[Abstract] Development of a soft cable-driven hand exoskeleton for assisted rehabilitation training

Abstract

Purpose

Hand motor dysfunction has seriously reduced people’s quality of life. The purpose of this paper is to solve this problem; different soft exoskeleton robots have been developed because of their good application prospects in assistance. In this paper, a new soft hand exoskeleton is designed to help people conduct rehabilitation training.

Design/methodology/approach

The proposed soft exoskeleton is an under-actuated cable-driven mechanism, which optimizes the force transmission path and many local structures. Specifically, the path of force transmission is optimized and cables are wound around cam-shaped spools to prevent cables lose during fingers movement. Besides, a pre-tightening system is presented to adjust the preload force of the cable-tube. Moreover, a passive brake mechanism is proposed to prevent the cables from falling off the spools when the remote side is relaxed.

Findings

Finally, three control strategies are proposed to assist in rehabilitation training. Results show that the average correlation coefficient of trajectory tracking is 90.99% and this exoskeleton could provide steady clamping force up to 35 N, which could meet the demands of activities in daily living. Surface electromyography (sEMG)-based intention recognition method is presented to complete assistance and experiments are conducted to prove the effectiveness of the assisted grasping method by monitoring muscle activation, finger angle and interactive force.

Research limitations/implications

However, the system should be further optimized in terms of hardware and control to reduce delays. In addition, more clinical trials should be conducted to evaluate the effect of the proposed rehabilitation strategies.

Social implications

May improve the ability of hemiplegic patients to live independently.

Originality/value

A novel under-actuated soft hand exoskeleton structure is proposed, and an sEMG-based auxiliary grasping control strategy is presented to help hemiplegic patients conduct rehabilitation training.

Source: https://www.emerald.com/insight/content/doi/10.1108/IR-06-2020-0127/full/html

[WEB SITE] A new grasp on robotic glove

Having achieved promising results in proof-of-concept prototyping and experimental testing, a soft robotic glove under development by Conor Walsh and a team of engineers at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and Wyss Institute for Biologically Inspired Engineering could someday help people suffering from loss of hand motor control regain some of their independence.

Most patients with partial or total loss of their hand motor abilities due to muscular dystrophy, amyotrophic lateral sclerosis (ALS), or incomplete spinal cord injury report a greatly reduced quality of life because of their inability to perform many activities of daily living. Tasks often taken for granted by the able-bodied — buttoning a shirt, picking up a telephone, using cooking and eating utensils — become frustrating, nearly impossible feats due to reduced gripping strength and motor control.

The stage is now set for that to change, however, thanks to Walsh’s expertise in soft, wearable robotic systems and a development approach that involves the glove’s potential end users in every step of testing and development. The holistic approach ensures that technology development goes beyond simple functionality to incorporate social and psychological elements of design that promote seamless adoption by its end users.

Continue —> A new grasp on robotic glove | Harvard Gazette.