Methods for Measuring Female Arousal
Vaginal Photoplethysmography (VPP): The most common and validated method. It is a tampon-sized acrylic probe, inserted by the woman, that uses light reflection to measure vaginal blood volume (VBV) and, more commonly, vaginal pulse amplitude (VPA). VPA is considered a specific indicator of sexual arousal.
Labial Thermistor: A small clip attached to the labia minora that measures changes in temperature, which directly correlate to blood flow and engorgement. It is less subject to movement artifacts than VPP.
Thermography: An infrared camera that creates a visual map of surface temperature changes in the genital region, particularly the clitoris and labia.
Laser Doppler Imaging (LDI): A noninvasive technique used to measure superficial skin blood flow in the clitoris, labia, and posterior fourchette.
Clitoral Photoplethysmograph (CPP): A device that measures blood volume changes specifically in the clitoris.
Other Physiological Markers: These include increased heart rate, increased respiration, skin conductance (sweat gland activity), and pupil dilation.