Study On Key Techniques Of Wide-area Imaging Of Infant Retina

The human retina is the only part of the human body that can directly observe blood vessels.There are many kinds of retinopathy in children,and the etiology is complicated.Some retinal diseases are related to systemic diseases.Early treatment and follow-up observation of lesions is a long-term process,and some serious inheritance.Sexual or congenital lesions become important blind eye diseases in children.One of the current urgent tasks is to timely detect and intervene in blinding eye diseases and reduce the blindness rate.The infant retinal wide-area imaging system studied in this paper can image the retina and its surrounding areas,and provide an effective basis for the observation and diagnosis of ophthalmic diseases.The paper focuses on the research of wide-area imaging system of infant retinal and its key technologies.The main research contents are as follows:1.According to the requirements of infant retinal disease examination,a retinal imaging system using corneal contact ophthalmoscope and multi-angle annular fiber optic illumination is proposed,which mainly includes imaging,illumination and image processing.The retinal wide-area imaging system is connected to the PC end,and the image processing software is designed to realize camera calibration,distortion correction and image acquisition.2.To realistically simulate the design requirements of the retinal imaging system,the Escudero-Sanz model eye was established according to the characteristics of the infant's eyeball.Analyze the characteristics of the human eye refractive system,study the eye aberration,eye tissue spectral characteristics and human eye safety standards.Determine the use of visible light as the imaging light source,and set the light intensity adjustment range to meet the light safety standards of human eyes.3.To study the principle of wide-area imaging of infant retina,introduce corneal contact ophthalmoscope to increase the imaging field of view,and determine the appropriate size of the objective lens and imaging objective.Among them,the objective lens can realize the adjustment of different diopter of the human eyes,and the adjustment range is-9D~9D.The optical design software ZEMAX simulates and analyzes the retinal imaging light path based on the Escudero-Sanz model eye,which can achieve clear imaging of the human eye retina with different diopter,and the imaging field of view reaches 85°.4.The human eye is a dark room.The internal light is used to design the LED light source transmitted by the multi-angle ring fiber as the illumination mode to form uniform annular light on the surface of the cornea contact lens.The coating on the corneal contact ophthalmoscope is used to reduce stray light and achieve uniform illumination.The non-sequential design of the optical design software ZEMAX is used to analyze the stray light conditions of the illumination path;the retinal illumination is analyzed in LightTools to meet the design requirements.5.The image processing software is designed with Visual Studio 2010 as the development platform,based on C++ object-oriented programming development technology,combined with OpenCV visual library.The software can realize camera calibration distortion processing,image acquisition,image archiving,medical record information establishment and other functions.