Real-time brain electrical impedance detection method based on high frequency excitation

Abstract

The invention discloses a real-time brain electrical impedance detection method based on high frequency excitation. The method is characterized by comprising an excitation unit, an impedance network, an analogue signal processing unit, a brain electricity amplifying unit and a digital signal processing unit. The method includes the steps that the excitation unit is a current source and generates an excitation current I which comprises sine components of high-frequency f1 and high-frequency f2; the excitation current acts on the impedance network and generates a voltage signal U which is processed by the analogue signal processing unit and the brain electricity amplifying unit respectively; the analogue signal processing unit conducts amplification, filtration and analog-digital (AD) convention on the voltage signal U at last and sends the voltage signal U to the digital signal processing unit; and the digital signal processing unit calculates electrode contact impedance of a brain electrical signal frequency range by using acquired voltage U and the known excitation current I. By means of the real-time brain electrical impedance detection method based on the high frequency excitation, the impedance in the brain electrical signal frequency range can be acquired in real time.

Description

technical field [0001] The invention relates to an EEG impedance detection method, in particular to a real-time EEG impedance detection method based on high-frequency excitation. Background technique [0002] The EEG signal is the electrophysiological signal generated by the electrical activity of neuron cells under the human brain cortex, which is transmitted through the brain tissue to the surface of the scalp and then collected by electrodes placed on it. The EEG under the physiological state has certain rules. When the brain is abnormal or pathological, the normal rule changes. In scientific research and clinical medicine, it is important to check the EEG to provide a basis for the diagnosis and treatment of most brain diseases. value. [0003] The EEG signal is very weak and the voltage value is at the microvolt level, which is easily affected by artifacts and various external factors, mainly including power frequency interference, inherent noise of the amplifier, and ...

AI Technical Summary

Problems solved by technology

[0005] In order to solve the problem that the existing EEG detection system cannot measure the electrode-scalp impedance in real time, the present invention proposes a method and circuit for measuring impedance with current excitation containing two high-frequency components. The impedance of the high-frequency band obtained directly passes through The algorithm of the present invention can back-calculate the impedance of the EEG signal frequency band

Images