Analyte sensor with lag compensation

• US 9,332,934 B2
• Filed: 02/08/2013
• Issued: 05/10/2016
• Est. Priority Date: 10/23/2007
• Status: Active Grant

• Current Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories)
• Original Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories)
• Inventors: Hayter, Gary Alan, Doniger, Kenneth J., Budiman, Erwin Satrya
• Primary Examiner(s): Natnithithadha, Navin
• Application Number:
  US13/763,518
• Publication Number:
  US 20130178727A1
• Time in Patent Office: 1,187 Days
• US Class Current: 1/1
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 2560/0252 using ambient temperature
• CPC Class Codes: A61B 5/0004 characterised by the type of physiological signal transmitted
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• 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 5/1486 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: A61B 5/7221 Determining signal validity, reliability or quality A61B5/7207 and A61B5/7217 take precedence
• CPC Class Codes: G01N 33/48792 Data management, e.g. communication with processing unit for in vivo diagnostics A61B5/0002; transmission systems for measured values G08C
• CPC Class Codes: G16H 40/40 for the management of medical equipment or devices, e.g. scheduling maintenance or upgrades

Abstract

In particular embodiments, methods, devices and systems including calibrating analyte data associated with a monitored analyte level received from an analyte sensor based on a reference measurement, determining a lag time constant associated with the calibrated analyte data, and performing lag correction of the calibrated analyte data based on the determined time lag constant are disclosed.

Claims

1. A computer implemented method for execution using one or more processors, the method comprising:

receiving analyte data obtained from an analyte sensor in fluid contact with interstitial fluid under a skin layer;

determining an analyte level in the interstitial fluid based at least in part on a nominal sensitivity associated with the analyte sensor and the received analyte data;

determining a lag time constant associated with the determined analyte level of a user;

performing lag correction of the determined analyte level based at least in part on the determined lag time constant;

updating a rate of change of the analyte level;

determining that the received analyte data has reached a predetermined count; and

modifying the lag corrected analyte level based on the updated rate of change of the analyte level and the determination that the received analyte data has reached the predetermined count.

2. The method of claim 1, further including outputting an indication associated with the lag corrected analyte level.

3. The method of claim 1, wherein the analyte level is a glucose level.

4. The method of claim 1, wherein the nominal sensitivity associated with the analyte sensor is determined prior the analyte sensor positioned in fluid contact with the interstitial fluid.

5. The method of claim 1, wherein performing lag correction of the analyte level is further based at least in part on the determined rate of change of the analyte level.

6. The method of claim 1, wherein determining the analyte level is further based at least in part on an average of at least two received analyte data.

7. The method of claim 1, wherein the subsequently received analyte data is updated based on the modified lag corrected analyte level.

8. A method performed using one or more processors, the method comprising:

receiving analyte data obtained from an analyte sensor in fluid contact with interstitial fluid under a skin layer;

determining an analyte level of the interstitial fluid based at least in part on a nominal sensitivity associated with the analyte sensor and the received analyte data;

estimating a lag time based on a time constant component or a time shift component associated with the determined analyte level of the interstitial fluid;

updating a rate of change of the analyte level;

determining a count has reached a predetermined count; and

modifying the lag corrected analyte level based on the updated rate of change of the analyte level and the determination that the count has reached the predetermined count.

9. The method of claim 8, further including performing lag correction of the determined analyte level based on one or more of the estimated lag time or the rate of change of the analyte level.

10. The method of claim 8, wherein determining the analyte level is based at least in part on an average of at least two received analyte data.

11. The method of claim 8, wherein subsequently received analyte data is updated based on the modified lag corrected analyte level.

12. An apparatus, comprising:

an analyte sensor;

one or more processors in signal communication with the analyte sensor; and

a memory coupled to the one or more processors, the memory for storing instructions which causes the one or more processors to receive analyte data obtained from the analyte sensor in fluid contact with interstitial fluid under a skin layer, determine an analyte level in the interstitial fluid based at least in part on a nominal sensitivity associated with the analyte sensor and the received analyte data, determine a lag time constant associated with the determined analyte level, perform lag correction of the determined analyte level based at least in part on the determined lag time constant, update a rate of change of the analyte level, determine that a count associated with the received analyte data has reached a predetermined count, and modify the lag corrected analyte level based on the updated rate of change of the analyte level and the determination that the count associated with the received analyte data has reached the predetermined count.

13. The apparatus of claim 12, wherein the memory coupled to the one or more processors, the memory for storing instructions which causes the one or more processors to output an indication associated with the lag corrected analyte level.

14. The apparatus of claim 12, wherein the analyte level is a glucose level.

15. The apparatus of claim 12, wherein the nominal sensitivity associated with the analyte sensor is determined prior to the analyte sensor positioned in fluid contact with the interstitial fluid.

16. The apparatus of claim 12, wherein the memory coupled to the one or more processors, the memory for storing instructions which causes the one or more processors to perform lag correction of the analyte level further based at least in part on the determined rate of change of the analyte level.

17. The apparatus of claim 12, wherein the memory coupled to the one or more processors, the memory for storing instructions which causes the one or more processors to determine the analyte level further based at least in part on an average of at least two received analyte data.

18. The apparatus of claim 12, wherein subsequently received analyte data is updated based on the modified lag corrected analyte level.