人工機械瓣自1950年發展至今，超過80種以上的設計曾經用於臨床試驗，但依然無法避免血栓現象(Thrombus)及溶血現象(Hemolysis)的發生。本研究採用翼型理論(Theory of Wing Sections)與飛行穩定力學(Flight Stability)的概念作為翼型人工瓣的設計基礎，以降低葉瓣對血球的傷害與減少葉瓣撞擊金屬支架的動量為設計目標。本研究結合計算流體力學(Computational Fluid Dynamics)、類神經網路(Artificial Neural Network)與基因演算法(Genetic Algorithms)進行二維葉瓣最佳化的設計，以獲得開啟至最大角度時的最佳葉瓣外型ASV-1與適當的旋轉中心位置。與傳統式平板葉瓣相比較，ASV-1的血動力(Hemodynamics)流場品質較佳，血液通過葉瓣時的壓力損耗低，駐流區小，較不易造成血栓現象，產生的雷諾應力(Reynolds Stress)亦較小，因此對血液傷害較低；同時，其開啟至最大角度時的力矩接近靜平衡，致使葉瓣撞擊金屬支架的動量最小，因此可避免支架疲勞斷裂及葉瓣振動(Fluttering)，非但優化了結構強度設計，亦避免了振動所產生的非定常尾流(Wake)對血液的傷害。

Since 1950, more than 80 prosthetic heart valves have been developed and used clinically, but none of them can be considered prefect hemodynamically. Thrombus and hemolysis still exist. Patients with prosthetic valves often have to receive long-term anticoagulant therapy. A new design concept is proposed here which fully utilizes the aeronautic wing design guidelines. The design objective lies in lowering the valve induced damage to the blood cells and minimizing the impact momentum between the occluder and the strut of the valve. Based on the theory of wing sections and the analogy of flight stability, an optimal procedure which integrates Computational Fluid Dynamics (CFD), Artificial Neural Network (ANN) and Genetic Algorithms (GA) is developed to search for an optimal occluder shape and a minimal-moment rotation center. Comparing the optimal ASV-1 design to the baseline plate occluder, ASV-1 has better hemodynamic characteristics of lower pressure loss and Reynolds stresses. Furthermore, ASV-1 has nearly zero-moment when it reaches the maximum opening angle where the resultant impact force is low. The concern of strut failure can thus be greatly relieved. The present work successfully integrates ANN and GA to result in an engineering optimization procedure that can be used to show the importance of the shape of the occluder and the position of the rotating center in the mono-leaflet heart valve design.

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