Study On The Control System Of Long Bone Shaft Fracture Reduction Robot

Long bone plays an important supporting and moving role in human bones.The effect of reduction treatment of long bone fracture may directly affect the limb function and quality of patient's life.Poor recovery will easily lead to limb dysfunction or even disability.In recent years,closed reduction cooperate with orthopaedic skeleton or intramedullary nail have become the mainstream treatment of long bone fracture.This method has the advantages of minimal surgical trauma,rapid recovery of patients,low risk of infection and high healing rate,but there are also some shortcomings.The first one is the high incidence of maladjustment and rotational deformity,the second one is that the time of accumulated X-ray exposure during operation was too long,and the third is the high intensity of labor during operators.In order to solve these problems,this paper developed a long bone fracture reduction robot system,for the purpose of improving the accuracy of fracture reduction,reducing the radiation damage and the labor intensity of operators during the operation.This paper mainly completes the following work,(1)This paper analyzed the operation process and clinical requirements of traditional reduction of long bone fracture,and then summarized the requirements and evaluation indexes of the robot system for reduction of long bone fracture,finally determined the overall design scheme.(2)The motion control form and structure of the slave manipulator are studied and designed.The left mechanical slave hand has two degrees of freedom of motion,and the right mechanical slave hand has six degrees of freedom of motion,which can meet the movement requirements of reduction and treatment of long bone fracture.(3)This paper focuses on the design,development and debugging of the control system of the long-bone fracture reduction robot.The control software of the upper computer and the control program of the micro-control system are compiled.The hardware circuit of the micro-control system is designed and manufactured.The joint debugging of the software and hardware of the system is completed.(4)Preliminary reduction experiments of bovine hind leg fracture in vitro and adult goats fracture in vivo were completed.The main results and conclusions are as follows,(1)The proposed two-manipulator slave structure based on rectangular coordinate motion control can improve the relative motion accuracy of the distal and proximal ends of the fracture.(2)Heterogeneous master design is adopted in the system.It increases the versatility of master and extends the degree of freedom of master.(3)The preliminary experimental results are superior to the clinical requirements and design objectives.In the in vitro reduction experiment,the maximum axial deviation is 2.2 mm,the maximum diameter(transverse)deviation is 2.0 mm,the maximum axis angle is 2.5 degrees,and the maximum rotation angle deviation is 3.24 degrees.The accuracy of in vitro reduction is better than the clinical requirements and design objectives.In vivo reduction experiment,the maximum time consumed in the experimental group was 36.4 minutes,the maximum amount of bleeding was 19.5 ml,the maximum number of fluoroscopy was 9 times,the maximum axial deviation was 2.8 mm,the maximum diameter(transverse)deviation was 1.8 mm,and the maximum angle between axes was 2.9 degrees;in the control group,the maximum time consumed was 39.5 minutes,the maximum amount of bleeding was 20.0 ml,the maximum fluoroscopy was 15 times,the maximum axial deviation was 3.1 mm,and the maximum diameter(transverse)deviation was 2.1 mm.The maximum angle between the axes was 3.9 degrees.There was no significant difference in the accuracy between the two groups.The number of fluoroscopy in the experimental group was less than that in the control group.The innovations of this paper are as follows,(1)The mechanical structure of two arms with six degrees of freedom is adopted,which effectively improves the accuracy and accuracy of the relative motion of the distal and proximal ends of the fracture.(2)Double master-hand control is adopted to control the proximal and distal movements of fractures,which can shorten the reduction time and improve the reduction accuracy.