Two-letters-key keyboard for predictive touchless typing with head movements

Abstract

Head operated interfaces offer touchless interaction with electronic devices for physically challenged people who are unable to operate standard input equipment. The great challenge of such interfaces is text entry. Most existing approaches are based on camera mouse where the on-screen keyboard is operated by the pointer controlled with head movements. Movements of the head are also employed to cycle through keys or their groups to access the intended letter. While the process of direct selection requires substantial precision the traverse procedure is time consuming. The main contribution of this paper is proposition of the Two-Letters-Key Keyboard for touchless typing with head movements. The solution offers substantial acceleration in accessing the desired keys. The typing proceeds with directional head movements and only two consecutive moves are required to reach the expected key. No additional mechanisms (like eye blink or mouth open) are required for head typing.