Customizing a discrete wavelet transform filter bank using the lifting scheme for improved compression ratios of an ECG

The lifting scheme is used to adaptively change a biorthogonal filter bank, which implements a discrete wavelet transform (DWT), for improved compression of an ECG waveform. The filter bank is initialized using a Haar wavelet and the associated filters are then lifted so as to minimize a reconstruction error. This error is based on the difference between an input ECG and a reconstructed ECG using only a fixed number of absolute maximum coefficients in the wavelet transform. The algorithm used to find the minimum error is stochastic and iterative.