Multi-chamber self-regulating ventricular assist device

1. A multi-chamber ventricular assist device (VAD) for pumping blood, comprising:

a rigid outer housing having an inlet and outlet;

a pre-filling chamber disposed within said housing fluidly connected to said inlet;

an ejection chamber disposed within said outer housing;

a movable plate flexibly secured to said housing in a flow path of said blood, said movable plate disposed between said pre-filling and said ejection chamber, said movable plate having a one way valve for flowing blood from said pre-filling chamber to said ejection chamber;

an outlet valve disposed between said ejection chamber and said outlet, and

structure for moving said movable plate.

2. The VAD of claim 1 , wherein said pre-filling chamber is a flexible chamber.

3. The VAD of claim 1 , wherein said flexible chamber is spaced apart front inner walls of said housing, wherein a gas holding chamber is formed between said flexible chamber and said housing.

4. The VAD of claim 3 , wherein a pressure differential between said gas holding chamber and said ejection chamber provides a passive driving force for automatic movement of said movable plate upward toward said pre-filling chamber.

5. The VAD of claim 4 , wherein a cross sectional area of said pre-filling and said ejection chamber remains substantially constant throughout cycling of said device.

6. The VAD of claim 5 , wherein a blood pumping rate of said VAD monotonically increases with increasing inflow pressure at said inlet, whereby said VAD is self-regulating.

7. The VAD of claim 1 , wherein said ejection chamber includes rigid walls.

8. The VAD of claim 7 , wherein said rigid walls of said ejection chamber are provided by inner walls of said outer housing.

9. The VAD of claim 7 , wherein said rigid walls include a textured surface, said textured surface promoting neointima formation.

10. The VAD of claim 1 , wherein a maximum volume of said pre-filling chamber is substantially less than a maximum volume of said ejection chamber.

11. The VAD of claim 10 , wherein said maximum volume of said pre-filling chamber is in a ratio with said maximum volume of said ejection chamber of between 1.5:1 and 3:1.

12. The VAD of claim 1 , wherein said outer housing is hermetically sealed.

13. The VAD of claim 1 , wherein said pump provides a continuous inflow of blood throughout a duration of a complete pumping cycle.

14. The VAD of claim 13 , wherein said inflow is a substantially constant inflow rate throughout said pumping cycle.

15. A self-regulating method of pumping blood using a ventricular assist device (VAD) disposed within a cardiac patient, comprising the steps of:

receiving a variable inflow pressure, and

automatically providing an output flow rate of blood based on said inflow pressure, wherein a rate of said blood flow monotonically increases with a level of physical activity performed by said patient.

16. The method of claim 15 , wherein said inflow pressure is atrial pressure.

17. The method of claim 15 , wherein said output flow is a pulsating flow.

18. The method of claim 15 , wherein said VAD includes a textured surface in contact with said blood, said textured surface promoting neointima formation.

19. The method of claim 15 , wherein a continuous inflow of blood throughout a duration of a complete pumping cycle is provided.

20. The VAD of claim 19 , wherein said inflow is a substantially constant inflow rate throughout said pumping cycle.