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光子衍射理论可用以获取一个将传输模式和反射模式脉搏血氧定量法测量得到的ac-dc强度比率与动脉氧饱和度(SaO_2)相关联的解析表达式。通过将光子衍射分析的结果与使用基于Beer-Lambert法则且忽略了散射效应的分析方法所获得的数据相比较,可对多重散射的效应进行研究。结果表明,红光和红外光传输路径的平均长度的差异,造成了血氧定量法的定标曲线易于受组织在两个波宽光谱带上的所有衰减因数以及被搏动的动脉血液吸收的影响。因此,定标曲线的形状会受到组织血液容积、源探测头置放的位置以及其它改变了组织衰减因数波长依赖性的变量的影
Photon diffraction theory can be used to obtain an analytical expression that correlates the ac-dc intensity ratio measured with pulse oximetry in the transmission mode and the arterial oxygen saturation (SaO_2). The effect of multiple scattering can be studied by comparing the results of photon diffraction analysis to those obtained using analytical methods based on the Beer-Lambert law and ignoring the scattering effects. The results showed that the difference in the average length of the red and infrared light transmission paths caused the calibration curve of oximetry to be susceptible to all the attenuation factors of the tissue in both wavebands and the pulsatile arterial blood absorption . Therefore, the shape of the calibration curve will be affected by the blood volume of the tissue, the position where the source probe is placed, and other variables that alter the wavelength dependence of the tissue attenuation factor