Design And Research Of Dual Wavelength Retinal Oximeter

As the only blood vessel in the body that can be directly observed without invasion,the retinal blood vessels have important research value in the diagnosis of some systemic diseases.The existing fundus examination equipment in China is still limited to the acquisition of fundus images,and cannot actively judge the state of the disease.The diagnosis of the disease needs to be judged by the doctor's experience.For some diseases that are still in the junior stage of development and have not caused substantial changes in vascular morphology,there will be missed diagnosis.A large number of studies have confirmed the existence of retinal vascular obstruction,diabetic retinopathy,retinal pigmentation,glaucoma,age-related macular degeneration and other diseases and the abnormal oxygen saturation in the retina there is an inevitable link.By measuring the oxygen saturation of the retina,an objective and accurate basis for the diagnosis of some diseases can be provided.After referring to a large number of literatures related to fundus detection equipment and retinal oxygen saturation measurement techniques,a non-invasive dual-wavelength retinal blood oxygen saturation measuring instrument was designed with a working wavelength of 570 nm and 600 nm based on the characteristics of blood absorption spectroscopy.Based on the Gullstrand-Le Grand human eye model with different diopters(-10D-10D),a zemax software was used to design an imaging optical path with internal focusing function that can simultaneously produce dual-wavelength images on a camera;According to the human eye's optical characteristics,and referring to the concept of the conjugate of the human eye pupil and the illumination light source,an illumination light path sharing the objective lens with the imaging light path is designed.Using ring light source illumination and adding polarizers to the optical path to eliminate stray light caused by corneal reflection in the system and the ghost image caused by the reflection of the objective lens,then carried on the illumination simulation analysis in the Tracepro software;atolerance Analysis was carried out for the system designed in this paper;After vessel segmentation and calculation of optic density ratio of the two images,The retinal oxygen saturation was measured...