平稳小波变换在膈肌肌电降噪中的应用  

Application of Stationary Wavelet Transform in Electromyography of Diaphragm Denoising

作　　者：杨智[1] 罗国[1] 袁芳芳[1] 

机构地区：[1]中山大学信息科学与技术学院,广州510006

出　　处：《数据采集与处理》2013年第5期546-552,共7页Journal of Data Acquisition and Processing

基　　金：国家自然科学基金(60704045)资助项目

摘　　要：为了去除膈肌肌电中的心电干扰,提出了一种基于平稳小波变换的"逆向"硬阈值的降噪方法。首先,对临床的膈肌肌电信号进行平稳小波变换,根据小波系数检测QRS并确定心电干扰范围;其次,逐层估计心电周期范围的小波系数均方差,并且通过均方差计算各个心电干扰的阈值;最后,对各层心电干扰范围小波系数进行"逆向"硬阈值处理,并进行小波逆变换得到降噪后的信号。实验结果表明,该方法能够有效地去除膈肌肌电信号中的心电干扰,并且能够较好地保留膈肌肌电信号的信号特征。To eliminate the electrocardiography （ECG） interference in diaphragmatic electromyographic （EMGdi）,an ＂inverse＂ hard threshold cancellation algorithm based on stationary wavelet transform is presented.Firstly,QRS is detected by wavelet coefficients and ECG interference range are determined after decomposing clinical EMGdi.Secondly,the mean square is estimated by wavelet coefficients in the ECG cycle at each level,and each ECG interference threshold is calculated by mean square.Finally,ECG interference wavelet coefficients are removed by ＂inverse＂ hard threshold,and the denoised signal is reconstructed by wavelet coefficients.The experimental results show that the method cancels the ECG interference in EMGdi signals effectively and reserves its signal characteristics satisfyingly.

关 键 词：膈肌肌电信号 心电干扰 平稳小波变换 "逆向"硬阈值 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]