The goal of this project is to produce a prototype wireless solution for monitoring real-time core temperatures in humans during hot and cold exposure, to include water immersion, for up to 24 hours in resting and exercising individuals,providing early warning of heat stress, heat stroke and hypothermia. Such a device that can save military medical costs and increase duty time does not currently exist. The fundamental principle of the proposed novel device is measurement of radio-frequency blackbody power naturally radiated by internal tissues, and an inverse algorithm applied to determine the temperature of each sub-surface tissue layer. Research challenges include development of a design methodology for an ultra-low noise RF receiver with a near-field wearable probe, finding efficient interference mitigation techniques, and developing an algorithm for accurate and fast temperature estimation, all with a focus on low-power compact implementations. This will result in specifications of prototype temperature sensitivity, spatial resolution, battery life, robustness, and ease of use. The initial proof of principle was demonstrated in laboratory conditions under NSF funding. This Phase I further develops the hardware by evaluating miniaturized sensor designs and body locations that allow minimal interference with warfighter performance under various environmental conditions.
