完整泪液膜层的干涉图像.docx

Interferometric imaging of the full thickness of theprecorneal tear film完整泪液膜的干涉图像A method is described for recording interference images from the full thickness of the precorneal tear film(PCTF). Simultaneous images are recorded by two video cameras. One camera responds to broadband spectralillumination and records interference from the superficial lipid layer of the tear film. The other camera usesnarrowband illumination and records interference from both the lipid layer and the full thickness of the PCTF.Thus the full-thickness interference fringes are derived from the difference between, or ratio of, narrowbandbroadband images. This method has the potential for evaluating the role of both tear film flow and evaporationin tear film thinning and breakup. It therefore may be applied to the analysis of dry eye disease. © 2006 OpticalSociety of AmericaOCIS codes: 170.0110, 170.3880, 170.4470, 260.3160, 310.6860.一种记录完整泪液膜（PCTF）干涉图像的方法。

图像同时被 2 个摄像头记录下来一个摄像头记录宽带光谱在泪膜脂质层产生的干涉图像另一个用来记录窄带光谱在脂质层和完整膜的干涉图像因此，窄带图像和宽带图像组成了完整薄膜的干涉图像这种方法具有评估泪膜流动性和蒸发（当泪膜稀释和干裂）的潜在能力他可以应用于分析干眼疾病1. 简介人类的泪膜有很多功能 它提供液体环境给表面角膜的上皮细胞而且帮助保护对抗微生物和异物外部表面PCTF 是主要部份使折射眼睛的表面；表面紧张帮助使这表面光滑，如此改良网膜图像的光学质量另外地，那PCTF 在眨眼期间有一个润滑功能这些功能能在干的眼睛情况被打乱，一些是最通常的眼睛见到的混乱在眼睛－照料开业者手边2干的眼睛疾病能带领到泪滴的早熟停止拍摄在一之后眨眼，带领对表面上皮 3,4 的损害和光学的使 .5 模糊PCTF 被帮助的瘦脂质层复盖到 减少在下面水的层的蒸发 Wolff6 计划，内部的黏液层被传布在 角膜表面被眨眼行动、但是现在视野 这一层是它有薄膜－范围黏液素 形成 glycocalyx 的分子Interferometry of the PCTF and pre-(contact)-lens tear film (PLTF) can be used both for the measurement of tear thickness and for imaging. Interference in a thin film is described byPCTF 和 PLTF 的干涉测量法都可以被用来测泪膜干涉图像。

干涉法在薄膜中描述为：where m_d,__ ,__ is the order of the fringe, n___ and d arethe refractive index and thickness of the film, __ is the(refracted) angle of the beam in the film, and _ is thevacuum wavelength.10 Reflectance of the tear film is thengiven by脂质层折射率比空气和水层高TDF 等厚干涉TDF 等倾干涉WDF 等波长干涉PLTF 的厚度 略小于 PCTF 的厚度There are two reasons why it is difficult to record corresponding images of the full thickness of the PCTF.First, WDF recordings demonstrate that the contrast of fringes (“spectral oscillations”) from the PCTF is always considerably less than the contrast that can be obtained from the PLTF. Second, these weak, full-thickness fringes tend to be masked by higher-contrast fringes from the lipid layer. As discussed above, imaging using broadband light should show the lipid layer, while greatly attenuating the contrast of the full-thickness fringes; imaging using narrowband light can maintain the contrast of both lipid and full-thickness fringes. Thus the principle of the current method is to record both broadband and narrowband images simultaneously; by taking the difference between (or ratio of) the two images, the interference fringes from the lipid layer can theoretically be eliminated, leaving the low contrast full-thickness fringes. Near-infrared radiation, rather than light, was used, because the contrast of full-thickness fringes is stronger at long wavelengths，while the contrast from the lipid layer tends to be less; additionally, the use of infrared avoids the generation of reflex tears that could be stimulated by bright light.有2个结果，因为很难记录PCTF的全部干涉图像。

首先，WDF证明PCTF明暗条纹对比PLTF 少第二，这些虚弱的全层条纹被油层条纹削弱了；窄带图像可以维持油脂层和全层当前方法是记录宽带和窄带图像，取得这个图像的差异，油脂层图像可以从全层图像中被消去红外线更好用，用长光波可以得到更清晰的像，当油脂层图像越来越弱的时侯；红外线比白光刺激性小2. METHODSA. Optical System图2展示了以个光学系统，同时得到宽带和窄带图像的方法在文献23的基础上修改得来的光从卤素灯S处发出，被分光器 PB1分成2束光，这两束光分别穿过宽带和窄带滤波器，FB和FN2束光被分光器PB2合成新的光源S’ 一个很大的透镜，使角膜可以在很远处成像光远入射角膜并反射到分光器PB3，它传送一个图像到L4V1 ，反射另一个图像到L5V2. 宽带（L4V1 ）和窄带（L5V2）图像同时获得并直接记录到计算机中从S’到L3的光学距离，S’ 在角膜的中心处成像，角膜在L3焦点上video cameras L4V1 and L5V2 聚焦在无穷远处定义：像素656*494，帧数：30/s, 曝光30ms ; 用STREAMPIX software 软件记录。

角膜图像 8 mm*7 mm.放一个热定位仪调整镜片L3使眼睛成像The video camera L6V3 呈现眼睛的侧面影像标示角膜位置光学系统，L7 plus video camera L8V4 是从横向和竖向将眼睛对准当眼睛横向移动的时候，光源的图像（居中于L4, L5, and L7）也跟着横向移动The video camera L8V4 成一个缩小的光源像，在位置调节器中调整至中心位置分束镜B1-B3 接近垂直入射为了减少光强变化，保证偏振效果B3 用来设计固定的目标Fig. 2. Optical system for recording simultaneous broadband and narrowband images. S, 6 V, 20W, tungsten halogen source; L1–L8, lenses [L3,L4,L5,L6, and L8 are multielement lenses; L3 is an f /0.8 custom-designed lens of focal length 50 mm; L4 and L5, are near-infrared lenses f / 1.9, focal length 35mm (Schneider Optics, Bad Kreuznach, Germany); L6 and L8 are close focus lenses]; PB1–PB3, polarizing beam splitters (Edmund’s Industrial Optics, Barrington, New Jersey); FB, broadband filter, RG780 (Schott, Duryea, Pennsylvania); FN, 850 nm interference filter; D, neutral filter, chosen to approximately equalize responses to broadband and narrowband beams; P1 and P2, wire-grid polarizers (Moxtek, Orem, Utah) to reduce cross talk from the broadband light source to the narrowband camera; M1–M3, front-surfaced mirrors; S’, image of S; B1–B3, glass plate beam splitters (B3 is used to project a fixation target for the subject; the rest of this optical system is not shown); V1–V4, monochrome video sensors [V1 and V。