Design and Analysis of the M3Rob: A Robotic Platform for Wrist and Hand Rehabilitation

Physical therapy plays a crucial role in the motor recovery. Rehabilitation robots have emerged as significant advancement, enabling repetitive therapeutic interventions in both clinical and home settings. In this context, the development of a highly functional, reliable, portable, and cost-effective mechatronic systems for wrist and hand rehabilitation represents a significant step in the field. This article focused on the design and implementation of the M3Rob device, a 3-DoF wrist exoskeleton equipped with a force sensor, allowing for the execution of active therapies, recognized for their effectiveness in motor recovery. Hence, a close-loop admittance control utilizing a joint-space target trajectory as input is presented and experimentally evaluated across three distinct levels of assistance. Moreover, to address the need for rehabilitation targeting activities of daily living, the device enables the incorporation of a hand exoskeleton for simultaneously performing hand and wrist rehabilitation. Featuring a range of motion of 180° for pronation/supination, 120° for flexion/extension, and 75° for ulnar/radial deviation, in combination with joint torques spanning from 7.85 to 43.86 Nm, the device covers the required motions and forces essential for daily activities. The presented device offers a comprehensive solution for wrist and hand rehabilitation, effectively addressing critical challenges in motor recovery.