Polymer membranes for continuous analyte sensors

• US 9,572,523 B2
• Filed: 09/22/2015
• Issued: 02/21/2017
• Est. Priority Date: 03/28/2008
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Boock, Robert, Swinney, Monica Rixman, Zhang, Huashi, Estes, Michael J., Lawrence, Kristina
• Primary Examiner(s): Natnithithadha, Navin
• Application Number:
  US14/861,963
• Publication Number:
  US 20160007897A1
• Time in Patent Office: 518 Days
• Field of Search: 600/309, 600345-366
• US Class Current: 1/1
• CPC Class Codes: A61B 5/14503 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors A61B5/1459, A61B5/1464, A61B5/1473, A61B5/1482, A61B5/14865 take precedence
• 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 5/1468 using chemical or electrochemical methods, e.g. by polarographic means A61B5/1486 takes precedence
• CPC Class Codes: A61B 5/1473 invasive, e.g. introduced into the body by a catheter A61B5/1482 takes precedence
• CPC Class Codes: A61B 5/1486 using enzyme electrodes, e.g. with immobilised oxidase
• 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 5/72 Signal processing specially adapted for physiological signals or for diagnostic purposes character recognition, recognising digital ink, document-oriented image-based pattern recognition G06V30/00; recognition or understanding of postal images G06V30/424
• CPC Class Codes: A61B 5/7475 User input or interface means, e.g. keyboard, pointing device, joystick
• CPC Class Codes: C12Q 1/006 for glucose
• CPC Class Codes: G01N 27/40 Semi-permeable membranes or partitions

Abstract

Devices and methods are described for providing continuous measurement of an analyte concentration. In some embodiments, the device has a sensing mechanism and a sensing membrane that includes at least one surface-active group-containing polymer and that is located over the sensing mechanism. The sensing membrane may have a bioprotective layer configured to substantially block the effect and/or influence of non-constant noise-causing species.

Claims

1. A device for continuous in vivo measurement of a glucose concentration, the device comprising:

an implantable sensor configured to continuously measure a signal indicative of a glucose concentration in a host, wherein the implantable sensor comprises an electroactive surface;

a membrane located over the sensor, wherein the membrane comprises a first domain comprising an enzyme configured to react with glucose to produce a measured species configured to be oxidized at the sensor, wherein the membrane comprises a second domain comprising a blend comprising;

a polymer comprising a hydrophilic segment, wherein the molecular weight of the polymer is from about 25,000 daltons to about 5,000,000 daltons, and

a polyurethaneurea,

wherein the blend of the polymer and the polyurethaneurea comprises both hydrophilic and hydrophobic regions; and

sensor electronics operably connected to the sensor, wherein the sensor electronics are configured to measure a current flow produced by the sensor to generate sensor data indicative of glucose concentration.

2. The device of claim 1, wherein the hydrophilic segment comprises acrylate.

3. The device of claim 1, wherein the membrane comprises a third domain configured to reduce permeation therethrough of an interfering species.

4. The device of claim 1, wherein the third domain is located between the sensor and the first domain.

5. The device of claim 1, wherein the third domain comprises a polymer comprising ionic components.

6. The device of claim 1, wherein the third domain is configured to limit diffusion of interfering species with a molecular weight greater than a molecular weight of hydrogen peroxide.

7. The device of claim 1, wherein the polymer comprising the hydrophilic segment comprises from about 5% to about 50% by weight of the blend.

8. The device of claim 1, wherein the device is configured to have a sensor session from 5 to 22 days.

9. The device of claim 1, wherein the polyurethaneurea comprises about 19% to about 40% silicone by weight.

10. The device of claim 1, wherein the device is configured to have an equivalent peak glucose response to a 1,000 mg dose of acetaminophen of less than about 20 mg/dL.

11. The device of claim 1, wherein the polyurethaneurea comprises a plurality of repeating hard segments and repeating soft segments, wherein a soft segment of the plurality of repeating soft segments has a molecular weight from about 200 Daltons to about 50,000 Daltons, wherein a hard segment of the plurality of repeating hard segments has a molecular weight from about 160 Daltons to about 10,000 Daltons.

12. A device for continuous in vivo measurement of a glucose concentration, the device comprising:

an implantable sensor configured to continuously measure a signal indicative of a glucose concentration in a host, wherein the implantable sensor comprises an electroactive surface;

a membrane located over the sensor, wherein the membrane comprises a first domain comprising an enzyme configured to react with glucose to produce a measured species configured to be oxidized at the sensor, wherein the membrane comprises a second domain comprising a blend comprising;

a polymer comprising a hydrophilic segment, wherein the molecular weight of the polymer is from about 25,000 daltons to about 5,000,000 daltons, and

a polyurea,

wherein the blend of the polymer and the polyurea comprises both hydrophilic and hydrophobic regions; and

sensor electronics operably connected to the sensor, wherein the sensor electronics are configured to measure a current flow produced by the sensor to generate sensor data indicative of glucose concentration.

13. The device of claim 12, wherein the hydrophilic segment comprises acrylate.

14. The device of claim 12, wherein the membrane comprises a third domain configured to reduce permeation therethrough of an interfering species.

15. The device of claim 12, wherein the third domain is located between the sensor and the first domain.

16. The device of claim 12, wherein the third domain comprises a polymer comprising ionic components.

17. The device of claim 12, wherein the third domain is configured to limit diffusion of interfering species with a molecular weight greater than a molecular weight of hydrogen peroxide.

18. The device of claim 12, wherein the polymer comprising the hydrophilic segment comprises from about 5% to about 50% by weight of the blend.

19. The device of claim 12, wherein the device is configured to have a sensor session from 5 to 22 days.

20. The device of claim 12, wherein the polyurea comprises about 19% to about 40% silicone by weight.

21. The device of claim 12, wherein the device is configured to have an equivalent peak glucose response to a 1,000 mg dose of acetaminophen of less than about 20 mg/dL.

22. The device of claim 12, wherein the polyurea comprises a plurality of repeating hard segments and repeating soft segments, wherein a soft segment of the plurality of repeating soft segments has a molecular weight from about 200 Daltons to about 50,000 Daltons, wherein a hard segment of the plurality of repeating hard segments has a molecular weight from about 160 Daltons to about 10,000 Daltons.

23. A device for continuous in vivo measurement of a glucose concentration, the device comprising:

an implantable sensor configured to continuously measure a signal indicative of a glucose concentration in a host, wherein the implantable sensor comprises an electroactive surface;

a membrane located over the sensor, wherein the membrane comprises a first domain comprising an enzyme configured to react with glucose to produce a measured species configured to be oxidized at the sensor, wherein the membrane comprises a second domain comprising a blend comprising;

a polymer comprising a hydrophilic segment, wherein the molecular weight of the polymer is from about 25,000 daltons to about 5,000,000 daltons, and

a polyurethane,

wherein the blend of the polymer and the polyurethane comprises both hydrophilic and hydrophobic regions; and

sensor electronics operably connected to the sensor, wherein the sensor electronics are configured to measure a current flow produced by the sensor to generate sensor data indicative of glucose concentration.

24. The device of claim 23, wherein the hydrophilic segment comprises acrylate.

25. The device of claim 23, wherein the membrane comprises a third domain configured to reduce permeation therethrough of an interfering species.

26. The device of claim 23, wherein the third domain is located between the sensor and the first domain.

27. The device of claim 23, wherein the third domain comprises a polymer comprising ionic components.

28. The device of claim 23, wherein the third domain is configured to limit diffusion of interfering species with a molecular weight greater than a molecular weight of hydrogen peroxide.

29. The device of claim 23, wherein the polymer comprising the hydrophilic segment comprises from about 5% to about 50% by weight of the blend.

30. The device of claim 23, wherein the device is configured to have a sensor session from 5 to 22 days.

31. The device of claim 23, wherein the polyurethane comprises about 19% to about 40% silicone by weight.

32. The device of claim 23, wherein the device is configured to have an equivalent peak glucose response to a 1,000 mg dose of acetaminophen of less than about 20 mg/dL.

33. The device of claim 23, wherein the polyurethane comprises a plurality of repeating hard segments and repeating soft segments, wherein a soft segment of the plurality of repeating soft segments has a molecular weight from about 200 Daltons to about 50,000 Daltons, wherein a hard segment of the plurality of repeating hard segments has a molecular weight from about 160 Daltons to about 10,000 Daltons.