Automation in urodynamics.

The information concerning bladder function during voiding and the size of the outlet resistance is found in relation to detrusor pressure and urinary flow (pressure flow plot). The lowest detrusor pressure during voiding (low-pressure flank) contains information on mechanical resistance (passive urethral resistance relation, PURR). The PURR curve is defined using foot point (cross-section with pressure axis) and slope. An increasing foot point as well as a decrease in the slope of the PURR curve indicate an increase in mechanical resistance. Optimally foot point and curvature must be classified separately as realized by the two-dimensional CHESS classification. The definition of PURR and its classification in CHESS are ideal procedures for a computer which simplifies the process.