Method, System and Computer Program Product for Real-Time Detection of Sensitivity Decline in Analyte Sensors

• US 20140244216A1
• Filed: 04/30/2014
• Published: 08/28/2014
• Est. Priority Date: 10/26/2006
• Status: Active Grant

• Current Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories Incorporated), University of Virginia Patent Foundation (University of Virginia)
• Original Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories Incorporated), University of Virginia Patent Foundation (University of Virginia)
• Inventors: Breton, Marc D., Kovatchev, Boris P., Budiman, Erwin Satrya, Doniger, Kenneth J.
• Granted Patent: US 9,882,660 B2
• Time in Patent Office: Days
• US Class Current: 702/189
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• 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 5/14503 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 5/1473 invasive, e.g. introduced into the body by a catheter A61B5/1482 takes precedence
• CPC Class Codes: G16H 10/40 for data related to laboratory analysis, e.g. patient specimen analysis
• CPC Class Codes: G16H 40/60 for the operation of medical equipment or devices
• CPC Class Codes: G16H 40/67 for remote operation
• CPC Class Codes: H04B 17/00 Monitoring; Testing of line transmission systems H04B3/46; arrangements for monitoring or testing transmission systems employing electromagnetic waves other than radio waves H04B10/07

Abstract

Method, system and computer program product for providing real time detection of analyte sensor sensitivity decline is continuous glucose monitoring systems are provided.

Claims

1. A computer implemented method for detecting early signal attenuation, comprising:

receiving a first plurality of analyte sensor related signals within a first predetermined time period after positioning an analyte sensor in fluid contact with interstitial fluid, wherein the first predetermined time period is determined within a first 24 hours of analyte sensor positioning;

determining a probability of early signal attenuation associated with the analyte sensor based at least in part on the first plurality of analyte sensor related signals;

determining a sensitivity of the analyte sensor based on a second plurality of analyte sensor related signals and a reference analyte measurement;

determining a sensitivity ratio based on the determined sensitivity of the analyte sensor divided by a nominal sensitivity, the nominal sensitivity determined prior to positioning the analyte sensor in fluid contact with the interstitial fluid; and

verifying a presence of early signal attenuation when the determined sensitivity ratio is less than a first predetermined threshold level.

2. The method of claim 1, wherein determining the probability of early signal attenuation includes determining one or more characteristics associated with the first plurality of analyte sensor related signals, wherein each of the one or more characteristics has a corresponding predetermined coefficient.

3. The method of claim 2, wherein the determined one or more characteristics includes one or more of a mean value associated with the first plurality of analyte sensor related signals, an average slope associated with the first plurality of analyte sensor related signals, a standard deviation associated with the first plurality of analyte sensor related signals, an average elapsed time from insertion of the analyte sensor, or a variance of the first plurality of analyte sensor related signals.

4. The method of claim 1, wherein when the determined probability of early signal attenuation does not exceed a second predetermined threshold level, generating a second output signal associated with an absence of early signal attenuation.

5. The method of claim 1, wherein verifying the presence of early signal attenuation includes:

selecting an early signal attenuation threshold level; and

confirming the presence of early signal attenuation based at least in part on a comparison of the determined sensitivity ratio and the selected early signal attenuation threshold level.

6. The method of claim 5, wherein the selected early signal attenuation threshold level is associated with the reference analyte measurement.

7. The method of claim 6, wherein the reference analyte measurement includes a blood analyte measurement.

8. The method of claim 5, wherein verifying the presence of early signal attenuation includes determining that the sensitivity ratio of the analyte sensor is less than the selected early signal attenuation threshold level.

9. The method of claim 1, wherein the sensitivity of the analyte sensor is determined as a ratio of the average of the second plurality of analyte sensor related signals and the reference analyte measurement.

10. An apparatus, comprising:

a processing unit configured to receive a first plurality of analyte sensor related signals within a first predetermined time period after positioning an analyte sensor in fluid contact with interstitial fluid, wherein the first predetermined time period is determined within a first 24 hours of analyte sensor positioning, to determine a probability of early signal attenuation associated with the analyte sensor based at least in part on the first plurality of analyte sensor related signals, to determine a sensitivity of the analyte sensor based on a second plurality of analyte sensor related signals and a reference analyte measurement, to determine a sensitivity ratio based on the determined sensitivity of the analyte sensor divided by a nominal sensitivity, the nominal sensitivity determined prior to positioning the analyte sensor in fluid contact with the interstitial fluid, and to verify a presence of early signal attenuation when the determined sensitivity ratio is less than a first predetermined threshold level.

11. The apparatus of claim 10, wherein the processing unit is configured to determine the probability of early signal attenuation is configured to determine one or more characteristics associated with the first plurality of analyte sensor related signals, and to apply a predetermined coefficient to the first plurality of analyte sensor related signals.

12. The apparatus of claim 11, wherein the determined one or more characteristics includes one or more of a mean value associated with the first plurality of analyte sensor related signals, a least square slope associated with the first plurality of analyte sensor related signals, a standard deviation associated with the first plurality of analyte sensor related signals, an average elapsed time from positioning the analyte sensor, or a variance about a least squares slope associated with the first plurality of analyte sensor related signals.

13. The apparatus of claim 10, wherein when the determined probability of early signal attenuation does not exceed the first predetermined threshold level, the processing unit is further configured to generate a second output signal associated with absence of early signal attenuation.

14. The apparatus of claim 10, wherein the processing unit is further configured to select an early signal attenuation threshold level and confirm the presence of early signal attenuation based at least in part on a comparison of the determined sensitivity ratio and the selected early signal attenuation threshold level.

15. The apparatus of claim 14, wherein the selected early signal attenuation threshold level is associated with the reference analyte measurement.

16. The apparatus of claim 15, wherein the reference analyte measurement includes a capillary blood analyte sample measurement.

17. The apparatus of claim 14, wherein the processing unit is further configured to determine that the sensitivity ratio of the analyte sensor is less than the selected early signal attenuation threshold level.

18. The apparatus of claim 10, wherein the sensitivity of the analyte sensor is determined as a ratio of the average of the second plurality of analyte sensor related signals and the reference analyte measurement.

19. The apparatus of claim 10, including a user output unit operatively coupled to the processing unit to display an output signal associated with the presence of early signal attenuation.

20. A system for detecting early signal attenuation, comprising:

an analyte sensor for transcutaneous positioning in fluid contact with interstitial fluid; and

a data processing device operatively coupled to the analyte sensor, the data processing device configured to receive a first plurality of analyte sensor related signals within a first predetermined time period determined within the first 24 hours of analyte sensor positioning, to determine a probability of early signal attenuation associated with the analyte sensor based at least in part on the first plurality of analyte sensor related signals, to determine a sensitivity of the analyte sensor based on a second plurality of analyte sensor related signals and a reference analyte measurement, to determine a sensitivity ratio based on the determined sensitivity of the analyte sensor divided by a nominal sensitivity determined prior to analyte sensor positioning, and to verify a presence of early signal attenuation when the determined sensitivity ratio is less than a first predetermined threshold level.