Development of the endurable prosthetic heart valves for the implantable total artificial heart.
| Project/Area Number |
61490025
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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 |
広領域
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| Research Institution | HIROSHIMA UNIVERSITY |
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Principal Investigator |
HAMANAKA Yoshiharu Hiroshima University School of Medicine, Research Assistant, 医学部, 助手 (20156409)
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| Co-Investigator(Kenkyū-buntansha) |
KAJIHARA Hiroki Hiroshima University School of Medicine, Associate Prof., 医学部, 助教授 (20034184)
FUKUNAGA Shintaro Hiroshima University School of Medicine, Research Assistant, 医学部, 助手 (70112183)
MATSUURA Yuichiro Hiroshima University School of Medicine, Prof., 医学部, 教授 (80190403)
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| Project Period (FY) |
1986 – 1988
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥6,200,000 (Direct Cost: ¥6,200,000)
Fiscal Year 1988: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1987: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1986: ¥3,000,000 (Direct Cost: ¥3,000,000)
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| Keywords | Total artificial heart / Prosthetic heart valve / Water hammer phenomenon / Valve holding ring / 人工弁固定リング / 衝撃緩衝材料 / 人工弁固定モデル / 攻撃緩撃物質 / 耐久性 / 弁前後の圧較差 / 先端圧測定用トランスデューサー / 差動増幅器 |
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| Research Abstract |
The causes of the valve failures of the total artificial heart were as follows: The valve was mounted in a rigid polyurethane and the dp/dt of the driving pressure of the artificial heart was higher than in the natural heart. High pressure gradient appearred across the valve at the moment of valve closing by water hammer phenomenon, and the clinically used cardiac valves were not strong enough to endure this high pressure.
The pressure gradient across the valve was measured by using mock circulation. maximum pressure gradient was measured at the moment of valve closing just after the valve opened completely. Maximum pressure gradient was lower in the bi-leaflet valve which had lower valve profile at valve opening. Maximum pressure gradient was higher in the valves which valve rings were enforced. In order to decrease the pressure gradient across the valve, the mechanical improvement of the valve was necessary. The clinically used bi-leaflet valve had relatively weak valve ring, it was hardly mounted in the artificial heart. Then the development of a new valve holding ring of the artificaial heart which decreased the pressure gradient across the valve was started. An experimental model (the valve holding ring model) was developed, in which the shock absorbent material was used in the valve holding ring. The pressure gradient across the valve by the water hammer phenomenon was decreased in the model in which the special shock absorbent material was used, compared with the control in which the valve was mounted in a rigid ring.
From the result obtained in those experiment, in order to prevent the valve failures, a new valve holding ring of the artificial heart was developed. further improvement is necessary to apply this new valve holding ring in the presently used artificial heart.
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Report
(4 results)
Research Products
(13 results)
