hifu相控换能器声压场和温度场的数值仿真分析-(5316)

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1、天津医科大学硕士学位论文AbstractUltrasoundtransducerisoneofthekeycomponentsofhighintensityfocusedultrasound(HIFU)tumortherapysystem.Singleelementtransducerwithfixedfocallengthhasbeenusedinclinicaltreatmentsuchasbreastcancer,uterinefibroids,prostatecancerwhichneedstobeadjustedmechanicallytheposi

2、tionbetweenpatientandtransducer.Whilephasedarraytransducerhastheadvantagesofdynamicfocusingandformingmultiplefocibyphasecontrol,whichcouldshortentreatmenttime,takecontrolofthelocationofthefocalregioneffectively.It’sresearchreceivesextensiveattentionfrommanyscholars.ObjectivePhasedar

3、raytransducerhastheadvantageofadjustablefocalregion,buttherearesomeproblemswhichincludenumerouselementnumber,complexstructure,highcostofphaseandexcitationcircuit,highacousticpressuresidelobepronetooccurinacousticpressurefield.Theseproblemslimitclinicalapplicationoftransducer.Inorder

4、tosolveit,thekeyistoensuregoodfocusperformanceundertheconditionoflessnumberofarrayelements.Thereducingofhighacousticpressuresidelobeandimprovementofacousticfielddistributionisaccomplishedformthepointofelementdistributionandtheoptimizationofeacharrayelementexcitationsignalbasedonthen

5、umericalsimulationmodelof82-elementphasedarraytransducer.Andthetreatmentofalargervolumeoftumorscanberealizedbyadjustingthefocalnumberanddistancebetweenfociwhichprovidetheoreticaldataandreferencedbasisforclinicalapplicationofphasedarraytransducer.MethodsThethree-dimensionalnumericals

6、imulationmodelisestablishedbasedonthe82-elementphasedarraytransducerwhoseelementsaredistributedinperiod,concentricandquasi-randommanner.Thephasedcontrolsignalofeachelementisabstractedbasedontimereversalmethod.Theacousticpressurefieldandtemperaturefieldisformedbyfinitedifferencetimed

7、omainmethodbasedWesterveltacousticnonlineartransmissionformulaandPennesbio-heattransferequation.Theacousticpressurefieldformedbydifferentelementdistributionarrayiscompared,theIII万方数据天津医科大学硕士学位论文variationwithdifferentfocuslocationandadjustableacousticfieldrangearealsodiscussedunderth

8、esinglefocusmode.An