Research On Imaging Algorithm For Swept Source OCT

Optical Coherence Tomography (OCT) is a kind of medical three-dimensional tomography technology which develops rapidly in recent years. The basic principle of OCT is the interference with weak coherence light. OCT utilizes the weak coherent light to irradiate the biological tissue. Then we can detect the interference signal including different depths information of the tissue to gain the image. The merits of OCT are high resolution, high sensitivity, non-radiant detection and imaging in vivo.By means of the in-depth analysis in the imaging principle of the swept source OCT and the light characteristics, I research the algorithms to enhance the imaging quality in the swept source OCT. Based on the traditional k-domain calibration method, I propose two kinds of improved k-domain calibration methods, resampling phase extraction method and real-time uniform k-domain sampling method to make sample points distributing uniformly in the k-domain. In the same time, I propose the single phase transform algorithm to eliminate the background noise and artifact. Then the imaging resolution and depth will be improved.The researches mainly include the followed aspects:1. The paper analyses the imaging principle of the swept source and the main parameters of the swept source OCT system in detail, then establishes the imaging math model, and proposes the algorithms to enhance the imaging quality.2. Researching the time-frequency characteristic of the swept source optical output in-depth. Proposing two kinds of k-domain calibration methods, resampling phase extraction method and real-time uniform k-domain sampling method to make sample points distributing uniformly in the k-domain and reduce the signal extension, improve the image resolution. The simulation results with Matlab software verify the algorithms effectiveness.3. Aiming at the parasitic components and artifact problem, proposing the single phase transformation method to eliminate the parasitic components and artifact and increase the imaging depth. The simulation results with Matlab software verify the algorithm effectiveness.4. Designing and establishing the swept source OCT system and using the swept source OCT system to image the biological and non-biological tissue.The experimental results verify the feasibility and effectiveness of above algorithms to improve the imaging resolution and the imaging depth.