| Project/Area Number |
11671760
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Ophthalmology
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| Research Institution | TOKYO DENKI UNIVERSITY |
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Principal Investigator |
KAWASUMI Masashi Tokyo Denki University, Department of Information and Communication Engineering, Assistant Professor, 工学部, 助教授 (40177689)
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| Co-Investigator(Kenkyū-buntansha) |
SAITO Masao Tokyo Denki University, Department of Information and Communication Engineering, Professor, 工学部, 教授 (60010708)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 2000: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1999: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | Magnetic Stimulation / Magnetophosphene / Electrophysiological test / Retina |
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| Research Abstract |
Magnetophosphene, a flickering light sensation perceived when a human head or visual system is exposed to an ELF magnetic field with sufficient intensity, is considered to be a sensation caused by activity of the stimulated retina. The magnetophosphene has been discussed not only to apply the magnetic stimulation method to the clinical test of the visual function but also to discuss the biological effect of the magnetic field. We studied on the estimation of the current density induced in the retina and the sphere of magnetophosphene in the visual field.(1)Electrophosphene is a similar light sensation perceived upon electrical stimulation to the eye. We calculated the current density distribution over all of the retina in an electrically stimulated human eye, using the finite element method. To discuss the threshold of current density that is required to cause retinal cell activity in a magnetically stimulated human eye, the density is compared with other results calculated under magnetic stimulation. (2)As the intensity of the magnetic field is increased, the sphere of the magnetophosphene spreads gradually over the visual field. We discuss the result with respect to not only the estimated current density induced in the retina by a magnetic field but also the threshold of the current density that is required to cause retinal cell activity in a magnetically stimulated human eye. The magnetophosphene is considered to be perceived in the local visual field corresponding to the retinal sphere of activity.
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