Determination of frictional conditions between electrode array and endosteum lining for use in cochlear implant models

Finite Element Analysis of Damage by Cochlear Implant Electrode Array’s Proximal Section to the Basilar Membrane

“…Surface-to-surface contact algorithm (11) was used to model the sliding of the electrode array (''slave'' surface) against the scala tympani (''master'' surface). A friction coefficient of 0.04 was incorporated into the model for the insertion of the Nucleus contour array, whereas the sliding of the Nucleus standard straight array and the single wire electrode was modeled using a friction coefficient of 0.12 (12). Enforced displacements were applied at the nodes at the basal end of the electrode array, whereas the nodes on the scala tympani model were fixed.…”

Development of a steerable cochlear implant electrode array

“…The mesh for the electrode array and the scala tympani was constructed using FEMAP and NE/NASTRAN 8.32 was used to undertake the analysis. Experimental values of friction coefficient between the electrode array and the endosteum lining covering the interior wall of the scala tympani for the Nucleus standard straight array were used in the finite element model [16]. Experimental values of friction coefficient between the electrode array and the endosteum lining covering the interior wall of the scala tympani for the Nucleus standard straight array were used in the finite element model [16].…”

3D finite element analyses of insertion of the Nucleus standard straight and the Contour electrode arrays into the human cochlea

“…A Poisson ratio n of 0.3 for the electrode array was adopted in the 3D FE model (Chen et al, 2003). A 'master-slave' interface was implemented for the sliding contact between the scala tympani and an electrode array with a friction coefficient of 0.12 (for the Nucleus standard straight array) and 0.04 (for the Contour array) (Kha and Chen, 2006), which were found to be an appropriate value for the contact between each electrode array and the endosteum lining of the cochlear wall lubricated by glycerin. While Healon has been widely used as a lubricant for cochlear implantation, glycerin has also been used to a lesser extent in a number of studies (Lehnhardt, 1993;Roland et al, 1995;Tykocinski et al, 2001;Laszig et al, 2002;Wardrop et al, 2005).…”