VALVE FOR VENTRICULAR ASSIST DEVICE
A ventricular-assist-device valve includes two flaps hinged to a peripheral wall by means of a couple of flexible struts. As each flap opens and closes during each cycle of operation, the struts flex and open passages for flow around them, around the flaps, and between the struts and the flaps, so as to prevent the formation of dead zones that contribute to the accumulation and deterioration of blood cells that produce clotting. The struts are tensioned so as to exert a pressure against the flow of the blood stream when the flaps are open. This tension creates a pressure differential between the underside and the peripheral regions of the flaps that forces blood flow around the hinges and washes out stagnant cells. As a result, clotting is materially reduced.
1 . A valve for an artificial blood pump comprising:
a valve seat defining a flow passage in a housing;
at least one flap adapted for meshing with the valve seat when the valve is closed; and
at least one flexible strut providing a hinge for the flap whereby the flap can move from a closed position to an open position and vice versa;
wherein said strut is tensioned to provide a bias toward said closed position of the flap, and said flap and strut define passages for fluid flow between the flap and the strut when the valve is open.
2 . The valve of claim 1 , wherein said flexible strut is attached to the housing.
3 . The valve of claim 1 , wherein said valve is made of polyurethane.
4 . The valve of claim 1 , wherein said valve is made of silicone rubber.
5 . The valve of claim 1 , wherein said valve is made of a thermoplastic elastomer.
6 . The valve of claim 1 , wherein said valve is made of polyvinyl chloride.
7 . The valve of claim 1 , wherein the valve includes two substantially identical flaps, each flap being adapted for meshing with the valve seat and with the other flap when the valve is closed.
8 . The valve of claim 7 , wherein each of said flaps comprises a portion shaped like a half dome.
9 . The valve of claim 7 , wherein each flap is attached to two substantially identical flexible struts, said struts providing a hinge for the flap whereby the flap can move from a closed position to an open position and vice versa; and wherein said struts are tensioned to provide a bias toward said closed position of the flap and said flap and struts define passages for fluid flow between the flap and the struts when the valve is open.
10 . The valve of claim 9 , wherein said flexible struts are attached to the housing.
11 . The valve of claim 9 , wherein each of said flaps comprises a portion shaped like a half dome.
12 . The valve of claim 9 , wherein said valve is made of polyurethane.
13 . The valve of claim 9 , wherein said valve is made of silicone rubber.
14 . The valve of claim 9 , wherein said valve is made of a thermoplastic elastomer.
15 . The valve of claim 9 , wherein said valve is made of polyvinyl chloride.
16 . A ventricular assist device comprising:
a pump chamber with an inlet port, an outlet port, and a mechanism for creating suction at the inlet port and pressure at the outlet port;
an inlet valve allowing flow into the chamber when said mechanism creates said suction at the inlet port and preventing backflow out of the chamber when the mechanism creates said pressure at the outlet port; and
an outlet valve preventing backflow into the chamber when said mechanism creates said suction at the inlet port and allowing flow out of the chamber when the mechanism creates said pressure at the outlet port;
wherein each of said inlet and outlet valves includes:
a valve seat defining a flow passage in a housing;
two substantially identical flaps, each flap being adapted for meshing with the valve seat and with the other flap when the valve is closed; and
two substantially identical flexible struts attached to each flap, said struts providing a hinge for the flap whereby the flap can move from a closed position to an open position and vice versa;
wherein the struts are tensioned to provide a bias toward said closed position of the flap and said flap and struts define passages for fluid flow between the flap and the struts when the valve is open.
17 . The valve of claim 16 , wherein each of said flaps comprises a portion shaped like a half dome.
18 . The valve of claim 16 , wherein said flexible struts are attached to the housing.
19 . The valve of claim 16 , wherein said valve is made of polyurethane.
20 . The valve of claim 16 , wherein each of said flaps comprises a portion shaped like a half dome, said flexible struts are attached to the housing, and the valve is made of polyurethane.