Research On Digital X-ray Imaging System Based On Optical Fiber Taper Coupling

At present, most portable digital X-ray imaging systems are orthoptic type, they cannot export video frequency signal, test quantificationally and analyze with computer straightly. For overcoming these defects, author brought forward a new project that using the nondistortion transport property of optical fiber taper, took it as optical relay component, the image which was exported from X-ray image intensifier optical fiber panel fluorescent screen coupled to photosensitive surface of CCD. We designed a new digital X-ray imaging system based on optical fiber taper coupling. It has some advantages of high resolution, less cubage, lighter weight and portability. It can satisfy the demand of small domain medical imaging and nondestructive testing.The hardware structure of the imaging system, capability parameters of the detailed apparatus have been presented in this paper. We analyzed the method and coupling techniques of optical fiber taper coupling with CCD, studied the influence of diverse medium on resolution of CCD camera coupled with optical fiber taper, then pointed out the key techniques. Theoretically, we also educed the math expressions of the coupling efficiency of optical fiber taper with CCD, analyzed all influence factors of coupling efficiency of optical fiber taper with CCD, presented some effective methods to improve the coupling efficiency of optical fiber taper with CCD, and then analyzed the influence of coupling efficiency of optical fiber taper with CCD on signal-to-noise ratio of image system. Aim at the characteristic of system image noise, using the algorithms of image noise filtering, multi-frame mean, neighborhood processing, we have obtained good results. The author complied the software of image collection and manipulation system. The X-ray experiment for radiographic image of people body indicates that image system can be well used to medical diagnoses.