摘要
心音信号幅值小，干扰多，采用常规的时、频域滤波方法往往不能收到良好的效果。本文根据信号和干扰在小波变换下的不同变化特性，利用二进小波变换的模极大值识别出心音信号中的干扰噪声的位置，剔除其相应的小波变换系数后，再通过小波逆变换重构出心音信号，并根据心音信号的特点选取了适当的母小波和分解尺度，给出了利用小波方法去噪前后的实际结果，结果表明，小波变换方法可有效地消除心音信号中的噪声干扰。
Heart sound signal is weak and disturbance is wide-spread, conventional timefrequency methods are of little effcet. In this paper, based on the behavior of different changing trends between signal and the disturbance in the wavelet transform, the position of the disturbance signals are deteted based on the dyadic wavelet transform modulus maxima. Heart sound signal is reconstructed by wavelet inverse transform which used wavelet transform coefficients eliminating the ones of the disturbance signal. A proper mother wavelet and decomposing scales are chosen based on characteristics of the heart sound signal. Along with comparison plots of original signal and denoised signal, the results show that the heart sound signal are denoised in the wavelet transform methos effectively.
出处
《生物数学学报》
CSCD
2004年第4期477-480,共4页
Journal of Biomathematics
关键词
心音信号
小波变换
尺度
模极大值
消噪
Heart sound signal
Wavelet transform
Scale
Modulus maxima
Denoising
