Computer-based holography and middle-ear function

描述（由申请人提供）：鼓膜（TM）是中耳将环境声音转化为内耳声音的初始结构。有充分的证据表明，中耳膜的形状有助于确定耳朵敏感的频率范围，包括听觉的灵敏度和范围与中耳膜的大小和形状之间的相关性。虽然我们知道一些关于健康TM在有限频率范围内运作的基本事实，但仍有许多问题尚未解决，包括TM形状对功能的影响，TM机械特性在物种之间的巨大差异的影响以及TM在更高频率下的功能。还有一些关于病理性TM的工作的问题，例如穿孔如何影响整个TM的运动？移植膜是否像正常的TMs一样工作？本文提出的工作将应用基于快速计算机视频处理的实时光纤电子全息系统来研究几种动物（包括人类）正常耳以及诱导病变和重建耳的中耳膜的声致位移。光学测量系统产生TM表面位移的连续更新的时间平均全息图显示（高达每秒500帧）。该显示器允许观察整个TM表面的等位移轮廓（分辨率为50-200纳米），同时刺激声音的振幅和/或频率连续变化。这样的观测结果可以很容易地识别临界频率和TM位移模式的水平依赖性。该系统的第二个版本（频闪全息）允许以1-10纳米的分辨率测量整个膜表面位移的大小和相位。第三个版本（双波长全息）允许以1-10纳米的分辨率测量TM的静态形状。这些光学技术的应用包括识别和量化正常TM表面的波传播，研究TM运动和TM力学参数的种间差异，以及关于膜位移模式对听骨疾病和TM穿孔的敏感性的假设测试，以及手术重建人耳中各种TM移植结构的运动。

DESCRIPTION (provided by applicant): The tympanic membrane (TM) is the initial structure involved in the middle-ear's acoustic-mechanical transformation of environmental sounds to sound within the inner ear. There is good evidence that the form of the TM helps define the frequency range to which the ear is sensitive, including correlations between the sensitivity and range of hearing and the size and shape of the TM. While we know some basic facts about the workings of the healthy TM in a limited frequency range, there are many issues that are unresolved including the effect of TM shape on function, the effect of large differences in TM mechanical properties across species as well as how the TM functions at higher frequencies. There are also questions regarding the workings of the pathologic TM, e.g. How do perforations affect the motion of the entire TM? and Do grafted membranes work like normal TMs? The work proposed here will apply a real-time fiber-optic electro-holographic system based on fast computer-based video-processing to the study of the sound-induced displacement of the TM in normal ears of several animal species (including humans) as well as in ears with induced pathologies and reconstructions. The optical measurement system produces a continuously updated display of time-averaged holograms (up to 500 frames a second) of the displacement of the surface of the TM. This display allows observations of iso-displacement contours of the entire TM surface (with a resolution of 50-200 nm) while the amplitude and/or frequency of the stimulus sound are continuously varied. Such observations lead to easy identification of the critical frequencies and the level dependence of TM displacement patterns. A second version of the system (stroboscopic holography) allows measurement with resolutions of 1-10 nm of the magnitude and phase of the displacement of the entire membrane surface. A third version (dual-wavelength holography) allows measurement of the static shape of the TM with 1-10 nm resolution. The applications of these optical techniques include the identification and quantification of wave travel on the surface of the normal TM, investigations of inter-specific differences in TM motion and TM mechanical parameters, and tests of hypotheses concerning the sensitivity of membrane displacement patterns to ossicular disorders and TM perforations as well as the motion of various TM graft configurations in surgically reconstructed human ears.