Research And Development Of Bone External Fixation System

The technique of external skeletal fixation has the advantages of wide application range,large fixed range,reliable fixation,minimally invasive,and so on,which is a common method for the treatment of fracture and limb deformity.But the existing external fixator has the disadvantages of low flexibility,low digital degree,complicated operation etc.This paper studied the structure of external skeletal fixation device and fracture deformity correction algorithm,which has good application value in the treatment of fracture and deformity correction.Fracture correction was chosen as the research object,a kind of external fixation system with the characteristics of flexible structure,excellent orthopedic and simple operation with a reduction and fixation was designed combining robot and CRP technology.The main research contents are as follows:(1)A six degrees of freedom parallel bone combined external fixation structure was designed on the basis of Taylor Spatial Frame.By adding a connecting piece structure,two ends of the connecting rod could be connected with the connecting piece or the fixed ring and the flexibility and practicality of orthopedic braces were improved.Mathematical modeling and kinematic analysis for the designed external fixator for bone external fixation were done.(2)X-ray photography was analyzed and X-ray model was built.Direct linear transformation(DLT)solution was improved by iterative calculation method and internal and external orientation elements of positive and lateral roentgenogram were solved based on the system calibration of the positive and lateral roentgenogram.(3)The position and orientation of the upper and lower bone segments in the space were determined by using the three-dimensional image pair of the positive and lateral roentgenogram,and the correction parameters were calculated.(4)According to the theoretical analysis,External fixation system Web application program was written,including the user management module,case management module,orthopedic frame parameter input module,system calibration module,image correction calculation module,and introduces the method of using the program.Multi group tibial fracture orthopedic simulation of frontal and lateral shoot pictures instead of X light on the experiment model using a digital camera.The angle of the upper and lower bone segment was less than 1°,and the gap between the upper and lower bone segments was less than 0.5mm.An external fixation system was designed in this paper,which main used in the treatment of deformity-correcting fracture,orthopedic effect is good,to meet the requirements of orthopedic fractures,for clinical application has laid a foundation.