Hydrodynamic evaluation of three artificial aortic valve chambers.

The effect of chamber geometry on the characteristics of turbulent steady flow through a newly designed artificial heart valve, "the jellyfish valve," has been investigated for flow rates matching those of peak systole. Laser Doppler Anemometry (LDA) was employed to determine the velocity and shear stress distributions at various locations downstream of the jellyfish valve. Three geometrically different aortic valve chambers have been investigated: namely, a chamber with sinuses of Valsalva, an ellipsoidal chamber, and a cylindrical chamber. The results of this investigation indicated that the aorta with sinuses of Valsalva model had the highest turbulent shear stresses whereas the ellipsoidal model gave the highest-pressure drops. However, for the various flow rates examined, including the systole peak value of 26 L/min, it appears that the ellipsoidal model displays better hydrodynamic characteristics in terms of shear stress and uniformity of axial velocity distributions downstream of the jellyfish valve.