Method and device for measuring blood oxygen saturation

Abstract

The application discloses a method for measuring oxygen saturation degree of blood, comprising the following steps of (1) direct current filtering and pre-processing the measured digital signals after analog-digital conversion; (2) wave filtering by an aliasing-resistant filter and signals extraction; (3) quick Fourier FFT transformation and elimination of motion interference signals; (4) calculation of oxygen saturation degree of blood. And after the elimination of motion interference signals and before the calculation of oxygen saturation degree of blood, a step can be added in the method, namely, the range of double frequency is more eliminated than that of base frequency; elimination of excursion by a lowpass can be also added in the method before the calculation of oxygen saturation degree of blood. The invention also discloses an instrument for measuring the oxygen saturation degree of blood with the method. The method and the instrument of the invention can quickly and effectively measure the oxygen saturation degree of blood, and an extraction technique is added in the invention, helping largely reduce the space for use and amount in calculation of an EMS memory. Waveshape recognition on the frequency domain helps filter the interference of motion state effectively and improve the accurateness of measurement by the instrument.

Description

technical field [0001] The invention relates to a method and a device for measuring the blood oxygen saturation of a human body, in particular to a method and a device for measuring the blood oxygen saturation in the frequency domain without trauma and using spectral analysis technology. Background technique [0002] Blood oxygen saturation refers to the percentage of oxyhemoglobin molecules in the human arterial blood to the total number of hemoglobin molecules. It is an important physiological parameter reflecting the oxygen supply status of the human body and an important clinical indicator. At present, non-invasive technology is mainly used to measure and monitor blood oxygen saturation, which overcomes the original invasive method of drawing blood samples, increasing patient pain and high infection rate. The basic principle of non-invasive measurement of blood oxygen saturation is to use the spectral analysis method to place two photocells emitting different spectra on ...

AI Technical Summary

Problems solved by technology

However, when the two photocurrent components are obtained, there are often noise signals, such as electromagnetic noise, background light noise and motion noise, etc.

These noisy signals make blood oxygen saturation measurements inaccurate

At present, there are different noise elimination methods for different noise effects, such as using light shielding or changing the light absorption coefficient of the illuminated surface to eliminate background light noise, using electromagnetic shielding to eliminate electromagnetic interference, and improving the mechanical anti-motion performance of the probe to eliminate the measured object. Motion interference with the probe, especially for motion noise, currently there is only a mechanical method similar to the above to eliminate the noise, without improving the ability to resist motion noise from the circuit signal processing of the instrument itself

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