Robust Skin Attachable Sensor for Core Body Temperature Monitoring

We designed a skin-attachable sensor for measuring core body temperature (CBT). Past studies on non-invasive CBT measurement did not consider heat loss and measurement errors caused by ambient convection. To address the effect of convection, we designed a heat flow path in the structure of the CBT sensor. Topology optimization provided a systematic design procedure without the need for numerous, complex trials. By using topology optimization, we developed an optimized aluminum structure, a truncated cone with a hole. The sensor with the aluminum structure was evaluated by numerical calculation and experiment. We determined that the heat loss induced by ambient convection was effectively reduced, and the CBT estimation accuracy and robustness to convection were improved. The feasibility of the CBT sensor was demonstrated in an experiment using a phantom with an accuracy of 0.1 °C, showing potential for applications to thermal and fluidic devices.