The Ph.D. Program for Medical Engineering and Rehabilitation Science, College of Biomedical Engineering, China Medical University, Taichung 406040, Taiwan.
School of Medicine, College of Medicine, China Medical University, Taichung 406040, Taiwan; Department of Public Health, College of Public Health, China Medical University, Taichung 406040, Taiwan; Department of Otolaryngology-Head and Neck Surgery, China Medical University Hsinchu Hospital, Zhubei City, Hsinchu County 302056, Taiwan.
Comput Methods Programs Biomed. 2022 Mar;215:106619. doi: 10.1016/j.cmpb.2022.106619. Epub 2022 Jan 5.
The Young's modulus of the tympanic membrane (TM) is an important modeling parameter in computer simulations of the sound transmission in the ear. Understanding the material mechanics of the TM is essential to improve the coupling between the tympanic membrane and the auditory ossicles. However, the impact of the age-related Young's modulus of the TM on sound transmission is not well known. The objective of this study was to use a comprehensive finite element (FE) model to assess the impact of Young's modulus on sound transmission from the ear canal to the stapes footplate over acoustic frequencies.
The FE model of the ear canal, the middle ear, and the inner ear, was constructed. The model was constructed with identical geometries and boundary conditions, but with three different Young's moduli for the TMs. The auditory ossicles, suspensory ligaments and tendons, and manubrium were also modeled as isotropic elastic materials. Beside, we evaluated the age-related Young's moduli of the TMs on sound transmission with the FE element fluid-structural interaction (FSI) model under acoustic loading conditions.
The impact of the age-related Young's moduli on the sound pressure distributions in the ear canal was significant over two frequency ranges of 1.4-3.2 and 8.6-10 kHz. Meanwhile, the significant differences of the displacement of the stapes occurred at around 1.6 kHz, where the displacement of the stapes decreased from 0.352 nm to 0.287 nm.
The FSI model could demonstrate the influence of Young's modulus of the TM on the transfer of sound-induced vibrations form the ear canal to the stapes footplate. The FE model may provide appropriate information to the medical device development of artificial ossicles and hearing aids.
鼓膜的杨氏模量是计算机模拟中耳声音传输的重要建模参数。了解鼓膜的材料力学性质对于改善鼓膜与听小骨之间的耦合至关重要。然而，鼓膜杨氏模量随年龄变化对声音传输的影响尚不清楚。本研究旨在使用全面的有限元（FE）模型评估杨氏模量对耳声道至镫骨足板的声音传输在声学频率范围内的影响。
构建了耳道、中耳和内耳的 FE 模型。模型具有相同的几何形状和边界条件，但鼓膜有三种不同的杨氏模量。听小骨、悬韧带和肌腱以及柄也被建模为各向同性弹性材料。此外，我们使用声学加载条件下的 FE 单元流固耦合（FSI）模型评估了与年龄相关的鼓膜杨氏模量对声音传输的影响。
杨氏模量与年龄相关对耳道中声压分布的影响在两个频率范围内非常显著，分别为 1.4-3.2kHz 和 8.6-10kHz。同时，镫骨位移在 1.6kHz 左右出现显著差异，镫骨位移从 0.352nm 减小到 0.287nm。
FSI 模型可以证明鼓膜杨氏模量对声音引起的振动从耳道传递到镫骨足板的影响。FE 模型可以为人工听小骨和助听器等医疗设备的开发提供适当的信息。
