Experiments in the Measurement of Intrauterine Pressure

Abstract

Summary A series of experiments investigating the quality of the signals obtained from intrauterine catheters was conducted in the labour rooms and laboratories. Clear evidence of signal attenuation due to partial blockage of catheters was obtained. Some methods which might help to overcome these problems are described.

Scar rupture in labour after previous lower uterine segment caesarean section: the role of uterine activity measurement

“…Intrauterine pressure was recorded using Sonicaid FM3R monitors, external transducers (Medex) and fluid filled catheters (Portex). The use of this equipment was in accord with manufacturers' instructions and current clinical guidelines for the siting of catheters and transducers and the regular flushing of catheters were observed (Odendall et al 1976).…”

Application of Fiberoptics to the Clinical Measurement of Intra‐Uterine Pressure in Labor

“…The fiberoptic tip within its protective dome does not react to compressional forces on the recording unit itself when in direct contact with the endometrium (3,14). The fluid-filled catheter can be obstructed by blood or vernix, which serves to damp the pressure wave reaching the external transducer (4). The fiberoptic transducer, on the other hand, has two large orifices in its protective dome which reduces the risk of this type of obstruction ocurring.…”

Technical Aspects of Fetal and Intrauterine Pressure Monitoring

“…The position of the catheter tip within the uterine cavity (provided that it is in continuity with the amniotic fluid) therefore has no effect on the measured pressure, as incorrectly claimed by some authors (Odendaal et al, 1976). The position of the catheter tip within the uterine cavity (provided that it is in continuity with the amniotic fluid) therefore has no effect on the measured pressure, as incorrectly claimed by some authors (Odendaal et al, 1976).…”