Haptic Interface for Finger Exercise and Virtual Rehabilitation

A haptic device with two active degrees of freedom and a tendon driven transmission system was designed, built and tested. It was constructed as a lightweight mechanism with a small workspace that wraps a finger workspace and can generate forces up to 10 N suitable for finger exercise. The control loop and user application were implemented on a personal computer within the MS Windowsreg environment. Together with the device an application including several different experiment types has been developed. The system has been evaluated in group of stroke patients during a one month therapy. The results for two experiment types are presented. The progression of the affected hand side for patients is observed to be higher than for nonaffected side but on the contrary the mean values of the relevant parameters at nonaffected side for patients are higher than for affected side

I. Introduction

Finger movement control together with grasping are the most meaningful and pretentious humans motion activities [1] [2] [3]. This is reflected in many daily living activities connected first to a motion ability of fingers e.g. grasping, picking up, and second to a grip force control e.g. holding objects, pushing buttons. Beside a reliable and stable grip, also a coordination of a finger move and force is needed [4] [5]. A good interconnection between a central neural system – CNS and muscles is necessary for motion and force coordination [5]. Persons with damaged CNS or after hand and finger injuries of skeletal or neuromuscular sistem, has limited hand functionality which causes an activity limitation in everyday life. A hand functionality assessment is used as a basis for a therapy prescription in a diagnostics and rehabilitation.