Design and development of a novel intra-vaginal pressure sensor.

INTRODUCTION AND HYPOTHESIS: The influence of intra-abdominal pressure (IAP) on prolapse development is poorly understood. Nonetheless, chronic cough, high BMI, or heavy lifting predisposes women to pelvic organ prolapse (POP). This study aims to develop and test a novel, wireless intra-vaginal pressure sensor (IVPS) to quantify intra-abdominal pressure changes across a range of well-defined activities.
METHODS: The IVPS shape was based on silicone moulds of the vagina and was designed to sit in the proximal vagina. It is thin, compliant and negligibly distorts the surrounding tissues. Repeatability was assessed in 14 volunteers performing three sets of activities (cycles). Each cycle consisted of 18 activities. The IVPS was removed and reinserted after completing either the first or second of the three-cycle exercise routine (order). Participants independently inserted and removed the device. A nested split-plot, factorial ANOVA determined the effect of order using mean IAP increase (mean) and peak-to-peak fluctuations in IAP (amplitude) as dependent variables. Descriptive analysis examined the relative change in IAP across the activities. Cronbach's alpha) determined repeatability.
RESULTS: All women found the IVPS comfortable and easy to insert. There was excellent correlation between cycles across all variables, r > 0.935 (mean) and r > 0.964 (amplitude). The order was not statistically significant, demonstrating a highly repeatable measurement.
CONCLUSION: This is the first device to measure IAP at high frequency with the freedom of a wireless system. The IVPS aims to provide information to advise women better on suitable pre- and post-operative activities.