A brain computer interface（BCI）system based on sensor technology is designed to realtime control cursor movement.The system consists of sensor and signal processing parts.The system requires two electrode O1

O2 for recording the EEG signal on the scalp to extract the α wave.The cursor movement in 2D space can be controlled rapidly and reliably by Fisher discriminant approach to judge the lasting time when the subject closing eyes to output different commands.The experimental results indicate that the subjects without pre-training can complete the task of cursor movement control quickly via this system.The developed BCI system operates in asynchronous mode and can output control command within 3.6

5

.4s with good usability.