基于集合经验模态分解和小波收缩算法的自适应心电信号去噪问题研究  

Adaptive Noise Reduction of ECG Signal Based on Ensemble Empirical Mode Decomposition and Wavelet Shrinkage

作　　者：宋美[1] 

机构地区：[1]鲁东大学数学与统计科学学院,山东烟台264025

出　　处：《生物数学学报》2015年第4期629-638,共10页Journal of Biomathematics

基　　金：国家自然科学基金项目(11001116;A010804);山东省高等学校科技计划项目(J09LA51);鲁东大学创新团队建设项目(08-CXB005)

摘　　要：本文将集合经验模态分解(EEMD)与小波软阈值去噪算法相结合,提出了一种新的心电图信号去噪EEMD-WS算法.算法首先对信号进行EEMD分解得到有限个固有模态函数(IMF);其次,根据实际含噪心电信号中各成分的特性,将所有IMF分为低阶含噪、中阶有用信号和高阶含基线漂移三类,对于低阶含噪IMF利用IMF能量变化分界点自适应地确定含噪IMF个数,随后对其利用小波收缩算法中的启发式软阈值选择算法进行去噪;对于高阶含基线漂移IMF根据其自身是否包含周期信息自适应地判断并去除与基线漂移关系密切的IMF.最后通过将滤除噪声的低阶IMF、中阶有用信号重构达到抑制噪声和去除基线漂移的目的.仿真信号和MIT-BIH心电数据库真实心电信号实验显示,EEMD-WS算法不仅能够克服小波去噪算法不能去除基线漂移的不足,而且能够比常用的EMD-WS算法更好地提高消噪效果,总体去噪性能优于传统算法.A novel integration electrocardiogram(ECG) denoising algorithm named EEMDWS is proposed,which is combined by Ensemble Empirical Mode Decomposition(EEMD) and Wavelet Shrinkage(WS) algorithm.The first step of the new algorithm is to decompose the original noisy ECG signal into a certain number of Intrinsic Mode Functions(IMFs) by EEMD.Then considering the character of the different fragments of the noisy ECG,we propose two kinds of algorithm for the problems.As for the lower order IMFs,an adaptive denoising algorithm based on Wavelet Shrinkage with Soft Threshold and Heuristic threshold selection algorithm is used to reduce the noise in them.And an adaptive screening algorithm is proposed to delete those IMFs which is close to Baseline Wander.Finally the first several denoised IMFs and the central several IMFs is reconstructed by summation.Then we construct a Simulink ECG and choose a real ECG from the MIT-BIH Arrhythmia Database for the test,and three methodologies including WS,EMD-WS and EEMD-WS,is untilized to test the Simulink and real ECG.The results indicate that the proposed EEMD-WS is generally predominant than the other two algorithm,and it performs better in Baseline Wander reduction than WS algorithm,also better in noise reduction than EMD-WS.

关 键 词：集合经验模态分解 小波收缩算法 心电信号 自适应去噪 

分 类 号：TN911.4[电子电信—通信与信息系统]