A carbon dioxide flowmeter.J Urol. 1977 Dec; 118(6):1035-6.JU
A simple and inexpensive uroflowmeter has been designed that uses a common carbon dioxide cystometer. The patient voids urine in a specially designed container connected at the bottom of the carbon dioxide source in the cystometer. After proper calibration (500 cc fluid for a 20 mm. deflection in the paper) the patient is asked to void while carbon dioxide flows through the container and the paper recording commences. Any change of volume in the container produces a change in the pressure recorded by the cystometer, which will allow us to know, following calibration, the 2 factors involved in flow: 1) volume voided and 2) time. A table of average flow is available for a quick reading of the findings only by superimposing the table on the uroflow study. The only attachment needed for the cystometer is the special container. Our results support the use of this economical new way to determine urinary flow.