Design of a Rope-Driven Finger Exoskeleton System with a Universal Double Grooved Roller for Adaptive Rehabilitation

Impaired hand function caused by neurological conditions, such as stroke, severely limits individuals' ability to perform daily tasks, highlighting the importance of accessible rehabilitation devices. Although the double grooved roller design in existing rope-driven exoskeletons reduces weight and enhances compactness, the different amount of change in the upper and lower traction cords when the fingers are flexed and torsioned can easily lead to slack and slippage of the traction cords, which affects the accuracy of movement. To address these limitations, a rope-driven exoskeleton system with a universal double grooved roller is designed for assisting finger movement based on a study of the index finger. In order to enhance the universal performance of the exoskeleton, in this study, 40 groups of index finger flexion and extension movements with upward and downward stretching are collected and statistically analyzed to find out the universal ratio of double grooved rollers. The experiment tested the finger-driving capability of the exoskeleton device, achieving a range of motion up to 94% of unassisted natural motion, with stable performance during repetitive movements. Additionally, the finger-driving success rate for seven subjects with varying finger sizes reached 100%, and the test results were analyzed in detail. The designed system demonstrates feasibility, reliability, and universality, offering a viable new solution for adaptive hand rehabilitation.