Wireless system for continuous monitoring of core body temperature

A wireless wearable device aimed at continuously monitoring internal temperature a few centimeters deep in the body is presented. A radiometer operating in the 1.4-1.427 GHz quiet band is used with a circular patch probe to measure the thermal radiation emitted by the body, which is proportional to temperature. The output is digitized and transmitted over Bluetooth by a TI CC2541. The wearable device is powered by a 3.7 V Li-Ion battery, through three buck-conversion circuits. The sensor design trades performance (continuous calibration) for simplicity to reduce size and power consumption. Validated measurement data of water temperature inside the cheek demonstrates the feasibility of radiometric internal temperature measurement in a wearable platform.