学科分类
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4 个结果
  • 简介:目的利用Micro-CT扫描数据建立中耳听骨链三维有限元模型。方法用Micro—CT扫描成人颞骨标本,将获得的图像数据通过MicroView、Mimics等软件进行三维重建。再将模型转入其有限元分析(finiteelementanalysis,FEA)模块的Remesh环境中进行调整、细化及面网格优化,通过SOLIDEWORK软件转换为实体网格。结果初步形成的三维几何模型可较清晰地辨别鼓室腔、听小骨和内耳系统,但部分图像不同程度存在噪点。最终形成了FEA软件可识别的成人中耳听骨链三维有限元网格模型,网格划分后的听骨链有限元模型中,完整听骨链的节点数降低,由原来包括805个不合理节点在内的12498个节点降低到2050个,在此基础上建立的有限元模型共1350个8节点四面体单元。结论结合Micro—CT技术及Mimics软件的三维建模方法可以快速获得较精确的听骨链三维数据,是建立听骨链三维有限元模型的有效途径。(中国眼耳鼻喉科杂志,2009.9.83。85)

  • 标签: Micro—CT 听骨链 有限元法 建模
  • 简介:AIM:Todefinetheultrasonographicstructureofnormallowereyelidanatomiccompartmentsandtheirspacialrelationshipindynamicmotion.METHODS:Highresolutionultrasound(15MHz)wasperformedonthelowereyelidsof7normalsubjects.Movementsofthelowereyelidanditscompartmentswerevisualizedwithultrasound.Inaddition,themaximalexcursionareaofthelowereyelidfatcompartmentsandretractormotionswasmeasuredbeforeandaftermotion.RESULTS:Theorbicularismusclecouldbeseenasanecholucentstructurebetweenthedermisandtheechodencefatpads.Lowereyelidfatpadseemstobedividedinto2compartmentsasrangeofmotionanddirectionofmovementofeachofthemvaries.Itseemsthatthesecompartmentshavealsodifferentbehavior.Themeasuredprofileareaofthevisiblenormallowereyelidfatpadsduringmovementofglobefromup-gazetodown-gazedecreasedby50%.Orderofmovementoflowereyelidstructuresseemstobeasfollows:afterglobemovementfistweseeretractormovement,anteriororbitalfatpad,thenskinandseptum,andfinallymovementofinferiorfatpad.CONCLUSION:Ultrasoundrepresentsanoninvasivetoolforthevisualizationoflowereyelidmorphology.Expandingitsapplicationcouldhelpusunderstandthecompartmentalchangesinphysiologicaleyelidmovement,inaginganddiseasedstudypopulations,aswellasassessoperativeoutcomes.

  • 标签: LOWER EYELID ULTRASONOGRAPHY DYNAMIC MOTION analysis
  • 简介:AIM:Toinvestigatetheaccuracyofintraocularpressure(IOP)asmeasuredbyaReichertOcularResponseAnalyzer(ORA),aswellastherelationshipbetweencentralcornealthickness(CCT)andIOPasmeasuredbyORA,Goldmannapplanationtonometry(GAT),anddynamiccontourtonometry(DCT).·METHODS:Atotalof158healthyindividuals(296eyes)werechosenrandomlyformeasurementofIOP.AfterCCTwasmeasuredusingA-ultrasound(A-US),IOPwasmeasuredbyORA,GAT,andDCTdevicesinarandomizedorder.TheIOPvaluesacquiredusingeachofthethreetonometrieswerecompared,andtherelationshipbetweenCCTandIOPvalueswereanalyzedseparately.TwoIOPvalues,Goldmann-correlatedIOPvalue(IOPg)andcorneal-compensatedintraocularpressure(IOPcc),weregotusingORA.ThreegroupsweredefinedaccordingtoCCT:1)thincornea(CCT<520μm);2)normal-thicknesscornea(CCT:520-580μm);and3)thickcornea(CCT>580μm)groups.·RESULTS:Innormalsubjects,IOPmeasurementswere14.95±2.99mmHgwithORA(IOPg),15.21±2.77mmHgwithORA(IOPcc),15.22±2.77mmHgwithGAT,and15.49±2.56mmHgwithDCT.Meandifferenceswere0.01±2.29mmHgbetweenIOPccandGAT(P>0.05)and0.28±2.20mmHgbetweenIOPccandDC(P>0.05).TherewasagreatercorrelationbetweenIOPccandDCT(r=0.946,P=0.000)thanthatbetweenIOPccandGAT(r=0.845,P=0.000).DCThadasignificantcorrelationwithGAT(r=0.854,P=0.000).GATwasmoderatelycorrelatedwithCCT(r=0.296,P<0.001),whileIOPccshowedaweakbutsignificantcorrelationwithCCT(r=0.155,P=0.007).TherewasastrongnegativecorrelationbetweenCCTandthedifferencebetweenIOPccandGAT(r=-0.803,P=0.000),withevery10increaseinCCTresultinginanincreaseinthisdifferenceof0.35mmHg.Thethickcorneagroup(CCT>580μm)showedtheleastsignificantcorrelationbetweenIOPccandGAT(r=0.859,P=0.000);whilethethincorneagroup(CCT<520μm)hadthemostsignificantcorrelationbetweenIOPccandGAT(r=0.926,P=0.000).ThecorrelateddifferencesbetweenIOPccan

  • 标签: INTRAOCULAR PRESSURE TONOMETRY CENTRAL CORNEAL thickness