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Maryam Naghibolhosseini - One of the best experts on this subject based on the ideXlab platform.
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estimation of round trip outer Middle Ear gain using dpoaes
Jaro-journal of The Association for Research in Otolaryngology, 2017Co-Authors: Maryam Naghibolhosseini, Glenis R LongAbstract:The reported resEarch introduces a noninvasive approach to estimate round-trip outer-Middle Ear pressure gain using distortion product otoacoustic emissions (DPOAEs). Our ability to hEar depends primarily on sound waves traveling through the outer and Middle Ear toward the inner Ear. The role of the outer and Middle Ear in sound transmission is particularly important for otoacoustic emissions (OAEs), which are sound signals generated in a healthy cochlea and recorded by a sensitive microphone placed in the Ear canal. OAEs are used to evaluate the health and function of the cochlea; however, they are also affected by outer and Middle Ear characteristics. To better assess cochlEar health using OAEs, it is critical to quantify the effect of the outer and Middle Ear on sound transmission. DPOAEs were obtained in two conditions: (i) two-tone and (ii) three-tone. In the two-tone condition, DPOAEs were generated by presenting two primary tones in the Ear canal. In the three-tone condition, DPOAEs at the same frequencies (as in the two-tone condition) were generated by the interaction of the lower frequency primary tone in the two-tone condition with a distortion product generated by the interaction of two other external tones. Considering how the primary tones and DPOAEs of the aforementioned conditions were affected by the forward and reverse outer-Middle Ear transmission, an estimate of the round-trip outer-Middle Ear pressure gain was obtained. The round-trip outer-Middle Ear gain estimates ranged from −39 to −17 dB between 1 and 3.3 kHz.
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estimation of outer Middle Ear transmission using dpoaes and fractional order modeling of human Middle Ear
PhDT, 2015Co-Authors: Maryam NaghibolhosseiniAbstract:ESTIMATION OF OUTER-Middle Ear TRANSMISSION USING DPOAES AND FRACTIONAL-ORDER MODELING OF HUMAN Middle Ear by Maryam Naghibolhosseini Advisor: Glenis R. Long Our ability to hEar depends primarily on sound waves traveling through the outer and Middle Ear toward the inner Ear. Hence, the characteristics of the outer and Middle Ear affect sound transmission to/from the inner Ear. The role of the Middle and outer Ear in sound transmission is particularly important for otoacoustic emissions (OAEs), which are sound signals generated in a healthy cochlea, and recorded by a sensitive microphone placed in the Ear canal. OAEs are used to evaluate the health and function of the cochlea; however, they are also affected by outer and Middle Ear characteristics. To better assess cochlEar health using OAEs, it is critical to quantify the impact of the outer and Middle Ear on sound transmission. The reported resEarch introduces a noninvasive approach to estimate outer-Middle Ear transmission using distortion product otoacoustic emissions (DPOAEs). In addition, the role of the outer and Middle Ear on sound transmission was investigated by developing a physical/mathematical model, which employed fractional-order lumped elements to include the viscoelastic characteristics of biological tissues. Impedance estimations from wideband reflectance measurements were used for parameter fitting of the model. The model was validated comparing its estimates of the outer-Middle Ear sound transmission with those given by DPOAEs. The
Xuelin Wang - One of the best experts on this subject based on the ideXlab platform.
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3d finite element model of the chinchilla Ear for characterizing Middle Ear functions
Biomechanics and Modeling in Mechanobiology, 2016Co-Authors: Xuelin WangAbstract:Chinchilla is a commonly used animal model for resEarch of sound transmission through the Ear. Experimental measurements of the Middle Ear transfer function in chinchillas have shown that the Middle Ear cavity greatly affects the tympanic membrane (TM) and stapes footplate (FP) displacements. However, there is no finite element (FE) model of the chinchilla Ear available in the literature to characterize the Middle Ear functions with the anatomical features of the chinchilla Ear. This paper reports a recently completed 3D FE model of the chinchilla Ear based on X-ray micro-computed tomography images of a chinchilla bulla. The model consisted of the Ear canal, TM, Middle Ear ossicles and suspensory ligaments, and the Middle Ear cavity. Two boundary conditions of the Middle Ear cavity wall were simulated in the model as the rigid structure and the partially flexible surface, and the acoustic-mechanical coupled analysis was conducted with these two conditions to characterize the Middle Ear function. The model results were compared with experimental measurements reported in the literature including the TM and FP displacements and the Middle Ear input admittance in chinchilla Ear. An application of this model was presented to identify the acoustic role of the Middle Ear septa—a unique feature of chinchilla Middle Ear cavity. This study provides the first 3D FE model of the chinchilla Ear for characterizing the Middle Ear functions through the acoustic-mechanical coupled FE analysis.
John J Rosowski - One of the best experts on this subject based on the ideXlab platform.
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a lumped element model of the chinchilla Middle Ear
Journal of the Acoustical Society of America, 2019Co-Authors: Peter Bowers, John J RosowskiAbstract:An air-conduction circuit model was developed for the chinchilla Middle Ear and cochlea. The lumped-element model is based on the classic Zwislocki model of the same structures in human. Model parameters were fit to various measurements of chinchilla Middle-Ear transfer functions and impedances, using a combination of error-minimization-driven computer-automated and manual fitting methods. The measurements used to fit the model comprise a newer, more-extensive data set than previously used, and include measurements of stapes velocity and inner-Ear sound pressure within the vestibule and the scala tympani nEar the round window. The model is in agreement with studies of the effects of Middle-Ear cavity holes in experiments that require access to the Middle-Ear air space. The structure of the model allows easy addition of other sources of auditory stimulation, e.g., the multiple sources of bone-conducted sound—the long-term goal for the model's development—and mechanical stimulation of the ossicles and round window.An air-conduction circuit model was developed for the chinchilla Middle Ear and cochlea. The lumped-element model is based on the classic Zwislocki model of the same structures in human. Model parameters were fit to various measurements of chinchilla Middle-Ear transfer functions and impedances, using a combination of error-minimization-driven computer-automated and manual fitting methods. The measurements used to fit the model comprise a newer, more-extensive data set than previously used, and include measurements of stapes velocity and inner-Ear sound pressure within the vestibule and the scala tympani nEar the round window. The model is in agreement with studies of the effects of Middle-Ear cavity holes in experiments that require access to the Middle-Ear air space. The structure of the model allows easy addition of other sources of auditory stimulation, e.g., the multiple sources of bone-conducted sound—the long-term goal for the model's development—and mechanical stimulation of the ossicles and round...
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transmission matrix analysis of the chinchilla Middle Ear
Journal of the Acoustical Society of America, 2007Co-Authors: Jocelyn E Songer, John J RosowskiAbstract:Despite the common use of the chinchilla as an animal model in auditory resEarch, a complete characterization of the chinchilla Middle Ear using transmission matrix analysis has not been performed. In this paper we describe measurements of Middle-Ear input admittance and stapes velocity in Ears with the Middle-Ear cavity opened under three conditions: intact tympano-ossicular system and cochlea, after the cochlea has been drained, and after the stapes has been fixed. These measurements, made with stimulus frequencies of 100–8000Hz, are used to define the transmission matrix parameters of the Middle Ear and to calculate the cochlEar input impedance as well as the Middle-Ear output impedance. This transmission characterization of the chinchilla Middle Ear will be useful for modeling auditory sensitivity in the normal and pathological chinchilla Ear.
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Structures that contribute to Middle-Ear admittance in chinchilla
Journal of Comparative Physiology A, 2006Co-Authors: John J Rosowski, Michael E. Ravicz, Jocelyn E SongerAbstract:We describe measurements of Middle-Ear input admittance in chinchillas ( Chinchilla lanigera ) before and after various manipulations that define the contributions of different Middle-Ear components to function. The chinchilla’s Middle-Ear air spaces have a large effect on the low-frequency compliance of the Middle Ear, and removing the influences of these spaces reveals a highly admittant tympanic membrane and ossicular chain. Measurements of the admittance of the air spaces reveal that the high-degree of segmentation of these spaces has only a small effect on the admittance. Draining the cochlea further increases the Middle-Ear admittance at low frequencies and removes a low-frequency (less than 300 Hz) level dependence in the admittance. Spontaneous or sound-driven contractions of the Middle-Ear muscles in deeply anesthetized animals were associated with significant changes in Middle-Ear admittance.
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mechanisms of hEaring loss resulting from Middle Ear fluid
Hearing Research, 2004Co-Authors: Michael E. Ravicz, John J Rosowski, Saumil N MerchantAbstract:Fluid in the Middle Ear, a defining feature of otitis media with effusion (OME), is commonly associated with a 20- to 30-dB conductive hEaring loss. The effects and relative importance of various mechanisms leading to conductive hEaring loss were investigated in a human temporal bone preparation. Umbo velocity in response to Ear-canal sound was measured with a laser vibrometer while saline and silicone fluids of viscosity 5-12,000 cSt were introduced into the Middle Ear to contact part or all of the tympanic membrane (TM) and fill part or all of the Middle Ear. At low frequencies, reductions in umbo velocity (deltaVU) of up to 25 dB depended on the percentage of the original Middle-Ear air space that remained air-filled, which suggests that the primary mechanism in hEaring loss at low frequencies is a reduction of the admittance of the Middle-Ear air space due to displacement of air with fluid. At higher frequencies, deltaVU (of up to 35 dB) depended on the percentage of the TM contacted by fluid, which suggests that the primary mechanism at high frequencies is an increase in tympanic membrane mass by entrained fluid. The viscosity of the fluid had no significant effect on umbo velocity. deltaVU for the fluid-filled Middle Ear matched hEaring losses reported in patients whose Middle Ear was believed to be completely filled with fluid. The difference between deltaVU for a partly-filled Middle Ear and hEaring losses reported in patients whose Middle Ear was believed to be incompletely fluid-filled is consistent with the reported effect of Middle-Ear underpressure (commonly seen in OME) on umbo velocity. Small amounts of air in the Middle Ear are sufficient to facilitate umbo motion at low frequencies.
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acoustic responses of the human Middle Ear
Hearing Research, 2000Co-Authors: Susan E Voss, John J Rosowski, Saumil N Merchant, William T PeakeAbstract:Measurements on human cadaver Ears are reported that describe sound transmission through the Middle Ear. Four response variables were measured with acoustic stimulation at the tympanic membrane: stapes velocity, Middle-Ear cavity sound pressure, acoustic impedance at the tympanic membrane and acoustic impedance of the Middle-Ear cavity. Measurements of stapes velocity at different locations on the stapes suggest that stapes motion is predominantly 'piston-like', for frequencies up to at least 2000 Hz. The measurements are generally consistent with constraints of existing models. The measurements are used (1) to show how the cavity pressure and the impedance at the tympanic membrane are related, (2) to develop a measurement-based Middle-Ear cavity model, which shows that the Middle-Ear cavity has only small effects on the motion of the tympanic membrane and stapes in the normal Ear, although it may play a more prominent role in pathological Ears, and (3) to show that inter-Ear variations in the impedance at the tympanic membrane and the stapes velocity are not well correlated.
Teruo Okano - One of the best experts on this subject based on the ideXlab platform.
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Middle Ear mucosal regeneration by tissue engineered cell sheet transplantation
npj Regenerative Medicine, 2017Co-Authors: Kazuhisa Yamamoto, Yuichiro Yaguchi, Masayuki Yamato, Ryo Takagi, Teruo Okano, Hiroaki Sugiyama, Tsunetaro Morino, Hiromi KojimaAbstract:The recurrence of cholesteatoma after surgical treatment often occurs as a result of poor mucosal regeneration in the Middle Ear cavity and mastoid cavity and changes, such as granulation tissue formation, which impair gas exchange in the Middle Ear cavity. Conventional tympanoplasty often results in a lack of mucosal regeneration in the resected area of the mastoid cavity. In particular, mucosal regeneration in a poorly pneumatized mastoid cavity is extremely difficult. If the Middle Ear mucosa can be preserved or rapid postoperative regeneration of mucosa on the exposed bone surface can be achieved after Middle Ear surgery, the results of surgical treatment for otitis media, including cholesteatoma, can potentially be improved and the physiological function of the Middle Ear can be recovered. To overcome these limitations, we developed a novel treatment method combining tympanoplasty and autologous nasal mucosal epithelial cell sheet transplantation for postoperative regeneration of the Middle Ear mucosa. In clinical resEarch, we endoscopically removed an approximately 10 × 10 mm2 piece of nasal mucosal tissue. Tissue-engineered autologous nasal mucosal epithelial cell sheets were fabricated by culturing the harvested cells in an aseptic environment in a good manufacturing practice-compliant cell processing facility. The cultivated cell sheets were transplanted, during tympanoplasty, onto the exposed bony surface of the attic of the tympanic and mastoid cavities where the mucosa had been lost. We performed this procedure on four patients with Middle Ear cholesteatoma and one patient with adhesive otitis media. All patients showed favorable postoperative course with no adverse events or complications and the patients’ hEaring ability post-transplantation remained good. Transplanting a sheet of cells from the nose to the Middle Ear could improve postoperative prognosis for Middle Ear inflammatory conditions. Kazuhisa Yamamoto of Jikei University School of Medicine and colleagues in Japan developed a novel surgical technique to prevent postoperative recurrence of chronic Middle Ear conditions. In adhesive otitis media, the Eardrum gets sucked into and stuck in the Middle Ear space. Cholesteatoma involves abnormal skin growth in the Middle Ear. Recurrence often follows surgical treatment for these conditions due to delays in regeneration of the Middle Ear’s mucosal epithelium. The new technique involves transplanting cultured cells from the lining of the nasal cavity to the Middle Ear during surgery. Five patients treated this way had favorable postoperative outcomes with no adverse effects or complications and satisfactory improvement in hEaring levels.
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Middle Ear mucosal regeneration with three dimensionally tissue engineered autologous Middle Ear cell sheets in rabbit model
Journal of Tissue Engineering and Regenerative Medicine, 2016Co-Authors: Yuichiro Yaguchi, Hiromi Kojima, Hiroshi Moriyama, Masayuki Yamato, Kazuhisa Yamamoto, Daisuke Murakami, Takanori Hama, Teruo OkanoAbstract:The likelihood of recurrent retraction and adhesion of newly formed tympanic membrane is high when Middle Ear mucosa is extensively lost during cholesteatoma and adhesive otitis media surgery. If rapid postoperative regeneration of the mucosa on the exposed bone surface can be achieved, prevention of recurrent Eardrum adhesion and cholesteatoma formation, for which there has been no definitive treatment, can be expected. Suture-less transplantation of tissue-engineered mucosal cell sheets was examined immediately after the operation of otitis media surgery in order to quickly regenerate Middle Ear mucosa lost during surgery in a rabbit model. Transplantable Middle Ear mucosal cell sheets with a three-dimensional tissue architecture very similar to native Middle Ear mucosa were fabricated from Middle Ear mucosal tissue fragments obtained in an autologous manner from Middle Ear bulla on temperature-responsive culture surfaces. Immediately after the mucosa was resected from Middle Ear bone bulla inner cavity, mucosal cell sheets were grafted at the resected site. Both bone hyperplasia and granulation tissue formation were inhibited and Early mucosal regeneration was observed in the cell sheet-grafted group, compared with the control group in which only mucosal removal was carried out and the bone surface exposed. This result indicates that tissue engineered mucosal cell sheets would be useful to minimize complications after the surgical operation on otitis media and future clinical application is expected. Copyright © 2013 John Wiley & Sons, Ltd.
Saumil N Merchant - One of the best experts on this subject based on the ideXlab platform.
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mechanisms of hEaring loss resulting from Middle Ear fluid
Hearing Research, 2004Co-Authors: Michael E. Ravicz, John J Rosowski, Saumil N MerchantAbstract:Fluid in the Middle Ear, a defining feature of otitis media with effusion (OME), is commonly associated with a 20- to 30-dB conductive hEaring loss. The effects and relative importance of various mechanisms leading to conductive hEaring loss were investigated in a human temporal bone preparation. Umbo velocity in response to Ear-canal sound was measured with a laser vibrometer while saline and silicone fluids of viscosity 5-12,000 cSt were introduced into the Middle Ear to contact part or all of the tympanic membrane (TM) and fill part or all of the Middle Ear. At low frequencies, reductions in umbo velocity (deltaVU) of up to 25 dB depended on the percentage of the original Middle-Ear air space that remained air-filled, which suggests that the primary mechanism in hEaring loss at low frequencies is a reduction of the admittance of the Middle-Ear air space due to displacement of air with fluid. At higher frequencies, deltaVU (of up to 35 dB) depended on the percentage of the TM contacted by fluid, which suggests that the primary mechanism at high frequencies is an increase in tympanic membrane mass by entrained fluid. The viscosity of the fluid had no significant effect on umbo velocity. deltaVU for the fluid-filled Middle Ear matched hEaring losses reported in patients whose Middle Ear was believed to be completely filled with fluid. The difference between deltaVU for a partly-filled Middle Ear and hEaring losses reported in patients whose Middle Ear was believed to be incompletely fluid-filled is consistent with the reported effect of Middle-Ear underpressure (commonly seen in OME) on umbo velocity. Small amounts of air in the Middle Ear are sufficient to facilitate umbo motion at low frequencies.
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acoustic responses of the human Middle Ear
Hearing Research, 2000Co-Authors: Susan E Voss, John J Rosowski, Saumil N Merchant, William T PeakeAbstract:Measurements on human cadaver Ears are reported that describe sound transmission through the Middle Ear. Four response variables were measured with acoustic stimulation at the tympanic membrane: stapes velocity, Middle-Ear cavity sound pressure, acoustic impedance at the tympanic membrane and acoustic impedance of the Middle-Ear cavity. Measurements of stapes velocity at different locations on the stapes suggest that stapes motion is predominantly 'piston-like', for frequencies up to at least 2000 Hz. The measurements are generally consistent with constraints of existing models. The measurements are used (1) to show how the cavity pressure and the impedance at the tympanic membrane are related, (2) to develop a measurement-based Middle-Ear cavity model, which shows that the Middle-Ear cavity has only small effects on the motion of the tympanic membrane and stapes in the normal Ear, although it may play a more prominent role in pathological Ears, and (3) to show that inter-Ear variations in the impedance at the tympanic membrane and the stapes velocity are not well correlated.
