Séance Séminaire

Séminaire des Doctorant·e·s

Heart valve prostheses

I am going to present some projects I worked on at the Department of Cardiovascular Engineering at the Institute of Applied Medical Engineering in Aachen, Germany. The tricuspid valve is situated between the right atrium and right ventricle and is prone to regurgitation, secondary to left sided heart valve diseases. A new concept was developed, anchoring not only inside the tricuspid annulus but inside the vena cava superior. The stents and leaflets designs were iteratively developed by using CAD and simulation software. After manufacturing of the valve, mock-loop tests were performed and the valve tested. The pulmonary valve is most affected by congenital diseases and the patients are already often operated in their childhood. The pulmonary artery and the right ventricular outflow tract can be deformed very differently from patient to patient. This is why an adaptable stentframe was developed. The stentframe consists of a basic element which contains the leaflets and two anchoring elements which can be smaller or bigger in diameter as the basic element to adapt to the anatomy of the treated patient. Also here, the stentframe was developed by using CAD and simulation software. After manufacturing, the leaflets were sewn into the stent with a certain suture pattern. Different tests were conducted, as mock-loop tests and durability tests to test the prosthesis' performance. The aortic valve is the most treated valve worldwide. This project had the idea to develop an aortic valve with leaflets made from polyurethane. In this project, I did some simulations for the radial force and leaflets behavior with different parameter settings in the simulation software. PIV (particle image velocimetry) is used to visualize the flow field inside (or outside) the measurement area in a non-intrusive, optical way. The PIV system consists of a laser to illuminate the particles inside the flow and a high-speed camera, which captures the emitted light of the particles. As fluid, mostly a water-glycerin mixture is used to adapt the refractive index of the fluid to the surrounding structure to minimize optical obstructions. The flow field of the Medtronic Corevalve prosthesis was analyzed. The first study contained the prosthesis itself, the second study the coronary arteries.