The lever ratio, the vibration mode and the stiffness of the ossicular joints were studied using the finite element (FE) analysis of the response of human ear under the outer ear sound excitation. The three-dimensional FE model was constructed based on serial micro CT images of a temporal bone block, and validated through comparison with the experimental data from previous literatures. The displacements of the umbo and stapes footplate and the vibration mode of the ossicles under different grades of stiffness of middle ear components were derived. It is suggested that the flexible ossicular joint combined with the shift of rotation axis causes the increase of lever ratio at high frequency. In addition, the flexible incudostapedial joint (ISJ) can reduce sound transmission especially at high frequency, meanwhile it also permits more vibration energy transmitted to the piston-like directions.
[1]Fudan Univ, Shanghai Zhongshan Hosp, Dept Otorhinolaryngol Head & Neck Surg, Shanghai 200032, Peoples R China.
[2]Shanghai Jiao Tong Univ, State Key Lab Ocean Engn, Shanghai 200240, Peoples R China.
[3]Shanghai Jiao Tong Univ, Dept Civil Engn, 800 Dongchuan Rd, Shanghai, Peoples R China.
(8.0+极速模式)