Robotic orthosis for bilateral rehabilitation of left hand for patients with hemiplegia

Abstract

This work describes the development of a mecha- tronic system to perform bilateral rehabilitation in stroke survivors with hemiplegia or movement difficulty in the left hand, based on mirror therapy. This kind of rehabilitation provides neurological feedback when the affected hand (left) mimics the unaffected hand (right) flexion/extension motion (biomechanics) of the fingers. This robotic system consists in one device for each hand. The first one identifies the range of motion (ROM) of all right hand fingers by measuring the resistance of flex sensors placed on each finger. The second device, an active orthosis, replicates the motion of all the fingers on the left hand driven by servomotors coupled in a mechanic system. The information of the flex, which establishes a relationship with the ROM of right hand fingers, are processed by an Arduino board and sent, by wireless communication, to another Arduino board that relates the received resistance value with the motion of the servomotors and the ROM of the impaired hand. Tests performed with five healthy subjects showed a movement replication of the fingers with 0.3ms delay and an average relative error of 6.77±5.01% in the ROM of the impaired hand compared with the healthy hand.