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I just returned from a workshop sponsored by the FDA (and the NHLBI and NSF) on Computer Methods for Cardiovascular Devices. It was an excellent workshop providing an audience of regulatory, academic and industrial interests a chance to get caught up on the state-of-the-art, trends and, in general, to exchange ideas on the issues of [...] There are many circumstances when it is necessary to model contact and contact interactions when analyzing medical implants. Such circumstances arise when devices interact with tooling, catheters, vessels and when self-contact occurs. This latter situation arises for example when a stent is crimped down tightly to catheter dimensions. ABAQUS/Standard provides a range of methods for defining [...] Finite Element Analysis is routinely used to evaluate the performance and durability of medical devices. When using an implicit method such as ABAQUS/Standard, FEA can also be used to evaluate the geometric stability of a proposed design. Such issues could arise for example when designing stents for large vessels, such as the aorta, [...] A typical process for making stents is electropolishing to remove material and processing defects and to impart a smooth finish with rounded corners. It is well known that a polished part will have superior fatigue resistance, but how much does the rounding of edges affect the stress and strain in the stent when loaded? We studied [...] Finite Element Analysis is an excellent engineering tool for optimizing medical implants. It provides a fast and reliable method for evaluating both the performance and safety issues associated with any given product. A variety of design concepts can be evaluated and relative safety factors determined for the full size range of an intended product. Parametric studies [...] Nitinol is a unique metallic alloy that is ideally suited to use in medical devices. It has excellent biocompatibility and most of all it has the ability to undergo significant recoverable deformations. This allows devices made with Nitinol to be reduced to catheter dimensions and expanded at the implant site. Much work has been done to [...] Significant advances are being made in simulations for medical devices. The picture on the left, shared with me by Dr. Tina Morrison, former post-graduate student in Charles Taylor’s group at Stanford University shows the predicted pressures in a patient specific aorta. Flow and pressure waves emanate from the heart and travel through the major arteries where they are [...] Finite Element Analysis (FEA) is routinely used to perform fatigue analyses of cardiovascular stents. For the case of balloon expandable stents, this means modeling the crimping of the stent onto the delivery balloon, the expansion and recoil of the stent as would occur during deployment and finally the simulation of fatigue deformations. Fatigue deformations typically [...] Follow this link to the ASTM website and find the long awaited for “Standard Guide for Finite Element Analysis of Metallic Vascular Stents Subjected to Uniform Radial Loading”. This guide establishes general requirements and considerations for using finite element analysis techniques for the numerical simulation of metallic stents subjected to uniform radial loading. These stents are [...] There is no excerpt because this is a protected post. |
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