Abstract: A car seat’s function is to support, protect, and make passengers and drivers feel comfortable during a trip. A more uniform pressure distribution and a larger contact area usually provide less discomfort. Consequently, the seat pan’s material and geometry play an essential role in the design process. A shaped pad was opportunely designed and realized, starting from the pressure distributions between the buttocks and the seat pan; pressure data were acquired during an initial experiment involving 41 people, representing a wide range of percentiles. The shaped pad was compared with a standard one by building a special seat with an interchangeable internal pad and testing the standard and the new seat; the second experiment involved 52 people that tested both seats. The tests were conducted to assess comfort (33 subjects were asked to be seated for 1 min each) and discomfort (19 subjects were asked to be seated for 15 min each); during the tests, pressure distribution and contact area data were gathered. The results showed that, for both tests, about 80% of the participants, among which 100% of the female sample, preferred the shaped seat pan pad. Even if the material was exactly the same, the shaped pad seemed to be softer, more comfortable, and more suited to the body’s shape than the standard one. The design methodology was demonstrated to be very useful for granting a more uniform pressure distribution and a wider contact area, i.e., higher comfort and less discomfort.

Keywords: car seat | design for comfort | experimental design | interface pressure

Abstract: Falls at height are among the major causes of fatal accidents at work, especially in the construction sector. Maintaining balance while performing a tool with both hands generates physical efforts and mental loading that needs to be managed for workers’ safety and health. The purpose of the study is to compare perceived (dis)comfort (overall and localized), the ergonomic risk, and the perceived effort through the acquired postures that subjects assumed during the execution of simple and common tasks both on a ladder and on the ground. 26 subjects were asked to perform four tasks in both conditions: top screwing, frontal screwing, object picking from the bottom forward, and object picking from the bottom sideways. Subjective and objective data were gathered for assessing subjective experience (discomfort and effort, perceived) and ergonomic risk. Results highlighted few ergonomic risk differences among “on ladder” and “on ground” tasks, while subjective data reveal significant differences in different scenarios. Furthermore, the knees and neck areas are the most critical ones.

Keywords: discomfort | ergonomics | hand tools | ladder | working at height

Abstract: As vehicles have become more complicated, Human-Machine Interaction (HMI) is becoming crucial. Nowadays, HMI is a substantial element in autonomous vehicles (AVs). Numerous studies are lately being published regarding significant parameters of AVs which can affect HMI. Hence, it is imperative to have a comprehensive prospect, to improve people's acceptance of AVs. In AVs, the driver's role will change to a passenger, however, it can be switched in some special situations. This work is divided in two parts: the first study has mapped from 299 papers in this area and found the most impressive concerns of people in using AVs. Various researchers’ approach has shown a dramatic shift from physical parameters to psycho-emotional ones; as results, trust and comfort are ranked first and second in the reviewed articles, respectively. The second part is dedicated to the explanation of methodology, the synthesis of findings and the perspectives about the future scenarios. Key findings and some insightful observations on the future of this approach are discussed in this section of the article. As a conclusion, we developed a novel model named 3p consisting of personal, psycho-emotional, and physical parameters, which states the current trend of momentous features affecting HMI in AVs.

Keywords: Comfort | Design model | Human-Autonomous Vehicle Interaction | Trust | User Experience

Abstract: As vehicles have become more complicated, Human-Machine Interaction (HMI) is becoming crucial. Nowadays, HMI is a substantial element in autonomous vehicles (AVs). Numerous studies are lately being published regarding significant parameters of AVs which can affect HMI. Hence, it is imperative to have a comprehensive prospect, to improve people’s acceptance of AVs. In AVs, the driver’s role will change to a passenger, however, it can be switched in some special situations. This work is divided in two parts: the first study has mapped from 299 papers in this area and found the most impressive concerns of people in using AVs. Regarding the researchers’ expertise and aim(s), each study has investigated the interactions between human and vehicle from a specific facet. In general, it can be claimed that a dramatic shift from physical parameters to psycho-emotional ones can be observed in recent years. The results showed that trust and comfort are ranked first and second in the reviewed articles, respectively. The second part is dedicated to the explanation of methodology, the synthesis of findings and the perspectives about the future scenarios. Finally, a novel model named 3p is proposed which includes personal, psycho-emotional, and physical parameters, and states the current trend of momentous features affecting HMI in AVs.

Keywords: Comfort | Design model | Human-Autonomous Vehicle Interaction | Trust | User experience

Abstract: The aim of this study is to provide an example of a methodology to simulate human–machine interaction in human centric design approach for performing ergonomics and (dis)comfort analyses. It consists of gathering data from the real world, creating a virtual model of the environment and a digital human model, and finally simulating interactions with artefacts and human body-parts motions in different software applications. Firstly, motion capture has been carried out using a low-cost motion-capture system with markers and cameras, then data acquired have been processed using Python© and MATLAB© codes to extract useful information about the movements. This information has been processed to recreate the movements in a virtual environment using DELMIA™ and Unreal Engine™. Both methods proved their reliability in testing reachability, but the comparison showed that Unreal Engine™ appears much more realistic in manikin and movements’ simulations than DELMIA™.

Keywords: Car Seat | Comfort | DELMIA | Ergonomics | Reachability | Unreal Engine | Virtual Environment

Abstract: The COVID-19 virus proliferated from its first emergence to a global phenomenon becoming a pandemic as declared by the World Health Organization on 11th March 2020. This sanitary emergency obliged people to suddenly face several changes in their way of life due to imposed countries’ lockdown and social distancing. One of these rapid changes involved schools and universities and, consequently, students and professors: with the sudden lockdown of universities and colleges worldwide, they had to turn the traditional “in presence” classes into online courses. A published survey among Italian academic staff and students allowed to identify and highlight the factors that affect ergonomics of workstation (learning and teaching workplace), postural and environmental comfort and teaching/learning effectiveness. This paper would like to give guidelines to set the right home environment and the timing of learning/teaching activities to improve global comfort, both for students and teachers, and improve learning effectiveness. Thirty-Five Master Degree students were involved in the experiment during the second-semester lessons (during Italian lockdown) and were asked to fill questionnaires and check their learning outcomes by answering multiple-choice tests. Data were statistically processed, and results were used to create guidelines to set the learning home-environment at best, where and when possible.

Keywords: Comfort | eLearning effectiveness | Workplace design method

Abstract: University students spend most of their time in a sitting position. Prolonged sitting on ill-fitted furniture and the resulting lousy posture make students have different musculoskeletal disorders (MSDs) and are strictly related to students' learning outcomes. This study aims to improve postural comfort of chairs placed inside the Science & Technology Library at the University of Salerno. A previous study about these library chairs showed that the lumbar area was the most suffering part while perceived (dis)comfort was dependent on time. Based on this, an ergonomic redesign and, consequently, manufacturing of the chair has been done. A perceived-comfort comparison between the library chair and the redesigned one has been performed. A statistical sample of 28 healthy students performed a 20-minutes experiment two times, alternatively on the library chair and the redesigned one. The 20-minutes experiment was divided into two 10minutes tasks (“Reading & Writing” and “Laptop use”) to simulate a study day. The participants' postures were acquired non-invasively using cameras and processed by Kinovea; questionnaires were used to rate the perceived subjective (dis)comfort. A procedure for improving an existing product through a comfort-driven redesign is proposed. Results showed the redesigned library chair lead on increasing postural comfort (particularly in the lumbar area) thanks to the new design and modifications.

Keywords: (dis)comfort | comfort-driven redesign | design method | postural comfort | redesign | student seat | Taguchi method design

Abstract: University students spend most of their time in a sitting position. Prolonged sitting on ill-fitted furniture and the resulting lousy posture is making students having different musculoskeletal disorders and is strictly related to students learning outcomes. This study aims to improve postural comfort of chairs placed inside the Science & Technology Library at the University of Salerno. A previous study about these library chairs showed that the lumbar area was the most suffering part while perceived (dis)comfort was dependent on time. Based on this, an ergonomic redesign and, consequently, manufacturing of the chair has been done. A perceived-comfort comparison between the library chair and the redesigned one has been performed. A statistical sample of 28 healthy students performed a 20-min experiment two times, alternatively on the library chair and the redesigned one. The 20-min experiment was divided into two 10-min tasks (“Reading & Writing” and “Laptop use”) to simulate a study day. The participants’ postures were acquired non-invasively using cameras and processed by Kinovea; questionnaires were used to rate the perceived subjective (dis)comfort. A procedure for improving an existing product through a comfort-driven redesign is proposed. Results showed the redesigned library chair lead on increasing postural comfort (particularly in the lumbar area) thanks to the new design and modifications.

Keywords: (dis)comfort | Design method | Postural comfort | Redesign | Student seat

Abstract: BACKGROUND: The sanitary emergency due to COVID-19 virus obliged people to face up several changes in their everyday life becauseWorld Health Organisation (WHO) guidelines and countries' Health Systems imposed lockdown of activities and social distancing to flatten the infection curve. One of these rapid changes involved students and professors that had to turn the traditional 'in presence' classes into online courses facing several problems for educational delivery. OBJECTIVES: This work aimed to investigate the factors that affected both teaching/learning effectiveness and general human comfort and wellbeing after the sudden transition from classrooms to eLearning platforms due to COVID-19 in Italy. METHODS: A workshop, involving students and experts of Human Factors and Ergonomics, has been performed to identify aspects/factors that could influence online learning. Then, from workshop output and literature studies, a survey composed of two questionnaires (one for students and one for teachers) has been developed and spread out among Italian universities students and professors. RESULTS: 700 people answered the questionnaires. Data have been analysed and discussed to define the most important changes due to the new eLearning approach. Absence of interactions with colleagues and the necessity to use several devices were some of the aspects coming out from questionnaires. CONCLUSIONS: The study shows an overview of factors influencing both teaching/learning effectiveness and general human comfort and wellbeing. Results could be considered as a basis for future investigation and optimization about the dependencies and correlations among identified factors and the characteristics of the products/interaction/environment during eLearning courses.

Keywords: comfort | COVID-19 | discomfort | human centred design | university lectures

Abstract: BACKGROUND: In recent years, a growing interest in ergonomics and comfort perception in secondary schools and universities can be detected, to go beyond the UNI-EN regulations and understanding how practically improve students' perceived comfort during lessons. OBJECTIVE: This study aimed to analyse the (dis)comfort perceived by students while sitting in a combo-desk during lessons; it proposed a method for understanding and weighing the influence of postural factors on overall (dis)comfort. METHODS: Twenty healthy students performed a random combination of three different tasks in two sessions - listening, reading on a tablet and writing. Subjective perceptions were investigated through questionnaires, in which the expected and the overall comfort were evaluated; postural angles were gathered by processing photos through Kinovea® software and were used for the virtual-postural analysis, using a DHM (Digital Human Modelling) software; statistical analysis was used to investigate the influence of subjective comfort of each body part on the overall perceived comfort. RESULTS: The statistical correlations were used to perform an optimization problem in order to create a general law to formulate the overall comfort function, for each task, as a weighted sum of the comfort perceived in each body part. The test procedure, additionally, evaluated the influence on comfort over time. The results showed how the upper back and the task-related upper limb are the most influencing factors in the overall comfort perception. CONCLUSIONS: The paper revealed a precise and straightforward analysis method that can be easily repeated for other design applications. Obtained results can suggest to designers easy solution to re-design the combo-desk.

Keywords: combo-desk | Perceived (dis)comfort | school activities | school seat | students wellbeing

Abstract: BACKGROUND: According to ergonomic researches regarding a good sitting posture, it is essential to ensure a natural back-curve in order to prevent musculoskeletal disorders. A brief observation among the Scientific Technology Library inside the University of Salerno showed that students used to complain about neck and lumbar pain, especially after a study day. OBJECTIVE: On the light of this background, a sitting posture comfort analysis had been performed on chairs inside the library to check the critical factors that influence the postural comfort and, consequently, the learning. METHODS: A prolonged sitting posture, that is common during the daily study activity, had been simulated with fifteen volunteer students performing 1-hour tests (divided into four 15-minutes tasks). Subjective perceptions had been gathered through questionnaires rating on a 5-point Comfort scale, both the expected comfort at the beginning of the experiment and the Localized Postural Comfort at the end of each task have been investigated. Then, postural angles had been gathered through photographic acquisition and Kinovea®. CaMAN software had been used to calculate the objective (dis)comfort indexes. Finally, subjective and objective data had been statistically processed and compared. RESULTS: Lumbar area scored the lowest perceived comfort while the perceived comfort was independent of participants and tasks, but dependent on time. CONCLUSIONS: After this comfort-driven analysis, critical factors of the chair-design were checked, and a proposal for a future re-design was hypothesized.

Keywords: Comfort | library | office seat | postural comfort-driven redesign | students

Abstract: BACKGROUND: Nowadays, the ergonomic study of the driving position is a critical aspect of automotive design. Indeed, due to the rising needs on the market, one focus for car industries is to improve the perceived comfort related to the cars' interior. Driving a car for a prolonged time could cause complaints in some body-regions, especially in the lumbar-sacral area. Thus, special lumbar-sacral supports for driver seat has been proposed for reducing this kind of complaints. OBJECTIVE: Development of two virtual and physical models of lumbar-sacral support for improving both the lumbar/sacral and overall perceived comfort while driving. METHODS: Two prototypes of lumbar/sacral support have been realized: the first one was integrated into the seat, and the second one was shaped as a removable pillow (removable support). Fifty participants were asked to rate the perceived comfort in lab tests performed on a seating-buck by comparing three configurations (5 min each): a standard seat, seat with the removable support, seat with integrated support. Subjective data (by questionnaires) and objective data (interface pressure between backrest and driver) have been acquired and statistically processed. In addition, real driving tests have been performed to test the actual performance of the removable support in term of perceived comfort comparing it with the standard seat. RESULTS: Statistical correlations between subjective and objective data showed interesting results in comfort improvement through the adopted solutions. Real driving tests showed an improvement in comfort perception with the lumbar-sacral support towards the standard seat. CONCLUSIONS: Thanks to the virtual prototyping and the application of previous knowledge, coming from literature and experience, a solution for improving the overall comfort and reduce the lumbar/sacral pain while driving has been developed, tested, and assessed.

Keywords: body-shaped pillow | Car seat comfort | lumbar-sacral support | seat design

Abstract: In recent years, comfort seat design has received widespread attention from researchers. One of the factors that could contribute to comfort is the thermal influence due to the interaction between the human and the seating surface, for which literature is limited. In this paper, a laboratory experimental setup was used to detect and analyse the temperature changes at interface between seated subjects and a sensorized automotive seat. Acquired temperatures were processed in order to identify a mathematical model for describing the temperature changes at the interface. The main target of the study was the identification of the most sensitive areas of the human body to temperature variation while seated and its effect on local and overall perceived thermal comfort. Statistical analysis showed that the effects of temperature were most perceived in the “Upper Body” (UB) and less in the “Lower Body” (LB). The shoulders, the sides of the back, the back and the buttocks were most sensitive to temperature changes at the interface. Differences have been highlighted also between male and female subjects. Relevance to industry: The identification of the most sensitive areas of the human body to temperature variation, while seated, and the identification of the logarithmic model for describing the temperature changes should allow seat designers to define targets and strategies in developing cooling and heating systems for car seats, taking into account, in a preventive evaluation, the most probable perceived thermal comfort.

Keywords: Comfort evaluation | Seat design | Temperature | Thermal comfort | Thermal sensitivity

Abstract: What type of mattress could improve human thermal comfort and sleep quality in hot/cold weather is open questions. In this study, using four different mattresses (temperature-controlled mattress with built-in circulating water pipes, temperature-controlled mattress with built-in integral water cushion, 3D air mesh fabric mattress, and latex foam mattress), a series of sleep experiments were conducted to establish the appropriate thermal comfort zone within bed microclimate for optimal sleep quality. The results showed that, compared with a common latex foam mattress, all temperature-controlled mattresses have excellent cooling performance. Different temperature-controlled devices generated different thermal responses. The mattress with built-in circulating water pipes offered subjects the best thermal comfort during sleep, while the mattress with an integral water cushion resulted in slightly cool and slightly humid states. As the application of innovative mattresses in hot weather, subjects experienced better sleep quality by using a mattress with built-in circulating water pipes and 3D air mesh fabric mattress. Moreover, the comfortable temperature ranges of the human-mattress interface and bed microclimate were 32.3–33.8 °C and 32.8–33.6 °C, respectively. These findings are helpful to better understand the effect of innovative designed mattresses on human thermal comfort, in order to obtain the optimal sleep quality.

Abstract: Ergonomic design principles can be applied to improve human interaction. In sport activities, ergonomic planning can be a key-point of development both for sportsman behaviour and for sport facilities/devices’ design, in order to reduce injuries and muscular-skeletal disease. In some sport activities, wears and shirts plays a role not only as “dress” for sport but also as “containers” for some sports’ devices like instruments, chronometers, bottle-holder and so on. In this study, we have focused our attention on long-running people (half-marathon/marathon) that usually use the running T-shirt also as a bottle holder. In this paper, a new prototype of running T-shirt has been realized and compared with the standard one. A comparative ergonomic and comfort assessment has been done. Interaction between human and T-shirt/bottle has been modelled in DELMIA® DHM environment. The video analysis and the acquisition of human joint’s angles were processed using the KINOVEA® software. The data were evaluated using the CA_Man® software. Results are related to the subjective ratings expressed by the subject s that filled a questionnaire.

Keywords: Comfort evaluation | Digital human modelling | Ergonomics

Abstract: Computer aided technologies (CAT) are becoming an indispensable instrument to design, improve and manufacture new products and services. Digital human modelling (DHM) systems allow to simulate the Human-artifact interface and to evaluate, in early step of design process, the ergonomic performances of new products or workplaces. In particular, for products that have to be used in a “constrained” workplace, different tasks and activities are associated with different postures. The aim of this study is to investigate the influence of anthropometric characteristics and expectations on the postural comfort perception through the CAT/DHM systems, while using four office devices: desktop computer, laptop computer, tablet and smartphone. A statistical sample of healthy students was selected and their anthropometric characteristics were measured. The postures assumed by the participants were gathered in a not-invasive way by cameras. The angular detection was performed directly on snapshots by using Kinovea® software. Human joints’ an-gles were used for the virtual-postural analysis, through DELMIA® software. The evaluation of postural comfort was obtained in two ways: CaMAN® software developed by the researchers from the Department of Industrial Engineering in Salerno (Italy) was used to calculate the objective comfort indexes while an appropriate questionnaire, given to subjects during the devices usage, was used to evaluate the subjective com-fort indexes. The results of analyses show a difference between subjective and objective postural comfort indexes for all the devices: this difference has been associated to the expectations.

Keywords: Comfort evaluation | Computer aided technologies | Expectations | Not-invasive postural analysis | Office devices

Abstract: Currently, the word ‘comfort’ is often used in relation to the marketing of products such as chairs, cars interiors, clothing, hand tools and even airplane tickets. In this field of research, the aim of this study is to investigate the influence of spinal posture on postural (dis)comfort perception; the test case is the analysis of the interaction between humans and vending machines for purchasing food or beverages. A statistical sample of 20 healthy students (subjects) performed the required tests, with each participant asked to take a product from three different vending machines (snacks, drinks and coffee). The subjects' postures were acquired non-invasively using cameras; software and instruments for virtual prototyping were used for posture analysis and interaction modelling, both questionnaires (subjective) and comfort-analysis software (objective) were used to rate the perceived (dis)comfort. The results obtained from simulations and questionnaires were compared, and a method to weigh the effect of the perceived spinal discomfort on overall postural (dis)comfort was proposed. These results reveal a good correlation between subjective perception and objective evaluation obtained through simulations, confirming the validity of the proposed method.

Keywords: Comfort evaluation | Information fusion | Non-invasive postural analysis | Spine discomfort | Vending machines

Abstract: The study of ergonomics and (dis)comfort is a major topic of interest to scientific literature since the introduction of ISO 11228. Over the past 30 years, researchers have attempted to understand the mechanisms underlying perceptions of (dis)comfort for a seated subject. Three main factors are recognized as paramount for the comfort performance of a seat: human body posture, pressure at interface, and load distribution on the contact area; this study investigates the relationships between them and examines their significance for (dis)comfort perception. Physiological factors are known to play a role in (dis)comfort perception, and we consider these as a consequence of the three main parameters above. An explanation is given for this hypothesis. Experimental tests were conducted using a school chair with a rigid seat pan and no armrests for reducing the number of factors of influence. Conclusions show the levels of correlation between acquired information and perceived (dis)comfort.

Keywords: Comfort | Posture | School furniture | Seating | User experience

Abstract: The application of ergonomic principles to the design of processes, workplaces and organizations is not only a way to respond to legal requirements but also an indispensable premise for any company seeking to pursue a business logic. This paper shows a cheap and effective method to perform the ergonomic analysis of worker postures in order to optimize productivity and obtain the highest ergonomic ratings. Evaluations were performed for the 5°, 50° and 95° percentiles according to OCRA and NIOSH methods of biomechanical risk assessment. The results highlighted the need for improvements. A virtual simulation using DELMIA® software and the use of workers’ checklists drew attention to problems causing significant physical stress, as identified by ergonomic tools. An ergonomic/ comfort-driven redesign of the work cell was carried out, and CaMAN® software was used to conduct a final comfort-based analysis of the worst workstation in the work cell.

Keywords: Comfort rating | Ergonomic evaluation | NIOSH analysis | OCRA Index | Redesign

Abstract: In this paper, the authors show the results of an anecdotic experiment about the effect the use of eyeglasses has on the body posture of people in seated positions using different kinds of electronic devices: a desktop computer, a laptop, a tablet and a smartphone. The tasks were performed using a fully reconfigurable seating buck on which a standard VDT (Video Display Terminal) workplace with a chair was set. Subjects performed different tasks in order to evaluate the subjective perception of postural comfort. A Digital Human Modeling system was used to model and evaluate, from an ergonomic point of view, the ergonomic level. Software CaMAN®, was used to perform an objective evaluation of the postural comfort of subjects’ upper limbs and to compare the results obtained for the different subjects. The results show that the use of glasses has a significant effect on the body postures of the subjects.

Keywords: Comfort | Discomfort | Electronic devices | Glasses | Posture | VDT/computer workplace

Abstract: In recent years, methods that allow for an objective evaluation of perceived comfort, in terms of postural, physiological, cognitive and environmental comfort, have received a great deal of attention from researchers. This paper focuses on one of the factors that influences physiological comfort perception: the temperature difference between users and the objects with which they interact. The first aim is to create a measuring system that does not affect the perceived comfort during the temperatures' acquisition. The main aim is to evaluate how the temperature at the human-mattress interface can affect the level of perceived comfort. A foam mattress has been used for testing in order to take into account the entire back part of the human body. The temperature at the interface was registered by fourteen 100 Ohm Platinum RTDs (Resistance Temperature Detectors) placed on the mattress under the trunk, the shoulders, the buttocks, the legs, the thighs, the arms and the forearms of the test subject. 29 subjects participated in a comfort test in a humidity controlled environment. The test protocol involved: dress-code, anthropometric-based positioning on mattress, environment temperature measuring and an acclimatization time before the test. At the end of each test, each of the test subject's thermal sensations and the level of comfort perception were evaluated using the ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) scale. The data analyses concerned, in the first instance, correlations between the temperature at the interface and comfort levels of the different parts of the body. Then the same analyses were performed independently of the body parts being considered. The results demonstrated that there was no strong correlation among the studied variables and that the total increase of temperature at interface is associated with a reduction in comfort.

Keywords: Bedding systems | Comfort evaluation | Mattress | Objectifying comfort | Temperature | Thermal comfort

Abstract: Knowledge about the effects of primary factors on comfort level is useful in Human-Machine-Interface (HMI) design. The study and the mathematical modeling of these effects strongly depends on cross relations between the different kinds of comfort, the primary factors’ effects, and the modifiers’ actions. Starting from a sizeable bibliographic analysis, this paper describes a study, based on the axiomatic design approach, of the interactions between the results, factors, and modifiers in comfort/discomfort evaluation. The modifiers’ influence was determined by measuring the changes in information content. This study allowed us to validate and optimize our equation for the perceived “level of well-being” in order to better study the perception of comfort/discomfort in HMI.

Keywords: Axiomatic design | Comfort rating | Discomfort | Evaluation criteria | Perception

Abstract: The application of ergonomic principles to the design of processes, workplace and organization, is not only a way to respond to legal requirements, but also an indispensable premise for any company that wants to pursue a business logic. One of the most stressful works, in terms of prolonged wrong postures and psych-cognitive effort, is the dentist's one. This paper shows a cheap and effective method to acquire workplaces, work-cycles and workers-postures, in a workenvironment (Dental clinic), in order to analyze how dentists (workers) move themselves into the work environment around the workstations (Dental clinic seat), with their own tools and devices, and do their jobs. The aim of the analysis is to determine the best way to plan the movement of the workers and their work-cycle in order to optimize the productivity and to obtain the best ergonomic rating for the workers. For those purposes, authors used Virtual Prototyping techniques and OCRA Analysis for making the biomechanical risk assessment; time acquisition and video acquisition has been made to analyze the work cycle. DELMIA® software was used to model the workstation and for modelling activities and postures associated with various repetitive actions; pictures taken by cameras have been processed through the KINOVEA® software and simulations have been made for the own worker percentile. An ergonomic/comfort driven redesign of the work-cycle has been suggested in order to optimize the work cycle in terms of risk minimization. The application has been made on the typical working day of an Italian dentist.

Keywords: Comfort evaluation | Dentist's work | Digital human modeling | Ergonomics | Not-invasive postural analysis

Abstract: The application of ergonomic principles to the design of processes, workplace and organization, is not only a way to respond to legal requirements, but also an indispensable premise for any company that wants to pursue a business logic. This paper shows a cheap and effective method to acquire workplaces, work-cycles and workers-postures, in a work-environment, in order to analyze how workers move themselves into the work environment around the workstations, with their own tools and devices, and do their jobs. The aim of the analysis is to determine the best way to plan the movement of the workers and their work-cycle in order to optimize the productivity and to obtain the best ergonomic rating for the workers. For those purposes, authors used Virtual Prototyping techniques and OCRA Analysis for making the biomechanical risk assessment; time acquisition and video acquisition has been made to analyze the work cycle. DELMIA® software was used to model the workstation and for modelling activities and postures associated with various repetitive actions; pictures taken by cameras have been processed through the KINOVEA® software and simulations have been made for the own worker percentile. If needed, an ergonomic/comfort driven redesign of the work-environment has been suggested in order to optimize the work cycle in terms of risk minimization. The application has been made on the lunch-boxes’ distribution station’s workers at University of Salerno (Italy).

Keywords: Comfort evaluation | Digital human modeling | Ergonomics | Not-invasive postural analysis | Redesign

Abstract: The application of ergonomic principles to the design of processes, workplace and organization, is not only a way to respond to legal requirements, but also an indispensable premise for any company that wants to pursue a business logic. This paper shows a cheap and effective method to acquire workplaces, work-cycles and workers-postures, in a work-environment, in order to analyze how workers move them-selves into the work environment around the workstations, with their own tools and devices, and do their jobs. The aim of the analysis is to determine the best way to plan the movement of the workers and their work-cycle in order to optimize the productivity and to obtain the best ergonomic rating for the workers. For those purposes, authors used Virtual Prototyping techniques and OCRA Analysis for making the biomechanical risk assessment; time acquisition and video acquisition has been made to analyze the work cycle. DELMIA® software was used to model the workstation and for modelling activities and postures associated with various repetitive actions; pictures taken by cameras have been processed through the KINOVEA® software and simulations have been made for the own worker percentile. If needed, an ergonomic/comfort driven redesign of the work-environment has been suggested in order to optimize the work cycle in terms of risk minimization. The application has been made on the University of Salerno’s Pizzeria’s workers.

Keywords: Comfort evaluation | Digital human modeling | Ergonomics | Postural analysis | Redesign

Abstract: The application of ergonomic principles to the design of processes, workplace and organization, is not only a way to respond to legal requirements, but also an indispensable premise for any company that wants to pursue a business logic. This paper shows a cheap and effective method to acquire workplaces, work-cycles and workers-postures, in a work-environment, in order to analyze how workers move themselves into the work environment around the workstations, with their own tools and devices, and do their jobs. The aim of the analysis is to determine the best way to plan the movement of the workers and their work-cycle in order to optimize the productivity and to obtain the best ergonomic rating for the workers. For those purposes, authors used Virtual Prototyping techniques and OCRA Analysis for making the biomechanical risk assessment; time acquisition and video acquisition has been made to analyze the work cycle. DELMIA® software was used to model the workstation and for modelling activities and postures associated with various repetitive actions; pictures taken by cameras have been processed through the KINOVEA® software and simulations have been made for the own worker percentile. If needed, an ergonomic/comfort driven redesign of the work-environment has been suggested in order to optimize the work cycle in terms of risk minimization. The application has been made on the lunch payment station’s workers at University of Salerno (Italy).

Keywords: Comfort evaluation | Digital human modeling | Ergonomics | Noninvasive postural analysis | Redesign

Abstract: The definitions of methods and tools used to evaluate how workers perceive the comfort during their activities remains an “open” problem at this time. Many researchers have dealt with that problem in the last twenty years, focusing their efforts primarily on the automotive sector and on VDT workstation comfort. This paper analyzes how workers position themselves at workstations used in industrial processes that sew together the edges of mattresses. The aim of the analysis is to determine whether workers can position themselves in ways that allow them to carry out activities in simple and economical ways. The Strain Index was used to identify the most critical and risky work phases in order to evaluate workers' risk of biomechanical overload. The OCRA checklist was used to evaluate the overall risk level associated with repeated completions of the total cycle of work and to develop a virtual-postural analysis to evaluate workers' perceived levels of discomfort. For the virtual-postural analysis, DELMIA® software was used to virtually model a workstation, and records of activities and the postures associated with various repetitive actions were gathered in a non-invasive manner with cameras and video cameras. CaMAN® software developed by the researchers from the Department of Industrial Engineering in Salerno (Italy) was used to calculate comfort indexes. An analysis of the comfort indexes was used to make as the basis for suggestions to correct workers' postures and for plans to redesign the workstations in order to improve ergonomics and allow workers to perceive them as more comfortable.

Keywords: Comfort evaluation criteria | Digital human modeling | Ergonomics | Non-invasive postural analysis | Redesign

Abstract: What are the new trends in research for comfort evaluation and the objective and predictive techniques for quantifying and qualifying comfort perception by humans? This paper has attempted to answer this question in a wide literature review, whereby it is possible to highlight many partial aspects that have been studied successfully. Just a few researchers [1–3] have studied the problem of comfort perception and evaluation under a wider point of view. Nevertheless, some aspects seem not to have yet been taken into account. In a previous paper, the authors extended the Vink–Hallbeck model to build a comfort perception/evaluation matrix in which four kinds of comfort related to different humans’ perception were studied and linked to the whole environment's characteristics. In the resultant perception-scheme and in the proposed “fusion rule” (for different kinds of perceived comfort/discomfort), one aspect that played a fundamental role in the final comfort/discomfort perception/evaluation was expectation. Expectation due to preconceived data (acquired or formed in the users’ minds) and the influence of the working environment, can act in terms of additive or subtractive factor in the comfort experience by altering the final comfort/discomfort perception and changing the subjective comfort/discomfort evaluation. This paper presents the results of expectation influence analysis on comfort evaluation. Using the placebo effect, authors conducted a wide experimental test with a wide sample of users, asking them to use and evaluate two identical mattresses that were dressed and described as two different products (the first one as a very cheap mattress and the second one as a high-level and expensive mattress). Differences between subjective evaluations have been statistically processed and correlated to anthropometric parameters to individuate and understand the role of expectation.

Keywords: Cognitive | Comfort evaluation | Expectations | Mattress | Physiological and environmental comfort | Postural

Abstract: Main purpose of this work is to show how easy and economics an ergonomic/comfort based approach, in re-design a manual assembly workplace, can be; authors, using a new comfort/ergonomic evaluation criterion, analyzed a workstation and identified the critical issues under ergonomic/comfort point of view and finally gave several guidelines to re-design the workplace, implementing minor modification, and improve work-safety, work-quality and productivity. The postural analysis was performed by non-invasive and especially inexpensive methods, based on cameras and video-recorder use and by photogrammetric analysis; DELMIA® DHM software has been used to perform all simulations; comfort analysis was performed by the software developed by researchers of Departments of Industrial Engineering of Salerno: CaMAN®. The test case is an automatic assembly machine that has been modeled and used for virtual postural analysis. Main results of this work can be found in a very good numerical/experimental correlation between acquired/simulated postures and real ones, and on the powerful use of an objective comfort evaluation method, based on biomechanics and posture analysis, for giving to designers the guidelines to re-design a workplace and a work-cycle. This kind of approach seemed to be very powerful in re-designing the work-place and in re-scheduling the work time-sheet because it allowed to improve an ergonomic corrective action with minor costs for company. Obtained results demonstrated the validity of re-design hypotheses through the increase of all comfort indexes and the improvement of workstation/operator productivity. © (2014) Trans Tech Publications, Switzerland.

Keywords: Comfort evaluation criteria | Digital human modeling | Ergonomics | Not-invasive postural analysis | Re-design