Simultaneous Measurement of Pelvic Floor Muscle Activity and Vaginal Blood Flow: A Pilot Study Stephanie Both, PhD,* and Ellen Laan, PhD † *Department of Psychosomatic Gynecology and Sexology, Academic Hospital, Leiden University, Leiden, the Netherlands; † Department of Sexology and Psychasomatic Obstetrics and Gynaecology, Academic Medical Centre, University of Amsterdam, Amsterdam, the Netherlands DOI: 10.1111/j.1743-6109.2007.00457.x ABSTRACT Introduction. Dyspareunia, defined as persistent or recurrent genital pain associated with sexual intercourse, is hypothesized to be related to pelvic floor hyperactivity and to diminished sexual arousal. Empirical research to support these hypotheses is scarce and concentrates mostly on the role of either pelvic floor activity or genital arousal in female dyspareunia. Currently, however, there is no measurement device to assess pelvic floor activity and genital response simultaneously. Aim. The aim of this study was to investigate the validity of a new device that enables simultaneous measurement of pelvic floor activity and genital response in women. Main Outcome Measures. Genital arousal measured as vaginal pulse amplitude, and vaginal surface electromyogram (EMG). Method. Thirty sexually functional women participated. To investigate the accuracy of genital response measure- ment with the adapted photoplethysmograph, and the sensitivity of the device for involuntary changes in pelvic floor activity, vaginal pulse amplitude and vaginal surface EMG were monitored during exposure to emotional, including erotic, films. In addition, vaginal surface EMG was monitored during instructed pelvic floor contractions. Results. The genital data obtained during emotional films proved accurate measurement of genital response. EMG values during the emotional films indicated limited sensitivity of the device for small, involuntary changes in pelvic floor activity due to emotional state. The EMG measurements during the instructed pelvic floor contractions proved sensitivity of the new probe to voluntary pelvic floor activity. Conclusion. It is concluded that following improvement of the sensitivity of the EMG measurement for small, involuntary changes in pelvic floor activity, the device will be a valuable tool in research on superficial dyspareunia. Both S, and Laan E. Simultaneous measurement of pelvic floor muscle activity and vaginal blood flow: A pilot study. J Sex Med 2007;4:690–701. Key Words. Pelvic Floor; Vaginal Surface EMG; Dyspareunia; Genital Response; Psychophysiology Introduction D yspareunia, defined by the Diagnostic and Statistical Manual of Mental Disorders, fourth edition text revision (DSM-IV-TR) as per- sistent or recurrent genital pain associated with sexual intercourse, is hypothesized to be related to pelvic floor hyperactivity and to diminished sexual arousal [1–3]. In the few psychophysiological studies that attended to the role of these compo- nents in female dyspareunia, the focus was on either pelvic floor activity or sexual arousal. Cur- rently there is no measurement device to simulta- neously assess pelvic floor activity and genital response. In this study, we report on a pilot study with a new device that was developed to concur- rently measure pelvic floor muscle activity and genital arousal in women. According to an explanatory model of dyspareu- nia, originally described by Spano and Lamont [4], pain during penetration, or memories of that pain, lead to fear of pain in new intercourse situations, 690 J Sex Med 2007;4:690–701 © 2007 International Society for Sexual Medicine