Vaginal photoplethysmograph

The Vaginal photoplethysmograph (VPG) is a controversial type of plethysmograph. It consists of a clear acrylic, rod-shaped device that contains a light source, and a light detector. The light source illuminates the capillary bed of the vaginal wall and the blood circulating within it. The amount of light that is backscattered is in direct relation to the transparency of engorged and unengorged tissue and, hence, serves as an indirect measure of vasoengorgement , an indication of sexual arousal.

The device was introduced in 1975, when Sintchak and Geer. It was the first practical and reliable device for the measurement of vaginal blood flow. The vaginal probe was designed to be easily inserted by the subject. Its introduction spurred great (research) interest in the area of female sexual arousal throughout the late 70s and early 80s. Research has since slowed.

Use

The device remains the most frequently used method for monitoring vaginal blood flow. This device, as well as the male version, has been used in attempts to identify homosexuals and latent homosexuals.

See also

Penile plethysmograph, Anal photoplethysmograph , Plethysmography .

External links

• http://homepage.psy.utexas.edu/homepage/group/MestonLAB/laboratory/plethysmograph.htm