声导抗基础知识

null声导抗基础知识培训声导抗基础知识培训Tympanometry and Acoustic Reflex Measurements 鼓室声导抗和声反射测试 +Infant test recommendations 婴儿测试的推荐方法 Sound travel 声音传导Sound travel 声音传导Getting sound into a different medium 声音在不同媒介中的传导Getting sound into a different medium 声音在不同媒介中的传导Most of the sound energy is reflected when confronting a another medium... 大部分声能在临界面处被反射回来…because different media are more or less easy to bring into motion (impedance) 因为不同媒介的声阻抗是不同的The role of the middle ear 中耳的作用 The role of the middle ear 中耳的作用 The Ossicles 听小骨The Ossicles 听小骨Malleus 锤骨Incus 砧骨Stapes 镫骨 Three small bones forming a chain between the tympanic membrane and the inner ear 听骨链位于鼓膜和内耳之间，由3块听小骨组成 Airborne sound wave energy becomes mechanical vibration 空气传导的声波能量转换为机械振动 Compensates for the air - fluid impedance difference 补偿气液相不同媒介的导抗差The Middle ear anatomy 中耳解剖The Middle ear anatomy 中耳解剖Air pressure must be near equal on both sides of the ear drum in order to optimise mobility of the whole system 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 The Eustachian tube (ET) ventilates the middle ear and allows pressure equalisation 咽鼓管是中耳的通气管道，可保证中耳气压平衡 The ET opens when swallowing or yawning 吞咽和打哈欠时咽鼓管开放Inner ear fluids 内淋巴Getting sound into a different medium 声音在不同媒介中的传导Getting sound into a different medium 声音在不同媒介中的传导The “stiletto” principle:圆锥效应 Force is collected over a larger area and focused on a smaller area (B) 作用力在锥底收集后聚焦到锥尖 How do we test the middle ear? 如何检测中耳功能How do we test the middle ear? 如何检测中耳功能中耳测试中耳测试精密的中耳系统 高精度的测试 高质量控制系统 Admittance - letting the sound wave in 声导纳－将声波导入Part of the probe tone is reflected, and some is admitted into the middle ear 一部分探测音被反射回来，另一部分则进入中耳 The admittance is continuously measured by a microphone 声导纳通过麦克风持续测量计算出来Admittance - letting the sound wave in 声导纳－将声波导入鼓室图鼓室图中耳 – 劲度Tympanometry 鼓室声导抗Tympanometry 鼓室声导抗Admittance-200 daPa200 daPa0Ear canal pressure1 & 3: Pressure stiffens the tympanic membrane so the probe tone bounces back, and the sound level in the middle ear decreases 1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: When pressure is equal on both sides, the sound level in the middle ear is at maximum 2：鼓膜两侧压力相等时传入中耳的声能最大 The Tympanogram curve, ECV and TPP 鼓室导抗图形，等效外耳道容积和峰压点The Tympanogram curve, ECV and TPP 鼓室导抗图形，等效外耳道容积和峰压点The TPP approximates the middle ear pressure 峰压点近似于鼓膜内侧的中耳压力 ECVTotal Admittance of the ear canal and the middle ear 外耳道和中耳的声导纳总值TPP The 226 Hz admittance of the air in the ear canal is directly proportional to the volume of that air. That gives us the Equivalent Ear Canal Volume, 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The Tympanogram curve and baseline compensation 鼓室导抗图形和基线补偿The Tympanogram curve and baseline compensation 鼓室导抗图形和基线补偿Subtraction of the ECV contribution gives us a baseline compensated tympanogram 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 Peak admittance becomes Static Admittance, SA 该图峰值处的声导纳称为静态声导纳(SA) The SA is the admittance of the middle ear alone. Now we can use the normative data! SA等于中耳的声导纳值The Tympanogram curve classification, Type 鼓室导抗图形分类Type Ad: Ossicular discontinuity or age related hypermobility Ad型：听骨链中断或鼓膜松弛Type B: “Flat” -Effusion or perforated ear drum depending on ECV value B型：平坦型。鼓室积液或鼓膜穿孔，根据ECV值区分Type As: Possible effusion or otosclerosis As型：鼓室积液可能或耳硬化症The Tympanogram curve classification, Type 鼓室导抗图形分类The Tympanogram curve and Tympanometric Width 鼓室导抗图形与鼓室图宽度（TW）Pressure Admittance The Tympanogram curve and Tympanometric Width 鼓室导抗图形与鼓室图宽度（TW）Tympanometric Width quantify the steepness of the tympanogram TW决定鼓室导抗图的坡度 Normative data exist for different age groups 不同年龄组标准化值不同 TW and SA are the criteria used in the ASHA tympanometric screening protocol 美国社会卫生学会的鼓室声导抗筛查把TW和SA作为诊断指标226 Hz: Different configurations of tympanometric results 226Hz鼓室声导抗测试结果与疾病的关系226 Hz: Different configurations of tympanometric results 226Hz鼓室声导抗测试结果与疾病的关系Tympanometry is an invaluable diagnostic tool when combined with other audiological tests 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The two middle ear muscles 中耳肌The two middle ear muscles 中耳肌121: Tensor muscle 鼓膜张肌 2: Stapedius Muscle 镫骨肌The muscles are believed to stabilise the mechanical system and protect the cochlea from excessive low frequency vibration 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The Acoustic Reflex 声反射The Acoustic Reflex 声反射Loud sounds make the stapedius muscle contract.This makes the middle ear system stiffer... 强声刺激可使镫骨肌收缩，从而增加中耳传声系统的劲度 …and less low frequency sound can get through the middle ear 因而进入中耳的低频声波减少The Middle ear - Immittance tests 中耳声导纳测试The Middle ear - Immittance tests 中耳声导纳测试Stapedius muscle controlled by facial nerve (CN VII) 镫骨肌由第七对颅神经－面神经支配 Network in brainstem consists of ipsilateral and contralateral paths 脑干层面由同侧和对侧神经通路组成 Reflex activated on both ears, even when stimulation only occurs in one ear 一侧耳受到刺激时，双侧镫骨肌都会收缩 Comparison of ipsilateral vs. contralateral acoustic reflexes helps to determine site of lesion 对比同侧和对侧声反射有助于判断病变部位Acoustic reflex threshold 声反射阈声反射声反射蹬骨肌Acoustic Reflex Thresholds 声反射阈Deflection criterion 声导纳偏移标准It is useful to study the growth with intensity to confirm a reflex threshold 继续增加声强观察偏移变化有助于进一步明确声反射阈?!Acoustic Reflex Thresholds 声反射阈Loud stimuli are presented, whilst the admittance is measured 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 Acoustic Reflex Decay 声反射衰减Half-Life Time (HLT), the time after stimulus onset when the admittance deflection has decreased by 50%. 半衰期是指声反射振幅减少50％的时程 A half-life time value <5 seconds is indicative of tumour 半衰期小于5秒提示蜗后病变，常见的疾病是听神经瘤No reflex decay present 阴性Admittance changeAcoustic Reflex Decay 声反射衰减Acoustic Reflex features 声反射特征 The reflex should be activated in both ears even if stimulated in only one ear 单耳刺激声可激活双耳声反射 The upper normal intensity limit for reflex thresholds in adults is 95 - 100 dB HL 正常成人声反射阈上限是95－100dB HL Reflex thresholds cannot be determined if there is a problem with the middle ear 中耳疾病时不能测出声反射阈 Broad Band Noise provokes a reflex at about 10 - 15 dB lower than pure tone stimuli 宽带噪声声反射阈较纯音刺激声低10－15dB Determines type of hearing loss when compared with the audiogram 声反射阈与听力图比较可帮助判断耳聋类型 Decays with neural fatigue (typically 8th nerve tumour) 衰减提示听神经疲劳，是听神经肿瘤的典型表现 Acoustic Reflex features 声反射特征Different configurations of Acoustic Reflex results 声反射结果与疾病的关系Different configurations of Acoustic Reflex results 声反射结果与疾病的关系Using this kind of table makes reflex interpretation easier 使用该表格有助于判断声反射的临床意义Tympanometry in infants younger than 4 - 7 months 4－7个月以下婴儿的鼓室声导抗226 Hz probe tone : Normal tympanogram in abnormal ear! 226Hz探测音：异常中耳显示正常鼓室导抗图Tympanometry in infants younger than 4 - 7 months 4－7个月以下婴儿的鼓室声导抗226 Hz probe toneThe infant outer and middle ears are still developing, and do not vibrate with sound the same way adult ears do. 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Use 1000 Hz probe tone in infants 推荐使用1KHz探测音Tympanometry in infants 婴儿鼓室声导抗Tympanometry in infants 婴儿鼓室声导抗1000 Hz tympanometry clearly indicates abnormal middle ear function! 1kHz鼓室声导抗明确显示中耳功能异常 Normal 226 Hz tympanograms for both ears! 226Hz鼓室声导抗显示双耳正常Acoustic reflexes confirm a healthy right side middle ear. 声反射证实右侧中耳功能正常 Traditional admittance magnitude tympanometry 传统鼓室声导抗中声导纳的成分Traditional admittance magnitude tympanometry 传统鼓室声导抗中声导纳的成分B/G component tympanogram 声纳/声导成分鼓室导抗图B/G component tympanogram 声纳/声导成分鼓室导抗图B: Susceptance 声纳G: Conductance 声导Susceptance and Conductance magnitude tympanometry 声导与声纳Susceptance and Conductance magnitude tympanometry 声导与声纳Component Compensated Static Admittance 成分补偿声导纳 CCSATraditional baseline compensationCCSA is not calculated through simple ECV subtraction, but through compensating the B and G components individually before putting them together CCSA不是简单减去ECV得到的，而是分别对声导和声纳补偿后再相加计算出来的 Component Compensated Static Admittance 成分补偿声导纳 CCSAMiddle ear assessment in infants, recommendations 婴儿中耳评估的推荐方法Middle ear assessment in infants, recommendations 婴儿中耳评估的推荐方法 Low frequency probe tone tympanometry is unreliable in infants and should not be used 低频探测音由于鼓室声导抗测试结果不可靠，不推荐使用于婴儿 1000 Hz probe tone is preferable to 678 Hz 1kHz探测音优于678Hz A low peak, below 1000 Hz norm data range, or no peak at all is likely due to effusion 低于1kHz正常数据范围的低峰或无峰的测试结果提示中耳积液 Reflex testing in infants: 婴儿声反射测试 1000 Hz probe tone 1kHz探测音 ipsilateral stimulation 同侧刺激音 broadband noise stimulus 宽带噪声刺激音 Combine 1000 Hz tympanometry and reflex testing 将1kHz鼓室声导抗与声反射测试相结合综合判断