3D Finite Element Modeling of Blast Wave Transmission From the External Ear to a Spiral Cochlea

2021 ◽  
Author(s):  
Marcus Brown ◽  
John Bradshaw ◽  
Rong Z. Gan
Keyword(s):  
Finite Element ◽  
Middle Ear ◽  
Basilar Membrane ◽  
Transverse Motion ◽  
Fe Model ◽  
Ear Canal ◽  
Blast Overpressure ◽  
Stapes Footplate ◽  
Human Ear ◽  
Temporal Bones

Abstract Blast-induced injuries affect the health of veterans, in which the auditory system is often damaged, and blast-induced auditory damage to the cochlea is difficult to quantify. A recent study modeled blast overpressure (BOP) transmission throughout the ear utilizing a straight, two-chambered cochlea, but the spiral cochlea's response to blast exposure has yet to be investigated. In this study, we utilized a human ear finite element (FE) model with a spiraled, two-chambered cochlea to simulate the response of the anatomical structural cochlea to BOP exposure. The FE model included an ear canal, middle ear, and two and half turns of two-chambered cochlea and simulated a BOP from the ear canal entrance to the spiral cochlea in a transient analysis utilizing fluid-structure interfaces. The model's middle ear was validated with experimental pressure measurements from the outer and middle ear of human temporal bones. The results showed high stapes footplate displacements up to 28.5µm resulting in high intracochlear pressures and basilar membrane (BM) displacements up to 43.2µm from a BOP input of 30.7kPa. The cochlea's spiral shape caused asymmetric pressure distributions as high as 4kPa across the cochlea's width and higher BM transverse motion than that observed in a similar straight cochlea model. The developed spiral cochlea model provides an advancement from the straight cochlea model to increase the understanding of cochlear mechanics during blast and progresses towards a model able to predict potential hearing loss after blast.

Finite Element Modeling of Sound Transmission Based on Micro-Computer Tomography for Human Ear

2013 ◽  
Vol 419 ◽  
pp. 593-601
Author(s):  
Jia Bin Tian ◽  
Na Ta ◽  
Zhu Shi Rao ◽  
Li Fu Xu ◽  
Xin Sheng Huang
Keyword(s):  
Finite Element ◽  
Middle Ear ◽  
Computer Tomography ◽  
Physiological Data ◽  
Fe Model ◽  
External Ear ◽  
Ear Canal ◽  
External Ear Canal ◽  
Hearing Devices ◽  
Human Ear

An accurate finite element (FE) model of the human ear can help in understanding the physiological mechanismof human ear and facilitate the design of implantable hearing devices. In this paper,a FE modelof the human ear consisting of the external ear canal, middle ear, and cochlea was developed. The geometry of the external ear canal and middle ear model was based on a fresh specimen of human temporal boneviamicro-computer tomography imaging. A harmonic sound pressure of 90 dB SPL was applied in the ear canal and the multi-field coupled FE analysis was conductedamong the ear canal air, cochlea fluid, and middle ear and cochlea structures. The results were compared with the established physiological data. The satisfactory agreements between the model and published experimental measurementsindicate the middle ear and cochlea functions can be well simulated and further application in terms of human ear can be achieved by the model.

scholarly journals Evaluation of Round Window Stimulation Performance in Otosclerosis Using Finite Element Modeling

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Shanguo Yang ◽  
Dan Xu ◽  
Xiaole Liu
Keyword(s):  
Finite Element ◽  
Middle Ear ◽  
Bone Growth ◽  
Round Window ◽  
Element Model ◽  
Annular Ligament ◽  
Fe Model ◽  
Sound Stimulation ◽  
Partial Fixation ◽  
Human Ear

Round window (RW) stimulation is a new type of middle ear implant’s application for treating patients with middle ear disease, such as otosclerosis. However, clinical outcomes show a substantial degree of variability. One source of variability is the variation in the material properties of the ear components caused by the disease. To investigate the influence of the otosclerosis on the performance of the RW stimulation, a human ear finite element model including middle ear and cochlea was established based on a set of microcomputerized tomography section images of a human temporal bone. Three characteristic changes of the otosclerosis in the auditory system were simulated in the FE model: stapedial annular ligament stiffness enlargement, stapedial abnormal bone growth, and partial fixation of the malleus. The FE model was verified by comparing the model-predicted results with published experimental measurements. The equivalent sound pressure (ESP) of RW stimulation was calculated via comparing the differential intracochlear pressure produced by the RW stimulation and the normal eardrum sound stimulation. The results show that the increase of stapedial annular ligament and partial fixation of the malleus decreases RW stimulation’s ESP prominently at lower frequencies. In contrast, the stapedial abnormal bone growth deteriorates RW stimulation’s ESP severely at higher frequencies.

FINITE ELEMENT ANALYSIS OF THE EFFECT OF ACTUATOR COUPLING CONDITIONS ON ROUND WINDOW STIMULATION

2015 ◽  
Vol 15 (04) ◽  
pp. 1550048 ◽  
Author(s):  
JIABIN TIAN ◽  
XINSHENG HUANG ◽  
ZHUSHI RAO ◽  
NA TA ◽  
LIFU XU
Keyword(s):  
Finite Element ◽  
Middle Ear ◽  
Round Window ◽  
Round Window Membrane ◽  
Fe Model ◽  
Ear Canal ◽  
Sound Stimulation ◽  
Fe Method ◽  
Coupling Conditions ◽  
Intracochlear Pressure

The finite element (FE) method was used to analyze the effect of coupling conditions between the actuator and the round window membrane (RWM) on the performance of round window (RW) stimulation. A FE model of the human ear consisting of the external ear canal, middle ear and cochlea was firstly developed, and then validation of this model was accomplished through comparison between analytical results and experimental data in the literature. Intracochlear pressure were derived from the model under normal forward sound stimulation and reverse RW stimulation. The equivalent sound pressure of RW stimulation was then calculated via comparing the differential intracochlear pressure produced by the actuator and normal ear canal sound stimulus. The actuator was simulated as a floating mass and placed onto the middle ear cavity side of RWM. Two aspects about the actuator coupling conditions were considered in this study: (1) the cross-section area of the actuator relative to the RWM; (2) the coupling layer between the actuator and the RWM. The results show that smaller actuator size can improve the implant performance of RW stimulation, and size requirements of the actuator can also be reduced by introducing a coupling layer between the actuator and RWM, which will benefit the manufacture of the actuator.

scholarly journals A simplified analytical model of sound propagation in the human ear

2019 ◽  
Author(s):  
Wiktor L. Gambin
Keyword(s):  
Elastic Wave ◽  
Sound Wave ◽  
Sound Source ◽  
Sound Propagation ◽  
Basilar Membrane ◽  
Round Window ◽  
Round Window Membrane ◽  
Ear Canal ◽  
Stapes Footplate ◽  
Human Ear

AbstractA simple mechanical model of sound propagation in the human ear from the entrance to the ear canal up to the round window membrane is outlined. The model shows the outer, middle and inner ear as two waveguides connected by a lever mechanism. The case when a sound wave from a sound source at a given frequency and intensity goes into the ear is considered. The sound as a plane elastic wave in the air of the ear canal is partially reflected from the eardrum and after relocation by a lever of the ossicles; it runs as a plane elastic wave in the cochlea fluid to be finally damped at the round window membrane. The basilar membrane excited by the running sound wave in the cochlea is taken as a chain of separate fibers. The power of the sound reaching the ear is compared with the power of the sound carriers in the ear. As a result, simple rules for the amplitude of the stapes footplate as well as for the amplitude and pressure of the forced acoustic wave in the cochlea are obtained. The formulas for the amplitudes of the membrane of the round window and the basilar membrane are also shown. The results of calculations based on these rules were compared with the measurements made on temporal bone specimens. The tests were done for the level of the sound source intensity of 90 dB and a set of frequencies from the range of 400-10,000 Hz. The amplitudes of the stapes-footplate and the round window membrane were measured. A mean difference, between the calculated and the measured values, for the stapes-footplate reached 31%, and for the round window membrane, it was 21%. A ratio of the basilar membrane velocity to the stapes footplate velocity as a function of the frequencies was shown. The obtained graph was close to that got by others as a result of the measurements.

FINITE ELEMENT MODELING OF THE HUMAN COCHLEA USING FLUID–STRUCTURE INTERACTION METHOD

2015 ◽  
Vol 15 (03) ◽  
pp. 1550039 ◽  
Author(s):  
LIFU XU ◽  
XINSHENG HUANG ◽  
NA TA ◽  
ZHUSHI RAO ◽  
JIABIN TIAN
Keyword(s):  
Finite Element ◽  
Transfer Functions ◽  
Basilar Membrane ◽  
Fluid Structure Interaction ◽  
Fe Model ◽  
Ear Canal ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Human Cochlea ◽  
Intracochlear Pressure

In this paper, a 3D finite element (FE) model of human cochlea is developed. This passive model includes the structure of oval window, round window, basilar membrane (BM) and cochlear duct which is filled with fluid. Orthotropic material property of the BM is varying along its length. The fluid–structure interaction (FSI) method is used to compute the responses in the cochlea. In particular, the viscous fluid element is adopted for the first time in the cochlear FE model, so that the effects of shear viscosity in the fluid are considered. Results on the cochlear impedance, BM response and intracochlear pressure are obtained. The intracochlear pressure includes the scala vestibule and scala tympani pressure are extracted and used to calculate the transfer functions from equivalent ear canal pressures to scala pressures. The reasonable agreements between the model results and the experimental data in the literature prove the validity of the cochlear model for simulating sound transmission in the cochlea. Moreover, this model predicted the transfer function from equivalent ear canal pressures to scala pressures which is the input to the cochlear partition.

J0206-4-4 Finite element modeling of human ear by coupling the ear canal and the middle ear

2010 ◽  
Vol 2010.6 (0) ◽  
pp. 115-116
Author(s):  
Yasuhiro FUJIWARA ◽  
Takuji KOIKE ◽  
Kyoji HOMMA ◽  
Michihito AOKI
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Middle Ear ◽  
Ear Canal ◽  
Element Modeling ◽  
Human Ear

STUDY ON THE ROLE OF OSSICULAR JOINT USING FINITE ELEMENT METHOD

2016 ◽  
Vol 16 (04) ◽  
pp. 1650041 ◽  
Author(s):  
LEI ZHOU ◽  
MIAOLIN FENG ◽  
WEI WANG ◽  
HUA TONG ◽  
JIANPING LIU ◽  
...  
Keyword(s):  
Finite Element ◽  
High Frequency ◽  
Vibration Mode ◽  
Rotation Axis ◽  
Three Dimensional ◽  
Bone Block ◽  
Fe Model ◽  
Stapes Footplate ◽  
Incudostapedial Joint ◽  
Human Ear

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.

Finite Element Model of Human Cochlea Considering of the Helicotrema Size

2013 ◽  
Vol 456 ◽  
pp. 576-581 ◽  
Author(s):  
Li Fu Xu ◽  
Na Ta ◽  
Zhu Shi Rao ◽  
Jia Bin Tian
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Basilar Membrane ◽  
Round Window ◽  
Element Model ◽  
Oval Window ◽  
Fe Model ◽  
Cochlear Duct ◽  
Human Cochlea ◽  
Set Up

A 2-D finite element model of human cochlea is established in this paper. This model includes the structure of oval window, round window, basilar membrane and cochlear duct which is filled with fluid. The basilar membrane responses are calculated with sound input on the oval window membrane. In order to study the effects of helicotrema on basilar membrane response, three different helicotrema dimensions are set up in the FE model. A two-way fluid-structure interaction numerical method is used to compute the responses in the cochlea. The influence of the helicotrema is acquired and the frequency selectivity of the basilar membrane motion along the cochlear duct is predicted. These results agree with the experiments and indicate much better results are obtained with appropriate helicotrema size.

Glomus tympanicum chemodectoma: unusual radiological findings

1994 ◽  
Vol 108 (7) ◽  
pp. 607-609 ◽  
Author(s):  
Abduljabbar Alshaikhly ◽  
Abdalla M. Hamid ◽  
Bahram Azadeh
Keyword(s):  
Middle Ear ◽  
Malignant Tumour ◽  
Canal Wall ◽  
Ear Canal ◽  
Radiological Findings ◽  
Glomus Tympanicum ◽  
History Of ◽  
One Year ◽  
The Right ◽  
Temporal Bones

AbstractA 64-year-old Qatari female, with a one-year history of right otorrhoea and deafness, had a reddish-white mass projecting into the right ear canal, through the tympanic membrane, that proved histopathologically to be a paraganglioma. Computerized tomography (CT) of the temporal bones showed extensive destruction of the right mastoid bone, the posterior ear canal wall, and the sinus plate, with total disruption of the ossicles, simulating a malignant tumour, which is unusual for a middle ear paraganglioma.

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