Dual electrode system for a continuous analyte sensor

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.

What is claimed is: 
     
         1 . A glucose sensor system configured for insertion into a host for measuring a glucose concentration in the host, the sensor comprising:
 a first working electrode configured to generate a first signal associated with glucose and non-glucose related electroactive compounds, the glucose and non-glucose related electro active compounds having a first oxidation potential;   a second working electrode configured to generate a second signal associated with noise of the glucose sensor comprising signal contribution due to non-glucose related electro active compounds with an oxidation potential that substantially overlaps with the first oxidation potential; and   electronics operably connected to the first working electrode and the second working electrode and configured to process the first signal and the second signal to generate a glucose concentration substantially without signal contribution due to non-glucose related noise.   
     
     
         2 . The system of  claim 1 , wherein the non-glucose related noise is substantially non-constant. 
     
     
         3 . The system of  claim 1 , wherein the electronics are configured to substantially remove noise caused by at least one of biochemical factors and chemical factors. 
     
     
         4 . The system of  claim 3 , wherein at least one of the biochemical factors and the chemical factors are substantially non-constant and are selected from the group consisting of compounds with electroactive acidic groups, compounds with electro active amine groups, compounds with electro active sulfhydryl groups, urea, lactic acid, phosphates, citrates, peroxides, amino acids, amino acid precursors, amino acid break-down products, nitric oxide, nitric oxide-donors, nitric oxide-precursors, electroactive species produced during cell metabolism, electro active species produced during wound healing, and electro active species that arise during body pH changes. 
     
     
         5 . The system of  claim 4 , wherein the first working electrode and the second working electrode are configured to substantially equally measure noise due to at least one of the biochemical factors and the chemical factors whereby noise caused by at least one of the biochemical factors and the chemical factors can be substantially removed. 
     
     
         6 . The system of  claim 1 , wherein the electronics are configured to subtract the second signal from the first signal, whereby a differential signal comprising at least one glucose sensor data point is determined. 
     
     
         7 . The system of  claim 6 , wherein the electronics are configured to electronically subtract the second signal from the first signal. 
     
     
         8 . The system of  claim 6 , wherein the electronics comprise at least one of hardware and software configured to digitally subtract the second signal from the first signal. 
     
     
         9 . The system of  claim 1 , wherein the first working electrode and the second working electrode are configured to be impacted by biochemical factors to substantially the same extent. 
     
     
         10 . The system of  claim 9 , wherein the first working electrode and the second working electrode have a symmetrical configuration. 
     
     
         11 . The sensor of  claim 1 , further comprising a non-conductive material positioned between the first working electrode and the second working electrode. 
     
     
         12 . The sensor of  claim 1 , wherein each of the first working electrode, the second working electrode, and the non-conductive material are configured provide at least two functions selected from the group consisting of electrical conductance, insulative property, structural support, and diffusion barrier. 
     
     
         13 . The sensor of  claim 1 , wherein the sensor comprises a diffusion barrier configured to substantially block diffusion of at least one of the analyte and the co-analyte between the first working electrode and the second working electrode. 
     
     
         14 . The sensor of  claim 1 , wherein the first working electrode, the second working electrode, and an insulator integrally form a substantial portion of the sensor configured for insertion in the host. 
     
     
         15 . The sensor of  claim 14 , further comprising a reference electrode, wherein the first working electrode, the second working electrode, and the reference electrode integrally form a substantial portion of the sensor configured for insertion in the host. 
     
     
         16 . An analyte sensor configured for insertion into a host for measuring an analyte in the host, the sensor comprising:
 a first working electrode disposed beneath an active enzymatic portion of a membrane;   a second working electrode disposed beneath an inactive-enzymatic or non-enzymatic portion of a membrane, wherein the first working electrode and the second working electrode are configured to substantially equally measure non-analyte related noise, whereby the noise is substantially removed; and   electronics operably connected to the first working electrode and the second working electrode, and configured to process the first signal and the second signal to generate sensor analyte data substantially without signal contribution due to non-analyte related noise.   
     
     
         17 . The system of  claim 16 , wherein the non-glucose related noise is substantially non-constant. 
     
     
         18 . The system of  claim 16 , wherein the non-analyte related noise is due to a factor selected from the group consisting of biochemical factors, chemical factors, and combinations thereof. 
     
     
         19 . The system of  claim 18 , wherein the electronics are configured to substantially remove noise caused by at least one of biochemical factors and chemical factors. 
     
     
         20 . The system of  claim 19 , wherein at least one of the biochemical factors and the chemical factors are substantially non-constant and are selected from the group consisting of compounds with electroactive acidic groups, compounds with electro active amine groups, compounds with electro active sulfhydryl groups, urea, lactic acid, phosphates, citrates, peroxides, amino acids, amino acid precursors, amino acid break-down products, nitric oxide, nitric oxide-donors, nitric oxide-precursors, electroactive species produced during cell metabolism, electro active species produced during wound healing, and electro active species that arise during body pH changes.