|
That’s me in the photo on the left during open heart surgery to replace my native aortic valve. Years ago I was diagnosed with an “organic murmur” and after following it closely with my cardiologist we decided it was a good time to have a replacement of my aortic valve. I was able to plan for [...] 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 [...] 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 [...] We dusted off the interferometer recently to perform some new experiments on Nitinol. The photo on the left shows our four beam phase shifted moire intereferometer trained on a Nitinol tension sample in a simple hand operated load frame. We had our expert photographer Andy on hand and took quite a few long exposure photos [...] 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 [...]
This is a picture of an excised mitral valve from a pig with suture and a clip holding the leaflets together in a novel approach to treating mitral valve regurgitation. It was placed percutaneously using a specially designed catheter. The superelastic Nitinol clip was designed and developed using Finite Element Analysis (FEA).
You can download the patent protecting this [...] 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 [...] |
|
|
Copyright © 2012 drperry.org - All Rights Reserved |
|