Research On Femtosecond Laser Eye Tissue Cutting Experimental System Based On Image Navigation

Cataract is a common eye disease.With the development of technology,traditional artificial cataract surgery has been difficult to meet the needs of patients,and femtosecond laser-assisted cataract surgery has been recognized by more and more people.Femtosecond laser-assisted cataract surgery obtains the depth information of the anterior segment of the eye through the OCT image,and the femtosecond laser is guided by the OCT image to cut the target surgical area.Compared with artificial surgery,femtosecond laser-assisted cataract surgery has the advantages of high control accuracy,short operation time,good cutting effect,good surgical effect and so on.At present,there are currently no related studies on the construction of femtosecond laser-assisted cataract surgery systems in China.The femtosecond laser-assisted cataract surgery system involves knowledge of optics,mechanical design,automation,image processing,etc.The difficulty is quite high.Most of the foreign studies have focused on the intraoperative and postoperative results due to the existence of finished equipment.In order to break the monopoly,this article intends to build a femtosecond laser-assisted cataract surgery experimental platform.First of all,the principle of femtosecond laser-assisted cataract surgery system is analyzed,the principle of femtosecond laser biotissue cutting is introduced,and the construction process of the three major modules of femtosecond laser-assisted cataract surgery platform is introduced in detail.Based on dichroic mirrors,the optical path was rationally laid out,and the construction process of the three modules of the femtosecond laser-assisted cataract surgery experimental platform was introduced in detail,and the construction of the entire experimental platform was completed.Secondly,on the basis of completing the construction of the entire experimental platform,the experimental platform is calibrated,mainly for OCT system calibration and laser cutting system calibration.The calibration of OCT system mainly includes OCT positioning scanning imaging and OCT image correction.OCT positioning scanning imaging realizes scanning imaging of any trajectory of the target position by controlling the galvanometer.OCT image correction is a method based on the basic law of optics to correct the reconstruction error of OCT images caused by optical refraction,A mathematical model of correction is established.After experimental verification,the correction is effective.The calibration process of laser cutting system is completed by OCT image and CCD image.After completing the calibration of the femtosecond laser-assisted cataract surgery experimental platform,the goal of fixed-point cutting under OCT image navigation can be achieved.Then,on the basis of building the experimental platform,in order to meet the needs of femtosecond laser cataract surgery navigation,compare the three-dimensional reconstruction method and OCT positioning scanning imaging navigation method.The 3D reconstruction method takes too long to meet the surgical requirements.Navigation is more suitable for surgery.Based on the OCT image under the specified trajectory imaging,the trajectory planning of the circular capsulorhexis,the lens trajectory and the self-closing corneal incision trajectory are completed.Finally,the applicability of femtosecond laser-assisted cataract surgery in congenital cataract was studied,and the conclusion that femtosecond laser-assisted cataract surgery was also superior in congenital cataract was obtained.Dilatation of the capsulorhexis due to children's highly elastic capsules in congenital cataracts is inversely related to children's age.