Analyte sensor

• US 8,862,197 B2
• Filed: 02/15/2013
• Issued: 10/14/2014
• Est. Priority Date: 03/25/2008
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Kamath, Apurv Ullas, Simpson, Peter C., Brister, Mark
• Primary Examiner(s): D'ANGELO, MICHAEL J
• Application Number:
  US13/768,916
• Publication Number:
  US 20130165756A1
• Time in Patent Office: 606 Days
• Field of Search: 600/309, 600/316, 600345-347, 600/365
• US Class Current: 600/345
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• 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 5/1455 using optical sensors, e.g. spectral photometrical oximeters
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/1459 invasive, e.g. introduced into the body by a catheter A61B5/1464 takes precedence
• 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 5/4094 Diagnosing or monitoring seizure diseases, e.g. epilepsy
• CPC Class Codes: A61B 5/6852 Catheters
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal

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 measuring an analyte in a host, comprising:

exposing a continuous analyte detection system to a sample, wherein the continuous analyte detection system comprises

a continuous analyte sensor configured for contact with a sample from a circulatory system of a host in vivo; and

a reference sensor;

generating a first signal of a glucose oxidase catalyzed reaction product with glucose; and

a second signal associated with a glucose reference analyte;

generating a non-glucose reference signal from the reference sensor;

receiving in a processor module the first signal, the second signal, and the reference signal;

calculating, using the processor module, a calibration factor based on the second signal and the reference signal, the calculated calibration factor providing a sensitivity of the continuous analyte sensor; and

calibrating the first signal using the calibration factor.

2. The method of claim 1, wherein the exposing step further comprises simultaneously exposing the continuous analyte sensor and the reference sensor to the sample.

3. The method of claim 1, wherein the receiving step further comprises receiving the first signal from a first working electrode disposed under an enzymatic portion of a membrane system.

4. The method of claim 3, wherein the receiving step further comprises receiving the second signal from the first working electrode.

5. The method of claim 3, wherein the receiving step further comprises receiving the second signal from a second working electrode disposed under the membrane system.

6. The method of claim 5, wherein the receiving step further comprises receiving a non-analyte-related signal from a third working electrode disposed under a non-enzymatic portion of the membrane system.

7. The method of claim 5, the exposing step comprises exposing the continuous analyte detection system to a substantially stagnant non-bodily fluid during a time period and the calculating step further comprises comparing a signal increase on each of the first and second working electrodes during the time period.

8. The method of claim 1, wherein the receiving step further comprises optically detecting the reference analyte.

9. The method of claim 1, wherein the exposing step comprises exposing the continuous analyte detection system to a bodily fluid and the calculating step further comprises comparing steady-state information of the first signal and steady-state information of the second signal.

10. A method for measuring an analyte in a host, comprising:

exposing a continuous analyte detection system to a sample, wherein the continuous analyte detection system comprises a continuous analyte sensor configured for contact with a sample from a circulatory system of a host in vivo and configured to generate a first signal associated with a test analyte and a second signal associated with a reference analyte, and a reference sensor configured to generate a reference signal associated with the reference analyte;

receiving the first signal from a first working electrode disposed under an enzymatic portion of a membrane system;

receiving the second signal from the first working electrode; and

receiving the reference signal;

calculating a calibration factor associated with a sensitivity of the continuous analyte sensor; and

calibrating the first signal, wherein calibrating comprises using the calibration factor.

11. The method of claim 10, wherein the receiving step further comprises receiving the first signal from a first working electrode disposed under an enzymatic portion of a membrane system.

12. The method of claim 11, wherein the receiving step further comprises receiving the second signal from a second working electrode disposed under the membrane system.

13. The method of claim 11, wherein the receiving step further comprises receiving a non-analyte-related signal from a third working electrode disposed under a non-enzymatic portion of the membrane system.