A Flexible Pulse Generator Based on a Field Programmable Gate Array Architecture for Functional Electrical...

Area of Science:

• Biomedical Engineering
• Rehabilitation Technology
• Neuroscience

Background:

• Non-invasive Functional Electrical Stimulation (FES) aids motor rehabilitation after central nervous system injury.
• Current FES systems often use microcontrollers with fixed architectures, limiting parameter control and scalability.
• Existing FPGA-based FES systems have limitations in parameter flexibility for non-invasive applications.

Purpose of the Study:

• To develop a flexible FPGA-based pulse generator for non-invasive FES applications (PG-nFES).
• To demonstrate the technical feasibility and potential of the PG-nFES system.
• To verify the system's capability for upper limb FES applications.

Main Methods:

• Developed a flexible FPGA-based pulse generator (PG-nFES).
• Performed electrical characterization of stimulation parameters (amplitude, pulse width, frequency).
• Implemented a six-channel version to demonstrate scalability and tested parameter independence.
• Verified system functionality with upper limb functional movements.

Main Results:

• Achieved highly linear (r² > 0.9998) and repeatable (>0.81) biphasic stimulation pulses.
• Demonstrated low average percentage error (<3% for amplitude/pulse width, 0% for frequency).
• Successfully implemented and verified a six-channel system for upper limb FES, including co-modulation patterns.

Conclusions:

• The FPGA-based PG-nFES offers a flexible and scalable solution for non-invasive FES.
• The system enables precise control and modulation of stimulation parameters, crucial for effective motor rehabilitation.
• This proof-of-concept validates the potential of the PG-nFES for advanced FES applications.