Brain Computer Interface

Abstract

This chapter introduces the current state of the art of brain—computer interface (BCI) technology based on noninvasive surface electroencephalogram (EEG) recordings. The basic idea of a BCI is to enable a new communication channel that bypasses the standard neural pathways and output channels in order to control an external device. The ultimate goal of BCI technology is to enable lost body or communication functions in handicapped persons. Persons suffering from, e.g., amyotrophic lateral sclerosis (ALS), stroke or spinal cord injuries might lose the ability to fully control (peripheral) muscle activity. Depending on the disease either the neural pathway might be affected or the muscle itself. In a first attempt one can substitute the neural pathways or the affected muscles with still functional pathways or muscles. This approach might be very beneficial to the subjects, though the approach might also have limitations. Subjects can use, e.g., eye movements for communication or control. In the BCI approach body functions are restored by detecting the proper neural or muscle activity above the level of injury. These signals can serve as input to the BCI, which properly encodes the patterns and converts the activity into control commands. After a certain time of training the BCI can predict the user’s intentions and the user can operate, e.g., the closing/opening of a robotic hand or control a wheelchair.