MP07-02\u2003A PILOT TRIAL TO EVALUATE A HIGH-RESOLUTION, NON-INVASIVE URODYNAMIC STUDY TO MONITOR ELECTRICAL ACTIVITY OF THE HUMAN BLADDER

Abstract

INTRODUCTION AND OBJECTIVES: Urodynamic studies are utilized in evaluating neurogenic bladder (NGB) and refractory overactive bladder (OAB), but are invasive and can cause significant bother to the patient. In addition, insertion of urethral catheters for vesical pressure monitoring and back-filling has a potential risk of urinary tract infection and its associated morbidity. In this pilot study, we combined the expertise of bioengineers, translational scientists and urologists to determine the feasibility and sensitivity of a novel non-invasive UDS (NI-UDS) system for dynamic bladder physiology assessment in healthy volunteers. METHODS: Cutaneous myoelectric recordings of the urinary bladder were measured from ten healthy subjects consisting of seven females (mean age 37.17±5.02 years) and three males (mean age 30.33±0.88 years) using NI-UDS. NI-UDS is performed with an array of eight surface electrodes (Ambu Blue Sensor-N) placed on the suprapubic region and left flank (ground) after reporting a full bladder. Data is recorded in three phases: (1) 5 mins 30 secs storage phase, (2) voluntary voiding, and (3) 5 minutes post-void phase. Statistical signal processing is performed with Python to determine spatial and temporal patterns in the three phases associated with wave propagation. Features include wave speed and whether or not a sustained wave is present at any point in time. RESULTS: Average percentages of sustained wave in the bladder of female subjects during storage, voiding and post-void phases were 0.71±0.05, 0.74±0.06 and 0.73±0.05, respectively. Interestingly, male subjects had lower average percentages of sustained wave compared to females (0.66±0.03, 0.68±0.03 and 0.67+0.03 for storage/filling phase, voluntary voiding and post-voiding phase, respectively). We also determined histograms of wave speed ranging 0-2, 2-4, 4-6, 6-8 and 8-9.5 mm/s. Strikingly, all subjects revealed lowest wave speeds during voluntary voiding, suggesting quiescent electrical activity in the bladder during this phase. CONCLUSIONS: Preliminary studies show that NI UDS is sensitive to determine physiological changes in gender-specific and voiding phase-specific manners. Furthermore, intrasubject consistency supports that NI UDS has potential in evaluating bladder dynamics in a non-invasive manner. Source of Funding: This study is supported by Adult and Pediatric Urology of University of California San Diego (UCSD) and San Diego Spina Bifida Association.