Direct static measurement of obstruction

The measurement of related values of pressure and cross‐sectional area along the urethra provides, on theoretical grounds, the means to detect local areas of obstruction. A probe was developed to make such measurements and was used in a preliminary study on tubes of known mechanical properties; it enabled the differentiation of elastic from nonelastic tubes, based on values of the “hydrostatic compliance.” The results obtained are discussed and compared to alternative techniques used for the measurement of urethral compliance that have been developed for and applied clinically on females.