Analyte sensor with increased reference capacity

• US 9,517,025 B2
• Filed: 05/12/2016
• Issued: 12/13/2016
• Est. Priority Date: 07/02/2009
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Rong, Daiting, Bhm, Sebastian, Wightlin, Matthew D.
• Primary Examiner(s): LEONG, SUSAN DANG
• Application Number:
  US15/153,586
• Publication Number:
  US 20160256092A1
• Time in Patent Office: 215 Days
• US Class Current: 1/1
• 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 electrochemical sensor for measuring an analyte concentration in a host, comprising:

a working electrode configured to measure a concentration of an analyte; and

a reference electrode comprising a material that depletes during sensor use, wherein the material is configured to be regenerated during sensor use, and wherein a rate of material depletion during sensor use substantially correlates with a rate of material regeneration during sensor use over a time period.

2. The electrochemical sensor of claim 1, wherein a correlation between the rate of material regeneration and the rate of material depletion is positive.

3. The electrochemical sensor of claim 1, wherein the sensor is configured to increase the rate of material regeneration responsive to an increase in the rate of material depletion.

4. The electrochemical sensor of claim 1, wherein the sensor is configured to decrease the rate of material regeneration responsive to a decrease in the rate of material depletion.

5. The electrochemical sensor of claim 1, wherein at least a portion of the reference electrode is covered with an enzyme layer.

6. The electrochemical sensor of claim 5, wherein the enzyme is an oxidase enzyme.

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

8. The electrochemical sensor of claim 1, wherein the material is silver chloride.

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

10. The electrochemical sensor of claim 1, wherein the enzyme layer has a thickness from about 0.01 microns to about 12 microns thick.

11. The electrochemical sensor of claim 1, wherein a percentage of a surface area of the reference electrode covered with the enzyme layer is from about 10% to about 100%.