Mechanics of Human Middle & Inner Ear: Basic Science & Clinical Application

描述（由申请人提供）：许多患者患有传导性听力损失（CHL），尽管他们的神经感觉系统完好无损，但难以治疗。圆窗（RW）和骨传导（BC）刺激已被证明可以改善各种治疗失败的CHL的听力。然而，这些替代的增产方法收效甚微。由于缺乏对声音通过这些刺激方法传递到耳蜗隔板的独特机制的了解，以及它们应用的方式的限制，阻碍了它们的应用。新鲜的人体尸体制备允许控制侵入性实验来阐明这些机制，模拟各种传导性疾病，评估和改进设备和治疗。通过我们的耳蜗内压力测量新技术，我们可以更好地理解这些不同于正常空气传导声刺激的替代声刺激途径的机制。此外，压差刺激（DP）的测定允许在正常和替代刺激以及内耳阻抗改变的疾病情况下（如上半规管破裂（SCD））监测耳蜗输入。我们使用这种技术来回答以前无法解决的问题：目标1)评估和改进刺激RW的方法。粗糙改良的中耳植入物的RW刺激已经帮助了许多其他方法无法帮助的CHL患者。然而，听力结果各不相同。我们将开发一种针对RW独特解剖结构和机械性能的“耦合系统”。该系统将提供更安全、更高效、更一致的井下钻速增产措施。通过在人体尸体制备的受控环境中测量DP，将我们的耦合系统的性能与其他RW刺激耦合方法进行定量比较，并确定手术实施的安全性，效率，一致性和便利性的关键特征。此外，还将确定优化RW致动器性能所需的机械规格。目的2)阐明BC刺激耳部的机制，并确定BC如何受到不同病理的影响。BC刺激被用于诊断感觉神经性听力损失以及治疗传导性和混合性听力损失，但BC刺激的机制尚不清楚。我们将通过测量人体尸体制剂中BC刺激引起的耳蜗内压差DP来加深对BC及其作用的理解。本研究将：1)确定听骨运动和耳蜗液体的惯性效应以及周围骨的压缩效应对BC的贡献；2)确定BC刺激方向的效果；3)确定SCD对BC的影响。测量BC诱发的DP将阐明BC的机制，并改善BC在诊断和治疗中的应用。

DESCRIPTION (provided by applicant): Many patients suffer from conductive hearing loss (CHL) that is intractable to treatment, although their neurosensory system is intact. Round-window (RW) and bone-conduction (BC) stimulation have been proven to provide improved hearing for CHL that have failed various treatments. However these alternative stimulation methods have limited success. Their application is hindered both by a lack of knowledge of the unique mechanisms by which sound is transmitted to the cochlear partition by these stimulus methods, and limitations in the manner in which they are applied. Fresh human cadaveric preparations allow for controlled invasive experiments to elucidate these mechanisms, simulate various conductive diseases and evaluate and improve devices and treatments. With our new technique of intracochlear pressure measurement, we can better understand the mechanisms of these alternative sound stimulus pathways that differ substantially from normal air-conducted sound stimulation. Furthermore, the determination of the differential pressure stimulus, DP, allows monitoring of the input to the cochlea during normal and alternative stimulation and in disease conditions where the inner-ear impedances are changed, such as superior semicircular canal dehiscence (SCD). We employ this technique to answer questions that could not be previously addressed: Aim 1) Evaluate and improve methods for stimulating the RW. RW stimulation with crudely-modified middle-ear implants has aided numerous patients with CHL that were not helped by other means. However, hearing results have varied. We will develop a "coupling system" for RW stimulation that is specific for the unique anatomy and mechanical properties of the RW. This system will provide safer, more efficient and consistent RW stimulation. By measuring DP in the controlled environment of human cadaveric preparations, the performance of our coupling system will be compared quantitatively to other RW stimulation coupling methods, and critical features for safety, efficiency, consistency and ease of surgical implementation will be ascertained. Furthermore, the mechanical specifications required to optimize performance of a RW actuator will be determined. Aim 2) Elucidate the mechanisms involved in BC stimulation of the ear and determine how BC is affected by different pathologies. BC stimulation is used to diagnose sensory-neural hearing loss and to treat conductive and mixed hearing loss, yet the mechanisms of BC stimulation are not well understood. We will advance the understanding of BC and its effects by measuring intracochlear differential pressure, DP, evoked by BC stimulation in human cadaveric preparations. The study will: 1) Determine the contributions to BC of the inertial effects of ossicular motion and cochlear fluids and the compression effect of surrounding bone; 2) Determine the effects of the direction of BC stimulation; and 3) Determine the effect of SCD on BC. The measurements of BC-evoked DP will elucidate BC mechanisms and improve applications of BC for diagnosis and treatment.