Schreiben mit dem Brain-Computer-Interface

A Brain-Computer Interface (BCI) enables a user to control a computer and other electronic devices solely with the power of her thoughts, without any muscle activity. It provides a new interface between the human brain and a computer and is sometimes the only communica-tion channel left of a completely paralyzed patient to its environment. We give an overview of several approaches that enable such a communication. Then the EEG-based P300 approach is discussed in detail. A P300 speller application was developed that enables a user to write symbols, words, and complete sentences on a computer without motor activity. We discuss the employed methods and processing techniques as well as an approach for automatic de-termination of the number of trials to use for each target item. This approach also allows de-tection of the user's activity and inactivity, respectively. We tested the developed speller with seven healthy test persons. An averaged information transfer rate of 5.84 symbols/min with an accuracy of 81.8% was achieved.