一种多谱勒胎音信号提取方法的研究

Research of a New Method for Abstracting Fetal Heart Rate from Doppler Ultrasonic Signal

对胎儿监护的主要方法是监听胎儿心率 ,而超声多谱勒测量胎儿心率是一种很好的无创方法。但是 ,由于测量得到的原始信号成分非常复杂 ,干扰严重 ,从而使其对胎心率的提取造成很大困难。文章提出一种新的胎音信号处理方法———平均频移自相关方法 :先在移动的时间间隔内对超声多谱勒信号进行傅立叶变换 ,得到信号的时频分布 ,然后求对应的每个频谱的平均频率得到多谱勒信号的平均频率曲线 ,最后利用自相关算法从平均频率曲线中提取胎儿心脏跳动曲线。通过模拟仿真和实际信号处理 。

fetal heart rate. A new method—autocorrelation of mean frequencies of the curve is presented in this paper. In this method, first, FFT is done for ultrasonic Doppler signals for each interval of time of displacement to obtain time frequency distribution of the signals. Then the curve of mean frequency of Doppler signals was computed corresponding to mean frequency of each frequency spectrum. Finally, the fetal heart beating curve was extracted from the curve of mean frequency using an autocorrelation algorithm. This method has been proved to be able to pick up the signal of fetal heart rate from Doppler ultrasonic signal precisely from simulated or actual signals.