A Wearable Multimodal Sensor for Simultaneous and Co-Located Muscle Electrophysiological and Mechanical Monitoring

Area of Science:

• Biomedical Engineering
• Wearable Technology
• Neuroscience

Background:

• Accurate neuromechanical coupling requires simultaneous electrical and mechanical muscle signal acquisition.
• Existing multi-device methods suffer from non-simultaneous recordings, spatial misalignment, and complex setups.
• These limitations hinder data integrity and complicate muscle monitoring.

Purpose of the Study:

• To develop a wearable multimodal sensor for simultaneous acquisition of surface electromyography (sEMG), surface muscle pressure (SMP), and mechanomyography (MMG).
• To address the limitations of existing methods by providing a single, integrated sensing solution.
• To enable robust and simplified muscle monitoring for research and clinical applications.

Main Methods:

• A novel wearable multimodal sensor utilizing a single sensing material and integrated structure was designed.
• The sensor simultaneously records sEMG, SMP, and mechanomyography (MMG) from the same anatomical location.
• System performance was evaluated for stability, reusability, signal-to-noise ratio (SNR), and mechanical characteristics (detection limit, pressure range, response time).

Main Results:

• The developed system achieved high SNR (27.4 dB) and reusability for electrophysiological recordings.
• Excellent mechanical performance was demonstrated with a low detection limit (≈25 Pa), broad pressure range (0-320 kPa), and fast response time (≈16 ms).
• System validation across exercise, fatigue, and rehabilitation scenarios confirmed its ability to robustly capture muscle neuromechanical dynamics.

Conclusions:

• This work presents a high-performance, simplified wearable platform for simultaneous muscle electrical and mechanical monitoring.
• The sensor overcomes previous limitations, offering a stable and accurate solution for studying neuromechanical coupling.
• The technology holds significant potential for applications in rehabilitation robotics and human-machine interfacing.