Wada H, Metoki T, Kobayashi T
Department of Mechanical Engineering, Tohoku University, Sendai, Japan.
J Acoust Soc Am. 1992 Dec;92(6):3157-68. doi: 10.1121/1.404211.
Applying the general-purpose finite-element package program (ISAP), a three-dimensional finite-element method (FEM) model of a human right middle ear, which included ossicles, was made and the mechanical properties and boundary conditions of the middle ear were determined by a comparison between the numerical results obtained from the FEM analysis and the measurement results of the fresh cadavers, normal subjects and patients, which were obtained by our developed sweep frequency middle ear analyzer (MEA). The "Elastic" boundary condition consisting of linear and torsional springs at the eardrum attachments to the annular ligament was more appropriate for the actual condition than "fully clamped" one. Rotational axis of the ossicular chain was assumed to be a fixed straight line from the anterior process of the malleus to the short process of the incus, and a load of the ossicular chain and cochlea was simplified to be expressed by the stiffness of the cochlea. Vibration patterns of the eardrum and ossicles at the first resonance frequency, obtained under these assumptions, were in agreement with the experimental results obtained by means of time-averaged holography and by using a video measuring system, except for the relatively large displacements at the tympanic ring.
应用通用有限元软件包程序（ISAP），建立了包含听小骨的人右中耳三维有限元模型，并通过比较有限元分析得到的数值结果与我们开发的扫频中耳分析仪（MEA）对新鲜尸体、正常受试者和患者的测量结果，确定了中耳的力学性能和边界条件。在鼓膜与环形韧带连接处由线性和扭转弹簧组成的“弹性”边界条件比“完全夹紧”边界条件更符合实际情况。听骨链的旋转轴假定为从锤骨前突到砧骨短突的固定直线，听骨链和耳蜗的载荷简化为用耳蜗的刚度来表示。在这些假设下得到的鼓膜和听小骨在第一共振频率下的振动模式，除了鼓膜环处位移相对较大外，与通过时间平均全息术和视频测量系统获得的实验结果一致。
