Method and installation for testing the integrity of a capillary dialyzer

Patent metadata

Field	Value
Publication number	US-12128362-B2
Application number	US-202017773070-A
Country	US
Kind code	B2
Filing date	Nov 3, 2020
Priority date	Nov 4, 2019
Publication date	Oct 29, 2024
Grant date	Oct 29, 2024

Abstract

A method is presented for checking the integrity of a hollow-fibre fluid filter, in particular a hollow-fibre dialyzer ( 1 ), which is constructed from a plurality of hollow fibres ( 15 ) enclosed by a membrane, with the steps of: perfusing the inside or outside of the hollow fibres ( 15 ) with a fluid, supplying the outside or inside of the hollow fibres ( 15 ) with a gas, wherein the gas has a higher pressure than the fluid, and determining a quantity of the gas which penetrates into the fluid through holes in the membrane. The method is characterized in that, after flowing through the hollow-fibre fluid filter ( 1 ), the fluid is channelled through a bubble trap ( 30 ), and in that a volume of gas ( 41 ) collecting in the bubble trap ( 30 ) during a predefined or predefinable reference period is determined. Furthermore, equipment for checking the integrity of a hollow-fibre fluid filter ( 1 ) is presented.

First claim

The invention claimed is:

1. A method for checking the integrity of a hollow-fibre fluid filter which is constructed from a plurality of hollow fibres enclosed by a membrane, with the steps of:
perfusing the inside of the hollow fibres with a fluid and
supplying the outside of the hollow fibres with a gas, or
perfusing the outside of the hollow fibres with the fluid and
supplying the inside of the hollow fibres with the gas, wherein in each case the gas has a higher pressure than the fluid, and
determining a quantity of the gas which penetrates into the fluid through holes in the membrane,
wherein,
after flowing through the hollow-fibre fluid filter, the fluid is channelled through a bubble trap, and in that
a gas volume collecting in the bubble trap during a predefined or predefinable reference period is determined.

2. The method according to claim 1 , wherein
an initial value of the gas volume is determined at the start of the reference period,
a final value of the gas volume is determined at the end of the reference period, and
in that the quantity of the gas that has penetrated into the fluid in the reference period is determined from the difference between the initial value and the final value.

3. The method according to claim 2 , wherein a flow system comprising the bubble trap and the hollow-fibre fluid filter is arranged on a conveyor operated in a pulsed manner, which is moved on at least one conveying position during the reference period.

4. The method according to claim 1 , wherein water is used as the fluid.

5. The method according to claim 1 , wherein a line system comprising the bubble trap and the hollow-fibre fluid filter is supplied with steam before the start of the check.

6. The method according to claim 1 , wherein the determination of the volume of the gas collected in the bubble trap is effected visually.

7. The method according to claim 6 , wherein the bubble trap has a transparent section, and in that, for the determination of the volume of the gas collected in the bubble trap, the location of a fluid surface in the transparent section is assessed.

8. The method according to claim 7 , wherein
at least one first camera image of the transparent section is captured at the start of the reference period and the initial location of the fluid surface is determined by means of an image evaluation method,
at least one second camera image of the transparent section is captured at the end of the reference period and the final location of the fluid surface is determined by means of the image evaluation method, and in that
the volume of the gas collected is determined from the initial location of the fluid surface and the final location of the fluid surface.

9. The method according to claim 8 , wherein the first and the second camera image are captured using a transmitted light method.

10. The method according to claim 9 , wherein the illumination is effected by means of a fluorescent film, which is illuminated with excitation light of a first wavelength, and which, in response to the illumination with excitation light, emits fluorescent light of a second wavelength, wherein the second wavelength is greater than the first wavelength, and wherein the camera images are captured through a color filter that is not transparent for light of the first wavelength.

11. An equipment for checking the integrity of a hollow-fibre fluid filter, which is constructed from a plurality of hollow fibres enclosed by a membrane, comprising:
a flushing system which is set up to channel a fluid through the interior of the hollow fibres of the hollow-fibre fluid filter to be checked and
a gas pressure system which is set up to supply the exterior of the hollow fibres of the hollow-fibre fluid filter to be checked with a gas, or
the flushing system which is set up to channel the fluid through the exterior of the hollow fibres of the hollow-fibre fluid filter to be checked and
the gas pressure system which is set up to supply the interior of the hollow fibres of the hollow-fibre fluid filter to be checked with the gas,
wherein in each case the pressure of the gas is higher than the pressure of the fluid, and
a measuring device for the determination of a quantity of the gas penetrating into the fluid through holes in the membrane during a predefined or predefinable reference period,
wherein
the flushing system comprises a bubble trap arranged downstream of the hollow-fibre fluid filter, and
in that the measuring device is set up to determine a volume of the gas collecting in the bubble trap during the predefined or predefinable reference period.

12. The equipment according to claim 11 , wherein the measuring device is set up
to determine an initial value of the gas volume at the start of the reference period,
to determine a final value of the gas volume at the end of the reference period, and
to determine the quantity of the gas that has penetrated into the hollow fibres in the reference period from the difference between the initial value and the final value.

13. The equipment according to claim 11 , wherein the measuring device is set up to determine the volume of the gas collecting in the bubble trap visually.

14. The equipment according to claim 13 , wherein the bubble trap has a transparent section, and in that, for the determination of the volume of the gas collected in the bubble trap, the measuring device is set up to assess the location of a fluid surface in the transparent section.

15. The equipment according to claim 14 , wherein the measuring device comprises at least one camera and an image evaluation system.

16. The equipment according to claim 15 , wherein the measuring device comprises at least one fluorescent film and at least one source for excitation light.

17. The equipment according to claim 15 , wherein the measuring device comprises a first camera which is arranged stationary adjacent to a conveying path of the conveying system.

18. The equipment according to claim 17 , wherein the measuring device comprises a second camera which is arranged stationary adjacent to the conveying path of the conveying system.

19. The equipment according to claim 17 , wherein the first and/or the second camera are arranged adjacent to a stopping position of the conveying system.

20. The equipment according to claim 11 , further comprising a plurality of the hollow-fibre fluid filter and a plurality of the bubble trap and wherein the equipment is a component of a conveying system driven in a pulsed manner, and comprises several conveying elements, wherein each conveying element is provided for receiving at least one of the plurality of the hollow-fibre fluid filter, and wherein each conveying element comprises, for each hollow-fibre fluid filter to be received, one of the plurality of the bubble trap which is movable along the conveying system together with the hollow-fibre fluid filter.

21. The equipment according to claim 20 , wherein the conveying system is a circular conveyor.

Assignees

• Fresenius Medical Care Deutschland Gmbh

Inventors

• Pitsch Stefan
• Wilhelm Manuel

Classifications

• B01D61/244

  comprising multiple dialysis steps · CPC title

• B01D63/02

  Hollow fibre modules · CPC title

• A61M2209/02

  Equipment for testing the apparatus · CPC title

• A61M2205/705

  Testing of filters for leaks · CPC title

• A61M2205/3331

  Pressure; Flow · CPC title