Measurement of Time-Dependent Stress Levels by Wavelet Analysis

Method commonly used to examine the degree of stress is a LF / HF, which is calculated by spectral analysis the RRI time series data. However, many data is required in the spectral analysis, it is impossible to calculate accurately the changes in a short time. In this study, it is able to be used Wavelet analysis to examine the time-dependence of the degree of stress. We made a comparison to the resting state (sitting with eyes closed) using fingertip pulse waves and or ECGs, when subjects were given 13 types of stimulus (eye mask, light pulse, white paper, red paper, English-language newspaper, cartoon, hard rock, classic, lavender, decimal subtraction, and one leg up, walk, running machine). Rather than obtaining the LF and HF values in the spectral analysis, we studied the advantages of the Wavelet analysis for measuring time-varying and ease when it is determined the LF and HF values approximately.