Ramtin Gharleghi: School of Mechanical and Manufacturing Engineering, University of New South Wales, High St. Sydney, Australia.
Heidi Wright: School of Mechanical and Manufacturing Engineering, University of New South Wales, High St. Sydney, Australia.
Vanessa Luvio: School of Mechanical and Manufacturing Engineering, University of New South Wales, High St. Sydney, Australia.
Nigel Jepson: Prince of Wales Hospital, 320-346 Barker St. Randwick, Sydney, Australia; Prince of Wales Clinical School of Medicine, 18 High St, University of New South Wales, Sydney, Australia.
Zhen Luo: School of Mechanical and Mechatronic Engineering, University of Technology Sydney, Australia.
Anushan Senthurnathan: School of Mechanical and Manufacturing Engineering, University of New South Wales, High St. Sydney, Australia.
Behzad Babaei: School of Mechanical and Manufacturing Engineering, University of New South Wales, High St. Sydney, Australia.
B Gangadhara Prusty: School of Mechanical and Manufacturing Engineering, University of New South Wales, High St. Sydney, Australia.
Tapabrata Ray: School of Engineering and Information Technology, University of New South Wales, Canberra, Australia.
Susann Beier: School of Mechanical and Manufacturing Engineering, University of New South Wales, High St. Sydney, Australia. Electronic address: s.beier@unsw.edu.au.
Stents are scaffolding cardiovascular implants used to restore blood flow in narrowed arteries. However, the presence of the stent alters local blood flow and shear stresses on the surrounding arterial wall, which can cause adverse tissue responses and increase the risk of adverse outcomes. There is a need for optimization of stent designs for hemodynamic performance. We used multi-objective optimization to identify ideal combinations of design variables by assessing potential trade-offs based on common hemodynamic indices associated with clinical risk and mechanical performance of the stents. We studied seven design variables including strut cross-section, strut dimension, strut angle, cell alignment, cell height, connector type and connector arrangement. Optimization objectives were the percentage of vessel area exposed to adversely low time averaged WSS (TAWSS) and adversely high Wall Shear Stress (WSS) assessed using computational fluid dynamics modeling, as well as radial stiffness of the stent using FEA simulation. Two multi-objective optimization algorithms were used and compared to iteratively predict ideal designs. Out of 50 designs, three best designs with respect to each of the three objectives, and two designs in regard to overall performance were identified.
