脉象信号的小波多分辨率分析方法

摘要

利用基于小波变换的多分辨率滤波技术,根据脉象时频分布特点,采用软阈值方法进行脉象信号的噪声消除,有效消除了工频干扰、肌电干扰和白噪声,噪声消除基本不损失信号细节。利用小波多分辨率分析技术消除噪声的方法受脉象测量条件、不同人生理特征差异性影响较小,并且在脉象消噪过程中,可以同时有效去除脉象信号的基线漂移,噪声消除和基线漂移消除在小波多分辨率分解和综合过程中一次完成。预处理后的脉象信号为后续脉象信号的特征提取提供了精确的基本前端输入和判别条件,对于后续的用小波模极大方法定位脉象信号特征点是否准确具有重要的作用。%According to the character of the time-frequency distributing,we apply the soft-threshold to eliminate the pulse signal.It is very effective to eliminate the 50Hz interfere,muscle electrical interfere and white noise.The method of eliminating noise does not lose the detail of noise,and the pre-processing of the signal is almost not improved with the condition of the measuring condition of the pulse,different people＇s physiological difference.We can eliminate the noise and baseline drift only for one time during the method of wavelet multi-distinguish decomposing and integrating.The pulse signal after pre-processing affords the basic input and distinguishing condition of the subsequent pulse signal＇s characteristic orientation.