含主动耳蜗的耳声传递有限元模型研究

发布时间：2018-09-12 09:56

【摘要】：由于人耳外周听觉系统的复杂性—几何上不规则，材料特性有变化，存在着流固耦合，导致普通的数值模拟或解析与数值相结合的模拟方法很难准确地捕获中耳及耳蜗的动力学特性参数。本文建立了外耳、中耳和简化直腔耳蜗集成的有限元模型，考虑了中耳的各韧带及听骨链，耳蜗简化成两直腔，包含正交各向异性材料基底膜并考虑尺寸和材料性质沿长度的变化。用ANSYS谐响应分析外耳道声音刺激下耳蜗的响应特性，在模拟过程中获得了不同条件下镫骨底板的位移，基底膜的位移沿长度方向的分布，前庭阶的压力分布，，还得到了基底膜的频率特性选择曲线，以上结果与实验结果有较好的一致性，说明了本模型的完整性，可以应用于模拟人耳传声的整个过程。主动耳蜗与被动耳蜗相比考虑了耳蜗内部柯蒂氏器对基底膜振动的放大作用，柯蒂氏器与听觉功能密切相关。本文的主动耳蜗是基于前馈反馈机制在有限元模型的基础上引入主动力，用主动放大增益系数来量化主动作用的强弱，分析了不同声音强度下主动耳蜗基底膜的响应特性，通过模拟得出了非线性压缩、频率选择等特性，并同被动耳蜗结果进行了对比。主动模拟结果表明低强度声音激励下主动放大作用小，高强度声音激励下主动放大作用大，并且基底膜共振点处放大作用最明显。主动耳蜗的成功模拟对听力诊断和耳声发射的研究都有重要的意义。
[Abstract]:Due to the complexity and geometric irregularity of the peripheral auditory system of human ears, the material characteristics change, and there is fluid-solid coupling. It is difficult to capture the dynamic characteristic parameters of middle ear and cochlea accurately. In this paper, a finite element model for the integration of the outer ear, the middle ear and the simplified straight cochlea is established. The ligaments and ossicular chains of the middle ear are considered, and the cochlea is simplified into two straight cavities. The substrate films of orthotropic materials are included and the size and properties of the materials vary with the length. The response characteristics of cochlea stimulated by external auditory canal sound were analyzed by ANSYS harmonic response. The displacement of stapes floor, the distribution of displacement of basal membrane along length and the pressure distribution of vestibular step were obtained under different conditions. The frequency characteristic selection curve of the basement membrane is also obtained, which is in good agreement with the experimental results, which shows the integrity of the model and can be used to simulate the whole process of human ear sound transmission. Compared with passive cochlea, active cochlea takes into account the amplification effect of cochlear internal Corti's organ on basilar membrane vibration. Corti's organ is closely related to auditory function. In this paper, the active cochlea is based on the feedforward feedback mechanism, which is based on the finite element model. The active amplification gain coefficient is used to quantify the intensity of the active cochlea. The response characteristics of the active cochlea basement membrane under different sound intensities are analyzed. The characteristics of nonlinear compression and frequency selection are obtained by simulation and compared with the results of passive cochlea. The results of active simulation show that the effect of active amplification is small under low intensity sound excitation and large under high intensity sound excitation, and the amplification effect is most obvious at the resonance point of basement membrane. Successful simulation of active cochlea plays an important role in hearing diagnosis and otoacoustic emission.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R318.19

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