System and methods for processing analyte sensor data for sensor calibration

• US 20060258929A1
• Filed: 03/09/2006
• Published: 11/16/2006
• Est. Priority Date: 03/10/2005
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Goode, Paul V. Jr., Brauker, James H., Kamath, Apurv U.
• Granted Patent: US 7,920,906 B2
• Time in Patent Office: Days
• US Class Current: 600/345
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/14503 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors A61B5/1459, A61B5/1464, A61B5/1473, A61B5/1482, A61B5/14865 take precedence
• CPC Class Codes: A61B 5/1451 for interstitial fluid
• 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 5/14735 comprising an immobilised reagent
• CPC Class Codes: A61B 5/1486 using enzyme electrodes, e.g. with immobilised oxidase
• 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: 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 are disclosed, including initiating calibration, updating calibration, evaluating clinical acceptability of reference and sensor analyte data, and evaluating the quality of sensor calibration. The sensor can be calibrated using a calibration set of one or more matched sensor and reference analyte data pairs. Reference data resulting from benchtop testing an analyte sensor prior to its insertion can be used to provide initial calibration of the sensor data. Reference data from a short term continuous analyte sensor implanted in a user can be used to initially calibrate or update sensor data from a long term continuous analyte sensor.

Claims

1. A method for calibrating an analyte sensor, the method comprising:

receiving sensor data from a first analyte sensor;

receiving sensor data from a second analyte sensor; and

calibrating the sensor data from the first analyte sensor using the sensor data from the second analyte sensor.

2. The method of claim 1, wherein the first analyte sensor is a long term substantially continuous analyte sensor and the second analyte sensor is a short term substantially continuous sensor.

3. The method of claim 2, further comprising:

receiving sensor data from a set of substantially continuous analyte sensors, the set of sensors comprising one or more short term sensors, and the set of sensors being employed in a host in series such that the overall time period during which sensor data from the set of sensors is received is greater than the useful lifespan of one of the short term sensors; and

calibrating the sensor data from the first analyte sensor using the sensor data from the second analyte sensor and the set of sensors.

4. The method of claim 2, wherein calibrating the long term sensor data further comprises using sensor data from the short term analyte sensor to update the calibration of the long term analyte sensor.

5. The method of claim 1, wherein the first analyte sensor and the second analyte sensor are each glucose sensors.

6. The method of claim 1, wherein the sensor data from the first analyte sensor comprises at least one sensor data point, wherein the sensor data from the second analyte sensor comprises at least one sensor data point, and wherein calibrating the sensor data further comprises forming at least one matched data pair by matching at least one sensor data point from the first analyte sensor to at least one sensor data point from the second analyte sensor and forming a calibration set comprising at least one matched data pair.

7. The method of claim 1, wherein the sensor data from the first analyte sensor comprises at least six sensor data points, wherein the sensor data from the second analyte sensor comprises at least six sensor data points, and wherein calibrating the sensor data further comprises forming at least six matched data pairs by matching each sensor data point from the first analyte sensor to a corresponding sensor data point from the second analyte sensor and forming a calibration set comprising at least six matched data pairs.

8. The method of claim 1, further comprising:

constructing a first curve from the sensor data from the first analyte sensor; and

constructing a second curve from the sensor data from the second analyte sensor;

wherein calibrating the sensor data from the first analyte sensor comprises matching the first curve with the second curve.

9. The method of claim 1, wherein the first analyte sensor is a short term substantially continuous analyte sensor and the second analyte sensor is a short term substantially continuous analyte sensor.

10. The method of claim 1, wherein the first analyte sensor is a long term substantially continuous analyte sensor and the second analyte sensor is a long term substantially continuous analyte sensor.

11. The method of claim 1, wherein the first analyte sensor is a short term substantially continuous analyte sensor and the second analyte sensor is a long term substantially continuous analyte sensor.

12. The method of claim 1, further comprising:

receiving data from a non-continuous reference source,

wherein said calibrating further comprises using data from the non-continuous reference source to calibrate the sensor data from the second analyte sensor.

13. The method of claim 12, wherein the non-continuous reference source is a blood glucose monitor.

14. The method of claim 12, wherein the non-continuous reference source is an in-vitro calibration.

15. The method of claim 12, wherein the non-continuous reference source is an optical sensor.

16. A method of processing data from a substantially continuous analyte sensor, the method comprising:

testing an analyte sensor prior to insertion into a host to determine at least one sensor data characteristic;

employing the analyte sensor in the host;

receiving sensor data from the analyte sensor; and

calibrating the sensor data using the sensor data characteristic.

17. The method of claim 16, wherein the substantially continuous analyte sensor is a short term sensor.

18. The method of claim 16, wherein the substantially continuous analyte sensor is an implantable long term sensor.

19. The method of claim 16, further comprising

receiving reference data from a reference analyte monitor, the reference data comprising at least one reference data characteristic;

and

calibrating the sensor data using the reference data characteristic.

20. A system for calibrating a substantially continuous analyte sensor, comprising:

a first substantially continuous analyte sensor;

a second substantially continuous analyte sensor;

a first sensor data receiving module operably linked to said first sensor and configured to receive at least one sensor data point from said first sensor;

a second sensor data receiving module operably linked to said second sensor and configured to receive at least one sensor data point from said second sensor; and

a processor module in data communication with said first sensor data receiving module linked to said first sensor and further in data communication with said second sensor data receiving module linked to said second sensor, said processor module configured to calibrate the sensor data from the first sensor using sensor data from the second sensor.

21. The system of claim 20, wherein the processor module is further configured to match at least one time-matched data point from said first analyte sensor and said second analyte sensor to form at least one calibration set for calibrating the first analyte sensor comprising at least one matched data pair.

22. The system of claim 20, wherein the first analyte sensor is a long term substantially continuous analyte sensor and the second analyte sensor is a short term substantially continuous analyte sensor.

23. The system of claim 20, wherein the first analyte sensor is a short term substantially continuous analyte sensor and the second analyte sensor is a short term substantially continuous analyte sensor.

24. The system of claim 20, wherein the first analyte sensor is a long term substantially continuous analyte sensor and the second analyte sensor is a long term substantially continuous analyte sensor.

25. The system of claim 20, wherein the first analyte sensor is a short term substantially continuous analyte sensor and the second analyte sensor is a long term substantially continuous analyte sensor.

26. The system of claim 20, wherein said first substantially continuous analyte sensor and said second substantially continuous analyte sensor are each glucose sensors.

27. A method for simultaneously utilizing at least two analyte sensors, the method comprising:

receiving sensor data from a first analyte sensor;

receiving sensor data from a second analyte sensor; and

processing the sensor data from the first analyte sensor using the sensor data from the second analyte sensor.

28. The method of claim 27, wherein the sensor data from the second analyte sensor comprises time delay information, and wherein processing comprises modifying the sensor data from a first analyte sensor responsive to the time delay information.

29. The method of claim 27, wherein the processing comprises utilizing the sensor data from the second analyte sensor to assess performance of the first analyte sensor.

30. The method of claim 27, wherein the first analyte sensor is a transcutaneous sensor.

31. The method of claim 27, wherein the first analyte sensor is a wholly implantable sensor.

32. The method of claim 31, wherein the second analyte sensor is a transcutaneous sensor.

33. The method of claim 27, wherein the second analyte sensor is a transcutaneous sensor.

34. The method of claim 27, wherein the second analyte sensor is a wholly implantable sensor.

35. The method of claim 27, wherein processing comprises calibrating the first analyte sensor.