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1

Bone conduction stimulation of the otic capsule: a finite element model of the temporal bone

Borkowski Paweł, Marek Piotr, Niemczyk Kazimierz, Lachowska Magdalena, Kwacz Monika, Wysocki Jarosław

Acta of Bioengineering and Biomechanics

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2019

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Vol. 21, no. 3

75--86

EN

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.

2

An alternative 3D numerical method to study the biomechanical behaviour of the human inner ear semicircular canal

Santos C. F., Belinha J., Gentil F., Parente M., Jorge R. N.

Acta of Bioengineering and Biomechanics

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2017

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Vol. 19, no. 1

3--15

EN

Purpose: The vestibular system is the part of the inner ear responsible for balance. Vertigo and dizziness are generally caused by vestibular disorders and are very common symptoms in people over 60 years old. One of the most efficient treatments at the moment is vestibular rehabilitation, permitting to improve the symptoms. However, this rehabilitation therapy is a highly empirical process, which needs to be enhanced and better understood. Methods: This work studies the vestibular system using an alternative computational approach. Thus, part of the vestibular system is simulated with a three dimensional numerical model. Then, for the first time using a combination of two discretization techniques (the finite element method and the smoothed particle hydrodynamics method), it is possible to simulate the transient behavior of the fluid inside one of the canals of the vestibular system. Results: The obtained numerical results are presented and compared with the available literature. The fluid/solid interaction in the model occurs as expected with the methods applied. The results obtained with the semicircular canal model, with the same boundary conditions, are similar to the solutions obtained by other authors. Conclusions: The numerical technique presented here represents a step forward in the biomechanical study of the vestibular system, which in the future will allow the existing rehabilitation techniques to be improved.

3

Analysis of a dynamic response of the cochlea using fluid-structure interaction model

Kamieniecki K., Piechna J., Borkowski P.

Engineering Transactions

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2016

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Vol. 64, iss. 4

573--579

EN

A one-dimensional (1D) model of the cochlea of the inner ear has been built and validated against the previously built three-dimensional (3D) fluid-structure interaction (FSI) model of the cochlea. The 1D model has been used to assess the influence of the round window impedance on the pressure distribution in the cochlea. It was shown that high impedance, which enables compression reflection pressure wave at the round window, leads to the biggest pressure difference between the scala vestibule and the scala tympani in the cochlea, which may lead to a stronger excitation of the basilar membrane.

4

Helmet mounted display based system for stereoscopic visualization supporting inner ear operation

Kucharski T., Kujawińska M., Leśniewski M., Niemczyk K., Bruzgielewicz A.

Elektronika : konstrukcje, technologie, zastosowania

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2004

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Vol. 45, nr 8-9

120-122

EN

In this paper authors present a system consisting of operational stereoscopic microscope with two image acquisition channels, data processing unit and Helmet Mounted Display (HMD) for stereoscopic of visualization field. Special attention is paid to the development of automatic image low contrast enhancement. The algorithms are optimized for stereo visualization of biological micro-structures of inner ear. Some of those structures have quasi-phase nature and are almost invisible by human eye. The tests performed at the images captured during operation have been positively evaluated by surgeons. The performance of the system presented ascertained that quality of inner ear processed images guaranties safety carrying of operations not undertaken so far.

PL

Autorzy prezentują system zawierający operacyjny mikroskop stereoskopowy obsługujący dwa kanały rejestrujące, program przetwarzający dane oraz hełm optyczny (HMD) służący do stereoskopowej wizualizacji wzbogaconego obrazu pola operacyjnego. W pracy poświęcono uwagę wzbogaceniu obrazu oryginalnego tkanek ucha wewnętrznego. Tkanki te posiadają quasi-fazową naturę i są trudno rozróżnialne przez ludzkie zmysły. Testy przeprowadzone podczas operacji zostały pozytywnie ocenione przez chirurgów. Projekt udowodnił, że jakość przetworzonych umożliwia podjąć się operacji zaniechanych jak dotąd.