Design and Evaluation of AIRGAIT Exoskeleton\u27s Leg Orthosis: Development of a Control Scheme and Strategy for a Noble Control of Antagonistic Mono- and Bi-Articular Actuators

芝浦工業大学201

Rehabilitation Engineering

Population ageing has major consequences and implications in all areas of our daily life as well as other important aspects, such as economic growth, savings, investment and consumption, labour markets, pensions, property and care from one generation to another. Additionally, health and related care, family composition and life-style, housing and migration are also affected. Given the rapid increase in the aging of the population and the further increase that is expected in the coming years, an important problem that has to be faced is the corresponding increase in chronic illness, disabilities, and loss of functional independence endemic to the elderly (WHO 2008). For this reason, novel methods of rehabilitation and care management are urgently needed. This book covers many rehabilitation support systems and robots developed for upper limbs, lower limbs as well as visually impaired condition. Other than upper limbs, the lower limb research works are also discussed like motorized foot rest for electric powered wheelchair and standing assistance device

Robotic exoskeleton with an assist-as-needed control strategy for gait rehabilitation after stroke

Stroke is a loss of brain function caused by a disturbance on the blood supply to the brain. The main consequence of a stroke is a serious long-term disability, and it affects millions of people around the world every year. Motor recovery after stroke is primarily based on physical therapy and the most common rehabilitation method focuses on the task specific approach. Gait is one of the most important daily life activity affected in stroke victims, leading to poor ambulatory activity. Therefore, much effort has been devoted to improve gait rehabilitation. Traditional gait therapy is mostly based on treadmill training, with patient’s body weight partially supported by a harness system. Physical therapists need to manually assist patients in the correct way to move their legs. However, this technique is usually very exhausting for therapists and, as a result, the training duration is limited by the physical conditions of the therapists themselves. Moreover, multiple therapists are required to assist a single patient on both legs, and it is very difficult to coordinate and properly control the body segments of interest. In order to help physical therapists to improve the rehabilitation process, robotic exoskeletons can come into play. Robotics exoskeletons consist of mechatronic structures attached to subject’s limbs in order to assist or enhance movements. These robotic devices have emerged as a promising approach to restore gait and improve motor function of impaired stroke victims, by applying intensive and repetitive training. However, active subject participation during the therapy is paramount to many of the potential recovery pathways and, therefore, it is an important feature of the gait training. To this end, robotics devices should not impose fixed limb trajectories while patient remains passive. These have been the main motivations for the research of this dissertation. The overall aim was to generate the necessary knowledge to design, develop and validate a novel lower limb robotic exoskeleton and an assist-as-needed therapy for gait rehabilitation in post-stroke patients. Research activities were conducted towards the development of the hardware and the control methods required to prove the concept with a clinical evaluation. The first part of the research was dedicated to design and implement a lightweight robotic exoskeleton with a comfortable embodiment to the user. It was envisioned as a completely actuated device in the sagittal plane, capable of providing the necessary torque to move the hip, knee and ankle joints through the walking process. The device, that does not extend above mid-abdomen and requires nothing to be worn over the shoulders or above the lower back, presumably renders more comfort to the user. Furthermore, the robotic exoskeleton is an autonomous device capable of overground walking, aiming to motivate and engage patients by performing gait rehabilitation in a real environment. The second research part was devoted to implement a control approach that assist the patient only when needed. This method creates a force field that guides patient’s limb in a correct trajectory. In this way, the robotic exoskeleton only applies forces when the patient deviates from the trajectory. The force field provides haptic feedback that is processed by the patient, thus leading to a continuous improvement of the motor functions. Finally, research was conducted to evaluate the robotic exoskeleton and its control approach in a clinical study with post-stroke patients. This study aimed to be a proof-of-concept of all design and implementation applied to a real clinical rehabilitation scenario. Several aspects were evaluated: the robotic exoskeleton control performance, patients’ attitudes and motivation towards the use of the device, patients’ safety and tolerance to the intensive robotic training and the impact of the robotic training on the walking function of the patients. Results have shown that the device is safe, easy to use and have positive impact on walking functions. The patients tolerated the walking therapy very well and were motivated by training with the device. These results motivate further research on overground walking therapy for stroke rehabilitation with the robotic exoskeleton. The work presented in this dissertation comprises all the way from the research to implementation and evaluation of a final device. The technology resulting from the work presented here has been transferred to a spin-o↵ company, which is now commercializing the device in different countries as a research tool to be used in clinical studies.Un accidente cerebrovascular es una pérdida de la función cerebral causada por una perturbación en el suministro sanguíneo al cerebro. La principal consecuencia de esta enfermedad es una grave discapacidad a largo plazo, que afecta a millones de personas en todo el mundo a cada año. La recuperación motora después de un accidente cerebrovascular se basa principalmente en la terapia física, y el método de rehabilitación más frecuente se centra en un entrenamiento específico. La marcha es una de las más importantes actividades de la vida diaria afectada por un accidente cerebrovascular, conduciendo a una capacidad ambulatoria deficiente. Debido a eso, mucho esfuerzo se ha dedicado a la rehabilitación de la marcha. La terapia tradicional de la marcha se basa principalmente en el entrenamiento en cinta rodante, con descarga de peso parcial usando un sistema de arnés. Los fisioterapeutas ayudan manualmente a los pacientes a mover sus piernas en la forma correcta. Sin embargo, esta técnica suele ser muy extenuante para los terapeutas, limitando la duración de la terapia por las condiciones físicas de estos. Además, se requieren múltiples terapeutas para asistir a un solo paciente en ambas piernas, siendo muy difícil de coordinar y controlar adecuadamente los segmentos corporales de interés. Con el fin de ayudar a los terapeutas físicos a mejorar el proceso de rehabilitación, los exosqueletos robóticos pueden ser muy útiles. Los exoesqueletos robóticos consisten en estructuras mecatrónicas conectadas a las extremidades del usuario, con el fin de asistir sus movimientos. Estos dispositivos robóticos han surgido como una forma prometedora de restaurar la marcha y mejorar la función motora en víctimas de accidentes cerebrovasculares, aplicando un entrenamiento intensivo y repetitivo. Sin embargo, la participación activa del paciente en la terapia es primordial para muchas de las posibles vías de recuperación y, por lo tanto, es una característica importante del entrenamiento de la marcha. Para este fin, los dispositivos robóticos no deben imponer trayectorias fijas en las extremidades del paciente mientras este permanece pasivo. Estos desafíos en los procesos de rehabilitación han sido la principal motivación para la investigación en esta tesis doctoral. El objetivo principal es generar los conocimientos necesarios para diseñar, desarrollar y validar un exoesqueleto robótico y una terapia de asistencia bajo demanda para la rehabilitación de la marcha en pacientes tras un accidente cerebrovascular. Actividades de investigación fueron llevadas a cabo para el desarrollo del hardware y de los métodos de control necesarios para una prueba de concepto mediante una evaluación clínica. La primera parte de la investigación fue dedicada a diseñar e implementar un exoesqueleto robótico ligero y cómodo para el usuario. Fue concebido un dispositivo completamente actuado en el plano sagital, capaz de proporcionar el par necesario para mover las articulaciones de la cadera, rodilla y tobillo durante la marcha. El dispositivo no se extiende por encima de mitad del abdomen y no requiere llevar nada sobre los hombros o en el tronco, proporcionando más comodidad al usuario. Además, el exoesqueleto robótico es un dispositivo autónomo capaz de asistir marcha ambulatoria, con el objetivo de motivar a los pacientes por medio de rehabilitación en un entorno real. La segunda parte de la investigación fue dedicada a implementar una estrategia de control para ayudar al paciente bajo demanda. El método crea un campo de fuerzas que guía la extremidad del paciente en la trayectoria correcta. De esta manera, el exoesqueleto robótico sólo aplica fuerzas cuando el paciente se desvía de la trayectoria. El campo de fuerza proporciona retroalimentación háptica que es procesada por el paciente, lo que conduce a una mejora continua de las funciones motoras. Por último, fue llevada a cabo una investigación para evaluar el exoesqueleto robótico y su estrategia de control en un estudio clínico con pacientes que han sufrido un accidente cerebrovascular. Este estudio fue una prueba de concepto del diseño y de la implementación del dispositivo aplicada a un escenario de rehabilitación clínica real. Se evaluaron varios aspectos: el desempeño de la estrategia de control, las actitudes y motivación de los pacientes hacia el uso del dispositivo, la seguridad del paciente y su tolerancia a la terapia robótica intensiva y el impacto de la rehabilitación en la marcha de los pacientes. Los resultados han demostrado que el dispositivo es seguro, fácil de usar y tiene un impacto positivo en la marcha. Los pacientes toleraron la terapia robótica muy bien y estuvieron motivados por el entrenamiento con el dispositivo. Estos resultados motivan a seguir la investigación con el exoesqueleto robótico aplicado a la rehabilitación de marcha en pacientes que han sufrido un accidente cerebrovascular. El trabajo presentado en esta tesis doctoral comprende todo el camino desde la investigación hasta la ejecución y evaluación de un dispositivo terminado. La tecnología resultante del trabajo que aquí se presenta ha sido transferida a una empresa spin-off, que ahora está comercializando el dispositivo en diferentes países como una herramienta de investigación para ser utilizada en estudios clínicos.Programa Oficial de Doctorado en Ingeniería Eléctrica, Electrónica y AutomáticaPresidente: Luís Enrique Moreno Lorente.-Secretario: Juan Aranda López.-Vocal: Jose María Azorín Poved

Biomedical Engineering

Biomedical engineering is currently relatively wide scientific area which has been constantly bringing innovations with an objective to support and improve all areas of medicine such as therapy, diagnostics and rehabilitation. It holds a strong position also in natural and biological sciences. In the terms of application, biomedical engineering is present at almost all technical universities where some of them are targeted for the research and development in this area. The presented book brings chosen outputs and results of research and development tasks, often supported by important world or European framework programs or grant agencies. The knowledge and findings from the area of biomaterials, bioelectronics, bioinformatics, biomedical devices and tools or computer support in the processes of diagnostics and therapy are defined in a way that they bring both basic information to a reader and also specific outputs with a possible further use in research and development

Remote vital signs monitoring based on wireless sensor networks

Tese de doutoramento em Líderes para as Indústrias TecnológicasGovernmental and private institutions face a major challenge to provide quality health care to a population consisting of a growing number of elderly and chronically ill patients. According to the World Health Organization, in 2006, the total global health expenditures exceeded US$ 4 trillion and are rising in the majority of countries including Portugal which, during 2006, expended 9.9% of its gross domestic product in health care. The use of remote vital signs monitoring systems increases the probability of early detection of risky situations, allows frequent monitoring of in-patients, elderly and chronically ill patients, and streamlines the work of health professionals. However, at present, these systems are expensive, complex and employ obtrusive sensors, which limit their application to intensive care units and cardiac intermediate care units. This work is part of a project that aims to design, prototype and evaluate a remote vital signs monitoring system based on the IEEE 802.15.4 and ZigBee protocols, which allow the development of small low-power sensors. The prototype system comprises electrocardiogram/heart rate and axillary thermometer sensors, networking devices and three informatics applications that collect, process, and exhibit medical data. The wireless sensors, the networking devices and one of the applications were developed under this work. Additionally, the wireless sensor network was evaluated through simulations at the MAC level and experimental and field tests. Field tests were performed at an in-patient floor of Hospital Privado de Guimarães, a Portuguese hospital. Finally, questionnaires were used to measure the satisfaction of users and catalog their critics and suggestions for improvement. Simulations considered different topologies, operation modes and a crescent number of sensors and hops. Experimental and field tests confirmed most of the results obtained by simulations, but revealed that networks which did not assign transmission time slots to electrocardiogram sensors were unable to maintain a high delivery ratio. Contention between devices, aggravated by the inability of routers in receiving incoming packets during backoff, and collisions between packets generated by hiddennodes were responsible for most message losses. On the other hand, beacon-enabled star IEEE 802.15.4 networks that assigned a guaranteed time slot to sensors were able to maintain a very high delivery ratio. In contrast, these networks are restricted in terms of the coverage area and the number of sensors. Also, field tests showed that under low traffic scenarios ZigBee nonbeacon-enabled networks can achieve a high delivery ratio even in presence of a high percentage of hidden-nodes.Instituições governamentais e privadas enfrentam um grande desafio para prestar cuidados de saúde de qualidade a uma população constituída por um número crescente de idosos e doentes crónicos. Segundo a Organização Mundial de Saúde, em 2006, a despesa mundial em saúde ultrapassou a quantia de 4 bilhões de dólares americanos e cresce anualmente na maioria dos países, incluindo Portugal, o qual, em 2006, gastou 9,9% do seu produto interno bruto em cuidados de saúde. O uso de sistemas de monitorização remota de sinais vitais aumenta a probabilidade de deteção precoce de situações de risco, permite que doentes internados, idosos ou doentes crónicos sejam frequentemente monitorizados e agiliza o trabalho dos profissionais de saúde. No entanto, atualmente, estes sistemas são caros e complexos, o que limita a sua aplicação a alguns setores dos hospitais, tais como as unidades de cuidados intensivos e as unidades de cuidados intermédios na área da cardiologia. O projeto no qual insere-se este trabalho visa a conceção, a prototipagem e a avaliação de um sistema de monitorização remota de sinais vitais com base nos protocolos IEEE 802.15.4 e ZigBee, os quais oferecem a possibilidade de construção de sensores com consumos energéticos muito baixos e reduzidas dimensões. O sistema consiste em sensores de eletrocardiograma/frequência cardíaca e temperatura axilar, dispositivos de rede e três aplicações que coletam, processam e apresentam o eletrocardiograma e os sinais vitais. No âmbito deste trabalho foram desenvolvidos os sensores sem fios, os dispositivos de rede e uma das aplicações informáticas. Além disso, foi feita a avaliação do desempenho da rede de sensores sem fios através da análise de simulações a nível da camada de acesso ao meio (MAC) e de testes de laboratório e de campo. Os testes de campo da rede de sensores sem fios foram executados em um dos pisos de internamento do Hospital Privado de Guimarães. Finalmente, foram usados questionários para medir a satisfação dos utilizadores e recolher críticas e sugestões de melhoria. As simulações consideraram diferentes topologias e modos de operação, além de um número crescente de sensores e saltos. Testes experimentais e de campo confirmaram grande parte dos resultados obtidos por simulação mas, adicionalmente, revelaram que as redes constituídas por vários sensores de eletrocardiograma e que não reservaram um intervalo de tempo de transmissão aos sensores não foram capazes de manter uma elevada taxa de entrega de mensagens. Perdas de mensagens ocorreram devido a disputas entre sensores pelo acesso ao canal sem fios e devido a ocorrência de colisões de pacotes transmitidos por nós escondidos. Por outro lado, as redes baseadas no protocolo IEEE 802.15.4 que atribuíram um intervalo de tempo de transmissão a cada sensor conseguiram manter uma elevada taxa de entrega. Entretanto, essas redes são limitadas em termos da área de cobertura e do número de sensores. Adicionalmente, durante os testes de campo em cenários de tráfego reduzido, as redes ZigBee que não empregaram beacons atingiram uma elevada taxa de entrega mesmo na presença de uma grande percentagem de nós escondidos

Proceedings of the COST Action TU1403 : Adaptive Facades Network Final Conference

info:eu-repo/semantics/publishedVersio

Optical Methods in Sensing and Imaging for Medical and Biological Applications

The recent advances in optical sources and detectors have opened up new opportunities for sensing and imaging techniques which can be successfully used in biomedical and healthcare applications. This book, entitled ‘Optical Methods in Sensing and Imaging for Medical and Biological Applications’, focuses on various aspects of the research and development related to these areas. The book will be a valuable source of information presenting the recent advances in optical methods and novel techniques, as well as their applications in the fields of biomedicine and healthcare, to anyone interested in this subject

Technology 2002: The Third National Technology Transfer Conference and Exposition, volume 2

Proceedings from symposia of the Technology 2002 Conference and Exposition, December 1-3, 1992, Baltimore, MD. Volume 2 features 60 papers presented during 30 concurrent sessions