Multi-lead ECG data compression with orthogonal expansions: KLT and wavelet packets

Presents the extension of transform coding compression methods to multilead ECG recordings in order to reduce the inter-lead correlation. Two orthogonal expansions are considered: the Karhunen-Loeve transform and a fast approximation of it based on wavelet packets, also known as best basis algorithm. The multilead compression algorithm with wavelet packets achieves an average compression ratio of 30.5:1 in two-leads records from MIT-BIH Arrythmia database, in contrast to 21.4:1 for the single-lead algorithm with the same distortion. Better results could be obtained in ECG recordings with more than two leads