Real-time BioContact assurance and status monitoring using human body communication

• A novel BioContact Assurance System (BCAS) uses human body communication to continuously monitor electrode contact status in real-time, overcoming limitations of traditional DC/AC lead-off detection methods. • The ultra-low power custom silicon transceiver achieves exceptional energy efficiency of 11.55 pJ/bit and consumes only 23.10 μ W in a compact 0.1 mm 2 footprint using TSMC 65 nm technology. • The system demonstrates superior detection accuracy in identifying loose connections under degraded electrode conditions, outperforming conventional threshold-based methods. • The modular design enables seamless integration into existing biomedical monitoring systems without hardware modifications. Reliable electrode-skin contact is essential for accurate biomedical signal acquisition, as poor contact leads to signal degradation and measurement errors in critical applications such as ECG, EEG, and EMG monitoring. Traditional lead-off detection methods face real-world challenges, including motion artifacts causing false detections, environmental noise reducing accuracy, and variations in skin-electrode impedance affecting reliability. To address these limitations, this paper presents a BioContact assurance system (BCAS) leveraging common-ground human body communication (CG-HBC) to continuously monitor electrode contact status. CG-HBC enables direct digital communication through the human body without complex modulation. The system consists of three core components: a CG-HBC transceiver, a processing unit, and an electrode interface module. The CG-HBC transceiver, fabricated using the TSMC 65 nm process, achieves 11.55 pJ/bit energy efficiency and consumes only 23.10 μ W, making it suitable for seamless integration into wearable medical devices. A custom timing protocol synchronized with biomedical sampling ensures consistent and reliable contact monitoring. BCAS accurately classifies electrode conditions (connected, loose, intermittent, disconnected) in real time by analyzing the bit error rate and transmission success rate between electrode pairs, ensuring reliable contact assessment while maintaining signal quality. Unlike traditional DC/AC lead-off techniques, it detects subtle contact degradations with high sensitivity while sustaining robust performance for fully connected or disconnected states. These advancements highlight its promise for next-generation continuous health monitoring systems and intelligent biomedical wearables.