MULTIPLE ELECTRODE SYSTEM FOR A CONTINUOUS ANALYTE SENSOR, AND RELATED METHODS

• US 20140088389A1
• Filed: 03/07/2013
• Published: 03/27/2014
• Est. Priority Date: 09/24/2012
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Simpson, Peter C., Bohm, Sebastian, Boock, Robert J., Wightlin, Matthew D., Zhang, Huashi
• Granted Patent: US 9,743,871 B2
• Time in Patent Office: Days
• US Class Current: 600/345
• CPC Class Codes: A61B 2562/125 characterised by the manufacture of electrodes
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• 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: C12Q 1/002 Electrode membranes

Abstract

In one embodiment, a continuous analyte sensor having more than one working electrode, and configured to reduce or eliminate crosstalk between the working electrodes. In another embodiment, a continuous analyte sensor having more than one working electrode, and configured so that a membrane system has equal thicknesses over each of the electrodes, despite having differing numbers of layers over each of the electrodes. In another embodiment, a configuration for connecting a continuous analyte sensor to sensor electronics. In another embodiment, methods for forming precise windows in an insulator material on a multi-electrode assembly. In another embodiment, a contact assembly for a continuous analyte sensor having more than one working electrode.

Claims

1. A continuous analyte sensor, comprising:

a first working electrode;

a second working electrode; and

a membrane overlying at least a portion of the sensor, including the first and second working electrodes, the membrane being continuous, but for a first portion located between the first and second working electrodes that has properties that differ from properties of other portions of the membrane.

2. The continuous analyte sensor of claim 1, wherein at least one of the properties is permeability.

3. The continuous analyte sensor of claim 2, wherein the first portion is cross-linked.

4. The continuous analyte sensor of claim 2, wherein the other portions are cross-linked, and the first portion is cross-linked by an amount different from the other portions.

5. The continuous analyte sensor of claim 2, wherein the first portion has a lower content of a hydrophilic species than the other portions.

6. The continuous analyte sensor of claim 5, wherein the hydrophilic species is removed by a secondary removal process, a leaching process, or a precipitation process involving heat, pH, or solvents.

7. The continuous analyte sensor of claim 1, wherein the first portion comprises a scavenging material, the scavenging material configured to scavenge at least a portion of a byproduct of a chemical reaction occurring at the first working electrode between an analyte and a reactant.

8. The continuous analyte sensor of claim 7, wherein the byproduct comprises hydrogen peroxide.

9. The continuous analyte sensor of claim 7, wherein the scavenging material comprises peroxidase or catalase.

10. The continuous analyte sensor of claim 7, wherein the scavenging material is deposited on the sensor using masking followed by dipping, or by selective spraying.

11. The continuous analyte sensor of claim 1, wherein the first portion comprises an interruption in the membrane properties.

12. The continuous analyte sensor of claim 1, wherein the first portion comprises a mechanical ring that encircles the membrane.

13. The continuous analyte sensor of claim 1, wherein the first working electrode is located on a first wire, the second working electrode is located on a second wire, and the first and second wires are non-concentric.

14. A continuous analyte sensor, comprising:

a first wire comprising a first working electrode;

a second wire comprising a second working electrode;

an insulating layer electrically insulating the first wire from the second wire;

a conductive layer at least partially surrounding the insulating layer;

a first window exposing a first area of the first wire that is electrically connected to the first working electrode and configured to electrically connect with sensor electronics;

a second window exposing a second area of the second wire that is electrically connected to the second working electrode and configured to electrically connect with the sensor electronics; and

an opening electrically isolating a first portion of the conductive layer adjacent the first area of the first wire from a second portion of the conductive layer adjacent the second area of the second wire.

15. The continuous analyte sensor of claim 14, wherein the first and second windows are created through the conductive layer.

16. The continuous analyte sensor of claim 15, wherein the first and second windows are created through the insulating layer.

17. The continuous analyte sensor of claim 14, wherein the opening is created through the conductive layer.

18. The continuous analyte sensor of claim 17, wherein the opening is created through the insulating layer.

19. The continuous analyte sensor of claim 14, further comprising a first elastomeric conductive band around the first portion of the conductive layer and contacting the first area of the first wire, and a second elastomeric conductive band around the second portion of the conductive layer and contacting the second area of the second wire.

20. The continuous analyte sensor of claim 19, wherein the elastomeric conductive bands comprise silicone rubber containing carbon particles.

21. The continuous analyte sensor of claim 19, wherein each of the elastomeric conductive bands includes a radially inwardly directed bulge that contacts a respective one of the wires.

22. The continuous analyte sensor of claim 19, further comprising a conductive paste disposed between at least one of the elastomeric conductive bands and a respective one of the wires.

23. The continuous analyte sensor of claim 19, wherein at least one of the first area of the first wire and the second area of the second wire extends completely around its respective one of the wires.

24. The continuous analyte sensor of claim 14, wherein the first and second working electrodes are located along an in vivo portion of the sensor, and the first and second windows are located along an ex vivo portion of the sensor.