Modeling Intracochlear Magnetic Stimulation: A Finite-Element Analysis

S. Mukesh, D. T. Blake, B. J. McKinnon, P. T. Bhatti

Research output: Contribution to journalArticle

1 Scopus citations

Abstract

This study models induced electric fields, and their gradient, produced by pulsatile current stimulation of submillimeter inductors for cochlear implantation. Using finite-element analysis, the lower chamber of the cochlea, scala tympani, is modeled as a cylindrical structure filled with perilymph bounded by tissue, bone, and cochlear neural elements. Single inductors as well as an array of inductors are modeled. The coil strength (100 nH) and excitation parameters (peak current of 1-5 A, voltages of 16-20 V) are based on a formative feasibility study conducted by our group. In that study, intracochlear micromagnetic stimulation achieved auditory activation as measured through the auditory brainstem response in a feline model. With respect to the finite element simulations, axial symmetry of the inductor geometry is exploited to improve computation time. It is verified that the inductor coil orientation greatly affects the strength of the induced electric field and thereby the ability to affect the transmembrane potential of nearby neural elements. Furthermore, upon comparing an array of micro-inductors with a typical multi-site electrode array, magnetically excited arrays retain greater focus in terms of the gradient of induced electric fields. Once combined with further in vivo analysis, this modeling study may enable further exploration of the mechanism of magnetically induced, and focused neural stimulation.

Original languageEnglish (US)
Article number7731169
Pages (from-to)1353-1362
Number of pages10
JournalIEEE Transactions on Neural Systems and Rehabilitation Engineering
Volume25
Issue number8
DOIs
Publication statusPublished - Aug 2017
Externally publishedYes

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Keywords

  • Cochlea
  • cochlear implants
  • finite-element analysis
  • induced electric fields
  • submillimeter inductors

ASJC Scopus subject areas

  • Neuroscience(all)
  • Biomedical Engineering
  • Computer Science Applications

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