Influence of Human Body Curvature on Body-Centric Wireless Communication

Wearable technology has become ubiquitous in addressing the rising need for remote health monitoring and fitness tracking while fulfilling the dream of an augmented lifestyle. Its ability to facilitate the precise monitoring of physiological indicators and real-time data sharing for prompt interventions in managing chronic health conditions has garnered interest among healthcare providers. The latest wearables, enhanced with artificial intelligence (AI), have started providing personalized diagnoses and reshaping our interactions with technology. Traditional radio frequency (RF) based wireless communication methods, being radiative, suffer from physical security vulnerabilities, high power consumption (>10s of mW), and limited data rates (≤3 Mbps) in non-line of sight (NLoS) scenarios. In contrast, Electro-Quasistatic Human Body Communication (EQS HBC), as a promising alternative, offers enhanced physical security and energy efficiency over RF. However, EQS HBC struggles with higher channel gain sensitivity to the change in the receiver (Rx) position relative to the transmitter (Tx) around the user's torso, especially for shorter channels (≤ 50 cm), strongly dominated by inter-device coupling. Recently, with the inclination towards energy-efficient high-speed communication and computing around us, Body-Resonance BR HBC has started gaining attention, as it offers ∼15-20 dB benefit in channel gain than EQS and supports higher data rates by using the body as a transmission line. This study analyzes how body curvature affects BR HBC's transfer characteristics. Results show that BR HBC incurs less variation in channel gain with changes in Rx position around the subject's torso compared to EQS for short channels (< 50 cm). With increased link length (∼ 60 cm or more), this sensitivity benefit of BR HBC over EQS goes down, though it remains beneficial compared to existing radiative wireless techniques like Bluetooth (2.4 GHz), MedRadio (434 MHz), and ZigBee (915 MHz) which demand line-of-sight during information transfer around user's body.Clinical relevance- This technology shows reduced sensitivity of channel gain to receiver position in non-line-of-sight locations compared to current radiative wireless methods, which could inspire a wireless network of wearable devices that mimic the nervous system and transform personalized healthcare and diagnostics.