Stent design parameters

1. Flexibility: Apply angular displacement on both ends and measure the reaction moment. The unit for this study is Moment(Nmm) vs. Angle/length (rad/mm)
2. Radial recoil: (R_load-R_unload)/R_load
3. Foreshortening: (L-L_load)/L
4. Radial Strength: force per unit of length when stent suddenly collapse
5. Fatigue Safety Factor (FSF).The FSF was estimated by using the modified Goodman relationship (Shigley, 2001)

FSF ≡ Fatigue Safety Factor response
• Sa ≡ Alternating Stress response
• Sm ≡ Mean Stress response
• Se ≡ Stent Material’s Endurance Limit (10 year fatigue life equivalent of blood pressure
loading)
• Suts ≡ Stent Material’s Ultimate Tensile Stress (defined in terms of true stress)

Reference: Baillargeon et al SCC 2011