Apparatus and method for selecting and outputting character by teeth-clenching

A method of selecting and outputting characters by a teeth clenching motion, comprising the steps of:

• a) sensing an electromyogram signal of a predetermined muscle activated by a teeth clenching motion made by a user through electromyogram sensors;
• b) dividing the sensed electromyogram signal by a predetermined time, extracting characteristics from the divided electromyogram time blocks, comparing the extracted characteristic value with a predetermined threshold, classifying the divided electromyogram time block into an On-state if the extracted characteristic value are larger than the threshold, classifying the divided electromyogram time block into an Off-state if the extracted characteristic value is smaller than the threshold, identifying a basic teeth clenching motion pattern having one of values ‘rest’, ‘left’, ‘right’ and ‘both’ at a basic pattern identifying unit, selecting a key location allocated on a keyboard based on the identified basic teeth clenching pattern of each block, and selecting one of characters in the selected key through a teeth clenching motion to completely input a corresponding character at a command generating unit;
• and
• c) outputting the selected character on a character displaying unit.