摘要
为了从超声多谱勒胎音信号中提取胎音信号,获得平滑的胎心率曲线,并计算胎心率,必须去除信号提取过程中的各种干扰和噪声。对平均频移算法获得的多谱勒信号的平均频率曲线采用小波变换中的五层强制去噪方法,使后续的相关计算能得到平滑的胎音信号,从而方便计算胎儿的心率。通过对实际超声多谱勒胎音信号的处理,获得了较好的结果,提取出了稳定、平滑的胎心率曲线,较准确地计算出了胎心率。
Various interference and noises should be eliminated while picking up the signal of fetal heart rate from the Doppler fetal signal in order to obtain smooth curve of the fetal heart Doppler signal and so to figure out the fetal heart rate. In this study,the mean frequency shift curve estimated from the Doppler fetal signals was smoothed using wavelet transform. The results showed that the fetal-heart rate obtained by computing from the autocorrelation waveform based on the smoothed mean frequency shift curve was more accurate than that based on unsmoothed curve.
出处
《生物医学工程学杂志》
EI
CAS
CSCD
北大核心
2005年第2期339-342,共4页
Journal of Biomedical Engineering
基金
云南省自然科学基金资助项目 (2 0 0 2 C0 0 0 2 Z)
云南省科技计划资助项目 (2 0 0 2 PY10 )
