A novel cycle-pool based compression method for 1-dimensional semiperiodical biomedical signals [ECG/blood pressure application]

The method presented here is, conceptually, an extension of dictionary-based text coding to the semi-periodical signal domain. A pool of cycles is used as the dictionary in this case. If a pool cycle matches a signal cycle within a given error criteria, it replaces it in the reconstructed signal. If a satisfactory match cannot be achieved, the signal cycle is placed as is in the compressor´s output. In order to be able to replace a signal cycle with one that occurred in the past the authors introduce a transformation method that enables them to preserve a number of preselected measurable features in the reconstructed signal. In addition to the above, the method presented exhibits some unique characteristics, unusual waveforms in the input signal (like in arrhythmia) are preserved exactly, and the reconstructed signal always ´looks´ like the original, i.e. no staircase effect is present. The method is suitable for both lossless and lossy compression.<>