本文以電腦模擬方式探討血管斑塊對於心血管支架設計與選用的影響,在模擬過程選用兩種血管內腔斑塊,一種為圓形內腔的血管斑塊,另一種為橢圓形內腔的血管斑塊;並且設計三種厚度尺寸的心血管支架,試圖在各種血管內腔中找出較適合的心血管支架。首先利用電腦繪圖軟體建構支架模型,再將模型匯入有限元素分析軟體進行模擬,以探討心血管支架厚度不同的情況下,支架擴張後因血管斑塊回彈而產生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、與狗骨效應等結果,並從中比較分析三種支架的優缺點。同時,本文亦記錄了用於不同的血管斑塊下,對各種支架擴張至適當尺寸時,氣球所需施加的壓力,以方便醫師未來執行手術時做為參考。研究結果顯示,橢圓形血管內腔斑塊對心血管支架的最大應力值、軸向變形及狗骨效應的影響皆大於圓形血管內腔斑塊。另外,支架本身厚度適當地增加,能降低支架放置後的徑向回彈量,將有助於穩定手術過後血管內腔維持圓形的能力。
This thesis uses computer simulation approach to investigate the effect of artery plaque on the design and selection of coronary stents. Two types of plaques in circular or elliptical artery lumens and three groups of coronary stents with different thickness are studied in the simulation. First, using CAD software constructs solid models of the stents. These models are used in finite-element-analysis software to simulate the mechanical behavior of the stents after implantation and then investigate their performance. The simulation results include the maximum stress, radial deformation, radial recoil, axial deformation, foreshortening, and dogboning effect of the stents. This thesis also makes a study of the expansion pressure for the stents, which can provide the guidance for doctors of selecting proper balloon catheters and their expansion pressure. The simulation results show that maximum stress, axial deformation and dogboning effect of the stents for using in elliptical artery lumen plaques are significantly larger than those for circular artery lumen plaques. In addition, properly increasing the thickness of the stents can reduce radial recoil of the stents and make the possibility of getting a near circular shape of the artery lumen after stent implantation.