SYSTEM AND METHODS FOR PROCESSING ANALYTE SENSOR DATA

• US 20100168544A1
• Filed: 12/11/2009
• Published: 07/01/2010
• Est. Priority Date: 08/01/2003
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Kamath, Apurv Ullas, Brauker, James H., Goode, Paul V. JR.
• Granted Patent: US 8,676,287 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 5/1495 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 method for matching continuous analyte sensor data with reference data, the method comprising:

receiving, with an electronic device, sensor data from a continuous analyte sensor, wherein the sensor data comprises one or more sensor data points;

receiving reference data from a reference analyte monitor, wherein the reference data comprises one or more reference data points;

forming a matched pair by pairing a sensor value with a reference value; and

calibrating sensor data in real-time, wherein the sensor data is calibrated using at least the matched pair.

2. The method of claim 1, wherein forming the matched pair comprises averaging a plurality of reference data points to obtain the reference value.

3. The method of claim 2, wherein averaging is performed by using at least one of an equally weighted average, a non-equally weighted average, a mean-value, or a median.

4. The method of claim 1, wherein forming the matched pair comprises averaging a plurality of time corresponding sensor data points to obtain the sensor value.

5. The method of claim 4, wherein averaging is performed by using at least one of an equally weighted average, a non-equally weighted average, a mean-value, or a median.

6. The method of claim 1, wherein forming the matched pair comprises averaging a plurality of reference data points to obtain the reference value and averaging a plurality of sensor data points to obtain the sensor value.

7. The method of claim 1, wherein the sensor value is measured at least about 5 minutes after the reference value is measured.

8. The method of claim 1, wherein the sensor value is measured at a time period after the reference value is measured, wherein the time period is configured to compensate for a time lag caused by at least one of a data smoothing filter or a physiological time lag.

9. The method of claim 1, wherein forming the matched pair comprises evaluating a plurality of matched pairs, wherein the plurality of matched pairs are obtained by matching a reference data point against a plurality of time-spaced sensor data points.

10. The method of claim 9, wherein forming the matched pair comprises selecting, from the plurality of matched pairs, a matched pair with the best correlation.

11. The method of claim 1, wherein the continuous analyte sensor is a continuous glucose sensor.

12. A system for matching continuous analyte sensor data with reference data, the system comprising:

a sensor data module configured to receive sensor data from a continuous analyte sensor, wherein the sensor data comprises one or more sensor data points;

a reference data module configured to receive reference data from a reference analyte monitor, wherein the reference data comprises one or more reference data points; and

a processor module configured to form a matched pair by pairing a sensor value with a reference value, wherein the processor module is further configured to calibrate sensor data in real-time, and wherein the sensor data is calibrated at least in part by using the matched pair.

13. The system of claim 12, wherein the processor module is configured to average a plurality of reference data points to obtain the reference value.

14. The system of claim 13, wherein the processor module is configured to average the plurality of reference data points using at least one of an equally weighted average, a non-equally weighted average, a mean-value, or a median.

15. The system of claim 12, wherein the processor module is configured to average a plurality of time corresponding sensor data points to obtain the sensor value.

16. The system of claim 15, wherein the processor module is configured to average the plurality of sensor data points using at least one of an equally weighted average, a non-equally weighted average, a mean-value, or a median.

17. The system of claim 12, wherein the processor module is configured to average a plurality of reference data points to obtain the reference value and to average a plurality of sensor data points to obtain the sensor value.

18. The system of claim 12, wherein the sensor value is measured at least about 10 minutes after the reference value is measured.

19. The system of claim 12, wherein the sensor value is measured at a time period after the reference value is measured, wherein the time period is configured to compensate for a time lag caused by at least one of a data smoothing filter and a physiological time lag.

20. The system of claim 12, wherein the processor module is further configured to evaluate a plurality of matched pairs, wherein the plurality of matched pairs are obtained by matching a reference data point against a plurality of time-spaced sensor data points.

21. The system of claim 20, wherein the processor module is further configured to select, from the plurality of matched pairs, a matched pair with a best correlation.

22. The system of claim 12, wherein the continuous analyte sensor is a continuous glucose sensor.