Finite element analysis of a reconstructed aortic valve

• Main Author: Chua, Zhong Yang.
• Other Authors: Yeo Joon Hock
• Format: Final Year Project
• Language: English
• Published: 2013
• Subjects: DRNTU::Engineering::Bioengineering
• Online Access: http://hdl.handle.net/10356/53604
• Institution: Nanyang Technological University

Statistics from the Registry of Births and Deaths in Singapore has shown that there is a rising trend of death due to cardiovascular diseases in 2012 [1]. For this reason, there are a lot of interests and researches involve, and one of the effective solutions would be aortic valve replacement surgery. There are two main types of artificial heart valves: Mechanical and Tissue heart valve. In recent years, bio-prosthetic (human or animal tissue) aortic valves are found to be preferred due to the advantage of avoiding anticoagulation. However, the disadvantage of bio-prosthetic valves is their limited durability which leads to calcification with tissue damage resulting in degeneration and dysfunction. Therefore, expanded Polytetrafluroethylene (ePTFE) material is recommended and with the unique properties of ePTFE membrane, it becomes a better choice for a number of pharmaceutical applications. The aim of the project is to reconstruct an artificial aortic valve which comes in tri-leaflet design with ePTFE material. Experimental results have shown that ePTFE material is not applicable with the previous designs (H-molded and Tubular valve) as it affects the leaflet normal functionality. Therefore, there is a need to create a new geometry of aortic valve leaflet which is suitable for ePTFE material. Finite element analysis was conducted on the new aortic valve leaflets designs to investigate the behavior and performance of the tri-leaflet valves which simulated to be made from ePTFE material. This led to the evolution of new tri-leaflet geometry: Design 7 having the advantages of better mobility of the leaflets and a satisfactory coaptation area of 307〖mm〗^2. The simulation results also show that increasing the total surface area and free edge length will have a better coaptation area and stress distribution of the leaflets. Through the use of finite element analysis software (ABAQUS), it brought continuous improvement of the new designs and the materials used for the aortic valve.