Abstract
The advances of computer hardware and signal processing made it possible to the usage of the brain signals for communication between human and computers. Extracting electroencephalographic (EEG) signals may help severely disabled individuals with an alternative means of communication and control. The degree of freedom control depends on the quality of the extracted signals. In this paper, we introduce many techniques and algorithms used to extract different EEG signals. To test our developed algorithms, we developed a wheelchair movement simulator as well as virtual keyboard applications. Other contributions in this paper include utilizing of Trie data structure along with T9 and binary search algorithm for efficient virtual keyboard application..