Hollow fiber filter for extracorporeal blood circuit

1. A filter for an extracorporeal blood circuit comprising:

a bundle of hollow fibers having an end section encased in a potting material, wherein said end section further comprises a stem of fibers and potting material and an annular disk of the potting material extending radially outward from the stem, wherein the annular disk of the potting material is substantially wider than the stem, the stem protrudes from the disk and the stem includes a side surface extending along a length of the stem;

an end surface of the stem substantially perpendicular to the length of the stem and including open ends of the fibers distributed throughout the end surface including open ends proximate to a perimeter of the end surface;

a filter housing through which extends said bundle, said filter housing comprising a tubular section and a first end section and a second end section at opposite ends of the tubular section, wherein the annular disk is seated in the first end section and the stem is narrower than the tubular section along the length of the stem;

a filter header cap mounted on the first end section of the filter housing, wherein the filter header cap includes an inlet connectable to a blood line and an open end, said filter header cap including a cap side surface abutting the stem side surface, and

the second end section connectable to a blood line.

2. The filter of claim 1 wherein the bundle of fibers has a diameter in the stem substantially the same diameter as the bundle of fibers in the filter housing.

3. The filter of claim 1 wherein the bundle of fibers has a substantially constant diameter through the stem, disk and filter housing.

4. The filter of claim 1 wherein an annular flow zone is formed between an inside surface of the filter header cap and the end surface of the stem, and a ratio of a diameter of the stem to a maximum depth of the annular flow zone is no greater than 1 to 10.

5. The filter of claim 1 and wherein at least one of the cap side surface and stem side surface is tapered.

6. The filter of claim 1 wherein the first end section includes a filter housing cap having an interior surface to receive the disk and an exterior surface to receive the filter head cap.

7. The filter of claim 6 wherein a filtrate chamber is defined between the bundle, filter housing cap and the disk.

8. The filter of claim 1 wherein the annular disk is substantially devoid of the fibers.

9. The filter as in claim 1 wherein the end surface includes a rim area of potting material, wherein the rim area is devoid of the open ends of the fibers and the rim has a width no greater on average than 0.508 mm.

10. The filter as in claim 1 wherein a diameter of the end surface is no greater than four times an internal passage diameter of the blood line.

11. A filter for an extracorporeal blood circuit comprising:

a bundle of hollow fibers having an end section encased in a potting material, wherein said end section further comprises a stem of fibers and potting material extending from a disk of the potting material, wherein the stem of fibers and potting material has an outside diameter of the stem substantially narrower than an outside diameter of the disk of potting material,

an end surface of the stem includes open ends of the fibers distributed throughout the end surface including open ends proximate to a perimeter of the end surface,

the stem including a stem side surface transverse to the end surface of the stem;

a filter housing through which extends said bundle, wherein an inside diameter of the housing is substantially greater than an outside diameter of the stem;

a filter housing cap at a first end of the filter housing, wherein an interior annular surface of the filter housing cap abuts an exterior annular surface of the disk;

a filter header cap including an inlet connectable to a blood line and an open end, said filter header cap including a cap side surface substantially parallel to the stem side surface, said cap side surface abuts the stem side surface, and at least one of the cap side surface and stem side surface is tapered along the abutment, and

the filter housing including a second end having an outlet connectable to a blood line.

12. The filter of claim 11 wherein the bundle of fibers has a diameter in the stem substantially the same diameter as the bundle of fibers in the filter housing.

13. The filter of claim 11 wherein the bundle of fibers have a substantially constant diameter through the stem, disk and filter housing.

14. The filter of claim 11 wherein the stem forms a post extending from the disk, and the disk includes an annular ring of potting material devoid of fibers and extending radially outward from the stem and the bundle of fibers.

15. The filter of claim 11 wherein an annular flow zone is formed between an inside surface of the filter header cap and the end surface of the stem, and a ratio of a diameter of the stem to a maximum depth of the annular flow zone is no greater than 1 to 10.

16. The filter as in claim 11 wherein the end surface includes a rim area of potting material, wherein the rim area is devoid of the open ends of the fibers and the rim has a width no greater on average than 0.508 mm.

17. The filter as in claim 11 wherein the end surface includes a rim of potting material devoid of the open ends of the fibers and the rim has an average width in a range of 0.025 mm to 0.508 mm.

18. The filter as in claim 11 wherein a diameter of the end surface is no greater than four times an internal passage diameter of the blood line.