Mechatronic Hand Exoskeleton for Rehabilitation after Stroke

Abstract

The article presents the results of the development of a prototype of a functional layout of a soft exoskeleton of the hand, which is part of a robotic complex for restoring the function of the upper limb of patients after a stroke. The use of the layout will allow for therapy based on a mixed approach, which implements both assistance in carrying out independent movements of the patient’s hand, and their full implementation using data on its movement recorded during rehabilitation procedures. The authors of the manuscript present a comparative and quantitative analysis of two options for laying a cable system that drives the patient’s hand and fingers. To determine the best option for laying cables, a parametric study of the amount of work performed and the bending time of one finger was carried out, depending on the options for laying with and without taking into account the load. In the first variant, the cables were laid with small stitches of the order of one centimeter along the lower surface of the finger. In the second variant, the cable passed through the glove in places of natural attachment of tendons to bones. Testing was carried out on the index finger of a relaxed healthy person. At the initial moment of time, the hand occupied a position along the body, the fingers were completely unclenched, while a load was fixed on the distal phalanx. The flexion time of the finger was determined by a touch sensor attached to the palm of the hand. The results of experimental studies showed that cables with a minimum number of attachment points to the base of the exoskeleton in places of natural attachment of tendons to the bone give maximum effort and ensure the achievement of the largest range of possible positions of the phalanges of the fingers. The results of studies of the developed efforts on the part of the device on the fingers of a healthy person are also presented, which allow us to conclude that it can be used for rehabilitation purposes.