Title :
Finite Element Bidomain Model of Epiretinal Stimulation
Author :
Joarder, S.A. ; Dokos, S. ; Suaning, G.J. ; Lovell, N.H.
Author_Institution :
Univ. of Newcastle, Newcastle
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 mum. 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.
Keywords :
bioelectric phenomena; biomedical electrodes; cellular biophysics; eye; mesh generation; neurophysiology; patient treatment; physiological models; active retinal tissue; bulk vitreous fluid; electrodes; epiretinal stimulation; finite element bidomain model; mammalian retina; mesh element size; retinal ganglion cell activation; transretinal electrical stimulation; Australia; Biomedical engineering; Blindness; Electrical stimulation; Electrodes; Extracellular; Finite element methods; Photoreceptors; Retina; Threshold current; Action Potentials; Animals; Computer Simulation; Differential Threshold; Electric Stimulation; Electric Stimulation Therapy; Evoked Potentials, Visual; Humans; Models, Neurological; Retinal Ganglion Cells;
Conference_Titel :
Engineering in Medicine and Biology Society, 2007. EMBS 2007. 29th Annual International Conference of the IEEE
Conference_Location :
Lyon
Print_ISBN :
978-1-4244-0787-3
DOI :
10.1109/IEMBS.2007.4352495
