Visible-light OCT spectrometer for microvascular oximetry
Visible-light OCT spectrometer for microvascular oximetry
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用于微血管血氧测定的可见光 OCT 光谱仪
DOI：
10.1117/12.761254
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
Gangnus S
中科院分区：
文献类型：
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作者：
Gangnus S
我们描述了一种可见光光谱OCT系统，旨在获得局部测量的血红蛋白氧合在浅表微循环，并获得局部测量的光学特性在可见波长。该装置基于在450-600 nm光谱范围内发射的超连续谱源，该光谱范围与血红蛋白的可见吸收带重叠。OCT检测系统采用线性CCD和自制光谱仪的谱域设置，并在单模光纤中实现。多光谱OCT图像可以在8个波长下同时采集，每个波长具有256个轴向像素，并且可以以1 kHz的线速率应用多线性回归处理。系统的动态范围的特点，并发现是有限的超连续谱源中的过量噪声。散射的波长依赖性确定为Intraperoid使用单散射模型。在可见光谱中检测来自全血的相干反向散射，并用于推断470 nm处的总衰减系数。证明了在薄至20微米的血液体积上获得血氧测定数据的可行性。这项工作描述了皮升分辨率的浅表微循环中血红蛋白氧合评估的第一步。
We describe a visible-light spectroscopic OCT system designed to obtain localized measurements of hemoglobin oxygenation in the superficial microcirculation and also to obtain localized measurements of optical properties at visible wavelengths. The device is based on a supercontinuum source emitting in the 450-600 nm spectral range, which overlaps the visible absorption band of hemoglobin. The OCT detection system uses a spectral domain set-up using a linear CCD and home-built spectrometer and is implemented in single-mode fiber. Multi-spectral OCT images can be acquired at eight wavelengths simultaneously each with 256 axial pixels, and multi-linear regression processing can be applied at a line-rate of 1 kHz. The dynamic range of the system is characterized and found to be limited by excess noise in the supercontinuum source. The wavelength-dependence of scatter is determined for Intralipid using a single-scatter model. Coherent back-scatter from whole blood is detected in the visible spectrum and used to infer the total attenuation coefficient at 470 nm. The feasibility of obtaining oximetry data over volumes of blood as thin as 20 microns is demonstrated. The work describes first steps towards assessment of hemoglobin oxygenation in the superficial microcirculation with picoliter resolution.