High-precision electroencephalogram signal acquisition method and device

Abstract

The invention discloses a high-precision electroencephalogram signal acquisition method and device. The method comprises the steps that S1, a data processing control circuit outputs a first voltage signal to a first impedance excitation circuit, and the frequency of the first voltage signal ranges from 0 Hz to 40 Hz; S2, the first impedance excitation circuit generates an alternating-current constant-current source according to the first voltage signal, and the alternating-current constant-current source is output to a signal electrode, so that second voltage signals are generated at the two ends of the signal electrode and the two end of a grounding electrode; S3, the second voltage signals are filtered and amplified by a filtering and amplifying unit, a bias driving circuit is connectedwith the the voltage of a human body end according to the grounding electrode, and a bias driving voltage is generated and input into the filtering and amplifying unit; S4, the data processing controlcircuit performs narrow-band filtering on the filtered and amplified second voltage signals, the peak-to-peak value of the narrow-band filtered second voltage signals are determined on the basis of narrow-band filtered second voltage signal, and the contact impedance of signal electrode and grounding electrode loops is determined on the basis of the peak-to-peak value and a AC constant current source; and S5, the data processing control circuit collects electroencephalogram signals.

Description

technical field [0001] Embodiments of the present invention relate to the technical field of EEG signals, and in particular, to a method and device for collecting high-precision EEG signals. Background technique [0002] The EEG signal is the bioelectrical signal obtained by conducting the spontaneous bioelectrical activity signal of the brain through the electrodes arranged on the scalp and amplified by the EEG acquisition system. By collecting and analyzing EEG signals, it is possible to diagnose brain diseases, judge mental states, or directly use "ideas" to control equipment. It has a large number of applications in medicine and daily life, and has important scientific research value. [0003] However, because the EEG signal is attenuated by the skull and scalp, the signal is extremely weak, and the voltage value is at the microvolt level, which requires multiple amplifications to be accurately collected. During the acquisition process, the EEG signal is easily affected...

AI Technical Summary

Problems solved by technology

However, the excitation input of the constant current source of the existing system is mostly a high-frequency current signal, which is much higher than the frequency of the commonly used EEG signal. It is necessary to use a more complex constant current source excitation input and calculation algorithm. First, the complex impedance under high-frequency excitation is obtained. Information, and then use the impedance formula model to convert the obtained high-frequency domain impedance to the low-frequency domain of commonly used EEG signals, and finally obtain the corresponding impedance value

The calculation process of this method is relatively complicated, and at the same time, there is a certain error in calculating the electrode contact impedance in the common frequency range of EEG signals.

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