Patent ID: 11868530
Assignee: nan
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 3:
4. The accurate control method of visual stimuli for a brain-computer interface according to claim 1, wherein the controller is implemented as follows:
at run time, the controller is a separate process; an asynchronous call mechanism between the controller and the actuator ensures that the controller will not be blocked by calls, and the controller returns immediately after successfully calling the interfaces “start” and “stop” of the actuator; the controller calls the interface “start” of the actuator at a specific moment as required by the experimenter to start the trail and calls the interface “stop” of the actuator to stop the trail; the controller has a function of accessing the hardware interface connected to the electroencephalograph instrument and immediately writes the marker into the electroencephalograph signals using this function after calling the interface “start” of the actuator; the controller also has a function of acquiring the electroencephalograph signals in real time; the controller acquires the electroencephalograph signals in real time by sharing a memory block with a process of collecting the electroencephalograph signals; the process of collecting the electroencephalograph signals stores collected new electroencephalograph signal data blocks in the shared memory block, and the controller acquires the new electroencephalograph signal data blocks from the memory block; to ensure that the electroencephalograph signal data blocks are correctly transmitted between the process of collecting the electroencephalograph signals and the controller, the two processes need to be kept in a synchronous relationship, which is referred to as a producer-consumer model and implemented by a semaphore mechanism; in addition, the controller also has a function of processing the electroencephalograph signals in real time using a preset algorithm, and every time obtaining one electroencephalograph signal data block, the controller processes corresponding signals, generates a feedback according to a processing result, and shows the feedback to users at the end of the trail.