Distribution of current intensities inside the electrically stimulated eye
Kawasumi, M.
Nippon Ganka Gakkai Zasshi 89(6): 766-772
1985
ISSN/ISBN: 0029-0203 PMID: 4061171 Document Number: 258921
Several techniques and analyses of the electrical stimulation of the visual system have been studied for the purpose of clinical application. The stimulus has possibility of activating the retina without influence from the optical media such as the lens and vitreous opacity and from the refractive error, and is expected to cause the cells to fire in the retina of the stimulated eye. There have been, however, no studies of the quantitative evaluation of the spatial sphere of the stimulus current of the eye. This might be due to the invisibility of the stimulus current and to the difficulty in measuring current intensities of each site in the eye. In order to provide such evaluation, some method of approximate numerical analyses and computer simulations were applied in this paper. (1) To do this stimulation, an approximate eye model which has electrical constants was introduced. Two metal lings in contact with the surface of a contact lens and they were assumed to be sources of the stimulus current. (2) A Finite Element Method algorithm was constructed to carry the numerical calculation. (3) The current intensities and the directions of each site in the stimulated eye (current density distribution) were calculated using above algorithm. (4) The results might be used as the reference when stimulus parameters were given in an experiment.