基于频域光学相干层析术的人体皮肤高分辨率光学断层成像研究

【作者】 夏扬；

【导师】 高万荣；

【作者基本信息】 南京理工大学 ， 光学工程， 2010， 硕士

【摘要】 光学相干层析成像技术(Optical Coherence Tomography,OCT)是近些年快速发展的一种超高分辨率的实时生物组织成像技术。频域光学相干层析成像(FDOCT)作为OCT的一个重要分支,在快速成像方面取得了突破性进展,它的特点是无需纵向的扫描,信号灵敏度大幅度提高,动态范围大。本文首先阐述了OCT的发展历史以及其在各种领域的应用。其次介绍OCT的实验装置,深入研究了频域OCT的原理,并分析了频域OCT技术的各种评价参数。第三部分深入探讨了直流项、寄生像噪声以及色散造成的脉冲展宽的产生,并在理论和实验上消除上述三项噪声。第四部分设计了一些软件算法实现相位线性化、参数替换法、傅里叶逆变换等方法进行信号处理,校正了光谱仪的像素与干涉信号波长的关系,为计算深度信息的离散傅里叶变换提高了准确度。最后获得了盖玻片以及皮肤层析图像,获得了表皮、真皮层信号,并计算出盖玻片以及表皮的厚度或者折射率。更多还原

【Abstract】 Optical Coherence Tomography (OCT) is a high resolution imaging technique for generating cross-sectional images of biological tissue in real time. Frequency Domain Optical Coherence Tomography (FDOCT) is an important branch of OCT, which is characterized by its high imaging speed, high sensitivity and large dynamic measurement range.In this thesis the development and the applications of OCT in various fields are reviewed in the first place. Second, the experimental system is described.The principles of the FDOCT as well as various parameters for evaluating the performance of FDOCT system are analyzed. Third, the methods of suppressing the noises, including DC term, complex-conjugate ambiguity (CCA) and the dispersion in OCT induced by samples and fibers are pointed out theoretically and experimentally. Forth, the software has been designed for realizing the phase linearization, interpolation, inverse Fourier transform and the spectrum signal processing to calibrate the wavelength according to CCD pixels for obtaining more accurate tomographic images. Finally, images of glasses and skin have been obtained with the system, with thicknesses and indexes of them calculated.更多还原