声导抗基础知识ppt课件

声导抗基础知识培训,TympanometryandAcousticReflexMeasurements鼓室声导抗和声反射测试+Infanttestrecommendations婴儿测试的推荐方法,1,Soundtravel声音传导,2,Gettingsoundintoadifferentmedium声音在不同媒介中的传导,Mostofthesoundenergyisreflectedwhenconfrontingaanothermedium.大部分声能在临界面处被反射回来,becausedifferentmediaaremoreorlesseasytobringintomotion(impedance)因为不同媒介的声阻抗是不同的,3,Theroleofthemiddleear中耳的作用,4,TheOssicles听小骨,Malleus锤骨,Incus砧骨,Stapes镫骨,Threesmallbonesformingachainbetweenthetympanicmembraneandtheinnerear听骨链位于鼓膜和内耳之间，由3块听小骨组成Airbornesoundwaveenergybecomesmechanicalvibration空气传导的声波能量转换为机械振动Compensatesfortheair-fluidimpedancedifference补偿气液相不同媒介的导抗差,5,TheMiddleearanatomy中耳解剖,Airpressuremustbenearequalonbothsidesoftheeardruminordertooptimisemobilityofthewholesystem应使鼓膜两侧气压接近，从而保证中耳传声系统的最佳活动性,TheEustachiantube(ET)ventilatesthemiddleearandallowspressureequalisation咽鼓管是中耳的通气管道，可保证中耳气压平衡TheETopenswhenswallowingoryawning吞咽和打哈欠时咽鼓管开放,Innerearfluids内淋巴,6,Gettingsoundintoadifferentmedium声音在不同媒介中的传导,The“stiletto”principle:圆锥效应Forceiscollectedoveralargerareaandfocusedonasmallerarea(B)作用力在锥底收集后聚焦到锥尖,7,Howdowetestthemiddleear?如何检测中耳功能,8,中耳测试,精密的中耳系统高精度的测试高质量控制系统,9,Partoftheprobetoneisreflected,andsomeisadmittedintothemiddleear一部分探测音被反射回来，另一部分则进入中耳Theadmittanceiscontinuouslymeasuredbyamicrophone声导纳通过麦克风持续测量计算出来,Admittance-lettingthesoundwavein声导纳将声波导入,10,鼓室图,中耳劲度,11,Tympanometry鼓室声导抗,Admittance,-200daPa,200daPa,0,Earcanalpressure,1&3:Pressurestiffensthetympanicmembranesotheprobetonebouncesback,andthesoundlevelinthemiddleeardecreases1和3：大压强使鼓膜僵硬从而探测音多被反弹回来，进入中耳的声能减少2:Whenpressureisequalonbothsides,thesoundlevelinthemiddleearisatmaximum2：鼓膜两侧压力相等时传入中耳的声能最大,12,TheTympanogramcurve,ECVandTPP鼓室导抗图形，等效外耳道容积和峰压点,TheTPPapproximatesthemiddleearpressure峰压点近似于鼓膜内侧的中耳压力,ECV,TotalAdmittanceoftheearcanalandthemiddleear外耳道和中耳的声导纳总值,TPP,The226Hzadmittanceoftheairintheearcanalisdirectlyproportionaltothevolumeofthatair.ThatgivesustheEquivalentEarCanalVolume,ECV以226Hz为探测音，测试探头与鼓膜之间的空气导纳值为外耳道容积，即等效外耳道容积,13,TheTympanogramcurveandbaselinecompensation鼓室导抗图形和基线补偿,SubtractionoftheECVcontributiongivesusabaselinecompensatedtympanogram去除外耳道容积成分后的鼓室图称为基线补偿鼓室导抗图PeakadmittancebecomesStaticAdmittance,SA该图峰值处的声导纳称为静态声导纳(SA)TheSAistheadmittanceofthemiddleearalone.Nowwecanusethenormativedata!SA等于中耳的声导纳值,14,TypeAd:OssiculardiscontinuityoragerelatedhypermobilityAd型：听骨链中断或鼓膜松弛,TypeB:“Flat”-EffusionorperforatedeardrumdependingonECVvalueB型：平坦型。鼓室积液或鼓膜穿孔，根据ECV值区分,TypeAs:PossibleeffusionorotosclerosisAs型：鼓室积液可能或耳硬化症,TheTympanogramcurveclassification,Type鼓室导抗图形分类,15,Pressure,Admittance,TheTympanogramcurveandTympanometricWidth鼓室导抗图形与鼓室图宽度（TW）,TympanometricWidthquantifythesteepnessofthetympanogramTW决定鼓室导抗图的坡度Normativedataexistfordifferentagegroups不同年龄组标准化值不同TWandSAarethecriteriausedintheASHAtympanometricscreeningprotocol美国社会卫生学会的鼓室声导抗筛查方案把TW和SA作为诊断指标,16,226Hz:Differentconfigurationsoftympanometricresults226Hz鼓室声导抗测试结果与疾病的关系,Tympanometryisaninvaluablediagnostictoolwhencombinedwithotheraudiologicaltests鼓室声导抗与其它听力学测试结合是不可替代的诊断工具,17,Thetwomiddleearmuscles中耳肌,1,2,1:Tensormuscle鼓膜张肌2:StapediusMuscle镫骨肌,Themusclesarebelievedtostabilisethemechanicalsystemandprotectthecochleafromexcessivelowfrequencyvibration中耳肌可稳定中耳机械系统，并保护耳蜗免受低频强声损伤,18,TheAcousticReflex声反射,Loudsoundsmakethestapediusmusclecontract.Thismakesthemiddleearsystemstiffer.强声刺激可使镫骨肌收缩，从而增加中耳传声系统的劲度,andlesslowfrequencysoundcangetthroughthemiddleear因而进入中耳的低频声波减少,19,Stapediusmusclecontrolledbyfacialnerve(CNVII)镫骨肌由第七对颅神经面神经支配Networkinbrainstemconsistsofipsilateralandcontralateralpaths脑干层面由同侧和对侧神经通路组成Reflexactivatedonbothears,evenwhenstimulationonlyoccursinoneear一侧耳受到刺激时，双侧镫骨肌都会收缩Comparisonofipsilateralvs.contralateralacousticreflexeshelpstodeterminesiteoflesion对比同侧和对侧声反射有助于判断病变部位,TheMiddleear-Immittancetests中耳声导纳测试,Acousticreflexthreshold声反射阈,20,声反射,蹬骨肌,21,Deflectioncriterion声导纳偏移标准,Itisusefultostudythegrowthwithintensitytoconfirmareflexthreshold继续增加声强观察偏移变化有助于进一步明确声反射阈,?,!,AcousticReflexThresholds声反射阈,Loudstimuliarepresented,whilsttheadmittanceismeasured强声刺激出现时，可测试出声导纳值的变化,22,声反射测试高精度的挑战,鼓膜处压力为TPP值时中耳蹬骨肌反射状况最佳正确的声反射是刺激音引起导纳在TPP处的变化耳道或中耳压力的改变导致错误的声反射对于鼓膜活动度过大可进行TPP补偿,23,Half-LifeTime(HLT),thetimeafterstimulusonsetwhentheadmittancedeflectionhasdecreasedby50%.半衰期是指声反射振幅减少50的时程Ahalf-lifetimevalue5secondsisindicativeoftumour半衰期小于5秒提示蜗后病变，常见的疾病是听神经瘤,Noreflexdecaypresent阴性,Admittancechange,AcousticReflexDecay声反射衰减,24,Thereflexshouldbeactivatedinbothearsevenifstimulatedinonlyoneear单耳刺激声可激活双耳声反射Theuppernormalintensitylimitforreflexthresholdsinadultsis95-100dBHL正常成人声反射阈上限是95100dBHLReflexthresholdscannotbedeterminedifthereisaproblemwiththemiddleear中耳疾病时不能测出声反射阈BroadBandNoiseprovokesareflexatabout10-15dBlowerthanpuretonestimuli宽带噪声声反射阈较纯音刺激声低1015dBDeterminestypeofhearinglosswhencomparedwiththeaudiogram声反射阈与听力图比较可帮助判断耳聋类型Decayswithneuralfatigue(typically8thnervetumour)衰减提示听神经疲劳，是听神经肿瘤的典型表现,AcousticReflexfeatures声反射特征,25,DifferentconfigurationsofAcousticReflexresults声反射结果与疾病的关系,Usingthiskindoftablemakesreflexinterpretationeasier使用该表格有助于判断声反射的临床意义,26,226Hzprobetone:Normaltympanograminabnormalear!226Hz探测音：异常中耳显示正常鼓室导抗图,Tympanometryininfantsyoungerthan4-7months47个月以下婴儿的鼓室声导抗,226Hzprobetone,Theinfantouterandmiddleearsarestilldeveloping,anddonotvibratewithsoundthesamewayadultearsdo.婴儿外耳和中耳正处于发育期，与成人的声波振动方式不同,Use1000Hzprobetoneininfants推荐使用1KHz探测音,27,Tympanometryininfants婴儿鼓室声导抗,1000Hztympanometryclearlyindicatesabnormalmiddleearfunction!1kHz鼓室声导抗明确显示中耳功能异常,Normal226Hztympanogramsforbothears!226Hz鼓室声导抗显示双耳正常,Acousticreflexesconfirmahealthyrightsidemiddleear.声反射证实右侧中耳功能正常,28,Traditionaladmittancemagnitudetympanometry传统鼓室声导抗中声导纳的成分,29,B/Gcomponenttympanogram声纳/声导成分鼓室导抗图,B:Susceptance声纳,G:Conductance声导,30,SusceptanceandConductancemagnitudetympanometry声导与声纳,31,Traditionalbaselinecompensation,CCSAisnotcalculatedthroughsimpleECVsubtraction,butt