[Numerical analysis of the effect of typical middle ear disease on bone conduction]

Lin Chuang Er Bi Yan Hou Tou Jing Wai Ke Za Zhi. 2020 May;34(5):402-405. doi: 10.13201/j.issn.2096-7993.2020.05.004.
[Article in Chinese]

Abstract
in English, Chinese

Objective:To study the effects of typical middle ear lesions on bone conduction, and to provide a theoretical basis for the optimized design of bone conduction hearing aids. Method:A finite element model including the middle ear and cochlea was established by using micro-CT scanning date from a case of adult male human-cadaver temporal bone. The reliability of the model was verified by comparison with relevant experimental data. Based on this model, the effects of several typical middle ear lesions on bone conduction were analyzed. Result:With the increase of tympanic membrane mass, the basilar membrane response at the frequency range of 0.25 kHz to 1 kHz was reduced, and the maximum decrease was 6.9 dB at the frequency of 0.5 kHz. The incus fixation reduced basilar membrane response at the frequency range of 0.2 kHz to 1 kHz, with the maximum decrease of 12.0 dB at 0.75 kHz. The ossicular chain disruption reduced the response of basilar membrane at the frequency range of 1 kHz to 4 kHz, which the decrease was 5.0 dB at 1.5 kHz in the case of incudomallear joint disruption and 11.0 dB at 2 kHz in the case of incudostapedial joint disruption. Conclusion:The results showed that the increased mass of the tympanic membrane and incus fixation mainly reduced the response of bone conduction at the low frequencies. The ossicular chain disruption mainly reduced the response of bone conduction at the middle frequencies. Moreover, the deterioration of incudostapedial disruption was more obvious.

目的：研究典型中耳病变对骨传导听力的影响，为骨传导助听装置优化设计提供理论基础。 方法：依据1例成年男性颞骨标本微CT扫描数据建立包括中耳和耳蜗的有限元模型，通过与文献实验数据对比验证模型的可信度。基于该模型，分析几种典型中耳病变对骨传导的影响。 结果：鼓膜质量增加，降低了0.25 ~1 kHz频率范围内的基底膜响应，在0.5 kHz频率处降幅最大，达到6.9 dB。砧骨固定降低了0.2~1 kHz频率范围内的基底膜响应，在0.75 kHz频率处降幅最大，达到12.0 dB。听骨链断裂降低了1 ~4 kHz频率范围内基底膜响应，其中在1.5 kHz频率处砧锤关节断裂降幅达5.0 dB，在2 kHz频率处砧镫关节断裂降幅高达11.0 dB。 结论：鼓膜质量增加和砧骨固定主要恶化了低频段骨传导响应；听骨链断裂主要恶化了骨传导中频段响应；且砧镫关节断裂恶化更为显著。.

Keywords: basilar membrane displacement; bone conduction; finite element model; hearing compensation; middle ear diseases.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Bone Conduction*
  • Ear Diseases*
  • Ear Ossicles
  • Ear, Middle
  • Humans
  • Male
  • Reproducibility of Results

Grants and funding

国家自然科学基金(No：51775547)；上海市科学与技术委员会基金项目(No：17411962200)