Research On Catheter-based Fourier Domain OCT System And Imaging Methods

Optical coherence tomography(OCT)can realize the high resolution imaging of biological tissue non-invasively,having wide clinical application prospect.Catheter-based fourier domain OCT system plays an important role in the cardiovascular imaging.With the high resolution and high imaging speed,it can realize the real-time circumferential scanning imaging of the cardiovascular wall,assisting the detection of cardiovascular disease and the guidance during the interventional therapy.So this paper researched on the catheter-based fourier domain OCT system and its imaging methods.In detail,this paper has completed those parts:1.The analysis and processing of cardiovascular OCT images.The attenuation coefficients of different plaques were calculated by using the attenuation coefficient evaluation algorithm.The attenuation compensation and contrast enhancement algorithm was studied theoretically.This paper analyzed the characteristics of tissue attenuation and stents in depth in the cardiovascular image,and proposed an optimized method for the attenuation compensation and contrast enhancement algorithm,achieving image enhancement,as well as preserving the attenuation characteristics of tissues and avoiding the artifact shadow in front of the deep stents.2.Research on catheter-based OCT imaging system.This paper designed and built the fourier domain OCT system based on the fast swept light source and the scanning catheter,including building the interferometer with optical fibers,acquiring the interference signal and controlling the imaging catheter.And the imaging software system was developed,which consists of the image acquisition and reconstruction,hardware control and so on.The imaging testing experiments were also conducted and the instrumentation work for this imaging system was completed.3.Study on spectral domain OCT system based on supercontinuum light source.This paper built the spectral interferometer system in free-space and acquired the supercontinuum interference signal.And it completed the theoretical analysis and simulation of the interference spectrum method for the measurements of the optical path difference.By using the numerical compensation method,this paper compensated the dispersion effect,eliminating the distortions of interference fringes and the broadening of the tomographic signal.