分娩時における子宮内歴について

抄録

For the measuring of intra-uterine pressure at labor, the authors made an improved apparatus which is made cf strain gauges and amplifiers. Two kinds of receptor, by which the intra-uterine pressure is directly received, were devised : one is bougie type and the other is catheter type. The former is a long rubber tube of which head is spherical and has the strain gauges in it. Wires for gauges are lead through the canal of the tube. This rubber tube is inserted into uterus between uterine wall and fetal membrane through the os uteri. The position of the head of tube in uterus is ascertained by x-ray photography. The catheter type equipment is a metal cylinder which is divided by a thin diaphragmatic membrane into upper and tower chambers. One strain gauge is pasted at the bottom of the surface of diaphragmatic membrane and the other one at the wall. The upper chamber is filled with amniotic fluid through a polyeteylene tube which is inserted in uterine cavity. Changes of intra-uterine pressure in accordance with contraction of uterus are transported to strain gauges. AC bridge circuit is arranged with the two strain gauges in the receptors and two constant resistances. The transported pressure to strain gauges is amplified as the potential changes and recorded.
The electromyograms of abdominal muscles were simultaneously recorded, thus the activity of the muscles was shown.
In case of normal labor, intra-uterine pressure followed by uterus contraction increased to 70 80 mmHg in the first stage and more than 100 mmHg in the second stage. The effect of abdominal pressure to intra-uterine pressure was not seen in the first stage but was seen in the second stage, conspicuously.
Administration of Oxytocine increased the intra-uterine pressure. Trichlorethylene and analgesics was not effective,