Simulation Studies On Smooth Performance For Magnesium Alloy Coronary Stents

As one of the new type coronary stents, magnesium alloy coronary stent has becomethe focus and hot spots and is one of development directions of coronary stents in thefuture. At the moment, many people have been researched on magnesium alloy coronarystent, but few researched on the flexibility of magnesium alloy coronary stent. Flexibilityisone of the principal factors evaluating the performance of stents.A stent which has a betterflexibility not only can be smoothly through the bend area of the vessels, but also can becompatible with lesions.This article separately simulated the staticcoupling process and thebending-deformation process of stents by using the finite element method, studied differentconnection structure, different connection width and different number of connection in thecircular direction of stents which have the impact on expansion and deformation of stentsand the flexibility. Above all, it would provide the effective theory basis for the optimizeddesign of magnesium alloy coronary stent in the future.The results show: in the static coupling process, the safety factor and the maximumequivalent stress of stent largely depend upon structure and size of the support, but nothingon the connection; however, the maximum equivalent strain is related to the positionwhichis connected between the support and the connection; changing the connection structure ofstents cannot reduce the radial spring rate, but it has an impact on the axial shortening rate,the waveform-connector can be effectively reduced axial shortening of the stent; changingthe connection structure of stent have little impact on the nonuniformity in expansion.Thedifferent connector structure has an important influence on the flexibility of stent, thewaveform-connector of stent is better than the straight-bar-connector; increasing thenumber of support is conducive to improve the flexibility of stent.Increasing the connection with can increase the radical spring rate, but decrease theaxial shortening rate; changing the connection width can improve the nonuniformity inexpansion, but it has a little impact; decreasing the connection width is conductive toimprove the flexibility of stent.The number of connector has nothing with the axial shortening rate; increasing thenumber of connector can reduce the axial shortening rate, but it has a little impact; decreasing the number of connector is conductive to improve the flexibility of stent; theopen-loop structure of stent which can largely improve the flexibility of stent is superior tothe closed-loop structure of stent. Above all, it has some significance in optimizingstructure of thr stent and clinical application.