Adaptive neural fault-tolerant prescribed performance control of a rehabilitation exoskeleton for lower limb passive training.

This article studies the passive tracking problem of a wearable exoskeleton for lower limb rehabilitation therapy in the face of unmodeled dynamics, interactive friction, disturbance, prescribed performance constraints, and actuator faults. Adaptive neural networks and a smooth performance function are incorporated to establish a novel fault-tolerant tracking scheme, which can not only compensate for the nonlinear uncertainties and disturbance, but also handle the actuator fault with guaranteed tracking performance. A state feedback controller is presented by using the full state information and an output feedback controller is developed when the angular velocity is unavailable. The differential explosion issue of the backstepping technique is resolved by constructing a first-order filter and the unmeasurable velocity is estimated by a nonlinear observer. Semiglobal uniform boundedness stabilities of the exoskeleton system are proved via the Lyapunov direct method. The tracking performances of the designed control approaches are tested by comparative simulations.

Robustness and Tracking Performance Evaluation of PID Motion Control of 7 DoF Anthropomorphic Exoskeleton Robot Assisted Upper Limb Rehabilitation.

Upper limb dysfunctions (ULD) are common following a stroke. Annually, more than 15 million people suffer a stroke worldwide. We have developed a 7 degrees of freedom (DoF) exoskeleton robot named the smart robotic exoskeleton (SREx) to provide upper limb rehabilitation therapy. The robot is designed for adults and has an extended range of motion compared to our previously designed ETS-MARSE robot. While providing rehabilitation therapy, the exoskeleton robot is always subject to random disturbance. Moreover, these types of robots manage various patients and different degrees of impairment, which are quite impossible to model and incorporate into the robot dynamics. We hypothesize that a model-independent controller, such as a PID controller, is most suitable for maneuvering a therapeutic exoskeleton robot to provide rehabilitation therapy. This research implemented a model-free proportional-integral-derivative (PID) controller to maneuver a complex 7 DoF anthropomorphic exoskeleton robot (i.e., SREx) to provide a wide variety of upper limb exercises to the different subjects. The robustness and trajectory tracking performance of the PID controller was evaluated with experiments. The results show that a PID controller can effectively control a highly nonlinear and complex exoskeleton-type robot.

Diseño de Exoesqueleto con base en Cuatro Casos de Estudio de Rehabilitación de Miembro Superior / Design of an Exoskeleton based on Four Cases of Upper Limb Rehabilitation Study

Resumen: En este artículo se presenta un enfoque para rehabilitación pasiva de miembro superior mediante la formulación de cuatro casos de estudio haciendo un análisis de las patologías y los ejercicios que se aplican. Para llevar a cabo la experimentación en los casos propuestos se registraron los datos de las trayectorias de las articulaciones del brazo de un paciente realizando los ejercicios de rehabilitación con un terapeuta. Se diseñó el exoesqueleto ERMIS de siete grados de libertad para emular los movimientos anatómicos en el brazo durante la rehabilitación a partir de los requerimientos de los casos de estudio. Para validar el funcionamiento del exoesqueleto en los casos se simuló el modelo dinámico del ERMIS y se compararon los datos con los datos muestreados de los ejercicios. Al final se presentan los resultados obtenidos de los ejercicios realizados con el exoesqueleto, obteniendo en la precisión un desempeño promedio del 95% en los movimientos de hombro, codo y muñeca al emular la terapia con timón.

Abstract: This paper presents an approach for passive upper limb rehabilitation based on four case studies by analyzing the pathologies and exercises that are applied. To carry out the experimentation in the proposed cases, the data from the trajectories of the patient's arm articulations were registered, performing the rehabilitation exercises with a therapist. The ERMIS exoskeleton´s seven degrees of freedom was designed to emulate the anatomical movements in the arm during rehabilitation from the requirements of the case studies. To validate the exoskeleton performance in the study cases, the ERMIS's dynamic model was simulated and the data were compared with the sampled data of the exercises. At the end, the results obtained from exoskeleton exercises emulating rudder therapy, where shoulder, elbow and wrist movements were showed with an accuracy of 95%.

Analgesia of Femoral Nerve Block on Knee Stiffness in Rehabilitation Training after Surgery / 中国康复理论与实践

@#ObjectiveTo compare the effect of rehabilitation training after surgical intervention of knee stiffness (SIKS) between femoral nerve block (FNB) and epidural nerve block (ENB).Methods60 patients undergoing SIKS at one knee joint were randomly assigned to two groups: 40 patients accepting a catheter for FNB in group A and 20 patients accepting a catheter for ENB in group B. All patients participated in passive rehabilitation therapy (PRT) and active rehabilitation therapy (ART) at 12 hours, 24 hours, 36 hours, and 48 hours after operation. 10 ml of lidocaine were applied via these catheters before rehabilitation therapy. The visual analogue score (VAS) for pain in PRT, the time needed from the end of PRT to the start of ART, and the incidence of side effects such as hypotension or nausea were recorded.ResultsThere was no significant difference in VAS between groups A and B. The time needed from the end of PRT to the start of ART in group A was significantly less than that of group B. The incidence of hypotension or nausea in group A was significantly less than those of group B.ConclusionFNB provides the same analgesic effect as ENB, has less time needed from the end of PRT to the start of ART, and lowers incidence of hypotension or nausea.