title: Finite element bidomain model of epiretinal stimulation.
abstract: A finite element model of epiretinal stimulation is presented, consisting of a continuum description of active retinal tissue in contact with bulk vitreous fluid. Simulations were undertaken to investigate the effect of mesh element size in the finite element model on threshold current. The threshold current varied by approximately 0.6% when the maximum mesh element size was changed from 125 to 225 microm. Threshold currents for activation of retinal ganglion cells were determined for electrodes placed at different heights above the retinal surface. These results compared favorably with published experimental data on transretinal electrical stimulation of mammalian retina in an isolated preparation. Model threshold values were some 2-5 times higher than that of the experimental values.
authors.affiliation: Faculty of Engineering, University of Newcastle, Callaghan, NSW 2038, Australia. Saiful.Joarder@studentmail.newcastle.edu.au
authors.forename: Saiful A
authors.initials: SA
authors.lastname: Joarder
authors.forename: Socrates
authors.initials: S
authors.lastname: Dokos
authors.forename: Gregg J
authors.initials: GJ
authors.lastname: Suaning
authors.forename: Nigel H
authors.initials: NH
authors.lastname: Lovell
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D003198:Computer Simulation; D004056:Differential Threshold / Q000502:physiology*; D004558:Electric Stimulation / Q000379:methods*; D004599:Electric Stimulation Therapy / Q000379:methods*; D005074:Evoked Potentials, Visual / Q000502:physiology*; D006801:Humans; D008959:Models, Neurological; D012165:Retinal Ganglion Cells / Q000502:physiology*