The Intelligent Numpad: Detection of Mode from Spatial and Temporal Keystroke Characteristics

A general input paradigm for blind and visually impaired users is proposed. Input is classified into three categories, namely input of text using Braille chords, input of digits and navigation and editing of text. A numpad input device is used for all the three modes of input. The required mode is automatically detected by analyzing the spatial and temporal properties of the device usage. Braille input chords are resolved dynamically and are therefore not bound to specific keys. Low-cost and widely available standalone numeric keypads are used as input devices.