Acquisition of Surface EMG Using Flexible and Low-Profile Electrodes for Lower Extremity Neuroprosthetic Control

Area of Science:

• Biomedical Engineering
• Prosthetics and Orthotics
• Rehabilitation Engineering

Background:

• Acquiring surface electromyography (sEMG) signals within prosthetic sockets is challenging for individuals with lower extremity (LE) amputations due to gait cycle dynamics.
• Existing sEMG solutions are often incompatible, uncomfortable, or costly, hindering clinical insights and advanced prosthesis control.
• High-quality sEMG data is crucial for understanding amputation effects and developing sophisticated control strategies for active LE prostheses.

Purpose of the Study:

• To introduce and evaluate a novel flexible, low-profile electrode for within-socket sEMG acquisition.
• To compare the performance and comfort of the new Sub-Liner Interface for Prosthetics (SLIP) electrode against commercial electrodes.
• To assess the feasibility of the SLIP electrode system for real-time sEMG data collection in ambulatory amputees.

Main Methods:

• Compared the SLIP electrode's sEMG signal quality with commercial Ag/AgCl electrodes in non-amputee subjects.
• Implemented the SLIP electrode system in a unilateral transtibial amputee during unconstrained movements and level-ground walking.
• Utilized a quantitative questionnaire to assess subjective comfort levels for both SLIP and commercial electrode setups.

Main Results:

• Quantitative analysis indicated comparable sEMG signal quality between the SLIP and Ag/AgCl electrodes.
• Qualitative analysis demonstrated the feasibility of the SLIP electrode for real-time sEMG acquisition in load-bearing, ambulatory amputees.
• The novel SLIP electrode system showed potential for improved comfort compared to existing solutions.

Conclusions:

• The SLIP electrode presents a viable alternative for within-socket sEMG acquisition in lower extremity prosthetics.
• This technology can facilitate better understanding of LE amputation and enhance control of active prostheses.
• The SLIP electrode offers a promising, comfortable, and potentially cost-effective solution for prosthetic research and application.