Development of a closed-loop controller for functional electrical stimulation therapy plus visual feedback balance
Jae W Lee1, Emerson Grabke1, Kelvin Chow1
1Institute of Biomedical Engineering, University of Toronto, 164 College St., Toronto, ON, M5S 3G9, Canada; KITE-Toronto Rehabilitation Institute, University Health Network, 520 Sutherland Dr., Toronto, ON, M4G 3V9, Canada.
Medical Engineering & Physics
|October 20, 2024
Summary
This study developed a novel system combining functional electrical stimulation (FES) with visual feedback balance training (VFBT) to improve balance in individuals with incomplete spinal cord injury (iSCI). The system
Area of Science:
- Neuroscience
- Rehabilitation Engineering
- Biomechanics
Background:
- Individuals with incomplete spinal cord injury (iSCI) experience significant balance impairments and increased fall risk.
- Task-specific visual feedback balance training (VFBT) and functional electrical stimulation (FES) therapy are known to improve motor function and balance individually.
- Combining these therapies may offer synergistic benefits for balance recovery in iSCI.
Purpose of the Study:
- To develop and evaluate a novel system integrating FES with VFBT (FES+VFBT) for enhancing upright balance control.
- To design a controller for the FES+VFBT system that delivers physiologically relevant electrical stimulation to key leg muscles.
- To assess the controller's ability to mimic natural muscle activation patterns during balance tasks.
Main Methods:
- A new FES+VFBT system was developed, delivering electrical stimulation to the soleus (SOL) and tibialis anterior (TA) muscles during VFBT.
- Kinematic, kinetic, and electromyography (EMG) data from able-bodied individuals performing balance tasks were used to design the FES controller.
- Controller outputs (stimulation intensities) were compared with recorded SOL and TA EMG to validate physiological relevance.
Main Results:
- The controller demonstrated high correlation between its output and recorded SOL and TA EMG during most VFBT tasks (excluding the bullseye task).
- This suggests the controller can generate electrical stimulation patterns that align with natural muscle activation during balance exercises.
- The developed system shows promise for delivering targeted muscle stimulation during balance training.
Conclusions:
- The FES+VFBT system is a viable approach for delivering physiologically relevant muscle stimulation during balance training.
- This combined therapy has the potential to synergistically improve standing balance in individuals with iSCI.
- Further research is warranted to confirm the efficacy of FES+VFBT in clinical populations with iSCI.
