Biological fluid filters having flexible walls and methods for making such filters

• US 10,159,778 B2
• Filed: 06/06/2014
• Issued: 12/25/2018
• Est. Priority Date: 03/24/2014
• Status: Active Grant

• Current Assignee: Fenwal Incorporated (Fresenius SE & Co. KGaA)
• Original Assignee: Fenwal Incorporated (Fresenius SE & Co. KGaA)
• Inventors: Lynn, Daniel, Day, Scott, Verri, Paolo
• Primary Examiner(s): Kim, John
• Application Number:
  US15/128,331
• Publication Number:
  US 20170151382A1
• Time in Patent Office: 1,663 Days
• CPC Class Codes: A61M 1/0281 Apparatus for treatment of blood or blood constituents prior to transfusion, e.g. washing, filtering or thawing
• 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 1/3635 Constructional details
• CPC Class Codes: A61M 1/3636 having a flexible housing
• CPC Class Codes: B01D 2201/30 Filter housing constructions
• CPC Class Codes: B01D 2201/306 Closures, lids, caps or filter heads forming one element with the filtering element
• CPC Class Codes: B01D 2239/065 More than one layer present in the filtering material apparatus incorporating such gas filtering material B01D2275/10
• CPC Class Codes: B01D 2239/1258 Permeability
• CPC Class Codes: B01D 29/50 with multiple filtering elements, characterised by their mutual disposition B01D29/39 takes precedence
• CPC Class Codes: B01D 35/30 Filter housing constructions
• CPC Class Codes: B01D 39/083 of organic material
• CPC Class Codes: B01D 39/086 of inorganic material
• CPC Class Codes: B01D 39/10 Filter screens essentially made of metal
• CPC Class Codes: B01D 39/1623 of synthetic origin

Abstract

Flexible housing filters for filtration of fluids and methods of making such filters are disclosed. The filters may include one or more peripheral seals in the flexible housing.

Claims

1. A biological fluid filter assembly comprising:

a) a housing having first and second flexible walls wherein one of said walls comprises an inlet housing wall associated with an inlet port and said other of said housing walls comprises an outlet housing wall associated with an outlet port;

b) a filter medium disposed between said flexible walls, said medium comprising at least first, second and third filter elements and including a sealed area and one or more unsealed areas wherein

(i) said first filter element comprises a material suitable for removing a component or particulate of a biological fluid and is disposed between said housing wall including said inlet port and said second element;

(ii) said second filter element comprises a material suitable for removing another component of said biological fluid and is disposed between said first filter element and said third filter element; and

(iii) said third filter element comprises an organic or inorganic material and is disposed between said housing wall including said outlet port and said second filter element, said third filter element having an air permeability per 1 cm of thickness of greater than 40 cm²/s at a pressure difference of 125 Pa.

2. The biological fluid filter assembly of claim 1 wherein said third filter element has an air permeability per 1 cm of thickness of approximately 40 cm²/s-800 cm²/s at a pressure difference of 125 Pa.

3. The biological fluid filter assembly of claim 1 wherein said third filter element has a thickness of approximately 0.5-4 mm.

4. The biological fluid filter assembly of claim 1 wherein said third filter element includes a porous region comprising a mesh.

5. The biological fluid filter assembly of claim 4 wherein said third filter element further includes a substantially non-porous frame surrounding said porous region.

6. The biological fluid filter assembly of claim 4 wherein said porous region comprises a mesh of polyvinyl chloride.

7. The biological fluid filter assembly of claim 1 wherein said first filter element has an overall thickness of approximately 0.127-1.106 mm in at least one of said one or more unsealed areas of said filter medium.

8. The biological fluid filter assembly of claim 7 wherein said first filter element is made of a material selected from the group consisting of polybutylene terephthalate, polyethylene terephthalate and polypropylene.

9. The biological fluid filter assembly of claim 1 wherein said second filter element has an overall thickness of approximately 0.254-15.24 mm in at least one of said one or more unsealed areas of said filter medium.

10. The biological fluid filter assembly of claim 9 wherein said second filter element is made of a material selected from the group of polybutylene terephthalate, polyethylene terephthalate and polypropylene.

11. The biological fluid filter assembly of claim 1 comprising an outer peripheral seal and at least one inner peripheral seal spaced from said outer peripheral seal.

12. The biological fluid filter assembly of claim 1 comprising an outer peripheral seal and a first inner peripheral seal and a second inner peripheral seal.

13. The biological fluid filter assembly of claim 12 wherein said first and second inner peripheral seals have a thickness of approximately 0.762-2.286 mm.

14. The biological fluid filter assembly of claim 12 wherein said outer peripheral seal comprises a seal between said housing walls.

15. The biological fluid filter assembly of claim 12 wherein said first and second inner peripheral seals include said housing walls and said first, second, and third filter elements.

16. The biological fluid filter assembly of claim 12 wherein said first and second inner peripheral seals include said housing walls and said first and second filter elements.

17. The biological fluid filter assembly of claim 16 wherein said third filter element includes a porous region comprising mesh.

18. The biological fluid filter assembly of claim 15 wherein said third filter element and said outlet housing wall are made of the same material.

19. The biological fluid filter assembly of claim 18 wherein said material comprises polyvinyl chloride.

20. The biological fluid filter assembly of claim 17 wherein said third filter element includes a non-porous frame surrounding said porous region.

21. The biological fluid filter assembly of claim 1 wherein said third filter element has an air permeability per 1 cm of thickness of approximately 50 cm²/s-400 cm²/s at a pressure difference of 125 Pa.

22. The biological fluid filter assembly of claim 1 wherein said third filter element has an air permeability per 1 cm of thickness of approximately 70 cm²/s-150 cm²/s at a pressure difference of 125 Pa.