Maeda Kazuo
Department of Obstetrics and Gynecology (Emeritus), Tottori University Medical School, Yonago, Japan.
J Obstet Gynaecol Res. 2016 Jan;42(1):5-10. doi: 10.1111/jog.12855. Epub 2015 Dec 29.
To enable scientific studies on fetal movements and its relation to fetal heart rate directly detecting fetal chest motion with ultrasonic Doppler method.
A prototype of an ultrasonic Doppler fetal actocardiograph (ACG) was designed and handmade by the author. A 2 MHz ultrasound fetal heart rate (FHR) monitor was remodeled to detect fetal heartbeat and chest movement Doppler signals with a single ultrasound probe. The fetal movement Doppler signal was 20-50 Hz using 2 MHz ultrasound, separated from the fetal heartbeat Doppler signal, which was 100 or more Hz and sent to the autocorrelation FHR meter to record FHR curve, while fetal movement Doppler signals were detected through 20-80 Hz band-pass filter, and changed to spikes recorded on a cardiotocography chart.
The spike amplitudes of a moving steel ball expressed fetal movement on the ACG. FHR acceleration synchronized with fetal movement bursts. Fetal resting and active states are separated using the ACG. Fetal hiccupping movements on ACG were regular continuous spikes with 2-3 s intervals.
Fetal movements and hiccups were correctly recorded with the FHR curve. The relation of FHR and movement will be further clarified in future ACG readings.
运用超声多普勒方法直接检测胎儿胸部运动，以开展关于胎动及其与胎儿心率关系的科学研究。
作者设计并手工制作了一台超声多普勒胎儿心动描记仪（ACG）原型。将一台2兆赫兹的超声胎儿心率（FHR）监测仪进行改造，使其能用单个超声探头检测胎儿心跳和胸部运动的多普勒信号。使用2兆赫兹超声时，胎儿运动多普勒信号为20 - 50赫兹，它与100赫兹及以上的胎儿心跳多普勒信号分离，然后被发送至自相关FHR测量仪以记录FHR曲线，而胎儿运动多普勒信号则通过20 - 80赫兹带通滤波器进行检测，并转换为尖峰记录在胎心监护图上。
移动钢球的尖峰幅度在ACG上表示胎动。FHR加速与胎动爆发同步。利用ACG可区分胎儿的静息和活动状态。ACG上的胎儿打嗝运动是间隔2 - 3秒的规则连续尖峰。
FHR曲线正确记录了胎儿运动和打嗝情况。FHR与运动的关系将在未来的ACG读数中得到进一步阐明。
