Visual brain-computer interface method based on field-programmable gate array local noise optimization

Abstract

The invention discloses a visual brain-computer interface method based on field-programmable gate array local noise optimization. The method comprises the following steps: placing an acquisition electrode in a head pillow area to acquire a visual electroencephalogram signal; generating a chessboard stimulation unit with local noise, and storing the chessboard stimulation unit in an internal memoryof the field programmable gate array; displaying the chessboard stimulation unit with the local noise through a field programmable gate array control mode; enabling a user to selectively gaze at anychessboard stimulation unit with local noise, collecting electroencephalogram signals of a visual pillow area of the user to carry out canonical correlation analysis, obtaining the visual stimulationunit corresponding to the maximum value in canonical correlation coefficients corresponding to all frequencies, and judging the visual stimulation unit as an identified target. According to the invention, the display stability of the chessboard visual stimulation unit can be improved, and the requirements of the steady-state visual evoked potential brain-computer interface system on hardware are reduced, so the implementation cost of the brain-computer interface system is reduced, and the recognition accuracy and stability of the steady-state visual evoked potential brain-computer interface can be improved.

Description

technical field [0001] The invention relates to the technical field of brain-computer interface technology in biomedical engineering and digital IC design in electronic information engineering, in particular to a visual brain-computer interface method based on field programmable gate array local noise optimization. Background technique [0002] The brain-computer interface establishes a reliable communication channel between the brain and external devices through the collection and analysis of EEG signals. At present, most brain-computer interface systems are based on laboratory conditions, and the equipment is often bulky and expensive. In order to improve the practicability of the system, it is necessary to design a portable and low-cost brain-computer interface device. [0003] As a common type of brain-computer interface, the brain-computer interface based on steady-state visual evoked potential has been widely used because of its advantages of strong stability, strong ...

AI Technical Summary

Problems solved by technology

In the process of generating steady-state visual evoked potentials, light flickering with a stable frequency is required to induce stimulation. There are two common eliciting methods. The main advantage is that it can generate flicker light at any stimulation frequency, but long-term light flicker is easy to cause visual fatigue, and it is not easy to use the brain-computer interface device for a long time; secondly, the visual stimulation of specific frequency can be controlled by computer. The stimulation unit performs motion flipping. This method can easily change the parameters of the visual stimulation unit, such as: brightness, color, size and number of stimulation units, etc., which can reduce the impact of visual fatigue to a certain extent.

However, during the display process, the image and refresh rate of each frame need to be strictly controlled. When the computer performs multi-task scheduling, it is easy to cause the frequency of the displayed visual stimulation unit to be inaccurate.

Furthermore, limited by the refresh rate, the stimulation frequency of the conventional display paradigm is limited

[0004] The Chinese patent "A Design Method for a Steady-state Visual Evoked Potential Brain-Computer Interface System Based on FPGA" (application number 201910669448.5) realizes the stable display of red and black rectangular visual stimulation units through field programmable gate arrays, but only through two A form of visual stimulation that flips the color matrix, which is easy to cause visual fatigue

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