| Project/Area Number |
61570399
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Circulatory organs internal medicine
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| Research Institution | Hokkaido University |
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Principal Investigator |
MIKAMI Tomohisa Faculty of Engineering, Hokkaido University, 工学部, 教授 (00001678)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAMOTO Katsuyuki Faculty of Engineering, Hokkaido University, 工学部, 助教授 (10088867)
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| Project Period (FY) |
1986 – 1987
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| Project Status |
Completed (Fiscal Year 1987)
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| Budget Amount *help |
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1987: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1986: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | Atherosclerosis / Ultrasound / Noninvasive measurement / Intravascular measurement / 血管弾性率 |
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| Research Abstract |
1. Measurement of arterial wall thickness
We proposed three kinds of signal processings on an ultrasonic echo for obtaining arterial wall thickness to measure elastic properties of the artery using ultrasound.Accuracy of methods was examined by computer simlation and by in vitro experiments. The thickness measurement by spectral analysis of the echo attained the accuracy of better than 5 micron and minimum detectable thickness of about 0.3 mm, when ultrasound of 5 MHz was used.
2. Development of intravascular ultrasonic transducer
An intravascular ultrasonic transducer for measuring regional elasticity along the aorta was developed. The transducer consists of PZT element, a flexible Ni-Ti wire for positioning the element and a catheter for blood pressure measurement, so as to obtain simultaneously four parameters concerning Young's modulus of the artery; i.e., diameter of the artery, pulsatile diameter change, artyerial wall thickness and pulse pressure. The progressive increase in Young's modulus of the aorta with distance to peripherals was found in in vivo experiments performed on dogs.
3. Clinical measurement of arterial elasticity
Pressure strain elastic modulus of the abdominal aorta was noninvasively measured in 70 healthy subjects, 31 patients with coronary artery disease, and 36 patients with hypertension. Significant increase of the elastic modulus found in the patient groups shows promise of early detection of atherosclerosis by this technique.
4. Future progress of this project
One future development of this project is clinical application of the intravascular ultrasonic transducer for an accurate examination of atherosclerosis, and the other is nonivasive detection ofage-related atherosclerotic change of the artery at an early stage.
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