Chan Wei Xuan, Lee Seong Hyuk, Kim Namkeun, Shin Choongsoo S, Yoon Yong-Jin
School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, S 639798, Singapore.
School of Mechanical Engineering, Chunh-Ang University, 221 Heuksuk-dong, Dongjak-gu, Seoul 156-056, South Korea.
Hear Res. 2017 Mar;345:1-9. doi: 10.1016/j.heares.2016.12.003. Epub 2016 Dec 14.
The frequency selectivity of a gerbil cochlea, unlike other mammals, does not depend on varying thickness and width of its basilar membrane from the basal to the apical end. We model the gerbil arched basilar membrane focusing on the radial tension, embedded fiber thickness, and the membrane arch, which replace the functionality of the variation in thickness and width. The model is verified with the previous gerbil cochlea model which estimated the equivalent basilar membrane thickness and is shown to be more accurate than the flat sandwiched basilar membrane model. The simple sinusoidal-shaped bending mode assumption in previous models is found to be valid in the present model with <12% error. Parametric study on the present model shows that fiber thickness contribution to the membrane stiffness is close to the 3rd order, higher than the 1st order estimation of previous models. We found that the effective Young's modulus of the fiber bundle is at least 6 orders higher than the shear modulus of the soft-cells and the membrane radial bending stiffness is more sensitive to the membrane arch and the shear modulus of the soft-cells near the apical end.
与其他哺乳动物不同，沙鼠耳蜗的频率选择性并不取决于其基底膜从基部到顶端的厚度和宽度变化。我们对沙鼠的拱形基底膜进行建模，重点关注径向张力、嵌入纤维厚度和膜拱，它们替代了厚度和宽度变化的功能。该模型通过先前估计等效基底膜厚度的沙鼠耳蜗模型进行了验证，并且显示出比平坦夹层基底膜模型更准确。先前模型中简单的正弦形弯曲模式假设在本模型中被发现是有效的，误差小于12%。对本模型的参数研究表明，纤维厚度对膜刚度的贡献接近三阶，高于先前模型的一阶估计。我们发现纤维束的有效杨氏模量比软细胞的剪切模量至少高6个数量级，并且膜的径向弯曲刚度对膜拱和顶端附近软细胞的剪切模量更敏感。
