On-X Heart Valve Prosthesis: Numerical Simulation of Hemodynamic Performance in Accelerating Systole

Abstract

Numerical simulation of the bileaflet mechanical heart valves (BMHVs) has been of interest for many researchers due to its capability of predicting hemodynamic performance. A lot of studies have tried to simulate this three-dimensional complex flow in order to analyze the effect of different valve designs on the blood flow pattern. However, simplified models and prescribed motion for the leaflets were utilized. In this paper, transient complex blood flow in the location of ascending aorta has been investigated in a realistic model by fully coupled simulation. Geometry model for the aorta and the replaced valve is constructed based on the medical images and extracted point clouds. A 23-mm On-X Medical BMHV as the new generation design has been selected for the flow field analysis. The two-way coupling simulation is conducted throughout the accelerating phase in order to obtain valve dynamics in the opening process. The complex flow field in the hinge recess is captured precisely for all leaflet positions and recirculating zones and elevated shear stress areas have been observed. Results indicate that On-X valve yields relatively less transvalvular pressure gradient which would lower cardiac external work. Furthermore, converging inlet leads to a more uniform flow and consequently less turbulent eddies. However, the leaflets cannot open fully due to middle diffuser-shaped orifice. In addition, asymmetric butterfly-shaped hinge design and converging orifice leads to better hemodynamic performance. With the help of two-way fluid solid interaction simulation, leaflet angle follows the experimental trends more precisely rather than the prescribed motion in previous 3D simulations.

Hemodynamic Effects of Subaortic Stenosis on Blood Flow Characteristics of a Mechanical Heart Valve Based on OpenFOAM Simulation

“…This research utilized the 23-mm On-X heart valve. The model was generated using SolidWorks software, with structural information obtained from Mirkhani et al [ 18 ]. The simulation domain consisted of four components: the front aortic section, the MHV, the Valsalva sinus, and the back aortic section, as illustrated in Figure 1 .…”

Design and Development of Impurities Free Pyrolytic Coated Mechanical Bi-Leaflet Heart Valve Prototype

“…The fabrication of Bileaflet Mechanical Mitral Heart Valve was carried out using graphite with 1.95g/cm 3 density because of its reported hemocompatibility and antithrombotic behavior in biomedical applications. 18 the 5-axis CNC machine was used for the fabrication of bileaflet mechanical heart valve whereas the PyC coating was done by the CVD technique. The main parts of the prototype were two leaflets and external orifice after machining and finishing of final parts leaflets were assembled into the butterfly, shaped hinges engraved in orifice.…”

Development of a novel piezoelectric-actuated inertial pump using bionic valve

“…Other researchers proposed a bionic double-leaf mechanical heart valve. The results showed that the bionic valve produced a smaller pressure gradient of the valve and reduced the generation of turbulence (Mirkhani et al, 2016). The application of the valve leads to better hemodynamic performance.…”