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【英文标准名称】:MedicaldiagnosticX-rayequipment-Radiationconditionsforuseinthedeterminationofcharacetristics
【原文标准名称】:医用诊断X射线设备.测定特性时使用的辐射条件
【标准号】:IEC61267-2005
【标准状态】:现行
【国别】:国际
【发布日期】:2005-11
【实施或试行日期】:
【发布单位】:国际电工委员会(IX-IEC)
【起草单位】:IEC/SC62C
【标准类型】:()
【标准水平】:()
【中文主题词】:特性;定义;测定;诊断;诊断设备;电气工程;电医学;医疗设备;医疗放射照相术;医学科学;医疗技术学;照射疗法;辐射;辐射防护;辐射学;X射线仪;X射线设备;X射线装置;X射线
【英文主题词】:Characteristics;Definitions;Determination;Diagnosis;Diagnosticequipment;Electricalengineering;Electromedicine;Irradiationcondition;Medicalequipment;Medicalradiography;Medicalsciences;Medicaltechnology;Phototherapy;Radiation;Radiationprotection;Radiology;X-rayapparatus;X-rayequipment;X-rayplants;X-rays
【摘要】:ThisInternationalStandardappliestotestprocedureswhich,forthedeterminationofcharacteristicsofsystemsorcomponentsofmedicaldiagnosticX-RAYEQUIPMENT,requirewell-definedRADIATIONCONDITIONS.Exceptformammography,thisstandarddoesnotapplytoconditionswherediscontinuitiesinradiationabsorptionofelementsaredeliberatelyusedtomodifypropertiesoftheRADIATIONBEAM(forexamplebyrareearthfilters).ThemostcompletespecificationofRADIATIONFIELDSisgivenbythespectraldistributionofthephotonfluence.SincethemeasurementofX-RAYSPECTRAisademandingtask,thisstandardexpressesRADIATIONQUALITIESintermsoftheX-RAYTUBEVOLTAGE,thefirstandsecondHALFVALUELAYER.InthecaseofRADIATIONCONDITIONS,specificationsareperformedadditionallyintermsofPHANTOMpropertiesandgeometry.TheattempttocharacterizeaspectraldistributionjustbymeansoftheX-RAYTUBEVOLTAGE,thefirstandpossiblythesecondHALF-VALUELAYERisthusacompromisebetweenthemutuallyconflictingrequirementsofavoidingexcessiveeffortsforestablishingaRADIATIONQUALITYandofthecompleteabsenceofanyambiguityinthedefinitionofaRADIATIONQUALITY.DuetodifferencesinthedesignandtheageofX-RAYTUBESintermsofanodeangle,anoderougheningandINHERENTFILTRATION,twoRADIATIONQUALITIESproducedatagivenXRAYTUBEVOLTAGEhavingthesamefirstHALF-VALUELAYERcanstillhavequitedifferentspectraldistributions.GiventheinherentambiguityinthecharacterizationofRADIATIONQUALITY,itisessentialthatfurthertolerancesintroducedbyallowingcertainrangesofvalues,e.g.forX-RAYTUBEVOLTAGEandfirstHALF-VALUELAYER,mustbesufficientlysmallnottojeopardisetheunderlyingobjectiveofthisstandard.ThisstandardistoensurethatmeasurementsofthepropertiesofmedicaldiagnosticequipmentshouldproduceconsistentresultsifRADIATIONQUALITIESorRADIATIONCONDITIONSincompliancewiththisstandardareused.Toachievethisobjective,certaindegreesoffreedominthewayinwhichaRADIATIONCONDITIONcouldbeestablishedintheframeworkofthefirsteditionofthisstandardhavebeenremoved.TheessentialrestrictionintroducedinthissecondeditionisthattheX-RAYTUBEVOLTAGEismeasuredandsettoits'correct'value.ThesecondstepistoattempttoestablishtheprescribedfirstHALF-VALUELAYERbyaddingintothebeamthenecessaryamountofADDITIONALFILTRATION.IftheINHERENTFILTRATIONprovidedbytheX-RAYTUBEaloneissostrongthattheHALF-VALUELAYERoftheRADIATIONBEAMemergingfromtheX-RAYTUBEASSEMBLYassuchislargerthanthattobeestablished,theX-RAYTUBEASSEMBLYusedisnotsuitedforproducingthedesiredRADIATIONCONDITION.ThismayoccuriftheanodeangleoftheX-RAYTUBEASSEMBLYistoosmalland/orinthecaseofexcessiveanoderougheningduetotubeageing.IntheapproachoutlinedinthetwoprecedingparagraphstheX-RAYTUBEVOLTAGEplaysadecisiverole.Itisthereforeessentialthatthe‘correct’X-raytubevoltageischosenirrespectiveofthetypeofhighvoltagegeneratorconnectedtotheX-RAYTUBE.ThewayinwhichthisisrealizedinthisstandardisbymeasuringtheX-RAYTUBEVOLTAGEintermsofthePRACTICALPEAKVOLTAGE.ThisquantityisaweightedmeanofallvaluesoftheX-RAYTUBEVOLTAGEoccurringduringanexposure.TheweightingisdoneinsuchawaythatidenticalvaluesofthePRACTICALPEAKVOLTAGEgiveidenticalvaluesofthelowlevelcontrastonaradiographirrespectiveofthewaveformsuppliedbythegenerator.
【中国标准分类号】:C43
【国际标准分类号】:11_040_50
【页数】:94P.;A4
【正文语种】:英语