Numerical analysis and hemolysis prediction in an implantable aortic valve-pump

An implantable aortic valve-pump was designed. There were a central rotor and a stator in the device. The rotor was consisted of driven magnets and an impeller, the stator was consisted of a motor coil with an iron core, an inducer and a diffuser. This pump has promisingly better antithrombogenicity than other heart pumps, for neither connecting conduits nor “bypass” circuits are necessary, which locates the position of aortic valve and delivers the blood directly from left ventricle to aorta. The three-dimensional flow patterns of the pump was simulated numerically using the unstructured mesh with computational fluid dynamics(CFD). The visualized velocity, pressure and wall shear fields were obtained from the simulation. Using the power law model of the relations among the hemolysis, shear stress and exposure time, the hemolysis at several rotating speeds(9000~15000r/min) were calculated and compared. The result shows that the normalized index of hemolysis (NIH) of the pump is less than the permitted value 0.1, the new pump has a good hemolysis, it is hopeful been applied to clinical for terminal cardiopathy.