声导抗基础知识.ppt

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 Soundtravel声音传导 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 Theroleofthemiddleear中耳的作用 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 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 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 Howdowetestthemiddleear 如何检测中耳功能 中耳测试 精密的中耳系统高精度的测试高质量控制系统 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 鼓室图 中耳 劲度 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 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 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 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 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 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 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 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 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 声反射 蹬骨肌 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 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 Half LifeTime HLT thetimeafterstimulusonsetwhentheadmittancedeflectionhasdecreasedby50 半衰期是指声反射振幅减少50 的时程Ahalf lifetimevalue 5secondsisindicativeoftumour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 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95 100dBHLReflexthresholdscannotbedeterminedifthereisaproblemwiththemiddleear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10 15dBDeterminestypeofhearinglosswhencomparedwiththeaudiogram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 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 226Hzprobetone Normaltympanograminabnormalear 226Hz探测音 异常中耳显示正常鼓室导抗图 Tympanometryininfantsyoungerthan4 7months4 7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 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 Traditionaladmittancemagnitudetympanometry传统鼓室声导抗中声导纳的成分 B Gcomponenttympanogram声纳 声导成分鼓室导抗图 B Susceptance声纳 G Conductance声导 SusceptanceandConductancemagnitudetympanometry声导与声纳 Traditionalbaselinecompensation CCSAisnotcalculatedthroughsimpleECVsubtraction butthr