Marvell C J, Kirk D L, Jenkins H M, Symonds E M
Br J Obstet Gynaecol. 1980 Sep;87(9):786-96. doi: 10.1111/j.1471-0528.1980.tb04614.x.
A real-time computer system was employed to monitor continuously the fetal electrocardiogram (ECG) during labour. Signals from a scalp electrode were amplified, filtered and passed through an interface system to a digital computer. From 110 patients studied, 37 were selected by rigid criteria which fulfilled a strict definition of normal fetal condition in labour and delivery. The mean values and the range of the various parameters of the fetal ECG complex were defined. As a large amount of data was generated by the system, a method was developed to display the short and long-term dynamic behaviour of the fetal ECG during labour in the form of labour profiles. By further averaging of these labour profiles, the pattern of normal behaviour was established. Certain changes in the fetal ECG, previously thought to be characteristic of fetal distress, occurred in normal patients. The P-R interval was up to 10 per cent shorter during contractions towards the end of labour and there was a long-term trend towards the end of labour for the P-R interval to fall by 7 per cent. The P wave amplitude fell by 30 per cent over the last hour. These trends were statistically significant. The QRS complex was found to lengthen slightly towards the end of labour, but the R-T interval and ST segment displacement displayed no significant changes.
采用实时计算机系统在分娩过程中持续监测胎儿心电图（ECG）。来自头皮电极的信号被放大、滤波，并通过接口系统传输到数字计算机。在研究的110名患者中，根据严格标准选取了37名，这些标准符合分娩和接生时正常胎儿状况的严格定义。确定了胎儿心电图复合波各种参数的平均值和范围。由于系统产生了大量数据，开发了一种方法，以分娩曲线的形式显示分娩过程中胎儿心电图的短期和长期动态行为。通过进一步平均这些分娩曲线，建立了正常行为模式。以前认为是胎儿窘迫特征的某些胎儿心电图变化，在正常患者中也会出现。在分娩接近尾声时，宫缩期间P-R间期缩短高达10%，并且在分娩接近尾声时，P-R间期有长期下降7%的趋势。在最后一小时内，P波振幅下降了30%。这些趋势具有统计学意义。发现QRS复合波在分娩接近尾声时略有延长，但R-T间期和ST段移位无明显变化。
