Heart disease is one of the most common causes of death in developed countries. Plaque deposits can accumulate on the walls of the arteries, this blockage restricts blood flow around the body. Traditionally this problem was addressed with invasive surgery that involved a long and uncomfortable recovery time. Coronary Stenting was developed as a non-invasive technique for opening the blockage, and providing on going support to the potential blockage.
The performance of a stent design is assessed with two different criteria, the medical performance and the structural performance. The structural performance of the stent is determined by:
The pressure required for expansion
The pressure it can withstand from the artery
The foreshortening of the stent during expansion
Finite element modelling is the industry standard method for assessing these performance characteristics. Simplifications of the stent geometry are common in this analysis.
The adequacy of these simplifications is assessed in this thesis by comparison against experimental data. A simple analytical analysis method is also compared in order to verify its suitability for this application. The findings from this investigation are presented, along with recommendations for the application of these methods.
The process know as ‘crimping’ is necessary in order for the stent to be restrained onto the balloon, unfortunately this process leaves all stents with an initial geometric imperfection. A study into the effect of stent imperfections is presented. The findings from this study suggest that imperfections in stent geometry could have a significant impact on the stent performance.
Recommendations are also presented for further study into stent deployment. The recommendations cover analysis techniques, experimental techniques and realistic modeling techniques.