AIR TRAP FOR A MEDICAL INFUSION DEVICE

• US 20090107335A1
• Filed: 08/27/2008
• Published: 04/30/2009
• Est. Priority Date: 02/27/2007
• Status: Abandoned Application

• Current Assignee: Deka Products Limited Partnership
• Original Assignee: Deka Products Limited Partnership
• Inventors: Demers, Jason A., Wilt, Michael J.
• Application Number:
  US12/199,166
• Publication Number:
  US 20090107335A1
• Time in Patent Office: Days
• US Class Current: 95/261
• CPC Class Codes: A61M 1/14 Dialysis systems; Artificial kidneys; Blood oxygenators semi-permeable membranes characterised by the material, manufacturing processes therefor B01D71/00; Reciprocating systems for treatment of body fluids, e.g. single needle systems for hemofiltration or pheresis
• CPC Class Codes: A61M 1/362227 the interface providing means for actuating on functional elements of the cassette, e.g. plungers
• CPC Class Codes: A61M 1/36225 with blood pumping means or components thereof
• CPC Class Codes: A61M 1/362263 Details of incorporated filters
• CPC Class Codes: A61M 1/362266 Means for adding solutions or substances to the blood
• CPC Class Codes: A61M 1/3627 Degassing devices; Buffer reservoirs; Drip chambers; Blood filters
• CPC Class Codes: B01D 19/00 Degasification of liquids

Abstract

An air trap for a blood circuit and method for removing air from blood in a dialysis unit. The air trap may include a blood inlet supply line, a blood outlet supply line, and a container having an approximately spherical internal wall, an inlet at a top end of the container connected to the blood inlet supply line, and an outlet at a bottom end of the container connected to the blood outlet supply line. The inlet may be offset from a vertical axis of the approximately spherical internal wall such that blood entering the container is directed to flow in a spiral-like path. The inlet port may be arranged to introduce blood into the container in a direction that is approximately tangential to the approximately spherical inner wall of the container and/or in a direction that is approximately perpendicular to the vertical axis of the container.

Claims

1. An air trap for a blood circuit in a dialysis unit, comprising:

a blood inlet supply line;

a blood outlet supply line; and

a container having an approximately spherical internal wall, an inlet at a top end of the container connected to the blood inlet supply line, and an outlet at a bottom end of the container connected to the blood outlet supply line, the inlet being offset from a vertical axis of the approximately spherical internal wall such that blood entering the container through the inlet is directed to flow in around the approximately spherical wall in a spiral-like path;

wherein when blood is supplied to the container via the blood inlet supply line and blood in the container is removed from the container via the blood outlet supply line, air in the blood entering the container remains in the container.

2. The air trap of claim 1, wherein the container is formed by an approximately spherical shell.

3. The air trap of claim 1, wherein the blood circuit includes a dialyzer and the air trap receives blood via the blood inlet supply line from the dialyzer.

4. The air trap of claim 1, further comprising:

a self-sealing port located at a top of the container.

5. The air trap of claim 4, wherein the self-sealing port is formed by a split septum.

6. The air trap of claim 4, wherein the split septum is arranged to permit introduction of fluid into, and withdrawal of liquid from, the container by inserting a needleless device through the split septum.

7. The air trap of claim 4, wherein the self-sealing port is arranged to be self-cleaning when disinfection liquid is circulated through the container.

8. The air trap of claim 7, wherein an inner surface of the self-sealing port is approximately flush with the internal wall of the container at a top of the container.

9. The air trap of claim 8, wherein the self-sealing port is cleaned by introducing liquid into the container via the blood outlet supply line and removing liquid from the container via the blood inlet supply line.

10. The air trap of claim 1, wherein the inlet port is arranged to receive air in the container when liquid is introduced into the container via the outlet port during a priming operation.

11. The air trap of claim 1, wherein the inlet port is arranged to introduce blood into the container in a direction that is approximately tangential to the approximately spherical inner wall of the container.

12. The air trap of claim 1, wherein the inlet port is arranged to introduce blood into the container in a direction that is approximately perpendicular to the vertical axis of the container.

13. A method for removing air from a flow of blood in a dialysis unit, comprising:

introducing blood into an upper portion of an approximately spherical container;

causing the blood to flow in a spiral-like path in the container; and

removing the blood from a lower portion of the approximately spherical container.

14. The method of claim 13, wherein the step of introducing comprises:

introducing blood into the container in a direction that is approximately tangential to an approximately spherical inner wall of the container.

15. The method of claim 13, wherein the step of introducing comprises:

introducing blood into the container in a direction that is approximately perpendicular to the vertical axis of the container.

16. An air trap for a blood circuit in a dialysis unit, comprising:

a blood inlet supply line;

a blood outlet supply line;

a container having an approximately spherical internal wall, an inlet at a top end of the container connected to the blood inlet supply line, and an outlet at a bottom end of the container connected to the blood outlet supply line, the inlet being offset from a vertical axis of the approximately spherical internal wall such that blood entering the container through the inlet is directed to flow in around the approximately spherical wall in a spiral-like path; and

a self-sealing port located at a top of the container, the self-sealing port having an inner surface that is approximately flush with the internal wall of the container at the top of the container,

wherein when blood is supplied to the container via the blood inlet supply line and blood in the container is removed from the container via the blood outlet supply line, air in the blood entering the container remains in the container, and wherein any air in the container is substantially completely removed by introducing liquid into the container via the blood outlet supply line and removing liquid from the container via the blood inlet supply line.

17. The air trap of claim 16, wherein the inlet, outlet and internal wall of the container and the self-sealing port are arranged to substantially eliminate stagnation regions.