1998 Fiscal Year Final Research Report Summary
Development of a chirp radar-type microwave computed tomography with the rotational scanner used for animal experiments
| Project/Area Number |
09558116
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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 | 展開研究 |
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| Research Field |
Biomedical engineering/Biological material science
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| Research Institution | Niigata University |
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Principal Investigator |
MIYAKAWA Michio Niigata University, Faculty of Engineering, Professor, 工学部, 教授 (50239357)
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| Co-Investigator(Kenkyū-buntansha) |
KANAI Yasushi Niigata Institute of Technology, Associate Professor, 工学部, 助教授 (00251786)
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| Project Period (FY) |
1997 – 1998
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| Keywords | Microwave / Chirp signal / CT (Computed Tomography) / Rotational scan / Imaging / Temperature variation |
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| Research Abstract |
The prototype system of the chirp radar-type microwave computed tomography (CP-MCT) was developed for noninvasive thermometry of the human body. High speed imaging of CP-MCT has been attempted in this study by introducing the rotational scan in the tomographic measurement. The prototype system, which uses the chirp pulse signal from 1 GHz to 2 GHz, collects projection data by repeating the translational scan and rotational scan of a pair of the transmitting- and receiving-antenna. The spatial resolution of the prototype system is estimated at approximately 1cm and 0.7 degree temperature variation has been visualized, although it takes approximately 100 minutes for data acquisition.
The developed rotational scanner is composed of a transmitting antenna that is the dielectric loaded transmitting antenna and a receiving array antenna, which is composed of 21 small dipole antennas. Chirp pulse signal from 1 GHz to 2 GHz is irradiated from the transmitting antenna to a target immersed in saline solution. Since gain pattern of the dielectric-loaded waveguide antenna is fairly broad so that, fan beam projection is secured. The transmitting- and receiving-antenna are facing each other at a distance of 282 mm. Each dipole is arranged at a distance of 14.7 mm from adjacent dipole antennas to reduce the mutual coupling effect. Where, fan angle of the scanner becomes 60 degrees.
Spatial resolution of the developed scanner is the same value with the predicted one that is worse than that of the prototype system due to its coarse sampling interval of the rotational scanner. However, this enabled us to develop the new rotational scanner with 41 small dipole antennas for animal experiments. It requires only 90 seconds for data acquisition.
In addition to high speed imaging, image deblurring technique has also been developed by using the point spread function computed by FD-TD method.
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