Author: Sajia Athai, Class of 2026

Figure 1. Accurate measurements of a fluid model are critical to the development of medical device design.

The vessels in the heart work like the hands of a clock. Sometimes the vessels become impacted, like a clock with a depleted battery. Patients with cardiovascular disease often fear the blood clotting mechanism called thrombosis because it can induce vascular injury and heart attack. Fluid-structure interaction models help locate regions where blood clotting occurs and the conditions that form ideal environments for thrombosis. Current research delves into solutions that can avoid risks of blood clotting and additional injury to the cardiovascular system. Led by Dr. Bluestein at Stony Brook University, a team of researchers based in Stony Brook and the University of Arizona published findings on how aortic valve replacements and devices can be designed to address the challenges that fluid models reveal.

Transcatheter aortic valve replacement (TAVR) is utilized to treat the narrowing of blood vessels and thrombosis (clotting). Through the utilization of fluid models, manufacturers can modify their design through analysis of fluid mechanics. A Fluid-Structure Model replicates the interactions between blood flow and the role of TAVR in the body. When inserting a foreign device such as the aortic valve replacement, scientists aim to avoid clotting.

Computational fluid dynamics and the software LS-DYNA were utilized to model the behavior that occurs in the vessels. A sample of cardiac CT scans from six distinct patients with 2 (rather than the normal 3) aortic valves undergoing TAVR was utilized for the experiment. Each patient was given a 29-mm TAVR device for a period of 1E-4 to 2E-4 seconds during the simulation. Scans based on each patient’s heart before the TAVR application were used to measure changes in fluid mechanics. LS-DYNA and the Finite Element Method – Arbitrary Lagrangian-Eulerian technique were used to record leaflet–the flaps that make up valves–motion. Leaflet behavior refers to the mechanism of opening and closing flaps located in heart valves. By comparing the results of the leaflet movement, thrombogenic risk was evaluated to test parameters that can modify TAVR devices.

The study reveals that the software tools are viable for measuring leaflet movement. Before adjusting device layouts, it’s important to be able to test for precision to avoid putting a person’s life in danger. The simulated effective orifice areas of TAVR devices and recorded leaflet movement align with the actual values recorded pre-experiment. This experiment can pave the way for innovation in cardiac device design.

Works Cited:

[1] Baylous K;Kovarovic B;Paz RR;Anam S;Helbock R;Horner M;Slepian M;Bluestein D; (n.d.). Thrombogenic Risk Assessment of transcatheter prosthetic heart valves using a fluid-structure interaction approach. Computer methods and programs in biomedicine. https://pubmed.ncbi.nlm.nih.gov/39461118/  

[2] Gardening tools on the wooden table · Free Stock Photo. (n.d.-b). https://www.pexels.com/photo/gardening-tools-on-the-wooden-table-5934017/