Thesis (Ph. D.)--University of Washington, 2005. / Vita. Includes bibliographical references.

Thesis (MScEng)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: This work entails the development and performance analysis of a human gait detection system based on radar micro-Doppler signals. The system consists of a tracking functionality and a target classifier. Target micro-Doppler signatures are extracted with Short-Time Fourier Transform (STFT) based spectrogram providing a high-resolution signatures with the radar that is used. A feature extraction mechanism is developed to extract six features from the signature and an artificial neural network (A-NN) based classifier is designed to carry out the classification process. The system is tested on real X-band radar data of human subjects performing six activities. Those activities are walking and speed walking, walking with hands in pockets, marching, running, walking with a weapon, and walking with arms swaying. The multiclass classifier was designed to discriminate between those activities. High classification accuracy of 96% is demonstrated. / AFRIKAANSE OPSOMMING: Hierdie werk behels die ontwikkeling, en analise van werksverrigting, van ’n menslike stapdetekor gebaseer op radar-mikrodoppleranalise. Die stelsel bestaan uit ’n teikenvolger en -klassifiseerder. Die mikrodoppler-kenmerke van ’n teiken word met behulp van die korttyd-Fourier-transform onttrek, en verskaf hoe-resolusie-kenmerke met die radar wat vir die implementering gebruik word. ’n Kenmerkontrekkingstelsel is ontwikkel om ses kenmerke vanuit die spektrogram te onttrek, en ’n kunsmatige neurale netwerk word as klassifiseerder gebruik. Die stelsel is met ’n X-band radar op werklike menslike beweging getoets, terwyl vrywilligers ses aktiwiteite uitgevoer het: loop, loop (hand in die sakke), marsjeer, hardloop, loop met ’n wapen, loop met arms wat swaai. Die multiklas-klassifiseerder is ontwerp om tussen hierdie aktiwiteite te onderskei. ’n Hoe klassifiseringsakkuraatheid van 96% word gedemonstreer.

Knee osteoarthritis (KOA) is the primary cause of chronic immobility in populations over the age of 65. It is a joint degenerative disease in which the articular cartilage in the knee joint wears down over time, leading to symptoms of pain, instability, joint stiffness, and misalignment of the lower extremities. Without intervention, these symptoms gradually worsen over time, decreasing the overall knee range of motion (ROM) and ability to walk. Current clinical interventions include offloading braces, which mechanically realign the lower extremities to alleviate the pain experienced in the medial compartment of the knee joint. Though these braces have proven effective in pain management, studies have shown a significant decrease in knee ROM while using the brace. Concurrently, development of active exoskeletons for rehabilitative gait has increased within recent years in efforts to provide patients with a more effective intervention for dealing with KOA. Though some developed exoskeletons are promising in their efficacy of fostering gait therapy, these devices are heavy, tethered, difficult to control, unavailable to patients, or costly due to the number of complicated components used to manufacture the device. However, the idea that an active component can improve gait therapy for patients motivates this study. This study proposes the design of an adjustable lower extremity exoskeleton which features a single linear actuator adapted onto a commercially available offloading brace. This design hopes to provide patients with pain alleviation from the brace, while also actively driving the knee through flexion and extension. The design and execution of this exoskeleton was accomplished by 3D computer simulation, 3D CAD modeling, and rapid prototyping techniques. The exoskeleton features 3D printed, ABS plastic struts and supports to achieve successful adaptation of the linear actuator to the brace and an electromechanical system with a rechargeable operating capacity of 7 hours. Design validation was completed by running preliminary gait trials of neutral gait (without brace or exoskeleton), offloading brace, and exoskeleton to observe changes between the different gait scenarios. Results from this testing on a single subject show that there was an observed, significant decrease in average knee ROM in the offloading brace trials from the neutral trials and an observed, significant increase in average knee ROM in the exoskeleton trials when compared to the brace trials as hypothesized. Further evaluation must be completed on the clinical efficacy of this device with a larger, and clinically relevant sample size to assess knee ROM, pain while using the device, and overall comfort level. Further development of this design could focus on material assessment, cost analysis, and risk mitigation through failure mode analysis.

Changes in the gait characteristics, such as walking speed and stride length, of a person living at home can be used to presage cognitive decline, predict fall potential, monitor long-term changes in cognitive impairment, test drug regimens, and more. This thesis presents a novel approach to gait analysis in a smart-home environment by leveraging new advances in inexpensive sensors and embedded systems to create novel solutions for in-home gait analysis. Using a simple, non-invasive hardware system consisting entirely of wall-mounted infrared and radio frequency sensor arrays, data is collected on the gait of subjects as they pass by. This data is then analyzed and sent to a clinician for further study. The system is non-invasive in that it does not use cameras and could be built into the molding of a home so that it would be nearly invisible. In a finished prototype version, the system presented in this thesis could be used to analyze the gait characteristics of one or more subjects living in a home environment while ignoring the data of visitors and other non-subject cohabitants. The ability to constantly collect data from a home environment could provide thousands of observations per year for clinical analysis. Providing such a robust data set may allow people with gait impairment to live at home longer and more safely before transitioning to a care facility, have a reduced fall risk due to better prediction, and live a healthier life in old age.

The effect of concurrent music on gait was investigated amongst Parkinson‟s disease (PD) patients and age-matched control subjects. Ten people (mean age 66.6 ± 6.5 years) with idiopathic Parkinson‟s disease and ten healthy age-matched (mean age 65.4 ± 6.3 years) control subjects completed steady state gait, dual task and obstacle negotiation trials in two differing test conditions; no music and whilst listening to music. Testing conditions were counterbalanced between subjects. The gait performance of PD patients was detrimentally affected by concurrently listening to music during steady state gait and obstacle negotiation, an effect that was further compounded in the dual task context. These findings imply that listening to music concurrent to gait may increase the attentional cost for PD patients. The findings of these studies have implications for patients, who may be at greater risk of falls in multi-task situations. / xi, 113 leaves ; 29 cm. --

[Truncated abstract] Knee osteoarthritis (OA) patients have high levels of pain, functional and strength deficits of the quadriceps, decreased proprioceptive acuity, and increased co-contraction and knee joint loading in gait, compared to age matched controls. The increased knee joint loading in this population occurs most commonly in the medial tibio-femoral compartment, due to increased external adduction moments, and with increasing disease severity there is a concomitant increase in the knee adduction moments. A key finding within the knee OA literature is that dynamic loading in gait, due to increased external adduction moments, strongly predicts pain and radiographic disease progression. Current research has shown that exercise interventions reduce pain and time to complete functional activities; however, the effect of these interventions on knee joint loading and muscular activation in gait is still unclear. In addition, the need for specific knee joint strengthening to cause these alterations has not been investigated and it remains unknown if improvements occur due to specific muscle strengthening or due to some general effect of exercise. Therefore, the primary aim of this research study was to examine the effects of general (upper body) and specific (lower body) resistance training interventions on self-perceived outcomes, neuromuscular function and kinematic, kinetic and muscle activation during gait of OA patients compared with asymptomatic controls. ... The examination of gait data following exercise (Study 4) showed trends for changes in the muscle co-contraction ratios. Specifically, the medial/lateral co-contraction ratio (MLCCR) displayed a trend in early stance where the upper body exercise group increased their lateral muscle activity and the lower body group reduced their lateral muscle activity, and the medial/lateral hamstring co-contraction ratio (HAMCCR) displayed this same trend during loading. The trend toward reduced lateral muscle activation, following lower body resistance training, suggests that specific muscle strengthening may have the ability to alter the load distribution. The kinematic and kinetic variables of gait were unchanged by the exercise interventions, highlighting the sensitivity of muscle activation pattern changes due to muscle strengthening. This thesis provides new insights into the co-contraction strategies utilised by knee OA patients. The directed co-contraction strategy employed by knee OA patients and its relationship to the external adduction moment in gait suggest an attempt to redistribute the loading within the knee joint, most likely in response to pain. Further, we have separated the effects of exercise and found differences in self-perceived outcomes based on exercise specificity. This first examination into muscle co-contraction following resistance training of knee OA patients has highlighted the possibility of alterations to the co-contraction patterns following lower body exercise. However, the implications of altering this muscle activation strategy and the consequent effect on distribution of load within the knee joint requires further consideration.

Introdução: A amputação transtibial é uma das amputações de membros inferiores mais frequentemente realizada. Objetivo: Este trabalho teve por objetivo comparar, através da análise tridimensional da marcha, as alterações de marcha de pacientes com amputação transtibial, previamente treinados, que utilizavam próteses com encaixe Kondylen Bettung Münster (KBM) e a vácuo. Metodologia: Foram avaliados voluntários com amputação transtibial que utilizavam encaixe KBM ou a vácuo disponibilizados pelos Sistema Único de Saúde (SUS). A amostra final foi de 12 participantes no grupo “KBM” e 5 no grupo “vácuo”. Todos eles passaram por um exame físico, que constou de goniometria, teste de força muscular e coleta de dados antropométricos. Eles também realizaram análise tridimensional (3D) da marcha. Para tal, eles foram paramentados com marcadores reflexivos em pontos anatômicos e os correspondentes da prótese, de acordo com o modelo Helen Hayes e caminharam por uma pista de 10 metros com uma velocidade auto selecionada. O sistema de captura consistiu em 6 câmeras Hawk e software Cortex versão 1.1.4.368, de captura e edição das caminhadas, ambos da Motion Analysis Corporation. A comparação entre os dois grupos foi realizada através da Pontuação do Perfil da Marcha (GPS), das Pontuações das Variáveis da Marcha (GVS) e dos parâmetros de tempo e espaço da marcha. Além disso, foi testada a correlação entre a GPS e as GVS e entre a GPS e os parâmetros de tempo e espaço da marcha. Resultados: Os dois grupos obtiveram velocidade da marcha significativamente menores, período de apoio significativamente maior e o tempo de apoio simples menor que o normal. Nos dois grupos ainda, os valores de GPS e GVS foram maiores que o normal, porém o “KBM” apresentou maiores desvios que o “vácuo”. Os maiores desvios do grupo do encaixe KBM foram nas GVS flexão/extensão dos quadris, flexão/extensão dos joelhos e dorsi/plantiflexão do tornozelo MIP, podendo assim caracterizar este como o padrão de desvio do Perfil de Análise do Movimento (MAP) deste grupo. O grupo “vácuo” teve os principais desvios nas GVS dorsi/plantiflexão dos tornozelos, flexão/extensão do joelho MIP e rotação pélvica, sendo este o padrão de desvio do MAP deste grupo. Encontraram-se, portanto, padrões diferentes de desvio nos dois grupos. Os dois grupos apresentaram desvios no MICL, os quais representam as compensações realizadas neste membro para possibilitar uma marcha mais funcional com a prótese. Os participantes que utilizaram o encaixe a vácuo apresentaram marcha mais simétrica que os participantes que utilizavam encaixe KBM. O grupo que utilizava o encaixe a vácuo obteve menores valores de GPS e de algumas GVS que o grupo “KBM”, entre elas estão a flexão/extensão do quadril MIP e MICL, flexão/extensão do joelho MIP e a flexão/extensão do joelho MICL, que foi a única diferença estatisticamente significante entre os grupos de encaixe. O mesmo grupo teve velocidade da macha maior que o grupo “KBM” e, apesar desta diferença não ter sido significativa, sugere uma maior funcionalidade da marcha com o encaixe a vácuo. Conclusão: Pode-se concluir que os indivíduos que utilizaram encaixe a vácuo apresentaram um padrão de marcha mais funcional e com menores desvios que aqueles que utilizaram encaixe KBM, quando comparados através da GPS, das GVS e dos parâmetros de tempo e espaço. / Introduction: Transtibial amputation is one of the lower limb amputations more often performed. Objective: The aim of this study was to compare, using 3D gait analysis, gait deviations of patients with transtibial amputation, previously trained, using KBM and vacum prosthetic fittings. Methodology: Transtibial amputees that used Kondylen Bettung Münster (KBM) and vacuum prosthetic fitting waived by the Sistema Único de Saúde (SUS) were evaluated. The final sample consisted of 12 participants in the "KBM" group and 5 in the "vacuum" group. They all underwent a physical examination, which consisted of goniometry, muscle strength testing and anthropometric data. They also performed three-dimensional (3D) gait analysis. For this, they were vested with reflexive markers on anatomical and prosthetic corresponding landmarkers according to the Helen Hayes and walked across a 10-m walk-way at their self-selected speed. The capture system consisted of 6 cameras Hawk and the Cortex software version 1.1.4.368 for capturing and editing the trials, both from Motion Analysis Corporation. The Gait Profile Scores (GPS), Gait Variable Score (GVS) and temporal-spatial parameters performed the comparison between the two groups. In addition, we tested the correlation between GPS and GVS and between GPS and temporal-spatial parameters. Results: The two groups had significantly lower gait speed, significantly longer period of support and shorter time of single support than normal. In both groups, GPS and GVS values were higher than normal, but the "KBM" showed greater deviations than the "vacuum". The largest deviations from the KBM group was in the GVS hips flexion / extension, knees flexion / extension and ankle dorsi / plantarflexion MIP and can thus characterize this as the deviation pattern of the Movement Analysis Profile (MAP) for this group. The "vacuum" group had major deviations of the GVS ankles dorsi / platarflexion, knee flexion / extension MIP and pelvic rotation, the deviation pattern of MAP in this group. There were, therefore, different deviation patterns I the two groups. Both groups showed deviations in MICL, which represent the compensation made by this limb to enable a more functional gait with prosthesis. Participants who used vacuum prosthetic fitting showed more a symmetrical gait than participants that used KBM prosthetic fitting. The group that used vacuum prosthetic fitting had lower values of GPS and some GVS than "KBM" group; these include hips flexion / extension, MIP knee flexion / extension and MICL knee flexion / extension, which was the only statistically significant difference between the groups. The same group had greater walking speed than the "KBM" group and, although this difference was not significant, it suggests more functionality of gait with vacuum prosthetic fitting. Conclusion: It can be concluded that individuals who used the vacuum prosthetic fitting showed more functional gait pattern and smaller deviations than those that used KBM prosthetic fitting, compared by GPS, GVS and temporal-spatial parameters.

As alterações neuro-motoras podem diminuir os movimentos, as atividades de vida diária e o convívio social. Dentro dessas alterações encontram-se as dispraxias ou apraxias dos movimentos que podem desequilibrar o movimento voluntário, principalmente dos músculos do tornozelo e desenvolver uma rigidez do movimento conhecida como "pé equino" diminuindo o apoio do calcanhar e consequentemente o controle do equilíbrio do corpo dificultando a deambulação. Como fonte de ajuda às pessoas acometidas por esse problema, desenvolveu-se um equipamento denominado Baropodômetro que utiliza o conceito de biofeedback, fornecendo informações audiovisuais, com o propósito de estimular e ou corrigir a falta de apoio do calcanhar no solo auxiliando na percepção do equilíbrio e correção da marcha. O equipamento faz a leitura da pressão aplicada pela parte da frontal e traseira dos pés sobre o solo por meio de sensores colocados em palmilhas e acomodados em calçados (e.g., sandálias). Essa ação é traduzida visualmente através de números mostrados em displays e por colunas de leds que acendem em sequência na medida em que a pressão sobre os sensores aumentam, bem como por um sinal de áudio com frequência variável e volume ajustável produzido por um alto-falante interno. O equipamento pode armazenar os dados coletados em um cartão de memória que pode ser lido em um microcomputador, permitindo montagens de tabelas e gráficos para análise posterior viabilizando o planejamento da ação de reabilitação. Com o auxilio de um método de reabilitação, o aparelho foi validado clinicamente com a participação de um grupo de dez pacientes voluntários que obtiveram um excelente resultado (i.e., todos os pacientes após 10 sessões conseguiram apoiar o pé comprometido) mostrando que é possível a reabilitação com a utilização do aparelho desenvolvido. / The neuro-motor changes can reduce the movements, activities of daily living and social life. Within these changes are the dyspraxia or apraxia of movements that can unbalance the voluntary movement, especially of the ankle muscles and develop a stiffness of movement known as "equinus foot". The equinus foot decreases the heel support and consequently the balance control of the body making it difficult to walking properly. As a source of help to people affected by this problem, we developed a device called Baropodometer that uses the concept of biofeedback, providing audiovisual information in order to stimulate and or correct the absence of heel strike on the ground assisting in the realization and correction of balance and gait. The device reads the pressure applied by the front and rear part of the foot on the ground by means of sensors placed in insoles and accommodated in shoes (e.g., sandals). This action is translated visually through numbers shown in displays and columns of LEDs that are illuminated according to the increase of the pressure on the sensors, as well as an audio signal with variable frequency and adjustable volume produced by an internal buzzer. The device can store the collected data in a memory card that can be read on a microcomputer, allowing creation of tables and graphs for further analysis enabling the planning of rehabilitation action. With the help of a method of rehabilitation, the device was clinically validated with the participation of ten volunteers who achieved an excellent result (i.e, all patients after 10 sessions were able to properly support the equinus foot) showing that the rehabilitation is possible with the use of the developed device.

FINEP; CAPES; CNPQ; Fundação Araucária; ANEEL / O presente trabalho apresenta uma aplicação de sensores à fibra ótica baseados em redes de Bragg encapsulados em compósito de resina polimérica com reforço de fibra de vidro no formato de tubo. O objetivo do trabalho foi projetar, fabricar e caracterizar o dispositivo sensor aplicado ao ciclo da marcha e a mudança do centro de gravidade em amputado transtibial, através da análise de de deformação e resistência do tubo conector da prótese transtibial. Para essa investigação foi produzido um tubo com o material compósito descrito anteriormente através do método de Moldagem por Transferência de Resina (RTM), com quatro sensores óticos. A prótese em que o tubo original foi substituído é classificada como endoesquelético, possui encaixe à vácuo, tem o tubo conector de alumínio e pé com amortecimento de fibra de carbono. O voluntário para os testes foi um homem de 41 anos, 1,65 metros de altura, 72 quilogramas e canhoto. Sua amputação ocorreu devido a trauma (secção cirúrgica nível medial feita abaixo do joelho do membro inferior esquerdo). Ele é usuário de prótese transtibial há dois anos e oito meses A caracterização dos sensores óticos e análise da deformação mecânica e resistência do tubo deu-se pelo ciclo da marcha e a variação do centro de gravidade do corpo através dos seguintes testes: levantar-se, apoiar na perna sem a prótese, apoiar na perna com a prótese, locomoção para frente e locomoção para trás. Os resultados mostram além da caracterização do ciclo da marcha em um amputado transtibial, também um elevado grau de integração das FBGs no compósito e uma alta resistência mecânica do material. / This work presents an application of optical fiber sensors based on Bragg gratings integrated to a transtibial prosthesis tube manufactured with a polymeric composite systrem of epoxy resin reinforced with glass fiber. The main objective of this study is to characterize the sensors applied to the gait cycle and changes in the gravity center of a transtibial amputee, trough the analysis of deformation and strengh of the transtibial prosthesis tube. For this investigation it is produced a tube of the composite material described above using the molding method of resin transfer (RTM) with four optical sensors. The prosthesis in which the original tube is replaced is classified as endoskeletal, has vacuum fitting, aluminium conector tube and carbon fiber foot cushioning. The volunteer for the tests was a man of 41 years old, 1.65 meters tall, 72 kilograms and left-handed. His amputation occurred due to trauma (surgical section is in the medial level, and was made below the left lower limb knee). He has been a transtibial prosthesis user for two years and eight months. The characterization of the optical sensors and analysis of mechanical deformation and tube resistance occurred through the gait cycle and the variation of the center of gravity of the body by the following tests: stand up, support leg without the prosthesis, support in the leg with the prosthesis, walk forward and walk backward. Besides the characterization of optical sensors during the gait cycle and the variation of the gravity center in a transtibial amputated, the results also showed a high degree of integration of the sensors in the composite and a high mechanical strength of the material.

Introdução: A instabilidade postural é uma das causas de incapacidade no individuo idoso e o uso de andadores é uma das estratégias para gerar maior estabilidade e segurança na manutenção da postura ortostática e na realização da marcha. Existem atualmente andadores considerados especiais por utilizarem coletes e sistemas de sustentação ou suporte parcial do corpo. Apesar dos benefícios da utilização destes andadores, estes apresentam alto custo. Com o intuito de se apresentar uma alternativa de qualidade e baixo custo, desenvolveu-se um andador com suporte de tronco confeccionado com PVC na UTFPR. O suporte de tronco acoplado ao andador tem o objetivo de suportar o peso do usuário no caso de uma queda. Objetivo: Avaliar a influência da utilização do andador desenvolvido com suporte de tronco, na oscilação corporal e marcha de idosos com instabilidade postural. Método: Foram realizados testes visando analisar a resistência mecânica do material utilizado e ensaios com o andador já construído. O PVC mostrou ser um material com alta resistência nos testes de flexão e impacto. A massa máxima suportada pelo andador no teste realizado foi de aproximadamente 226 kg. Após a avaliação do equipamento, 9 idosos com instabilidade postural foram submetidos à avaliação da oscilação corporal ou estabilometria e, 3 idosos à análise de marcha, sem e com a utilização do andador desenvolvido. Resultados: Com a utilização do andador desenvolvido houve diminuição da oscilação corporal em todos os idosos participantes. Sem a utilização do equipamento o valor médio da estabilometria foi de 10,297 cm² e com o andador foi de 3,264 cm². Na avaliação da análise de marcha com sensores acelerômetros localizados na articulação do quadril, sem o andador desenvolvido, os idosos tiveram uma maior extensão e menor flexão e, com o andador estes valores inverteram-se. Com o andador, a média da flexão direita passou de 15,33° para 20,67° e a extensão de 10° para 7,33°. O tempo necessário para realização de um percurso de 12 metros foi maior com a utilização do andador desenvolvido. Os resultados apontam para uma melhora na estabilidade e equilíbrio do idoso com a utilização do andador. A análise da marcha demonstrou uma reorganização da amplitude da passada, mas sem uma alteração significativa. / Introduction: Postural instability is one of the causes of disability in the elderly and the use of walkers is one of the strategies to generate greater stability and safety in the maintenance of orthostatic posture and gait. There are currently walkers considered to be specials because they have braces and support systems or offer partial support of the body. Despite the benefits of using these walkers, they are very expensive. In order to present an alternative of quality and low cost, a walker with trunk support was developed, made of PVC. The trunk support attached to the walker is intended to support the weight of the user in the event of a fall. Objective: To evaluate the influence of the use of the walker with trunk support on body sway and gait of the elderly with postural instability. Method: Tests were carried out to analyze the mechanical resistance of the material used as well as the structure of the walker. PVC has proven to be a material with high resistance when submitted to flexion and impact tests. The maximum mass supported by the walker in the test was approximately 226 kg. After testing the equipment, 9 elderly with postural instability were submitted to evaluation of the body sway or stabilometry, and 3 elderly to gait analysis, with and without the use of the walker developed. Results: Using the walker there was a decrease of body sway in all elderly participants. Without the use of the equipment the stabilometry average value was 10,297 cm² and when using the walker it was 3.264 cm². In the evaluation of gait analysis with accelerometer sensors located at the hip joint, without the walker the elderly had greater hip extension and lower hip flexion and, with the walker the results had inverted values. For that, the average flexion on the right hip rose from 15.33° to 20.67° and the extension decreased from 10° to 7.33°. The time needed to finish a course of 12 meters was higher using the walker. The results point to an improvement in stability and balance for the elderly using the walker. The gait analysis demonstrated a reorganization of the length of the stride but without a significant change.