Heart Valves

 

Heart valve replacement is a common clinical intervention in today's aging society.  Several factors contribute to the outcome of such interventions, e.g., manufacturability, price, interventional complexity, performance as well as the longevity of the prostheses. 
Our experimental framework includes pulsatile flow loops, silicone casting facilities, as well as modern optical measurement technology for quantifying the complex three-dimensional blood flow interacting with the valve tissue.
Our computational lab develops high-fidelity numerical methods for multiphysics simulations targeting world-leading high-perfomance computing platforms. In particular we focus on fluid-structure interaction of the heart valves, laminar-turbulent transition and data assimilation.
This enables us to perform ex vivo, in vitro and in silico tests of different valves.

Tomographic PIV behind aortic valve prosthesis

The flow profile in the ascending aorta is strongly affected by the geometry and the condition of the aortic valve. This is also the case if the native valve is replaces with a prosthetic valve, each type influencing the hemodynamics in a specific way. We use a tomographic PIV setup together with a silicone phantom of the aorta and a pulse replicator to tackle flow structures and quantify the shear stresses within the three-dimensional flow field behind a trans-catheter valve implant (TAVI).

Bioprosthetic valve performance in compliant aortic roots

Bioprosthetic aortic valves (BAVs) degenerate over time due to calcification and structural deterioration, and the reasons behind are not fully understood. Surgically implanted BAVs are designed in a symmetric, circular fashion to mimic the native valve. While stented BAVs assure undistorted circular implantation due to a rigid stent, sutureless and stentless BAVs implantation might be influenced by the morphology of the patient. This project aims to investigate the impact of patient-specific aortic root parameters on valve kinematics and hemodynamic performance of BAVs.

 

Contact: Silje Ekroll Jahren, PhD, Prof. Dr. Dominik Obrist

High-performance numerical analysis of AV hemodynamics

Our group aims at full characterization of heart valve hemodynamics. In parallel to in-vivo and in-vitro analysis, we work on developing a tool for numerical fluid-structure interaction analysis. Working in-silico provides the benefit of obtaining quantitative and reproducible data whitout relying on clinical tests such as animal experiments. Our code is targeted at newly emerging hybrid node supercomputer architectures. Eventually, the library shall be made available to other researchers working in Biofluiddynamics.

Hemodynamics in the pivoting area of the Triflo heart valve

Our research is targeted towards the investigation of the hemodynamics in the hinge region of a novel trileaflet mechanical heart valve prosthesis.  Micro particle image velocimetry (µPIV) offers a scientific tool to investigate the flow on a small scale in an in vitro setup. An experimental configuration was built that allows to simulate the function of the heart and the cardiovascular system and to study the hemodynamics of the mechanical heart valve throughout the cardiac cycle.