Middle-ear Mechanics in Normal and Pathological Ears

这项工作的目标是了解声音通过正常，患病和重建中耳的传输，以便为中耳疾病患者提供更好的诊断测试和手术治疗。 中耳疾病，如慢性中耳炎和耳硬化症，在美国影响超过1000万人，是严重传导性听力损失的常见原因。 目前的诊断测试（耳镜检查，听力测定，鼓室测试）电池不能可靠地区分听骨病变，特别是当鼓膜是完整的或如果有以前的中耳手术。 此外，普遍认为慢性中耳炎的鼓室成形术后的术后听力结果通常不令人满意。 导致手术结果不佳的因素包括对重建耳的关键结构-功能关系缺乏清晰的理解，以及当前诊断测试未能确定此类关系。已经证明激光多普勒振动测定法在评估中耳功能方面比听力测定法和鼓室压测定法更敏感，因为激光光斑（仅100微米直径）可以聚焦在鼓膜和锤骨上的各个点处，并且因为振动测定法不受耳道的影响（与鼓室压测定法不同）。 我们建议使用振动测量法，其他声学测量（导纳和反射），听力测定和鼓室压测定法来研究（a）正常耳，（B）听骨病变耳，和（c）接受手术治疗慢性中耳炎或耳硬化症的重建耳的结构-功能关系。类似的振动和声学测量也将在模拟患病和重建耳朵的经骨修饰的人颞骨制备中进行。我们的方法应导致更好地了解正常和病理中耳的结构-功能关系，提高中耳病变的鉴别诊断，更好的术前患者咨询和手术计划，优化手术技术和听力结果，并减少手术失败的数量。

The goal of this work is to understand sound transmission through normal, diseased and reconstructed middle ears so that better diagnostic tests and surgical procedures can be offered to patients with middle-ear disease. Middle-ear diseases such as chronic otitis media and otosclerosis, which affect over 10 million people in the US, are common causes of significant conductive hearing loss. The current battery of diagnostic tests (otoscopy, audiometry, tympanometry) cannot reliably differentiate ossicular pathology, especially when the tympanic membrane is intact or if there has been prior middle-ear surgery. Additionally, it is commonly acknowledged that post- operative hearing results after tympanoplasty procedures for chronic otitis media are often unsatisfactory. Factors contributing to the modest nature of surgical results include lack of clear understanding of the critical structure-function relationships in the reconstructed ear, and failure of current diagnostic tests to determine such relationships. Laser Doppler vibrometry has been demonstrated to be more sensitive than audiometry and tympanometry in assessing middle- ear function, because the laser spot (only 100 micrometers diameter) can be focused at various points on the tympanic membrane and malleus, and because vibrometry is unaffected by the ear canal (unlike tympanometry). We propose to use vibrometry, other acoustical measurements (admittance and reflectance), audiometry and tympanometry to investigate structure-function relationships in (a) normal ears, (b) diseased ears with ossicular pathologies, and (c) reconstructed ears that have undergone surgery for chronic otitis media or otosclerosis. Similar vibrometry and acoustical measurements will also be made in a surgically-modified human temporal bone preparation that mimics diseased and reconstructed ears. Our approach should lead to a better understanding of the structure-function relationships in normal and pathological middle ears, improved differential diagnosis of middle-ear lesions, better pre-operative patient counseling and surgical planning, optimization of surgical techniques and hearing results, and reduction in the number of failed surgeries.