Construction Of Custom Bone Plate Fitting Surface And Implementation Of Visualization Platform

With the aging population and frequent traffic accidents,fractures become a common illness of life.In fracture surgery,a huge amount of bone plates are used.Owing to the individual differences of patients,bone plates,as standard part,have low anastomosis with the fracture site of patients.Bone plates are often reshaped by doctors based on their experience,which may cause problems such as shortened the life of bone plate.The customized bone plate can be designed and manufactured according to patient’s bone characteristics and fracture pathology.Its core is to construct fitting surface of bone plate.These put forward higher requirements on doctor’s ability of analyzing curves and surfaces,modeling level,and operating engineering software,and limit the use and promotion of customized bone plate technology.Software platform for customized bone plate is designed and developed,and it focus on the rapid construction of fitting surface of bone plate.Bone state of patient and usage habits of doctor group have been fully considered and studied,a customized fitting surface of bone plate that fits patient’s bone is designed.The main research work includes:(1)A method of selecting lesion interest areas for doctor user groups is proposed.This method includes the contour strategy and the center line reference curve strategy,which are used to accurately select the region of interest contour on bone surface.According to the shape of design object,selection tools such as rectangle,ellipse,free shape based on Bezier curve and cubic spline interpolation curve are designed to improve the selection efficiency.Local texture processing is carried out on the bone model of the region of interest,and then dynamic texture construction is used.linear calculation method based on line of sight is adopted to establish the mapping relationship between model feature points and two-dimensional texture,which realize accurate matching of local model feature points,and improve degree of anastomosis between fitting surface of bone plate and patient’s bone.(2)A fast construction method of bone-bonded surface based on point cloud of bone interest area is proposed.On basis of obtained region of interest,different densities of interest region on two-dimensional plane are divided to obtain two-dimensional feature points including the contour.Three-dimensional feature points on bone surface are obtained by ray projection technology and used as point cloud data of bone plate fitting surface.Bezier surface algorithm is used to fit point cloud to build bone plate fitting surface.Using UG secondary development,surface construction programs arewritten,which realize the rapid construction of surface.During construction process,the parameters are adjusted and visualized,and surface construction process is basically realized automatically,which improves the efficiency of construction of bone plate fitting surface.(3)A prototype system for customized fitting surface of bone plate construction platform are developed.The system is developed based on Unity 3D engine,and MVC design framework is adopted to realize visual presentation of construction of laminate surface in bone plate.System mainly includes three modules: document management,surface design and surface construction.System is able to read,display and save relevant operation data of patient’s bone model,and realize selection of outline of bone plate fitting surface and extraction of point cloud data.Furthermore,System constructs fitting surface of bone plate quickly,customizes model of bone plate,and generates processing data of bone plate.Operation example of prototype system shows that proposed method can complete precise customization of bone plates.