The quality of visual perception with epiretinal electric stimulation strongly depends on the configuration of electrode arrays. Such arrays at the surface of the retina should excite only cells within a local area, but in practice, they exhibit some cross-talk, possibly leading to a smearing of focal activation of the retina. In this study, a passive model of extracellular voltage distribution arising from epiretinal stimulation is solved using the method of finite differences, in order to explore the voltage and current distributions of a hexagonal electrode array configuration. Results of this study suggest that the hexagonal electrode arrangement is effective in providing targeted focal activation of retinal tissue. Cross-talk between hexagonal clusters may be minimized by stimulus paradigms which utilize six return (or guard) electrodes around each stimulus electrode.
| Identifer | oai:union.ndltd.org:ADTP/187059 |
| Date | January 2005 |
| Creators | Cheng, Jia, Graduate School of Biomedical Engineering, Faculty of Engineering, UNSW |
| Publisher | Awarded by:University of New South Wales. Graduate School of Biomedical Engineering |
| Source Sets | Australiasian Digital Theses Program |
| Language | English |
| Detected Language | English |
| Rights | Copyright Jia Cheng, http://unsworks.unsw.edu.au/copyright |
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