Method and system for providing calibration of an analyte sensor in an analyte monitoring system

• US 9,833,181 B2
• Filed: 07/13/2016
• Issued: 12/05/2017
• Est. Priority Date: 08/09/2006
• Status: Active Grant

• Current Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories Incorporated)
• Inventors: Hayter, Gary Alan, Doniger, Kenneth J., Budiman, Erwin Satrya, Zhang, Songbiao, Mazza, John Charles
• Primary Examiner(s): Natnithithadha, Navin
• Application Number:
  US15/209,743
• Publication Number:
  US 20160317069A1
• Time in Patent Office: 510 Days
• Field of Search: 600309, 600345-366
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 5/0004 characterised by the type of physiological signal transmitted
• CPC Class Codes: A61B 5/14503 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors A61B5/1459, A61B5/1464, A61B5/1473, A61B5/1482, A61B5/14865 take precedence
• 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 5/1495 Calibrating or testing of in-vivo probes
• CPC Class Codes: G01N 27/3274 Corrective measures, e.g. error detection, compensation for temperature or hematocrit, calibration coding of calibration information G01N33/48771

Abstract

Method and apparatus for providing calibration of analyte sensor including applying a control signal, detecting a measured response to the control signal, determining a variance in the detected measured response, and estimating a sensor sensitivity based on the variance in the detected measured response is provided.

Claims

1. A method of processing analyte sensor signals, comprising:

applying a poise voltage to an analyte sensor;

while applying the poise voltage to the analyte sensor, applying a control signal to the analyte sensor;

measuring a response signal based on the poise voltage and the control signal from the analyte sensor;

estimating, with one or more processors, a sensor sensitivity based on a predetermined calculated correlation to a variance in the measured response; and

determining a calibrated analyte value based on the estimated sensor sensitivity;

wherein the control signal comprises a time-varying perturbation signal that provides for the analyte sensor a duty cycle and the variance is determined from a transient response of the analyte sensor to the control signal during the duty cycle.

2. The method of claim 1, wherein measuring the response signal includes determining a work electrode current signal.

3. The method of claim 1, wherein the control signal is a square-wave signal.

4. The method of claim 1, wherein the variance is determined from the difference in the measured response signal from the analyte sensor between a beginning and an end of an ‘

on’

period of the control signal.

5. The method of claim 1, wherein estimating the sensor sensitivity includes retrieving a predetermined sensor sensitivity associated with the determined variance in the measured response.

6. The method of claim 5, wherein the determined variance comprises a number of analog to digital counts.

7. The method of claim 1, further including determining a validity of the estimated sensor sensitivity.

8. The method of claim 7, wherein determining the validity of the estimated sensor sensitivity includes comparing the estimated sensor sensitivity to a predetermined range.

9. The method of claim 1, wherein determining the calibrated analyte value includes applying the estimated sensor sensitivity to a signal received from the analyte sensor.

10. The method of claim 1, wherein the calibrated analyte value corresponds to an analyte level in bodily fluid under a skin surface.

11. A device, comprising:

an analyte sensor;

a processor; and

a memory storing instructions which, when executed by the processor, cause the processor to;

apply a poise voltage to the analyte sensor;

while applying the poise voltage to the analyte sensor, apply a control signal to the analyte sensor;

measure a response signal based on the poise voltage and the control signal from the analyte sensor;

estimate, with the processor, a sensor sensitivity based on a predetermined calculated correlation to a variance in the measured response; and

determine a calibrated analyte value based on the estimated sensor sensitivity;

wherein the control signal comprises a time-varying perturbation signal that provides for the analyte sensor a duty cycle and the variance is determined from a transient response of the analyte sensor to the control signal during the duty cycle.

12. The device of claim 11, storing instructions which cause the processor to measure the response signal by determining a work electrode current signal.

13. The device of claim 11, wherein the control signal is a square-wave signal.

14. The device of claim 11, wherein the variance is determined from the difference in the measured response signal from the analyte sensor between a beginning and an end of an ‘

on’

period of the control signal.

15. The device of claim 11, storing instructions which cause the processor to estimate the sensor sensitivity by at least retrieving a predetermined sensor sensitivity associated with the determined variance in the measured response.

16. The device of claim 15, wherein the determined variance comprises a number of analog to digital counts.

17. The device of claim 11, storing instructions which cause the processor to determine a validity of the estimated sensor sensitivity.

18. The device of claim 17, storing instructions which cause the processor to determine the validity of the estimated sensor sensitivity by at least comparing the estimated sensor sensitivity to a predetermined range.

19. The device of claim 11, storing instructions which cause the processor to determine the calibrated analyte value by at least applying the estimated sensor sensitivity to a signal received from the analyte sensor.

20. The device of claim 11, wherein the calibrated analyte value corresponds to an analyte level in bodily fluid under a skin surface.