Single-channel acquisition device and method for multi-channel signal modulated by bioelectricity and square wave

Abstract

The invention discloses a single-path acquisition device for multiple paths of signals modulated by bioelectricity and square waves and a method for the single-path acquisition device. The acquisition device is used for acquiring N paths of biomedical signals through a single-path analog / digital converter, wherein the biomedical signals comprise high-frequency square waves loaded with PPG (Photoplethysmography) signals and a low-frequency bioelectric signal; a current signal is converted into a voltage signal with a preset amplitude by a current / voltage conversion amplifier; the bioelectric signal with a preset amplitude is obtained by a bioelectric signal detection circuit; the voltage signal with the preset amplitude and the bioelectric signal with the preset amplitude are added by an additive operation circuit to obtain a mixed signal; the mixed signal is converted into a digital signal by the single-path analog / digital converter; the digital signal is processed and separated by a microprocessor to obtain a modulated square wave signal and the low-frequency bioelectric signal; multiple paths of PPG signals can be demodulated from the modulated square wave signal. According to the single-path acquisition device and the method disclosed by the invention, synchronous acquisition of multiple paths of biomedical signals is realized by the single-path analog / digital converter; in addition, the single-path acquisition device and the single-path acquisition method have the characteristics of simple circuit, low cost and accurate measurement.

Description

technical field [0001] The invention relates to the field of biomedical signal acquisition, in particular to a single-channel acquisition device and method for multi-channel signals modulated by bioelectricity and square waves. Background technique [0002] The amount of information-carrying changes such as voltage signals is expressed in analog form in its natural state. However, in order to facilitate computer processing, transmission and storage, it is usually converted into a digital signal through an analog-to-digital converter. Therefore, in biological In medical signal processing, analog-to-digital conversion is essential. [0003] The inventor found in the process of realizing the present invention that in the existing multi-channel biomedical signal acquisition, it is usually necessary to use a multi-chip ADC or a multi-channel analog switch with a single-chip ADC. The former has complex circuits, high system power consumption and low The disadvantage of large circ...

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Problems solved by technology

[0003] The inventor found in the process of realizing the present invention that in the existing multi-channel biomedical signal acquisition, it is usually necessary to use a multi-chip ADC or a multi-channel analog switch with a single-chip ADC. The former has complex circuits, high system power consumption and low The disadvantage of large circuit size; the latter will introduce switching noise due to the switching of multi-way switches during the acquisition process, and due to the establishment time of multi-way switches, it will cause mutual interference between adjacent channel signals

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