ANALYTE SENSOR

• US 20090137887A1
• Filed: 11/07/2008
• Published: 05/28/2009
• Est. Priority Date: 10/04/2006
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Kamath, Apurv Ullas, Simpson, Peter C., Yang, Richard C., Li, Ying, Shariati, Mohammad Ali
• Granted Patent: US 8,478,377 B2
• Time in Patent Office: Days
• US Class Current: 600/345
• 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 5/145 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 5/14542 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 25/007 Side holes, e.g. their profiles or arrangements; Provisions to keep side holes unblocked
• 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 performing a diagnostic of an analyte sensor system, comprising:

providing a sensor system comprising an analyte sensor and a flow control device configured to intermittently expose the analyte sensor to a biological sample and an infusion solution, wherein the analyte sensor comprises;

a first working electrode configured to provide a first signal comprising an analyte component and a baseline component; and

a second working electrode configured to provide a second signal comprising a baseline component substantially without an analyte component; and

evaluating the sensor system based at least in part on the second signal.

2. The method of claim 1, wherein the second signal comprises a signal waveform, and wherein the step of evaluating the sensor system comprises evaluating the signal waveform for at least one of an expected shape and a pattern when the analyte sensor is exposed to at least one of the biological sample and the infusion solution.

3. The method of claim 2, wherein the step of evaluating the signal waveform comprises evaluating at least one of a similarity and a correlation between the signal waveform and a waveform template.

4. The method of claim 3, wherein the waveform template is based at least in part on a priori information.

5. The method of claim 3, wherein the waveform template is based at least in part on a signal waveform measured by the sensor system.

6. The method of claim 3, wherein the step of evaluating at least one of a similarity and a correlation of the signal waveform to a waveform template comprises performing a correlation waveform analysis.

7. The method of claim 3, further comprising updating the waveform template when at least one of the similarity and the correlation between the signal waveform and the waveform template meets one or more criteria.

8. The method of claim 7, further comprising detecting a level of interferent in the biological sample, wherein the waveform template is updated when the level of interferent meets one or more criteria.

9. The method of claim 2, wherein the step of evaluating the signal waveform comprises evaluating a monotonicity of the signal waveform.

10. The method of claim 9, wherein the step of evaluating a monotonicity of the signal waveform comprises performing a correlation waveform analysis of the signal waveform with the waveform template.

11. The method of claim 9, wherein the step of evaluating a monotonicity of the signal waveform comprises performing a time-series analysis.

12. The method of claim 1, wherein the step of evaluating the sensor system comprises detecting an interferent by evaluating at least one of an amplitude, a change in amplitude, a signal waveform, and a change in a signal waveform of the second signal when the sensor is exposed to the biological sample.

13. The method of claim 12, wherein the step of detecting an interferent is further based at least in part on a calibrated analyte value.

14. The method of claim 12, further comprising controlling a display of the sensor system based at least in part on a level of interferent detected on the second signal.

15. The method of claim 12, further comprising processing the first signal and the second signal to obtain a subtracted signal, wherein the step of processing is based at least in part a level of interferent of the sensor system.

16. The method of claim 1, further comprising determining a level of reliability of the sensor system by comparing at least one of an amplitude, a change in amplitude, a signal waveform, and a change in a signal waveform of the second signal to one or more criteria.

17. The method of claim 16, further comprising controlling a display of the sensor system based at least in part on the level of reliability of the sensor system.

18. The method of claim 1, wherein the step of evaluating comprises determining a success of a biological sample draw-back from a host'"'"'s circulatory system to the analyte sensor.

19. The method of claim 18, further comprising displaying an analyte value measured during the biological sample draw-back in response to a determination of a successful biological sample draw-back.

20. The method of claim 1, wherein the step of evaluating comprises determining a success of infusing the infusion solution such that the biological sample is washed from the sensor.

21. The method of claim 20, wherein the step of determining a success of infusing comprises displaying an analyte value measured in the biological sample after infusing the infusion solution in response to a determination of a successful infusion.