Effect of a Condom Cover on Vaginal Photoplethysmographic Responses

Introduction The vaginal photoplethysmograph (VPP) is a reusable intravaginal device often employed in sexual psychophysiology studies to assess changes in vaginal blood flow, an indicator of sexual arousal. Aim To test whether placing a disposable cover on the VPP probe impacts the acquired data. A condom cover would reduce risk of disease transmission and likely increase participant comfort but may negatively impact the VPP signal. Method The genital responses of 25 cisgender women (mean age = 21.3 years, standard deviation = 2.6) were assessed with VPP in a within-subjects design with 2 conditions—with and without a polyisoprene condom cover. Sexual responses were elicited by audiovisual film clips that varied in erotic intensity: nonsexual (nonsexual male-female interaction), low-intensity sexual (nude exercise), and high-intensity sexual (male-female intercourse). Women continuously rated their sexual arousal during stimulus presentations. Main Outcome Measure Change in vaginal pulse amplitude and also self-reported sexual arousal. Results The magnitude of sexual response to each stimulus category and the overall pattern of results were found to be highly similar in the cover-off and cover-on conditions. The high-intensity sexual stimulus category elicited a greater sexual response than all other categories. The low-intensity sexual category elicited a (small) genital response in only the cover-on condition, although we suspect this is a spurious finding. There was no difference in the average number of edited movement artifacts across conditions. Clinical Implications Potential benefits of encasing the VPP probe with a protective cover include enhanced participant safety and comfort, especially if assessing genital responses of high-risk or immunocompromised samples. The use of a cover complies with current guidelines for reprocessing semi-critical medical devices (eg, vaginal ultrasound probes) in many regions. Strengths & Limitations Although the idea of a VPP probe cover had been discussed among sexual psychophysiology researchers, this is the first study to empirically test whether a cover could jeopardize VPP data. Potential limitations include the use of a 10-Hz VPP sampling rate and a cover that was not tailored to the size of the VPP probe. Conclusion Placing a protective cover on the VPP probe did not appear to meaningfully impact sexual arousal or the VPP data. Based on these results and the potential advantages of a protective cover, researchers may wish to integrate the use a condom cover in their experiment protocols and clinical applications.