Body-coupled communication for body sensor networks

Abstract

Body sensor networks (BSNs) offer a wealth of opportunities for precise, accurate, continuous, and non-invasive sensing of physiological phenomena, but their unique operating environment, the body-area, poses unique technical challenges. Popular communications solutions that utilize 2.4 GHz radio transmission suffer from significant and highly variable path loss in this setting. To compensate for such loss, radio transceivers often transmit at power levels at or above 1 mW - a reality that limits battery life. We propose the use of body-coupled communication to address this issue, as it presents several distinct advantages over existing solutions, namely: reduced power consumption, minimal interference, and increased privacy. In this paper, we demonstrate a 23 MHz body-coupled channel that supports reliable data transfer with an average received power of 30 dBm over a 2.4 GHz radio frequency link. This scheme reduces power needed for transmission and increases battery life by up to 100%, while maintaining a favorable environment for application-specific quality of service requirements. Finally, we propose a system-level hardware architecture and explore its implications on BSN infrastructure.