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A prosthesis control strategy using a nearest neighbor electromyographic pattern classifier was investigated with both a real time microprocessor-based controller and offline computational facilities. Four active electrodes for myoelectric signal amplitude detection were interfaced with a microcomputer for data logging and pattern classification. A nearest neighbor algorithm correctly identified arm motions as belonging to one of six pattern classes from 72 percent to 100 percent of the time. There were five vectors for each class in the look-up table. The nearest neighbor pattern classifier was compared to a minimum error rate Bayes classifier under the assumption that the probability densities were distributed as a multivariate normal distribution. Comparable error rates were obtained with the same data vectors. A condensed nearest neighbor classifier was constructed to determine what minimum number of vectors was necessary in the look-up table. This minimum number of vectors ranged from two to six for the majority of the classes. Larger numbers of vectors were placed in the look-up table for classes that were more difficult to classify. / Ph. D.

Orientador: Marcelo Augusto Assunção Sanches / Resumo: Neste trabalho é apresentado o desenvolvimento de um sistema de alinhamento referenciado de prótese de membro inferior, denominado PASyLL (Prosthesis Alignment System of Lower Limbs). A qualidade do alinhamento e ajuste de próteses de membros inferiores é fundamental no processo de reabilitação, principalmente porque contribui para que não ocorra o abandono do uso da prótese. Atualmente, muitos alinhamentos de próteses ainda são realizados de forma subjetiva, sem auxílio de equipamentos, ou seja, apenas com base na experiência e conhecimento do profissional de saúde. Diante disso, desenvolveu-se o PASyLL, um sistema para auxiliar o profissional da saúde no alinhamento de prótese. Este equipamento mede parâmetros importantes para um alinhamento adequado, fornece ao terapeuta dados objetivos, auxiliando-o na tomada de decisão. Com este sistema é possível medir e realizar ajustes no comprimento, medir a distribuição do peso no membro protetizado e não protetizado, verificar a posição do centro de pressão do paciente (COP), desta forma auxiliar no ajuste médio lateral e anteroposterior. O sistema possui fachos laser na horizontal e vertical, permitindo assim um alinhamento referenciado. O erro percentual na medição do peso foi inferior a 1% e na medida do COP, inferior a 5%. / Abstract: In this work the development of a referenced alignment system of lower limb prosthesis, called PASyLL (Prosthesis Alignment System of Lower Limbs), is presented. The quality of the alignment and adjustment of lower limb prostheies is fundamental in the rehabilitation process, mainly because it contributes to the abandonment of prosthesis use. Currently, many prosthesis alignments are still performed subjectively, without the aid of equipment, that is, only based on the experience and knowledge of the health professional. Therefore, the PASyLL, a system to assist the health professional in the prosthesis alignment, was developed. This equipment measures important parameters for proper alignment, provides the therapist with objective data, assisting him in decision making. With this system it is possible to measure and adjust the length, measure the weight distribution in the amputated and not amputated limb, verify the position of the patient pressure center (COP) in this way assist in the lateral lateral and anteroposterior adjustment. The system has horizontal and vertical laser beams, allowing a referenced alignment. The percentage error in weight measurement was less than 1% and in the COP, less than 5%. / Mestre

A perda óssea progressiva ao redor da plataforma dos implantes dentários é um desafio a ser vencido na clínica, uma vez que, interfere na manutenção e controle dos tecidos peri-implantares e pode afetar a estética. Esta pesquisa teve como objetivo avaliar a concentração de tensões ao redor de diferentes implantes dentários, variando a macrogeometria, conexão protética e profundidade da inserção da plataforma protética, sob carregamento axial ou oblíquo. Foram criados três modelos de resina fotoelástica para cada tipo de implante avaliado (hexágono externo, hexágono externo wedge, hexágono interno e cone Morse). Cada corpo de prova se diferenciou pelo posicionamento da plataforma do implante em relação à margem superior do bloco, em três posições diferentes: I - plataforma posicionada 2mm abaixo da margem do bloco; II - plataforma posicionada no mesmo nível da margem do bloco; III - plataforma posicionada 2mm acima da margem do bloco. Foi aplicada uma força de 100N através de um dispositivo instalado sobre pilares retos e angulados, simulando um carregamento axial e oblíquo respectivamente. Um total de 4 pontos foram avaliados de um lado do implante. Dados quantitativos foram coletados e utilizados para análise estatística. A regressão linear múltipla mostrou relação entre a distribuição das tensões com relação à profundidade de inserção independentemente do tipo de conexão protética ou do carregamento oclusal. O grupo I (2mm abaixo da margem) foi o que apresentou os menores valores (p<0.05) de tensão quando comparado com os outros grupos (II e III). De acordo com as limitações deste estudo pode-se concluir que a macrogeometria, profundidade de inserção da plataforma e tipo de carregamento oclusal influenciam no comportamento da distribuição das tensões ao redor dos implantes. Em relação à conexão protética, os resultados mostraram padrões de franjas semelhantes independentemente do tipo de conexão / The progressive bone loss at the neck of dental implant is a clinical concern since it affects the maintenance of dental esthetics. The stress concentration, the connection type and the microgap appear to be factors that cause alterations at the marginal bone level. The aim of this research was to evaluate the stress concentration around different dental implants, varying the macrogeometry, prosthetic connection and depth of the insertion of the prosthetic platform, under axial or oblique loading. Three blocks of photoelastic resin for each type of implant connection (external hexagon, external hexagon flattened, internal hexagon and Morse taper) were built. Each block differed in the position of the implant platform in relative to the upper margin of the block: I (2mm below), II (at the same level) and III (2mm above). A force of 100N was applied to both a straight and tilted abutments. A multiple linear regression showed the relation between the stress distribution and the insertion depth. For all the implant types, both with straight and tilted abutments, Group I presented the lowest stress concentration around the fixture when compared to group II and III (p<0,05). According to the limitations of this study it could be concluded that the macrogeometry, depth of insertion of the platform and type of occlusal loading influence the behavior of the distribution of stresses around the implants. Regarding the prosthetic connection, the results showed similar patterns of fringes regardless of the type of connection

Introdução: A reconstrução de grandes defeitos da face nem sempre é passível de correção cirúrgica, podendo ser restaurados com as próteses faciais. Apesar da prótese óculopalpebral apresentar uma aparência natural, ela é facilmente notada, pois não apresenta os movimentos palpebrais de abertura e fechamento sincronizadas com o olho contralateral, tornando assim a reconstrução protética um grande desafio. Objetivos: Planejar, desenhar, viabilizar e construir um protótipo com recurso mecânico/elétrico possibilitando sincronia dos movimentos palpebrais com o olho sadio para utilização em prótese óculopalpebral. Material e Métodos: Confecção de uma prótese óculopalpebral com um dispositivo de pálpebra móvel em silicone médico capaz de conectar-se a um sistema mecânico-elétrico responsável por realizar movimentos de abertura e fechamento da pálpebra móvel da prótese. Resultados e Discussão: Foi confeccionada uma prótese óculo-palpebral em resina acrílica termicamente ativada, criando-se um nicho para a acomodação de um sistema elétrico e possibilitar a livre movimentação de uma fina pálpebra em silicone interligada ao dispositivo tornando possível a conexão desse sistema com um sensor que capta o movimento palpebral de um olho saudável. Conclusão: No presente estudo um protótipo mecânico - elétrico foi planejado, desenhado e desenvolvido acoplado a uma prótese óculopalpebral estabelecendo e sincronizando seus movimentos palpebrais com o olho sadio. / Introduction: Surgical reconstruction of large facial defects may not be always possible. Extraoral maxillofacial prosthesis are a good restorative option. Even though when the oculopalpebral prosthesis presents a natural appearance, it can be easily noticed because its eyelids do not move. It is desirable for the eyelids to open and close synchronously with contralateral eye. Thus, prosthetic reconstruction of oculopalpebral region is a great challenge. Objectives: To plan, design, enable and build a oculopalpebral prosthesis prototype with mechanical and electric features allowing eyelid motion with synchronization with the sound eye. Material and method: Fabrication of an oculopalpebral prosthesis with a medical grade silicone movable eyelid which has the capability to connect itself to an mechanical-eletrical system responsible to make opening and closing movements on prosthesis movable eyelid. Results and discussion: An oculopalpebral prosthesis was made in thermoactivated acrylic resin. A gap was created to accomodate an electrical system and also allow free motion of a thin silicone eyelid attached to the dispositive. This system can be connected to a sensor which captured the eyelid motion of a sound eye. Conclusion: A mechanical-electrical prototype was planned, designed and developed attached to an oculopalpebral prosthesis stablishing and synchronizing its eyelid movements with the sound eye.

abstract: Locomotion is of prime importance in enabling human beings to effectively respond in space and time to meet different needs. Approximately 2 million Americans live with an amputation with most of those amputations being of the lower limbs. To advance current state-of-the-art lower limb prosthetic devices, it is necessary to adapt performance at a level of intelligence seen in human walking. As such, this thesis focuses on the mechanisms involved during human walking, while transitioning from rigid to compliant surfaces such as from pavement to sand, grass or granular media. Utilizing a unique tool, the Variable Stiffness Treadmill (VST), as the platform for human walking, rigid to compliant surface transitions are simulated. The analysis of muscular activation during the transition from rigid to different compliant surfaces reveals specific anticipatory muscle activation that precedes stepping on a compliant surface. There is also an indication of varying responses for different surface stiffness levels. This response is observed across subjects. Results obtained are novel and useful in establishing a framework for implementing control algorithm parameters to improve powered ankle prosthesis. With this, it is possible for the prosthesis to adapt to a new surface and therefore resulting in a more robust smart powered lower limb prosthesis. / Dissertation/Thesis / Masters Thesis Biomedical Engineering 2019

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2010.

After amputation possibilities of human body motion are very limited. Amputation usually changes inert characteristics of human body parts and asymmetry of gait is visible. After prosthetics, gait with prosthesis remains asymmetric in relation with impaired body balance control. Loss of proprioreception in amputated side reduces regulation of stance. To retrieve stance skills and to train body balance pneumatic prosthesis is usually applied. The aim of this investigation was to assess influence of pneumatic prosthesis to stance and walking characteristics. To achieve this aim there were two main objectives 1) to evaluate influence of pneumatic prosthesis to stance symmetry in early period of prosthetics; 2) to evaluate influence of pneumatic prosthesis to gait symmetry in early period of prosthetics. Investigation was conducted using computerised pedobarograph „Parotec System“. Changes of weight center position were analyzed at the beginning and the end of rehabilitation period, time characteristics of weight bearing phases were assessed, vertical force and index of gait asymmetry were calculated. Investigation was performed at the department of Physical medicine and rehabilitation of Joint-stock company „Ortopedijos technika“. Patients who underwent below knee amputation were included. Testing was performed twice for every patient: at the beginning and the end of prosthetics. Weight center position in regard to both lower limbs was analyzed. At the end of prosthetics gait... [to full text]

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2006. / Härtill 5 uppsatser.

Thesis (doctoral)--Lund University, 1993. / Added t.p. with thesis statement inserted.