Presented at SMST-2010, and now published in the journal Biomaterials, Amanda Runciman and her collaborators present new studies on the multiaxial fatigue performance of Nitinol.
Download the paper here: 163_Runciman_EquivalentStrain_Coffin-Manson_MultiaxialFatigue.pdf
Now in its third year, the FDA / NHLBI / NSF Workshop on Computer Methods for Cardiovascular Devices brings together a unusual mix of folks from industry, academia, regulatory, and funding organizations. This year’s theme focuses on the integration of nonclinical and computer models. Like previous years, a common thread has been the need for sharing and collaboration, especially in the area of biomechanics data and modeling methodologies. Last year, Craig advocated an open source model for medical development, and this year, he presented a collection of creative commons licensed resources for Open Stent Design. Read on for the slides… Read more »
At the recent SMST conference, we presented our Open Stent Design for the first time, and received lot of great feedback from the crowd. We previously introduced the idea here, and posted a detailed manuscript describing the CAD model and theory behind the calculations. Today. we have posted the Stent Calculator worksheet to the same page. Read more »
In this SMST-2010 presentation, Craig advocates for applying some principles from the open source and creative commons movements to medical implant design. Power to the people! This project was first introduced in a previous post, and has a permanent home at the Open Stent Design feature page. The slide show embedded below was presented at Asilomar today, and it’s offered under a creative commons attribution-share alike license – you’re free to download, adapt, and reuse the content within simple terms of the license. The presentation gives an overview of the Open Stent Design project, and presents results from some trend analysis and statistical exploration of inputs and outputs. Read on for more… Read more »
“Killer App” may not be the best term to use to describe a medical component, but if such a thing exists in the world of Nitinol, its the vascular stent. In the past fifteen years or so, these tiny metallic scaffolds have changed the practice of medicine, improved the lives of countless people around the world, and have dominated the landscape of Nitinol component manufacturing. At NDC, we’ve made more of these beautiful little objects than we can count, and we are frequently asked to help current and prospective customers improve their designs, develop new ones, perform testing and analysis, run simulations, and more. Today, we are pleased to release some resources and tools that we have developed to help new and experienced designers get started with stent design. Read on for more… Read more »
By the year 2003, Nitinol stents played a dominant role in the treatment of peripheral vascular disease. A great variety of designs had been launched into clinical service, some more successfully than others. This review was authored by the familiar NDC trio of Dieter Stoeckel, Alan Pelton, and Tom Duerig, and published in European Radiology. It’s just about tied for for first place in the prestigious race for most popular download from Nitinol.com! This paper presents some of the earliest data to describe nickel ion release for various surface conditions, including mechanically polished, electropolished, and passivated surfaces, and compared Nitinol with stainless steel and MP35N. The conclusions of this study reinforce what we know well today: the corrosion and biocompatibility performance of Nitnol is excellent when processed properly, but can be compromised if improper processes are applied. The paper presents a visual survey of various stent designs from 2003, including laser cut, wire formed, and sheet welded varities. It also discusses the concepts of radial resistive force (RRF) and chronic outward force (COF), as well as radiopacity enhancments such as tantalum crimps and rivets. Still a good read for anyone interested in Nitinol stent design. Read more »
In this paper from the proceedings of proceedings of SPIE, Tom Duerig, Dieter Stoeckel, and David Johnson presents some basic information on the properties of superelasticity and shape memory exhibited by Nitinol. The authors describe vascular applications including stents and filters, and some testing and characterization techniques applicable to such devices. This paper is notable in its early description of novel thin film based components fabricated from Nitinol. Read more »
