声场与结构的耦合分析及其在耳声传递模拟中的应用

发布时间：2018-09-12 06:55

【摘要】：有限元分析是模拟声音在人耳内传递的有效方法,通过声场——结构耦合有限元模型计算可模拟中耳结构变化对耳声传递的影响。本文建立了包括耳道和耳腔内的空气、中耳结构、简化直腔耳蜗及淋巴液集成的有限元模型。通过声场——结构耦合分析计算声音由外耳道向内耳的传递过程,获得了鼓膜、镫骨足板的位移、中耳的声压增益、前庭阶的压力分布及前庭阶与鼓阶的压力差,模拟了基底膜自蜗底到蜗顶的频率选择特性。在声场正向传递分析的基础上,通过建立的简化直腔耳蜗模型,分析圆窗激励条件下的声音由圆窗经过鼓阶、前庭阶传递至卵圆窗并到达中耳的逆向传递过程,获得了耳声逆向传递下的耳蜗压力分布、鼓阶与前庭阶压力差分布。最后,本文建立了中耳与中耳植入辅助听力装置的有限元模型,计算了助听装置植入中耳前后的鼓膜和镫骨足板的位移响应,分析了不同安装条件下植入式助听质量对中耳声传递功能的影响。中耳与耳蜗集成模型计算获得的鼓膜及镫骨位移响应、中耳压力增益、圆窗处的压力增益和声音逆向传递条件下压力差分布等结果与相关实验数据较一致,说明了本文建立的中耳模型、耳蜗模型和基底膜力学参数的合理性。因此,本文建立的中耳与简化耳蜗集成模型可进一步应用于不同条件下中耳功能和耳蜗运动功能的数值模拟。
[Abstract]:Finite element analysis (FEM) is an effective method to simulate the sound transmission in human ear. The effect of the change of middle ear structure on the acoustic transmission can be simulated by using the coupled finite element model of sound field and structure. In this paper, a finite element model of air, middle ear structure, simplified cochlea and lymphatic fluid in ear canal and ear cavity is established. The sound transfer process from the external auditory canal to the inner ear was calculated by sound field-structure coupling analysis. The displacement of the tympanic membrane, stapes foot plate, the sound pressure gain of the middle ear, the pressure distribution of the vestibular step and the pressure difference between the vestibular and tympanic steps were obtained. The frequency selection characteristics of the basement membrane from the cochlea base to the cochlea apex were simulated. On the basis of forward transmission analysis of sound field, a simplified straight cavity cochlear model is established to analyze the reverse transmission process of sound from round window to oval window and to middle ear under circular window excitation condition, in which the sound passes through the drum step, the vestibular step passes to the oval window, and the sound is transferred to the middle ear. The cochlear pressure distribution and the pressure difference between the tympanic and vestibular steps were obtained. Finally, the finite element model of middle ear and middle ear implants is established, and the displacement responses of tympanic membrane and stapes footplate before and after middle ear implantation are calculated. The effect of implantable hearing aid quality on middle ear sound transmission was analyzed under different installation conditions. The results of tympanic membrane and stapes displacement response, middle ear pressure gain, pressure gain at the round window and pressure difference distribution under the condition of sound reverse transmission obtained by the integrated model of middle ear and cochlea were in good agreement with the experimental data. The rationality of the middle ear model, cochlea model and the mechanical parameters of the basement membrane were demonstrated. Therefore, the integrated model of middle ear and simplified cochlea can be further applied to the numerical simulation of middle ear function and cochlear motor function under different conditions.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：Q62;R764

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