Karlsson B, Pourcelot D, Helgason T, Pourcelot L, Berson M
National University Hospital, Reykjavik, Iceland.
Med Eng Phys. 1998 Jul;20(5):325-31. doi: 10.1016/s1350-4533(98)00033-2.
Foetal heart rate (FHR) monitoring using the Doppler shift resulting from the movements of the foetal heart is a standard examination in most obstetrical wards. Other movements also give rise to a low frequency Doppler shift. These signals are incompletely understood. Their characteristics may offer a way for diagnostic exploitation through complementing or replacing time consuming ultrasound observation of foetal movements. It is shown that a wealth of information is contained in these signals which can easily be extracted on line by a standard PC computer using straightforward methods of signal processing. In its amplitude an ultrasonic Doppler signal contains information concerning the size of the reflector in movement and speed as frequency. The displacement of the reflector can also be derived from the phase evolution of a complex Doppler signal. Examples of signals generated by various types of foetal activity are shown and analyzed.
利用胎儿心脏运动产生的多普勒频移进行胎儿心率（FHR）监测是大多数产科病房的标准检查。其他运动也会产生低频多普勒频移。这些信号尚未被完全理解。它们的特征可能为通过补充或取代耗时的胎儿运动超声观察来进行诊断利用提供一种方法。结果表明，这些信号中包含了大量信息，使用标准的个人电脑，通过简单的信号处理方法就可以很容易地在线提取这些信息。超声多普勒信号在其幅度上包含有关运动中反射体大小和速度（作为频率）的信息。反射体的位移也可以从复多普勒信号的相位演变中推导出来。展示并分析了由各种类型的胎儿活动产生的信号示例。
