Biological fluid filters with molded frame and methods for making such filters

• US 9,968,738 B2
• Filed: 03/24/2014
• Issued: 05/15/2018
• 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, Flanagan, Patrick, Chrzan, James
• Primary Examiner(s): Gonzalez, Madeline
• Application Number:
  US14/223,831
• Publication Number:
  US 20150265755A1
• Time in Patent Office: 1,513 Days
• Field of Search: 210435, 210445, 210782, 210645, 210488, 156242, 604406
• 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 1/3636 having a flexible housing
• CPC Class Codes: A61M 2005/1655 Filter with fibers, e.g. filtering element in form of hollow fibers
• CPC Class Codes: A61M 2202/0439 White blood cells; Leucocytes lymphocytes A61M2202/0407
• CPC Class Codes: A61M 2207/00 Methods of manufacture, assembly or production
• CPC Class Codes: A61M 5/165 Filtering accessories, e.g. blood filters, filters for infusion liquids A61M1/14 , A61M1/34, A61M1/3627, A61M1/3679, A61M1/3687 take precedence; needle sets with incorporated air inlet filters A61M5/162

Abstract

Flexible housing filters for filtration of fluids and methods of making such filters are disclosed. The filters include a molded frame with no peripheral seal that houses a filter medium.

Claims

1. A biological fluid filter assembly comprising:

a) a molded frame having an inlet side and an outlet side and comprising a rim defining a central opening in said inlet side and a central opening in said outlet side, said frame comprising an inner surface and an outer surface;

b) a single filter medium comprising a plurality of stacked sheets, said stacked sheets having outer edges which are captured by and enclosed within said frame;

c) at least one inlet port at said inlet side and one outlet port at said outlet side; and

d) a first flexible sheet defining a housing wall adjacent to said frame at said central opening at said inlet side and a second flexible sheet defining a housing wall adjacent to said frame at said central opening at said outlet side of said frame.

2. The biological fluid filter of claim 1 wherein said first and second flexible sheets defining said housing walls are joined to said frame at the outer surfaces of said inlet and outlet sides, respectively.

3. The biological fluid filter of claim 1 wherein said stacked sheets spaced from said inner surface of said frame at said outlet side.

4. The biological fluid filter of claim 1 wherein there is no direct seal between a flexible housing wall and said filter medium.

5. The biological fluid filter of claim 1 wherein there is no direct seal between said first and second flexible housing walls.

6. The biological fluid filter assembly of claim 1 wherein said inlet port is attached to said first flexible sheet that is adjacent to said frame at said inlet side and said outlet port is attached to said second flexible sheet that is adjacent to said frame at said outlet side.

7. The biological fluid filter assembly of claim 1 wherein said inlet port and said outlet port are in said frame.

8. The biological fluid filter assembly of claim 1 wherein said frame comprises polyvinyl chloride.

9. The biological fluid filter assembly of claim 1 wherein at least one of said flexible sheets is made of a material comprising polyvinyl chloride.

10. The biological fluid filter assembly of claim 1 wherein said filter medium comprises first and second filter regions.

11. The biological fluid filter assembly of claim 10 wherein at least one of said filter regions comprises a non-woven fibrous material having a porosity suitable for removing leukocytes from blood or a blood component.

12. The biological fluid filter assembly of claim 10 wherein one of said filter regions comprises a non-woven, fibrous material having a porosity suitable for removing microaggregates from blood or a blood component.

13. The biological fluid filter assembly of claim 10 wherein at least one of said filter regions includes a melt blown material selected from the group of polyethylene terephthalate, polybutylene terephthalate and polypropylene.

14. The filter assembly of claim 1 wherein flow through said assembly proceeds from said inlet port, through said single filter medium to said outlet port.

15. The filter assembly of claim 1 wherein said frame and said first and second flexible walls define a single chamber housing said single filter medium.

16. The filter assembly of claim 1 wherein said stacked sheets are arranged one on top of next from the one of the inlet side and outlet side to the other of said inlet side and said outlet side.

17. The filter assembly of claim 1 wherein said first and second housing walls are attached to the outer surface of said frame rim.

18. The filter assembly of claim 1 wherein said first and second housing walls are captured within the said frame.

19. The filter assembly of claim 18 wherein said first and second flexible housing walls separate said filter medium from said frame.

20. The filter assembly of claim 17 wherein said frame rim is located between said flexible housing walls and said filter medium.

21. The filter assembly of claim 1 wherein said frame comprises a unitary, one-piece frame.