最新新生儿先天性心脏病筛查 课件课件PPT.ppt 32页

'新生儿先天性心脏病筛查课件 ThepurposeoftheCongenitalHeartDisease(CHD)ScreeningProgramistoidentifynewbornswithCHDpriortoclinicaldeteriorationoftheaffectedinfant.Delayeddiagnosisofcriticalcongenitalheartdisease(CCHD)canresultindeathorinjurytoinfants.Whydoweneedtoscreen? TheDepartmentofHealthandHumanServiceshereintheUnitedStatesmadethisCHD(alsocalledCCHD—CriticalCongenitalHeartDisease)screeningrecommendationSeptemberof2011.InJanuaryofthisyear,theAmericanAcademyofPediatricsendorsedthisrecommendation.OurOB–PEDSteamhasrecentlyapprovedthepolicyandwearereadytogetstartednow!Wehadsomequestionstoansweraboutnewbornechocardiogramsbeforewecouldgetstarted!Whoendorsesthis? Somebabiesbornwithaheartdefectcanappearhealthyatfirstandcanbesenthomewiththeirfamiliesbeforetheirheartdefectisdetected.Ithasbeenestimatedthatatleast280infantswithanunrecognizedCCHDaredischargedeachyearfromnewbornnurseriesintheUnitedStates.Thesebabiesareatriskforhavingseriouscomplicationswithinthefirstfewdaysorweeksoflifeandoftenrequireemergencycare.WhyisthisImportant? NewbornscreeningusingpulseoximetrycanidentifysomeinfantswithaCCHDbeforetheyshowsignsofaCCHD.Onceidentified,babieswithaCCHDcanbeseenbycardiologistsandcanreceivespecializedcareandtreatmentthatcouldpreventdeathordisabilityearlyinlife.Treatmentcanincludemedicationsandsurgery.WhyPulseOximetry? Pulseoximetryisasimplebedsidetesttodeterminetheamountofoxygeninababy’sbloodandthebaby’spulserate.LowlevelsofoxygeninthebloodcanbeasignofaCCHD.Screeningisdonewhenababyis24to48hoursofage,oraslateaspossibleifthebabyistobedischargedfromthehospitalbeforeheorsheis24hoursofage.Pulseoximetryscreeningdoesnotreplaceacompletehistoryandphysicalexamination.Whenarebabiesscreened? MakethenewborniswarmandquietKnowhowtocorrectlyusetheequipmentandwheretogetsupplies.Makesureyouaregettingaccuratereadingsbyassuringagoodwaveformandheartrateonthemonitor.ALWAYSusetherighthandandrightfootPractice!HowcanIhavethemostsuccess? RightHandandRightFootWheredoperformthetestonthebaby? Anurseshouldperformthetestafter24hoursofageorascloseaspossibletodischargeALLNEWBORNSWILLBESCREENEDUsetheAlgorithmstodeterminewhattodo.Thereisapassingalgorithmandafailingalgorithm.Whoperformsthetest? 1.PlaceO2SatProbeonthenewbornsrighthandorrightfootfirst.O2satprobesareachargeitemandinPyxis.Thereare2sizestochoosefromNeo-LandInf-L,bothmadebyMasimo.2.Recordthereadingandthenswitchtowhateverextremityyoudidn’tstartwith.ONLYscreenRighthandandRightfoot.StepOne… IftheNewborn’ssaturationisgreaterthanorequalto95%inEITHERextremitywithalessthanorequalto3%differencebetweenthetwo,thewillbeconsideredaPASS.NoadditionalevaluationwillberequiredunlesssignsandsymptomsofCHDarepresent.Results… PulseOx95%(RHORRF)andDifferenceof3%BetweenRHandRFPASSNormalNewbornCarePassingAlgorithmPassingAlgorithm: IftheoxygenSaturationsarelessthan95%inboththehandandfootorthereisgreaterthan3%differencebetweenthetwoonthreemeasureseachseparatedbyonehour,thenewbornshouldbereferredforadditionalevaluation.Ifthenewborn’ssaturationislessthan90%ineitherthehandorfoot,heorsheshouldbeimmediatelyreferredforadditionalevaluation.“Failing”Results… PulseOx<95%(inBOTHRHANDRF)orDifferenceif>3%betweenRHANDRF.PASSFAILRepeatPulseOxin1hourPASSFAILRepeatPulseOxin1hourPASSFAILClinicalAssessmentandCallPhysicianFailingAlgorithm Ifyouhaveafailingresultafterthethirdscreening:NotifythePhysicianInfectiousandpulmonarypathologyshouldbeexcludedCompleteechocardiogramasdirectedbytheinfantsphysician.Ifinfantissymptomatic,CALLphysicianimmediately!!Whatnext??? YES,wecan.JamieinRadiologyisgettingtrainedCURRENTLY!Shehasbeenworkingonthisforafewmonths.Shehastogether‘practice’inbeforesheisonherown.Youwillsoonseeinformationaboutgettingher‘practice’newborns!!Canwedoechocardiogramshere? RecordtheResultsonthe‘CongenitalHeartDiseaseScreeningProgramForm.(clickhere)Alsocheckoffthe‘DischargeChecklist-Baby’inMeditechwhenitiscomplete.WheretoRecordResults… Pleaseclickhere:Whattowetellpatients? PleaseclickheretoaccessthepolicyIsthereaPolicy? Don’thesitatetoaskquestions!Thank-you! AmericanAcademyofPediatricsPolicyStatement.Pediatrics.Volume129,Number1,January2012.EndorsementofHealthandHumanServicesRecommendationforPulseOximetryScreeningforCriticalCongenitalHeartDisease.References 涡流检测基础涡流涡流检测特点涡流检测基本原理变压器耦合式互感电路——涡流检测模型趋肤效应渗透深度 涡流:金属在变动的磁场中或相对于磁场运动，金属体内感生出漩涡状流动的电流涡流检测特点（1）只适用于产生涡流的导电材料；（2）涡流检测时不要求检测线圈与被检材料紧密接触（3）检测时无需耦合剂。不必在检测线圈和工件之间充填，从而容易实现自动化检测；（4）对高温状态的导电材料进行涡流检测。尤其重要的是加热到居里温度以上的材料，检测时不再受到磁导率的影响，可以像非磁性金属那样用涡流法进行探伤、材质检验以及棒材直径、壁厚等测量；（5）涡流及反作用磁场对金属材料工件的物理和工艺性能的多种参数有反应，是一种多用途的检测方法。 涡流检测基本原理涡流检测是以电磁感应原理为基础。当载有交变电流的检测线圈靠近导电材料时，由于线圈磁场的作用，材料中会感生出涡流。涡流的大小、相位以及流动方式等受到材料导电性能的影响，而涡流产生的反作用磁场又使检测线圈的阻抗发生变化，因此，通过测定检测线圈阻抗的变化，可以得到被检材料有无缺陷的结论。 耦合系数：表示两个线圈耦合紧密程度两个线圈的轴线一致时，靠的越近，耦合越紧密,M值越大，耦合系数随之增大。但是耦合系数K始终是一个小于1的正数。因为有漏磁存在。 R、L、C串联电路R:电阻X：电抗Z：阻抗XL:感抗Xc：容抗变压器耦合式互感电路-涡流检测模型 原、副边的回路电压方程副边(原边)中的电流在原边(副边)中产生的互感电动势变压器耦合式互感电路 折合电阻、折合电抗、折合阻抗意义在这种变压器耦合式互感电路中，尽管原、副边之间没有直接的电的联系，但由于互感的存在，副边电路的闭合而得到的副边电流，会通过互感影响原边电路中电压和电流之间的关系。作用在以电磁感应原理为基础的涡流检测中，检测线圈和被检金属之间就可以等效为这种电路，因此，可以参照这种电路的分析方法来分析涡流检测的问题。 趋肤效应：当交变电流通过导体时(例如圆截面的直长导线)，由于导线周围存在电磁场，导线本身就会产生涡流;涡流的磁场会引起高频交变电流趋向导线表面，使导线横截面上电流的分布不均匀;表面层上的电流密度最大，随着进入导体深度的增大而减小的现象渗透深度：把电流密度下降到表面电流密度1／e倍(大约37％)处的深度；与导线的电导率、磁导率及交变电流频率有关；？？为什么说涡流试验法只能对金属材料的表面或近表面进行检测(对内部缺陷因灵敏度过低而效果不佳）？'