Virtual scaffolding and radial strength testing of stents

Virtual design tools are gaining more and more importance in the development and evaluation of medical devices. Inherently each medical device is subjected to (very) different (patient) specific loading conditions and thus requires dedicated simulation strategies. In addition, specific post-processing of the data obtained from the numerous simulations is needed to evaluate the device behavior. For example, stents can be virtually subjected to radial compression, bending, torsion and are characterized by a number of important design characteristics such as flexibility, radial strength, fatigue resistance, foreshortening, recoil, vessel scaffolding, etc. As a result, to virtually design a stent, each design iteration undergoes the same series of numerical simulations. In other words each (intermediate) stent design has to be preand post-processed in exactly the same way, urging the need for automation. Over the past years the Abaqus solver has proven to be very efficient, accurate and robust to study the above mentioned stent design characteristics, both for balloon and self-expandable stents. This paper presents a novel simulation strategy and post-processing tool to accurately analyze balloon expandable stents in terms of radial strength and scaffolding. The underlying platform for this advanced and interactive preand post-processing tool is the open-source pyFormex design software.