Method and apparatus for ultrafiltration of blood

• US 8,603,021 B2
• Filed: 05/02/2011
• Issued: 12/10/2013
• Est. Priority Date: 05/23/2000
• Status: Active Grant

• Current Assignee: Gambro Lundia AB (Baxter International Inc.)
• Original Assignee: Gambro UF Solutions, Inc. (Baxter International Inc.)
• Inventors: Levin, Howard R., Gelfand, Mark, O'Mahony, John, Polaschegg, Hans-Dietrich
• Primary Examiner(s): DEAK, LESLIE R
• Application Number:
  US13/098,853
• Publication Number:
  US 20110208106A1
• Time in Patent Office: 953 Days
• Field of Search: 604/5.01, 604/5.04, 604/5.09, 604/6.06, 604/6.11, 604/6.16, 604/6.09, 604 65- 67, 210650-651, 210645-647, 210/90, 210/500.21, 210/600, 210/634, 210/195.2, 210/200, 210/203, 210/321.6, 21032178- 8, 21032188- 9, 210/416.1, 210/433.1, 210/500.23
• US Class Current: 604/6.09
• CPC Class Codes: A61M 1/1692 Detection of blood traces in dialysate
• 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 1/341 by measuring the filtrate rate or volume
• CPC Class Codes: A61M 1/361 before treatment
• CPC Class Codes: A61M 1/3612 after treatment
• CPC Class Codes: A61M 2205/3393 by weighing the reservoir
• CPC Class Codes: A61M 2205/50 with microprocessors or computers
• CPC Class Codes: A61M 2205/7563 with means preventing clogging of filters

Abstract

An ultrafiltration filter for an extracorporeal blood circuit having an input for blood withdrawn from a human patient and a blood output for filtered blood to be infused into the patient including: a filter body having a length of at least 20 centimeters (cm) and an interior diameter of no greater than 1.5 cm; an input at a first end of the body to receive the withdrawn blood; an output at a second end of the body to discharge the filtered blood; a filter membrane in the body defining a blood passage through the body, wherein the membrane has an active filter membrane surface area of no greater than 0.2 meters squared (m²) and the filter membrane blocks passage of blood molecules having a molecular weight cut of greater than 60,000 Daltons and a volume of the blood passage in the filter being less than two percent of a cardiac output of the patient, and an ultrafiltrate output to the body and open to a side of the filter surface area opposite to the blood passage.

Claims

1. An ultrafiltration filter for an extracorporeal blood circuit having an input for blood withdrawn from a human patient and a blood output for filtered blood to be infused into the patient, said ultrafiltration filter comprising:

a filter body having a length of at least 20 centimeters (cm) and an interior diameter of no greater than 1.5 cm;

an input at a first end of the body to receive the withdrawn blood;

an output at a second end of the body to discharge the filtered blood;

a filter membrane in the body defining a blood passage through the body, wherein the membrane has an active filter membrane surface area of no greater than 0.2 meters squared (m²) and the filter membrane blocks passage of blood molecules having a molecular weight cut of greater than 60,000 Daltons and a volume of the blood passage in the filter being less than two percent of a cardiac output of the patient, and

an ultrafiltrate output to the body and open to a side of the filter surface area opposite to the blood passage.

2. The filter as in claim 1 wherein the active filter membrane surface area is no greater than 0.1 m².

3. The filter as in claim 1 wherein the filter membrane surface is an interior surface of a bundle of filter fibers.

4. The filter as in claim 1 wherein the filter fibers have a length of at least 20 centimeters.

5. The filter as in claim 1 wherein the bundle of filter fibers has at least 620 fibers.

6. The filter as in claim 1 wherein the filter body is substantially straight.

7. The filter as in claim 1 wherein the filter membrane comprises hollow fibers and said fibers are arranged in a substantially straight bundle no greater than 1.5 centimeters in diameter.

8. An ultrafiltration filter for an extracorporeal blood circuit having an input for blood withdrawn from a human patient and a blood output for filtered blood to be infused into the patient, said ultrafiltration filter comprising:

a filter body having a length of at least 20 centimeters (cm) and an interior cross-sectional area of no greater than 1.77 cm²;

an input at a first end of the body to receive the withdrawn blood;

an output at a second end of the body to discharge the filtered blood;

a filter membrane in the body defining a blood passage through the body, wherein the membrane has an active filter membrane surface area of no greater than 0.2 meters squared (m²) and the filter membrane blocks passage of blood molecules having a molecular weight cut of greater than 60,000 Daltons and a volume of the blood passage in the filter being less than two percent of a cardiac output of the patient, and

an ultrafiltrate output to the body and open to a side of the filter surface area opposite to the blood passage.

9. The filter as in claim 8 wherein the active filter membrane surface area is no greater than 0.1 m².

10. The filter as in claim 8 wherein the filter membrane surface is an interior surface of a bundle of filter fibers.

11. The filter as in claim 8 wherein the filter fibers have a length of at least 20 centimeters.

12. The filter as in claim 8 wherein the bundle of filter fibers has at least 620 fibers.

13. The filter as in claim 8 wherein the filter body is substantially straight.

14. The filter as in claim 8 wherein the filter membrane comprises hollow fibers and said fibers are arranged in a substantially straight bundle no greater than 1.5 centimeters in diameter.

15. The filter as in claim 8 wherein the cross-sectional area of the filter body is circular an has a diameter no greater than 1.5 cm.