摘要
目的 本文介绍一种在心音图 (PCG)中定位第一心音 (S1)和第二心音 (S2 )的算法。方法 利用小波变换多分辨分析将PCG信号分解成不同的频带 ,然后按时间顺序分段计算频段的规一化香农能量 ,能量大于某一合适阈值的时刻作为S1和S2 的候选点 ,结合心音的特点确定S1和S2 。结果 在对 2 880个心动周期的运用中 ,正确定位率达到了 96%以上。结论 小波变换多分辨分层后的分段算法能对S1和S2 定位 ;如果不分段处理 ,求整体香农能量 。
Objective An algorithm located the first sound(S 1) and the second sound(S 2) on phonocardiogram(PCG) was introduced. Methods The PCG signals were decomposed into different frequency bands by multiresolution analysis of wavelet transformation. Then the normalized Shannon energy of the frequency bands was calculated segmentally on time sequencial basis. The moments at which the energy was larger than a certain appropriate threshold were defined as candidate points, and S 1 and S 2 points were located according to the characteristics of heart sound. Results This approach was applied to 2 880 cardiac cycles, the accurate location rate of S 1 and S 2 had reached>96%. Conclusions S 1 and S 2 can be successfully located with segmental algorithm after multiresolution analysis of wavelet transformation. The frequency range of heart sound and heart murmur can also be defined after getting the total Shannon energy without segmental processing.
出处
《生物医学工程与临床》
CAS
2002年第4期181-184,共4页
Biomedical Engineering and Clinical Medicine
基金
云南省自然科学基金资助项目
编号 2 0 0 1C0 0 0 4M
关键词
小波变换
心音定位
规一化香农能量
heart sound
multiresolution analysis of wavelet transformation
normalized Shannon energy
heart sound location
