Development
VPG was first introduced in 1967 by Palti and Berovici, who affixed a light source and photosensitive cell onto a gynecological speculum and recorded vaginal pulse waves. Sintchak and Geer improved on the device in 1975 by using a vaginal probe. The vaginal photoplethysmograph was the first practical and reliable device for the measurement of vaginal blood flow.
Read more about this topic: Vaginal Photoplethysmograph
Famous quotes containing the word development:
“There are two things which cannot be attacked in front: ignorance and narrow-mindedness. They can only be shaken by the simple development of the contrary qualities. They will not bear discussion.”
—John Emerich Edward Dalberg, 1st Baron Acton (1834–1902)
“I hope I may claim in the present work to have made it probable that the laws of arithmetic are analytic judgments and consequently a priori. Arithmetic thus becomes simply a development of logic, and every proposition of arithmetic a law of logic, albeit a derivative one. To apply arithmetic in the physical sciences is to bring logic to bear on observed facts; calculation becomes deduction.”
—Gottlob Frege (1848–1925)
“The work of adult life is not easy. As in childhood, each step presents not only new tasks of development but requires a letting go of the techniques that worked before. With each passage some magic must be given up, some cherished illusion of safety and comfortably familiar sense of self must be cast off, to allow for the greater expansion of our distinctiveness.”
—Gail Sheehy (20th century)