Low oxygen in vivo analyte sensor

• US 7,901,354 B2
• Filed: 05/01/2008
• Issued: 03/08/2011
• Est. Priority Date: 03/04/1997
• Status: Expired due to Term

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Rhodes, Rathbun K., Shults, Mark C., Brauker, James H., Updike, Stuart J.
• Primary Examiner(s): Mallari; Patricia C
• Application Number:
  US12/113,724
• Publication Number:
  US 20080296155A1
• Time in Patent Office: 1,041 Days
• Field of Search: 600/347, 600/365
• US Class Current: 600/365
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 5/14 Devices for taking samples of blood hypodermic syringes A61M5/00; Measuring characteristics of blood in vivo, e.g. gas concentration within the blood, pH-value of blood measuring of blood pressure A61B5/02; non-radiation detecting or locating of foreign bodies in blood A61B5/06
• CPC Class Codes: A61B 5/1411 by percutaneous method, e.g. by lancet
• CPC Class Codes: A61B 5/14514 using means for aiding extraction of interstitial fluid, e.g. microneedles or suction
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• 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 5/150022 for capillary blood or interstitial fluid
• CPC Class Codes: A61B 5/6833 Adhesive patches
• CPC Class Codes: A61B 5/6848 Needles
• CPC Class Codes: A61B 5/6849 in combination with a needle set

Abstract

The present invention relates generally to systems and methods for measuring an analyte in a host. More particularly, the present invention relates to systems and methods for transcutaneous and subcutaneous measurement of glucose in a host.

Claims

1. A device for measuring a concentration of glucose in a biological fluid, the device comprising:

a glucose determining apparatus comprising an electrode and a membrane impregnated with glucose oxidase, wherein the glucose determining apparatus is configured to determine a concentration of glucose in a biological sample via measurement of hydrogen peroxide produced by an enzyme-catalyzed reaction of glucose with oxygen; and

a housing comprising an electronic circuit operatively connected to the electrode;

wherein the glucose determining apparatus is configured to measure glucose concentration with substantial linearity at glucose concentrations of up to about 400 mg/dL at an oxygen concentration of less than about 0.3 mg/L and with a sensitivity of from about 1 pA/mg/dL to about 100 pA/mg/dL.

2. The device of claim 1, further comprising a semipermeable film configured to maintain an aqueous layer at an electrochemically reactive surface of the electrode.

3. The device of claim 2, wherein a permeability ratio of the semipermeable film is at least about 200:

1 of glucose to oxygen.

4. The device of claim 1, wherein the device is configured to have an operable life implanted within a host of at least about one week.

5. The device of claim 1, wherein the device is configured to have an operable life implanted within a host of at least about one month.

6. The device of claim 1, wherein the impregnated oxidase is present in an amount sufficient for a device life of at least about one year.

7. The device of claim 1, wherein the device is configured to have an operable life implanted within a host of at least about one year.

8. The device of claim 1, wherein the membrane comprises a porous outer layer configured for tissue ingrowth.

10. The device of claim 1, wherein the device is configured to measure glucose with substantial linearity at an oxygen concentration of less than about 0.15 mg/L.

11. The device of claim 1, wherein the device is configured to measure glucose with substantial linearity at an oxygen concentration of less than about 0.05 mg/L.

12. The device of claim 1, wherein the device is configured to measure glucose with substantial linearity at an oxygen concentration of less than about 0.02 mg/L.

15. The device of claim 1, wherein the device is configured such that less than about 1 μ

g of enzyme is consumed over 7 days of continuous operation.

16. The device of claim 1, wherein the membrane comprises a polyurethane.

9. A device for measuring a concentration of glucose in a biological fluid, the device comprising:

a glucose apparatus comprising an electrode and a membrane impregnated with glucose oxidase, wherein the glucose determining apparatus is configured to determine a concentration of glucose in a biological sample via measurement of hydrogen peroxide produced by an enzyme-catalyzed reaction of glucose with oxygen; and

a housing comprising an electronic circuit operatively connected to the electrode;

wherein the glucose determining apparatus is configured to measure glucose with substantial linearity at glucose concentrations of up to about 400 mg/dL at an oxygen concentration of less than about 0.3 mg/L.

17. The device of claim 9, wherein the device is configured to have an operable life implanted within a host of at least about one week.

18. The device of claim 9, wherein the device is configured such that less than about 1 μ

g of enzyme is consumed over 7 days of continuous operation.

19. The device of claim 9, wherein the membrane comprises a polyurethane.

13. A device for measuring a concentration of glucose in a biological fluid, the device comprising:

a glucose determining apparatus comprising an electrode and a membrane comprising a fluorine-containing polymer, wherein the membrane is impregnated with glucose oxidase, wherein the glucose determining apparatus is configured to determine a concentration of glucose in a biological sample via measurement of hydrogen peroxide produced by an enzyme-catalyzed reaction of glucose with oxygen; and

a housing comprising an electronic circuit operatively connected to the electrode;

wherein the glucose determining apparatus is configured to measure glucose concentration with substantial linearity at glucose concentrations of up to about 400 mg/dL at an oxygen concentration of less than about 0.6 mg/L.

20. The device of claim 13, wherein the device is configured to have an operable life implanted within a host of at least about one week.

21. The device of claim 13, wherein the device is configured to measure glucose with substantial linearity at an oxygen concentration of less than about 0.3 mg/L.

22. The device of claim 13, wherein the device is configured such that less than about 1 μ

g of enzyme is consumed over 7 days of continuous operation.

23. The device of claim 13, wherein the membrane comprises a polyurethane.

14. A device for measuring a concentration of glucose in a biological fluid, the device comprising:

a glucose determining apparatus comprising an electrode and a membrane comprising a silicone-containing polymer, wherein the membrane is impregnated with glucose oxidase, wherein the glucose determining apparatus is configured to determine a concentration of glucose in a biological sample via measurement of hydrogen peroxide produced by an enzyme-catalyzed reaction of glucose with oxygen; and

a housing comprising an electronic circuit operatively connected to the electrode;

wherein the glucose determining apparatus is configured to measure glucose concentration with substantial linearity at glucose concentrations of up to about 400 mg/dL at an oxygen concentration of less than about 0.6 mg/L.

24. The device of claim 14, wherein the device is configured to have an operable life implanted within a host of at least about one week.

25. The device of claim 14, wherein the device is configured to measure glucose with substantial linearity at an oxygen concentration of less than about 0.3 mg/L.

26. The device of claim 14, wherein the device is configured such that less than about 1 μ

g of enzyme is consumed over 7 days of continuous operation.

27. The device of claim 14, wherein the membrane comprises a polyurethane.