FLUID PUMPING APPARATUS FOR USE WITH A REMOVABLE FLUID PUMPING CARTRIDGE

• US 20140194820A1
• Filed: 03/11/2014
• Published: 07/10/2014
• Est. Priority Date: 07/20/1999
• Status: Active Grant

• Current Assignee: Deka Products Limited Partnership
• Original Assignee: Deka Products Limited Partnership
• Inventors: Gray, Larry B., Lanigan, Richard J.
• Granted Patent: US 9,115,709 B2
• Time in Patent Office: Days
• US Class Current: 604/153
• CPC Class Codes: A61M 1/1649 with pulsatile dialysis fluid flow
• CPC Class Codes: A61M 1/267 used for pumping
• 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 1/362261 at least one cassette surface or portion thereof being flexible, e.g. the cassette having a rigid base portion with preformed channels and being covered with a foil
• CPC Class Codes: A61M 1/362264 the filter being a blood filter
• CPC Class Codes: A61M 1/362265 Details of valves
• CPC Class Codes: A61M 1/362266 Means for adding solutions or substances to the blood
• CPC Class Codes: A61M 1/367 Circuit parts not covered by the preceding subgroups of group A61M1/3621
• CPC Class Codes: A61M 2205/12 with interchangeable cassettes forming partially or totally the fluid circuit
• CPC Class Codes: A61M 2209/02 Equipment for testing the apparatus
• CPC Class Codes: A61M 39/228 with a tubular diaphragm constrictable by radial fluid force
• CPC Class Codes: A61M 5/14 Infusion devices, e.g. infusing by gravity; Blood infusion; Accessories therefor
• CPC Class Codes: A61M 5/14224 Diaphragm type
• CPC Class Codes: A61M 5/14593 the diaphragm being actuated by fluid pressure
• CPC Class Codes: A61M 5/172 electrical or electronic A61M5/16804, A61M5/16831 take precedence
• CPC Class Codes: F04B 43/067 the fluid being actuated directly by a piston
• CPC Class Codes: F04B 45/00 Pumps or pumping installations having flexible working members and specially adapted for elastic fluids
• CPC Class Codes: F04B 45/02 having bellows
• CPC Class Codes: F04B 49/065 and making use of computers
• CPC Class Codes: F04B 49/12 : by varying the length of stroke of the working members
• CPC Class Codes: F04B 53/10 : Valves; Arrangement of valves
• CPC Class Codes: F04B 53/16 : Casings; Cylinders; Cylinder liners or heads; Fluid connections
• CPC Class Codes: G01M 3/26 : by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors
• CPC Class Codes: G01M 3/32 : for containers, e.g. radiators
• CPC Class Codes: G05D 16/20 : characterised by the use of electric means

Abstract

The present invention involves, in some embodiments apparatus, such as dialysis apparatus, and methods for pumping fluid. Certain embodiments comprise a housing enclosing a pump drive assembly for actuating at least one pump on a removable fluid pumping cassette. The housing may comprise a door connected to the housing for enclosing an installed cassette in the housing upon closure of the door. The pump drive assembly may comprise a mating block configured for operative association with an installed cassette and to may be configured to permit a sealing engagement with an installed cassette upon closure of the door. To facilitate sealing, certain embodiments of the door include a movable compression plate configured to exert a compressive force on an installed cassette against the mating block when the door is in a closed position.

Claims

1. An apparatus for pumping fluid comprising:

a housing enclosing a pump drive assembly for actuating at least one pump on a removable fluid pumping cassette;

a door connected to the housing for enclosing an installed cassette in the housing upon closure of the door;

the pump drive assembly comprising a mating block configured for operative association with an installed cassette;

the mating block configured to permit a sealing engagement with an installed cassette upon closure of the door;

wherein

the door includes a movable compression plate configured to exert a compressive force on an installed cassette against the mating block when the door is in a closed position.

2. The apparatus of claim 1, wherein the pump drive assembly is configured to actuate a flexible membrane of an installed cassette when the cassette is placed in operative association with the mating block.

3. The apparatus of claim 2, wherein the mating block includes a depression configured to align with a corresponding depression in an installed cassette upon operative association of the mating block with the cassette, the alignment forming a pump chamber in the cassette separated from a control chamber in the mating block by the flexible membrane.

4. The apparatus of claim 3, wherein the pump drive assembly is configured to deliver pneumatic pressure to the flexible membrane in order to pump fluid into or out of the pump chamber of the cassette.

5. The apparatus of claim 1, further comprising a latch on the door, the latch configured to inhibit the door from being opened when the door is closed and the compression plate is applying a compressive force on an installed cassette.

6. The apparatus of claim 1, wherein the door is configured to apply a pneumatic force on the compression plate to generate a compressive force on an installed cassette.

7. The apparatus of claim 1, wherein the door further comprises an expandable bladder adjacent the compression plate and configured to be pressurized against the compression plate to generate a compressive force on an installed cassette.

8. The apparatus of claim 7, wherein the bladder is pneumatically inflatable or deflatable.

9. The apparatus of claim 8, wherein the housing includes one or more pneumatic channels connecting a positive pneumatic pressure source to the bladder.

10. The apparatus of claim 8, wherein the housing includes one or more pneumatic channels connecting a negative pneumatic pressure source to the bladder.

11. The apparatus of claim 7, further comprising a controller configured to control expansion of the bladder.

12. The apparatus of claim 10, wherein the controller is configured to receive a signal from one or more sensors to detect whether the door is in a closed position.

13. The apparatus of claim 1, comprising a cassette installation region having a perimeter shape that requires a cassette having a corresponding perimeter shape to be installed in only one orientation for operative association with the mating block.

14. The apparatus of claim 1, wherein the mating block includes a region for actuating a valve on an installed cassette, and wherein the pump drive assembly is configured to provide a force to open or close the valve.

15. The apparatus of claim 14, wherein the region comprises a valve actuating depression configured to align with the valve of the cassette when the cassette is placed in operative association with the mating block.

16. The apparatus of claim 15, wherein the valve actuating depression is configured to provide a positive or negative pressure on a flexible membrane overlying the valve of the cassette, the flexible membrane being configured to occlude a fluid port on the cassette upon exposure to a positive or negative pressure.

17. A dialysis apparatus comprising:

a base unit configured to receive and control a removable fluid handling cassette;

a stationary mating surface on the base unit configured for operative association with an installed cassette; and

a door connected to the base unit for enclosing the cassette upon closure of the door;

wherein

the door includes a compression plate configured to exert a compressive force on an installed cassette against the mating surface when the door is in a closed position.

18. The apparatus of claim 17, wherein the mating surface is configured to form a fluid seal with an installed cassette when the compression plate exerts a compressive force on the cassette.

19. The apparatus of claim 17, wherein the mating surface is configured to actuate one or more fluid valves or one or more fluid pumps on an installed cassette.

20. The apparatus of claim 19, wherein the mating surface is configured to deliver pneumatic pressure to the one or more fluid valves or the one or more fluid pumps on an installed cassette.

21. The apparatus of claim 20, wherein the mating surface comprises valve control or pump control depressions that align with respective valves or pumps on an installed cassette.

22. The apparatus of claim 21, wherein the valve control or pump control depressions are in selective fluid communication with a source of positive pneumatic pressure, the depressions configured to provide positive pressure to one or more flexible membranes overlying the respective valves or pumps on an installed cassette.

23. The apparatus of claim 21, wherein the valve control or pump control depressions are in selective fluid communication with a source of negative pneumatic pressure, the depressions configured to provide negative pressure to one or more flexible membranes overlying the respective valves or pumps on an installed cassette.

24. The apparatus of claim 17, further comprising a door latch configured to inhibit opening the door when the compression plate is exerting a compressive force on an installed cassette.

25. The apparatus of claim 17, wherein the door is configured to apply a pneumatic force on the compression plate to generate a compressive force on an installed cassette.

26. The apparatus of claim 17, wherein the door further comprises an expandable bladder adjacent the compression plate and configured to be pressurized against the compression plate to generate a compressive force on an installed cassette.

27. The apparatus of claim 25, wherein the bladder is pneumatically inflatable or deflatable.

28. The apparatus of claim 27, wherein the base unit includes one or more selectable pneumatic channels connecting a positive or negative pneumatic pressure source to the bladder.

29. The apparatus of claim 26, further comprising a controller configured to control expansion of the bladder, and configured to receive a signal from one or more sensors to detect whether the door is in a closed position, and whether a cassette is installed in the base unit.