Device and method for determining analyte levels

• US 7,970,448 B2
• Filed: 04/19/2010
• Issued: 06/28/2011
• Est. Priority Date: 03/04/1997
• Status: Expired due to Fees

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Shults, Mark C., Updike, Stuart J., Rhodes, Rathbun K.
• Primary Examiner(s): Mallari; Patricia C
• Assistant Examiner(s): D'Angelo; Michael
• Application Number:
  US12/763,016
• Publication Number:
  US 20100204559A1
• Time in Patent Office: 435 Days
• Field of Search: 600345-347, 600/365, 702/19
• US Class Current: 600/345
• CPC Class Codes: A61B 5/0004 characterised by the type of physiological signal transmitted
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14865 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors
• CPC Class Codes: A61B 5/1495 Calibrating or testing of in-vivo probes
• CPC Class Codes: C12Q 1/006 for glucose

Abstract

Devices and methods for determining analyte levels are described. The devices and methods allow for the implantation of analyte-monitoring devices, such as glucose monitoring devices, that result in the delivery of a dependable flow of blood to deliver sample to the implanted device. The devices comprise a unique microarchitectural arrangement in the sensor region that allows accurate data to be obtained over long periods of time.

Claims

1. A system for processing sensor data from a continuous analyte sensor, comprising:

a sensor comprising an electrode configured for implantation in a subcutaneous tissue of a host, wherein the sensor configured to continuously measure an analyte concentration, whereby sensor data associated with the subcutaneous analyte concentration is generated; and

electronic circuitry operably connected to the sensor and configured to calibrate the sensor data during a useful life of the system using pre-implant calibration information;

wherein the system is configured to provide a substantially accurate measurement of the analyte concentration in the host such that at least 95% of calibrated sensor analyte values are within 25% of actual analyte values as determined by analysis of blood obtained during the useful life of the system.

2. The system of claim 1, wherein the pre-implant calibration information comprises a value obtained from an in vitro calibration.

3. The system of claim 2, wherein the in vitro calibration is obtained by measuring at least two different analyte concentrations.

4. The system of claim 2, wherein the in vitro calibration is obtained at about 37 degrees C.

5. The system of claim 1, wherein the analyte is glucose, and wherein the sensor is configured to respond substantially linearly to changes in glucose concentration at glucose concentrations ranging from about 40 mg/dL to about 500 mg/dL.

6. The system of claim 1, wherein the system is configured to provide a stable sensor offset during the useful life of the sensor.

7. The system of claim 1, wherein the electronic circuitry is configured to determine trends in analyte concentration.

8. The system of claim 1, wherein the electronic circuitry is configured to physically couple the sensor.

9. The system of claim 1, wherein the electronic circuitry is configured to couple, via radio telemetry, the sensor.

10. The system of claim 1, wherein the analyte is glucose.

11. The system of claim 1, wherein the useful life of the system is more than about 3 days of implantation.

12. The system of claim 1, wherein the useful life of the system is more than about 5 days of implantation.

13. The system of claim 1, wherein the useful life of the system is more than about 7 days of implantation.

14. The system of claim 1, wherein the useful life of the system is more than about one month of implantation.

15. The system of claim 1, wherein the electronic circuitry is configured to perform recalibration during the useful life of the sensor.

16. The system of claim 15, wherein the electronic circuitry is configured to perform recalibration throughout the useful life and the sensor.

17. The system of claim 16, wherein the recalibration is performed periodically.

18. The system of claim 16, wherein the recalibration is based on reference data.

19. The system of claim 1, wherein the electronic circuitry is configured to perform a calibration check during the useful life of the sensor.

20. The system of claim 1, wherein the sensor is configured to maintain a stability of calibration within 10% for one week.

21. A method for processing sensor data from a continous analyte sensor, comprising:

receiving sensor data from an analyte sensor, the sensor data indicative of an analyte concentration in a host;

calibrating the sensor data during a useful life of the sensor using pre-implant calibration information, and

generating, using an electronic system, a substantially accurate measurement of the analyte concentration, such that at least 95% of calibrated sensor analyte values are within 25% of actual analyte values as determined by analysis of blood obtained during the useful life of the sensor system.

22. The method of claim 21, wherein the pre-implant calibration information comprises a value obtained from an in vitro calibration.

23. The method of claim 22, wherein the in vitro calibration is obtained by measuring at least two different analyte concentrations.

24. The method of claim 22, wherein the in vitro calibration is obtained at about 37 degrees C.

25. The method of claim 21, wherein the analyte is glucose, and wherein the sensor configured to respond substantially linearly to changes in glucose concentration at glucose concentrations ranging from about 40 mg/dL to about 500 mg/dL.

26. The method of claim 21, further comprising maintaining a stable sensor offset during the useful life of the sensor.

27. The method of claim 21, further comprising determining trends in analyte concentration.

28. The method of claim 21, wherein the analyte is glucose.

29. The method of claim 21, wherein the useful life of the sensor is greater than about 3 days of implantation.

30. The method of claim 21, wherein the useful life of the sensor is greater than about 5 days of implantation.

31. The method of claim 21, wherein the useful life of the sensor is greater than about 7 days of implantation.

32. The method of claim 21, wherein the useful life of the sensor is about one month of implantation.

33. The method of claim 21, further comprising recalibrating the sensor data during the useful life of the sensor.

34. The method of claim 33, wherein the recalibrating is performed throughout the useful life of the sensor.

35. The system of claim 34, wherein the recalibration is performed periodically.

36. The method of claim 34, wherein the recalibration is based on reference data.

37. The method of claim 21, further comprising checking calibration during the useful life of the sensor.

38. A system for processing sensor data from a continuous analyte sensor, comprising:

a sensor comprising an electrode configured for implantation in a subcutaneous tissue of a host, wherein the sensor is configured to continuously measure an analyte concentration, whereby sensor data associated with the subcutaneous analyte concentration is generated; and

electronic circuitry operably connected to the sensor and configured to calibrate the sensor data throughout a useful life of the system using pre-implant calibration information;

wherein the system is configured to provide a substantially accurate measurement of the analyte concentration in the host such that at least 95% of calibrated sensor analyte values are within 25% of actual analyte values as determined by analysis of blood obtained throughout the useful life of the system.

39. The system of claim 38, wherein the pre-implant calibration information comprises a value obtained from an in vitro calibration.

40. The system of claim 39, wherein the in vitro calibration is obtained by measuring at least two different analyte concentrations.

41. The system of claim 39, wherein the in vitro calibration is obtaines at about 37 degrees C.

42. The system of claim 38, wherein the analyte is glucose, and wherein the sensor is configured to respond substantially linearly to changes in glucose concentration at glucose concentrations ranging from about 40 mg/dL to about 500 mg/dL.

43. The system of claim 38, wherein the system is configured to provide a stable sensor offset during the useful life of the sensor.

44. The system of claim 38, wherein the electronic circuitry is configured to determine trends in analyte concentration.

45. The system of claim 38, wherein the electronic circuitry is configured to physically couple the sensor.

46. The system of claim 38, wherein the electronic circuitry is configured to couple, via radio telemetry, the sensor.

47. The system of claim 38, wherein the analyte is glucose.

48. The system of claim 38, wherein the useful life of the system is more than about 3 days of implantation

49. The system of claim 38, wherein the useful life of the system is more than about 5 days of implantion.

50. The system of claim 38, wherein the useful life of the system is more than about 7 days of implantation.

51. The system of claim 38, wherein the useful life of the system is more than about one month of implantation.

52. The system of claim 38, wherein the electronic circuitry is configured to perform recalibration during the useful life of the sensor.

53. The system of claim 52, wherein the electronic circuitry is configured to perform recalibration throughout the useful life of the sensor.

54. The system of claim 53, wherein the recalibration is performed periodically.

55. The system of claim 52, wherein the recalibration is based on reference data.

56. The system of claim 38, wherein the electronic circuitry is configured to perform a calibration check throughout the useful life of the sensor.

57. The system of claim 38, wherein the sensor is configured to maintain a stability of calibration within 10% for one week.

58. A method for processing sensor data from a continuous analyte sensor, comprising:

receiving sensor data from an analyte sensor, the sensor data indicative of an analyte concentration in a host;

calibrating the sensor data throughout a useful life of the sensor using pre-implant calibration; and

generating, using an electronic system, a substantially accurate measurement of the analyte concentration, such that at least 95% of calibrated sensor analyte values are within 25% of actual analyte values as determined by analysis of blood obtained throughout the useful life of the sensor.

59. The method of claim 58, wherein the pre-implant calibration information comprises a value obtained from an in vitro calibration.

60. The method of claim 59, wherein the in vitro calibration is obtained by measuring at least two different analyte concentrations.

61. The system of claim 59, wherein the in vitro calibration is obtained At about 37 degrees C.

62. The method of claim 58, wherein the analyte is glucose, and wherein the sensor is configured to respond substantially linearly to changes in glucose concentration at glucose concentrations ranging from about 40 mg/dL to about 500 mg/dL to about 500 mg/dL.

63. The method of claim 58, further comprising maintaining a stable sensor offset during the useful life of the sensor.

65. The method of claim 58, wherein the analyte is glucose.

66. The method of claim 58 wherein the useful life of the sensor is greater than about 3 days of implanation.

67. The method of claim 58, wherein the useful life of the sensor is greater than about 5 days of implantation.

68. The method of claim 58, wherein the useful life of the sensor is greater than about 7 days of implantation.

69. The method of claim 58, wherein the useful life of the sensor is about one month of implanation.

70. The method of claim 58, further comprising recalibrating the sensor data throughout the useful life of the sensor.

71. The method of claim 70, wherein the recalibrating is performed periodically.

72. The method of claim 70, wherein the recalibrating is based on reference data.

73. The method of claim 58, further comprising checking calibration throughout the useful life of the sensor.

64. The method of 58, further comprising determining trends in analyte concentration.

74. A system for processing sensor data from a continuous analyte sensor, comprising:

a sensor comprising an electrode configured for implantation in a subcutaneous tissue of a host, wherein the sensor is configured to continuously measure an analyte concentration, whereby sensor data associated with the subcutaneous analyte concentration is generated; and

electronic circuitry operably connected to the sensor and configured to calibrate the sensor data during a useful life of the system using pre-implant calibration information, wherein the electronic circuitry is further configured to perform recalibration after an initial calibration time period;

wherein the system is configured to provide a substantially accurate measurement of the analyte concentration in the host such that at least 95% of calibrated sensor analyte values are within 25% of actual analyte values as determined by analysis of blood obtained during the useful life of the system.

75. The system of claim 74, wherein the pre-implant calibration information comprises a value obtained from an in vitro calibration.

76. The system of claim 75, wherein the in vitro calibration is obtained by measuring at least two different analyte concentrations.

77. The system of claim 75, wherein the in vitro calibration is obtained at about 37 degrees C.

78. The system of claim 74, wherein the analyte is glucose, and wherein the sensor is configured to respond substantially linearly to changes in glucose concentration at glucose concentrations ranging from about 40 mg/dL to about 500 mg/dL.

79. The system of claim 74, wherein the system is configured to provide a stable sensor offset during the useful life of the sensor.

80. The system of claim 74, wherein the electronic circuitry is configured to determine trends in analyte concentration.

81. The system of claim 74, wherein the electronic circuitry is configured to physically couple the sensor.

82. The system of claim 74, wherein the electronic circuitry is configured to couple, via radio telemetry, the sensor.

83. The system of claim 74, wherein the analyte is glucose.

84. The system of claim 74, wherein the useful life of the system is more than about 3 days of implantation.

85. The system of claim 74, wherein the useful life of the system is more than about 5 days of implantation.

86. The system of claim 74, wherein the useful life of the system is more than about 7 days of implantation.

87. The system of claim 74, wherein the useful life of the system is more than about one month of implantation.

88. The system of claim 74, wherein the recalibration is performed during the useful life of the sensor.

89. The system of claim 88, wherein the recalibration is performed throughout the useful life of the sensor.

90. The system of claim 89, wherein the recalibration is performed periodically.

91. The system of claim 88, wherein the recalibration is based on reference data.

92. The system of claim 74, wherein the electronic circuitry is configured to perform a calibration check during the useful life of the sensor.

93. The system of claim 74, wherein the sensor is configured to maintain a stability of calibration within 10% for one week.

94. A method for processing sensor data from a continuous analyte sensor, comprising:

receiving sensor data from an analyte sensor, the sensor data indicative of an analyte concentration in a host;

calibrating the sensor data during a useful life of the sensor using pre-implant calibration;

periodically recalibrating the sensor data after an initial calibration time period; and

generating, using an electronic system, a substantially accurate measurement of the analyte concentration, such that at least 95% of calibrated sensor analyte values are within 25% of actual analyte values as determined by analysis of blood obtained during the useful life of the sensor.

95. The method of claim 94, wherein the pre-implant calibration information comprises a value obtained from an in vitro calibration.

96. The method of claim 95, wherein the in vitro calibration is obtained by measuring at least two different analyte concentrations.

97. The method of claim 95, wherein the in vitro calibration is obtained at about 37 degrees C.

98. The method of claim 94, wherein the analyte is glucose, and wherein the sensor is configured to respond substantially linearly to changes in glucose concentration at glucose concentrations ranging from about 40 mg/dL to about 500 mg/dL.

99. The method of claim 94, further comprising maintaining a stable sensor offset during the useful life of the sensor.

100. The method of claim 94, further comprising determining trends in analyte concentration.

101. The method of claim 94, wherein the analyte is glucose.

102. The method of claim 94, wherein the useful life of the sensor is greater than about 3 days of implantation.

103. The method of claim 94, wherein the useful life of the sensor is greater than about 5 days of implantation.

104. The method of claim 94, wherein the useful life of the sensor is greater than about 7 days of implantation.

105. The method of claim 94, wherein the useful life of the sensor is about one month of implantation.

106. The method of claim 94, wherein the recalibrating is performed during the useful life of the sensor.

107. The method of claim 106, wherein the recalibrating is performed throughout the useful life of the sensor.

108. The method of claim 107, wherein the recalibrating is performed periodically.

109. The method of claim 106, wherein the recalibrating is based on reference data.

110. The method of claim 94, further comprising checking calibration during the useful life of the sensor.