Expected growth of elderly populations and the corresponding increase in healthcare costs mandate systems for automated monitoring of physiological conditions, triage, and remote diagnosis. Automated physio logical monitoring plays a part in smart-soldier applications and assessment of modern battlefields as well. Wireless communication has a critical role in facilitating the technology by allowing the gathering of data from compact sensor- nodes distributed on the body and by providing a link to the Internet for remote diagnosis. A body sensor-node operates under strict design constraints, such as low computation power and energy consumption. The wireless transceiver is the largest energy-consuming component, and securing the communication link requires resources unavailable to a compact sensor-node.
Ongoing research in the Communications Lab at the electrical and microelectronic engineering department looks for ways of utilizing the unique on-body signal propagation environment to obtain reliable and secure communications with low overhead on sensor- node resources. “On-body wireless communication is characterized by strong and dynamic signal attenuation due to mobility and shadowing of body parts,” explains Gill Tsouri, assistant professor and director of the Communications Lab. “Our research aims to utilize the tendency of wirelessly propagating signals to bend around the curvature of the body as an alternative to existing methods of transmission.
The result is a communication link based on signals hugging the body, instead of wasting energy by radiating signals to open space. “The wireless signal exhibits intrinsic randomness due to the changing signal propagation environment. We design algorithms for utilizing the randomness of the wireless signal to secure the communication link from eavesdropping and malicious attacks. These algorithms make use of existing data- carrying signals and impose virtually no overhead on system resources.” A prototype is being developed and tested in the Communications Lab with application to wireless electrocardiogram systems. The work is supported by Blue Highway, a Welch-Allyn company.