The aim of this study was to enhance patient comfort and diagnostic accuracy in urodynamic studies (UDS) by developing a novel framework that uses a single vesical pressure (Pves) channel combined with a surface abdominal electromyography (AEMG) electrode array to estimate detrusor pressure (Pdet) without the need for an abdominal catheter. The proposed method was designed to operate in real-time, and to be compatible with current UDS clinical hardware.

Data were collected from consecutive UDS studies at two US urology sites on adult male and female patients that presented with LUTD. Cystometry and Pressure-Flow UDS recordings (n=40) were prospectively collected using 7 French air-charged catheters (TDOC-7F series, Laborie Medical Technologies, Portsmouth, NH) with an EasyPro Urodynamics system (SRS Medical, Chelmsford, MA). A surface AEMG electrode array (Smart Sensor series, SRS Medical) was placed approximately two inches both laterally and below the patient naval. Forty UDS studies (11 men and 29 women) were performed with AEMG measured simultaneously with both Pves and Pabd. A predefined, provocative abdominal maneuver was used before each study to ensure accurate coupling between the AEMG signal and associated abdominal pressures seen in Pves and determine "Go"/"No Go" to proceed to single catheter cystometry if coupling was sufficient for Pdet estimation from Pves and AEMG. Criteria were based on signal to noise ratio in AEMG and correlation between AEMG and corresponding change in Pves as measured by the Euclidean distance between the two signals. After passing the provocative maneuver stage, Pves data during cystometry was passed to a wavelet multiresolution analyzer and decomposed into fundamental frequency components. Different urodynamic events (Valsalva, cough, bladder contraction, void) and their combinations were detected based on signal characteristics and Pves was appropriately divided into Pabd and Pdet based on known sources of these events and as confirmed by AEMG activity for abdominal events. An event-based scoring metric was used to determine how accurately this approach estimated Pdet by calculating the percentage of signal contained in the appropriate channel for that event (Pdet vs abdominal pressure).

The results showed that 30 of the 40 cases indicated a "Go" status after the provocative maneuver, demonstrating feasibility of this method in a majority of UDS studies. Across the 30 “Go” studies included in this analysis, estimated Pdet resulted in a median score of 93%, while subtracted Pdet had a median score of 64%. For the example Urodynamics study shown in the Figure, the average scores for estimated Pdet were 96.3±2.8% for coughs, 95.2±2.2% for pushes, and 87.6±1.4% for bladder contractions, yielding an overall average score of 93±2.6%. On the other hand, applying the same metric to subtracted Pdet yielded the following results: 93.5±3.1% for coughs, 67.5±2.4% for pushes, and 52.7±4.7% for bladder contractions, resulting in an overall average score of 71.2±3.7%. Note in this case the reduced accuracy was due to artifacts induced by the abdominal pressure catheter, which were not present when Pdet was estimated from Pves as validated with AEMG.

High correlation values and scores indicated that the estimated Pdet closely followed the calculated Pdet pressure, reinforcing the reliability of the proposed method.

This innovative approach has the potential to revolutionize urodynamic studies by providing a more comfortable and accurate diagnostic tool for assessing bladder function. This is particularly beneficial for vulnerable populations, such as the elderly and children, reducing the need for multiple catheters and improving the overall patient experience during UDS.