Hemodialysis systems and methods

• US 20090008331A1
• Filed: 02/27/2008
• Published: 01/08/2009
• Est. Priority Date: 02/27/2007
• Status: Active Grant

• Current Assignee: Deka Products Limited Partnership
• Original Assignee: Deka Products Limited Partnership
• Inventors: Tracey, Brian, Grant, Kevin L., Demers, Jason A., Dale, James D., Wilt, Michael J.
• Granted Patent: US 8,246,826 B2
• Time in Patent Office: Days
• US Class Current: 210/647
• 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 1/1601 Control or regulation
• CPC Class Codes: A61M 1/1621 Constructional aspects thereof semi-permeable membranes for separation processes characterised by their properties B01D69/00; semi permeable membranes characterised by their material B01D71/00
• CPC Class Codes: A61M 1/1654 Dialysates therefor
• CPC Class Codes: A61M 1/1694 with recirculating dialysing liquid
• CPC Class Codes: A61M 1/267 used for pumping
• CPC Class Codes: A61M 1/3401 Cassettes therefor
• CPC Class Codes: A61M 1/341 by measuring the filtrate rate or volume
• CPC Class Codes: A61M 1/3413 Diafiltration
• CPC Class Codes: A61M 1/3424 Substitution fluid path
• CPC Class Codes: A61M 1/3609 Physical characteristics of the blood, e.g. haematocrit, urea
• CPC Class Codes: A61M 1/3621 Extra-corporeal blood circuits single-needle circuits A61M1/30
• CPC Class Codes: A61M 1/36224 with sensing means or components thereof
• 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 1/362263 : Details of incorporated filters
• 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 1/3623 : Means for actively controlling temperature of blood
• CPC Class Codes: A61M 1/3638 : with a vapour trap
• CPC Class Codes: A61M 1/3643 : Priming, rinsing before or after use
• CPC Class Codes: A61M 1/3644 : Mode of operation
• CPC Class Codes: A61M 1/3646 : Expelling the residual body fluid after use, e.g. back to the body
• CPC Class Codes: A61M 1/3649 : using dialysate as priming or rinsing liquid
• CPC Class Codes: A61M 1/365 : through membranes, e.g. by inverted trans-membrane pressure [TMP]
• CPC Class Codes: A61M 1/3652 : using gas, e.g. air
• CPC Class Codes: A61M 1/3672 : Means preventing coagulation
• CPC Class Codes: A61M 2205/07 : having air pumping means
• CPC Class Codes: A61M 2205/12 : with interchangeable cassettes forming partially or totally the fluid circuit
• CPC Class Codes: A61M 2205/123 : with incorporated reservoirs
• CPC Class Codes: A61M 2205/125 : with incorporated filters
• CPC Class Codes: A61M 2205/128 : with incorporated valves
• CPC Class Codes: A61M 2205/15 : Detection of leaks
• CPC Class Codes: A61M 2205/16 : with back-up system in case of failure
• 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 2205/3331 : Pressure; Flow
• CPC Class Codes: A61M 2205/3334 : Measuring or controlling the flow rate
• CPC Class Codes: A61M 2205/3368 : Temperature
• CPC Class Codes: A61M 2205/36 : related to heating or cooling
• CPC Class Codes: A61M 2205/505 : Touch-screens; Virtual keyboard or keypads; Virtual buttons; Soft keys; Mouse touches
• CPC Class Codes: A61M 2205/82 : Internal energy supply devices
• CPC Class Codes: A61M 2205/8218 : Gas operated
• CPC Class Codes: A61M 2205/8225 : using incorporated gas cartridges for the driving gas
• CPC Class Codes: Y10T 137/87893 : With fluid actuator

Abstract

The present invention generally relates to hemodialysis and similar dialysis systems, including a variety of systems and methods that would make hemodialysis more efficient, easier, and/or more affordable. One aspect of the invention is generally directed to new fluid circuits for fluid flow. In one set of embodiments, a hemodialysis system may include a blood flow path and a dialysate flow path, where the dialysate flow path includes one or more of a balancing circuit, a mixing circuit, and/or a directing circuit. Preparation of dialysate by the preparation circuit, in some instances, may be decoupled from patient dialysis. In some cases, the circuits are defined, at least partially, within one or more cassettes, optionally interconnected with conduits, pumps, or the like. In one embodiment, the fluid circuit and/or the various fluid flow paths may be at least partially isolated, spatially and/or thermally, from electrical components of the hemodialysis system. In some cases, a gas supply may be provided in fluid communication with the dialysate flow path and/or the dialyzer that, when activated, is able to urge dialysate to pass through the dialyzer and urge blood in the blood flow path back to the patient. Such a system may be useful, for example, in certain emergency situations (e.g., a power failure) where it is desirable to return as much blood to the patient as possible. The hemodialysis system may also include, in another aspect of the invention, one or more fluid handling devices, such as pumps, valves, mixers, or the like, which can be actuated using a control fluid, such as air. In some cases, the control fluid may be delivered to the fluid handling devices using an external pump or other device, which may be detachable in certain instances. In one embodiment, one or more of the fluid handling devices may be generally rigid (e.g., having a spheroid shape), optionally with a diaphragm contained within the device, dividing it into first and second compartments.

Claims

1. A hemodialysis system, comprising:

a blood flow path;

a first cassette defining an inner dialysate fluid path;

a dialyzer in fluid communication with the blood flow path and the inner dialysate fluid path;

a second cassette defining an outer dialysate fluid path; and

a filter fluidly connecting the first cassette to the second cassette.

2. A hemodialysis system, comprising:

a blood flow path;

an inner dialysate fluid path;

a dialyzer in fluid communication with the blood flow path and the inner dialysate fluid path;

an outer dialysate fluid path;

a filter fluidly connecting the inner dialysate fluid path and the outer dialysate fluid path;

a first dialysate pump for pumping dialysate through the inner dialysate fluid path; and

a second dialysate pump for pumping dialysate through the outer dialysate fluid path, wherein the second dialysate pump and the first dialysate pump are operably connected such that flow through the inner dialysate fluid path is substantially equal to flow through the outer dialysate fluid path.

3. A hemodialysis system, comprising:

a blood flow path through which blood is drawn from a patient and passed through a dialyzer; and

a dialysate flow path through which dialysate flows from a dialysate supply through the dialyzer, the dialysate flow path comprising;

a balancing cassette which controls the amount of dialysate passing through the dialyzer,

a mixing cassette which forms dialysate from dialysate precursor and water, and

a directing cassette which passes water from a water supply to the mixing cassette and passes dialysate from the mixing cassette to the balancing cassette.

4. A hemodialysis system, comprising:

a cassette system, comprising a directing cassette, a mixing cassette and a balancing cassette,

wherein the directing cassette is able to direct water from a water supply to the mixing cassette and direct dialysate from the mixing cassette to a balancing cassette, the mixing cassette is able to mix water from the directing cassette with dialysate precursor from a dialysate precursor supply to produce a dialysate, and the balancing cassette is able to control the amount of dialysate passing through a dialyzer.

5. A hemodialysis system, comprising:

a blood flow path through which blood is drawn from a patient and passed through a dialyzer, the blood flow path including a blood flow pump;

a dialysate flow path through which dialysate flows from a dialysate supply through the dialyzer, the dialysate flow path including a dialysate pump; and

a control fluid path through which a control fluid actuates the blood flow pump and the dialysate pump.

6. A hemodialysis system, comprising:

a blood flow path through which blood is drawn from a patient and passed through a dialyzer; and

a dialysate flow path through which dialysate flows from a dialysate supply through the dialyzer, the dialysate flow path comprising at least one pneumatic pump.

7. A valving system, comprising:

a valve housing containing a plurality of valves, at least two of which valves each comprises a valving chamber and an actuation chamber, each of the at least two valves being actuatable by a control fluid in the actuation chamber;

a control housing having a plurality of fluid-interface ports for providing fluid communication with a control fluid from a base unit; and

a plurality of tubes extending between the valve housing and the control housing, each tube providing fluid communication between one of the fluid-interface ports and at least one of the actuation chambers, such that the base unit can actuate a valve by pressurizing control fluid in the fluid interface port.

8. A pumping system, comprising:

a pump housing containing a plurality of pumps, at least two of which pumps each includes a pumping chamber and an actuation chamber, each of the at least two pumps being actuatable by a control fluid in the actuation chamber;

a control housing having a plurality of fluid-interface ports for providing fluid communication with a control fluid from a base unit; and

a plurality of tubes extending between the pump housing and the control housing, each tube providing fluid communication between one of the fluid-interface ports and at least one of the actuation chambers, such that the base unit can actuate a pump by pressurizing control fluid in the fluid interface port.

9. A hemodialysis system, comprising:

a first pump comprising a pumping chamber and an actuation chamber;

a second pump comprising a pumping chamber and an actuation chamber;

a control fluid in fluidic communication with each of the actuation chambers of the first and second pumps; and

a controller able to pressurize the control fluid to control operation of the first and second pumps.

10. A hemodialysis system, comprising:

a first valve comprising a valving chamber and an actuation chamber;

a second valve comprising a valving chamber and an actuation chamber;

a control fluid in fluidic communication with each of the actuation chambers of the first and second valves; and

a controller able to pressurize the control fluid to control operation of the first and second valves.

11-12. -12. (canceled)

13. A method for measuring the clearance of a dialyzer, the dialyzer being located in a blood flow path, through which untreated blood can be drawn from a patient and passed through the dialyzer, and in a dialysate flow path, through which dialysate can flow from a dialysate supply through the dialyzer, the blood flow path being separated from the dialysate flow path by membranes in the dialyzer, the method comprising:

urging a liquid through the dialysate flow path to the dialyzer, so as to keep the membranes wet and prevent the flow of a gas through the membranes;

urging a gas through the blood flow path to the dialyzer so as to fill the blood flow path in the dialyzer with the gas;

measuring the volume of gas in the dialyzer; and

calculating the clearance of the dialyzer based on the volume of gas measured in the dialyzer.

14. (canceled)

15. A method for measuring the clearance of a dialyzer, the method comprising:

passing water through the dialyzer;

measuring the amount of ions collected by the water after passing through the dialyzer; and

determining the clearance of the dialyzer based on the amount of ions collected by the water after passing through the dialyzer.

16. A method for measuring the clearance of a dialyzer, the method comprising:

passing water through the dialyzer;

measuring the conductivity of the water; and

determining the clearance of the dialyzer based on changes in the conductivity of the water.

17. A method for introducing a fluid into blood, the method comprising:

providing a cassette including an integrally formed spike for receiving a vial of fluid, and a valving mechanism for controlling flow of the fluid from the vial into the cassette;

attaching a vial containing the fluid to the spike;

pumping blood through the cassette; and

introducing the fluid from the vial into the blood.

18. (canceled)

19. A hemodialysis system, comprising:

a blood flow path through which blood is drawn from a patient and passed through a dialyzer;

a cassette containing at least a portion of the blood flow path; and

a spike integrally formed with the cassette, the spike able to receive a vial of fluid, the integrally formed spike in fluidic communication with the blood flow path within the cassette.

20. A hemodialysis system, comprising:

a blood flow path through which untreated blood is drawn from a patient and passed through a dialyzer;

a dialysate flow path through which dialysate flows from a dialysate supply through the dialyzer, the dialyzer permitting dialysate to pass from the dialysate flow path to the blood flow path; and

a gas supply in fluidic communication with the dialysate flow path so that, when activated, gas from the gas supply causes the dialysate to pass through the dialyzer and urge blood in the blood flow path back to the patient.

21. A hemodialysis system, comprising:

a blood flow path through which untreated blood is drawn from a patient and passed through a dialyzer;

a dialysate flow path through which dialysate flows from a dialysate supply through the dialyzer, the dialyzer permitting dialysate to pass from the dialysate flow path to the blood flow path;

a fluid supply;

a chamber in fluid communication with the fluid supply and the dialysate fluid path, the chamber having a diaphragm separating fluid of the fluid supply from dialysate of the dialysate flow path; and

a pressurizing device for pressurizing the fluid supply to urge the diaphragm against the dialysate in the chamber, so as to cause the dialysate to pass through the dialyzer and urge blood in the blood flow path back to the patient.

22. A hemodialysis system, comprising:

a blood flow path through which untreated blood is drawn from a patient and passed through a dialyzer;

a dialysate flow path through which dialysate flows from a dialysate supply through the dialyzer, the dialysate flow path and the blood flow path being in fluidic communication; and

a pressure device able to urge dialysate in the dialysate flow path to flow into the blood flow path.

23. A method, comprising:

providing a hemodialysis system comprising a blood flow path through which untreated blood is drawn from a patient and passed through a dialyzer, and a dialysate flow path through which dialysate flows from a dialysate supply through the dialyzer;

putting the blood flow path and the dialysate flow path into fluidic communication; and

urging dialysate through the dialysate flow path to cause blood in the blood flow path to pass into the patient.

24. (canceled)

25. A method of performing hemodialysis, the method comprising:

providing a blood flow path, through which untreated blood can be drawn from a patient and passed through a dialyzer;

providing a dialysate flow path, through which dialysate can flow from a dialysate supply through the dialyzer;

providing ingredients for preparing a total volume of dialysate;

providing water for mixing with the dialysate ingredients;

mixing a volume of water with a portion of the ingredients so as to prepare a first partial volume of dialysate, the first partial volume being less than the total volume;

pumping the partial volume of dialysate through the dialysate flow path and through the dialyzer;

pumping blood through the blood flow path and through the dialyzer, while the first partial volume of dialysate is being pumped to the dialyzer; and

mixing a volume of water with a portion of the ingredients so as to prepare a second partial volume of dialysate and storing the second partial volume of dialysate within a vessel while the blood and the first partial volume of dialysate are pumped through the dialyzer.

26. A method of performing hemodialysis, the method comprising:

passing blood from a patient and dialysate through a dialyzer contained within a hemodialysis system at a first rate; and

forming dialysate within the hemodialysis system at a second rate that is substantially different from the first rate, wherein excess dialysate is stored within a vessel contained within the hemodialysis system.

27. (canceled)

28. A pumping system for balancing flow to and from a target, the pumping system comprising:

a system inlet;

a supply line to the target;

a return line from the target;

a system outlet;

a pumping mechanism for causing fluid to flow from the system inlet to the supply line and from the return line to the system outlet, the pumping mechanism including a pod pump comprising;

a rigid spheroid wall defining a pumping volume and having an inlet and an outlet;

a pump diaphragm mounted within and to the spheroid wall; and

a port for connecting the pod pump to a pneumatic actuation system so that the diaphragm can be actuated to urge fluid into and out of the pumping volume, wherein the pump diaphragm separates the fluid from a gas in fluid communication with the pneumatic actuation system;

a balancing chamber comprising;

a rigid spheroid wall defining a balance volume; and

a balance diaphragm mounted within and to the spheroid wall, wherein the balance diaphragm separates the balance volume into a supply side and a return side, each of the supply side and the return side having an inlet and an outlet,

wherein fluid from the system inlet flows to the supply side inlet, fluid from the supply side outlet flows to the supply line, fluid from the return line flows to the return side inlet, and fluid from the return side outlet flows to the system outlet; and

valving mechanisms located at each of the inlets and outlets of the supply side and the return side, the valving mechanisms being pneumatically actuated.

29-35. -35. (canceled)

36. A hemodialysis system, comprising:

a first housing containing a positive-displacement pump actuated by a control fluid;

a fluid conduit fluidly connecting the positive-displacement pump with a control fluid pump; and

a second housing containing the control fluid pump, wherein the second housing is detachable from the first housing.

37. A hemodialysis system, comprising:

a housing comprising a first section and a second section separated by an insulating wall, the first section being sterilizable at a temperature of at least about 80°

C., the second section containing electronic components that, when the first section is heated to a temperature of at least about 80°

C., are not heated to a temperature of more than 60°

C.

38. A hemodialysis system, comprising:

a blood flow path through which untreated blood is drawn from a patient and passed through a dialyzer, the blood flow path including at least one blood valve;

a control fluid path for providing a control fluid from an actuator mechanism to the blood valve for actuating the blood valve;

a dialysate mixing system fluidly connected to the dialyzer, including at least one dialyzer valve; and

a heater for heating the dialysate.

39-137. -137. (canceled)