Temat: cochlea - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Numerical investigation of the basilar membrane vibration induced by the unsteady fluid flow in the human inner ear
Autorzy:: Wahl, Philipp
Ziegler, Pascal
Eberhard, Peter
Powiązania:: https://bibliotekanauki.pl/articles/1845019.pdf
Data publikacji:: 2020
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: human cochlea
basilar membrane
unsteady viscous fluid flow
fluid-structure interaction
pressure-displacement-based fluid element
viscous boundary layer
tonotopy
auditory threshold
ludzki ślimak
membrana podstawna
niestabilny przepływ cieczy lepkiej
interakcja płyn-struktura
element hydrauliczny oparty na ciśnieniu wyporowym
lepka warstwa graniczna
tonotopia
próg słyszalności
Opis:: For a deeper understanding of the inner ear dynamics, a Finite-Element model of the human cochlea is developed. To describe the unsteady, viscous creeping flow of the liquid, a pressure-displacement-based Finite-Element formulation is used. This allows one to efficiently compute the basilar membrane vibrations resulting from the fluid-structure interaction leading to hearing nerve stimulation. The results show the formation of a traveling wave on the basilar membrane propagating with decreasing velocity towards the peaking at a frequency dependent position. This tonotopic behavior allows the brain to distinguish between sounds of different frequencies. Additionally, not only the middle ear, but also the transfer behavior of the cochlea contributes to the frequency dependence of the auditory threshold. Furthermore, the fluid velocity and pressure fields show the effect of viscous damping forces and allow us to deeper understand the formation of the pressure difference, responsible to excite the basilar membrane.
Źródło:: Archive of Mechanical Engineering; 2020, LXVII, 4; 381-414
0004-0738
Pojawia się w:: Archive of Mechanical Engineering
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Bone conduction stimulation of the otic capsule: a finite element model of the temporal bone
Autorzy:: Borkowski, Paweł
Marek, Piotr
Niemczyk, Kazimierz
Lachowska, Magdalena
Kwacz, Monika
Wysocki, Jarosław
Powiązania:: https://bibliotekanauki.pl/articles/306896.pdf
Data publikacji:: 2019
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:: FEM
kośc skroniowa
ucho wewnętrzne
bone conduction
finite element analysis
temporal bone
otic capsule
cochlea
inner ear
Opis:: Bone conduction stimulation applied on the otic capsule may be used in a conductive hearing loss treatment as an alternative to the bone conduction implants in clinical practice. A finite element study was used to evaluate the force amplitude and direction needed for the stimulation. Methods: A finite element model of a female temporal bone with a precisely reconstructed cochlea was subjected to a harmonic analysis assuming two types of stimulation. At first, the displacement amplitude in the form of air conduction stimulation was applied on the stapes footplate. Then the force amplitude was applied on the otic capsule in the form of bone conduction stimulation. The two force directions were considered: 1) the primary direction, when a typical opening is performed during mastoidectomy, and was coincident with the axis of an imaginary cone, inscribed in the opening, and 2) the direction perpendicular to the stapes footplate. The force amplitude was set so that the response from the cochlea corresponded to the result of air conduction stimulation applied on the stapes footplate. Results: The amplitude and phase of vibration and the volume displacement on the round window membrane were considered as well as vibrations of the basilar membrane, spiral lamina, and promontory. Conclusions: The cochlear response was comparable for the two types of stimulation. The efficiency of bone conduction stimulation depended on the force direction. For the primary direction, the force was a few times smaller than for the direction perpendicular to the stapes footplate.
Źródło:: Acta of Bioengineering and Biomechanics; 2019, 21, 3; 75-86
1509-409X
2450-6303
Pojawia się w:: Acta of Bioengineering and Biomechanics
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Air-conducted cervical and ocular vestibular evoked miogenic potentials in patients with Susac’s syndrome
Autorzy:: Lachowska, Magdalena
Zakrzewska-Pniewska, Beata
Nojszewska, Monika
Niemczyk, Kazimierz
Powiązania:: https://bibliotekanauki.pl/articles/1399904.pdf
Data publikacji:: 2018
Wydawca:: Index Copernicus International
Tematy:: Susac’s syndrome
branch retinal artery occlusion
cochlea
hearing loss
microangiopathy
vestibular nerve
vertigo
Opis:: Aim: To evaluate acoustically evoked cervical and ocular vestibular miogenic potentials (AC cVEMP and oVEMP) in patients with Susac’s syndrome. We did not seek for a diagnostic replacement test in those patients, but we investigated if the combined application of AC cVEMP and oVEMPs might be helpful as an additional source of information about the disease. Material and methods: To record VEMPs, the EMG standardization method was used to continuously monitor and minimize the variability of the recordings. The stimuli were presented unilaterally one ear at a time. The waveforms were analyzed for the response, latency and amplitude. Susac’s syndrome is a rare disease and two patients were analyzed in this study. Results: In patient #1 stimulation resulted in responses on both sides with latencies within normal and symmetry limits for both c- and oVEMPs; however, the responses presented small amplitudes for cVEMPs. In patient #2, only cVEMPs were present. The P1 latencies were within normal values but amplitudes were low, in addition showing asymmetry between sides, with right side amplitude being smaller. Conclusion: The information provided by the combined application of AC cVEMP and oVEMP might be useful in the diagnostics of Susac’s syndrome revealing additional information about the affected vestibular system and be of help in the treatment and rehabilitation planning.
Źródło:: Polski Przegląd Otorynolaryngologiczny; 2018, 7, 2; 8-15
2084-5308
2300-7338
Pojawia się w:: Polski Przegląd Otorynolaryngologiczny
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: The origins of the cochlea and impedance matching hearing in synapsids
Autorzy:: Laaß, M.
Powiązania:: https://bibliotekanauki.pl/articles/20432.pdf
Data publikacji:: 2016
Wydawca:: Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:: origin
cochlea
Therapsida
Anomodontia
tympanic hearing
Permian
South Africa
synapsid
tetrapod
Opis:: The origin of tympanic hearing in early synapsids is still controversial, because little is known about their inner ear and the function of their sound conducting apparatus. Here I describe the earliest known tympanic ear in the synapsid lineage, the ear of Pristerodon (Therapsida, Anomodontia) from the Late Permian of South Africa, which was virtually reconstructed from neutron tomographic data. Although Pristerodon is not a direct ancestor of mammals, its inner ear with distinctive cochlear cavity represents a connecting link between the primitive therapsid inner ear and the mammalian inner ear. The anatomy of the sound conducting apparatus of Pristerodon and the increased sound pressure transformer ratio points to a sensitivity to airborne sound. Furthermore, the origins of the cochlea and impedance matching hearing in synapsids coincided with the loss of contact between head and substrate, which already took place at least in Late Permian therapsids even before the postdentary bones became detached from the mandible.
Źródło:: Acta Palaeontologica Polonica; 2016, 61, 2
0567-7920
Pojawia się w:: Acta Palaeontologica Polonica
Dostawca treści:: Biblioteka Nauki

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