SYSTEM AND METHODS FOR PROCESSING ANALYTE SENSOR DATA

• US 20080183061A1
• Filed: 04/04/2008
• Published: 07/31/2008
• Est. Priority Date: 08/01/2003
• Status: Abandoned Application

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Goode, Paul V., Kamath, Apurv U., Brauker, James H.
• Application Number:
  US12/098,359
• Publication Number:
  US 20080183061A1
• 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 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 method for evaluating clinical acceptability of at least one of reference and sensor analyte data, the method comprising:

receiving a data stream from an analyte sensor, including one or more sensor data points;

receiving reference data from a reference analyte monitor, including one or more reference data points; and

evaluating the clinical acceptability at least one of said reference and sensor analyte data using substantially time corresponding reference or sensor data, wherein said at least one of said reference and sensor analyte data is evaluated for deviation from its substantially time corresponding reference or sensor data and clinical risk associated with that deviation based on the glucose value indicated by at least one of said sensor and reference data.

2. The method of claim 1, further comprising providing an output through a user interface responsive to said clinical acceptability evaluation.

3. The method of claim 2, wherein the step of providing an output includes alerting the user based on said clinical acceptability evaluation.

4. The method of claim 2, wherein the step of providing an output includes altering the user interface based on said clinical acceptability evaluation.

5. The method of claim 4, wherein the step of altering the user interface includes at least one of providing color-coded information, trend information, directional information, and fail-safe information.

6. The method of claim 1, wherein the step of evaluating the clinical acceptability includes using one of a Clarke Error Grid, a mean absolute difference calculation, a rate of change calculation, a consensus grid, and a standard clinical acceptance test.

7. The method of claim 1, further comprising requesting additional reference data if said clinical acceptability evaluation determines clinical unacceptability.

8. The method of claim 7, further comprising repeating the clinical acceptability evaluation step for said additional reference data.

9. A computer system for evaluating clinical acceptability of at least one of reference and sensor analyte data, the computer system comprising:

a sensor data receiving module that receives a data stream comprising a plurality of time spaced sensor data points from a substantially continuous analyte sensor;

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

a clinical acceptability evaluation module that evaluates at least one of said reference and sensor analyte data using substantially time corresponding reference and sensor data, wherein said at least one of said reference and sensor analyte data is evaluated for deviation from its substantially time corresponding reference or sensor data and clinical risk associated with that deviation based on the glucose value indicated by at least one of said sensor and reference data.

10. The computer system of claim 9, further comprising an interface control module that controls the user interface based on said clinical acceptability evaluation.

11. The computer system of claim 10, wherein said interface control module alerts the user based on said clinical acceptability evaluation.

12. The computer system of claim 10, wherein said interface control module alters the user interface based on said clinical acceptability evaluation.

13. The computer system of claim 12, wherein said interface control module alters the user interface by providing at least one of providing color-coded information, trend information, directional information, and fail-safe information.

14. The computer system of claim 9, wherein said clinical acceptability evaluation module uses one of a Clarke Error Grid, a mean absolute difference calculation, a rate of change calculation, a consensus grid, and a standard clinical acceptance test to evaluate clinical acceptability.

15. The computer system of claim 10, wherein said interface control module that requests additional reference data if said clinical acceptability evaluation determines clinical unacceptability.

16. The computer system of claim 15, wherein said interface control module evaluates said additional reference data using clinical acceptability evaluation module.

17. The computer system of claim 9, further comprising a fail-safe module that controls the user interface responsive to the clinical module evaluating clinical unacceptability

18. A method for evaluating clinical acceptability of at least one of reference and sensor analyte data, the method comprising:

receiving a data stream from an analyte sensor, including one or more sensor data points;

receiving reference data from a reference analyte monitor, including one or more reference data points; and

evaluating the clinical acceptability at least one of said reference and sensor analyte data using substantially time corresponding reference and sensor data, including using a Clarke Error Grid.

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

receiving a signal from a glucose sensor, the signal comprising one or more sensor data points;

receiving reference data from a reference glucose monitor, the reference data comprising one or more reference data points;

evaluating a clinical acceptability of at least one of the reference data and the sensor data using substantially time corresponding reference data or sensor data, wherein at least one of the reference data and the sensor data is evaluated for deviation from substantially time corresponding reference data or sensor data, and wherein a clinical risk associated with that deviation is based on the glucose value indicated by at least one of the sensor data and the reference data; and

outputting information to a user interface, wherein the information is reflective of the sensor data responsive to the step of evaluating the clinical acceptability.

20. The method of claim 19, wherein the step of outputting information comprises altering the user interface responsive to a result of the clinical acceptability evaluation below a predetermined threshold.

21. The method of claim 20, wherein the step of altering the user interface comprises at least temporarily discontinuing a display of sensor data on the user interface

22. The method of claim 20, wherein the step of altering the user interface comprises providing at least one of color-coded information, trend information, directional information, a gauge, and fail-safe information.

23. The method of claim 19, further comprising requesting one or more reference data points from a user responsive to a result of the clinical acceptability evaluation below a predetermined threshold.

24. The method of claim 19, wherein the step of outputting information comprises controlling a plurality of different user interface screens in response to a predetermined level of clinical acceptability obtained from the evaluating step.

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

a sensor data module configured to receive a signal from a continuous glucose sensor, the signal comprising one or more sensor data points;

a reference input module configured to receive reference data from a reference glucose monitor, the reference data comprising one or more reference data points;

a processor module configured to evaluate a clinical acceptability of at least one of the reference data and the sensor data using substantially time corresponding reference data or sensor data, wherein at least one of the reference data and the sensor data is evaluated for deviation from substantially time corresponding reference data or sensor data, and wherein a clinical risk associated with that deviation based on the glucose value is indicated by at least one of the sensor data and the reference data; and

an output module configured to output information to a user interface, wherein the information is reflective of the sensor data responsive to the step of evaluating the clinical acceptability.

26. The system of claim 25, wherein the output module is configured to alter the user interface responsive to a result of the clinical acceptability evaluation below a predetermined threshold.

27. The system of claim 25, wherein the output module is configured to alter the user interface by at least temporarily discontinuing a display of sensor data on the user interface

28. The system of claim 25, wherein the output module is configured to alter the user interface by providing at least one of color-coded information, trend information, directional information, a gauge, and fail-safe information.

29. The system of claim 25, wherein the processor module is configured to request one or more reference data points from a user responsive to a result of the clinical acceptability evaluation below a predetermined threshold.

30. The system of claim 25, wherein the processor module is configured to control a plurality of different user interface screens in response to a predetermined level of clinical acceptability obtained from the evaluating step.