Optimization of a Wearable Device for Core Body Temperature Monitoring Based on the Dual-Heat-Flux Model

This paper presents an improved structure of core body temperature (CBT) probe based on the dual-heat-flux (DHF) principle. A new frustum-shaped architecture of sensor, instead of traditionally cylinder-shaped, is presented to decrease the transverse heat flow which is the major obstacle to fit the DHF theory. Besides, finite element simulation is conducted to compare the heat concentration in those two structures and reveal the relationship between the measuring accuracy and the thermal conductivity of the shell. Nylon Glass Fiber Mixture (NGFC) is introduced to improve the performance of probes based on the above simulation. Finally, to verify the effectiveness of the models simulated accordingly, wearable probes based on CBT monitoring system is presented and hot-plate (produced by Thermo Scientific) experiments are carried out. The new probe shows an error, i.e. 0.09±0.05°C, at different CBTs, which promises higher stability within acceptable error in congeneric researches. (paper)