| Project/Area Number |
12557112
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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 |
Thoracic surgery
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
NISHIMURA Kazunobu GRADUATE SCHOOL OF MEDICINE, ASSOCIATE PROFESSOR, 医学研究科, 助教授 (70252450)
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| Co-Investigator(Kenkyū-buntansha) |
NOJIRI Chisato TERUMO CO., RESEARCH CENTER, TECHNOLOGY DEPT., PROFESSOR, 研究開発センター, 主任研究員
AKAMATSU Teruaki SETSUNAN UNIVERSITY, TECHNOLOGY DEPT, PROFESSOR, 工学部, 教授 (40025896)
KOMEDA Masashi GRADUATE SCHOOL OF MEDICINE, PROFESSOR, 医学研究科, 教授 (20303810)
斉藤 能彦 京都大学, 医学研究科・循環器内科学, 助教授 (30250260)
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| Project Period (FY) |
2000 – 2002
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| Project Status |
Completed (Fiscal Year 2002)
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| Budget Amount *help |
¥10,200,000 (Direct Cost: ¥10,200,000)
Fiscal Year 2002: ¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 2001: ¥2,700,000 (Direct Cost: ¥2,700,000)
Fiscal Year 2000: ¥5,000,000 (Direct Cost: ¥5,000,000)
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| Keywords | Centrifugal Pump / Control System / Failing Heart / Cannulation site / Left Ventricular Assist / 左室脱血 / 磁気浮上型遠心ポンプ / 心不全 / 拍動流 / 自動制御法 |
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| Research Abstract |
1) Study 1
This study was designed to investigate how the inflow cannulation site of the left ventricular assist system (LVAS) with centrifugal pump would influence cardiac function on failing heart models. In 10 sheep, LVAS was instituted by two inflow cannulae in the left atrium (LA) and the left ventricle (LV), and connecting those cannulae to a magnetically suspended centrifugal pump. The pump flow with LV cannulation increased during the systolic phase and decreased during the diastolic phase, while it was constant with LA cannulation. Ejection fraction with LA cannulation decreased as the assist rate increased, while that with LV cannulation was maintained up to 75% assist. The external work with LA cannulation decreased gradually as the assist rate increased, while the EW with LV cannulation did not decrease until the assist rate reached 75%. The myocardial oxygen consumption of both cannulation decreased proportionally as the assist rate increased, and were significantly less wi
… More
th LV cannulation at the 100% assist rate than with LA cannulation. The LV cannulation during LVAS maintains EF, and provides effective reduction in oxygen consumption.
2) Study 2
Control system of centrifugal pump in response to necessary demanding of body was devised. An inflection point was set on P-Q curve (Relationship between pressure head and flow). We set two modes of pump control: one is the disease mode with steep slope where the pump flow is less than the inflection point, and the other is the healthy mode with mild slope where the pump flow is more than the inflection point. The disease mode was well operated to keep the minimal pump flow rate. However, the healthy mode did not work well.
3) Study 3
Estimation of the heart recovering from failing was assessed by only pump parameters. The LV pressure and electricity current were recorded simultaneously. The pump flow increased as the LV pressure increased with some delay. The change between electricity-current and pump flow had phase difference. Therefore, we needed correction formula to estimate LV pressure. Less
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