Electroencephalogram collecting device and method based on active electrode

Abstract

The invention discloses an electroencephalogram collecting device based on an active electrode. The electroencephalogram collecting device comprises the active electrode, an electroencephalogram signal collector and an electrode wire, wherein the electrode wire is connected between the active electrode and the electroencephalogram signal collector, an electroencephalogram electrode and a unit gainamplifier are arranged in the active electrode, the electroencephalogram signal collector comprises a differential amplifier, a data converter, a digital signal processor and an interface circuit which are connected in sequence, and the electroencephalogram electrode is used for acquiring an electroencephalogram signal; the unit gain amplifier is used for carrying out amplifying treatment on theelectroencephalogram signal; the differential amplifier is used for carrying out differential amplification on the electric signal output by the unit gain amplifier for a preset times; the data converter is used for converting the electric signal output by the differential amplifier into a digital signal; the digital signal processor is used for receiving the digital signal output by the data converter and uploading the digital signal to an uplink device through the interface circuit. According to the device and the method, the interference resistance and signal collecting quality are improved, and meanwhile, the device has the features of miniaturization, portability and the like.

Description

technical field [0001] The present invention relates to an EEG signal acquisition device, in particular to an EEG acquisition device and method based on active electrodes. Background technique [0002] EEG signals contain a large amount of physiological and pathological information. Through the processing of EEG signals, it can not only provide doctors with the basis for clinical diagnosis, but also provide effective auxiliary treatment for certain brain diseases. The research on characteristic analysis and feature extraction of EEG signals at home and abroad has made great progress and achievements. The main characteristics of the EEG signal are: the amplitude of the EEG signal is 5uV-100uV, generally only about 50uV; the frequency range is 0.5Hz-35Hz, with strong power frequency 50Hz interference and polarization voltage interference; the internal resistance ranges from several thousand ohms It varies from hundreds of kiloohms and is easy to change. [0003] The mainstre...

AI Technical Summary

Problems solved by technology

[0003] The mainstream EEG acquisition systems or equipment on the market are all built with separate components, which are bulky, bulky and not portable; and these solutions basically use single-chip microcomputers as data conversion and controllers, and the accuracy of the collected signals is relatively low

In the traditional EEG acquisition circuit, due to the large internal resistance of the human body and the factors of contact resistance, most of the acquisition electrodes use wet electrodes, the contact resistance is greatly reduced, and the requirements for the impedance of the subsequent stage are also reduced. The device improves the input impedance of the acquisition circuit, but the use of wet electrodes leaves a large amount of conductive paste on the acquisition site of the subject, causing great inconvenience

[0004] In the prior art, combined with figure 1 and figure 2 As shown, in the acquisition scheme using dry electrodes, the EEG acquisition electrode 100 is connected to the acquisition circuit board 106 through the electrode wire 101, and the acquisition circuit board 106 includes a sequentially connected emitter follower 102, instrumentation amplifier 103, and data converter 104. and single-chip microcomputer 105, in this scheme, add emitter follower 102 at the front end of acquisition circuit board 106, to improve the input impedance of acquisition circuit, but under normal circumstances, there is a relatively large gap between the EEG acquisition electrode 100 and the emitter follower 102 Long electrode wires 101 will cause large fluctuations in the collected signals

Moreover, this solution uses a single-chip microcomputer as a data conversion and controller, and the accuracy of the collected signal is relatively low

[0005] It can be seen that in the two schemes in the prior art, because the amplitude of the EEG signal is very low, the equivalent input noise of the emitter follower and the instrumentation amplifier will reduce the signal-to-noise ratio of the signal acquisition circuit, and most of them use a single-chip microcomputer for data conversion and processing, resulting in relatively low signal accuracy

At the same time, the current EEG acquisition solutions in the market are mainly built with discrete components, which are bulky and the acquisition method is not simple.

In addition, if the wet electrode scheme is used, although a relatively stable and accurate signal can be obtained, a large amount of conductive paste remains after collection, causing great inconvenience

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