Active electrode device and active amplification unit thereof

Abstract

The invention provides an active electrode device and an active amplification unit of the active electrode device. The active electrode device is used for acquiring signals and comprises an electrode plate and an electrode cavity which are connected with each other. The electrode cavity comprises a battery, the active amplification unit, a first connecting wire and a second connecting wire, wherein the battery and the active amplification unit are connected through the first connecting wire and the second connecting wire. The active amplification unit comprises a power supply unit, a direct current restraining unit, a band-pass filter, a gain amplifier and a buffer, wherein the direct current restraining unit, the band-pass filter, the gain amplifier and the buffer are sequentially connected with the power supply unit in series. Through the active electrode device and the active amplification unit, input impedance can be increased, direct-current bias can be restrained, low-frequency noise interference can be reduced, the signal-to-noise ratio can be increased, and thus electric physiological signals can be effectively amplified and preprocessed. Moreover, the active electrode device is simple in structure and suitable for single-chip integration.

Description

technical field [0001] The invention relates to signal collection, in particular to an active electrode device and an active amplifying unit thereof. Background technique [0002] Traditional electrophysiological signals, such as electrocardiogram signals, are low-frequency and low-amplitude signals. Wet electrodes (passive electrodes) are generally used for signal acquisition. However, if the material properties of the conductive medium change, the contact impedance between the electrode and human skin will change. And the movement artifact effect of the lead wire will affect the quality of the collected electrophysiological signal. During the use of the electrode, the contact between the electrode and the human skin will generate a DC polarization voltage of up to several hundred mv. If the front-end circuit cannot eliminate this DC bias, it will cause the op amp to be overloaded and cannot be effectively amplified. Now adopting the active electrode method to add active d...

AI Technical Summary

Problems solved by technology

[0003] There are several common forms, such as the use of ECG dry electrodes with amplifiers. Although this method is simple and portable, it cannot be designed due to the noise introduced by the resistance, which makes the gain of the operational amplifier affected by the DC bias. too big

If the existing DC offset elimination method with error feedback needs to use FIR filter and DAC (Digital Audio Compress), the design of the active electrode is complicated and the cost is high

If the existing RC integrator is used for DC suppression, the required R and C values ​​are relatively large, which is not easy to integrate in the chip

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