System and method for collecting electroencephalogram signal on basis of impedance self-adaption

Abstract

The invention discloses a system for collecting an electroencephalogram signal on the basis of impedance self-adaption. The system comprises an electrode cap, wherein a plurality of electrodes are arranged on the electrode cap and also comprises an impedance detection device for detecting an impedance value of the electrode, and a conductive liquid injection device for supplying conductive liquid to the electrode; the conductive liquid injection device comprises a dosing execution mechanism connected to each electrode and a controller connected with the impedance detection device, and the controller controls the dosing execution mechanism to dose liquid to the electrode of which a real-time impedance value is in a dosing threshold range according to the real-time impedance value of each electrode measured by the impedance detection device. The system has the advantages of being simple to operate and convenient to use; low electrode impedance can be kept for a long time and electroencephalogram data can keep high signal-to-noise ratio and high stability. A method for collecting the electroencephalogram signal on the basis of impedance self-adaption is also disclosed by the invention.

Description

technical field [0001] The invention relates to brain-computer interface technology, in particular to a system and method for collecting brain electrical signals based on impedance self-adaptation. Background technique [0002] Brain-Computer Interface (BCI) is a communication system that does not rely on the normal output pathways composed of peripheral nerves and muscles. It detects brain activity signals by certain means, and then uses signal processing and pattern recognition methods to identify people's intentions, thereby converting people's thinking activities into computer instructions, and realizing the control of external devices or information exchange with the outside world. Since the brain-computer interface does not require the direct participation of human body movements or language expressions, this technology can not only provide more effective medical rehabilitation and life assistance equipment for the disabled, but also serve as a new type of human-machin...

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Problems solved by technology

The use of wet electrodes can effectively reduce the electrode impedance under the condition of good preparation, and the signal-to-noise ratio of the collected EEG data is high, but there are also two shortcomings that are difficult to overcome: one is that the experimental preparation process is complicated, and the experiment operator must It takes a lot of time and energy to apply conductive paste to each collection location, or soak the electrodes in conductive liquid. This process generally takes tens of minutes to one or two hours, and the experimental effect has a great influence on the operation. Second, the conductive medium will change during the experiment. For example, the fluidity of the conductive paste will lead to poor contact between the electrode and the scalp, and even contact between the conductive paste of adjacent electrodes will occur, causing signal crosstalk. , while the conductive liquid (such as physiological saline) will be affected by the body temperature and evaporate continuously during the experiment

This advantage of the dry electrode makes it more and more favored by many researchers. However, experiments show that the impedance value of this electrode is generally greater than that of the wet electrode, and the signal-to-noise ratio of the collected EEG data is high; at the same time, the experiment During the process, factors such as the oil secreted by the scalp will also affect the contact between the electrode and the scalp, which will gradually increase the electrode impedance and affect the stability of the experimental data.

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