EEG-Based Brain-Computer Interface for Tetraplegics

Abstract

Movement-disabled persons typically require a long practice time to learn how to use a brain-computer interface (BCI). Our aim was to develop a BCI which tetraplegic subjects could control only in 30 minutes. Six such subjects (level of injury C4-C5) operated a 6-channel EEG BCI. The task was to move a circle from the centre of the computer screen to its right or left side by attempting visually triggered right- or left-hand movements. During the training periods, the classifier was adapted to the user's EEG activity after each movement attempt in a supervised manner. Feedback of the performance was given immediately after starting the BCI use. Within the time limit, three subjects learned to control the BCI. We believe that fast initial learning is an important factor that increases motivation and willingness to use BCIs. We have previously tested a similar single-trial classification approach in healthy subjects. Our new results show that methods developed and tested with healthy subjects do not necessarily work as well as with motor-disabled patients. Therefore, it is important to use motor-disabled persons as subjects in BCI development.

Psychophysiology and Autonomic Responses Perspective for Advancing Hybrid Brain-Computer Interface Systems

“…The task familiarity and acclimatization to the environment are thus highly important to get efficient BCI performance. 9,67 In many research articles, an enhanced motor performance has been reported after the mental practice and adaptation to the experimental environment in comparison to the novices. 30 Therefore, the practicing of MI is a promising intervention and has been observed to have significant correlation in improvement of performance of motor execution in patients with all types of motor impairments as well as in sports.…”

ERS and ERD analysis during the imaginary movement of arms

“…Commonly, researchers measure EEG signals at many electrode locations of brain. For examples, they measure 19 electrodes [3], 32 electrodes [1], 41 electrodes [4] or more than it. And they extract features from the electrodes to be aware of thinking of a subject (Fig.…”

“…Brain-Computer Interface (BCI) is an interface technique between human and computer which can help severely motor-disabled persons to communicate and control their environment [1].…”

“…Some researchers observe changes of EEG signals at each frequency [3,4] and others survey EEG signals at P300 (positive peak at about 300ms point after event) [5]. These signals are used for disabled persons by applying it to control signals of mouse or neuroprosthesis [1,6].…”

Membership Function-based Classification Algorithms for Stability improvements of BCI Systems

“…BCI is a system for communication and control with thoughts [14]. It can help severely motor-disabled persons to communicate and control their environments through many applications [15][16][17][18]. BCI systems can substitute for the loss of normal neuromuscular outputs by enabling people to interact with their environment through brain signals rather than thought muscles [19].…”