Denoising of electrocardiogram signal based on Hilbert-Huang transform

A new electrocardiogram (ECG) signal noise reduction method is presented. The core of this method is Hilbert-Huang transform (HHT) and threshold denoising, divide intrinsic mode functions (IMF) that decomposed using empirical mode decomposition (EMD) into the noise dominative layers and useful signal dominative layers. Threshold denoising proposed by Donoho et al. is adapted for the noise dominative layer, and for useful signal dominative layer, the noise level can be obtained by the product of the energy and mean period of the high frequency layers. Discuss how to distinguish the noise dominative layer and useful signal dominative layer. This method overcomes estimated level deviation of the noise for useful signal dominative layer using threshold denoising. Experiments indicate that several main noise of ECG signal detecting can be removed well and the distortion is very little.