摘要
为了有效的从超声多普勒胎儿心脏回波信号中提取胎心率,分析了多普勒回波信号的特点,通过空域相关法估计了原始噪声方差,提出了一种自适应去噪阈值计算方法,该算法能根据实际信号的强度、噪声的方差以及分解的层数,自适应的得到不同尺度的去噪阈值。最后通过对实际超声多普勒回波信号的处理,能有效地降低噪声,提取出胎儿心音信号,较准确地计算出胎儿心率值。
To extract heart rate effectively from the Doppler fetus heart signals, the characteristics of Doppler echo signal was analyzed. Through the spatial correlation estimated original noise variance, an adaptive method was proposed that calculated de-noising threshold for different scales based on actual signal intensity, the noise variance and the number of decomposition layers. Through processing actual Doppler fetal heart sound signal, the method could effectively reduce the noise and extract fetal heart sounds, and more accurately calculate fetal heart rate.
出处
《系统仿真学报》
EI
CAS
CSCD
北大核心
2008年第12期3138-3140,3145,共4页
Journal of System Simulation
基金
国家自然科学基金资助项目(60271022
60271025)
关键词
超声多普勒
胎儿心率
小波阈值滤波
空域相关
ultrasonic Doppler
fetal heart rate
wavelet threshold de-noising
spatial correlation
