Why “PUL Interventional Urodynamic Test” figure2 is a powerful and accurate test
It is known that SUI occurs when the pressure in the urethra, or preferably, the internal resistance to flow, is less than the motive pressure (expulsive force) arising in the bladder. The pressure measured in the urethra is actually a function of the urethral diameter (Pressure =Force /Area). It is the area of “C” or “O”, figure1, which determines whether urine is lost (or not). Area = πr2. Simplistically, resistance to flow is inversely proportional to πr4, the 4th power of the radius of “O”. So though the pressure measured is only relative to the 2nd power of “O”, the same diameter “O”, figure1, also actually reflects a 4th power change in resistance to flow, which is a far more powerful parameter of change.