OCT扫描装置在体组织成像中的应用研究

发布时间：2018-07-15 11:18

【摘要】：光学相干层析(Optical Coherence Tomography,OCT)技术,是近些年来得到迅速发展的一种新型光学成像技术。OCT技术具有分辨率高、无损伤、实时成像等优点。OCT基于低相干干涉原理,可以对生物组织表面及内部的细微结构进行成像,对组织内部信息进行有效的提取。光学相干层析技术目前在眼科、口腔、心血管等医学诊断领域已经得到了广泛的应用。 OCT技术对于在体组织的成像检测以及将该技术应用于临床诊断具有重要的理论价值和实际意义。本文在课题组前期研究的基础上,根据OCT系统基本原理,主要完成了以下几个方面的工作: 1、对OCT系统的横向扫描装置进行了深入研究。设计了以微机电系统(Micro Electro Mechanical Systems,MEMS)作为横向扫描装置的OCT探头的机械结构。针对不同的应用对象,设计了手持式和腕式两种不同的探头机械结构并完成加工。 2、设计了基于MEMS扫描装置的OCT系统的光路结构。对MEMS探头的扫描轨迹进行了深入分析,提出了一种光学校正方法和一种软件校正方法,并利用后一种方法对MEMS扫描图像成功进行了校正。 3、根据MEMS探头的成像原理,设计了OCT探头的处理程序与数据采集程序,成功的实现了对干涉信号的采集、处理、显示。基于DSP电路,设计了系统的同步控制程序,使系统中数据采集、MEMS横向扫描能够同步工作。利用该系统对玻片、皮肤组织进行实验,验证了所设计OCT探头的准确性。 4、对牙齿组织和皮肤组织的光学特性进行了理论与实验研究。基于扩展的惠更斯-菲涅尔(Extended Huygens Fresnel,EHF)原理推导了OCT外差信号的表达式。利用该表达式对在体组织的OCT信号曲线进行拟合,提取了在体组织的光散射系数,验证了OCT应用于在体组织成像的可行性。
[Abstract]:Optical coherence Tomography Oct (Oct) is a new type of optical imaging technology, which has been developed rapidly in recent years. Oct has the advantages of high resolution, no damage and real-time imaging. Oct is based on the principle of low coherence interference. The fine structure of the surface and interior of biological tissue can be imaged, and the information inside the tissue can be extracted effectively. Optical coherence tomography is currently used in ophthalmology and oral cavity. Oct has been widely used in the field of cardiovascular and other medical diagnosis. Oct has important theoretical value and practical significance for the imaging detection of in vivo tissue and the application of Oct in clinical diagnosis. In this paper, based on the previous research and the basic principle of Oct system, the following work has been accomplished: 1. The transversal scanning device of Oct system has been deeply studied. The mechanical structure of Oct probe with Micro Electro Mechanical Systems MEMS (MEMS) as transverse scanning device is designed. For different objects of application, two kinds of mechanical structures of hand-held probe and carpal probe are designed and processed. 2. The optical structure of Oct system based on MEMS scanning device is designed. An optical correction method and a software correction method are proposed, and the latter method is used to correct the MEMS scanning image successfully. 3. According to the imaging principle of MEMS probe, the scanning trajectory of MEMS probe is analyzed. The processing program and data acquisition program of Oct probe are designed, and the interference signal is collected, processed and displayed successfully. Based on DSP circuit, the synchronous control program of the system is designed to synchronize the horizontal scanning of MEMS in the system. The optical properties of tooth tissue and skin tissue were studied theoretically and experimentally by using the system to test the accuracy of the Oct probe. Based on the extended Huygens Fresnelen EHF principle, the expression of Oct heterodyne signals is derived. The expression is used to fit the Oct signal curve of in vivo tissue, and the light scattering coefficient of in vivo tissue is extracted, which verifies the feasibility of using Oct in vivo tissue imaging.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R318.51;TP391.41

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