ABSTRACT
The urine loss itself needs to be evaluated. Using a weighed perineal pad for the length of the test gives some idea of the severity of the incontinence, but gives little information about when the loss occurred. If the timing of the loss can be calculated, then the manometric changes leading to incontinence can be interpreted and may be helpful in determining the cause of urinary leakage. There are three ways of achieving this. The first is the Urilos (Exeter) ( Fig. 35.4 ) electronic diaper, which has already been alluded to. It has elongated, interleaved electrodes embedded in absorbent material. A 50 mV (low voltage) alternating current is passed between the two electrodes; as the urine loss increases, so does this current. Obviously this depends on the electrodes being within the urine, which is definitely not guaranteed, and so the pad has to be preloaded with a known volume of electrolyte solution. This method is suitable only for volumes between 1 and 100 ml and is reproducible within 20%.
