1. Department of Biomedical Engineering, Mc Gill University, 3775 University Street, Montreal, Qc, H3A 2B4, Canada, Faculté de Pharmacie et département de Chimie, Université de Montréal, C.P. 6128 Succ. Centre ville, Montreal, Qc, H3C 3J7 Canada, Montreal Heart Institute, 5000 rue Belanger Est, Montreal, H1T 1C8, Canada, and Cordis CorporationNitinol Devices & Components (NDC), 47533 Westinghouse Drive, Fremont, California 94539