Computer-based holography and middle-ear function

描述（由申请人提供）：鼓膜（TM）是在中耳的环境声音到内耳内的声音的声学-机械转换中涉及的初始结构。有很好的证据表明，TM的形式有助于定义耳朵敏感的频率范围，包括灵敏度和听力范围与TM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在有限频率范围内工作的基本事实，但仍有许多问题尚未解决，包括TM形状对功能的影响，不同物种之间TM机械特性差异的影响以及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？接枝膜是否像正常的TM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）正常耳中TM的声音诱导位移以及诱导病理和重建的耳。光学测量系统产生TM表面位移的时间平均全息图（每秒高达500帧）的连续更新显示。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 nm），同时刺激声音的振幅和/或频率连续变化。这样的观察导致容易识别的临界频率和TM位移模式的水平依赖性。第二个版本的系统（频闪全息术）允许测量分辨率为1-10 nm的幅度和相位的整个膜表面的位移。第三个版本（双波长全息）允许测量的静态形状的TM与1-10纳米的分辨率。这些光学技术的应用包括识别和量化的波的表面上的正常TM，TM运动和TM的机械参数的种间差异的调查，和测试的假设有关的敏感性膜位移模式的听骨疾病和TM穿孔以及手术重建的人耳的各种TM移植配置的运动。

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.