【作者】 贾甲；

【导师】 冯音琦；

【作者基本信息】 北京化工大学 ， 机械电子工程， 2009， 硕士

【摘要】 光学相干断层成像(Optical Coherence Tomography,OCT)技术是一种可对生物组织、各种材料进行非侵入检测的新型光学诊断检测三维成像技术。宽场光学相干断层成像(Wide Field optical coherencetomography,WFOCT)技术是传统OCT技术的扩展,无论传统OCT还是WFOCT技术往往都忽略样品的自然色,只能通过后期图像处理得到样品的伪彩色图像。而一幅真彩色的样品图像所包含的信息比伪彩色图像更丰富,得到的图像更逼真,可为专业的医学诊断以及其它光学检测提供了更加有用的信息。基于WFOCT技术,提出了一种彩色成像方法,搭建了三维彩色WFOCT系统。系统通过红、绿、蓝滤波片滤出宽场白光的三原色光作为光源,分别在三色光下得到样品的三色图像,通过图像处理,将样品三色光图像合成彩色图像。设计了相关的系统控制软件,实现了滤波片选择的自动控制、三原色光图像的采集和系统纵向扫描;完成了样品图像重构、三原色光图像合成彩色图像和样品的三维图像重建等系统的图像处理过程。利用该成像方法研究了彩色成像机理,模拟了白光成像,为以后直接在白光下获得彩色图像打下了基础。以载波片上表面和下表面、塑料表面和硬币表面作为样品,利用三维彩色WFOCT系统进行了相关实验,获得了相应的单色和彩色图像。实验结果表明该系统可以对一些透明介质及反射系数较高的彩色样品成像。最后对系统性能进行了研究和测试,分析了系统的横向分辨率、纵向分辨率以及系统的成像速率的影响因素,初步得到了系统性能的理论值和测量值。着重分析了实验平台振动等外界因素对系统成像造成的影响,并利用ZEMAX光学设计软件对单色宽场光学系统的干涉效果进行了模拟,根据实验与模拟结果,给出获得较为清晰、分辨率较高的样品图像的实验条件。更多还原

【Abstract】 Optical coherence tomography(OCT) is a non-immersion new optical diagnosis three dimensional reconstruction imaging technology which be can used for biological tissue and various materials. Wide Field optical coherence tomography(WFOCT) is an extention for the traditional OCT, whaterever system in OCT sample’s nature colors are neglected and its pseudo-color images are obtained by image processing. Actually the information contained in a nature color image is more rich than that in a pseudo-color image with higher fidelity. It could provide more useful information for a professional medical diagnosis and other optical detections.Based on WFOCT technology, an color imaging method is proposed and a 3D WFOCT system is constucted. Three primary colors lights filtered out from broadband white source are used as light source. Three primary color images of a sample are obtained respectively using the primary color lights. A nature color image of the sample is synthesized by imaging processing. Prgram pertinent to the control uint in the system are designed, Which can implement auto filter selection, image acquisition, axial scanning. Imaging processing in the system has fulfilled sample’s sectional image reconstruction, sample’s nature color image synthesization with the primary color images and sample’s 3D image rebuild. Using the method, The color imaging mechanism has been studied and the imaging using white light has been simulated, which are the foundation for directly obtaining color images using white light later.Using the 3D colore WFOCT system, correlative experiments have been carried out with glass slides、plastic surfaces and coin surfaces as samples. Corresponding monochromatic and color images have been acquired. Experimental results indicate that some transparent media and high reflection factor color samples could be imaged using this system.Finally the system performance has been investigated and tested. Influence factors effecting on system transverse resolution, axial resolution as well as imaging speed have been analyzed. The initial theoretical values and observed values of the system properties have been obtained. Influences on the system imaging by platform oscillation or vibration and experimental environments have been analyzed emphatically. Interference effects in the system with monochromatic light are simulated using ZEMAX software. By the experimental and emulational results, experimental conditions are given for acquiring a clearer sample image with a higher resolution.更多还原