| Modelling a Nitinol Device for the Repair of Abdominal Aortic Aneurysms | ||
| Ms. E. McCummiskey1, Dr. W. M. Dempster1, Dr. D. H. Nash1, Mr. T. Ashton2 and Mr. D. Stevenson2, 1Department of Mechanical Engineering, University of Strathclyde, James Weir Building, 75 Montrose Street, Glasgow, G1 1XJ, United Kingdom, 2Research and Development, Vascutek Terumo, Newmains Avenue, Inchinnan, PA4 9RR, United Kingdom
Abdominal aortic aneurysms (AAAs) are areas of localised swelling in the abdominal aorta due to a weakening of the arterial wall. The performance of a nitinol endovascular device for AAA repair is primarily dictated by its ability to seal the aneurysm from the blood flow and endure continuous cyclic loading due to blood pressure pulsations. The functionality of the device relies heavily on the use of superelastic nitinol to withstand the large deformations that occur during deployment and operation of the device. In the present work the proximal ring of the device is modelled using FE analysis to ascertain the strain levels in vivo. Tests on the material have been carried out to establish its specific stress-strain characteristic in the development of the FE model and both compression-tension dissimilarities and low magnitude cycling effects have been investigated. The effects of these material characteristics on calculation accuracy are discussed. | ||