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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Desenvolvimento de um aro de propulsão manual ergonômico para cadeira de rodas / Development of an ergonomic manual wheelchair pushrim

Fausto Orsi Medola 12 November 2010 (has links)
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.
42

Low Cost NeuroChairs

Pike, Frankie 01 December 2012 (has links) (PDF)
Electroencephalography (EEG) was formerly confined to clinical and research settings with the necessary hardware costing thousands of dollars. In the last five years a number of companies have produced simple electroencephalograms, priced below $300 and available direct to consumers. These have stirred the imaginations of enthusiasts and brought the prospects of "thought-controlled" devices ever closer to reality. While these new devices were largely targeted at video games and toys, active research on enabling people suffering from debilitating diseases to control wheelchairs was being pursued. A number of neurochairs have come to fruition offering a truly hands-free mobility solution, but whether these results could be replicated with emerging low cost products, and thus become a viable option for more people is an open question. This thesis examines existing research in the field of EEG-based assistive technologies, puts current consumer-grade hardware to the test, and explores the possibility of a system designed from the ground up to be only a fraction of the cost of currently completed research prototypes.
43

Bezbariérové sportovní haly a tělocvičny v moravskoslezském regionu / Barrier-free sports halls and gyms in the Moravian-Silesian region

Podešvová, Simona January 2011 (has links)
Title: Possibilities of the use of sport facilities by wheelchairs in the Moravian region and the perception of their sport activities by the public Objective: The aim of the work is to prepare a list of sports clubs of wheelchairs and suitable indoor sports facilities for their activities in the Moravian region. Based on the knowledge it is possible to create a CD presentation, which can serve for staff of rehabilitation centers and the organizers of competitions for people with disability in the region. It would increase awareness of their clients about sports in this locality. Method: The thesis is presented as a preliminary study which used a quantitative research method in the public inquiry. A part of the thesis is a questionnaire survey - it focuses on public awareness of the Moravian- Silesian region of sport for disabled and the perception of architectural modifications. Results: Summary of available information on sports halls and gymnasiums for wheelchairs in the Moravia-Silesia region may serve for organizers of events or trauma rehabilitation work. Knowledge which were found out in via the form of a public questionnaire may be used in the formation of social and sporting program of the Moravia-Silesia region for people with a disability. Public questionnaire was participated 58 men and...
44

Assisted control of wheelchair based on driver's behaviour modelling.

Kinfack, Fabrice Prosper Anouboudem. January 2011 (has links)
M. Tech. Electrical Engineering. / Investigates a new approach of wheelchair control, based on the user behaviour recognition. This objective involves two steps in the resolution of the problem. The first step is to determine the action the user initiates. Therefore, the present study will mostly refer to literatures on car driver behaviour modelling, as several studies have been conducted in that domain. The proposed model of user's behaviour presented here is based on probabilistic graphical model, for instance, Bayesian network. The second step is the generation of an assistive control signal that will compensate the user input, depending on the driving task inferred by the Bayesian network.Experiments have been conducted on a virtual environment model developed in Matlab and several users participated to the experiments. The results show a great potential of Bayesian Network model to infer on human behaviour and also a satisfying output from the ANFIS model as it delivers signals following the user's behaviour.
45

The influence of altering wheelchair propulsion technique on upper extremity demand

Rankin, Jeffery Wade 27 October 2010 (has links)
Most manual wheelchair users will experience upper extremity injury and pain during their lifetime, which can be partly attributed to the high load requirements, repetitive motions and extreme joint postures required during wheelchair propulsion. Recent efforts have attempted to determine how different propulsion techniques influence upper extremity demand using broad measures of demand (e.g., metabolic cost). However studies using more specific measures (e.g., muscle stress), have greater potential to determine how altering propulsion technique influences demand. The goal of this research was to use a musculoskeletal model with forward dynamics simulations of wheelchair propulsion to determine how altering propulsion technique influences muscle demand. Three studies were performed to achieve this goal. In the first study, a wheelchair propulsion simulation was used with a segment power analysis to identify muscle functional roles. The analysis showed that muscles contributed to either the push (i.e. delivering handrim power) or recovery (i.e. repositioning the hand) subtasks, with the transition period between the subtasks requiring high muscle co-contraction. The high co-contraction suggests that future studies focused on altering transition period biomechanics may have the greatest potential to reduce upper extremity demand. The second study investigated how changing the fraction effective force (i.e. the ratio of the tangential to total handrim force, FEF) influenced muscle demand. Simulations maximizing and minimizing FEF both had higher muscle work and stress relative to the nominal simulation. Therefore, the optimal FEF value appears to balance increasing FEF with minimizing upper extremity demand and care should be taken when using FEF to reduce demand. In the third study, simulations of biofeedback trials were used to determine the influence of cadence, push angle and peak handrim force on muscle demand. Although minimizing peak force had the lowest total muscle stress, individual stresses of many muscles were >20% and the simulation had the highest cadence, suggesting that this variable may not reduce demand. Instead minimizing cadence may be most effective, which had the lowest total muscle work and slowest cadence. These results have important implications for designing effective rehabilitation strategies that can reduce upper extremity injury and pain among manual wheelchair users. / text
46

Development of a Human Accompanying Wheelchair using Ultrasonic Tethering

Pingali, Theja Ram 05 July 2019 (has links)
In social situations, people who use a powered wheelchair must divide their attention between navigating the chair and conversing with people. As a solution that maintains a good conversation distance between the wheelchair and the accompanying person, a wheelchair control system was introduced to provide automated side-by-side following by wirelessly tethering the wheelchair to the person. This thesis designed, developed, and evaluated a wireless tethering system using ultrasonic sensors. Two ping sensors and three piezoelectric ultrasonic transducers were used to identify the accompanying person and determine their pose. A trajectory algorithm determined the person’s direction of motion and a drive control algorithm determined the wheelchair’s required direction by maintaining a comfortable conversation distance between the person and the wheelchair user. A plug-and-play prototype was developed using commercially available components and the firmware was implemented using an open-source platform. The prototype developed in this thesis was mounted to a Permobil F3 Corpus powered wheelchair with a modified Eightfold Technologies SmartChair Remote, which controlled the wheelchair direction. Results demonstrated that the system can navigate a wheelchair beside an accompanying person and maintain a comfortable conversation distance, which is advantageous for users who require hands-free wheelchair control during social activities.
47

Proposta para certificação compulsória de cadeira de rodas com base nas normas técnicas específicas e nas percepções de usuários cadeirantes

Costa, Luiz Antonio Citty da 24 August 2015 (has links)
Made available in DSpace on 2016-04-27T17:05:59Z (GMT). No. of bitstreams: 1 Luiz Antonio Citty da Costa.pdf: 975694 bytes, checksum: 14e1fb858f4bac7446f3146a6b8fa32e (MD5) Previous issue date: 2015-08-24 / The conformity trend evaluation results of manual wheelchairs simple model, made by Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMETRO) according to the perception of wheelchair users through this work, showed the need to develop an appropriate regulatory wheelchairs system, setting up safety requirements to ensure the integrity of user during use, considering that the wheelchair is used as a means of locomotion for disabled / Os resultados na avaliação de tendência da conformidade das cadeiras de rodas manuais de modelo simples, realizada pelo Instituto Nacional de Metrologia, Qualidade e Tecnologia INMETRO, em conjunto com a percepção de usuários cadeirantes através do presente trabalho, mostraram a necessidade de elaborar um sistema adequado de regulamentação das cadeiras de rodas, estabelecendo-se requisitos de segurança para garantir ao usuário a sua integridade durante a utilização, considerando-se que a cadeira de rodas é utilizada como meio de locomoção para portadores de deficiência
48

An intelligent database for PSUBOT, an autonomous wheelchair

Mayi, Dieudonne 01 January 1992 (has links)
In the design of autonomous mobile robots, databases have been used mainly to store information on the environment in which the device is to operate. For most of the models and ready systems, the database when used, is not a stand alone component in the system, rather it is only intended to keep static information on the disposition and properties of objects on the map.
49

Tweel (TM) technology tires for wheelchairs and instrumentation for measuring everyday wheeled mobility

Meruani, Azeem 04 April 2007 (has links)
This thesis is focused on two aspects related to wheeled mobility: 1) Evaluating the impact of a new tire design on powered mobility, and 2) Instrumentation that permits better monitoring and assessment of wheeled mobility in everyday use. The Tweel technology tires developed by Michelin USA are comprised of an outer polyurethane ring supported by polyurethane fins instead of metal spokes, which allow the tire to deflect under pressure. As a wheelchair tire they offer a potential breakthrough as they have deflection properties similar to a pneumatic tire while maintaining the low maintenance of a solid foam-core tire. A study was conducted to compare the Tweel technology tires to standard solid foam-core tires for vibration transmission, traction and overall life span. The Tweel technology tires failed produce any significant difference in vibration transmitted to the user compared to solid foam-core tires. Additionally, the Tweel technology tires showed significant signs of deterioration after a month long field trial, thus indicating a short life span. However, Tweel technology tires provided better traction on both dry and wet concrete. Overall, Tweel technology tires have to be re-engineered to provide better damping properties, leading to lower vibrational levels transmitted to the user. The second section this thesis addressed the need to develop a methodology of measuring mobility in everyday usage. This section is part of a greater ongoing research project at CATEA (Center for Assistive Technology and Environmental Access) aimed at understanding everyday wheelchair usage. Methodology was developed to measure bouts of mobility that characterize wheelchair usage; which includes the number of starts, stops, turns and distance traveled through the day. Three different technologies which included, Accelerometer unit on the rim of the drive wheel, Gyro-Accelerometer unit on the frame of the chair and Reed switches, were tested. Testing included various criteria for accuracy, durability and compatibility for measuring bouts of everyday wheeled mobility. Although a single technology could not be used to measure all aspects of mobility, the Accelerometer unit on the rim met the design criteria for measuring starts stops and distance, while the Gyro-Accelerometer unit met the requirements for measuring turns.
50

The Design of a Switchable Double-Action Manual/Electric Wheel-chair with an Auxiliary Driving Wheel

Chen, Jin-hwan 23 July 2004 (has links)
In the wheelchair family, a manual wheelchair is most commonly used by the lower-limb disabled, while its manual mode creates the lowest mechanical effi-ciency and the highest rate of upper-limb injury. Electric wheelchairs on the market are much more labor-saved; however, with their drive systems mostly combining with the bodies of the wheelchair, electric wheelchairs appear to be bulky and are not easily-carried. While in a limited space, on a short-distance moving, or in/off the elevator, electric wheelchairs cannot be practicably switched to manual ones. Thus, this text aims to develop a switchable dou-ble-action manual/electric wheelchair with an auxiliary driving wheel, expect-ing to increase the mechanical efficiency and not to enlarge the body of the wheelchair; the module-disassembled drive system is intended for the conven-ience of carrying. Besides, in order to keep both the manual and the electric functions, the caster contains a set of separable orientation control system, while enables the caster to be switched in both the modes of 360-degree rotation and of being controlled by the user. In this way, the use of the wheelchair would be-come much more multiple-choice.

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