title: Conversion of urodynamic pressures measured simultaneously by air-charged and water-filled catheter systems.
abstract: OBJECTIVE
  The objective of this study was to compare the simultaneous responses of water-filled (WFC) and air-charged (ACC) catheters during simulated urodynamic pressures and develop an algorithm to convert peak pressures measured using an ACC to those measured by a WFC.
  
  
  METHODS
  Examples of cough leak point pressure and valsalva leak point pressure data (n = 4) were obtained from the literature, digitized, and modified in amplitude and duration to create a set of simulated data that ranged in amplitude from 15 to 220 cm H2 O (n = 25) and duration from 0.1 to 3.0 sec (n = 25) for each original signal. Simulated pressure signals were recorded simultaneously by WFCs, ACCs, and a reference transducer in a specially designed pressure chamber. Peak pressure and time to peak pressure were calculated for each simulated pressure signal and were used to develop an algorithm to convert peak pressures recorded with ACCs to corresponding peak pressures recorded with WFCs. The algorithm was validated with additional simulated urodynamic pressure signals and additional catheters that had not been utilized to develop the algorithm.
  
  
  RESULTS
  ACCs significantly underestimated peak pressures of more rapidly changing pressures, as in coughs, compared to those measured by WFCs. The algorithm corrected 90% of peak pressures measured by ACCs to within 5% of those measured by WFCs when simultaneously exposed to the same pressure signals.
  
  
  CONCLUSIONS
  The developed algorithm can be used to convert rapidly changing urodynamic pressures, such as cough leak point pressure, obtained using ACC systems to corresponding values expected from WFC systems.
authors.affiliation: Department of Biomedical Engineering, The Cleveland Clinic, Cleveland, Ohio.|Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio.
authors.forename: Hassan K
authors.initials: HK
authors.lastname: Awada
authors.affiliation: Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio.
authors.forename: Paul C
authors.initials: PC
authors.lastname: Fletter
authors.affiliation: Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Zaszczurynski
authors.affiliation: Department of Biomedical Engineering, The Cleveland Clinic, Cleveland, Ohio.|Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio.
authors.forename: Mitchell A
authors.initials: MA
authors.lastname: Cooper
authors.affiliation: Department of Biomedical Engineering, The Cleveland Clinic, Cleveland, Ohio.|Advanced Platform Technology Center, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio.|Glickman Urological & Kidney Institute, The Cleveland Clinic, Cleveland, Ohio.
authors.forename: Margot S
authors.initials: MS
authors.lastname: Damaser
mesh_terms: D000388:Air; D000465:Algorithms; D003198:Computer Simulation; D003371:Cough / Q000503:physiopathology; D006801:Humans; D011312:Pressure; D015203:Reproducibility of Results; D014160:Transducers, Pressure; D014546:Urinary Catheterization / Q000295:instrumentation* / Q000379:methods*; D014563:Urodynamics; D014636:Valsalva Maneuver; D014867:Water
chemical_list: D014867:Water
keywords: bladder; cough; leak point pressure; pressure chamber; valsalva