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

• US 9,408,566 B2
• Filed: 02/13/2013
• Issued: 08/09/2016
• 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:
  US13/766,673
• Publication Number:
  US 20130231541A1
• Time in Patent Office: 1,273 Days
• US Class Current: 1/1
• 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 measuring an analyte level, comprising:

applying, using sensor electronics, a control signal to an analyte sensor;

measuring, using the sensor electronics, a response to the control signal applied to the sensor;

determining, using the sensor electronics, an estimated sensor sensitivity based on a variance in the measured response to the control signal applied to the analyte sensor;

calibrating, using the sensor electronics, the analyte sensor using the estimated sensor sensitivity;

receiving, using the sensor electronics, a sensor data signal from the analyte sensor; and

determining, using the sensor electronics, an analyte level based on the received sensor data signal.

2. The method of claim 1, wherein calibrating the analyte sensor includes applying the control signal that varies over time to the analyte sensor.

3. The method of claim 1, wherein applying the control signal includes opening and closing the current path to the analyte sensor.

4. The method of claim 1, wherein the measured response is determined based on determining one of a working electrode current signal, a counter electrode current signal or a reference electrode current signal.

5. The method of claim 1, wherein the variance in the measured response is determined based on comparing a difference between a beginning of a half duty cycle and an end of the half duty cycle of the measured response to the control signal.

6. The method of claim 1, wherein the estimated sensor sensitivity is determined using a predetermined relationship between sensor sensitivity and the variance in the measured response.

7. The method of claim 1, wherein the estimated sensor sensitivity is determined by retrieving a predetermined sensor sensitivity corresponding to the variance in the measured response.

8. The method of claim 1, further comprising determining if the estimated sensor sensitivity is within a valid range.

9. A system for monitoring analyte concentration, comprising:

an analyte sensor;

a processor operatively coupled to the analyte sensor; and

a memory coupled to the processor, the memory storing processor executable instructions to;

apply a control signal to the analyte sensor;

measure a response to the control signal;

determine an estimated sensor sensitivity based on a variance in the measured response to the control signal applied to the analyte sensor;

calibrate the analyte sensor using the estimated sensor sensitivity;

receive a sensor data signal from the analyte sensor; and

determine an analyte level based on the received sensor data signal.

10. The system of claim 9, wherein the instructions to calibrate the analyte sensor includes an instruction to apply the control signal that varies over time to the analyte sensor.

11. The system of claim 9, wherein the instructions to apply the control signal includes an instruction to open and close the current path to the analyte sensor.

12. The system of claim 9, wherein the variance in the measured response is determined by an instruction to compare a difference between a beginning of a half duty cycle and an end of the half duty cycle of the measured response to the control signal.

13. The system of claim 9, wherein the estimated sensor sensitivity is determined by an instruction that uses a predetermined relationship between sensor sensitivity and variance in the measured response.

14. The system of claim 9, wherein the estimated sensor sensitivity is determined by an instruction to retrieve a predetermined sensor sensitivity corresponding to the variance in the measured response.

15. The system of claim 9, wherein the instructions further include an instruction to determine if the estimated sensor sensitivity is within a valid range.

16. An analyte monitoring system, comprising:

an on-body device including an analyte sensor and sensor electronics operatively coupled to the sensor; and

a receiver operative to receive sensor data from the on-body device;

wherein the sensor electronics is operative to apply a control signal to the analyte sensor, detect a measured response to the control signal, and transmit the measured response and sensor data to the receiver, and

wherein the receiver is operative to determine a variance in the detected measured response, estimate a sensitivity of the analyte sensor based on the variance in the detected measured response, and determine an analyte level based on the received sensor data.

17. The analyte monitoring system of claim 16, wherein the sensor electronics is configured to vary the level of the control signal over time applied to the sensor.

18. The analyte monitoring system of claim 16, wherein the sensor electronics is operative to apply the control signal by opening and closing the current path to the analyte sensor.

19. The analyte monitoring system of claim 16, wherein the receiver being operative to determine the variance in the detected measured response includes the receiver being operative to compare a difference between a beginning and an end of a half duty cycle of the measured response to the control signal.

20. The analyte monitoring system of claim 16, wherein the receiver being operative to estimate a sensitivity of the sensor includes the receiver being operative to use a predetermined relationship between sensor sensitivity and variance in the measured response.