Study on resistance training for upper-limb rehabilitation using an exoskeleton device

Rehabilitation robotics has received more and more attention during the last decades, especially the exoskeleton device for the upper limb rehabilitation, but most of them are heavy and large. In our study, a light and wearable exoskeleton device was proposed, which can be used in home rehabilitation and it can also be used to implement passive and active training. In this paper, we proposed to perform the active rehabilitation based on the upper limb exoskeleton rehabilitation device (ULERD) with variable stiffness elastic actuators, which improves the safety for human-robot interaction and produces adjustable stiffness capacity and resistance training to meet the demand for safe active-passive elbow rehabilitation. It provides a wide approach for human machine interface (HMI) in which the device is non-backdrivable, and at the same time it is difficult to obtain the contact force information directly. The proposed method was verified by the experiments conducted under two conditions with passive DoFs unlocked and with passive DoFs locked during elbow flexion and extension performance. Each experiment has three level resistances provided to the user. The surface electromyography (sEMG) signals derived from biceps and triceps were used to evaluate the efficacy of this method in both experiments.