FES-Induced Cycling in Complete SCI: A Simpler Control Method Based on Inertial Sensors

Area of Science:

• Biomedical Engineering
• Rehabilitation Technology
• Neuroprosthetics

Background:

• Functional electrical stimulation (FES) is used to restore movement in individuals with paralysis.
• Current FES cycling systems often rely on complex crank angle sensors for stimulation timing.
• Adapting FES timing patterns to individual users and diverse cycling devices remains a challenge.

Purpose of the Study:

• To introduce a novel FES controller for cycling utilizing inertial measurement units (IMUs).
• To simplify the design of FES stimulation timing patterns.
• To develop an adaptable method for different users and cycling devices.

Main Methods:

• Utilized thigh inclination, measured by IMUs placed above each knee, as the primary input for stimulation timing.
• Implemented an IF-THEN rule algorithm to automatically detect thigh peak angles for online stimulation control.
• Targeted quadriceps muscle stimulation based on detected thigh inclination events.

Main Results:

• Successfully demonstrated FES-induced cycling using the novel thigh inclination-based controller.
• A single participant with complete paraplegia achieved propulsion of a recumbent trike.
• Required only a short setup time for the participant to effectively use the system.

Conclusions:

• The proposed IMU-based FES controller offers a simplified and user-friendly approach to FES cycling.
• This method allows for automatic design of stimulation patterns adaptable to various users and bike types.
• Paves the way for more accessible and clinically relevant FES cycling applications.