Groome L J, Mooney D M, Bentz L S, Wilson J D
Department of Obstetrics and Gynecology, University of South Alabama, Mobile 36617.
Dev Psychobiol. 1994 Nov;27(7):453-66. doi: 10.1002/dev.420270704.
The purpose of this paper was to calculate vagal tone (V) for 17 normal human fetuses in quiet sleep (QS) between 36 and 40 weeks gestation. The fetal cardiac electrical signal was captured transabdominally in 3-min blocks at a rate of 833 times per second and fetal R-waves were extracted using adaptive signal processing techniques. Fetal R-wave interbeat intervals were converted to equally spaced, time-based data, and the low-frequency component was removed using a 21-point third-order moving polynomial. The parameter V was calculated by taking the natural logarithm of the sum of the power densities between 0.3 Hz and 1.3 Hz. We found that fetal breathing was associated with an approximately 25% increase in V as compared to nonbreathing, 3.33 +/- 0.48 versus 2.57 +/- 0.47, p < 0.0001. Furthermore, there was a significant linear relationship between the mean single-fetus V during spontaneous respiration and the mean single-fetus V during normally occurring apneic periods, r = 0.772, p < 0.002. We conclude that respiratory activity is associated with a significant increase in vagal tone for normal human fetuses in QS.
本文的目的是计算17例妊娠36至40周处于安静睡眠（QS）状态的正常人类胎儿的迷走神经张力（V）。经腹采集胎儿心脏电信号，以每秒833次的速率采集3分钟的数据块，并使用自适应信号处理技术提取胎儿R波。将胎儿R波的心动间期转换为等间距的基于时间的数据，并使用21点三阶移动多项式去除低频成分。通过对0.3Hz至1.3Hz之间的功率密度总和取自然对数来计算参数V。我们发现，与非呼吸状态相比，胎儿呼吸时V值增加约25%，分别为3.33±0.48和2.57±0.47，p<0.0001。此外，自发呼吸期间的平均单胎儿V值与正常出现的呼吸暂停期间的平均单胎儿V值之间存在显著的线性关系，r=0.772，p<0.002。我们得出结论，对于处于QS状态的正常人类胎儿，呼吸活动与迷走神经张力的显著增加有关。
