SYSTEM AND METHODS FOR PROCESSING ANALYTE SENSOR DATA

• US 20120215462A1
• Filed: 04/27/2012
• Published: 08/23/2012
• Est. Priority Date: 08/01/2003
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Brauker, James H., Thrower, James P., Goode, Paul V. Jr., Kamath, Apur U.
• Granted Patent: US 8,761,856 B2
• Time in Patent Office: Days
• US Class Current: 702/19
• CPC Class Codes: A61B 5/0015 characterised by features of the telemetry system
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• 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 5/7275 Determining trends in physiological measurement data; Predicting development of a medical condition based on physiological measurements, e.g. determining a risk factor
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: G16H 40/40 for the management of medical equipment or devices, e.g. scheduling maintenance or upgrades
• 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 processing reference glucose values, the method comprising:

receiving sensor data from a continuous glucose sensor;

receiving reference data from a reference glucose monitor, the reference data corresponding in time to the sensor data;

determining, using a processor module, an acceptability of the reference data, the determination comprising evaluating a deviation between the reference data and the sensor data by comparing the sensor data to a range of acceptable values, wherein the range of acceptable values varies depending upon a glucose concentration of a host as indicated by the reference data; and

processing, using the processor module, the reference data responsive to the acceptability determination.

2. The method of claim 1, wherein the processing comprises calibrating the sensor data based at least in part on the reference data when it is determined that the reference data is acceptable.

3. The method of claim 1, wherein the processing comprises requesting new reference data when it is determined that the reference data is unacceptable by prompting a user to provide the new reference data, wherein the prompting comprises prompting on a user interface.

4. The method of claim 1, wherein the range of acceptable values complies with clinical acceptability standards based on one of a Clarke Error Grid or a Consensus Grid.

5. The method of claim 1, wherein the sensor data and the range of acceptable values are both in units of glucose concentration.

6. The method of claim 1, further comprising forming, using the processor module, a matched data pair by matching the at least one sensor data point of the sensor data and at least one time corresponding reference data point of the reference data, wherein the at least one sensor data point and the at least one reference data point of the matched data pair are in units of blood glucose concentration.

7. The method of claim 1, wherein the determining is performed in real time during continuous glucose sensing of the glucose sensor.

8. The method of claim 1, wherein the reference glucose monitor is a self-monitored blood analyte test and wherein the continuous glucose sensor is an implantable glucose sensor.

9. The method of claim 1, further comprising periodically receiving additional reference data during real-time continuous glucose sensing of the glucose sensor.

10. The method of claim 1, wherein the processing comprises calculating a conversion function based at least in part on the reference data only when it is determined that the reference data is acceptable, and converting the sensor data to an estimated blood glucose concentration value based on the conversion function.

11. The method of claim 10, wherein the processing further comprises causing a display to display information representative of the estimated blood glucose concentration value, the estimated blood glucose concentration value indicative of a real-time blood glucose concentration of a host.

12. A system for processing reference glucose values, the system comprising:

a sensor data module configured to receive sensor data from a continuous glucose sensor;

a receiving module configured to receive reference data from a reference glucose monitor; and

a processor module configured to;

determine an acceptability of the reference data, the determination comprising evaluating a deviation between the reference data and the sensor data by comparing the sensor data to a range of acceptable values, wherein the range of acceptable deviation values varies depending upon a glucose concentration of a host as indicated by the reference data, and

process the reference data responsive to the acceptability determination.

13. The system of claim 12, further comprising a calibration module configured to calibrate the sensor data based at least in part on the reference data when it is determined that the reference data is acceptable.

14. The system of claim 12, wherein the range of values complies with clinical acceptability standards based on one of a Clarke Error Grid or a Consensus Grid.

15. The system of claim 12, wherein the range of values comprises numerical values in units of glucose concentration.

16. The system of claim 12, wherein the processor module is further configured to form a matched data pair by matching the at least one sensor data point of the sensor data and the at least one time corresponding reference data point of the reference data, wherein the at least one sensor data point and the at least one reference data point of the matched data pair are in units of blood glucose concentration.

17. The system of claim 12, wherein the processor module is further configured to calibrate the sensor data based on the reference data when it is determined that the reference data is acceptable and prompting a user via a user interface for new reference data when it is determined that the reference data is unacceptable, wherein determining that the reference data is acceptable is based at least in part on the sensor data falling within the range and determining that the reference data is unacceptable is based at least in part on the sensor data falling outside of the range.

18. The system of claim 12, wherein determining an acceptability is performed in real time during continuous glucose sensing of the glucose sensor.

19. The system of claim 12, wherein the reference glucose monitor is a self-monitored blood analyte test and wherein the continuous glucose sensor is an implantable glucose sensor.

20. The system of claim 12, wherein processing the reference data responsive to the acceptability determination includes:

forming a matched data pair using the reference data and the sensor data;

calculating a conversion function based at least in part on a statistical association of the matched data pair with additional matched data pairs;

converting the sensor data to an estimated real-time blood glucose concentration value based on the conversion function; and

displaying information on a display representative of the estimated blood glucose concentration value.