基于3D打印技术的眼科OCT设备计量校准装置研制

为了评估眼科光学相干断层成像（OCT）设备的分辨率、视场角、图像匹配度、深度测量准确性等多个关键参数，确保设备输出量值的准确性与有效性，设计并研制了一种模拟真实人眼结构且参数可溯源的模拟眼，包含角膜和晶状体等人眼主要屈光结构。设计并依托3D打印技术加工了用于横向与轴向分辨率检测的三维分辨率板；设计加工了用于视场角检测的阶梯状同心圆环结构；同时设计加工了用于图像匹配度检测的交叉光纤组件和用于深度测量准确性参数检测的平行玻璃板组件，可适配于模拟眼眼底凹槽内。使用共焦拉曼显微镜对三维分辨率板尺寸溯源，横向和轴向最小可检测分辨率分别为9.7 μm和5.7 μm；使用尼康投影仪对同心圆环尺寸及光纤直径溯源，最大可检测视场角109.03°以及最小62.5 μm的图像匹配度检测；使用尼康高度计对平行玻璃板中心厚度溯源，其测量不确定度小于5 μm。经过对商用眼科OCT设备测试表明，结合微纳3D打印技术的计量校准用模拟眼具有精度高、集成度高、适用范围广、稳定性强等优点，适用于眼科OCT设备的计量校准。

Development of metrology and calibration devices for ophthalmic OCT equipment based on 3D printing technology

To evaluate the resolution, angular field of view (FOV), coalignment of fundus images and OCT scans, depth scaling and other key parameters of optical coherence tomography (OCT) equipment and ensure the accuracy and validity of the equipment output values. In this paper, a model eye simulating real human eye structure was designed and developed, including the main refractive structures, such as cornea and lens, and its parameters are traceable. A 3D resolution board for lateral and axial resolution detection was designed and fabricated based on 3D printing technology. A stepped concentric ring structure was designed and machined for FOV detection. At the same time, the cross fiber module for image matching detection and the parallel glass module for depth scaling detection were designed and manufactured, which can be adapted to the fundus groove of the model eye. Confocal Raman microscopy was used to trace the size of the 3D resolution board, and the minimum detectable values for lateral and axial resolutions were 9.7 μm and 5.7 μm, respectively. The sizes of the concentric rings and fiber diameter can be traced by a Nikon projector. The maximum detectable FOV is 109.03°, and the image matching minimum accuracy is 62.5 μm. The center thickness of the parallel glass plate was traced by a Nikon digital height gauge, and the measurement uncertainty was less than 5 μm. The test of commercial ophthalmic OCT equipment showed that the model eye metrology and calibration device based on 3D printing technology has the advantages of high accuracy, high integration, wide application range and strong stability, so it is suitable for metrology and calibration of ophthalmic OCT equipment.