Capillary dialyzers

Abstract

The present disclosure relates to capillary dialyzers for blood purification comprising from 85-95% crimped fibers and from 5-15% non-crimped fibers.

Claims

1. A capillary dialyzer comprising a housing and a bundle of semi-permeable hollow fiber membranes disposed therein, characterized in that the bundle of hollow fiber membranes comprises from 85 to 95% crimped fibers and from 5 to 15% non-crimped fibers, relative to the total number of fibers in the bundle.

2. The capillary dialyzer of claim 1, wherein the bundle of hollow fiber membranes comprises from 88 to 92% crimped fibers and from 8 to 12% non-crimped fibers.

3. The capillary dialyzer of claim 1, wherein the packing density of the hollow fiber membranes in the dialyzer is 55 to 65%.

4. The capillary dialyzer of claim 1, wherein the fibers have a sinusoidal texture with a wavelength in the range of from 6 to 9 mm.

5. The capillary dialyzer of claim 4, wherein the amplitude of the sinusoidal texture is in the range of from 0.1 to 0.5 mm.

6. The capillary dialyzer of claim 1, wherein the hollow fiber membranes have an outer diameter of from 150 to 320?.Math.?.

7. The capillary dialyzer of claim 1, wherein the fiber bundle in the dialyzer has a diameter of from 20 to 50 mm.

8. The capillary dialyzer of claim 1, wherein the effective fiber length within the bundle is in the range of from 120 to 280 mm.

9. The capillary dialyzer of claim 1, wherein the effective membrane surface area of the hollow fiber membranes within the dialyzer is in the range of from 0.25 to 2.5 m.sup.2.

10. The capillary dialyzer of claim 9, wherein the effective membrane surface area of the hollow fiber membranes within the dialyzer is in the range of from 1.1 to 2.1 m.sup.2.

11. The capillary dialyzer of claim 1, wherein the semi-permeable hollow fiber membranes comprise 80-99 wt % of polysulfone or polyethersulfone; and 1-20 wt % of polyvinylpyrrolidone.

12. The capillary dialyzer of claim 1, wherein the semi-permeable hollow fiber membranes comprise a polyamide.

13. The capillary dialyzer of claim 1, wherein the semi-permeable hollow fiber membranes comprise a copolymer of acrylonitrile and sodium methallylsulfonate.

14. The capillary dialyzer of claim 1, wherein the semi-permeable hollow fiber membranes comprise a polyacrylonitrile.

Description

EXAMPLES

Comparative Example 1

(1) Using standard state-of-the-art processes, capillary dialyzers were produced from a bundle of 12,960 crimped hollow fiber membranes. Fiber crimp had a wavelength of 7.5 mm and an amplitude of 0.3 mm. The individual fibers had an outer diameter of 250 ?m. The dialyzers had a cylindrical housing with an inner diameter of 38 mm. Packing density of the fibers within the dialyzers thus was 56.1%. Effective fiber length was 236 mm; effective membrane surface area was 1.73 m.sup.2. The dialyzers were packed in sterile bags and steam-sterilized at 121? C.

(2) Clearance of urea and vitamin B12 of six capillary dialyzers were measured according to EN1283. The dialyzers were operated in hemodialysis mode using a dialysis flow rate of Q.sub.D=500 ml/min, a blood flow rate of Q.sub.D=400 ml/min, and an ultrafiltration rate UF of 0 ml/min. The results obtained are summarized in the following table.

(3) TABLE-US-00002 Clearance [ml/min] Mean STD Urea 356 2 Vitamin B12 245 2 Cytochrome C 170 0

Example 1

(4) Using standard state-of-the-art processes, capillary dialyzers were produced from a bundle of 12,960 hollow fiber membranes. 11,520 fibers (89%) had a crimp with a wavelength of 7.5 mm and an amplitude of 0.3 mm. The bundle contained 1,440 non-crimped fibers (11%) evenly distributed throughout the bundle. The individual fibers had an outer diameter of 250 ?m. The dialyzers had a cylindrical housing with an inner diameter of 38 mm. Packing density of the fibers within the dialyzers thus was 56.1%. Effective fiber length was 236 mm; effective membrane surface area was 1.73 m.sup.2. The dialyzers were packed in sterile bags and steam-sterilized at 121? C.

(5) Clearance of urea and vitamin B12 of six capillary dialyzers were measured according to EN1283. The dialyzers were operated in hemodialysis mode using a dialysis flow rate of Q.sub.D=500 ml/min, a blood flow rate of Q.sub.D=400 ml/min, and an ultrafiltration rate UF of 0 ml/min. The results obtained are summarized in the following table.

(6) TABLE-US-00003 Clearance [ml/min] Mean STD Urea 358 1 Vitamin B12 252 2 Cytochrome C 184 1