Study of Using Fourier Transform to Capture the ECG Signals between Awakeness and Dozing

摘要

The most obvious peak in electrocardiogram (ECG) is the R-wave. This paper contends that while many previous ECG and heart rate variability (HRV) studies have focused on using R-wave and R-wave interval (RRI) as the primary method for analyzing physiological data, this study differs from many conventional methods by using R-Wave Amplitude (RWA) as a source of data, and found that during awakeness, sleep and the transition between awakeness and sleep, RWA showed significant changes. This characteristic can be applied to determine if a subject is in the initial threshold of dozing, and allows the assessment program to respond clearly and rapidly. The study results showed that the analysis of RRI frequency domain represents autonomic nervous (ANS) activities in that a low/high frequency ratio of less than 1(LF / HF <;1) corresponding to a similar decrease in heart rate (HR) indicates the official dozing threshold. If the same RWA data is used for detrended fluctuation analysis (DFA), the results showed that although α1 is sensitive to changes during dozing, its characteristic irregularity cannot explain RWA changes.