Design, simulation, and experimental evaluation of a light weight, and wearable cable driven ForeWrist exoskeleton robot for assistance and rehabilitation

Abstract

Injuries and diseases such as wrist nerve injuries, stroke, neurological disorders, and other wrist-related conditions have significantly impacted people’s quality of life. This study aims to develop a lightweight, affordable, and portable ForeWrist (forearm and wrist) exoskeleton. This device is intended to assist and rehabilitate individuals with wrist disabilities, mainly stroke survivors, to enhance wrist range of motion and strength. The device can offer one active degree of freedom (DOF) responsible for pronation-supination (PS) of the forearm and two passive DOFs for the wrist joint. The design of the ForeWrist PS mainly consists of a cable-driven C-shaped guide rail and stationary bearing-carriage mechanism that can be attached to the user’s wrist. The simulation and experimental analysis are conducted for the design validation and performance analysis. The experimental results indicate that the designed device should demonstrate promising potential for practical applications. The root mean squared error for joint position and velocity exhibit low values, and the peak torque for an average weight of the human lower arm was found to be under 10% of the device’s total capacity. The developed exoskeleton provides a full range of motion for daily activities and covers 75% of the forearm’s total range of motion with a consistency error of less than \(1^\circ \). The device can be effective for both at home and outdoor assistance and rehabilitation training with its low weight of 300 g and peak velocity and torque of 70 deg/sec and 6 Nm, respectively.