BLOOD TREATMENT SYSTEMS AND METHODS

• US 20170326282A1
• Filed: 02/28/2017
• Published: 11/16/2017
• Est. Priority Date: 04/14/2006
• Status: Active Grant

• Current Assignee: Deka Products Limited Partnership
• Original Assignee: Deka Products Limited Partnership
• Inventors: Wilt, Michael J., van der Merwe, Dirk A., Dale, James D., Tracey, Brian D., Grant, Kevin L., Demers, Jason A., Flynn, Catharine N.
• Granted Patent: US 10,537,671 B2
• Time in Patent Office: Days
• 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 1/16 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 1/166 Heating for sterilisation A61M1/1686
• CPC Class Codes: A61M 1/1664 with temperature control
• CPC Class Codes: A61M 1/1666 by dissolving solids
• CPC Class Codes: A61M 1/267 used for pumping
• CPC Class Codes: A61M 1/287 Dialysates therefor
• CPC Class Codes: A61M 1/36225 with blood pumping means or components thereof
• CPC Class Codes: A61M 1/36226 Constructional details of cassettes, e.g. specific details on material or shape
• 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 1/3638 with a vapour trap
• CPC Class Codes: A61M 1/3672 Means preventing coagulation
• 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 2205/15 : Detection of leaks
• CPC Class Codes: A61M 2205/18 : with alarm
• 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 2205/3337 : Controlling, regulating pressure or flow by means of a valve by-passing a pump
• CPC Class Codes: A61M 2205/3368 : Temperature
• CPC Class Codes: A61M 2205/502 : User interfaces, e.g. screens or keyboards
• CPC Class Codes: A61M 2205/52 : with memories providing a history of measured variating parameters of apparatus or patient
• 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 60/43 : using vacuum at the blood pump, e.g. to accelerate filling
• CPC Class Codes: A61M 60/523 : using blood flow data, e.g. from blood flow transducers
• CPC Class Codes: A61M 60/531 : using blood pressure data, e.g. from blood pressure sensors
• 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 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 43/0733 : with fluid-actuated pump inlet or outlet valves; with two or more pumping chambers in series
• CPC Class Codes: F04B 45/02 : having bellows
• CPC Class Codes: F04B 49/06 : Control using electricity regulating by means of floats actuating electric switches F04B49/04
• 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 7/0216 : and having an oscillating movement
• 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: 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

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. According to one aspect, a blood pump is configured to pump blood to a dialyzer of a hemodialysis apparatus, the blood pump comprising a pneumatically actuated or controlled reciprocating diaphragm pump. In an embodiment, the diaphragm of the pump comprises a flexible membrane formed or molded to generally conform to a curved inner wall of a pumping chamber or control chamber of the pump, wherein the diaphragm is pre-formed or molded to have a control side taking a convex shape, so that any elastic tension on the diaphragm is minimized when fully extended into a control chamber of the pump. In another aspect, a system for monitoring the adequacy of blood flow in a blood line of the hemodialysis apparatus allows a controller to suspend dialysate pumping operations if the adequacy of blood flow in the blood line is sub-optimal, and to present information on a display on the quality of blood flow in the blood line.

Claims

1-24. -24. (canceled)

25. A system for controlling fluid flow in a hemodialysis apparatus comprising:

a dialysate pump configured to receive a fluid from a dialysate outlet of the dialyzer;

a reciprocating diaphragm-based blood pump configured to deliver blood from an extracorporeal blood circuit to a blood inlet of the dialyzer, a pumping chamber of the blood pump separated from a control chamber of the blood pump by a flexible diaphragm, the control chamber configured to transmit positive or negative pressure to operate the diaphragm;

a pressure sensor configured to measure pressure in the control chamber of the blood pump;

a controller configured to receive information from the pressure sensor, and configured to control the delivery of pressure to the control chamber of the blood pump;

wherein the controller is configured to cause the application of a time-varying pressure waveform on the blood pump diaphragm during a fill-stroke of the blood pump, and to monitor a pressure variation in the control chamber measured by the pressure sensor, and wherein a magnitude of the measured pressure variation that deviates from a pre-determined value causes the controller to initiate a procedure to pause or stop the dialysate pump.

26. The system of claim 25, wherein the controller is configured to compare a pressure variation in the control chamber measured by the pressure sensor with a target signal or target pressure variation induced by the controller, and wherein a deviation between the measured pressure variation and the target signal or pressure variation that is greater than a pre-determined value causes the controller to initiate a procedure to pause or stop the dialysate pump.

27. The system of claim 25, wherein the controller is configured to compare a measured pressure in the control chamber with a target signal or pressure during time periods when an absolute value of the applied pressure is decreasing, and wherein a deviation between the measured pressure and the target signal or pressure that is greater than a pre-determined value causes the controller to initiate a procedure to pause or stop the dialysate pump.

28. The system of claim 26, wherein the comparison by the controller comprises calculating a cross-correlation value between the measured pressure variation and the target signal or pressure variation, and wherein a cross-correlation value that is less than a pre-determined value causes the controller to initiate the procedure to pause or stop the dialysate pump.

29. The system of claim 28, wherein the controller calculates a phase-insensitive cross-correlation value.

30. The system of claim 28, wherein the controller signals the dialysate pump to pause or stop only if the cross-correlation value is less than the pre-determined value for two or more consecutive blood pump fill-strokes.

31. The system of claim 28, wherein the controller calculates a filtered or averaged cross-correlation value during a fraction of a pump fill-stroke period, and re-calculates one or more additional filtered or averaged cross-correlation values during one or more successive fractions of the fill-stroke period, and wherein the controller compares a highest filtered or averaged cross-correlation value during said fill-stroke period with the pre-determined value to determine whether to initiate the procedure to pause or stop the dialysate pump.

32. The system of claim 25, wherein the time-varying pressure waveform comprises a sinusoidal pressure waveform.

33. The system of claim 25, wherein the controller controls the application of the pressure waveform by controlling a variable restriction valve interposed between the control chamber and a source of positive or negative pressure.

34. The system of claim 33, wherein the source of positive or negative pressure comprises a source of positive or negative pneumatic pressure.

35. The system of claim 25, wherein the dialysate pump comprises a reciprocating diaphragm-based pump, and wherein the pre-determined value is based on a pressure over a period of time generated by the blood pump that provides sufficient pressure in a blood compartment of the dialyzer to allow the dialysate pump to receive a full stroke-volume of fluid from the dialyzer.

36. A system for monitoring fluid flow in an extracorporeal blood circuit comprising:

a pumping chamber of the blood pump separated from a control chamber of the blood pump by a flexible diaphragm, the control chamber configured to transmit positive or negative pressure to operate the diaphragm;

a pressure sensor configured to measure pressure in the control chamber of the blood pump;

a controller configured to receive information from the pressure sensor, and configured to control the delivery of pressure to the control chamber of the blood pump;

wherein the controller is configured to cause the application of a time-varying pressure waveform on the blood pump diaphragm during a fill-stroke of the blood pump, and to monitor a pressure variation in the control chamber measured by the pressure sensor, and wherein the controller transmits a value representing a magnitude of the measured pressure variation to a display associated with the extracorporeal blood circuit.

37. The system of claim 36, wherein a magnitude of the measured pressure variation that deviates from a pre-determined value causes the controller to provide a notification to the display.

38. The system of claim 36, wherein the controller is configured to compare a pressure variation in the control chamber measured by the pressure sensor with a target signal variation or target pressure variation induced by the controller, and wherein a deviation between the measured pressure variation and the target signal or pressure variation that is greater than a pre-determined value causes the controller to provide a notification to the display.

39. The system of claim 38, wherein the controller compares the measured pressure variation with the target signal or pressure variation during time periods when the absolute value of the applied pressure is decreasing.

40. The system of claim 38, wherein the comparison by the controller comprises calculating a cross-correlation value between the measured pressure variation and the target signal or pressure variation.

41. The system of claim 36, wherein the time-varying pressure waveform comprises a sinusoidal pressure waveform.

42. The system of claim 36, wherein the controller controls the application of the pressure waveform by controlling a variable restriction valve interposed between the control chamber and a source of positive or negative pressure.

43. The system of claim 42, wherein the source of positive or negative pressure comprises a source of positive or negative pneumatic pressure.

44. The system of claim 36, wherein the value is displayed on a graphical user interface.

45. The system of claim 44, wherein the controller is configured to transmit one of a plurality of representative values to the graphical user interface, each said representative value representing a pre-determined range of values of the measured pressure variation.

46. A method for controlling fluid flow in a hemodialysis apparatus comprising:

a controller receiving information from a pressure sensor in a control chamber of a reciprocating diaphragm-based blood pump;

the controller causing the application of a time-varying pressure waveform on a diaphragm of the blood pump during a fill-stroke of the blood pump;

the controller monitoring a pressure variation in the control chamber measured by the pressure sensor;

the controller comparing the measured pressure variation to a pre-determined value; and

the controller initiating a procedure to pause or stop a dialysate pump of the hemodialysis apparatus if the magnitude of the measured pressure variation deviates from the pre-determined value.

47. The method of claim 46, further comprising the controller comparing a pressure variation in the control chamber measured by the pressure sensor with a target signal or target pressure variation induced by the controller, and the controller initiating a procedure to pause or stop the dialysate pump if a deviation between the measured pressure variation and the target signal or pressure variation is greater than a pre-determined value.

48. The method of claim 46, further comprising the controller comparing a measured pressure in the control chamber with a target signal or pressure during time periods when an absolute value of the applied pressure is decreasing, and the controller initiating a procedure to pause or stop the dialysate pump if a deviation between the measured pressure and the target signal or pressure is greater than a predetermined value.

49. The method of claim 47, wherein the controller performs the comparison by calculating a cross-correlation value between the measure pressure variation and the target signal or pressure variation, and the controller initiates the procedure to pause or stop the dialysate pump if the cross-correlation value is less than a pre-determined value.

50. The method of claim 49, wherein the controller calculates a phase-insensitive cross-correlation value.

51. The method of claim 49, wherein the controller signals the dialysate pump to pause or stop only if the cross-correlation value is less than the pre-determined value for two or more consecutive blood pump fill-strokes.

52. The method of claim 49, further comprising the controller calculating a filtered or averaged cross-correlation value during a fraction of a pump fill-stroke period, and re-calculating one or more additional filtered or averaged cross-correlation values during one or more successive fractions of the fill-stroke period, and determining whether to initiate the procedure to pause or stop the dialysate pump by comparing a highest filtered or averaged cross-correlation value during said fill-stroke period with the pre-determined value.

53. The method of claim 46, wherein the time-varying pressure waveform comprises a sinusoidal pressure waveform.

54. The method of claim 46, wherein the controller controls the application of the pressure waveform by controlling a variable restriction valve interposed between the control chamber and a source of positive or negative pressure.

55. The method of claim 54, wherein the source of positive or negative pressure comprises a source of positive or negative pneumatic pressure.

56. The method of claim 46, wherein the dialysate pump comprises a reciprocating diaphragm-based pump, wherein the pre-determined value is based on a pressure over a period of time generated by the blood pump that provides sufficient pressure in a blood compartment of the dialyzer to allow the dialysate pump to receive a full stroke-volume of fluid from the dialyzer.

57-66. -66. (canceled)