摘要光学相干层析术(Optical Coherence Tomography,OCT)是实现对生物组织在体非侵入性地高分辨微观结构断层成像的具有前景的工具。首先概述了OCT技术的发展,比较了功能OCT应用于获取血流速度信息的各种研究方法与结果。之后详细说明了谱域OCT的成像原理,描述了实验室所搭建的谱域OCT系统,介绍了对干涉信号进行处理的一些方法。提出了一种利用互相关性测量空间横向流速的方法。通过设定谱域OCT系统的扫描模式X和Y,利用同一深度位置的相邻A扫信号之间的互相关性与空间横向速度分量之间的数学关系,求得空间横向流速的绝对大小。详细阐述了该方法的测量原理。通过毛细管模拟实验描绘了截面的横向流速分量分布,并验证了所测得的平均横向流速大小与用注射泵设定的值基本一致。30514
关键词 谱域光学相干层析术 互相关 成像 空间横向速度
毕业论文设计说明书外文摘要
Title Study of Spectral Domain Optical Coherence Tomography-based Techniques for Blood Flowing Velocity Imaging
Abstract
Optical coherence tomography (OCT) is a promising tool for in vivo imaging sectional parts of microstructure in biological tissues with no invasion and high resolution. Firstly, the development of OCT is summarized. Varieties of methods and results of acquiring information about blood flowing velocity by functional OCT are compared. And then, the imaging principle of spectral domain OCT is explained in detail, the OCT system set up in our laboratory is described and some techniques on processing the interferometric signals are presented. A method is proposed to use cross-correlation to measure the spatial transverse flowing velocity. By setting the scanning pattern X and Y based on the spectral domain OCT system, the absolute value of the velocity is achieved according to the mathematical relation of the cross-correlation between the adjacent A-scans to the spatial transverse flowing velocity. The measuring principle of this method is elaborated. The transverse velocity component distribution of the section is described through the simulation experiment using a capillary. It is demonstrated that the measured mean value of the transverse flowing velocity is in accordance with the set value by using the syringe pump.
Keywords spectral domain optical coherence tomography cross-correlation imaging spatial transverse flowing velocity
目 次
1 绪论 1
1.1 OCT技术概述 1
1.2 OCT技术在血流研究方面的功能性拓展 3
1.3 本文的主要研究工作 4
2 谱域OCT系统原理与信号处理 6
2.1 基本原理 6
2.2 系统装置 8
2.2.1 光源 9
2.2.2 扫描装置 9
2.2.3 样品臂准直系统 9
2.2.4 光谱仪 10
2.3 干涉信号处理 10
2.3.1 平均法去除直流项 10
2.3.2 希尔伯特变换消除复共轭 10
2.4 本章小结 12
3 基于谱域OCT的空间横向流速成像 13
3.1 数学模型与理论分析 13
3.2 实验研究与结果分析 16
3.2.1 实验系统 16
3.2.2 实验过程与结果分析 16
3.3 本章小结 19
结 论 20
致 谢 21
参考文献 22
1 绪论 基于频谱域OCT的血流速度成像技术研究:http://www.youerw.com/tongxin/lunwen_26246.html