Bioinspired Musculoskeletal Model-based Soft Wrist Exoskeleton for Stroke Rehabilitation

Ning Li,Peng Yu,Lianqing Liu,Imad H Elhajj,Tie Yang,Guoli Song,Yang Yang,Wenxue Wang,Xiujuan Xue,Xingang Zhao,Ning Xi

doi:10.1007/s42235-020-0101-9

Abstract

Exoskeleton robots have demonstrated the potential to rehabilitate stroke dyskinesia. Unfortunately, poor human-machine physiological coupling causes unexpected damage to human of muscles and joints. Moreover, inferior humanoid kinematics control would restrict human natural kinematics. Failing to deal with these problems results in bottlenecks and hinders its application. In this paper, the simplified muscle model and muscle-liked kinematics model were proposed, based on which a soft wrist exoskeleton was established to realize natural human interaction. Firstly, we simplified the redundant muscular system related to the wrist joint from ten muscles to four, so as to realize the human-robot physiological coupling. Then, according to the above human-like musculoskeletal model, the humanoid distributed kinematics control was established to achieve the two DOFs coupling kinematics of the wrist. The results show that the wearer of an exoskeleton could reduce muscle activation and joint force by 43.3% and 35.6%, respectively. Additionally, the humanoid motion trajectories similarity of the robot reached 91.5%. Stroke patients could recover 90.3% of natural motion ability to satisfy for most daily activities. This work provides a fundamental understanding on human-machine physiological coupling and humanoid kinematics control of the exoskeleton robots for reducing the post-stroke complications.

Highlights

Robotic-aided neuro-rehabilitation is a clinically viable option to improve rehabilitation outcomes for stroke dyskinesia[1,2] which can assist 90% of patients to regain motion ability[3]
These results demonstrate that the simplified muscle model enables the human run in a low-power state without harm to the physiological structure
To verify the simplified muscle model and kinematics models, wrist flexion/extension, wrist adduction/abduction and circular motions were carried on the physical humanoid platform as shown in Figs. 5g and 5h

Summary

Introduction

Robotic-aided neuro-rehabilitation is a clinically viable option to improve rehabilitation outcomes for stroke dyskinesia[1,2] which can assist 90% of patients to regain motion ability[3]. Exoskeleton robot for wrist rehabilitation could effectively improve rehabilitative outcomes. The problems of rigid exoskeletons, such as poor dynamic responses and misalignment of the motion axes, limit its application in the wrist joint. The UHD only can assist joints to move the horizontal plane, which cannot meet the normal range of ADLs. the UHD only can assist joints to move the horizontal plane, which cannot meet the normal range of ADLs This limitation was overcome by a wrist exoskeleton, RiceWrist[15,16].

Methods

Results

Conclusion