The Spectral Domain OCT System And Endoscopic Probe Design And Optimization

Spectral domain optical coherence tomography imaging technology is a new technology in bio-medical field, which has the advantages of high spatial resolution and fast imaging speed, being widely used to prevent and detect the Department of Ophthalmology, cardiovascular, cancer and other medical fields?The development, application and background of OCT are introduced firstly. Based on the principle and characteristics of OCT, the infulence of the light splitting ratio on the imaging contrast and the relationship between the optical component and the imaging resolution through optical simulation are discussed. This paper also analyzes the scanning track of the horizontal scanning device, and propses an optimization algorithm for trajectory error, which effectively improves the imaging quality. Based on LabVIEW platform, it developes the imaging software of high speed spectrum domain OCT, and accomplishes the galvanometer scanning and image acquistion card synchronous control, the real-time acquisition and control of the signal, and reconstructs two-dimensional gray image from the envelope of te interference signal, and finally realizes real-time imaging of the system. Experiments with the sample like cover glass, mirror were carried out to verify the performance of the system.In view of the limitation of galvanometer scanning system among the lateral scanning device that it can't scan tubular or cavity tissue, a probe is designed to be applied in the lateral scanning structure, which is convenient to switch to vibrating mirror scanning system. This paper selects GRIN lens as the core of the optical devices, systematically analyzes the optical transmission model of GRIN lens, obtains the relation curve of the distance between GRIN lens and single-mode fiber and probe working distance and the output spot. By using the coating light splitting prism, the integrated design of the system reference arm and sample arm is completed. The confirmatory experiment of endoscope system working distance and imaging resolution is carried out taking the plane mirror as sample. The results show that the system has high precision and long working distance.