A Finger Rehabilitation Exoskeleton: Design, Control, and Performance Evaluation

Finger impairment is a common challenge in post-stroke patients which leads to the loss of hand function. To regain normal movement abilities, rehab exercise is essential in the recovery process and rehab robots can play a key role to facilitate physical therapy especially for post-stroke patients. In this paper, a finger exoskeleton is developed to assist the three essential passive rehabilitation training. The desired finger joint trajectories for three rehab exercises were determined. A novel mechanism with two degrees of freedom (DOF) was then designed and fabricated for assistive training. A position control was finally implemented that satisfies the motion characteristics of the finger. The device performance was then verified experimentally. The tests were conducted on two post-stroke subjects with finger lengths of 60 and 90 mm to evaluate the kinematics and control attributes of the exoskeleton. The results indicated that the exoskeleton provides good kinematic compatibility to the human finger within a wide range of motion (ROM). Furthermore, the paths traced by the exoskeleton’s joints were in good agreement with the desired joint trajectory.