Sexuo-physiological functioning after cervical cancer treatment

Vaginal pulse amplitude (VPA) in response to sexual stimuli. VPA will be measured by a vaginal photoplethysmograph. The photoplethysmograph is a menstrual tampon-sized device, containing an orange-red light source and a photocell. The light source illuminates the capillary bed of the vaginal wall and the phototransistor responds to the light backscattered by the vaginal wall and the blood circulating within it. When the signal is connected to an alternating current (AC) amplifier, vaginal pulse amplitude (VPA) is measured, which reflects the phasic changes in vaginal engorgement accompanying each heartbeat, with larger amplitudes reflecting higher levels of vaginal vasocongestion. VPA is a sensitive, specific, and reliable measure of vaginal vasocongestion and is used in earlier studies that observed diminished vaginal blood flow in women with neurological damage and in women after radical hysterectomy (see publication of Pieterse et al, 2008, protocol P05.095). VPA will be recorded continuously during the experimental session. The stimulus material will be identical to the previous studies. All women will be exposed to two erotic 5.5 min film excerpts (consisting of videos depicting cunnilingus and intercourse). The erotic films will be preceded by 5 min neutral film (during which a non-erotic documentary film excerpt will be shown). The erotic film excerpts are taken from so-called women-made, female-centred erotic videotapes. VPA is sampled at 20 Hz across baseline and subsequent trails. A two-pass algorithm for automatic artefact removal (© Molenkamp Technical Support Group University of Amsterdam) is used to analyse the VPA data. After artefact deletion peak-to-trough amplitude is calculated for each remaining pulse. For each 5-minute baseline recording, a mean baseline score per subject is calculated. Mean and maximum VPA for each subject within the entire session is identified (i.e. either within erotic stimulus one or two).