A method is proposed to analyze the heartbeat waveform that can yield a reliable characterization of the structure after only a few pulses. The measure suggested is entropy index that is related to the one found effective in describing chaotic behaviors in a wide variety of physical systems. When applied to the ECG data that include ventricular fibrillation, the index is shown to change drastically within a few pulses. Wavelet analysis is used to exhibit different scaling behaviors in different phases.
@article{arxiv.physics/9809041,
title = {Entropy Index as a Measure of Heartbeat Irregularity},
author = {Rudolph C. Hwa},
journal= {arXiv preprint arXiv:physics/9809041},
year = {2007}
}