Valved tip catheters

1. A split-tip catheter comprising:

a body defining first and second lumens and first and second separated distal tip portions, each of the separated distal tip portions defining a lumen which communicates with one of the first or second lumens, each of the separated distal tip portions including at least one distally located normally closed, one-way valve, each of the distally located one-way valves being configured to open in response to an increase in pressure within a respective one of the first and second lumens to enable fluid to be discharged from the respective first or second lumen;

at least one proximally located normally closed, one-way valve associated with each of the first and second lumens, each of the proximally located one-way valves being spaced proximally of the distally located one-way valves and being configured to open in response to a decrease in pressure within a respective one of the first and second lumens to enable fluid to enter the respective first or second lumen; and

a support structure formed in the body adjacent at least one of the proximally located, one-way valves.

2. The catheter according to claim 1 , wherein each of the distally located one-way valves is a slit valve.

3. The catheter according to claim 2 , wherein each of the proximally located one-way valves is a slit valve.

4. The catheter according to claim 1 , wherein each of the proximally located one-way valves includes a slit which extends through the body and a concavity formed about the slit.

5. The catheter according to claim 4 , wherein the at least one proximally located one-way valve includes two proximally located one-way valves associated with a respective one of each of the first and second lumens.

6. The catheter according to claim 1 , wherein each of the proximally located one-way valves is a flap-valve, the flap valve including a deformable flap.

7. The catheter according to claim 6 , wherein the deformable flap is rectangular.

8. The catheter according to claim 6 , wherein the flap is triangular.

9. The catheter according to claim 1 , wherein each of the proximally located one-way valves is a duckbill valve.

10. The catheter according to claim 1 , wherein each of the separated distal tip portions include at least one of the proximally located one-way valves.

11. The catheter according to claim 1 , wherein at least one of the proximally located one-way valves is formed in the body proximally of the separated distal tip portions.

12. The catheter according to claim 1 , wherein each of the proximally located one-way valves includes a membrane supported within the respective one of the first and second lumens of the body, the membrane being positioned to cover a throughbore formed in the body and being inwardly movable to enable fluid to enter the throughbore, at least a portion of the membrane being secured to the body.

13. The catheter according to claim 12 , further including a support rib extending across the throughbore, the support rib being positioned to prevent outward movement of the membrane.

14. A split-tip catheter comprising:

a body defining first and second lumens and first and second separated distal tip portions, each of the separated distal tip portions defining a lumen which communicates with one of the first or second lumens, each of the separated distal tip portions including at least one distally located normally closed, one-way valve, each of the distally located one-way valves being configured to open in response to an increase in pressure within a respective one of the first and second lumens to enable fluid to be discharged from the respective first or second lumen; and

at least one proximally located normally closed, one-way valve associated with each of the first and second lumens, each of the proximally located one-way valves being spaced proximally of the distally located one-way valves and being configured to open in response to a decrease in pressure within a respective one of the first and second lumens to enable fluid to enter the respective first or second lumen, wherein each of the proximally located one-way valves includes tapered inwardly deformable flaps.

15. A split-tip catheter comprising:

a body defining a venous lumen, an arterial lumen and first and second separated distal tip portions, the first distal tip portion defining a first lumen which communicates with the venous lumen and the second distal tip portion defining a second lumen which communicates with the arterial lumen, a distal end of the first distal tip portion extending distally beyond a distal end of the second distal tip portion;

a one-way valve formed in the first distal tip portion and configured to enable fluid to be discharged from the venous lumen upon an increase in pressure within the venous lumen;

a one-way valve formed in the second distal tip portion and configured to enable fluid to enter the arterial lumen upon a decrease in pressure within the arterial lumen; and

a support structure formed in the body adjacent at least one of the one-way valves.

16. The catheter according to claim 15 , further comprising a catheter hub having a first end secured to a proximal end of the body, the catheter hub supporting a valve assembly having two inlet one-way valves which communicate with the venous lumen and enable fluid to flow into the venous lumen and two outlet one-way valves which communicate with the arterial lumen and enable fluid to flow from the arterial lumen.

17. The catheter according to claim 16 , further comprising a conduit defining first and second lumens and having a first end connected to a second end of the catheter hub such that each of the first and second lumens communicates with one of the inlet one-way valves and one of the outlet one-way valves.

18. The catheter according to claim 17 , wherein the conduit is adapted to communicate with a medical device.

19. A split-tip catheter comprising:

a body defining first and second lumens and first and second separated distal tip portions, each of the separated distal tip portions defining a lumen which communicates with one of the first and second lumens;

at least one distally located normally closed, one-way valve in fluid communication with at least one of the first and second lumens, each of the distally located one-way valves being configured to open in response to an increase in pressure within the respective first and second lumens to which the distally located one-way valve is in fluid communication to enable fluid to be discharged from the respective first or second lumen; and

at least one proximally located normally closed, one-way valve in fluid communication with at least one of the first and second lumens, each of the proximally located one-way valves being spaced proximally of the distally located one-way valves and being configured to open in response to a decrease in pressure within the respective first and second lumens to which the proximally located one-way valve is in fluid communication to enable fluid to enter the respective first or second lumen; and

a support structure formed in the body adjacent at least one of the proximally located, one-way valves.