Basic and clinical investigations on fetal blood pressure monitoring in labor by the difference in electrocardiogram and pulse oxymetry.

在动物实验中，我们使用长期仪器化的胎羊，通过施用降压药或抽取一定量的胎血，使胎血压降低了约10毫米汞柱。我们连续测量胎儿血管内血压（实际血压）、心率、脉搏血氧计波形。利用心电图（r波峰值）和脉搏血氧测量（斜率最大增幅）的时间差，用预先确定的公式“HASTE”估算血压（estimate- bp）。所有动物的实际血压和估算血压之间均有显著相关性（p<0.01），具有良好的偏差值（<8mmHg）和精度值（< 5mmhg）。这项技术有可能提供胎儿每拍的血压信息，这将有助于解释分娩和分娩过程中胎儿心率监测。

In animal experiments using chronically instrumented fetal goat, we decreased fetal blood pressure by about 10 mmHg by administrating hypotensive agents or by withdrawing some amount of fetal blood. We measured intravascular blood pressure (actual-BP), heart rate, pulse oxymeter waveforms of the fetuses continuously. The time difference in electrocardiogram (the peak R-wave) and pulse oxymetry (the maximum increase in slope) was used to estimate the blood pressure (estmate-BP) with a predetermined equation "HASTE" A significant correlation (p<0.01) with good bias values (<8mmHg) and precision values (<5 mmHg) was obtained between the actual-BP and estimate-BP in all animals. This technique has the potential to provide information on fetal blood pressure on a beat-by-beat basis, which will aid in the interpretation of fetal heart rate monitoring in labor and delivery.