Method and device for providing offset model based calibration for analyte sensor

• US 10,089,446 B2
• Filed: 09/03/2013
• Issued: 10/02/2018
• Est. Priority Date: 01/29/2009
• Status: Active Grant

• Current Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories Incorporated)
• Inventors: Budiman, Erwin Satrya
• Primary Examiner(s): Brusca, John S
• APPLICATION: US 20140005968A1
• Time in patent office: 1855 Days
• Field of Search: None
• 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 5/14865 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: G06F 19/36 Computer-assisted acquisition of medical data, e.g. computerised clinical trials or questionnaires measuring analogue medical signals A61B5/00
• CPC Class Codes: G16H 10/20 for electronic clinical trials or questionnaires
• CPC Class Codes: G16H 10/40 for data related to laboratory analysis, e.g. patient specimen analysis
• CPC Class Codes: G16H 40/63 for local operation
• CPC Class Codes: Y10T 436/144444 Glucose

Abstract

Methods and devices to detect analyte in body fluid are provided. Embodiments include processing sampled data from analyte sensor, determining a single, fixed, normal sensitivity value associated with the analyte sensor, estimating a windowed offset value associated with the analyte sensor for each available sampled data cluster, computing a time varying offset based on the estimated windowed offset value, and applying the time varying offset and the determined normal sensitivity value to the processed sampled data to estimate an analyte level for the sensor.

Claims

1. A method, comprising:

positioning a first portion of an analyte sensor in fluid contact with bodily fluid under a skin surface;

electrically coupling a second portion of the analyte sensor with a power source to provide power to the analyte sensor while the first portion of the analyte sensor is positioned in fluid contact with the bodily fluid under the skin surface;

generating, with the analyte sensor, signals corresponding to an analyte level in the bodily fluid;

generating a sampled data based on the signals from the analyte sensor;

determining that the sampled data is associated with an abnormal sensor sensitivity event;

estimating an offset value based on the sampled data;

determining a time varying offset based on the estimated offset value;

estimating the analyte level based on the determined time varying offset; and

providing a predictive alarm to a user based on the estimated analyte level.

2. The method of claim 1, further including performing retrospective lag correction of the sampled data.

3. The method of claim 1, further including smoothing the sampled data.

4. The method of claim 1, further including performing temperature correction for the sampled data.

5. The method of claim 1, further including determining a sensitivity value associated with the analyte sensor.

6. The method of claim 5, wherein determining the sensitivity value includes pairing the sampled data with one or more time corresponding reference measurement values.

7. The method of claim 5, further including applying the sensitivity value to the sampled data.

15. The method of claim 1, further including outputting on a display device information associated with the estimated analyte level.

16. The method of claim 15, wherein the information associated with the estimated analyte level includes one or more of a visual or an audible representation corresponding to the estimated analyte level, a rate of change of the estimated analyte level, and a direction of the rate of change of the estimated analyte level.

17. The method of claim 1, wherein the abnormal sensor sensitivity event includes an early signal attenuation event.

8. An apparatus, comprising:

an analyte sensor having a first portion and a second portion, the first portion positioned in fluid contact with a bodily fluid under a skin surface, the analyte sensor configured to generate signals corresponding to an analyte level in the bodily fluid;

a power source electrically coupled to the second portion of the analyte sensor to provide power to the analyte sensor for generating the signals while the first portion of the analyte sensor is in fluid contact with the bodily fluid under the skin surface;

a data communication interface;

one or more processors operatively coupled to the data communication interface and the analyte sensor; and

a memory operatively coupled to the one or more processors for storing instructions which, when executed by the one or more processors, causes the one or more processors to generate a sampled data based on the signals from the analyte sensor, and to determine that the sampled data is associated with an abnormal sensor sensitivity event, to estimate an offset value based on the sampled data, to determine a time varying offset based on the estimated offset value, to estimate the analyte level based on the determined time varying offset, and provide a predictive alarm to a user based on the estimated analyte level.

9. The apparatus of claim 8, wherein the memory for storing instructions, when executed by the one or more processors, causes the one or more processors to perform retrospective lag correction of the sampled data.

10. The apparatus of claim 8, wherein the memory for storing instructions, when executed by the one or more processors, causes the one or more processors to smooth the sampled data.

11. The apparatus of claim 8, wherein the memory for storing instructions, when executed by the one or more processors, causes the one or more processors to perform temperature correction for the sampled data.

12. The apparatus of claim 8, wherein the memory for storing instructions, when executed by the one or more processors, causes the one or more processors to determine a sensitivity value associated with the analyte sensor.

13. The apparatus of claim 12, wherein the memory for storing instructions, when executed by the one or more processors, causes the one or more processors to pair the sampled data with one or more time corresponding reference measurement values.

14. The apparatus of claim 12, wherein the memory for storing instructions, when executed by the one or more processors, causes the one or more processors to apply the sensitivity value to the sampled data.

18. The apparatus of claim 8, wherein the data communication interface wirelessly communicates the estimated analyte level to a receiver having a display to output information associated with the estimated analyte level on the display.

19. The apparatus of claim 18, wherein the information associated with the estimated analyte level includes one or more of a visual or an audible representation corresponding to the estimated analyte level, a rate of change of the estimated analyte level, and a direction of the rate of change of the estimated analyte level.

20. The apparatus of claim 8, wherein the abnormal sensor sensitivity event includes an early signal attenuation event.