Evaluation of the fan method of adaptive sampling on human electrocardiograms

The fan is a method of adaptive sampling that selects samples from electrocardiograms more rapidly during periods of rapid waveform change and more slowly otherwise. One attribute of the fan is the guarantee that the original waveform can be reconstructed within tolerance ε. Many questions about the particulars of the fan's performance on human ECGs have been undocumented, e.g. what ε choice leads to good quality recording, how does the choice of ε affect visual quality, and what average sampling rates occur? The paper provides answers to these and other questions. It is based on retrospective analysis of 20700 human ECG waveforms from subjects of all ages. The results show, for example, that ε=10μV leads to high quality waveforms sampled at an average rate of 266 samples s−1 with maximum errors only 1/24th the maximum errors using uniform sampling at 250 samples s−1, and that ε=30μV leads to waveforms showing all deflections at an average rate of 45 samples s−1 with maximum errors only 1/57th of the maximum errors from uniform sampling at 45 samples s−1.