Towards Clinical Implementation of an FES&Exoskeleton to Rehabilitate the Upper Limb in Disabled Patients

Abstract

Robotics rehabilitation is a research field that involves robotic devices adapted to assist various sensory-motor functions, to assist therapy and to evaluate the sensory-motor performance. Rehabilitation robots are catching popularity among patients and are generally well tolerated. This paper presents the development and the control structure of an exoskeleton designed as a tool for rehabilitation of the upper limb in disabled people. The system uses a combined control method to facilitate the upper arm movements using electrical drives and functional electrical stimulation (FES). The mechanical structure is lightweight, robust and it has four degrees of freedom. A software interface was designed in order to integrate the control of both systems: the electrical drives and functional electrical stimulation responsible for the muscle contraction. The exoskeleton can be controlled either in a direct loop or in a closed loop. The position references are obtained from potentiometers with linear characteristic which are mounted on the gear shafts of the DC motors. The exoskeleton was tested in vivo on healthy subjects showing good premises for initiating the clinical tests.