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Letteratura scientifica selezionata sul tema "Cochlea"

Autore: Grafiati

Pubblicato: 4 giugno 2021

Ultima modifica: 30 luglio 2024

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Articoli di riviste sul tema "Cochlea"

Balkany, Thomas, Bruce J. Gantz, Ronald L. Steenerson e Noel L. Cohen. "Systematic Approach to Electrode Insertion in the Ossified Cochlea". Otolaryngology–Head and Neck Surgery 114, n. 1 (gennaio 1996): 4–11. http://dx.doi.org/10.1016/s0194-59989670275-9.

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Ossification of the fluid spaces of the cochlea occurs often in candidates for cochlear implantation, especially children. When noted before surgery on computerized tomography, ossification previously was thought to contraindicate cochlear implantation because of possible mechanical obstruction and uncertainty about the level of function that could be achieved by stimulating an ossified cochlea. However, during the preceding 6 years, techniques have been developed that permit implantation in ossified cochleas. We present a systematic approach that has been developed to treat the three clinically important categories of cochlear ossification: round window niche obliteration, inferior segment obstruction, and upper segment obstruction. Case reports are presented for each of these three drill-out procedures, demonstrating results often similar to those expected for implantation of the nonossified cochlea.

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Englisch, Colya N., Jakob Steinhäuser, Silke Wemmert, Martin Jung, Joshua Gawlitza, Gentiana Wenzel, Bernhard Schick e Thomas Tschernig. "Immunohistochemistry Reveals TRPC Channels in the Human Hearing Organ—A Novel CT-Guided Approach to the Cochlea". International Journal of Molecular Sciences 24, n. 11 (26 maggio 2023): 9290. http://dx.doi.org/10.3390/ijms24119290.

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TRPC channels are critical players in cochlear hair cells and sensory neurons, as demonstrated in animal experiments. However, evidence for TRPC expression in the human cochlea is still lacking. This reflects the logistic and practical difficulties in obtaining human cochleae. The purpose of this study was to detect TRPC6, TRPC5 and TRPC3 in the human cochlea. Temporal bone pairs were excised from ten body donors, and the inner ear was first assessed based on computed tomography scans. Decalcification was then performed using 20% EDTA solutions. Immunohistochemistry with knockout-tested antibodies followed. The organ of Corti, the stria vascularis, the spiral lamina, spiral ganglion neurons and cochlear nerves were specifically stained. This unique report of TRPC channels in the human cochlea supports the hypothesis of the potentially critical role of TRPC channels in human cochlear health and disease which has been suggested in previous rodent experiments.

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Yu, J.-F., K.-C. Lee, Y.-L. Wan e Y.-C. Peng. "Curvature measurement of human bilateral cochleae". Journal of Laryngology & Otology 129, n. 11 (21 settembre 2015): 1085–90. http://dx.doi.org/10.1017/s0022215115002480.

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AbstractObjective:This study aimed to characterise the geometry of the human bilateral spiral cochlea by measuring curvature and length.Method:Eight subjects were recruited in this study. Magnetic resonance imaging was used to visualise the right and left cochlea. Visualisation of the cochlear spiral was enhanced by T2 weighting and further processing of the raw images. The spirals were divided into three segments: the basal turn, the middle turn and the apex turn. The length and curvature of each segment were non-invasively measured.Results:The mean left and right cochlear lengths were 3.11 cm and 3.95 cm, respectively. The measured lengths of the cochlear spiral are consistent with data in the literature derived from anatomical dissections. Overall, the apex turn segment of the cochlea had the greatest degree of curvature (p < 0.05). The mean apex turn segment curvatures for left and right cochleae were 9.65 cm−1 and 10.09 cm−1, respectively.Conclusion:A detailed description of the cochlear spiral is provided, using measurements of curvature and length. These data will provide a valuable reference in the development of cochlear implantation procedures for minimising the potential damage during implantation.

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Dong, Wei, e Nigel P. Cooper. "An experimental study into the acousto-mechanical effects of invading the cochlea". Journal of The Royal Society Interface 3, n. 9 (2 marzo 2006): 561–71. http://dx.doi.org/10.1098/rsif.2006.0117.

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The active and nonlinear mechanical processing of sound that takes place in the mammalian cochlea is fundamental to our sense of hearing. We have investigated the effects of opening the cochlea in order to make experimental observations of this processing. Using an optically transparent window that permits laser interferometric access to the apical turn of the guinea-pig cochlea, we show that the acousto-mechanical transfer functions of the sealed (i.e. near intact) cochlea are considerably simpler than those of the unsealed cochlea. Comparison of our results with those of others suggests that most previous investigations of apical cochlear mechanics have been made under unsealed conditions, and are therefore likely to have misrepresented the filtering of low-frequency sounds in the cochlea. The mechanical filtering that is apparent in the apical turns of sealed cochleae also differs from the filtering seen in individual auditory nerve fibres with similar characteristic frequencies. As previous studies have shown the neural and mechanical tuning of the basal cochlea to be almost identical, we conclude that the strategies used to process low frequency sounds in the apical turns of the cochlea might differ fundamentally from those used to process high frequency sounds in the basal turns.

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Robles, Luis, e Mario A. Ruggero. "Mechanics of the Mammalian Cochlea". Physiological Reviews 81, n. 3 (1 luglio 2001): 1305–52. http://dx.doi.org/10.1152/physrev.2001.81.3.1305.

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Abstract (sommario):

In mammals, environmental sounds stimulate the auditory receptor, the cochlea, via vibrations of the stapes, the innermost of the middle ear ossicles. These vibrations produce displacement waves that travel on the elongated and spirally wound basilar membrane (BM). As they travel, waves grow in amplitude, reaching a maximum and then dying out. The location of maximum BM motion is a function of stimulus frequency, with high-frequency waves being localized to the “base” of the cochlea (near the stapes) and low-frequency waves approaching the “apex” of the cochlea. Thus each cochlear site has a characteristic frequency (CF), to which it responds maximally. BM vibrations produce motion of hair cell stereocilia, which gates stereociliar transduction channels leading to the generation of hair cell receptor potentials and the excitation of afferent auditory nerve fibers. At the base of the cochlea, BM motion exhibits a CF-specific and level-dependent compressive nonlinearity such that responses to low-level, near-CF stimuli are sensitive and sharply frequency-tuned and responses to intense stimuli are insensitive and poorly tuned. The high sensitivity and sharp-frequency tuning, as well as compression and other nonlinearities (two-tone suppression and intermodulation distortion), are highly labile, indicating the presence in normal cochleae of a positive feedback from the organ of Corti, the “cochlear amplifier.” This mechanism involves forces generated by the outer hair cells and controlled, directly or indirectly, by their transduction currents. At the apex of the cochlea, nonlinearities appear to be less prominent than at the base, perhaps implying that the cochlear amplifier plays a lesser role in determining apical mechanical responses to sound. Whether at the base or the apex, the properties of BM vibration adequately account for most frequency-specific properties of the responses to sound of auditory nerve fibers.

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Hosoya, Makoto, Masato Fujioka, Hideyuki Okano e Kaoru Ogawa. "Distinct Expression Pattern of a Deafness Gene,KIAA1199, in a Primate Cochlea". BioMed Research International 2016 (2016): 1–8. http://dx.doi.org/10.1155/2016/1781894.

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Deafness is one of the most common types of congenital impairments, and at least half of the cases are caused by hereditary mutations. Mutations of the geneKIAA1199are associated with progressive hearing loss. Its expression is abundant in human cochlea, but interestingly the spatial expression patterns are different between mouse and rat cochleae; the pattern in humans has not been fully investigated. We performed immunohistochemical analysis of a nonhuman primate, common marmoset (Callithrix jacchus), cochlea with a KIAA1199-specific antibody. In the common marmoset cochlea, KIAA1199 protein expression was more widespread than in rodents, with all epithelial cells, including hair cells, expressing KIAA1199. Our results suggest that the primate pattern of KIAA1199 expression is wider in comparison with rodents and may play an essential role in the maintenance of cochlear epithelial cells.

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Toulemonde, Philippine, Michaël Risoud, Pierre Emmanuel Lemesre, Cyril Beck, Jean Wattelet, Meryem Tardivel, Juergen Siepmann e Christophe Vincent. "Evaluation of the Efficacy of Dexamethasone-Eluting Electrode Array on the Post-Implant Cochlear Fibrotic Reaction by Three-Dimensional Immunofluorescence Analysis in Mongolian Gerbil Cochlea". Journal of Clinical Medicine 10, n. 15 (28 luglio 2021): 3315. http://dx.doi.org/10.3390/jcm10153315.

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Cochlear implant is the method of choice for the rehabilitation of severe to profound sensorineural hearing loss. The study of the tissue response to cochlear implantation and the prevention of post-cochlear-implant damages are areas of interest in hearing protection research. The objective was to assess the efficacy of dexamethasone-eluting electrode array on endo canal fibrosis formation by three-dimensional immunofluorescence analysis in implanted Mongolian gerbil cochlea. Two trials were conducted after surgery using Mongolian gerbil implanted with dexamethasone-eluting or non-eluting intracochlear electrode arrays. The animals were then euthanised 10 weeks after implantation. The cochleae were prepared (electrode array in place) according to a 29-day protocol with immunofluorescent labelling and tissue clearing. The acquisition was carried out using light-sheet microscopy. Imaris software was then used for three-dimensional analysis of the cochleae and quantification of the fibrotic volume. The analysis of 12 cochleae showed a significantly different mean volume of fibrosis (2.16 × 108 μm3 ± 0.15 in the dexamethasone eluting group versus 3.17 × 108 μm3 ± 0.54 in the non-eluting group) (p = 0.004). The cochlear implant used as a corticosteroid delivery system appears to be an encouraging device for the protection of the inner ear against fibrosis induced by implantation. Three-dimensional analysis of the cochlea by light-sheet microscopy was suitable for studying post-implantation tissue damage.

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Soliman, A. M. "An improved technique for the study of immunofluorescence using non-decalcified frozen guinea pig cochlea". Journal of Laryngology & Otology 102, n. 3 (marzo 1988): 215–18. http://dx.doi.org/10.1017/s0022215100104554.

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SummaryA technique for producing frozen sections from the non-decalcified guinea pig cochlea is described. The sections can be utilised or various immunofluorescent studies, including the detection of humoral anti-bodies against different cellular elements in patients with cochleo-vestibular disorders. The technique assures the preservation of the cochlear architecture and the tissue antigenicity, and it avoids damage to the fine cochlear structural details.

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Moore, David R., Nina J. Rogers e Stephen J. O'Leary. "Loss of Cochlear Nucleus Neurons following Aminoglycoside Antibiotics or Cochlear Removal". Annals of Otology, Rhinology & Laryngology 107, n. 4 (aprile 1998): 337–43. http://dx.doi.org/10.1177/000348949810700413.

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This study compared the effects of aminoglycoside ototoxicity and surgical ablation of the cochlea in infancy on the survival of neurons in the rat cochlear nucleus (CN). Ototoxicity was induced by a single, systemic dose of gentamicin sulfate and furosemide on postnatal day 6 (P6), P7, or P10, and assessed by the elevation of auditory brain stem response thresholds, as described in a companion paper. Unilateral cochlear removals were performed under Saffan anesthesia on P6, P9, and P12. Rats were painlessly sacrificed in adulthood, and the formalin-perfused brains and cochleas were embedded in wax, sectioned, and stained. Ototoxic treatment at P6 through P10 did not reduce neuron counts in the CN. Cochlear removal at P6 resulted in a 40% loss of CN neurons, but removal at P12 did not result in CN neuron loss. These data suggest that the critical period for the dependence of CN neurons on afferent input from the cochlea ends at the same time that susceptibility to aminoglycoside ototoxicity begins.

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Lin, Wei-Ching, Anes Macic e Jong-Hoon Nam. "Characterizing the primary resonator in the cochlea". Journal of the Acoustical Society of America 155, n. 3_Supplement (1 marzo 2024): A308. http://dx.doi.org/10.1121/10.0027608.

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The cochlear traveling waves are explained by a bank of independent resonators coupled longitudinally by lymphatic fluids. Many cochlear models require at least two resonators to account for observed responses. To investigate the resonators in the cochlea, we used high-resolution optical coherence tomography to measure 2-D vibration patterns of the organ of Corti in acutely excised cochleae from young Mongolian gerbils. The excised tissues were acoustically stimulated. The transverse and radial vibrations of the basilar membrane (BM) and the tectorial membrane (TM) were obtained over their radial span. The BM vibrated from the primary to a higher mode transversely as the stimulating frequency increased. The higher-order mode appeared near the best frequency (BF) of the measured location. Meanwhile, the TM showed no sign of a mode transition up to 1 octave above the BF in radial or transverse vibrating patterns. Within the physiological frequency range, the BM exhibits the characteristic behavior of a resonator. In contrast, the TM does not. Our results suggest that the TM as the second resonator is not the universal mechanism across the entire cochlea.

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Più fonti

Tesi sul tema "Cochlea"

Giese, Arnaud. "Régulation de la protéine centrale de la polarité planaire cellulaire Vangl2 dans l’organe de Corti". Thesis, Bordeaux 2, 2010. http://www.theses.fr/2010BOR21761/document.

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Outre leur polarité apico-basale, certaines cellules épithéliales développent une seconde polarité, appelée Polarité Planaire Cellulaire (PCP). L'axe de la PCP est orienté perpendiculairement à l'axe de polarité apico-basale et régit l'orientation uniforme de certaines structures, comme les poils ou cils, non seulement à l'échelle de la cellule mais également au sein du tissu. L'épithélium cochléaire est l'un des meilleurs modèles d'étude de PCP chez les mammifères. En effet, les cellules neuro-épitheliales qui le composent, soutenues par des cellules de soutien, présentent à leur apex, des touffes ciliaires dont l'orientation est parfaitement coordonnée par la voie de la polarité planaire. Les deux premiers gènes impliqués dans la PCP chez les mammifères, Vangl2 et Scrib1, ont été identifiés sur la base du phénotype de la cochlée chez les mutants. L'analyse de la localisation de Vangl2 dans l'organe de Corti a également révélé une localisation asymétrique proximo-distale et transitoire de la protéine, perpendiculaire à l'axe apico-basal classique. Cette asymétrie apparaît à la jonction entre deux types cellulaires : une cellule sensorielle ciliée et une cellule de soutien. J'ai pu montrer au cours de mes travaux de thèse que cette asymétrie était majoritairement due à une accumulation de Vangl2 du côté distal des cellules de soutien, et que dans une moindre mesure, Vangl2 pouvait ségréger du côté distal des cellules ciliées. Cette localisation subcellulaire très précise et limitée dans l'espace semble être indépendante de l'expression du gène Scrib1 dans les cellules ciliées. La délétion du gène Scrib1 dans les cellules ciliées m'a toutefois permis de mettre en évidence que ce gène avait un rôle autonome dans la régulation de la PCP, et que les cellules de soutien de l'organe de Corti pouvaient jouer un rôle prépondérant dans le contrôle de la PCP. Mes travaux ont également permis de mettre en évidence que GIPC1 avait un rôle dans la régulation de la PCP et le maintien de l'intégrité des touffes ciliaires des cellules sensorielles, et que le complexe GIPC1/Myosine VI pouvait réguler l'établissement de l'asymétrie de Vangl2 dans l'organe de Corti
Several epithelia exhibit a second polarity perpendicular to the apico-basal axis, called planar polarity and that governs the orientation of structures such as stereocilia and hear. Our laboratory studies planar polarity, using mammalian cochlear sensory epithelium and we focus our studies on Vangl2, that we identified as the first mammalian planar polarity gene. Vangl2 encodes a four-transmembrane protein that contains a PDZ binding domain in its C-terminus tail. Vangl2 is asymmetrically located at the junction between mechanosensory hair cells and supporting cells, and this asymmetry appears important for planar cell polarity. I have shown in my thesis, using STED microscopy, that Vangl2 asymmetry is mainly due to an accumulation of Vangl2 to the distal side of supporting cells. I sought to dissect the molecular role of Vangl2 by analysing its trafficking within the cochlear epithelium. Deletion analysis shows that the last 12 amino acids, unlike its N-terminus tail are essential for Vangl2 endoplasmic reticulum sorting, its plasma membrane targeting and its function. Conditional mutant mice analysis show that Scrib1, which we have previously shown, interacts with Vangl2 through the PDZ binding domain of its C-terminal tail, is not the protein mediating this asymmetry. My work also highlight that GIPC1 had a role in the regulation of PCP and maintaining the integrity of hair bundles of sensory cells, and that the complex GIPC1/Myosin VI could regulate Vangl2 asymmetry in the organ of Corti

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Ku, Emery Mayon. "Modelling the human cochlea". Thesis, University of Southampton, 2008. https://eprints.soton.ac.uk/64535/.

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One of the salient features of the human cochlea is the incredible dynamic range it possesses—the loudest bearable sound is 10,000,000 times greater than the softest detectable sound; this is in part due to an active process. More than twelve thousand hairlike cells known as outer hair cells are believed to expand and contract in time to amplify cochlear motions. However, the cochlea’s response is more than just the sum of its parts: the local properties of outer hair cells can have unexpected consequences for the global behaviour of the system. One such consequence is the existence of otoacoustic emissions (OAEs), sounds that (sometimes spontaneously!) propagate out of the cochlea to be detected in the ear canal. In this doctoral thesis, a classical, lumped-element model is used to study the cochlea and to simulate click-evoked and spontaneous OAEs. The original parameter values describing the microscopic structures of the cochlea are re-tuned to match several key features of the cochlear response in humans. The frequency domain model is also recast in a formulation known as state space; this permits the calculation of linear instabilities given random perturbations in the cochlea which are predicted to produce spontaneous OAEs. The averaged stability results of an ensemble of randomly perturbed models have been published in [(2008) ‘Statistics of instabilities in a state space model of the human cochlea,’ J. Acoust. Soc. Am. 124(2), 1068-1079]. These findings support one of the prevailing theories of SOAE generation. Nonlinear simulations of OAEs and the model’s response to various stimuli are performed in the time domain. Features observed in the model include the saturation of the forces generated by the OHCs, compression of amplitude growth with increasing stimulus level, harmonic and intermodulation distortion, limit cycle oscillations that travel along the cochlear membranes, and the mutual suppression of nearby linear instabilities.

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van, der Vyver Johannes Petrus. "A biomorphic electronic Hopf cochlea /". Zürich : ETH, 2006. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=16941.

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Morell, Ybarz Maria. "Ultrastructural analysis of odontocete cochlea". Doctoral thesis, Universitat Politècnica de Catalunya, 2012. http://hdl.handle.net/10803/125113.

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The morphological study of the Odontocete organ of Corti including possible pathological features resulting from sound over-exposure, represent a key conservation issue to assess the effects of acoustic pollution on marine ecosystems. Through the collaboration with stranding networks belonging to 26 countries, 150 ears from 13 species of Odontocetes were processed. In this dissertation, we present a standard protocol to 1) compare the ultrastructure of the cochlea in several Odontocete species and 2) investigate possible damage as a consequence of sound exposure, using scanning (SEM) and transmission (TEM) electron microscopy, and immunohistochemistry. In a preliminary study, computerized tomography scans were performed before decalcification with ears of 15 odontocete species, proposing a set of standard measurements which classified very well the species. In addition, the constant ratio between measurements of inner and middle ear structures contributed to confirm the active role of the odontocete middle ear in sound reception mechanism. We established a decalcification protocol using the fast commercial decalcifier RDO® and EDTA (Ethylendiaminetetraacetic acid). Although further experiments should be conducted to assess the suitability of using one or the other method (because the number of samples treated with EDTA was comparatively small), RDO® at specific dilutions decreased the decalcification time of cetacean ear bones with control of the decalcification endpoint, helping a faster access to inner structures. The complementary use of electron microscopy and immunofluorescence allowed the description in odontocetes of new morphological features of tectorial membrane, spiral limbus, spiral ligament, stria vascularis, hair cells and their innervation. Furthermore, this study revealed qualitative and quantitative morphological characteristics of the organ of Corti in high-frequency hearing species, including 1) an outer hair cell (OHC) small length, 2) a thick cuticular plate in OHC, and a thick reticular lamina, 3) robust cup formation of the Deiters cell body, 4) the high development of cytoskeleton in Deiters and pillar cells and 5) the basilar membrane high stiffness. Interestingly, all these features, including a common molecular design of prestin, are also shared by echolocating bats, suggesting a convergent evolution in echolocating species. The presence of scars among hair cell rows, the pattern of stereocilia imprints in the tectorial membrane and the condition of fibrocytes II and IV were criteria suitable to determine or discard possible acoustic trauma, despite the numerous artefacts that rapidly develop as a consequence of tissue autolysis. Consequently, matching the preliminary approximation of the cochlear frequency map with the damaged region would bring information on the sound source that would have triggered a possible lesion.

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Jia, Huan. "Stratégies pharmacologiques pour la prévention de la fibrose intra-cochléaire". Thesis, Montpellier 1, 2012. http://www.theses.fr/2012MON1T001.

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L'implantation cochléaire reste à ce jour le seul moyen capable de restaurer la perception auditive chez les personnes présentant une surdité sévère ou profonde en échec d'appareillage conventionnel. Son principe repose sur la stimulation électrique directe des neurones auditifs de la cochlée par un faisceau d'électrode inséré dans l'oreille interne. Malgré les progrès réalisés dans le manufacturage des électrodes et dans la technique chirurgicale, le geste d'insertion du faisceau d'électrode demeure traumatique. Ce traumatisme est souvent responsable de la perte de l'audition résiduelle sur les fréquences graves et d'une réaction inflammatoire conduisant à une cicatrisation fibreuse. Cette réaction fibreuse est délétère à la fois pour le fonctionnement de l'implant, car augmentant l'impédance des électrodes, mais aussi pour l'audition résiduelle lorsqu'elle est préservée, limitant ainsi les possibilités de stimulation hybride électro-acoustique. Aussi les recherches actuelles tendent à réduire cette fibrose par des moyens pharmacologiques limités, utilisant un corticoïde (dexaméthasone), sans pour autant que son efficacité n'ait été démontrée de manière formelle in vitro ou in vivo. En outre, les cibles moléculaires visées lors de la réaction inflammatoire et fibrotique dans la cochlée n'étant pas clairement identifiées, il est difficile de savoir si cette approche thérapeutique est la plus adaptée. Dans ce travail nous avons donc mis au point des modèles in vitro de culture de tranche de cochlée et d'explant cochléaire de rat pour tester l'efficacité antifibrotique et la toxicité de plusieurs drogues, dont la dexaméthasone, mais aussi l'aracytine, antimitotique non ototoxique et d'utilisation sûre au contact du système nerveux central. Entre nos mains, il apparaît que la stratégie antimitotique par application d'aracytine était plus efficace contre la fibrose et moins toxique pour les cellules sensorielles que la dexamethasone. Dans une seconde partie de ce travail, nous avons utilisé deux modèles in vivo de fibrose cochléaire, à savoir : l'induction d'une labyrinthite immune à Keyhole Limpet Hemocyanin et l'implantation chronique d'un corps étranger intra-cochléaire. A nouveau, l'aracytine délivrée par pompe osmotique intracochléaire permettait de réduire significativement la fibrose dans le modèle de labyrinthite alors que l'effet de la dexamethasone n'était pas significatif. De même la préservation de l'audition était statistiquement meilleure dans le groupe des animaux traités par antimitotiques. Aussi seule l'aracytine a été testée dans l'autre modèle de corps étranger intracochléaire. Elle permettait également de réduire la fibrose observée dans la cochlée, sans effet toxique sur les neurones auditifs. Si la préservation de l'audition était impossible dans le groupe contrôle, l'audition sur les basses fréquences était conservée chez les animaux traités par aracytine. Enfin, les seuils de stimulation électrique capables de provoquer une réponse électrophysiologique par le potentiel évoqué auditif étaient significativement inférieurs dans le groupe traité par aracytine. Ainsi, nous avons pu montrer qu'une stratégie antimitotique était capable d'inhiber efficacement la fibrose dans la cochlée in vitro et in vivo, et ce avec une efficacité supérieure à la dexaméthasone. Nous recommandons donc d'envisager en pratique clinique l'utilisation de l'aracytine pour prévenir la fibrose cochléaire. De plus, ce travail souligne l'intérêt de mieux décortiquer les voies cellulaires conduisant à l'inflammation et à la fibrose cochléaire, de sorte à déterminer les meilleures cibles et molécules candidates. Ces mêmes molécules pourront être testées sur les modèles que nous avons mis au point afin de proposer de nouvelles alternatives thérapeutiques à la prévention de la fibrose cochléaire
Cochlear implantation is the only treatment capable of restoring the auditory pathways in patient suffering from severe to profound hearing loss with poor benefit from hearing aids. Its functioning relies on direct electric stimulation of primary auditory neurons through an electrode array inserted into the cochlea.Despite the advances in electrode design and surgical technique, the act of inserting the electrode array is still traumatic. These traumas result in the loss of residual hearing in low frequencies and provoke an inflammatory reaction leading to fibrous scarring. This fibrous reaction is deleterious to not only the implant performance by increasing the impedance of the electrodes, but also the preserved residual hearing which limit the possibilities of hybrid electro-acoustic stimulation.Current researches aim at limiting this fibrosis by drug application, such as corticosteroids. Therefore dexamethasone is frequently used, but its effectiveness has been only demonstrated formally in vitro or in vivo. Furthermore, the molecular targets set in the fibrotic and inflammatory reaction in the cochlea are not clearly identified, and it is unclear whether this therapeutic approach is best suited.In this study we have developed in vitro models of rat cochlear slice and cochlear explants culture to test the antifibrotic efficacy and toxicity of various drugs, including dexamethasone, but also aracytine, an antimitotic drug with very low ototoxicity which is safely used in contact with the central nervous system. In our hands, it appears that antimitotic aracytine is more effective against fibrosis and less toxic to the sensory cells than the anti-inflammatory drug dexamethasone.In the second part of this study, we used two in vivo models of cochlear fibrosis namely the KLH(keyhole limpet hemocyanin)-induced sterile labyrinthitis and the foreign-body-induced chronic labyrinthitis. Again, the intracochlear fibrosis in the model of KLH-induced labyrinthitis was signticantly reduced by the osmotic pump with aracytine, while the effect of dexamethasone was not significant. Also the preservation of the hearing was statistically better in the group of animals treated with this antimitotic drug. Consequently, aracytine was the only drug tested in the other model of foreign-body-induced labyrinthitis. Again, aracytine reduced fibrosis in the cochlea, without any toxic effects on auditory neurons. While the preservation of the hearing was not achieved in the control group, the low frequencies hearing was preserved in animals treated with aracytine. Finally, the thresholds of electrical stimulation eliciting auditory brainstem response recordings were significantly lower in the treated group by aracytine.Thus, we have shown that an antimitotic strategy was able to inhibit fibrosis effectively in the cochlea in vitro and in vivo, and this with a greater efficiency than dexamethasone. We therefore recommend considering in clinical practice the use of aracytine to prevent cochlear fibrosis. In addition, this study stresses the importance of analyzing the cellular pathways of cochlear inflammation and fibrosis, in order to determine the best targets and candidate molecules. These molecules could be tested on the models that we have developed in order to offer new therapeutic options to prevent cochlear fibrosis

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Edelmann, Karola. "Richtungshören bei Kindern mit bilateralen Cochlea-Implantaten im Vergleich zu Kindern mit unilateralem Cochlea-Implantat". [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=976294052.

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Fragnière, Eric. "Analogue VLSI emulation of the cochlea /". Lausanne, 1998. http://library.epfl.ch/theses/?nr=1796.

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Blomkvist, Anna, e Anna Fritz-Sundström. "Språkutveckling hos barn med cochlea implantat". Thesis, Örebro University, School of Humanities, Education and Social Sciences, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-9919.

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Shiraishi, Hisako. "Design of an Analog VLSI Cochlea". University of Sydney. Electrical and Information Engineering, 2003. http://hdl.handle.net/2123/556.

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The cochlea is an organ which extracts frequency information from the input sound wave. It also produces nerve signals, which are further analysed by the brain and ultimately lead to perception of the sound. An existing model of the cochlea by Fragni`ere is first analysed by simulation. This passive model is found to have the properties that the living cochlea does in terms of the frequency response. An analog VLSI circuit implementation of this cochlear model in CMOS weak inversion is proposed, using log-domain filters in current domain. It is fabricated on a chip and a measurement of a basilar membrane section is performed. The measurement shows a reasonable agreement to the model. However, the circuit is found to have a problem related to transistor mismatch, causing different behaviour in identical circuit blocks. An active cochlear model is proposed to overcome this problem. The model incorporates the effect of the outer hair cells in the living cochlea, which controls the quality factor of the basilar membrane filters. The outer hair cells are incorporated as an extra voltage source in series with the basilar membrane resonator. Its value saturates as the input signal becomes larger, making the behaviour rather closer to that of a passive model. The simulation results show this nonlinear phenomenon, which is also seen in the living cochlea. The contribution of this thesis is summarised as follows: a) the first CMOS weak inversion current domain basilar membrane resonator is designed and fabricated, and b) the first active two-dimensional cochlear model for analog VLSI implementation is developed.

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Kallweit, Nicole [Verfasser]. "Laserinduzierte Stimulation der Cochlea / Nicole Kallweit". Garbsen : TEWISS - Technik und Wissen GmbH, 2019. http://d-nb.info/1176156241/34.

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Libri sul tema "Cochlea"

Bacon, Sid P., Richard R. Fay e Arthur N. Popper, a cura di. Compression: From Cochlea to Cochlear Implants. New York: Springer-Verlag, 2004. http://dx.doi.org/10.1007/b97241.

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P, Bacon Sid, Fay Richard R e Popper Arthur N, a cura di. Compression: From cochlea to cochlear implants. New York: Springer-Verlag, 2004.

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Pauka, Charles K. Place-pitch and vowel-pitch comparisons in cochlear implant patients using the Melbourne-Nucleus cochlear implant. Ashford, Kent: Headley Brothers, 1989.

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Dallos, Peter, Arthur N. Popper e Richard R. Fay, a cura di. The Cochlea. New York, NY: Springer New York, 1996. http://dx.doi.org/10.1007/978-1-4612-0757-3.

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Lenarz, Thomas, a cura di. Cochlea-Implantat. Berlin, Heidelberg: Springer Berlin Heidelberg, 1998. http://dx.doi.org/10.1007/978-3-642-80004-7.

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Peter, Dallos, Popper Arthur N e Fay Richard R, a cura di. The cochlea. New York: Springer, 1996.

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International Cochlear Implant Conference. (8th 2004 Indianapolis, Ind.). Cochlear implants: Proceedings of the VIII International Cochlear Implant Conference held in Indianapolis, Indiana, USA between 10 and 13 May 2004. A cura di Miyamoto Richard T. Amsterdam: Elsevier, 2004.

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Manley, Geoffrey A., Anthony W. Gummer, Arthur N. Popper e Richard R. Fay, a cura di. Understanding the Cochlea. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-52073-5.

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A, Merchán Miguel, North Atlantic Treaty Organization. Scientific Affairs Division. e NATO Advanced Research Workshop on the Mammalian Cochlear Nuclei: Organization and Function (1991 : Salamanca, Spain), a cura di. The Mammalian cochlear nuclei: Organization and function. New York: Plenum Press, 1993.

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Tillman, Peggie S. Cochlear implants: April 1988 through March 1995 : 881 citations. Bethesda, Md: U.S. Dept. of Health and Human Services, Public Health Service, National Institutes of Health, National Library of Medicine, Reference Section, 1995.

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Capitoli di libri sul tema "Cochlea"

Donnelly, Kerry. "Cochlea". In Encyclopedia of Clinical Neuropsychology, 829. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-57111-9_719.

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Donnelly, Kerry. "Cochlea". In Encyclopedia of Clinical Neuropsychology, 1. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-56782-2_719-2.

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Khalil, Michael. "Cochlea". In Encyclopedia of Evolutionary Psychological Science, 1–4. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-16999-6_987-1.

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McCullagh, Jennifer. "Cochlea". In Encyclopedia of Autism Spectrum Disorders, 683. New York, NY: Springer New York, 2013. http://dx.doi.org/10.1007/978-1-4419-1698-3_1100.

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Kangelaris, Gerald T., e Lawrence R. Lustig. "Cochlea". In Encyclopedia of Otolaryngology, Head and Neck Surgery, 480. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-23499-6_200080.

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McCullagh, Jennifer. "Cochlea". In Encyclopedia of Autism Spectrum Disorders, 1017–18. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-319-91280-6_1100.

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Donnelly, Kerry. "Cochlea". In Encyclopedia of Clinical Neuropsychology, 607. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-0-387-79948-3_719.

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Rybak, Leonard P. "The Cochlea". In Inflammatory Mechanisms in Mediating Hearing Loss, 1–13. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-92507-3_1.

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Peroulis, Dimitrios, Prashant R. Waghmare, Sushanta K. Mitra, Supone Manakasettharn, J. Ashley Taylor, Tom N. Krupenkin, Wenguang Zhu et al. "Cochlea Implant". In Encyclopedia of Nanotechnology, 457. Dordrecht: Springer Netherlands, 2012. http://dx.doi.org/10.1007/978-90-481-9751-4_100153.

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Adunka, Oliver F. "Cochlea, Anatomy". In Encyclopedia of Otolaryngology, Head and Neck Surgery, 481–87. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-23499-6_534.

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Atti di convegni sul tema "Cochlea"

Nankali, Amir, e Karl Grosh. "Stability and Bifurcation Analysis of a Nonlinear Cochlear Model". In ASME 2014 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/detc2014-35657.

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Hearing relies on a series of coupled electrical, acoustical (fluidic) and mechanical interactions inside the cochlea that enable sound processing. The stability of the cochlea is studied using a nonlinear, micromechanical model of the organ of Corti (OoC) coupled to the electrical potentials in the cochlear ducts. The OoC is part of the mammalian cochlea that contains auditory sensory cells that both identify fluid-born vibrations in the cochlea and amplify the cycle-by-cycle motions of the cochlear structures. This process occurs through local resonance of the OoC system. In the mammalian cochlea, an active process accounts for the ear’s exquisite sensitivity and its remarkable responsiveness for a range of frequencies and intensities. Numerical and analytical techniques are utilized to examine the stability of this system. It is observed that the cochlear active process, controls the stability. We show that instability in this model is generated through a supercritical Hopf bifurcation. Furthermore, a reduced order model of the system is approximated and it is shown that the tectorial membrane (TM) transverse mode effect on the dynamics is significant while the radial mode can be simplified from the equations. We compare the cross sectional model with the comprehensive 3-dimensional model of the cochlea. It is indicated that the global model qualitatively inherits some characteristics of the local model, but the longitudinal coupling along the cochlea enhances stability (i.e., shifts the Hopf bifurcation point).

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Meaud, Julien, Thomas Bowling e Charlsie Lemons. "Computational Modeling of Spontaneous Otoacoustic Emissions by the Mammalian Cochlea". In ASME 2018 Dynamic Systems and Control Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/dscc2018-9044.

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The mammalian cochlea is a sensory system with high sensitivity, sharp frequency selectivity and a broad dynamic range. These characteristics are due to the active nonlinear feedback by outer hair cells. Because it is an active nonlinear system, the cochlea sometimes emits spontaneous otoacoustic emissions (SOAEs) that are generated in the absence of any external stimulus due to the emergence of limit cycle oscillations. In this work, we use a computational physics-based model of the mammalian cochlea to investigate the generation of SOAEs. This model includes a three-dimensional model of the fluid mechanics in the cochlear ducts, a micromechanical model for the vibrations of the cochlear structures, and a realistic model of outer hair cell biophysics. Direct simulations of SOAEs in the time-domain demonstrate that the model is able to capture key experimental observations regarding SOAEs. Parametric studies and analysis of model simulations are used to demonstrate that SOAEs are a global phenomenon that arises due to the collective action of a distributed region of the cochlea rather than from spontaneous oscillations from individual outer hair cells.

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Marnell, Daniel, Srdjan Prodanovic e Jong-Hoon Nam. "Probing Cochlear Resonators Using a New Microchamber". In ASME 2013 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/sbc2013-14467.

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The mammalian cochlea is an acoustic spectrum analyzer and pressure transducer with a remarkable operating range, both in frequency and amplitude (Fettiplace & Hackney, 2006). A young, healthy human ear can capture sounds of 40 to 20,000 Hz in frequency and 20 μPa to 20 Pa (0 to 120 dB sound pressure level) in amplitude. One of the most significant achievements in decades regarding cochlear research is the identification of the cochlear amplifier. Tiny acoustic vibrations are amplified in the organ of Corti (OC)–sensori-eptithelium in the cochlea. Mechano-transducer receptors in the OC, called the outer hair cells, have been identified as the cellular actuators that provide energy to boost small pressure waves. However, the underlying mechanism of this amplification is still unclear.

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Narr, Paul, Alex Ringo, Daniel Marnell e Jong-Hoon Nam. "Microchamber System to Experiment Mechanotransduction in the Organ of Corti". In ASME 2012 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/sbc2012-80137.

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The mammalian cochlea is an acoustic spectrum analyzer and pressure transducer with a remarkable operating range, both in frequency and amplitude (Fettiplace & Hackney, 2006). A young healthy human ear can capture sounds of 40 to 20,000 Hz in frequency and 20 μPa to 20 Pa (0 to 120 dB sound pressure level) in amplitude. In research on the cochlea, one of the most significant achievements in decades is the identification of the cochlear amplifier. Tiny acoustic vibrations are amplified in the organ of Corti (OC)—sensori-eptithelium in the cochlea. Mechano-transducer receptors in the OC, called the outer hair cells, have been identified as the cellular actuators that provide energy to boost small pressure waves. However, how the amplification is achieved is still unclear.

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Narasimhan, Narendran, Katherine E. Riojas, Trevor L. Bruns, Jason E. Mitchell, Robert J. Webster e Robert F. Labadie. "A Simple Manual Roller Wheel Insertion Tool for Electrode Array Insertion in Minimally Invasive Cochlear Implant Surgery". In 2019 Design of Medical Devices Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/dmd2019-3249.

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Image-guided, minimally-invasive cochlear implant surgery is a novel “keyhole” surgical approach for placing a cochlear implant electrode array eliminating the need for a wide-field mastoidectomy approach. Image guidance is used for path planning which is followed by the construction of a customized micro-stereotactic frame to drill a narrow channel from the skull surface to the cochlea. Herein, we present an insertion tool that uses roller wheels to advance the electrode array through the narrow tunnel and into the cochlea. Testing in a phantom revealed that when compared to insertions with surgical forceps, the new insertion tool was on average 26s faster, produced complete insertions more often (i.e. in 6/6 trials, vs. 1/6), and reduced array buckling (0/6 trials vs. 5/6). The tool provides a viable solution to complete the last step of this novel, minimally-invasive procedure. It also provides the advantage over previously developed manual insertion tools of enabling the surgeon to blindly actuate the roller wheel tool to advance the electrode into the tunnel. This allows the surgeon to visualize and guide insertion into the cochlea from a more advantageous visual perspective.

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Steele, Charles R., Alissa Fitzgerald, Thomas Kenny, Kian-Meng Lim e Sunil Puria. "Possibilities for a Silicon Model of the Cochlea". In ASME 2000 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2000. http://dx.doi.org/10.1115/imece2000-1604.

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Abstract The purpose of this study is to resolve questions regarding the fundamental physical behavior of the cochlea of the inner ear. We seek a convergence of measurement and computation on physical models that capture essential features. Since there are unique features in the performance of the cochlea, the physical models could lead to device development. A much longer-term goal is a device for the assistance of hearing impaired individuals. The cochlea can be modeled as a tube of fluid divided by a partition, a portion of which is elastic and called the basilar membrane (BM). In preliminary work, the cochlear partition is constructed on a silicon wafer using current capabilities for micro-machining. The silicon nitride partition is inserted into a chamber of Plexiglas which is filled with solute and has a “stapes” for acoustic input and a “round window”. The silicon BM has the correct length, but is wider and isotropic. The measurements, supported by calculations, show that the deviation from the actual structure has a detrimental effect on the sharpness of the spatial distribution of the response for a fixed input frequency. Possibilities for improved models and for an active non-linear model with distributed sensors and actuators are discussed.

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Vandaele, Mathieu, Bryan S. Joyce e Pablo A. Tarazaga. "Design and Characterization of Piezo-Based Stereocilia". In ASME 2013 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/smasis2013-3189.

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The hair cells in the cochlea are responsible for transforming sound-induced vibration into electrical signals. Damage to these hair cells is among the most common forms of hearing loss in the developed world. Researchers have studied various artificial hair cell (AHC) designs for replacing these hair cells. One such method uses piezoelectric beams to mimic the hair cell’s mechanoelectrical transduction. A piezoelectric beam will produce an electric potential from an applied sound pressure. In the literature, the response of the cochlea to sound pressures is often described using tuning curves. Tuning curves plot the sound pressure level at a given frequency which produces a particular displacement, velocity, or neuron firing rate. The work presented here examines using piezoelectric AHC’s to mimic cochlear hair cells by creating tuning curves of constant tip velocity and voltage. A piezoceramic (PZT) beam and a piezo film (PVDF) bending sensor are examined. An output feedback controller based on PID control is developed to vary the sound pressure from a speaker to create tuning curves for the piezoelectric AHC’s. The tuning curves for the piezoelectric beams are compared to measurements obtained from the biological cochlea.

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Givelberg, E., J. Bunn e M. Rajan. "Detailed Simulation of the Cochlea: Recent Progress Using Large Shared Memory Parallel Computers". In ASME 2001 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2001. http://dx.doi.org/10.1115/imece2001/fed-24963.

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Abstract We have developed and are refining a detailed three-dimensional computational model of the human cochlea. The model uses the immersed boundary method to calculate the fluid-structure interactions produced in response to incoming sound waves. An accurate cochlear geometry obtained from physical measurements is incorporated. The model includes a detailed and realistic description of the various elastic structures present. Initially, a macro-mechanical computational model was developed for execution on a CRAY T90 at the San Diego Supercomputing Center. This code was ported to the latest generation of shared memory high performance servers from Hewlett Packard. Using compiler generated threads and OpenMP directives, we have achieved a high degree of parallelism in the executable, which has made possible to run several large scale numerical simulation experiments to study the interesting features of the cochlear system. In this paper, we outline the methods, algorithms and software tools that were used to implement and fine tune the code, and discuss some of the simulation results.

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Biswas, Amitava. "A Novel Analysis of the Mechanics of Cochlea, the Inner Ear". In ASME 2003 International Mechanical Engineering Congress and Exposition. ASMEDC, 2003. http://dx.doi.org/10.1115/imece2003-42394.

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The human ear is often regarded as a paragon of mechanical engineering. To understand how the hearing system works, scientists have proposed detailed models of its specific aspects—the transfer of acoustic energy from the atmosphere to the tympanic membrane via the external ear; the coupling of the tympanic membrane to the oval window of the cochlea via ossicles; the resultant fluidic oscillations in the cochlear ducts; the formation of traveling waves in the basilar membrane of the cochlea; the mechanical stimulation of inner hair cells by the basilar membrane; and the consequential transduction of nerve impulses. Scientists have also proposed models to explain the phenomenon of enhancement of the traveling waves in the basilar membrane by synchronized co-contraction in the length of outer hair cells (OHCs). Although it is unrealistic that any OHC would contract in length without expanding in diameter, the models proposed by other analysts have so far incorporated the longitudinal contraction of OHCs only, suggesting that the impact of any diametric expansion of OHCs would be relatively trival. Here we show that the basilar membrane would behave like a Beam-Column system, which may be significantly influenced by the diametric expansion of OHCs.

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Joyce, Bryan, Jacob Dodson e Janet Wolfson. "Beam Array Designs for a Cochlea-Inspired Accelerometer for Impact Measurements". In ASME 2017 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/smasis2017-3723.

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Limitations on neuron firing rates restrict the frequency bandwidth of many biological sensory systems. The cochlea overcomes these limitations to hear high frequency sounds through its tonotopic structure and non-synchronous sampling. The cochlea’s tapering basilar membrane serves as a filter bank decomposing an applied sound into its frequency components. Auditory hair cells produce neural impulses at the peaks in the local basilar membrane oscillations resulting in an event-driven, sub-Nyquist rate sampling strategy. These two effects extend the human hearing range to about 20 kHz despite maximum neuron firing rates of just a few hundred hertz. Inspired by this, this paper presents a concept demonstration of an accelerometer and signal compression strategy for high-rate impact events using a similar filter bank approach. A series of clamped-clamped beams will serve as analog analysis filters much like the cochlea’s basilar membrane. This paper focuses on the design and simulation of such a beam array and how the natural frequencies and damping ratios of the beams’ first modes affect measuring a broadband impact excitation.

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Rapporti di organizzazioni sul tema "Cochlea"

Jones, Karen. High frequency acoustic reflexes in cochlea-impaired and normal ears. Portland State University Library, gennaio 2000. http://dx.doi.org/10.15760/etd.5979.

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Xin, Jack. Nonlinear Nonlocal Cochlear Models, Multitones, Noises and Masking Thresholds. Fort Belvoir, VA: Defense Technical Information Center, dicembre 2002. http://dx.doi.org/10.21236/ada413900.

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Ross, Carol. Some effects of cochlear implant use on loudness modulation. Portland State University Library, gennaio 2000. http://dx.doi.org/10.15760/etd.5408.

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Shofner, William P. Information Processing of Complex Sounds in the Anteroventral Cochlear Nucleus. Fort Belvoir, VA: Defense Technical Information Center, aprile 1988. http://dx.doi.org/10.21236/ada198576.

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Heath, Dianne. One-third octave band augmented speech discrimination testing for cochlear impaired listeners. Portland State University Library, gennaio 2000. http://dx.doi.org/10.15760/etd.3300.

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Herreros Bódalo, Juan Luis, e Marta Vivar García. Diseño de una fotolinera para carga de coches de radiocontrol. Fundación Avanza, maggio 2023. http://dx.doi.org/10.60096/fundacionavanza/2782022.

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En este artículo se presenta el diseño e implementación de una fotolinera (sistema autónomo fotovoltaico) para la carga de coches de radiocontrol. El sistema se ha probado a sol real en las instalaciones de la Escuela Politécnica Superior de Linares

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Patterson, James H., Lomba-Gautier Jr., Curd Ilia M. e Dennis L. The Effect of Impulse Intensity and the Number of Impulses on Hearing and Cochlear Pathology in the Chinchilla. Fort Belvoir, VA: Defense Technical Information Center, giugno 1985. http://dx.doi.org/10.21236/ada161230.

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Kupfer, Monica E. Perceptive Strokes: Women Artists of Panama. Inter-American Development Bank, marzo 2013. http://dx.doi.org/10.18235/0006215.

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The IDB Cultural Center is proud to host this exhibit honoring the Republic of Panama, host country of the IDB Annual Meeting, which will take place from March 14¿20, 2013. The exhibition highlights the history of modern and contemporary art by Panamanian women and will include paintings, photographs, sculptures, and video art from the 1920s to the present. The 22 artworks, selected by Panamanian curator Dr. Monica E. Kupfer, reveal the ways in which a varied group of female artists have experienced and represented significant geopolitical events in the nation¿s history. Their interpretations also show the position of women in Panamanian society, and their views of themselves through their own and others¿ eyes. Among the artists are: Susana Arias, Beatrix (Trixie) Briceño, Fabiola Buritica, Coqui Calderón, María Raquel Cochez, Donna Conlon, Isabel De Obaldía, Sandra Eleta, Ana Elena Garuz, Teresa Icaza, Iraida Icaza, Amelia Lyons de Alfaro, Lezlie Milson, Rachelle Mozman, Roser Muntañola de Oduber, Amalia Rossi de Jeanine, Olga Sánchez, Olga Sinclair, Victoria Suescum, Amalia Tapia, Alicia Viteri, and Emily Zhukov.

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Galindo Alfonso, Jorge, Javier Martínez Santos e Natalia Collado Van-Baumberghen. ¿Logró la subvención al transporte público metropolitano sacar coches de las ciudades? Un análisis con datos de tráfico en tiempo real de la ciudad de Madrid. Esade EcPol, ottobre 2023. http://dx.doi.org/10.56269/20231016/jga.

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En este documento se analiza el efecto de la subvención al transporte metropolitano (cercanías y metro) en el tráfico de vehículos privados en Madrid. A partir de los datos de los medidores de tráfico a tiempo real, se utiliza un método de impacto causal basado en un control sintético para evaluar el impacto de la subvención. Nuestro análisis no encuentra un impacto significativo de la subvención sobre el tráfico de vehículos en Madrid. Este efecto no aparece ni en términos acumulados desde el 1 de septiembre de 2022 hasta el 30 de junio de 2023, ni medios día a día. Tampoco se encuentra efecto en nuestro análisis de heterogeneidad agrupando los medidores de vías rápidas (M-30); de entrada, o salida de la ciudad; en zonas de más o menos tráfico de partida; de renta alta, media o baja; de acceso cercano o no a paradas de transporte. En vista de esos resultados, para fomentar el uso del transporte público recomendamos priorizar la inversión en la mejora de la accesibilidad y frecuencia del transporte, medidas focalizadas a hogares con ingresos más bajos, y peajes basados en proxies de renta (como peso de vehículo) para incentivar el cambio modal y cimentar la inversión adicional.

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Cochlear Implants. Rockville, MD: American Speech-Language-Hearing Association, 2004. http://dx.doi.org/10.1044/policy.tr2004-00041.

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