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An important input to FEA is material characterization and limit information. In our laboratory we use a Bose 3230 test system for achieving test speeds up to 200Hz. Depending on the project, we may test complete devices, sub-components, coupon samples and/or simple material characterization samples. Many times, we will test more than one [...] 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 [...] My first job out of graduate school and post-doctorate work was with the footwear company, NIKE. I was fortunate to hire into the heart of the most advanced footwear technology department in the world and I could not have had a more exciting job description. I began by learning how to design NIKE AIR cushioning [...] 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 (FEA) can produce an enormous amount of data as output. Solution variables such as stress and strain are computed throughout an analysis for each increment and at each location within the model. These solution variables are computed at what are called “integration points”. These locations ARE NOT the same as the nodes [...] 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 [...] With the growing use of Nitinol in medical implants, there is a need for improved characterization of the material behavior of Nitinol and methodologies for better product design and engineering. While it is a good starting point, the typical approach of employing the force-deformation response from uniaxial tension tests for input and validation of material [...] |
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