Research On Prediction Method And Diffusion Mechanism Of Bone Material Milling Temperature

Robotic bone milling is widely used in different orthopedic operations,and its processing precision and the speciality of milling processing form are very popular among doctors and patients.Bone milling is becoming more and more popular,and the resulting temperature problems have received attention.High-speed bone milling produces a large amount of temperature,which is prone to thermal necrosis,which can reduce the accuracy of prosthesis fixation and prolong bone recovery time.Therefore,this thesis studies the temperature prediction method and diffusion mechanism in the process of bone material milling.The threedimensional finite element temperature simulation is used to analyze the milling temperature of the bone material,and the experimental data is used to fit the optimal model to predict the temperature of the bone milling.Theoretical analysis of temperature generation and diffusion during high-speed bone milling.The details are as follows:(1)Research status and analysis of the difficulty of cutting temperature of bone materials.From the bone cutting temperature prediction method,finite element simulation and temperature diffusion mechanism,the research status of bone cutting temperature at home and abroad is summarized.In clinical surgery,the cutting temperature of bone material is difficult to measure,the uncertainty of the influence of milling parameters on the cutting temperature of bone material,and the difficulty of the diffusion of cutting temperature are constrained by the development of robotic bone milling.(2)Introduction to robotic orthopedic surgery and study of bone material properties.The basic conditions of three orthopedic surgery procedures,including the knee joint replacement surgery,bone tumor resection and lumbar vertebroplasty,were summarized.The key problems in robotic orthopedic surgery were analyzed.Then the structural characteristics,main chemical composition and temperature characteristics of the bone material structure were analyzed in detail,and the difference in temperature distribution between the bone material and the metal material during the drilling process was compared and analyzed.(3)Three-dimensional finite element temperature rise simulation and parameter influence of bone material milling process.The DEFORM three-dimensional finite element simulation software was used to simulate the bone milling process.The SolidWorks was used to geometrically model the milling tool and the bone workpiece.The constitutive model of the bone material was established to determine the relationship between material stress and strain,and the detailed analysis was made.Meshing and separation criteria for cortical bone materials and tools,and friction and foundation models,heat transfer boundary conditions.The temperature of the bone material at a specific position was obtained by thermodynamic simulation,and the different processing parameters were changed to study the influence of different parameters on the milling temperature.(4)Establishment of bone milling temperature prediction model.The influencing factors of the milling process were analyzed,and a three-stage bone milling temperature prediction model was established to predict the tool temperature and surface temperature of the bone material during bone milling.Then the experimental method is used to determine the optimal parameters of the three-stage temperature prediction model,and the rationality of the prediction model is verified by verification experiments.(5)Research on temperature diffusion mechanism of high speed bone milling.Based on the three-stage bone milling temperature prediction model,the heat production and heat transfer process during bone material milling were theoretically modeled,and the model of bone milling temperature diffusion mechanism was established,including milling thermal model,cutting edge model and temperature distribution.model.The availability of the bone milling temperature diffusion mechanism model was then verified using a milling experimental platform.