Detection circuit for high-performance brain electrical signal of brain-machine interface

Abstract

The invention relates to a high-performance EEG signal detection circuit provided with a brain-machine interface. The detection circuit comprises a pre-amplifier circuit and a post-amplifier circuit, wherein the pre-amplifier circuit consists of a first-level amplifier circuit and a second-level amplifier circuit which are connected by a high-pass filter circuit; and the pre-amplifier circuit is connected with the post-amplifier circuit by a 50Hz trap circuit and a low-pass filter circuit. The detection circuit has the characteristics of high input impedance, high common mode rejection ratio, high gain, low noise and low drift, and has the advantages of simple structure, strong capacity of resisting disturbance and good reliability. The invention can be used as a high-performance EEG signal detection circuit, and lay a foundation for realizing the brain-machine interface.

Description

technical field [0001] The invention relates to the field of electroencephalogram signal detection and can be applied to a brain-computer interface (BCI) system. Background technique [0002] The brain-computer interface mainly includes two aspects: the detection of EEG signals and the recognition of EEG signals. Among them, accurate detection of EEG signals is the premise and foundation. The EEG signal is the overall reflection of the electrical activity on the surface of the cerebral cortex or scalp when the brain nerve cells conduct information. It is a weak and low-frequency bioelectrical signal. In strong background noise, the input signal-to-noise ratio can reach 1:10 5 . The key to the detection circuit design is to extract the EEG signal from the powerful background noise and amplify it with high gain. To collect clear and accurate EEG signals, the detection circuit must have high input impedance, high common mode rejection ratio, high gain, low noise, low drift,...

AI Technical Summary

Problems solved by technology

Sun Youming and others designed a new type of EEG signal amplification and detection circuit (Medical and Health Equipment, Vol. 28, No. 1, 2007: 15-17), but the structure of the preamplifier circuit is complex, adding many redundant links, resulting in circuit The increase in cost and power consumption is not conducive to miniaturization and low power consumption; Wang Sanqiang and others designed a new type of EEG signal preamplifier circuit (Journal of Chongqing University (Natural Science Edition), Volume 29, Issue 6, 2006:51-53) Although the structure is simplified, the instrumentation amplifier is used as the first stage of amplification, and a 330uV capacitor is connected in series with the gain adjustment resistor of the first stage. In practice, the leakage of such a high-capacity electrolytic capacitor in series is too large

[0004] In short, the existing EEG signal detection circuits often have complex structures and unsatisfactory performance, which limits their application in BCI systems

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