摘要： 为实现心音信号的有效分割，提出一种基于非平稳系统辨识的心音信号特征包络自适应分割方法。根据非平稳系统辨识原理，提取心音信号特征包络并对包络作平滑与展宽处理。基于重尺度小波降噪信噪比与特征包络均值参数，创建自适应阈值函数进行心音信号分割，同时利用包络与时域特征剔除因噪音及杂音引起的错误分割点。实验结果表明，该方法能够有效提取基础心音信号特征，分割精度达到89.21%，相比维奥拉积分包络分割法、改进型希尔伯特-黄变换包络双阈值分割法等对比方法分割精度更高、实时性更强。

关键词: 非平稳系统辨识, 心音信号, 心音分割, 自适应阈值, 包络提取

Abstract: To effectively segment Heart Sound Signal(HSS),this paper proposes an adaptive segmentation method for heart sound based on Non-Stationary System Identification(NSSI),so as to extract the envelope of HSS,and smooth and broaden it.The method uses the noise reduction Signal to Noise Rate(SNR) of heavy-scale wavelet and the mean parameter of feature envelope to establish the adaptive threshold function for signal segmentation of heart sound.Also,the false segmentation points caused by noise and murmur are excluded according to the envelope and time domain features.Experimental results show that the proposed method can effectively extract the basic features of HSS,increasing the segmentation accuracy to 89.21%.Compared with the envelope segmentation method of Viola integral,improved double-threshold envelope segmentation method based on Hilbert-Huang transform and other methods,the proposed method has higher segmentation accuracy and real-time performance.

Key words: Non-Stationary System Identification(NSSI), Heart Sound Signal(HSS), heart sound segmentation, adaptive threshold, envelope extraction

中图分类号: 

• TN912