Development of the apparatus using focused ultrasound for cancer-heat therapy and its fundamental study
| Project/Area Number |
03454309
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
General surgery
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| Research Institution | Teikyo University |
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Principal Investigator |
ISHIOKA Kuniaki Teikyo Univ., Dep, of Radiol. Lecturer, 医学部, 講師 (40082250)
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| Co-Investigator(Kenkyū-buntansha) |
YASUKOCHI Hiroshi Teikyo Univ., Dep, of Radiol. Professor, 医学部, 教授 (70174505)
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| Project Period (FY) |
1991 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 1993: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1992: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1991: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | Focused ultrasound / Cancer therapy / heat therapy / Apparratus development / Hyperthermia / 音場分布 / 温熱 |
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| Research Abstract |
1. Firstly 1)Double focusing by multiple spherical oscillators is more desirable than single focusing by a single spherical oscillator. 2)From computer simulation results as ultrasonic frequency, 700KHz is more suitable than 500KHz. 3)The similar finding was obtained that ultrasonic convergence changed by adjusting each phase of applied voltage of adjacent oscillators from the simulation result.
2. We made a prototype apparatus consisting of eight spherical oscillators with 700KHz frequency based on the above-mentioned findings.
3. Using the apparatus. 1)Field distribution of ultrasound in water and beam profiles by each phase were obtained. The results were in good agreement with those by the computer simulation. 2)Thereafter, visualization of ultrasonic intensity by radiation pressure was tried. Tapering rise of water on medium surface was formed by radiation pressure, and excellent convergence of eight ultrasonic fluxes was observed.
4. Furthermore, using agar phantom with soft part ti
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ssue equivalent and press hum, the studies concerning 1)time course of temperature rise, and 2)temperature distribution (thermogram) were done. The results indicated that a heating area with the highest temperature in a technological focusing position was formed, and that temperature rise was hardly recognized in a position 4cm away from the focus. The values of a heating half magnitude area changed in the range of 2.5cm to 3.5cm by exchange of the phase as above-mentioned.
5. Time course of temperature rise in a blood circulating femoral part and a cancerbearing femoral part of the rabbit showed that a better heating area was obtained at a targeted convergent site of ultrasound.
6. As histological effects on a femoral part of the rabbit, inflammatory change of the soft part tissue and partial leakage of blood out of capillaries were recognized by treatment at 50ﾟC and for five min. However, distinct changes were not observed in relatively large blood vessels. It is our next step to determine the optimal condition for cauterization therapy in the near future. Less
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Report
(4 results)
Research Products
(4 results)
