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Urodynamics 2.0: A Sneak Peek at Next Generation Urodynamics Technology

By: Adam P. Klausner, MD, Virginia Commonwealth University School of Medicine, Richmond; John E. Speich, PhD, Virginia Commonwealth University College of Engineering, Richmond | Posted on: 20 Mar 2024

Although utilized as the gold standard for the diagnosis of functional bladder disorders for decades, the challenges of urodynamics are clear: lack of reproducibility, variable diagnostic accuracy, artifacts, infections, and the need for invasive catheters. Several groups, including our own, performed urodynamics studies (UDS) on normal healthy volunteers without lower urinary tract symptoms. These studies found high rates (∼70%) of artifactual and inaccurate diagnoses, likely due to irritation from catheters and supraphysiologic fill rates.1 In terms of the voiding phase, UDS performs fairly well. However, filling phase data are more limited, only providing information about involuntary detrusor contractions and compliance. The problem is that a great deal of patient-reported lower urinary tract symptoms (ie, urgency and frequency) occur during the filling phase where UDS may not provide clinically useful data. Bottom line: we need to do better, and here’s a sneak peek at some new ideas.


During UDS, the way we measure sensation is to prompt patients to report verbal sensory thresholds. However, there are insufficient guidelines for what these thresholds mean or what is considered normal. To address this, our group developed a tablet-based sensation meter (Figure 1) which allows patients to record real-time sensation from 0% to 100%.2 The data are then used to generate sensation-capacity curves, and we have shown that curve slopes and how they change are associated with different sensory phenotypes. Furthermore, this technology is simple, cheap, and can be incorporated into UDS equipment or used in stand-alone natural filling studies.


Figure 1. A, Screenshot of the tablet sensation meter with the slider bar participant interface (bottom) and graphical display of real-time bladder fullness sensation from 0% to 100% (middle). B, Example sensation meter data for a participant who reported 7 increases in sensation during 5 minutes of urodynamic filling.


Figure 2. Example of M-mode ultrasound where a linear section of bladder wall (A; intersection of red and green lines) allows real-time mapping of wall thickness vs time along the axes of the red (B) and green (C) lines as measures of micromotion.


Bladder wall micromotion, or spontaneous low amplitude rhythmic detrusor contractions, are thought to be involved in overactive bladder pathophysiology. In fact, investigators have shown that changes in rhythmic activity are associated with increased urgency.3 Unfortunately, techniques to identify micromotion during UDS are limited. In one study, investigators used a urinary catheter with balloon-mounted electrodes inflated to the bladder diameter and demonstrated increased micromotion in women with urgency,4 but the invasivity and discomfort with this technique limits its use. Our group developed an automated detection algorithm during UDS and identified a clear subgroup of patients (∼15%) with micromotion.5 We, and others, have also developed techniques to identify bladder wall micromotion, noninvasively, using linear (M-mode) ultrasound (Figure 2).6

Noninvasive Urodynamics

The goal of a well-done urodynamic study is to reproduce a patient’s functional bladder pathology. In this regard, catheters are problematic, and the ideal UDS upgrade would be catheter free. Our group, and others, have used ultrasound to identify bladder biomechanical properties including shape7 and micromotion.6 Newer technologies include a wireless bladder insert that can record bladder pressures8 and even functional MRI techniques.9 Ultrasound has also been used to measure bladder wall thickness10 and wall elasticity using ultrasonic waves in a technique called vibrometry.11

Preclinical Urodynamics

There are a few groups (including ours) that are successfully using a working in vitro porcine bladder as a model for UDS. We have used this preclinical method to develop new UDS techniques that can be readily translated into human clinical studies. Using this model, we have shown how blood flow and ischemia can alter wall tension,12 how compliance can be acutely regulated,13 and have even shown how upstream afferent nerve signaling can be recorded as a surrogate measure of bladder sensation.14


Unlike many other diagnostic techniques in urology and other areas of medicine, UDS has not evolved much in the last few decades. However, researchers are now working on upgrades to measure sensation, micromotion, and to noninvasively evaluate bladder function using ultrasound and other techniques. There are also multiple groups exploring the brain-bladder axis with functional MRI and near-infrared spectroscopy. While this sneak peek only scratches the surface, hold on, because next-generation UDS upgrades are already in development.

  1. Swavely NR, Speich JE, Klausner AP. Artifacts and abnormal findings may limit the use of asymptomatic volunteers as controls for studies of multi-channel urodynamics. Minerva Urol Nephrol. 2021;73(5):655-661.
  2. Sheen D, Kolli H, Nagle AS, et al. Validation of a real-time bladder sensation meter during oral hydration in healthy adults: repeatability and effects of fill rate and ultrasound probe pressure. Low Urin Tract Symptoms. 2019;11(4):224-231.
  3. Drake MJ, Kanai A, Bijos DA, et al. The potential role of unregulated autonomous bladder micromotions in urinary storage and voiding dysfunction; overactive bladder and detrusor underactivity. BJU Int. 2017;119(1):22-29.
  4. Drake MJ, Harvey IJ, Gillespie JI, Van Duyl WA. Localized contractions in the normal human bladder and in urinary urgency. BJU Int. 2005;95(7):1002-1005.
  5. Cullingsworth ZE, Kelly BB, Deebel NA, et al. Automated quantification of low amplitude rhythmic contractions (LARC) during real-world urodynamics identifies a potential detrusor overactivity subgroup. PLoS One. 2018;13(8):e0201594.
  6. Nagle AS, Cullingsworth ZE, Li R, Carucci LR, Klausner AP, Speich JE. Bladder wall micromotion measured by non-invasive ultrasound: initial results in women with and without overactive bladder. Am J Clin Exp Urol. 2021;9(1):44-52.
  7. Li R, Nagle AS, Maddra KM, et al. Irregular bladder shapes identified in women with overactive bladder: an ultrasound nomogram. Am J Clin Exp Urol. 2021;9(5):367-377.
  8. Frainey BT, Majerus SJA, Derisavifard S, et al. First in human subjects testing of the UroMonitor: a catheter-free wireless ambulatory bladder pressure monitor. J Urol. 2023;210(1):186-195.
  9. Pewowaruk R, Rutkowski D, Hernando D, Kumapayi BB, Bushman W, Roldán-Alzate A. A pilot study of bladder voiding with real-time MRI and computational fluid dynamics. PLoS One. 2020;15(11):e0238404.
  10. Ali M, Ahmed A, Khaled S, Abozeid H, AbdelMagid M. Accuracy of ultrasound-measured bladder wall thickness for the diagnosis of detrusor overactivity. Afr J Urol. 2015;21(1):25-29.
  11. Bayat M, Kumar V, Denis M, et al. Correlation of ultrasound bladder vibrometry assessment of bladder compliance with urodynamic study results. PLoS One. 2017;12(6):e0179598.
  12. Swavely NR, Cullingsworth ZE, Nandanan N, Speich JE, Klausner AP. Phases of decompensation during acute ischemia demonstrated in an ex vivo porcine bladder model. Transl Androl Urol. 2020;9(5):2138-2145.
  13. Duval DLM, Weprin S, Nandanan N, et al. Regulation of bladder dynamic elasticity: a novel method to increase bladder capacity and reduce pressure using pulsatile external compressive exercises in a porcine model. Int Urol Nephrol. 2021;53(9):1819-1825.
  14. Moore RH, Ghatas MP, Rogers D, et al. A porcine bladder model of pre-clinical urodynamics demonstrates increased afferent nerve activity during filling. Neurourol Urodyn. 2023;42(6):1181-1187.