Deformation Measurements of Bioprosthetic Heart Valves by Digital Image Correlation
Heart disease has and continues to be the leading cause of death in the United States, attracting the attention of many people, across all fields, searching for a way to prevent it. Dr. Ali Azadani and Dr. Chadd Clary, in collaboration with researchers at the University of Washington in Seattle, recently performed a side-by-side comparison of leaflet displacement and strain fields of three commonly used bioprosthetic heart valves.
Aortic valve stenosis is a cardiovascular disease that is caused by a narrowing of the aortic valve. Traditionally, aortic valve stenosis was treated through the replacement of the aortic valve with a device referred to as a SAV (Surgical Aortic Valve). This procedure, while proven effective, is invasive, requiring open heart surgery, which is not the best option for many patients. Another, newer option is what’s called Transcatheter Aortic Valve Replacement or TAVR, does not require open heart surgery. While this newer procedure is minimally invasive, limited clinical data is available regarding the long-term durability of transcatheter aortic valves (TAVs).
To assess longevity and mechanical strength of TAVs in comparison to surgical bioprosthetic valves, three-dimensional deformation analysis and strain measurement of the leaflets become an inevitable part of the evaluation. The research team at the Daniel Felix Ritchie School of Engineering and Computer Science measured leaflet displacement of two commonly used TAVs (Edwards SAPIEN 3, Medtronic CoreValve) and made a side-by-side comparison with a commonly used SAV (Carpentier-Edwards PERIMOUNT Magna surgical bioprosthesis) using a high-resolution digital image correlation (DIC) system. The experimental DIC measurements was then used to characterize the anisotropic materiel behavior of the bioprosthetic heart valve leaflets.
The high-quality experimental data from DIC measurements can play a pivotal role in design and development of transcatheter heart valves. As this kind of technology continues to become more accessible, it has the potential to save countless lives all over the world, serving as a less invasive alternative to current options for patients with aortic stenosis.
Displacement contour plots of Carpentier-Edwards PERIMOUNT Magna surgical heart valve (Edwards Lifesciences, CA) as pressure increased on the leaflets.