Embroidered archimedean spiral electrodes for contactless prosthetic control

Area of Science:

• Biomedical Engineering
• Rehabilitation Technology
• Wearable Sensors

Background:

• Electromyography (EMG) is crucial for prosthetic control but susceptible to signal degradation from sweat and sensor movement.
• Skin-contact-based EMG faces challenges in maintaining signal quality and user comfort over time.
• Advancements in active prosthetics necessitate improved methods for detecting user intention.

Purpose of the Study:

• To evaluate Archimedean Spiral (AS) electrodes as a non-contact alternative to traditional EMG sensors.
• To assess the feasibility of integrating AS electrodes into textile layers for prosthetic applications.
• To compare the performance of AS electrodes against conventional EMG electrodes in detecting muscle activation.

Main Methods:

• Developed and tested Archimedean Spiral (AS) electrodes in textile layers, with and without a non-conductive barrier.
• Recorded muscle activation signals from the extensor digitorum muscle group during loaded wrist extension in 9 volunteers.
• Compared signal amplitude and noise levels between AS electrodes and traditional EMG electrodes.

Main Results:

• AS electrodes successfully detected muscular activation without direct skin contact.
• The AS electrode design demonstrated potential for improved signal quality compared to traditional EMG under tested conditions.
• Signal analysis indicated the feasibility of using AS electrodes in a non-contact configuration.

Conclusions:

• Archimedean Spiral electrodes offer a viable, non-contact method for detecting muscle activation, addressing key limitations of traditional EMG.
• This technology presents a low-cost alternative for integration into prosthetic sockets, potentially reducing user adaptation issues.
• The findings support the development of more robust and user-friendly prosthetic control systems.