Analyte sensor

• US 8,447,376 B2
• Filed: 11/07/2008
• Issued: 05/21/2013
• Est. Priority Date: 10/04/2006
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Shariati, Mohammad Ali, Li, Ying, Kamath, Apurv Ullas, Simpson, Peter C., Yang, Richard C., Brister, Mark
• Primary Examiner(s): Mallari, Patricia
• Assistant Examiner(s): D'ANGELO, MICHAEL J
• Application Number:
  US12/267,531
• Publication Number:
  US 20090137886A1
• Time in Patent Office: 1,656 Days
• Field of Search: 600/347
• US Class Current: 600/347
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 2560/04 Constructional details of apparatus
• CPC Class Codes: A61B 2562/085 combined with means for recording calibration data
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• 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 5/14865 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 5/4839 combined with drug delivery
• CPC Class Codes: A61B 5/6848 Needles
• CPC Class Codes: A61B 5/6849 in combination with a needle set
• CPC Class Codes: A61B 5/7275 Determining trends in physiological measurement data; Predicting development of a medical condition based on physiological measurements, e.g. determining a risk factor
• CPC Class Codes: A61M 2005/14296 Pharmacokinetic models
• 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: A61M 5/1723 : using feedback of body parameters, e.g. blood-sugar, pressure measurement of body parameters A61B5/00
• 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 system for performing a diagnostic of an analyte sensor system, comprising:

an analyte sensor system comprising a sensor, wherein the analyte sensor comprises a first working electrode configured to provide a first signal comprising an analyte component and a baseline component and a second working electrode configured to provide a second signal comprising a baseline component substantially without an analyte component;

a flow control device configured to intermittently expose the analyte sensor to a biological sample and an infusion solution; and

a processor module configured to evaluate the analyte sensor system based at least in part on the second signal, wherein the second signal comprises a signal waveform, and wherein the processor module is configured to evaluate the signal waveform for at least one of an expected shape or a pattern when the analyte sensor is exposed to at least one of the biological sample or the infusion solution.

2. The system of claim 1, wherein the processor module is configured to evaluate the signal waveform by evaluating at least one of a similarity or a correlation between the signal waveform and a waveform template.

3. The system of claim 2, wherein the waveform template is based at least in part on a priori information.

4. The system of claim 2, wherein the waveform template is based at least in part on a signal waveform measured by the analyte sensor system.

5. The system of claim 2, wherein the processor module is configured to evaluate at least one of a similarity or a correlation between the signal waveform and the waveform template by performing a correlation waveform analysis.

6. The system of claim 2, wherein the processor module is further configured to update the waveform template when at least one of a similarity or a correlation between the signal waveform and the waveform template meets one or more criteria.

7. The system of claim 6, wherein the processor module is configured to detect a level of an interferent in the biological sample, and wherein the processor module is further configured to update the waveform template when the level of the interferent meets one or more criteria.

8. The system of claim 1, wherein the processor module is configured to evaluate the signal waveform by evaluating a monotonicity of the signal waveform.

9. The system of claim 8, wherein the processor module is configured to evaluate a monotonicity at least in part by performing a correlation waveform analysis of the signal waveform with a waveform template.

10. The system of claim 8, wherein the processor module is configured evaluate a monotonicity at least in part by performing a time-series analysis.

11. The system of claim 1, wherein the processor module is configured to detect an interferent at least in part by evaluating at least one of an amplitude, a change in amplitude, a signal waveform, or a change in a signal waveform of the second signal when the sensor is exposed to a biological sample.

12. The system of claim 11, wherein the processor module is configured to detect an interferent at least in part by evaluating a calibrated analyte value with one or more criteria.

13. The system of claim 12, wherein the one or more criteria is based on physiological feasibility.

14. The system of claim 11, wherein the processor module is configured to control a display of the analyte sensor system based at least in part on a level of an interferent detected on the second signal.

15. The system of claim 11, wherein the processor module is further configured to process the first signal and the second signal to obtain a subtracted signal based at least in part on a level of an interferent of the sensor system.

16. The system of claim 1, wherein the processor module is configured evaluate a level of reliability of the sensor system at least in part by comparing at least one of an amplitude, a change in amplitude, a signal waveform, or a change in a signal waveform of the second signal to one or more criteria.

17. The system of claim 16, wherein the processor module is configured to control a display of the sensor system based at least in part on a level of reliability of the sensor system.

18. A system for performing a diagnostic of an analyte sensor system, comprising:

an analyte sensor system comprising a sensor, wherein the analyte sensor comprises a first working electrode configured to provide a first signal comprising an analyte component and a baseline component and a second working electrode configured to provide a second signal comprising a baseline component substantially without an analyte component;

a flow control device configured to intermittently expose the analyte sensor to a biological sample and an infusion solution; and

a processor module configured to evaluate the anal sensor system based at least in part on the second signal, wherein the processor module is further configured determine a success of drawing-back of a biological sample from a host'"'"'s circulatory system to the analyte sensor, based at least in part on the evaluation of the analyte sensor system.

19. The system of claim 18, wherein the processor module is configured to display an analyte value measured during the biological sample draw-back, in response to a determination of a successful draw-back of the biological sample.

20. The system of claim 18, wherein the processor module is configured to evaluate a signal waveform by evaluating at least one of a similarity or a correlation between the signal waveform and a waveform template.

21. The system of claim 20, wherein the waveform template is based at least in part on a priori information.

22. The system of claim 20, wherein the waveform template is based at least in part on a signal waveform measured by the analyte sensor system.

23. The system of claim 20, wherein the processor module is configured to evaluate at least one of a similarity or a correlation between the signal waveform and the waveform template by performing a correlation waveform analysis.

24. The system of claim 20, wherein the processor module is further configured to update the waveform template when at least one of a similarity or a correlation between the signal waveform and the waveform template meets one or more criteria.

25. The system of claim 24, wherein the processor module is configured to detect a level of an interferent in the biological sample, and wherein the processor module is further configured to update the waveform template when the level of the interferent meets one or more criteria.

26. The system of claim 18, wherein the processor module is configured to evaluate a signal waveform by evaluating a monotonicity of the signal waveform.

27. The system of claim 26, wherein the processor module is configured to evaluate a monotonicity at least in part by performing a correlation waveform analysis of the signal waveform with a waveform template.

28. The system of claim 26, wherein the processor module is configured evaluate a monotonicity at least in part by performing a time-series analysis.

29. The system of claim 18, wherein the processor module is configured to detect an interferent at least in part by evaluating at least one of an amplitude, a change in amplitude, a signal waveform, or a change in a signal waveform of the second signal when the sensor is exposed to a biological sample.

30. The system of claim 18, wherein the processor module is configured evaluate a level of reliability of the sensor system at least in part by comparing at least one of an amplitude, a change in amplitude, a signal waveform, or a change in a signal waveform of the second signal to one or more criteria.

31. The system of claim 30, wherein the processor module is configured to control a display of the sensor system based at least in part on a level of reliability of the sensor system.

32. The system of claim 18, wherein the processor module is further configured to determine a success of infusing the infusion solution such that the biological sample is washed from the sensor.

33. The system of claim 32, wherein the processor module is configured to display an analyte value measured in the biological sample after infusing the infusion solution, in response to a determination of a successful infusion.

34. A system for performing a diagnostic of ananalyte sensor system, comprising:

an analyte sensor system comprising a sensor, wherein the analyte sensor comprises a first working electrode configured to provide a first signal comprising an analyte component and a baseline component and a second working electrode configured to provide a second signal comprising a baseline component substantially without an analyte component;

a flow control device configured to intermittently expose the analyte sensor to a biological sample and an infusion solution; and

a processor module configured to evaluate the analyte sensor system based at least in part on the second signal, wherein the processor module is further configured to determine a success of infusing the infusion solution such that the biological sample is washed from the sensor.

35. The system of claim 34, wherein the processor module is configured to display an analyte value measured in the biological sample after infusing the infusion solution, in response to a determination of a successful infusion.

36. The system of claim 34, wherein the processor module is configured to evaluate a signal waveform by evaluating at least one of a similarity or a correlation between the signal waveform and a waveform template.

37. The system of claim 36, wherein the waveform template is based at least in part on a priori information.

38. The system of claim 36, wherein the waveform template is based at least in part on a signal waveform measured by the analyte sensor system.

39. The system of claim 36, wherein the processor module is configured to evaluate at least one of a similarity or a correlation between the signal waveform and the waveform template by performing a correlation waveform analysis.

40. The system of claim 36, wherein the processor module is further configured to update the waveform template when at least one of a similarity or a correlation between the signal waveform and the waveform template meets one or more criteria.

41. The system of claim 40, wherein the processor module is configured to detect a level of an interferent in the biological sample, and wherein the processor module is further configured to update the waveform template when the level of the interferent meets one or more criteria.

42. The system of claim 34, wherein the processor module is configured to evaluate a signal waveform by evaluating a monotonicity of the signal waveform.

43. The system of claim 42, wherein the processor module is configured to evaluate a monotonicity at least in part by performing a correlation waveform analysis of the signal waveform with a waveform template.

44. The system of claim 42, wherein the processor module is configured evaluate a monotonicity at least in part by performing a time-series analysis.

45. The system of claim 34, wherein the processor module is configured to detect an interferent at least in part by evaluating at least one of an amplitude, a change in amplitude, a signal waveform, or a change in a signal waveform of the second signal when the sensor is exposed to a biological sample.

46. The system of claim 34, wherein the processor module is configured evaluate a level of reliability of the sensor system at least in part by comparing at least one of an amplitude, a change in amplitude, a signal waveform, or a change in a signal waveform of the second signal to one or more criteria.

47. The system of claim 46, wherein the processor module is configured to control a display of the sensor system based at least in part on a level of reliability of the sensor system.

48. The system of claim 34, wherein the processor module is further configured determine a success of drawing-back of a biological sample from a host'"'"'s circulatory system to the analyte sensor, based at least in part on the evaluation of the analyte sensor system.

49. The system of claim 48, wherein the processor module is configured to display an analyte value measured during the biological sample draw-back, in response to a determination of a successful draw-back of the biological sample.