2D Modeling of the Human Ear Using the Equivalent Mechanical Impedance

2020 ◽  
Author(s):  
Chahbi Aziz ◽  
Assif Safaa ◽  
Faiz Adil ◽  
Hajjaji Abdelowahed.
Keyword(s):  
Tympanic Membrane ◽  
Middle Ear ◽  
Sound Pressure ◽  
Mechanical Impedance ◽  
Ossicular Chain ◽  
Body Parts ◽  
Frequency Range ◽  
Ear Canal ◽  
Finite Elements Analysis ◽  
Human Tympanic Membrane

Several mass–spring–damper models have been developed to study the response of the human body parts. In such models, the lumped elements represent the mass of different body parts, and stiffness and damping properties of various tissues. The aim of this research is to develop a 2D axisymmetric model to simulate the motion of the human tympanic membrane. In this contribution we develop our model using a Comsol Multiphysics software to construct a 2D axisymmetric objects, the acoustic structure interaction between the ear canal (field of propagation of the acoustic wave) and the structure of ear (skin, cartilage, bone, tympanic membrane) was solved using finite elements analysis (FEA). A number of studies have investigated the motion of the human tympanic membrane attached to the ossicular chain and the middle ear cavity. While, in our model the tympanic annular is assumed to be fixed and the loading of what comes behind the tympanic membrane as the ossicular chain, middle ear cavity and cochlea were replaced by the equivalent mechanical impedance of a spring mass damper system. The obtained results demonstrate that the maximum displacements of the umbo are obtained at the frequency range of [0.9 - 2.6] kHz, the sound pressure gain had the shape of peak with a maximum at [2 – 3] kHz frequency range. The umbo displacement depends on the damping coefficient d, and the sound pressure at the tympanic membrane was enhanced compared to that at the ear canal entrance.

TIME AVERAGE HOLOGRAPHY STUDY OF HUMAN TYMPANIC MEMBRANE WITH ALTERED MIDDLE EAR OSSICULAR CHAIN

2009 ◽  
Author(s):  
JEFFREY T. CHENG ◽  
MICHAEL E. RAVICZ ◽  
JOHN J. ROSOWSKI ◽  
NESIM HULLI ◽  
MARIA S. HERNANDEZ-MONTES ◽  
...  
Keyword(s):  
Tympanic Membrane ◽  
Middle Ear ◽  
Ossicular Chain ◽  
Time Average ◽  
Human Tympanic Membrane

Ossicular Chain Reconstruction in a Developing Country

2018 ◽  
Vol 127 (5) ◽  
pp. 306-311 ◽  
Author(s):  
Es-Hak Bedri ◽  
Miriam Redleaf
Keyword(s):  
Tympanic Membrane ◽  
Developing Country ◽  
Middle Ear ◽  
Granulation Tissue ◽  
Ossicular Chain ◽  
Single Stage ◽  
Limited Resources ◽  
Closure Rate ◽  
Average Improvement ◽  
Ossicular Chain Reconstruction

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.

scholarly journals Macroscopic description of the external and middle ear of paca (Cuniculus paca Linnaeus, 1766)

2015 ◽  
Vol 35 (6) ◽  
pp. 583-589 ◽  
Author(s):  
Leandro L. Martins ◽  
Ijanete Almeida-Silva ◽  
Maria Rossato ◽  
Adriana A.B. Murashima ◽  
Miguel A. Hyppolito ◽  
...  
Keyword(s):  
Tympanic Membrane ◽  
Middle Ear ◽  
Gross Anatomy ◽  
Experimental Models ◽  
Temporal Region ◽  
External Ear ◽  
Wild Animals ◽  
Ear Canal ◽  
Macroscopic Description ◽  
Mouse Ear

Abstract: Paca (Cuniculus paca), one of the largest rodents of the Brazilian fauna, has inherent characteristics of its species which can conribute as a new option for animal experimantation. As there is a growing demand for suitable experimental models in audiologic and otologic surgical research, the gross anatomy and ultrastructural ear of this rodent have been analyzed and described in detail. Fifteen adult pacas from the Wild Animals Sector herd of Faculdade de Ciências Agrárias e Veterinárias, Unesp-Jaboticabal, were used in this study. After anesthesia and euthanasia, we evaluated the entire composition of the external ear, registering and ddescribing the details; the temporal region was often dissected for a better view and detailing of the tympanic bulla which was removed and opened to expose the ear structures analyzed mascroscopically and ultrastructurally. The ear pinna has a triangular and concave shape with irregular ridges and sharp apex. The external auditory canal is winding in its path to the tympanic mebrane. The tympanic bulla is is on the back-bottom of the skull. The middle ear is formed by a cavity region filled with bone and membranous structures bounded by the tympanic membrane and the oval and round windows. The tympanic membrane is flat and seals the ear canal. The anatomy of the paca ear is similar to the guinea pig and from the viewpoint of experimental model has major advantages compared with the mouse ear.

scholarly journals Application of Multispectral Imaging in the Human Tympanic Membrane

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Tien Tran Van ◽  
Mi Lu Thi Thao ◽  
Linh Bui Mai Quynh ◽  
Cat Phan Ngoc Khuong ◽  
Linh Huynh Quang
Keyword(s):  
Tympanic Membrane ◽  
Middle Ear ◽  
Multispectral Imaging ◽  
Biological Tissues ◽  
Image Features ◽  
Surrounding Tissue ◽  
Surrounding Area ◽  
Boundary Determination ◽  
Intensity Images ◽  
Human Tympanic Membrane

Multispectral imaging has recently shown good performance in determining information about physiology, morphology, and composition of tissue. In the endoscopy field, many researches have shown the ability to apply multispectral or narrow-band images in surveying vascular structure based on the interaction of light wavelength with tissue composition. However, there has been no mention to assess the contrast between other components in the middle ear such as the tympanic membrane, malleus, and the surrounding area. Using CT, OCT, or ODT can clearly describe the tympanic membrane structure; nevertheless, these approaches are expensive, more complex, and time-consuming and are not suitable for most common middle ear diagnoses. Here, we show the potential of using the multispectral imaging technique to enhance the contrast of the tympanic membrane compared to the surrounding tissue. The optical absorption and scattering of biological tissues constituents are not the same at different wavelengths. In this pilot study, multiwavelength images of the tympanic membrane were captured by using the otoscope with LED light source at three distinct spectral regions: 450 nm, 530 nm, and 630 nm. Subsequently, analyses of the intensity images as well as the histogram of these images point out that the 630 nm illumination image features an evident contrast in the intensity of the tympanic membrane and malleus compared to the surrounding area. Analysis of such images could facilitate the boundary determination and segmentation of the tympanic membrane (TM) with high precision.

scholarly journals Study on the Prosthesis Structural Design and Vibration Characteristics Based on the Conduction Effect of Human Middle Ear

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Wu Ren ◽  
Huijuan Yan ◽  
Yi Yu ◽  
Jinghong Ren ◽  
Jinlong Chang ◽  
...  
Keyword(s):  
Frequency Response ◽  
Inner Ear ◽  
Tympanic Membrane ◽  
Middle Ear ◽  
Transmission Function ◽  
Ossicular Chain ◽  
Sound Signal ◽  
Sound Perception ◽  
Response Characteristics ◽  
Middle Ear Prosthesis

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.

scholarly journals External ear canal cholesteatoma after ventilation tube insertion and mastoidectomy

2012 ◽  
Vol 69 (4) ◽  
pp. 363-366 ◽  
Author(s):  
Dragoslava Djeric ◽  
Milan Jovanovic ◽  
Ivan Baljosevic ◽  
Srbislav Blazic ◽  
Milanko Milojevic
Keyword(s):  
Tympanic Membrane ◽  
Middle Ear ◽  
Membrane Surface ◽  
Tube Placement ◽  
External Ear ◽  
Ventilation Tube ◽  
Ear Canal ◽  
Tube Insertion ◽  
Tissue Mass ◽  
External Ear Canal

Introduction. Etiopathogenetically, there are two types of chollesteatomas: congenital, and acquired. Numerous theories in the literature try to explain the nature of the disease, however, the question about cholesteatomas remain still unanswered. The aim of the study was to present a case of external ear canal cholesteatoma (EEC) developed following microsurgery (ventilation tube insertion and mastoidectomy), as well as to point ant possible mechanisms if its development. Case report. A 16-yearold boy presented a 4-month sense of fullness in the ear and otalgia on the left side. A year before, mastoidectomy and posterior atticotomy were performed with ventilation tube placement due to acute purulent mastoiditis. Diagnosis was based on otoscopy examination, audiology and computed tomography (CT) findings. CT showed an obliterative soft-tissue mass completely filled the external ear canal with associated erosion of subjacent the bone. There were squamous epithelial links between the canal cholesteatoma and lateral tympanic membrane surface. They originated from the margins of tympanic membrane incision made for a ventilation tube (VT) insertion. The position of VT was good as well as the aeration of the middle ear cavity. The tympanic membrane was intact and of normal appearance without middle ear extension or mastoid involvement of cholesteatoma. Cholesteatoma and ventilation tube were both removed. The patient recovered without complications and shortly audiology revealed hearing improving. Follow-up 2 years later, however, showed no signs of the disease. Conclusion. There could be more than one potential delicate mechanism of developing EEC in the ear with VT insertion and mastoidectomy. It is necessary to perform routine otologic surveillance in all patients with tubes. Affected ear CT scan is very helpful in showing the extent of cholesteatoma and bony defects, which could not be assessed by otoscopic examination alone.

Using Average Correction Factors to Improve the Estimated Sound Pressure Level Near the Tympanic Membrane

2012 ◽  
Vol 23 (09) ◽  
pp. 733-750
Author(s):  
Karrie LaRae Recker ◽  
Tao Zhang ◽  
Weili Lin
Keyword(s):  
Tympanic Membrane ◽  
Sound Pressure Level ◽  
Hearing Aids ◽  
Best Practice ◽  
Sound Pressure ◽  
Pressure Level ◽  
Correction Factors ◽  
Ear Canal ◽  
Frequency Components ◽  
Ear Canals

Background: Sound pressure-based real ear measurements are considered best practice for ensuring audibility among individuals fitting hearing aids. The accuracy of current methods is generally considered clinically acceptable for frequencies up to about 4 kHz. Recent interest in the potential benefits of higher frequencies has brought about a need for an improved, and clinically feasible, method of ensuring audibility for higher frequencies. Purpose: To determine whether (and the extent to which) average correction factors could be used to improve the estimated high-frequency sound pressure level (SPL) near the tympanic membrane (TM). Research Design: For each participant, real ear measurements were made along the ear canal, at 2–16 mm from the TM, in 2-mm increments. Custom in-ear monitors were used to present a stimulus with frequency components up to 16 kHz. Study Sample: Twenty adults with normal middle-ear function participated in this study. Intervention: Two methods of creating and implementing correction factors were tested. Data Collection and Analysis: For Method 1, correction factors were generated by normalizing all of the measured responses along the ear canal to the 2-mm response. From each normalized response, the frequency of the pressure minimum was determined. This frequency was used to estimate the distance to the TM, based on the ¼ wavelength of that frequency. All of the normalized responses with similar estimated distances to the TM were grouped and averaged. The inverse of these responses served as correction factors. To apply the correction factors, the only required information was the frequency of the pressure minimum. Method 2 attempted to, at least partially, account for individual differences in TM impedance, by taking into consideration the frequency and the width of the pressure minimum. Because of the strong correlation between a pressure minimum's width and depth, this method effectively resulted in a group of average normalized responses with different pressure-minimum depths. The inverse of these responses served as correction factors. To apply the correction factors, it was necessary to know both the frequency and the width of the pressure minimum. For both methods, the correction factors were generated using measurements from one group of ten individuals and verified using measurements from a second group of ten individuals. Results: Applying the correction factors resulted in significant improvements in the estimated SPL near the TM for both methods. Method 2 had the best accuracy. For frequencies up to 10 kHz, 95% of measurements had <8 dB of error, which is comparable to the accuracy of real ear measurement methods that are currently used clinically below 4 kHz. Conclusions: Average correction factors can be successfully applied to measurements made along the ear canals of otologically healthy adults, to improve the accuracy of the estimated SPL near the TM in the high frequencies. Further testing is necessary to determine whether these correction factors are appropriate for pediatrics or individuals with conductive hearing losses.

scholarly journals Experimental and Modeling Study of Human Tympanic Membrane Motion in the Presence of Middle Ear Liquid

2014 ◽  
Vol 15 (6) ◽  
pp. 867-881 ◽  
Author(s):  
Xiangming Zhang ◽  
Xiying Guan ◽  
Don Nakmali ◽  
Vikrant Palan ◽  
Mario Pineda ◽  
...  
Keyword(s):  
Tympanic Membrane ◽  
Middle Ear ◽  
Human Tympanic Membrane ◽  
Modeling Study

scholarly journals Significance of a notch in the otoacoustic emission stimulus spectrum

2012 ◽  
Vol 126 (9) ◽  
pp. 897-901
Author(s):  
J Grenner
Keyword(s):  
Tympanic Membrane ◽  
Otitis Media ◽  
Clinical Observation ◽  
Otoacoustic Emission ◽  
Emission Measurement ◽  
Frequency Range ◽  
Ear Canal ◽  
Secretory Otitis Media ◽  
Middle Ear Pressure ◽  
Transient Evoked Otoacoustic Emission

AbstractObjective:To explain a clinical observation: a notch in the stimulus spectrum during transient evoked otoacoustic emission measurement in ears with secretory otitis media.Methods:The effects of tympanic under-pressure were investigated using a pressure chamber. A model of the ear canal was also studied.Results:Tympanic membrane reflectance increased as a consequence of increased stiffness, causing a notch in the stimulus spectrum. In an adult, the notch could be clearly distinguished at an under-pressure of approximately −185 daPa. The sound frequency of the notch corresponded to a wavelength four times the ear canal length. The ear canal of infants was too short to cause a notch within the displayed frequency range. The notch was demonstrated using both Otodynamics and Madsen equipment.Conclusion:A notch in the otoacoustic emission stimulus spectrum can be caused by increased stiffness of the tympanic membrane, raising suspicion of low middle-ear pressure or secretory otitis media. This finding is not applicable to infants.

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