So in this paper , the principle of electroptical non - invasive dual - ray methods are fist present in detail . in the theorem of simple structure and low power consumption , we select detecter with fitble wavelenth and low power msp430 processor , and design high stable ray - emitt circuit , low noise pre - amplifier , background disturbance counteract circuit , the signal are low - filtered and sent to msp430 " a / d transform directly to digital signal processing 为此,本文详细分析了光电无创双光束法测定脉搏血氧饱和度的基本原理,在结构简单,功耗小的原则下,选用合适发光波长的探头和信号处理器,设计出光强稳定的发光电路,低噪声前级,以及本底干扰对消电路,通过两级低通直接送至ti公司的超低功耗混合信号处理器msp430进行a / d变换得到原始的数字信号。
Determining oxygen saturation in human blood by transmittance oxymetry is well developed as a monitoring technique , which is applied widely in clinical diagnosis or house health care . however , reflectance detecting is necessary in many circumstances , such as cerebral oxygen saturation , muscle oxygen saturation , or fetal oxygen saturation monitoring . how to get an exact and dependable reflectance oxygen saturation value by non - invasive and economic means is always concerned by researchers in biomedical engineering 采用透射式检测方法确定人体血液中的氧饱和度已经是较为成熟的监护手段，在临床和家庭保健场合有广泛的应用；但在很多需要进行反射检测的场合，如脑血氧、肌血氧、胎儿血氧监护等，如何用无创、经济的方法获得准确、可靠的血氧饱和度值仍是生物医学工程领域不断在探索的问题。
However , a new method is brought forward when dealing with alternating components of emitting light in reflectance detection , which entirely reflect the concentration of oxy - hemoglobin and deoxy - hemoglobin in blood , to improve the system sensitivity on oxygen saturation alternation . the new method is an innovative reference to reflectance oxygen saturation detection 在对检测到的完全反应血液中氧合血红蛋白和脱氧血红蛋白含量变化的脉动分量的处理上，由于透射检测中的处理方法用于反射时灵敏度降低，论文中提出了一种新的能更灵敏反应血氧变化的参量作为确定血氧饱和度的依据。
At first , the principle and technique employed in transmittance oxymetry is analyzed . the lambert - beer law and the difference in extinction coefficient of components in tissues relate to different light wavelength is applicable in reflectance oximetry as well as in transmittance oximetry , as both are relate to near - infrared spectroscopy 本文在深入了解透射式血氧饱和度测定原理及其方法之后，首先明确用近红外光谱法测定组织血氧饱和度时，无论是透射式检测手段还是反射式检测，其依据的基本原理都是lambert - beer定律和组织中各成分对应不同波长光的吸收系数的差异。
