Research On Brain-Machine Interface Environment Control System Based On Stereo Vision Stimulation

Brain-computer interface(BCI)is a communication and control interface that can establish a direct connection between the brain and external devices.It is mainly used in functional assistance and medical rehabilitation for paralyzed patients.P300-based BCI has become a research hotspot because of its high classification accuracy and easily induced signal.Considering the aspect of application,this paper mainly studies the influence of three-dimensional(3D)stereoscopic stimuli on the performance of P300 BCI system,and the application of stereo vision stimuli based P300 BCI in environmental control.Firstly,based on the character spelling system,this paper compares the performance of the P300 BCI system based on 3D stereoscopic stimuli and that of the 2D planar visual stimuli-based BCI.Results of the off-line experiment show that 3D stereo stimulation is 16% higher than 2D planar stimuli in terms of the peak value of induced P300 signal;in the offline training session,the classification accuracy and information transmission rate of the 3D stereo stimuli-based BCI are higher than or equal to those of the 2D planar visual stimuli-based BCI.Furthermore,the results of the online experiment shows that the 3D stereoscopic stimuli can improve the classification accuracy rate by 5.4% compared with the 2D planar visual stimuli,increase the information transmission rate by 10.8bits/min,and reduce the response time by 0.35 s.Contrasting experiments have demonstrated that 3D stereoscopic stimuli really help to improve signal quality and optimize system performance.This paper also analyzes and discusses the reasons why 3D stereo stimulation has better results,and the selection of the experimental parameters.Secondly,in order to solve the problem of multi-device communication and improve system performance,this paper designs an asynchronous environment control system based on P300 based on stereo vision stimulation.The system uses P300 BCI based on stereo vision stimulation to obtain control instructions,and validates control instructions by detecting blink signals.Then,the control instructions are output via WiFi to the environmental control system including a nursing bed,a television,an air conditioner,and several electric lights.Each device performs a corresponding action once it receives an control instruction.In terms of system method design,it mainly includes the design of stereoscopic stimuli graph user interface(GUI),electroencephalography(EEG)and electrooculography(EOG)signal processing,and multi-device communication design;in terms of system implementation,the hardware design mainly includes the selection of the main controller and circuit design,as well as the circuit design of each environmental control device.The software design mainly includes the communication control and the programming of various environmental control devices.Finally,10 subjects were invited to test the system,and three experiments including an EOG experiment,an off-line experiment and an online experiment were designed to test the system.The test results have shown the good practicability and reliability of the system in this paper.