Multi-frequency time sequence combined steady-stage visual evoked potential brain-computer interface method

Abstract

The invention discloses a multi-frequency time sequence combined steady-stage visual evoked potential brain-computer interface method. The method comprises the following steps of: putting a measurement electrode on the head of a subject and connecting the measurement electrode with an electroencephalogram amplifier, a computer and a computer screen; and forming n different representation targets by using n stimulus frequencies, wherein n is an integer more than 1; and realizing the representation of the visual targets and the visual feedback of the subject by using the computer screen. The method improves the information transmission rate of the brain-computer interface by constructing a plurality of representation targets from a few stimulus frequencies, has the advantages of multiple representation targets and high specificity of the detection result, can realize communication between the disabled having normal mind but suffering from paralysis of the neuromuscular system and an external apparatus, and is suitable for a normal person on occasions that the limbs are inconvenient to control.

Description

technical field [0001] The invention relates to the technical field of neural engineering, in particular to a steady-state visual evoked potential brain-computer interface method of multi-frequency time series combination. Background technique [0002] Brain-computer interface is the abbreviation of human brain-computer interface. It refers to a technology that allows the human brain to communicate directly with the computer without relying on the normal output pathway of the brain. The brain-computer interface analyzes the EEG of the human brain in real time. Signals, to a certain extent, interpret people's thinking and translate them into control instructions to realize the control of external equipment. Consciousness controls the movement of intelligent wheelchairs; it can also be used in occasions where normal people are inconvenient to control their limbs, such as astronauts' mind-controlled spacewalks, etc. Brain-computer interface is an emerging technology intersectin...

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Problems solved by technology

[0004] Compared with other types of brain-computer interfaces, the brain-computer interface based on the steady-state visual evoked potential has the characteristics of simple operation, high information transmission rate, no need for training, and strong signals can be induced by all subjects, so it has become a The most practical type of all brain-computer interfaces. In traditional BCI applications based on steady-state visual evoked potentials, a computer screen is usually used as a stimulus source so that stimulus presentation, signal analysis, and target feedback can be performed simultaneously. , and the stimulation frequency has a one-to-one correspondence with the presentation target. Due to the influence of the inherent vertical refresh rate of the screen, the highest stimulation frequency that can be used can only reach half of the screen refresh rate. In addition, the real-time nature of the computer system itself and the single stimulation cycle The limitation of the number of internal display frames makes there be a certain frequency interval between the stimulation frequencies. The above situation results in a small number of frequencies that can stimulate the steady-state visual evoked potential, a small number of targets, and non-specific detection results. How to construct more presentation targets with less stimulation frequency has always been a problem to be solved in the brain-computer interface based on steady-state visual evoked potentials.

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