Correlation between human core body temperature fluctuation and sleep efficiency using time series analysis

Core body temperature has relation to sleep. However, unlike body surface temperature, it is difficult to obtain time series data on core body temperature, and few studies have focused on the variability of core body temperature. In this study, we focused on the measurement of core body temperature using a non-contact infrared sensor, measured continuous time-series data of core body temperature during sleep, and investigated the correlation between indices obtained from core body temperature data and sleep indices obtained from a wristband-type wearable sensor. The results showed a negative correlation between the very low frequency component (VLF) calculated from core body temperature fluctuations and deep sleep (r=-0.69). The results suggest that VLF values of core body temperature may be useful as a new sleep evaluation index.