[Should the presence of coiled blood flow in the left heart ventricle and aorta be taken into consideration when constructing artificial heart valves?].

The use of an original device developed by the authors which was introduced in the blood flow in experiments in dogs has confirmed the presence of coiled blood flow in different parts of the aorta. The rate, direction and angle of coiling were calculated. The results obtained suggest that the fact of coiling the blood flow should be taken into account when constructing new models of artificial valves of the heart in order to decrease the energy value of the cardiac output, to prevent injury of the formed elements of blood and thrombogenesis.

[Autovibration of a circular locking element of the aortic valve prosthesis].

Some experimental results when studying self-sustained vibrations of the ball locking element for an artificial heart valve are presented. The sign-changing dependence of a ball drag coefficient upon the ball stroke has been shown to cause these vibrations. Undamped oscillations result in a considerable growth of the valve hydrodynamic resistance.

[Flow past an artificial heart valve with a lens-shaped shutoff element].

An axisymmetric stream-line steady flow of perfect noncompressible liquid through the artificial heart valve with the lens-shaped shut-off element is considered. The liquid motion is described by a continuity equation for which the Dirichlet's problem in the plane of the valve meridional section is stated. Written in the finite differences the differential equation is solved by using a digital computer (ZDBM-220).