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標題: | 血管支架上微型儲藥槽對血管支架臨床性質的影響 Effects of Micro-sized Drug Reservoirs on Key Clinical Attributes for Drug-eluting Depot Stents |
作者: | Yi-Hsiang Chiu 邱奕翔 |
指導教授: | 蕭浩明(Hao-Ming Hsiao) |
關鍵字: | 心血管疾病,氣球擴張式血管支架,有限元素分析,塗藥血管支架,儲藥槽,血管支架疲勞壽命, Vascular Disease,Balloon-Expandable Stent,Finite Element Analysis,Drug-Eluting Stent,Drug Reservoir,Stent Fatigue Life, |
出版年 : | 2012 |
學位: | 碩士 |
摘要: | 血管支架為一微型醫療器材,佈署於阻塞的動脈以恢復血流。本論文首先對血管支架進行參數分析,以了解各項設計參數對於血管支架臨床性質的影響。依據美國食品藥品管制局(FDA)提出的血管支架臨床性質,包含應力/應變分佈、抗疲勞強度、徑向強度以及擴張回彈。我們建立了一系列的有限元素模型來模擬分析血管支架在各階段的物理性質,從血管支架壓縮至心導管,支架於血管內擴張並且受血管壁壓力的徑向強度測試,以及在血管中受到脈衝負載的疲勞壽命。
接著利用這些模型探討一種新型的塗藥血管支架,此新型設計是在血管支架上加工微型儲藥槽,使得藥物的釋放時間和空間可受到精準的控制,相較於傳統的塗藥血管支架有更多的發展潛力。然而,加工儲藥槽將會降低血管支架支撐的能力,因此我們系統性的探討了加工微型儲藥槽對於血管支架性質的影響,同時提出理想的儲藥槽設計,可以在最低限度的降低血管支架性質的前提下,提升儲藥量達傳統塗藥血管支架的三倍。 最後,近期醫學期刊如Eurointervention以及JACC: Cardiovascular Intervention上報導一項新的介入性心血管手術(PCI)併發症,我們利用有限元素模型對於此一議題進行工程角度的探討,研究不同的血管支架設計對於該併發症可能的影響。本論文所提出的各項分析工具可以用於探究血管支架的基本性質、臨床議題,以及協助瞭解不同支架設計對於支架臨床表現的影響。期望藉由未來完備更多分析方法,能得到最佳化的血管支架設計,達到理想的機械性質。 A stent is a miniature medical device deployed in a stenotic artery to restore the blood flow. In this thesis, we first carried out a sensitivity analysis using the developed finite element models and the parametric stent design to investigate several key clinically-relevant functional attributes recommended by FDA. These key clinical attributes include stresses/strains, fatigue resistance, radial strength, and expansion recoil. The finite element models were able to predict the mechanical integrity of a balloon-expandable stent at various stages such as crimping onto a balloon catheter, stent expansion, radial strength to resist blood vessels from collapsing, and service life in the human body when subjected to pulsatile blood pressure. Subsequently, we used these models to investigate an innovative variation of the drug-eluting stent (DES) with micro-sized drug reservoirs-the depot stent. It allows programmable drug delivery with both spatial and temporal control and has several potential advantages over traditional DESs. However, creating such reservoirs on the stent struts may weaken the structure of the stent scaffolding and compromise its mechanical integrity. Thus, we systematically evaluated the effects of these micro-sized drug reservoirs on stent attributes and proposed an optimized depot stent that could triple drug capacity than the current DESs with marginal trade-off in its attributes. Finally, we introduced a newly-found percutaneous coronary intervention complication called the longitudinal deformation and evaluated the effect of different stent designs on stent longitudinal integrity via computational modeling. We found that the stent strut phase and the connector number had significant effect on stent longitudinal integrity. In summary, the developed analytical schemes allow us to gain deeper insight into the fundamental stent issues and evaluate the mechanical behavior of various stent designs, in the hope to optimize the overall stent attributes. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/65419 |
全文授權: | 有償授權 |
顯示於系所單位: | 機械工程學系 |
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