Analyte sensor sensitivity attenuation mitigation

• US 10,045,739 B2
• Filed: 03/23/2015
• Issued: 08/14/2018
• Est. Priority Date: 09/30/2008
• 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, Mazza, John Charles, Doniger, Kenneth J.
• Primary Examiner(s): WESTON, TIFFANY C
• Application Number:
  US14/665,603
• Publication Number:
  US 20150190097A1
• Time in Patent Office: 1,240 Days
• CPC Class Codes: A61B 2505/07 Home care
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 2560/0481 in implanted apparatus
• CPC Class Codes: A61B 2562/043 in a linear array
• CPC Class Codes: A61B 2562/046 in a matrix array
• CPC Class Codes: A61B 5/002 Monitoring the patient using a local or closed circuit, e.g. in a room or building A61B5/0017 takes precedence
• CPC Class Codes: A61B 5/1451 for interstitial fluid
• CPC Class Codes: A61B 5/14517 for sweat
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• 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 5/14865 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

Abstract

Method and apparatus for receiving a first signal from a first working electrode of a glucose sensor positioned at a first predetermined position under the skin layer, receiving a second signal from a second working electrode of the glucose sensor positioned at a second predetermined position under the skin layer, the second signal received substantially contemporaneous to receiving the first signal, detecting a dropout in the signal level associated with one of the first or second signals, comparing the first signal and the second signal to determine a variation between the first and second signals, and confirming one of the first or second signals as a valid glucose sensor signal output when the determined variation between the first and the second signals is less than a predetermined threshold level are provided.

Claims

1. An apparatus, comprising:

a glucose sensor having a first sensing area and a second sensing area configured for fluid contact with biofluid under a skin surface for monitoring glucose level in the biofluid;

one or more processors operatively coupled to the glucose sensor; and

a memory operatively coupled to the one or more processors and configured to store instructions which, when executed by the one or more processors, receives a first and second signals respectively from the first and second sensing areas of the glucose sensor, detects a dropout in a signal level associated with one of the first signal or the second signal, compares the first signal and the second signal to determine a variation between the first signal and the second signal, the dropout is detected, confirms the one of the first signal or the second signal as a valid glucose sensor signal corresponding to the monitored glucose level when the determined variation between the first signal and the second signal is less than a predetermined threshold level, determines a glucose level based on the valid glucose sensor signal, and provides the determined glucose level for output on a display.

2. The apparatus of claim 1, wherein when the variation between the first signal and the second signal is not less than the predetermined threshold level, the memory storing instructions which, when executed by the one or more processors, confirms the first signal or the second signal as invalid sensor output signals.

3. The apparatus of claim 1, wherein when the variation between the first signal and the second signal exceeds the predetermined threshold level, the memory storing instructions which, when executed by the one or more processors, performs a rate of change determination of signals from one of the first sensing area or the second sensing area, and confirms the one of the first signal or the second signal as the valid glucose sensor signal when the determined rate of change level is less than a predetermined rate threshold level.

4. The apparatus of claim 3, wherein the rate of change determination is performed on signals, from the one of the first or the second sensing areas, that are larger in magnitude.

5. The apparatus of claim 3, wherein, when the determined rate of change level is greater than the predetermined rate threshold level, the memory storing instructions which, when executed by the one or more processors, confirms the first and the second signals as invalid sensor signals.

6. The apparatus of claim 1, wherein the biofluid includes one or more of interstitial fluid or dermal fluid.

7. The apparatus of claim 1, wherein the valid glucose sensor signal is the larger signal between the first signal and the second signal.

8. The apparatus of claim 1, wherein the memory operatively coupled to the one or more processors and configured to store instructions which, when executed by the one or more processors, confirms the one of the first or second signals is an invalid signal.

9. The apparatus of claim 1, wherein when the variation between the first and the second signals exceeds the predetermined threshold level, the memory operatively coupled to the one or more processors and configured to store instructions which, when executed by the one or more processors, confirms the first and second signals as invalid sensor output signal.

10. The apparatus of claim 1, wherein at least a portion of the glucose sensor with the first sensing area and the second sensing area are in fluid contact with the biofluid.

11. The apparatus of claim 1, wherein the first sensing area is separated by a predetermined distance from the second sensing area such that glucose sensor signal attenuation is minimized.

12. The apparatus of claim 1, wherein the first sensing area is disposed on a first surface of the glucose sensor and the second sensing area is disposed on a second surface of the glucose sensor.

13. The apparatus of claim 12, wherein the first surface and the second surface are co-planar.

14. The apparatus of claim 12, wherein the first surface and the second surface are on opposing sides of the glucose sensor.

15. The apparatus of claim 1, wherein the glucose sensor is configured to require no user calibration.

16. The apparatus of claim 1, wherein the glucose sensor is factory calibrated.