Influence Of Cortical Bone Drilling Parameters On Drilling Surface Quality

Bone drilling is a common adjunctive treatment in medical clinical surgery,and is commonly used in trauma orthopedics,stomatology,and orthopedics.Ultrasound assisted drilling has been used in orthopedic surgery today,but most remain by handheld electrical drills performed by surgeons.The drilling surface quality is an indicator to directly evaluate whether the drilling hole meets the surgical requirements.In orthopedic surgery,the inappropriate choice of drilling parameters,will cause cracking in the drilling hole and tearing in the orifice,it also affects the postoperative rehabilitation and diagnosis and treatment yield of patients,and seriously even cause re injury.Bone material is a composite material with bioactive,fiber-like reinforcement properties,as well as the dual properties of biomaterials and composites,which affected by its processing environment and material characteristics.Drilling parameters and tool types are important factors affecting drilling force,drilling temperature and drilling quality.In this paper,the drilling quality of bone materials was studied from two aspects,namely simulation test and in vitro test.And the effect of drilling parameters on the surface quality of bone drilling was investigated.Firstly,a finite element simulation model of drilling process of bone material was established and simulated tests were conducted;Secondly,the drilling test platform was built up for drilling test.Based on the in vitro test results,the simulation test model was optimized,and the rationality of the simulation model was examined.Finally,the prediction model of the roughness of the surface of bone drilling was established by using SPSS software and based on the least square method,and the parameters of drilling bone material were optimized with the aid of the particle group algorithm.The content of this article is mainly divided into the following four sections:(1)The structural composition,material characteristics,mechanical characteristics,thermal characteristics as well as drilling and machining processing characteristics of the bone materials were investigated.(2)With the help of finite element simulation ABAQUS,the finite element simulation model of bone material drilling process is established,and the simulation test was carried out according to the same orthogonal test scheme as in vitro test.The results of stress,drilling force,drilling temperature,orifice tear and the distribution of drilling cuttings under different drilling parameters are obtained.(3)The in vitro drilling test platform of bone material was built.Taking fresh bovine femur instead of human bone as the test material,the three factor and four level orthogonal test was carried out to explore the changes of orifice tear,drilling surface roughness,drilling force,drilling temperature and drilling cuttings with processing parameters under different drilling parameters.The errors between the simulation test and in vitro test results were calculated,and the rationality of the simulation model was optimized and verified.(4)Combined with the in vitro test data,based on the least square method and with the help of SPSS software,the prediction model of bone drilling surface roughness is established,and the significance of the prediction model is tested.Using MATLAB software,the drilling parameters are optimized based on particle swarm optimization algorithm.The experimental results show that the results obtained by particle swarm optimization algorithm are within the allowable error range,and the optimization results are effective.