基于频谱域OCT的血流速度成像技术研究
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