Claims
- 1. A mid-dilution hemodiafiltration/hemofiltration cartridge comprising:
a cartridge body having a first end and an opposing second end, said cartridge body being in communication with a blood inlet and a blood outlet and a dialysate inlet and outlet; a first hemodiafiltration stage including a first filtering element disposed between said first and second ends of said cartridge body, said blood inlet communicating with said first filtering element at said first end so that blood flows through said first filtering element toward said second end; a second hemofiltration stage including a second filtering element disposed between said first and second ends of the cartridge body, said blood outlet communicating with said second filtering element; and an inter-stage connector disposed at said second end of said cartridge body and defining an inter-stage header space, said inter-stage header space permitting blood that has been discharged from said first hemodiafiltration stage to flow through said second filtering element to said blood outlet, said inter-stage connector having a substitution fluid inlet port for reception of a solution for diluting the blood prior to the blood entering said second filtering element of said second stage, wherein dialysate fluid enters from said dialysate inlet and flows through said first hemodiafiltration stage and then flows out said dialysate outlet.
- 2. The mid-dilution hemodiafiltration/hemofiltration cartridge of claim 1, further including:
a separating wall disposed within the cartridge body and partitioning the cartridge body into a first compartment associated with said first stage and a second compartment associated with said second stage.
- 3. The mid-dilution hemodiafiltration/hemofiltration cartridge of claim 1, wherein each of said first and second filtering elements comprises high flux semi-permeable hollow fibers.
- 4. The mid-dilution hemodiafiltration/hemofiltration cartridge of claim 2, wherein said first and second filtering elements are separated by said separating wall along their full length.
- 5. The mid-dilution hemodiafiltration/hemofiltration cartridge of claim 2, wherein said separating wall contains an orifice to allow dialysate to pass from said first compartment across said second compartment before exiting through said dialysate outlet.
- 6. The mid-dilution hemodiafiltration/hemofiltration cartridge of claim 5, wherein said orifice is substantially axially aligned with said dialysate outlet.
- 7. The mid-dilution hemodiafiltration/hemofiltration cartridge of claim 1, wherein said first end of said cartridge body is sealed with a first header cap which has the blood inlet and blood outlet formed therein.
- 8. The mid-dilution hemodiafiltration/hemofiltration cartridge of claim 7, wherein said first header cap has a internal wall member for dividing an inner header space into a first header space and a second header space.
- 9. The mid-dilution hemodiafiltration/hemofiltration cartridge of claim 8, wherein said first header space permits the blood to only flow from said blood inlet port to said first filtering elements of said first stage and wherein said second header space permits the blood to only flow from said second filtering elements to said blood outlet port.
- 10. The mid-dilution hemodiafiltration/hemofiltration cartridge of claim 8, whereinblood entering said first header space through said blood inlet is excluded from said second filtering element by said internal wall member which prevents the blood from flowing into said second header space.
- 11. The mid-dilution hemodiafiltration/hemofiltration cartridge of claim 2, wherein said first end of said cartridge body is seated with a first header cap, said first header cap having an internal wall member for defining a first header space and a second header space, said internal wall member being axially aligned with said separating wall.
- 12. The mid-dilution hemodiafiltration/hemofiltration cartridge of claim 11, wherein said internal wall member is integral to said first header cap and includes a pair of O-rings to provide a seal between said first header cap and said cartridge body at an attachment interface therebetween.
- 13. The mid-dilution hemodiafiltration/hemofiltration cartridge of claim 1, wherein said first end of said cartridge body is sealed with first and second header caps, said first header cap including the blood inlet and defining a first header space in communication only with said first filtering element, said second header cap including the blood outlet and defining a second header space in communication only with said second filtering element.
- 14. The mid-dilution hemodiafiltration/hemofiltration cartridge of claim 5, wherein said orifice is dimensioned so as to cause said first compartment to have a first dialysate pressure and said second compartment to have a second dialysate pressure which is greater than the first dialysate pressure.
- 15. A mid-dilution hemodiafiltration/hemofiltration cartridge comprising:
a housing providing hemodiafiltration in a first stage and hemofiltration in a second stage, the first hemodiafiltration stage having a first filtering element and the second hemofiltration stage having a second filtering element, both stages being provided in one housing, said housing including an inter-stage section where a substitution fluid inlet port is formed for receiving a solution for diluting blood discharged from the first hemodiafiltration stage prior to the blood flowing into said second filtering element of the second hemofiltration stage, said housing including a blood inlet in communication with the first stage, a blood outlet in communication with the second stage, a dialysate fluid inlet, and a dialysate fluid outlet.
- 16. The mid-dilution hemodiafiltration/hemofiltration cartridge of claim 15, wherein the dialysate inlet is in communication with the first stage and the dialysate outlet is in communication with the second stage, the housing having a separating wall partitioning the housing into the first and second stages, the dialysate fluid flowing from the first stage to the second stage through an orifice formed in the separating wall.
- 17. The mid-dilution hemodiafiltration/hemofiltration cartridge of claim 16, wherein blood flows through said first filtering element at a first fluid pressure and flows through said second filtering element at a second fluid pressure which is less than the first fluid pressure, and wherein a first compartment defining the first stage has a first associated pressure which is greater than a second associated pressure of a second compartment defining the second stage.
- 18. The mid-dilution hemodiafiltration/hemofiltration cartridge of claim 17, wherein said orifice is dimensioned so as to cause the first associated pressure to be greater than the second associated pressure.
- 19. A hemodiafiltration/hemofiltration cartridge comprising:
a cartridge body having a first end and an opposing second end, said cartridge body being in communication with a blood inlet and a blood outlet and a dialysate inlet and outlet; a first hemodiafiltration stage including a first filtering element disposed between said first and second ends of said cartridge body, said blood inlet communicating with said first filtering element at said first end so that blood flows through said first filtering element toward said second end; a second hemofiltration stage including a second filtering element disposed between said first and second ends of said cartridge body, said blood outlet communicating with said second filtering element; and an inter-stage connector disposed at said second end of said cartridge body and defining an inter-stage header space, said inter-stage header space permitting blood that has been discharged from said first hemodiafiltration stage to flow through said second filtering element to said blood outlet, wherein dialysate fluid enters said cartridge body through said dialysate inlet and flows through said first hemodiafiltration stage and then flows out said dialysate outlet.
- 20. The hemodiafiltration/hemofiltration cartridge of claim 19, further including:
a separating wall disposed within said cartridge body and partitioning said cartridge body into a first compartment associated with said first hemodiafiltration stage and a second compartment associated with said second hemofiltration stage, said separating wall including an orifice through which the dialysate fluid flows from said first hemodiafiltration stage to said second hemofiltration stage.
- 21. The hemodiafiltration/hemofiltration cartridge of claim 19, wherein said blood inlet and said blood outlet are formed in a first header cap disposed at said first end of said cartridge body and the inter-stage connector is defined by a second header cap disposed at said second end of said cartridge body, said first header cap being configured so that said blood inlet is only in communication with said first hemodiafiltration stage and said blood outlet is only in communication with said second hemofiltration stage.
- 22. The hemodiafiltration/hemofiltration cartridge of claim 20, wherein said orifice is substantially axially aligned with said dialysate outlet to limit the area of said second compartment through which the dialysate fluid flows.
- 23. A method of hemodiafiltration/hemofiltration in a single cartridge, the method comprising the steps of:
receiving a blood inflow; diafiltering said blood inflow in a first stage to provide a partially diafiltered blood outflow having a first concentration of toxins; mixing said partially diafiltered blood outflow with a substitution fluid at an inter-stage section to provide a blood/substitution fluid mixture; and hemofiltering said blood/substitution fluid mixture in a second stage to produce blood having a second concentration of toxins, the first concentration being greater than the second concentration, wherein said diafiltering and said hemofiltering steps occur within said single cartridge; and passing dialysate fluid through a dialysate inlet and into said first stage, the dialysate fluid flowing within the first stage before flowing through a restrictive orifice and across a discrete area of the second stage to a dialysate outlet.
- 24. The method of claim 23, further including the step of:
partitioning said single cartridge into said first and second stages with a separating wall, the first stage including a first filtering element and the second stage including a second filtering element, and wherein passing the dialysate fluid from the first stage across the second stage includes passing the dialysate fluid through an orifice formed in the separating wall.
- 25. The method of claim 24, further including the step of:
dimensioning the orifice so that an area around said first filtering elements has a first pressure and an area around said second filtering elements has a second pressure, the first pressure being greater than the second pressure.
- 26. A method of hemodiafiltration/hemofiltration in a single cartridge, the method comprising the steps of:
receiving a blood inflow; diafiltering said blood inflow in a first stage to provide a partially diafiltered blood outflow having a first concentration of toxins; hemofiltering said partially diafiltered blood in a second stage to produce hemodiafiltered/hemofiltered blood having a second concentration of toxins, the first concentration being greater than the second concentration, wherein said diafiltering and said hemofiltering steps occur within said single cartridge; and passing dialysate fluid through a dialysate inlet and into said first stage, the dialysate fluid flowing within the first stage before flowing through a restrictive orifice and across a discrete area of the second stage to a dialysate outlet.
CROSS REFERENCE TO RELATED APPLICATION
[0001] The present application claims the benefit of U.S. provisional application Serial No. 60/254,741, filed Dec. 11, 2000, which is hereby incorporated by reference in its entirety.
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
PCT/US01/47541 |
12/11/2001 |
WO |
|