基于经验模式分解和最小二乘支持向量机的胎儿心电信号提取  

Extraction of Fetal Electrocardiogram Signal Using Empirical Mode Decomposition and Least Squares Support Vector Machines

作　　者：蒲秀娟[1] 曾孝平[1] 韩亮[1] 程军[2] 姜文浩[1] 

机构地区：[1]重庆大学通信工程学院,重庆400044 [2]第三军医大学西南医院心内科,重庆400038

出　　处：《四川大学学报（工程科学版）》2010年第6期158-165,共8页Journal of Sichuan University (Engineering Science Edition)

基　　金：国家自然科学基金资助项目(30570473;60971016);重庆市自然科学基金资助项目(2008BB2322);中国博士后科学基金资助项目(20090460707);中央高校基本科研业务费(CDJRC10160001)

摘　　要：针对心电信号的非平稳特性,将非平稳信号处理方法与非线性估计方法相结合,提出一种从母体腹壁混合信号中提取胎儿心电信号的新方法。采用经验模式分解(EMD)方法将非平稳的母体心电信号分解为有限个本征模函数(IMF)和一个残差信号;母体腹壁混合信号中的母体心电成分为母体心电信号的非线性变换,采用最小二乘支持向量机(LSSVM)拟合这一非线性变换;将EMD分解所得的本征模函数和残差信号经由所拟合的非线性变换得到母体腹壁混合信号中母体心电成分的最优估计,从母体腹壁混合信号中减去该最优估计得到胎儿心电信号。引入基于特征值分析和基于互相关系数计算信噪比的方法,评估胎儿心电信号提取方法的性能。实验结果表明,在胎儿心电信号和母体心电信号QRS波分离或者重叠的情况下,通过提出的方法均可得到清晰的胎儿心电信号,且信噪比相对于传统方法有明显提高。实验结果验证了该方法的有效性。According to the non-stationary characteristic of Electrocardiogram（ECG） signal,a new method combined non-stationary signal processing and nonlinear estimation was proposed to extract the Fetal ECG（FECG） signal from the abdominal composite signal of the pregnant woman.The non-stationary Maternal ECG（MECG） signal was firstly decomposed into finite Intrinsic Mode Functions（IMFs） and one residue utilizing Empirical Mode Decomposition（EMD）.The MECG component in the abdominal composite signal was a nonlinear transformation of the MECG signal and Least Squares Support Vector Machine（LSSVM） was used to fitting the nonlinear transformation.An optimal estimation of the MECG component in the abdominal composite signal was obtained by the finite IMFs and one residue undergoing the nonlinear transformation.The FECG was extracted by removing the optimal estimation of the MECG component from the abdominal composite signal.To evaluate the performance of FECG extraction method,eigenvalue analysis and cross correlation were used to estimate the Signal-to-Noise（SNR） ratio for an ensemble of FECG waveforms.The experimental results showed that the clear FECG can be extracted even under the condition of the fetal QRS wave being entirely overlapped with the maternal QRS wave in the abdominal composite signal and its SNR ratio was significantly increased compared with traditional methods.The experimental results verified the proposed method.

关 键 词：胎儿心电信号提取 经验模式分解 支持向量机 

分 类 号：TN911.72[电子电信—通信与信息系统]