Finite-element analysis of inner ear hair bundles: a parameter study of bundle mechanics

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dc.contributor.authorDuncan, Robert Keithen
dc.contributor.committeechairGrant, John Wallaceen
dc.contributor.committeememberGriffin, Odis Hayden Jr.en
dc.contributor.committeememberLandgraf, Ronald W.en
dc.contributor.departmentEngineering Mechanicsen
dc.date.accessioned2014-03-14T21:46:36Zen
dc.date.adate2009-09-29en
dc.date.available2014-03-14T21:46:36Zen
dc.date.issued1993-08-15en
dc.date.rdate2009-09-29en
dc.date.sdate2009-09-29en
dc.description.abstractInner ear hair cells have been identified as the sites of mechanoelectrical transduction from a mechanical event (e.g. hearing, motion) to an electrical event (e.g. neural response). Deflection of bundles of hair-like stereocilia extending from these cells has been associated with the transduction process. Stereocilia bundle structure and stiffness controls deflection and thus the fundamental sensitivity of the transduction process. The finite-element method was used along with analytical techniques to characterize individual stereocilium and stereocilia bundle stiffnesses. A three ‘stack’ bundle with a Young’s modulus of 3 GPa (F-actin protein) and Poisson’s ratio of 0.4 (nearly incompressible) resulted in a stiffness of K = 2.1 x 10⁻³ N/m. This value is within the range of experimentally determined stiffmesses. Tip-link and subapical band interconnecting structures each contribute significantly to bundle stiffness and each could act as the gating-spring in transduction models, which propose gating structures as a means of regulating ionic activity and therefore neural activity. Stiffness depends most strongly on individual stereocilium geometry and material description, tip-link orientation and material description, and stereocilia bundle width. Stiffness depends least on stereocilia height variations and subapical bands configuration. Linear analysis was reliable up to deflections of 3.5 um, the upper limit of physical response. Preliminary dynamic response indicates a natural frequency of 382 kHz for the vibration mode resembling physical deformation behavior. Future models should include hexagonal bundle arrangements, transversely isotropic stereocilia material descriptions, and viscoelastic tip-link behavior.en
dc.description.degreeMaster of Scienceen
dc.format.extentix, 109 leavesen
dc.format.mediumBTDen
dc.format.mimetypeapplication/pdfen
dc.identifier.otheretd-09292009-020226en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-09292009-020226/en
dc.identifier.urihttp://hdl.handle.net/10919/44930en
dc.language.isoenen
dc.publisherVirginia Techen
dc.relation.haspartLD5655.V855_1993.D862.pdfen
dc.relation.isformatofOCLC# 29150948en
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subject.lccLD5655.V855 1993.D862en
dc.subject.lcshCilia and ciliary motion -- Mathematical modelsen
dc.subject.lcshFinite element methoden
dc.subject.lcshLabyrinth (Ear) -- Mathematical modelsen
dc.subject.lcshLabyrinth (Ear) -- Physiologyen
dc.subject.lcshSensory receptorsen
dc.titleFinite-element analysis of inner ear hair bundles: a parameter study of bundle mechanicsen
dc.typeThesisen
dc.type.dcmitypeTexten
thesis.degree.disciplineEngineering Mechanicsen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

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