Dual electrode system for a continuous analyte sensor

• US 9,579,053 B2
• Filed: 03/26/2010
• Issued: 02/28/2017
• Est. Priority Date: 12/05/2003
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Brister, Mark, Petisce, James R., Simpson, Peter
• Primary Examiner(s): JANG, CHRISTIAN YONGKYUN
• Application Number:
  US12/748,024
• Publication Number:
  US 20100185070A1
• Time in Patent Office: 2,531 Days
• Field of Search: 600/309, 600/316, 600345-347, 600/365, 435/4, 435/14, 436/68, 422/50, 422420-429, 20440301-40315, 702/23, 604 64- 66, 606/167, 606181-183
• US Class Current: 1/1
• 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 5/14865 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 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing

Abstract

Disclosed herein are systems and methods for a continuous analyte sensor, such as a continuous glucose sensor. One such system utilizes first and second working electrodes to measure additional analyte or non-analyte related signal. Such measurements may provide a background and/or sensitivity measurement(s) for use in processing sensor data and may be used to trigger events such as digital filtering of data or suspending display of data.

Claims

1. A transcutaneous analyte sensor configured for insertion into a host for measuring an analyte in the host, the sensor comprising:

a first conductive layer comprising a working electrode, wherein the working electrode is configured to generate a signal indicative of an analyte concentration;

a first insulative layer covering at least a portion of the first conductive layer;

a second conductive layer covering at least a portion of the first insulative layer, wherein the second conductive layer comprises a reference or counter electrode;

a second insulative layer covering at least a portion of the second conductive layer;

a membrane covering at least a portion of the first electrode, wherein the membrane comprises a silicone-urethane copolymer and an acrylate polymer; and

electronics operably connected to the working electrode and the reference electrode, and configured to process the first signal;

wherein the working electrode and the reference or counter electrode are horizontally displaced along a longitudinal axis defined by the first conductive layer such that the second electrode extends outwardly beyond the working electrode, wherein a portion of the first insulative layer is configured to act as a diffusion barrier between the working electrode and the reference or counter electrode, and wherein the horizontal displacement comprises a distance sufficient to prevent diffusion of an electroactive species between the working electrode and the reference or counter electrode; and

wherein the sensor comprises an in vivo portion configured for insertion into the host and an ex vivo portion configured for operable connection with sensor electronics;

wherein the sensor is configured to extend across a skin of the host and to flex in response to a mechanical pressure and to then to regain its original shape during use.

2. The sensor of claim 1, wherein the sensor is configured for implantation into the host.

3. The sensor of claim 2, wherein the sensor is configured for subcutaneous implantation in a tissue of the host.

4. The sensor of claim 2, wherein the sensor is configured for indwelling in a blood stream of the host.

5. The sensor of claim 1, wherein the sensor substantially continuously measures an analyte concentration of the host.

6. The sensor of claim 1, wherein the analyte sensor comprises a glucose sensor, and wherein the first working electrode is configured to generate a first signal associated with glucose and non-glucose related electroactive compounds, the glucose and the non-glucose related electro active compounds having a first oxidation potential.

7. The sensor of claim 1, wherein the working electrode and the reference electrode integrally form a substantial portion of the sensor configured for insertion in the host.

8. The sensor of claim 1, wherein the first conductive layer and the second conductive layer are substantially coaxial.

9. The sensor of claim 1, further comprising a membrane disposed over the first working electrode, wherein the membrane comprises a first domain configured to reduce a flux of glucose therethrough, wherein the first domain comprises a product of a reaction of an isocyanate compound with a compound comprising a hydroxyl group and/or a compound comprising an amine group.

10. The sensor of claim 9, wherein the membrane further comprises a second domain, wherein the second domain comprises an enzyme configured to react with glucose.

11. The sensor of claim 1, wherein the membrane comprises a blend comprising the silicone-urethane copolymer and a polymer comprising a hydrophilic segment.

13. The sensor of claim 9, wherein the membrane comprises a blend comprising the polyurethaneurea and a polymer comprising a hydrophilic segment.

12. A transcutaneous analyte sensor configured for insertion into a host for measuring an analyte in the host, the sensor comprising:

a first conductive layer comprising a working electrode, wherein the working electrode is configured to generate a signal indicative of an analyte concentration;

a first insulative layer covering at least a portion of the first conductive layer;

a second conductive layer covering at least a portion of the first insulative layer, wherein the second conductive layer comprises a reference or counter electrode;

a second insulative layer covering at least a portion of the second conductive layer;

a membrane covering at least a portion of the first electrode, wherein the membrane comprises a polyurethaneurea and an acrylate polymer; and

electronics operably connected to the working electrode and the reference electrode, and configured to process the first signal;

wherein the working electrode and the reference or counter electrode are horizontally displaced along a longitudinal axis defined by the first conductive layer such that the second electrode extends outwardly beyond the working electrode, wherein a portion of the first insulative layer is configured to act as a diffusion barrier between the working electrode and the reference or counter electrode, and wherein the horizontal displacement comprises a distance sufficient to prevent diffusion of an electroactive species between the working electrode and the reference or counter electrode;

wherein the sensor comprises an in vivo portion configured for insertion into the host and an ex vivo portion configured for operable connection with sensor electronics;

wherein the sensor is configured to extend across a skin of the host and to flex in response to a mechanical pressure and to then to regain its original shape during use.