Quantification of erection.

In the study of impotence the objective measurement of erection is not yet available. The commercially available nocturnal penile tumescence device records penile expansion only. Penile stiffness and intracavernosal pressure have not been measured. We only developed a penile model in which the simultaneous measurement of expansion and intraluminal pressure could be recorded. In the patient a similar measuring system has been used in acutely produced penile erection and serves as a point of reference to be compared to spontaneous erections recorded at night with the nocturnal penile tumescence device. The ratio between the artificial acute erection and the spontaneous nocturnal erection was calculated and aided in the evaluation of impotence.