MOT: A Low-Latency, Multichannel Wireless Surface Electromyography Acquisition System Based on the AD8232 Front-End

Area of Science:

• Biomedical Engineering
• Wearable Technology

Background:

• Commercial wearable surface electromyography (sEMG) systems often compromise performance for size, hindering research reproducibility and customization.
• Proprietary designs of existing sEMG systems limit accessibility and cost-effectiveness for academic laboratories.

Purpose of the Study:

• To develop a fully wireless, multichannel platform for high-fidelity sEMG acquisition using commodity components.
• To overcome limitations of commercial systems, enabling reproducible and cost-effective research in biomechanics, rehabilitation, and human-machine interfaces.

Main Methods:

• Developed MOT, a platform integrating AD8232 front-end and 12-bit ADC (1 kS/s) on each sensor node.
• Utilized ESP-NOW protocol for low-latency data broadcast and a central hub for timestamping and PC streaming.
• Configured system for 19-690 Hz bandwidth and tested for analog response, interference, packet loss, and latency.

Main Results:

• Achieved 19-690 Hz bandwidth with 59 dB gain; mains interference was over 40 dB below voluntary contraction levels.
• Demonstrated cumulative packet loss below 0.5% for six channels at 100m, with end-to-end latency under 3 ms.
• MOT system reduced 60 Hz artifact by up to 22 dB while preserving signal bandwidth; nodes weigh 22g and operate for 1.8 hours.

Conclusions:

• MOT provides a compact, economical, and reproducible solution for mobile, high-fidelity sEMG acquisition.
• The platform facilitates advancements in biomechanics, rehabilitation, and human-machine interface research.
• Commodity components enable academic replication, fostering innovation in wearable biosensing.