An new approach of ambulatory urodynamic system for measuring the abdominal pressure

We developed a system to perform fully ambulatory monitoring studies of the bladder and a new method of measuring the abdominal pressure noninvasively using the bio-impedance method. To verify this system, bladder and abdominal pressures and surface EMG signals were recorded during artificial filling cystometry. The system was evaluated in 10 AUM studies, whose mean duration was 11 minutes 42 seconds(standard deviation plusmn 4 minutes 16 seconds). Visual inspection of the recorded data showed that the subtraction of the abdominal trace from the bladder trace provided a useful detrusor trace when the subjects were either active or resting. Also, the amplitude of the bio-impedance signal was much higher when the subject coughed, sneezed or talked than when he or she was resting(p<0.05). Therefore, the bio-impedance method is a useful tool to measure the change in the abdominal pressure in an AUM study. We concluded that the proposed system can provide good quality recordings and should prove useful in future evaluations of natural filling urodynamics studies.