Optimal FES parameters based on mechanomyographic efficiency index

Area of Science:

• Biomedical Engineering
• Rehabilitation Technology
• Neuroscience

Background:

• Functional Electrical Stimulation (FES) aids movement in spinal cord injury (SCI) patients.
• Optimizing FES parameters is crucial to prevent muscle fatigue and neural adaptation.
• Mechanomyography (MMG) measures muscle oscillations during contraction.

Purpose of the Study:

• To develop and validate an MMG-based Efficiency Index (EI) for optimizing FES parameters.
• To identify the most effective FES electrical settings for eliciting functional movements in SCI subjects.

Main Methods:

• Developed an EI incorporating MMG Root Mean Square (RMS) and median frequency.
• Applied four FES profiles to ten healthy and three SCI volunteers.
• Monitored muscle responses and calculated EI over two FES sessions with rest intervals.

Main Results:

• The EI demonstrated an increasing trend throughout the testing period.
• The most efficient FES profile was identified as 1kHz pulse frequency, 200µs active pulse duration, and 50Hz burst frequency.
• This specific FES configuration showed superior performance in controlling functional movements.

Conclusions:

• The developed MMG-based EI is a viable tool for optimizing FES parameters.
• Specific FES settings (1kHz, 200µs, 50Hz) are most effective for controlled functional movements in SCI.
• This research contributes to improved FES control strategies for SCI rehabilitation.