Electromyogram analysis and electrical stimulation control of paralysed wrist and hand

Area of Science:

• Biomedical Engineering
• Neurorehabilitation
• Rehabilitative Medicine

Background:

• Restoring paralyzed hand function requires precise control of joint angles, speed, and power for grasping.
• Functional electrical stimulation (FES) is a key technology for enabling movement in individuals with paralysis.
• Existing FES methods need refinement for effective restoration of complex hand and wrist functions.

Purpose of the Study:

• To develop and evaluate standard FES patterns derived from electromyogram (EMG) analysis for restoring hand and wrist functions in quadriplegics.
• To assess the efficacy of EMG-derived FES patterns in achieving functional joint positions and grasping capabilities.
• To investigate methods for controlling joint angle and motion speed using FES.

Main Methods:

• Collected EMG data from 15 healthy subjects performing hand and wrist movements.
• Developed standard FES patterns based on the analyzed EMG data.
• Applied these FES patterns to C4 and C5 quadriplegic subjects to stimulate hand muscles.
• Adjusted stimulation parameters (voltage, reading speed) to control joint angle and motion speed.

Main Results:

• EMG-derived FES patterns successfully induced wrist joint fixation in functional positions.
• Stimulation enabled grasping movements comparable to those of healthy individuals.
• Controlling stimulation voltage and reading speed allowed for precise adjustment of joint angle and motion speed.
• The method demonstrated significant restoration of hand and wrist joint functions.

Conclusions:

• EMG-derived FES patterns are effective in restoring hand and wrist functions for C4 and C5 quadriplegics.
• This approach successfully enables grasping and supports the resumption of some normal daily activities.
• The developed FES method offers a promising avenue for improving the quality of life for individuals with paralysis.