Pulse wave extraction method and acquisition system based on wavelet decomposition and reconstruction

Abstract

The invention provides a method capable of achieving direct current component and alternating current component separation in human body pulse wave sample signals and a pulse signal acquisition system based on wavelet decomposition and reconstruction. According to the pulse signal acquisition system, the sample frequency is set in the range from 100 Hz to 200 Hz, and the layer number of the wavelet decomposition and reconstruction is automatically selected; firstly, direct current components in an original sample data sequence are separated; secondly, an arithmetic mean value of a direct current component sequence is taken out to serve as a direct current signal with the constant amplitude; thirdly, an alternating current signal (pulse wave) with the more stable amplitude and phase position is separated from the original sample data sequence according to the direct current signal for the application such as blood pressure calculation, blood oxygen monitoring and hemodynamics PWV monitoring to use.

Description

technical field [0001] The invention relates to the field of electronic information technology for pulse signal extraction, in particular to a method for extracting pulse wave signals from sampled data by using wavelet analysis, which can be conveniently implemented on a single-chip microcomputer (such as ARM7). Background technique [0002] In the field of medical electronics, in many occasions, it is necessary to separate and extract the pulse wave signal of the human body from the sampled data of the sensor. Typical applications are as follows: [0003] (1) Non-invasive blood pressure measurement based on the "oscillometric method", which is used to separate and extract the pulse wave signal from the sampling data of the pressure sensor, so as to form the envelope curve of the pulse wave signal and perform blood pressure calculation; [0004] (2) Based on photoplethysmography (PPG) non-invasive blood oxygen measurement or PWV monitoring, the photoplethysmography wave is s...

AI Technical Summary

Problems solved by technology

This method is suitable for the case where the magnitude of the DC component in the sampling data is relatively constant, which makes the use of this method have great limitations. For example, if the magnitude of the DC component of the sampling data is not a constant value, but If the change of the frequency becomes larger or smaller, then such a DC component will contain abundant harmonics when it is transformed into the frequency domain by FFT, making it very difficult to separate the DC component, and it will also become very difficult to obtain the AC component

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