3D Modelling and Numerical Analysis of Human Inner Ear by Means of Finite Elements Method

Authors: C. Castro-Egler, A. Durán-Escalante, A. García-González

Abstract:

This paper presents a method to generate a finite element model of the human auditory inner ear system. The geometric model has been realized using 2D images from a virtual model of temporal bones. A point cloud has been gotten manually from those images to construct a whole mesh with hexahedral elements. The main difference with the predecessor models is the spiral shape of the cochlea with its three scales completely defined: scala tympani, scala media and scala vestibuli; which are separate by basilar membrane and Reissner membrane. To validate this model, numerical simulations have been realised with two models: an isolated inner ear and a whole model of human auditory system. Ideal conditions of displacement are applied over the oval window in the isolated Inner Ear model. The whole model is made up of the outer auditory channel, the tympani, the ossicular chain, and the inner ear. The boundary condition for the whole model is 1Pa over the auditory channel entrance. The numerical simulations by FEM have been done using a harmonic analysis with a frequency range between 100-10.000 Hz with an interval of 100Hz. The following results have been carried out: basilar membrane displacement; the scala media pressure according to the cochlea length and the transfer function of the middle ear normalized with the pressure in the tympanic membrane. The basilar membrane displacements and the pressure in the scala media make it possible to validate the response in frequency of the basilar membrane.

Keywords: Finite elements method, human auditory system model, numerical analysis, 3D modelling cochlea.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1124215

References:

[1] R. Z. Gan, X. Zhang, X. Guan. Modeling Analysis of Biomechanical changes of Middle Ear and Cochlea in Otitis Media. Aip Conference Proceedings. American Institute of Physics, 1403, (2011), pp. 539-546.
[2] Voie AH, Spelman FA. 1995. Three-dimensional reconstruction of the cochlea from two-dimensional images of optical sections. Computerized medical imaging and graphics.19:377-384.
[3] Ghiz AF, Salt AN, DeMott JE, Henson MM, Henson Jr OW, Gewalt SL. 2001. Quantitative anatomy of the round window and cochlear aqueduct in guinea pigs. Hearing research.162:105-112.
[4] Hofman R, Segenhout J, Wit H. 2009. Three-dimensional reconstruction of the pigeon inner ear. Journal of Vestibular Research.19:21-26.
[5] Li S-F, Zhang T-Y, Wang Z-M. 2006. An approach for precise three-dimensional modeling of the human inner ear. ORL.68:302-310.
[6] Liu B, Gao XL, Yin HX, Luo SQ, Lu J. 2007. A detailed 3D model of the guinea pig cochlea. Brain Structure and Function.212:223-230.
[7] Wada H, Sugawara M, Kobayashi T, Hozawa K, Takasaka T. 1998. Measurement of guinea pig basilar membrane using computer-aided three-dimensional reconstruction system. Hearing research.120:1-6.
[8] R.Gan, B. Reeves, X. Wang. Modeling of sound transmission from ear canal to cochlea. Annals of Biomedical Engineering. (2007) 35, pp. 2180-2195.
[9] Wang X, Wang L, Zhou J, Hu Y. 2014. Finite element modelling of human auditory periphery including a feed-forward amplification of the cochlea. Computer methods in biomechanics and biomedical engineering.17:1096-1107.
[10] R. Gan, B. Reeves, X. Wang. Modeling of sound transmission from ear canal to cochlea. Annals of Biomedical Engineering, 35 (2007), 2180-2195.
[11] B. J.L. Flores Espejo, A. Durán Escalante, A. García González. Análisis Numérico del Oído Interno Humano con el Método de los Elementos Finitos. XX Congreso Nacional de Ingeniería Mecánica, Málaga, España, (2014).
[12] A. Garcia-Gonzalez, A. Gonzalez-Herrera. Effect of the middle ear cavity on the response of the human auditory system. The Journal of the Acoustical Society of America, 133:5, 3544-2103.
[13] Von Békésy, Georg. Experiments in hearing. Ed. Ernest Glen Wever. (8) (1960).
[14] García-González, Antonio Luis. Análisis numérico de la influencia de la cavidad timpánica en el sistema auditivo humano. Málaga, (2013)
[15] Gan, R., Reeves, B., Wang, X. Three-Dimensional Finite Element Modelling of Human Ear for Sound Transmission. Annals of Biomedical Engineering. (2004), 32, 847-859.