Comfort evaluation during bathing based on time-series analysis of physiological indices

Abstract

In a bathing environment, it is needed to evaluate an emotional effect quantitatively and continuously at stage of the product design for improving stress-relaxation effect. This study aimed to propose an index which can evaluate the comfort quantitatively and continuously on bathing. To search the physiological indices correlated to the comfortable feeling, we measured subjective evaluation of comfortable feeling in one-minute increments, with continuous measurement of physiological parameter before bathing, on bathing, after bathing. We analyzed the relationship between time-series data of the subjective evaluation and the physiological parameter. As a result, we proposed the evaluation index of comfortable feeling by using HF content obtained from spectral analysis of heart rate variability, and confirmed that the evaluation index can evaluate comfortable feeling quantitatively and continuously including the effect of personal preferences related to bathing.