Chen Siyu, Yi Ji, Liu Wenzhong, Backman Vadim, Zhang Hao F
IEEE Trans Biomed Eng. 2015 Sep;62(9):2308-15. doi: 10.1109/TBME.2015.2424689. Epub 2015 May 4.
Optical coherence tomography (OCT) oximetry explores the possibility to measure retinal hemoglobin oxygen saturation level (sO2). We investigated the accuracy of OCT retinal oximetry using Monte Carlo simulation in a commonly used four-layer retinal model. After we determined the appropriate number of simulated photon packets, we studied the effects of blood vessel diameter, signal sampling position, physiological sO2 level, and the blood packing factor on the accuracy of sO2 estimation in OCT retinal oximetry. The simulation results showed that a packing factor between 0.2 and 0.4 yields a reasonably accurate estimation of sO2 within a 5% error tolerance, which is independent of vessel diameter and sampling position, when visible-light illumination is used in OCT. We further explored the optimal optical spectral range for OCT retinal oximetry. The simulation results suggest that visible spectral range around 560 nm is better suited than near-infrared spectral range around 800 nm for OCT oximetry to warrant accurate measurements.
光学相干断层扫描（OCT）血氧测定法探索了测量视网膜血红蛋白氧饱和度水平（sO2）的可能性。我们在常用的四层视网膜模型中使用蒙特卡罗模拟研究了OCT视网膜血氧测定法的准确性。在确定了合适的模拟光子包数量后，我们研究了血管直径、信号采样位置、生理sO2水平和血液填充因子对OCT视网膜血氧测定法中sO2估计准确性的影响。模拟结果表明，当OCT中使用可见光照明时，0.2至0.4之间的填充因子可在5%的误差容限内对sO2进行合理准确的估计，这与血管直径和采样位置无关。我们进一步探索了OCT视网膜血氧测定法的最佳光谱范围。模拟结果表明，对于OCT血氧测定法以保证准确测量，560nm左右的可见光谱范围比800nm左右的近红外光谱范围更合适。
