Mehnert
Fakultäten » Medizinische Fakultät » Universitätsklinik Balgrist und Schweizerisches Paraplegikerzentrum » Paraplegikerzentrum » Prof. Dr. Volker Dietz (emeritiert) » Mehnert
Completed research project
| Title / Titel | The quest for an objective measure of bladder sensibility: a new approach using heart rate variability and skin conductance level analysis in urodynamics | ||||
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| Abstract (PDF, 14 KB) | |||||
| Summary / Zusammenfassung | Introduction & Objectives: The bladder is closely coupled to the autonomic nervous system (ANS). Heart rate variability (HRV) and skin conductance level (SCL) analysis are useful tools to monitor the ANS in short or long terms. The aim of this study is to evaluate the use of HRV and SCL as objective measures for bladder sensibility during filling cystometry. Methods: After approval of the local ethic committee, a group of healthy female subjects will be recruited and written informed consent will be obtained. A standard filling cystometry at 25ml/min through a transurethral 8Ch filling catheter will be performed with subjects lying comfortably on an urodynamic examination table in a quite ambience and with ear plugs to avoid possible distraction. A 3-lead electrocardiogramm and the SCL will be continuously recorded using surface disc electrodes. SCL will be recorded from the right palmar and plantar skin with a reference electrode on the right forearm. Room temperature will be kept stable at 22°C. Special care will be taken that all subjects feel comfortable with temperature and have not any disturbing perceptions from the catheter. To reduce artefacts and allow subjects to get used to the situation, they will lie relaxed for 15 min and the catheter will be connected to a urine bag to keep the bladder empty until filling will be started. During filling cystometry subjects will have to indicate first filling sensation (FFS), first desire to void (FDV) and strong desire to void (SDV) by pressing a pushbutton. After the first measurement, subjects will be allowed to empty the bladder on the toilette and after 5 hours the same measurement will be repeated to verify reproducibility. The analysis of HRV, based on power spectrum analysis, will be performed with a flexible scientific software (SOLEASY™) as follows: 1) detection of R-waves in ECG 2) calculation of RR-intervals and generation of discrete event series (DES) 3) calculation of power spectrum from DES 4) calculation of integral of very low frequency (VLF), low frequency (LF) and high frequency (HF) ranges. These 3 parameters will be determined in a moving window of 5 minutes (short-term analysis). The HF fraction is supposed to reflect the parasympathetic component and the LF/HF ratio the sympathovagal balance. LF/HF ratio and normalized values of LF and HF will be calculated and overlaid with the pushbutton signal. The SCL signals will be analysed by calculation of the area under the curve (AUC) of consecutive 30s intervals using the same software. Statistical analysis will be performed between LF/HF ratios within one measurement and between both measurements at different bladder sensations. The same applies for the SCL analysis. Signficancy analysis will be performed with SPSS using Wilcoxon signed ranks test. The graphs from the moving window analysis of HRV and SCL will be summarized to show mean, median and standard deviation during the course of the two filling cystometries. |
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| Keywords / Suchbegriffe | bladder filling sensation, autonomic nervous system, herat rate variability, skin conductance level, urodynamics | ||||
| Project leadership and contacts / Projektleitung und Kontakte |
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| Funding source(s) / Unterstützt durch |
SNF (Personen- und Projektförderung) |
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| Duration of Project / Projektdauer | May 2006 to Apr 2008 |