Clinical evaluation of a high-fidelity wireless intravaginal pressure sensor

Abstract

Introduction and hypothesis: A wireless intravaginal pressure sensor (IVPS) has been developed to quantify abdominal pressure (P(abd)) changes during exercise and activities of daily living to guide post-operative advice given to women. In this pilot study, we aimed to compare IVPS performance, comfort, retention, and acceptability to a standard fluid-filled intrarectal pressure catheter currently used to measure P(abd) during routine urodynamics.

Methods: A Life-Tech 3-mm urodynamic intrarectal catheter and IVPS were inserted concurrently in volunteers attending a urodynamics clinic. The IVPS was positioned above the levator plate and the intrarectal catheter positioned in routine fashion well above the anal sphincter. Routine urodynamics was undertaken, with women asked to perform star jumps if coughing or Valsalva did not invoke leakage. Subjects rated device comfort using a visual analogue scale (0-10). Repeated measures Bland-Altman analysis determined level of agreement (LOA) between the two devices for peak pressures for each activity.

Results: Twenty-seven women were recruited, 67% of the participants preferred the IVPS, 18% the intrarectal catheter, while 15% had no preference. Mean comfort score was 0.9 ± 1.7 and 2.1 ± 2.6 (p = 0.049) for the IVPS and intrarectal catheter respectively. Bland-Altman analysis demonstrated minimal bias for cough and Valsalva, however LOA were wide. Differences were more prominent during star jumps where rapid dynamic pressure changes occurred.

Conclusions: The IVPS had a higher comfort score and was well retained. The LOA between the two systems was moderate, but the high sampling rate and lower susceptibility to motion artefacts of the IVPS may provide more accurate information that will be important clinically.