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DHM Tables of Contents: 07091113-113-21415-115-2

DHM 2013: 4th International Conference on Digital Human Modeling and Applications in Health, Safety, Ergonomics, and Risk Management, Part II: Human Body Modeling and Ergonomics

Fullname:DHM 2013: 4th International Conference on Digital Human Modeling and Applications in Health, Safety, Ergonomics, and Risk Management, Part II: Human Body Modeling and Ergonomics
Note:Volume 23 of HCI International 2013
Editors:Vincent G. Duffy
Location:Las Vegas, Nevada
Dates:2013-Jul-21 to 2013-Jul-26
Publisher:Springer Berlin Heidelberg
Series:Lecture Notes in Computer Science 8026
Standard No:DOI: 10.1007/978-3-642-39182-8 hcibib: DHM13-2; ISBN: 978-3-642-39181-1 (print), 978-3-642-39182-8 (online)
Links:Online Proceedings
  1. DHM 2013-07-21 Volume 2
    1. Digital Human Modeling and Ergonomics in Working Environments
    2. Ergonomics of Work with Computers
    3. Anthropometry, Posture and Motion Modeling

DHM 2013-07-21 Volume 2

Digital Human Modeling and Ergonomics in Working Environments

A Knowledge Transfer Process: Establishing Training in New Technology for an Ageing Workforce BIBAKFull-Text 3-9
  Conne Mara Bazley; Denise Brooks
Learning new technology can transform the lives of older workers. Worldwide older workers remain in the workplace longer and continue to work for various personal and economic reasons. Some leave one workplace and take up a second or even a third career. The new technology training required for many industries is generally focused on younger workers already trained in new technology basics. Ideally, to keep a diverse workforce motivated and productive, training for younger and older workers is necessary. New technology training for older workers is designed differently than that of younger workers to address some of the physical and cognitive changes that occur with age. If older workers are given the appropriate training and help, there is evidence to show they are able to master the new technology.
Keywords: ageing; workforce; new technology; training
Towards Anthropomorphic Movements for Industrial Robots BIBAKFull-Text 10-19
  Christian Brecher; Simon Müller; Sinem Kuz; Wolfram Lohse
In order to increase productivity for processes that involve the interaction of human and robot, a promising approach is to increase the transparency of robot movements. Based on the hypothesis that anthropomorphic movements are more transparent to a human operator, this paper presents methodologies and techniques to generate humanlike movements for industrial robots.
Keywords: Anthropomorphic movements; industrial robot; movement parameters
Ergonomic Assessment of Patient Barrow Lifting Technique Using Digital Human Modeling BIBAKFull-Text 20-29
  Wen Cao; Meng Jiang; Ying Han; Mohammad T. Khasawneh
Healthcare personnel involved in patient handling activities are often exposed to work-related musculoskeletal disorders (WMSDs). Therefore, the objective of this study is to conduct a comprehensive assessment of the Barrow lifting technique using digital human modeling (DHM). This study investigates the effects of patient weight and height (PWH), clinical staff weight and height (CSWH), clinical staff position (CSP) during lift, and clinical staff gender (CSG) on the clinical staff's low back compression force (LBCF). In addition, the impact of specific postural variables was evaluated using Comfort Assessment (CA). The results of this research showed that clinical staff in the larger weight and height percentiles that are male experienced higher LBCF. While the trunk of the clinical staff member was exposed to higher flexion angles that are still in the comfort range, the ratings associated with the trunk thigh and elbow were outside the comfort range. The results of this research are of paramount importance in designing lifting protocols and training programs with the ultimate goal being a reduction in the risk of developing low back injuries.
Keywords: Patient Barrow Lifting; Digital Human Modeling; Ergonomics
An Interface Design Method for E-commerce Sites' Homepage Considering Users' Emotions BIBAKFull-Text 30-39
  Fu Guo; Yaqin Cao; Meng Wang; Yi Ding; Lin Wei Liu
This paper proposes a useful method to understand the relationship between web design elements, Kansei evaluation and users' emotions based on Kansei Engineering, taking E-commerce sites for example. Firstly it establishes customers' evaluation image words through a survey of the web interface preference. Then it collects the data of Kansei evaluation and users' emotions to different websites by an emotion assessment test. Lastly it builds the relation models between web design elements, Kansei evaluation and users' emotions using the quantification theory I and partial least squares (PLS) method, and confirms the validity of the models.
Keywords: E-commerce; Emotion; Kansei engineering; Web design; PLS
Safety and Health at Work through Persuasive Assistance Systems BIBAKFull-Text 40-49
  Matthias Hartwig; Armin Windel
In working environments, violations against safety regulations like the use of personal protective equipment pose a significant threat to well-being and health of working people. A laboratory study investigated the potential of different computer generated feedback forms encouraging users to wear protective equipment (PPE), even when this PPE hinders their primary work task, thus threatening their financial compensation. The results show a substantial increase in usage of PPE when being confronted with a persuasive designed feedback like a traffic light or an emotional expression of a virtual avatar. In contrast, solely informative feedback showed no significant impact of safety behavior. In summary, the findings indicate a potential of persuasive technology for occupational safety affairs and underline the importance of the outward appearance of computer generated persuasive messages.
Keywords: Adaptive Work Assistance Systems; Chances and Risks; Evaluative Feedback; Persuasion; Safety and Health
Evaluating Ergonomics Risks for Digital Radiologists BIBAKFull-Text 50-58
  Alan Hedge
Modern radiology is digital and the work of the radiologist now shares many features with that of other high technology computer work. Many digital reading rooms are poorly designed in terms of ergonomics and how they accommodate computer technology. Lighting is typically inadequate resulting in visual health problems of eyestrain and headaches and inadequate lighting also adversely affects image reading performance. The prevalence of musculoskeletal symptoms among radiologists often exceeds levels seen among other computer workers. An innovative reading room design is briefly described that incorporates some ergonomic design features and this has resulted in high levels of workplace satisfaction. Finally, the Cornell Digital Reading Room Ergonomic Checklist is presented which aims to give guidance on the ergonomic design of future reading rooms.
Keywords: Digital radiology; Ergonomics checklist; Innovative Reading Room; Musculoskeletal symptoms; Visual health
A Study of the Effect of the Shape, the Color, and the Texture of Ikebana on a Brain Activity BIBAFull-Text 59-65
  Yuki Ikenobo; Yoshiyuki Kida; Noriaki Kuwahara; Akihiko Goto; Akio Kimura
A study was performed on the difference between beginners and experts of Ikebana. The brain activity measurement results showed that for beginners, the incidence of α wave increased with time both during the planning and the production of the arrangement. However, for experts, the incidence of α wave decreased with time during the planning and increased during the production of the arrangement. This result indicated that the experts concentrate the mind more during the planning through the course of the arrangement, and relaxes more during the production of the arrangement. Also, the result of questionnaire survey showed that beginners were unable to recognize the formal beauty of an Ikebana arrangement, while experts were able to evaluate it correctly. It indicates that the experts have the special criteria of the formal beauty of Ikebana cultivated through the long-term training.
Application and Future Developments of EMA in Digital Production Planning and Ergonomics BIBAKFull-Text 66-75
  Benjamin Illmann; Lars Fritzsche; Wolfgang Leidholdt; Sebastian Bauer; Markus Dietrich
The Editor for Manual Work Activities (EMA), a planning method based on a 3D digital human model, addresses the need for realistic and holistic assessment of time and ergonomics in an early phase of product, process and resource planning. Since the first introduction of EMA in 2011 practical applications have triggered several improvements driven by the requirements of various industrial customers. Experiences in different branches called for a wide focus of new developments that now allow a broader application. This paper illustrates the connection between practical requirements and technical improvements of EMA within the past years. It also demonstrates how EMA may contribute to cost-efficient and accurate planning in different phases of the product development cycle. Finally, some of the future developments are illustrated.
Keywords: Digital Human Modeling; Production Planning; Ergonomics
Using Anthropomorphism to Improve the Human-Machine Interaction in Industrial Environments (Part I) BIBAKFull-Text 76-85
  Sinem Kuz; Marcel Ph. Mayer; Simon Müller; Christopher M. Schlick
The concept of socio-technical systems emphasizes the mutual interrelationship between humans and technical system considering the human operator as an integral part of the system. However, to use the full potential of this idea the technical system has to be perceived and accepted as a team-partner. Anthropomorphism is a promising approach to improve the acceptance of a robotic system as a team-partner. In the first part of this joint contribution we introduce a study focusing on the effect of anthropomorphism in industrial environments. A virtual environment consisting of a robotized assembly cell was utilized to conduct a prediction experiment with 24 participants comparing anthropomorphic movements and trajectories based on linear and angular kinematics of an articulated robot. The task was to predict the target position during movement. The corresponding reaction value and the prediction accuracy were analyzed.
Keywords: Human-robot interaction; anthropomorphism; socio-technical system; prediction; self-optimization
Changes in Heart Rate Variability during Manual Controlled Rendezvous and Docking with Task Complexity BIBAKFull-Text 86-92
  Pengjie Li; Bin Wu; Yijing Zhang; Zhi Yao; Weifen Huang; Xiang Zhang
This research aims to study how HRV parameters change with task complexity during manual controlled Rendezvous and Docking (RVD). One one-factor experiment was conducted. The experiment task was manual controlled Rendezvous and Docking (RVD) operation and the factor was task complexity which was divided into three levels. Eight male volunteers participated in this experiment, which consisted of three trials, and each of which consisted of ten operation units containing three complexity levels. The dependent variables were main performance parameters and HRV parameters. Results showed that operation time and fuel consumption changed significantly with different complexity levels. Besides, there were significant differences on partial HRV parameters. It can be inferred that some HRV parameters are useful for mental workload evaluation. However, the relationship between the insignificant parameters and complexity levels needs to be validated and the way how HRV should be used for mental workload evaluation deserves further study.
Keywords: Heart rate variability; Rendezvous and Docking; Task complexity; Mental workload
Using Anthropomorphism to Improve the Human-Machine Interaction in Industrial Environments (Part II) BIBAKFull-Text 93-100
  Marcel Ph. Mayer; Sinem Kuz; Christopher M. Schlick
The idea of socio-technical systems emphasizes the mutual interrelationship between humans and technical system considering the human operator as an integral part of the system. However, to use the full potential of this idea the technical system has to be perceived and accepted as a team-partner. Anthropomorphism is a promising approach to improve the acceptance of non-human entities as team-partners. In the second part of this joint contribution we present a revised experimental setup of the studies presented in the first part. A virtual environment consisting of a robotized assembly cell was utilized to conduct a prediction experiment with nine subjects comparing anthropomorphic and robotic speed profiles on a gantry robot. As in the first part the task of the participants was to predict the target position during movement. The results show significant effects towards shorter prediction time and less errors when using anthropomorphic speed profiles.
Keywords: Human-robot interaction; anthropomorphism; socio-technical system; prediction; self-optimization
Numerical Reconstruction of the Real-Life Fatal Accident at Work: A Case Study BIBAKFull-Text 101-110
  Marcin Milanowicz; Pawel Budziszewski
Every year about 2.8 million people are injured in accidents at work in Europe. The resulting high costs are incurred by the victims themselves, their families, employers, and the society. A numerical simulation can be used to reconstruct accidents and to provide information about the course and cause of those accidents. This knowledge is crucial in developing successful safety systems and safety procedures.
   This paper presents a multi-body approach to reconstructing a real-life fatal accident of a forklift that overturned with its operator. A reconstruction took place to find out why forklift overturned. This study consisted of about 700 simulations. Their results were compared to data from the real accident. The path of simulated wheels and the location of the model of a forklift after the accident corresponded to the real tire tracks and the final location of the real machine. The location and position of the computer model of the operator was similar, too. The injury criteria obtained in the simulation exceeded the critical values for the head and neck, which corresponded to the operator's injuries: numerous fractures of the skull and cervical spine fracture with dislocation. Thus, speeding and a sudden turning maneuver caused the accident.
Keywords: accident reconstruction; computer simulation; multi-body; MADYMO; human model
The Relationship between Nursing Students' Attitudes towards Learning and Effects of Self-learning System Using Kinect BIBAKFull-Text 111-116
  Mitsuhiro Nakamura; Yasuko Kitajima; Jun Ota; Taiki Ogata; Zhifeng Huang; Ayanori Nagata; Kyoko Aida; Noriaki Kuwahara; Jukai Maeda; Masako Kanai-Pak
The purpose of this study is to clarify the relationship between nursing students' attitudes towards learning and effects of Kinect self-learning system for skill acquisition. Five students received feedback after each performance from the Kinect self-learning system. The students' performance was evaluated before (pre-test) and after (post-test) using 21 checkpoints. In order to investigate the students' attitudes towards learning, a survey questionnaire was distributed before the study. Based on the score, each student's attitudes towards learning were identified as either "active" or "passive". The difference between the pre-test and post-test scores for each student was calculated. Pearson product-moment correlation coefficients were calculated of the difference in the number of learning characteristics. There was a strong negative correlation between learning characteristic (Passive learning attitude) and the difference of score (r=-.80 p=.11). From this study, it is recommended that the Kinect self-learning system is not effective for skill acquisition for students whose attitudes were passive.
Keywords: Kinect; Medical Error & Simulation; Nursing Student; Nursing skill; Nursing Education
Extending Global Education through Remote Laboratory Access BIBAKFull-Text 117-123
  Uwe Reischl; Scott Harris
Advanced software technologies that are integrated with physical laboratories now allow students and researchers to access laboratory equipment and instruments remotely through the Internet. While this capability has been used in engineering and science education successfully for some time, application of this approach to human factors engineering and ergonomics education is new. The development of a remote ergonomics laboratory based on such an Internet technology is described. The focus of this new laboratory is to provide a method of evaluating protective clothing heat stress using a thermal manikin technology. The laboratory has generated global interest and created international collaboration in teaching and research.
Keywords: Remote laboratory; ergonomics education; thermal manikin; international collaboration
Combining Motion Capture and Digital Human Modeling for Creating Instructions in Industrial Settings BIBAKFull-Text 124-133
  Ulrike Schmuntzsch; Ulas Yilmaz; Matthias Rötting
In this paper, a hybrid framework for creating an instruction video by means of motion capture technologies will be explained. In this video an animated pedagogical agent named Anastasia (animated assistant for tasks in industrial applications) provides human operators with assistance while performing maintenance tasks in IPS2. Firstly, the paper contains a description of the creation process of an animated pedagogical agent which will be illustrated step by step on Anastasia. Secondly, the motion capture technology in form of a data glove will be presented. Thirdly, the concept and implementation how to improve realism of Anastasia by using the data glove will be introduced.
Keywords: animated pedagogical agent; instruction video; human modeling; motion capturing; data glove; wearable computing technologies; smart clothes
Digital Human Modeling for Physiological Factors Evaluation in Work System Design BIBAKFull-Text 134-142
  Lingyan Wang; Henry Y. K. Lau
This paper aims to develop a theoretical framework for physiological factors evaluation in work system design, and the goal has been achieved by combining principles and techniques derived from Digital Human Modeling (DHM). In more specific terms, geometrical, biomechanical, and graphical models are constructed to realize the simulation of worker's physical status in the virtual working environment, then to detect and evaluate work-related musculoskeletal disorders (WMSDs) which have a great potential of causing occupational impairment and disability. Furthermore, the ultimate object of this proposed framework is to fit the work system to the worker, and prevent the WMSDs from the original design phase.
Keywords: Work-related Musculoskeletal Disorders; Digital Human Modeling; Work System Design
Cognitive Behavior Modeling of Manual Rendezvous and Docking Based on the ACT-R Cognitive Architecture BIBAKFull-Text 143-148
  Chunhui Wang; Yu Tian; Yanfei Liu; Shanguang Chen; Zhiqiang Tian; Junsong Li
Astronauts are exposed to numerous stressors during spaceflights, to reduce the faulty operations and improve human performance in manually controlled rendezvous and docking (manual RVD) of space vehicles, a method, which applies sophisticated cognitive architecture Adaptive control of thought -- rational (ACT-R ) to model astronaut's cognitive behaviors and investigate the cognitive components influencing human performance, is proposed in this paper. To model the cognitive behaviors in completing manual RVD task, the declarative knowledge of the cognitive processes was obtained from experiments, the procedural knowledge was acquired by analyzing the relationship between cognitive processes and behaviors, and the model parameters were set up according to the boundary conditions and task characteristics. Manual RVD cognitive behavior model is then built up based on the declarative knowledge, the procedural knowledge and the model parameters. Comparisons of model running results and manual control results were performed to test the model's validation. ACT-R control panel tool was also used to analyze the process of model's running and manual control behaviors. Results of the comparisons indicate that the ACT-R model proposed in this paper is in accordance with human cognitive behaviors.
Keywords: ACT-R; manually controlled Rendezvous and docking task; cognitive behavior modeling; model's validation
Serious Gaming Used as Management Intervention to Prevent Work-Related Stress and Raise Work-Engagement among Workers BIBAKFull-Text 149-158
  Noortje Wiezer; Maartje Bakhuys Roozeboom; Esther Oprins
Work-related stress is a large occupational risks in the Netherlands but interventions to reduce this risk are not implemented in organizations. The characteristics of a serious game make it a useful training tool for managers to raise awareness on their role in stimulating work engagement and managing work-related stress. In this research project a serious game for managers is developed and implemented and will be evaluated as an intervention to reduce work-related stress and raise work-engagement among employees. The evaluation will be done in a longitudinal case-control study, using a generic, standardized evaluation framework for validation of serious games. Focus of the evaluation will be on the direct effects of playing the game and on long-term effects, cf. transfer of training. In this paper the development of the game and the design for the evaluation study will be described.
Keywords: work-related stress intervention; management intervention; work-engagement; serious gaming
Validation of an Integrated Biomechanical Modeling Approach to the Ergonomic Evaluation of Drywall Installation BIBAKFull-Text 159-168
  Lu Yuan
The present study validated an integrated biomechanical modeling approach that the researcher has previously developed to study the physical demands for drywall installers. In particular, a sensitivity analysis was conducted to examine the impact of some quantitative assumptions that have been made to facilitate the modeling approach. Through setting up null hypothesis for each assumption and changing one parameter at a time, the new model output values were compared to the original ones. Using student t-tests to evaluate the statistical differences of the mean values, the sensitivity analysis was achieved by determining if any assumption or parameter has significant impact on the model. The results indicated that the modeling approach seemed to be the most sensitive to both the distribution of work cycles for a typical 8-hour workday and the distribution and values of Euler angles that are used to determine the "shoulder rhythm." Whereas other assumptions including the distribution of trunk postures did not appear to have significant impact on the model output values. It was concluded that the integrated approach might provide an applicable examination of exposure variability particularly reflected by the non-routine feature of the work.
Keywords: Biomechanical Modeling; Sensitivity Analysis
Optimization for Lunar Mission Training Scheme Based on AnyBody Software BIBAKFull-Text 169-178
  Jing Zhang; Rong Zhou; Jingwen Li; Li Ding; Li Wang
Since majority of the lunar missions are accomplished by the upper limbs according to literature analysis, it is necessary for us to focus on studying astronauts' upper limb movement. This paper aims at studying the training schemes for the lunar mission through computer simulation with AnyBody software. Knocking, one of the typical lunar missions was selected as the study subject. Based on the verification experiment of earth's gravity level, the model of AnyBody software can be used to simulate lunar missions. An optimization of knocking move were provided by our AnyBody model.
Keywords: simulation; lunar mission training; optimization
Evaluation of Muscle Fatigue Based on Surface Electromyography and Subjective Assessment BIBAKFull-Text 179-185
  Qian-Xiang Zhou; Zhong-Qi Liu; Fang Xie
In this paper, an assessment model for muscle fatigue was constructed with mean fatigue energy and subjective feeling of fatigue degree for the entire process of the experiment. The model which combined objective and subject data will be valuable for improving work efficiency and for monitoring muscle fatigue. To investigate the relationship between surface electromyography and subjective assessment of muscle fatigue, twenty young male volunteers participated in the experiment of pistol holding and aiming. sEMG of the anterior deltoid was recorded during the entire process, while fatigue assessments (Borg scale) were collected every 30s. We divided the signal into several parts and then octave band method was used to calculate mean energy of each part. An equation was derived based on the relationship between the mean energy of sEMG and Borg scale. The results demonstrated that a quadratic curve reflected the relationship between fatigue energy and fatigue sensation, which suggests that fatigue energy can be calculated to use to collect sEMG activity recordings, and that fatigue sensation can be determined using this evaluation model. This model therefore provides a suitable basis for developing fatigue-monitoring equipment based on sEMG activity, as well as providing a theoretical and design basis for monitoring the fatigue levels of operators, and designing and planning jobs to make them more ergonomic and intuitive.
Keywords: sEMG; subjective assessment; muscle fatigue; octave band; fatigue energy

Ergonomics of Work with Computers

The Effectiveness of Alternative Keyboards at Reducing Musculoskeletal Symptoms at Work: A Review BIBAKFull-Text 189-195
  Nancy Baker
Alternatively configured keyboards have been extensively marketed as one method to reduce musculoskeletal symptoms and musculoskeletal disorders in computer operators. This paper reviews current evidence about the effectiveness of alternative keyboards at reducing risky postures and improving musculoskeletal symptoms. In general, the literature strongly supports the ability of alternative keyboards to reduce potentially risky postures, but is much more equivocal about their ability to reduce musculoskeletal symptoms in the workplace.
Keywords: Computer keyboards; ergonomics; musculoskeletal symptoms
The Biomechanical and Physiological Effect of Two Dynamic Workstations BIBAKFull-Text 196-204
  Juliane Botter; Eva-Maria Burford; Dianne Commissaris; Reinier Könemann; Suzanne Hiemstra-van Mastrigt; Rolf Peter Ellegast
The aim of this research paper was to investigate the effect, both biomechanically and physiologically, of two dynamic workstations currently available on the commercial market. The dynamic workstations tested, namely the Treadmill Desk by LifeSpan and the LifeBalance Station by RightAngle, were compared to the more conventional seated and standing workstations, through a randomized repeated measures design. Hypothesized was that the use of these dynamic workstations would have an effect on posture, physical activity, energy expenditure and muscular activity. Preliminary results suggest that the dynamic workstation increase physical activity and heart rate compared to the seated workstation.
Keywords: physical activity; computer work; dynamic workstations; joint angle; electromyography; energy expenditure; heart rate
The Effect of Dynamic Workstations on the Performance of Various Computer and Office-Based Tasks BIBAKFull-Text 205-212
  Eva-Maria Burford; Juliane Botter; Dianne Commissaris; Reinier Könemann; Suzanne Hiemstra-van Mastrigt; Rolf Peter Ellegast
The effect of different workstations, conventional and dynamic, on different types of performance measures for several different office and computer based task was investigated in this research paper. The two dynamic workstations assessed were the Lifespan Treadmill Desk and the RightAngle LifeBalance Station, and the two conventional workstations assessed were a seated and a standing workstation. Through a randomized repeated measures design, the effect of these different workstations was assessed for a series of tasks consisting of a reading, typing, telephone, mouse dexterity task and a battery of computer-based cognitive tasks. Hypothesized was that the use of these dynamic workstations would have different effects on the performance measures for the different types of tasks.
Keywords: task performance; computer work; dynamic workstations; reaction time; accuracy
Evaluating Comfort Levels of a Workstation with an Individually Controlled Heating and Lighting System BIBAKFull-Text 213-222
  Elsbeth M. de Korte; Lottie F. M. Kuijt-Evers; Marleen Spiekman; Linda Hoes-van Oeffelen; Bianca van der Zande; Gilles Vissenberg; Gerard Huiskes
Comfort complaints, such as high or low temperatures, lack of privacy and concentration loss, are regularly reported in today's offices. Most comfort aspects, such as lighting, ventilation, decoration and climate are regulated on global level, while for optimal comfort experience customized settings on personal level is desired, which requires a more direct personal control. A method is described to evaluate comfort levels of a workstation with individually controlled radiant heating and lighting. The aim is to examine the band-width of peoples' comfort zone of radiant temperature and illumination when doing office work.
Keywords: Office; personal environmental control; workstation; heating; lighting; comfort; energy efficiency; intelligent building
Assessment of Body Surface Potential Mapping in VDT-Operators BIBAKFull-Text 223-231
  Anna Janocha; Marcin Grabowski; Witold Pilecki; Robert Skalik; Krystyna Laszki-Szczachor; Ewa Janocha; Piotr Fraszczak; Malgorzata Sobieszczanska
Computer is a genius invention that has made human work more efficient. In spite of undeniable benefits, everyday long-term contact with computer screens is an occupational risk, which induces various undesirable health consequences. Exposure of the VDT-operators to the harmful occupational factors may lead to functional disorders like arrhythmia. BSPM is a diagnostic method enabling global and precise sampling the heart potentials all over the thoracic surface owing to the large number of recording electrodes. Data collected from 87 ECG waveforms is graphically presented as the body surface maps of various formats. Non-dipolar distribution of QRST isointegral maps reflects a heterogeneity of the refractory periods of the ventricles, which is supposed to account for creating a substrate for malignant and life-threatening arrhythmias. This method can be a specific indicator of the increased risk of severe ventricular arrhythmias occurring prior to abnormalities detectable on the standard 12-lead ECG recordings.
Keywords: VDT-operators; BSPM; QRST maps; ventricular arrhythmias
Hand and Arm Support for Computer Workstation BIBAKFull-Text 232-238
  Ghi-Hwei Kao; T. K. Philip Hwang
Individuals who spend long hours leaning on the desk in tasks like writing, typing or operating a mouse often suffer from Cumulative Repetitive Stress such as Tendonitis, Carpal Tunnel Syndromes and general tissue pain. Increased instance of excessive mechanical stress in the shoulders can also be a product of improper wrist and forearm support. This study use Rapid Upper limb Assessment to examine user's working action and posture on writing, typing and mouse operation. Proposed wrist support and palm inclined plane were attached at the table edge for improving desk support structure. Users test was carried out to validate the usability of wrist support design with positive result.
Keywords: arm support; occupational musculoskeletal symptoms; working area
The Effects of Touch Screen Virtual Keyboard Key Sizes on Typing Performance, Typing Biomechanics and Muscle Activity BIBAKFull-Text 239-244
  Jeong Ho Kim; Lovenoor S. Aulck; Ornwipa Thamsuwan; Michael C. Bartha; Christy A. Harper; Peter W. Johnson
The goal of the present study was to determine whether different touch screen virtual keyboard key sizes affected typing productivity, typing forces, and muscle activity. In a repeated-measures laboratory experiment with 21 subjects, typing speed, accuracy, muscle activity, and typing forces were measured and compared between four different key sizes: 13x13, 16x16, 19x19, and 22x22 mm. The results showed that 13 mm keyboard had a 15% slower typing speed (p < 0.0001) and slightly higher static (10th %tile) shoulder muscle activity (2%, p = 0.01) as compared to the other keyboards with larger keys. The slower typing speed and slightly higher shoulder muscle activity indicated that 13 mm keyboard may be less optimal for touch typing compared to the larger key sizes.
Keywords: Virtual interface; typing forces; electromyography; typing speed; accuracy
Model Reconstruction of Human Buttocks and the Shape Clustering BIBAKFull-Text 245-251
  Lijing Wang; Xueli He
The purpose of this study is to reconstruct the buttock model of Chinese young men, and categorize the buttock model by k-means clustering algorithm. Thirty men participated in our anthropometric study. The buttocks of subjects were pasted with the mark-points: coccyx (upper margin), trochanters (both sides of the margin), and the middle points on separation line between hip and thigh (lower margin) as the points of the boundary mark-points; ischial tuberosities, anus, as the function mark-points. Three-dimensional (3D) points cloud data, obtained by scanner, was imported into reverse engineering software for the reconstruction of buttock surface model. Then surface models were imported into CATIA software. The horizontal width, the vertical width, and the thickness of the buttocks were measured in 3D shape model. The k-means clustering algorithm was used to individually cluster the dimensions of horizontal width, the vertical width, and the thickness into two groups. The 3D buttock model was successfully reconstructed by 3D scan technology. The models of buttock can be categorized into eight types: long - wide - thick, long - wide - thin, long - narrow - thick, long - narrow - thin, short - wide - thick, short - wide - thin, short - narrow - thick, short - narrow - thin.
Keywords: Reconstruction; anthropometric; k-means clustering algorithm; three-dimensional (3D); buttock model
Visualizing Design Problems and Solutions of Workstations on Ships BIBAKFull-Text 252-260
  Monica Lundh; Mikael Blomé; Steven Mallam; Joanna Paraïso
The prevailing knowledge of ergonomics is not always taken into consideration while designing ships or introduced too late for it to be effective. Studies have shown that improvements of the working environment can be done with small efforts. Dissemination of research results is not always straight forward or effective due to failure to present research findings in appropriate and accessible forms for different audiences Research suggests that an interactive and explorative learning experience should be supported by technology like web resources. To reach the end users involved in the design of ships, the aim of the current study was to design and evaluate a prototype of an interactive multimedia module. The results showed good scores considering the usability aspects learning, understanding and meaningfulness. A Multimedia module like this can serve two purposes; create a learning situation and be used as a channel through which research results can be disseminated.
Keywords: case study; ergonomics; education; maritime design; multimedia; working environment
Chair Based Measurements of Sitting Behavior a Field Study of Sitting Postures and Sitting Time in Office Work BIBAKFull-Text 261-268
  Matthijs P. Netten; L. H. M. van der Doelen; Richard H. M. Goossens
In order to understand the relation between prolonged sitting and the relation to health outcome, the behavior while being seated must be studied.
   A total of 41 office workers participated in a study whilst performing their regular work for eight weeks, whilst sitting on a measuring office chair (Smart Chair). The first two (control) weeks they were not aware of the measuring abilities of the chair. After this, two groups were made to distinguish between the effects of chair instruction and smart feedback on sitting postures (Van der Doelen et al. 2011).
   In this paper the data has been analyzed in another way. The aim of this paper is to explore the characteristics of sedentary behavior for 41 subjects during their regular office work over eight weeks by measuring the events of sitting and absence from their office chair.
   Results showed that the office workers in this study on average have very long sitting events, that exceed general recommendations. Results showed that the office workers in this study on average have very long sitting events, that exceed general recommendations. Recommendations for 5 minute breaks every hour are met by 85% of the participants. However recommendations on sitting les than 20 minutes were met by 5% of the participants. None of the participants met the recommendations on all of their days during the field study.
   The sedentary behavior shown in this study underlines the importance to monitor and influence sedentary behavior while considering the individual sedentary patterns. Further knowledge on analyzing sedentary patterns is needed.
Keywords: device-based measures; sedentary behavior
Temporal Dependence of Trapezius Muscle Activation during Sustained Eye-Lens Accommodation at Near BIBAKFull-Text 269-275
  Hans O. Richter; Camilla Zetterberg; Mikael Forsman
In this experimental study different levels of oculomotor load were induced via optical trial lenses. The aim was to investigate the temporal dependence of a moderate visual load on trapezius muscle activity. Trapezius muscle activity was measured with bipolar surface electromyography (EMG). Sixty-six subjects with a median age of 36 (range 19-47, std 8) viewed a black and white Gabor grating (5 c/deg) through 0 D, and -3.5 D lenses, in periods of 7-min. An auto refractor was used to continuously sample data on eye-lens accommodation during the vision tasks. Response-diopters were used as a dichotomous high/low accommodation grouping variable. For these groups EMG amplitudes during minutes 1-7 per each lens trial were studied separately with Generalized Estimating Equations (GEE). The analysis results showed significant increases in trapezius muscle activity over time for both viewing conditions. For the binocular -3.5 D condition response-diopters gave a significant positive contribution to the EMG amplitude. The results indicate that sustained eye-lens accommodation at near, during ergonomically unfavorable viewing conditions, may increase the risk for trapezius muscle myalgia.
Keywords: Visual ergonomics; Gaze stabilization; Electromyography; Eye-lens accommodation; Computer work; Neck
Setting That Mouse for Tracking Tasks BIBAKFull-Text 276-281
  Ransalu Senanayake; Ravindra S. Goonetilleke
A pointing device plays an important role in human-computer interaction. The computer mouse is a convenient device for both pointing and steering. The literature related to the effect of mouse gain on steering tasks is scarce. An experiment was conducted with 10 participants and each participant was asked to traverse a constrained path using a computer mouse. There were three levels of gain approximately equal to 2.3, 10, and 15. The experiment had 11 levels of difficulty (D/P) based on path width (P) and path length (D) and three trials for each combination of D and P. Performance was evaluated using movement time taken to traverse the path. The results showed that movement time is minimized, in feedback-controlled steering tasks, at a gain of around nine.
Keywords: Pointing devices; Mouse; Gain; Drury's Law; Steering Law
Considering Ergonomic Aspects of Head-Mounted Displays for Applications in Industrial Manufacturing BIBAKFull-Text 282-291
  Sabine Theis; Thomas Alexander; Marcel ph. Mayer; Matthias Wille
In this paper, we apply a comprehensive approach to evaluate and analyze potential physiological and subjective workload effects of the application of head-mounted displays (HMDs) during a typical 3.5 hrs assembly operation. The approach refers to physical as well as cognitive workload associated with HMDs. The methods for capturing and determining physiological workload include an analysis of visual acuity, of visual field, electromyography (EMG), and general posture analysis (OWAS). Subjective ratings for overall workload (BLV, RSME) and simulator sickness (SSQ) are considered and analyzed in order to complete the analysis. Their feasibility and practical implementations are discussed based on the results of a pre-test with a smaller sample size in order to give recommendations for their practical use during on-going experiments and for future industrial applications.
Keywords: Head-mounted displays; ergonomics; physiological measures; strain; electromyography; visual field; BLV; SSQ
Extraction of Light Stripe Centerline Based on Self-adaptive Thresholding and Contour Polygonal Representation BIBAKFull-Text 292-301
  Qingguo Tian; Yujie Yang; Xiangyu Zhang; Baozhen Ge
Extracting light stripe centerline is the key step in the line-structure light scanning visual measuring system. It directly determines the quality of three-dimensional point clouds obtained from images. Due to the reflectivity and/or color of object surface, illumination condition change and other factors, gray value and curvature of light stripe in image will vary greatly that makes it very difficulty to completely and precisely extract sub-pixel centerline. This paper presents a novel method for light stripe centerline extraction efficiently. It combines the integral image thresholding method, polygon representation of light stripe contour and adaptive center of mass method together. It firstly locates light stripe region and produces binary image no matter how change gray values of light stripe against background. Then the contour of light stripe is extracted and approximately represented by polygon. Based on the local orthogonal relationship between directions of light stripe cross-section and corresponding polygon segment, the direction of light stripe cross-section is calculated quickly. Along this direction, sub-pixel centerline coordinates are calculated using adaptive center of mass method. 3D scanning experiments with human model dressed colorful swimsuit on a self-designed line laser 3D scanning system are implemented. Some comparisons such as light stripe segmentation using 3 thresholding methods, the time used and the smoothness are given and the results show that the proposed method can acquire satisfying data. The mean time used for one image is not beyond 5 ms and the completeness and smoothness of point clouds acquired by presented methods are better than those of other two methods. This demonstrates the effectiveness and practicability of the proposed method.
Keywords: centerline extraction; light stripe; integral image thresholding; polygon representation; adaptive center of mass

Anthropometry, Posture and Motion Modeling

Artificial Neural Network-Based Prediction of Human Posture BIBAKFull-Text 305-313
  Mohammad Bataineh; Timothy Marler; Karim Abdel-Malek
The use of an artificial neural network (ANN) in many practical complicated problems encourages its implementation in the digital human modeling (DHM) world. DHM problems are complicated and need powerful tools like ANN to provide acceptable solutions. Human posture prediction is a DHM field that has been studied thoroughly in recent years. This work focuses on using a general regression neural network (GRNN) for human posture prediction. This type of ANN has advantages over others when incorporated in DHM problems like posture prediction. A new heuristic approach is also presented in this study to determine the GRNN parameters that lead to the best performance and prediction capability. The results are promising: a high success rate is obtained for predicting 41 outputs, which represent the upper-body degrees of freedom of a human model. This work initiates future focus on embedding GRNN to generalize human posture prediction in a task-based manner.
Keywords: Digital human modeling and simulation; artificial neural network; posture prediction
Markerless Motion Capture Integrated with Human Modeling for Virtual Ergonomics BIBAKFull-Text 314-323
  Giorgio Colombo; Daniele Regazzoni; Caterina Rizzi
This paper refers to the context of virtual ergonomics and specifically addresses a case study of the commercial refrigeration industry. The aim is to develop a computer-aided platform to analyse end-users' postures and movements and ergonomically validate the design of device a man or woman may deal with. This paper describes the integrated use of human modeling and motion capture (Mocap) systems to perform ergonomic analysis relying exactly on real movements. Two optical Mocap systems, both low cost and markerless, have been considered: one based on six Sony Eye webcams and another one on two Microsoft Kinect sensors. Analogously, two human modeling tools have been adopted: Jack, specifically targeted for ergonomics and integrated with Microsoft Kinect, and LifeMod, a biomechanical simulation package. The proposed virtual ergonomics solutions have been experimented considering the case study of vertical refrigerator display units.
Keywords: Virtual ergonomics; Mocap; Digital human modeling; commercial refrigeration
Automatic 3D Reconstruction of Transfemoral Residual Limb from MRI Images BIBAKFull-Text 324-332
  Giorgio Colombo; Giancarlo Facoetti; Caterina Rizzi; Andrea Vitali; Alessandro Zanello
This work is part a new design platform for lower limb prosthesis centered on the patient's digital model and based on the integrated use of virtual prototyping tools. In particular, 3D detailed model of residual limb, that includes not only the external skin but also bones and soft tissues, is needed for socket design and finite element analysis to study the socket-residual limb interaction. In this paper, we present a procedure for 3D automatic reconstruction of the residual starting from MRI images. The output is a 3D geometric model, in a neutral format (IGES), which permits CAD information exchange among the modules composing the design platform. The reconstruction procedure consists of three different phases: image pre-processing, voxel segmentation, 3D models generation. Results have been considered promising and future activities to enhance the algorithm performance have been planned.
Keywords: Lower limb prosthesis design; MRI; 3D automatic reconstruction; segmentation
Human Pose Estimation from Depth Image Using Visibility Estimation and Key Points BIBAKFull-Text 333-342
  Sungjin Huh; Gyeonghwan Kim
In this paper, we propose the upper body pose estimation algorithm using 3-dimensional model and depth image. The conventional ICP algorithm is modified by adding visibility estimation and key points - extreme points and elbow locations. The visibility estimation keeps occluded points from participating in pose estimation to alleviate the affection of self-occlusion problem. Introduction of extreme points and elbow locations, which are extracted using geodesic distance map and particle filter, improves the accuracy of pose estimation result. The optimal parameters of the model are obtained from nonlinear mathematical optimization solver. The experimental results show that the proposed method accurately estimates the various human poses with self-occlusion.
Keywords: human pose estimation; 3D model based; modified ICP; self-occlusion; key points; geodesic distance
Using Methods-Time Measurement to Connect Digital Humans and Motion Databases BIBAKFull-Text 343-352
  Ali Keyvani; Dan Lämkull; Gunnar Bolmsjö; Roland Örtengren
To simulate human motions in DHM tools, using techniques which are based on real human data is one promising solution. We have presented a solution in this study to connect motion databases with DHM tools. We have showed that using a motion database with MTM-based annotations is a promising way in order to synthesize natural looking motions. A platform consists of a Motion Database, a Motion Generator, and a DHM tool was introduced and tested. The results showed successful application of the presented platform in the designed test case.
Keywords: Digital Human Modeling; Motion Databases; Human Motion Simulation
Note: Best paper award
Grip Force and CR-10 Ratings for Youth Females BIBAKFull-Text 353-358
  Kai Way Li; Yu C. Lin
In this study, an experiment was conducted to measure the grip force for teenaged females at four pre-determined exertion levels on the CR-10 scale. The exertion levels of 2, 5, 7, and 10 corresponded to the 20%, 50%, 70%, and 100% of the maximum voluntary contraction (MVC). The subjects were required to grip a dynamometer using both dominant and non-dominant hand. The posture of the elbow was either straight down or at 90 degree flexion. Eight one females participated in the study. The analysis of variance (ANOVA) results indicated that the exertion level, elbow posture, handedness were all significant factors affecting the grip force. The Duncan's multiple range test results indicated that the grip force at exertion level 10 (208.95 N) was significantly (p<0.05) higher than those of the levels 7 (164.66 N), 5 (128.08 N), and 2 (56.65 N). The grip force at exertion level 7 was significantly (p<0.05) higher than those of the levels 5 and 2. The grip force at exertion level 5 was significantly (p<0.05) higher than that of level 2. The Duncan's multiple range test results indicated that the grip force at 180 degree elbow posture (142.26 N) was significantly (p<0.05) higher than that of the 90 degree posture (136.91 N). The interaction effects of the exertion level and hand used were also significant (p=0.0035). The overall Pearson's correlation coefficient between the CR-10 ratings and the grip forces was 0.84 (p<0.0001).
Keywords: hand exertion; power grip; subjective rating; CR-10
Oxygenation and Blood Volume in Skeletal Muscle in Response to External Force BIBAKFull-Text 359-365
  Hao Li; Chunhui Wang; Zheng Wang
Oxygenation and blood volume in skeletal muscle have been used to evaluate muscle contraction force. This paper aims to reveal the correlations between local oxygenation, blood volume and external force. Eight subjects performed isometric elbow flexion exercise of different force levels and isokinetic elbow exercise. In isometric exercise, oxygenation and blood volume indices were significantly correlated with joint torques; and their relationships could be described by linear equations. Compared with the oxygenation rate, the change of blood volume between rest and muscle contraction was more suitable to evaluate static muscle contraction force than oxygenation. In isokinetic exercise, blood volume demonstrated obvious periodicity in different motion cycles, and had low correlations with joint moments. Oxygenation indices demonstrated obvious differences between the five motion cycles. In conclusion, blood volume was found to be suitable to estimate the static and dynamic muscle contraction force, and validate musculoskeletal system biomechanical model.
Keywords: oxygenation; blood volume; near-infrared spectroscopy; isometric exercise; isokinetic exercise
Simulating a Walk of Digital Human Model Directly in Massive 3D Laser-Scanned Point Cloud of Indoor Environments BIBAKFull-Text 366-375
  Tsubasa Maruyama; Satoshi Kanai; Hiroaki Date
Recently, human behavior simulations in 3-dimensional environment models have been enabled by the advance in computer performances. However, manually building the 3D models for the simulations are still costly and time-consuming, and the resultant models are sometimes inaccurate and do not necessarily reflect as-built environments. The final goal of our research is to realize the accessibility evaluation of "as-built" environments based on the human behavior simulation. To achieve the goal, in this study, we developed a technology where as-built 3D environment models could be constructed in a fully automatic way from laser-scanned 3D point clouds measured from as-built indoor environments. Additionally, we realized a basic walking simulation function in the as-built environment model represented by the point clouds. The modeling and simulation efficiency and accuracy were evaluated.
Keywords: human behavior simulation; laser scanning; 3D point clouds
Modeling Body Shape from Surface Landmark Configurations BIBAKFull-Text 376-383
  Matthew P. Reed
Detailed statistical models of body size and shape are valuable for wide range of statistical analyses. Most body shape models represent a single posture, usually standing. Previous efforts to model both posture and body shape have parameterized posture using joint angles. This paper presents a statistical model of body shape in supported seated postures using a posture measured derived from surface landmarks rather than internal joint locations and angles. This method is not limited by a particular kinematic linkage deformation and so is particularly well suited to model the effects on body shape of posture changes in complex linkages such as the spine or shoulder.
Keywords: body shape; laser scanning; anthropometry; posture
Anatomy-Based Variational Modeling of Digital Hand and Its Verification BIBAFull-Text 384-392
  Yulai Xie; Satoshi Kanai; Hiroaki Date
This study proposed a method to construct an anatomy-based variational modeling of a Digital Hand model, which can be used to efficiently generate various individual hand models with different dimensions for virtual ergonomic assessments. The skin surface of a generic hand model was hierarchically partitioned into 15 segments according to the hand surface anatomy. Then it was deformed by scaling and aligning the segments so that it satisfied individual hand dimensions. Moreover, the hand models of different hand postures with markers were reconstructed using a multi-view 3D model reconstruction technique. The extracted positions of markers were used to estimate the individual bone-link structure. The proposed method was validated through comparing the generated hand skin model which fitted the hand dimensions of a subject with his MRI-measured hand surface, and comparing the generated bone-link structure, which fitted joint motion of the subject, with the reconstructed hand models based on a multi-view 3D reconstruction technique.
Simulation of Pushing the Push-Pull Rod Action Based on Human Body Dynamics BIBAKFull-Text 393-401
  Zheng Yang; Yiyuan Zheng; Shan Fu
Using the software Anybody Modeling System, a human static-standing musculoskeletal model based on inverse dynamics is presented. According to the environmental constraints of cockpit, the human body model is defined, especially the selection and design of the input parameters on muscles, bones, joints, drive, and other aspects. From the model, the design simulates the flight operations of the pilot during the plane is approaching and landing, especially the right arm pushing the push-pull rod. According to the principle of inverse dynamics, the muscle forces on the right arm will be researched to elect larger ones. And the paper focuses on muscle parametric analysis and design. On the basis of muscle metabolism which is the parameter to evaluate the muscle fatigue, the design is optimized to find where the least muscle fatigue is. Results show that metabolism can provide an experimental basis for the design layout of the cockpit instruments, operating device.
Keywords: human factors; human body dynamics; numerical simulation; AnyBody optimal design
Higher Order Statistics Analyses Based on the Mathematical Model of Surface Electromyography BIBAKFull-Text 402-408
  Yan Zhao; DongXu Li; Jian Zhang
Evaluation to surface electromyographic (sEMG) of muscles is one of the important topics in human-computer interaction filed. This paper aims to quantitatively describe the difference in non-Gaussianity and non-linearity levels between the large muscle sEMG (i.e. biceps brachii, BB) and the small muscle sEMG (i.e. first dorsal interossei, FDI), which is changed with the increase of the motor unit (MU) recruitment numbers and exertion, as well the patterns of firing rate (FR). The mathematical physiology model of the BB and the FDI sEMG was developed under ten isometric maximum voluntary contraction (MVC) levels from 10% to 100% MVC for a period of 5s. Higher order statistics (HOS) detected the non-linearity and non-Gaussianity of the BB and the FDI sEMG. The Wilcoxon signed-rank test described the significant differences in non-Gaussianity/ linearity between the BB and the FDI at p<0.05. Results showed that the BB sEMG signals tended to a non-Gaussian distribution at 10%, 40%, 60~100% MVC and a non-linear distribution at 90% MVC. The FDI sEMG signals tended towards nonGaussianity at 40%~60%, 80% MVC and non-linearity at 30% MVC. The BB's Gaussianity and linearity results were compared with FDI's. The linearity test showed no significant differences between two sEMG signals. However, The Gaussianity test exhibited a significant difference between them. There are three reasons for this: 1) the difference in MU recruitment range between the BB and the FDI; 2) FR and recruitment respectively play a important role in the small and the large muscles activity. 3) the difference in MUs recruitment order between small and largest muscles. The findings of this study have guiding significance on large and small muscles capability assessment.
Keywords: Higher order statistics; sEMG; Mathematical Physiology Model; Biceps Brachii; First Dorsal Interossei