Impact of anthropometric measurements on ergonomic driver posture and safety

Basic properties of vehicle interior are described. Car seat design, upholstery fabrics and passenger safety have been particularly emphasized. Textile fabrics as products providing comfort, safety and esthetics of the vehicle interiorwere dealt with. Safety belts, airbags and car seat covers were specially pointed out. Specific problems related to the safety of passengers, whose anthropometric measurements deviate from the average ones, were addressed

Investigation into suitability of current ATDs to represent ageing drivers

Ageing car occupants are expected to become a larger part of the driver and passenger population in developed countries in the future. Currently, Anthropomorphic Test Devices (ATDs) are essential tools to assess safety of automobiles; however, they do not fully embody the features of all occupant groups in the world population. This study investigates the features of ageing drivers. The data are collected and analysed with respect to age and gender. Information particularly on driverautomobile interaction is provided in the form of distances and angles measured in-car. The physical characteristics of existing ATDs are investigated and compared with the anthropometric data of ageing drivers. Comparisons indicate that the current ATDs do not incorporate some of the features of ageing drivers. The requirements of future ATDs such as sitting height, abdominal depth and posture are discussed. These specifications are essential for the development of new ATDs representing ageing drivers

Driving ergonomics for an elevated seat position in a light commercial vehicle

With more legislation being enforced to achieve a reduction in road transport CO2 emissions, automotive companies are having to research and develop technologies that deliver greener driving . Whilst emissions from passenger vehicles have dropped over recent years, there has been an increase in emissions from light commercial vehicles (LCVs). The nature of LCV delivery work is a routine of ingress/egress of the vehicle, changing from a standing to a seated posture repetitively throughout the day. One research focus is packaging occupants in to a smaller vehicle space, in order to reduce the amount of vehicle emissions over its lifecycle. For LCVs, benefits from space saving technology could be an increase in overall loading space (with the same vehicle length) or a reduction in the overall length/weight of the vehicle. Furthermore, an elevated seat posture could reduce the strain on drivers during ingress/egress, as it is closer than that of a conventional seat to a standing posture. Whilst space saving technology has obvious benefits, current driving conventions and standards are not inclusive of new and novel seated postures when packaging a driver in to a vehicle. The fundamental purpose of a vehicle driver s seat is to be comfortable and safe for the occupant and to facilitate driving. It has been shown that a seat needs both good static and dynamic factors to contribute to overall seat comfort. Additionally, comfortable body angles have been identified and ratified by studies investigating comfortable driving postures; however, this knowledge only applies to conventional driving postures. For an elevated posture , defined as having the driver s knee point below the hip point, there is little research or guidance. The overall aim of this thesis is to identify the ergonomic requirements of a wide anthropometric range of drivers in an elevated driving posture for LCVs, which was investigated using a series of laboratory based experiments. An iterative fitting trial was designed to identify key seat parameters for static comfort in an elevated posture seat. The results showed that in comparison with a conventional seat: Seat base length was preferred to be shorter (380mm compared with 460mm); Seat base width was preferred to be wider (560mm compared with 480mm); Backrest height was preferred to be longer (690mm compared with 650mm). These findings provided a basis for a seat design specification for an elevated posture concept seat, which was tested in two subsequent laboratory studies. A long-term discomfort evaluation was conducted, using a driving simulator and a motion platform replicating real road vibration. Discomfort scores were collected at 10-minute intervals (50-minutes overall) using a body map and rating scale combination. The results indicated that in comparison with the conventional posture, the elevated posture performed as well, or better (significantly lower discomfort for right shoulder and lower back; p<0.05, two-tailed), in terms of long-term discomfort. Furthermore, the onset of discomfort (i.e. the time taken for localised discomfort ratings to be significantly higher than the baseline ratings reported before the trial) occurred after as little as 10 minutes (conventional posture) and 20 minutes (elevated posture) respectively. A lateral stability evaluation was conducted using low-frequency lateral motion on a motion platform (platform left and right rolls of 14.5°). Stability scores were reported after each sequence of rolls, comparing scores on a newly developed lateral stability scale between three seats: Conventional posture seat; Elevated posture concept seat (EPS1); Elevated posture concept seat with modifications aimed at improving stability (EPS2). Participants reported being more unstable in EPS1, compared with the conventional posture seat (p<0.05, Wilcoxon). However, the EPS2 seat performed equally to the conventional posture seat. These findings suggest that the elevated posture seat developed in this research is a feasible and comfortable alternative to a conventional posture seat. Furthermore, the final elevated seating positions showed that real space saving can be achieved in this posture thus allowing for more compact and lighter vehicles and potentially reducing strain on drivers during ingress/egress

Investigation into suitability of current ATDs to represent ageing drivers

Ageing car occupants are expected to become a larger part of the driver and passenger population in developed countries in the future. Currently, Anthropomorphic Test Devices (ATDs) are essential tools to assess safety of automobiles; however, they do not fully embody the features of all occupant groups in the world population. This study investigates the features of ageing drivers. The data are collected and analysed with respect to age and gender. Information particularly on driver-automobile interaction is provided in the form of distances and angles measured in-car. The physical characteristics of existing ATDs are investigated and compared with the anthropometric data of ageing drivers. Comparisons indicate that the current ATDs do not incorporate some of the features of ageing drivers. The requirements of future ATDs such as sitting height, abdominal depth and posture are discussed. These specifications are essential for the development of new ATDs representing ageing drivers. © 2013 Taylor and Francis Group, LLC

Plasma lipid profiles and risk of cardiovascular disease in occupational lead exposure in Abeokuta, Nigeria

In order to investigate the effects of lead exposure on risk of cardiovascular disease during occupational exposure to this metal, plasma cholesterol and its fractions as high-density liporotein (HDL), low-density liporotein (LDL) and triglyceride were determined in various artisans in Abeokuta, Nigeria who have been shown to be occupationally exposed to lead and these were related to blood lead levels. Increased risk of cardiovascular disease was observed in the artisans. Total cholesterol in the artisans was between 1.5 and 2.0 times higher in the artisans than that present in controls while LDL cholesterol was between 1.6 and 2.4 times higher in the artisans when compared with control subjects [p < 0.001]. HDL cholesterol and triglyceride levels were not affected [p > 0.05]. A significant positive correlation was observed between blood lead and total cholesterol on one hand [r = 0.372; p = 3.0 × 10(-5)] and blood lead and LDL cholesterol on the other hand [r = 0.283; p = 0.001]. LDL/HDL cholesterol ratio was also higher in the artisans when compared with control. Blood pressure (systolic and diastolic) and other anthropometric parameters were not significantly different between the artisans and the control subjects [p > 0.05]. Results suggest that lead exposure increases cholesterol synthesis and transport to peripheral tissues whereas reverse cholesterol transport to the liver is not affected

Vehicle ergonomics and older drivers

There is a growing population of older people around the world and the population of older drivers is increasing in parallel. UK government figures in 2012 reported that there were more than 15 million people with a driving license aged over 60; more than 1 million of these were over 80. The aim of this thesis is to determine the requirements of older users for an improved driving experience leading to recommendations for the automotive industry. Initially it was necessary to understand some of the key issues concerning the driving experiences of older drivers; therefore a questionnaire survey of drivers of all ages (n=903) was conducted supplemented by interviews with drivers aged ≥ 65 years (n=15). Areas covered included: musculoskeletal symptoms, the vehicle seat, driving performance and driving behaviour. Respondents reported that they were dissatisfied with adjusting specific seat features, for example the head rest height and distance from the head; females reported more difficulty than males. Reaching and pulling the boot door down to close was difficult for 12% of older females. Older males and females also reported more difficulties with parallel parking and driving on a foggy day than younger drivers (p<0.01). Nearly half of the sample (47%) reported that other drivers lights restrict their vision when driving at night. An in depth study was conducted to compare participants own vehicle (familiar) and a test vehicle (unfamiliar) to understand how design of the vehicle cab impacts on posture, comfort, health and wellbeing in older drivers (n=47, ≥50 years). The study involved functional performance assessments, seat set-up process evaluation (observations and postural analysis), ergonomics and emotional design based evaluations of car seat controls. Many issues were identified related to the seat controls such as operating, accessing, reaching and finding, particularly for the head rest height and lumbar support adjustments. Approximately 40% of the participants had difficulty turning their head and body around to adjust the head rest height, and the majority of these were over 80. This led to a series of workshops (including a participatory design exercise) with 18 participants (4 groups, ≥ 65 years).The aim was to explore the optimum positioning and operation of controls for older drivers. This research has provided foundational data and makes design recommendations for the automotive industry with a focus on making seat controls more inclusive (operation, location, type, size, colour and materials) and meet the requirements of older drivers

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

Postural and Muscular Responses of Car Occupants under Pre-Crash Conditions

Advanced integrated safety technologies in modern cars such as collision avoidance intervention and pre-crash activated restraint systems require comprehensive research on how vehicle occupants respond to these systems. The aim of this thesis is to provide insights into car passengers’ body kinematics and muscle activations in representative pre-crash circumstances with respect to two belt configurations (i.e., standard versus pre-pretensioner). Another objective is to explore the influence of occupants’ individual characteristics — namely age, stature, and sex — on their body kinematics. A complementary objective is to provide validation data for human body models (HBMs).A set of in-vehicle experiments was carried out in which front-row passengers were traveling at 73 km/h and subjected to autonomous lane changes and lane changes combined with braking, each with two belt configurations: standard and reversible pre-pretensioner belts. Volunteer muscle activations were measured by the surface electromyography (EMG) technique. Transformation of coordinates corresponding to several film targets attached to the head and upper torso was used to calculate the kinematics in 3-D. The volunteers’ EMG and kinematics were processed, and the quantified kinematics were statistically explored using principal component analysis and linear mixed model.Compared to the standard belt, pre-tensioning the seat belt prior to the maneuvers reduced lateral and forward displacements of the head and upper torso significantly. Seat belt pre-tensioning was also associated with earlier muscle activation onset and significantly lower activation amplitude for specific muscles. The influence of sex, stature, and their interaction on the head and upper torso kinematics were found statistically significant but accounted for a small amount of variance. A statistical model was developed which can predict head and upper torso kinematics of occupants with different stature and sex. The data provided in this thesis can be used for further enhancement and validation of HBMs. Consequently, the design of integrated safety systems in modern cars can benefit from more biofidelic models representing a wide range of population more accurately. Further statistical investigations for other types of omnidirectional loading scenarios and, preferably with a larger and more diverse sample space, are required to establish more accurate statistical models that can be generalized to the whole population