Comparative study of HD-EMG electrode setups for Smart Mechatronic Ankle-Foot Orthoses development.

Area of Science:

• Biomedical Engineering
• Rehabilitation Technology
• Human-Machine Interfaces

Background:

• Smart ankle-foot orthoses (AFOs) utilize advanced interfaces to improve mobility assistance and rehabilitation.
• High-density electromyography (HD-EMG) offers potential for sophisticated control but faces challenges in signal quality and sensor integration.
• Optimizing electrode configuration is crucial for effective integration into AFOs.

Purpose of the Study:

• To evaluate various HD-EMG electrode configurations for signal quality in the context of AFO development.
• To identify electrode designs that enhance signal-to-noise ratio and stability for improved AFO functionality.
• To compare the performance of conventional versus printed electrode technologies for AFO applications.

Main Methods:

• HD-EMG arrays were applied to the tibialis anterior and gastrocnemius medial muscles of 4 healthy participants.
• Signal quality was analyzed during dorsiflexion and plantarflexion movements.
• Performance metrics included signal-to-noise ratio and signal stability for different electrode sizes and types (conventional vs. printed).

Main Results:

• Electrodes with smaller sensor surface areas and reduced interelectrode distances yielded higher signal-to-noise ratios and more stable signals.
• Conventional electrodes outperformed flexible printed electrodes in terms of signal quality, despite printed electrodes offering greater comfort.
• Printed electrodes demonstrated lower performance, indicating a need for material and interface advancements.

Conclusions:

• Smaller, densely packed HD-EMG sensors are preferable for enhancing signal quality in smart AFOs.
• Further investigation into novel printed electrode materials and designs is required to balance comfort with robust signal acquisition for AFOs.
• This research provides critical insights for designing next-generation HD-EMG-integrated AFOs for mobility rehabilitation.