Design and preliminary evaluation of a facial EMG–TENS wearable platform for trigeminal neuralgia therapy
DOI:
https://doi.org/10.58368/MTT.24.7-8.2025.10-14Keywords:
Trigeminal Neuralgia, EMG, sEMG, TENS, Instrumentation Amplifier, Gold-coated ElectrodesAbstract
Trigeminal neuralgia (TN) is a severe facial pain condition characterized by unpredictable, electric shock-like episodes that are hard to assess continuously outside clinical settings. This study presents the design and preliminary validation of a skin-conformal facial electromyography (sEMG) wearable capable of identifying neuromuscular activity associated with TN and delivering transcutaneous electrical nerve stimulation (TENS) for pain relief. The system integrates flexible gold-coated electrodes, a low-noise instrumentation amplifier, and a high-resolution delta-sigma ADC (ADS1115) interfaced with an ESP32 for real-time acquisition, processing, and wireless data transfer. Initial recordings from facial muscle sites demonstrated consistent EMG bursts in the microvolt-to-millivolt range, confirming an adequate signal-to-noise ratio for activity detection. The measurement chain preserved dynamic range without saturation, with residual noise originating mainly from low-frequency drift and mains interference—issues that will be addressed through improved filtering and biasing in future revisions. The platform enables closed-loop operation by triggering TENS based on EMG-derived features to anticipate or suppress TN pain events. Future development involves upgrading to an ADS1299-based, multi-channel front end with dry, conformal electrodes to enhance noise performance, comfort, and scalability. Overall, the proposed system demonstrates feasibility for continuous, home-based TN monitoring and adaptive stimulation, representing a step toward personalized, responsive neuromodulation for facial pain management.
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