Design And Research Of Large Field Of View Endoscope Based On Curved Surface Multiprobe

Endoscopy is currently one of the most basic and extensive observation tools in medical research and clinical practice,and the use of endoscopic imaging plays an extremely important role in the diagnosis and adjuvant treatment of lesions.However,the existing endoscopic system has the problem that the imaging range is small,which makes the surgical field easily limited,which limits the accurate diagnosis of lesions by physicians.Endoscopic optical systems are designed to be small and lightweight while having a larger field of view.The curved compound eye system has the characteristics of large field of view and compact structure,which just meets the needs of endoscopic optical systems.Therefore,this paper proposes to use the curved compound eye system as part of the endoscopic optical system.In this paper,a large-field surface multi-probe endoscopic optical system is designed to realize endoscopic large-field imaging.The specific research content is as follows:(1)The optical imaging principle model was established.The arrangement of probes and the relationship between the field of view angle of the probe and the optical axis of adjacent probes were analyzed.By establishing a field stitching mathematical model,the number of radial and total probes was analyzed.It is proposed that by designing the image system,the curved image made of the curved compound eye is converted into a planar image that can be received by the plane detector,and the system can effectively correct the aberration of the optical system.(2)The overall design index of the endoscopic optical system was determined,and the relevant parameters were calculated according to the imaging principle model.Using the modular design method,the probe,image transfer system,and overall optical structure are optimized according to the principle of pupil matching.The comprehensive image quality evaluation and tolerance analysis of the entire optical system are carried out to ensure that the designed optical system meets the imaging quality requirements and that the tolerance tolerance of the optical system is determined.(3)According to the optical imaging characteristics of the designed endoscope,the image stitching algorithm is studied.The SIFT algorithm is selected for feature point extraction,and the fade-in and fade-out fusion algorithm is selected for image fusion.An imaging experimental platform was built to obtain image sequences under multiple fields of view,and the images with overlapping regions were stitched to verify the effectiveness of the algorithm.The endoscopic optical system designed in this paper has a field of view of 135° and a total optical system length of 28 mm.The optical system design results are at 166lp/mm,the MTF at each field of view is higher than 0.5,the rms radius of the dot column plot under each field of view is small and concentrated,and the image quality of the system is good.The tolerance analysis results show that the design has good robustness and meets the processing requirements.Compared with traditional endoscopic optical systems,its imaging range is larger,and the design results have broad application prospects in the field of endoscopic testing.