A Wearable EMG-Driven Closed-Loop TENS Platform for Real-Time, Personalized Pain Modulation

Abstract

Highlights: What are the main findings? Development of a wearable closed-loop TENS system: The proposed system integrates real-time sEMG acquisition, adaptive signal processing, and a boost-regulated power supply, enabling personalized, responsive neuromodulation. System validation with low-latency and stable output: The system demonstrates a closed-loop latency of less than 10 ms, stable biphasic waveforms (±22 mA) under prolonged operation, and minimal inter-channel leakage (<1.2%). What is the implication of the main finding? Real-time, ambulatory neuromodulation: The system provides a platform for personalized, mobile neuromodulation, offering potential for non-invasive pain management and motor rehabilitation. Enhanced clinical feasibility: The low-latency and reliable multi-channel output could pave the way for future clinical applications, such as biofeedback-based therapies and neurorehabilitation. A wearable closed-loop transcutaneous electrical nerve stimulation (TENS) platform has been developed to address the limitations of conventional open-loop neuromodulation systems. Unlike existing systems such as CLoSES—which targets intracranial stimulation—and electromyography-triggered functional electrical stimulation (EMG-FES) platforms primarily used for motor rehabilitation, the proposed device uniquely integrates low-latency surface electromyography (sEMG)-driven control with six-channel current stimulation in a fully wearable, non-invasive format aimed at ambulatory pain modulation. The system combines real-time sEMG acquisition, adaptive signal processing, a programmable multi-channel stimulation engine, and a high-voltage, boost-regulated power supply within a compact, battery-powered architecture. Bench-top evaluations demonstrate rapid response to EMG events and stable biphasic output (±22 mA) across all channels with high electrical isolation. A human-subject protocol using the Cold Pressor Test (CPT), heart rate variability (HRV), and galvanic skin response (GSR) has been designed to evaluate analgesic efficacy. While institutional review board (IRB) approval is pending, the system establishes a robust foundation for future personalized, mobile neuromodulation therapies.