherent psychological states may increase the risk of developing MSD. Second one, workstation design and task demand factors such as duration of computer use, breaks frequency, method of keyboard operation, position of computer monitors, type and use of input devices have been associated with MSD [7]. Finally, workplace psychosocial factors are thought to play a role in the development of MSD [8, 9]. According to the VIII National study made in Colombia in 2014, most of the studied working population exhibits musculoskeletal pain in different parts of the body. Specifically, 23.6% corresponds to low back pain and 34.8% of the people suffering from this pathology manifest that this pain negatively affects their work performance [10]. Furthermore, according to the latest report about risk management system conducted by the Industrial University of Santander (UIS, according to its Spanish initials) in collaboration with its occupational hazard insurance company in 2016, 90.11% of total absenteeism corresponded to office workers, being female 61.4%. It was also shown that 13.05% of reported illnesses were musculoskeletal system diseases. Due to these findings, prevention and detection of MSD through an early detection of pain and discomfort symptoms could allow to estimate office-work risk levels. This in turn could allow to introduce an ergonomic transformation to office-work constraints [11]. This research work looks forward to characterizing the labor situation of the office workers at the UIS in terms of pain and discomfort, using as tool the Nordic questionnaire of musculoskeletal symptoms.

2 Materials and Methods 2.1

Nordic Questionnaire

Self-report questionnaires based on graphics tools checklists are commonly used to perform ergonomic analyses, specifically in jobs that feature low intensity, repetitive tasks, or require that the workers keep awkward postures [12]. Among several tools to evaluate such symptoms, the Nordic Musculoskeletal Symptoms Questionnaire (NMSQ) was developed to standardize musculoskeletal pain and discomfort, thus allows the results to be compared with different studies and populations [13].

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Self-report questionnaires based on graphics tools are commonly used for ergonomic analysis especially in work activities characterized by low intensity, repetitiveness or bad postures. NMSQ was conceived to address the question: Do musculoskeletal problems occur in a population, and if so, in which parts of the body are they located? On this basis, the questionnaire presents the human body graphically divided in five anatomic regions. 2.2

Participants

This study involved adult workers (18 years old or more) in administrative or teaching positions at the University. 845 people were invited to participate, 121 of whom were voluntarily enrolled. In order to evaluate musculoskeletal symptoms, each participant was asked using the Nordic questionnaire whether or not he/she has suffered pain or discomfort in different parts of the body in the last 12 months and 7 days. The study surveilled neck, shoulders, elbows, low back and wrists. The questionnaire included aspects like the presence or absence of musculoskeletal pain, as well as the intensity level of discomfort or pain. The first part was structured in seven questions to stablish the general characteristics of the worker, gender, age, enrolment time at the institution as a teacher or administrative, number of weekly working hours and presence of pain or discomfort in any body part during the last 12 months. Subsequently, if the worker responded negatively to the last question, the questionnaire was completed. Otherwise, the following questions looked forward to evaluating the presence of pain: duration, level of pain or discomfort. This level was reported in a Visual Analogue Scale (VAS) graded from cero to ten. Cero indicates no pain and ten indicates the worst pain possible [14, 15]. This questionnaire was filled out and sent using the free online app Google Forms. Because this research was explorative, noninvasive and voluntary, there was a tacit and de facto agreement of all participants who first read the consent statement on the top of the questionnaire before its submission online. On the other hand, processing and analysis of data required the creation of some contingency tables under IBM-SPSS statistics software version 19.0, where variables were expressed in terms of frequencies and percentages. The Chi-square test for nonparametric data was used for the statistical analysis; the significance level was 5%, considering statistically significant differences for p < 0.05.

3 Results 3.1

Demographic Characteristics

Table 1 shows the distribution of participants according to gender, age, time worked at the University in months, hours spent in sitting posture, job type, and Body Mass Index (BMI). These results indicate that the mean age of the participants was 42 years (range 20–66) and the average working time was 125.4 months (10.4 years). The proportion of women and men was 45.5% (n = 55) and 54.5% (n = 66) respectively, from which 52.1% were administrative workers and 47.9% were university teachers.

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44.64% (n = 54) of workers reported BMI values between 18.5 and 24.9, which is categorized as normal, while 38.84% (n = 47) of them turn out to be between 25 and 29.9, categorized as overweight. Besides, a large proportion of participants (18.2%) remain seated between 35 and 40 h per week. An identical percentage of people spend between 6 and 10 h per week, and a 13.84% remain seated between 20 and 24 h per week. Administrative personnel reported a high percentage of work hours on seated position, mostly from 2 to 10 h intervals and from 31 to 40 h intervals. On the other hand, university teachers turned out to work on seated position in three major intervals: 11 to 20 h, 26 to 30 h or 41 to 60 h. These results indicate that administrative personal and teachers carry out their labor activities on a seated posture over an extended period. Moreover, the higher value was in the range of 30 to 35 h, corresponding to 26.45% of the entire population. Table 1. Demographic characteristics. Demographic characteristics Gender

Range Male Female Age 20–29 30–39 40–49 20–59  60 Working time after recruitment (months)  12 13–59 60–119 120–359  360 Hours spent in sitting posture 2–6 7–10 11–20 21–25 30–35 36–40 40–70 Job type Administrative Teacher BMI Low weight Normal weight Overweight Obesity Morbid obesity

Frequency (n) Percent (%) 66 54.50 55 45.5 22 18.18 30 24.79 30 24.79 31 25.62 8 6.61 23 19.01 24 19.83 16 13.22 34 28.10 16 13.22 16 13.22 22 18.18 5 4.13 17 14.05 32 26.45 22 18.18 7 5.79 63 52.07 58 47.93 5 4.13 54 44.63 47 38.84 14 11.57 1 0.83

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Musculoskeletal Symptoms (MSD)

Contingency tables were used as a statistical technique to find the association between the physical pain occurring in the last 12 months and 7 days with the type of labor (teacher or administrative worker). First, Table 2 makes evident that physical pain in the low back, hands and wrist affected mainly administrative employees. On the contrary, physical pain in the neck, shoulders and elbows was higher in teachers. The same table shows that physical pain in neck (21.4%), shoulders (11.5%), low back (23.1%), elbows (4.9%) and wrists/hands (8.2%) during the last 7 days was higher among teachers than administrative workers. Table 2. Comparison of physical pain in different body parts in the last 12 months and 7 days according to worker occupation. Worker Neck Shoulder Low back Elbows Pain in the last 12 months UTa 35% 22% 30% 7% Adb 33% 18% 33% 2% Pain in the last 7 days UTa 21% 11% 23% 5% Adb 17% 7% 21% 1% a University teacher. b Administrative worker.

Wrists/hands 16% 18% 8% 7%

Table 3 shows the prevalence of physical pain in different body parts. Results reveal higher and similar values in neck and low back. Table 3. Prevalence of musculoskeletal symptoms among the UIS workers in the last 12 months (n = 121). Part of the body Neck Shoulder Low back Elbows Wrists/hands

Prevalence 0.677 0.404 0.632 0.099 0.347

Percentage 67.77 40.50 63.2 9.92 34.71

Over the past 12 months, 67.8% (n = 82) of participants reported physical pain in the neck; likewise, 63.2% (n = 77) reported pain in the lower back. At the same time, the self-reported physical pain or discomfort over the past 7 days was 53.1% (n = 52) in the low back and 48% (n = 47) in the neck. The relationship between pain intensity and its duration is shown in Table 4. The neck exhibits the higher value when the pain is present more than 30 interrupted days. At the same time, the low back pain is high with values between 1 to 7 days (n = 30). Low back and neck pain show the highest frequency of pain every day.

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Duration none 1–7 days 8–30 days >30 interrupted days every day

Neck 47 28 20 22 4

Shoulders 81 13 12 13 2

Low back Elbows 50 107 30 7 23 3 12 1 6 3

Wrists/hands 83 15 15 7 1

Finally, the comparison between the presence of physical pain in the last 12 months and 7 days (see Table 5), evidences that neck pain and low back pain are persistent, while the physical pain in shoulders, hands and wrists have more presence in the last 12 months than in the last 7 days. Table 5. Presence of physical pain in the last 12 months and 7 days.

Neck pain in the last 12 months

Yes No

Shoulder pain in the last 12 months

Yes No

Low back pain in the last 12 months

Yes No

Wrists/hand pain in the last 12 months

Yes No

3.3

Neck pain in the last 7 days Yes No 46 36 1 38 Shoulder pain in the last 7 days Yes No 21 28 2 70 Low back pain in the last 7 days Yes No 51 26 1 43 Wrists/hand pain in the last 7 days Yes No 19 23 0 79

Associations Between Work-Related Exposures, Demographic Characteristics and Symptoms

Association between gender and symptoms in the last 12 months and 7 days with a Chi-squared test (p < 0.05) is clear only for shoulders pain in the last 7 days (see Table 6). In this instance women present higher values than men but in general, there is not differences in pain according to gender.

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Table 6. Presence of physical pain in the last 12 months and 7 days. Body Part 12 months Neck Shoulders Low back Elbows Wrist/hands 7 days Neck Shoulders Low back Elbows Wrist/hands

Men Woman Total Chi- squared p-value 40 23 45 7 25

42 26 32 5 17

82 49 77 12 42

0.065 0.166 0.255 0.781 0.423

21 6 32 6 13

26 17 20 1 6

47 23 52 7 19

0.082 0.002 0.180 0.088 0.186

4 Discussion This research evidences that the prevalence of MSD symptoms in UIS workers is a health problem. The 121 participants surveyed reported high values of pain prevalence in the last 12 months in neck (67.7%, n = 82) and in low back (63.6%, n = 77), and only 7.4% reported no pain or discomfort in any part of the body. On the other hand, the prevalence in the last 7 days was 53.1% in low back and 48% in the neck. These high values are possible related to the percentage of hours in sitting posture; 18.2% workers maintain this posture from 35 to 40 h. But, the association between worked h per week and the symptoms presence have showed no significant associations (p < 0.05) when workers remain continuously in workstations during inactivity periods. This is coherent with Castillo and Ramirez [2] findings, however, other study sustains that a prolonged sitting posture increases the relative risk of low back pain the first working year [16]. The prevalence described in this study can also be compared with the 2016 report about risk management system conducted by the UIS. This report compares working time with illnesses and it reveals that musculoskeletal symptoms count for a 13.05% (n = 742) of total population. These symptoms are also accountable for the highest value of absenteeism in office work (i.e. administrative tasks). In this framework, the findings could suggest that UIS office work conditions have a high effect on musculoskeletal symptoms. In this regard, research works conducted by Gerr et al. [17], Jensen et al. [18] and Korhonen et al. [19], show that occupational computer use is a primary cause of musculoskeletal disorders of upper limbs, head, neck and back [12]. At the same time, Woods [20] found a high prevalence of pain/discomfort reported by data entry operators and computer workers. McLean [21] concludes that office workers could reduce the impact of their work by alternating activities and regulating resting times. In fact, taking regular breaks reduces discomfort in neck, shoulders and low back of computer workers without affecting their productivity.

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The Chi-squared test of the association between gender and symptoms in the last 12 months and 7 days only evidences a relationship for shoulders pain in the last 7 days (p < 0.05); in this instance, women present higher values than men. On the whole, the gender has not association with prevalence of MSD symptoms in the five regions of the body, however Viikari-Juntura et al. [22] findings indicate that there is association due to anthropometric differences. Other conditions for developing musculoskeletal symptoms are related to worker’s health, for example, the rise in calories intake and the decline on physical activity levels for a sedentary work [23]. In this regard, 44.64% of the participants in this study present a normal IBM, while 38.84% present overweight. The association between IBM and symptoms presence showed no significant associations (p < 0.05), however this high overweight population should receive especial preventive attention. On the other hand, Ghasemkhani et al. [24] and Mahbub et al. [25] found that employment’s duration has a significant association with MSD. Notwithstanding, in this study there was no significant association (p < 0.05). The association between pain intensity and duration is higher in the neck and the low back than in other parts of the body. The frequency of these two pains in the lapse 8–30 days was 17.3% for the neck and 19% for the low back. This situation is reflected on efficiency and productivity reduction, with a 49.5% in low back, 43.3% in neck, 27.8% in wrists/hands and 23.7% in shoulders as McGorry et al. [26] and Karakolis and Calleghan [27] have already demonstrated. The intensive introduction of computer technology and the need to remain seated have led to the appearance of DSM symptoms linked to work activity and repetitive tasks, which have an impact on labor productivity [2]. In relation to the job type and the presence of pain, literature has showed that the visual display unit (VDU) users exhibit a higher risk for neck and/or shoulder symptoms relative to the risk expected in low exposure office or industrial tasks [7, 28]. In relation with teachers, the prevalence is high in cervical region [29, 30], with supposed associations with head tilting movements and especially with muscle tensions generated by the maintenance of postures for long periods of time. The administrative activities expose teachers to pressure sources beyond their regular academic duties, such as high workload, short resting pauses, intensive working pace and high levels of attention and concentration. When such situations are associated to a high level of stress, quality of life of this category is considerable impaired [31], inducing several health disorders, such as musculoskeletal problems which are prevalent among professors [32]. This study found that in the last 12 months, administrative workers had pain in low back and hands/wrists, while teachers had pain in neck, shoulders and elbows with worst pain in the last 7 days. Besides, teachers presented higher values of pain in all parts of the body in comparison to administrative workers; this could be attributed to a prolonged stand up position combined to a prolonged seated posture [2]. Nonetheless, it is important to outline that pain values among teachers and administrative workers are quite similar.

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5 Conclusions This research found a high prevalence of musculoskeletal symptoms among UIS workers. On the one hand, pain in neck and shoulders are the higher during the last 12 months and 7 days. These values are representative because influence low efficacy and low productivity. In this way, high values of pain in low back and hands/wrists among administrative workers were identified. On the other hand, teachers have the higher pain values in neck, shoulders and elbows in the last 12 months. It must be outlined that teachers and administrative workers exhibit pain in all parts of the body in the last 7 days, which indicates that an appropriate intervention is required to avoid these symptoms becoming musculoskeletal pathologies, injuries and disabilities. Computer workstations in offices should be planned following ergonomic standards, guidelines and recommendations, because these areas can contribute to the development of musculoskeletal pain by forcing certain body parts to adopt awkward or static postures [33, 34]. Employees must be trained in ergonomic layout and organization of their workstations. Regarding musculoskeletal symptoms, the implementation of preventive measures is an urgent matter.

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12. Sonne, M., Villalta, D.L., Andrews, D.M.: Development and evaluation of an office ergonomic risk checklist: ROSA–Rapid office strain assessment. Appl. Ergon. 43, 98–108 (2012) 13. Pinheiro, F.A., Tróccoli, B.T., de Carvalho, C.V.: Validity of the Nordic Musculoskeletal Questionnaire as morbidity measurement tool. Rev. Saude Publica 36, 307–312 (2002) 14. Takekawa, K.S., Goncalves, J.S., Moriguchi, C.S., Coury, H.J.C.G.: Can a self-administered questionnaire identify workers with chronic or recurring low back pain? Ind. Health 53, 340– 345 (2015) 15. Salerno, D., Copley-Merriman, C., Taylor, T., Shinogle, J., Schulz, R.: A review of functional status measures for workers with upper extremity disorders. Occup. Environ. Med. 59, 664–670 (2002) 16. Van Nieuwenhuyse, A., et al.: Risk factors for first-ever low back pain among workers in their first employment. Occup. Med. 54, 513–519 (2004) 17. Gerr, F., Monteilh, C.P., Marcus, M.: Keyboard use and musculoskeletal outcomes among computer users. J. Occup. Rehabil. 16, 259 (2006) 18. Jensen, C., Finsen, L., Søgaard, K., Christensen, H.: Musculoskeletal symptoms and duration of computer and mouse use. Int. J. Ind. Ergon. 30, 265–275 (2002) 19. Korhonen, T., Ketola, R., Toivonen, R., Luukkonen, R., Häkkänen, M., Viikari-Juntura, E.: Work related and individual predictors for incident neck pain among office employees working with video display units. Occup. Environ. Med. 60, 475–482 (2003) 20. Woods, V.: Musculoskeletal disorders and visual strain in intensive data processing workers. Occup. Med. 55, 121–127 (2005) 21. McLean, L., Tingley, M., Scott, R.N., Rickards, J.: Computer terminal work and the benefit of microbreaks. Appl. Ergon. 32, 225–237 (2001) 22. Viikari-Juntura, E., Vuori, J., Silverstein, B., Kalimo, R., Kuosma, E., Videman, T.: A lifelong prospective study on the role of psychosocial factors in neck-shoulder and low-back pain. Spine 16, 1056–1061 (1991) 23. Organización Mundial de la Salud: Obesidad y sobrepeso. https://www.who.int/es/newsroom/fact-sheets/detail/obesity-and-overweight 24. Ghasemkhani, M., Mahmudi, E., Jabbari, H.: Musculoskeletal symptoms in workers. Int. J. Occup. Saf. Ergonomics. 14, 455–462 (2008) 25. Mahbub, M.H., et al.: Prevalence of cervical spondylosis and musculoskeletal symptoms among coolies in a city of Bangladesh. J. Occup. Health. 48, 69–73 (2006) 26. McGorry, R., Dempsey, P., O’Brien, N.: The effect of workstation and task variables on forces applied during simulated meat cutting. Ergonomics 47, 1640–1656 (2004). https://doi. org/10.1080/00140130412331303894 27. Karakolis, T., Callaghan, J.P.: The impact of sit–stand office workstations on worker discomfort and productivity: a review. Appl. Ergon. 45, 799–806 (2014) 28. Blatter, B., Bongers, P.: Duration of computer use and mouse use in relation to musculoskeletal disorders of neck or upper limb. Int. J. Ind. Ergon. 30, 295–306 (2002) 29. Caran, V.C.S., de Freitas, F.C.T., Alves, L.A., Pedrão, L.J., Robazzi, M.L. do C.C.: Riscos ocupacionais psicossociais e sua repercussão na saúde de docentes universitários. Rev. enferm. UERJ, 255–261 (2011) 30. Barreto Mozzini, C., Cunha Polese, J., Rubia Beltrame, M.: Prevalência de sintomas osteomusculares em trabalhadores de uma empresa de embalagens metálicas de Passo Fundo-RS. Rev. Bras. Em Promoção Da Saúde 21 (2008) 31. Suda, E.Y., Coelho, A.T., Bertaci, A.C., dos Santos, B.B.: Relação entre nível geral de saúde, dor musculoesquelética e síndrome de burnout em professores universitários. Fisioter. E Pesqui. 18, 270–274 (2011)

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The Understanding and Influence of the Connotation of Semantics on the Figurative Product Ching-Yi Wang(&) and Peng-Jyun Liu Department of Creative Product Design, Asia University, 500, Lioufeng Rd, Wufeng, Taichung 41354, Taiwan, ROC [email protected], [email protected]

Abstract. In general, many products in the function and shape of the interpretation of the lack of clarity or abstract may affect the user for the use of the product in the misunderstanding or the shape of the do not understand. In this research, we examined the figurative design. Then, these images will measure the correlations between the different semantics according, including: the congruous, incongruous related, incongruous categories. These can be as a new tool to measure the semantic study. Consumers understand and recognize the look and feel of products and use products intuitively. Keywords: Figurative design

 Product semantics  Product design

1 Introduction The appearance of the product is the most direct medium of communication between the product and the recipient. Designers translate the different functions of the product into symbols so that it can be understood by potential users. Human beings can identify external things through the stimulation of visual senses. However, the process of judgment in the process of identification is often limited by the influence of the knowledge and experience behind it [1]. From the designer’s point of view, the designer uses abstract symbols to interpret the appearance of the product. However, is it possible for every user to interpret the same knot Fruit? For example, the design of butterfly chair looks like the butterfly’s wing form. To the user, it is not necessary to think that appearance is the image of butterfly, which is the problem of styling cognition. This type of product is a metaphorical design technique. The order of interpretation of metonymy (60%) was highest, followed by metaphor (24.5%) and analogy (20%), while metonymy (13.3%) and allegory (11.1%) had the lowest recognition rate [1]. Moreover, the functional identification rate is higher than the modeling identification rate, and the modeling identification rate is higher than the related meaning identification rate, regardless of the background of industrial design or non-industrial design. Therefore, if the designer is not clear or too abstract in the interpretation of the product, it may affect the user’s understanding of the Misjudgment of the use of product functions or incomprehension of modelling. © Springer Nature Switzerland AG 2020 R. S. Goonetilleke and W. Karwowski (Eds.): AHFE 2019, AISC 967, pp. 146–156, 2020. https://doi.org/10.1007/978-3-030-20142-5_15

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The Definition of Metaphorical Design

Metaphorical design is defined as: “people can use metaphors to perform abstract thinking and to interpret abstract concepts” (Lakoff,) “metaphor transfers or maps knowledge from the original domain (the familiar domain of knowledge) to the target domain (unfamiliar area or situation)” [2]. Therefore, people can use their own experience of knowledge, to get the understanding of figurative products. 1.2

Figurative Product Design

Figurative product design will affect the user’s perception of product function. In addition to describing its own functions, the product also expresses another layer of additional meaning. Metaphorical design is widely used in products. According to [1] comprehensive product semantics point of view, metaphorical design is divided into five types, including: metaphor, metonymy, allegory, metonymy, analogy. This study focuses on metaphorical, metaphorical and analogous metaphorical design, which has a better recognition degree in function, shape and meaning.

2 Simile A rhetorical metaphor in the form of “A is like B”. It means a direct way to show the meaning without concealment or clarity. Figure 1 is a umbrella frame, the shape is the use of umbrella skeleton, interpretation of the function of the umbrella. The product uses the apparent shape of the umbrella frame as the symbol of the product (Fig. 2) [3]. The design is direct and explicit as a metaphor or metaphor.

Umbrella shape skeleton

Umbrella function

Fig. 1. Figure of speech in the form of “A is like B”

Fig. 2. Examples of metonymy products: umbrellas

The purpose of this study is to use card classification to define the design of figurative products, and to classify product images into three groups according to different semantic dimensions: metonymy, metaphor and analogy, and to explore the differences between product semantics. Judging from the understanding de-gree of metaphor, metaphor and analogy, these three kinds of comprehension are easy to

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understand, general understanding and difficult to understand. This study hypothesizes that analogy may lead to incomprehensible metaphors, followed by metaphors of general comprehension, and directly to comprehensible degrees.

3 Metaphor Metaphor, a rhetorical metaphor in the form of “A is B”. It literally refers to something, but in a sentence it refers to something else to describe its resem-blance. Figure 3 Kataguruma chairs. The styling uses the father’s shoulder as the symbol of the product, quoting the memory of sitting on the father’s shoulder, referring to the posture of sitting on the chair, with the common attribute of riding between the two (Fig. 4) [4], By using the product, the user can associate the pos-ture of sitting on the chair with the concept of sitting on the shoulder as a meta-phor.

The memories of sitting on Dad

The posture of a chair

Fig. 3. Figure of speech in the form of “A is B”

Fig. 4. Product examples metaphor: Kataguruma

of

4 Analogy Analogies or analogies, figurative figures of speech in the form of “a is not like B”. It means that there is no direct connection between the product and the borrowed symbol, but the association is formed by a certain characteristic or using situation, which makes the product more imaginative and paradoxical. Figure 5 shows the Peakco vase, using the peacock pattern, representing the concept of “vase and flower” to interpret the product [5]. But peacock symbols do not make up the association of vases, but the nature of “open” is inferred from the concept of “flower” to form a connection (Fig. 6).

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The vase bloomed with flowers (e.g., a peacock's feathers)

Fig. 5. “A is not B” like method of repair

Fig. 6. Examples of products by analogy or analogy: Peakco

5 Method 5.1

Subjects

Four design experts (4 male, Mean = 52.75, Std = 5.9), with rich product design background and more than 20 years teaching experience, were invited. 5.2

Sample

This study takes figurative products as an example, collects all kinds of possible cases to measure widely, and assumes that the sample may contain figurative product pictures. Photo collection from the web search engine and product design sites, collected a variety of “figurative” pictures, a total of 160. Four design experts were invited to intuitively delete similar images, group images according to their subjective perception (the number of clusters is not equal), and reduce the number of images to 120. Finally, each picture is made into a 10 cm  10 cm color card, and the upper right corner is marked with the picture number, as shown in Fig. 7.

Fig. 7. Color chart sample (Motica, 2016)

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Experimental Program

First of all, let the design experts browse through all the product pictures, and screen out 120 metaphorical, metaphorical and analogous metaphorical products with 160 product drawings that meet the needs of the experiment, and then divide each of them into nine scales of meaning that are easy to understand. The degree of understanding of general and difficult-to-understand three stages, each of which is divided into three groups. Finally, 9 groups of images are obtained from left to right and coded at 1 to 9 levels. During clustering, the number of categories is allowed to be uneven or vacant. The experiment lasted about 1–1.5 h per person. In categorical logic (Fig. 8), the metonymy appearance of the product represents a more direct, unhidden and comprehensible indication of the product’s characteristics. Such as number 4, is the design of the bulb, the exterior uses acrylic plate, after laser cutting presents the characteristics of Edison lamps: light bulb and filament, and using the new lighting concept LED to make it easy to understand the concept designers want to express [6]. Metaphorical products, which are different in appearance and substance, describe their similarities through cues. Such as number 19, for simple hanging key rings, decorated on walls The treehouse on the tree reminds you to let the sparrows return to their warm homes [7]. And the return of the key and sparrow is the return of the master safely. Analogous products, appearance and borrowed symbols are not directly related to each other, but in a particular feature or use context to form association. If the number 7 out of the hat out of the rabbit can not only change the toothpick, if toothpick demand, the hat back to the rabbit head, is the sweetest and most discreet salute [8]. Like magic, rabbits are turned from top hats to rabbits. When rabbits are snatched from top hats, toothpicks pop up radially and cause surprise, creating associations through the operation of the product in the context.

Fig. 8. Categorical Logic of metaphorical, metaphorical and analogy samples

5.4

Data Analysis

From the result of card sorting, the descriptive statistical analysis is carried out by using SPSS 20 statistical software, and the total average value and standard difference of each sample are listed, and the scores of the top 40 in easy to understand, general and difficult to understand are obtained respectively. If an easy-to-understand score is closer to 9, the general understanding score is closer to 5, and the less comprehensible score is close to 1, the better.

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6 Result 6.1

Metonymy Product

Figure 9 is the classification result of metonymy. Metonymy products express their meanings and modeling symbols directly and clearly in the products. If the number 20 is the highest score (average score 8.75), the use of English word OPEN and can opener is clearly indicated. Among them, the shape of the English letter O is skillfully used to convert it into the knife edge of the can opener, and the latter three letters are designed to be handle, which makes it easy to take and intuitively use [7]. On the contrary, most of the symbols borrowed from the product modeling that can not be identified are more difficult to identify at first glance, and are not clear enough to express the concept of the product directly, which also results in a slightly lower score.

Fig. 9. Metonymy product picture

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Metaphor Product

Figure 10 shows the classification of metaphor. Metaphorical products are intended to convey and understand product meaning by observing the visual appearance of the product, or by suggesting the use of it during operation. If the number 124 is the highest score (average score 7.75), the appearance of the product refers to the dancer’s styling symbol, and it is necessary to rotate the axis by pulling the paper towel, implying the operating mode of the product. However, although metonymy is expressed directly on the product, it is easy to misunderstand the meaning because of the difference of the user’s cognition. 6.3

Analogous Product

Figure 11 is the result of classification by analogy. Analogy products need to be compared with association to analogy its implications. If the number 137 is the highest (average score 6.00), the shape is conveyed through the shape of the tank pencil sharpener, and the military force of the tank conveys the meaning that the war problem

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is not solved by the military force of the tank, but in a wise and friendly way. Help you use text or image to express your ideas in the wisest and softest way and defend your rights [9]. On the other hand, unidentifiable analogous products, from the appearance of the product sample is too simplified or very different from the meaning of the product, Easy to cause users to compare, this is the main reason that the average number of such products is mostly slightly lower.

Fig. 10. Metaphorical product picture

Fig. 11. Analogy product picture

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7 Discussion This study uses card sorting to define different semantic figurative products. According to the results of the analysis, the average score of analogical products is almost lower than that of metaphorical products, and the reasons are summarized as follows: 7.1

Differences in Modeling Identification

Product appearance often misappropriates common symbols to represent product functionality, such as notes representing doorbell. Or the use of plants, animal modeling, to express product characteristics. However, the use of modeling is inappropriate or indistinct, it is difficult to identify the appearance of modeling, and even cause confusion of modeling. In addition, the shape is too abstract or simple, the shape of the outer profile lost the product flavor, making it difficult to intuitively understand. In metonymy products (see Fig. 12), the external form is the Chinese character “product”, which belongs to the hieroglyphics in the six books of China, that is, the way in which the symbolic meaning or the visual shape of what the word refers to is described. The design starts from the Chinese character culture, disassembles the design from the font and the character meaning is composed of three mouth, each “mouth” represents the dish of the sauce, the different seasoning brings out the different food flavor, like the chemical change, The perfect combination is produced and the meaning of “product” is realized. In metaphorical products (see Fig. 13), product shapes use envelopes as door styling. This paper refers to the postman’s action in the door gap, extends the image of the door stall, conveys the connection between the door stall and the envelope, and also indicates the position of the envelope door stall by this action. At the same time, the special envelope shape symbolizes the connection with the world. This chic and interesting email is not only a door stall, but also a bridge between you and the outside world, turning it into a temporary mail folder for messages from all sides [10]. In the analogous product (see Fig. 14), the material is made using a tape belt as the styling. In the old tape, the axis on the left and right side of the tape rolls the tape, causing the axis to rotate as it is pulled through the tape table, and the sound flows out of the tape to explain the use of the product [11]. Today, however, cassette cassettes are virtually non-existent, and younger users may not be familiar with cassette operations, unable to intuitively associate and manipulate them.

Fig. 12. Product disc

Fig. 13. You’ve got mail

Fig. 14. Cassette tape dispenser

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Differences in Meaning Interpretation

Understand the meaning of the product by extending or converting the imagination of appearance. Because the subjects’ knowledge background and past experience are different, the product association degree is different, which makes the product interpretation result completely different. In metonymy products (see Fig. 15), the appearance is the use of hand symbols, the form of the hand knife to interpret the kitchen knife. Although the hand is not directly related to the knife, in body language the hand knife means “cut” [12]. The product uses hand knives and sharp blade edges as symbolic symbols, and users can operate through visible shapes. In metaphorical products (see Fig. 16), the nozzle shape of the seasoning can is modeled after Japanese pronunciation: soy sauce, salt, pepper, and pepper [13]. The user may not be able to clearly understand the contents of the product at first glance, but through the mouth shape association of the nozzle of the flavoring tank, it is more interesting to connect the product with the symbol, and to insinuate the content of the product cleverly. In analogous products (see Fig. 17), the rocking chair exterior is shaped by the image of a parent, and a rocking chair and stool called “make a cow and a horse” will interpret the way many parents love and get along with their children. However, it is not easy to create association in use. It is easier to misunderstand that it is purely a styling design, but to ignore its implication.

Fig. 15. Karate Lettuce Chopper

7.3

Fig. 16. Talking

Fig. 17. SLAVE work like a horse and cattle

Operational Intuitive Differences

Because of each person’s different past experience, it is easy to cause different usage recognition and confusion or unavailability in the operation of the product. Examples such as the following: In the metaphorical product (Fig. 18), the surface uses an hourglass as a symbol of time, an instrument for timing. This watch has two dial, one is hour dial at the top and the other is minute dial at the bottom. When they rotate, the middle hourglass prompts time [14]. The product uses the obvious appearance of the hourglass as an indication

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and allows the user to understand the meaning of the symbol more clearly than the usual pointer in operating the product. In metaphorical products (Fig. 19), the appearance uses the shape of a woodpecker as a symbol, through the word “pounding” at the door, and by the woodpecker’s pecking of wood. The common attribute [15] of the sound made by a woodpecker hitting wood between a woodpecker and a doorbell. When using the product, the user will associate with the woodpecker’s image of beating wood and understand the hidden meaning. In the analogous product (Fig. 20), the appearance uses the block brick in the Super Mary game scene, and the switch operation of the lamp must be hit from the bottom up [16]. It is used in the same way as game control. However, the subjects who have not come into contact with this game are easily confused in their use; moreover, the switch mode of general lamps seldom uses the impact mode, and the non-general use method makes it easy for the emissary not to use it. Problems such as these often occur in analogous products.

Fig. 18. OZO Watch

Fig. 19. Kitsutsuki

Fig. 20. Super Mario lamp

8 Conclusion Product appearance often misappropriates common symbols to represent product functionality, such as notes representing doorbells, or animal and plant modeling to express product features. However, the use of modeling is inappropriate or indistinct, it is difficult to identify the appearance of modeling, and even cause confusion of modeling. In addition, the shape is too abstract or simple, the shape of the outer profile lost the product flavor, making it difficult to intuitively understand. Must through the external imagination to carry on the extension or the transformation interpretation, the thorough understanding product connotation. Because the subjects are limited by the knowledge background and past experience, the product association degree is different, which makes the product interpretation result completely different. In addition, Because of each person’s different experience, it is easy to create confusion or unavailability in the operation of the product. In this study, the popular and well-known examples of figurative products are summarized, which can be used as reference models for creative databases and course materials. In addition, through the classification of experts, a more clear and objective

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judgment mechanism can be provided in the design research, so that the design beginners can understand their background and successful design more clearly.

References 1. Lin, M.H., Huang, C.C.: The logic of the figurative expressions and cognition in design practices. J. Des. 7(2), 1–22 (2002) 2. Neale, D.C., Carroll, J.M.: Handbook of Human-Computer Interaction, 2nd edn. Elsevier Science, New York (1997) 3. Italiandesign: Products- Casambrella 1710 - Steel Progetti umbrella stand (n.d.). https:// www.italiandesigncontract.com/en/accessories/coat-racks-umbrella-holders-dustbins-ashtrays-boxes/casambrella-1710-steel-progetti-umbrella-stand/. Accessed 8 Aug 2017 4. Design: Original Works: Kataguruma (2008). https://83design.jp/original-products/144/. Accessed 15 Aug 2017 5. mydesy: Product design. Peakco (2014). https://pick.mydesycom/archives/40454. Accessed 5 Aug 2017 6. The interior design: The light in the bubble: The evocative light with a classic design (2017). https://www.theinteriordesign.it/en/article/the-light-in-the-bubble-the-evocative-light-with-aclassic-design/1503. Accessed 22 July 2017 7. Qualy: Qualy: Sparrow Keyring (n.d.). https://www.damanwoocom/shop/product/1211#detail. Accessed 15 July 2017 8. Alessi: Magic rabbit and toothpick holder (1998). http://www.alessifunclub.com.tw/product. php?mode=all&pcid=&cid=&id=603&p1=&p2=&SearchKey=#. Accessed 12 July 2017 9. 28biaugust: Love&Peace: A friendly tank (2011). http://28.biaugust.com/pro03.html. Accessed 18 July 2017 10. Saksirisilp, S.: Behance: You’ve got mail (2014). https://www.behance.net/gallery/ 11133223/QUALY-YOUVE-GOT-MAIL. Accessed 29 Aug 2017 11. Noupe: Comment to win: design products by j-me for you (2013). https://www.noupe.com/ essentials/deals-giveaways/comment-to-win-design-products-by-j-me-for-you-78291.html. Accessed 25 Aug 2017 12. Jimmyjames: Fooddity: This is one kick ass karate chop lettuce knife (2014). http:// foododdity.com/this-is-one-kick-ass-karate-chop-lettuce-knife/. Accessed 14 July 2017 13. +d: Products 2002–2005: Talking (n.d.a). https://plus-d.com/talking02/. Accessed 28 Aug 2017 14. Anton & Irene design studio: Behance: OZO Watch (2015). https://www.behance.net/ gallery/27527207/OZO-Watch. Accessed 12 July 2017 15. +d: Products 2014–2018: Kitsutsuki (n.d.b). https://plus-d.com/kuuki/. Accessed 28 Aug 2017 16. Bduxbury: Instructables: Assemble a super mario brothers coin block lamp (2012). http:// www.instructables.com/id/Assemble-a-Super-Mario-Brothers-Coin-Block-Lamp/. Accessed 15 Aug 2017

Human Sweating Measurements Xiaoli Fan1,2, Chaoyi Zhao1,2(&), Hong Luo1,2, and Wei Zhang3 1

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SAMR Key Laboratory of Human Factors and Ergonomics, Beijing 102200, China China National Institute of Standardization, Beijing 100191, China {fanxl,zhaochy,luohong}@cnis.gov.cn 3 Tsinghua University, Beijing 100084, China [email protected]

Abstract. With the correlation study on human sweating measurements at home and abroad gradually deepening, the evaluation on human sweating has been valued and used in the fields like nuclear and chemical protection. Though the research of sweating measurement has permeated different domains, the measurement about heat-moisture comfort is still for thorough research. Methods of determination of human sweating measurements currently at home and abroad were reviewed in the study. Three methods were about the measurements of systemic dominant sweating. They were respectively net weight, dressed weight and clothing weight. Five methods were about the measurements of local dominant sweating, and they are gauze-spongy pad, filter paper, vinyl bag, ventilated bag, and absorb sweat patch. The theories of these methods and application were reviewed, as well as their advantages and disadvantages respectively. Although the measurement methods have their limitations, they still lay a foundation for exploring new and more superior measurement methods for measuring the sweating rate of human body in the future. Keywords: Sweating measurement  Net weight  Dressed weight Clothing weight  Gauze-spongy pad  Filter paper  Vinyl bag  Ventilated bag  Absorb sweat patch



1 Introduction Sweating is a kind of body temperature regulation method that relies on sweat evaporation to increase body heat loss, which is a physiological adaptation phenomenon [1]. Human body heat dissipation mainly includes: conduction, convection, radiation and evaporation. Among them, evaporation is the main way of heat dissipation in the thermal environment and movement conditions, which also includes non-perceived evaporation and perceived evaporation. When the ambient temperature rises or the activity intensity increases, the human body can’t timely discharge the metabolic heat through radiation and convection. At this time, evaporating sweat fluid which is secreted by sweat glands on the skin surface is needed to take away the latent heat of vaporization, so as to maintain the normal body temperature [2, 3]. According to the difference of human body’s perception of sweating, sweating can be divided into nondominant sweating and dominant sweating [4]. There is no uniform definition of © Springer Nature Switzerland AG 2020 R. S. Goonetilleke and W. Karwowski (Eds.): AHFE 2019, AISC 967, pp. 157–164, 2020. https://doi.org/10.1007/978-3-030-20142-5_16

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non-dominant sweating, Spruit [5] believed that non-dominant sweating refers to the amount of water evaporated from the skin surface when sweat glands showed no activity. Fallon [6] pointed out in his analysis of the relationship between heat injury and non-dominant sweating of the skin that non-dominant sweating was the imperceptible moisture from the body entering the air through the skin and lungs. Nondominant sweating is that, when people is in intense activity or the temperature of surrounding rises abruptly, the sweat gland begins to produce perspiration actively. In addition, sweating caused by extreme mental excitement or taste stimulation is also an overt sweating. Human sweating is closely related to the thermal and humidity comfort of clothing, which is of great significance for maintaining the comfort of micro-climate in the air layer inside or under clothing. Studies have found that, with the increase of environmental temperature or exercise intensity, when wearing different matching clothes, physiological parameters such as sweating amount, skin temperature and humidity inside the clothes change significantly, and human stress level increases and human discomfort level increases [7]. Sweating rate is an important index to evaluate the thermal tolerance of clothing, the thermal intensity of operation and the level of human thermal stress [8–10].

2 The Relationship Between Human Sweating and Thermal Comfort of Clothing Comfort refers to a pleasant state of physical, psychological and physical coordination between human beings and the environment. Thermal comfort is defined as the ideology of human being’s satisfaction with the thermal environment. It is a cognitive process, which is influenced by physical, physiological and psychological factors [11]. It is generally believed that when body temperature is kept in a narrow range, skin moisture content is low, and human physiological regulation activities are minimum, people will be in a comfortable state of heat and humidity [12]. The comfort of clothing is related to the microclimate in clothing, clothing pressure and skin touch to clothing. Among them, microclimate refers to the temperature, humidity and airflow in the small space between clothing and skin [13]. Generally speaking, the comfortable inner microclimate environment is: temperature (32 ± 1) °C, relative humidity (50 ± 10)%, air velocity (0.25 ± 0.15) m/s [14]. Thermal and wet comfort includes thermal comfort and wet comfort. Thermal comfort is mainly used to measure the warmth of clothing to protect body temperature, while wet comfort is mainly used to reflect the comfort index of clothing when the moisture of human skin is lost and sweat is overflowing. Non-dominant sweating is mainly the transmission of gaseous water. Most of the moisture on the skin surface cannot penetrate into the fabric, leaving it in the microenvironment and evaporating into the external environment in the form of gaseous. In dominant sweating, sweat accumulates on the skin surface and clothing is in close contact with skin. Therefore, sweat transmits moisture in two forms: moisture and sweat, of which liquid is the main form. Under the condition of high ambient temperature or movement, the human body expels heat through sweating and evaporation. At this time, the wet transfer

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performance of clothing is an important factor to maintain human thermal balance and comfort. If sweat and sweat cannot penetrate the fabric in time, it will cause the humidity of the micro-environment in the garment to increase, thus affecting the human body’s heat dissipation, resulting in the uncomfortable feeling of mugginess, humidity and so on. At the same time, clothing will stick to the skin, causing tactile discomfort. In some cases, the warmth retention of clothing will decrease [15]. Therefore, the study of sweating volume is an important prerequisite to measure and improve the thermal and wet comfort of clothing.

3 Sweating Measurements 3.1

Measurement of Systemic Dominant Sweating

At present, there are three main methods to measure sweating rate, including net weight, dressed weight and clothing weight. Although these three methods have their own advantages, they all have some limitations. As the basic idea of measuring sweating rate, they lay a foundation for exploring new and more superior measurement methods in the future. (1) Net weight method. Nowadays, net weight was widely used in the research of measuring the total body sweating rate around the world. It mainly used precise electronic scales to measure the weight of clothes and nudes before and after the experiment. Among them, the difference of net weight before and after the experiment represents sweat amount, while the difference of dress weight before and after the experiment was sweat evaporation amount, that was, sweat amount = net weight before the experiment − net weight after the experiment, sweat evaporation amount = dress weight before the experiment − dress weight after the experiment. Sweat rate and sweat evaporation rate were defined as sweat and sweat evaporation per unit time, per unit area, dehydration rate as a percentage of sweating and net weight before the experiment [16]. In some studies, due to the large time span, liquid input and excretion during the experiment needed to be considered. For example, measuring the sweat volume of the army during the march, there were: sweat amount = (net weight before March + water consumption during March) − (net weight after March + urine + stool volume) [17]. This measurement method required that the weighing instrument has both high precision and large range, which was difficult to achieve. Secondly, for some experiments with large time span, we also needed to collect excreta such as human urine, feces, etc. to obtain relevant data, which has some difficulties in the actual work. (2) Dressed weight method. Precision electronic scales were used to measure the body weight (Wpre and Wpost) before and after exercise. Meanwhile, wet gas flowmeter and gas analyzer were used to obtain the ventilation volume per unit time and the concentration of O2/CO2 intake/discharge. On this basis, the loss of water (WH2O) and carbon loss (WC) from respiratory tract were calculated, and the sweating volume = Wpre − Wpost − WH2O − WC. Dressed weight method also had high requirements for the accuracy and range of measuring equipment. At the same time, in the process of experiment, many kinds of

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equipment should be used to measure many kinds of parameters, the error superposition was bigger, and the operation was more complicated. (3) Clothing weight method [18]. Its idea was to collect sweat by using close-fitting clothes with good hygroscopicity. The weight gained of clothes before and after exercise is the sweat amount in the process of exercise, so as to calculate the sweat rate. Before exercise, wrap all clothes in plastic bags and measure their weight, including split raincoats, Pure Cotton autumn clothes, autumn pants, pure cotton underwear, towels, and ensured that the plastic bags and clothes were dry before exercise. After exercise, the clothes removed were quickly put into the plastic bags before, and the perspiration remaining on the body surface was wiped off with a towel and weighed together in the plastic bags. The clothing weight increment method only required high accuracy of the symmetrical gravimeter. It can measure clothing in different stages, so it does not need a large range. 3.2

Measurement of Local Dominant Sweating

In the study of human sweating rate, most of the literatures focus on measuring the sweating rate of the whole body, but less on the local sweating rate of the human body. In recent years, with the increase of people’s interest in outdoor sports and the technological innovation of various protective clothing, the research related to local sweating rate of human body has gradually increased, and more methods for measuring local sweating rate have been formed. At present, the methods of local sweating measurement mainly include gauze-spongy pad method, vinyl bag method, filter paper method, ventilated bag method, absorb sweat patch method. (1) Gauze-spongy pad method. Verde [19] proposed the use of gauze-spongy pad to collect sweat in the 1980s. To avoid contamination caused by exfoliated cells, 70% isopropanol was first used to wipe the measured area, then a 12-layer gauze sponge pad was clamped with tweezers and placed on the skin. To prevent water vapor evaporation, a clean plastic sheet was covered on the gauze sponge pad, and waterproof plastic adhesive material was used to paste around the skin. Before the experiment, the gauze pad should be weighed in a closed circular conical tube. After the experiment, the gauze pad should be weighed in the same tube. The difference between the weight before and after the experiment was the sweating amount of the corresponding parts. The disadvantage of gauze sponge pad method was that it will cause the skin temperature of the measured part to rise, so it would inevitably interfere with the sweating rate. (2) Vinyl bag method. Consolazio [20] proposed the vinyl bag method in the 1960s and used it to obtain the arm sweat rate. Before the experiment, fingernails should be cleaned, tap water and deionized water should be used to wash the arm several times, and then the arm should be wrapped in polyethylene bag to collect sweat. After the experiment, sweat should be extracted from the sweat bag through the catheter and weighed. Some scholars at home and abroad had also used this method to measure local sweating rate in other parts. The direct use of ethylene bags to collect sweat would pollute the sweat components and easily cause measurement errors.

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(3) Filter paper method. In the 1970s, Japanese scholars used filter paper fractions to collect sweat from the subjects’ chest and back every 15 min. The filter paper was three overlapping circular filter paper of 12.6 cm2. It was washed and dried in distilled water beforehand. The weight of the filter paper was increased by local sweating. Shuo et al. [21] used filter paper method to collect and measure the local sweating rate of young athletes after supplementing sports drinks in hot environment. The filter paper method was simple and economical. The filter paper was compact and light. It can be used to collect sweat from many different parts. The thickness of the filter paper can be adjusted according to the amount of sweat collected, so that the sweat volume was not too small to be disadvantageous to analysis, nor too much to saturate the filter paper. Moreover, the impermeable plastic film outside the filter paper can greatly reduce the evaporation of water in the collection process, and improved the accuracy of collection and determination. The main problem of using filter paper method was that long collection time or excessive sweating could cause sweat secreted by the skin around the paper to inhale the filter paper, thus affecting the accuracy of the measurement. Therefore, the collection time should not be too long, and only a small part of the body surface area could be measured. (4) Ventilated bag method. Since the 1940s, many scholars had used different types of ventilated bag to measure local sweat rate [22]. The ventilated bag could be ventilated and soaked in lithium chloride saturated solution before the experiment, so that the air velocity in the sweat sac could be controlled at 600 mL/min, and the relative humidity at the entrance could be kept at 12%. Before the experiment, sweat sacs were adhered to the skin at the measured position. After the experiment, air humidity in sweat sacs was measured by hygrometer. The sweat sac was connected with the sweating data acquisition system. The local sweating rate was calculated by a sample of air temperature and humidity which enters and discharges from the root canal at intervals. The hygrometer needed to be calibrated with saturated salt solution before the experiment [23]. The coverage area of ventilatory sweat sac was 2–9 cm2, and the percentage of coverage area to the total area of the measured part was generally less than 2%. Therefore, the amount of sweat collected was less, and the sweat situation in this area was illustrated by fewer sweat samples, The error was large and not very accurate. (5) Absorb sweat patch. Havenith [24] applied the new absorbent for the first time to sweat collection on a large area of human skin surface, which could simultaneously measure sweat rate in various parts of the body. This method of collecting sweat by using absorb sweat patch required pre-measuring the body size of the subjects, so as to make absorb sweat patch suitable for the size of individual parts of the body, while ensuring that the subjects can be covered in the same area in each experiment. One side of the sweat absorbent patch was adhered to the customized plastic sheet so that it could be quickly applied to the skin surface to avoid errors caused by sweat evaporation during the experiment. Before the beginning of the exercise, the women subjects who wore T-shirts with better elasticity needing to wear bras with absorb sweat patch inside first, and used the slight pressure generated by clothing to make the absorb sweat patch stick to the skin surface.

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Before the experiment, absorb sweat patch were placed in sealed self-sealing bags and weighed. After the experiment, absorb sweat patch were put into bags again to weigh. Finally, sweat rate could be calculated according to the weight gain and area of absorb sweat patch. The formulas used were as follows [25]: Sweat rate = (weight gain of absorb sweat patch/area of absorb sweat patch)  time of adherence of absorb sweat patch to skin The area of the sweat patch = the weight of the dry sweat patch  the weight of the unit area of the sweat patch Sweat patch method could compensate for some shortcomings of ventilated bag method in measuring local sweat rate, such as the sweat sample collected by ventilated bag was too small. However, the coherence of the experiment was worse than that of the ventilated bag method. The ventilated bag could be adhered to the skin, and the sweat situation in this area could be recorded continuously. However, the application of the sweat patch required a period of reaction time. In addition, Havenith [24] used sweat-absorbing patches to absorb materials with good absorptivity and maintain low relative humidity. The effect of Verde T’s gauzespongy pad method on the skin temperature at the site under test could be reduced by using a short sample collection time (5 min interval). Moreover, because it covered all parts of the skin area at the same time, even if sweating would increase slightly, it will also change synchronously, without affecting the analysis of the regional distribution of sweating. George H also explained the effect of clothing pressure on the determination of local sweating rate by sweat patch method. The use of elastic clothing to make the sweat absorbent patches close to the skin would cause slight pressure, which may lead to changes in sweat rate, but Ferres [26] confirmed that the sweat rate of the stressed part did not decrease, but the sweat rate of the non-stressed part increased significantly. Later, she further proved that clothing pressure up to 0.13 N/cm2 would not have any effect on sweating at all, and the pressure produced by the elastic T-shirt used in the experiment was more uniform and much lower than 0.13 N/cm2, so moderate clothing pressure would not affect the sweat patch method to measure local sweating rate.

4 Conclusion The measurement of sweating can provide scientific basis for ensuring the labor safety of individual protective equipment personnel. Although the research of sweat has been extended to many fields, it is still urgent to study sweat from the perspective of clothing thermal and wet comfort. Among the three methods for measuring sweating volume, the net weight method is widely used because of its simple principle. However, this method required rigorous experimental equipment, and the weighing instrument used must achieve a fairly high accuracy. At the same time, the measuring range should be within the normal body weight range. Moreover, net weight method caused many errors. In some experiments with large time span, liquid intake and excretion must be recorded, collected and weighed. Therefore, the experiment was cumbersome and prone to errors. The accuracy of weighing instruments used in some experiments was quite different, so the accuracy

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of sweating volume was also quite different. The precision of the same symmetrical measuring instrument was required by the method of wearing weight difference. At the same time, the experimental equipment and acquisition parameters of the method are more, so the operation was more complicated. Compared with the first two methods, the clothing weight method requires less range of weighing instruments, did not need a large range, can be measured in different stages, the parameters collected were relatively simple, but the accuracy of the symmetrical weighing instrument is also higher. The research progress of local sweating rate of human body was slow in our country. Most textbooks on clothing comfort only summarized the distribution of sweating rate in different parts of human body, and rarely putted forward new methods for measuring local sweating rate and analysis of relevant results. Overseas research on measuring local sweating rate of human body was relatively in-depth, and new testing methods and optimized experimental design were constantly put forward. But there was still much space for improvement. Among them, the disadvantage of gauze sponge pad method was that it will cause the skin temperature of the measured part to rise, so it would inevitably interfere with the sweating rate. For vinyl bag method, direct using of vinyl bag would cause certain pollution for sweat components, and easy to cause measurement errors. The main problem of using filter paper method was that long collection time or excessive sweating could cause sweat secreted by the skin around the paper to inhale the filter paper, thus affecting the accuracy of the measurement. Therefore, the collection time should not be too long, and only a small part of the body surface area could be measured. The sweat sample collected by ventilated bag was too small to explain the sweat situation of a part through fewer sweat samples. The error was large and not very accurate. Sweat patch method could make up for the defect of small sample size in measuring local sweat rate, but the coherence of sweat absorption patch method was worse than that of ventilation sweat sac method in experiment. The ventilation sweat sac could be pasted on the skin, and the sweat situation in this area could be recorded continuously. The application of sweat absorption patch required a period of reaction time, so the real-time performance is poor. Although the measurement methods have their own advantages, they all have certain limitations. As the basic ideas for the determination of systemic sweating rate, they lay a foundation for the exploration of new and more superior measurement methods in the future. Acknowledgments. This research was supported by 2017NQI project (2017YFF0206603), General Administration of Quality Supervision, Inspection and Quarantine of the People’s Republic of China (AQSIQ) science and technology planning project (2016QK177) and Project of the President’s Fund for China National Institute of Standardization (522018Y-5984; 522016Y-4488).

References 1. Huai, J., Lantian, L., Xiong, S.: Functional Composition, Evaluation and Prospect of Common/Special Clothing (Part 1). Donghua University Press, Shanghai (2016). 216 pages 2. Ying, J.: Sweat! sweat! sweat! Sci. Fitness 10, 128–129 (2005)

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3. Hal: Health: active sweating. Health J. 4, 320–322 (2013) 4. Yan, G.: Sweat and health. PLA Health 6, 38–39 (2004) 5. Spruit, D., Herweyer, H.: The ability of skin to change its insensible perspiration. Dermatological 134(5), 364–370 (1967) 6. Fallon, R., Moyer, C.: Rates of insensible perspiration through normal, burned, tape stripped, and epidermally denuded living human skin. Ann. Surg. 158(6), 915–923 (1963) 7. Yuhong, C., Zhihua, J., Junqin, H.: Study on thermal comfort of human wearing under thermal environment. Hum. Ergon. 11(2), 13–15 (2005) 8. Werner, J.: Control aspects of human temperature regulation. Automatic 17(2), 351–362 (1981) 9. Qiu, M., Wu, J., Chang, S.: Human sweat regulation at different activity intensity under different ambient temperature conditions. Chin. J. Appl. Physiol. 21(1), 90–93 (2005) 10. Yongkai, Z., Jianchun, Z.: Clothing comfort and evaluation. Beijing arts and crafts press, 51 (2006) 11. Qunmin, L.: Research on thermal and wet comfort of clothing in sweat state. Suzhou University, 10 (2004) 12. Ashrae: Thermal Environment Conditions for Human Occupancy. Atlanta, GA (1992) 13. Yuhong, C., Shijun, T., Jingjiang, B.: Study on microclimate measurement system in garment. J. Tianjin Text. Inst. 4(18), 79–82 (1999) 14. Yuhong, C., Shijun, T., Pengze, X.: Portable in-garment microclimate tester. China Individ. Protective Equipment 1, 25–26 (2001) 15. Guangzhou, X.: Human sweat and the liquid comfort of knitted clothing. Knitting Industry 4, 122–124 (2002) 16. Xiaohua, Y., Xiansen, Z., Songtao, D.: Field study on the amount of sweat of personal protective equipment personnel. In: The 20th Anniversary Conference of Human-MachineEnvironment System Engineering and the 5th National Human-Machine-Environment System Engineering Bachelor Conference (2001) 17. Rui, R., Xueling, Z.: Investigation of sweating amount during marching in desert and gobi hot and dry environment. Chin. J. Civ. Health 14(3), 137–140 (1995) 18. Yang, W., Gehui, W.: Determination of human sweat rate under different ambient temperature and activity intensity. Res. Protective Equipment Technol. 5, 9–13 (2011) 19. Verde, T.: Exercise and heat-induced sweat. In: Knuttgen, H.G. (ed.) Biochemistry of exercise. Human Kinetics Publishers, Champaign (1983) 20. Consololazion, C.: Comparisons of nitrogen, calcium and iodine excretion in arm and total body sweat. Am. J. Clin. Nutr. 18, 443–447 (1966) 21. Shuo, Z., Jidi, C., Leji, K.: Study on sweat electrolyte during thermal environmental rehydration of youth athletes. Sports Sci. 18(2), 66–72 (1998) 22. Sodeman, W., Burch, G.: Regional variations in water loss from the skin of diseased subjects living in a subtropical climate. J. Clin. Invest. 23(1), 37–43 (1994) 23. Machado, C., Smith, F.: Sweat secretion from the torso during passively-induced and exercise-related hyperthermia. Eur. J. Appl. Physiol. 104, 265–270 (2008) 24. Havenit, G., Fogarty, A.: Male and female upper body sweat distribution during running measured with technical absorbents. Eur. J. Appl. Physiol. 104, 245–255 (2008) 25. Smith, C., Havenit, G.: Body mapping of sweating patterns in male athletes in mild exerciseinduced hyperthermia. Eur. J. Appl. Physiol. 111, 1391–1404 (2011) 26. Ferres, H.: The effect of pressure on sweating. J. Physiol. 151, 591–597 (1960)

Review of the Evaluation Methods of Mental Workload Xiaoli Fan1,2, Chaoyi Zhao1,2(&), Huimin Hu1,2, and Yuwei Jiang3 1

3

SAMR Key Laboratory of Human Factors and Ergonomics, Beijing 102200, China 2 China National Institute of Standardization, Beijing 100191, China {fanxl,zhaochy,huhm}@cnis.gov.cn China Mobile Communications Corporation Government and Enterprise Service Company, Beijing 100191, China [email protected]

Abstract. The research of mental workload evaluation methods is a hotspot nowadays. At present, there are three main types of mental workload evaluation methods: subjective evaluation method, work performance evaluation method and physiological evaluation method. This paper introduces the three methods, summarizes their application, compares the three methods, summarizes their three advantages and disadvantages, and concludes that the future evaluation of mental workload will develop in the direction of combining various methods, make up for their shortcomings, give full play to their advantages, and better evaluate mental workload. Keywords: Mental workload Physiological indicators



Subjective evaluation



Work performance



1 Introduction Mental workload is an important research topic in the field of human factors engineering. Human-machine system has experienced the development process from manual operation to automation system, which reduces physical labor and increases mental labor in modern human-machine system. Human labor has changed from operational operation to knowledge-based operation. Mental workload, also known as psychological load, mental workload, and mental burden, can be understood as the amount of brain activity per unit time, the occupancy rate of brain resources, mental stress or information processing ability in work [1]. It is a multi-dimensional concept across physiological, cognitive, psychological, behavioral and other disciplines [2]. The higher the amount of brain activity, the higher the occupancy rate of brain, the greater the psychological pressure, or the more information processing ability, the higher the mental workload will be. Research shows that higher mental load will cause rapid fatigue, reduced flexibility, stress response, increased human errors and frustration, which will lead to errors in information acquisition and analysis and decisionmaking. Therefore, it is an important cause of human-caused accidents. The low mental workload will result in the waste of human resources and other resources, cause © Springer Nature Switzerland AG 2020 R. S. Goonetilleke and W. Karwowski (Eds.): AHFE 2019, AISC 967, pp. 165–172, 2020. https://doi.org/10.1007/978-3-030-20142-5_17

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disgust, and lead to the decline of job performance [3]. Therefore, in the actual task and work, the research on the evaluation method of mental workload is very important. The research on mental workload started earlier in the world. In the 1960s, some people have used sub-task [4] and subjective measurement [5] to study the human mental load [6]. In recent years, the research on the method of mental workload has been developing continuously. This paper briefly summarizes the research on the method of mental workload assessment. The purpose of mental workload evaluation is to evaluate the mental workload of the human-machine system in order to better understand the operation process, optimize the task and system design. On the other hand, real-time feedback based on mental load and dynamic adjustment of human-machine task assignment To avoid excessive or too low mental workload, in order to achieve the best human-machine task assignment and human-machine collaboration process, improve the performance and safety of the human-machine system, and improve the subjective experience of the operators.

2 Mental Workload Evaluation Method 2.1

Subjective Evaluation

The subjective evaluation method means that the occupation of the brain power of the operator is related to the degree of self-motivation of their subjective perception. When the degree of self-motivation is high, the brain power capacity is also occupied and the mental workload is high. As summarized in [2], subjective metrics are easy to use, and because they are post-evaluation, they are basically non-interfering with human work, so they are the most popular method of mental workload evaluation. This method is also considered to be the most effective method for assessing the current mental workload and is still widely used in various studies [7–10]. At present, there are many subjective evaluation methods reported by foreign countries. The National Aeronautics and Space Administration’s mission load index developed by NASA is NASA’s Task Load Index (NASX), a US Air Force Base Aviation Medicine. Subjective Work Load Assessment Technique (SWAT) developed by the Institute, Cooper-Harper’s “CooperHarper” method and full-duty workload (Feature Workload), which was established in 1969 to measure flight operations. Scale, OW), the first two are multi-factor evaluation methods, and the latter two are single factor evaluation methods. 2.2

Work Performance Evaluation

Work performance evaluation is the ability of an operator to perform tasks in a simulated or real operating environment. According to the type of operation task, there are two methods: the main task evaluation method and the sub-task evaluation method. The main task evaluation method is to calculate the mental load imposed on the operator by the performance results of the operator in the work. The hypothesis of this method is that the increase of mental workload will occupy more limited mental resources, which is reflected in the decrease of efficiency and the increase of error rate

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in the performance of the main task [11]. As an indicator of mental workload, its performance directly reflects the results of the operator’s efforts, so the chief task assessment method is a very meaningful load assessment method. However, performance evaluation is task-based. If we use different dimensions, it is difficult to compare the results between different tasks, nor to measure the performance of the two tasks. We can not fully believe that changes in the difficulty of tasks affect the mental workload of individuals. Moreover, in many cases, most systems do not provide equipment for operator performance information, and it is difficult to obtain performance data directly. Measuring the speed and accuracy of target search and detection is a common indirect measurement method used by researchers to assess the operator’s mental load. Some domestic researchers have used “flight parameter retention rate” (on the ground simulator) as the evaluation index of director’s performance, and achieved satisfactory results [12]. Sub-task evaluation method regards human as a single channel information processor with limited capacity. Sub-task technology is a very common workload assessment technology, which is developed on the basis of research results such as multi-task attention allocation and multi-resource theory. Its basic idea is to let the operator carry out the load operation at the same time (called the main task) and then complete another pre-selected task (called the sub-task), through the sub-task performance to reflect the changes in the load of the chief task [13]. However, it is generally believed that the impact of sub-tasks on task difficulty is more sensitive than that of main tasks [14, 15]. The commonly used sub-tasks are memory, numeric calculation, response time, time estimation, tracking, etc. Among them, time estimation is considered to be the most effective sub-task (for a detailed review, see document [16]. In recent years, researchers have made new progress in searching for small and reliable sub-tasks and choosing suitable occasions for use of sub-tasks. For example, the study in document [17] shows that prospective memory task sitting is a better way to study the sub-task of mental workload. 2.3

Physiological Evaluation Method

The study of mental workload evaluation based on physiological parameters can be traced back to NASA’s Research Report “Development of techniques for measuring pilot workload” in 1971, which combines ECG, respiration, skin impedance and EEG to study the pilots’ workload. In 1976, the importance of measuring mental workload in a new man-machine system was raised at a special meeting on the theme of “Monitoring Behavior and Supervisory Control” held under the chairmanship of the NATO Special Committee on Human Resources. In 1979, a series of NATO conference journals with the theme of “Theory and Measurement of Mental Workload” systematically discussed the theoretical basis of mental workload detection based on physiological signals. From a physiological point of view, mental workload should be regarded as a processing load in the central nervous system. This load exerted on the central nervous system will affect its related functional structure, such as energy supply. With metabolism, loss and repair, and other physiological processes, which can be

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easily detected [19]. At present, the commonly used physiological indicators for evaluating mental workload include brain indicators, eye indicators and electrocardiogram indicators. Brain Indicators. Brain indicators are divided into spontaneous EEG and event-related potentials. The study of spontaneous EEG based on spontaneous EEG generally studies the changes of each frequency band under different levels of brain load, and establishes the model of brain load recognition by using pattern recognition algorithm, which is the most commonly used method in the study of mental workload. Previous studies have shown that the energy of theta, alpha, beta and other bands of EEG is sensitive to the change of mental workload. When people are in a high alert state and perform a difficult task, the main components of EEG activity tend to be in a low amplitude and high frequency beta band. When people are awake but low alert, the alpha wave activity of EEG increases. When people are in a sleepy state, theta wave activity increases. The wave will increase markedly. It is generally believed that psychological stress, active thinking and attention can promote EEG activity to move to higher frequencies and inhibit alpha wave activity [20, 21]. The energy of alpha wave and theta wave was negatively correlated with task difficulty and mental workload [22–26]. Event-related potentials usually start with the changes of the amplitude and latency of ERP under different mental loads. The generation of ERP needs regular stimulation tasks. Therefore, the research of ERP in mental loads is generally based on the tasks that can induce stable ERP itself or on the tasks of main task plus auxiliary stimulation. Therefore, the application of ERP research will be limited and more regular. Research. Early research on ERP-based mental workload was inspired by the relationship between ERP components and brain states such as fatigue, arousal and alertness. ERP was first combined with auxiliary task method as a method to assess the mental workload of directors. It was found that the range of P300 induced by main task increased with the increase of chief task difficulty, while that induced by auxiliary task was the opposite. Later, other scholars’ research also proved that the range of directorship P300 increased with the difficulty of directorship [27–29]. Eye Indicators. Eye indicators can be divided into two categories, the Eye Signals collected from physiological records and Eye Signals collected by Eye Moving Instrument. Commonly used are pupil size, gaze, blink rate and blink duration. Researchers found that the size of pupils increased with the increase of mental workload. In the simulated flight task, the pupil diameter and the Eye-face opening have significant differences under different mental loads [30, 31]. For visual tasks in flight missions, eye movements are more diagnostic [32]. With the flight mission, the blinking frequency decreases, but in real flight, the blinking frequency increases significantly, the duration of blinking shortens, and the blinking amplitude increases [33]. Task-related eye indicators are widely used in human information processing such as perception, memory, reasoning and thinking. Eye indicators have been widely used in the field of brain load related research, and the corresponding research is relatively mature. Different signal processing methods can be used to process the basic eye indicators (pupil diameter, blink rate, etc.) in order to explore the relationship between eye indicators and occupancy of brain resources induced by flight tasks.

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ECG Indicators. Heart rate and heart rate variability are common indexes of ECG. They are closely related to autonomic nervous system, can reflect people’s psychological stress state, and are sensitive to changes in task needs and their own efforts. They are the most commonly used mental workload detection indicators. They are easy to be accepted by workers in the actual working environment, and are also the earliest used in the brain. One of the physiological parameters of force load study. As early as 1971, NASA’s research report reported that the characteristics of ECG were used to identify pilots’ workload. It was found that ECG was highly correlated with the performance of chief and minor tasks [18]. When spectrum analysis is used to analyze ECG signals, heart rate variability is divided into three frequency bands: low frequency (0.02–0.06 Hz), intermediate frequency (0.07–0.14 Hz) and high frequency (0.15– 0.5 Hz). Studies have shown that heart rate can be used as a simple and sensitive mental load parameter. Compared with other frequency bands, the middle frequency band of heart rate variability is more sensitive to mental load and can be used as a reliable one. Brain load index [35–40].

3 Comparison of Three Evaluation Methods Subjective evaluation method has many advantages, such as simple operation and easy implementation. It can be used not only in simulation environment, but also in real environment. In the design stage of the system, subjective evaluation plays a very important role because of the limitation of conditions. Subjective evaluation is very sensitive to assess the mental workload of the whole process, but the main drawback is the lack of objectivity [41]. There are obvious shortcomings in the evaluation method of chief affairs. Firstly, most mental tasks involve different mental resources, and their intrinsic mechanism is very complex, so it is difficult to express them directly with one or two indicators of director’s work. Secondly, the different nature of mental tasks makes it difficult to unify the measurement indicators of director’s work performance. There are some defects in sub-task assessment, such as “intrusiveness” and “sensitivity”. Its intrusive defect refers to the intervention of the mission to interfere with the main task, that is, flight operations, thereby reducing flight safety; the sensitivity of the indicators of the sensitive defect refers to the mission changes with many factors, thus affecting the reliability of workload assessment [13]. The advantage of physiological evaluation method is that it can record the changes of physiological signals continuously with high time resolution, and the subjective will of the subjects participating in the experiment can hardly affect the recording results of physiological signals. It can realize real-time and objective detection, so it can greatly expand the application scope of brain load. However, the reliability of physiological measurement is also questioned. It assumes that changes in mental load may cause changes in some physiological indicators, but many other factors unrelated to mental load may also cause these changes.

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4 Conclusion Subjective evaluation method and work performance evaluation method are difficult to achieve real-time, objective and efficient monitoring of mental workload, and it is impossible to realize online feedback based on mental workload. But extraordinary physiological signals can be detected in real time and objectively, so it can greatly expand the scope of application of mental load. Closed-loop feedback based on physiological signals to detect mental workload has become the focus of research. Therefore, compared with the limitations of the single evaluation method, the future evaluation method of mental workload will tend to adopt a variety of methods to measure the situation of mental work comprehensively, so that the various methods complement each other and avoid their shortcomings. However, the specific method to synthesize and which indicators to synthesize are still debatable and need further study. With the continuous development of the theory, there will be more perfect evaluation methods of mental workload. Acknowledgments. This research was supported by 2017NQI project (2017YFF0206603), General Administration of Quality Supervision, Inspection and Quarantine of the People’s Republic of China (AQSIQ) science and technology planning project (2016QK177) and Project of the President’s Fund for China National Institute of Standardization (522018Y-5984; 522016Y-4488).

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36. Tattersall, A.J., Hockey, G.R.J.: Level of operator control and changes in heart rate variability during simulated flight maintenance. Hum. Factors: J. Hum. Factors Ergon. Soc. 37(4), 682–698 (1995) 37. Backs, R.W., Lenneman, J.K., Sicard, J.L.: The use of autonomic components to improve Cardiovascular assessment of mental workload in flight. Int. J. Aviat. Psychol. 9(1), 33–47 (1999) 38. Cui, K., Sun, L.Y., Sun, L.H.: The validity of heart rate variability of measuring mental workload. Ind. Eng. Manag. 3, 56–58 (2008) 39. Yao, Z.H., Wang, M.: The application of heart rate variability in the evaluation of mental workload during manual controlled rendezvous and docking. Chin. J. Ergon. 3, 1–5 (2013) 40. Hicks, T.G., Wierwille, W.W.: Comparison of five mental workload assessment procedures in a moving base driving simulator. Hum. Factors: J. Hum. Factors Ergon. Soc. 21(2), 129–143 (1979)

Experts and Novices on the Recognition and Cognitive Differences of Brand Color Ching-Yi Wang(&), Peng-Jyun Liu, Yu-Hsuan Chung, and Yu-Ting Chen Department of Creative Product Design, Asia University, 500, Lioufeng Rd., Wufeng, Taichung 41354, Taiwan, ROC catincar,[email protected], [email protected], [email protected]

Abstract. Color is one of the major influences on consumers’ willingness to purchase products. The color conforms to the brand’s personality and image to highlight the brand’s characteristics and influence the consumer’s perception and purchase behavior. Therefore, the purpose of this study is to investigate whether the average consumer can identify different brands by color. In this study, two lipstick brands were investigated, including: French Dior and Japanese-style plant village show, 29 colors, using semantic difference method, to investigate 12 experts and 18 novices on the brand color differences and the degree of connection. The results show that the cognitive standard of brand color is different between them. The color discrimination and sensitivity of the subjects with design background were more common than those of the subjects, indicating that the educational background might affect brand recognition. This result may provide the designer’s reference to the marketing color plan. Keywords: Product identity

 Brand color  Marketing

1 Introduction 1.1

Background

Lipstick plays the most important role in the beauty field. In order to meet the needs of life and personal desires, human beings constantly create a lipstick color suitable for the times. Lipstick has also evolved under the influence of changing times and environments. The world’s first lipstick dates back to the ancient Sumerian civilization, in the city of Ur (now in Iraq), where people began to grind white lead and red rock into powder to smear their lips. In ancient Egypt, lipstick was used mostly from ochre and gum to increase stickiness; at the same time, men also used lipstick in those days, showing the charm of lipstick [1]. Chinese Tang Dynasty aristocratic women and Jiefang geisha like to use sandalwood (ochre red) to note lips. In the Victorian era, lipstick was considered the product of prostitutes, and the use of lipstick was taboo. And Elizabeth I used lipstick to smear against death. In addition, ancient Chinese called lipo-fat, which is made into a tube shape, and some are powdery. The use of powdered lipstick is to apply the pigment on both sides of the paper. After the lips are covered, the color will naturally be attached to the lips [2]. The meaning of lipstick from ancient © Springer Nature Switzerland AG 2020 R. S. Goonetilleke and W. Karwowski (Eds.): AHFE 2019, AISC 967, pp. 173–186, 2020. https://doi.org/10.1007/978-3-030-20142-5_18

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times to the present is no longer a simple cosmetic, but an indispensable daily necessities for every woman’s life. According to the UK website database [3] surveyed 12,240 consumers in the Asia-Pacific region about the use of beauty products. The results showed that the top three most popular cosmetics were lipstick, liquid foundation and eyebrow pencil. Because the modern social environment pays more attention to the personal image, most women will use cosmetics to modify their appearance to make themselves more beautiful, making the brand and function of the current cosmetics diversified. Since the price of lipstick is a low price in cosmetics, in the current economic stagnation, consumers’ purchases of lipstick have increased. This study selects Shu Uemura and Dior, which are popular and different styles, as a sample to investigate the interviewee’s orientation towards the brand’s lipstick color, as well as the perception and heterogeneity of brand colors by design experts and general consumers. 1.2

Research Purpose

In this study, two different types of lip gloss series are selected as the main research samples, and two index brands, Shu Uemura and Dior, which are popular in Japanese and French style in color makeup, are selected to compare with each other. Through the questionnaire survey to analyze and understand the general consumers and experts, whether there are differences in color discrimination. 1. Understand the differences in brand color perception between experts and novices. 2. to explore the degree of connection between experts and novices to brand color.

2 Literature Discussion 2.1

Brand Definition

(American Marketing Association, AMA), gives a representative definition of the brand, which is a Name, Term, Sign, Symbol, and the use of a combination or combination of designs. The main purpose of the brand is to distinguish and identify the services and products between the sellers in a competitive environment to avoid confusion. [4] believes that brand not only conveys product scope, attribute, quality and use, but also includes brand personality, relationship with users, user image, country of origin, enterprise organization association, symbol, emotional interest and self-expression interest. For consumers, brand is a synonym for product quality, which makes people think of the possible quality and reliability of products. In addition, the product identification function and product information provided by brand can also help buyers distinguish numerous commodities of the same value and improve the purchasing efficiency of consumers [5].

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Brand Color

Brand color to the visual point of view, first has the color attraction, only then has the shape existence. In addition to shaping factors, the level of enterprise color also occupies a very important position. In order to obtain a better corporate image, the enterprise uses these characteristics of color to demand the distinction of the enterprise in a planned and strategic way, and is also one of the important design elements that can be used in the marketing strategy. The standardization of such colors is called enterprise standard color. Standard setting is based on building corporate image, informing production content, and strengthening competitive strategy [6]. [7] refers to the function of enterprise color, when prompted to specific colors, there is a phenomenon of enterprise association. If the “red” is Coca-Cola, if the “yellow” is Kodak phenomenon. People show all kinds of perceptual reactions to color. There is a more sensual appeal than letters or graphics. In addition, [8] mentioned that the performance of color image is related to industry attribute. Such as steam industry, electrical industry technology industry belongs to rational impression. But sometimes salespeople don’t follow such rules in order to win, but the most important thing is to choose a suitable one. The color of one’s own brand personality. Because the color image has the value of market observation, the brand impression is vague when the color opinion is different, otherwise, the brand impression is clear. Japanese Little Red Lip. Before the Edo era, the basic colors used by the Japanese in makeup were red, white and black. Among them, the historical development of “red” in lip color began in the middle and late stages of the Edo era. Due to the increasing demand for makeup, dyes, and the use of “red” in medicinal materials, the “red” pigment was extracted from the safflower flower with a very small amount of red pigment (Fig. 1). Lin, 2018 used to make aristocratic makeup. As a result, affordable chemical dyes are imported into Japan, compressing the make-up red market. In the end, only the “Ishi-half Group” held on to the traditional “red” method and sought to break through and innovate (Fig. 2). In 1908, the stick lipstick imported from Europe and the United States entered the Japanese market. In 1918, “imju” learned to imitate it. The first stick lipstick made in Japan was successfully made and named “Opera” (Fig. 3). In recent years, returning to the original brand, the launch of the Opera new series (Fig. 4) lipstick combination, hit sales of more than 1.7 million units [9]. In addition, the makeup brand Shu Uemura, which tested more than 3000 Asian women for color and countless color blending tests, launched the “RD163”. Shu uemura, which is suitable for Asian women, and said that the popular color in the 1970s was yellowish red. In the 1980s, it was dominated by bluish red. Now, “I want to create a RD163. that surmounts the trend, beautifies every face, a pure, meaningful red, and creates an Asian-only red RD163” [10]. French Dior Red Lips. Dior (Dior)’s product style is colorful, experience art and efficient skin care technology, and occupies an important position in the global perfume and cosmetics market (Fig. 5). Founder Christine Dior (Christian Dior) was influenced by roses grown in his hometown, and pink and red have been two of the most important colors in his creation since 1947. Figure 6 was introduced in 1949. In 1953, Dior launched the Rouge Dior classic Fig. 7, which is the same color as it is today.

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Figure 8, its elegant golden shell is Christian Dior’s last work. In 1987, creative director Serge Lutens introduced Fig. 9, a radical revamp of Dior. Figure 10 is the classic main color of Dior [11].

Fig. 1. Ramming out the viscosity of safflower with acetabulum, and making red safflower in ancient times

Fig. 2. Ishi half group small town red advertisement

Fig. 3. 1918 Opera Advertising

2.3

Product Identification

Product (Product Identity, PI) is a combination of words, images, ideas, and consumer perceptions of the brand [12]. Among them, the color is a brand recognition, such as IBM Thinkpad with black, Apple computer translucent color, Acer notebook computer

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Fig. 4. 2018 Opera Advertising

Fig. 5. Shu Uemura offers a RD163 line of lipstick for Asian women: # moisturized, # luxurious velvet, and # lacquer sparkling

Fig. 6. Crystal and metal candlestick “Dior Red” lipstick and advertising in 1949

Fig. 7. 1953 Rouge Dior Classic Red 9

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Fig. 8. Today’s signboard No. 999

Fig. 9. Big change Dior packaging of Blue Gold hexagonal shape

Fig. 10. Dior classic color: # 999 legendary red lip, # 028 Monaco kiss, and # 532 holiday orange

wallet design, are in other product areas. Because the product itself affects other tangible, color, and texture factors, giving consumers a sensory impression combined into this product [13]. [14] also mentioned that products are judged on the basis of color, square or smooth appearance, simplicity or complexity of the whole. Designers must master the characteristics of human visual perception in order to design products that attract users [15]. 2.4

Differences Between Experts and Novices

Experts and novices have been doing research for decades, and researchers have explored the characteristics of experts in many ways, such as how novices become experts, how experts solve problems, what experts are good at, or the difference between experts and novices [16]. The main difference between experts and students is

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not IQ level or cognitive development. Experts with domain-specific expertise, understanding, memory, learning or problem-solving processes and outcomes may be better than novice users of these skills [16, 17]. These knowledge structures may affect human behavior. Information processing developed by [18]. When external stimuli are transmitted to the brain via sensory reception, the brain encodes and classifies them, some of which are first stored in memory and knowledge structures. Other messages then enter memory and knowledge structures through further reasoning, decision making and judgment processes, and choose whether to react externally. When new forms and structures emerge, experts and novices should differ in classifying and judging information. In the field of design, experts can immediately identify art according to form, structure, material and composition The style of the product. However, the novice is unfamiliar with the design style and may not be able to detect small functional differences. Experts have a better hierarchical knowledge structure to encode, store, and capture new information in the field of expertise; they can quickly identify similar patterns and generate appropriate responses in the new environment [19, 20]. When dealing with problems, experts perform intuitive behaviors to recompile known knowledge into minimized and most efficient uses to deal with new or complex problems in automated programs, This results in better performance than the novice [16, 21]. As a result, experts are faster than novices in performing skills in their field and can quickly solve the error-prone problem [22].

3 Research Technique 3.1

Subjects

This study invited 12 (1 male; 11 female; average age 23.67; standard deviation 2.02) with design background and 18 (3 males; 15 females; average age 28.78; standard deviation 6.68) as experts, and non-Students in colleges and universities with design backgrounds are novices. All subjects had no visual or neurological disorders. 3.2

Sample

In this study, the color of Japanese Shu Uemura’s colorless powder mist moisturizing series and Dior’s blue star lipstick were selected. 29 color symbols were selected as the main color samples, such as Fig. 11 display. 3.3

Questionnaire Design

The questionnaire was designed to be divided into basic information and two brands of lipstick color image survey (e.g. Fig. 12). Basic data include sex, age, educational background and educational attainment to determine whether the subject was a professional (expert) or consumer in general (novice).) In terms of image survey, semantic difference method (Semantic Differential, SD) was used to investigate the subjects’ preference for lipstick color in Japanese or French style, and the seven-point scale was used as the rating scale, which were as follows: 1. A very typical Japanese color;

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Fig. 11. Lip balm color block of Japanese Shu Uemura and legal system Dior

2. Typical Japanese color; 3. Incline to Japanese color; 4. Not sure; 5. Incline to French color; 6. A typical French color; 7. A very typical French color. Its color capture method, with the drawing software photoshop function, from the official website of lipstick products to extract the screen color and make 3  3 cm color block, finally in the lower right corner of the number.

Fig. 12. Online questionnaire content

3.4

Data Analysis

The data were divided into three data types to explore the evaluation scores of Japanese Shu Uemura and French Dior, including descriptive verification, color cognitive differences, and brand color connectivity. In terms of descriptive verification, the average value of color, the difference in standard and the selection of the top five Japanese and French colors are calculated respectively. In terms of color cognitive differences, the differences between Japanese and French colors were examined by independent samples. In terms of the degree of brand color connection, the evaluation scores of single sample T test experts and novices on Japanese and French colors were taken as variables. Set the value to 4.

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4 Research Results 4.1

Descriptive Test

Table 1 shows experts and novices’ ratings on Shu Uemura and Dior brand colors. From a numerical point of view, design experts in the Japanese Shu Uemura brand recognition, slightly higher than the average person (scores were 3.99 and 4.22 respectively). But the Dior brand color judgment, the design expert thinks may be inclined to the Japanese style feeling, the average person expresses the feeling which is not definite (the score is 3.94 and 4.00 respectively). Table 1. The result of experts’ and novices’ scores on the color of the two brands. Brand Educational background N Average value Standard difference Shu Uemura Experts 29 3.99 0.34 Novices 29 4.22 0.36 Dior Experts 29 3.94 0.59 Novices 29 4.00 0.36

Tables 2 and 3 shows the top five colors of Japanese and French brands evaluated by experts and novices, and the difference of color evaluation. In terms of Shu Uemura brands, experts believe Japanese brands tend to be light red and orange, while new hands are represented by dark brown and orange. In addition, in the Dior brand, they believe that the French color system should have a different variety of colors, such as experts tend to be dark red and dark orange, while the new hands think light orange and pink line. Interestingly, both choose dark blue (E.g. 602) as the representative color. 4.2

Differences in Color Cognition Between Experts and Novices

Table 4 shows the independent sample T test results of Shu Uemura and Dior brand color by experts and new hands, and finds that the color cognition of French Dior tends to be significant [t (28) = −2.00, p0. 06]. It indicates that there may be color differences between the two brands. 4.3

The Degree of Brand Color Connection Between Experts and Novices

Table 5 is a single sample T-test result of Shu Uemura and Dior brand colors by experts and beginners. The results show that the average person has significant difference to the Japanese Shu Uemura brand [t (28) = 3.02, p < 0.01], which indicates that the average person’s connection to the Japanese brand color is weaker than that of the design expert. However, there is no significant difference in the color connection between the Japanese and French brands (p0. 92 and p0. 58, respectively), indicating that the color match of the two lipstick is accurate and unbiased.

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Table 2. Experts and novices on the Shu Uemura brand color of the top five evaluation scores and color patterns (the lower the value is closer to the Japanese color). Experts Color pattern

Color number 21-334

Average value 2.92

Standard difference 1.17

22-342

2.92

36-530

Novices Color pattern

Color number 2-071

Average value 3.22

Standard difference 1.52

1.08

22-342

3.28

1.49

2.92

1.51

33-376

3.39

1.24

24-344

3.00

1.35

13-165

3.56

1.38

20-332

3.33

1.30

28-355

3.61

1.34

Table 3. Experts and novices on the top five Dior brand color evaluation scores and color patterns (the higher the value is closer to French color). Experts Color pattern

Color number 42-634

Average value 4.67

Standard difference 1.30

34-458

4.50

10-099

Novices Color pattern

Color number 14-169

Average value 5.06

Standard difference 1.39

1.68

26-351

4.83

1.30

4.33

1.44

44-652

4.78

1.11

14-169

4.33

1.37

35-459

4.56

1.38

41-602

4.33

1.56

41-602

4.50

1.34

Table 4. Independent sample T test results of two brand colors by experts and novices. Brand t Free degree Significance (double tail) Shu Uemura −0.58 28 0.57 Dior −2.00 28 0.06

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Table 5. Test results of single sample T for two brand colors by experts and novices. Brand

Educational background

Verification = 4 t Free degree −0.12 3.20 −0.56 −0.02

Shu Uemura

Experts Novices Dior Experts Novices *p < .05; **p < .01

28 28 28 28

Significance (double tail) 0.92 0.003 ** 0.58 0.98

The second single sample T test, based on the color analysis of all Japanese Shu Uemura brands, found that three lipstick colors (such as Table 6 No. 071342376) were significantly different or close to significant [t (17) = –2.18, “ P < 0.05; T (17) = -2.06, p0. 06; t (17) = –2. 09, p0. 05]. The average scores of these three lip colors are 3.22/3.28 and 3.39, respectively, which may be biased towards Japanese color, but the result is a display of There are differences, indicating that the new hand inside the evaluation of the phenomenon. Table 6. The color of the Japanese brand (the lower the value is, the closer it is to the Japanese color). Color pattern

Color number

Average value

Standard difference 1.52

Verification = 4 t Free degree −2.18 17

Significance (double tail) 0.04*

2-071

3.22

22-342

3.28

1.49

−2.06

17

0.06

33-376

3.39

1.24

−2.09

17

0.05*

*p < .05; **p < .01

5 Discussion This study investigated the differences and links between Japanese Shu Uemura and French Dior brands. The results show that there is a difference in color cognition between the two groups, and the experts are more connected to the brand than the new hands. The detailed results are explained below:

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Color Cognitive Difference

The expert and the new hand both have the color cognition difference to the French brand. The reason for this study may be that the culture of East and West is different and the understanding and knowledge of European brands is limited unless the users of Dior products are used. Cultural differences may lead to cognitive deviations between the two, which may lead to differences in choice. Interestingly, experts and Sanghou Street agree that dark blue (such as Table 3 No. 602) is a good color for the French brand. In fact, this color is not Dior’s classic color (see Fig. 10). This highlights the subjects’ understanding of European brands. Limited. Relatively speaking, Japanese style is an Asian brand. The subjects know and understand Japanese cultural content, color or dress of makeup to a certain extent, so the difference between them lies in the depth of color. 5.2

Brand Color Link Factor

Different educational backgrounds (such as experts and beginners) are one of the factors influencing brand color link: [16, 17]. Especially in the field of design, it is easy for experts to distinguish the color from the beginner. This study concluded that there are two reasons why experts can better understand the color differences of different brands compared with new hands. First, experts have hierarchical concepts and coding patterns for storing new information in their design knowledge [19, 20], can infer the brand’s main color system from the brand appeal, country, culture cocoon related information, and quickly identify the similar pattern to produce the appropriate response. Conversely, the beginner is not familiar with the design pattern, and there is no brand corresponding to the detection of its color. Second, due to the experience of color matching and color planning in product design, experts can reasonably master the standard colors suitable for the brand identification [6–8]. Third, because the design expert for color Visual sensitivity and awareness are better than those of untrained designers. In addition, there are significant differences in the color links of the Japanese brands (such as Table 5), indicating that the brand links of the beginners are lower than those of the experts and the ratings are different. Experts have a common view of brand color and high consistency.

6 Conclusions and Recommendations Different educational backgrounds may indeed affect the brand’s color image. Although the two groups are slightly inadequate, the results may be affected. According to the current research results, we can see the color trend of different educational backgrounds. The cognitive level and cultural difference of the subjects are also one of the factors that influence the color choice in the future research. In addition, the questionnaire design still needs to be improved. The suggestions are as follows: (1) to increase the brand experience, the subjects can be divided into groups with or without use experience. (2) increase the number of subjects, design background and non-design background. The results of the two groups should have a high difference and significant effect.

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(3) increasing the brands generally recognized by the subjects, such as Shiseido, should increase the awareness of the brands. Can distinguish the color difference between the brand obviously.

References 1. Liu, X.: Three thousand years of grace on the lips: lipstick from the glaring scarlet letter to the symbol of women’s liberation. People’s net (2011). http://history.people.com.cn/BIG5/ 205396/14950790.html. Accessed 20 Aug 2017 2. Wikipedia. The history of lipstick (2009). https://kknews.cc/zh-tw/fashion/gzl8v9.html. Accessed 5 Oct 2018 3. YouGov Cube. For cosmetics, the Asia-Pacific region can be said to be consistent; for essential lipstick, quality is often more important than price (2016). https://hk.yougov.com/ zh-hk/news/2016/12/02/make-up-culture-hk/. Accessed 29 Aug 2018 4. Aaker, D.A.: Measuring brand equity across products and markets. Calif. Manag. Rev. 38 (3), 102–120 (1996) 5. Wen, C.C., Lee, P.C.: The study of affecting factors in cosmetic brand equity. Unpublished master’s thesis, Yuan Ze University, Taoyuan, Taiwan (2002) 6. Cheng, K.Y., Lin, P.S.: Color Plan. Yi-Fong Press, Taipei (1987) 7. Chung, H.Y.N.: Corporate Image Classic. Two-way Communication Co., Ltd., Taipei (1994) 8. Chieh, M.L., Chen, H.H.: A study of the relationship between brand identity and brand image. Unpublished master’s thesis, National Yunlin University of Science and Technology, Yunlin, Taiwan (1998) 9. Yamamura, B.: Japan’s History of Makeup: A Sense of Beauty. Yoshikawa Ishikawa, Japan (2016) 10. Liu, Y.H.: What kind of red can Asian women control? Yoshimura show this color lip gloss red just good! (2019). http://istyle.ltn.com.tw/article/9451. Accessed 15 Jan 2019 11. Pacific Fashion Network: counting Dior’s 62 years of lipstick history (2016). https://read01. com/zh-tw/kgy7d2.html#.XE_b_S33V0s. Accessed 16 Oct 2018 12. Upshaw, L.B.: Building Brand Identity (W.C. Wu Trans.). Taipei: TTV Cultural (2000) 13. Chen C.H., Chen, W.Y.: A study on the consumer’s recognition of product identity: a case of automobile styling. Unpublished master’s thesis, National Taipei University of Technology, Taipei, Taiwan (2003) 14. Lin, I.R., Chuang, M.C.: Exploring the form factor in the constitution of product identity using consumer electric products as examples. Unpublished master’s thesis, National Chiao Tung University, Hsinchu, Taiwan (1996) 15. Lin, S.Y., Chen, C.C.: A study on the relationships between corporate identity image and product form using mobile phone design as an example. Unpublished master’s thesis, Huafan University, New Taipei City, Taiwan (2003) 16. Robertson, S.I.: Problem Solving. Psychology Press, Luton (2001) 17. Atkinson, R.L., Atkinson, R.C., Smith, E.E., Bem, D.J., Nolen-Hoeksema, S.: Hilgord’s Introduction to Psychology. Thomson Learning, Inc., Belmont, CA (1996) 18. Bless, H., Fiedler, K., Strack, F.: Socialcognition: How Individuals Construct Reality. Psychology Press, New York (2004) 19. Searleman, A., Herrmann, D.J.: Memory from a Broader Perspective. McGraw-Hill, New York (1994)

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20. Patel, V.L., Ramoni, M.F.: Cognitive models of directional inference in expert medical reasoning. In: Feltovich, P.J., Ford, K.M., Hoffman, R.R. (eds.), Expertise in Context, pp. 67–99. London: MIT Press (1997) 21. Frensch, P., Sternberg, R.J.: Expertise and intelligent thinking: when is it worse to know better? In: Sternberg, R.J. (ed.), Advances in the Psychology of Human Intelligence, vol. 5, pp. 157–188. Hillsdale, NJ: Lawrence Erlbaum Associates Inc (1989) 22. Chi, M.T.H., Glaser, R., Farr, M.J.: The nature of expertise. Lawrence Erlbaum Associates Inc, Hillsdale, NJ (1988)

Ergonomic Requirements in the Design of High Performance Sports Suits: BMX Clothing Fausto Zuleta Montoya(&), Gustavo Sevilla Cadavid, Blanca Echavarria-Bustamante, and Johana Hoyos-Ruiz Universidad Pontificia Bolivariana, Campus Laureles, Circular 1ra 70-01, Bloque 10 of 306, Medellín, Colombia [email protected]

Abstract. The project sought the identification and analysis of the knowledge that currently exists on sports suits of the BMX. A bibliographic analysis of scientific and technical journals of the sector was carried out; panels and interviews were carried out with athletes, coaches and experts. Nonparticipatory observations were carried out in real context to determine aspects of the practice, such as the studies of the assumed positions, career points of more tension, pledge-user-practice behavior, etc. In addition, companies and products of the market were tracked to know technical, functional, perceptual, and other peculiarities about the sports suit. Subsequently, an analysis of the regulatory in the BMX-clothing was made. In this phase, techniques and tools for the analysis of usability, aerodynamics, postures and other information were developed to understand the pledge-user relationship. The intention of this proposal is to expose the requirements for the design of clothing for the practice of BMX. Keywords: Ergonomics

 Clothing design  Design requirements  BMX

1 Introduction The present text presents the first findings of the research project “Ergonomic design of a suit for BMX” carried out by the Universidad Pontificia Bolivariana and the company HAS bicycles S.A of the city of Medellín. The findings refer to the general design requirements that a suit for the practice of this sport discipline must contemplate. A literature review was made based on the keywords, aerodynamics, ergonomics, and technical function and sports suits. For the bibliographic research process, there were 39 articles among informative material such as books, scientific or scientific research magazines, academic databases Web sites. Afterwards, non-participatory observations were made in real context to determine aspects of the practice, such as studies of assumed positions, points of the tensest career, pledge-user-practice behavior. Finally, an analysis of the regulatory suit for BMX practice was made. In this phase, techniques and tools for the analysis of usability, aerodynamics, postures and other information were developed to understand the pledge-user relationship, and it was determined in a timely manner, which are the

© Springer Nature Switzerland AG 2020 R. S. Goonetilleke and W. Karwowski (Eds.): AHFE 2019, AISC 967, pp. 187–196, 2020. https://doi.org/10.1007/978-3-030-20142-5_19

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design aspects that should be contemplated to improve the suit for the benefit of comfort, usability and performance. From the collected data, the information collected was reinterpreted in terms of requirements to compile them in a PDS format (product design specification) classified into seven variables: (1) Aerodynamics, (2) Biomechanics, (3) Safety, (4) Temperature, (5) Touch comfort, (6) Aesthetics and (7) Muscle performance. These design requirements, defined in the information stage of the design process, detail the requirements that must be met so that the product in this case the sports suit allows the user to optimize the activity from the point of view of performance. The document lays the foundation for all engineering design activities and ensures that all relevant factors are taken into account and listened to by all interested parties. Traditionally, the sportswear industry has developed competitive products from a functional and ergonomic point of view in various sports disciplines such as road cycling, sky and others, through the integration of biomechanical, anatomical, aerodynamic, usability criteria, in addition to the application of new technologies in materials and processes. Currently, these types of developments can substantially improve athletic performance. Proof of this has been the progress made in different investigations from different parts of the world on functional clothing, applied to the improvement of activity [1]. Based on the above considerations, the company HA Bicicletas SA, official sponsor of Olympic champion Mariana Pajón, BMX cyclist and double Olympic gold medalist, along with the Research Line in Ergonomics and the Line of Functional-Technological Research of the Universidad Pontificia Bolivariana de Medellin Colombia, determined as a research objective the development of a suit, which integrates the necessary ergonomic criteria, to improve the performance of the athlete in BMX practice. To achieve this, the project will be framed in the User Centered Design (DCU), in this case, the members of the professional team, Elite category, of B Bicycles, which are the main users of this type of products, in addition to the trainers as collateral users, who, although they do not use the uniform directly, have a broad knowledge of their function within the activity. It is clear that the investigation is ongoing and will soon show some developments at the level of prototyping.

2 Background While in cycling disciplines such as route and track have been numerous research and development to determine design criteria, clothing, aerodynamics, including ergonomic and comfort related to sports clothing [2–6], in the case of BMX, there is less knowledge about the needs of BMX and only the normative references established by the International Cycling Union (UCI) [7], are the greatest reference. The needs of this sport differ significantly from those of other cycling styles, since the postures, race time, efforts, types of movement, type of bicycle, anatomy, body size, are particular and can not be unified with the other genres. Despite all these differences, the industry does not have now, with scientific knowledge and/or studies on the subject, from an adequate and rigorous perspective to understand how to make sports suits

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for BMX practice properly respond to their needs. The idea of research and establish the requirements associated with the practice, are initially the keys to the developments and subsequent validation.

3 Methodology In the first stage of the project, information stage, whose objective is the identification and analysis of the knowledge that currently exists on sports suits of different cycling modalities, including the BMX. For this, 39 documents were reviewed among books, physical or virtual journals, and they were assessed according to the relevance they might have within the project. Subsequently, a bibliographic analysis of scientific and technical journals of the sector was carried out, panels and interviews were held with athletes, coaches and experts in areas such as aerodynamics and sportswear design. Within this same phase, non-participatory observations were made in real context to determine aspects of the practice, such as studies of assumed positions, points of the most tense career, pledge-user-practice behavior, etc. In addition, a tracking was carried out to companies and products of the market to know technical, functional, perceptual, and other peculiarities about the sports suit. The idea of this theoretical search phase is to establish information to find product tensions (functional, material, etc.), formal patterns, functional patterns, ergonomic criteria, production techniques and materials. Subsequently, an analysis of the regulatory suit for BMX practice was made. In this phase, techniques and tools for the analysis of usability, aerodynamics, postures and other information were developed to understand the pledge-user relationship, and it was determined in a timely manner which are the design aspects that should be contemplated to improve the suit for the benefit of comfort, usability and performance. The intention of this proposal is to expose the requirements for the design of clothing for BMX practice (See Fig. 1).

Fig. 1. Methodological process

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Fig. 2. Design process

Subsequently, the information collected in terms of general design requirements is incorporated into the Formalization and Conformation phases of the design process (See Fig. 2). Phase 1. Information Stage: Here the identification and analysis of the current knowledge on sports suits of different cycling modalities including the BMX, was the point to study and understand. A theoretical bibliographic analysis (previously discussed) was carried out. The idea of the above, connects with the determination of methods and techniques of performance validation (aerodynamic, ergonomic, usability, etc.) - From the information collected and analyzed, the design criteria for the sports suit were defined, translated for the design team in a requirements table. Phase 2. Formalization Stage: After Phase 1. These requirements will be translated into formal proposals that account for each of the specified specifications. The most viable proposal from the ergonomic, aerodynamic and production point of view will be selected based on compliance criteria to develop a detailed and possible design. Prototypes of different nature will be carried out to perform tests of use, techniques, and real user feedback to define details from their expert vision. Phase 3. Stage of Conformation: From the information on the results of the tests of the previous prototypes, plus the information in the feedback sessions and use with real users, changes will be made in the configuration of the suit to determine the design in detail and to re-test to finally validate it in biomechanical laboratory and competences.

4 Results Within the investigation, different variables have been found for the determination of requirements from, for and with the design of a suit for BMX. Initially a characteristic that stood out, were the established norms and associated to garments (UCI, 2018), whose guidelines establish the object of the initial analysis. Relevant issues emerged about the type of clothing and safety equipment, categorizing them into recommendations that compromised the protection and safety of the athlete. The documents establish recommendations on the back, elbow, knee and shoulder

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made of rigid materials, as well as protection in the cervical vertebrae. It should be noted that these are not obligatory and may not be taken into account. On the other hand, on the upper garment of the athlete, the UCI indicates that: “The jersey shall be a loose fitted long-sleeved shirt whose sleeves extend down to the rider’s wrists.” PART 6 BMX. Version on 4.04.14 (2018). The above, visualizes that garments related to other disciplines are accepted and the range of information search is widened. Additionally, within the fieldwork and interviews conducted with the elite athletes of the company in question, it is rectified that the use of Moto-cross garments is common, above those of BMX. The above, justified in the low variety of brands, garments and/or access to them. Now, the exclusion does indicate more routes in terms of more requirements to be taken into account. For example, it is described that: “The following is not permitted for BMX jerseys: Lycra, Zippers above the waist, Back pockets, Jerseys for Road/track cycling. The jersey must be tucked into the pants before the start to not cause interference.” PART 6 BMX. Version on 4.04.14 (2018). With the described, not only appear established requirements in the conditions of use, but also in the productive of the possible suit. Functions to be reviewed are inferred, in terms of existing suits and the ways in which they already meet the regulations. When we go to review the possible requirements established by the standard, the UCI indicates that: The trousers and providing protection or reducing the risk of injury is the objective. This can be achieved with long pants or shorts combined with adequate protection for the knee and shin. These long or short pants must be of a type that is specifically designed and sold for protection in BMX, Motocross or Downhill Mountain Bike events. The descriptions leave open the guidelines for the design of the garment and for the practice. Here the descriptions made for shorts or long, are expanded a little, however, are not restrictive and therefore the requirements should be raised according to more considerations. Other clothing items should be taken into account as a whole, within the articulation they may have with the garments to be developed, for example, the gloves in front of the union or connection with the sweater to be solved. But, for purposes of this investigation and its possible developments, were limited to the following garments; upper and lower garments, including for the upper garment, the jersey/shirt/jersey adding its possible inner garment for the case of women. As for the lower clothing, you will find pants and underwear for each category and gender. Subsequent to the analyzes presented above, it is found that within the methodology and its phases for the collection of information, contrasting them with the references in other categories of cycling and adding all this to the interviews to the athletes, the following are compiled General requirements for the development of possible clothings: 1. Aerodynamics; The suit must allow to generate the least aerodynamic resistance in the body of the athlete doing the practice. Aerodynamic resistance, is called the opposition of the air to the advance. This is the greatest resistance that an athlete must win in competition. As for the areas of the body that generate greater aerodynamic drag, much is related to the front area of the cyclist’s body (See Table 1).

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2. Biomechanics (comfort); The suit should allow the body movements typical of sports practice within natural biomechanical angles. The ranges of mobility that must be respected by body segment are related to neck, spine, hip, shoulders, elbow-forearm, wrist, fingers, knee, ankle, feet (See Table 1). 3. Security; The suit must protect the areas of the body likely to present an impact risk - abrasion - friction due to bumps and falls in sports practice. The most common BMX injuries will happen in the head, neck and back, followed by wrists, shins, knees and elbows. The best way to prevent a BMX injury is with the BMX protection equipment. BMX protection equipment comes in a variety of styles and levels of protection, depending on where you need to protect and how much protection you may need. 4. Temperature (comfort); The suit must maintain an optimal temperature in the body areas of the user of more heat concentration in sports practice. It must also allow to maintain an optimal body temperature (37 ± 0.5 °C) in high performance athletes there is an increase of ±1 or 2 °C. In addition to the above, it must allow optimal transpiration in the body areas of greater thermal concentration, as well as the optimal evaporation of sweating in body areas with a higher concentration of sweating (See Table 1). a. Humidity; The suit must maintain optimal moisture control (concentration of sweating) in the body areas of more sweating in sports practice (See Table 1). 5. Tactile perception (comfort); Two aspects of the comfort of the clothes are: 1. Thermal comfort (previously taken into account), and which establishes the achievement of a more than acceptable thermal and humidity state; That implies the transport of heat and moisture through the tissue. 2. Sensory comfort: the provocation of various sensations when a textile is felt, all in contact with the skin (See Table 1). 6. Esthetic; The suit must present in its conformation and finished a professional design/appearance. Several of the interviewees could not define what they were referring to, so the investigation is still in process to define this aspect (See Table 1). 7. Muscle performance; The suit should allow a better performance in the muscles that show more effort in the activity (pedaling phases), should not limit them (See Table 1). With these findings, began to analyze body maps, materials, processing techniques and/or clothing production, as well as began to make contacts with different laboratories of biomechanics, textiles and characterization of users or materials that may give more specific specifications for the development of the garments to be developed.

General requirement

The suit should allow to generate the least aerodynamic resistance in the body of the athlete by performing the practice Low resistance to fluids (air)

# Variable

1 Aerodynamics

(continued)

The material of the suit must Select materials with low air permeability (less porous materials) generate the least aerodynamic Reduce the roughness of the surface resistance Check the orientation of the fiber (it must be in the same direction as the air flow) Must contain elastomeric materials (stretch fabric) The textile material must be covered with polyurethane in the body areas that generate more aerodynamic resistance (finishes) Reduce roughness in the buso - trouser interface (reduce turbulence) The shape of the suit must generate the least aerodynamic Reduce the roughness in the buso interface - gloves (reduce resistance turbulence) Reduce the roughness in the interface pants - slippers (reduce turbulence) Integrate aerodynamic morphologies in the body areas that generate more aerodynamic resistance (reduce turbulence) Integrate micro-perforations in areas where air flow must be improved The suit must be as tight as possible (Fit) to the body (determine degree of adjustment to the norm) Minimize the deformations of the material in the movement of the body segments (flexion and extension of knees, feet, trunk) The construction of the suit Select the type of seam that generates less prominence (gauge) in the must generate the least suit aerodynamic resistance Move the seams to the back of the frontal plane of the body Reduce the size of the seam Reduce the number of seams (less than the reference suit) The weight of the suit as a whole must be less than the reference suit

Table 1. General design requirements

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2 Biomechanics

General requirement

The suit should allow the body movements typical of sports practice within natural biomechanical angles

(continued)

Neck movements (rotation, hyperextension and flexion, lateral tilt) Movements of the spinal column (lateral tilt, rotation, flexion and hyperextension) Hip movements (permanent flexion, flexion, abduction and adduction, rotation in flexion and extension rotation) Movement of the shoulders (abduction, adduction, elevation, rotation in the neutral position, hyperextension and flexion, rotation in abduction) Elbow - forearm movement (flexion, extension, pronation and supination) Movement of the wrist (flexion and extension, deviation) Knee movement (hyperextension and flexion) Ankle movements (dorsal and palmar flexion) 3 Security The suit must protect the It must protect the lateral sides of the arms (biceps - brachioradial) areas of the body likely to It must protect the lateral sides of the legs (hamstring tract - vastus lateralis) present an impact risk It must protect the lateral sides of the thorax (dorsal - intercostal) abrasion - friction due to bumps and falls in sports practice The textile material must be breathable (convection, conduction or 4 Temperature/Thermoregulation The suit must maintain an The suit should allow to maintain an optimal body evaporation) optimum temperature in the body areas of the user temperature (37 ± 0.5 °C) in The shape of the suit should allow perspiration (microperforated) high performance athletes is with the highest The material or the form of perspiration should be located in the body, concentration of heat in the given an increase of ± 1 or 2 ° areas with the highest thermal concentration (see map of heat C practice of de-portiva concentration) Optimal regulation of heat The suit must maintain a control of humidity (concentration of and humidity sweating) optimo in the corporal zones of more duration in sports Rapid moisture absorption practice (Steam permeability) and transport capacity

# Variable

Table 1. (continued)

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7 Muscular performance

6 Esthetic

5 Tactile perception

Excessive pressures should be avoided It must allow freedom of movement (biomechanical ranges) variable 2 Reduce the perception of load (weight reduction) variable 1 The material must decrease the rough feeling in the movement (friction moment in the pedaling) The textile material should not generate itching/itching. The material must be flexible, understandable and extensible The suit must present in its Define professional appearance conformation and finished a professional design/appearance The suit should allow a The suit may have textiles and Flexors of the hip (Psoas iliacus) better performance in the shapes that allow progressive Knee extenders (Quadriceps) muscles that have the most containment by exerting Plantar flexors (hamstrings, calf and soleus, gluteal and anterior tibial) stress on the activity specific pressures at the level (pedaling phases) of specific muscles to accelerate vascular return

General requirement

The suit must diminish negative tactile perception in practice Pleasant for the skin, soft, not abrasive and without chafing

# Variable

Table 1. (continued)

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Acknowledgments.. This research is sponsored by the U.P.B. and H.A. Bicicletas. Thanks to them for the economic and intellectual support.

References 1. Gupta, D.: Functional clothing-definition and classification. Indian J. Fibre Text. Res. 36, 321–326 (2011) 2. Uttam, D.: Active sportswear fabrics. Int. J. IT Eng. Appl. Sci. Res. (IJIEASR) 2(1), 34–40 (2013) 3. Van Parys, M.: Development and research of smart functional clothing textiles (2013). https:// expertise.hogent.be/files/14910378/Smart_Functional_Clothing_Textiles.pdf 4. Chunyan, Q., Yue, H.: The review of smart clothing design research based on the concept of 3F+1I. Int. J. Bus. Soc. Sci. 6(1), 199–208 (2015) 5. Chowdhury, H., Alam, F., Mainwaring, D., Beneyto-Ferre, J., Forster, D., Tate, M., Subic, A.: Experimental evaluation of ski suit performance. In: Proceedings of the 17th Australian Fluid Mechanics Conference (AFMC2010), Paper 173, Auckland, New Zealand (2010). ISBN: 978-0-86869-129-9 6. Chowdhury, H.: Aerodynamic design of sports garments. In: Lerner, J.C. (ed.) Applied Aerodynamics, pp. 21–41, InTech (2012). https://doi.org/10.5772/2099, http://www. intechopen.com/books/appliedaerodynamics/aerodynamic-design-of-sports-garments. ISBN: 978-953-51-0611-1 7. UCI. PART VI BMX, Versión 01.02.2018 (2018). http://www.uci.org/docs/default-source/ rules-and-regulations/part-vi–bmx.pdf?sfvrsn=c7be9239_6

A Study on the Correlation of Foot Data with Body Height and Weight of Chinese Adults Linghua Ran(&), Hong Luo, Chaoyi Zhao, Xin Zhang, Huimin Hu, and Zhongting Wang China National Institute of Standardization, Beijing, China {ranlh,luohong,zhaochy,zhangx,huhm, wangzht}@cnis.gov.cn

Abstract. Body height and weight are the most prominent parameters of body shape characteristics. Many body parameters are related to stature and weight. Based on the data of the second national anthropometric survey conducted from 2014 to 2018, this study analyzed five data of foot length, foot width, foot circumference, toe height and tarsal point height for male and female, and established the multivariate linear regression equation between foot items and stature and weight. The regression equation can be used as the basis of ergonomic product design. Keywords: Correlation

 Foot data  Chinese adults

1 Introduction The application of anthropometry and statistics in labor protective articles has broad prospects. The human body is a unified whole, and the growth and development of each part are in harmony. There is also a regular relationship between foot data and some human body measurement items, and the correlation is one of them. It is impossible for any anthropometric work to measure and count all the parameters of human body. Generally, the main parameters of human body (such as weight, height, chest circumference, etc.) are chosen to carry out the investigation. Based on the latest anthropometric data of Chinese adults, this paper studies the correlations between the basic items of human foot measurement, stature and weight to find out the correlations between the measured data of human foot, and to optimize the measurement items of human foot size.

2 Research Background In 1986–1988, China National Institute of Standardization undertook the first nationwide body size measurement survey, in which the number of men and women measured was 11,550 respectively, and the measurement area covered six major natural areas nationwide. Among them, four foot data were measured. The GB/T 10000 [1] © Springer Nature Switzerland AG 2020 R. S. Goonetilleke and W. Karwowski (Eds.): AHFE 2019, AISC 967, pp. 197–203, 2020. https://doi.org/10.1007/978-3-030-20142-5_20

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National Standard Human Dimensions of Chinese Adults published in 1988 included the sizes of foot length and foot breadth. For adult men and women in China, and they were presented by percentiles. These data played a role in promoting the improvement of the relevant products’ quality and design levels. It has been nearly 20 years since the release of the 1998 Standard. In the past 20 years, Chinese people’s living standard has developed rapidly, and their body shapes has undergone tremendous changes as well, so the previous data and standards have been incapable to accurately reflect the current physical conditions of Chinese nationals, and are no longer suitable to serve as the fundamental basis of the current product design and production. In 2013, with the support of the Ministry Science and Technology’s project, China National Institute of Standardization carried out the second large-scale ergonomic survey in China. The measurement survey was conducted from 2014 to 2017. This survey included body sizes, biomechanics, human sight, hearing, touch and many other parameters. Human foot data was also an important part of this measurement. By means of the combination of manual measurement and 3D scanning, the nationwide measurement was aimed to build a Chinese adult foot database. For foot data, many scholars have also carried out relevant research. Qiuli [2] and Cui [3] analyzed the data characteristics of foot length and plantar toe circumference in different areas of China, and summarized the characteristics of adult foot type in China. Yu Ship [4], Xiong [5], Luo [6], Guan [7] studies the relationship among foot width, foot length and body height.

3 Sampling Methods 3.1

Overall Sampling Principles

The nationwide body size measurement adopts the stratified random cluster sampling method, and the sampling locations and the number of samples are determined according to the distribution of population at different levels, the standard deviation of various types of data and the required sampling accuracy so as to ensure the representativeness of samples. 3.2

Age Distribution

By the end of 2018, the data of 260 million persons was collected in total, including 130 million males and females respectively. The age range was 18–75 years old. During the sampling, the subjects were divided into four age groups (Table 1). Table 1. Number of samples in all age groups Age groups 18–25 26–35 36–55 56–75 Male 2469 3003 5317 2523 Female 2081 2379 6120 3129

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4 Measurement Methods 4.1

Definitions of Measurement Items

The foot measurement method as defined in the GB/T 5703-1999 basic human body measurements for technological design [8]. The measurement items included 5 items: foot length, foot width, foot circumference, toe height and tarsal point height. 4.2

Measurement Equipment

The nationwide foot data collection adopted the combination method of manual measurement and three-dimensional scanning. Manual measurement was conducted with the use of Martin measuring scale, and the surveyors received unified training measured. Three-dimensional scanning was carried out with the use of threedimensional human foot scanner to get the three-dimensional point cloud data.

5 Data Analysis 5.1

Foot Length and Foot Width Data Analysis

The mean data of foot length and foot width for different age groups are shown in Figs. 1 and 2.

260.0

252.1

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248.4 230.5

230.0 220.0

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210.0

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200.0 190.0 180.0 18-25

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Fig. 1. Foot length for different age groups

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110.0 100.0 90.0

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Fig. 2. Foot width for different age groups

From the above two figures, we can see that the average values of foot length and foot width of men are larger than those of women. The difference between men and women is significant (P < 0.01). For men, the foot length decreases with age. The age of 18–25 is 3.7 mm which is smaller than that of 56–75. Female foot length data did not change much in different age groups. Foot width data for both men and women increased with age. The foot width for males was 95.3 mm in 18–25 years old, 97.6 mm in 56–75 years old, and increased by 2.3 mm. The foot width for females was 86 mm in 18–25 years old and 89.9 mm at 56–75 years old, which increased by 3.9 mm. It can be seen from the two figures that with the increase of age, the human foot data has a trend to develop broadly. 5.2

Coefficients of the Items

According to the physiological characteristics of human body, the parameters of various parts of the human body are not completely independent, and there is a strong correlation among the characteristic parameters. The statistical analysis software SPSS was used to analyze the correlation of five items of human foot data, and the correlation coefficients of seven items were obtained, as shown in Tables 2 and 3. The results showed that the five foot data of men and women were positively correlated with body height, and the correlation coefficients were 0.167–0.685 and 0.125–0.617, respectively. There was a high correlation between foot length and height (P < 0.01). Five foot data of men and women were positively correlated with body weight, with correlation coefficients between 0.258–0.466 and 0.223–0.446, respectively. Foot width was highly correlated with body weight (P < 0.01). For the five foot data, foot length and foot width, foot length and foot circumference, foot width and foot circumference, toe height and tarsal point height all have high correlation items.

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Table 2. Correlation coefficients for male Items

Weight Stature Foot length 1 .439** 1 .436** .685** 1 .466** .265** .498** .258** .167** .221** .396** .226** .408**

Weight Stature Foot length Foot width Toe height Foot circumference Tarsal point .324** .271** .222** height

Foot width

Toe height

Foot Tarsal point circumference height

1 .236** .574**

1 .206**

1

.223**

.417**

.219**

1

Table 3. Correlation coefficients for female Items

Weight Stature Foot length 1 .288** 1 .400** .617** 1 .446** .163** .441** .223** .125** .182** .384** .196** .334**

Foot width

Toe height

Foot Tarsal point circumference height

1 .155** .456**

1 .193**

1

.233** .181**

.113**

.449**

.171**

Weight Stature Foot length Foot width Toe height Foot circumference Tarsal point .246** height

5.3

1

Linear Regression Equation

From the previous correlation analysis results, we can see that there is a statistical linear relationship between human height, weight data and foot data. The foot data were analyzed by multivariate stepwise regression analysis using height and weight. The regression equations were shown in Table 4. Table 4. Regression equations of measurement items Items Foot length Foot width

Gender Male Female Male Female

Regression equation R2 71.257 + 0.1X1 + 0.161X2 0.492 76.909 + 0.088X1 + 0.252X2 0.43 73.354 + 0.006X1 + 0.2X2 0.221 68.580 + 0.003X1 + 0.264X2 0.220 (continued)

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R2 0.160 0.155 0.125 0.088 0.070 0.053

The results show that the regression equation and the regression coefficients of each variable have passed the significance test, and the regression equation can accurately reflect the corresponding relationship among the measurement items.

6 Conclusions In this study, the correlation between body height, weight and foot data was studied. Human body data came from the second large-scale survey of ergonomic parameters conducted in China from 2013 to 2018. The results showed that the five foot data of men and women were positively correlated with body height and weight. After regression analysis, the multivariate linear regression equations of foot length, foot width, foot circumference, toe height and tarsal point height with height and weight were obtained. The regression equation can be used as the basis of ergonomic product design. Acknowledgments. This research is supported by “Special funds for the basic R&D undertakings by welfare research institutions” (522016Y-4680), National Key R&D Program of China (2017YFF0206602), National Science and Technology Basic Research (2013FY110200).

References 1. GB/T 10000-1988 human dimensions of Chinese adults, National standard (1988) 2. Qiuli: Study on the Law of Chinese foot shape - Basic Law of Chinese adult foot shape. Chin. Leather 34(5), 135–138 (2005) 3. Cui, R., Li, Z.: Application of Chinese population foot type database-preliminary analysis of foot type in Northeast, Northwest and South China. Chin. Leather 32(10), 142–143 (2003) 4. Yu, J., Xia, J., Wang, W.L., et al.: The relationship between the length of the hand, the length of foot and body height of special men living in Guizhou. Acta Academiae Medicinae Zunyi 26(6), 515–516 (2003) 5. Xiong, W., Zhao, Y.: The correlation between hand length, foot length and body height of young college students in Hunan province. J. Nanhua Univ. (Medical Edition) 29(4), 351–352 (2001)

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6. Luo, W.B., Zhang, W., Yu, Y.Sh., et al.: The relationship between body height and hand length, metacarpale length and fingers length in undergraduates of Miao nationality. J. Qiannan Med. Coll. Nationalities 22(2), 79–84 (2009) 7. Guan, H.Zh., Lu, R.X., Gan, Z.M., et al.: The relationship between the foot length and the stature in young people of Uygur nationality in Xinjiang. Acta Academiae Medicinae Xinjiang 13(1), 9–12 (1990) 8. GB/T 5703-1999 Basic human body measurements for technological design. National standard (1999)

Design, Anthropometry and Posture

The Influence of the Transformation Between Standing and Cycling Position on Upper Body Dimensions Thomas Peeters1(&), Jochen Vleugels1, Stijn Verwulgen1, and Guido De Bruyne1,2 1

Department Product Development, Faculty of Design Sciences, University of Antwerp, Prinsstraat 13, 2000 Antwerp, Belgium {thomas.peeters2,jochen.vleugels,stijn.verwulgen, guido.debruyne}@uantwerpen.be 2 Lazer Sport NV, Lamorinierestraat 33-37, Bus D, Antwerp, Belgium

Abstract. For cyclists, well-fitting clothing is essential for comfort and performance during cycling. Preference towards a clothing size is mostly based on comfort perception in a standing position, although the shape of the upper body obviously changes in cycling position. This study gives an indication of the conversion factors from a standing position to a cycling position for five relevant upper body dimensions. In this experiment, 57 amateur cyclists’ upper body dimensions were measured in both standing condition and cycling position on an adjustable fitting bike. The most pronounced conversion factors are seen in the waist front length, which decreases with 13.81 ± 7.98% and the back length, which increases with 18.39 ± 9.04% when sitting on the bike compared to the standing posture. The calculated factors can be used to determine the optimal jersey size for cyclists without measuring them in cycling condition. Keywords: Posture transformation

 Upper body dimensions  Cycling

1 Introduction When designing cycling jerseys, several aspects may affect quality that can depend of the type of cyclist. Aerodynamic [1, 2], biomechanical [3] and thermal [4] properties should be optimized for efficient cycling performances. Therefore, cycling clothes are developed to provide a tight fit, but without disturbing the comfort. High-quality cycling jerseys should achieve an optimum between aerodynamics, biomechanics, thermal properties and comfort, with the aim to make cyclists feel comfortable on the bike to get excellent performances. Where the aerodynamic and biomechanical aspects of cycling clothing are optimized by the manufacturer, the comfort is assessed by the subject itself. Currently, the preferred size of cycling clothing is determined using former cycling experiences, sizing tables or pass sessions. The last two techniques score the comfort during wearing the clothing in standing posture. During the selection of the right jersey size, it is difficult to try several sizes of the clothing in a cycling position. However, the optimal © Springer Nature Switzerland AG 2020 R. S. Goonetilleke and W. Karwowski (Eds.): AHFE 2019, AISC 967, pp. 207–212, 2020. https://doi.org/10.1007/978-3-030-20142-5_21

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position on the bike is totally different compared to standing position for the subjects themselves and for the dimensions of the optimal jersey. Furthermore, the pressure of cycling jerseys on the body differs for cycling position compared to standing position [5], which has an influence on the comfort as well. Therefore, this study investigates the relation between standing and cycling position dimensions of the upper body. The aim of this paper is to provide general conversion factors from standing to cycling position, which can be taken into account by developing well-fitting cycling jerseys. Furthermore, the preferences of well-fitting jerseys are different for men and women in terms of biomechanics, aerodynamics, thermal properties and comfort. Therefore, this study also makes a distinction between male and female subjects by calculating the transformation from standing to cycling position.

2 Materials and Methods 2.1

Experiments

This study included 57 amateur cyclists between 18 and 65 years old. In the first part of the experiment, the participants were measured when standing upright with a straight back. Five upper body dimensions were measured by one researcher as in Fig. 1. The chest circumference, minimal waist circumference, waist front length and back length were measured using tape measure, while the hip width was determined with a caliper. The chest circumference was defined as the distance over the chest, the minimal waist circumference represented the minimal circumference over the waist, the hip width was the widest distance of the hip, the waist front length was the length starting from the pants height to the top of the sternum, and the back length was the length from the pants height to the processus spinosus C7. Subjects wore tight-fitted cycling jerseys and pants, determined using sizing tables to eliminate measurement errors due to folds in the clothing (Fig. 2 left).

Fig. 1. The five upper body measurements in standing position. For all participants, chest circumference, minimal waist circumference, hip width, waist front length and back length were determined using the same method. These five measurements were repeated when subjects were on the bike.

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In the second part, the five measurements per subject were repeated in cycling position, wearing the same clothing. The subjects were asked to take a cycling position with their hands on the drops of the handlebar with the right foot down on an adjustable bike as in Fig. 2 right. The bike was adjusted in saddle height and steer-saddle length to provide an optimal position for each subject.

Fig. 2. The two postures in which subjects were measured. The left figure was the standing position with a straight back. The right figure represented the position on the adjustable bike. Subjects wore the same well-fitting cycling clothing.

2.2

Statistical Analysis

The experiments deliver five measurements in standing and five measurements in cycling position for all subjects. For each measurement and each subject, the relation between standing and cycling position was calculated. The percentage of increase in dimensions in cycling position was calculated by dividing the dimensions in cycling position by the measurements in standing position as in the formula below. 

measurement in cycling position 1 measurement in standing position

  100ð% )

ð1Þ

Positive values indicate that there is an increase in dimension in cycling position compared to the standing position. The negative values, however, demonstrate a decrease in dimension from standing to cycling position.

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For the five upper body measurements, the average percentages of increase in dimensions with associated standard deviations were calculated. Furthermore, the difference between male and female participants was investigated. After considering Kolmogorov-Smirnov, the independent samples T-test was used to consider differences between conversion factors for male and female subjects.

3 Results The included participants were 43 male and 14 female subjects. The amateur cyclists were 35 ± 11 years, with an age range between 20 and 63 years. The average weight of the participants was 71.7 ± 10.9 kg and their length was 177.6 ± 8.4 cm. Considering Table 1. The average increase in percentage from standing to cycling position with associated standard deviation for the five upper body measurements. Positive values mean an increase in dimensions, where a negative value indicates a decrease in dimension in cycling position compared to standing posture. Measurement Percentage ratio cycling to standing position (%) Chest circumference +3.09 ± 4.54 Minimal waist circumference +6.06 ± 8.07 Hip width +4.94 ± 6.18 Waist front length −13.81 ± 7.98 Back length +18.39 ± 9.04

Fig. 3. The difference in gender for conversion factors from standing to cycling position. The average percentage in increase from standing to cycling position as well as the 95% confidence interval are shown for the five measurements.

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all participants, Table 1 shows the average increase in percentage from standing to cycling position with associated standard deviation according to formula (1). Figure 3 shows the differences between male and female subjects for the five measurements using average values and 95% confidence intervals. Table 2 shows the average values for male and female subjects and the p-values to indicate the statistical difference between both. Table 2. The average increase in percentage with associated standard deviation for male and female subjects for the five measurements. Furthermore, the p-value of the difference between both is shown. Measurement Male (%) Chest circumference +2.70 ± Minimal waist circumference +6.29 ± Hip width +4.56 ± Waist front length −15.51 ± Back length +16.75 ±

Female (%) 4.59 +4.27 ± 4.33 9.27 +5.37 ± 1.96 6.85 +6.04 ± 3.53 7.10 −8.70 ± 8.56 7.89 +23.31 ± 10.73

p-value 0.27 0.71 0.45 0.01 0.02

4 Discussion The results show that the chest circumference increases with 3.09 ± 4.54% in cycling position with hands on the drops compared to the standing reference condition. Similar results are obtained for the minimal waist circumference and the hip breadth, where an increase of 6.06 ± 8.07% and 4.94 ± 6.18% is found, respectively. The most pronounced conversion factors are seen in the anthropometric parameters waist front length and the back length, which undergo more substantial transformations in cycling position. The waist front length decreases with 13.81 ± 7.98%, where the back length increases with 18.39 ± 9.04%. These results show that circumferences and widths of the upper body slightly increase when sitting on a bike compared to standing upright. The waist front length decreases when taking the cycling position, where the back length increases with an even higher percentage. Furthermore, the waist front length and back length alters differently for male and female subjects. For female subjects, the decrease in waist front length is significantly smaller (15.51 ± 7.10% for male, 8.70 ± 8.56% for female, p < 0.05), which can be declared by the presence of the breasts in female participants. The back length increases significantly more for female subjects (16.75 ± 7.89% for male, 23.31 ± 10.73% for female, p < 0.05). However, to provide a more detailed comparison between male and female subjects, more measurements of female participants are recommended. Furthermore, the chest circumference, the waist circumference and the hip breadth supply similar results for male and female subjects (p > 0.05). The calculated conversion factors can be used to determine the optimal jersey size for cyclists without measuring them in cycling position. However, these conversion factors from standing to cycling condition are average values from 57 subjects.

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Therefore, it is important to realize that these values cannot be used for each individual cyclist to predict the exact upper body dimensions in cycling position starting from the standing dimensions. Since each subject is different, the proposed conversion factors only give an indication of the changes of the upper body in cycling position. Furthermore, the cycling position in this study is a passive posture, which can be different from an active cycling movement [6]. Besides the use for cyclists to better estimate the optimal size of their cycling jersey, the outcome values of this study can be used by manufacturers to implement the insights in the development of cycling clothes. Manufacturers can take the conversion factors into account in the design since it is more important to have well-fitting clothes in cycling position than in standing condition.

5 Conclusion This paper investigated the transformation of the upper body between a standing position and a cycling position. Measurements of upper body circumferences and lengths indicate which parts undergo an increase or a decrease in dimensions when positioned on a bike. The research provides conversion factors to predict upper body dimensions in cycling position based on standing measurements. Circumferences of the upper body increase slightly, where the back length increases with 18.39% on average and the waist front length decreases with 13.81%. Using these factors, it is possible to better estimate and design the right cycling jerseys to optimize the comfort of cyclists.

References 1. Oggiano, L., Troynikov, O., Konopov, I., Subic, A., Alam, F.: Aerodynamic behaviour of single sport jersey fabrics with different roughness and cover factors. Sport. Eng. 12, 1–12 (2009). https://doi.org/10.1007/s12283-009-0029-0 2. Brownlie, L., Kyle, C., Carbo, J., Demarest, N., Harber, E., Macdonald, R., Nordstrom, M.: Streamlining the time trial apparel of cyclists: the Nike Swift Spin project Technical R & D Article. Sport. Technol. 2, 53–60 (2009). https://doi.org/10.1002/jst.12 3. Liu, K., Kamalha, E., Wang, J., Agrawal, T.: Optimization design of cycling clothes’ patterns based on digital clothing pressures. Fibers Polym. 17, 1522–1529 (2016). https://doi.org/10. 1007/s12221-016-6402-2 4. Tastan Ozkan, E., Meric, B.: Thermophysiological comfort properties of different knitted fabrics used in cycling clothes. Text. Res. J. 85, 62–70 (2015). https://doi.org/10.1177/ 0040517514530033 5. Liu, K., Wang, J., Zhu, C., Hong, Y.: Development of upper cycling clothes using 3D-to-2D flattening technology and evaluation of dynamic wear comfort from the aspect of clothing pressure. Int. J. Cloth. Sci. Technol. 28 (2016). https://doi.org/10.1108/ijcst-02-2016-0016 6. Vuruskan, A., Ashdown, S.P.: Fit analyses of bicycle clothing in active body poses. In: International Textile and Apparel Association (ITAA) Annual Conference Proceedings, p. 53 (2016)

Ergonomic Improvements in Heavy-Duty Four-Wheel Cart with Pelvis Support Jaimin Patel, Nader Madkour, Jay Jani, Guru Prasadh Rao, Pawan Sharma, and Yueqing Li(&) Department of Industrial Engineering, Lamar University, Beaumont, TX 77710, USA {jpatel49,nmadkour,jjani1,grao,psharam5, yueqing.li}@lamar.edu

Abstract. Industrial carts require significant pushing/pulling forces causing postural discomfort to operators in shoulder, neck, lower back. The purpose of this study was to diminish postural uneasiness during the operation of the cart by modifying it. The modified cart includes a pelvis support with a waist belt, an increased handle height and all swivel wheels to scale down the discomfort levels in specific regions and assist with improved motion of the cart. After modification, the discomfort levels on shoulder, lower arms, mid back and lower back are significantly lesser. The results of this study indicate significant difference in discomfort levels and better maneuverability with the modified cart. Keywords: Pelvis support Pushing-pulling force

 Industrial cart  Ergonomics 

1 Introduction A cart is used to move heavy object(s) from one station to another, or a warehouse in industries and services like logistics, warehousing, construction, agriculture, hospitals and many others, either by pushing or pulling. Most of the industrial tasks of the carts are associated with pushing and pulling. Around 80% of carts are pushed more than once per day and 30% are pushed more than 10 times per day [1]. An estimation suggests that manual handling constitutes up to 50% of pushing and pulling maneuvers in certain industries [2]. Apart from pushing/pulling the cart, bending and lifting are a part of handling the cart. According to cross-sectional epidemiological studies [3] shoulder and low-back pains are associated with pushing and pulling forces. The stresses to the musculoskeletal system from applied hand force are directly related to pushing and pulling of the carts. According to the literature, these tasks increase the risk of musculoskeletal disorders (MSDs), presumably due to high loads and/or frequent task repetitions [4]. Another review by [5]. Summarizes, most consistently overuse and pain were found in the shoulder. The objective of this paper is to analyze the various stresses from pushing/pulling a cart, distribute the forces by recommending a pelvis support with waist belt, and increase the maneuverability by modifying casters. © Springer Nature Switzerland AG 2020 R. S. Goonetilleke and W. Karwowski (Eds.): AHFE 2019, AISC 967, pp. 213–221, 2020. https://doi.org/10.1007/978-3-030-20142-5_22

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2 Literature Review Heavy duty Industrial carts are used by operators in various industries and for different applications. If the cart is not operated properly, it increases the risk of lower back, lower and upper limb injuries. Lower back injuries should be critically examined as spine is one of the important parts of human body. Studies examining spine shear tolerances have reported much lesser tolerance to shear forces than compressive forces. McGill’s 1000 N tolerance value is generally cited as a limit above which there is increased risk of sustaining injury [6]. Cart handle is the heart of the cart as height of the handle, grips, and distance between the handle help operator to move the cart in desire forces (Pushing or Pulling). Handle of the height and inter-handle distance directly results on upper limb exertion especially shoulders. Study proved that inter-handle length of more than 40 cm [7] causes change in shoulder angles as 40 cm is the average breadth of the shoulders. Similarly, height of the handle which is not between 91–114 cm [8] causes change in elbow joint angles. As stated before, most of the industrial tasks of the carts are associated with pushing and pulling. Hence the prevalence of these activities causes lower back, lower and upper limb injuries. Regarding pushing the cart, wheels have lesser friction than runners. Runners are used in industrial carts for transporting materials from one station to another. A research has been done by Kragelsky et al. on rolling friction, which shows that using wheels instead of runners and bearings instead of sleeve bearings decreases the rolling friction [9]. So, an ideal cart should be accurately designed with optimum handle height, ease of pushing and pulling and lesser friction on wheels. Pushing/pulling the cart is quite frequent in an industry. While performing these activities it is important that lower back should be safe and do not get hurt in long term. Research conducted in industrial settings has reported that workers lean against the objects to push the cart. This results into vertical as well as horizontal forces [10, 11]. This repetitive bending or bad posture could damage the lower back of the workers. Several sources report that as much as 20% of low back injury claims are associated with pushing and pulling [12, 13]. Hence, this study shows the significance of pelvis support with Velcro belt which alleviates the effect and injuries associated with pushing and pulling.

3 Methodology 3.1

Participates

A total of 10 male participants were randomly selected for the survey. The subject’s height ranges from 60 to 72 in (Mean = 70, SD = 3.63) and are aged from 21 to 35 years old (Mean = 27.5, SD = 5.68).

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Apparatus

Industrial cart: Conventional industrial heavy-duty cart (Fig. 1) was used for this survey which has 36.2 in handle height with 4.2 diameter of wheels. Load: The load (Fig. 2) for the experiment is approximately 265 pounds during survey. Objects like car’s tires and four ‘5 gallons’ of water bottles were used as load. Modified Cart: The cart is modified by increasing the handle height to 42.5 in and castors to 10 in. The Pelvis support with a length of 13.78 in (Fig. 3), can be adjusted to 17.32 in in vertical position and 13 in in the horizontal direction. Velcro waist belts with a length of 63 in are bolted on either ends to the pelvis support. Questionnaires: Three questionnaires were provided to all participants, containing questions such as demographic information, postural discomfort levels and stress levels for different body parts.

Fig. 1. Conventional cart

3.3

Fig. 2. Cart load

Fig. 3. Modified cart

Independent Variables

Given the nature of the experiment, there is only one independent variable with two levels: (a) Conventional design. (b) Modified cart with Pelvis support. 3.4

Dependent Variables

All the below mentioned dependent variables are responses by the participants after filling out a questionnaire, post the completion of the task. (a) (b) (c) (d) (e) (f)

Stress on shoulders. Stress on neck. Stress on lower back. Height of the handle. Maneuverability of the cart. Turning motion.

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Experiment Task

The path defined for the experiment is rectangular in shape with dimensions 10 m in length by 3 m in width. Each participant needs to complete two clock-wise runs on the path with the cart pushing the 265-pound load, finishing at the starting point. After this, the participant needs to pull the cart with the 265 pound-load in an anti-clockwise direction originating from the same point for one run on the defined path. Each participant needs to perform the task on both the conventional and the modified cart, which in total is 156 m. This whole experiment is randomized by selecting different paths for every task. 3.6

Procedure

The participant is asked to fill a questionnaire for demographic information before riding the cart post which step wise procedure is explained on how to complete the task. The participant is then randomly assigned one of the carts (modified and conventional) to ride on the pre-defined path. After the random selection of pushing or pulling activity (clockwise or anti-clockwise) the participant needs to ride the cart. The questionnaire for the particular task is asked to complete immediately after riding the cart. Depending on the cart ridden in the previous task, the next cart is assembled for the final task. The participant is asked to ride the now assembled cart in the pre-defined path and then the particular questionnaire for this activity is completed. One of the members of the team takes verbal feedback about the experience from the participant. 3.7

Cart Modification

3.7.1 Pelvis Support for Reducing Pushing and Pulling Force: The modified cart (Fig. 6) was fixed with pelvis support, rather than using just hand (Fig. 4) for pushing and pulling. This pelvis support effectively divides the stresses in between shoulder and pelvic region and reduces postural discomforts in fore-arms, hands, shoulder and trunk. The pelvis support can be moved in both vertical and horizontal directions, to adjust according to operator’s height. This support is designed in a “C” shape (Fig. 5) and has cushion on the inside of its curve which will help the operator to have a comfortable ride. Similarly, during the pulling and stopping activity, the ends of the support fit with a Velcro belt (Fig. 7) assists greatly in reducing the pulling force. This belt is attached on the outer edge of the pelvis support and it can be worn similarly like other waist belts. This will reduce the operator’s pulling force on arms, shoulder and hands comparatively. 3.7.2 Four Swiveling Wheels to Improve Turning Radius of the Cart: Modified luggage cart is fit with 4 swiveling wheels, which not only reduces the force required to turn the cart, but also decreases the turning radius. This modification is intended to decrease the postural discomfort on body parts like arms, lower back, and shoulder.

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Fig. 4. Cart before modification

Fig. 5. Cart after modification

Fig. 6. Cart after modification

Fig. 7. Cart after modification

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3.7.3 Modified Casters for Smoother Riding: Almost all conventional carts have wheels with smaller diameter and are made of hard plastic without springs (suspension). Here, evaluated cart is fit with large diameter wheel made of hard rubber, so the cart will have smoother ride on humps, holes, cracks and other floor obstructions and decrease the postural discomfort on operators.

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4 Results • One of the ten subjects was a little higher than 72 in, though the range for the experiment we have chosen is 60–72 in. • Every subject had to move 78 m in total, in two parts. The path is rectangular with 10 m length and 3 m width, on a smooth RCC terrain. • The average discomfort levels before the modification (Fig. 9) and the addition of the pelvis support (Fig. 10) at different body parts as numbered in the below image (Fig. 8) are as following.

Fig. 8. Body regions numbered to depict different areas [14]

Average discomfort levels in different regions before modification. X-axis–>Percentage average of discomfort. Y-axis–>Body regions numbered according to the left image where discomfort is experienced. The data was analyzed using a paired t-Test. The results are as reported below. (a) Stress on shoulder The result revealed a significant difference in shoulder stress between the conventional and modified cart (t = 5.1859, p = 0.000575). The shoulder stress with the modified cart (M = 3.1, SD = 2.7) was significantly smaller than that with the conventional cart (M = 7, SD = 1.49).

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Fig. 9. Discomfort modification

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Fig. 10. Discomfort level after modification

(b) Stress on lower back The result revealed a significant difference in lower back stress between the conventional and modified cart (t = 6.4968, p = 0.0001). The stress levels with the modified cart (M = 2.1, SD = 2.96) were significantly smaller than that with the conventional cart (M = 7.6, SD = 1.58). (c) Height of the Handle of the cart The enhanced height of the handle results in lower pushing/pulling forces (t = 8.64, p = 5.91472E−06). The modified handle revealed significantly reduced stresses at elbows and shoulders (M = 3.7, SD = 2.26) compared with the conventional cart (M = 8.6, SD = 0.96). (d) Maneuverability of the cart The result showed that the maneuverability of the modified cart has a significant increase (t = 4.7142, p = 0.001) after the addition of all swivel wheels with bigger diameter (M = 5, SD = 1.63), compared with the conventional cart (M = 8.3, SD = 1.16). (e) Turning motion of the cart The turning motion of the modified cart indicated a significant progress (t = 4.4956, p = 0.0014) with bigger diameter and all swivel wheels (M = 4.4, SD = 1.77) when compared to the conventional cart (M = 7.6, SD = 1.18).

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Discomfort level Height of the handle Back Pain Neck stress Shoulder stress Turning motion Convenience Satisfaction

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Average numbers based on survey Fig. 11. Average of different variables based on survey.

(f) Stress on neck The stress levels in the neck with the modified cart (M = 3.5, SD = 2.8) were significantly smaller (t = 2.2769, p = 0.0488) than that with the conventional cart (M = 6, SD = 1.94).

5 Discussion The proposed design has proved significant changes in terms of reduced stresses in lower back, shoulders, neck, along with improved maneuverability, height of the handle and turning motion (Fig. 10). Pelvis support and Velcro belt gives a comfortable posture for the cart rider, a higher strength capability. The addition of the pelvis support and Velcro belt divides the pushing/pulling force on the rider’s shoulder on to the pelvic region as well, thus managing the stresses on shoulders and lower back in a much efficient way. Coming to the maneuverability and motion of the cart, the durable pneumatic rubber wheels with all swivel wheels, helps to decrease the turning radius. The 10″ pneumatic wheels give better ride comfort in an uneven surface as well. This modification not only increases the maneuverability but also decreases the pulling/pushing force while treading on bumps, cracks etc. The participants with a previous experience in pushing/pulling a heavy industrial cart felt that the presence of the Velcro belt attached with the pelvis support grips to their lower back providing a better handling of the cart. A difference of 6.3 in has made a significant effect on stresses on shoulders when compared to the conventional height of the handle. The increase in the height of the handle has reduced the angle between elbows and fore-arms, bringing it to right angle (closely), thus reducing the pushing/pulling force and causing lesser stresses on shoulders and back of the participant. The overall modifications on the conventional cart including the all- swivel wheels, increased height of the handle have reduced the stresses in the neck.

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6 Conclusion The aim of the study is to decrease postural discomfort levels caused by operating heavy duty luggage cart, which is achieved by adding a pelvis support with Velcro belts and increase the maneuverability by adding bigger wheels on the cart. There are however some limitations associated with this research, like all the participants are males and not all the volunteers were skilled or have had an experience with a heavy industrial cart prior to this experiment. This study is preliminary with respect to sample size, though the results show that modified cart has significant changes in discomfort levels in different regions of the body owing to the pelvis support and Velcro belt.

References 1. Mack, K., Haslegrave, C.M., Gray, M.I.: Usability of manual handling aids for transporting materials. Appl. Ergon. 26(5), 353–364 (1995) 2. Baril-Gingras, G., Lortie, M.: The handling of objects other than boxes: univariate analysis of handling techniques in large transport company. Ergonomics 38(5), 905–920 (1995) 3. Marras, W.S., Knapik, G.G., Ferguson, S.: Lumbar spine forces during manoeuvring of ceiling based and floor-based patient transfer devices. Ergonomics 52(3), 384–397 (2009) 4. Velasco Garrido, M., Bittner, C., Harth, V., Preisser, A.M.: Health status and health-related quality of life of municipal waste collection workers – a cross-sectional survey. J. Occup. Med. Toxicol. 10(1) (2015) 5. Hoozemans, M.J., Knelange, E.B., Frings-Dresen, M.H., Veeger, H.E., Kuijer, P.P.: Are pushing and pulling work-related risk factors for upper extremity symptoms? A systematic review of observational studies. Occup. Environ. Med. 71(11), 788–795 (2014) 6. McGill, S.M.: The biomechanics of low back injury: implications on current practice in industry and the clinic. J. Biomech. 30(5), 465–475 (1997) 7. Ohnishi, A., Takanokura, M., Sugama, A.: Evaluation of interhandle distance during pushing and pulling of a four-caster cart for upper limb exertion. Saf. Health Work. 7(3), 237–243 (2016) 8. Ayoub, M.M., McDaniel, J.W.: Effects of operator stance on pushing and pulling tasks. AIIE Trans. 6(3), 185–195 (1974) 9. Kragelsky, I.V., Dobychin, M.N., Kombalov, V.S.: Friction and Wear: Calculation Methods. Pregamon Press, Oxford (1982) 10. de Looze, M.P., Stassen, A.R., Markslag, A.M., Borst, M.J., Wooning, M.M., Toussaint, H. M.: Mechanical loading on the low back in three methods of refuse collecting. Ergonomics 38(10), 1993–2006 (1995) 11. van der Beek, A.J., Kluver, B.D., Frings-Dresen, M.H., Hoozemans, M.J.: Gender differences in exerted forces and physiological load during pushing and pulling of wheeled cages by postal workers. Ergonomics 43(2), 269–281 (2000) 12. National Institute for Occupational Safety and Health: U.S. Department of Health and Human Services: A work practices guide for manual lifting, p. 198 (1981) 13. Hoozemans, M.J., van der Beek, A.J., Frings-Dresen, M.H., Van Dijk, F.J., van der Woude, L.H.: Pushing and pulling in relation to musculoskeletal disorders: a review of risk factors. Ergonomics 41(6), 757–781 (1998) 14. Emİnoğlu, M.B., Yegül, U., Öztürk, R.: Comparison of Postural Discomfort during Hoeing Operation with Two Different Machinery Combinations (2010)

Incidence and Postural Risk Factors for Low Back Pain Among Informal Garment Female Workers Sunisa Chaiklieng1,2(&) and Thanyawat Homsombat1

2

1 Department of Environmental and Occupational Health, and Safety, Faculty of Public Health, Khon Kaen University, Khon Kaen, Thailand [email protected] Research Center in Back, Neck, Other Joint Pain and Human Performance (BNOJPH), Khon Kaen University, Khon Kaen, Thailand

Abstract. This nine-month prospective cohort study aimed to investigate the incidence of low back pain (LBP) and the correlation of LBP with postural risk factors among informal garment female workers. Data was collected by using a follow-up questionnaire to assess the LBP incidence. Ergonomics risk assessment was conducted by using the standard Rapid Upper Limb Assessment (RULA) tool. The incidence of nine-month LBP was presented at 30.98% and the highest incidence was found at month 9th (5.99%). The postural ergonomic factors which were significantly associated with LBP were shoulder flexion 45o– 90o, shoulder abduction, elbow flexion 60o–100o, wrist twist, neck twist and trunk twist. The findings confirmed that the LBP incidence was subsequently accumulated every longer period and the working risk posture played a role in that higher risk to LBP development. The findings suggest for ergonomics training for workers in order to perform safe posture while sewing and ergonomics workstation modification. Keywords: Informal garment workers Ergonomic  RULA

 Low back pain  Risk factor 

1 Introduction The informal sector workers are the large number of workforce for many developing countries including Thailand. In 2014, there were 4,908,725 Thai informal workers (56.35% of males, 43.65% of females) and more than 50% of those numbers occupied in the Northeast region of Thailand alone (2,061,641 workers with 56.79% of males and 43.21% of females). Udon Thani, a province located in that northeast region has the highest number of informal workers compared to other provinces (669,425 informal workers with 53.70% of males, 46.30% of females) [1]. The characteristics of informal workers were likely predominant in female gender. In addition, those workers might be exposed to the work environmental factors, one of those is ergonomics factor which is normally found as the main cause of work-related musculoskeletal disorders (WMSDs) in garment work [1, 2]. The garment routine tasks are repetitive tasks and most of the workers had prolonged sitting [3]. Shuval and Donchin [4] found that repetitive work © Springer Nature Switzerland AG 2020 R. S. Goonetilleke and W. Karwowski (Eds.): AHFE 2019, AISC 967, pp. 222–230, 2020. https://doi.org/10.1007/978-3-030-20142-5_23

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with static posture causes more local muscular fatigue than the workers with frequency changes of posture. Every day working with static posture for many years may cause painful diseases and degenerative muscles including joints, tendons and soft tissues, and finally shoulder pain occured [3] or other types of chronic diseases such as low back pain (LBP). Low back pain is one of the most common health problems among WMSDs worldwide and includes a large burden to economics. Hoy et al. [5] estimated the prevalence of LBP from 165 studies among 54 countries, found that one month prevalence was 23.2%. In a literature review of 2009, Sealetsa and Thatcher [6] reported that risk factors associated with LBP were combined with physically heavy work and prolonged work. A research has reported that workers who work with heavy physical jobs have a higher incidence or severity of LBP than those with less heavy physical jobs. The high one-month prevalence of LBP in sewing occupation workers was reported to be 30.7% [7]. Latest study in Thailand, annual LBP incidence reached 83.0% presented in university office workers [8], which is very high. The previous findings by another study revealed among adult population in South Manchester, United Kingdom that showed a new low back pain episode presented at higher in men compared to women [9]. Similar to Thai office worker’s LBP, the incidence of chronic LBP was reported among general workers with low physical work activity and static posture was 71.0% for men and 81.0% for women [10]. Postural risk assessment tools had been continuously developed for a use in various production worksites. Each tool of assessment technique is used for specific work and objective, as appropriate. The one often used technique is so called rapid upper limb assessment (RULA). RULA is a survey method developed for a use in ergonomic investigations of workplaces where work related upper limb disorders are reported. It is a screening tool that assesses biomechanical and postural loading on the whole body with particular attention to the neck, trunk and upper limbs [11]. The goal of implementing these tools is to reduce work related musculoskeletal disorders. The tool will also help to identify areas where ergonomic solutions are needed to improve workers’ health, comfort and performance at work. Currently, knowledge of the incidence of LBP among informal garment female workers is limited. Since it is believed that the physical posture might play a role on LBP in different occupations. Thus, the study of postural factors in informal garment female workers was interesting. Therefore, this nine-month prospective cohort study aimed to investigate the incidence of LBP and to evaluate if the working postural factors related to LBP among informal garment female workers. The outcome will be guideline for the health related sector and organization to implement the planning of control and prevention program to reduce LBP among garment workers and other workers who are working in similar worksites. Moreover, their own enterprise will have knowledge of their ergonomics and planning to avoid postural risk to promote quality of workers’ life that may be a result in higher productivity.

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2 Materials and Method 2.1

Subjects

The nine-month prospective cohort study was to investigate the incidence of low back pain and to evaluate working postural risk factors for LBP among informal garment female workers in Udon Thani province, Thailand. The total subjects were 2,013 informal garment female workers who had registered as informal garment female workers at Udon Thani municipality in Udon Thani province. The sample size was calculated to detect the incidence rate of low back pain using an approach of a simple method of calculation in prospective cohort study for simple logistic regressions. The proportion of low back pain in garment workers = 0.48 [12]. The Precision of estimation of 5% = 0.05 and statistical value under standard normal curve = 1.96. From the calculation of sample size was 316 informal garment female workers. Finally, the study sample size was set at 523 to cope with approximate 30% loss from study during follow-up. Subjects were recruited based on the following inclusion criteria: Thai citizen and volunteer, age between 30–64 years old, working as garment workers at least 8 h per day and at least 4 h continuous, work experience at least 1 year and working in Udon Thani province, no prolonged absence from work anticipated within the next nine months and move to another province, no history of an episode of care for low back pain in the past three months, no pregnant workers, no medical history of serious injury and, no congenital pathology or severe disability with surgeries. From 1,674 informal garment female workers in Udon Thani Province, there were only 523 were included to the cohort group. 2.2

Materials

The structured questionnaire for investigation of the incidence of low back pain was applied from Chaiklieng et al. [8]. Monthly follow-up of LBP cases was done by an interview with structured questionnaire with the questions included as following: (1) had you experience of LBP lasting more than 24 h during the last month?, (2) when did it occurs/start? (time/date), (3) did LBP occur during sewing work?, (4) was LBP treated/did you meet doctor/physical therapy?, (5) If you answer “yes”, did the doctor identify that it was work-related LBP?, (6) how long was LBP lasting?, (7) did LBP affect your work/life style?, (8) others as follows: what is the frequency of LBP in 1 month?, what is the severity level of LBP?, can LBP improve if you stop sewing work? Postural ergonomics risk assessment was conducted with the use of the standard Rapid Upper Limb Assessment (RULA) [10] by observations from video record of working posture. RULA comprising working posture of the forearms, wrists, neck, trunk and legs. The researchers derived the final scores and ranked the ergonomics risk level as shown in 4 levels; level 1 (score 1–2) = low, level 2 (score 3–4) = moderate, level 3 (score 5–8) = high, level 4 (score 9–16) = very high. These levels mean of ergonomics risk assessment that RULA level 1 was acceptable, level 2 should be checked and may need to be corrected, level 3 should be checked and corrected as soon as possible and level 4 should be corrected immediately.

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Data Collection

Data collecting had been done by interviewing informal garment female workers at their home/workplaces for inclusion of the subject into the cohort group. For baseline data, evaluation of postural risk of cohort group by observations and video record. Subjects in cohort group were interviewed with the follow up questionnaire of for new case finding every one month period, for 9 months. This study was approved by the Khon Kaen University Ethics Committee for Human Research based on the Declaration of Helsinki, as decision no. HE562131. All participants were volunteers to this study and they had given their informed consent prior at the start. 2.4

Statistical Analysis

Statistical analysis by using STATA 13, Texas USA 2007. The descriptive statistics were frequency, percentage, mean and standard deviation (SD). Low back pain incidence rate in each month was calculated from this formula (new case in each month x 100)/number of informal garment female workers in cohort group left in each month. LBP cases were dropped out of the total number of cohort group in the later months. Simple logistic regression analysis was used to study the association between postural risk factors and LBP. Risk ratio (RR) and 95% confidence intervals (95% CI) were presented and p-value less than 0.05 (p < 0.05) was used for determining significant association.

3 Results and Discussion 3.1

Demographic and Work Characteristic

The results showed that 523 informal garment female workers were age between 30–64 years old. Most of them had an education level lower than secondary school, average work experience 5.21 years (1–14 years). More than fifty percent of the workers had a waist circumference of over standard of not more than 80 cm (62.91%). In addition, 41.49% of workers had underlying disease, some of those reported that 46.08% had diabetes mellitus, and 32.72% had hypertension and anxiety or others were 21.19%, all of them did not smoke and 70.17% reported that they had no regularly exercise (3 times/week) as shown in Table 1. Garment works included in the study were sewing, cutting fabrics, finishing the garment. The nature of work was sitting more than 2 h or prolong posture, however, some activities was sitting or standing more than 2 h in each working period of task. 3.2

Incidence Rate in Each Month and Accumulated Incidence of LBP

The follow up of 523 informal garment female workers found that the incidence rate of low back pain for the total 9 months follow up was 30.98%. The highest one month incidence rate was found in month 9th (5.99%), followed by month 4 (4.26%) and month 8th (4.24%) as shown in Table 2. By the result, the reason for these findings might be due to the nature of the garment work by static and awkward posture work.

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Table 1. Demographic and work characteristic of informal garment female workers (n = 523). Variables n (%) p-value Age (year) 0.452 30–39 185 (35.37) 40–49 182 (34.80) 50–59 141 (26.96) >60 15 (2.87) Median (min-max) 46 (30–64) Education 0.349 Primary school 209 (39.96) Secondary school 204 (39.01) Diploma 110 (21.03) BMI (kg/m2) 0.054 Underweight (9 72 (13.77) Median (min-max) 6 (1–14) Underlying disease 0.049a No 306 (58.51) Yes 217 (41.49) a significant at p-value < 0.05

Most of the workers were working at above elbow level with repetitive movement; this posture may lead to the load of the trunk muscles as a fixed position. The accumulated incidence rate of LBP across the 9 months was 30.98%. The incidence rate of LBP among informal garment female workers was similar to a new low back pain episode in men (81.7%) and women (82.1%) adults among the Australian diabetes, obesity and lifestyle (AusDiab) study [13].

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Table 2. Incidence rate in each month of LBP among informal garment female workers. Month Number of follow-up New cases of LBP Incidence rate 95%CI 1st 523 20 3.82 1.63–4.87 2nd 503 17 3.38 1.67–4.45 3rd 486 16 3.29 1.33–5.54 b 3.78–5.86 4th 470 20 4.26 5th 450 18 4.00 3.39–5.11 6th 432 17 3.94 1.97–4.39 7th 415 14 3.37 1.29–4.32 8th 401 17 4.24c 2.03–5.61 9th 384 23 5.99a 4.83–6.12 Remark: athe first-place ranking of incidence rate, bthe second-place ranking and c the third-place ranking.

The present findings were lower than the previous findings of the incident rate of LBP of office workers in University of Thailand (83.0%) [8], and also to female adult population in Norway (81.0%) [10]. However, it is higher rate than the finding of Chou et al. [13], revealed that the incidence rate among adult male workers who participated in the 5-year follow-up of the Geelong Osteoporosis Study (GOS) from 2006 to 2010 in Australia was 15.1%. Our result could show that female gender is higher risk to low back in low physical activity work condition. Accumulated incidence rate of LBP in 1 month was 3.82%, 3 months was 10.13%, 6 months was 22.65% and 9 months was 30.98%. The highest increasing rate was found after 6 months (55 cases, 12.52) as shown in Table 3. Table 3. Accumulated incidence rate of LBP among informal garment female workers. Period of follow-up 1 month 3 months 6 months 9 months

3.3

New cases n 20 53 108 162

Accumulated incidence rate (%) 3.82 10.13 22.65 30.98

Increasing incidence at the end of each period (n, %) 0 (0.00) 13 (6.31) 55 (12.52) 54 (8.33)

Postural Assessment

The findings of postural ergonomics risk factors significantly associated with LBP were shoulder flexion degree 45o–90o (RR = 2.41), shoulder abduction (RR = 2.32), elbow flexion 60o–100o (RR = 2.81), wrist twist (RR = 1.79), neck twist (RR = 2.51) and trunk twist (RR = 1.98) as shown in Table 4. The postural ergonomics risk factors indicated which postures for a specific type of work were hazardous and what actions should be implemented to protect the body. These working postures indicated that there may be increased ergonomic risk of LBP. Thus, awareness should be promoted to

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Table 4. The association between postural ergonomics factors and LBP by simple logistic regression analysis (n = 523). Variables

n

LBP Pain n (%)

RR

95% CI

p-value

No pain n (%)

Upper arm Shoulder flexion 45o–90o 123 69 (56.10) 54 (43.90) Shoulder flexion 20o–45o 400 93 (23.25) 307 (76.75) Shoulder abduction Yes 208 98 (47.12) 110 (52.88) No 315 64 (20.32) 251 (79.68) Lower arm Elbow flexion 60o–100o 207 105 (50.72) 102 (49.28) Elbow flexion 0o–60o 316 57 (18.04) 259 (81.96) Wrist twist Yes 238 97 (40.76) 141 (59.24) No 285 65 (22.81) 220 (77.19) Neck Neck flexion >20o 215 74 (34.42) 141 (65.58) Neck flexion 0o–20o 308 88 (28.57) 220 (71.43) Neck twist Yes 192 96 (50.00) 96 (50.00) No 331 66 (19.94) 265 (80.06) Trunk Trunk flexion 20o–60o 412 135 (32.77) 277 (67.23) Trunk flexion 0o–20o 111 27 (24.32) 84 (75.68) Trunk twist Yes 400 130 (32.50) 270 (67.50) No 123 32 (26.02) 91 (73.78) a significant at p-value < 0.05.

2.41 1.90–3.05 0, ð k 4 b þ k 4 c  f Þ þ ð i  k 2 g  qÞ [ 0

ð17Þ

The two parts of this inequality means different payoff for the government and company under two regulatory modes. The inequality holds only when both of these conditions exist simultaneously. (A) The loss of strategy {No self-management} of companies is more than the amount that was penalized for non-compliance. (B) The benefits of strategy {Regulation} government regulators are more than the sum of the benefits of the strategy {Non-compliance} of companies in CSM and {Inspection} of regulators in SRM. G3 < F3 means G3 − F3 < 0, the result is the opposite of the above. G4 > F3 means G4 − F3 > 0, ð k4 b þ k4 c  k2 cÞ þ ð h þ j  k2 g  q Þ [ 0

ð18Þ

The inequality holds only when both of these conditions exist simultaneously. (C) The loss of strategy {No self-management} of companies is more than the accident loss of strategy {Non-compliance}. (D) The sum of the expected costs of the government under CSM is greater than the payoff of the strategy {Inspection} under SRM. Four kinds of situations exist in theory, which gives the governments of various countries the judgment basis for macro-security regulatory decisions. In China, government regulators have more penalties for companies that have occurred accidents or non-compliance behavior [20]. This coincides with the situation in (A). The payoff of government regulation includes not only reducing accident losses, but also the impact of the public. In China, the planned economy has been gradually developing into a socialist market mechanism. Administrative orders still play an important role in most industrial sectors [21]. Therefore, the government is more willing to choose the strategy {Regulation} under CSM. However, G3 and G4 are equilibrium points of pure strategy with local stability under CSM. In this case, the company will choose compliance, but the government regulators is vacillating. This means that the system is still unstable and there will be uncertainty in regulation.

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4 Conclusion The purpose of this paper is to calculate the final payoff of the game model between the government and the company under CSM and SRM. The final results show that the difference in the benefits of the two regulatory modes is different under different stations. Under Chinese national conditions, the payoff of SRM are less than CSM. This has a certain relationship with political condition and public sense. Therefore, it is unrealistic to adopt a full SRM in China. However, it is uncertain for the strategy of the two players of the game corresponding to the equilibrium point of the local regulatory stability under the pure strategy. This shows that compliance regulation still has great potential. Further comparison of the payoff of the CSM model and the SRM model can help to better explore the effective combination of the two regulatory modes. Game analysis under a hybrid strategy will likely accomplish this task. This paper provides a new perspective for the government’s macro-regulation issues by the cost-benefit analysis of the regulatory model based on game theory. Acknowledgement. The authors would like to thank all participants from some Chinese government safety regulatory authority. The authors are also grateful to the National Nature Science Foundation of China [NSFC Grant No. 51474193] for providing funding for this work.

References 1. Hale, A., Borys, D., Adams, M.: Safety regulation: the lessons of workplace safety rule management for managing the regulatory burden. Saf. Sci. 71, 112–122 (2015) 2. Wang, B., Wu, C., Kang, L., Reniers, G., Huang, L.: Work safety in China’s thirteenth fiveyear plan period (2016–2020): current status, new challenges and future tasks. Saf. Sci. 104, 164–178 (2018) 3. Production safety law of the People’s Republic of China. http://www.npc.gov.cn/wxzl/ gongbao/2014-11/13/content_1892156.htm 4. Hopkins, A.: Beyond compliance monitoring: new strategies for safety regulators. Law Policy 29, 210–225 (2010) 5. Susan, H.: Self-regulation, corporate social responsibility, and the business case: do they work in achieving workplace equality and safety? J. Bus. Ethics 92, 585–600 (2010) 6. Robens, L.: Report of the Committee on Safety and Health at Work. Majesty’s Stationery Office, London (1972) 7. Hopkins, A.: Risk-management and rule-compliance: decision-making in hazardous industries. Saf. Sci. 49, 110–120 (2011) 8. Binglin, Y.: A comparison of adversarial and collaborative regulatory models. Chin. Public Adm. 22, 31–36 (2015). (in Chinese) 9. Yuan, G., Yunxiao, F., Jing, W., Jingjing, P.: Procedural management of safety regulations and rules for the chemical industry. Process Saf. Prog. 39, 1–15 (2019) 10. Yuan, G., Yunxiao, F., Yifan, W., Zhao, D., Peng, W.: A system thinking based study of reducing pressure on special equipment regulation authorities. China Saf. Sci. J. 26, 128–133 (2016). (in Chinese) 11. Øyvind, D.: Safety compliance in a highly regulated environment: a case study of workers’ knowledge of rules and procedures within the petroleum industry. Saf. Sci. 60, 185–195 (2013)

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12. Ling, Z., Gui, F.: Analysis of model on the occupational safety and health legislation and regulation. Hebei Law Sci. 64, 877–886 (2013). (in Chinese) 13. Nie, H., Jiang, M., Wang, X.: The impact of political cycle: evidence from coalmine accidents in China. J. Comp. Econ. 41, 995–1011 (2013) 14. Common sense, common safety. https://assets.publishing.service.gov.uk/government/ uploads/system/uploads/attachment_data/file/60905/402906_CommonSense_acc.pdf 15. Walls, C.B., Dryson, E.W.: Failure after 5 years of self-regulation: a health and safety audit of New Zealand engineering companies carrying out welding. Occup. Med. 52, 305–309 (2002) 16. Sinclair, D.: Self-regulation versus command and control? Beyond false dichotomies. Law Policy 19, 529–559 (2010) 17. Gibbons, R.: Game Theory for Applied Economists. Princeton University Press, Princeton (1992) 18. Herbert, G.: Game Theory Evolving: A Problem-Centered Introduction to Modeling Strategic Interaction. Princeton University Press, Princeton (2009) 19. Friedman, D.: Evolutionary game in economics. Econ. Erica 59, 637–666 (1991) 20. Yuan, G., Yunxiao, F., Peng, W., Defeng, Y.: Research on the safety violation cause model for special equipment based on stpa. Ind. Saf. Environ. Prot. 43, 49–52 (2017) 21. Ma, Y., Zhao, Q.: Decision-making in safety efforts: role of the government in reducing the probability of workplace accidents in China. Saf. Sci. 104, 81–90 (2018)

Design for People

Observing or Experiencing – The Effect of Age Simulation on the Sensitivity to Age-Related Impairment in Elderly Care Danny Rueffert(&) and Angelika C. Bullinger Chemnitz University of Technology, Chair for Ergonomics and Innovation, Erfenschlager Str. 73, 09125 Chemnitz, Germany [email protected]

Abstract. Demographic change in Germany will lead to a 17% increase in the need for elderly care by 2030. Following, knowledge among care givers concerning age and age related impairments of their patients and residents needs to be increased. This field study examined whether wearing an age simulation suit (intervention group) can also lead to an enhanced sensitization compared to participants who observed the intervention (control group). For the study 40 training courses (n = 330) were conducted in the areas of outpatient and inpatient elderly care, consisting of information on age related impairments and the possibility of wearing an age simulation suit. The results show a high sensitivity of age-related impairments both for the intervention and for the control group. However, the intervention group has significantly higher sensitivity values (M = 5,1) than the control group (M = 4,8). It is concluded that observing of age simulation intervention can nevertheless be a good way to make training effective. Keywords: Age simulation Field study

 Sensitivity  Elderly care  Health care  Age 

1 Introduction The age structure of the German population is characterized by rising life expectancy and low birth rates [1]. These developments lead to a higher absolute and relative proportion of older people, and thus to an overall increase in the average age of the population which is also associated with an increase in the demand for elderly care [2]. With this structural change in the population, the need for supporting and activating service offers concerning the elderly is steadily increasing. The creation of high-quality services requires social service providers whose attitudes and actions can make an effective and efficient contribution to the self-determined life of their customers [3]. The growing demand requires more training and readiness of care givers [4]. Without the knowledge of age-related physical changes, it can be difficult to ensure a highquality care process [5]. For this reason, there is a demand for increasing the skills of employees in dealing with the elderly [6] and for making future care givers aware of the specific needs of older people [7]. © Springer Nature Switzerland AG 2020 R. S. Goonetilleke and W. Karwowski (Eds.): AHFE 2019, AISC 967, pp. 339–347, 2020. https://doi.org/10.1007/978-3-030-20142-5_34

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Interventions are one way of bringing knowledge about age-related changes to relevant stakeholders. These interventions vary from theoretical interventions, to roleplaying games, simple simulations to the application of complex age simulation suits. Furthermore, Tullo et al. showed in their review that longer interventions are more effective than shorter ones [8]. However, due to scarce time and financial resources in the field of care work, long training sessions often cannot be implemented. Interventions with age simulation have been shown to be effective also within short training periods [8]. In age simulation, different age-related changes are simulated using simple simulation methods or complex age simulation suits [9]. Often the term “aging game” is used for a special training to sensitize target groups in order to experience the limitations of older people and to change attitudes towards impairments persons [10]. In a production environment, age simulation suits which allow for the experience of age-related impairments have been shown to be effective to raise understanding of management for the aging work force and to identify age-critical workplaces. Thus it is also a needful tool for ergonomic design of workplaces and products for the elderly [9, 11]. Literature also suggests that age simulation is suitable to raise sensitivity among medical personnel, in particular medical students [12–14], pharmacy students [15, 16] and care givers [5]. Filz et al. [17] and Douglass [18] showed that students, who played an “aging game” were better able to empathize with the situation of geriatric patients, especially their physical needs. Interestingly, a recent study by Lucchetti and colleagues [19] found that experience-based aging activities led to an increase in empathy with the elderly but produced a poorer attitude towards the aging process (cf. also [20]). Many studies examined the effectiveness of age simulation on attitudes toward the elderly. Questionnaires such as The Aging Semantic Differential (ASD), The University of California Los Angeles Geriatric Attitude Scale (UCLA_GAS), The Maxwell-Sullivan Attitudes Survey (MSAS), Kogan’s Attitude to Old Person Scale were used in previous studies [21]. Kramersmeyer [22] used a different assessment approach. He used the construct sensitization to collect data about young people’s sensitivity of technical education. It consists of the substructures of motivation, emotion and cognition. Sensitivity, then, is the emotional, cognitive and motivational state of the person actively or passively acquired through an impulse for a specific topic [22]. This construct also makes it possible to investigate the effect of a training to sensitization of employees in the care of the elderly to age-related changes. In most cases only a certain number of age simulation suits are available for training measures. Up to 10 min or more are required to put on a suit [9]. A lot of time is needed to give all participants the opportunity to try the suit. For use in studies or education, this is easier to implement than in everyday professional life. Organizational obstacles that stand in the way of employees being released from work are a high reason for foregoing further training [23]. Accordingly, the timetable should be kept as compact as possible. In order to save time, it is a good idea not to put every workshop participant in a suit, but that one part of the training participants observes the intervention. This would allow more participants to be effectively trained in less time. Also it saves financial resources. The question now is whether the same sensitization effects can be achieved between the groups, if one group experience the age simulation and the other group observe the experiencing group. For this study it was then hypothesized

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that wearing an age simulation suit (experiencing group, intervention) may result in sensitization levels to age related impairment than by observing the intervention (observing group, control).

2 Methods To answer the research question, a further training course was developed for employees in outpatient and inpatient elderly care. The main topic was “Experiencing Age”. Through a requirements analysis theoretical and practical contents of the individual modules were collected. With experts from the field of elderly care the modules were coordinated. Following an agreement on a practical timetable, a further training period of 120 min was set. The trainings program “Experiencing Age” consists of 3 sections. The first module includes theoretical fundamentals. Besides information about demographic change in Germany, typical age-related changes and their impact on daily life were addressed. Physiological changes concerning the vision, hearing, tactile sense and the musculoskeletal system were explained. The second part includes trying out the Age Simulation Suit. The modular age simulation suit “MAX” used in our study, was developed from 2007 to 2010 at the Chair for Ergonomics and Innovation, Chemnitz University of Technology in cooperation with an automotive group. The concept of this suit is based on more than 200 different scientific studies in the fields of work science, medicine, sports science and gerontology [9]. Through the specific restriction of the perceptional ability (vision, hearing, tactile sense) and motor skills, people can experience the age-related changes within a short time. For vision impairment, specially developed glasses are used which reduce the field of vision and visual acuity (visual acuity) and cause lens opacity with color filtering. In the case of hearing impairment, capsule hearing protectors are used, which reduce the acoustic recording capacity in the desired frequency range. The reduced ability of haptic perception is simulated using thin gloves. Special joint cuffs and weights are used to limit the conditional and coordinative abilities. In addition, the fit of the suit influences the flexibility of the spine. Especially in the area of the lumbar spine there is a high reduction of the normal movement amplitude of a healthy young person. The Experiencing group (intervention group) performed several tasks of daily living (climbing stairs, sitting and getting up, combing hair, going to toilet and bed, communicate, take medicine out of packaging, and other tasks) in the age simulation suit, while the observing group (control group) observed their colleagues performing these tasks. Based on this, the participants were assigned to the groups “observing the age simulation” and “experiencing”. In the last part of the training course, both groups discussed their experiences together. The following questions and suggestions were put into the round. • • • •

Please describe how you perceived the activities! What was particularly difficult or what surprised you? Do you know these experiences from their dealings with older people? Does the suit reflect reality?

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Setting and Participants

For the study various social service providers (outpatient and inpatient elderly care) were able to register for the 120 min training course “Experiencing Age” voluntary and free of charge. 40 service providers used this offer. The trainings were completed in the respective care facilities or their headquarters. The analysis included 330 persons (observing group n = 133, experiencing group n = 197) from the field of inpatient and outpatient geriatric care. The participants had an average age of 36,2 years (SD = 14,2, range 17 to 63), 50 (15,4%) were male and 275 (84,6%) females. The statement regarding the sex is missing for 5 participants. The current professional activity has been carried out by the participants for an average of 6,3 years (SD = 7,43). Both newcomers (0 years of experience) and long-term care givers (35 years of experience) attended the training. The average contact frequency of the participants with elderly is 5,7 (SD = 1,86) and is closer to the end of the scale (1–7). 2.2

Data Collection

The first questionnaire (baseline comparison) covers general demographic issues (age, gender, profession, years of service) and the subjective estimation of contact to older people (“Please estimate how often you deal with older people in your current work!”) on a 7-point Likert scale (1 - never and 7 - always). Furthermore, the participants were asked to state their subjective expertise, methodical competence, social competence, learning competence, communication competence and self-competence, especially in relation to the elderly. A 6-point Likert scale ranging from 1 (not competent at all) to 7 (very competent) was used for the competence ratings. This questionnaire was completed after the introductory round and before the main training and served to check whether both groups had comparable starting conditions with regard to their subjectively assessed competence. The second questionnaire was completed immediately after the event. The questionnaire is based on items of professional competence [24] and was evaluated and modified by four experts before the application. Participants were asked to assess on a 6-point Likert scale (does not apply at all to is absolutely apply) to what extend their interaction with older people will change as a result of the training. A confirmatory factor analysis (CFA) was conducted to examine if the three sensitization factors postulated by Kramersmeyer [22] can also be gathered by the used item pool. The cognitive component is covered by 9 items (e.g.: “Identifying problems and changes in my field of expertise will be easier for me.”), the emotional component is covered by 4 items (e.g.: “I will raise more understanding for older people.”) and the motivational component by 11 items (e.g.: “The event inspired me to find out more about other topics.”). Reliability, as indicated by Cronbach’s alpha, was excellent for each scale (aCognition = ,92, aEmotion = ,92, aMotivation = ,94). 2.3

Data Analysis

Data analysis was performed using IBM SPSS Version 25.0. Only participants who completed the second questionnaire were included in the analysis. As a result,

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34 (9,34%) participants with incomplete data were excluded from the further analysis. Average values were calculated for the three sensitivity scales. Because the assumptions regarding normal distribution for parametric tests were not met, the nonparametric Mann-Whitney-U-test was conducted to analyze the differences in sensitivity. Statistical analyzes tested bilaterally at 5% significance level. A manipulation check using a one-factor Anova (factor: Observing or Experiencing) was used to analyze group differences in baseline data (competence check).

3 Results The results of the ANOVA with the factor (Observing or Experiencing) shows no significant differences between the groups in the baseline comparison. It can be seen that the participants’ assessments are at the upper end of the scale. All values are over 5 on the 7-point Likert scale. Participants who have worn the modular age simulation suit did not differ statistically significant regarding their contact frequency with elderly and self-assessed competencies from the participants who were only observing. Table 1 shows the results separated by scales. Table 1. Results of the competence check between the experiencing and observing group Scale Contact frequency Expertise Self competence Social competence Methodical competence Communication competence Learning competence

M (SD) Experiencing 5,80 (1,80) 5,41 (1,13) 5,59 (0,92) 5,73 (0,83) 5,20 (1,16) 5,62 (0,90) 5,32 (1,00)

Observing 5,62 (1,94) 5,33 (1,24) 5,65 (0,89) 5,56 (0,99) 5,25 (0,98) 5,64 (0,87) 5,37 (0,99)

df 1,307 1,309 1,310 1,308 1,309 1,308 1,309

F 0,66 0,35 1,36 2,71 0,15 0,07 0,16

p-value ,417 ,553 ,550 ,101 ,702 ,792 ,686

By contrast the baseline, significant differences were found between the groups in all factors of sensitivity (cognition, emotion and motivation) after the further training “Aging Experiencing”. For the factor cognition there is a significant main effect of the age simulation suit. The non-parametric Mann-Whitney U tests (U = 15518,00, z = 2,85, p = ,004, r = ,16) confirm that people wearing the age simulation suit have significantly higher scores on the scale cognition as persons who have only observed the intervention. Similar results are also shown for the dimension emotion (U = 15281,00, z = 2,60, p = ,009, r = ,14) and motivation (U = 15071,0, z = 2,32, p = ,020, r = ,13). According to Cohen [25], for all factors, a small effect can be detected by wearing the age simulation suit (0,1 < r < 0,3). The mean values of the individual sensitivity factors are shown in the lower table (Table 2).

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Group Observing Experiencing Emotion Observing Experiencing Motivation Observing Experiencing

N 133 197 133 197 133 197

M 4,76 5,03 5,12 5,32 4,65 4,87

SD 0,85 0,73 0,80 0,76 0,86 0,80

4 Discussion and Conclusion The baseline survey found no differences between the groups. Accordingly, both groups have the same prerequisites. For the sensitization, all participants show high values on the scales cognition, emotion and motivation. Due to the wearing and the experiencing the age simulation suit, the participants who have worn the suit show higher sensitization values immediately after the event than the group of participants who have not worn the suit or have not worn it completely. This can be used to confirm the original hypothesis. Similar to previous studies [14, 15, 26], wearing an age simulation suit results in significant differences between those who wore it and those who did not. In contrast to existing studies, the groups (experiencing and observing) were not strictly separated in the present study. Both groups had contact with age simulation, whether direct or indirect. This makes the results all the more important. The high scale values of the observation group indicate that sensitization is also achieved through observation and joint reflection and that individuals can thus indirectly benefit from age simulation. Nevertheless, there is a significant difference between the groups. This illustrates the high importance of continuing education with age simulation and that it should be tried out if time remains. In order to be able to integrate training into day-to-day business, a time and economic training concept is important. The method used here to combine experiencing and observing seems to be a first approach to keeping the training courses lean, but nevertheless to sensitizing them. Further studies should follow to compare the concept with a control group. It is also necessary to carry out further research to check what proportion of age simulation is actually necessary to achieve an effect. 4.1

Limitation

Since the age simulation suit MAX has a modular design, individual components (glasses, capsule hearing protectors, gloves) can be tested independently of the entire suit. This means that subjects from the observation group have partially tested individual components of the age simulation suit. Especially the simulation glasses and the capsule hearing protectors were tried out. Alone the wearing of these components could lead to a sensitizing effect and explain the high evaluation points by the observing group. Therefore, as proposed by Coelho [27], the effect of individual components of the suit should be investigated. Similarly, this study lacks a control group that includes

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only the informational intervention. However, a control group with no intervention at all could not be provided due to the existing conditions of the training “Experiencing Age”. It should also be noted that the wearing of the age simulation suit was done on a voluntary basis. Furthermore, the extent to which gender has an influence was not taken into account. The question remains unanswered whether any training measures are sustainable and favor a relevant change of behavior in favor of those affected. 4.2

Practical Implication

The study was able to show that continuing education through age simulation also has an effect on experienced geriatric care givers. The study situation indicates that the application of the described training measures currently only takes place in nursing care. Due to demographic change, new target groups are emerging for this topic. In the field of barrier-free construction, for example, there are many stakeholders who need to be informed or sensitized to the needs of their clientele with age-related restrictions. Consequently, the authors see future training needs for craftsmen, architects, but also employees of housing cooperatives. This justifies further research needs and the examination of whether the results can also be transferred to other occupational directions. 4.3

Conclusion

The aim of the study was to examine whether an intervention with age simulation suit causes greater values in the sensitivity to age-related impairment than observing the intervention. Significant differences between the groups were found. The present study complements the training concept “Instant Aging” with the setting of observation, thereby providing a new approach to reviewing the effectiveness of age simulation in raising the sensitivity of caregivers. Furthermore, the high scale values of the observation group show that this approach can be a possible method to sensitize many participants quickly and effectively. Acknowledgements. This research was partially supported by the German Federal Ministry of Education and Research (project: “Chemnitz + Zukunftsregion lebenswert gestalten”, 02K12 8010). The sponsor had no role in the study design, the collection, analysis and interpretation of data, the writing of the report, or the submission of the paper for publication. We are very grateful to Anne Zeiler for her assistance with data analysis.

References 1. Pötzsch, O., Rößger, F.: Bevölkerung Deutschlands bis 2060. 13. koordinierte Bevölkerungsvorausberechnung (2015). https://www.destatis.de/DE/Publikationen/Thematisch/Bevoel kerung/VorausberechnungBevoelkerung/BevoelkerungDeutschland2060Presse5124204 159004.pdf?__blob=publicationFile. Accessed 14 Feb 2019 2. Dinkel, R.H.: Die langfristige Entwicklung der Sterblichkeit in Deutschland (The long-run development of mortality in Germany). Zeitschrift fur Gerontologie und Geriatrie (2002)

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3. Viehweger, A.: Ein Plädoyer für bezahlbares Wohnen. In: Buchenau, P., Geßner, M., Geßner, C., Kölle, A. (eds.) Chefsache Nachhaltigkeit, pp. 269–286. Springer, Wiesbaden (2016) 4. de Abreu, I.D., Hinojosa-Lindsey, M., Asghar-Ali, A.A.: A simulation exercise to raise learners’ awareness of the physical and cognitive changes in older adults. Acad. Psychiatry: J. Am. Assoc. Dir. Psychiatr. Resid. Train. Assoc. Acad. Psychiatry 41(5), 684–687 (2017) 5. Yu, C.-Y., Chen, K.-M.: Experiencing simulated aging improves knowledge of and attitudes toward aging. J. Am. Geriatr. Soc. 60, 957–961 (2012) 6. Mast, M.E., Sawin, E.M., Pantaleo, K.A.: Life of a caregiver simulation: teaching students about frail older adults and their family caregivers. J. Nurs. Educ. 51(7), 396–402 (2012) 7. Johnson, C.E., Jilla, A.M., Danhauer, J.L.: Didactic content and experiential aging simulation for developing patient-centered strategies and empathy for older adults. In: Seminars in Hearing (2018) 8. Tullo, E.S., Spencer, J., Allan, L.: Systematic review: helping the young to understand the old. Teaching interventions in geriatrics to improve the knowledge, skills, and attitudes of undergraduate medical students. J. Am. Geriatr. Soc. 58(10), 1987–1993 (2010) 9. Scherf, C.: Entwicklung, Herstellung und Evaluation des Modularen AlterssimulationsanzugseXtra (MAX), 1st edn. Universitätsverlag der TU Chemnitz, Chemnitz, Sachs (2014) 10. Pacala, J.T., Boult, C., Hepburn, K.: Ten years’ experience conducting the Aging Game workshop: was it worth it? J. Am. Geriatr. Soc. 54, 144–149 (2006) 11. Groza, H.L., Sebesi, S.B., Mandru, D.S.: Age simulation suits for training, research and development. In: Vlad, S., Roman, N.M. (eds.) International Conference on Advancements of Medicine and Health Care Through Technology, IFMBE Proceedings, Cluj-Napoca, Romania, 12–15 October 2016, vol. 59, pp. 77–80. Springer, Cham (2017) 12. Pacala, J.T., Boult, C., Bland, C., O’Brien, J.: Aging game improves medical students’ attitudes toward caring for elders. Gerontol. Geriatr. Educ. 15, 45–57 (1995) 13. Chen, A.M.H., Kiersma, M.E., Yehle, K.S., Plake, K.S.: Impact of the geriatric medication game® on nursing students’ empathy and attitudes toward older adults. Nurse Educ. Today 35, 38–43 (2015) 14. Turpie, I.D., Bloch, R., Edwards, M., Rangachari, P., Patterson, C.J., Tainsh, S.M.: A program to sensitize students to issues of geriatric care. Acad. Med. 67, 304–306 (1992) 15. Evans, S., Lombardo, M., Belgeri, M., Fontane, P.: The geriatric medication game in pharmacy education. Am. J. Pharm. Educ. 69, 46 (2005) 16. Chen, A.M.H., Kiersma, M.E., Yehle, K.S., Plake, K.S.: Impact of an aging simulation game on pharmacy students’ empathy for older adults. Am. J. Pharm. Educ. 79, 65 (2015) 17. Filz, S., Swoboda, W., Voelker, W., Faller, H., Jelitte, M.: Mit Simulation die Fähigkeit zum Perspektivwechsel erhöhen. Geriatr. J. 2009, 37–39 (February 2009) 18. Douglass, C., Henry, B.W., Kostiwa, I.M.: An aging game simulation activity for allied health students. Educ. Gerontol. 34(2), 124–135 (2008) 19. Lucchetti, A.L.G., Lucchetti, G., de Oliveira, I.N., Moreira-Almeida, A., da Silva Ezequiel, O.: Experiencing aging or demystifying myths? Impact of different “geriatrics and gerontology” teaching strategies in first year medical students. BMC Med. Educ. 17, 35 (2017) 20. Fink, S., Rüffert, D.: Altersbilder junger Erwachsener. In: Aw&I Conference, Bd. 3 (2018): innteract2018 (2018) 21. Wilson, M.A.G., Kurrle, S., Wilson, I.: Medical student attitudes towards older people: a critical review of quantitative measures. BMC Res. Notes 11, 71 (2018) 22. Kramersmeyer, J.: Nachhaltige Sensibilisierung von Jugendlichen für technische Bildung. Sensibilität im pädagogischen Kontext. Didaktik in Forschung und Praxis, vol. 82 (2016) 23. IW-Trends- Vierteljahresschrift zur empirischen Wirtschaftsforschung

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Strength and Motor Function in an Aging Population in Dependence to Work Position Marek Bures(&) and Vera Cadkova University of West Bohemia, Regional Technological Institute, Univerzitni 8, 30614 Pilsen, Czech Republic {buresm,cadkovav}@rti.zcu.cz

Abstract. The paper aims at clarification if a job type has an influence on three physical properties of humans. Those are dexterity of fingers and hands, grip strength and range of motions. A group of 67 manual and 99 office workers both males and females in different age groups were assessed by Purdue Pegboard Test, Grooved Pegboard Test and Complete Minnesota Dexterity Test. For hand grip the Jamar dynamometer was used and range of motions were measured by standard goniometers. In dexterity area male office workers proved higher dexterity than manual in all kinds of testes. Female office workers proved significant differences only in half of the tests. Grip strength differences were not statistically significant between office and manual workers. Only differences between males and females were confirmed. Regarding range of motions male office workers had better values only in 7 joints from 36, however females had better values in 22 from 36 joints. Keywords: Demographic changes Range of motions  Job type

 Hand dexterity  Grip strength 

1 Introduction Nowadays, the demographic changes and an aging population affect mainly Europe and part of Asia, by the end of the 21st century other continents and countries will follow. Based on the [1] there are three trends which are responsible for these demographic changes: continued rise in life expectancy due to better healthcare, the increase in the number of people aged 65+ years and constantly low birth rate, i.e. low fertility. Preston et al. [1] states that population ageing is caused by falling in mortality since the 1970s among older people rather than low fertility. United Nations statistics indicates that the ratio of people aged over 65 years to the people aged 15–64 years will increase from 26.4% in 2015 to 48.7% in 2050. In 2100, this ratio is expected to increase to 54.6%, i.e. two people in working population for each person aged over 65 years. This phenomenon will have a massive impact on working population. Many countries are already developing strategies to improve working conditions for people who choose to work after 60 or 65 years of age. Nevertheless, the employment of people aged over 50 years is problematic in many countries. In Europe, employment of people over 50 is improving due to the evolving strategy and labor shortages. According to Eurostat, the average employment of persons over 50 years of age was 55.2%. © Springer Nature Switzerland AG 2020 R. S. Goonetilleke and W. Karwowski (Eds.): AHFE 2019, AISC 967, pp. 348–359, 2020. https://doi.org/10.1007/978-3-030-20142-5_35

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With aging, health problems and chronic illnesses are becoming more frequent as a result of changing physiology. The most common physiological changes are e.g. reduced physical fitness, reduced range of motion in joints, motor disorders, deteriorated senses such as sight and hearing, and many others. These changes cause the need to change the working environment so that older people do not retire early. In our research, we focused on three areas: range of motion, motor skills and physical strength, and relations between these areas. The results will be used to improve the working conditions of aging people in the workplace. Mobility of joints is necessary for performing the movement in the corresponding range. Within the industrial practice the range of motions (ROM) are extremely important in workplace design and design of various equipment and tools [2, 3]. Dexterity tests are usually used to assess motor abilities. These tests are most often used in healthcare for evaluation of improvement in patient’s condition after injuries or illnesses [4, 5]. Dexterity tests are also used in industrial companies, e.g. for convalescence of workers after illness or for recruitment of new workers [6]. The hand grip is important for many common daily activities like eating, dressing, personal hygiene, writing or computer use. The measurement of grip strength is used primarily in physiotherapy and orthopedics to determine the severity of injuries, to monitor the process of recovery or changes in health status. The authors of previous research have already dealt with the development of physiological changes in these areas however, the mutual relations between areas have not yet been explored. In this paper we would like to explore the relation between physiological changes and job type. The following hypotheses were stated. • H1: Higher dexterity of fingers and hands will occur at employees working on manual job type rather than office workers. • H2: Higher grip strength will occur at employees working on manual job type rather than office workers. • H3: Lower range of motions will occur at employees working on manual job type rather than office workers. To verify all hypotheses, measurements of dexterity, different kinds of grip strengths, and a range of joint movements for a selected sample of subjects were performed. The methodology was described in detail in [7]. The proposed measurement methodology is based on a literature review and recommended practices. Clear measurement rules have been established to make results comparable to previous studies.

2 Methodology 2.1

Participants

A group of females and males from the Czech population aged 20 to 75 years were measured and evaluated. In total we measured 86 females (38 manual work, 48 office work) and 80 males (29 manual work, 51 office work) in different age groups as described in Tables 1 and 2. The females have been divided into five age groups, males only to four age groups as there were so few participants above age 55. This merging

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was done due to statistical analysis. Averages of height, weight and BMI can be also seen in the table. Those data nicely show how weight and BMI is raising with higher age and on the other hand the height is lowering with higher age. Except of those characteristics we gathered data about laterality, job type, health status, sports activities and if the participant is smoker or not. Most of the participants, especially the younger ones, didn’t have any serious health problems or movement disorders. Most of them was university students or administrative employees who work mostly sitting with a computer. Participants above 30 years were from various industrial companies either working in the office (administration or technicians) or in the production. Some of them, especially production workers, had some health problems such as back pain (mainly lumbar spine), prolapsed intervertebral discs, hip surgery, tendonitis in the wrist, broken wrist, rheumatism and others. The results were not used in the statistical evaluation if the health problems were more serious and visible during the measurement (especially ROM). Table 1. Female participants’ characteristics. Age group 20–29 30–39 40–49 50–59 60–75

Amount N = 31 N = 11 N = 13 N = 16 N = 15

Weight in kg 64.31 (±11.3) 69.27 (±14.4) 78.69 (±14.8) 80.56 (±19.7) 78.87 (±11.2)

Height in cm 168.3 (±6.6) 168.4 (±7.5) 166.5 (±5.6) 162.5 (±5.9) 166.2 (±4.2)

BMI 22.66 24.36 28.54 30.30 28.60

Table 2. Male participants’ characteristics. Age group 20–29 30–39 40–49 50–65

Amount N = 36 N = 22 N = 10 N = 12

Weight in kg 81.67 (±9.6) 87.59 (±15.7) 90.80 (±19.6) 92.08 (±13.8)

Height in cm 181.0 (±5.9) 182.1 (±8.0) 181.6 (±7.9) 176.6 (±8.4)

BMI 24.94 26.32 27.27 29.57

Each of these participants completed and extensive assessment. The dexterity and motor skills were assessed by Purdue Pegboard Test, Grooved Pegboard Test and Complete Minnesota Dexterity test. The hand strength was evaluated on 3 types of hand grips and was measured by Jamar dynamometer. The ranges of motions were assessed on arm (wrist, elbow and shoulder joints) and trunk joints and were measured by standard goniometers. 2.2

Measurements

Measuring of each participant was done in the same way. At the beginning the personal data were entered into the measurement protocol and then the measurement started.

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Firstly the ranges of motion (ROM) were measured according to the methodology of American Academy of Orthopedic Surgeons (AAOS) which is most commonly used. It was measured 20 joints movements on neck, torso and arms, 16 of them were measured bilaterally. Each movement was always explained and demonstrated to the participant. Then the active movement in each joint using Jamar steel goniometers was measured until the deviation between the two measurements wasn’t biggest than 4°. The result was then the average of these two values [3]. First the shoulder was measured, then the elbow, wrist, neck, and lumbar spine. Next, the maximum grip strength was measurement using the Jamar Plus+ dynamometer, whose handle was set to the second position which, according to the [8, 9], is the best position to exert the greatest force. First, the maximal voluntary grip force (MVGF) of the palmar grip was measured, then the key grip and the pinch grip. The standard procedure and standard test position recommended by American Society of Hand Therapists have been followed [10]. First the subject performed a trial round of measurement on both hands in order to warm up the muscle, then the measurements were made three times for each hand and each grip as is recommended in the user guide or in Hanten et al. [10], Mathiowetz et al. [11] or Innes [12]. The hand was changed in each round and after each round was one minute rest for muscle regeneration as described also in [12]. Last, measurements of the hand motor skills with dexterity tests were performed in the following order: 1. Complete Minnesota Dexterity Test (CMDT), 2. Purdue Pegboard Test (PPT), 3. Grooved Pegboard Test (GPT). The process of all tests was performed on the basis of instructions from manuals and recommendations from previous studies. The CMDT can be used to measure manual dexterity of arms, hands and overall eye-hand coordination. Based on test type and test board size it was selected the standing position for performing the test which was confirmed by [13]. According to ergonomic standards, the ideal working height is between 90 and 110 cm depending on the sex so it was chosen 100 cm for testing. The CMDT is composed of two boards with holes and 60 short round red-black blocks. The test consists in placing the round blocks in the plate holes, rotating them and combining these two movements. This will create a series of five subtests: placing test, turning test, displacing test, one-hand turning and placing test and two-hand turning and placing test. Completion time was measured for all subtests and each subtest was repeated three times. PPT is used to measure finger dexterity using three objects, collars, washers and pegs that are inserted on a pegboard [14]. The PPT consisted of four subsets. In the first three subsets, each participant has 30 s to fill the holes with pegs firstly with the dominant hand, then with the non-dominant hand, and finally with both hands simultaneously. In the fourth subset, participant has 60 s to assemble in sequence a peg, a washer, a collar, and then another washer with both hands. The score of all subtests is calculated as the number of placed pieces. Based on the PPT manual, previous studies and the nature of the test, it is recommended to do it in a sitting position. The test was

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repeated three times, which is sufficient according to [15], then the average was calculated from the repetition. The last test was GPT which consist of 25-holes desk in which the pegs are being inserted. GPT has only two subtest. The first subtest is performed by the dominant hand, the second by the non-dominant hand. Time needed to fill all holes with pegs is measured. GPT is very similar in nature to PPT the only difference is that GPT requires even more precise and fine handling of pegs. Therefore, it was decided that the test participants will also sit during the test and that the test will be repeated three times as in previous cases. There are not many studies containing normative data for GPT [16, 17] so the results of this study will be very useful. 2.3

Statistical Evaluation

For the statistical evaluation the Matlab R201ne7a software was used. First of all, the obtained data were tested for normality by Jarque-Bera test and Lilliefors test in order to decide if we should use parametric or nonparametric statistical tests. Usually the data were not normal, so we used non-parametric Wilcoxon test for two independent samples. We tested the null hypothesis at level of significance 0.05 that data by manual workers and office workers are samples from continuous distributions with equal medians, against the alternative that they are not. We rejected the null hypothesis if pvalue of the test is less than level of significance. It means that results of manual and office workers are not samples from distribution withe equal medians and there is difference between them.

3 Results 3.1

Dexterity and Motor Skills

The Wilcoxon test showed that there is a difference between manual and office workers in all skill tests in men and in some skill test in women. See Table 3 where are medians of all tests scores and p-value of Wilcoxon test. We rejected hypothesis about the same medians when p-value of test is smaller than 0.05. In case of men it is in all tested variation, in case of women we rejected the null hypothesis only in 5 test variations. Males: In all three tests the office workers had better results than manual workers. In PPT the office workers manage to place more pieces and in GPT and CMDT they were able to perform the test quicker. Females: In PPT there is a significant difference between manual and office workers only in 1st and 4th test, it means where the test was done with dominant hand and in assembly from pin, pad, and collar with both hands. Office workers had better results than manual in these tests. In GPT there is a significant difference in both variation and office workers had better results than manual workers as they have been able to perform the tests in shorter time. In the last CMDT there were the significant differences only in 1st and 2nd test variation, it means in placing test and turning test. Office workers had better results than manual workers as they performed the test in shorter time except the 4th test (turning and placing with one hand).

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Table 3. Medians of scores and p-values of Wilcoxon test, test variation are numbered by order in Sect. 2.2 Test variation PPT [pcs.]

1 2 3 4 GPT [score] 1 2 CMDT [score] 1 2 3 4 5

Males Manual 15.33 14 11.67 29.67 84.67 90 198 168 150 237 153

Office 16 15 12.67 38.33 78.67 81.33 181 146 130 217 129

p-value 0.028 0.002 0.002 3.00. In terms of the experience of pain, the ‘pain’ MS between 0.00 and 9.00 is based upon the percentage responses to a ten-point scale of: never; monthly at home; monthly at work; monthly at work & home; weekly at home; weekly at work; weekly at work & home; daily at home; daily at work, and daily at work & home. MSs < the midpoint of 4.50 indicate that they do so infrequently as opposed to frequently. The lower back (3.75) has the highest MS, followed relatively closely by the left foot (3.62). Table 12. Frequency at which respondents’ use and experience pain in 32 anatomic regions. Anatomic region Lower back Left foot Right foot Left upper arm

Use MS 3.27 3.68 4.16 3.82

Rank 19 8 1 5

Pain MS 3.75 3.62 3.35 2.89

Rank 1 2 3 4 (continued)

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Table 12. (continued) Anatomic region Right upper arm Right shoulder Upper back Left hand (palm) Pelvis Left shoulder Left lower leg Right hand (palm) Right forearm Left elbow Right elbow Left eye Left forearm Right eye Left wrist Head Left knee Right knee Right wrist Left upper leg (thigh) Right lower leg Neck Right ankle Chest Left ankle Right upper leg (thigh) Left ear Right ear

Use MS 3.92 3.76 2.75 4.16 3.91 3.35 3.22 3.08 3.65 3.42 3.72 3.32 3.58 3.40 3.25 2.84 3.05 3.32 3.06 3.06 3.59 2.48 2.71 2.26 2.65 3.52 3.09 3.54

Rank 3 6 28 2 4 16 21 23 9 14 7 17 11 15 20 27 26 18 24 24 10 31 29 32 30 13 22 12

Pain MS 2.68 2.49 2.46 2.40 2.08 2.03 1.78 1.77 1.75 1.69 1.68 1.49 1.40 1.35 1.35 1.23 1.15 1.14 1.12 1.09 1.05 1.03 0.95 0.92 0.89 0.75 0.18 0.17

Rank 5 6 7 8 9 10 11 12 13 14 15 16 17 18 18 20 21 22 23 24 25 26 27 28 29 30 31 32

5 Conclusions The findings of the study overall indicate shortcomings in workers’ perceptions with respect to the frequency of use of the various anatomic regions, and their experience of pain. Environmental conditions such as working in heat, cold, humidity, and in noisy areas featured to varying degrees. Working in heat achieved a rank of 5th, cold 10th, noise 12th, and are aspects that could be deemed to affect workers, and which can be addressed through engineering modifications. Bending or twisting the back, repetitive movements, handling heavy materials, and reaching away from the body predominate in terms of ergonomics problems

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encountered. Given that the respondents cited these as frequent as opposed to infrequent, the work can be deemed repetitive in nature in general. The right foot, left hand, upper arms, and pelvis are the anatomic regions mostly used, and each within the top 10 areas where pain is experienced. This is attributable to the nature of the work. Age is a consideration to be addressed as 28% of workers are older than 40 years of age, and given the reduction of physical ability to work, the need for the work processes to and the work environment to be reviewed requires. Reference to ergonomics as part of work instructions by supervisors achieved a MS of 2.92/5.00, which indicates that ergonomics is not a value in the work place. The number of casual or contract workers was marginally more than those who were permanently employed (45%). The contractual nature of employment is known to be more stressful as such employment is of limited duration. Stress exacerbates physical conditions and could increase the likelihood of symptoms or occupational disease. Where workers experience symptoms of such illness, the reporting process to the Compensation Commissioner for costs and possibly compensation could have negative effects on the claims ratio of the organization and increase the stress levels of the worker and their family.

6 Recommendations Training of workers in positional work and working with load, investigating the ability to sit while working and worker participation in ergonomic solutions are selected recommendations. Workers should be reminded of positional work and ergonomic related risks relating thereto when commencing a task, or series of tasks, by supervisors. The prevalence of the predominating ergonomic problems is reinforced by the ‘ergonomic’ aspects which predominate in terms of degree of attention required, namely: things within easy reach; adjustable work surfaces; being able to sit down; elbow height work, and mechanical assistance. Areas of work where repetitive tasks are more than 50% of a shift could be assessed, and worker rotation instituted. Older workers benefit the environment with positive culture, and experience, but may not be able to do the physical level of work required, and alternative work, mentoring and fewer extreme physical tasks could be considered. Claims to the Compensation Commissioner are laborious and onerous on all parties and should be avoided at all costs. Risks identified in this research could be used by the H&S staff to identify other risks not previously considered and used in training and further changes to the processes and the building itself. Doing so will be in line with the incoming Ergonomic Regulations, and assist with compliance thereof.

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References 1. Republic of South Africa: Government Gazette No. 14918. Occupational Health & Safety Act: No. 85 of 1993. Pretoria (1993) 2. Republic of South Africa: Draft Ergonomics Regulations No. 40578. Pretoria (2017) 3. Bush, P.M.: Ergonomics: Foundational Principles, Applications, and Technologies, 1st edn. CRC Press, New York (2011) 4. Crawford, J.O.: Ergonomics and human factors. In: Snashall, D., Dipti, P. (eds.) The ABC of Occupational and Environmental Medicine, 3rd edn., pp. 107–112. Wiley, London (2012) 5. Republic of South Africa: No. R. 84 Occupational Health and Safety Act, 1993 Construction Regulations 2014. Government Gazette No. 37305. Pretoria (2014) 6. Makhbul, Z.M., Abdullah, N.L., Senik, Z.C.: Ergonomics and Stress at the Workplace: Engineering Contributions to Social Sciences. Jurnal Pengurusan 37, 125–131 (2013) 7. Republic of South Africa: Government Gazette No 15158. Compensation for Occupational Injuries and Diseases Act: No 130 of 1993. Pretoria (1993) 8. Harper, S.: The ageing workforce. In: Snashall, D., Dipti, P. (eds.) The ABC of Occupational and Environmental Medicine, 3rd edn., pp. 117–121. Wiley, London (2012) 9. Bihm, J.: An exploratory study of ergonomic work practices in selected small manufacturing engineers. Unpublished Masters of Commerce Degree in Management, Faculty of Management, University of Kwa-Zulu Natal, Durban (2004) 10. Smallwood, J.J., Deacon, C.H.: Ergonomics in printing: workers’ perceptions of strain. In: Proceedings of the XVth Triennial Congress of the IEC Association and the 7th Joint Conference of the Ergonomics Society of Korea/Japan Society, 24–29 August, CD-Rom \00545.pdf (2003)

Enhancing the Life of the Elderly An Application of Design Thinking Ravindra S. Goonetilleke(&) and Emily Yim Lee Au Department of Industrial Engineering and Decision Analytics, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong [email protected], [email protected]

Abstract. Design thinking is a mindset to find a solution for a real need using an iterative method. Its fundamental philosophy is to empathize and reframe a problem so that one can innovate faster using systematic methods. In this study, we illustrate the use of design thinking to enhance the life of older people. A total of forty students from two universities spent 2 days talking and playing with senior citizens to evaluate and understand their daily activities, likes and dislikes. Based on observations, systematic interviews, and storytelling, a series of innovative products were designed. In this manuscript, two of them will be described. The first was an entertainment system called Memo-TV for those with short-term memory loss and the second, Shadow Play, was a means to enhance their upper body strength using an innovative and interactive game. Keywords: Design thinking

 Design  Elderly  Internet of things

1 Introduction Successful products need to provide the necessary functions, offer acceptable return on investment, generate enthusiasm in the market and meet global standards related to environmental sustainability. However, the success of a product cannot depend only on its technical merits. The usability and aesthetically pleasing appearance is much sought out today leading to more important user-centered or empathy-driven design. Designing products by identifying a problem, reframing the problem, ideating, prototyping and testing is known as Design Thinking (Fig. 1) [1–4]. Rather than make products based on a company’s capabilities, the design thinking process starts with the user. It is an effective methodology to use when designing products for older people as many of them have physical, cognitive and emotional needs. There are different versions of this methodology such as inspiration, ideation, implementation; dream, design, do; discover, dream, design, deliver; discover, interpret, ideate, experiment, evolve; discover, define, develop, deliver and so on. Even though these may appear to be different, the basic concept is essentially the same with a different emphasis in the various steps involved. Most of the older people experience a negative mood due to differing reasons. They may be sad because they are in their last stages of their lives or because they miss their family or belongings. Human intervention is one way that these elderly can gain some © Springer Nature Switzerland AG 2020 R. S. Goonetilleke and W. Karwowski (Eds.): AHFE 2019, AISC 967, pp. 388–396, 2020. https://doi.org/10.1007/978-3-030-20142-5_39

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Fig. 1. The design thinking process of empathize, define, ideate, prototype and testing. (Adapted from Stanford d-school)

solace. However, that is not always possible. Equipping care centers with intelligent technology to drive the elderly towards more positive experiences will bring added value to their health and well-being [5]. The living environment plays significant role in the quality of life of the elderly. It is sometimes more effective than pharmacological treatment. The question we set out to answer was how we can help the elderly using technology that is concealed so that what is visible maps to the mental model of the elderly. In other words, what is required is invisible technology. The emphasis was primarily on the conceiving and designing of products that would be of benefit to the elderly. Older adults live in a variety of settings known as, “the housing continuum for persons with dementia” [6]. They start from living independently at home and then transition into living institutionally if their health drastically declines, although, most elderly prefer to “age-in-place” [7–10]. The transition from home to a care facility or a day-care center mainly occurs when severe behavioral disturbances make it difficult for caregivers to take care of elderly patients. It also depends on the public care services provided and the availability of family care. In unfamiliar environments, people with dementia can easily become confused, agitated and stressed. They may even behave quite aggressively in some situations. This is related to their “sense of identity”, and the “sense of belonging” in the place where they live. The sense of belonging, which is intrinsic in every individual, is generally sought when individuals move from home to a new living environment (e.g., care facility). It not only represents a personal sense of being part of a certain context, but also the feeling of being accepted as an individual with unique needs for personal space and companionship. The lack of a sense of belonging in a living environment, causes anxiety and stress in people with dementia. These feelings are expressed through purposeless wandering, aggressive and suspicious behavior, agitation, vocalisms, repeated movements, and other “unusual” behaviors. The result is decreased well-being and poor quality of life. The aim of what is reported here was to change the life style of the older people so that they are engaged in activities while maintaining their physical and mental health.

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2 The Process The intellectual domain of product design is rather fragmented among different disciplines because there is no common foundation to address the design issues from the differing perspectives leave alone any interaction or discussion among professionals of the different disciplines. To address at least some issues and generate worthwhile interactions, we proposed to have a design thinking course with one of the finest Art and Design institutions in China, the China Academy of Art (CAA) in Hangzhou. The intention was to offer a unique one-month summer course as a platform for students to train up their ‘Design Thinking’ mindset and resolve constraints arising from technical, aesthetic and human factors, as well as business concerns. This course offered a student an opportunity to work in a multi-disciplinary team comprising designers and engineers to design and develop a real product. The course was aimed at providing the basic concepts of design thinking and design methodology. The goal was for students to be able to apply the concepts of design thinking by integrating their knowledge in the various disciplines to construct a tangible product. This involved building and leading an innovative team as well as working within a group situation comprising different individuals from diverse backgrounds and cultures in order to achieve a common objective. To cater to the differing mental models of students in art, engineering and design, we had to use various formats of teaching to generate an environment that was conducive to divergent and disruptive thinking. Guest speakers formed an integral part of the course to focus on some specialized topics. However, we did have some basic concepts taught in a not so ideal lecture format as well. A total of 20 Hong Kong University of Science and Technology (HKUST) students, together with an equal number of students from CAA were selected after a rigorous interview process to establish their suitability to design and develop products for the elderly. Students from HKUST were drawn from the School of Engineering, School of Business and the School of Science; CAA’s students were from the School of Intermedia and School of Industrial Design. Over the 4-week period, all 40 students spent two weeks at each of the two universities. They certainly benefitted from the multidisciplinary academic exchange and received instruction in areas of design with a special focus on both physical and affective design. Students had to structure problems, create new ideas, be innovative in problem solving, evaluate alternatives and construct product prototypes. Students learnt how to resolve constraints arising from technical, aesthetic, human factors and business concerns to make a successful product. The project deliverable was a product prototype demonstration, a presentation and a public exhibit. They participated in a series of workshops on topics such as principles of design and what design means for each discipline; techniques for idea generation, divergent thinking method and many others. Besides the various workshops, the students were required to work on a project in groups of four with two from each institution. An added constraint was that no two students could have the same background or major. They generated and tested their project ideas and then developed the final prototypes. Students gained hands-on experience by broadening ideas and combining all the technology, for example, software programming, and art elements through the design process.

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During the first few days the two groups of students familiarized themselves as it was a mix of science, business and engineering students with art and design students. A series of ice-breaking exercises were carried out to get-to-know each student in the class. On the second day, the basics of empathy and empathizing techniques such as fly-on-the-wall, interviewing and contextual inquiry were taught and practiced [11]. Empathy, which is understanding what another person is experiencing from their perspective is a key component in design thinking. A field trip to an elderly day care center and an elderly home to meet elderly people was the highlight for the rest of the week. During this time, the students experienced elderly care living, their environment, how they spent their day and most importantly mingling and talking to the elderly. This was one of the highlights for the students as many of them had no little or no knowledge about elderly living. Based on the field visit, each student in the class had to identify at least three problems they had seen or heard. Each of these problems were written on a post-it-note sheet and displayed for all students to view (Fig. 2). Of course, there were some that overlapped or were similar. Those were eliminated. Affinity clustering was the next step (Fig. 3). Thereafter, methods for disruptive innovation were introduced. The main idea was to be able to solve the problem with innovative thinking. There is no one single method for this process. Students were encouraged to try differing methods to match their thinking and analytical capabilities [12–15]. Students were encouraged to work by themselves at first, followed by group discussions (Fig. 4). An example storyboard that was generated is shown in Fig. 5.

Fig. 2. Listing and understanding problems faced by older people living in care facilities.

At this juncture, it was important to consider the motivation al level of elderly and their capabilities prior to embarking on any ideation [16]. The students designed and fabricated many different products. Two of them will be described here.

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Fig. 3. Problem clustering.

Fig. 4. Group interaction and ideation after the problem to be solved was reframed.

Fig. 5. The first storyboard and related comments by others on post-it-notes.

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3 Products to Enhance Living 3.1

Memo-TV

Memory loss is a common problem with older people. In Hong Kong, approximately 8 out of every 100 persons above the age of 65 suffer from dementia. Even though there is no way to prevent dementia, it was hypothesized that cognitive stimulation and reducing boredom may help lower the risk of being diagnosed with dementia. The process workflow for this product is illustrated in Fig. 6.

Fig. 6. The design methodology for the development of the memo-TV.

Most elderly people tend to avoid technology and they have to be comfortable when using such a device. This is where the Fogg motivation-ability curve was helpful [16]. A TV of the 1940s was purchased and only its outside casing was used for the

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project (Fig. 7). Even though the TV was old, it was modified to contain the latest technology. An LED display, a computer and an Arduino board formed the basic framework for the unit. The final product was the memo-TV that was capable of displaying past photos of various sights in Hong Kong, videos, news clippings and music of any chosen decade from 1915–1925 to 2005–2015. The two knobs were used for controlling the decade and the type of entertainment (i.e., new, videos, music or images). The testing was conducted with over 40 elderly participants at a gathering at the HKUST campus (Fig. 8).

Fig. 7. The “ancient” exterior and the state-of-the-art technology in the interior.

Fig. 8. Testing the memo-TV with elderly people.

3.2

Shadow Play

To maintain their physical strength, the people in the care centers are requested to perform pulling and pushing exercises on a regular basis (Fig. 9a). These were deemed to be quite boring and the engagement was rather low. The product developed was a two-person interactive game to maintain their upper body physical strength. With a wheel and a pair of resistance sliders, the two players can control the “old lady on a cart” projected on to a screen safely travel on a path (Fig. 9b). Rewards and “animals” were randomly presented on each track such that the players should either grab the reward or avoid the animal to gain the highest score. One person controls the speed the cart travels by rotating the hand wheel. The higher the wheel speed, the faster the cart will travel. The other person controls the direction of the cart by pulling down on the

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left or right resistance weights. The two players have to collaborate to gain as many points, adding fun to the originally boring exercise routine. The game can be customized too by selecting an optimum speed to change the level of difficulty.

(a)

(b)

Fig. 9. (a) The existing and (b) proposed physical exercise system components: wheel, sliders, visual interface

4 Conclusions The design thinking process was very effective to design and develop new products for the elderly. The empathizing stage of the process revealed the need for new ways of approaching an old problem of changing the mood of the elderly so that they can feel a sense of belonging in the environment they live in. The product testing did show that further improvements were possible. Given the 4-week time period to determine the needs, ideate and fabricate, the students did perform creditably. The products had great appeal with the older people when tested. Acknowledgments. The authors would like to thank all the students and instructors who participated in this course. A special word of thanks to Ms. Karen Kit Sum Chow for arranging the numerous visits to the Sun Chui Lutheran Centre for the elderly, Ms. Diana Chan and Edwin W. K. Leung of the HKUST library for all exhibition arrangements. The memo-TV was designed and developed by Urvil Rakesh Sheth, Naveen Pitipornvivat, Lin Yan Zhao and Zhou Lin Wei. Shadow play was the work of Kwok Hin Kwan, Chau Man Chun, Wang Zi Lin, and Li Jie Ying.

References 1. Kelley, T.A.: The Art of Innovation: Lessons in Creativity from IDEO, America’s Leading Design Firm. Broadway Business, New York (2001) 2. Martin, R.L.: The Design of Business: Why Design Thinking is the Next Competitive Ddvantage. Harvard Business School Press, Cambridge (2009)

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3. Liedtka, J.: Innovative ways companies are using design thinking. Strat. Leadersh. 42(2), 40–45 (2014) 4. Kolko, J.: Design thinking comes of age. Harvard Bus. Rev. 93(9), 66–71 (2015) 5. Fredrickson, B.L.: Cultivating positive emotions to optimize health and well-being. Prev. Treat. 3 (2000) 6. Van Hoof, J., Kort, H.S.: Supportive living environments: a first concept of a dwelling designed for older adults with dementia. Dementia 8(2), 293–316 (2009) 7. Davey, J.: “Ageing in Place”: The Views of Older Homeowners About Housing Maintenance, Renovation and Adaptation. Centre for Social Research and Evaluation, Ministry of Social Development, Wellington, New Zealand (2006) 8. Grabowski, D.C.: The cost-effectiveness of non-institutional long-term care services: review and synthesis of the most recent evidence. Med. Care Res. Rev. 63, 3–28 (2006) 9. Oswald, F., Jopp, D., Rott, C., Wahl, H.: Is aging in place a resource for or risk to life satisfaction? Gerontologist 51, 238–250 (2010) 10. Wiles, J.L., Leibing, A., Guberman, N., Reeve, J., Allen, R.E.S.: The meaning of “aging in place” to older people. Gerontologist 52(3), 357–366 (2012) 11. LaConte, V., Kumar, V.: 101 Design Methods: A Structured Approach for Driving Innovation in Your Organization. Wiley, Hoboken (2012) 12. Osborn, A.F.: Applied Imagination: Principles and Procedures of Creative Problem Solving. Charles Scribner’s Sons, New York (1953) 13. Eberle, B.: Scamper: Games for Imagination Development. Prufrock Press Inc., Waco (1996) 14. De Bono, E.: Serious Creativity: Using the Power of Lateral Thinking to Create New Ideas. Harper Business, New York (1993) 15. IDEO: The Field Guide to Human-Centered Design. IDEO.ORG, Canada (2015) 16. Fogg, B.J.: Persuasive Technology: Using Computers to Change What We Think and Do. Morgan Kaufmann, San Francisco (2003)

Human Listener’s Misperception Between Signal Comprehension in Noise and Noise Acceptability Bankole K. Fasanya(&) College of Technology, Environmental Health and Safety Conc., Purdue University Northwest, Hammond, IN, USA [email protected]

Abstract. Hearing loss in the United States (US) between the ages of 20–69 years old is increasing at an alarming rate and the growth rate of the hearing aid industry is increasing rapidly. These days, many people depend on hearing aids for their hearing effectiveness; therefore, early intervention in hearing protection and hearing loss prevention should not be underrated. Hence, listener’s clarification between signal comprehension in noise (SCN) and tiredness in background noise is important to assist the younger generation to protect their hearing. In light of this, an empirical laboratory study was conducted to determine the differences between signal comprehension in noise and an acceptable noise level (ANL). Thirty students participated in the study with ages ranging from 19 to 44 years old. Babble noise was used as the background noise, while comedian speech was used as the signal. Findings show that the background noise level accepted during an ANL task was 8% higher than the background noise level accepted during SCN. Results further revealed no statistically significant difference between listener’s ANL and SCN (P = 0.0609). Additionally, findings reveal no statistically significant differences of the effect that the background noise level posed on both ANL and SNC. However, listeners were more sensitive toward signal intensity during SCN task than during ANL task. This could be because ANL only measures listener’s willingness to work in noisy conditions while SCN task measures listener ability to seek meaning out of a signal presented in noisy conditions. Findings from this study could be used to assist listeners who are in the habit of setting their music listening volume at high levels while studying. Keywords: Signal-comprehension in noise (SCN)  Sensitivity  Temporal fine structure (TFS)  Acceptable noise level (ANL)  Hearing

1 Introduction Hearing loss in United State (US) between the ages of 20–69 is increasing at an alarming rate. According to Frantz [18] the growth rate of the hearing aid manufacturing industry in the US is rapid as many people now depend on hearing aids for their hearing effectiveness. Therefore, early and continuous intervention in hearing loss protection and prevention should not be underrated. It was acknowledged in the Wayne © Springer Nature Switzerland AG 2020 R. S. Goonetilleke and W. Karwowski (Eds.): AHFE 2019, AISC 967, pp. 397–404, 2020. https://doi.org/10.1007/978-3-030-20142-5_40

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[1] article, that understanding speech in the presence of background noise can be challenging for older adults. The difficulty in speech comprehension and perception in background noise depends on several factors such as age [2], speech rate [3], hearing loss [4] working memory and executive-control processes [5], and speech processing ability [6]. Hearing sensitivity through pure Audiometric testing may not be enough to explain the difficulty associated with the speech perception in background noise [7]. People who find it difficult to understand speech in background noise likewise depends on hearing aids. In 1991, Nabelek et al. [8] developed a metric to measure a listener’s willingness to listen to speech in background noise without being tired. This metric is known as acceptable noise level (ANL). As such, a listener’s willingness and speech perception or comprehension in background noise are two separate metrics to measure listener’s comfortability in noise. Therefore, the hearing satisfaction of the younger generation should go beyond tiredness in background noise and should be extended to the ability to comprehend speech in background noise effectively. Hearing loss among the younger generation is escalating every year. The American Osteopathic Association report confirmed the rate of hearing loss in teens to be 30% higher than it was in the 1990s [9]. The most prescribed solution for hearing impairment with the younger generation is hearing aids, forgotten that hearing aids only amplified sound for hearing sensitivity but do not work properly for frequencies selectivity, which is important for separating speech from background noise [10]. Although Nabelek et al. [19] findings on the comparison between listeners’ speech perception and ANL in background noise confirmed that speech perception in background noise was not related to hearing aid use or satisfaction. However, ANL was found to be related to hearing aid use satisfaction. It is made clear in the Perez et al. [10] study that prior to receiving hearing aids, people who participated in the study completed a test to assess sensitivity to temporal fine structure (TFS) and the hearing performance of listener at pre-fitting is higher with high TFS compared with listener with low TFS listeners. Likewise, a Strelcyk and Dau [11] finding revealed that in multi-talker background noise, sensitivity to TFS was associated with speech reception thresholds, but not against an amplitude-modulated noise masker. Killion et al. [12] findings from the study on normal hearing and hearing impairment listeners revealed that diverse listening conditions in background noise or reverberation frequently cause communication difficulty. Listening in degraded environments, such as with background noise, is a frequent occurrence, as many activities are performed in a natural environment. Therefore, comprehensive research is needed to fully understand the factors contributing to the negative effects of speech comprehension in such environments. The nature of the link between SCN and ANL is not necessarily clear to many listeners, especially the younger generation. Therefore, it is necessary to empirically study listeners and to draw a clear distinction between the two terminologies; Signal Compression in Noise (SCN) and Acceptable Noise Level (ANL). The clear distinction between the two terms will help audiologists restructure the questions normally asked to patients during interviews for hearing loss and before recommending hearing aids. Likewise, the clear distinction is important to assist the younger generation to protect their hearing, as well as workers and military personnel who work in noisy environments.

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ANL is basically the maximum amount of background noise a listener is willing and ready to accept without getting tired or bored when listening to a signal in the presence of noise [8]. SCN is the ability of a listener to understand the signal in the presence of background noise [13]. Likewise, Wilson and Spaulding [14] findings quantified speech comprehension as the degree to which a listener can interpret the meaning of the speaker’s intended message. Research is needed to help establish strategies for better speech understanding and worker performance without tiredness or distraction in the presence of background noise. These two terms are critical in the listener performance in any environment to perform optimally. If the distinction is known, then the psychology behind the two metrics can be extended beyond the designing of hearing aids and be extended into the workplace where signal detection activities are required. Nabelek et al. [19] findings suggested that speech understanding in noise may not be as important as the willingness to listen in the presence of noise. Notwithstanding, research is necessary to verify the statement reported in Nabelek et al. [19] findings. Many studies have considered the relationship between speech intelligibility and speech comprehension in noise, while only few studies have considered the differences between ANL and speech comprehension in noise. Therefore, the goal of this study is to investigate the differences between the two terminologies under the same signal and the same background noise. It is therefore hypothesized that the average ANL of listeners will be statistical significantly different from their mean SCN.

2 Methodology 2.1

Method

This study was conducted in a laboratory setting with college students at one university in Southeast US. Thirty subjects participated in the study. Participants’ ages ranged from 19 to 44 years old, with an average age of 27 years and a standard deviation of 6.7 years. Subjects include 10 females and 20 males. The background noise used was multi-talker babble while comedian speech was used as a signal. Noise loudspeakers were positioned at 0- and 180-degree azimuths (see Fig. 1), and signal loudspeaker at 90-degree azimuth, all were located three feet away from the subject seating position. Kattel et al. [15] used the same degree azimuths for both the signal and the background noise in their study. Several methods have been implemented to determine human speech comprehension in noise, for example; Samar and Metz [16] used listener’s speech transcription to measure listener intelligibility, and the semantic content of the spoken message of listeners was used by Hustad [17]. The study was divided into two phases; ANL and SCN. In phase I, the listeners comprehended the signal and the difference between the speech comprehension at comfort level (SCCL) and the BNL was recorded as (i.e., SCCL – BNL = SCN). In phase II, during the ANL experiment, signal comprehension was not an issue. Therefore, the difference between listener most comfortable listening level (MCLL) and the BNL was recorded as the listener’s ANL (i.e., MCLL – BNL = ANL).

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Fig. 1. Experimental set-up

2.2

Procedure

This experiment required the measurement of listener’s ANL and SCN under the same signal and background noise. Primary procedure included obtaining “informed consent” through the university’s Institutional Review Board (IRB). Participants were recruited via posted flyers and personal acquaintance. Prior to starting the experiment, the audiometer and the loudspeakers in the acoustic chamber were set to predetermined readings. Pre-run tests of the signal and the noise on the loudspeakers were conducted to ensure all loudspeakers worked perfectly before the experiment began. Participants were briefed on the purpose of the study, and participant’s tasks. Those who agreed to proceed with the experiment were given an informed consent form to sign. Participants were also given a pre-hearing screening form to complete the demographic portion. During the hearing screening test, participants were asked to push a button in response to every tone heard, and to do nothing if no tone was heard. Participant responses were recorded on their hearing screening form. The hearing screening was conducted on the participant both ears at 25 dB for octave band at frequencies between 250 and 4000 Hz. With the use of pure tone, the hearing screening was conducted to ensure that all participating subjects had normal hearing. The audiometric testing was performed using a Fonix Hearing Evaluator (FA-10 Digital Audiometer) and TDH-39P, C13357 Telephonics headphones calibrated according to ANSI specifications for audiometers (ANSI [21]). Participants who passed the hearing screening continued with the experiment, and those who failed were released from the experiment. Prior to starting the experiment, the researcher told each participant to imagine himself/herself working in a factory performing a mundane task and listening to a recording of a comedian’s performance for on-the-job relaxation. At a certain point, a coworker started a noisy operation that made listening to the recording more difficult. The noise from the operation was represented by the background noise from the loudspeaker. The listener’s task was to first adjust the signal level (i.e., the volume of the recording) to a most comfortable listening level (MCLL) and then to adjust the noise level to the maximum tolerable level (BNL) above which he or she would simply stop listening to or turn off the source of the signal for the ANL task. For the SCN task

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the point at which the listener felt he/she could no longer comprehend the speech was recorded as BNL. Participants were told to use hand gestures (i.e., hand up, hand down, hand flat) to request changes in the signal levels. Hand up, hand down, and hand flat indicated volume up, volume down, and volume okay, respectively. Participants were also asked to choose one of four comedian recordings, according to preference. The comedian recordings on the CD were from the Army Research Laboratory in Aberdeen, Maryland. These recordings included (a) “Bar Jokes,” (b) “Complimentary Peanuts,” (c) “Mad Cows & Udder,” and (d) “Are There Golf Courses in Heaven?” from the “Delight Yourself and Be the Enemy of Others” CD (Garrison Keillor and Prairie Home Companion 2004). Participants were told to ensure they comprehend the speech signal and be able to paraphrase the content of the speech signal orally to the researcher after each trial during any session that involved SCN. During ANL task, speech comprehension is not a criterion for the trails. Speech looping was controlled using Sound Forge software. Signal was presented first, and participants were allowed to remain at this condition (i.e. signal with the mundane task) for approximately 3 min during which time they maintained the same signal. Later, background noise was introduced, participants were also given 3 min at this condition (i.e., signal and noise with mundane task). The level at which participant indicated as the maximum level for the introduced background noise was recorded by the researcher as participant BNL. During ANL session, participants MCLL and BNL were measured and participants SCCL and BNL during the SCN session. Participants were given break time between sessions. The entire sessions lasted for an hour, thirty minutes each session.

3 Results Data are compiled in Excel spreadsheet version 2010 and SAS software was used for data analysis. The mean, range, and the standard deviation results for both ANL and SCN for the entire 30 participants are shown in Table 1. When compared across the two metrics (i.e., SCN and ANL), ANL was higher by 8% on the average to the SCN. The background noise level accepted was 0.6% higher for SCN compared with the background noise accepted during the ANL task. Table 1. Means, ranges, and standard deviations for Both SCN and ANL SNL Ave 7.69 SD 2.62 Range 1.45–13.49

ANL 8.96 3.04 4.55–16.29

The difference between the average ANL and the average SCN was small in magnitude so an inferential statistic was performed on all participants data to check if the difference is statistically significant or not. Prior data analysis, a normality test conducted on the dataset shows that data were normally distributed. The normality

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results for SCN dataset with the Shapiro-Wilk test were (W = 0.966; p = 0.460), and with the Anderson-Darling test (A2 = 0.427; p = 0.293) and for ANL, the results for the Shapiro-Wilk test was (W = 0.968, p = 0.502). The results of the paired two-tail t-test revealed that the difference was not statistically significant (p = 0.0071). Oneway ANOVA result on the background noise accepted by participants during the two sessions also revealed no statistically significant difference (p = 0.0609). However, participants tend to accept higher BNL during the SCN session than during ANL session and lower signal level during SCN session compared with the signal level accepted during the ANL session. On average, BNL during SCN was found to be (Ave = 42.99) and (Ave = 42.60) during the ANL session.

4 Discussion ANL and SCN are good two techniques to measure reactions to moderate levels of noise that could enhance listeners’ performance. The ANOVA results for the background noise used during this study shows no statistically significant difference. Likewise, the differences between the participant average ANLs and average SCNs also were not statistically significant under a two-tail t-test. Since, there is no statistically significant difference found between the two sessions, we could conclude that under multi-taker babble noise, our findings aligned with Nabelek et al. [19] findings. Nabelek et al. findings revealed that speech understanding in noise may not be as important as the listener willingness to listen in the presence of background noise. Participants accepted more signal during the ANL session compared with the signal level accepted during the SCN session, which means that participants were more sensitive toward signal intensity during SCN task than during the ANL task. This could be because ANL only measures participant’s willingness to work in noisy conditions while SCN task measures listener ability to seek meaning out of signal presented in noisy conditions. Generally, people tend to enjoy background speech or music while doing mundane tasks than listening to background noise. Findings also indicate that the participant’s ANL does not appear to be associated to speech perception in background noise.

5 Conclusion In the current study, our hypothesis was that the average score of the participant during an SCN task would have significant outcomes on the listener than during the ANL task. Our results revealed no statistically significant difference between the two tasks. ANL has been a reliable model to measure listeners’ willingness to accept background noise while performing a mundane task and while several methods have been used to measure listener’s speech perception in background noise. This study utilizes SCN to measure listener’s ability to comprehend speech in a background noise. Findings from this study supported previous findings that speech perception in background noise is not as important as listener’s willingness to listen in background noise. Participants in this study accepted higher background noise during the SCN task than during the ANL task.

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Acknowledgement. The author would like to acknowledge the assistance rendered by Ms. Precious Fasanya and Prof. Roy Evan for their valuable contributions in this study.

References 1. Wayne, R.V., Hamilton, C., Jones Huyck, J., Johnsrude, I.S.: Working memory training and speech in noise comprehension in older adults. Front. Aging Neurosci. 8, 49 (2016) 2. Schneider, B.A., Daneman, M., Pichora-Fuller, M.K.: Listening imaging adults: from discourse comprehension to psychoacoustics. Can. J. Exp. Psychol. 56, 139–152 (2002). https://doi.org/10.1037/h0087392 3. Adams, E.M., Moore, R.E.: Effects of speech rate, background noise, and simulated hearing loss on speech rate judgment and speech intelligibility in young listeners. J. Am. Acad. Audiol. 20(1), 28–39 (2009) 4. Zekveld, A.A., Rudner, M., Johnsrude, I.S., Heslenfeld, D.J., Rönnberg, J.: Behavioral and fMRI evidence that cognitive ability modulates the effect of semantic context on speech intelligibility. Brain Lang. 122, 103–113 (2012). https://doi.org/10.1016/j.bandl.2012.05.006 5. Heald, S.L.M., Nusbaum, H.C.: Speech perception as an active cognitive process. Front. Syst. Neurosci. 8, 35 (2014). https://doi.org/10.3389/fnsys.2014.00035 6. Nejime, Y., Moore, B.C.J.: Simulation of the effect of speech rate slowing on speech intelligibility in noise using a simulation of cochlear hearing loss. J. Acoust. Soc. Am. 103, 572–576 (1998) 7. Gordon-Salant, S., Frisina, R.D., Popper, A.N., Fay, R.R.: The Aging Auditory System: Perceptual Characterization and Neural Bases of Presbycusis. Springer, New York (2010) 8. Nabelek, A.K., Tucker, F.M., Letowski, T.R.: Toleration of background noises: relationship with patterns of hearing aid use by elderly persons. J. Speech Lang. Hear. Res. 34(3), 679– 685 (1991) 9. Foy, J.E.: American Osteopathic Association. Hearing loss and headpones—is anyone listening? (2017). https://doctorsthatdo.org/hearing-loss-headphones-listening. Accessed 28 Mar 2017 10. Perez Vallejos, E., McCormack, A., Edmonds, B.: Sensitivity to temporal fine structure and hearing-aid outcomes in older adults. Front. Neurosci. 8, 7 (2014) 11. Strelcyk, O., Dau, T.: Relations between frequency selectivity, temporal fine-structure processing, and speech reception in impaired hearing. J. Acoust. Soc. Am. 125, 3328–3345 (2009). https://doi.org/10.1121/1.3097469 12. Killion, M.C., Niquette, P.A., Gundmundsen, G.I., Revit, L.J., Banerjee, S.: Development of a quick speech-in-noise test for measuring signal-to-noise ratio loss in normal-hearing and hearing-impaired listeners. J. Acoust. Soc. Am. 116, 2395–2405 (2004) 13. Fasanya, B.K.: Quantitative analyses of acceptable noise level for air conduction listening. Doctoral dissertation, North Carolina Agricultural and Technical State University (2013) 14. Wilson, E.O., Spaulding, T.J.: Effects of noise and speech intelligibility on listener comprehension and processing time of Korean-accented English. J. Speech Lang. Hear. Res. 53, 1543–1554 (2010) 15. Kattel, B., Fasanya, B.K., Letowski, T., Hargrove, K.S.: The effect of background noise on the acceptable noise levels in individuals with normal hearing. In: Proceedings of the IJIE 2008 Conference, Las-Vegas (2008) 16. Samar, V.J., Metz, D.E.: Criterion validity of speech intelligibility rating-scale procedures for the hearing-impaired population. J. Speech Lang. Hear. Res. 31, 307–316 (1988)

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17. Hustad, K.C.: The relationship between listener comprehension and intelligibility scores for speakers with dysarthria. J. Speech Lang. Hear. Res. 51, 562–573 (2008) 18. Grand View Research (GVR – 2019): Hearing Aids Market Size, Share & Trends Analysis Report By Product Type (Behind-the-Ear, Canal), By Technology Type (Digital, Analog), By Sales Channel, By Region, And Segment Forecasts, 2019 – 2025. Report ID: 978-168038-166-5. Accessed 05 Jan 2019. https://www.grandviewresearch.com/industry-analysis/ hearing-aids-market 19. Nabelek, A.K., Tampas, J.W., Burchfield, S.B.: Comparison of speech perception in background noise with acceptance of background noise in aided and unaided conditions. J. Speech Lang. Hear. Res. 47(5), 1001–1011 (2004) 20. Keillor, G., Prairie Home Companion.: Delight Yourself and Be the Enemy of Others CD (2004) 21. American National Standards Institute (ANSI): American National Standard Specification for Audiometers. ANSI S3.6-1996. New York, NY (1996)

Ergonomics Design of Wearables

Exploring the Balance Between Utilitarian and Hedonic Values of Wearable Products Hassan Iftikhar, Parth Shah, and Yan Luximon(&) School of Design, The Hong Kong Polytechnic University, Hung Hom, Hong Kong SAR {hassan.iftikhar,parth.shah}@connect.polyu.hk, [email protected]

Abstract. It has been a matter of great interest for designers and researchers to investigate the potential balance between product’s aesthetics and functionality. This study will try to explore the concept of hedonics, utilitarian value and their balance by incorporating some case studies from design literature. In this research paper, the tradeoffs between hedonics and utilitarian values will discussed by having the wearable products as a core. The discussion in this study would help designers in understanding the metrics of balance in attributes of product design process for smart wearables and helping them to design wearable products by enhancing user experience. Keywords: Utilitarian values  Hedonic product values  Hedonic-utilitarian balance  Smart wearable products  Smart watches

1 Introduction Product utilitarian value is one of the key criteria considered by the designers while designing products to address user needs [1–3]. However, various studies related to the holistic nature of product design have helped in identifying additional parameters responsible for user satisfaction and judgments like elegance [4], functionality [5] and social importance [6]. Products have both utilitarian and symbolic purposes and not only bought for aesthetics [7]. A study [8] by Hollins and Pugh identified the hedonic nature of products, as one of the influential attributes involved in product design process. Product hedonic value is influenced by elements of product aesthetics like form, texture, experience and presence [9]. Studies [10, 11] have suggested that in addition to functionality, aesthetics experience has its own personalized value and is majorly used as the form of objects [12, 13]. Products are always appreciated holistically in the field of product design. It should have functionality and hedonic tradeoffs to attract the costumer intention before buying and to attract the customer satisfaction and pleasure while using it [14]. These tradeoffs play quite an important role in achieving the ultimate goal of designing good products. There is no absolute definition of good design however, “Good design” can be described as an optimal balance in functionality and aesthetics [15]. Functionality is considered to be an extrinsic value of product perception and pleasure can be considered as intrinsic product values [16]. A study conducted by Rogers [17] also insisted on the important role of products’ © Springer Nature Switzerland AG 2020 R. S. Goonetilleke and W. Karwowski (Eds.): AHFE 2019, AISC 967, pp. 407–416, 2020. https://doi.org/10.1007/978-3-030-20142-5_41

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intrinsic and extrinsic values on consumers’ perceptions and behavioral intentions. The potential balance in product design bears a significant importance in consumers’ buying intentions and usage behaviour. In recent years, usage of wearable devices has increased tremendously. With the advancement in technology, smart wearable products have provided users with an extensive range of added utilities. Wearable products are not just for interaction, we are living with them. With the change in understanding of aesthetics and user perceptions, designers have a huge challenge of satisfying the users with an optimal product experience, which has a balance between utilitarian and hedonic values.

2 Parameters for Wearable Products’ Classification In the field of smart wearables, the development is considerable in off-body products in comparison to the wearable ones. The wearables need to be more mature in order to find it attractive and accepted in consumers’ perception [18, 19]. Many studies like Bodine and Gemperle [20] have considered functionality and wearing comfort as the main features for accepting it. While in the other studies [21, 22] it is quite evident that functionality, comfort, ease of use and maximum usefulness are considered as the important factors. These pragmatic qualities are very important however for a smart wearable, hedonic qualities are as important as pragmatic qualities [14]. In another investigation [23] for the adoption of smart wearables it has been established that users’ care about the styling most followed by the price and functionality of the smart wearable. In addition to that, a study [24] conducted by Yang incorporated the brand image as a parameter of consumer buying intention and it has a direct impact on the benefit values. Wearable products have their role not as a useful product but also as a fashion product or considered as jewelry. The basic parameters for wearable product classification contain utilitarian, hedonic and fashion values as a prime importance. 2.1

Product Utilitarian Value

Product utilitarian value or product function serves as an important role in product perceived values. Utilitarian value often termed as the potential purpose of the product and its reliability in terms of repeating the same task. This purpose of the product is defined by the customer needs and termed as functional requirement of a product in the product design parameters [1]. Utility and core functions come first according to many researchers depending upon the product type. Once the issues of utility has been satisfied then the emphasis may shift towards other product values like decorative, symbolic and emotional values [25]. Customer perception about product and its usage is primarily related to the core function offered by the product utility values. As a general concept, costumers give higher priority to the utilitarian benefits [26, 27]. This is also verified in the study conducted by Kivetz and Simonson [3] that consumer attach greater weight to the utilitarian benefits of product. The consumption nature of these benefits is quite different than those associated with hedonic benefits [28, 29]. The nature of utilitarian benefits in product design is considered as the must meet nature of human necessities. This must meet nature focus the customers intentions towards the

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product’s utilitarian value because it is considered to be closer to human necessities and needs [27, 28]. By utilitarian benefits, the fulfilment of prevention goals develop the sense of confidence and security [30]. In terms of wearable technology, we need to acknowledge the fact about user’s needs other than functionality. A little research is available on the wearable technology because it is on the very early stage of commercialization [24]. For this reason, wearable technology is behaving more than a mere functional product arising other needs than functionality as well. These needs may refer to style, expression [31], fashion, trend and personal satisfaction in terms of user experience. 2.2

Product Hedonic Value

Hedonic values are concerned about the pleasure, joy, cheerfulness [32, 33] and fun aspects of a product. The presence of hedonic value in usable products makes it more appealing to customers as it demeans the monotony in product usage experience. Conventional design process considers product aesthetic as an integral part, but is generally given importance after functionality cut-off has been achieved [26, 34]. The functionality cut off represents the primary function of the wearable product. Hence, product styling is a major factor, which can enhance user’s living experience after meeting the product’s base utilitarian purpose. Researchers [26, 34, 35] like Chitturi and Hoegg have investigated the trade-offs between product styling and functionality to enhance user experience. Once the functionality requirement is met, users tend to attract towards more aesthetical products as it satisfy the sense of delight [26]. The sense of delight may refer to benefits in product’s experience as a plus. This sense bears an important role in critical user’s responses regarding consumer experience. User’s critical responses about the product helps the designers to attain a good balance between usability and styling. Chitturi et al. suggested that user’s aesthetical expectations are directly related to user satisfaction, while lack of functional expectations are related to sense of irritation [30]. Irritation and satisfaction refers to the two states of consumers’ experience similar to needs and wants. Wants can be compromised up to some extent but needs are not dealt in the same way. However studies [36] suggest that in case of appropriate styling minor issues in functionality could be disregarded. These minor issues can evoke the state of dissatisfaction, but product’s hedonic motivation can be balance that. Smart wearable products, are the type of wearable products used external to the body [37] and more like a fashion jewelry [38] to the user. These smart wearable products contain smart watches, smart rings, smart eyeglasses, health bands, smart clothing, smart head mounted displays and smart jewelry etc. These are the latest IT products after smart phone and tablets [24]. As investigated by Gartner [39] many smart phone brands entered into the field of smart wearable products. As wearables are considered to be the collective or collaborative technology with mobile phone and cloud services, because of this it captured the interest of many smart phone companies to enter this niche. The share of smart wearables is increasing day-by-day and will reach to 112 million units in 2018 [40]. Therefore, these wearable create a new gap of user behaviour understanding as being new and demanding in terms of user’s perception. Wearable devices mostly seen as the fashion products as they are exposed to

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people in various forms so people can enjoy them as a fashion items [24]. Therefore, In the recent study conducted by Jeong et al. [41], it is demonstrated that aesthetics and style has a evident role in the adoption of wearable devices. 2.3

Product Fashion Value

Fashion is a style of product designing, which satisfies the specific trends or manners concerning users’ feelings [42, 43] and social status. It is also contributing as a strong attribute in wearable products. A strong attribute of smart wearable devices is that they considered as a fashion product because of their potential exposure to the people [24]. Fashion products have the sense of style, luxury along with the comfort. Since smart wearable devices have a possible exposure to the people, therefore they demand a high level of social presence and style. These products evaluated as a sense of joy and pleasure along with the functionality and comfort [44, 45]. Since these products require a good balance in terms of fashion and technology, Rauschnabel and Ro [46] coined a term of “fashionology” for the smart wearable devices. Devices are generally considered as a useful piece of technology but in the case of smart wearable devices, it is different [47]. Particularly, smart watches in the category of wearable devices is seen as fashion accessory by most of the users [48]. Now considering it as a fashion statement, it demands a high value of aesthetics and styling [49]. This styling significantly increases the perceived value of smart watches. Sundar et al. [50] have investigated the perception of smart watches in consumer perception and acknowledged that smart watches are viewed both as utilitarian and fashion products. Now the introduction of smart watches in consumer market led the concept of form follows function in new direction. In today’s market, product design and fashion trends are significantly affecting the consumers’ feelings and emotions as well as their buying intentions [42, 43]. According to the previous studies, product hedonic values were considered the added benefits after the functionality cutoff. However, the introduction of smart wearable devices in consumer product markets merging the trend of useable products and fashion. Users are more concern about the product hedonics and the level of comfortability on the body [51]. This new trend demands a thorough research on the new consumer trends in product expectation and its impact on smart wearable device design process. These trends will require a good amount of balance in product hedonics and product utility depending upon the wearable product types. However, this balance between utilitarian and hedonic values in field of wearable product design has not explored extensively. 2.4

Need of Balance of Attributes

The tradeoffs between functionality and hedonic values in product design creates a sense of balance in order to appeal the consumer buying intentions. It is not necessary that increase in aesthetic and hedonic appeal necessarily decrease the functionality aspect to attain a perfect balance [36]. However, balance is considered to be the tangible and intangible perception of product’s design. Aristotle, the philosopher suggested the sense of balance in all things. This suggested balance between aesthetics

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and functionality should preserve its core as overstyling in product design sometimes backfire. Norman [15] also acknowledged the sense of balance in beauty and usability as “good design”. In addition to that, to achieve this good design, the parameters should be constant across time and cultures to maximize the goals of life [52]. As a basic principle of design, balance is useful in every stage of product design process in the consideration of functionality and hedonics. Gombrich [53] defined delight somewhere in between bore and confusing states of consumer perception and Berlyne [54] also acknowledged that hedonic values are associated with stimulus peak of psychological arousal. These studies suggesting the balance itself possess a great importance in hedonic values of product design. Many researchers tried to investigate the sense of optimal balance in product hedonics and usability. This cannot be defined in percentages or some preset values due to the subject nature of design process, consumer demands, consumer behaviors and consumer perception. This optimal balance is principally based on types of products and its basic functionality. The literature studied in this research proposed an optimal balance in the attributes in wearable smart products. A relationship diagram (Fig. 1) has been developed to represent the balance of attributes and potential benefits by having enhanced product user experience. The concentration of these values in combination enhance user perception, buying intentions and styling. Wearable products bears a different consumer approach being a fashionology product and its premature existence in consumer markets. There is a strong need of research for consumer perception, buying intention, social status and consumer behaviour based on different wearable products.

Fig. 1. Balance of attributes for enhanced user experience

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3 A Striking Challenge for Wearable Devices Raskovic [37] formulated a definition of wearable devices. According to his study, the wearable devices are being used as an external device attached as an accessory or clothes’ attachment. By wearing it as an accessory, it is exposed to the people and making it a product needs to be stylized. The term fashionology as described before is ideal for wearable devices by holding fashion and technology together. By the introduction of smart watches, bone conduction and Bluetooth headphones for mobile technology, it opened up the doorways for a strong need of research on product design. Conventionally, product’s functionality and ease of use were considered as an ultimate goal of satisfaction. However, as the products grew smaller and technologically smarter, they produced a special place in everyday life being part of it [55]. Especially in terms of smart watches, they have become the indispensable tool in daily life also having the potential of helping users in dangerous situations [56]. In the present day smart watches being used as daily life style and health indicators by capturing body stats and giving user suggestions [57]. In this study, planners also prioritized the design value of smart watches to meet consumer expectations. Wearable devices bear an important place in the today’s consumer market being an emerging techno-fashion product. It also possesses an added striking challenge for the product design process and empathetic problem-solving methodology. Especially taking the examples of smartwatch and its development in the previous years. Starting from a simple technology piece to indispensable product, smartwatch gains an important role of people’s daily life style. According to the studies [24, 58], watches are considered to be a jewelry piece for men and commonly worn as adornment, so its pleasing and hedonic approaches will attract more customers. A recent study [59] estimated that smartwatch sales would grow significantly in 2020 by reaching $17.8 billion. This growth in buying and consumers growing dependence created a strong need to rethink the product design process considering hedonics as a stronger value than before in wearable devices.

4 Conclusions and Future Research Product design and its empathetic methodology in design process evokes a strong demand to rethink. Rethinking may involve the whole contribution of design attribute on a different scale. According to the previous studies discussed in this research paper, as functionality cutoff is essential, the strong arguments whether leaning more towards functionality or hedonics in product design ended. The discussion is about to create the perfect balance in both approaches to attract the customer attention. In case of wearable devices, the design process would be much different. The existence of wearables is clear in the consumer market as fashion and styling product and as a new emerging trend in product design. The wearable product would demand a good sense of balance in techno-style to attract the customers. Mobile phone brands have joined hands with sports brands in order to make the wearables more acceptable and useful product. However, there is a strong need of the collaborations of different style brands and jewelry brands to shake hands together and form a contributive design process to satisfy the needs of this niche. A piece of jewelry and a piece of useful technological

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product merged into one could be the new realm in future product design. This trend would need a strong contribution from the tech giants and luxury fashion brands to evolve the existing problem-solving methodologies. This research contributes for the new niche of product design process for wearable products. By considering wearables as fashion wears and fashion wears as techno wares, the idea is to demean the gap of these product lines. This research can open the doorways for future research based on the consumer adaptive models of smart wearables and their application in design process. Process design is based on the needs defined, therefore this research defines the new needs for existing product design process and hence to provide a new baseline for improvement. Future research could involve the case studies by having the different smart wearables (one by one) and their market trends based on the consumers’ requirements. Smartwatches, smart glasses, Bluetooth and bone conduction headphones, smart clothing, medical exterior body products, smart bracelets, smart pendants, smart rings and smart body stats indicators could be the potential wearables for the future consumer and designer research. The balance of hedonic and utility values can be studied from different case studies of the above-mentioned products to form a creative product design process. The metrics of essential elements for each smart wearable product can be identified. These metrics can help the designers and marketers to evaluate the needs for new emerging potential consumer market of enhanced product-user experience. Acknowledgments. This study was supported by the UGC Funding Scheme from The Hong Kong Polytechnic University.

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A Comparison of Traditional and 3D Scanning Measurement in Ear Anthropometry Fang Fu1, Ameersing Luximon2, and Yan Luximon1(&) 1

School of Design, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR [email protected] 2 EMEDS Ltd., Kowloon, Hong Kong SAR

Abstract. Ear anthropometry is important in physical ergonomics for earrelated products. With various anthropometric methods, comparisons between different measuring techniques have not been sufficiently studied especially for ear dimensions. This study aimed at comparing traditional measurement and 3D scanning method for ear anthropometry, with addressing their usages in practice. For thirty participants, ear length and ear width were measured by the same investigator with two measuring methods. Traditional measurement was directly conducted with a caliper, whereas dimensions using 3D scanning technique were extracted from the point cloud acquired from a structured light scanner. Statistical results showed the differences between traditional and 3D scanning measurement, which can provide empirical evidences of differences between different measuring techniques for ear anthropometry. Additionally, the usages of different methods were discussed so that the proper method can be selected to match specific goals for future research. Keywords: Anthropometry

 Comparison  Ear measurement

1 Introduction Anthropometry can provide valuable information in physical ergonomics. Particularly, ear anthropometry has been conducted to provide size and shape reference for earrelated ergonomic design. Researchers have applied different measuring techniques to conduct ear anthropometry in the past, including direct measurement [1–3], 2D photogrammetry [4, 5] and 3D modelling method [6, 7]. Hence, comparison between different methods is necessary to gain a comprehensive understanding of these methods. Some researchers have reviewed different measuring methods involving particular body parts, such as human body [8], feet [9], head and face [10]. However, comparison between traditional measurement and 3D measuring techniques in ear anthropometry has not been sufficiently studied. Among the measuring methods, traditional measurement was the mostly used method to obtain ear dimensions, with direct measuring selected dimensions with tools, such as caliper, tape and protractor [1–3]. With the development of computer-aided design techniques, 3D scanning was extensively used in anthropometry for research and industrial use. Researchers have tried to use 3D scanning technology to study © Springer Nature Switzerland AG 2020 R. S. Goonetilleke and W. Karwowski (Eds.): AHFE 2019, AISC 967, pp. 417–423, 2020. https://doi.org/10.1007/978-3-030-20142-5_42

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external ear [6, 11], even though some challenges occurred when applying 3D scanning techniques in ear anthropometry due to the complex structure of external ear. Based on the consideration, the study selected direct measurement using caliper and indirect measurement through 3D scanning technique as the compered objectives. The main aim of the study was to compare traditional measurement and 3D scanning method for ear anthropometry, with addressing their usages in practice. The comparisons in the study provided a statistical verification and usage discussion, so that proper measuring method can be selected to match specific goals for future research.

2 Methods Thirty Chinese adults (15 males and 15 females) aged between 20 to 30 years were recruited in Hong Kong. Participants with deformities of bone and soft tissue around the ear region were not included. The demographic information is shown in Table 1. Table 1. Demographic information of participants. Age (years) Body height (cm) Body weight (kg) Male 23.7 ± 3.3 172.2 ± 4.9 64.2 ± 9.2 Female 23.4 ± 2.9 159.3 ± 6.2 63.1 ± 6.5

For each participant, ear length and ear width were acquired through both traditional and 3D scanning measurement. Only right ear was involved in the study. A caliper was used to manually measure the two dimensions, and a structured-light

Fig. 1. Landmarks and dimensions involved in the study. Landmarks are (1) Superaurale, (2) Subaurale, (3) Posraurale, (4) Preaurale, and (5) Lobule anterior; Dimensions include (EL) ear length from Superaurale to Subaurale, and (EW) ear width from Postaurale to the ear base.

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scanner (Artec Eva®) was used to scan the ear region. After scanning, a point cloud of the ear was acquired for dimension extraction. Five landmarks, including Superaurale, Subaurale, Postaurale, Preaurale, and Lobule anterior, were positioned on the 3D ear model, and then the ear length and ear width were calculated accordingly [12]. The landmarks and dimensions are demonstrated in Fig. 1. Statistical analysis was conducted to compare the ear dimensions in SPSS software. Descriptive statistics demonstrated the overall information of ear dimensions using different measurements. Paired t-test was used to compare the mean values through different anthropometric methods. Correlation coefficient and mean absolute difference were computed to compare the reliability of the two measuring methods.

3 Results Descriptive statistics provided general information of selected ear dimensions measured with the caliper and 3D scanning technique. The mean, standard deviation (SD), minimum (Min), maximum (Max) and 95% confidence interval of ear dimensions are listed in Table 2. Table 2. Ear dimensions by traditional and 3D scanning measurement (mm)

Ear length Traditional measurement 3D scanning measurement Ear width Traditional measurement 3D scanning measurement

Mean SD

Min

Max

61.44 59.92 30.77 31.50

54.10 54.39 26.40 26.76

71.10 68.70 36.50 37.40

3.98 3.88 2.49 2.81

95% confidence Lower Upper 59.95 62.93 58.48 61.37 29.84 31.70 30.45 32.56

Ear dimensions through traditional and 3D scanning measurement were compared with paired t-test. The analysis results indicated the differences between traditional and 3D scanning measurement, as shown in Table 3. Specifically, 3D scanning measurement provided slightly smaller ear length and slightly larger ear width than traditional measurement with significant differences. Table 3. Comparison of mean value between traditional and 3D scanning measurement Mean diffferencea Std. error mean T df p Ear length 1.51 0.22 6.81 29 0.000* Ear width −0.73 0.22 −1.18 29 0.003* *p < 0.05 Mean differencea = traditional measurement – 3D scanning measurement

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To compare the inter-observer reliability, correlation coefficients and mean absolute difference of the ear dimensions were calculated. As shown in Table 4, the results indicated the correspondence of the two anthropometric methods. The correlation results suggested an excellent agreement between traditional and 3D scanning measurement for both ear length and ear width. Additionally, the absolute values of MD (mean difference) and MAD (mean absolute difference) were similar, even though the difference of ear width is slightly larger than ear length. Table 4. Inter-observer reliability between traditional and 3D scanning measurement Correlation coefficient (r) p Mean absolute difference Ear length 0.952 0.000* 1.74 Ear width 0.903 0.000* 1.16 *p < 0.05

4 Discussion and Conclusion In previous studies, traditional and 3D scanning measurements were compared for different body components, including human body [8], feet [9], head and face [10, 13, 14]. As for ear anthropometry, Coward compared computerized tomography (CT), magnetic resonance imaging (MRI) and laser scanning for selected ear dimensions [19]. However, with various anthropometric methods, the comparative studies between these methods have not been adequately conducted in ear anthropometry. Therefore, this study statistically compared traditional measurement with structured light scanning measurement, with addressing the using conditions for specific methods. Researchers have compared the mean values between using traditional and 3D scanning measurements for human body [8, 9], head and face [10, 13]. In these studies, differences between the two measuring methods were discovered to vary upon particular dimensions. Compared with traditional measurement, 3D scanning measurement provided larger values for most of the circumferences and lengths for human body, and smaller values for armscye circumference, arm length and cervical height, with significant differences, while no significant difference was found for neck base circumference, bust circumference, waist back length [8], shoulder breath and abdominal depth [9]. Moreover, the differences of mean values between traditional and 3D scanning measurement were found to differ along with specific scanner for head and face dimensions [13]. In this study, traditional measurement of ear length was slightly larger than 3D scanning measurement, the reason could be the influence of hair near Superaurale landmark. As for ear width, traditional measurement provided slightly smaller value than 3D scanning measurement. This could be due to the difficulty of locating the ear baseline in traditional measuring method. The mean differences between traditional and 3D scanning measurement were 1.51 mm and 0.73 mm for ear length and ear width individually, which could be considered as acceptable error (within 2 mm) according to ISO 20685 [14]. Additionally, mean absolute difference (MAD) and mean difference (MD) are commonly compared to test discrepancy between different measuring methods [15].

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Bougourd [16] compared the inter-observer variability of selected body dimensions based on MAD, while Han [8] associated the values between MD and MAD with interpretation for distinguished dimensions. In this study, the absolute values of MD and MAD for both dimensions were similar, even though the difference between two absolute values for ear width was slightly larger than that for ear length. This was due to the occasional obstacles of hair around Preaurale, despite that hair around the region was taken care with hairpins and covered with a cap. Previous research suggested that 3D scanning measurement provided reliable data for specific dimensions, such as selected body dimensions [16], head and face dimensions [17]. Consistently, the inter-observer reliability, tested with correlation coefficient (ear length: r = 0.952; ear width: r = 0.903), showed a strong relationship between traditional and 3D scanning measurement, which meant that structured light scanning was as reliable as traditional measurement for selected ear dimensions. Other than above quantitative comparisons, the usages of traditional and 3D scanning measurements also needed to be compared for ear anthropometry. As the mostly used method in previous ear anthropometric research, traditional measurement is convenient to conduct with selected or specific designed equipment. Limitations of the method exist obviously, such as time-consuming procedure, restricted information of dimensions and difficulty to acquire certain dimensions. Without providing the shape information and particular dimensions, ear anthropometry using traditional measurement may not fit with current lifestyle requirements for ear-related ergonomic design. Based on the considerations, 3D scanning technology provided an opportunity to overcome these limitations. Nowadays, 3D scanning was widely used to reconstruct the 3D model of the surface for a target item in research and industry. However, limitations still exist under certain conditions when applying 3D scanning techniques in ear anthropometry. Due to the principle of light, 3D scanning encounters problem when scanning surface covered by hair and with complex structures [18]. Some regions near hairline or posterior part of pinna mostly encountered scanning issue, and ear canal was difficult to be directly scanned. In addition, small movement of head might influence the scanning results, so it might be challenging to acquire scanning results with good quality for children or other related population [12]. Therefore, researchers need to pay critical focus on these areas and consider the physical condition of the participant, when applying 3D scanning in ear anthropometry. Overall, even though there were significant differences between traditional and 3D scanning measurement for ear dimensions, the values of mean differences and mean absolute differences were relatively small. With the high correlation coefficients, the 3D scanning measurement was comparable to the traditional measurement for ear length and ear width. The study provided statistical verification for comparison between traditional and 3D scanning measurement with addressing the advantages and disadvantages of different measurements. Limitations of the study include relatively small sample size and restricted ear dimensions considering the variation of ear size and shape. Therefore, further studies can be conducted more systematically with a larger sample size, further dimensions, and additional measuring methods. Acknowledgments. The study was supported by Hong Kong RGC/GRF project B-Q57F.

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References 1. Farkas, L.G., Posnick, J.C., Hreczko, T.M.: Anthropometric growth study of the ear. Cleft Palate Craniofacial J. 29, 324–329 (1992) 2. Bozkir, M.G., Karakaş, P., Yavuz, M., Dere, F.: Morphometry of the external ear in our adult population. Aesthetic Plast. Surg. 30, 81–85 (2006) 3. Alexander, K.S., Stott, D.J., Sivakumar, B., Kang, N.: A morphometric study of the human ear. J. Plast. Reconstr. Aesthetic Surg. 64, 41–47 (2011) 4. Liu, B.S.: Incorporating anthropometry into design of ear-related products. Appl. Ergon. 39, 115–121 (2008) 5. Ma, L., Tsao, L., Yu, C., Zhou, W.: A quick method to extract earphone-related ear dimensions using two-dimensional (2D) image. In: International Conference on Applied Human Factors and Ergonomics, pp. 321–328. Springer, Cham (2017) 6. Sforza, C., Grandi, G., Binelli, M., Tommasi, D.G., Rosati, R., Ferrario, V.F.: Age- and sexrelated changes in the normal human ear. Forensic Sci. Int. 187(103), 110-e1 (2009) 7. Yu, J.F., Lee, K.C., Wang, R.H., Chen, Y.S., Fan, C.C., Peng, Y.C., Tu, T.H., Lin, K.Y.: Anthropometry of external auditory canal by non-contactable measurement. Appl. Ergon. 50, 50–55 (2015) 8. Han, H., Nam, Y., Choi, K.: Comparative analysis of 3D body scan measurements and manual measurements of size Korea adult females. Int. J. Ind. Ergon. 40, 530–540 (2010) 9. Sims, R.E., Marshall, R., Gyi, D.E., Summerskill, S.J., Case, K.: Collection of anthropometry from older and physically impaired persons: traditional methods versus TC23-D body scanner. Int. J. Ind. Ergon. 42, 65–72 (2012) 10. Aung, S.C., Ngim, R.C.K., Lee, S.T.: Evaluation of the laser scanner as a surface measuring tool and its accuracy compared with direct facial anthropometric measurements. Br. J. Plast. Surg. 48, 551–558 (1995) 11. Modabber, A., Galster, H., Peters, F., Möhlhenrich, S.C., Kniha, K., Knobe, M., Hölzle, F., Ghassemi, A.: Three-dimensional analysis of the ear morphology. Aesthetic Plast. Surg. 42, 766–773 (2018) 12. Fu, F., Luximon, Y., Shah, P.: A growth study of Chinese ears using 3D scanning. In: International Conference on Digital Human Modeling and Applications in Health, Safety, Ergonomics and Risk Management, pp. 54–63. Springer, Cham (2018) 13. Weinberg, S.M., Naidoo, S., Govier, D.P., Martin, R.A., Kane, A.A., Marazita, M.L.: Anthropometric precision and accuracy of digital three-dimensional photogrammetry: comparing the genex and 3dMD imaging system with one another and with direct anthropometry. J. Craniofac. Surg. 17, 477–483 (2006) 14. International Organization for Standardization: ISO 20685: 3D scanning methodologies for internationally compatible anthropometric databases (2010) 15. Bradtmiller, B., Gross, M.E.: 3D Whole Body Scans: Measurement Extraction Software Validation, No. 1999-01-1892. SAE Technical Paper (1999) 16. Bougourd, J.P., Dekker, L., Ross, P.G., Ward, J.P.: A comparison of women’s sizing by 3D electronic scanning and traditional anthropometry. J. Text. Inst. 91, 163–173 (2000) 17. Baca, D.B., Deutsch, C.K., D’Agostino, R.B.: Correspondence between direct anthropometry and structured light digital measurement. Anthr. Head Face, Raven Press New York, 235–237 (1994)

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18. Luximon, Y., Martin, N.J., Ball, R., Zhang, M.: Merging the point clouds of the head and ear by using the iterative closest point method. Int. J. Digit. Hum. 1(3), 305–317 (2016) 19. Coward, T.J., Brendan, J.J., Watson, R.M., Richards, R.A.: Comparison between computerized tomography, magnetic resonance imaging, and laser scanning for capturing 3-dimensional data from a natural ear to aid rehabilitation. Int. J. Prosthodont. 19(1), 92–100 (2006)

A Novel Hybrid Personal Cooling System Incorporated with Dry Ice and Ventilation Fans to Mitigate the Heat Strain of Mascot Actors in a Hot and Humid Environment Cathy Sin-Wei Chow and Faming Wang(&) Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR [email protected]

Abstract. In this work, a hybrid personal cooling suit incorporated with dry ice and ventilation fans (HYB), and a water-cooling suit (WCS) were chosen to examine actual cooling performance on mascot actors while performing a moderate activity at 34 °C & RH = 78%. The total trial duration was 60 min (40-min walking at 4.0 km/h followed by 20-min resting at room temperature [24 ± 1°C, RH = 55 ± 5%]). Results showed that both HYB and WCS successfully prevented the mascot wearers’ core temperature from rising above 38.0 °C during trials. In contrast, core temperatures of CON (i.e., no cooling) reached 38.0 °C in 35 min. Heart rates in HYB and WCS were decreased by 11 and 17 beats/min compared to that of CON. Perceptual responses have been greatly improved by wearing HYB and WCS. It was concluded that HYB and WCS could mitigate heat stress on mascot wearers during a performance in the studied condition. Keywords: Personal cooling  Dry ice Perceptual responses  Hot climate

 Heat stress  Core temperature 

1 Introduction Mascot costumes have been widely used as a symbolic character for entertainment or celebration purposes [1, 2]. In general, a mascot costume consists of three pieces: a mascot head, a jumpsuit and foot spats. Molded and stiff materials are normally used to fabricate the sturdy mascot head which is later covered with a furry fabric outer layer. Synthetic wadding is normally used as the filling material in the mascot’s jumpsuit for illusion effect. The foot spats are worn over the shoes. The majority of mascot costumes are bulky, heavy, poorly ventilated and vision impaired from inside the costumes. Hence, wearers could suffer from extreme heat stress issues and accidental injuries while wearing mascot costumes either during intensive activities or in warm climates [3]. The only documented research survey [4] found that over 58% of mascot users reported severe heat related injuries. Heat illnesses resulted from the use of mascots are the most severe health problem among mascot wearers. Unfortunately, the health and safety of mascot performers are often ignored. There is a great need to find effective cooling methods to solve the heat stress issues associated with mascot costumes. © Springer Nature Switzerland AG 2020 R. S. Goonetilleke and W. Karwowski (Eds.): AHFE 2019, AISC 967, pp. 424–435, 2020. https://doi.org/10.1007/978-3-030-20142-5_43

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The most common method to cool the mascot actors is to install a small fan inside the mascot head. Fan ventilation would lose its cooling power in humid environments because the evaporative cooling capacity has been greatly restricted under such conditions [5]. The most often used cooling systems to alleviate heat strain in humid environments are the ice cooling vest and the liquid cooling suit [6]. Studies on ice cooling vests have shown the great power to alleviate both thermophysiological and perceptual stresses while wearing protective garments in warm environments [7, 8]. Unfortunately, ice vests could induce severe local body cold discomfort. Portable liquid cooling suits use battery powered pumps to circulate cool water through the hose [9] and they are mostly often worn under protective garments and work wear used by construction workers, firefighters, and miners, etc. No documented work has addressed the use of PCS to mitigate heat stress associated with mascot costumes. Mascot costumes and protective clothing are quite different in terms configurations, i.e., mascots are normally much bulkier than protective clothing and the mascot head is much bulkier than existing headgears. Therefore, it is highly necessary to examine the actual performance of existing personal cooling systems on the alleviation of heat strain of mascot performers during performance in hot environments. Hence, in this study, a commercial water-cooling suit (WCS) was chosen to investigate the cooling effectiveness on mascot wearers while performing a moderate-intensity activity in a hot and humid environment. Moreover, a novel hybrid personal cooling system based on dry ice and air ventilation fans has been developed in this work. The cooling performance of the newly developed hybrid cooling system (referred to as HYB) was compared against WCS. Thermophysiological and perceptual responses of eight male participants while wearing a mascot costume have been investigated. It was hypothesized that the two cooling systems could significantly reduce both physiological and perceptual heat strain of mascot wearers compared to no cooling.

2 Method 2.1

Participants

Eight healthy male volunteers participated in this study. Their age, weight, height, body surface area and body mass index were 21.0 ± 2.1 years, 65.5 ± 6.4 kg, 1.74 ± 0.04 m, 1.79 ± 0.10 m2, and 21.7 ± 1.5 kg/m2, respectively. This study was approved by The Hong Kong Polytechnic University’s Human Subjects Ethics Sub-committee. 2.2

Mascot Costume

A set of mascot suit, including a mascot head, a jumpsuit and a pair of foot spats, was used (see Fig. 1, manufacturer: Meiqi Cartoon Costume Company, China). The mascot head was made of 2.5 cm thick structural material, i.e., ethylene vinyl acetate (EVA) covered with a layer of 100% polyester short pile faux fur. The jumpsuit consisted of a furry fur layer, a batting layer and a cotton satin lining. The entire

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jumpsuit and the footwear weighed 1,634 and 253 g, respectively. The total weight of the three-piece bear mascot costume was 4,233 g. In order to provide sufficient air circulation inside the sturdy mascot head, two brushless ventilation fans (power: 3.12 W) were installed at the mouth hole and the center-top part of the head to blow ambient air into the microclimate space of the mascot head.

Fig. 1. The teddy bear mascot costume.

2.3

Hybrid Cooling System (HYB)

A hybrid cooling system (HYB) incorporated with dry ice and ventilation fans was developed (see Fig. 2). This HYB suit has a 4-layer structure, the shell fabric layer treated with silver-based reflective coating, the airtight fabric layer, the multiple mesh layer and a fourth layer which is also made from the same type of nylon airtight fabrics as used in the second layer. Thus, a relatively airtight space (i.e., air sac) could be formed in between the two airtight layers. Two brushless fans (voltage: 12 V) were mounted to the right upper chest and left upper scapular regions of the HYB suit’s shell fabric to facilitate air circulation within the air sac. Fans are powered by a lithium-ion battery (capacity: 4,900 mA h, weight: 616 g) and the battery could provide up to 8 h of fan ventilation on the maximum rotation speed. Four dry-ice bags (material: 100% polyester 3D spacer fabric, size: 30.5 cm  13.0 cm) were fabricated and they were evenly and vertically placed inside the air sac at the HYB’s waistline area. A 2.0 mm thick mesh fabric assembly was placed into the inner inside of dry-ice bags to insulate the dry ice. The four bags could house a maximum of 2.6 kg dry ice. In addition, two air vents were created at the crotch area of the HYB suit for quick releasing the gaseous CO2. The total weight of the HYB suit is 2.1 kg (excluding dry ice slabs) and HYB mainly covers the torso, upper arms and upper legs of the wearer with a covering area of around 1.05. In HYB trials, 2.6 kg dry ice slabs were added to the dry-ice bags. 2.4

Water Cooling Suit (WCS)

A portable water-cooling suit (referred to as WCS, manufacturer: Compcooler Technology Co. Ltd., Shenzhen, China) that covered the entire body excluding the face, hands and feet was used to examine the relative cooling performance against the newly

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Fig. 2. The hybrid personal cooling suit (HYB) incorporated with dry ice and ventilation fans. (left) a photo showing the participating was wearing the HYB suit, (middle) front view, (right) rear view. 1-shell fabric layer; 6-vents designed for quick suit releasing; 8-brushless fans; 9-rechargeable battery.

developed HYB suit. WCS was made up of a one-piece cooling suit and a backpack where the water circulation unit was housed. The water circulation unit consisted of a 3-litre freezable bladder, a mini pump, and a rechargeable lithium battery (capacity: 7,500 mA h, voltage: 7.4 V). Four groups of PVC tubing with an inner diameter of 3 mm that sandwiched between two mesh fabric layers (materials: nylon blended with spandex; thickness: 0.46 mm) were used for circulating cold water throughout the entire WCS suit. The total weight of WCS excluding cooling sources is 3.3 kg and WCS covers a body area of around 1.46 m2. A mixture of 2 kg ice and water (1 kg ice and 1 kg water) was used in WCS and the overall weight of WCS is around 5.3 kg. The water flow rate of the WCS suit was set to 500 ml/min. 2.5

Test Protocol

Participants swallowed a calibrated core temperature capsule (CorTemp, HQ Inc., Palmetto, FL, USA) with a cup of 200 ml tepid water about 3–4 h before each trial to facilitate the capsule transition to the small intestine. Upon arrival at the laboratory, participants rested on an armless chair at room temperature (24 ± 1 °C, RH = 55 ± 5%) for 30 min. During the resting period, they were briefed on the test procedure and also, were instructed to get familiar with perceptual rating scales. Participants were then instrumented with physiological testing devices. A Polar H10 heart rate watch with a chest strap (Polar Electro Oy, Kempele, Finland) were used to continuously record the heart rate at an interval of 1 min. Local skin temperatures were measured using wireless skin temperature loggers (iButton DS1922L, Maxim Integrated, San Jose, CA) that were taped to 10 body sites, namely, the head, left chest, left abdomen, right upper arm, left forearm, left hand, right scapular, left lower back, right thigh, and the left calf. A core temperature recorder (HQ Inc., Palmetto, FL) was placed at the waist region

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using a fabric belt. Participants were dressed in briefs, a short sleeve t-shirt (100% polyester), cotton socks, the cooling suit (if any), a pair of sports shoes and the threepiece mascot costume. Afterwards, they entered the test chamber, had their clothed body weight measured and then started to walk on a motorized treadmill at 4.0 km/h for 40 min. The experimenter stopped the treadmill immediately after the 40 min of the trial. Participants were weighed again and afterwards, they took off the mascot head, exited the chamber and then seated on an armless chair for 20 min at room temperature. All trials were performed in a randomised, counter-balanced order and participants were blinded to test scenarios. In HYB and WCS trials, cooling systems were kept on throughout the entire 60 min. Perceptual responses were acquired every 10 min throughout the whole trials. Physiological parameters were recorded at 1 min intervals. Trials were terminated if any one of the following conditions was satisfied: (i) the core temperature reached 38.5 °C; (ii) the sustained heart rate greater than 95% of the maximum heart rate (i.e., 220-age); (iii) the participant wished to stop, and (iv) participants completed the 60 min trials. 2.6

Calculations

The mean skin temperature (Tskin) was calculated using the following equation [17] Tskin ¼ 0:07  Tforehead þ 0:175  Tright scapular þ 0:175  Tleft upper chest þ 0:07  Tright upper arm þ 0:07  Tleft lower arm þ 0:05  Tleft hand þ 0:19  Tright anterior thigh þ 0:2  Tleft calf

ð1Þ

The total sweat production (SWp) and the total sweat evaporated (SWevap) were calculated as SWp ¼ Wnude;0  Wnude;posttrial

ð2Þ

SWevap ¼ Wclothed;0  Wclothed;posttrial

ð3Þ

where, Wnude,0, and Wnude,post-trial are the nude body weight before and after the trials, g; Wclothed,0, and Wclothed,post-trial are the clothed body weight before and after the trials, g. 2.7

Perceptual Responses

Participants were requested to report their thermal sensation votes (TCVs), thermal comfort votes (TCVs), and skin wetness sensations (WSs) at intervals of every 10 min. TSVs were assessed using a 9-point thermal sensation vote [16], ranging from −4 (very cold), −3 (cold), −2 (cool), −1 (slightly cool), 0 (neutral), +1 (slightly warm), +2 (warm), +3 (hot) to +4 (very hot). TCVs were assessed by a 5-point thermal comfort vote (ISO 10551-2001), ranging from 0 (comfortable), +1 (slightly uncomfortable), +2 (uncomfortable), +3 (very uncomfortable) to +4 (extremely uncomfortable). WSs were evaluated using a 5-point scale ranging from 0 (neutral), +1(slightly wet), +2 (wet), +3 (very wet) to +4 (extremely wet).

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429

Test Conditions

Two test conditions were used in the present study. The 40-min treadmill walking was performed in a test chamber where a hot-humid subtropical summer outdoor condition was simulated. The air temperature was maintained at 34.0 ± 0.5 °C, RH = 78 ± 5%, the air velocity was 0.15 ± 0.05 m/s. The 20-min resting was conducted at an office room outside of the test chamber, where the air temperature was 24 ± 1 °C, RH = 55 ± 6%, and the air velocity was 0.15 ± 0.05 m/s. 2.9

Statistical Analysis

Descriptive data were presented as means ± SD (standard deviation). Two-way factorial analysis of variance (fixed factors: test scenario [CON, WCS and HYB], time [every 5-min for physiological variables or every 10-min for perceptual variables, and scenario  time]) with repeated measures (dependent variables: heart rate, core temperature, mean skin temperature, and perceptual responses) was performed to examine statistical differences between trial conditions. Bonferroni corrected paired-samples ttests were conducted if a significant effect was observed between the test scenarios to detect which pair(s) of dependent variables had significant differences. Differences were considered statistically significant at p < 0.05 level. All statistical analyses were carried out in SPSS (IBM Corp., Armok, NY).

3 Result 3.1

Heart Rate, Core Temperature and Mean Skin Temperature

Figure 3 presents the time course of heart rates, core temperatures and mean skin temperatures in CON, HYB and WCS. Significant differences were found in the heart rate between CON and WCS throughout the 5–60th min (p = 0.045). Similarly, significant differences were also found between CON and HYB at the 5th min, and throughout the 20–35th min and the 45–60th min (p = 0.019). The heart rate was reduced by 11 and 17 bpm in HYB and WCS compared with CON over the 60-min trials. In contrast, no significant difference was registered in the heart rate between HYB and WCS during the entire trials (p = 0.763). With regard to core temperatures in CON, HYB, and WCS, significant lower core temperatures were registered in HYB as compared to that in CON during the 5–60th min (p = 0.002). In contrast, no significant difference was found in core temperatures either between CON and WCS (p = 0.067) or between WCS and HYB (p = 0.060). WCS and HYB successfully prevented the wearers’ mean core temperatures from rising above 38.0 °C, whereas the mean core temperature in CON reached 38.0 °C at the 35th min of the trial and it plateaued at above 38.0 °C throughout the remaining 25 min. The maximum core temperature in CON was registered at the 45th min, i.e., 38.3 °C. Significantly lower mean skin temperatures were noted between WCS and CON during the 5–60th min (p < 0.001), between HYB and CON throughout the 5–40th min (p = 0.010), and also between WCS and HYB throughout the 5–40th min of the trials

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Fig. 3. Heart rates, core temperatures and mean skin temperatures in CON, HYB and WCS.

(p = 0.001). WCS brought remarkable cooling to local skin during the initial 10 min of the trials and the mean skin temperature was lowered down to 0.156) but HYB presented a significantly lower WS than WCS at the 60th min (p = 0.048).

4 Discussion Researchers [10] have pinpointed both the physical work capacity and mental task ability decreased when the core temperature exceeded 38.0 °C. Thus, a core temperature of 38.0 °C has been widely adopted as the threshold limit by reputable organizations such as WHO to protect workers [11]. The present study found that both two cooling systems (i.e., HYB and WCS) successfully prevented the wearers’ core temperatures from rising >38.0 °C. In contrast, we were not surprised to observe the mascot wearers’ core temperature in CON (i.e., no cooling) rose to above 38.0 in about 35 min. In addition to the core temperature, heart rate and sweat rate are the other two most important physiological parameters to illustrate the physiological strain of an individual person. The current findings indicated that HYB and WCS, compared with CON, depressed the heart rate by 11 and 17 beats/min, respectively. Moreover, the sweat rate

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in HYB and CON was considerably reduced by 16.0% and 48.5% as compared with that of CON (i.e., 579 g/h). Our results demonstrated WCS could provide around one-hour body cooling to the mascot wearers, though the temperature gradient between the free running water inlet temperature and mean skin temperature was decreased to 5.9 °C after 40-min’s treadmill walking. During the initial 10 min, participants reported ‘slightly cool’ TSVs and ‘slightly uncomfortable’ TCVs, which was evidenced by the pretty low mean skin temperatures during this period, i.e., 32.0 °C. Hence, the participants were somewhat overcooled during the initial 10 min period. Further, similar to the previous observations reported in many documented studies [12, 13], a small increase in the core temperature during the initial 20 min’s cooling in WCS was noted (see Fig. 3). This was mainly because the overcooling brought by WCS resulted in peripheral vasoconstriction, which shunted warm blood to the core [14]. HYB showed promising cooling performance on the alleviation of mascot wearers’ heat strain. Significantly lower core temperatures were found when wearing HYB compared to CON and WCS. No participant reported shivering in HYB trials, which indicated there was no overcooling issue on HYB. This outcome was evidenced by the time course of mean skin temperatures. Even though significantly lower mean skin temperatures were noted in HYB as compared with CON, overcooling issue found in WCS during the initial 10 min was not seen in HYB. In this work, only 30.9% of dry ice sublimated during the one-hour trials. The sublimation rate of HYB was calculated by dividing the total time duration from the mass different of dry ice over the one-hour trials. The sublimation rate in HYB was 13.4 g/min, which was much greater than the value (i.e., 8.3 g/min) reported in Konz et al. [15]. Such a big difference was mainly caused by the forced ventilation adopted in the presented study, which greatly enhanced the dry ice sublimation. Besides, the cooling area of HYB was much greater than the dry-ice jacket developed by Konz et al. [15]. As hypothesized, the perceptual strain has also been greatly reduced by using HYB and WCS cooling suits. It could be deduced from Fig. 4 that participants had significantly lower TSVs, TCVs and WSs in both HYB and WCS as compared with those in CON. In general, perceptual responses in HYB were quite close to those in WCS, as evidenced by the insignificant differences found in TSVs, TCVs and WCs between WCS and HYB. Considering the majority of dry ice was not sublimated during the onehour trial, the amount of dry ice added to HYB could be further reduced to around 1 kg without compromise of the HYB’s cooling performance. Hence, the total weight of HYB would be 3.7 kg only, which was 1.6 kg lighter than WCS at the very beginning of the trials. More important, the weight difference between WCS and HYB would become gradually larger due to the continuous sublimation of dry ice. The weight difference between HYB and WCS at the end of the one-hour trial would be around 2.6 kg. This novel feature of HYB could definitely contribute to reducing uncompensated heat strain to some extent during the performance in the studied hot and humid condition.

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5 Conclusion The present study demonstrated both the two selected cooling suits successfully prevented the core temperature of the mascot wearers from rising above 38.0 °C. Besides, HYB and WCS could alleviate thermophysiological strain by reducing the heart rate, skin temperature, sweating rate and dehydration. Furthermore, perceptual responses including thermal comfort votes, thermal sensation votes and skin wetness sensations have been greatly improved by using HYB and WCS. In conclusion, HYB and WCS were able to significantly alleviate the heat strain of mascot wearers during the onehour performance in the studied hot and humid condition.

References 1. Freeman, I., Knight, P., O’Reilly, N.: Symbolism and the effectiveness of Olympic mascots. Int. J. Sport Manag. Market 2(1/1), 41–58 (2007) 2. Halloran, D.P.: Personal cooling device and method. US Patent 6272877B1, 14 August 2001 (2001) 3. Repin, I.: Keep your mascot cool. Phys. Sportsmed 29(9), 5 (2001) 4. Daily, M.C.: Mascot: performance and fetishism in sport culture. Platform J. Media Commun 3(1), 40–55 (2011) 5. Berglund, L.G., Gonzalez, R.R.: Evaporation of sweat from sedentary man in humid environments. J. Appl. Physiol. 42(5), 767–772 (1977) 6. Wang, F., Song, W.: An investigation of thermophysiological responses of human while using four personal cooling strategies during heatwave. J. Therm. Biol. 70, 37–44 (2017) 7. Smolander, J., Kuklane, K., Gavhed, D., Nilsson, H., Holmér, I.: Effectiveness of a lightweight ice-vest for body cooling while wearing fire fighter’s protective clothing in the heat. Int. J. Occup. Saf. Ergon. 10(2), 111–117 (2004) 8. Kenny, G.P., Schissler, A.R., Stapleton, J., Piamonte, M., Binder, K., Lynn, A., Lan, C.Q., Hardcastle, S.G.: Ice cooling vest on tolerance for exercise under uncompensable heat stress. J. Occup. Environ. Hyg. 8(8), 484–491 (2011) 9. Nunneley, S.A.: Water cooled garments: a review. Space Life Sci. 2(3), 335–360 (1970) 10. Kjellstrom, T., Holmér, I., Lemke, B.: Workplace heat stress, health and productivity-an increasing challenge for low-and-middle-income countries during climate change. Glob. Health Action 2, 2047 (2009) 11. World Health Organization (WHO).: Health factors involved in working under conditions of heat stress. Technical report no. 412, World Health Organization, Geneva, Switzerland (1969) 12. Huizenga, C., Zhang, H., Arens, E., Wang, D.: Skin and core temperature responses to partial- and whole-body heating and cooling. J. Therm. Biol. 29(7–8), 549–558 (2004) 13. Song, W., Wang, F., Wei, F.: Hybrid cooling clothing to improve thermal comfort of office workers in a hot indoor environment. Build. Environ. 100, 92–101 (2016) 14. Webster, J., Holland, E.J., Sleivert, G., Laing, R.M., Niven, B.E.: A light-weight cooling vest enhances performance of athletes in the heat. Ergonomics 48(7), 821–837 (2005) 15. Konz, S., Hwang, C., Perkins, R., Borell, S.: Personal cooling with dry ice. Am. Ind. Hyg. Assoc. J. 35(3), 137–147 (1974)

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16. International Organization for Standardization.: ISO 10551 Ergonomics of the thermal environment—assessment of the influence of the thermal environment using subjective judgement scales. International Organization for Standardization, Geneva (1995) 17. International Organization for Standardization.: ISO 9886 Ergonomics—evaluation of thermal strain by physiological measurements. International Organization for Standardization, Geneva (2004)

Modern Textile-Based Compression Device for Improving Venous Haemodynamics of Lower Extremities Xinbo Wu and Rong Liu(&) Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hung Hom, Hong Kong SAR [email protected]

Abstract. Chronic venous insufficiency (CVI) is a common disorder condition worldwide. Compression therapy is the mainstay of prophylaxis and treatment of CVI in practice. The aim of this study is to investigate effects of the designed knee-high open-toe compression stocking (OTCS) on venous cross-sectional areas and flow velocities of the superficial and deep venous systems of the lower extremities. The results indicated that the designed OTCS (23 mmHg at ankle on average in a standard degressive pressure gradient from the distal to the proximal) can effectively squeeze limb tissues and generate different influences on the studied cross-sectional areas and flow velocities of the superficial and deep venous system. In general, the cross-sectional areas reduced by approximate 13%–16% along the tested superficial veins (Great Saphenous Vein and Small Saphenous Vein) in both healthy subjects (Group 1) and CVI patients (Group 2). The decreased venous cross-sections may squeeze superficial venous blood to deep venous system via perforator veins, leading to increased venous cross-sectional areas by 7% in Popliteal Vein vein in Group 1 (healthy subjects) and increased flow velocity of deep veins by approximate 6.5% and 19.6% in Group 1 and 2, respectively. These finding suggest that the designed new OTCS would improve venous haemodynamics of the lower limbs in dynamic daily use, especially for deep venous system of the CVI suffers. Keywords: Chronic venous insufficiency  Compression therapy  Compression stocking  Venous hemodynamics  Medical textiles

1 Introduction Chronic venous insufficiency (CVI) is a common medical problem in which blood pooling reduces venous return, resulting in heaviness, itchiness, tiredness, varicosities, and even ulceration in the lower limb [1], which influences not only appearance and beauty of legs, but also physical and psychological wellbeing [2]. Compression therapy is the mainstay of prophylaxis and treatment of CVI through applying static or dynamic modalities to reverse venous hypertension [3, 4], augment muscular pumping action [5], or promote venous return [6] and lymphatic drainage [7]. Textile-based functional compression devices have been increasingly employed in forms of socks, boot, kneehigh or thigh-high elastic compression stockings, pantyhose, elastic or non-elastic © Springer Nature Switzerland AG 2020 R. S. Goonetilleke and W. Karwowski (Eds.): AHFE 2019, AISC 967, pp. 436–442, 2020. https://doi.org/10.1007/978-3-030-20142-5_44

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bandages, and intermittent pneumatic compression pump (IPC) [8, 9]. In general, the highest pressure is exerted distally (e.g., ankle) and gradually decreasing proximally up to the knee or thigh1 [10]. Different pressure dosages (15–40 mmHg) can be delivered to the lower limbs, thus triggering complex physiological and biochemical responses on blood vessels, soft tissues and lymphatic systems [11]. Textile materials can be fabricated using hybrid elastic yarns and laid-in structures to achieve diverse physical and mechanical properties. Based on our previous studies [12–15], applying advanced 3D seamless knitting technology, compression stockings with controllable segmental pressures along different zones of the lower limbs can be achieved to deliver 15–25 mmHg pressure at ankle and a designed gradient pressure proportion (%) from the ankle, brachial to the knee (i.e.,100%:100–70%:50%). The purpose of this study is to examine hemodynamic effects of the developed compression stocking in terms of variations of venous cross-sections and flow along main superficial and deep venous system of the lower limbs.

2 Methods The textile-based compression device in form of seamless knee-high open-toe compression stockings (OTCS) (23 mmHg at ankle) were fabricated by employing hybrid Lycra cored double covered polyamide fibers in linear densities of 260 deniers and polyamide elastomers with linear densities of 40 deniers. Through controlling stitch tension and loop density, the newly designed OTCS produced a highly bi-axial stretches in fabric wale and course directions to facilitate stocking donning on and off and meanwhile to centripetally squeeze limb tissues for pressure delivery. A total of 40 lower limbs from 10 healthy volunteers aged 48–79 in Group 1 without CVI signs (i.e., C0) and 30 patients aged 39–70 in Group 2 with primary CVI symptoms (i.e., C1–C2) were recruited in the wear trials (Table 1). The venous cross-sectional areas and average blood flow velocity along superficial veins (i.e., Great Saphenous Vein (GSV) and Small Saphenous Vein (SSV)) at calf height and deep veins (i.e., Popliteal veins (POP)) at popliteal fossa of the lower limb were assessed by using Color Doppler Ultrasonographic scanner (MyLab™Twice, Esaote, Genova, Italy) with a 4–13 MHz linear-array transducer (LA523, 192 elements, Esaote, Italy) in a peripheral vascular mode (Fig. 1). The dynamic and static 2D transverse and longitudinal grey-scale Color Doppler images and quantitative values (cross-sectional areas and flow velocities) on the studied veins were obtained when subjects being with and without OTCS in standing posture. All the measurements were conducted under a climatic-controlled environment (22 °C–24 °C). A designed experimental protocol (Table 2) was performed involving both static and dynamic activities, including condition (I) without OTCS, i.e., walking at 2.0 km/h for 5 min and standing still for 5 min after natural supine in a testing bed for 15-min physiological equilibrium; and condition (II) with OTCS, i.e., walking for 5 min and followed by standing still for 5 min at the same speed. Between the two conditions, a 15-min resting in supine was performed for each subject. Doppler tests were conducted in standing position following Fig. 1 Color Ultrasound Doppler test along the studied superficial and deep venous system subject’s walking in both conditions (I) and (II), respectively.

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Fig. 1. Color Ultrasound Doppler test along the studied superficial and deep venous system

Table 1. Basic characteristics of the studied subjects Group 1 Subjects with C0

Variable Age (year) Height (cm) Weight (kg) BMI (kg/m2)

Mean (SD) 56 (9.05) 160 (7.17) 53 (6.36) 21 (1.32)

Min to Max 48-79 154-177 48-65 19.2-23.5

Group 2 Subjects with C1-C2

Variable Age (year) Height (cm) Weight (kg) BMI (kg/m2)

Mean (SD) 62 (8.47) 161 (7.05) 52 (6.93) 21 (1.29)

Min to Max 39-70 156-175 42-68 19.0-23.1

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Table 2. Experimental protocol Experimental activities in a total of 75 min Supine Walking Standing* Supine Sitting (baseline) (2.0 km/h) 15-min 15-min 15-min 5-min 5-min● Rest Condition (I) Without OTCS

Walking Standing* (2.0 km/h) 5-min 5-min● (II) With OTCS

Supine 15-min Rest

* Doppler test in a standing position after walking (●).

3 Results and Discussion The results indicated that the intervention of OTCS reduced the cross-sections of the tested SSV and GSV by approximate 15% at GSV and 14% at SSV at the calf height in Group 1, and decreased by approximate 16% at GSV and 13% at SSV in Group 2 (Fig. 2). Compared with the superficial veins, the cross-sections of the tested deep veins POP increased by 7% in Group 1 and decreased by 3% in Group 2, respectively. Meanwhile, with intervention of OTCS, the average blood flow (Vmn) of the tested SSV and GSV decreased by 12.1% at GSV and 11.5% at SSV at the calf in Group 1, and decreased by 6.2% at GSV, and by 22.2% at SSV in Group 2, respectively. Compared with the superficial veins, the OTCS enhanced Vmn of the tested deep veins (POP) by 6.5% in Group 1 and 19.6% in Group 2, respectively (Fig. 3).

Fig. 2. Compression effects on cross-sectional area at GSV, SSV and POP under with and without OTCS

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Fig. 3. Compression effects on average blood flow at GSV, SSV and POP under with and without OTCS

Figure 4 illustrates the working mechanisms of the elastic compression on venous system of the lower extremities. The squeezing pressures by OTCS delivered onto skin surface were transmitted into deeper tissues to compress the superficial veins, resulting in reductions of venous cross-section and flow. The compressed superficial veins may direct venous blood to deep venous system via perforator veins, thus leading to increased venous cross-sections in POP veins in Group 1 (healthy subjects) and increased venous flow of POP veins in both healthy and patient groups. In addition, one interesting result was observed that the pressure applied by OTCS exerted more

Fig. 4. The mechanism of action of OTCS on vein system.

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squeezing force to the POP veins of CVI patients, resulting in an obvious reduction in venous cross-sections of POP vein among the tested subjects in Group 2. It was considered that the malfunction of venous wall and valves in POP veins of CVI patients could have less resistance to external elastic pressure, thus causing more deformation in venous cross-sectional structures under intervention of OTCS. More experimental studies are required to explore the effects of compression in CVI treatment, and hemodynamic modeling is highly needed to visualize and quantitatively characterize variations of vascular morphologies and flow rate under action of compression in our future work.

4 Conclusions The physiological responses of healthy subjects and CVI patients towards the same biomechanical stimulation by OTCS could be different in compression therapy. The studied knee-high open-toe compression stocking have been demonstrated to improve haemodynamics in deep venous system of the lower limbs, which could exert positive effectiveness for leg health-care in daily use. The CVI patients could be more sensitive to pressure dosage delivered due to their insufficient venous elasticity and function. More explorations mixing experimental studies and numerical simulation are highly required to investigate compression mechanisms in depth. Acknowledgments. This work was supported by Innovation and Technology Fund of the Hong Kong SAR Government through Research Project ITS/031/17 and Central Research Grants of the Hong Kong Polytechnic University through Research Projects 1-ZE7K and 1-ZVLQ.

References 1. Howlader, M.H., Coleridge Smith, P.D.: Symptoms of chronic venous disease and association with systemic inflammatory markers. J. Vasc. Surg. 38(5), 950–954 (2003) 2. Renner, R., Erfurt-Berge, C.: Depression and quality of life in patients with chronic wounds: ways to measure their influence and their effect on daily life. Chronic Wound Care Manag. Res. 4, 143–151 (2017) 3. Van Bemmelen, P.S., Beach, K., Bedford, G., Strandness, D.E.: The mechanism of venous valve closure: its relationship to the velocity of reverse flow. Arch. Surg. 125(5), 617–619 (1990) 4. Lattimer, C.R., Azzam, M., Kalodiki, E., Makris, G.C., Geroulakos, G.: Compression stockings significantly improve hemodynamic performance in post-thrombotic syndrome irrespective of class or length. J. Vasc. Surg. 58(1), 158–165 (2013) 5. Miller, J.D., Pegelow, D.F., Jacques, A.J., Dempsey, J.A.: Skeletal muscle pump versus respiratory muscle pump: modulation of venous return from the locomotor limb in humans. J. Physiol. 563(3), 925–943 (2005) 6. Sochart, D., Hardinge, K.: The relationship of foot and ankle movements to venous return in the lower limb. Bone Joint J. 81(4), 700–704 (1999) 7. Chan, V., Duffield, R., Watsford, M.: The effects of compression garments on performance of prolonged manual-labour exercise and recovery. Appl. Physiol. Nutr. Metab. 41(2), 125–132 (2016)

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8. Andriessen, A., Apelqvist, J., Mosti, G., Partsch, H., Gonska, C., Abel, M.: Compression therapy for venous leg ulcers: risk factors for adverse events and complications, contraindications. A review of present guidelines. J. Eur. Acad. Dermatol. Venereol. 31 (9), 1562–158 (2017) 9. Liu, R., Guo, X., Lao, T.T., Little, T.: A critical review on compression textiles for compression therapy: textile-based compression interventions for chronic venous insufficiency. Text. Res. J. 87(9), 1121–1141 (2017) 10. Henry, R., Rowe, J., O’Mahony, D.: Haemodynamic analysis of efficacy of compression hosiery in elderly fallers with orthostatic hypotension. Lancet 354(9172), 45–46 (1999) 11. Lim, C.S., Davies, A.H.: Graduated compression stockings. Can. Med. Assoc. J. 186(10), E391–E398 (2014) 12. Liu, R., Lao, T.T., Little, T.J., Wu, X., Ke, X.: Can heterogeneous compression textile design reshape skin pressures? A fundamental study. Text. Res. J. 88(17), 1915–1930 (2018). https://doi.org/10.1177/0040517518779254 13. Liu, R.: Pressure reconstruction by heterogeneous compression textiles. Veins Lymphat. 7(2), 7621 (2018) 14. Liu, R., Liu, J., Lao, T.T., Ying, M., Wu, X.: Determination of leg cross-sectional curvatures and application in pressure prediction for lower body compression garments. Text. Res. J. 89(10), 1835–1852 (2019). https://doi.org/10.1177/0040517518779246 15. Liu, R., Xu, B.: 3D digital modeling and design of custom-fit functional compression garment. In: International Conference on Artificial Intelligence on Textile and Apparel, pp. 161–169. Springer, Cham (2018)

Author Index

A Ahmed, Sarah, 231 Akrim, Aisha, 231 Altaboli, Ahamed, 231 Am-Eam, Nanthawan, 106 Au, Emily Yim Lee, 388 B Babris, Sandis, 14 Bokse, Kristine, 14 Braga, Ana Cristina, 117 Bu, Weiping, 95 Bullinger, Angelika C., 339 Bureš, Marek, 34, 348 C Cadkova, Vera, 348 Cao, Yaqin, 86 Carneiro, Paula, 117 Castellanos, Javier, 135 Chaiklieng, Sunisa, 222 Chen, Chien-Liang, 3, 70, 360 Chen, Peng-Je, 3 Chen, Yu-Ting, 173 Chow, Cathy Sin-Wei, 424 Chung, Yu-Hsuan, 173 Costa, Nélson, 117 D De Bruyne, Guido, 207 Deacon, Claire, 377 Deng, Lue, 95

Dias, Natália Fonseca, 57 Ding, Yi, 86 Donič, Jan, 309 dos Reis, Diogo Cunha, 57 E Echavarria-Bustamante, Blanca, 187 F Fan, Xiaoli, 157, 165 Fan, Yunxiao, 327 Fasanya, Bankole K., 397 Fernandes, Agostinho, 117 Fu, Fang, 417 G Galvis, Paula, 124 Gao, Yuan, 327 Glatz, Juraj, 287 Goonetilleke, Ravindra S., 388 Görner, Tomáš, 34 Guerrero, Laura, 124 Guo, Bing, 296 H Habina, Karol, 277 Hamad, Fatima, 231 Homsombat, Thanyawat, 222 Hoyos-Ruiz, Johana, 187 Hu, Hong, 252 Hu, Huimin, 165, 197

© Springer Nature Switzerland AG 2020 R. S. Goonetilleke and W. Karwowski (Eds.): AHFE 2019, AISC 967, pp. 443–445, 2020. https://doi.org/10.1007/978-3-030-20142-5

444 I Iftikhar, Hassan, 407 J Jan, Yih-Kuen, 3, 360 Jani, Jay, 213 Jankaew, Patompong, 106 Jiang, Yuwei, 165 K Kába, Martin, 34 Kačerová, Ilona, 34 Kalkis, Henrijs, 14, 22 Koppel, Tarmo, 22 Kuo, Fang-Chuan, 360 L Lee, Fang-Hsin, 70 Lee, Liang-Cheng, 70 Li, Fangyu, 44 Li, Wanqiang, 252 Li, Yueqing, 213 Liau, Ben-Yi, 3, 70, 360 Lin, Chih-Yang, 3 Lin, Yen-Hui, 80 Liu, Chengcheng, 315, 369 Liu, Heqing, 95 Liu, Peng-Jyun, 146, 173 Liu, Rong, 436 Liu, Yi-Chun, 3 Lu, Jin-Huei, 360 Lu, Shih-Yi, 80 Lung, Chi-Wen, 3, 70, 360 Luo, Hong, 157, 197 Luo, Yongchang, 95 Luximon, Ameersing, 417 Luximon, Yan, 407, 417 M Madkour, Nader, 213 Maradei, Fernanda, 124, 135 Moro, Antônio Renato Pereira, 57 N Nagyova, Anna, 267 Ninthappho, Kunthara, 106 Noosom, Thaweeuk, 106 O Omar, Entsar, 231 Oravec, Milan, 267 Ortiz, Luis, 124 Ou, Jing, 296

Author Index P Pacaiova, Hana, 267 Patel, Jaimin, 213 Peeters, Thomas, 207 R Ran, Linghua, 197 Rao, Guru Prasadh, 213 Rodriguez, Jenny, 135 Roja, Inara, 14 Roja, Zenija, 14 Rueffert, Danny, 339 S Sevilla Cadavid, Gustavo, 187 Shah, Parth, 407 Sharma, Pawan, 213 Sinay, Juraj, 287 Smallwood, John, 377 T Tang, Jing-Shia, 70 Tint, Piia, 22 Tirloni, Adriana Seára, 57 Tomašková, Marianna, 287 Trcka, Jan, 277 Tsai, Jen-Yung, 3 Tsenter, Olga, 22 V Vargová, Marta, 287 Ventins, Ansis, 14 Verwulgen, Stijn, 207 Vilcane, Inese, 22 Vleugels, Jochen, 207 W Wang, Ching-Yi, 146, 173 Wang, Faming, 424 Wang, Wei, 44 Wang, Wenjing, 242 Wang, Xingwei, 95 Wang, Yi, 86 Wang, Zhongting, 197 Wu, Xinbo, 436 Y Yao, Qin, 95 Yi, Jun, 296 Yu, Nan-Ying, 70 Z Zhang, Wei, 157 Zhang, Xin, 197

Author Index Zhao, Chaoyi, 157, 165, 197 Zhao, Yang, 315, 369 Zheng, Yun-shuang, 296

445 Zhou, Hailiang, 95 Zhou, Jie, 252 Zuleta Montoya, Fausto, 187