RESUMO
AIMS: To explore the use of time-frequency analysis as an analytical tool to automatically detect pattern changes in bladder pressure recordings of patients with overactive bladder (OAB). To provide quantitative data on the bladder's non-voiding activity which could improve the current diagnosis and potentially the treatment of OAB. METHODS: We developed an algorithm, based on time-frequency analysis, to analyze bladder pressure during the filling phase of urodynamic studies. The algorithm was used to generate a bladder overactivity index (BOI) for a quantitative estimation of the average bladder non-voiding-activity. We tested the algorithm with one control group and two groups of patients with OAB symptoms: one group with detrusor overactivity (DO), assessed by an experienced urologist (OAB-with-DO group), and another group for which detrusor overactivity was not diagnosed (OAB-without-DO group). RESULTS: The algorithm identified diagnostically significant data on the bladder non-voiding activity in a specified frequency range. BOI was significantly higher for both OAB groups compared to the control group: the median value of BOI was twice as big in OAB-without-DO and more than four times higher in OAB-with-DO compared to control group. Moreover the algorithm was successfully tested to detect episodes of detrusor overactivity. CONCLUSIONS: We have shown that a simple algorithm, based on time-frequency analysis of bladder pressure, may be a promising tool in the clinical setting. The algorithm can provide quantitative data on non-voiding bladder activity in patients and quantify the changes according to phenotype. Moreover the algorithm can detect DO, showing potential for triggering conditional bladder stimulation.
