Analyte sensor

• US 8,287,453 B2
• Filed: 11/07/2008
• Issued: 10/16/2012
• Est. Priority Date: 12/05/2003
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Li, Ying, Kamath, Apurv Ullas, Brister, Mark
• Primary Examiner(s): Mallari, Patricia
• Assistant Examiner(s): D'Angelo, Michael
• Application Number:
  US12/267,518
• Publication Number:
  US 20090182217A1
• Time in Patent Office: 1,439 Days
• Field of Search: 600345-347, 600/365, 435/4, 435/14, 422/50, 422420-429, 20440301-40315, 702/23, 604 64- 66
• US Class Current: 600/365
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 2560/04 Constructional details of apparatus
• CPC Class Codes: A61B 2562/085 combined with means for recording calibration data
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• 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 5/14542 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 5/14865 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 5/412 Detecting or monitoring sepsis
• CPC Class Codes: A61B 5/4839 combined with drug delivery
• CPC Class Codes: A61B 5/6848 Needles
• CPC Class Codes: A61B 5/6849 in combination with a needle set
• CPC Class Codes: A61B 5/7275 Determining trends in physiological measurement data; Predicting development of a medical condition based on physiological measurements, e.g. determining a risk factor
• CPC Class Codes: A61B 5/743 Displaying an image simultaneously with additional graphical information, e.g. symbols, charts, function plots
• CPC Class Codes: A61M 2005/14296 Pharmacokinetic models
• CPC Class Codes: A61M 2230/201 Glucose concentration
• CPC Class Codes: A61M 5/14 Infusion devices, e.g. infusing by gravity; Blood infusion; Accessories therefor
• CPC Class Codes: A61M 5/16804 Flow controllers
• CPC Class Codes: A61M 5/1723 : using feedback of body parameters, e.g. blood-sugar, pressure measurement of body parameters A61B5/00
• CPC Class Codes: C12Q 1/001 : Enzyme electrodes
• CPC Class Codes: C12Q 1/006 : for glucose
• CPC Class Codes: G16H 10/40 : for data related to laboratory analysis, e.g. patient specimen analysis
• CPC Class Codes: G16H 20/17 : delivered via infusion or injection
• CPC Class Codes: G16H 40/40 : for the management of medical equipment or devices, e.g. scheduling maintenance or upgrades
• CPC Class Codes: Y02A 90/10 : Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

Abstract

Systems and methods of use for continuous analyte measurement of a host'"'"'s vascular system are provided. In some embodiments, a continuous glucose measurement system includes a vascular access device, a sensor and sensor electronics, the system being configured for insertion into communication with a host'"'"'s circulatory system.

Claims

1. A method for determining a stability of an analyte sensor, the method comprising:

exposing an analyte sensor to a biological sample, wherein the analyte sensor comprises a first working electrode that measures an analyte component and a baseline component and a second working electrode that measures a baseline component substantially without an analyte component;

receiving sensor data from the analyte sensor, wherein the sensor data comprises first sensor data associated with the first working electrode and second sensor data associated with the second working electrode; and

determining, using a processor module, a stability of the analyte sensor based at least in part on the second sensor data.

2. The method of claim 1, wherein the second sensor data comprises a plurality of time spaced data points, and wherein the step of determining a stability of the analyte sensor comprises evaluating a change in amplitude of two or more of the plurality of time spaced data points.

3. The method of claim 2, wherein the step of exposing the analyte sensor to a biological sample comprises intermittently exposing the analyte sensor to a biological sample and to an infusion solution.

4. The method of claim 3, wherein the step of evaluating comprises comparing a plurality of time spaced points measured when the analyte sensor is exposed to the biological sample.

5. The method of claim 3, wherein the step of evaluating comprises comparing a first point measured when the analyte sensor is exposed to the biological sample to a second point measured when the analyte sensor is exposed to the infusion solution.

6. The method of claim 3, wherein the step of evaluating comprises evaluating transient information of the second sensor data during a step change from exposure of the sensor to the infusion solution to exposure of the sensor to the biological sample.

7. The method of claim 2, further comprising determining a predetermined level of stability when a change in an amplitude of the second sensor data meets one or more criteria.

8. The method of claim 7, further comprising controlling a display associated with the analyte sensor system in response to the determination of the predetermined level of stability.

9. The method of claim 8, wherein the step of controlling a display comprises providing at least one of a numeric estimated analyte value, a directional trend of analyte concentration, and a graphical representation of a plurality of estimated analyte values.

10. The method of claim 8, wherein the step of controlling a display comprises requesting reference analyte data.

11. The method of claim 1, wherein the step of determining a stability of the analyte sensor is performed during a predetermined time period.

12. The method of claim 1, wherein the step of determining a stability of the analyte sensor is performed after a predetermined time period.

13. The method of claim 1, further comprising repeating the step of determining a stability, wherein the step is conducted after a system re-start.

14. The method of claim 1, wherein the analyte sensor is a glucose sensor.

15. A system for determining a stability of an analyte sensor, the system comprising:

an analyte sensor; and

a computer system, the computer system comprising;

an input module operatively connected to the analyte sensor and configured to receive sensor data from an analyte sensor, wherein the analyte sensor comprises a first working electrode configured to provide first sensor data comprising an analyte component and a baseline component and a second working electrode configured to provide second sensor data comprising a baseline component substantially without an analyte component; and

a processor module configured to determine a stability of the analyte sensor based at least in part on the second sensor data.

16. The system of claim 15, wherein the processor module is configured to determine a stability of the analyte sensor at least in part by evaluating a change in amplitude of a plurality of time spaced points from the second sensor data.

17. The system of claim 16, wherein the system further comprises a flow control device configured and arranged to intermittently expose the analyte sensor to a biological sample and to an infusion solution.

18. The system of claim 17, wherein the processor module is configured to evaluate the change in amplitude at least in part by comparing a plurality of time spaced points from the second sensor data measured when the analyte sensor is exposed to the biological sample.

19. The system of claim 17, wherein the processor module is configured to evaluate the change in amplitude at least in part by comparing a first point measured when the analyte sensor is exposed to the biological sample to a second point measured when the analyte sensor is exposed to the infusion solution.

20. The system of claim 17, wherein the processor module is configured to evaluate the change in amplitude at least in part by evaluating transient information of the second sensor data during a step change from exposure of the sensor to the infusion solution to exposure of the sensor to the biological sample.

21. The system of claim 16, wherein the processor module is configured to determine a level of stability when a change in amplitude of a plurality of time spaced points from the second sensor data meets one or more criteria.

22. The system of claim 21, wherein the processor module is configured to control a display of calibrated sensor based at least in part on the level of stability.

23. The system of claim 22, wherein the calibrated sensor data comprises at least one of a numeric estimated analyte value, a directional trend of analyte concentration, and a graphical representation of a plurality of estimated analyte values.

24. The system of claim 21, wherein the processor module is configured to request reference analyte data based at least in part on the level of stability.

25. The system of claim 15, wherein the processor module is further configured to determine a stability of the analyte sensor during a predetermined time period.

26. The system of claim 15, wherein processor module is further configured to determine a stability of the analyte sensor after a predetermined time period.

27. The system of claim 15, wherein the analyte sensor is a glucose sensor.