A one-handed keyboard from Infogrip, Ventura, CA (www.infogrip.com) for people with the use of only one hand. Invented in 1986 and placed on the market in 1991, the Bat keys are pressed in combination like piano chords. Speeds up to 60 words per minute can be obtained. Some people also use the Bat in applications that require a lot of text and graphics manipulation, typing with one hand while moving the mouse with the other. See keyboard.