Estimation of rate-distortion bounds for compression of ambulatory ECGs

The theoretical rate-distortion bounds for compression of ambulatory electrocardiograms (ECGs) are presented. These bounds estimate the minimum data rate for coding the ECG signal with a given mean-square-error distortion relative to ECGs recorded with a 100-Hz bandwidth. The rate-distortion bounds are calculated from the average power spectrum of an arrhythmia database. The calculations indicate that average coding distortions on the order of 15 μV RMS are required for storage of 24 h of two-channel ECG in 4 MB. The ECG can be stored with average distortions on the order of 11 μV when average beats are subtracted before compression. Average beat subtraction reduces the data rate necessary for storage by approximately 100 b/s regardless of distortion level