Transform-based reduction of inter-channel correlation applied to lossless coding of multichannel ECG

This work discusses the practical aspect of the transform-based decorrelation of simultaneously recorded ECG channels. High data redundancy may be observed in the conventional 12-lead ECG recordings. Eliminating this redundancy opens new possibilities for lossless coding of the ECG that complies with the most severe expectations about the signal storage. The uncorrelated signals have significantly narrower dynamic range, in result, the statistical properties featured by uncorrelated signals in the transform domain are more appropriate for various data distribution-based coding techniques (Huffman). Four linear transforms are studied and numerically verified with use of the real ECG data. Some practical considerations on the data representation format the additional overhead bits and the round-off errors complement the final result. The compression efficiency significantly exceeds the values obtained with use of general-purpose lossless algorithms.