Specialized hollow fiber membranes for in-vivo plasmapheresis and ultrafiltration

• US 6,802,820 B1
• Filed: 04/13/2000
• Issued: 10/12/2004
• Est. Priority Date: 04/13/2000
• Status: Expired due to Fees

• Current Assignee: Transvivo, Inc.
• Original Assignee: Transvivo, Inc.
• Inventors: Grage, Henry, Gorsuch, Reynolds
• Primary Examiner(s): KIM, SUN U
• Application Number:
  US09/549,131
• Time in Patent Office: 1,643 Days
• Field of Search: 604/4.01, 604/5.01, 604/5.04, 604/6.01, 604/6.04, 604/6.09, 604/27, 604/28, 210/650, 210/651, 210/500.23
• US Class Current: 604/6.04
• CPC Class Codes: A61M 1/1678 intracorporal peritoneal dialysis A61M1/28
• CPC Class Codes: A61M 1/34 Filtering material out of the blood by passing it through a membrane, i.e. hemofiltration or diafiltration
• CPC Class Codes: A61M 1/3403 Regulation parameters
• CPC Class Codes: A61M 1/3413 Diafiltration
• CPC Class Codes: A61M 1/3696 with means for adding or withdrawing liquid substances during the centrifugation, e.g. continuous centrifugation
• CPC Class Codes: B01D 2325/022 Asymmetric membranes
• CPC Class Codes: B01D 67/0011 Casting solutions therefor
• CPC Class Codes: B01D 69/02 characterised by their properties
• CPC Class Codes: B01D 69/08 Hollow fibre membranes manufacture of hollow fibres D01D5/24, D01F1/08
• CPC Class Codes: B01D 69/12 Composite membranes; Ultra-thin membranes
• CPC Class Codes: B01D 71/68 Polysulfones; Polyethersulfones

Abstract

An in-vivo plasmapheresis and/or in-vivo ultrafiltration membrane comprises a plurality of elongated hollow fibers each fiber having an interior lumen extending along the fiber length, the fiber wall having a plurality of zones between the inner and outer wall surfaces, each of the zones having a mass density different than the mass density of an adjacent zone. The fiber wall is characterized by having a lower mass density zone at the inner wall surface and a higher mass density zone at the outer wall surface.

Claims

1. A method of carrying out in-vivo plasmapheresis and/or in-vivo ultrafiltration of a patient'"'"'s blood, comprising:

implanting a filter device within a blood vessel of a patient, said filter device comprising a plurality of elongated hollow fibers each fiber having an outer wall, an inner wall and an interior lumen extending along the length thereof, and wherein the fiber wall structure is a continuous change in mass density from said outer wall to said inner wall and comprises a continuum of voids bounded by solid frames, said fiber wall having an asymmetrical pore size and asymmetrical mass density morphology between inner and outer fiber wall surfaces wherein the mass density adjacent to said outer wall is greater than the mass density adjacent to said inner wall, and passing blood plasma and toxins through said fiber wall from the outer wall surface to said interior lumen and directing said blood plasma and toxins from the patient through said interior lumen.

2. A method of claim 1 wherein said filter device includes a catheter in direct fluid communication with said interior lumen of said fibers, said method including directing said blood plasma and toxins from the patient through said catheter.

21. A method of claim 1 wherein said fiber wall comprises a plurality of concentric circumferential zones between inner and outer wall surfaces, each of said circumferential zones comprising a continuous wall structure of pores and frames, wherein the mass density of adjacent concentric circumferential zones is different and wherein the mass density of said concentric circumferential zones decreases from said outer wall to said inner wall.

22. A method of claim 21 wherein said membrane fiber wall has two mass density zones.

23. A method of claim 21 wherein said membrane fiber wall has three mass density zones.

24. A method of claim 21 wherein membrane fiber wall has four or more mass density zones.

3. A method of carrying out in vivo plasmapheresis and/or in-vivo ultrafiltration of a patient'"'"'s blood, comprising:

implanting a filter device within a blood vessel of a patient, said filter device comprising a plurality of elongated hollow fibers each fiber having an outer wall, an inner wall and an interior lumen extending along the length thereof, and wherein the fiber wall structure is a continuous change in mass density from said outer wall to said inner wall and comprises a continuum of voids bounded by solid frames, said fiber wall having a plurality of zones between inner and outer wall surfaces, each of said zones having a mass density different than the mass density of an adjacent zone, said fiber wall characterized by having a lower mass density zone at the inner wall surface and a higher mass density zone at the outer wall surface and passing blood plasma and toxins through said fiber wall from the outer wall surface to said interior lumen and directing said blood plasma and toxins from the patient through said interior lumen.

4. A method of claim 3 wherein said filter device includes a catheter in direct fluid communication with said interior lumen of said fibers, said method including directing said blood plasma and toxins from the patient through said catheter.

5. A method of claim 3 wherein said membrane fiber wall has two mass density zones.

6. A method of claim 3 wherein said membrane fiber wall has three mass density zones.

7. A method of claim 3 wherein membrane fiber wall has four or more mass density zones.

8. A method of claim 3, 4, 5, 6 or 7 wherein each of said zones is characterized by a different average nominal pore size.

9. A method of claim 3 wherein said lower mass density zone is characterized by a nominal average pore diameter of between about 1 μ

m and about 60 μ

m.

10. A method of claim 3 wherein said higher mass density zone is characterized by a nominal average pore diameter of between about 0.3 μ

m and about 1 μ

m.

11. A method of claim 9 wherein said higher mass density zone is characterized by a nominal average pore diameter of between about 0.3 μ

m and about 1 μ

m.

12. A method of claim 3 comprising extracting at least 0.75 ml/min/cm²/mm Hg of blood plasma at trans-membrane pressures of between about 5 mm Hg and about 20 mm Hg.

13. A method of claim 3 wherein said higher mass density zone is characterized by a nominal average pore diameter of between about 0.005 μ

m and about 0.05 μ

m.

14. A method of claim 9 wherein said higher mass density is characterized by a nominal average pore diameter of between about 0.005 μ

m and about 0.05 μ

m.

15. A method of claim 9 wherein said membrane has a plasma trans-membrane flux of between about 0.5 ml/min/cm² and about 9 ml/min/cm²@ 10 mm Hg.

16. A method of claim 3 wherein said lower mass density is characterized by a nominal average pore diameter of between about 5 μ

m and about 40 μ

m.

17. A method of claim 16 wherein said higher mass density is characterized by a nominal average pore diameter of between about 0.7 μ

m and about 0.8 μ

m.

18. A method of claim 16 wherein said membrane has plasma trans-membrane flux of between 0.75 ml/min/cm² and about 4 ml/min/cm²/@ 10 mm Hg.

19. A method of claim 16 wherein said higher mass density is characterized by a nominal average pore of between about 0.01 μ

m and about 0.03 μ

m.

20. A method of claim 3 wherein said membrane has a trans-membrane flux (H₂O) of between about 0.75 and about 4 ml/min/cm²/@ 10 mm Hg.