UC Irvine

Low power wireless devices can be placed on human subjects to monitor changes in physiology forming a wireless body area network (WBAN). WBANs allows various sensors to communicate and provide real-time health monitoring without impairing normal activities. In this paper, we investigate the common wireless power standards, Near Field Communication (NFC), Qi, and AirFuel, and compare their specifications for wireless power transmission. These standards were designed to power mobile devices such as smartphones or RFID tags but an update to their protocols could enable their use in WBANs. Here, each standard was modified with a passive intermediate relay (PIR), which extends the range of power transmission and enables the support of multiple nodes from a single source. The designs were optimized to power a network of passive wireless sensors from a single wireless transmitter, overcoming the limitation of a single conventional receiver. Custom transmitters and receivers were developed for each wireless standard and tested for wireless data communication with sensing nodes. This paper covers the hardware and software implementations of the WBANs. All three wireless power standards were successfully adapted extending their range up to 60 cm and enabling support of up to 6 nodes. Future work and limitations of the technologies are also discussed.