Ambulation after incomplete spinal cord injury with electromyogram-triggered functional electrical stimulation

Area of Science:

• Biomedical Engineering
• Neurorehabilitation
• Spinal Cord Injury Research

Background:

• Ambulation is a critical goal for individuals with spinal cord injury (SCI).
• Functional electrical stimulation (FES) offers a promising assistive technology for restoring gait.
• Incomplete spinal cord injury (iSCI) presents unique challenges due to residual volitional control.

Purpose of the Study:

• To investigate the use of surface electromyogram (sEMG) to detect stepping intent in iSCI.
• To integrate sEMG-based intent detection with FES for a coordinated walking system.
• To evaluate the efficacy of an sEMG-triggered FES system for FES-assisted ambulation.

Main Methods:

• Utilized an 8-channel implanted stimulation system for FES.
• Recorded surface electromyogram (sEMG) from the Erector Spinae muscle to infer stepping intent.
• Developed an inference system to trigger FES-assisted swing-phase of gait during overground walking.

Main Results:

• The sEMG inference system accurately detected stepping intent in a volunteer with iSCI.
• The system successfully triggered FES-assisted gait with a low false positive rate of 1%.
• Demonstrated effective coordination between volitional and stimulated muscle activity.

Conclusions:

• sEMG-based intent detection provides a natural command interface for FES-assisted walking.
• This approach offers improved coordination compared to traditional manual switches.
• Highlights potential for enhanced FES-assisted community ambulation for individuals with iSCI.