Analyte sensor with increased reference capacity

• US 10,470,691 B2
• Filed: 12/06/2016
• Issued: 11/12/2019
• Est. Priority Date: 07/02/2009
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Rong, Daiting, Bohm, Sebastian, Wightlin, Matthew D.
• Primary Examiner(s): Leong, Susan D
• Application Number:
  US15/370,357
• Publication Number:
  US 20170079566A1
• Time in Patent Office: 1,071 Days
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 2562/0209 Special features of electrodes classified in A61B5/24, A61B5/25, A61B5/283, A61B5/291, A61B5/296, A61B5/053
• CPC Class Codes: A61B 2562/043 in a linear array
• 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 5/14865 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors

Abstract

Systems and methods of use for continuous analyte measurement of a host'"'"'s vascular system are provided. In some embodiments, a continuous glucose measurement system includes an electrochemical sensor incorporating a silver/silver chloride reference electrode, wherein a capacity of the reference electrode is controlled.

Claims

1. An implantable electrochemical sensor for measuring an analyte concentration in a host, comprising:

a two-electrode sensor assembly configured to be implanted in a host and be exposed to interstitial fluid, wherein the two-electrode sensor assembly comprises;

a working electrode configured to measure a signal associated with a concentration of an analyte;

a reference electrode, wherein the reference electrode comprises a conductive material, wherein the reference electrode is configured to provide substantially stable reference potential for sixteen days while continuously responding to a signal current of 20 nA from the working electrode; and

an enzyme-containing membrane disposed over at least a portion of the working electrode, and wherein at least a portion of the reference electrode is in direct contact with the enzyme-containing membrane.

2. The implantable electrochemical sensor of claim 1, wherein the enzyme-containing membrane comprises an oxidase enzyme.

3. The implantable electrochemical sensor of claim 1, wherein the analyte is glucose.

4. The implantable electrochemical sensor of claim 1, wherein the conductive material comprises silver chloride.

5. The implantable electrochemical sensor of claim 1, wherein the reference electrode is formed of a chloridized elongated silver body.

6. The implantable electrochemical sensor of claim 1, wherein the enzyme-containing membrane has a thickness from about 0.01 microns to about 12 microns thick.