Three-dimensional numerical modeling for global cochlear dynamics
Three-dimensional numerical modeling for global cochlear dynamics
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DOI：
10.1121/1.428352
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发表时间：
2000-01-01
影响因子：
2.4
通讯作者：
Nuttall, AL
中科院分区：
文献类型：
--
作者：
Parthasarathi, AA;Grosh, K;Nuttall, AL
用Galerkin近似的变分方程建立了一个混合的分析-数值模型来预测全球的耳蜗声响应。该公式提供了一种灵活的框架，能够结合基于形态的耳蜗区和真实几何的机械模型。该框架被应用于简化模型，重点是混合方法在三维建模中的应用。由此得到的公式是模块化的，其中表示流体和耳蜗区的矩阵是独立构造的。采用两种方法来降低计算量，一种是模态有限元方法，另一种是边界元-有限元方法。第一种采用流体压力的交叉模展开(2.5维模型)，第二种采用基于波导格林函数的边界元方法(BEM)。一种新的波数方法用于内部问题的边界元列式，从而提高了有限元矩阵的计算效率。对于这两种方法，使用简化的被动结构耳蜗区模型进行了收敛研究。结果表明，接近最佳位置的基底膜速度受流体离散化和结构离散化的影响。还显示了耳蜗管压力场，展示了最佳位置附近压力的3D性质。(C)2000年美国声学学会。[S0001-4966(99)08012-1]。
A hybrid analytical-numerical model using Galerkin approximation to variational equations has been developed for predicting global cochlear responses. The formulation provides a flexible framework capable of incorporating morphologically based mechanical models of the cochlear partition and realistic geometry. The framework is applied for a simplified model with an emphasis on application of hybrid methods for three-dimensional modeling. The resulting formulation is modular, where matrices representing fluid and cochlear partition are constructed independently. Computational cost is reduced using two methods, a modal-finite-element method and a boundary element-finite-element method. The first uses a cross-mode expansion of fluid pressure (2.5D model) and the second uses a waveguide Green's-function-based boundary element method (BEM). A novel wave number approach to the boundary element formulation for interior problem results in efficient computation of the finite-element matrix. For the two methods a convergence study is undertaken using a simplified passive structural model of cochlear partition. It is shown that basilar membrane velocity close to best place is influenced by fluid and structural discretization. Cochlear duct pressure fields are also shown demonstrating the 3D nature of pressure near best place. (C) 2000 Acoustical Society of America. [S0001-4966(99)08012-1].