Human cochlear hydrodynamics: A high-resolution μCT-based finite element study.
Human cochlear hydrodynamics: A high-resolution μCT-based finite element study.
复制标题
DOI：
10.1016/j.jbiomech.2016.11.020
复制
发表时间：
2017-01-04
影响因子：
2.4
通讯作者：
Cardoso L
中科院分区：
文献类型：
--
作者：
De Paolis A;Watanabe H;Nelson JT;Bikson M;Packer M;Cardoso L
人类耳蜗淋巴周围流体动力学的测量很少，主要局限于前庭鳞片和鼓室底部或顶部的流体压力。事实上，流体压力或体积流速的测量只在动物模型中报道过。在这项研究中，我们使用μCT扫描在6.7和3 μm分辨率下对人耳进行成像，以产生高精度的全耳，特别是耳蜗鳞片的3D模型。我们使用对比剂更好地区分软硬组织，包括耳道、鼓膜、锤骨、镫骨、韧带、椭圆形和圆形窗、鳞状前庭和鼓室。利用计算流体动力学（CFD）方法和解剖学上正确的人类耳蜗三维模型，我们检查了听觉范围内压力和淋巴周围血流速度作为位置、时间和频率的函数。每绕耳蜗螺旋中心轴旋转45度计算周长、表面、液压直径、沃默斯利数和雷诺数。CFD结果显示了沿耳蜗的空间和时间压力梯度。较小的雷诺数和较大的沃默斯利值表明，在听觉频率下，淋巴周围流体的流动是层流的，其速度分布呈塞状。在耳垢前庭和鼓室处，压力与流体流速的相位分别为102 ~ 106°。在20 ~ 100 Hz时，平均流速在亚μm/s ~ nm/s范围内；在1 ~ 20 kHz时，平均流速在nm/s以下。
Measurements of perilymph hydrodynamics in the human cochlea are scarce, being mostly limited to the fluid pressure at the basal or apical turn of the scalae vestibuli and tympani. Indeed, measurements of fluid pressure or volumetric flow rate have only been reported in animal models. In this study we imaged the human ear at 6.7 and 3-μm resolution using μCT scanning to produce highly accurate 3D models of the entire ear and particularly the cochlea scalae. We used a contrast agent to better distinguish soft from hard tissues, including the auditory canal, tympanic membrane, malleus, incus, stapes, ligaments, oval and round window, scalae vestibule and tympani. Using a Computational Fluid Dynamics (CFD) approach and this anatomically correct 3D model of the human cochlea, we examined the pressure and perilymph flow velocity as a function of location, time and frequency within the auditory range. Perimeter, surface, hydraulic diameter, Womersley and Reynolds numbers were computed every 45 degrees of rotation around the central axis of the cochlear spiral. CFD results showed both spatial and temporal pressure gradients along the cochlea. Small Reynolds number and large Womersley values indicate that the perilymph fluid flow at auditory frequencies is laminar and its velocity profile is plug-like. The pressure was found 102–106° out of phase with the fluid flow velocity at the scalae vestibule and tympani, respectively. The average flow velocity was found in the sub-μm/s to nm/s range at 20–100 Hz, and below the nm/s range at 1–20 kHz.