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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.
21

Desenvolvimento de um sistema neuro-fuzzi para análise de sinais mioelétricos do segmento mão-braço

Favieiro, Gabriela Winkler January 2012 (has links)
Pesquisas científicas no campo da engenharia de reabilitação estão proporcionando cada vez mais mecanismos que visam ajudar pessoas portadoras de alguma deficiência física a executar tarefas simples do dia-a-dia. Com isso em mente, esse trabalho tem a finalidade de desenvolver um sistema que utiliza sinais musculares e redes neuro-fuzzy para a caracterização de determinados movimentos de um braço humano, com o objetivo de possibilitar futuramente a integração em sistemas de reabilitação. Ensaios preliminares demonstraram que para a caracterização de movimentos simples realizados por um braço humano, o uso exclusivo de técnicas simples de processamento de sinal é suficiente, como a utilização do valor rms. No entanto, para a caracterização de movimentos complexos é necessário um processamento mais robusto do sinal. Para isso foi desenvolvido um sistema experimental que adquire, através de um eletromiógrafo (EMG) de 8 canais, o sinal mioelétrico com eletrodos de superfície posicionados em lugares estratégicos do braço. O sinal é adquirido utilizando como estímulo um modelo virtual que demonstra ao usuário os movimentos do segmento mão-braço que devem ser executados de forma aleatória. Finalmente, com o uso de uma rede neuro-fuzzy, que possibilita a distinção tanto de movimentos simples como de movimentos compostos, se adaptando a diferentes usuários, os movimentos executados foram caracterizados em 12 movimentos distintos, previamente definidos, com uma taxa de acerto médio de 65%. / The scientific researches in the field of rehabilitation engineering are increasingly providing mechanisms to help people with a disability to perform simple tasks of day-to-day. With that in mind, this work aims to develop an experimental robotic prosthesis in order to implement, in the same, a control system that uses muscle signals and neuro-fuzzy networks for characterization of certain movements of a human arm, in order to enable further integration in rehabilitation systems. Preliminary tests showed that for the characterization of simple movements performed by a human arm, the exclusive use of simple techniques of signal processing is sufficient, as the use of the rms value. However, for the characterization of complex movements is required a more robust signal processing. For this was developed an experimental system that acquires through an electromyography (EMG) of 8 channels, the myoelectric signal with surface electrodes positioned in strategic places of the arm. The acquired signal uses, as a stimulus, a virtual model that demonstrates the hand-arm segment movements to be executed by the user at random. Finally, through a neuro-fuzzy network, which enables the distinction of both simple and compound movements, self-adapting to different users, the movements performed were characterized in 12 distinct movements, previously defined, with an average accuracy of 65%.
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22

Řízení myoelektrické protézy / Controlling of myoelectric prothesis

Tomanová, Markéta January 2014 (has links)
The Master´s thesis summarizes the knowledge about controlling of myoelectric prostheses. The Introduction part of this work provides an overview of the anatomy of muscles and their contraction. In case of restricted function of hand, it is necessary to compensate this deficiency by using prosthetic limbs. Among one of the most technically difficult is robotic prosthesis. In this semestral work is myoelectric prosthesis replaced by a robotic arm. Arm is controlled by the electromyographic signals. The signals are recorded by Biopac acquision unit, then processed in LabVIEW and robotic system is controlled by the Arduino platform.
23

Variational Autoencoder and Sensor Fusion for Robust Myoelectric Controls

Currier, Keith A 01 January 2023 (has links) (PDF)
Myoelectric control schemes aim to utilize the surface electromyography (EMG) signals which are the electric potentials directly measured from skeletal muscles to control wearable robots such as exoskeletons and prostheses. The main challenge of myoelectric controls is to increase and preserve the signal quality by minimizing the effect of confounding factors such as muscle fatigue or electrode shift. Current research in myoelectric control schemes are developed to work in ideal laboratory conditions, but there is a persistent need to have these control schemes be more robust and work in real-world environments. Following the manifold hypothesis, complexity in the world can be broken down from a high-dimensional space to a lower-dimensional form or representation that can explain how the higher-dimensional real world operates. From this premise, the biological actions and their relevant multimodal signals can be compressed and optimally pertinent when performed in both laboratory and non-laboratory settings once the learned representation or manifold is discovered. This thesis outlines a method that incorporates the use of a contrastive variational autoencoder with an integrated classifier on multimodal sensor data to create a compressed latent space representation that can be used in future myoelectric control schemes.
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24

Design and Validation of a Myoelectric Bilateral Cable-driven Upper Body Exosuit and a Deep Reinforcement Learning-based Motor Controller for an Upper Extremity Simulator

Fu, Jirui 01 January 2024 (has links) (PDF)
Upper Limb work-related musculoskeletal disorders (WMSDs) present a significant health risk to industrial workers. To address this, rigid-body exoskeletons have been widely used in industrial settings to mitigate these risks while exosuits offer advantages such as reduced weight, lower inertia, and no need for precise joint alignment, However, they remain in the early stages of development, especially for reducing muscular effort in repetitive and forceful tasks like heavy lifting and overhead work. This study introduces a multiple degrees-of-freedom cable-driven upper limb bilateral exosuit for human power augmentation. Two control schemes were developed and compared: an IMU based controller, and a myoelectric controller to compensate for joint torque exerted by the wearer. The results of preliminary experiments showed a substantial reduction in muscular effort with the exosuit's assistance, with the myoelectric control scheme exhibiting reduced operational delay. In parallel, the neuromusculoskeletal modeling and simulator (NMMS) has been widely applied in various fields. Most of the research works implements the PD-based internal model of human’s central nervous system to simulate the generated muscle activation. However, the PD-based internal models in recent works are tuned by the empirical data which requires empirical data from human subject experiments. In this dissertation, an off-policy DRL algorithm, Deep Deterministic Policy Gradient was implemented to tune the PD-based internal model of human’s central nervous system. Compared to the conventional approaches, the DRL-based auto-tuner can learn the optimal policy through trial-and-error which doesn’t require human subject experiment and empirical data. The experiment this work showed promising results of this DRL-based auto-tuner for internal-model of human’s central nervous system.
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25

Metodika práce ergoterapeuta u pacientů s myoelektrickou protézou / Occupational therapist's methodics of work for patients with myoelectric prosthesis

Hoidekrová, Kristýna January 2016 (has links)
The aim of this study was to develop methodics of occupational therapy for patients with moelectric prosthesis, which is used by patients with amputation of upper limbs as well as patients with congenital problems. In the Czech republic there are no complex methodics about occupational therapy and myoelectric prosthesis, despite the huge mount of foreign studies of this topic. Myoelectric prosthesis uses the principle of sensing myoelectrical signals which are then transformed to the motor output in the terminal portion of the prosthesis. Occupational therapy intervention begins at the preprosthetic phase, the occupational therapist assesses the general potential for the use of myoelectric prosthesis and picks up myoelectric signals from the stump. In interprosthetic phase occupational therapist is dedicated to the training of activities of daily living with myoelectric prosthesis and training residual stump on the basis of myotest. The phase after prosthetic content of occupational therapy evaluation and assessment, which focus on patients ability of myoelectric control and prosthesis involvement in activities of daily living and training of grip. Within the training of grip, occupational therapist is dedicated to training proper grip within the pace, grip strength and targeted movements. The...
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26

Desenvolvimento de um projeto de experimentos para a caracterização de sinais mioelétricos através do uso de regressão logística

Cene, Vinicius Horn January 2016 (has links)
Através dos dispositivos e técnicas desenvolvidas na área da Instrumentação Biomédica é possível oferecer um tratamento ou de forma geral soluções que permitam uma vivência mais plena em sociedade para pessoas que possuem algum tipo de deficiência ou doença. Com o aumento da capacidade computacional nos últimos anos foi possível desenvolver muitas técnicas e dispositivos apoiados em processamento digital de sinais e há um grande interesse pelo desenvolvimento de interfaces mais naturais, como sinais biológicos para o controle de próteses e dispositivos. Este trabalho tem por objetivo apresentar o desenvolvimento de um método de Inteligência Computacional baseado em Regressão Logística capaz de classificar 17 movimentos do segmento mão-braço realizados pelos voluntários do estudo através do processamento do sinal mioelétrico (SME) adquiridos dos sujeitos em questão. Adicionalmente é realizada uma avaliação da influência de alguns dos canais, características do sinal e movimentos executados na taxa de acerto global. Para a realização do sistema foi utilizado um aparato experimental capaz de adquirir os SME através de 12 canais utilizando eletrodos não invasivos e posteriormente digitalizá-los. Logo após efetua-se a extração das três características utilizadas no trabalho, que servem de entrada para o método de Regressão Logística. Para este estudo foram processados três bancos de dados que perfazem um total de 50 voluntários. A taxa média de acerto alcançada foi de 70,1%, considerando todas as variações de testes realizados enquanto a média para os melhores casos de cada variação de entrada realizada foi de 92,5%. / Through the devices and techniques developed in the field of Biomedical Instrumentation commonly is possible to offer treatment or solutions to provide a more pleasurable experience in society for people who have a disability or illness. With increasing computing capability in recent years, it has been possible to develop many techniques and devices supported by digital signal processing, and there is a great interest in the development of more natural interfaces, such as biological signals for the control of devices and prostheses. This work aims to present the development of a computational intelligence method based on Logistic Regression able to classify 17 movements of the hand-arm segment performed by the subjects of this study through the processing of the myoelectric signal (SME) acquired from the subject in question. Additionally, an assessment of the influence of some of the combination of the channels, signal characteristics and movements performed in the overall hit rate is additionally performed. To conduct the system has built an experimental apparatus able to acquire the SME through 12 channels using non-invasive electrodes and scan them. Thereafter there is a three features extraction from the signal which serves as input to the Logistic Regression method. For this study were processed three databases that compose 50 volunteers. The average hit rate achieved was 70.1%, considering all tests variations while the average for the best cases for each input variation performed was 92,5 %.
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27

Proposta de um sistema baseado em redes neurais e wavelets para caracterização de movimentos do segmento mão-braço

Bermudez, Rosa Maria Jimenez January 2018 (has links)
Este trabalho apresenta um sistema para o processamento do sinal mioelétrico baseado em Redes Neurais e Wavelets. Com a aquisição dos sinais mioelétricos dos músculos do segmento mão-braço, é possível determinar diversos parâmetros para a caracterização dos movimentos executados. A Transformada Wavelets foi utilizada na etapa de segmentação do sinal e a rede neural artificial na caracterização do movimento executado. O sistema é constituído de um eletromiógrafo (EMG de 8 canais), placa de aquisição de dados e um computador responsável pelo processamento dos dados. Foram utilizado eletrodos de superfície posicionados em lugares estratégicos no segmento mão-braço. O experimento consiste em repetir movimentos do segmento mão-braço executados por um modelo virtual. Os movimentos avaliados, neste trabalho, são: contração da mão, extensão do punho, flexão do antebraço, flexão do punho, rotação do braço, rotação e flexão do antebraço, rotação do braço e contração da mão, extensão e flexão do punho, contração da mão e elevação do braço. Esses movimentos são apresentados ao sujeito em determinadas sequências através dos modelos virtuais desenvolvidos, permitindo assim, a padronização do movimento a ser executado pelo voluntário O sinal é adquirido através de uma placa de aquisição e processado. As etapas principais de processamento são: segmentação do sinal de interesse através da Wavelet Discreta, extração de características (r.m.s, variância, desvio padrão, sesgo, curtose ) e uso da Rede Neural para determinar o movimento executado final dos testes, foi verificado que o movimento contração da mão e elevação do braço apresentou uma taxa de acerto média de 75%; o movimento flexão do antebraço obteve 81% de acerto médio; a contração da mão obteve 33% de acerto médio, o movimento contração da mão 76% de acerto médio; o movimento de flexão do punho 100 % de acerto médio, rotação e flexão do antebraço 66% de acerto médio, extensão e flexão do punho um 16% de acerto médio, extensão do punho 83,3% de acerto médio, rotação do braço 16,7% de acerto médio. Rotação do braço e contração da mão 83,3% de acerto médio. / This work presents a neural-network myoelectric processing-based system. With the acquisition of myoelectric signals from the muscles of the hand-arm segment, it is possible to determine the parameters that characterize the executed movements. Therefore, in this work Artificial Neural Networks are implemented to recognize patterns in order to determine the executed movement. The system is constituted by an electromyography (8-channel EMG), a data acquisition board and a computer responsible for data processing. In this research an experimental system is developed to capture the myoelectric signals by means of an EMG and a data acquisition board. Surface electrodes located in strategic places in the hand-arm segment are used. The experiment consists of repeated movements of the hand-arm segment executed by a virtual model. The movements examined in this work are: hand contraction, fist extension, forearm flexion, fist flexion, arm rotation, forearm rotation and flexion, fist contraction and extension and arm elevation. Those movements are presented to a volunteer in a random way by means of the virtual models developed, permitting a standardization of the movements that are to be executed by the volunteer. In the last part it is verified that the hand-contraction movement and the arm-elevation movement present an accuracy rate average of 75%; the forearm-flexion movement reaches 81% of accuracy rate average, the hand-contraction movement with 33% of accuracy rate average, the hand-contraction movement with 76% of accuracy rate average, the fist-flexion movement reached a 100% in the accuracy rate average, the forearm rotation flexion movement with a 66% in the accuracy rate average, the fist extension and flexion movement reaches the 16% in the accuracy rate average and the fist-extension movement with a 83.3% of accuracy rate average.
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28

Design and Testing of an Agonist-Antagonist Position-Impedance Controlled Myoelectric Prosthesis

Aymonin, Christopher 01 January 2019 (has links)
Intuitive prosthetic control is limited by the inability to easily convey intention and perceive physical requirements of the task. Rather than providing haptic feedback and allowing users to consciously control every component of manipulation, relegating some aspects of control to the device may simplify operation. This study focuses on the development and testing of a control scheme able to identify object stiffness and regulate impedance. The system includes an algorithm to detect the apparent stiffness of an object, a proportional nonlinear EMG control algorithm for interpreting a user’s desired grasp aperture, and an antagonistically acting impedance controller. Performance of a testbed prosthetic simulation used to controllably extrude pastes of different properties from a compliant tube was compared to that of the non-dominant human hand. The paste volume extrusion error and response time to perform the task were recorded for comparison. Statistical analysis using (GEE) and (TOST) suggests the prosthetic controller and human hand performed similarly along these metrics. Performance differences in the trials were more strongly correlated to tube type and repetition block. The results suggest that the developed controller allows users to perform a controlled squeezing task at a level comparable to the human hand with minimal training. It also suggests that a priori stiffness estimation acquired through quick palpations may be sufficient for effective control during simple manipulation. The lack of a learning curve suggests that the development of systems that automatically control aspects of mechanical interaction may offer users more advanced control capabilities with low cognitive load.
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29

Desenvolvimento de um projeto de experimentos para a caracterização de sinais mioelétricos através do uso de regressão logística

Cene, Vinicius Horn January 2016 (has links)
Através dos dispositivos e técnicas desenvolvidas na área da Instrumentação Biomédica é possível oferecer um tratamento ou de forma geral soluções que permitam uma vivência mais plena em sociedade para pessoas que possuem algum tipo de deficiência ou doença. Com o aumento da capacidade computacional nos últimos anos foi possível desenvolver muitas técnicas e dispositivos apoiados em processamento digital de sinais e há um grande interesse pelo desenvolvimento de interfaces mais naturais, como sinais biológicos para o controle de próteses e dispositivos. Este trabalho tem por objetivo apresentar o desenvolvimento de um método de Inteligência Computacional baseado em Regressão Logística capaz de classificar 17 movimentos do segmento mão-braço realizados pelos voluntários do estudo através do processamento do sinal mioelétrico (SME) adquiridos dos sujeitos em questão. Adicionalmente é realizada uma avaliação da influência de alguns dos canais, características do sinal e movimentos executados na taxa de acerto global. Para a realização do sistema foi utilizado um aparato experimental capaz de adquirir os SME através de 12 canais utilizando eletrodos não invasivos e posteriormente digitalizá-los. Logo após efetua-se a extração das três características utilizadas no trabalho, que servem de entrada para o método de Regressão Logística. Para este estudo foram processados três bancos de dados que perfazem um total de 50 voluntários. A taxa média de acerto alcançada foi de 70,1%, considerando todas as variações de testes realizados enquanto a média para os melhores casos de cada variação de entrada realizada foi de 92,5%. / Through the devices and techniques developed in the field of Biomedical Instrumentation commonly is possible to offer treatment or solutions to provide a more pleasurable experience in society for people who have a disability or illness. With increasing computing capability in recent years, it has been possible to develop many techniques and devices supported by digital signal processing, and there is a great interest in the development of more natural interfaces, such as biological signals for the control of devices and prostheses. This work aims to present the development of a computational intelligence method based on Logistic Regression able to classify 17 movements of the hand-arm segment performed by the subjects of this study through the processing of the myoelectric signal (SME) acquired from the subject in question. Additionally, an assessment of the influence of some of the combination of the channels, signal characteristics and movements performed in the overall hit rate is additionally performed. To conduct the system has built an experimental apparatus able to acquire the SME through 12 channels using non-invasive electrodes and scan them. Thereafter there is a three features extraction from the signal which serves as input to the Logistic Regression method. For this study were processed three databases that compose 50 volunteers. The average hit rate achieved was 70.1%, considering all tests variations while the average for the best cases for each input variation performed was 92,5 %.
Read more
30

Proposta de um sistema baseado em redes neurais e wavelets para caracterização de movimentos do segmento mão-braço

Bermudez, Rosa Maria Jimenez January 2018 (has links)
Este trabalho apresenta um sistema para o processamento do sinal mioelétrico baseado em Redes Neurais e Wavelets. Com a aquisição dos sinais mioelétricos dos músculos do segmento mão-braço, é possível determinar diversos parâmetros para a caracterização dos movimentos executados. A Transformada Wavelets foi utilizada na etapa de segmentação do sinal e a rede neural artificial na caracterização do movimento executado. O sistema é constituído de um eletromiógrafo (EMG de 8 canais), placa de aquisição de dados e um computador responsável pelo processamento dos dados. Foram utilizado eletrodos de superfície posicionados em lugares estratégicos no segmento mão-braço. O experimento consiste em repetir movimentos do segmento mão-braço executados por um modelo virtual. Os movimentos avaliados, neste trabalho, são: contração da mão, extensão do punho, flexão do antebraço, flexão do punho, rotação do braço, rotação e flexão do antebraço, rotação do braço e contração da mão, extensão e flexão do punho, contração da mão e elevação do braço. Esses movimentos são apresentados ao sujeito em determinadas sequências através dos modelos virtuais desenvolvidos, permitindo assim, a padronização do movimento a ser executado pelo voluntário O sinal é adquirido através de uma placa de aquisição e processado. As etapas principais de processamento são: segmentação do sinal de interesse através da Wavelet Discreta, extração de características (r.m.s, variância, desvio padrão, sesgo, curtose ) e uso da Rede Neural para determinar o movimento executado final dos testes, foi verificado que o movimento contração da mão e elevação do braço apresentou uma taxa de acerto média de 75%; o movimento flexão do antebraço obteve 81% de acerto médio; a contração da mão obteve 33% de acerto médio, o movimento contração da mão 76% de acerto médio; o movimento de flexão do punho 100 % de acerto médio, rotação e flexão do antebraço 66% de acerto médio, extensão e flexão do punho um 16% de acerto médio, extensão do punho 83,3% de acerto médio, rotação do braço 16,7% de acerto médio. Rotação do braço e contração da mão 83,3% de acerto médio. / This work presents a neural-network myoelectric processing-based system. With the acquisition of myoelectric signals from the muscles of the hand-arm segment, it is possible to determine the parameters that characterize the executed movements. Therefore, in this work Artificial Neural Networks are implemented to recognize patterns in order to determine the executed movement. The system is constituted by an electromyography (8-channel EMG), a data acquisition board and a computer responsible for data processing. In this research an experimental system is developed to capture the myoelectric signals by means of an EMG and a data acquisition board. Surface electrodes located in strategic places in the hand-arm segment are used. The experiment consists of repeated movements of the hand-arm segment executed by a virtual model. The movements examined in this work are: hand contraction, fist extension, forearm flexion, fist flexion, arm rotation, forearm rotation and flexion, fist contraction and extension and arm elevation. Those movements are presented to a volunteer in a random way by means of the virtual models developed, permitting a standardization of the movements that are to be executed by the volunteer. In the last part it is verified that the hand-contraction movement and the arm-elevation movement present an accuracy rate average of 75%; the forearm-flexion movement reaches 81% of accuracy rate average, the hand-contraction movement with 33% of accuracy rate average, the hand-contraction movement with 76% of accuracy rate average, the fist-flexion movement reached a 100% in the accuracy rate average, the forearm rotation flexion movement with a 66% in the accuracy rate average, the fist extension and flexion movement reaches the 16% in the accuracy rate average and the fist-extension movement with a 83.3% of accuracy rate average.
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