Objective: To evaluate the performance of a simplified fluid monitoring device for monitoring fluid deficit and uterine perforation during hysteroscopic surgery.
Material and Method: A novel fluid deficit monitoring device was developed using a weighing system operated by a microcontroller. The deficit volume in milliliters (mL) is continuously monitored with an updated display every 30 seconds. The deficit LED is preset to begin flashing with an alarm sound if a fluid deficit reaches 750 mL, 1,000 mL, and 2,500 mL. A new algorithm for detection of small uterine perforations was also developed. The device can be loaded with a maximum of four bottles of 1 liter distention media and has two 2 liters collecting canisters. After having passed laboratory testing, the prototype was clinically used in hysteroscopic surgeries.
Results: The laboratory testing showed a precision of ±7 mL at 500 mL, with an accuracy of ±8.9% for deficit volume measurement with 100% alarm at the preset levels. The perforation alarm could detect a small uterine perforation with 80.0% accuracy in an average (±standard deviation; S.D.) latency time of 3.2±0.2 minutes with an average (±S.D.) fluid leakage of 472±35 mL. The device performed well in a preliminary series of 42 hysteroscopic surgery cases from October 2014 to February 2016. Deficit-volume detection by the device correlated well with clinical evaluations by operating room personnel (r=0.840, p-value<0.001).
Conclusion: The newly developed fluid monitoring device can provide acceptable precision and accuracy for monitoring fluid deficits and detection of small uterine perforations during hysteroscopic surgery.