Modeling And Software Design Of Digital External Fixator

Bone external fixation technology is a common method to treat complicated orthopedic miscellaneous diseases such as limb deformities and limb trauma.It has the advantages of wide application,high cure rate,low complication rate,stable and reliable fixation effect and so on.However,the current bone external fixators used in orthopedic treatment have problems such as poor stability,low digitalization,and complex structure operations.Therefore,it is necessary to design a sturdy,universal,adjustable,accurate,and intelligent external fixator and supporting software system,so that the treatment of fractures and orthopedic deformities can be truly minimally precise and intelligent.This paper takes tibial fracture deformity correction as the research object and combines the characteristics of existing external fixators to design an intelligent external fixator with minimal invasiveness,precision,high stability,and digital control.And using robotics and binocular stereo vision technology to design a simple,accurate and intelligent external fixator system,the main research content is as follows:(1)Based on the structure of the Ortho-SUV bone external fixator,a new intelligent bone external fixator with high stability and digital control has been designed.The structure mainly consists of: fixation rings,universal joints,connecting pieces,electric support bars,micro motors,motion controllers and user terminal.(2)The structure of the digitally controlled bone external fixator is analyzed,and the mathematical model and the forward and inverse kinematics analysis are carried out.Through numerical examples,the relative error between the conditional data of the positive solution and the resulting data of the inverse solution is less than 0.01%,which verifies the correctness of the kinematics model and its forward and inverse solutions.At the same time,the threedimensional visual kinematics model diagram of the intelligent bone external fixator under known conditions can be obtained,which can help the surgeon make a preliminary preoperative plan.(3)Use binocular stereo vision technology to establish X-ray imaging model,use reprojection errors to screen good-quality calibration images during calibration,obtain accurate internal and external parameters,and perform distortion correction and stereo correction on the binocular image,,and finally obtain an undistorted line-aligned image.(4)Transform medical terms into mathematical models,calculate the position and posture of the upper and lower bone segments of the tibial fracture relative to the intelligent bone external fixator in space,and formulate a fracture correction prescription.(5)Development of a web application for the bone fixator system,which mainly includes:user login module,medical record management module,parameter input module,photo reading and correction module,control point selection module,bone segment image point selection Module and output orthopedic prescription module.A simulation experiment of tibial fracture correction was carried out.Two 12-megapixel high-precision cameras were used to take pictures of tibial fracture models on a stereoscopic experimental platform built instead of X-rays.After the simulation correction,the tibial fracture is basically anastomosed up and down,and the anatomical axis of the upper and lower sections is also basically anastomosed.so the correction effect was good,it has laid the foundation for later research and clinical use.