Systems and methods for replacing signal artifacts in a glucose sensor data stream

Patent metadata

Field	Value
Publication number	US-9585607-B2
Application number	US-201213439675-A
Country	US
Kind code	B2
Filing date	Apr 4, 2012
Priority date	Aug 22, 2003
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

Systems and methods for minimizing or eliminating transient non-glucose related signal noise due to non-glucose rate limiting phenomenon such as interfering species, ischemia, pH changes, temperatures changes, known or unknown sources of mechanical, electrical and/or biochemical noise, and the like. The system monitors a data stream from a glucose sensor and detects signal artifacts that have higher amplitude than electronic or diffusion-related system noise. The system processes some or the entire data stream continually or intermittently based at least in part on whether the signal artifact event has occurred.

First claim

What is claimed is:

1. A method of analyzing data from an analyte sensor using a continuous analyte monitoring system, comprising:
receiving data from an analyte sensor, the data comprising at least one sensor data point;
filtering the received data to generate filtered data;
comparing the received data with the filtered data to obtain at least one residual;
determining a first signal artifact event has occurred when the at least one residual is exceeds a first threshold value;
determining a second signal artifact event has occurred when the at least one residual exceeds a second, different threshold value;
disabling or enabling display of a first graphical representation of the received data based on the determination that the first signal artifact has occurred, wherein the first graphical representation is selected from a group consisting of a graphical indication of glucose trend, a numerical estimated analyte value, and a range of glucose values; and
disabling or enabling display of a second graphical representation of the received data based on the determination that the second signal artifact has occurred,
wherein the second graphical representation is selected from the group consisting of the graphical indication of glucose trend, the numerical estimated analyte value, and the range of glucose values,
wherein the selected second graphical representation is different than the selected first graphical representation, and
wherein the selected second graphical representation is according to the second threshold value that is higher than the first threshold value, and corresponds to the second signal artifact event that indicates a higher severity than the first signal artifact event.

2. The method of claim 1 , wherein the first or second signal artifact event is determined to have occurred if the residual exceeds the respective threshold value for a predetermined period of time or for a predetermined amount of data.

3. The method of claim 2 , wherein determining whether the first or second signal artifact has occurred further comprises determining whether a predetermined number of residuals exceeds a threshold over a predetermined period of time, or whether a predetermined amount of data exceeds a threshold.

4. The method of claim 1 , wherein determining whether the first or second signal artifact event has occurred further comprises determining a differential between a first residual of the one or more residuals at a first time point and a second residual of the more or more residuals at a second time point.

5. The method of claim 4 , wherein determining whether the first or second signal artifact event has occurred further comprises determining whether a predetermined number of differentials exceeds a threshold over a predetermined period of time, or whether an amount of data exceeds a threshold.

6. The method of claim 1 , further comprising receiving reference data from a reference analyte monitor, the reference data including at least one reference data point.

7. The method of claim 1 , wherein processing the received data comprises displaying a graphical representation of the filtered data, wherein processing is conducted if one of the first or second signal artifact event is determined to have occurred.

8. The method of claim 1 , wherein processing the received data comprises utilizing the residual to modify the filtered data.

9. The method of claim 1 , further comprising deriving a differential of the residual by calculating a first derivative of the residual, and wherein processing the received data comprises utilizing the differential to modify the filtered data.

10. The method of claim 1 , wherein processing the received data comprises compensating for a time lag.

11. The method of claim 1 , wherein processing the received data comprises displaying a graphical representation of the received data.

12. The method of claim 11 , wherein the received data is an unfiltered digital signal.

13. The method of claim 1 , wherein, when the first signal artifact is determined to have occurred, the disabling or disabling display comprises enabling display of the range of analyte values and disabling the display of one or both of the graphical indication of analyte trend and the numerical estimated analyte value.

14. The method of claim 1 , wherein processing the received data comprises generating a confidence interval for at least one estimated analyte value and displaying a graphical representation of the confidence interval, wherein processing is conducted if the first or second signal artifact event is determined to have occurred.

15. A continuous analyte monitoring system configured to process data from an analyte sensor, the continuous analyte monitoring system comprising:
a data receiving module configured to receive sensor data from the analyte sensor, the data comprising at least one sensor data point;
a signal artifacts module configured to filter the received data to generate filtered data, compare the received data with the filtered data to obtain at least one residual, and determine a first signal artifact event has occurred when the at least one residual is exceeds a first threshold value and to determine a second signal artifact event has occurred when the at least one residual exceeds a second, different threshold value;
a processor module configured to disable or enable display of a first graphical representation of the received data based on the determination that the first signal artifact has occurred, wherein the first graphical representation is selected from a group consisting of a graphical indication of glucose trend, a numerical estimated analyte value, and a range of glucose values, and configured to disable or enable display of a second graphical representation of the received data based on the further determination that the second signal artifact has occurred, wherein the second graphical representation is selected from the group consisting of the graphical indication of glucose trend, the numerical estimated analyte value, and the range of glucose values, wherein the selected second graphical representation is different than the selected first graphical representation, and wherein the selected second graphical representation is according to the second threshold value that is higher than the first threshold value, and corresponds to the second signal artifact event that indicates a higher severity than the first signal artifact event.

16. The system of claim 15 , wherein the signal artifacts module is configured to detect the first or second signal artifact if a predetermined number of residuals exceed a threshold value for a predetermined period of time or for a predetermined amount of data.

17. The system of claim 15 , wherein the signal artifacts module is configured to compare a first residual with a second signal residual to determine a differential.

18. The system of claim 17 , wherein the signal artifacts module is configured to detect the first or second signal artifact if the differential exceeds a threshold value.

19. The system of claim 17 , wherein the signal artifacts module is configured to detect the first or second signal artifact if a predetermined number of differentials exceed a threshold value for a predetermined period of time or for a predetermined amount of data.

20. The system of claim 15 , further comprising a reference data module configured to receive reference data from a reference glucose monitor, the reference data comprising at least one reference data point.

Assignees

• Kamath Apurv
• Brauker James H
• Mahalingam Aarthi
• Li Ying
• Dexcom Inc

Inventors

• Kamath Apurv
• Brauker James H
• Mahalingam Aarthi
• Li Ying

Classifications

• A61B5/01

  Measuring temperature of body parts {; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue} (clinical contact thermometers G01K13/20) · CPC title

• A61B2560/0252

  using ambient temperature · CPC title

• A61B5/14865 Primary

  invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors · CPC title

• A61B5/145

  Measuring characteristics of blood in vivo, e.g. gas concentration or pH-value {; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid or cerebral tissue} (non-radiation detecting or locating of foreign bodies in blood A61B5/06) · CPC title

• A61B5/7203 Primary

  for noise prevention, reduction or removal · CPC title