WIRED StaffScienceJan 12, 2007 12:00 AMGallery: Sex Research DevicesThe napkin-ring myograph, developed in 1984, uses three electrodes to measure muscle contractions in the vaginal wall. It has been used to study the effect of stimulation of the clitoris and G spot.Photo: InContiNetSave StorySave this storySave StorySave this storyPhoto: University of British ColumbiaPhoto: Journal of Applied Behavior AnalysisPhoto: Barry KomisarukPhoto: Barry KomisarukPhoto: Barry KomisarukPhoto: Barry Komisaruk