An experimental approach for the characterization of prolonged sitting postures using pressure sensitive mats

The adoption of prolonged sitting posture,which is a condition commonly encountered in several working tasks,is known to induce a wide range of negative effects,including discomfort,which has been recognized as an early predictor for musculoskeletal disorders (particularly low back pain).In this regard,the continuous monitoring of worker’s psychophysical state while sitting for long periods of time, may result useful in to preventing and managing potentially risky situations and to promote ergonomics and macroergonomics interventions,aimed to better organize work shifts and workplaces.The aim of this dissertation is to provide and test the reliability of a set of monitoring parameters,based on the use of quantitative information derived from body-seat contact pressure sensors.In particular, he study was focused on the assessment of trunk postural sway (the small oscillations resulting from the stabilization control system) and the number of In Chair Movements (ICM) or postural shifts performed while sitting, proven as a reliable tool for discomfort prediction. This thesis is articulated into four experimental campaigns.The first is a pilot study which aimed to define the most reliable algorithm and the set of parameters useful to assess the performed postural shifts or In chair Movements (ICM), which result useful to characterize postural strategies in the long term-monitoring. In this regard, a pilot study was conducted in which two different algorithms for the ICM computing were tested, based on different parameters and having different thresholds. The chosen algorithm was used, together with trunk sway parameters, to evaluate postural strategies in the other three experiments of this thesis. The second and the third studies evaluated sitting postural strategies among bus drivers during regular, long-term work shifts performed on urban and extra-urban routes. The results, in this case, showed that, all drivers reported a constant increase in perceived discomfort levels and a correspondent increase in trunk sway and overall number of ICM performed. This may indicate the adoption of specific strategies in order to cope with discomfort onset, a fatigue-induced alteration of postural features, or both simultaneously. However, it was interesting to observe differences in ICM vs trunk sway trend considering the single point-to-point route in the case of urban drivers. This difference between may indicate that these parameters refer to different aspects of sitting postural strategies: ICM may be more related to discomfort while sway may be more representative of task-induced fatigue. Trunk sway monitoring, as well as the count of ICM performed by bus drivers may thus be a useful tool in detecting postural behaviors potentially associated with deteriorating performance and onset of discomfort. Finally, the last experiment aimed to characterize modifications in sitting behavior, in terms of trunk sway and ICM among office workers during actual shifts. Surprisingly, results showed a decreasing trend in trunk sway parameters and ICM performed over time, with significant modifications in sitting posture in terms of trunk flexion-extension. Subjects were also stratified basing on their working behavior (staying seated or making short breaks during the trial) and significant differences were identified among these two groups in terms of postural sway and perceived discomfort. This may indicate that the adoption of specific working strategies can significantly influence sitting behavior and discomfort onset. In conclusion, the trunk sway monitoring and the ICM assessment in actual working environments may represent a useful tool to detect specific postural behaviors potentially associated with deteriorating performance and onset of discomfort, both among professional drivers and office workers.They might effectively support the evaluation of specific working strategies,as well as the set-up of macroergonomics interventions

Estimating hand-grip forces causing Cumulative Trauma Disorder

Wearable sensors have garnered considerable interest because of their potential for various applications. However, much less has been studied about the Stretchsense pressure sensor characteristics and its workability for industrial application to prevent potential risk situations such as accidents and injuries. The proposed study helps investigate Stretchsense pressure sensors\u27 applicability for measuring hand-handle interface forces under static and dynamic conditions. The BendLabs sensors - a multi-axis, soft, flexible sensing system was attached to the wrist to evaluate the wrist angle deviations. In addition, the StretchSense stretch sensors were attached to the elbow joint to help estimate the elbow flexion/extension. The research tests and evaluates the real-time pressure distribution across the hand while performing given tasks and investigates the relationship between the wrist and elbow position and grip strength. The research provides objective means to assess the magnitudes of high pressures that may cause pressure-induced discomfort and pain, thereby increasing the hand\u27s stress. The experiment\u27s most significant benefit lies in its applicability to the actual tool handles outside the laboratory settings

Fiber Optic-Based Pressure Sensing Surface for Skin Health Management in Prosthetic and Rehabilitation Interventions

Applied physic

Investigation of the Dynamic Interaction between the Human Body and Car Seat Using a Unique Simulation Technique

Numerical simulations and mathematical models have been developed over last many years on the certain portions of human body, car seat or automobile to characterise, monitor and assess the level of vibration and its effects on the human occupant inside the automotive. Though, the numerical simulations can define the level and nature of vibration and its transmissibility up to a certain stage, vibration measurement techniques have also been gaining importance for last several years to fill the limitations of the theoretical models. Efforts have also been made to carry out vibration related investigations using combined numerical simulation and measurement procedure for the car seat and the seated human body inside car, though the numbers of case studies carried out with the combination of simulation and measurement procedure are very less. Some technologies have been achieved to judge the level of vibration inside the car seat and its human occupant, though those technologies cover only effects of vibration, dynamics or measurement techniques on specific portions of the car or the human body without considering all the real life factors, e.g., human gender, shape of the human portions, size specific stiffness properties, in-vehicle operating conditions and damping factors. Approaches to provide a comprehensive solution to estimate the level of vibration without real life testing have not been carried out by the existing technologies very well. More than that the existing technologies investigate only particular modules of the entire human-car dynamic systems, e.g., a specific human part, seat and human interaction, vibration transmission from seat to human body or the vibration measurement technique. So, there is enormous scope of further improvement and the aim of this research work is to provide a unique simulated system considering all the critical real life factors. Outcome of this simulation study will evaluate the vibration levels inside the segments of seated human body inside a car and car seat omitting the necessity of real-life practical testing and provide the solution by linking module-wise investigations of human body and car seat. Initiative has been taken to fill up the gaps in the existing technologies and offer a novel study on the comprehensive simulation model of the combined human body and car seat bio-dynamic system to optimize the health, safety and comfort levels of the car seated human body. Present research work covered the tasks of establishing the simulations for non-linear bio-dynamic model of the seated human body, feasibility and behaviour inspection of polyurethane foam cushions, contact mechanism assignment between the human body and the car seat and establishing the simulation of car seated human occupant under the real life environment. Vertical displacements, vertical accelerations and frequencies at designated points of human body and car seat have been extracted from the simulation outcome and the obtained results have been validated though real-life vibration testing data. This unique simulation methodology can successfully be implemented to predict the final vibration levels inside the car seat and the car seated human body to optimize the health, safety and comfort of the human-car seat system. The outlined novel technique contributed knowledge to the entire human body and car seat dynamic system rather than focusing only on a very specific portion of the system. An industrial guideline has been presented to implement this unique simulation methodology in similar sectors, which will lead various industries to avoid time consuming and expensive bio-dynamic vibration testing methods and help to understand the impact of vibration on the in-vehicle human body in a better way

Design of an acoustically transparent pressure sensor for breast elastography

Breast cancer is the most commonly occurring cancer in women. Only in 2018 there were over 2 million new cases all over the world. The MURAB project, pursued at the University of Twente, has the aim to improving the breast biopsy procedure by reducing costs, patient discomfort and false negative rates. A 7-DOF KUKA robot arm steers an ultrasound transducer along a precise scanning trajectory to gather 3D volume image and stiffness values of the breast. Elasticity is the property of a body to be deformed and differs between tumors tissue and soft tissue. Elastography is a non-invasive technique in which the elasticity of a tissue is determined. The aim of this study is to design an acoustically transparent pressure sensor, mounted on the tip of the ultrasound probe, that can measure pressure differences across its surface during the scan, and assess elastographic measurements. The main idea is to use a pad of a characterized material and sequentially ultrasound images able to visualize the section of the pad and evaluate its deformation during time. The transmission of ultrasound waves into a solid depends on the mechanical characteristics of the material and on its physic state. In this work the relations between the acoustic properties and the mechanical behavior of an acoustically transparent pad are studied and evaluated

Smart system for aircraft passenger neck support

Air travel is becoming increasingly more accessible to people due to the availability of low cost air travel. However, long distance air travel is not a normal activity for human. During air travel, people experience different levels of physiological and psychological discomfort. The discomfort may affect the passenger’s health and feeling. With the rapid development of technology, the comfort of service has become an important issue. Nowadays, comfort is an attribute which is highly demanded by aircraft passengers. The comfort of aircraft passengers depends on different features and the cabin environment during air travel. Seat is one of the important features for the passengers and in which a passenger spends almost all their time during air travel. Different seat aspects have to be seen and taken into account in the comfort model. The research has five goals. First goal, literature research starts with the study on the state of the art and recent development of vehicle seat design which is available in current literature and products. The literature review gives a general idea about the research and the measurement method related to seating comfort and discomfort. Second goal, four surveys were conducted to identify the comfort factor of economy class aircraft passenger, body discomfort for truck driver, body discomfort for economy class aircraft passenger and relationship between seat location and sitting posture. The first survey is to identify and investigate the comfort factors for economy class aircraft passenger seat. Subsequently, survey on the body back sitting discomfort over travel time was conducted for truck driver and economy class aircraft passenger. The third survey is to investigate the relationship of the seat location and sitting posture of passengers in the economy class aircraft cabin. The postures of subjects were observed and recorded based on seven predefined sitting postures. Third goal, we contributed to develop a smart neck support system for economy class aircraft passenger. Our system aims to support and reduce neck muscle stress. A functional and working prototype was built to demonstrate the design concept and to perform experimental validation. Forth goal, we developed a low cost aircraft cabin simulator and we utilized it to validate our developed smart neck support system. The aircraft cabin simulator was built with motion platform and it is able to simulate a broad range of flight procedures. Next, a calibration experiment was conducted to investigate SCM muscle stress in relation to different support conditions, time interval and head rotation angle. Fifth goal, a validation experiment was conducted in the aircraft cabin simulator to evaluate the smart neck support system. The objective and subjective results show that the smart neck support system is able to reduce SCM muscle stress adaptively in a fully automate manner

Design and analysis of experiments aimed at improving the aircraft seat comfort for young and elderly passengers

Population ageing is becoming a global phenomenon. According to the United Nations report World Population Ageing, "the number of older people aged 60 or over was about 202 million in 1950, accelerated to 841 million in 2013, and will triple by 2050". The contextual implementation of active and healthy ageing policies, modifying the expectation, quality and lifestyle of the elderly, is offering opportunities and challenges on various aspects of daily life and health management: among the various positive aspects, this has determined an increase in mobility for recreational purposes and therefore an increasing complexity of the needs connected to it. These changing needs must be considered in the design of transport environments to ensure dignity and autonomy for passengers, in accordance with the policy of non-discrimination promoted by European regulations for users with reduced mobility (EC n.1107/2006). In 2017, following a positive trend begun in 2010, passengers who used air transport for their journeys to or from European Union countries exceeded the record figure of one billion for the first time. In 2018, according to Eurostat data, air traffic increased by a further 6% at European level, involving 1 billion 106 million passengers. In this European scenario, Italy is the fifth country in the EU ranking for the number of transported passengers, preceded in order by the United Kingdom, Germany, Spain and France, and is even in second place, preceded only by Spain, if referring to the transport of passengers on the national territory. In 2019, passengers transited through the 39 Italian airports monitored by Assaeroporti amounted to 193 million, i.e. 7.4 million more than the previous year equal to +4%, in line with the positive trend of previous years; among them, 19% on average were between 55 and 64 years old and 12% over 65 (Istat, May 2020). Together with the diversity of passenger population, it should be emphasized the change of their needs, helped by rapid technological development that allows passengers to carry out various activities from the comfort of their seats. Therefore, the heterogeneity of new transport needs makes it necessary to adopt an inclusive design approach, aimed at designing and implementing products that are accessible and usable by the largest number of potential users. The proposed research aims to support the ergonomic design of aircraft interiors in order to improve the quality of the mobility experience of both elderly passengers and passengers with reduced mobility. Specifically, the research started from the generation phase of their concept and went through the development of experimental protocols and methods for the evaluation of different design solutions and the continuous monitoring of postural comfort through temporal analysis of data collected by pressure and movement sensors. The research activity focused on the aspects of passive mobility, that is the context in which the air passenger operates (although the same can be extended to other contexts different from air transport, such as rail, sea or road transport): 1. identification of strategies and methods for assessing the accessibility and passenger comfort; 2. characterization of critical postural parameters to maximize passenger comfort; 3. elaboration of experimental protocols aimed at validating the feasibility of the proposed design solutions through experimental campaigns in real life. The activities related to the first point were carried out through an extensive analysis of the specialized literature concerning the analysis of (dis-)comfort both in aircraft environment and transport in general. The investigation then focused on methods for assessing the accessibility and (dis-)comfort of the passenger seat. Literature studies have focused most of the research activity on the evaluation and analysis of the experiences of young and healthy passengers who are able to move independently. Each study adopted different strategies preventing both comparison and generalization of results. Indeed, recent literature reviews have highlighted the need to develop methodologies for collecting and analyzing comfort data producing statistically significant evidence to provide diagnostic information to all stakeholders The activities inherent to the second point concerned the formulation of an evaluation strategy suitable to identify the needs of passengers, both young and old, and the critical features of the seat on which to intervene to maximize the comfort experience with respect to the functional characteristics of interest. These strategies were implemented during several experimental campaigns which, as described in the third point, involved the establishment of specific experimental protocols that allowed for replicability of the experimental tests and reliability of the results. In order to carry out the outlined activities, it was necessary to make use of different skills and tools. First of all, the experimental tests were designed with respect to appropriate methodologies for planning experiments (i.e. Design of Experiments, DOE) in order to minimize the number of tests and the impact of the main noise factors such as anthropometric characteristics of potential users, time and duration of the test. Two types of data were collected: subjective and objective measures. The collected subjective measures involved directly the selected sample who carried out an assessment of personally perceived (dis-)comfort, usability and accessibility (ease of ingress/egress) with respect to the conditions tested each time. The selected sample of participants was always sufficiently representative of the population of interest and was trained in advance to perform the test. To detect subjective measures, survey instruments such as questionnaires or checklists existing in the literature or specially elaborated and previously validated were used. The objective measures (i.e. pressure at the seat-occupant interface) were obtained using different instruments: mats equipped with sensors for both seat and backrest were used for the detection of pressures at the seat-occupant interface

Capacitive Sensing and Communication for Ubiquitous Interaction and Environmental Perception

During the last decade, the functionalities of electronic devices within a living environment constantly increased. Besides the personal computer, now tablet PCs, smart household appliances, and smartwatches enriched the technology landscape. The trend towards an ever-growing number of computing systems has resulted in many highly heterogeneous human-machine interfaces. Users are forced to adapt to technology instead of having the technology adapt to them. Gathering context information about the user is a key factor for improving the interaction experience. Emerging wearable devices show the benefits of sophisticated sensors which make interaction more efficient, natural, and enjoyable. However, many technologies still lack of these desirable properties, motivating me to work towards new ways of sensing a user's actions and thus enriching the context. In my dissertation I follow a human-centric approach which ranges from sensing hand movements to recognizing whole-body interactions with objects. This goal can be approached with a vast variety of novel and existing sensing approaches. I focused on perceiving the environment with quasi-electrostatic fields by making use of capacitive coupling between devices and objects. Following this approach, it is possible to implement interfaces that are able to recognize gestures, body movements and manipulations of the environment at typical distances up to 50cm. These sensors usually have a limited resolution and can be sensitive to other conductive objects or electrical devices that affect electric fields. The technique allows for designing very energy-efficient and high-speed sensors that can be deployed unobtrusively underneath any kind of non-conductive surface. Compared to other sensing techniques, exploiting capacitive coupling also has a low impact on a user's perceived privacy. In this work, I also aim at enhancing the interaction experience with new perceptional capabilities based on capacitive coupling. I follow a bottom-up methodology and begin by presenting two low-level approaches for environmental perception. In order to perceive a user in detail, I present a rapid prototyping toolkit for capacitive proximity sensing. The prototyping toolkit shows significant advancements in terms of temporal and spatial resolution. Due to some limitations, namely the inability to determine the identity and fine-grained manipulations of objects, I contribute a generic method for communications based on capacitive coupling. The method allows for designing highly interactive systems that can exchange information through air and the human body. I furthermore show how human body parts can be recognized from capacitive proximity sensors. The method is able to extract multiple object parameters and track body parts in real-time. I conclude my thesis with contributions in the domain of context-aware devices and explicit gesture-recognition systems

Becoming Human with Humanoid

Nowadays, our expectations of robots have been significantly increases. The robot, which was initially only doing simple jobs, is now expected to be smarter and more dynamic. People want a robot that resembles a human (humanoid) has and has emotional intelligence that can perform action-reaction interactions. This book consists of two sections. The first section focuses on emotional intelligence, while the second section discusses the control of robotics. The contents of the book reveal the outcomes of research conducted by scholars in robotics fields to accommodate needs of society and industry

Innovative Technologies and Services for Smart Cities

A smart city is a modern technology-driven urban area which uses sensing devices, information, and communication technology connected to the internet of things (IoTs) for the optimum and efficient utilization of infrastructures and services with the goal of improving the living conditions of citizens. Increasing populations, lower budgets, limited resources, and compatibility of the upgraded technologies are some of the few problems affecting the implementation of smart cities. Hence, there is continuous advancement regarding technologies for the implementation of smart cities. The aim of this Special Issue is to report on the design and development of integrated/smart sensors, a universal interfacing platform, along with the IoT framework, extending it to next-generation communication networks for monitoring parameters of interest with the goal of achieving smart cities. The proposed universal interfacing platform with the IoT framework will solve many challenging issues and significantly boost the growth of IoT-related applications, not just in the environmental monitoring domain but in the other key areas, such as smart home, assistive technology for the elderly care, smart city with smart waste management, smart E-metering, smart water supply, intelligent traffic control, smart grid, remote healthcare applications, etc., signifying benefits for all countries