Abstract: A heart valve prosthesis disclosed in two- and three-leaflet versions includes a ring-shaped body, leaflets, and leaflet turn stops. For the two-leaflet version, the stops represent two pairs of prominences located on a body end surface facing the blood down-flow. The first pair has internal surfaces, at least partially made flat, adapted to interact with flat sections of the leaflets to restrict the return blood flow in the closed position. The first pair is equipped with at least two rests interacting with a leaflet top surface facing the blood down-flow in its open position determining a leaflet turning angle. Each prominence of the second pair is located opposite a portion of the lateral surface of the corresponding leaflet most distant from a leaflet central surface and can interact with its internal surface with that part of the lateral surface during opening of the heart valve prosthesis.

Abstract: The cardiac valve prosthesis comprises a circular body (1) accomodating a locking element in the form of two folds (2) mounted pivotable in relation to the body (1). The internal surface of the body (1) is made concave and suhstantially spherical, while the side surface of each fold (2) is made convex and substantially spherical, the center (0) of the spherical surfaces lying on the central axis (5) of the prosthesis. The folds (2) are pivotable around an axis extending in the plane of the cross-section of the prosthesis and intersecting its central axis (5). The prosthesis is intended for use in cardiosurgery for replacement of affected natural aortic and mitral valves of the human heart.

Abstract: A cardiac valve prosthesis comprising an annular body housing a closure member in the form of two cusps. The cusps open and close freely and rotate simultaneously around the body axis, checking the forward and reverse blood flows through the prosthesis to simulate the operation of the cardiac valve. To have the operation of the prosthesis resemble that of the natural valve, the lateral surface of at least one cusp is provided with a recess to produce a controlled blood backflow through the prosthesis by causing the blood flow through the prosthesis to swirl.