Research On Material's MR Compatibility And Machinability Of MR-guided Surgical Robot

Due to the particularity of nuclear environment,it's necessary to choose a kind of suitable material to manufacture a kind of MRI(magnetic resonance image,MRI)navigation robot.This kind of robot should be able to deal with the adverse factors,which including the induced force,torque and artifact,and avoid the influence to running stability of surgical robots,patient's safety and image quality.For this reason,two material properties(MR compatiblity and machinablity)are studied.The main job content can be concluded as following.Firstly,MR compatiblity and machinablity are analyzed.Then three factors are chosen for experiment item respectively,i.e.,induced force,torque and artifact are chosen to be the influence factors of MR compatibility,and cutting force,surface roughness and chip shape are chosen to be the influence factors of machinability.At the same time,four kinds of materials are chosen for the experiments,including brass,aluminum,nylon and polyformaldehyde.Different experiments are designed to test MR compatibility and machinability to make the preparation for the next step: comprehensive evaluation of material's MR compatibility and machinability.Secondly,fuzzy evaluation method is chosen to evaluate the four kinds of materials,and get the rank of evaluation: polyformaldehyde,nylon,aluminum,brass.The evaluation results are analyzed.At last,the magnetic field model of cylinder material is founded,and artifact is simulated according to the formation principle.Then this model is verified by comparing the simulation result with experiment image.By modifying the parameters in this model,the conclusion is obtained: the artifact get smaller as the magnetic susceptibility become smaller,as the size of chamfer get greater,as the shape of corner get smoother.Suggestions are given to the shape of medical apparatus and instruments working in magnetic resonance environment.The research achievement of this paper make sense for the evaluation and selection of material used for manufacturing MR surgical robot,and will provide theoretical basis for the design and manufacturing of surgical robot working in MR environment.