Use of a force measuring instrument during cervical dilatation

Mechanical Properties of the Pregnant Human Uterine Cervix Use of an Instrument to Measure the Index of Cervical Distensibility

“…Pregnancy Pregnancy Postpartum 22 ± 2 40 ± 1 5+h day weeks weeks methods are not accurate enough to reveal the small changes that may correspond to information on the length of the pregnancy; (3) measurement of the forces encountered during surgical dilatation of the uterine cer vix (using a series of stainless steel dilators of increasing diameter) have been previously described by several investigators [7][8][9]. But these methods, measuring the forces required to overcome cervical resistance passing each dilatator through the cervix: (a) mix parameters related to dilatation of the uterine cervix (friction forces) and cervical consistency, and (b) can be used, in clinical practice, only before diagnostic curettage in nonpregnant patients and in therapeutic abortion by suction curettage during the first trimester of pregnancy.…”

Cervical Dilatation before First Trimester Elective Abortion: A Comparison between Laminaria and a Newly Developed Hydrogel Tent, the A Rod

“…The cervical resistance was also measured by attaching the Pratt dilators to a force sensing handle equipped with a pressure transducer and connected to a chart recorder. Techni cal details of the instrument have been previously published [7,8]. The resistance registered was not accessible to the operator.…”

Evaluation of the Clinical Method of Measuring Cervical Dilatation after Treatment of the Cervix prior to First Trimester Abortion

“…Concomitantly, the resistance to dilatation was measured, for each dilator, by attaching the dilator to a force-sensing handle containing a pressure transducer in each case. Details of this instrument have pre viously been published [10,11], The cervical dilatation measured objectively was defined as the largest Pratt dilator that passed the cervix with a resistance of less than 0.3 kg. All operations in study A were performed by 1 operator, while in study B, 12 different physi cians were engaged.…”