Powering body area networks using the body as a transmission medium

Abstract

Body area networks (BAN) are an enabling technology for individually monitoring health or delivering care in a real-time, effective, and minimally obtrusive way. An ideal BAN requires both a high efficiency signal and power bus. Recent research shows promising signal transmission efficiency using the body as a transmission medium. However, these BAN systems require the sensor nodes to carry on-board power or use through-air transmitted power, whose utility is limited by the power transmission efficiency and/or distance. This paper reports an initial study to investigate, design and evaluate a through-body power transmission system that can distribute power to sensor nodes in the network. Our preliminary results show that it is feasible to distribute 0.5-1.0mW, at 50MHz, to sensor nodes over a distance of 40cm with ~18dB loss, which is ~10-100 times more efficient than through-air transmission. This result is instrumental for realizing a through-body signal and power bus for next generation BAN.