中国激光, 2011, 38 (5): 0504001, 网络出版: 2011-05-09
屈光介质中谱域光学相干层析成像的重构
Image Reconstruction in Dioptric Media for Spectral Domain Optical Coherence Tomography
生物光学 光学相干层析 成像误差 几何光学 屈光介质 biotechnology optical coherence tomography image distortions geometrical optics dioptric media
摘要
在屈光介质中,由于光线的折射以及光程与实际物理距离的错配,使得光学相干层析(OCT)成像存在重构误差。将几何光学中光线追迹的方法应用于光纤型谱域光学相干层析成像系统所成图像的重构误差矫正,在理论上推导了屈光介质所成层析图像与其真实物理结构的映射关系。实验中,将提出的方法应用于玻璃毛细管和人眼眼前节图像的重构误差矫正,在矫正后的图像中玻璃毛细管的剖面结构得到了准确的还原,所测人眼的眼角膜厚度、前房深度和宽度、眼角膜前后表面以及晶状体前表面的曲率半径等各种参数都符合模型眼给出的参考值。该方法能够使光学相干层析成像系统应用于具有任意多层折射界面的屈光介质,包括由透镜组组成的复杂光学系统等的成像。
Abstract
In dioptric media, due to the refraction of probe light in the sample and the mismatch of the optical distance with the actual distance, a major impediment to the use of optical coherence tomography (OCT) is its image distortions. This paper describes ray trace method of geometrical optics algorithm for numerical correction of the unavoidable image distortions in the raw image obtained by fiber based spectral domain OCT system, and theoretically deduces the mapping from the raw image of dioptric media to its actual structure. Experimentally, this method is adopted to correct the image of the glass tube and the anterior segment of human eye. The reconstructed image of the glass tube is coincident with the actual structure, and the measured physiological parameters of the human eye, such as cornea thickness, anterior chamber depth and width, pupil width, curvature radius of front and rear surface of cornea, and curvature radius of front surface of lens, are within the reference ranges given by the model one. The method enables OCT system to be applied to dioptric media containing multiple refraction interfaces, including the imaging of complicated optical system consisting of battery of lenses.
杨柳, 王川, 丁志华, 洪威, 黄良敏. 屈光介质中谱域光学相干层析成像的重构[J]. 中国激光, 2011, 38(5): 0504001. Yang Liu, Wang Chuan, Ding Zhihua, Hong Wei, Huang Liangmin. Image Reconstruction in Dioptric Media for Spectral Domain Optical Coherence Tomography[J]. Chinese Journal of Lasers, 2011, 38(5): 0504001.