Onsens's BODY is currently available for licensing.
Body is small adhesive patch sensor used to determine the body core temperature of a wearer. The Body sensor can be integrated with commercial smartwatches by mean of a Bluetooth Low Energy link (BLE). Using its proprietary algorithm, Body dynamically computes the core temperature of a wearer from two low cost temperature sensors. The computed core temperature stays accurate even in wide changes of ambient temperatures or wind conditions. The Body algorithm is based on a dynamic model that take into account the thermal capacities of the skin and the device.
Performances
The graph below illustrates how the BODY algorithm adapts to large swings of ambient temperature. There are two temperature sensors, one in contact with a wearer’s skin (Tskin), and another on top of the device (Tcase). As can be seen on the graph, Tskin does not represent the actual body temperature (Tbody). Even in spite of ambient temperature changes (Tambient), the BODY algorithm determines the body temperature (Tbody measured), which is very close to actual body temperature.