Abstract: Systems and methods are described for microwave-frequency, passive sensing of internal body temperature. Some implementations include one or more wearable sensors that wirelessly transmit temperature data continuously to a remote receiver. The sensor can include a probe designed to be placed on a skin site of an individual to receive near-field radiation at the skin site, and a radiometer to detect a total power of the received near-field radiation. The remote receiver includes a signal processing system that can convert the detected total power to an internal tissue temperature measurement by applying the detected power to a tissue stack model. The tissue stack model can characterize the skin site according to a set of weighting functions, each weighting function corresponding at least to electromagnetic characteristics of an associated tissue layer of the tissue stack model.

Abstract: Systems and methods are described for microwave-frequency, passive sensing of internal body temperature. Some implementations include one or more wearable sensors that wirelessly transmit temperature data continuously to a remote receiver. The sensor can include a probe designed to be placed on a skin site of an individual to receive near-field radiation at the skin site, and a radiometer to detect a total power of the received near-field radiation. The remote receiver includes a signal processing system that can convert the detected total power to an internal tissue temperature measurement by applying the detected power to a tissue stack model. The tissue stack model can characterize the skin site according to a set of weighting functions, each weighting function corresponding at least to electromagnetic characteristics of an associated tissue layer of the tissue stack model.