Electrocardiosignal denoising method based on morphological filtering and lifting wavelet transformation

Abstract

The invention discloses an electrocardiosignal denoising method based on morphological filtering and lifting wavelet transformation. Firstly, three times of decomposing are conducted on electrocardiosignals f based on the lifting wavelet theory, three layers of high-frequency coefficients and three layers of low-frequency coefficients are obtained, a lifting threshold denoising method is used for processing the high-frequency coefficients, the high-frequency coefficients on the bottom layer and the low-frequency coefficients are reconstructed twice, the reconstructed low-frequency coefficients can be obtained, morphological filtering is conducted on the reconstructed low-frequency coefficients, signal reconstruction is conducted according to the processed reconstructed low-frequency coefficients and the processed high-frequency coefficients on the highest layer, and denoised electrocardiosignals f' are obtained. The electrocardiosignal denoising method has the advantages that the method is simple and easy to achieve, the morphological algorithm and the lifting wavelet transformation algorithm are organically combined, compared with a traditional wavelet algorithm, the high-frequency electrocardio-noise and the low-frequency electrocardio-noise can be removed at the same time, the quality of the denoised signals is improved, computing is easy, the occupied space is small, and the electrocardiosignal denoising method can be achieved on hardware more easily.

Description

technical field [0001] The invention relates to the technical field of biomedical signal noise processing, in particular to an electrocardiographic signal denoising method based on morphological filtering and lifting wavelet transform. Background technique [0002] ECG is one of the vital sign signals of people, which can accurately reflect the information of heart activity in different states. It not only provides a valuable reference for changes in heart function and diagnosis of heart diseases, but also A new way of identity verification is provided in biometric identification technology. [0003] The ECG signal is a typical non-stationary weak signal with low amplitude and low frequency, so it is very susceptible to various interferences during the extraction process of the ECG signal. Among them, the noise of the ECG signal is mainly divided into three categories: ① Baseline drift, mainly caused by body movement, breathing, ECG acquisition method and acquisition circui...

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Problems solved by technology

[0004] In terms of ECG denoising, there are many methods. The denoising effect is better like the traditional wavelet denoising method, which has a good effect in removing high-frequency noise, but it cannot efficiently remove low-frequency noise.

In order to overcome the deficiency of traditional wavelet denoising, someone designed a combined ECG noise filter based on morphology and wavelet, using morphological filters to remove low-frequency noise of ECG signals, and using threshold denoising method to remove high-frequency noise , has achieved good results in denoising ECG signals. However, the traditional wavelet calculation is too large, and it is not easy to implement on hardware.

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