冠狀動脈疾病(Coronary Artery Disease, CAD)是指冠狀動脈內發生斑塊堆積進而導致動脈變狹窄、血管硬化甚至阻塞的現象，此時會出現心絞痛或心肌梗塞的症狀，而常見治療方式是以氣球導管將塗藥支架(Drug-Eluting Stent)置入狹窄的部位，經由氣球擴張及支架支撐恢復血流通暢。
本研究以有限元素模擬分析兩款市售代表性支架Xience V (Abbott Vascular)以及Resolute (Medtronic Cardio Vascular)在支架壓縮及擴張時聚合物塗層的等效應力應變，及探討其與塗層缺陷的關聯性。本研究也以有限元素模擬分析鎂合金支架塗層在支架壓縮、擴張及彎曲時的等效應變分佈與支架降解速率的關係。接著，本研究使用可進行破壞模擬(Fracture)的連接區模型(Cohesive Zone Model, CZM)的混合模式(Mixed Model)探討支架與塗層界面在壓縮與擴張過程中的黏脫機制。最後，本研究製作有聚合物塗層的傳統V型支架，及使用漸進式擴張方法觀察支架與塗層界面的分離情形，並與模擬結果進行比較。
本研究的有限元素模擬結果可以成功預估塗藥支架在壓縮與氣球擴張時，塗層可能產生缺陷的區域及型式，並可解釋鎂合金支架塗層等效應變分佈與支架降解情形的關係。

Coronary artery disease (CAD) is a condition in which plaque builds up in coronary arteries, leading to stenosis, sclerosis, or even blockage of the arteries, which can lead to angina or myocardial infarction. The common treatment is to place a drug-eluting stent through a balloon catheter into the stenosis, then blood flow can be restored through balloon expansion and stent support.
In this study, Finite element analysis (FEA) was performed to simulate the stress response of two commercial stents, Xience V (Abbott Vascular) and Resolute (Medtronic Cardio Vascular), during compression and expansion, and to investigate the association with the defects of stent coating. In the following, the strain distribution of magnesium alloy stent coating during the stent compression, expansion and bending was analyzed in relation to the stent degradation rate using FEA. Then, the mixed model of Cohesive Zone Model (CZM) was used to investigate the adhesion and separation mechanism of a stent-coating interface during compression and expansion. Finally, a conventional V-shaped polymer coated stent was manufactured. The adhesion and separation phenomena between the stent and coating was investigated by expanding the stent progressively, and the experimental result was compared with simulation.
The finite element simulation results of this study can successfully predict the defect location and type of stent polymer coating during the stent compression and balloon expansion, and it can explain the relationship between the strain distribution of magnesium alloy stent coating and stent degradation.

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