KSII TRANSACTIONS ON INTERNET AND INFORMATION SYSTEMS VOL. 5, NO. 10, October 2011 1770 Copyright ⓒ 2011 KSII The part of this paper was presented in the ICONI (International Conference on Internet) 2010, December 16-20, 2010, Philippines. This version includes a concrete analysis and supporting implementation results. This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (No. 2011-0018014). DOI: 10.3837/tiis.2011.10.005 Brain-Operated Typewriter using the Language Prediction Model Saebyeok Lee and Heuiseok Lim Dept. of Computer Science Education, Korea University Seoul, Republic of Korea [e-mail: saebyeok@blp.korea.ac.kr, limhseok@korea.ac.kr] *Corresponding author: Heuiseok Lim Received March 31, 2011; revised July 20, 2011; accepted August 30, 2011; published October 31, 2011 Abstract A brain-computer interface (BCI) is a communication system that translates brain activity into commands for computers or other devices. In other words, BCIs create a new communication channel between the brain and an output device by bypassing conventional motor output pathways consisting of nerves and muscles. This is particularly useful for facilitating communication for people suffering from paralysis. Due to the low bit rate, it takes much more time to translate brain activity into commands. Especially it takes much time to input characters by using BCI-based typewriters. In this paper, we propose a brain-operated typewriter which is accelerated by a language prediction model. The proposed system uses three kinds of strategies to improve the entry speed: word completion, next-syllable prediction, and next word prediction. We found that the entry speed of BCI-based typewriter improved about twice as much through our demonstration which utilized the language prediction model. Keywords: Language prediction model, brain-computer interface, Korean typewriter