Method and apparatus for prevention of catheter air intake

• US 20090163864A1
• Filed: 12/19/2008
• Published: 06/25/2009
• Est. Priority Date: 12/21/2007
• Status: Active Grant

• Current Assignee: Indian Wells Medical, Inc.
• Original Assignee: Indian Wells Medical, Inc.
• Inventors: Lenker, Jay A., Wieting, David W., Breznock, Eugene M.
• Granted Patent: US 7,935,102 B2
• Time in Patent Office: Days
• US Class Current: 604/122
• CPC Class Codes: A61M 5/36 with means for eliminating or preventing injection or infusion of air into body dialysis systems, blood oxygenators A61M1/14; haemofiltration equipment A61M1/34; automatic tube cut-off A61M39/281

Abstract

A system is disclosed for preventing air from entering a first catheter or cannula of a multi-catheter system. Air is prevented from entering the proximal end of the first catheter by an axially elongate chamber having an impeller, the chamber being affixed to the proximal end of the first catheter. The first catheter is affixed at an offset location, near the periphery of the chamber. The impeller is driven by a motor drive and imparts rotational energy to the fluid within the chamber forcing any air within the chamber to migrate to the center of the chamber by buoyancy effects. The air is removed through a port near the centerline of the chamber. Liquid removed with the air is returned to the chamber to minimize liquid loss during the procedure. Hemostasis valves or seals can be provided at the entrance and the exit of the chamber. A second catheter inserted through the chamber and into the first catheter is unable to entrain gas into the first catheter because any gas that enters the chamber is routed to the centerline of the chamber where it is removed. The first catheter can be a cannula or an introduction sheath, devices suited for endovascular access into the mammalian cardiovascular system where pressures may fall below ambient room pressure, a condition, which could encourage the possibility of air embolism to a patient. Inflow of fluid from an external pump scrubs the second catheter shaft of air bubbles attached by surface tension.

Claims

1. An apparatus adapted for preventing gas from entering a catheter, sheath, introducer, or cannula, wherein the catheter interior is exposed to blood or other liquid, said apparatus comprising:

a shell, wherein the interior volume of the shell defines an axially elongate chamber having a centerline;

an impeller operable to rotate about or near the centerline of the shell, wherein the impeller is located within the interior volume of the shell and is configured to directly rotate the blood or other liquid within the chamber;

a motor drive to actively rotate the impeller;

an electrical power source to power the motor drive;

a gas vent or gas outlet port located near a central axis of the shell, and in fluid communication with the interior volume of the shell;

a catheter inlet port located near a periphery of said shell; and

a catheter outlet port located near a periphery of said shell;

wherein the catheter inlet port is axially aligned with the catheter outlet port so that a second catheter inserted therethrough is guided from catheter inlet port into the catheter outlet port.

2. The apparatus of claim 1 further comprising a liquid return port.

3. The apparatus of claim 1 further comprising a gas collection chamber.

4. The apparatus of claim 1 wherein the proximal end of the catheter outlet port comprises a funnel to guide a flexible catheter into the lumen of the catheter outlet port.

5. The apparatus of claim 1 wherein said impeller spins at a rate of from 100 to 10,000 RPM.

6. The apparatus of claim 3 further comprising a gas vent to remove gas from the gas collection chamber.

7. The apparatus of claim 1 further comprising a pump to move liquid from a gas collection chamber to a liquid return port.

8. The apparatus of claim 1 wherein the electrical power source is a battery.

9. The apparatus of claim 1 wherein the interior surfaces of said chamber are coated with anti-thrombogenic materials.

10. The apparatus of claim 1 wherein said impeller is further operable to pump gas and liquid out of, or into, the chamber.

11. The apparatus of claim 1 wherein said first and second catheter ports are located lower than the centerline of the chamber with respect to a gravitational vector.

12. The apparatus of claim 1 wherein said gas vent is located higher than the catheter inlet and outlet ports.

13. The apparatus of claim 1 wherein said impeller is magnetically coupled to said motor drive.

14. The apparatus of claim 1 wherein said impeller comprises a plurality of vanes to spin the blood.

15. The apparatus of claim 1 wherein said impeller comprises a substantially smooth outer surface to spin the blood using viscous or shear effects.

16. The apparatus of claim 1 wherein said catheter inlet port comprises a hemostasis valve, wherein the hemostasis valve is operable to substantially seal fluid from passing therethrough whether or not a catheter is inserted through the apparatus.

26. The apparatus of claim 1 wherein the shell, the impeller, the motor drive, the gas vent, the catheter inlet port, the catheter outlet port, the electrical power source, and all components are integrated into a single module with no flexible interconnections.

17. A method for preventing gas from entering a catheter, wherein the catheter interior is exposed to blood or other liquid, said method comprising:

affixing an axially elongate shell at or near the proximal end of a first catheter, wherein said shell comprises a chamber having a centerline;

rotating an impeller about or near the centerline of the chamber, wherein said rotation of said impeller directly imparts rotational energy to a fluid within the chamber causing any gas collected within the chamber to migrate toward the centerline due to buoyancy effects;

removing the gas from the chamber through a gas removal port near the centerline of said shell;

affixing a catheter inlet port to the shell near a periphery of said chamber, said catheter inlet port operably connected to the chamber;

affixing a catheter outlet port near the distal end of the shell, said catheter outlet port being affixed, and operably connected to the proximal end of the first catheter, and near a periphery of said chamber, wherein the catheter inlet port is axially aligned, substantially concentrically, with the catheter outlet port;

Inserting a second catheter through the catheter inlet port, through the chamber, through the catheter outlet port, through the first catheter, and on into the cardiovascular system of a patient.

18. The method of claim 17, which includes the step of separating any liquid removed from the chamber from the gas.

19. The method of claim 17, wherein said impeller is spun at a rate of between 100 and 10,000 revolutions per minute.

20. The method of claim 17, wherein the impeller is rotated by an electric motor.

21. The method of claim 17 further comprising the step of affixing a valve to the catheter inlet port to substantially prevent air or other gas from entering the chamber from an outside room environment.

22. The method of claim 17 further comprising the step of affixing a hemostasis valve to the catheter outlet port to substantially prevent air or other gas from entering the first catheter from a the chamber.

23. The method of claim 17 further comprising the step of pumping the blood and other liquid, along with any air entrained within a central vortex, toward an end of the chamber where the air can be drawn off into the gas removal port.

24. The method of claim 23 wherein the pumping step is performed by rotating the impeller.

25. The method of claim 18 further comprising the step of returning the liquid to the chamber through a return line.

27. An apparatus adapted for removing air from the proximal end of an introducer sheath comprising:

an shell, wherein the interior volume of the shell defines an axially elongate chamber having a centerline;

a fluid pump operable to remove fluid from the interior volume of the shell;

a motor drive to actively operate the pump;

an electrical power source to provide power to rotate the motor drive;

an electrical bus operably connecting the electrical power source and the motor drive;

a gas vent or gas outlet port located near a central axis of the shell;

a catheter inlet port located near a periphery of said shell, said catheter inlet port further comprising a hemostasis valve;

a catheter outlet port located near a periphery of said shell;

a gas separation chamber in fluid communication with the gas vent; and

a liquid return line operable to route liquid fluid from the gas separation chamber through the fluid pump and back into the interior volume of the shell;

wherein the catheter inlet port is axially, concentrically, aligned with the catheter outlet port so that a second catheter inserted therethrough is guided from catheter inlet port into the catheter outlet port; and

wherein the shell, the gas vent, the gas separation chamber, the pump, the liquid return line, the catheter inlet port, the catheter outlet port, the electrical power source, and all interconnections are integrated into a single module.

28. The apparatus of claim 27 wherein the return line is aligned tangent to the interior wall of the shell, such that liquid returning to the interior of the shell causes a strong rotational flow within the shell.

29. The apparatus of claim 27, wherein no flexible tubes lead from the apparatus to a volume of liquid external to the apparatus.

30. The apparatus of claim 27 wherein the return line is aligned substantially perpendicular to the interior wall of the shell such that the outlet of the return line is directed at a catheter inserted through the catheter inlet port and through the catheter outlet port.