光学相干断层扫描(OCT)具有成像速度快, 分辨率高的特点, 被广泛应用于眼科疾病诊断。针对眼科手术中需要快速获取指定手术区域的深度信息, 本文提出了一种将OCT应用到眼科手术导航的方法。基于扫频OCT系统, 以二向色镜结合CCD相机进行实时观测, 对扫描坐标系和相机坐标系进行坐标匹配, 完成OCT的扫描定位。对于由样品自身折射所带来的图像重建与实际坐标的误差, 基于费马原理与斯涅尔定律进行OCT图像重构误差矫正, 在理论上推导了OCT图像与样品实际结构的映射关系。实验结果表明, 能够以较低的误差(深度误差约为50 μm)获取特定位置的OCT图像, 并完成OCT图像信息的矫正。该系统能够测量样品指定位置的准确信息。

Optical Coherence Tomography (OCT) has the characteristics of fast imaging speed and high resolution. It is widely used in the diagnosis of ophthalmic disease. In order to quickly obtain the depth information of the designated surgical area in ophthalmic surgery, this paper proposes a method of applying OCT to ophthalmic surgery navigation. Based on the swept-frequency OCT system, and the real-time observation is performed by a dichroic mirror combined with a CCD camera, and the coordinates of the scanning coordinate system and the camera coordinate system are matched. The scan positioning of the OCT is completed. For the error of image reconstruction and actual coordinates caused by the self-refraction of the sample, the OCT image reconstruction error correction is based on Fermat′s principle and Snell′s law, and the mapping relationship between the OCT image and the actual structure of the sample is theoretically derived. Experimental results indicate that the OCT image of a specific location can be acquired with a low error, and the OCT image information can be corrected accordingly. The system is capable of measuring accurate information on the location of the sample.