A fall-detection system that uses body area network and thermal energy harvesting technologies

The research in technologies for body worn sensors has reached a maturity level that empowers the development of small sensors, which encompass wireless and energy harvesting capabilities. By deploying these sensors in body area networks new unique ambient assisted living services can be created. A key service in this area is a fall-detector for the elderly, which is able to sense falls and transmit alarms wirelessly. However, a major challenge in relation to this service is the dependency of batteries which limits the data-collecting capabilities, the data-processing capabilities, and the wireless communication capabilities. In addition, the process of changing batteries is costly, risky and impractical. In this paper the challenges with the batteries are overcome by deploying an energy harvesting system. The energy is harvested from the thermal flux emitted from human skins to its surroundings. A considerable part of this energy is used to overcome the challenges in transmitting the fall-detector data wirelessly. From simulations it has been found that a small form factor fall-detector sensor is able to harvest enough energy to transmit an alarm over the needed distance.