A propulsão manual representa a principal forma de locomoção das pessoas que necessitam de cadeira de rodas, e tem sido relacionada com a alta prevalência de dor e inflamação nos membros superiores, devido principalmente à carga elevada e aos movimentos repetitivos durante a atividade de propulsão da cadeira de rodas. O aro de propulsão convencional é um tubo metálico circular instalado lateralmente à roda, através do qual o usuário impulsiona e freia a cadeira, e apresenta diâmetro insuficiente para preensão adequada das mãos, oferecendo superfície de contato e atrito insuficientes, o que exige maior força para segurar o aro, diminuindo a eficiência da propulsão. Este estudo tem como objetivo desenvolver um aro de propulsão manual ergonômico para cadeira de rodas. Os procedimentos metodológicos foram divididos em três etapas: desenvolvimento do conceito, que envolve a criação do design do produto, com base em dados antropométricos e ergonômicos; confecção de um modelo, através da técnica de prototipagem rápida e moldagem para reprodução seqüencial de peças; avaliação do equipamento, composta de experimentação feita por usuários de cadeira de rodas seguida de aplicação de questionário para da percepção de qualidade do equipamento. A técnica utilizada de prototipagem rápida e moldagem para reprodução de peças mostrou-se adequada a este estudo, ao produzir um modelo idêntico ao projetado em software de CAD. O modelo, produzido em poliuretano, apresentou acoplamento adequado com a mão, e cumpriu os objetivos de minimizar a postura flexora dos dedos e oferecer maior superfície de contato, através de seu desenho ergonômico baseado em medidas antropométricas da mão. Os usuários de cadeira de rodas consideraram que o aro ergonômico oferece, em comparação ao aro original: maior conforto na propulsão e frenagem da cadeira; melhor encaixe para as mãos; menor exigência de força nas mãos para segurar o aro; maior facilidade para propulsionar e manobrar a cadeira. Ainda que os resultados indiquem boa adequação da mão ao aro ergonômico, com conforto e facilidade na locomoção referidos pelos pacientes, há a necessidade de melhor avaliação do equipamento, através de estudos que explorem os aspectos cinéticos e cinemáticos da propulsão manual com o aro ergonômico. Ainda, há a necessidade de compreender os efeitos do uso prolongado do aro ergonômico, com o usuário utilizando-o em seu ambiente, realizando suas atividades e enfrentando as dificuldades rotineiras de locomoção com a cadeira de rodas. A utilização de conceitos inovadores no design de produtos de tecnologia assistiva, característica que define a essência deste trabalho, sinaliza a tendência de desenvolvimento de produtos e soluções cada vez mais avançados e personalizados para pessoas com necessidades especiais. / The manual propulsion represents the main form of locomotion of persons who need a wheelchair, and has been associated with high prevalence of pain and inflammation in the upper limbs, due mainly to high load and repetitive movements during wheelchair propulsion. The wheelchair pushrim is a circular metal tube installed laterally on the wheel, through which the user pushes and breaks the wheelchair. The conventional wheelchair pushrim has insufficient diameter to proper grip of the fingers, providing insufficient surface contact area and friction, which requires greater strength to hold the pushrim, reducing the efficiency of propulsion. This study aims to develop an ergonomic wheelchair pushrim. The methodological procedures were divided into three stages: concept development, which involves the design of the product, based on anthropometric and ergonomic data; construction of a model, using the technique of rapid prototyping and molding for reproduction of parts; equipment evaluation, consisting of experimentation by wheelchair users, followed by a questionnaire for assessing the perceived quality of the equipment. The technique of rapid prototyping and molding for reproduction of parts of the pushrim was appropriate to this study by producing a model identical to that designed in CAD software. The model, made of polyurethane, showed adequate coupling with the hand, and fulfilled the objective of minimizing the flexor posture of the fingers and providing greater contact surface, through its ergonomic design based on anthropometric measures of hand. The wheelchair users found that the ergonomic pushrim design offers, compared to the conventional pushrim: greater comfort in propelling and braking the wheelchair; better fit for the hands; lower demand for force in the hands to hold the pushrim; easier to propel and maneuver the wheelchair. Although the results indicate good adaptation of the hand to the ergonomic pushrim, with comfort and ease of locomotion reported by patients, there is a need for better assessment of the equipment, through studies that explore the kinetic and kinematic aspects of manual wheelchair propulsion with the ergonomic pushrim. Still, there is a need to understand the effects of prolonged use of the ergonomic pushrim, with the users using it in their environment, making their activities and facing the difficulties of locomotion with a wheelchair. The use of innovative concepts in the design of assistive technology products, a characteristic that defines the essence of this study, indicates the trend of developing products and solutions increasingly advanced and customized for people with special needs.

Manual lifting is dynamic in nature and involves asymmetrical loading of the human body. This study investigated kinematic and kinetic characteristics of asymmetrical lifting in three dimensions, and then constructed a 3-D biomechanical force model of the lower back which is capable of quantifying torsional stress on the human spine. Eleven healthy adult male manual workers were recruited as subjects and lifted a 1 Okg load placed at the sagittal plane (0°) and at 30°, 60° and 90° lateral planes to the right, from 150mm and 500mm initial lift heights, respectively, to an 800mm high bench in the sagittal plane. Subjects' spinal motions and the trajectorial movements of the load in three-dimensional space were monitored simultaneously by a Lumbar Motion Monitor and a V-scope Motion Analyzer. Generally, the spinal motion factors increased as a function of increasing task asymmetry and differed (p < 0.05) between the lower (150mm) and higher (500mm) levels in the sagittal plane. In all asymmetrical conditions the motion factors showed a dramatic increase at the 500mm level compared to the increase at the 150mm level. The rates of increase in the horizontal and frontal planes were greater than those in the sagittal plane. Task asymmetry had a significant effect on the spinal kinematic parameters in the frontal plane at the two lift heights, and only at the high level (500mm) in the horizontal plane, with exception of average acceleration . Initial lift height exerted a significant effect on peak velocity and acceleration in both frontal and horizontal planes and on range of motion in the horizontal plane. Kinetic characteristics of the object being lifted in three-dimensions increased with an increase in task asymmetry. The increase was more dramatic in the lateral direction in the horizontal plane. However, motion factors in the vertical direction dominated the full range of the lift, irrespective of task asymmetry and lift height. The kinetic measures differed (p < 0.05) between the lower ( 1 50mm) and the higher (500mm) levels in the vertical direction except for average force. Task asymmetry had a significant effect on dynamic measures in the anterior-posterior direction. Both task asymmetry and lift height had a significant effect on dynamic motion factors in the lateral direction. From insights gained in the empirical study a three-dimensional biomechanical force model of the lower back was constructed based on a mechanism of muscle force re-orientation in the lumbar region. Acknowledging that the lower back is designed to be able to rotate around its longitudinal axis, the proposed model accounts for compression and shear forces and a torsional moment. The model has similar predictability to Schultz and Andersson's (1981) model when the human trunk exerts only a flexion-extension moment in the sagittal plane, but additionally predicts dramatic increases in shear forces, oblique muscle forces and torsional moment under asymmetrical lifting conditions which the Schultz-Andersson model does not. The increase rates in these forces and moment are not linearly related over task asymmetric angle.

Changes in the industrial job profile, from lifting and lowering to repetitive dynamic pushing and pulling have been facilitated through the use of manual vehicles, aimed at minimising the workload. Yet, the demands of pushing and pulling have not been well documented. Using measures of the horizontal component of the hand forces, spinal kinematics, muscle activity at various sites on the upper body and body discomfort ratings, this study aimed at quantifying the biomechanical and perceptual demands of various dynamic push/pull techniques. 36 healthy male participants performed two-handed forward pushing, two-handed backward pulling and one-handed forward pulling, employing an industrial pallet jack supporting two loads of 250kg or 500kg. While no single technique was definitively identified as preferable regarding hand forces, pushing at 500kg elicited higher initial and sustained forces (p<0.05) than one- and two-handed pulling respectively. Increments in load mass from 250kg to 500kg resulted in significant differences in the initial, sustained and ending forces. With regard to spinal kinematics in the sagittal plane, two-handed pulling elicited the highest trunk flexion, and may therefore expose individuals to prolonged forward bending. Generally this technique was found to evoke the highest sagittal responses. Spinal kinematic measures in the lateral and transverse planes suggested that one-handed pulling was accompanied by the highest measures, and hence the greatest risk of developing lower back disorders related to this plane. Although various combinations of muscles were active during each technique, one-handed pulling and pushing, most often induced the highest muscle activation levels and two-handed pulling, the lowest. While erector spinae evidenced no significant differences between techniques at each load or between loads for the same technique, activation levels were high under all conditions. Perceptual ratings of body discomfort revealed that not only is the upper body susceptible to injuries during pushing and pulling, but also that the lower extremities may have a considerable role to play in these tasks, with the calves being a particular area of concern. Findings concluded that symmetrical pushing and pulling tasks are preferable.

Orientador: José Carlos Plácido da Silva / Coorientador: Luis Carlos Pachoarelli / Banca: José Jorge Boueri Filho / Banca: José Roberto Gomes de Faria / Banca: Paulo Kawauchi / Banca: João Eduardo Guarnetti dos Santos / Resumo: Raros os problemas registrados na História que despertaram tanto o interesse do homem como o processo que antecede sua morte, a velhice, com suas alterações relacionadas ao corpo e a mente, produzindo a medida que envelhece, incapacidade funcional, e em consequencia, a perda da qualidade de vida. o crescimento da população de idoso nos últimos anos, fenômeno mundial e que se apresenta também nas estatísticas brasileiras, leva a ciência a um estado de atenção visando promover rápidas mudanças e adaptações do espaço construído, de seus mobiliários e equipamentos, provendo esta etapa de vida, maior conforto e segurança. Objetivo: o presente estudo busca estabelecer protocolo para orientações de projetos de design no ambiente asilar onde o idoso passa a conviver mais tempo. Procura também, caracterizar e avaliar as alterações morfológicas, relacionadas ao envelhecimento por meio da antropometria, estabelecendo prioridades para uma melhor qualidade de vida desta população. Conhecer os diferentes ambientes disponibilizados pela sociedade, do espaço privado, coletivo e chegando ao espaço público que acolhem ou que estão sendo preparados para acolher o cidadão em sua velhice. Materiais e Métodos: Inserido dentro de um espaço delimitado, representando o universo brasileiro, este trabalho foi definido como sendo transversal exploratório e observacional de base populacional para os eventos mais frequentes da população idosa. Com a participação de vários atores em diferentes estudos de caso, representando diferentes tipologias do ambiente asilar, cria-se um repertório de conhecimento para análise e discussão das necessidades deste público alvo em seu ambiente pessoal. Resultados: O estudo mostrou que, de maneira geral, o ambiente destinado a acolher o homem em sua velhice, sendo este, particular ou público, está... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: There are rare problems recorded in history that aroused so much interest of humanity as the process preceding their death, old age, with its related changes to the body and mind, producing as it ages, functional disability, and as a result, the gradual loss of quality of life. The growth of the elderly population in recent years, worldwide phenomenon and it also presents in statistics on Brazilian science, leads to a state of attention to promote fast changes and adaptations of built space, its furniture and equipment, providing to this stage of life, comfort a safety. Objectives: This study tries to establish a protocol for guidance on design rest home's projects where the elderly start to live in a certain period of their life. It also seeks to characterize and evaluate the morphological changes related to aging by anthropometry, establishing priorities for a better quality of life for this population. Getting to know the different environments provided by the society, the private, collective and public space that welcome or is being prepared to accommodate the citizen in his old age. Materials and Methods: Inserted within a delimited space, representing the Brazilian universe, this study was defined as exploratory transversal population-based, observational for the most frequent events in the elderly population. With the participation of several actors in different case studies, representing different types of rest home's environments, it creates a repertoire of knowledge to anlyze and discuss the needs on this target group in their personal environment. Results: The study revealed that, in general, the environment, private or public, for receiving the man in his old age does not attend fully and safely the expectations of this social group. Through the analysis of its... (Complete abstract click electronic access below) / Doutor

This dissertation develops a holistic usability framework for distributed simulation systems (DSSs). The framework is developed considering relevant research in human-computer interaction, computer science, technical writing, engineering, management, and psychology. The methodology used consists of three steps: (1) framework development, (2) surveys of users to validate and refine the framework, and to determine attribute weights, and (3) application of the framework to two real-world systems. The concept of a holistic usability framework for DSSs arose during a project to improve the usability of the Virtual Test Bed, a prototypical DSS, and the framework is partly a result of that project. In addition, DSSs at Ames Research Center were studied for additional insights. The framework has six dimensions: end user needs, end user interface(s), programming, installation, training, and documentation. The categories of participants in this study include managers, researchers, programmers, end users, trainers, and trainees. The first survey was used to obtain qualitative and quantitative data to validate and refine the framework. Attributes that failed the validation test were dropped from the framework. A second survey was used to obtain attribute weights. The refined framework was used to evaluate two existing DSSs, measuring their holistic usabilities. Ensuring that the needs of the variety of types of users who interact with the system during design, development, and use are met is important to launch a successful system. Adequate consideration of system usability along the several dimensions in the framework will not only ensure system success but also increase productivity, lower life cycle costs, and result in a more pleasurable working experience for people who work with the system.

A preliminary system design and human factors analysis of a home computer workstation has been presented. Systems are proposed for families modifying existing furniture, as well as those purchasing new workstations. The systems are designed to meet standard human factors criteria to minimize potential injuries and discomfort. In both cases, the design assures enough flexibility to suit all members of the family. Environmental factors such as noise and light are discussed, as well as personal preference, safety, and budget. A description of the workspace requirements, the human factors criteria, and the cost analysis included. / Master of Science

Users are often frustrated when a touch screen monitor inaccurately records their touches. Enlarging touch sensitive regions improves touch accuracy, but few specific guidelines are available in the literature. A controlled field experiment determined the effect of target location and visual target size on user accuracy and empirically derived quantitative guidelines for determining touch target size based. on target location. The experiment was conducted in a grocery store using a piezo-electric monitor in a public access kiosk. Participants pressed the screen as target squares appeared one at a time. Visual target size, horizontal viewing location, and screen sector of target were varied. X and Y offset between the target center and the touch location were recorded. Results showed Significant differences caused by target sector in X offsets among columns and in Y offsets among rows, but no differences caused by target size. Results showed that persons tended to touch below the target, with touch distance increasing as the location of the target moved down the screen. To a lesser extent, persons tended to touch toward the sides of the screen. Using collected data for each of nine screen sectors, graphs were prepared showing the relationship between touch target size and expected accuracy under harsh conditions. These empirically derived, quantitative guidelines will help designers plan for the worst case and create screens that decrease user errors and frustration. / Master of Science

Human factors research of automobile driver behavior often calls for timing in-car manual tasks. By measuring the time that a driver directs resources away from the primary task of driving, investigators can determine both if and where improvements need to be made in the driver-vehicle relationship. The present study was designed to compare the accuracy of various techniques for measuring in-car manual task durations. Additionally, this research was intended to reveal how closely these techniques approach the accuracy of the frame-by-frame video analysis method, which is time-consuming and expensive to perform. The study required three male and three female subjects to use an electronic stopwatch to measure "hand-off-wheel" times for 30 driver tasks. Each subject performed this procedure three times: once while sitting as an observer in the back seat of a research vehicle, once while watching a real-time video recording of task performance, and once while watching a one-sixth real-time video recording of task performance. Three independent variables were examined: timing Method (three levels), Duration of in-car task (three levels), and Subject (six levels). Dependent measures gathered were raw timing error (a measure of response bias), absolute timing error (a measure of response accuracy), and squared timing error (a measure of response consistency). Timing error was obtained by subtracting the measured time for a particular task from the "true" task time obtained by using the frame-by-frame video analysis technique. Analysis of the data indicated a significant effect of Method on response bias. Specifically, use of the slow-motion video technique resulted in overestimation of in-car task durations, and use of the two real-time techniques resulted in estimates of task durations that were either equal to or less than the true durations. Significant effects of Subject, Gender, and Subject x Method were also revealed. The results suggest that the on-road timing technique should be used in the future, since this procedure requires little in terms of cost and implementation time, and errors are small when compared with the frame-by-frame technique. Furthermore, it is recommended that only one experimenter serve as a timing analyst during an experiment to ensure a constant level of accuracy. / Master of Science

This thesis examined the effects of luminance contrast, raster modulation, and ambient illumination on readability and image quality of text presented on a CRT display. Participants read a Tinker Speed of Reading text passage on the monitor and then responded when they found the out-of-context word in the passage. Correct responses and response times were recorded. Participants also rated the image quality of the monitor by selecting a number between one (worst imaginable) and nine (best imaginable). An ANOVA revealed that luminance contrast significantly affected errors. It is suggested that luminance contrasts of 7:1 be used to maintain low error rates. None of the independent variables affected the time required to read the Tinker passages. However, luminance contrast, raster modulation, and illumination significantly affected the subjective quality ratings. Participants rated the 3:1 luminance contrast, the 1.2 RAR, and the 1000 lux ambient illumination conditions as possessing the lowest image quality. From this research, it can be concluded that 7:1 is the preferred contrast ratio. This conclusion is based upon the findings that the 3:1 and 7:1 luminance contrast conditions produced the fewest errors and the 5:1 and 7:1 luminance contrast conditions produced the highest subjective image quality ratings. This recommendation holds over a RAR range of 0.8 to 1.2 and an ambient illumination range of 10 to 100 lux. High illumination levels would require special attention due to the low image quality ratings for the 7:1/1000 lux interaction. / Master of Science

User-System Interface (USI) design is a highly iterative process involving empirical testing and evaluation. The existence of a design specification is implicit in this design process. The quality of the design specification impacts the length and cost of the design cycle. A survey was made of available USI specification tools to determine: which USI components they can specify; their relation to a finite state model of the USI; and if they are usable by the human factors engineer as a basis for an analytic analysis of a USI design to detect violations of excepted USI design guidelines. Four categories of tools were surveyed: semi-formal techniques, Backus-Naur Form grammars, programming languages, and transition networks. An engineering tradeoff analysis was performed based on four pragmatic criteria: understandability, efficiency, expressive power, and fidelity. The results of the tradeoff analysis suggest that specification tools differ in representational strength and it is best to use a set of tools for a complete specification. A behavioral study using human factors engineers was performed to validate the results of the tradeoff analysis. Human factors graduate students were trained in the use of one of three specification tools and asked to perform an analytic analysis looking for design defects. Fifteen design defects were embedded in each of the specifications. Results suggest that using two of the tools together is the most effective specification technique. In light of these results, current and future software design practices were examined to determine what role the human factors engineer can have on the design team. / Master of Science