左心室輔助器之血液動力學研究

本研究利用動物模型與資料收集系統，針對台大一號離心式葉輪幫浦進行流線型流場的改良，並探討左心室輔助器與心臟血管系統之間血液動力學的交互影響；經量測波形的時間校正，可瞭解心臟搏動的運作機制；從犬隻實驗中，可知葉輪幫浦的輸出血流，會受心臟搏動週期的影響而呈現脈動流場。 LVAD輸入導管可分別由心房和心尖置入的手術縫合方式，而由心尖置入的方式可得較佳的運轉效率。當幫浦轉速增加時，心臟輸出血流量及血壓值都會被驅動而上昇，而其血壓脈動波形（POP與ABP）之振幅則會明顯降低；當LVAD分流量高於70%以上時，冠狀動脈血流會些微減少，而頸動脈流量則會些微增加；實驗結果顯示此小型左心室輔助器，可作為心臟移植前，輔助衰竭心臟的短期使用。實驗中亦發現，左心室輔助器可在犬隻心臟衰竭時，維持基本的血液循環，避免週邊組織衰竭，且可刺激並等待心肌細胞恢復功能，所以可作為心臟衰竭的急救工具。

關鍵字

脈動流場；心臟衰竭；血液動力學；犬隻模型；離心式葉輪幫浦；左心室輔助器

並列摘要

A revised Tai-Ta centrifugal impeller pump was designed to study the hemodynamic interaction of left ventricular assist device (LVAD) with the cardiovascular system in a canine model for pediatrics. After correcting the time delay between flow wave and pressure wave, we could realize the function of heart stroke. The LVAD outflow appeared to be pulsatile that matched with the cardiac cycle. The efficiency of pumping for LVAD inlet inserted directly through apex of heart was better than that through atrium. When the LVAD was operated at a higher rotational speed, the ABP, POP, pump flow, and the cardiac output flow increased. However, the fluctuating amplitudes of ABP, POP, and pump flow decreased prominently. When the share flow of LVAD was more than 70%, the flow of coronary artery decreased slightly, but the flow of common carotid artery increased slightly. This study showed that the centrifugal impeller pump could be used as an assist device when the cardiac function was impeded. When the canine suffered heart failure,the LVAD could support the function of circulation to avoid the other organ failure. The myocardiac function could be recovered by pulsatile stimulus of LVAD.The LVAD could be used as an aid apparatus of heart failure in urgency.

並列關鍵字

pulsatile flow ； canine model ； left ventricular assist device ； hemodynamics ； centrifugal impeller pump ； heart failure

參考文獻

[1] Chan, W.K. et al. 2002, Numerical Investigation of the effect of Blade Geometry on Blood Trauma in a Centrifugal Blood Pump. Artificial Organs 26(9):785-793.

[2] Chou, NK. et al. 2001, Development of a totally implantable pulsatile centrifugal pump as ventricular assist device. Artificial Organs 25(8): 603-606.

[3] Chou, NK. et al. 2001, Physiological analysis of cardiac cycle in an implantable impeller centrifugal left ventricular assist device. Artificial Organs 25(8):613-616.

[4] Christiansen, S. et al. 2002, Successful Cardiac Transplantation After 4 Cases of DeBakey LVAD Failure. J. Heart Lung Transplant 21:706-709.

[5] Chu, SH., Wang, SS., Chou, NK., Qian, KX., 1994, First assessment of a pulsatile impeller pump as left ventricular assist device(LVAD) in calves. J Surg Assoc 27:2460-2466.

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左心室輔助器之血液動力學研究

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