Objective Quantification of Detrusor Overactivity using Spectral Measures of Cystometry Data

Published:January 25, 2023DOI:



      To develop scalable objective methods for differentiating patients with and without detrusor overactivity (DO) using quantitative Fast Fourier Transform (FFT)-based measures and routinely captured cystometry data


      Retrospective cystometry data were collected as pre-void vesical and abdominal pressure signals from 18 DO and 10 SUI (non-DO) cystometry recordings. Data were filtered and divided into two equal-duration segments, Early and Late Fill, representing the first and second halves of filling. FFT was applied, followed by subtraction of abdominal spectra from vesical spectra. Spectral Power (SP) and Weighted Average Frequency (WAF) measures were calculated for each segment spectra within 1-6 cycles min−1.


      Compared to non-DO, the mean SP was significantly higher in DO patients for both Early and Late Fill segments. WAF was significantly lower in DO patients for both segments. Changes in spectral pressures appeared to be linked to the presence of detrusor contractions (DCs) and were especially visible when DCs were present in the Early Fill segments of cystometry.


      FFT-based spectral measures derived from routinely captured cystometry data are significantly different between DO and non-DO patients. This preliminary method is clinically scalable and can be further developed to facilitate the detection of DO, classify disease phenotype, and capture therapeutic efficacy.



      DO (Detrusor Overactivity), UDS (Urodynamics), DC (Detrusor Contractions), LUTS (Lower Urinary Tract Symptoms), FFT (Fast Fourier Transform), SP (Spectral Power), WAF (Weighted Average Frequency), SUI (Stress Urinary Incontinence), OAB (Overactive Bladder)
      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Urology
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Winters JC
        • Dmochowski RR
        • Goldman HB
        • et al.
        Urodynamic studies in adults: AUA/SUFU guideline.
        J Urol. 2012; 188: 2464-2472
        • Whiteside JL
        • Hijaz A
        • Imrey PB
        • et al.
        Reliability and agreement of urodynamics interpretations in a female pelvic medicine center.
        Obstet Gynecol. 2006; 108: 315-323
        • Zimmern P
        • Nager CW
        • Albo M
        • Fitzgerald MP
        • McDermott S
        Urinary Incontinence Treatment Network. Interrater reliability of filling cystometrogram interpretation in a multicenter study.
        J Urol. 2006; 175: 2174-2177
        • van Waalwijk van Doorn ES
        • Ambergen AW
        • Janknegt RA.
        Detrusor activity index: quantification of detrusor overactivity by ambulatory monitoring.
        J Urol. 1997; 157: 596-599
        • 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; 13e0201594
        • Cullingsworth ZE
        • Li R
        • Klausner AP
        • Speich JE.
        Quantification of Spontaneous Rhythmic Contractions in Individuals With and Without Overactive Bladder: Is All Detrusor Overactivity Clinically Relevant?.
        Neurourology and Urodynamics. 2020; (Published onlineAccessed April 1, 2021)
        • Colhoun AF
        • Speich JE
        • Cooley LF
        • et al.
        Low amplitude rhythmic contraction frequency in human detrusor strips correlates with phasic intravesical pressure waves.
        World J Urol. 2017; 35: 1255-1260
        • Niederhauser T
        • Gafner ES
        • Cantieni T
        • et al.
        Detection and quantification of overactive bladder activity in patients: Can we make it better and automatic?.
        Neurourology and Urodynamics. 2018; 37: 823-831
        • Lentle RG
        • Reynolds GW
        • Janssen PWM
        • Hulls CM
        • King QM
        • Chambers JP.
        Characterisation of the contractile dynamics of the resting ex vivo urinary bladder of the pig.
        BJU International. 2015; 116: 973-983
        • Clavica F
        • Choudhary M
        • van Asselt E
        • van Mastrigt R.
        Frequency analysis of urinary bladder pre-voiding activity in normal and overactive rat detrusor.
        Neurourol Urodyn. 2015; 34: 794-799
        • Byrne Michael D
        • Klausner Adam P
        • Speich John E
        • Southern Jordan B
        • Habibi Joseph R
        • Ratz Paul H
        Fourier Transform Analysis of Rabbit Detrusor Autonomous Contractions Reveals Length Dependent Increases in Tone and Slow Wave Development at Long Lengths.
        Journal of Urology. 2013; 190: 334-340
        • Hobbs KT
        • Choe N
        • Aksenov LI
        • et al.
        Machine Learning for Urodynamic Detection of Detrusor Overactivity.
        Urology. 2021; (Published online October 29S0090-4295(21)00990-0)
        • Ravishankar B
        • Upchurch W
        • Iaizzo P
        • Timm G
        • Nelson D.
        Quantification of Low, Amplitude Rhythmic Signals in Bladder Contractions: Cholinergic Stretch-Tension Interactions, Measured Using Porcine Bladder Strips In-vitro.
        in: Society of Urodynamics, Female PelvicMedicine & Urogenital Reconstruction (SUFU) Annual Meeting BS#33. 2021
        • Ravishankar B
        • Vasdev R
        • Timm GW
        • Nelson DE.
        Measurement and Quantification of Cystometric Bladder Pressure Spectra in an in-vivo Sheep Model: A Feasibility Study.
        in: 43rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC). 2021
        • Ravishankar B
        • Elliott SP
        • Nakib NA
        • Timm GW
        • Nelson DE.
        Retrospective clinical study of spectral power and frequency in urodynamics pressure data: Workflow and preliminary tests of fill-dependence.
        Neurourology and Urodynamics. 2020; (Published onlineAccessed May 7, 2021)
        • 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: 22-29
        • Ouyang Z
        • Sperry ZJ
        • Barrera ND
        • Bruns TM.
        Real-time Bladder Pressure Estimation for Closed-loop Control in a Detrusor Overactivity Model.
        IEEE Trans Neural Syst Rehabil Eng. 2019; 27: 1209-1216
        • Wang HHS
        • Cahill D
        • Panagides J
        • Nelson CP
        • Wu HT
        • Estrada C.
        Pattern recognition algorithm to identify detrusor overactivity on urodynamics.
        Neurourol Urodyn. 2021; 40: 428-434