A Tactile P300 Based Brain Computer Interface System for Communication in iOS Devices

摘要

A Brain Computer Interface (BCI) based assistive technology device offers great reliability and access to individuals who are affected by neurodegenerative motor disabilities. As the disease progresses, individuals lose their physical and voluntary movements and only their brain signals remain active. A BCI system using an individual's electroencephalograph (EEG) signal provides a mechanism for these individuals to communicate with the external world. As most of the communication depends on the use of smartphones or tablets, an EEG based iOS communication device is presented in this study. A tactile feedback mechanism, which evokes P300 event related response is used to obtain EEG signals. This tactile or haptic feedback system comprises of three vibrational coin motors attached at the fingertips of the user. When the user concentrates on these motor vibrations, a P300 response is generated. Three P300 responses can be obtained for each of the three motors as these motors run at different revolutions per minute (rpm). The signals obtained are preprocessed, filtered, feature extracted, and given as the control signals to an Arduino. These signals are mapped to an iPhone device by enabling the Bluetooth and Switch control feature for performing various actions such as "move to previous item", "move to next item", and "tap". Three experiments involving four participants were conducted to test the accuracy and reliability of the system. Our results show that a user can correctly navigate to their desired location 66.67% of the time. The system presented in this study can also be used to navigate from an iPhone's home screen to Google in approximately six minutes. The results obtained are promising for individuals who are completely paralyzed. Lastly, the proposed system can also be used to navigate third party applications, such as Sounding Board which is a commonly used assistive technology application that allows the users to select a phrase that will be heard through the iPhone's speaker.