Finite element cochlear models and their steady state response

Kagawa, Y.; Yamabuchi, Tatsuo; Watanabe, Naoya; Mizoguchi, Tsuyoshi

doi:10.1016/0022-460x(87)90456-1

Cited by 12 publications

(16 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The governing equations were solved using integral formulations, finite difference, finite element, and immersed boundary methods. Kagawa et al (1987) performed three-dimensional simulations of the fluid motion inside a spiraling cochlea and confirmed that the results are in qualitative agreement with those of simpler two-dimensional geometries.…”

Section: Introductionsupporting

confidence: 82%

“…Numerical solutions of two-dimensional cochlear models were presented by several authors including Lesser and Berkley (1972), Viergever and Kalker (1975), Viergever (1977), Allen (1977), Sondhi (1978), Allen and Sondhi (1979), Neely (1981), Kagawa et al (1987), Diependaal and Viergever (1989), and Beyer (1992). Prior to Lesser and Berkley (1972), all authors had assumed that the fluid motion is one-dimensional.…”

Section: Introductionmentioning

confidence: 99%

“…Lighthill (1981) used energy-flow arguments to identify the necessary key features of mathematical models. Numerical solutions of three-dimensional cochlear models were presented by Taber and Steele (1981), Kagawa et al (1987), Kolston and Ashmore (1996), Parthasarathi et al (2000) and Givelberg and Bunn (2003). The governing equations were solved using integral formulations, finite difference, finite element, and immersed boundary methods.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Boundary-integral modeling of cochlear hydrodynamics

Pozrikidis¹

2008

Journal of Fluids and Structures

View full text Add to dashboard Cite

Section: Introductionsupporting

confidence: 82%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Boundary-integral modeling of cochlear hydrodynamics

Pozrikidis¹

2008

Journal of Fluids and Structures

View full text Add to dashboard Cite

“…Steele and Taber (19) and de Boer and Viergever (20), among others, present 3D cochlear models by using the Wentzel-Kramer-Brillouin asymptotic technique. A number of finite element models of the cochlea have also been described, such as those by Parthasarathi et al (15), Kolston and Ashmore (21), and Kagawa et al (22). A direct application of these methods is not appropriate for the system considered in this study because the viscous boundary layer occupies a large fraction of the 110-m duct height, causing these approaches to underestimate the viscous fluid damping.…”

Section: Modelingmentioning

confidence: 99%

Microengineered hydromechanical cochlear model

White

Grosh

2005

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Micromachined fluid-filled variable impedance waveguides intended to mimic the mechanics of the passive mammalian cochlea have been fabricated and experimentally examined. The structures were microfabricated with dimensions similar to those of the biological system. Experimental tests demonstrate acoustically excited traveling fluid-structure waves with phase accumulations between 1.5 and 3 radians at the location of maximum response. The resulting measured frequency-position mapping function, with similarities to that observed in the cochlea, is presented. Results for both isotropic and orthotropic membranes are reported, demonstrating that the achieved orthotropy ratio of 8:1 in tension is insufficient to produce the sharp filtering observed in animal experiments and many computational models that use higher ratios. It is also shown experimentally that high viscosity fluids must be used to provide sufficient damping to avoid the formation of a nonphysiological standing wave pattern. A mathematical model incorporating a thin-layer viscous, compressible fluid approximation coupled to an orthotropic membrane model is validated against experimental results. The work presented herein is motivated by the possibility of producing microfabricated cochlear-like filters, thus the structure is designed for production in a scalable microfabrication process.acoustic ͉ micro-electro-mechanical systems ͉ sensor ͉ viscosity T he cochlea is the organ in the inner part of the mammalian ear that is responsible for the transduction of acoustic signals into neurological signals. The typical human cochlea operates over a 3-decade frequency band, from 20 Hz to 20 kHz, covers 120 dB of dynamic range, and can distinguish tones that differ by Ͻ0.5% (1). The cochlea is also very small, occupying a volume of Ϸ1 cm 3 . Perhaps most importantly, the cochlea uses a mechanical process to separate audio signals into Ϸ3,500 channels of frequency information. Thus, the cochlea is a sensitive real-time mechanical frequency analyzer.The effectiveness of the cochlea as a time-frequency analyzer motivates our efforts to construct a hydromechanical analog that can be fabricated repeatably and in a batch fashion. Integration of sensing elements with the mechanical structure would result in a combined acoustic sensor͞filter with a unique operating modality. During the design of the mechanical structure, we also learn more about some aspects of the biological cochlea. von Békésy's (2, 3) observation of traveling waves on the basilar membrane (BM) of cadaver cochleae motivated the construction of a number of physical models of the cochlea. The first group of these models involved scaled-up versions of the cochlea. Helle's (4) model is seven times life size and exhibits tonotopic structure in the 25-to 800-Hz band. Chadwick et al. (5) built a 24 times life-size model and clearly show strong standing wave patterns and the resulting discrete resonances. Because of the standing wave nature of their response, a tonotopic map is not demonstrated (5). Lechner'...

show abstract

“…In those few cochlear models where coiling has been considered, the CP was often reduced to the basilar membrane (BM) only (Viergever 1978;Loh 1983;Steele & Zais 1985;Kagawa et al 1987;Kohllöffel 1990;Manoussaki & Chadwick 2000;Givelberg & Bunn 2003). Most of these models reported a negligible effect of curvature on cochlear macromechanics.…”

Section: Introductionmentioning

confidence: 99%

Effects of coiling on the micromechanics of the mammalian cochlea

Cai

Manoussaki

Chadwick

2005

J. R. Soc. Interface.

View full text Add to dashboard Cite

The cochlea transduces sound-induced vibrations in the inner ear into electrical signals in the auditory nerve via complex fluid-structure interactions. The mammalian cochlea is a spiralshaped organ, which is often uncoiled for cochlear modelling. In those few studies where coiling has been considered, the cochlear partition was often reduced to the basilar membrane only. Here, we extend our recently developed hybrid analytical/numerical micromechanics model to include curvature effects, which were previously ignored. We also use a realistic cross-section geometry, including the tectorial membrane and cellular structures of the organ of Corti, to model the apical and basal regions of a guinea-pig cochlea. We formulate the governing equations of the fluid and solid domains in a curvilinear coordinate system. The WKB perturbation method is used to treat the propagation of travelling waves along the coiled cochlear duct, and the O(1) system of the governing equations is solved in the transverse plane using finite-element analysis. We find that the curvature of the cochlear geometry has an important functional significance; at the apex, it greatly increases the shear gain of the cochlear partition, which is a measure of the bending efficiency of the outer hair cell stereocilia.

show abstract

Finite element cochlear models and their steady state response

Cited by 12 publications

References 12 publications

Boundary-integral modeling of cochlear hydrodynamics

Boundary-integral modeling of cochlear hydrodynamics

Microengineered hydromechanical cochlear model

Effects of coiling on the micromechanics of the mammalian cochlea

Contact Info

Product

Resources

About