Medical hemodialysis container including a self sealing vent

• US 8,038,886 B2
• Filed: 06/26/2009
• Issued: 10/18/2011
• Est. Priority Date: 09/19/2007
• Status: Active Grant

• Current Assignee: Fresenius Medical Care Holdings Incorporated (Fresenius SE & Co. KGaA)
• Original Assignee: Fresenius Medical Care North America (Fresenius SE & Co. KGaA)
• Inventors: Crnkovich, Martin Joseph, Folden, Thomas Irvin, Weaver, Colin
• Primary Examiner(s): Menon; Krishnan S
• Assistant Examiner(s): FITZSIMMONS, ALLISON G
• Application Number:
  US12/492,725
• Publication Number:
  US 20090320684A1
• Time in Patent Office: 844 Days
• Field of Search: None
• US Class Current: 210/646
• CPC Class Codes: A61M 1/1656 Apparatus for preparing dialysates
• CPC Class Codes: A61M 1/1658 Degasification
• CPC Class Codes: A61M 1/1666 by dissolving solids
• CPC Class Codes: A61M 1/1668 Details of containers
• CPC Class Codes: A61M 1/36224 with sensing means or components thereof
• CPC Class Codes: A61M 1/362261 at least one cassette surface or portion thereof being flexible, e.g. the cassette having a rigid base portion with preformed channels and being covered with a foil
• CPC Class Codes: A61M 1/362262 Details of incorporated reservoirs
• CPC Class Codes: A61M 1/362264 the filter being a blood filter
• CPC Class Codes: A61M 1/3627 Degassing devices; Buffer reservoirs; Drip chambers; Blood filters
• CPC Class Codes: A61M 1/3641 Pressure isolators
• CPC Class Codes: A61M 1/3643 Priming, rinsing before or after use
• CPC Class Codes: A61M 1/3644 Mode of operation
• CPC Class Codes: A61M 2205/7527 liquophilic, hydrophilic
• CPC Class Codes: A61M 2205/7536 allowing gas passage, but preventing liquid passage, e.g. liquophobic, hydrophobic, water-repellent membranes
• CPC Class Codes: A61M 2205/7563 with means preventing clogging of filters

Abstract

A container for use with a hemodialysis apparatus having a vent structure is described. The vent structure is porous, and allows air in the container to vent when the container is being filled with fluid, but expands when the vent structure becomes wet, when filling is complete, thereby closing off the pores and inhibiting (e.g., preventing) fluid from flowing through the vent structure, and reentry of air into the container. The vent structure can also include a micro-porous membrane.

Claims

1. A container for use in an apparatus for dialysis to accommodate solid or fluid concentrate for preparation of dialysis fluid, the container comprising:

a body having a inside and an outside;

at least one opening; and

a vent structure, wherein the vent structure comprises;

a micro-porous membrane;

a first porous layer; and

a second porous layer capable of swelling when moistened,

wherein the first porous layer is disposed between the micro-porous membrane and the second porous layer and the first porous layer is less responsive to the presence of moisture than the second porous layer.

2. The container of claim 1, wherein the vent structure is positioned at or near the top of the container to allow air in the container to exit the container through the vent structure when the container is being filled.

3. The container of claim 1, wherein the container may be made of any materials suitable for use in hemodialysis applications, including polypropylene, polyethylene or polyvinylchloride.

4. The container of claim 1, wherein the vent structure has an average pore size of between about 5 microns and about 50 microns.

5. The container of claim 1, wherein the vent structure comprises polypropylene, polyethylene or polystyrene.

6. The container of claim 1, wherein the vent structure comprises carboxymethylcellulose.

7. The container of claim 1, wherein the vent structure is comprised of hydrophilic polymers selected from the group consisting of:

polyvinylpyrrolidone, polyvinyl alcohol, polyacrylic acid, polymethacrylic acid, polyacrylic amides, polymethacryl amides, and grafts or copolymers of any of these polymers, e.g. copolymers with maleic anhydride (such as poly(methyl vinyl ether/maleic anhydride)), succinic anhydride or the corresponding acids, as well as polyamides, polyethylene glycols (PEG), gelatin, polysaccharides (e.g. cellulose derivatives such as carboxymethylcellulose, cellulose acetate, and cellulose acetate propionate, and chitosan), hydrophilic polyurethanes (e.g. one-shot or prepolymer-based polyurethanes), and carboxylated butadiene styrene rubbers.

8. The container of claim 1, wherein the vent structure is comprised of a blend of polyethylene and carboxymethylcellulose.

9. The container of claim 1, wherein the vent structure is comprised of a blend of polyethylene and polymethacrylate.

10. The container of claim 1, wherein the first porous layer comprises a porous material capable of swelling when moistened, and wherein the second porous layer has a greater propensity to swell in the presence of moisture than the first porous layer.

11. The container of claim 1, wherein the first porous layer has an average pore size of about 5 microns to about 45 microns.

12. The container of claim 1, wherein the first porous layer has an average pore size of about 10 microns.

13. The container of claim 1, wherein the second porous layer has an average pore size of about 15 to about 45 microns.

14. The container of claim 1, wherein the second porous layer has an average pore size of about 30 microns.

15. The container of claim 1, wherein the second porous layer has an average pore size that is greater than an average pore size of the first porous layer.

16. The container of claim 1, wherein the second porous layer comprises about 5% to about 50% by weight carboxymethylcellulose.

17. The container of claim 1, wherein the first porous layer comprises about 0.1% to about 10% carboxymethylcellulose.

18. The container of claim 1, wherein the first porous layer comprises less than 5% carboxymethylcellulose.

19. The container of claim 1, wherein the outlet comprises an elongate tube extending from a first end to a second end and which sealingly surrounds the opening at the second end and provides a flow path of fluid which exits the container.

20. The container of claim 1, wherein the vent structure is positioned at or near the top of the container to allow air to exit the container through the vent structure when the container is being filled with liquid.

21. The container of claim 1, wherein the container is a bag comprised of a flexible material, such as, for example, PVC, PVP, or polyethylene.

22. The container of claim 1, wherein the container comprises a plug component suitable for use with a dialysis apparatus.

23. The micro-porous membrane of claim 1, wherein the material of the membrane is selected from the group consisting of polytetrafluoroethylene (PTFE) or expanded polytetrafluoroethylene (ePTFE).

24. The micro-porous membrane of claim 1, wherein the membrane is a fibrous carrier with a matted and woven layer of polyethylene or other polymer, on top of which ePTFE or other micro-porous hydrophobic material is applied.

25. The micro-porous membrane of claim 1, wherein the membrane has an average pore size of about 0.05 microns to about 0.45 microns.

26. The micro-porous membrane of claim 25, wherein the membrane has an average pore size of about 0.20 to about 0.22 microns.

27. The container of claim 1, wherein the micro-porous membrane of the vent structure is proximal to the inside of the container.

28. The container of claim 1, wherein the micro-porous membrane of the vent structure is proximal to the inside of the container.

29. The container of claim 1, wherein the container is adapted for use in a hemodialysis apparatus.