Hardware keyboards for one-handed people have existed long-time ago. But what if the user had a partial second hand, or even just an elbow pushbutton, or a box with four corners which the elbow could push on to achieve the effect of pushing a SELECT-KEYBOARD-KEYS button. Thus, either this for people with an elbow and no hands (use the feet instead of the elbow input-device on a place next to the chair. Moving the elbow should feel like operating the gears of a tractor or car).
A person with no hands (just feet could use two [cyclically arranged switch]-machines. They look loke roulette-machine circles, but have an metal icon with a clamp that goes around the foot. As you move the clamp with the part above the ankle (which is part of the 3/8 area down the leg), the slider moves, making a click the person can hear to know what position they are in. A little bit at a tine, the no-arm(es) person will get accustomed to what letter each position will correspond to.
A separate, but similar, hooked-roulette wheel device around the waist (a special chair, would need to be present here), allows the armless person to type each time they move the waist around the waist-wheel, making a click moving the device to wherever they want to click, thus selecting the letter corresponding to the feet.
Bite a braces like device in your mouth to toggle between 1-D selection (both directions around the waist-wheel click, or 2-D selection: counterclockwise for imaginary selection of keyboard language (one click to switch to the next of M languages *.spoken by the user), and any movement in the clockwise direction to type.
Are there any such interfaces?
