In vitro measurements of absolute blood oxygen saturation using pulsed near-infrared photoacoustic spectroscopy:: accuracy and resolution
In vitro measurements of absolute blood oxygen saturation using pulsed near-infrared photoacoustic spectroscopy:: accuracy and resolution
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DOI：
10.1088/0031-9155/50/18/011
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发表时间：
2005-09-21
影响因子：
3.5
通讯作者：
Beard, P
中科院分区：
文献类型：
--
作者：
Laufer, J;Elwell, C;Beard, P
使用脉冲光声光谱法测量体外血氧饱和度。光学参量振荡器激光系统提供波长范围为 740-1040 nm 的纳秒激发脉冲，用于在比色皿中产生光声信号，红细胞盐悬浮液通过比色皿循环。从光声信号中提取信号幅度和有效衰减系数作为波长的函数，以提供血液的光声光谱。由此，利用基于扩散理论的吸收能量分布正向模型确定氧合血红蛋白和脱氧血红蛋白的相对浓度，以及血氧饱和度 (SO2)。吸光度对发色团浓度依赖性的标准线性模型也用于根据信号幅度谱计算血氧饱和度。扩散近似模型显示出血液 SO2 的准确度最高。发现光声确定的氧饱和度对于信号幅度数据具有+/- 4% SO2 的准确度，对于有效衰减光谱具有+/- 2.5% SO2 的准确度。使用该技术可以测量的最小氧饱和度变化为 1% SO2。
Pulsed photoacoustic spectroscopy was used to measure blood oxygen saturation in vitro. An optical parametric oscillator laser system provided nanosecond excitation pulses over the wavelength range 740-1040 nm which were used to generate photoacoustic signals in a cuvette through which a saline suspension of red blood cells was circulated. The signal amplitude and the effective attenuation coefficient were extracted from the photoacoustic signals as a function of wavelength to provide photoacoustic spectra of the blood. From these, the relative concentrations of oxy- and deoxyhaemoglobin, and therefore blood oxygen saturation (SO2), were determined using forward models of the absorbed energy distribution based on diffusion theory. A standard linear model of the dependence of absorbance on the concentration of chromophores was also used to calculate the blood oxygen saturation from the signal amplitude spectra. The diffusion approximation model was shown to produce the highest accuracy in blood SO2. The photoacoustically determined oxygen saturation was found to have an accuracy of +/- 4% SO2 for signal amplitude data and +/- 2.5% SO2 for effective attenuation spectra. The smallest change in oxygen saturation that can be measured using this technique was 1% SO2.