Assessment of erectogenic drugs by numeric plethysmography

A method of assessment of the erection in man, using numeric penile plethysmography, is presented. The data concerning the sensor, the electronic circuit, and the computer interfacing with an IBM PC are described. As a validation of this method, apomorphine (0.009 mg/kg) was tested in a double-blind, placebo-controlled study, carried out in healthy volunteers. Apomorphine induced an erection starting, as a mean, at the fourth minute postinjection. The treatment increased the penis volume without any other stimulation (p = 0.0008) and potentiated the physiologic response induced by visual erotic stimulation (p = 0.0012). The limits of plethysmography are discussed in reference to rigidimetry.