Computer-based holography and middle-ear function

鼓膜（TM）是参与中耳声-机械传导的初始结构， 环境声音在内耳内转化为声音。有充分的证据表明， 的TM有助于定义耳朵敏感的频率范围，包括 灵敏度和听力范围以及TM的大小和形状。虽然我们知道一些基本事实， 在有限的频率范围内的健康TM的工作，有许多问题尚未解决 包括TM形状对功能的影响，TM机械性能差异大的影响， 以及TM如何在更高频率下发挥作用。还有一些问题是关于 病理性TM的工作原理，例如，穿孔如何影响整个TM的运动？和做 接枝膜像正常TM一样工作？这里提出的工作将应用实时光纤电- 全息系统的基础上快速计算机为基础的视频处理的研究， 在几种动物物种（包括人）的正常耳中以及在患有 诱发的病理和重建。光学测量系统产生连续的 更新显示表面位移的时间平均全息图（每秒高达500帧） 的TM。该显示允许观察整个TM表面的等位移等值线（具有 分辨率为50-200 nm），同时刺激声的振幅和/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的水平依赖性 位移模式。该系统的第二个版本（频闪全息术）允许测量， 整个膜表面位移的幅度和相位的分辨率为1-10 nm。一 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 分辨率这些光学技术的应用包括波的识别和量化 旅行的表面上的正常TM，调查种间差异TM运动和TM 力学参数，以及关于膜位移敏感性的假设检验 听骨疾病和TM穿孔的模式以及各种TM移植物配置的运动 在手术重建的人耳中。

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.