Sexual armour patent, 1908. Artwork of a device (seen from the rear) invented by American nurse Ellen E. Perkins. It was designed to be worn by male and female asylum patients to prevent masturbation. The armour was made from a cloth based body suit and featured a metal crotch that could only be opened using a key. A leather vest was also secured by padlock. Masturbation was considered by some at the time to be one of the causes of insanity.