EMG-BASED BIOMECHANICAL AND MOLECULAR BIOMARKER ASSESSMENT OF ROBOT-ASSISTED UPPER LIMB REHABILITATION

Abstract

The increasing scarcity of therapists and caregivers for individuals with physical disability underscores the need for readily available, home-based rehabilitation options. To address this aspect, this study introduces a compact and versatile two-degree-of-freedom planar manipulator specifically designed to aid in upper limb rehabilitation, with a focus on the shoulder and elbow joints. The manipulator can be used for both tabletop and vertical configuration with simplified set-up. Forward and inverse kinematics were mathematically derived to govern the movements of the manipulator to enable the execution of common physiotherapy exercises- characterized by straight lines, L-shapes, arcs, circles and loops. The motion of the simulated manipulator was validated using Robo Analyzer, where trajectory paths generated in Python were used to simulate typical exercise patterns. Experimental trials were conducted to replicate fundamental upper limb movements, including shoulder flexion/extension and abduction/adduction, as well as elbow flexion/extension. Furthermore, integrated electromyography (EMG) and force sensors facilitate the automated detection of patient interaction and movement. The tabletop configuration yielded experimental results showing shoulder flexion ranging from 0° to approximately 180°, shoulder extension to around 35°, and elbow flexion reaching approximately 150°. It should be noted that extension is limited to 0° due to the design focused on elbow rehabilitation. In the vertical configuration, the manipulator achieved shoulder extension of 60°, elbow hyperextension of approximately -5°, shoulder abduction from 0° to 180°, and shoulder adduction to 75°. These findings prove that the manipulator can assist a broad range of upper limb rehabilitation exercises, which is potentially an economical and feasible assistive device that can be used by the patient in both domestic and clinical locations.