新型三葉人工心瓣關閉動力研究

The closing dynamics of a new trileaflet heart valve

陳孝杰(Hsiao-Chien Chen)

指導教授 ： 盧博堅

淡江大學/工學院/水資源及環境工程學系碩士班/碩士(2010年)

https://doi.org/10.6846/TKU.2010.00189

摘要

目前臨床使用的人工機械心瓣可能會導致穴蝕的發生，造成心瓣本身與血球的破壞，並可能導致溶血與血栓的生成。穴蝕現象主要在葉片關閉的瞬間產生，因此與心瓣的關閉機制有很大的關聯。由於目前仍未有完美的人工心瓣，因此新型人工心瓣的設計與開發仍在不斷進行中。本研究針對穴蝕現象的生成，利用本實驗室所研發的新型三葉片機械心瓣與臨床上使用廣泛之St. Jude Medical雙葉片機械心瓣及Medtronic-Hall Standard 單葉片心瓣在體外模擬測試台中進行測試。實驗結果指出在葉片關閉速度、最大負壓(NPP)、壓力擾動之均方根值(RMS)以及左心室負載率(dp/dt)這些與穴蝕現象生成有關的各參數中，三葉片機械心瓣的表現較其他兩個心瓣為佳；而利用高速攝影機拍攝心瓣關閉瞬間的穴蝕汽泡影像的結果發現三葉片機械心瓣未有明顯的穴蝕汽泡生成，因此本實驗室所設計之三葉片機械心瓣其關閉行為應較其他單雙葉片心瓣設計為佳。

關鍵字

機械心瓣 ； 穴蝕現象 ； 葉片關閉速度 ； 壓力擾動之均方根值 ； 左心室負載率

並列摘要

Cavitation inception caused by clinical implanted mechanical heart valve (MHV) may destroy the constitution of MHV and blood cells, and it also may induce hemolysis and thrombosis. The closing mechanisms of MHV are more relevant to cavitation inception because the cavitation bubbles often be observed at the instant of MHV closure. To date, the new design of artificial heart valves are still developing because there are no perfect artificial valves yet. In this study, we used the new design Trileaflet MHV of our laboratory to study the inception of cavitation in in vitro physiological mock loop. We also used the St. Jude medical MHV (SJM) and Medtronic Hall standard MHV (MHS), which are implanted extensively in clinical, to compare the results of Trileaflet MHV.
Our results indicated that the valve closing velocity, the negative peak pressure (NPP), the root mean square of pressure fluctuation (RMS), and the loading rate (dp/dt), which are the important factors of cavitaion inception, were lower in Trileaflet MHV than SJM and MHS, and the cavitaion bubbles images captured from high speed CCD camera also displayed the unobvious cavitation bubbles in Trileaflet MHV than other two MHVs. This illustrate that the closing behavior of our new design trileaflet MHV is better than the monoleaflet and bileaflet MHVs.

並列關鍵字

mechanical heart valve ； Cavitation ； the valve closing velocity ； root mean square of pressure fluctuation ； the loading rate

參考文獻

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