| Project/Area Number |
19K04253
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 20010:Mechanics and mechatronics-related
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| Research Institution | The University of Electro-Communications |
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Principal Investigator |
Nomura Hideyuki 電気通信大学, 大学院情報理工学研究科, 教授 (90334763)
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| Project Period (FY) |
2019-04-01 – 2022-03-31
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| Project Status |
Completed (Fiscal Year 2021)
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| Budget Amount *help |
¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2021: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2020: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2019: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
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| Keywords | 音響放射圧 / 音響流 / 音響パワー / 音圧 / 超音波プローブ |
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| Outline of Research at the Start |
超音波プローブの新たな評価方法の確立を目的を目指す．
超音波診断・治療おいて，使用される超音波プローブの出力評価は重要な検査項目である．特に安全面から，プローブから放射された音響エネルギーが「どの位置にどのくらい集中しているか」を測定することが重要である．
本研究では，超音波が液面に入射するときに生じる，音響放射圧による液面形状変化を光学的に測定し，さらに音響放射圧分布・音圧分布・音響パワーを推定する方法の確立を目指す．
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| Outline of Final Research Achievements |
To establish a new evaluation method for ultrasonic probes, we proposed and evaluated a method based on the measurement of water surface shape change by acoustic radiation pressure.
First, a theoretical model that takes into account the large-amplitude of water surface displacement was developed and compared with measurements. The results were not sufficient to explain the water surface displacement proportional to the cube of the sound pressure as shown in the measurement results. Next, instead of an unstable water surface, a thin film was used to measure the displacement due to radiation pressure, and its stability was verified. Finally, radiant power was measured from the obtained water surface displacement. The results showed larger values than those estimated by the hydrophone method.
Further studies on the relationship between water surface displacement and sound pressure and more accurate measurement methods are needed.
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| Academic Significance and Societal Importance of the Research Achievements |
放射圧による水面変位計測によって音響パワーと放射圧分布の同時計測が可能となる点が，社会的に意義ある成果である．この手法が確立されることで，現場における超音波プローブの評価が容易になる．
音響パワーに比例する放射圧が，今回の研究では示されなかった．このことは今後解決する必要があるが，同時に新たな物理メカニズムが潜んでいる可能性を示唆している．したがって，この現象の追求は新たな超音波現象の発見につながる可能性がある点で，学術的意義を有する．
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