Peritoneal dialysis sensor apparatus systems, devices and methods

• US 8,366,655 B2
• Filed: 10/12/2007
• Issued: 02/05/2013
• Est. Priority Date: 02/27/2007
• Status: Active Grant

• Current Assignee: Deka Products Limited Partnership
• Original Assignee: Deka Products Limited Partnership
• Inventors: Kamen, Dean, Perry, N. Christopher, Demers, Jason A., Tracey, Brian
• Primary Examiner(s): Sirmons, Kevin C
• Assistant Examiner(s): OSINSKI, BRADLEY JAMES
• Application Number:
  US11/871,828
• Publication Number:
  US 20080208111A1
• Time in Patent Office: 1,943 Days
• Field of Search: 604/29, 604 64- 67, 210/258
• US Class Current: 604/29
• CPC Class Codes: A61M 1/154 with sensing means or components thereof
• CPC Class Codes: A61M 1/155 with treatment-fluid pumping means or components thereof
• CPC Class Codes: A61M 1/1561 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 1/15625 the reservoirs acting as balance chambers
• CPC Class Codes: A61M 1/1565 Details of valves
• CPC Class Codes: A61M 1/16 with membranes
• CPC Class Codes: A61M 1/1605 Physical characteristics of the dialysate fluid
• CPC Class Codes: A61M 1/1639 linked by membranes
• CPC Class Codes: A61M 1/1656 Apparatus for preparing dialysates
• CPC Class Codes: A61M 1/1664 with temperature control
• CPC Class Codes: A61M 1/1666 by dissolving solids
• CPC Class Codes: A61M 1/287 Dialysates therefor
• CPC Class Codes: A61M 2205/12 with interchangeable cassettes forming partially or totally the fluid circuit
• CPC Class Codes: A61M 2205/128 with incorporated valves
• CPC Class Codes: A61M 2205/3317 Electromagnetic, inductive or dielectric measuring means
• CPC Class Codes: A61M 2205/3324 PH measuring means
• CPC Class Codes: A61M 2205/3368 Temperature
• CPC Class Codes: A61M 60/113 in other functional devices, e.g. dialysers or heart-lung machines
• CPC Class Codes: A61M 60/268 the displacement member being flexible, e.g. membranes, diaphragms or bladders
• CPC Class Codes: A61M 60/37 Haemodialysis, haemofiltration or diafiltration
• CPC Class Codes: A61M 60/427 : the force acting on the blood contacting member being hydraulic or pneumatic
• CPC Class Codes: A61M 60/43 : using vacuum at the blood pump, e.g. to accelerate filling
• CPC Class Codes: A61M 60/837 : Aspects of flexible displacement members, e.g. shapes or materials
• CPC Class Codes: A61M 60/847 : arranged in a cassette
• CPC Class Codes: A61M 60/849 : Disposable parts
• CPC Class Codes: A61M 60/851 : Valves
• CPC Class Codes: A61M 60/892 : Active valves, i.e. actuated by an external force
• CPC Class Codes: A61M 60/894 : Passive valves, i.e. valves actuated by the blood
• CPC Class Codes: F04B 13/02 : of two or more fluids at the same time
• CPC Class Codes: F04B 23/06 : the pumps being all of reciprocating positive-displacement type
• CPC Class Codes: F04B 41/06 : Combinations of two or more pumps
• CPC Class Codes: F04B 43/00 : Machines, pumps, or pumping installations having flexible working members pumps or pumping installations specially adapted for elastic fluids F04B45/00
• CPC Class Codes: F04B 43/026 : each plate-like pumping flexible member working in its own pumping chamber
• CPC Class Codes: F04B 43/06 : Pumps having fluid drive
• CPC Class Codes: F04B 43/0736 : with two or more pumping chambers in parallel
• CPC Class Codes: F04B 45/02 : having bellows
• CPC Class Codes: F04B 45/0536 : the actuating fluid being controlled by one or more valves
• CPC Class Codes: F04B 49/02 : Stopping, starting, unloading or idling control
• CPC Class Codes: F04B 49/22 : by means of valves F04B49/03 takes precedence
• CPC Class Codes: F04B 53/06 : Venting
• 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: F04B 7/02 : the valving being fluid-actuated
• CPC Class Codes: F04B 9/109 : having plural pumping chambers
• CPC Class Codes: F17D 3/00 : Arrangements for supervising or controlling working operations
• CPC Class Codes: Y02A 90/10 : Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation
• CPC Class Codes: Y10T 137/0324 : With control of flow by a condition or characteristic of a fluid
• CPC Class Codes: Y10T 137/0379 : By fluid pressure
• CPC Class Codes: Y10T 137/2521 : Flow comparison or differential response
• CPC Class Codes: Y10T 137/85978 : With pump
• CPC Class Codes: Y10T 137/86139 : Serial

Abstract

A sensor apparatus and sensor apparatus system for use in conjunction with a cassette-based peritoneal dialysis system is described, including a disposable cassette. In some embodiments, the cassette includes a thermal well for permitting the sensing of various properties of a dialysate. The thermal well includes a hollow housing of a thermally conductive material. In other embodiments, the cassette includes sensor leads for sensing of various properties of a dialysate. The thermal well has an inner surface shaped so as to form a mating relationship with a sensing probe. The mating thermally couples the inner surface with a sensing probe. In some embodiments, the thermal well is located on a disposable portion and the sensing probe on a reusable portion.

Claims

1. A method for determining temperature and conductivity of a dialysate in a peritoneal dialysis pump cassette, said pump cassette comprising a first region formed of a flexible membrane and a second region formed of a rigid material and not comprising a flexible membrane, said second region having at least two thermal wells formed in the rigid material and extending into a liquid flow path in the cassette, at least one of said thermal wells having at least a portion comprising an electrically conductive material configured for contacting a liquid contained in said liquid flow path, said method comprising the steps of:

placing the cassette in a dialysis machine having at least two sensing probes, each sensing probe adapted to mate with one of the thermal wells;

thermally coupling each thermal well with a sensing probe such that temperature and conductivity can be determined;

transferring thermal and conductivity signals through at least 3 leads from at least one of said sensing probes; and

determining temperature and conductivity of a liquid contained in the liquid flow path using said signals.

2. The method of claim 1, wherein the pump cassette comprises a first side comprising the first region formed of the flexible membrane, a second side opposite the first side, and a third side comprising the second region having the at least two thermal wells.

3. A method for determining the temperature and conductivity of dialysate in a peritoneal dialysis pump cassette, said pump cassette comprising a first region formed of a flexible membrane and a second region formed of a rigid material and not comprising a flexible membrane, said second region having at least two thermal wells formed in the rigid material and extending into a liquid flow path in the cassette, at least one of said thermal wells having at least a portion comprising an electrically conductive material configured for contacting a liquid contained in said liquid flow path, said method comprising the steps of:

placing the cassette in a dialysis machine having at least two sensing probes, each sensing probe adapted to mate with one of the thermal wells;

thermally coupling each thermal well with a sensing probe such that temperature and conductivity can be determined;

transferring thermal and conductivity signals through at least 3 leads from at least one of said sensing probes;

determining temperature and conductivity of a liquid contained in the liquid flow path using said signals; and

comparing the conductivity determined to a preset conductivity level.

4. A method according to claim 3, wherein said method further comprises the step of sending a signal to the dialysis machine if the determined conductivity is not within a specified range of the preset conductivity level.

5. A method according to claim 4, wherein said method further comprises the step of suspending peritoneal dialysis treatment if the determined conductivity is not within the specified range of the preset conductivity level.

6. The method of claim 3, wherein the pump cassette comprises a first side comprising the first region formed of the flexible membrane, a second side opposite the first side, and a third side comprising the second region having the at least two thermal wells.

7. A disposable pump cassette for performing peritoneal dialysis comprising:

a) a first side comprising a flexible membrane for pumping or directing liquid in the cassette;

b) an opposing second side adapted and configured to receive a force urging at least a portion of the cassette against the flexible membrane when the cassette is mounted in a dialysis machine; and

c) a third side not comprising a flexible membrane, wherein at least a portion of said third side;

is not parallel to said first side;

is not parallel to said opposing second side;

spans at least a portion of the distance separating said first side from said opposing second side; and

comprises a thermal well extending into a liquid path in the cassette, wherein

the thermal well has a liquid side for making contact with liquid in the cassette and an opposing probe side for reversible mating with a sensing probe, said thermal well being thermally conductive between the liquid side and the probe side.

8. A cassette according to claim 7, wherein the cassette comprises at least one pump chamber.

9. A cassette according to claim 7, wherein the cassette comprises at least one valving station.

10. A cassette according to claim 7, wherein the cassette comprises at least one pump chamber and one valving station.

11. A cassette according to claim 7, wherein the thermal well is a first thermal well, and the cassette comprises a second thermal well spaced apart from the first thermal well, wherein the liquid side of the first thermal well is in fluid communication with the liquid side of the second thermal well through a liquid flow path in the cassette.

12. A cassette according to claim 11, wherein the first thermal well can be reversibly coupled with a first sensing probe, the second thermal well can be reversibly coupled with a second sensing probe, and at least a portion of each thermal well is electrically conductive, said couplings permitting conductivity sensing of a liquid in the liquid flow path in the cassette.

13. A cassette according to claim 12, wherein at least one of the first sensing probe and the second sensing probe has three leads for transmitting thermal and electrical conductivity signals.

14. A cassette according to claim 7, wherein the well is secured to the cassette using at least one of press fit connection, flexible tabs, adhesive, ultrasonic weld, and a retaining plate with fastener.

15. A disposable pump cassette for performing peritoneal dialysis comprising:

a) a first region formed of a flexible membrane; and

b) a second region, not co-planar with said first region, that is formed of a rigid material, does not comprise a flexible membrane and has at least two thermal wells formed in the rigid material and extending into a liquid flow path in the cassette;

wherein

each thermal well has a liquid side for making contact with liquid in the cassette and an opposing probe side for reversible mating with a sensing probe, each thermal well being thermally conductive between the liquid side and the probe side.

16. A cassette according to claim 15, wherein the cassette comprises at least one pump chamber.

17. A cassette according to claim 15, wherein the cassette comprises at least one valving station.

18. A cassette according to claim 15, wherein the cassette comprises at least one pump chamber and one valving station.

19. A cassette according to claim 15, wherein the thermal wells are spaced apart from each other and wherein the liquid side of each thermal well is in fluid communication with the liquid side of each other thermal well through the liquid flow path in the cassette.

20. A cassette according to claim 19, wherein a first thermal well can be reversibly coupled with a first sensing probe, a second thermal well can be reversibly coupled with a second sensing probe, and at least a portion of each thermal well is electrically conductive, said couplings permitting conductivity sensing of a liquid in the liquid flow path.

21. A cassette according to claim 20, wherein at least one of the first sensing probe and the second sensing probe has three leads for transmitting thermal and electrical conductivity signals.

22. A cassette according to claim 15, wherein the at least two wells are secured to the cassette using at least one of press fit connection, flexible tabs, adhesive, ultrasonic weld, and a retaining plate with fastener.