3D SPIHT for multi-lead ECG compression

In this paper we proposed the implementation of 3D Set Partitioning In Hierarchical Trees (SPIHT) algorithm to a multi-lead ECG signal compression. The implementation of 3D SPIHT decorrelates three types of redundancy that commonly found on a multi-lead electrocardiogram (ECG) signal i.e. intra-beat, inter-beat, and inter-lead redundancies. To optimize overall compression performance we also proposed beat reordering and residual calculation technique. Beat reordering rearranges beat order in 2D ECG array based on the similarity between adjacent beats. This rearrangement reduces variances between adjacent beats so that the 2D ECG array contains less high frequency component. Residual calculation optimizes required storage usage further by minimizing amplitude variance of 2D ECG array. The experiments on selected records from St Petersburg INCART 12-lead Arrhythmia Database show that proposed method gives relatively low distortion at compression rate 8 and 16.