Analyte sensor

• US 9,451,908 B2
• Filed: 12/19/2012
• Issued: 09/27/2016
• Est. Priority Date: 10/04/2006
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Kamath, Apurv Ullas, Leach, Jacob S., Li, Ying, Rong, Daiting, Saint, Sean, Simpson, Peter C., Brister, Mark
• Primary Examiner(s): Natnithithadha, Navin
• Assistant Examiner(s): MESSERSMITH, ERIC J
• Application Number:
  US13/720,227
• Publication Number:
  US 20130123596A1
• Time in Patent Office: 1,378 Days
• US Class Current: 1/1
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 5/145 Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissuemeasuring of blood pressure or blood flow A61B5/02; non-radiation detecting or locating of foreign bodies in blood A61B5/06
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14539 for measuring pH
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/1473 invasive, e.g. introduced into the body by a catheter A61B5/1482 takes precedence
• 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: A61B 5/412 Detecting or monitoring sepsis
• CPC Class Codes: A61B 5/6848 Needles
• CPC Class Codes: A61B 5/6849 in combination with a needle set
• CPC Class Codes: A61B 5/6852 Catheters
• CPC Class Codes: A61B 5/7235 Details of waveform analysis A61B5/349 takes precedence
• CPC Class Codes: A61M 2230/201 Glucose concentration
• CPC Class Codes: A61M 25/007 Side holes, e.g. their profiles or arrangements; Provisions to keep side holes unblocked
• CPC Class Codes: A61M 5/14 Infusion devices, e.g. infusing by gravity; Blood infusion; Accessories therefor
• CPC Class Codes: A61M 5/16804 Flow controllers
• CPC Class Codes: C12Q 1/001 Enzyme electrodes
• CPC Class Codes: C12Q 1/006 for glucose
• CPC Class Codes: G16H 10/40 : for data related to laboratory analysis, e.g. patient specimen analysis
• CPC Class Codes: G16H 20/17 : delivered via infusion or injection
• CPC Class Codes: G16H 40/40 : for the management of medical equipment or devices, e.g. scheduling maintenance or upgrades
• CPC Class Codes: Y02A 90/10 : Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

Abstract

Systems and methods of use for continuous analyte measurement of a host'"'"'s vascular system are provided. In some embodiments, a continuous glucose measurement system includes a vascular access device, a sensor and sensor electronics, the system being configured for insertion into communication with a host'"'"'s circulatory system.

Claims

1. A method for processing analyte sensor data, the method comprising:

exposing an analyte sensor of an analyte sensor system to a biological fluid, wherein the sensor system comprises the sensor and sensor electronics, wherein the sensor is configured to measure a signal associated with an analyte concentration of a host; and

providing a fail-safe module comprising a processor for executing computer program code stored in memory to cause the processor to;

perform a steady state analysis and a transient analysis of the signal;

evaluate a relationship between the steady state analysis and the transient analysis; and

detect a malfunction of the sensor system based on the relationship.

2. The method of claim 1, further comprising generating a signal associated with glucose.

3. The method of claim 1, wherein the detecting step further comprises detecting an electrical malfunction.

4. The method of claim 1, wherein the detecting step further comprises detecting a fluidics malfunction.

5. The method of claim 1, wherein the detecting step further comprises detecting a sensor malfunction.

6. The method of claim 1, wherein the detecting step further comprises performing a waveform analysis of the signal.

7. The method of claim 1, wherein the detecting step further comprises performing an equilibrium and/or kinetic analysis of the signal.

8. The method of claim 7, wherein the performing step further comprises evaluating a relationship between the equilibrium analysis and the kinetic analysis.

9. The method of claim 1, further comprises providing at least one of an alert, an alarm, or an instruction.

10. The method of claim 9, further comprising evaluating the detected malfunction against a criterion.

11. The method of claim 1, wherein the evaluating step further comprises evaluating baseline information.

12. The method of claim 1, wherein the evaluating step further comprises evaluating sensitivity information.

13. The method of claim 1, further comprising calibrating the sensor system with a calibration solution.

14. The method of claim 1, further comprising applying a potential to the sensor to generate the signal.

15. The method of claim 14, further comprising switching the potential from a first setting to a second setting.

16. The method of claim 15, wherein the first setting is held long enough for equilibration.

17. The method of claim 16, wherein the second setting is held long enough for equilibration.

18. The method of claim 15, wherein the first setting is a configured to be a measurement potential and the second setting is configured for non-measurement.

19. The method of claim 15, wherein the switching of the potential from a first setting to a second setting is performed to measure a concentration of a non-glucose analyte.

20. The method of claim 19, wherein the non-glucose analyte is oxygen.

21. The method of claim 1, wherein the analyte sensor is configured to measure glucose and a non-glucose analyte.

22. The method of claim 21, wherein the non-glucose analyte is oxygen.

23. The method of claim 1, further comprising automatically detecting a code from the analyte sensor upon coupling of the sensor to sensor electronics.

24. The method of claim 23, wherein the code is a calibration code.

25. The method of claim 1, further comprising receiving an input from the user related to mealtime information.

26. The method of claim 25, further comprising alerting the user responsive to detection of hyperglycemic or hypoglycemic conditions.

27. The method of claim 26, further comprising displaying glucose concentration data over a period of time.

28. The method of claim 1, wherein the sensor is associated with a priori information.

29. The method of claim 28, wherein the a prior information is associated with sensor sensitivity to glucose.

30. The method of claim 1, wherein the biological fluid is blood.

31. The method of claim 6, wherein the step of performing a waveform analysis of the signal is performed to determine fluidics malfunction related to transport of the biological fluid to the sensor, wherein the biological fluid is blood.

32. The method of claim 1, wherein the sensor comprises a first electrode, a second electrode and an enzyme-containing film disposed between the first electrode and the second electrode, wherein the first electrode and the second electrode are separated by a distance from 115 microns to 135 microns.

33. The method of claim 32, wherein the first electrode is a working electrode and the second electrode is a reference or counter electrode.

34. The method of claim 33, wherein the enzyme-containing film comprises a cellulosic derivative.

35. The method of claim 1, wherein the sensor is configured to maintain substantial linearity at glucose concentrations from 0 mg/dL to 400 mg/dL during sensor use.

36. The method of claim 1, wherein the sensor is configured to maintain substantial linearity at glucose concentrations from 50 mg/dL to 550 mg/dL during sensor use.

37. The method of claim 1, wherein the sensor is configured to maintain substantial linearity at glucose concentrations from 0 mg/dL to 400 mg/dL at an O₂ concentration of 0.4 mg/L.

38. The method of claim 1, wherein the sensor system is configured to provide an accuracy level corresponding to having substantially all glucose concentration measurement values within ±

15mg/dl or ±

20% of YSI values.

39. The method of claim 1, wherein the sensor is configured to receive a sample volume of biological fluid of less than 1 μ

l.

40. The method of claim 1, wherein the sensor and sensor electronics are configured to generate analyte concentration data substantially without signal contribution due to interfering species.

41. The method of claim 40, wherein the interfering species is acetaminophen.

42. The method of claim 40, wherein the interfering species is at least one of ascorbic acid, uric acid, or bilirubin.

43. A method for processing glucose sensor data, the method comprising:

exposing a glucose sensor of a glucose sensor system to a blood sample, wherein the sensor system comprises the sensor and sensor electronics;

applying a potential to the sensor;

switching the potential from a first setting to a second setting;

measuring at least one signal from the sensor to obtain a glucose concentration value of a user;

providing a fail-safe module comprising a processor for executing computer program code stored in memory to cause the processor to;

perform a steady state analysis and a transient analysis of the at least one signal;

evaluate a relationship between the steady state analysis and the transient analysis; and

detect a malfunction of the sensor system based on the relationship;

displaying, on a user interface, glucose concentration data over a period of time;

receiving an input from the user related to mealtime information and displaying mealtime information on the user interface; and

alerting the user responsive to detection of hyperglycemic or hypoglycemic conditions.

44. The method of claim 43, wherein the detecting step further comprises detecting an electrical malfunction.

45. The method of claim 43, wherein the detecting step further comprises detecting a fluidics malfunction.

46. The method of claim 43, wherein the detecting step further comprises detecting a sensor malfunction.

47. The method of claim 43, wherein the detecting step further comprises performing an equilibrium and/or kinetic analysis of the at least one signal.

48. The method of claim 47, wherein the performing step further comprises evaluating a relationship between the equilibrium analysis and the kinetic analysis.

49. The method of claim 43, further comprises providing at least one of an alert, an alarm, or an instruction.

50. The method of claim 43, further comprising evaluating the detected malfunction against a criterion.

51. The method of claim 43, wherein the evaluating step further comprises evaluating baseline information.

52. The method of claim 43, wherein the evaluating step further comprises evaluating sensitivity information.

53. The method of claim 43, further comprising calibrating the sensor system with a calibration solution.

54. The method of claim 43, wherein the first setting is configured to be a measurement potential and the second potential is configured for non-measurement.

55. The method of claim 43, wherein the switching of the potential from a first setting to a second setting is performed to measure a concentration of a non-glucose analyte.

56. The method of claim 55, wherein the non-glucose analyte is oxygen.

57. The method of claim 43, wherein the glucose sensor is configured to measure glucose and a non-glucose analyte.

58. The method of claim 57, wherein the non-glucose analyte is oxygen.

59. The method of claim 43, further comprising automatically detecting a code from the sensor upon coupling of the sensor to sensor electronics.

60. The method of claim 59, wherein the code is a calibration code.

61. The method of claim 43, wherein the sensor is associated with a priori information.

62. The method of claim 43, wherein the a prior information is associated with sensor sensitivity to glucose.

63. The method of claim 43, wherein the detecting step further comprises performing a waveform analysis of the at least one signal.

64. The method of claim 63, wherein the step of performing a waveform analysis of the at least one signal is performed to determine fluidics malfunction related to transport of the biological fluid to the sensor, wherein the biological fluid is blood.

65. The method of claim 43, wherein the first setting is held long enough for equilibration.

66. The method of claim 65, wherein the second setting is held long enough for equilibration.

67. The method of claim 43, wherein the sensor comprises a first electrode, a second electrode and an enzyme-containing film disposed between the first electrode and the second electrode, wherein the first electrode and the second electrode are separated by a distance from 115 microns to 135 microns.

68. The method of claim 67, wherein the first electrode is a working electrode and the second electrode is a reference or counter electrode.

69. The method of claim 68, wherein the working electrode is configured to operate within a range of current density to glucose concentration from 2 nA/mm²mg/dL to 298 nA/mm²mg/dL during application of the potential.

70. The method of claim 43, wherein the at least one signal comprises a first signal and a second signal.

71. The method of claim 70, wherein the sensor electronics are configured to determine a glucose concentration value based at least in part on the first signal and the second signal.

72. The method of claim 43, wherein the sensor is configured to maintain substantial linearity at glucose concentrations from 0 mg/dL to 400 mg/dL during sensor use.

73. The method of claim 43, wherein the sensor is configured to maintain substantial linearity at glucose concentrations from 50 mg/dL to 550 mg/dL during sensor use.

74. The method of claim 43, wherein the sensor is configured to maintain substantial linearity at glucose concentrations from 0 mg/dL to 400 mg/dL at an O₂ concentration of 0.4 mg/L.

75. The method of claim 43, wherein the sensor system is configured to provide an accuracy level corresponding to having substantially all glucose concentration measurement values within ±

15mg/dl or ±

20% of YSI values.

76. The method of claim 43, wherein the sensor is configured to receive a blood sample volume of less than 1 μ

l.

77. The method of claim 43, wherein the enzyme-containing film comprises a cellulosic derivative.

78. The method of claim 43, wherein the sensor system is configured to generate glucose concentration data substantially without signal contribution due to interfering species.

79. The method of claim 78, wherein the interfering species is acetaminophen.

80. The method of claim 78, wherein the interfering species is at least one of ascorbic acid, uric acid, or bilirubin.

81. A method for processing glucose sensor data, the method comprising:

exposing a glucose sensor of a glucose sensor system to a blood sample, wherein the sensor system comprises the sensor and sensor electronics, wherein the sensor is configured to maintain substantial linearity at glucose concentrations from 0 mg/dL to 400 mg/dL during sensor use, wherein the sensor comprises a first electrode, a second electrode and an enzyme-containing film disposed between the first electrode and the second electrode, wherein the first electrode and the second electrode are separated by a distance from 115 microns to 135 microns;

automatically detecting a code from the sensor upon coupling of the glucose sensor to sensor electronics;

applying a potential to the sensor;

switching the potential from a first setting to a second setting;

measuring at least one signal from the sensor to obtain a glucose concentration value of a user;

providing a fail-safe module comprising a processor for executing computer program code stored in memory to cause the processor to;

perform a steady state analysis and a transient analysis of the at least one signal by analyzing a plurality of waveforms formed by the at least one signal over time;

evaluate a relationship between the steady state analysis and the transient analysis; and

detect a malfunction of the sensor system based on the relationship;

displaying, on a user interface, glucose concentration data over a period of time;

receiving an input from the user related to mealtime information and displaying mealtime information on the user interface; and

alerting the user responsive to detection of hyperglycemic or hypoglycemic conditions.

82. The method of claim 81, wherein the at least one signal comprises a first signal and a second signal.

83. The method of claim 81, wherein the sensor electronics are configured to determine a glucose concentration value based at least in part on the first signal and the second signal.

84. The method of claim 81, wherein the detecting step further comprises detecting an electrical malfunction.

85. The method of claim 81, wherein the detecting step further comprises detecting a fluidics malfunction.

86. The method of claim 81, wherein the detecting step further comprises detecting a sensor malfunction.

87. The method of claim 81, wherein the detecting step further comprises performing an equilibrium and/or kinetic analysis of the at least one signal.

88. The method of claim 87, wherein the performing step further comprises evaluating a relationship between the equilibrium analysis and the kinetic analysis.

89. The method of claim 81, further comprises providing at least one of an alert, an alarm, or an instruction.

90. The method of claim 81, further comprising evaluating the detected malfunction against a criterion.

91. The method of claim 81, wherein the evaluating step further comprises evaluating baseline information.

92. The method of claim 81, wherein the evaluating step further comprises evaluating sensitivity information.

93. The method of claim 81, further comprising calibrating the sensor system with a calibration solution.

94. The method of claim 81, wherein the first setting is configured to be a measurement potential and the second potential is configured for non-measurement.

95. The method of claim 81, wherein the switching of the potential from the first setting to the second setting is performed to measure a concentration of a non-glucose analyte.

96. The method of claim 95, wherein the non-glucose analyte is oxygen.

97. The method of claim 81, wherein the sensor is configured to measure glucose and a non-glucose analyte.

98. The method of claim 97, wherein the non-glucose analyte is oxygen.

99. The method of claim 81, wherein the code is a calibration code.

100. The method of claim 81, wherein the sensor is associated with a priori information.

101. The method of claim 100, wherein the a prior information is associated with sensor sensitivity to glucose.

102. The method of claim 81, wherein the first setting is held long enough for equilibration.

103. The method of claim 102, wherein the second setting is held long enough for equilibration.

104. The method of claim 81, wherein the first electrode is a working electrode and the second electrode is a reference or counter electrode.

105. The method of claim 104, wherein the working electrode is configured to operate within a range of current density to glucose concentration from 2 nA/mm²mg/dL to 298 nA/mm²mg/dL during application of the potential.

106. The method of claim 81, wherein the sensor is configured to maintain substantial linearity at glucose concentrations from 50 mg/dL to 550 mg/dL during sensor use.

107. The method of claim 81, wherein the sensor is configured to maintain substantial linearity at glucose concentrations from 0 mg/dL to 400 mg/dL at an O₂ concentration of 0.4 mg/L.

108. The method of claim 81, wherein the sensor system is configured to provide an accuracy level corresponding to having substantially all glucose concentration measurement values within ±

15mg/dl or ±

20% of YSI values.

109. The method of claim 81, wherein the sensor is configured to receive a blood sample volume of less than 1 μ

l.

110. The method of claim 81, wherein the enzyme-containing film comprises a cellulosic derivative.

111. The method of claim 81, wherein the sensor system is configured to generate glucose concentration data substantially without signal contribution due to interfering species.

112. The method of claim 111, wherein the interfering species is acetaminophen.

113. The method of claim 111, wherein the interfering species is at least one of ascorbic acid, uric acid, or bilirubin.

114. A method for processing glucose sensor data, the method comprising:

exposing a glucose sensor of a glucose sensor system to a blood sample, wherein the sensor system comprises the sensor and sensor electronics, wherein the sensor is configured to receive a blood sample volume of less than 1 μ

l, wherein the sensor comprises a first electrode, a second electrode and an enzyme-containing film disposed between the first electrode and the second electrode, wherein the first electrode and the second electrode are separated by a distance from 115 microns to 135 microns, wherein the first electrode is a working electrode and the second electrode is a reference or counter electrode, wherein the sensor is configured to maintain substantial linearity at glucose concentrations from 50 mg/dL to 550 mg/dL during sensor use;

applying a potential to the sensor;

switching the potential from a first setting to a second setting;

measuring at least one signal from the sensor, wherein the at least one signal comprises a first signal and a second signal;

determining, with sensor electronics, a glucose concentration value based at least in part on the first signal and the second signal;

providing a fail-safe module comprising a processor for executing computer program code stored in memory to cause the processor to;

perform a steady state analysis and a transient analysis of the at least one signal;

evaluate a relationship between the steady state analysis and the transient analysis; and

detect a malfunction of the sensor system based on the relationship;

displaying, on a user interface, glucose concentration data over a period of time;

receiving an input from the user related to mealtime information and displaying mealtime information on the user interface; and

alerting the user responsive to detection of hyperglycemic or hypoglycemic conditions.

115. The method of claim 114, wherein the working electrode is configured to operate within a range of current density to glucose concentration from 2 nA/mm²mg/dL to 298 nA/mm²mg/dL during application of the potential.

116. The method of claim 114, wherein the enzyme-containing film comprises a cellulosic derivative.

117. The method of claim 114, wherein the sensor electronics are configured to determine fluidics malfunction related to transport of the blood sample to the sensor by performing a waveform analysis of the at least one signal.

118. The sensor system of claim 114, wherein the sensor electronics are configured to automatically detect a code from the sensor upon coupling of the sensor to sensor electronics.

119. A glucose sensor system, the sensor system comprising:

a glucose sensor configured to be exposed to a blood sample of a user, wherein the sensor comprises a first electrode, a second electrode and an enzyme-containing film disposed between the first electrode and the second electrode, wherein the first electrode and the second electrode are separated by a distance from 115 microns to 135 microns, wherein the first electrode is a working electrode and the second electrode is a reference or counter electrode, wherein the sensor is configured to receive a blood sample volume of less than 1 μ

l, wherein the sensor is configured to maintain substantial linearity at glucose concentrations from 0 mg/dL to 400 mg/dL during sensor use;

sensor electronics comprising a processor for executing computer program code stored in memory to cause the processor to;

apply a potential to the sensor;

switch the potential from a first setting to a second setting;

measure at least one signal from the sensor to obtain a glucose concentration value of the use;

perform a steady state analysis and a transient analysis of the at least one signal;

evaluate a relationship between the steady state analysis and the transient analysis; and

detect a malfunction of the sensor system based on the relationship; and

a user interface configured to;

display glucose concentration data over a period of time;

receive an input from the user related to mealtime information and display mealtime information on the user interface; and

alert the user responsive to detection of hyperglycemic or hypoglycemic conditions.

120. The glucose sensor system of claim 119, wherein the malfunction is an electrical malfunction.

121. The glucose sensor system of claim 119, wherein the malfunction is a fluidics malfunction.

122. The glucose sensor system of claim 119, wherein the malfunction is a sensor malfunction.

123. The glucose sensor system of claim 119, wherein the sensor electronics are configured to perform an equilibrium and/or kinetic analysis of the at least one signal.

124. The glucose sensor system of claim 123, wherein the sensor electronics are configured to evaluate a relationship between the equilibrium analysis and the kinetic analysis.

125. The glucose sensor system of claim 119, wherein the user interface is configured to interact with the user via one of an alert, an alarm, or an instruction.

126. The glucose sensor system of claim 119, wherein the sensor electronics are further configured to evaluate the detected malfunction against a criterion.

127. The sensor system of claim 119, further comprising a calibration solution configured to calibrate the sensor system.

128. The sensor system of claim 119, wherein the first setting is a configured to be a measurement potential and the second potential is configured for non-measurement.

129. The sensor system of claim 119, wherein sensor electronics are configured to measure a concentration of a non-glucose analyte based on the switching of the potential from a first setting to a second setting.

130. The glucose sensor system of claim 129, wherein the non-glucose analyte is oxygen.

131. The glucose sensor system of claim 119, wherein the sensor is configured to measure glucose and a non-glucose analyte.

132. The glucose sensor system of claim 131, wherein the non-glucose analyte is oxygen.

133. The sensor system of claim 119, wherein the sensor electronics are configured to automatically detect a code from the sensor upon coupling of the sensor to sensor electronics.

134. The glucose sensor system of claim 133, wherein the code is a calibration code.

135. The glucose sensor system of claim 119, wherein the sensor is associated with a priori information.

136. The sensor system of claim 135, wherein the a priori information is associated with sensor sensitivity to glucose.

137. The glucose sensor system of claim 119, wherein the sensor electronics are configured to detect the malfunction by performing a waveform analysis of the at least one signal.

138. The glucose sensor system of claim 119, wherein the sensor electronics are configured to determine fluidics malfunction related to transport of the blood sample to the sensor by performing a waveform analysis of the at least one signal.

139. The glucose sensor system of claim 119, wherein the sensor electronics are configured to hold the first setting long enough for equilibration.

140. The glucose sensor system of claim 139, wherein the sensor electronics are configured to hold the second setting long enough for equilibration.

141. The glucose sensor system of claim 119, wherein the at least one signal comprises a first signal and a second signal.

142. The glucose sensor system of claim 141, wherein the sensor electronics are configured to determine a glucose concentration value based at least in part on the first signal and the second signal.

143. The glucose sensor system of claim 119, wherein the sensor is configured to maintain substantial linearity at glucose concentrations from 50 mg/dL to 550 mg/dL during sensor use.

144. The sensor system of claim 119, wherein the sensor is configured to maintain substantial linearity at glucose concentrations from 0 mg/dL to 400 mg/dL at an O₂ concentration of 0.4 mg/L.

145. The glucose sensor system of claim 119, wherein the sensor system is configured to provide an accuracy level corresponding to having substantially all glucose concentration measurement values within ±

15mg/dl or ±

20% of YSI values.

146. The glucose sensor system of claim 119, wherein the enzyme-containing film comprises a cellulosic derivative.

147. The sensor system of claim 119, wherein the working electrode is configured to operate within a range of current density to glucose concentration from 2 nA/mm²mg/dL to 298 nA/mm²mg/dL during application of the potential.

148. The glucose sensor system of claim 119, wherein the sensor system is configured to generate analyte concentration data substantially without signal contribution due to interfering species.

149. The glucose sensor system of claim 148, wherein the interfering species is acetaminophen.

150. The glucose sensor system of claim 148, wherein the interfering species is at least one of ascorbic acid, uric acid, or bilirubin.

151. A glucose sensor system, the sensor system comprising:

a glucose sensor configured to be exposed to a blood sample of a user, wherein the sensor comprises a first electrode, a second electrode and an enzyme-containing film disposed between the first electrode and the second electrode, wherein the first electrode and the second electrode are separated by a distance from 115 microns to 135 microns, wherein the first electrode is a working electrode and the second electrode is a reference or counter electrode, wherein the sensor is configured to receive a blood sample volume of less than 1 μ

l, wherein the sensor is configured to maintain substantial linearity at glucose concentrations from 50 mg/dL to 550 mg/dL during sensor use;

sensor electronics comprising a processor for executing computer program code stored in memory to cause the processor to;

apply a potential to the sensor, wherein the working electrode is configured to operate within a range of current density to glucose concentration from 2 nA/mm²mg/dL to 298 nA/mm²mg/dL during application of the potential;

switch the potential from a first setting to a second setting;

measure at least one signal from the sensor to obtain a glucose concentration value of the use;

perform a steady state analysis and a transient analysis of the at least one signal;

evaluate a relationship between the steady state analysis and the transient analysis; and

detect a malfunction of the sensor system based on the relationship; and

a user interface configured to;

display glucose concentration data over a period of time;

receive an input from the user related to mealtime information and display mealtime information on the user interface; and

alert the user responsive to detection of hyperglycemic or hypoglycemic conditions.

152. The glucose sensor system of claim 151, wherein the enzyme-containing film comprises a cellulosic derivative.

153. The glucose sensor system of claim 151, wherein the sensor electronics are configured to determine fluidics malfunction related to transport of the blood sample to the sensor by performing a waveform analysis of the at least one signal.

154. The glucose sensor system of claim 151, wherein the at least one signal comprises a first signal and a second signal.

155. The glucose sensor system of claim 154, wherein the sensor electronics are configured to determine a glucose concentration value based at least in part on the first signal and the second signal.