Finite element modelling of cochlear electrical coupling

Abstract

The operation of each hair cell within the cochlea generates a change in electrical potential at the frequency of the vibrating basilar membrane beneath the hair cell. This electrical potential influences the operation of the cochlea at nearby locations and can also be detected as the cochlear microphonic signal. The effect of such potentials has been proposed as a mechanism for the non-local operation of the cochlear amplifier, and the interaction of such potentials has been thought to be the cause of the broadness of cochlea microphonic tuning curves. The spatial extent of influence of these potentials is an important parameter for determining the significance of their effects. Calculations of this extent have typically been based on calculating the longitudinal resistance of each of the scalae from the scala cross sectional area, and the conductivity of the lymph. In this paper, the range of influence of the electrical potential is examined using an electrical finite element model. It is found that the range of influence of the hair cell potential is much shorter than the conventional calculation, but is consistent with recent measurements.

Computational Simulation Expands Understanding of Electrotransfer-Based Gene Augmentation for Enhancement of Neural Interfaces

“…Finite element computational modeling of electrical stimulation in the cochlea has been the subject of many investigations for over 30 years (Finley et al, 1987; Finley, 1989; Finley et al, 1990). More recent models based on image reconstructions (Ceresa et al, 2014; Kalkman et al, 2015; Kang et al, 2015; Malherbe et al, 2016; Tachos et al, 2016; Teal and Ni, 2016; Wong et al, 2016; Cakir et al, 2017; Schafer et al, 2018) or simplified geometries (Briaire and Frijns, 2000, 2006; Hanekom, 2001; Rattay et al, 2001; Goldwyn et al, 2010; Saba et al, 2014; Nogueira et al, 2016) of the cochlea have been applied to predict electric potential and field distributions following electric stimulation by electrode arrays of cochlear implants.…”

Using Cochlear Microphonic Potentials to Localize Peripheral Hearing Loss

“…Perhaps the attenuation rate seen at the RW differs from the rate observed intracochlearly because of the different positions of the recording and/or the reference electrodes. Although these relationships are challenging to test experimentally, models that incorporate realistic cochlear dimensions and material properties (e.g., Teal and Ni, 2016) may provide insight on how attenuation is affected by electrode position.…”

A full-head model to investigate intra and extracochlear electric fields in cochlear implant stimulation

“…In order to gain a better understanding of the underlying biophysics of CI electrical stimulation, the use of computational models have increasingly gained the attention of researchers. This is the case of volume conduction or volume EF models, which, based on general or user-specific anatomical models of the cochlea, permit the prediction of the EF and current density using numerical techniques such as the finite element method (FEM) (Rattay et al 2001, Wong et al 2015, Hanekom and Hanekom 2016, Kalkman et al 2016, Nogueira et al 2016, Teal and Ni 2016, Dang 2017, Gerber et al 2017, Mangado López et al 2018b, Potrusil et al 2020, Sriperumbudur et al 2020, Cheng et al 2022, Hrncirik et al 2023. However, models restricted to the cochlea present the limitation that they do not realistically emulate boundary conditions and cannot be used for the analysis of extracochlear current flow through head tissues.…”