Research On Methods And System For Measuring SpO₂ With Smart Terminal

Oxygen saturation is an important vital sign of the human body,which reflects the body’s respiratory cycle,cardiovascular system and other physiological conditions.It has an important position in the clinical treatment.With the exacerbation of aging and the rapid development of electronic information technology,more and more people choose portable wearable equipment for the elderly to detect oxygen saturation.However,there are still some problems when to popularize these wearable equipment: high cost for ordinary family to afford;cumbersome to operate which may become a barrier for elderly to use;a strong sense of existence which brings some trouble to carry around.Aiming these problems,studies the pulse oximetry based on YUV spectroscopy,and put forward the pulse oximetry based on energy spectrum,the thesis realizes the pulse oximetry based on intelligent terminals.The main work is as follows:(1)This paper theoretically analyzes the oxygen saturation measured under mixed light.Considering the change value of the density of oxygenated hemoglobin and reduced hemoglobin as variables,using the U and V channel signals in YUV video,the theoretical conclusions that U and V channel signals can map the changes of oxygenated hemoglobin and hemoglobin are deduced.(2)According to the theoretical conclusion of(1),the pulse oximetry based on YUV spectrum is proposed.Using the trough and peak-to-peak value of U and V channels,the change of light intensity is obtained,and then the oxygen saturation degree.Comparing to the data measured by professional equipment,the data measured by the method has high accuracy,basically higher than 97%,which verifies the effectiveness of the method.(3)According to the strong correlation between the luminance signal curve and the oxygen content in the blood,this paper presents the parameter regression method of the oxygen saturation based on energy spectrum.According to the relationship between oxygenated hemoglobin and blood flow volume in the cardiac cycle,and the relationship between the change of oxygen content and the change of blood color,the paper regard the value of the energy of luminance signal in the blood flow video of the current cardiac cycle and the value of peak-to-peak of brightness change curve as feature points,calculates the oxygen saturation in real-time.Comparing the data measured by the method with the data measured by professional equipment,the results show that the method is stable and reliable.(4)Combining the pulse oximetry based on spectroscopy,the pulse oximetrybased on energy spectrum and smartphones,the thesis designs and implements a system to detect SpO which making it possible to make real-time and continuous measurement of the human body oxygen saturation value through smartphones.In addition,the core algorithm of oxygen saturationdetection engine can be used across platforms.It has been able to be called in the Android platform and iOS platforms.This system module is clearly defined,and the oxygen saturation detection engine is packed.Thus it is available for third-party calls,and it has been through a large number of tests to verify the system’s practicality and accuracy.