2003 Fiscal Year Final Research Report Summary
A Study on Microwave Mammography
| Project/Area Number |
14580824
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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 |
Biomedical engineering/Biological material science
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| Research Institution | Nagasaki University |
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Principal Investigator |
TAKENAKA Takashi Nagasaki University, Faculty of Engineering, Professor, 工学部, 教授 (40117156)
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| Co-Investigator(Kenkyū-buntansha) |
ZHOU Hui Nagasaki University, Faculty of Enginnerng, Research Associate, 工学部, 助手 (20346927)
TANAKA Toshiyuki Nagasaki University, Graduate School of Science and Technology, Associate Professor, 生産科学研究科, 助教授 (50202172)
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| Project Period (FY) |
2002 – 2003
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| Keywords | Breast Cancer / Mammography / Mivrowave / Inverse Problem / Tomography |
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| Research Abstract |
1.A new reconstruction algorithm referred to as the three-dimensional forward-backward time-stepping (3-D FBTS) algorithm has been developed for imaging the electrical parameter (pennittivity, conductivity, and permeability) distributions of a three-dimensional lossy inhomogeneous object in a lossy medium from the transient data of the scattered field by the object under the illumination with a pulsed microwave.
2.A dipole antenna is supposed to be used as an element of array antenna of a measuring part of microwave mammography. The 3-D FBTS algorithm developed under the assumption of an ideal infinitesimal dipole is extended by considering the effects of the finite length of the dipole antenna in real situation.
3.A two-step image reconstruction algorithm has been developed to speed up the processing time. First, existence of the abnormal tissue and its rough position and size are estimated using synthetic aperture processing or genetic algorithm. Then, by selecting small region in its vicinity as an estimation region and applying the FBTS method to the region to reconstruct dielectric constant and conductivity distribution, we can distinguish whether it is the cancer or not.
4.The numerical simulation of the image reconstruction of a three dimensional object surrounded by array antenna which places antenna element on a cylinder was carried out. The effectiveness of the 3-D FBTS image reconstruction method considering the size of the antenna was confirmed. The numerical simulation of the image reconstruction of an object surrounded by array antenna which places antenna element on a plane was also carried out and the speedup of image reconstruction by synthetic aperture processing or genetic algorithm combined with FBTS method was confirmed.
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