| Project/Area Number |
13480293
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Biomedical engineering/Biological material science
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| Research Institution | Osaka University |
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Principal Investigator |
HARUNA Masamitsu Osaka University, Faculty of Medicine, Professor, 医学部, 教授 (20029333)
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| Co-Investigator(Kenkyū-buntansha) |
MAKI Atsushi Hitachi Ltd., Research Scientist, 研究員
OHMI Masato Osaka University, Faculty of Medicine, Research Associate, 医学部, 助手 (60273645)
KANOSUE Kazuyuki Osaka University, Faculty of Medicine, Professor, 医学部, 教授 (50127213)
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| Project Period (FY) |
2001 – 2002
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| Project Status |
Completed (Fiscal Year 2002)
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| Budget Amount *help |
¥9,300,000 (Direct Cost: ¥9,300,000)
Fiscal Year 2002: ¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2001: ¥5,800,000 (Direct Cost: ¥5,800,000)
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| Keywords | Functional reflection optical tomography (f-ORT) / Coherence gate (OCT) / Neural activation potential / Measurement of refractive index of biological tissue / Analysis of brain function |
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| Research Abstract |
Our research target is proposal and demonstration of a novel functional optical reflection tomography (f-ORT). This unique technique is used for measurement of spatial and temporal distribution of neural activation potential of the cerebral cortex of rats, showing that the f-ORT is effective for brain neurology.
(1) A SLD is used as the light source of the existing optical coherence tomography (OCT); however, the coherence length of SLD is 10 to 20 μm which is insufficient for detection of neural activation potential. In order for the detection, the SLD was replaced by a mode-locked Ti:sapphire laser which supplied the pulsewidth as short as lOfs. This laser can provide us OCT with the spatial resolution of 3 μm after proper compensation of chromatic dispersion of the interferometer.
(2) In order to the high-resolution OCX described above, we developed the 1,3-μm OCT in which the imaging depth is improved to be 1.5mm or more. Subsequently, the desired optical reflection tomography was de
… More
veloped by combination of the coherence-gate optics and confocal optics.
(3) The imaging data must be acquired as fast as possible in order to detect the neural activation potential in synchronization with the cardiac rate. Such a high-speed data acquisition can be realized by non-mechanical optical-delay scanning. In the f-ORT, the optical-delay scanning is performed by PZT fiber phase modulators, as a result, more than 50 optical-delay scans per second were obtained. All the raster scan signals are summed up to improve drastically the signal-to-noise ratio.
(4) In the preliminary experiment, a refractive index change was detected by the f-ORT when a sound stimulus was applied to a rat. The index change may correspond to the neural activation potential due to a sound stimulus. A remarkable change of the optical reflection signal was detected in a 100-μm deep area 20s after application of the sound stimulus. On the basis of research results, as mentioned above, we have been developing the f-ORT for brain neurology. Less
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