Polymer membranes for continuous analyte sensors

• US 9,693,721 B2
• Filed: 06/17/2015
• Issued: 07/04/2017
• Est. Priority Date: 03/28/2008
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Boock, Robert J., Zhang, Huashi, Lawrence, Kristina, Estes, Michael J., Rixman, Monica A.
• Primary Examiner(s): Natnithithadha, Navin
• Application Number:
  US14/742,137
• Publication Number:
  US 20150282750A1
• Time in Patent Office: 748 Days
• Field of Search: 600309, 600345-366
• 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 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: B33Y 70/00 Materials specially adapted for additive manufacturing
• 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 in vivo measurement of a glucose concentration, the device comprising:

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

a membrane located over the sensor, wherein the membrane comprises;

a second domain comprising a polymer comprising 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, wherein the polymer comprises a hydrophilic segment, wherein the second domain comprises both hydrophilic and hydrophobic regions, whereby diffusion of glucose and oxygen through the second domain is controlled; 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 polymer is a polyurethaneurea.

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

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

5. The device of claim 4, further comprising a first domain comprising an enzyme configured to react with glucose to produce a measured species, wherein the third domain is located between the sensor and the first domain.

6. The device of claim 4, wherein the third domain comprises a polymer comprising ionic components.

7. The device of claim 4, wherein the third domain is configured to limit diffusion of interfering species with a molecular weight greater than a molecular weight of hydrogen peroxide.

8. The device of claim 1, wherein the polymer is polyurethaneurea, wherein the hydrophilic segment comprises acrylate.

9. The device of claim 1, wherein the polymer is polyurethaneurea, wherein the hydrophilic segment comprises acrylate, wherein the membrane comprises a third domain configured to reduce permeation therethrough of an interfering species.

10. The device of claim 1, further comprising a first domain comprising an enzyme configured to react with glucose to produce a measured species, wherein the polymer is polyurethaneurea, wherein the hydrophilic segment comprises acrylate, wherein the membrane comprises a third domain configured to reduce permeation therethrough of an interfering species, wherein the third domain is located between the sensor and the first domain.

11. The device of claim 1, wherein the hydrophilic segment is selected from the group consisting of:

polyvinyl acetate, poly(ethylene glycol), polyacrylamide, acetates, polyethylene oxide, polyvinylpyrrolidone, and poly ethyl acrylate.

12. The device of claim 1, wherein the polyurethane polymer comprises silicone.

13. The device of claim 12, wherein the polymer comprises from about 10% to about 50% silicone by weight.

14. The device of claim 13, wherein the polymer comprises from about 20% to about 40% silicone by weight.

15. The device of claim 1, wherein the polymer is polyurethaneurea, wherein the hydrophilic segment comprises acrylate, wherein the polyurethane polymer comprises silicone.

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

17. The device of claim 1, wherein the polyurethane polymer is polyurethaneurea, wherein the hydrophilic segment comprises acrylate, wherein the polymer comprising the hydrophilic segment comprises from about 5% to about 50% by weight of the blend.

18. The device of claim 1, wherein the device is configured to have a sensor session from 5 to 10 days.

19. The device of claim 1, wherein the sensor is configured to continuously measure a signal indicative of a glucose concentration in a host.