Designing a Hierarchical Keyboard Layout for Brain Computer Interface Based Text Entry

Human beings are naturally blessed with sensory and motor functionalities. These abilities help us understand our surroundings and respond accordingly. However, sometimes, due to innate reasons or trauma, some people are deprived of these functionalities. In order to restore the natural motor functionalities to people with such disabilities, Brain Computer Interface (BCI) has been widely employed with other Human Computer Interaction (HCI) measures to find an optimum solution that ensures a high speed system with reasonable accuracy. In this paper, we have explored one of such systems for Text Entry mechanism using BCI. We have addressed the following three challenges for a BCI based Text Entry system-i)Four motor imagery signal based interaction ii)Processing and classification of noisy EEG data using the available methods iii) Language prediction model to increase input speed. We have tried to contribute in designing the Keyboard Layout for the Text Entry. Existing soft keyboard layouts for BCI systems have either a flat layout or a hierarchical static layout with very few functionalities in more than 2 layers. We propose to improve the hierarchical layout using a 2 layer multi-functional approach. We have prepared a prototype solution to substantiate our hypothesis. With a cognitive walkthrough based evaluation we have validated our hierarchical layout's performance to be accurate and more functional.