scholarly journals High-Speed Holographic Shape and Full-Field Displacement Measurements of the Tympanic Membrane in Normal and Experimentally Simulated Pathological Ears

2019 ◽  
Vol 9 (14) ◽  
pp. 2809 ◽  
Author(s):  
Haimi Tang ◽  
Payam Razavi ◽  
Koohyar Pooladvand ◽  
Pavel Psota ◽  
Nima Maftoon ◽  
...  
Keyword(s):  
Tympanic Membrane ◽  
Middle Ear ◽  
High Speed ◽  
Sound Pressure ◽  
Motion Pattern ◽  
Motion Patterns ◽  
Full Field ◽  
Field Displacement ◽  
Frequency Domains ◽  
Before And After

To improve the understanding of the middle-ear hearing mechanism and assist in the diagnosis of middle-ear diseases, we are developing a high-speed digital holographic (HDH) system to measure the shape and acoustically-induced transient displacements of the tympanic membrane (TM). In this paper, we performed measurements on cadaveric human ears with simulated common middle-ear pathologies. The frequency response function (FRF) of the normalized displacement by the stimulus (sound pressure) at each measured pixel point of the entire TM surface was calculated and the complex modal indicator function (CMIF) of the middle-ear system based on FRFs of the entire TM surface motions was used to differentiate different middle-ear pathologies. We also observed changes in the TM shape and the surface motion pattern before and after various middle-ear manipulations. The observations of distinguishable TM shapes and motion patterns in both time and frequency domains between normal and experimentally simulated pathological ears support the development of a quantitative clinical holography-based apparatus for diagnosing middle-ear pathologies.

scholarly journals Combined high-speed holographic shape and full-field displacement measurements of tympanic membrane

2018 ◽  
Vol 24 (03) ◽  
pp. 1 ◽  
Author(s):  
Payam Razavi ◽  
Haimi Tang ◽  
John J. Rosowski ◽  
Cosme Furlong ◽  
Jeffrey T. Cheng
Keyword(s):  
Tympanic Membrane ◽  
High Speed ◽  
Full Field ◽  
Field Displacement ◽  
Displacement Measurements

scholarly journals Flaw Detection and Characterization Using Shearography

1997 ◽  
Author(s):  
Siew-Lok Toh ◽  
Fook-Siong Chau
Keyword(s):  
High Speed ◽  
Flaw Detection ◽  
Electronic Version ◽  
Interferometric Method ◽  
Full Field ◽  
Computer Image Processing ◽  
Before And After ◽  
Fringe Patterns ◽  
Laser Interferometric ◽  
High Pass

Shearography is a laser interferometric method developed originally for full field observation of surface strains of components. Since flaws usually induce strain concentrations around them, shearography can be employed to detect the flaws. Conventional shearography involves exposing high resolution films before and after the components are loaded. The exposed films are developed and then viewed via a high-pass filtering optical setup. Though the images obtained are good, this method is time-consuming. With the advent of high-speed computers, associated sophisticated imaging hardware and software, the Digital Speckle Shearing Interferometry (DSSI) method which employs a CCD (charged-coupled device) camera and computer image processing to produce the interferometric fringe patterns has been developed. In contrast with the conventional shearography, the electronic version does not require any film and is faster. The techniques are used to detect and characterise (a) flaws simulating delaminations in composites and (b) thinning in pipes.

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.

On the hearing effects of a cholesteatoma growing: A biomechanical study

2021 ◽  
pp. 095441192110466
Author(s):  
Leonor Mendonça ◽  
Carla F Santos ◽  
Fernanda Gentil ◽  
Marco Parente ◽  
Bruno Areias ◽  
...  
Keyword(s):  
Tympanic Membrane ◽  
Middle Ear ◽  
Sound Pressure ◽  
Chronic Otitis Media ◽  
Biomechanical Study ◽  
The Finite Element Method ◽  
High Frequencies ◽  
Initial Stage ◽  
Hearing Function ◽  
Stapes Footplate

Chronic otitis media enables the appearance of a benign middle ear tumor, known as a cholesteatoma, that may compromise hearing. To evaluate the influence of a cholesteatoma growth on the hearing function, a computational middle ear model based on the finite element method was used and three different size of cholesteatoma were modeled. The cholesteatoma solidification and the consequent degradation of the ossicles were also simulated as two condition that commonly occurs during cholesteatoma evolution. A sound pressure level of 80 dB SPL was applied in the tympanic membrane and a steady state analysis was performed for frequencies from 100 Hz to 10 kHz. The displacements of both the tympanic membrane and the stapes footplate were measured. The results were compared with a healthy case and it was shown that the cholesteatoma development leads to a decrease in the umbo and stapes displacements. The ossicles degradation simulation showed the higher difference comparing with the cholesteatoma in an initial stage, with lower displacements in the stapes footplate mainly for high frequencies. The observed displacement differences are directly connected to hearing loss, being possible to conclude that cholesteatoma evolution in the middle ear will lead to hearing problems, mainly in an advanced stage.

High-speed holographic system for full-field transient vibrometry of the human tympanic membrane

2014 ◽  
Author(s):  
I. Dobrev ◽  
E. J. Harrington ◽  
T. Cheng ◽  
C. Furlong ◽  
J. J. Rosowski
Keyword(s):  
Tympanic Membrane ◽  
High Speed ◽  
Full Field ◽  
Human Tympanic Membrane

scholarly journals Numerical Model on Sound-Solid Coupling in Human Ear and Study on Sound Pressure of Tympanic Membrane

2011 ◽  
Vol 2011 ◽  
pp. 1-13
Author(s):  
Yao Wen-juan ◽  
Ma Jian-wei ◽  
Hu Bao-lin
Keyword(s):  
Tympanic Membrane ◽  
Middle Ear ◽  
External Auditory Canal ◽  
Sound Pressure ◽  
Least Squares Method ◽  
Three Dimensional ◽  
Element Model ◽  
Response Analysis ◽  
Fe Model ◽  
Pressure Function

Establishment of three-dimensional finite-element model of the whole auditory system includes external ear, middle ear, and inner ear. The sound-solid-liquid coupling frequency response analysis of the model was carried out. The correctness of the FE model was verified by comparing the vibration modes of tympanic membrane and stapes footplate with the experimental data. According to calculation results of the model, we make use of the least squares method to fit out the distribution of sound pressure of external auditory canal and obtain the sound pressure function on the tympanic membrane which varies with frequency. Using the sound pressure function, the pressure distribution on the tympanic membrane can be directly derived from the sound pressure at the external auditory canal opening. The sound pressure function can make the boundary conditions of the middle ear structure more accurate in the mechanical research and improve the previous boundary treatment which only applied uniform pressure acting to the tympanic membrane.

The Effect of Stapedectomy on the Loudness of One’s Own Voice

1965 ◽  
Vol 8 (3) ◽  
pp. 223-234 ◽  
Author(s):  
William Melnick
Keyword(s):  
Middle Ear ◽  
Normal Subjects ◽  
Sound Energy ◽  
Loudness Function ◽  
Before And After ◽  
Increased Sensitivity

Five subjects with normal middle ear mechanisms, and otosclerotic patients, before and after stapedectomy, matched the loudness of their voices to the loudness of a 125-cps-sawtooth noise. The results showed loudness matching functions with gradual slopes, less than 1.00, for the normal subjects and the patients prior to stapedectomy. Post-surgically, the loudness function for the patients increased in steepness to considerably more than 1.00. These results are explained, most logically, in terms of increased sensitivity of the altered middle ear to sound energy generated by the listener’s own voice.

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