SYSTEM AND METHODS FOR PROCESSING ANALYTE SENSOR DATA

• US 20100185072A1
• Filed: 03/23/2010
• Published: 07/22/2010
• Est. Priority Date: 08/01/2003
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Brauker, James H., Carr-Brendel, Victoria, Kamath, Apurv U., Goode, Paul V. JR.
• Granted Patent: US 8,332,008 B2
• Time in Patent Office: Days
• US Class Current: 600/365
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 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

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 computer system for initializing a continuous glucose sensor, the computer system comprising:

a sensor data receiving module that receives sensor data from the substantially continuous glucose sensor via a receiver, including one or more sensor data points;

a reference data receiving module that receives reference data from a reference glucose monitor, including one or more reference data points;

a data matching module that forms one or more matched data pairs by matching reference data to substantially time corresponding sensor data; and

a stability determination module that determines a stability of the continuous glucose sensor in real-time, wherein said stability determination module evaluates a level of oxygen.

2. The computer system of claim 1, further comprising an interface control module that provides output to the user based on a stability of said sensor.

3. The computer system of claim 2, wherein said output from said interface control module comprises at least one of a numeric estimated glucose value, an indication of directional trend of glucose concentration, and a graphical representation of an estimated glucose value.

4. The computer system of claim 1, wherein said reference data receiving module is adapted to receive sensor data from a blood glucose test.

5. The computer system of claim 1, wherein said reference data receiving module is adapted to receive reference data from an internal reference glucose monitor that is housed integrally with said computer system.

6. The computer system of claim 1, wherein said stability determination module evaluates an amplitude and/or variability of the sensitivity.

7. The computer system of claim 1, further comprising an interface control module comprising alerts configured to warn a user of a present and/or upcoming hypoglycemic and/or hyperglycemic event.

8. The computer system of claim 1, further comprising a processor module configured to predict one or more glucose values at one or more future points in time.

9. The computer system of claim 1, further comprising an interface control module configured to send the sensor data to an insulin pump.

10. A method for initializing a substantially continuous glucose sensor, the method comprising:

receiving sensor data from a substantially continuous glucose sensor, including one or more sensor data points;

forming one or more matched data pairs by matching reference data to substantially time corresponding sensor data; and

providing output reflective of said sensor data after a predetermined level of stability has been determined, wherein determining a stability of the substantially continuous glucose sensor comprises evaluating a level of oxygen.

11. The method of claim 10, wherein determining a stability of the substantially continuous glucose sensor comprises waiting a predetermined time period between about ten and thirty minutes.

12. The method of claim 10, wherein the step of providing output comprises providing at least one of an audible, visual or tactile output to a user based on a stability of said sensor.

13. The method of claim 12, wherein the step of providing output based on predetermined level of stability of said sensor comprises indicating at least one of a numeric estimated glucose value, a directional trend of glucose concentration, and a graphical representation of an estimated glucose value.

14. The method of claim 10, further comprising receiving reference data from a reference glucose monitor.

15. The method of claim 14, wherein receiving reference data from a reference glucose monitor comprises receiving a wired internal communication.

16. The method of claim 10, wherein determining a stability of the substantially continuous glucose sensor comprises evaluating an amplitude and/or variability of the sensitivity.

17. The method of claim 10, wherein providing output comprises alerting a user of a present and/or upcoming hypoglycemic and/or hyperglycemic event.

18. The method of claim 10, further comprising predicting one or more glucose values at one or more future points in time.

19. The method of claim 10, wherein providing output comprises sending the sensor data to an insulin pump.

20. A system for initializing a continuous glucose sensor, comprising:

a sensor data module operatively linked to an implantable continuous glucose sensor and configured to receive sensor data from said sensor; and

a processor module associated with the sensor data module and programmed to match reference data points with time-matched sensor data points to form a calibration set comprising at least one matched data pair, wherein the processor module is programmed to evaluate a stability of the implantable continuous glucose sensor, and wherein the processor module is further programmed to output information reflective of said sensor data after a predetermined level of stability has been determined, wherein said processor module is programmed to evaluate a level of oxygen to determine the stability.

21. The system of claim 20, wherein said predetermined level of stability is based on a time period since the implantable continuous glucose sensor was implanted.

22. The system of claim 20, further comprising an output module associated with said processor module and programmed to control output of sensor data.

23. The system of claim 22, wherein said output of sensor data indicates at least one of a numeric estimated glucose value, a directional trend of glucose concentration, and a graphical representation of an estimated glucose value.

24. The system of claim 20, further comprising a reference input module configured to receive reference data from a blood glucose test, wherein the reference data comprises one or more reference data points.

25. The system of claim 20, further comprising a reference glucose monitor integral with the system and wherein the system further comprises a reference input module configured to receive an internal communication from the reference glucose monitor, wherein the internal communication comprises one or more reference data points.

26. The system of claim 20, wherein said processor module is programmed to evaluate an amplitude and/or variability of the sensitivity.

27. The system of claim 20, further comprising an output module comprising alerts configured to warn a user of a present and/or upcoming hypoglycemic and/or hyperglycemic event.

28. The system of claim 20, wherein the processor module is configured to predict one or more glucose values at one or more future points in time.

29. The system of claim 20, further comprising an output module configured to send the sensor data to an insulin pump.