ECG Signal Denoising Based On Wavelet Analysis

The theory of the wavelet originates with mathematicians, physicists and engineers together, and now, the wavelet analysis is very popular in many fields of science as one of the most efficient tool to analysis or deal the problem, furthermore, it will still progress forward in the future. To study the new theory, methods and applications of wavelets is of great theoretical significance and practical value. Estimating the original signals from noise has always been an important part in the field of signal processing. Because of it's fine time-frequency localization characteristic, wavelet transform can effectively discriminate signals from noise and achieves pretty good performance. This paper chiefly studying the application of wavelet analysis in ECG signal denoising.Firstly, this paper introduce the theory of wavelet and principle of signal denoising based on wavelet, and then studying several denoising methods. Because threshold denoising has simple algorithm and good denoising result, moreover it is the base of other denoising methods discussed in this paper, this paper make a comparison study of ECG signal denoising based on MATLAB platform, using different threshold functions and threshold value, but using one wavelet function.Based on principle of threshold denoising, several new wavelet analysis are introduced to ECG signal denoising. With same condition, this paper compared the results of these methods with the result of threshold denoising. For the sake of suppressing Gibbs phenomena and reserves character of ECG signal,the stationary wavelet transform is proposed in this paper, it's experiment result is pretty good;Wavelet packet analysis can get more time-frequency localization characteristic information, it's application in ECG signal denoising is researched, experimental result is better than the method based on wavelet;At present, lifting scheme is an new method for constructing wavelets and performing wavelet transform, it is introduced in ECG signal denoising. Experiment result shows denoising performance of the method based on lifting wavelet is approximate to the method based on wavelet transform. As a rising branch of the theory of wavelet analysis, Multiwavelets is now being studied on the firststep, More researches on the theory and application of Multiwavelets need to be carried out. Multiwavelets simultaneously has several advantages such as compact-support, orthogoality, symmetryand so on which are known to be important in signal processing, so it is introduced in ECG signal denoising and achieved superior performance.