Balanced flow dialysis machine

• US 9,415,150 B2
• Filed: 11/09/2007
• Issued: 08/16/2016
• Est. Priority Date: 11/09/2007
• Status: Active Grant

• Current Assignee: Baxter Healthcare SA (Baxter International Inc.), Baxter International Inc.
• Original Assignee: Baxter Healthcare SA (Baxter International Inc.)
• Inventors: Hogard, Michael E., Busby, Donald D., Childers, Robert W., Ding, Yuanpang S., Holian, Katherine M., Jablonski, Mark E., Kelly, Thomas D., Lo, Ying-Cheng, Maliekkal, Shincy J., Roger, Rodolfo G., Smith, Donald A., Yardimci, Atif M.
• Primary Examiner(s): Bosworth, Kami A
• Assistant Examiner(s): Engel, Matthew A
• Application Number:
  US11/938,083
• Publication Number:
  US 20090124963A1
• Time in Patent Office: 3,203 Days
• Field of Search: 604/29, 604/67, 604/5.04, 604/210
• US Class Current: 1/1
• 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 1/1522 the interface being evacuated interfaces to enhance contact
• CPC Class Codes: A61M 1/153 the cassette being adapted for heating or cooling the treating fluid, e.g. the dialysate or the treating gas
• 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 1/15632 the filter being a dialyser
• 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 1/1613 Profiling or modelling of patient or predicted treatment evolution or outcome
• CPC Class Codes: A61M 1/1635 with volume chamber balancing devices between used and fresh dialysis fluid
• CPC Class Codes: A61M 1/166 Heating for sterilisation A61M1/1686
• CPC Class Codes: A61M 1/1696 with dialysate regeneration
• CPC Class Codes: A61M 1/28 Peritoneal dialysis ; Other peritoneal treatment, e.g. oxygenation
• CPC Class Codes: A61M 1/284 Continuous flow peritoneal dialysis [CFPD]
• CPC Class Codes: A61M 1/288 Priming priming in extracorporeal blood circuits A61M1/3643
• 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 1/3417 : using distinct filters for dialysis and ultra-filtration
• CPC Class Codes: A61M 1/342 : Adding solutions to the blood, e.g. substitution solutions for preventing coagulation A61M1/3672
• CPC Class Codes: A61M 1/3427 : back through the membrane, e.g. by inverted trans-membrane pressure [TMP]
• CPC Class Codes: A61M 1/3434 : with pre-dilution and post-dilution
• CPC Class Codes: A61M 1/3437 : downstream of the filter, e.g. post-dilution with filtrate
• CPC Class Codes: A61M 1/3441 : Substitution rate control as a function of the ultrafiltration rate
• CPC Class Codes: A61M 1/3444 : in which the collected ultra-filtrate expels an equal volume of substitution fluid from a reservoir
• CPC Class Codes: A61M 1/3458 : having electrolytes not present in the dialysate
• CPC Class Codes: A61M 1/3465 : using dialysate as substitution fluid
• CPC Class Codes: A61M 1/3468 : using treated filtrate as substitution fluid
• CPC Class Codes: A61M 1/362223 : the interface being evacuated interfaces to enhance contact
• CPC Class Codes: A61M 1/36224 : with sensing 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 1/362262 : Details of incorporated reservoirs
• 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 2205/12 : with interchangeable cassettes forming partially or totally the fluid circuit
• 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 2205/3393 : by weighing the reservoir

Abstract

A system and method for balancing flows of renal replacement fluid is disclosed. The method uses pressure controls and pressure sensing devices to more precisely meter and balance the flow of fresh dialysate and spent dialysate. The balancing system may use one or two balancing devices, such as a balance tube, a tortuous path, or a balance chamber.

Claims

1. A dialysis system comprising:

a renal therapy machine including a controller; and

a cassette operable with the machine, the cassette including

a housing configured and arranged to be placed in the machine,

a flexible membrane attached to the housing, the membrane and housing cooperating with the machine to perform a valving function controlling a flow of a renal failure therapy fluid,

fluid pathways within the housing for routing the renal failure therapy fluid, and

at least one balancing system and at least four valves operably connected to the at least one balancing system, the at least one balancing system operably connected to the fluid pathways and to pumps for pumping the renal failure therapy fluid, the at least one balancing system configured to equalize the flow of the renal failure therapy fluid to and from a dialyzer or a patient,

at least one pressure sensor for (i) sensing a pressure of the renal failure therapy fluid including a fresh pumping cycle pressure and a spent pumping cycle pressure, and (ii) conveying a signal representative of the pressure of the renal failure therapy fluid to the controller of the machine, and

wherein the controller is configured to use the signal to control the pumps and the at least four valves for the flow of renal failure therapy fluid to and from the at least one balancing system so that a pressure of fresh renal failure therapy fluid to the at least one balancing system is approximately equal to a pressure of spent renal failure therapy fluid to the at least one balancing system by (i) selecting an operating pressure based on the sensed fresh pumping cycle pressure and the sensed spent pumping cycle pressure from the at least one pressure sensor, and (ii) adjusting one of (a) the fresh renal failure therapy fluid pressure or (b) the spent renal failure therapy fluid pressure to be equal to the selected operating pressure.

2. The dialysis system of claim 1, wherein the cassette is configured for one of hemodialysis and peritoneal dialysis and optionally, at least one temperature sensor within the cassette for sensing a temperature of the renal failure therapy fluid.

3. The dialysis system of claim 1, wherein at least one of the at least four valves is a pressure-regulating valve or further comprising at least one pressure regulator configured for regulating the pressure of fresh or spent renal failure therapy fluid.

4. The dialysis system of claim 1, wherein the selected operating pressure is the higher of the sensed fresh pumping cycle pressure and the sensed spent pumping cycle pressure.

5. The dialysis system of claim 1, further comprising a separator in the at least one balancing system, wherein the separator is selected from the group consisting of a ball, a piston, a balloon, a wiper, and a membrane.

6. The dialysis system of claim 5, wherein the at least one balancing system is configured to prevent the separator from completely blocking flow into or from the at least one balancing system.

7. The dialysis system of claim 1, wherein the at least one pressure sensor comprises two pressure sensors, a first pressure sensor for monitoring and controlling a flow of spent renal failure therapy fluid and a second pressure sensor for monitoring and controlling a flow of fresh renal failure therapy fluid.

8. The dialysis system of claim 1, wherein the at least one balancing system is fabricated separately in at least two pieces and then attached to the housing.

9. The dialysis system of claim 1, wherein the at least one balancing system is at least one balancing tube comprising at least one inlet port and at least one outlet port that each face approximately 90 degrees relative to the at least one balancing tube.

10. The dialysis system of claim 1, wherein the at least one balancing system has a form selected from a group consisting of a right cylinder, an ovate cylinder, a balloon, a bellows, and a half cylinder.

11. A dialysis system comprising:

a renal therapy machine including a controller; and

a cassette operable with the machine, the cassette including

a housing for the cassette configured and arranged to be placed in the machine,

a flexible membrane attached to the housing, the membrane and housing cooperating with the controller of the machine to operate at least four valves controlling a flow of a renal failure therapy fluid,

fluid pathways within the housing for routing the renal failure therapy fluid, and

at least one balancing apparatus operably connected to the fluid pathways, and the at least four valves, at least one inlet port and at least one outlet port operably connected to the at least one balancing apparatus, wherein the at least one inlet port and at least one outlet port are configured to allow the removal of air from each port, and wherein the at least one balancing apparatus is configured to equalize the flow of the renal failure therapy fluid to and from a dialyzer or a patient, and

a separator in the at least one balancing apparatus, the separator configured to move freely within the at least one balancing apparatus, wherein the balancing apparatus includes obstructers configured to prevent the separator from moving to opposing ends of the at least one balancing apparatus,

at least one pressure sensor for (i) sensing a pressure of the renal failure therapy fluid including a fresh pumping cycle pressure and a spent pumping cycle pressure, and (ii) conveying a signal representative of the pressure of the renal failure therapy fluid to the controller of the machine, and

wherein the controller is configured to control the at least four valves for the flow of the renal failure therapy fluid to and from the at least one balancing apparatus so that a pressure of the fresh renal failure therapy fluid to the at least one balancing apparatus is approximately equal to a pressure of the spent renal failure therapy fluid to the at least one balancing apparatus by (i) selecting an operating pressure based on the sensed fresh pumping cycle pressure and the sensed spent pumping cycle pressure from the at least one pressure sensor, and (ii) adjusting one of (a) the fresh renal failure therapy fluid pressure, or (b) the spent renal failure therapy fluid pressure, to be equal to the selected operating pressure.

12. The dialysis cassette of claim 11, wherein the separator is joined to a moving cylinder or piston, and the cassette is configured so that movement of the cylinder or piston is controlled by a motor or a shaft from the renal therapy machine.

13. The dialysis system of claim 11, wherein the cassette further comprises at least one pressure regulating valve or pressure regulator in fluid communication with the at least one balancing system.

14. The dialysis cassette of claim 11, wherein the at least one balancing system comprises two balancing systems.