[Biopotentials of the urinary bladder during functional load].

The study aimed to investigate the specific bioelectrical activity of the urinary bladder walls at a functional load.

MATERIALS AND METHODS: The study comprised five subjects aged 18-22 years who had no diseases of the urinary system. Participants signed an informed consent form before entering the study, which was approved by the Ethics Committee of our organization. Biopotentials from the ureter and urinary bladder area were recorded using the Neuro-Spectrum NeuroSoft-21 Neuron Spectrum-4 electroencephalograph, which has a higher sensitivity compared to other biopotential amplifiers. The sensitivity range of the electroencephalograph according to the manufacturer was in the frequency range from 0.05 to 250 Hz 1-1000 V/mm, the quantization frequency - up to 5000 Hz, the noise level - less than 0.3 V. The obtained data were in agreement with the results of the ultrasound and urodynamic studies, which implied the possibility to consider this method of registration of bladder biopotentials suitable for such a purpose.

RESULTS: The analysis of the background spectra for the same time (at rest and under load) identified a correlation between them (correlation coefficient > 0.8). Three frequencies were chosen in the range from 0.5 to 2 Hz, for which the changes of the amplitude were most clearly traced in time. A correlation analysis (using the STATISTICA 10 software) showed a correlation between these three frequencies and background load (correlation coefficient 0.2).

CONCLUSIONS: The water loading resulted in an increase in the activity of the bladder wall biopotentials after the 10th minute of registration. The functional load changed the pattern of the changes of the harmonics of the bioelectrical activity spectrum of the bladder walls: in the background record, the harmonics behaved almost identically in time, but after water loading, the amplitudes of the harmonics changed with the passage of time. One of the main findings of the work is the detection of several frequencies ranged from 0.5 to2 Hz (0.7, 1.5 and 1.7 Hz), which can be used to assess the functional state of the bladder wall.