Using CELP for compression of ECG signals

A parametric coder of the Code Excited Linear Prediction (CELP) family is presented, aimed at coding of digitised Electrocardiograms (ECG). Identifying the various parts of an ECG is done to assess the coder performance on a subjective scale. This is used to adjust the parameters of the CELP to better fit the signal. Variants of the CELP are presented, especially designed for ECG coding; this includes a "copy" long term predictor and a recursive search in the VQ codebook, both resulting in a variable bitrate. Using the Percent Root-Mean-Square Distortion measure, the coder is shown to deliver results around 7.6% at a mean rate of 2.1 bits per sample. This is on par with or above coders reported elsewhere. The coders presented are shown to be very robust.