全场光学相干层析术的信号探测技术研究
时间:2018-07-05 15:18 来源:毕业论文 作者:毕业论文 点击:次
| 摘要全场光学相干断层扫描成像技术在生物医学领域获得高分辨率的图像信息方面具有极大的发展潜力。它主要同过光照射到生物组织上然后在生物组织中传播会发生向后散射光，通过向后散射回来的光与参考光进行干涉，来获取生物组织的深度信息，进而恢复其组织形貌。本系统使用宽带光源，可以获得更高横向分辨率的高数值孔径物镜，而用CCD并行扫描的方式也使其可以具有更快的成像速度。本文研究了对基于改进的科勒照明方式的林尼克干涉结构的全场光学相干层析成像系统采集到的信号进行处理与优化，使其获得更好的对比度。首先分析成像原理，搭建实验平台进行实验，分析了FFOCT的信号的产生、采集与处理，对成像系统的性能进行分析，主要针对其成像深度与分辨率方面进行分析与优化，讨论了生物组织中光的散射模型，进而对成像图片进行散射衰减补偿，提高图像的对比度，为获得更深层次的生物组织信息打下良好基础。25236 毕业论文关键词：全场光学相干层析成像 分辨率 成像深度 散射补偿 像差 毕业设计说明书外文摘要 Title Study of Signal Detection Techniques in Full optical coherence tomography Abstract Full optical coherence tomography can generate high resolution optical sectioning images and has great application potential in the field of the biomedical medicine. It is mainly based on the detection of the light backward scattered from biological tissue, and the light from the sample is superposed with the light reflected from the reference arm of the interferometer and generate interference fringes. The information about the object can be obtained by measuring the envelope of the interference envelope. In this device a light source with broad bandwidth and the microscopic objective lenses with high numerical apertures are used to obtain high depth and the transverse resolution.The CCD is employed to detect the imaging signal and a high imaging speed can be achieved.In this work, the signal measured by a FFOCT system based on the combination of the Linnik interference microscope and the Koller illumination were processed and optimiaed to improve the imaging speed. First of all, the imaging principles were considered and a FFOCT system was established. The genaration of the imaging signal, detection and processing were discussed. The imaging performance were then analyzed with theamphasis on the imaging depth and the resolution. The light sacttering model of tissue was discussed and the signal attenuation induced by the scattering wrere compensated to increase the image contrast, which is helpful for imaproving the imaging depth in the future. Keywords Optical coherence tomography resolution Imaging depth Scattering compensation aberration 目 次 1 引言 1 1.1 生物组织成像的现状与发展趋势 1 1.2 光学相干层析成像研究的发展历程 3 1.3 本课题研究的内容与改进 4 2 全场光学相干层析成像的理论基础 5 2.1 OCT的原理与FFOCT的原理 5 2.2光源 7 2.3 照明系统 7 2.4 干涉仪 9 2.5信号采集 9 3 系统成像性能分析 12 3.1 纵向分辨率 12 3.2 横向分辨率 13 3.3 成像中的噪声 14 3.4 生物组织中散射模型 15 3.5 成像深度的分析及优化 17 4 全场光学相干层析成像的实验与结果 18 4.1 实验系统成像与图片采集 18 4.2 生物组织引起的像差的影响及其补偿 19 4.3 实验结果 20 结论 22 致谢 23 参考文献24 1 引言 (责任编辑：qin) |