A Compositional Calibration Framework for Multi-Channel Functional Electrical Stimulation Enabling Hand Gesture...

Area of Science:

• Rehabilitation Engineering
• Neuroprosthetics
• Biomechanics

Background:

• Restoring hand motor function with functional electrical stimulation (FES) is challenging due to difficulties in calibrating multi-channel stimulation for coordinated movements.
• Existing methods struggle to precisely control individual finger actions and combine them into functional gestures.

Purpose of the Study:

• To propose and validate a compositional FES calibration framework for customizing isolated finger actions and combining them into functional hand gestures.
• To assess the effectiveness of this framework in achieving coordinated multi-finger control.

Main Methods:

• A two-session experimental study involving 13 participants.
• Session 1: Subject-specific stimulation sites and parameters identified for 8 individual finger movements using a spatial grid.
• Session 2: Combination of isolated movements to generate 7 hand gestures in 5 participants.

Main Results:

• 10 out of 13 participants achieved at least 6 movements; 3 achieved all targeted motions.
• Individual finger movements were generally well-isolated, with challenges noted for thumb and ring/little finger extensions.
• Individually calibrated activations successfully combined to produce coordinated multi-finger movements matching expected patterns.

Conclusions:

• Preliminary results support compositional calibration strategies for achieving functional multi-finger control with multi-channel FES.
• This approach offers a promising avenue for enhancing hand function restoration in individuals with motor impairments.