System and methods for processing analyte sensor data

• US 7,583,990 B2
• Filed: 04/14/2008
• Issued: 09/01/2009
• Est. Priority Date: 08/01/2003
• Status: Expired due to Term

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Goode, Paul V. Jr., Brauker, James H., Carr-Brendel, Victoria, Kamath, Apurv U.
• Primary Examiner(s): Nasser; Robert L
• Application Number:
  US12/102,745
• Publication Number:
  US 20080195967A1
• Time in Patent Office: 505 Days
• Field of Search: None
• 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 3/10 Objective types, i.e. instruments for examining the eyes independent of the patients' perceptions or reactions
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/1433 provided with locking means details of syringes A61M5/315
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/1468 using chemical or electrochemical methods, e.g. by polarographic means A61B5/1486 takes precedence
• 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 5/150022 for capillary blood or interstitial fluid
• CPC Class Codes: A61B 5/4839 combined with drug delivery
• CPC Class Codes: A61B 5/743 Displaying an image simultaneously with additional graphical information, e.g. symbols, charts, function plots
• CPC Class Codes: G01N 33/48707 by electrical means G01N33/49, G01N33/493 take precedence
• 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 for processing sensor analyte data, including initiating calibration, updating calibration, evaluating clinical acceptability of reference and sensor analyte data, and evaluating the quality of sensor calibration. During initial calibration, the analyte sensor data is evaluated over a period of time to determine stability of the sensor. The sensor may be calibrated using a calibration set of one or more matched sensor and reference analyte data pairs. The calibration may be updated after evaluating the calibration set for best calibration based on inclusion criteria with newly received reference analyte data. Fail-safe mechanisms are provided based on clinical acceptability of reference and analyte data and quality of sensor calibration. Algorithms provide for optimized prospective and retrospective analysis of estimated blood analyte data from an analyte sensor.

Claims

1. A system for displaying data from a substantially continuous glucose sensor, the system comprising:

a sensor data receiving module configured to receive sensor data including one or more sensor data points from the substantially continuous glucose sensor; and

an interface control module configured to display sensor data on a user interface responsive to a level of stability of the sensor data, wherein the level of stability is based at least in part on an evaluation of a sensitivity associated with the substantially continuous glucose sensor.

2. The system of claim 1, wherein the interface control module is configured to display sensor data only after a predetermined level of stability has been determined.

3. The system of claim 1, wherein the interface control module is configured to alter the user interface based on the level of stability of the sensor data.

4. The system of claim 1, wherein the interface control module is configured to provide an indication of the level of stability of the sensor data.

5. The system of claim 4, wherein the indication comprises flashing information and/or faded information on the user interface.

6. The system of claim 1, wherein the interface control module is configured to display sensor data in a display format comprising a numeric glucose value, a directional trend of glucose data, and/or a graphical representation of glucose data.

7. The system of claim 6, wherein the interface control module is configured to selectively alter the display format based on the level of stability of the sensor data.

8. The system of claim 1, wherein the interface control module is configured to request a fingerstick after a predetermined level of stability is determined.

9. The system of claim 1, wherein the evaluation of a sensitivity is based at least in part on an amplitude of a sensitivity associated with the substantially continuous glucose sensor.

10. The system of claim 1, wherein the evaluation of a sensitivity is based at least in part on a variability of a sensitivity associated with the substantially continuous glucose sensor.

11. The system of claim 1, wherein the level of stability is determined during initialization of the substantially continuous glucose sensor.

12. The system of claim 1, wherein the level of stability is further based at least in part on a baseline associated with the sensor data.

13. The system of claim 1, wherein the interface control module is configured to display a request for reference glucose value after a predetermined level of stability is determined.

14. A method for displaying data from a substantially continuous glucose sensor, the method comprising:

receiving sensor data including one or more sensor data points from the substantially continuous glucose sensor; and

displaying sensor data on a user interface responsive to a level of stability of the sensor data, wherein the level of stability is determined at least in part by evaluating of a sensitivity associated with the substantially continuous glucose sensor.

15. The method of claim 14, wherein displaying sensor data on a user interface responsive to a level of stability of the sensor data comprises displaying sensor data only after a predetermined level of stability has been determined.

16. The method of claim 14, further comprising altering the user interface based on the level of stability of the sensor data.

17. The method of claim 14, further comprising providing an indication of the level of stability of the sensor data.

18. The method of claim 17, wherein the indication comprises flashing information and/or faded information on the user interface.

19. The method of claim 14, wherein displaying sensor data on a user interface responsive to a level of stability of the sensor data comprises displaying the sensor data in a display format comprising a numeric glucose value, a directional trend of glucose data, and/or a graphical representation of glucose data.

20. The method of claim 19, further comprising selectively altering the display format based on the level of stability of the sensor data.

21. The method of claim 14, further comprising requesting a fingerstick after a predetermined level of stability is determined.

22. The method of claim 14, wherein evaluating a sensitivity is based at least in part on evaluating an amplitude of a sensitivity associated with the substantially continuous glucose sensor.

23. The method of claim 14, wherein evaluating a sensitivity is based at least in part on evaluating a variability of a sensitivity associated with the substantially continuous glucose sensor.

24. The method of claim 14, wherein the level of stability is determined during initialization of the substantially continuous glucose sensor.

25. The system of claim 14, wherein the level of stability is further based at least in part on a baseline associated with the sensor data.

26. The method of claim 14, further comprising displaying a request for a reference glucose value after a predetermined level of stability is determined.

27. A substantially continuous glucose sensor system, comprising:

a substantially continuous glucose sensor configured to substantially continuously measure a concentration of glucose in a host; and

a computer system configured to receive sensor data associated with the concentration of glucose in the host and configured to process the sensor data to provide displayable sensor data, wherein the computer system is configured to display sensor data on a user interface responsive to a level of stability of the sensor data, wherein the level of stability is based at least in part on an evaluation of a sensitivity associated with the substantially continuous glucose sensor.

28. The system of claim 27, wherein the computer system is configured display the sensor data on the user interface only when a predetermined level of stability of the substantially continuous glucose sensor is determined.

29. The system of claim 27, wherein the computer system is configured to alter the user interface based on the level of stability of the sensor data.

30. The system of claim 27, wherein the computer system is configured to provide an indication of the level of stability of the sensor data.

31. The system of claim 30, wherein the indication comprises flashing information and/or faded information on the user interface.

32. The system of claim 27, wherein the computer system is configured to display sensor data in a display format comprising a numeric glucose value, a directional trend of glucose data, and/or a graphical representation of glucose data.

33. The system of claim 32, wherein the computer system is configured to selectively alter the display format based on the level of stability of the sensor data.

34. The system of claim 27, wherein the computer system is configured to request a fingerstick after a predetermined level of stability is determined.

35. The system of claim 27, wherein the evaluation of a sensitivity is based at least in part on an amplitude of a sensitivity associated with the substantially continuous glucose sensor.

36. The system of claim 27, wherein the evaluation of a sensitivity is based at least in part on a variability of a sensitivity associated with the substantially continuous glucose sensor.

37. The system of claim 27, wherein the level of stability is determined during initialization of the substantially continuous glucose sensor.

38. The system of claim 27, wherein the level of stability is further based at least in part on a baseline associated with the sensor data.

39. The system of claim 27, wherein the computer system is configured to display a request for reference glucose value after a predetermined level of stability is determined.