Robot Assisted Shoulder Rehabilitation: Biomechanical Modelling, Design and Performance Evaluation

The upper limb rehabilitation robots have made it possible to improve the motor recovery in stroke survivors while reducing the burden on physical therapists. Compared to manual arm training, robot-supported training can be more intensive, of longer duration, repetitive and task-oriented. To be aligned with the most biomechanically complex joint of human body, the shoulder, specific considerations have to be made in the design of robotic shoulder exoskeletons. It is important to assist all shoulder degrees-of-freedom (DOFs) when implementing robotic exoskeletons for rehabilitation purposes to increase the range of motion (ROM) and avoid any joint axes misalignments between the robot and human’s shoulder that cause undesirable interaction forces and discomfort to the user. The main objective of this work is to design a safe and a robotic exoskeleton for shoulder rehabilitation with physiologically correct movements, lightweight modules, self-alignment characteristics and large workspace. To achieve this goal a comprehensive review of the existing shoulder rehabilitation exoskeletons is conducted first to outline their main advantages and disadvantages, drawbacks and limitations. The research has then focused on biomechanics of the human shoulder which is studied in detail using robotic analysis techniques, i.e. the human shoulder is modelled as a mechanism. The coupled constrained structure of the robotic exoskeleton connected to a human shoulder is considered as a hybrid human-robot mechanism to solve the problem of joint axes misalignments. Finally, a real-scale prototype of the robotic shoulder rehabilitation exoskeleton was built to test its operation and its ability for shoulder rehabilitation

ReHand - a portable assistive rehabilitation hand exoskeleton

This dissertation presents a synthesis of a novel underactuated exoskeleton (namely ReHand2) thought and designed for a task-oriented rehabilitation and/or for empower the human hand. The first part of this dissertation shows the current context about the robotic rehabilitation with a focus on hand pathologies, which influence the hand capability. The chapter is concluded with the presentation of ReHand2. The second chapter describes the human hand biomechanics. Starting from the definition of human hand anatomy, passing through anthropometric data, to taxonomy on hand grasps and finger constraints, both from static and dynamic point of view. In addition, some information about the hand capability are given. The third chapter analyze the current state of the art in hand exoskeleton for rehabilitation and empower tasks. In particular, the chapter presents exoskeleton technologies, from mechanisms to sensors, passing though transmission and actuators. Finally, the current state of the art in terms of prototype and commercial products is presented. The fourth chapter introduces the concepts of underactuation with the basic explanation and the classical notation used typically in the prosthetic field. In addition, the chapter describe also the most used differential elements in the prosthetic, follow by a statical analysis. Moreover typical transmission tree at inter-finger level as well as the intra- finger underactuation are explained . The fifth chapter presents the prototype called ReHand summarizing the device description and explanation of the working principle. It describes also the kinetostatic analysis for both, inter- and the intra-finger modules. in the last section preliminary results obtained with the exoskeleton are shown and discussed, attention is pointed out on prototype’s problems that have carry out at the second version of the device. The sixth chapter describes the evolution of ReHand, describing the kinematics and dynamics behaviors. In particular, for the mathematical description is introduced the notation used in order to analyze and optimize the geometry of the entire device. The introduced model is also implemented in Matlab Simulink environment. Finally, the chapter presents the new features. The seventh chapter describes the test bench and the methodologies used to evaluate the device statical, and dynamical performances. The chapter presents and discuss the experimental results and compare them with simulated one. Finally in the last chapter the conclusion about the ReHand project are proposed as well as the future development. In particular, the idea to test de device in relevant environments. In addition some preliminary considerations about the thumb and the wrist are introduced, exploiting the possibility to modify the entire layout of the device, for instance changing the actuator location

Impact of Ear Occlusion on In-Ear Sounds Generated by Intra-oral Behaviors

We conducted a case study with one volunteer and a recording setup to detect sounds induced by the actions: jaw clenching, tooth grinding, reading, eating, and drinking. The setup consisted of two in-ear microphones, where the left ear was semi-occluded with a commercially available earpiece and the right ear was occluded with a mouldable silicon ear piece. Investigations in the time and frequency domains demonstrated that for behaviors such as eating, tooth grinding, and reading, sounds could be recorded with both sensors. For jaw clenching, however, occluding the ear with a mouldable piece was necessary to enable its detection. This can be attributed to the fact that the mouldable ear piece sealed the ear canal and isolated it from the environment, resulting in a detectable change in pressure. In conclusion, our work suggests that detecting behaviors such as eating, grinding, reading with a semi-occluded ear is possible, whereas, behaviors such as clenching require the complete occlusion of the ear if the activity should be easily detectable. Nevertheless, the latter approach may limit real-world applicability because it hinders the hearing capabilities.</p

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

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