Attempt to Apply Empirical Mode Decomposition to Heart Rate Variability on Functional Food

Abstract

The purpose of this study was to analyze heart rate variability on functional food using Empirical Mode Decomposition (EMD), which is used for nonlinear analysis, and to compare EMD results with those obtained by Fast Fourier Transform (FFT). Two experimental sessions of Gamma-Aminobutyric Acid (GABA) or placebo intake were conducted in a healthy man. Electrocardiogram (ECG) was measured before and after the intake of GABA or placebo. After obtaining the time series of RR intervals from ECG, both analyses were performed to calculate each index of autonomic nerve activity. The results showed that the LF/HF ratio was not a difference in both intake by FFT analysis, but by EMD analysis, which was a small tendency for LF/HF ratio in intake of GABA compared with placebo. The EMD analysis suggested that it could obtain sufficient changes of autonomic nerve activity than the FFT analysis on functional food.