Touchless virtual keyboard controlled by eye blinking and EEG signals Krzysztof Dobosz and Klaudiusz Stawski Silesian University of Technology, Institute of Informatics, Akademicka 16, Gliwice, Poland krzysztof.dobosz@polsl.pl,klausta435@student.polsl.pl Abstract. The paper describes the idea of touchless virtual keyboard designed for disabled people with tetraparesis. Each key can be selected by three double eye blinks registered by EMG sensor. EEG signals are used as a support that allows the user to change the input mode of sin- gle characters to the mode of predicted words selection. The keyboard was implemented and evaluated during provided experiments. Obtained result (WPM =1.11) partially confirms the calculated typing speed (WPM =1.23). It is also found that the keyboard efficiency can be im- proved by using a list of predicted words, even the number of those words is low and they are short (WPM =1.27). Provided discuss presents that improved keyboard used by experienced users could achieve the typing efficiency even up to WPM =3.15. Keywords: virtual keyboard, text entry, brain-computer interface, BCI, eye blinking 1 Introduction Communication and the ability to interact with the environment, especially to other people, are fundamental needs for human relationships. For people who suffer from severe physical disabilities, because they are completely paralyzed, ability to comply with this need is almost impossible. Their physical activities very often are limited to eye blinking. Although it is sufficient to communicate using Morse code - this method is very cumbersome. Human-Computer Interac- tion (HCI) researchers explore opportunities of using as many sensors channels as possible [24]. Among others, in support to impaired physical activity, bioelec- trical brain signals can be used to provide an alternative communication channel. A Brain-Computer Interface (BCI) is able to recognize changes in the ongoing bioelectrical signals and to use them to appropriate commands in order to realize the communication aids. The aim of the project was to propose useful BCI, which allow users with severe motor disabilities to use virtual keyboard. The electroencephalographic (EEG) devices mostly measure fundamental human activity states as atten- tion and relaxation (meditation). The devices sometimes integrates also an elec- tromyographic sensor that can be used for eye blinks recognition. Such signals