Embedded electroencephalogram impedance measurement system

Abstract

The invention provides an electroencephalogram impedance measurement scheme based on an embedded system. The embedded system comprises a signal acquisition system and a control system, and involves impedance value calculation and storage; when a lower computer acquisition system completes electroencephalogram data acquisition, the contact impedance between an electrode and the skin is measured inreal time, and impedance calculation in an upper computer and a lower computer can be supported; by configuring the parameters of ADS1299, the embedded system can separate electroencephalogram signalsfrom impedance measurement signals through a digital filter, so that the electroencephalogram signals and the impedance measurement signals cannot influence each other; impedance measurement in the lower computer is conducted, impedance values and electroencephalogram data are stored in SD cards in a BDF format at the same time, and reprocessing analysis is facilitated; and the impedance value ateach moment is used for evaluating the contact condition of the electrode and the skin at the moment, so that the quality of the electroencephalogram data acquired at the moment is judged, which plays a key role in signal processing. The scheme is high in impedance measurement precision, high in integration level, small in occupied space, and suitable for a mode that the lower computer independently collects electroencephalogram data and a mode that the lower computer works in cooperation with the upper computer.

Description

technical field [0001] The invention mainly relates to the field of medical detection equipment, in particular to a system for measuring electroencephalogram signals. Background technique [0002] The EEG signal is sent to the input part of the EEG machine through the brain electrodes placed at the recording site, and processed after being amplified by the amplifier. Since the EEG signal itself is very weak, it will be affected by various influences during the measurement process, resulting in artifacts, which will further affect the quality of the EEG signal. In order to obtain more realistic and accurate extremely weak EEG signals, the requirements for the contact impedance between the electrodes and the scalp are extremely strict. The quality of the contact between the electrode and the scalp affects the size of the electrode resistance. The larger the contact impedance, the poor contact between the electrode and the skin, and the low quality of the collected EEG signal...

AI Technical Summary

Problems solved by technology

[0003] In the existing schemes, some impedance measurement circuits and EEG acquisition circuits are independent of each other, resulting in a large system volume and unreasonable resource utilization; The electrical signal has a certain influence, the measured impedance value fluctuates greatly, and the accuracy is low; the impedance measurement of the existing scheme is almost all placed on the host computer, and the bulky host computer must be carried when collecting EEG, which is very inconvenient

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