A Sensitivity Study on a Hybrid FE/MB Human Middle Ear Model

Author(s):  
Gaia Volandri ◽  
Francesca Di Puccio ◽  
Paola Forte

The human middle ear includes the tympanic membrane and the ossicular chain. The finite element method is capable of representing the complex geometry and the material orthotropy of the tympanic membrane. On the contrary, the ossicles can be considered as rigid bodies and a multi-body approach can be adopted. In the present study a multi-body model of the ossicular chain and other structures (joints, ligaments and muscle tendons) of the middle ear was developed and combined with a finite element model of the tympanic membrane through a feedback control strategy. An optimization procedure was used to calibrate unspecified or uncertain parameters with the aim of reproducing ascertained experimental literature data. The sensitivity of the calibrated models to both tympanic membrane and ossicular chain parameters was investigated. Material, geometrical and inertial parameters were considered, in particular those whose values were most widespread in the literature.

2012 ◽  
Vol 34 (9) ◽  
pp. 1339-1355 ◽  
Author(s):  
G. Volandri ◽  
F. Di Puccio ◽  
P. Forte ◽  
S. Manetti

2018 ◽  
Vol 127 (5) ◽  
pp. 306-311 ◽  
Author(s):  
Es-Hak Bedri ◽  
Miriam Redleaf

Objectives: In Ethiopia, 2-stage operations with middle ear prostheses are economically unfavorable. We hypothesized that single-stage autologous ossiculoplasty results in acceptable tympanic membrane (TM) and hearing improvements in a setting of limited resources. Methods: One hundred eighty-eight patients (197 ears) who underwent 1-stage autologous ossiculoplasty for ossicular dysfunction are presented. All but 14 of these ears also had perforations of the TM. Conditions of the middle ear were granulation tissue, ossicular disruption only, tympanosclerosis, and cholesteatoma. Reconstructions of the ossicular chain were performed with autologous ossicles only. Results: The closure rate of TM perforations was 95%. Preoperative air bone gaps were 27 to 60 dB (mean [SD] = 44 [7] dB); postoperative air bone gaps were 0 to 50 dB (average [SD] = 23 [10] dB), for an average improvement of 21 dB across all reconstruction types ( P < .001). The largest favorable changes in air bone gaps were with incus and malleus columellas from the footplate to the TM (33 and 23 dB, respectively) ( P < .001). No patient had worsening of sensorineural hearing levels or extrusion of the reconstructed ossicles. Conclusion: Autologous ossiculoplasty performed well in this setting. Acceptable TM closure rates and improvement of air bone gaps were seen in 1-stage operations without the use of prostheses.


Author(s):  
Houguang Liu ◽  
Hu Zhang ◽  
Jianhua Yang ◽  
Xinsheng Huang ◽  
Wen Liu ◽  
...  

As a novel application of implantable middle ear hearing device, round-window stimulation is widely used to treat hearing loss with middle ear disease, such as ossicular chain malformation. To evaluate the influence of ossicular chain malformations on the efficiency of the round-window stimulation, a human ear finite element model, which incorporates cochlear asymmetric structure, was constructed. Five groups of comparison with experimental data confirmed the model’s validity. Based on this model, we investigated the influence of three categories of ossicular chain malformations, that is, incudostapedial disconnection, incus and malleus fixation, and fixation of the stapes. These malformations’ effects were evaluated by comparing the equivalent sound pressures derived from the basilar membrane displacement. Results show that the studied ossicular chain malformations mainly affected the round-window simulation’s performance at low frequencies. In contrast to the fixation of the ossicles, which mainly deteriorates round-window simulation’s low-frequency performance, incudostapedial disconnection increases this performance, especially in the absence of incus process and stapes superstructure. Among the studied ossicular chain malformations, the stapes fixation has a much more severe impact on the round-window stimulation’s efficiency. Thus, the influence of the patients’ ossicular chain malformations should be considered in the design of the round-window stimulation’s actuator. The low-frequency output of the round-window simulation’s actuator should be enhanced, especially for treating the patients with stapes fixation.


2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Wu Ren ◽  
Huijuan Yan ◽  
Yi Yu ◽  
Jinghong Ren ◽  
Jinlong Chang ◽  
...  

As a bridge from the sound signal in the air to the sound perception of the inner ear auditory receptor, the tympanic membrane and ossicular chain of the middle ear transform the sound signal in the outer ear through two gas-solid and solid-liquid conversions. In addition, through the lever principle formed by three auditory ossicle structure, the sound was concentrated and amplified to the inner ear. However, the sound transmission function of the middle ear will be decreased by disease, genetic, or trauma. Hence, using middle ear prosthesis to replace the damaged ossicles can restore the conduction function. The function realization of middle ear prosthesis depends on the vibration response of the prosthesis from the tympanic membrane to the stapes plate on the human auditory perception frequency, which is affected by the way the prosthesis combined with the tympanic membrane, the material, and the geometric shape. In this study, reasonable prosthetic structures had been designed for different types of ossicular chain injuries, and the frequency response characteristics were analyzed by the finite element method then. Moreover, in order to achieve better vibration frequency response, a ball structure was designed in the prosthesis to simulate its amplification function. The results showed that the middle ear prostheses constructed by different injury types can effectively transfer vibration energy. In particular, the first- and second-order resonant frequencies and response amplitudes are close to each other when ball structure models of different materials are added. Instead, the resonance frequency of the third stage formed by aluminum alloy ball materials is larger than that of the other two, which showed good response features.


2015 ◽  
Vol 66 (1) ◽  
pp. 16-27 ◽  
Author(s):  
Luis A. Vallejo Valdezate ◽  
Antonio Hidalgo Otamendi ◽  
Alberto Hernández ◽  
Fernando Lobo ◽  
Elisa Gil-Carcedo Sañudo ◽  
...  

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