2005 Fiscal Year Final Research Report Summary
Transillumination imaging of biological body using snake photons
| Project/Area Number |
15300149
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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 | HOKKAIDO UNIVERSITY |
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Principal Investigator |
SHIMIZU Koichi Hokkaido Univ., Grad.Sch.of Inf.Sci. & Tech., Professor, 大学院・情報科学研究科, 教授 (30125322)
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| Co-Investigator(Kenkyū-buntansha) |
KATO Yuji Hokkaido Univ., Grad.Sch.of Inf.Sci. & Tech., Instructor, 大学院・情報科学研究科, 助手 (50261582)
YAMASHITA Masaji Hokkaido Inst.of Tech., Fac.of Eng., Professor, 工学部, 教授 (40210421)
KITAMA Masataka Hokkaido Inst.of Tech., Fac.of Eng., Professor, 工学部, 助教授 (50285516)
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| Project Period (FY) |
2003 – 2005
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| Keywords | snake photon / near-axis scattered light / near-infrared light / scattering / transillumination imaging / optical CT / light diffusion / time-resolved measurement |
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| Research Abstract |
For transillumination imaging of a biological body by near-infrared light, a technique has been developed to realize the imaging of absorption distribution in diffuse scattering medium. Through this study, the following results were obtained.
(1)In theoretical and experimental analyses, it was verified that a detectable amount of snake photons is emitted through the dense medium which could not see through with the conventional technique using ballistic photons.
(2)A technique has been developed to detect the snake photon efficiently through the scattering object which corresponds to the mammalian tissue with 10-20 mm thickness. This technique is based on the time-resolved measurement of output pulse shape for ultra-fast light-pulse incidence.
(3)A new technique has been developed to apply the above principle to the much simpler continuous wave (CW) measurement using a CW light source.
(4)An experimental system was newly developed which consisted of a snake-photon detection device, a model phantom to simulate the optical property of mammalian tissue and an imaging system.
(5)The effectiveness of the proposed principle and the usefulness of the developed system were verified in the imaging experiment using the above experimental system.
(6)The proposed principle and the developed system were applied to the transcutaneous fluorescent imaging.
(7)An analytical solution was obtained to describe the photon propagation in a dense random medium by applying the diffusion approximation to the equation of transfer. Using this solution, a technique to improve the transillumination image through a diffusing medium was newly developed.
(8)Through this study, a concrete measure was obtained to realize the transillumination imaging using snake photons as well as clarifying the problems to be solved.
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