Determination of the urethral stress profile with the aid of perfused catheters.

To make manometric studies of urethral function and obtain exact recordings of the so-called stress profile requires a pressure rise rate which exceeds that of the pressure complex due to coughing. The syringe perfusion pump commonly used in urodynamics limits the pressure rise rate. The rate ist also reduced by catheters with high compliance. A suitable recording accuracy necessitates values greater than 150 kPa/s. This can be achieved with the aid of an improved pneumatic-hydraulic infusion system and low-compliance catheters. We describe the improvement of a recording system and demonstrate the importance of a suitable pressure rise rate.