本文設計兩類心血管支架,一類中各組支架為晶格厚度與肋線厚度相同的對照組,另一類中各組支架則為肋線厚度與晶格厚度不同的實驗組。首先利用PRO-E繪圖軟體建構支架模型,再將模型匯入有限元素分析軟體-ANSYS進行模擬,以探討心血管支架的晶格厚度與肋線厚度不同的情況下,支架受氣球擴張膨脹後的各種機械力學行為,如最大應力值、徑向變形、軸向變形、縮短率、狗骨效應程度、撓曲度與疲勞壽命等結果,並從中比較分析兩類支架的優缺點。同時,本文亦探討不同的氣球體擴張壓力下,對各種模擬結果會有什麼樣的影響。研究結果顯示,縮小肋線厚度的過程中,支架的最大應力值會變小,且發生位置將從支架的徑向肋線與晶格交接處漸漸轉移至軸向肋線與晶格交接處。因此,若能夠適度地縮小支架的肋線厚度,將可使支架適度地膨脹,最大應力值反而變小;而且可改善支架的撓曲性與提升其使用壽命,同時亦可減少金屬支架經氣球膨脹後與血管的接觸表面積,以減輕血管再度造成阻塞的可能性。
This thesis uses the finite-element-analysis software to investigate the mechanical behavior, such as maximum stress, radial deformation, axial deformation, foreshortening, dogboning, flexibility, and fatigue life, of expanded coronary stents with different thickness of cells and links. This thesis also makes a study of the mechanical behavior of stents with different bolloon-expanding pressures. The simulation results show that, during the reduction of link thickness, the location of the maximum stress will transfer from radial links to axial links and its value becomes smaller. Therefore, if the link thickness is properly reduced, the stent can properly expand and the maximum stress lowers in value. The reduction of link thickness can also improve the flexibility and the fatigue life of the stents and decrease the surface contact area between the expanded metal stent and vascular wall. As a result, the possibility of coronary occlusion after the stent is implanted may become less.