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

• US 9,282,925 B2
• Filed: 03/25/2010
• Issued: 03/15/2016
• Est. Priority Date: 02/12/2002
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Kamath, Apurv Ullas, Brauker, James H., Mahlingam, Aarthi
• Primary Examiner(s): Natnithithadha, Navin
• Assistant Examiner(s): JANG, CHRISTIAN YONGKYUN
• Application Number:
  US12/732,097
• Publication Number:
  US 20100179409A1
• Time in Patent Office: 2,182 Days
• Field of Search: 600/345, 600/347, 600/365
• US Class Current: 1/1
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 5/145 Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissuemeasuring of blood pressure or blood flow A61B5/02; non-radiation detecting or locating of foreign bodies in blood A61B5/06
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14539 for measuring pH
• 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 5/6848 Needles
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/725 using specific filters therefor, e.g. Kalman or adaptive filters A61B5/316 take precedence
• CPC Class Codes: A61B 5/7257 using Fourier transforms
• CPC Class Codes: A61B 5/726 using Wavelet transforms
• CPC Class Codes: A61B 5/743 Displaying an image simultaneously with additional graphical information, e.g. symbols, charts, function plots
• CPC Class Codes: A61B 5/7475 User input or interface means, e.g. keyboard, pointing device, joystick

Abstract

Systems and methods for detecting noise episodes and processing analyte sensor data responsive thereto. In some embodiments, processing analyte sensor data includes filtering the sensor data to reduce or eliminate the effects of the noise episode on the signal.

Claims

1. A method for processing sensor data from a continuous glucose sensor, the method comprising:

receiving data at an electronics unit from a continuous glucose sensor indicative of a host'"'"'s glucose concentration;

determining, using a signal reliability module operating on a processor in the electronics unit, a level of reliability of the continuous glucose sensor based on the data received from the continuous glucose sensor, wherein the level of reliability is selected by the processor from three or more predetermined reliability levels stored in a memory in the electronics unit; and

controlling the administration of a medicament, using a medicament administration device, based on the level of reliability.

2. The method of claim 1, wherein the determining comprises performing pattern recognition.

3. The method of claim 1, wherein the determining comprises identifying a drift in sensitivity.

4. The method of claim 1, wherein the determining comprises identifying a drift in baseline.

5. The method of claim 1, wherein the determining comprises measuring signal residuals.

6. The method of claim 1, wherein the determining comprises measuring a level of signal artifact associated with the sensor data.

7. The method of claim 6, wherein the measuring is based on a predetermined period of time or a predetermined amount of the data.

8. The method of claim 6, wherein the signal artifact comprises transient non-glucose related signal artifacts in the data.

9. The method of claim 1, wherein the determining is further based on detecting at least one of oxygen, pH, temperature, pressure or stress.

10. The method of claim 1, wherein the level of reliability comprises a numerical value.

11. The method of claim 1, wherein the level of reliability comprises a rating in terms of a percentage.

12. The method of claim 1, further comprising requesting additional reference analyte data depending upon the level of reliability.

13. The method of claim 1, further comprising prompting a user for a reference glucose value depending upon the level of reliability.

14. A system for processing sensor data from a continuous glucose sensor, comprising:

an input, the input configured to receive data from a continuous glucose sensor indicative of a host'"'"'s glucose concentration when the continuous glucose sensor is coupled to the input;

a processor configured to determine signal reliability of the signal received at the input, the signal reliability based on the data received from the continuous glucose sensor, wherein the signal reliability is selected from three or more predetermined reliability levels; and

a medicament delivery device in communication with the processor, wherein the medicament delivery device is configured to control the administration of a medicament to the host based on the selected level of reliability.

15. The system of claim 14, wherein the processor is further configured to perform pattern recognition when determining the signal reliability.

16. The system of claim 14, wherein the processor is further configured to identify a drift in sensitivity when determining the signal reliability.

17. The system of claim 14, wherein the processor is further configured to identify a drift in baseline when determining the signal reliability.

18. The system of claim 14, wherein the input is further configured to receive data corresponding to a signal residual when determining the signal reliability.

19. The system of claim 14, wherein the input is further configured to receive data corresponding to a level of signal artifact.

20. The system of claim 14, wherein the processor is further configured to determine signal reliability over a predetermined period of time or using a predetermined amount of data.

21. The system of claim 14, wherein the processor is further configured to detect at least one of oxygen, pH, temperature, pressure, or stress.

22. The system of claim 14, further comprising a display configured to prompt a user to enter additional reference analyte data based on the level of reliability.

23. The system of claim 14, further comprising a display configured to prompt a user to enter a reference glucose value based on the level of reliability.