A 2-D ECG compression algorithm based on wavelet transform and vector quantization

In this paper, we proposed a new two-dimensional (2-D) wavelet-based electrocardiogram (ECG) data compression algorithm. A 1-D ECG data is first segmented and aligned to a 2-D data array, thus the two kinds of correlation of heartbeat signals can be fully utilized. And then 2-D wavelet transform is applied to the constructed 2-D ECG data array. A modified vector quantization (VQ) is employed to the wavelet coefficients. This modified VQ algorithm constructs a new tree vector (TV) which well utilizing the characteristics of the wavelet coefficients. Records selected from the MIT/BIH arrhythmia database are tested contrastively using the proposed algorithm, some compression algorithms based on wavelet transform and the other 2-D ECG compression algorithms. The experimental results show that the proposed method is suitable for various morphologies of ECG data, and that it achieves higher compression ratio with the characteristic features well preserved.