title: Frequency analysis of urinary bladder pre-voiding activity in normal and overactive rat detrusor.
abstract: OBJECTIVE
  To test the hypothesis that voiding in anesthetized rats is preceded by recurrent changes in the pattern of bladder pressure. To explore the use of frequency analysis as an analytical tool for automatically detecting these changes and to provide quantitative data on bladder pre-voiding activity.
  
  
  METHODS
  We developed an algorithm, based on frequency analysis, to study bladder pressure during the filling phase in anesthetized rats. Two applications of the algorithm were tested: (i) as a predictor of a voiding contraction with alarms generated which would make conditional nerve stimulation to prevent incontinence possible; and (ii) as a new index to quantify rapid pressure transients in normal and overactive detrusor conditions (i.e., induced by acetic acid instillation into the bladder).
  
  
  RESULTS
  The results show that a very high percentage (∼90%) of the alarms was generated by the algorithm within 100 sec before voiding. The index of rapid transients and the bladder volume before voiding were respectively ∼13% less and ∼42% less in acetic acid.
  
  
  CONCLUSIONS
  We have shown that a simple algorithm, based on frequency analysis of bladder pressure, can be used to predict voiding and to provide quantitative data on non-voiding bladder activity and its changes due to pathology. Although the results refer to anesthetized rats, they are promising and warrant further urodynamic investigation to identify if similar patterns occur in non-anesthetized rats and in humans.
authors.affiliation: Department of Urology, Sector FURORE, Erasmus MC, Rotterdam, The Netherlands.|Bristol Urological Institute, Southmead Hospital, Bristol, United Kingdom.
authors.forename: Francesco
authors.initials: F
authors.lastname: Clavica
authors.affiliation: Department of Urology, Sector FURORE, Erasmus MC, Rotterdam, The Netherlands.
authors.forename: Mahipal
authors.initials: M
authors.lastname: Choudhary
authors.affiliation: Department of Urology, Sector FURORE, Erasmus MC, Rotterdam, The Netherlands.
authors.forename: Els
authors.initials: E
authors.lastname: van Asselt
authors.affiliation: Department of Urology, Sector FURORE, Erasmus MC, Rotterdam, The Netherlands.
authors.forename: Ron
authors.initials: R
authors.lastname: van Mastrigt
mesh_terms: D000465:Algorithms; D000818:Animals; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D001743:Urinary Bladder / Q000503:physiopathology*; D053201:Urinary Bladder, Overactive / Q000503:physiopathology*; D014554:Urination / Q000502:physiology*; D014563:Urodynamics / Q000502:physiology*
keywords: bladder filling; conditional nerve stimulation; non voiding activity; overactive bladder