Feature Analysis for Classification of Physical Actions using surface EMG Data

Based on recent health statistics, there are several thousands of people with limb disability and gait disorders that require a medical assistance. A robot assisted rehabilitation therapy can help them recover and return to a normal life. In this scenario, a successful methodology is to use the EMG signal based information to control the support robotics. For this mechanism to function properly, the EMG signal from the muscles has to be sensed and then the biological motor intention has to be decoded and finally the resulting information has to be communicated to the controller of the robot. An accurate detection of the motor intention requires a pattern recognition based categorical identification. Hence in this paper, we propose an improved classification framework by identification of the relevant features that drive the pattern recognition algorithm. Major contributions include a set of modified spectral moment based features and another relevant inter-channel correlation feature that contribute to an improved classification performance. Next, we conducted a sensitivity analysis of the classification algorithm to different EMG channels. Finally, the classifier performance is compared to that of the other state-of the art algorithm

Towards a human-in-the-loop control for a smart orthotic system

Dissertação de mestrado integrado em Engenharia Biomédica (área de especialização em Eletrónica Médica)Stroke is the main cause of paralysis. This pathology has provoked a considerable increase of persons with motor impairments. With a therapy focused on each clinical case, the total or partial recovery can be achieved. Powered orthoses have been developed to promote an effective recover, based on repetitive gait training and user’s active participation. Many control approaches have been developed to control these devices, but none of them promotes an user-oriented strategy focused to the user’s needs. In an attempt of solving this issue, a new approach named Human-in-the-loop is emerging. This strategy allows the adaptation of some assistive parameters based on the user’s energetic cost, promoting a therapy tailored to each end-user needs. However, to estimate the energy expenditure, the use of non-ergonomic sensors, not suitable for clinical context, is required. Thus, it is necessary to find new ways of estimating energy expenditure using wearable and comfortable sensors. In this dissertation, the first steps to introduce the Human-in-the-loop strategy into a powered orthosis are presented. For this purpose, two strategies were developed: a strategy that allows the angular trajectory adaptation in real-time and other that promotes a stiffness adaptation all over the gait cycle. Both strategies were validated with healthy subjects. In the first strategy, the orthosis was able to modify its assistance in a fraction of microseconds, and the end-users were able to follow her with a median error below 10%. Regarding the second strategy, the results show that the orthosis allowed an effective change in the systems’ interaction stiffness, promoting an active participation of each user during its assistance. The energetic impact of using the robotic assistive device is also presented. As it promotes an energy expenditure augmentation in more than 30% in comparison to walk without the device, the necessity of implementing the Human-in-the-loop strategy was highlighted. In an attempt of finding an ergonomic technique to estimate the energetic cost, the use of machine learning algorithms was tested. The results, obtained with a MLP and a LSTM, prove that it is possible to estimate the energy expenditure with a mean error close to 11%. Future work consists in the implementation of the model in real-time and the collection of more data with the aforementioned control approaches, in a way of constructing a more robust model.O AVC é uma das maiores causas de paralisia. Esta patologia, cada vez mais com maior incidência nos jovens, tem provocado um aumento considerável de pessoas com problemas de mobilidade. Com uma terapia focada a cada caso clínico, a recuperação total ou parcial pode ser conseguida. As ortóteses ativas têm vindo a ser desenvolvidas com o propósito de promover uma recuperação eficaz, baseada em treinos repetitivos e numa participação ativa dos utilizadores. Várias abordagens de controlo têm vindo a ser desenvolvidas para controlar estes dispositivos, mas nenhuma delas promove uma estratégia orientada às necessidades do utilizador. Na tentativa de solucionar este problema, uma nova abordagem, designada por Human-in-the-loop está a emergir. Baseada no custo energético, esta estratégia permite adaptar parâmetros da assistência, promovendo uma terapia focada e direcionada a cada utilizador. No entanto, para estimar o custo energético, recorre-se ao uso de sensores que não são adequados para contexto clínico. Assim, torna-se necessário estudar novas formas de estimar o custo energético. Nesta dissertação são apresentados os primeiros passos para introduzir o controlo Human-in-the-loop numa ortótese ativa. Para isso, duas estratégias foram apresentadas: uma estratégia que permite adaptar a trajetória angular da ortótese, em tempo real, e outra que promove a adaptação da complacência do sistema ao longo do ciclo da marcha. Ambas foram validadas com sujeitos saudáveis. Relativamente à primeira abordagem, a ortótese foi capaz de modificar a sua assistência em microssegundos, e os utilizadores foram capazes de a seguir com um erro mediano inferior a 10%. No que diz respeito à segunda abordagem, os resultados mostram que a ortótese promoveu uma alteração eficaz da complacência de interação, promovendo uma participação ativa do utilizador durante a sua assistência. O impacto energético do uso do sistema robótico é, também, apresentado. Promovendo um aumento do custo energético em mais de 30%, a necessidade da estratégia Human-in-the-loop foi realçada. Na tentativa de encontrar uma técnica para estimar o custo energético, recorreu-se ao uso de machine learning. Os resultados, obtidos com uma MLP e uma LSTM, provam que é possível estimar o custo energético com um erro médio próximo dos 11%. Trabalho futuro passa pela implementação do modelo em tempo real e a recolha de mais dados com as abordagens de controlo apresentadas, de forma a construir um modelo mais robusto

Design of a wearable active ankle-foot orthosis for both sides

Dissertação de mestrado integrado em Engenharia Biomédica (área de especialização em Biomateriais, Reabilitação e Biomecânica)Portugal is the west European country with the highest rate of stroke-related mortality, being that, of those who suffer cerebrovascular accidents, 40% feature an impairment which can manifest itself through motor sequelae, namely drop foot. An ankle-foot orthosis is often recommended to passively accommodate these motor problems; however, active/powered exoskeletons are also a suitable solution for post-stroke patients. Due to the high complexity of the human ankle joint, one of the problems regarding these active devices is the misalignment occurring between the rehabilitation device and the human joint, which is a cause of parasitic forces, discomfort, and pain. The present master dissertation proposes the development of an adjustable wearable active ankle-foot orthosis that is able to tackle this misalignment issue concerning commercially available lower limb orthotic devices. This work is integrated on the SmartOs – Smart, Stand-alone Active Orthotic System – project that proposes an innovative robotic technology (a wearable mobile lab) oriented to gait rehabilitation. The conceptual design of a standard version of the SmartOs wearable active orthosis was initiated with the analysis of another ankle-foot orthosis – Exo-H2 (Technaid) – from which the necessary design changes were implemented, aiming at the improvement of the established device. In order to achieve a conceptual solution, both the practical knowledge of the Orthos XXI design team and several design methods were used to ensure the accomplishment of the defined requirements. The detailed design process of the standard SmartOs wearable active orthosis prototype is disclosed. With the purpose of validating the design, the critical components were simulated with the resources available in SolidWorks®, and the necessary CAD model’s adaptations were implemented to guarantee a reliable and safe design. The presented design is currently set for further production in Orthos XXI, followed by the mandatory mechanical tests.Portugal é o país da Europa ocidental com maior taxa de mortalidade por acidente vascular cerebral (AVC), sendo que, dos que sofrem acidentes vasculares cerebrais, 40% apresentam uma deficiência que pode manifestar-se por sequelas motoras, nomeadamente o pé pendente. Uma ortótese do tornozelo é recomendada frequentemente para acomodar passivamente esses problemas motores; no entanto, exoesqueletos ativos são também uma solução adequada para pacientes pós-AVC. Devido à alta complexidade da articulação do tornozelo humano, um dos problemas associados a esses dispositivos ativos é o desalinhamento que ocorre entre o dispositivo de reabilitação e a articulação humana, que é uma causa de forças parasitas, desconforto e dor. A presente dissertação de mestrado propõe o desenvolvimento de uma ortótese ativa do tornozelo ajustável e vestível, que seja capaz de resolver esse problema de desalinhamento relativo aos dispositivos ortóticos de membros inferiores disponíveis comercialmente. Este trabalho está integrado no projeto SmartOs - Smart, Stand-alone Active Orthotic System - projeto que propõe uma tecnologia robótica inovadora (wearable mobile lab) direcionada para a reabilitação da marcha. O projeto conceptual de uma versão padrão da ortótese ativa vestível do projeto SmartOs foi iniciado com a análise de outra ortótese do tornozelo – Exo-H2 (Technaid) - a partir da qual foram implementadas as alterações de projeto necessárias, visando o aprimoramento do dispositivo estabelecido. Para se chegar a uma solução conceptual, tanto o conhecimento prático da equipa de projeto da Orthos XXI como os diversos métodos de projeto foram utilizados para garantir o cumprimento dos requisitos definidos. O processo do desenho detalhado da versão padrão da ortótese ativa SmartOs será também divulgado. Com o objetivo de validar o projeto, os componentes críticos foram simulados com os recursos disponíveis no SolidWorks® e as adaptações necessárias do modelo CAD foram implementadas para garantir um projeto fidedigno e seguro. O projeto apresentado está atualmente em preparação para produção na empresa Orthos XXI, depois do qual se seguem os ensaios mecânicos obrigatórios

Desarrollo de un guante ortótico para proveer asistencia en la extensión de los dedos a pacientes que han sufrido derrame cerebral

An externally actuated glove, controlled by a microprocessor, is being developed to assist fi nger extension in stroke survivors. The goal of this device is to allow repeated practice of specifi c tasks for hand therapy in the home environment. The device allows the user three control modes: voice recognition, electromyography or manual. These modes can be used either independently or combined according to the needs of the user. Both position and force feedback are available for control and safety. Initial testing of the prototype has shown promising performance.Se presenta el desarrollo de un guante activado externamente y controlado por un microprocesador para asistir la extensión de los dedos en pacientes con derrame cerebral. La meta del dispositivo es permitir la repetición de tareas específi cas para realizar terapia de la mano en un ambiente casero. El usuario puede controlar el dispositivo por tres medios diferentes: reconocimiento de voz, electromiografía o manualmente. Estos medios pueden ser usados tanto independientemente como en combinación según las necesidades del paciente. Para el control y la seguridad, se tiene retroalimentación de posición y de fuerza. Las pruebas iniciales del prototipo han demostrado un desempeño prometedo

Role of Gait Training in Recovery of Standing and Walking in Subjects with Spinal Cord Injury

Gait training has an important role in rehabilitation of standing and walking in spinal cord injury (SCI) patients. There were different types of gait training in these subjects. Both the body weight support treadmill training and robotic-assisted and robotic exoskeleton are effective and secure methods for gait training and improving the energy demand and metabolic cost in SCI patients in different level of injury. The powered exoskeletons can provide patients with SCI the ability to walk with the lowest energy consumption. The powered exoskeleton’s energy consumption and speed of walking depend on the training duration. Based on different types of gait training methods, training time, and other affected parameters, the aim of this chapter was to evaluate the role of gait training in recovery of standing and walking in SCI patients

Home-based rehabilitation of the shoulder using auxiliary systems and artificial intelligence: an overview

Advancements in modern medicine have bolstered the usage of home-based rehabilitation services for patients, particularly those recovering from diseases or conditions that necessitate a structured rehabilitation process. Understanding the technological factors that can influence the efficacy of home-based rehabilitation is crucial for optimizing patient outcomes. As technologies continue to evolve rapidly, it is imperative to document the current state of the art and elucidate the key features of the hardware and software employed in these rehabilitation systems. This narrative review aims to provide a summary of the modern technological trends and advancements in home-based shoulder rehabilitation scenarios. It specifically focuses on wearable devices, robots, exoskeletons, machine learning, virtual and augmented reality, and serious games. Through an in-depth analysis of existing literature and research, this review presents the state of the art in home-based rehabilitation systems, highlighting their strengths and limitations. Furthermore, this review proposes hypotheses and potential directions for future upgrades and enhancements in these technologies. By exploring the integration of these technologies into home-based rehabilitation, this review aims to shed light on the current landscape and offer insights into the future possibilities for improving patient outcomes and optimizing the effectiveness of home-based rehabilitation programs.info:eu-repo/semantics/publishedVersio