有限要素法を用いた病変時の中耳の伝音特性解析

抄録

This research concerns sound transmission characteristic analysis for human middle ear lesions using finite element method. A large number of patients are suffering from the middle ear lesions, such as the tympanic membrane perforation, the arthrosclerosis, and the tympanosclerosis. These lesions can change the dynamic properties of middle ear, cause various kinds of hearing problems, as well as the decline of the quality of life. For an early detection of illness and the improvement of the cure, it is important to clarify the influence on hearing ability at the time of lesion of the middle ear. However, it is difficult to grasp the dynamic properties of the auditory organ of a human body by an experiment. In this paper, the dynamic analysis of the middle ear at the time of lesions using the finite element method was conducted. Firstly, a finite element model of a healthy middle ear was built up, and used to verify the validity of the model. The analysis results showed good correspondence to the experiment results of other study. Secondly, the influences of tympanic membrane perforations with different size and position are investigated. The analysis results showed that the decrease of hearing ability is proportional to the size of the tympanic membrane perforation. Especially, the perforation at lower part showed an obvious decrease of hearing ability. Thirdly, the influences of arthrosclerosis and tympanosclerosist occurring at different positions are investigated. The results showed that the arthrosclerosis of incudostapedial joint and the tympanosclerosist at upper part of the TM can obviously decrease the hearing ability.