In the field of urodynamics, microcomputers have become used for various data processing.This report introduced a uroflowmeter for on-line data processing. In this case, a higher precision uroflowmeter was required and this type uroflowmeter has been developed. In this flowmeter, sample and hold circuits were used for the weight-to-flow converter. As a result, a low drift and high stability of the flow curve were obtained. Further the measurement of the flow rate was able to started within 6 seconds after the power was turned on. The urine volume was calculated by a microcomputer from the flow curve obtained, and error rates in this case remained less than 2 % mostly.
