Blood oxygen saturation measuring device and measuring method

Abstract

The invention discloses a blood oxygen saturation measuring device and a measuring method. The measuring device is characterized in that a microprocessor outputs square waves at different frequencies and in twice rate relationship, the square waves drive at least two kinds of light emitting diodes, light emitted by the light emitting diodes is received by a photosensor after passing through a finger to be measured, the light is converted into voltage signals by the photosensor, the voltage signals are converted into preset amplitude voltage signals through a current / voltage conversation amplifier, an analog to digital converter converts the preset amplitude voltage signals into digital signals, the microprocessor processes the digital signals, and the blood oxygen saturation is obtained. The measuring method comprises the steps that: the microprocessor carries out separation processing on the digital signals, photoelectric volume pulse waves are obtained, and the background light interference is eliminated; a valley value and a peak value are obtained according to the photoelectric volume pulse waves; the valley value and the peak value are calculated to obtain a Q value; and the blood oxygen saturation is calculated through the Q value, and the blood oxygen saturation is obtained. Square wave frequency division modulation and digital demodulation are adopted, and the blood oxygen saturation measuring device and the measuring method have the characteristics that the measurement is accurate, the circuit is simple, and the cost is low.

Description

technical field [0001] The invention relates to a blood oxygen saturation measuring device and a measuring method. Background technique [0002] In the prior art, the measurement of blood oxygen saturation is based on empirical formulas, that is, measuring the PPG (Photo Plethysmo Graphy, photoplethysmography) of red light and infrared light and extracting the respective AC and DC components from it, and then using these The so-called R value (blood oxygen content) is extracted from the signal, and then the blood oxygen saturation is calculated according to the empirical formula, such as the invention patent "A Method for Detection of Blood Oxygen Saturation" proposed by Li Qingbo (public number: CN101433463A, public date: 2009 May 20) etc. [0003] In order to improve the measurement accuracy of blood oxygen saturation, the invention patent "blood oxygen saturation measurement method and device" (publication number: CN101347334, published on January 21, 2009) proposed by L...

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Problems solved by technology

[0007] The technical problem to be solved by the present invention is to provide a blood oxygen saturation measuring device and a measuring method, which solve the problems of complex circuit structure, large amount of calculation, and inaccurate calculation results. For details, see Described below:

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