Devices and methods for use in assessing a flow condition of a fluid

• US 20050249606A1
• Filed: 04/13/2005
• Published: 11/10/2005
• Est. Priority Date: 10/09/2002
• Status: Active Grant

• Current Assignee: Therasense Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Therasense Incorporated (Abbott Laboratories Incorporated)
• Inventors: Rush, Benjamin M.
• Granted Patent: US 7,399,401 B2
• Time in Patent Office: Days
• US Class Current: 417/53
• CPC Class Codes: A61M 2005/1726 the body parameters being measured at, or proximate to, the infusion site
• CPC Class Codes: A61M 2205/0288 Electro-rheological or magneto-rheological materials
• CPC Class Codes: A61M 2205/3317 Electromagnetic, inductive or dielectric measuring means
• CPC Class Codes: A61M 2205/3569 sublocal, e.g. between console and disposable
• CPC Class Codes: A61M 2205/3592 using telemetric means, e.g. radio or optical transmission
• CPC Class Codes: A61M 2205/702 automatically during use
• CPC Class Codes: A61M 5/14216 Reciprocating piston type
• CPC Class Codes: A61M 5/14244 adapted to be carried by the patient, e.g. portable on the body
• CPC Class Codes: A61M 5/16886 for measuring fluid flow rate, i.e. flowmeters
• CPC Class Codes: F04B 2205/09 Flow through the pump
• CPC Class Codes: F04B 43/043 Micropumps
• CPC Class Codes: F04B 49/065 and making use of computers
• CPC Class Codes: F04B 51/00 Testing machines, pumps, or pumping installations
• CPC Class Codes: F05C 2251/08 Shape memory
• CPC Class Codes: G01F 1/64 by measuring electrical currents passing through the fluid flow; measuring electrical potential generated by the fluid flow, e.g. by electrochemical, contact or friction effects G01F1/58 takes precedence
• CPC Class Codes: G01F 1/708 Measuring the time taken to traverse a fixed distance
• CPC Class Codes: G01F 1/7088 using electrically charged particles as tracers
• CPC Class Codes: G01F 25/10 of flowmeters

Abstract

A device for use in assessing a flow condition of a fluid, or a fluid in a flow path, is provided. The device comprises at least one electrochemical cell, comprising a working electrode and at least one other electrode, sufficient for communication with the fluid, or sufficient for communication with a flow path, such that when sufficient fluid is in the flow path, the cell is in communication with the fluid. The fluid comprises a component sufficient to affect a mass-transport limited electrochemical reaction at the working electrode. The device also comprises at least one microcontroller operably connected to the at least one electrochemical cell for providing a potential or a current to the working electrode and for assessing the electrochemical reaction. A method of assessing a flow condition of a fluid, or a fluid in a flow path, is also provided. The device and the method of the present invention may be used in connection with the delivery of a fluid-borne or fluidized drug or medicament to a subject.

Claims

1. A method of assessing a flow condition of a fluid, comprising:

providing a fluid sufficient to support an electrochemical reaction at a working electrode of an electrochemical cell, the fluid comprising a component sufficient to affect the electrochemical reaction such that the electrochemical reaction is mass-transport limited;

providing at least one electrochemical cell comprising the working electrode and at least one other electrode in communication with the fluid; and

obtaining an indicator of a rate of the electrochemical reaction.

2. The method of claim 1, wherein the fluid comprises a drug, a medicament, a nutrient, a dietary supplement, a health supplement, any source thereof, and any combination thereof.

3. The method of claim 1, wherein the fluid comprises a material selected from insulin, an antibiotic, a nutrient, a dietary supplement, a health supplement, total parenteral nutrition, an analgesic, an anesthetic, a pain reliever, a hormone, a hormonal drug, a gene therapy drug, an anticoagulant, a cardiovascular drug, AZT, a chemotherapeutic drug, and any combination thereof, any source thereof, and any combination thereof.

4. The method of claim 1, wherein the component is sufficient to participate in, promote, or interfere with the electrochemical reaction.

5. The method of claim 1, wherein the component is sufficient to change the rate of the electrochemical reaction from what it would be were the component absent.

6. The method of claim 1, wherein the component comprises a material selected from an ionic species, a metallic species, a metal oxide species, an organic species, oxygen, water, any source thereof, and any combination thereof.

7. The method of claim 1, wherein the component comprises at least one bubble of gas.

8. The method of claim 1, wherein the component is dilute relative to the fluid.

9. The method of claim 1, wherein the component is of a concentration of from about 10⁻

7 M to about 10<sup>−

2</sup> M relative to the fluid.

10. The method of claim 1, wherein the fluid comprises a drug and the component comprises a reactant in the electrochemical reaction that is dilute relative to the fluid.

11. The method of claim 10, wherein the drug is insulin.

12. The method of claim 10, wherein the reactant is an ionic species.

13. The method of claim 10, wherein the drug is insulin and the reactant is ionic zinc.

14. The method of claim 1, wherein the fluid comprises a reactant in the electrochemical reaction and the component is sufficient to interfere with transport of the reactant to the working electrode.

15. The method of claim 14, wherein the fluid comprises a drug and the reactant is an ionic species.

16. The method of claim 14, wherein the fluid comprises insulin and the reactant is ionic zinc.

17. The method of claim 14, wherein the component comprises at least one bubble of gas.

18. The method of claim 1, wherein the electrochemical reaction at the working electrode is a promoted electrochemical reaction, the fluid comprises a reactant in the promoted electrochemical reaction, and the component is sufficient to promote the promoted electrochemical reaction and sufficient to affect the promoted electrochemical reaction such that the promoted electrochemical reaction is mass-transport limited.

19. The method of claim 18, wherein the fluid comprises a drug.

20. The method of claim 18, wherein the reactant is an ionic species.

21. The method of claim 18, wherein the drug is insulin and the reactant is ionic zinc.

22. The method of claim 18, wherein the component is dilute relative to the fluid.

23. The method of claim 1, wherein said providing at least one electrochemical cell comprises providing at least two electrochemical cells.

24. The method of claim 23, wherein one electrochemical cell of the at least two electrochemical cells is sufficient for communication with a path via which the fluid flows at one location and another electrochemical cell of the at least two electrochemical cells is sufficient for communication with the path at another location.

25. The method of claim 1, further comprising providing a path via which the fluid flows toward the electrochemical cell.

26. The method of claim 1, further comprising providing a source of the fluid in communication with a path via which the fluid flows toward the electrochemical cell.

27. The method of claim 26, wherein the source comprises a pump.

28. The method of claim 26, wherein the source is sufficient for providing the fluid in a continuous manner.

29. The method of claim 26, wherein the source is sufficient for providing the fluid in a non-continuous manner.

30. The method of claim 26, wherein the source is sufficient for providing the fluid in at least two pulses.

31. The method of claim 30, wherein said obtaining comprises obtaining an indicator of the rate of the electrochemical reaction associated with the at least one electrochemical cell and associated with each of the at least two pulses.

32. The method of claim 30, wherein said obtaining comprises obtaining an indicator of the rate of the electrochemical reaction associated with the at least one electrochemical cell and associated with the at least two pulses at a predetermined interval.

33. The method of claim 1, wherein the indication is selected from a group consisting of a current, a potential, a charge, a resistance, and any combination thereof.

34. The method of claim 1, further comprising calibrating the providing of the fluid based on the indicator.

35. The method of claim 1, further comprising controlling the providing of the fluid based on the indicator.

36. The method of claim 35, wherein the controlling is automated.

37. The method of claim 1, further comprising determining a flow rate associated with the fluid.

38. The method of claim 37, wherein the determining comprises providing a first pair of electrodes at a first point relative to the electrochemical cell and a second pair of electrodes at a second point relative to the electrochemical cell, each of the first and the second pair of electrodes in communication with a path via which the fluid flows from the first point to the second point, each of the first and the second pair of electrodes sufficient for indicating an absence or a presence of the fluid, and determining the flow rate associated with the flow of the fluid from the first point to the second point.

39. The method of claim 37, further comprising controlling the providing of the fluid based on the flow rate.

40. The method of claim 39, wherein the controlling is automated.

41. The method of claim 1, further comprising obtaining a temperature of the fluid.

42. The method of claim 41, further comprising controlling the providing of the fluid based on the temperature.

43. The method of claim 42, wherein the controlling is automated.

44. A device for use in assessing a flow condition of a fluid sufficient to support an electrochemical reaction, comprising:

at least one electrochemical cell comprising a working electrode and at least one other electrode, the electrochemical cell sufficient for communication with a path via which the fluid flows, such that when sufficient fluid is in the path, the electrochemical cell is in communication with the fluid;

at least one microcontroller operably connected to the at least one electrochemical cell, the at least one device sufficient to provide a current or a potential to the working electrode sufficient for the electrochemical reaction to take place at the working electrode, the at least one microcontroller sufficient to receive information concerning a mass-transport limiting affect of a component of the fluid on the electrochemical reaction.

45. The device of claim 44, wherein the working electrode comprises a material selected from carbon, gold, silver, platinum, copper, a conductive polymer, and any combination thereof.

46. The device of claim 44, wherein the at least one other electrode comprises a counter electrode.

47. The device of claim 46, wherein the counter electrode comprises a material selected from carbon, gold, silver, platinum, copper, a conductive polymer, and any combination thereof.

48. The device of claim 44, wherein the at least one other electrode comprises a reference electrode selected from an Ag/AgCl electrode, an Hg/HgO electrode, an Hg/Hg₂SO₄ electrode, an Hg/Hg₂Cl₂ electrode, a normal hydrogen electrode, and a reversible hydrogen electrode.

49. The device of claim 44, wherein the at least one electrochemical cell comprises at least two electrochemical cells.

50. The device of claim 44, wherein one electrochemical cell of the at least two electrochemical cells is sufficient for communication with the path at one location and another electrochemical cell of the at least two electrochemical cells is sufficient for communication with the path at another location.

51. The device of claim 44, wherein the fluid comprises a drug, a medicament, a nutrient, a dietary supplement, a health supplement, any source thereof, and any combination thereof.

52. The device of claim 44, wherein the fluid comprises a material selected from insulin, an antibiotic, a nutrient, a dietary supplement, a health supplement, total parenteral nutrition, an analgesic, an anesthetic, a pain reliever, a hormone, a hormonal drug, a gene therapy drug, an anticoagulant, a cardiovascular drug, AZT, a chemotherapeutic drug, and any combination thereof, any source thereof, and any combination thereof.

53. The device of claim 44, wherein the component is sufficient to participate in, promote, or interfere with the electrochemical reaction.

54. The device of claim 44, wherein the component is sufficient to change the rate of the electrochemical reaction from what it would be were the component absent.

55. The device of claim 44, wherein the component comprises a material selected from an ionic species, a metallic species, a metal oxide species, an organic species, oxygen, water, any source thereof, and any combination thereof.

56. The device of claim 44, wherein the component comprises at least one bubble of gas.

57. The device of claim 44, wherein the component is dilute relative to the fluid.

58. The device of claim 44, wherein the component is of a concentration of from about 10⁻

7 M to about 10<sup>−

2</sup> M relative to the fluid.

59. The device of claim 44, wherein the fluid comprises a drug and the component comprises a reactant in the electrochemical reaction that is dilute relative to the fluid.

60. The device of claim 59, wherein the drug is insulin.

61. The device of claim 59, wherein the reactant is an ionic species.

62. The device of claim 59, wherein the drug is insulin and the reactant is ionic zinc.

63. The device of claim 44, wherein the fluid comprises a reactant in the electrochemical reaction and the component is sufficient to interfere with transport of the reactant to the working electrode.

64. The device of claim 63, wherein the fluid comprises a drug and the reactant is an ionic species.

65. The device of claim 63, wherein the fluid comprises insulin and the reactant is ionic zinc.

66. The device of claim 63, wherein the component comprises at least one bubble of gas.

67. The device of claim 44, wherein the electrochemical reaction at the working electrode is a promoted electrochemical reaction, the fluid comprises a reactant in the promoted electrochemical reaction, and the component is sufficient to promote the promoted electrochemical reaction and sufficient to affect the promoted electrochemical reaction such that the promoted electrochemical reaction is mass-transport limited.

68. The device of claim 67, wherein the fluid comprises a drug.

69. The device of claim 67, wherein the reactant is an ionic species.

70. The device of claim 67, wherein the drug is insulin and the reactant is ionic zinc.

71. The device of claim 67, wherein the component is dilute relative to the fluid.

72. The device of claim 44, further comprising the path.

73. The device of claim 44, further comprising a source of the fluid in communication with the path.

74. The device of claim 73, wherein the source comprises a pump.

75. The device of claim 73, wherein the source is sufficient for providing the fluid in a continuous manner.

76. The device of claim 73, wherein the source is sufficient for providing the fluid in a non-continuous manner.

77. The device of claim 73, wherein the source is sufficient for providing the fluid in at least two pulses.

78. The device of claim 77, wherein the information comprises an indicator of the rate of the electrochemical reaction associated with the at least one electrochemical cell and associated with each of the at least two pulses.

79. The device of claim 77, wherein the information comprises an indicator of the rate of the electrochemical reaction associated with the at least one electrochemical cell and associated with the at least two pulses at a predetermined interval.

80. The device of claim 44, wherein the information comprises an indicator of the rate of the electrochemical reaction associated with the at least one electrochemical cell.

81. The device of claim 44, wherein the information comprises an indicator selected from a current, a potential, a charge, a resistance, and any combination thereof.

82. The device of claim 44, wherein the at least one microcontroller is sufficient to control a delivery of the fluid based on the information.

83. The device of claim 44, further comprising a device sufficient for determining a flow rate associated with the fluid in the path.

84. The device of claim 83, wherein the device comprises a first pair of electrodes at a first point relative to the electrochemical cell and a second pair of electrodes at a second point relative to the electrochemical cell, each of the first and the second pair of electrodes in communication with the path, each of the first and the second pair of electrodes sufficient for indicating an absence or a presence of the fluid.

85. The device of claim 83, wherein the at least one microcontroller is sufficient to control a delivery of the fluid based on the flow rate.

86. The device of claim 44, further comprising a device sufficient for determining a temperature of the fluid in the path.

87. The device of claim 86, wherein the at least one microcontroller is sufficient to control a delivery of the fluid based on the temperature.

88. The device of claim 44, further comprising a housing for the at least one electrochemical device, the at least one microcontroller, and a source of the fluid.

89. The device of claim 44, further comprising a housing for the at least one electrochemical device, the at least one microcontroller, a source of the fluid, and at least a portion of a device sufficient for delivery of the fluid to a location outside of the housing.

90. The device of claim 89, wherein the housing is sufficient for wearing on a skin surface and the location is beneath the skin surface.