Reconstruction of three-dimensional organ of Corti micromechanical motion patterns via optical coherence tomography

光学相干层析成像(OCT)用于耳蜗力学研究中的成像和测量 Corti复合体(OCC)器官的振动，即在耳蜗内螺旋运动的感觉组织。OCT可以 用于同时测量光轴上多个点的亚纳米级振动。 然而，这个光轴通常与大脑的解剖结构没有直接的关系。 耳蜗骨。这导致了两个模糊：1)测量的运动是真实的三个投影-- 在解剖学上不重要的轴上的空间运动，以及2) 测量的结构仅沿光轴已知，这不足以将结构关联起来 从解剖学上讲。这导致对OCT数据的解释受到限制，因为在两个小时内进行测量 不同的取向不能合理地相互比较。即使是同时测量的 单次测量中的结构无法进行充分比较，因为它们的相对位置无法进行比较 必然是众所周知的。本项目的目的是克服当代OCT的这些局限性 实验并获得了沙土鼠耳蜗底的全三维细观力学图像。 这些定量的三维测量将揭示 耳蜗的调谐和转导，如OCC有效质量和立体纤毛枢转。在目标1中，我们 建议在沙土鼠耳蜗基底部的体积中使用密集间隔的OCT测量 不同的方向重建OCC的三维运动。在目标2中，我们建议使用 压缩传感以减少这种重建所需的空间样本数量，以及 从而缩短了这种三维振动数据的采集时间。目标2的基础是 期望-这将在本项目中得到测试-控制中心的运动模式可以被表达出来 在一些基函数组中稀疏，例如，小波基。找到这样的基础将会给你 对体内耳蜗微力学的空间结构有重要的洞察力。该方法将被制定 可通过公共GitHub存储库获取。

Optical coherence tomography (OCT) is used in cochlear mechanics research to image and measure vibrations in the organ of Corti complex (OCC), the sensory tissue that spirals within the cochlea. OCT can be used to measure sub-nanometer vibrations at many points along the optical axis simultaneously. However, this optical axis does not generally bear a straightforward relation to the anatomy of the cochlea. This results in two ambiguities: 1) the measured motion is a projection of the true three- dimensional motion onto an axis that is not anatomically important, and 2) the relative locations of measured structures are known only along the optical axis, which is not sufficient to relate the structures anatomically. This results in limitations for the interpretation of OCT data, as measurements taken at two different orientations cannot be reasonably compared to one another. Even simultaneously measured structures in a single measurement cannot be adequately compared, as their relative locations are not necessarily known. The purpose of this project is to overcome these limitations of contemporary OCT experiments and gain a full three-dimensional picture of micromechanics in the base of the gerbil cochlea. These quantitative three-dimensional measurements will reveal mechanical properties governing cochlear tuning and transduction, such as the OCC effective mass and stereocilia pivoting. In Aim 1, we propose the use of densely spaced OCT measurements in a volume of the gerbil cochlea base at three different orientations to reconstruct the three-dimensional OCC motion. In Aim 2, we propose the use of compressed sensing to reduce the number of spatial samples required for this reconstruction, and consequently reduce the acquisition time of this three-dimensional vibration data. Aim 2 is based in the expectation - which will be tested in this project - that the motion pattern of the OCC can be expressed sparsely in some set of basis functions, for example, a wavelet basis. Finding such a basis would give significant insight into the spatial structure of in vivo cochlear micromechanics. The method will be made available through a public GitHub repository.