Design And Experimental Research Of Ultrasonic Cambered Bone Cutting Device

With the continuous progress of society and the rapid development of China’s economy,the aging of the population has led to an increasing incidence of various orthopedic diseases,such as cervical spondylosis,lumbar disc herniation and bone deformity.Arch of the foot’s bone abnormalities have affect the production and living of people seriously.In the foot deformity correction treatment,which is usually done by cutting two more knives at the site of the deformity,a wedgeshaped small piece of the deformity is cut off,so as to make clubfoot back to normal.This kind of treatment will inevitably lead to shorter foot.With the development of modern scientific technology and medical equipment,people pay more and more attention to minimally invasive or even non-invasive treatment,and complete the treatment of diseases with the minimum of surgical injury.In order to reduce the injury,this thesis is proposes a method of ultrasonic arc cutting to treat foot deformity.The main research contents of this thesis are as follows:(1)The clinical techniques of bone tissue treatment in orthopedic department are introduced,such as bone cutting,bone drilling,bone sawing and related ultrasonicassisted bone tissue treatment.Based on the main research contents and trends,and according to the relevant research theories,a method of ultrasonic-arc cutting to optimize the treatment of foot bone deformity is proposed.(2)According to the simplified cutting track of the cambered surface,the calculation formula of the horizontal clearance distance of the cambered surface is derived.The parameters affecting the horizontal clearance distance of the cambered surface are studied,and the influences of the cutter section size and the selected cutting radius on the horizontal clearance distance of the cambered surface are investigated.At the same time,based on the fracture theory,the crack growth and fracture process of ultrasonic cambered bone cutting are explained,and the influence mechanism of ultrasonic vibration on the crack growth and the mechanism of ultrasonic bone cutting are given.(3)Based on transfer matrix theory and the design method of half wave,the overall equivalent four-terminal network of piezoelectric ultrasonic vibration system is established,and the structures of the cutting system are calculated,which include piezoelectric transducer,ultrasonic horn as well as switching device and cutting tools.The connection to components of each part are given.(4)The modal analysis and structural size optimization of the piezoelectric transducer,horn and transfer device of piezoelectric ultrasonic arc cutting system are carried out by using finite element analysis software,and the final structural sizes of each part of the components are given.According to the results of harmonic response analysis,the rationality of the design of piezoelectric ultrasonic arc cutting system is verified.At the same time,the relationship between the excitation voltage and the output displacement amplitude of the piezoelectric ultrasonic vibrator is explored.By using ABAQUS,the simulation of ordinary and ultrasonic cambered bone cutting are carried out respectively,and the role of ultrasonic vibration in the process of cambered bone cutting is given.(5)An experimental platform for ultrasonic cambered bone cutting is built,and the impedance characteristics of the piezoelectric ultrasonic vibration system are tested to verify the rationality of the ultrasonic vibration structure.Different bone cutting experiments are performed,and the corresponding experimental conclusions are drawn.At the same time,the shortcomings in the experimental process are analyzed from the experimental results.