Analyte sensors having a signal-to-noise ratio substantially unaffected by non-constant noise

Abstract

Systems and methods of use involving sensors having a signal-to-noise ratio that is substantially unaffected by non-constant noise are provided for continuous analyte measurement in a host. In some embodiments, a continuous analyte measurement system is configured to be wholly, transcutaneously, intravascularly or extracorporeally implanted.

What is claimed is: 
     
         1 . An electrochemical continuous glucose sensor configured for implantation in a host, the glucose sensor comprising:
 an electrode configured to measure a signal indicative of a glucose concentration of a host, wherein the signal comprises a glucose-related component and a non-glucose related component; and   a membrane covering at least a portion of the electrode, wherein the membrane is configured to reduce passage of an interfering species therethrough, whereby the non-glucose-related component of the signal is less than about 20% of the signal over a period of at least one day;   wherein the glucose sensor has a sensitivity to glucose of from about 25 pA/mg/dL to about 500 pA/mg/dL.   
     
     
         2 . The glucose sensor of  claim 1 , wherein the interfering species has an oxidation potential that overlaps with an oxidation potential of a measured species indicative of the concentration of the analyte. 
     
     
         3 . The glucose sensor of  claim 1 , wherein the measured species is a product of an enzymatic reaction between glucose and an enzyme and is measured by the electrode. 
     
     
         4 . The glucose sensor of  claim 1 , wherein the membrane comprises a silicone-containing polymer. 
     
     
         5 . The glucose sensor of  claim 4 , wherein the silicone-containing polymer is a polysiloxanes. 
     
     
         6 . The glucose sensor of  claim 4 , wherein the silicone-containing polymer is a polycarbosiloxane. 
     
     
         7 . The glucose sensor of  claim 4  wherein the silicone-containing polymer is a copolymer comprising a silicone segment and a polyurethane segment. 
     
     
         8 . The glucose sensor of  claim 1 , wherein the membrane comprises a fluorocarbon-based material. 
     
     
         9 . The glucose sensor of  claim 1 , wherein the non-glucose-related component is less than about 10% of the signal over a time period of at least about one day. 
     
     
         10 . The glucose sensor of  claim 1 , wherein the glucose sensor has a sensitivity to glucose of from about 25 pA/mg/dL to about 100 pA/mg/dL. 
     
     
         11 . The glucose sensor of  claim 1 , wherein the glucose sensor comprises an enzyme configured to react with glucose. 
     
     
         12 . An electrochemical continuous glucose sensor configured for implantation in a host, the glucose sensor comprising:
 an electrode configured to measure a signal indicative of a glucose concentration of a host, wherein the signal comprises a glucose-related component and a non-glucose related component; and   an enzyme-containing membrane covering at least a portion of the electrode, wherein the enzyme-containing membrane comprises an outer domain comprising a discontinuously hydrophilic surface, wherein the outer domain comprises at least about 5 wt. % of a hydrophilic component.   
     
     
         13 . The glucose sensor of  claim 12 , wherein the discontinuously hydrophilic outer domain comprises a blend comprising a silicone-containing polymer and a hydrophilic polymer. 
     
     
         14 . The glucose sensor of  claim 12 , wherein the membrane comprises a fluorocarbon-based material. 
     
     
         15 . The glucose sensor of  claim 12 , wherein the hydrophilic polymer is a copolymer of poly(ethylene oxide) and poly(propylene oxide). 
     
     
         16 . The glucose sensor of  claim 12 , wherein the discontinuously hydrophilic outer domain comprises a polyurethane-based domain that has been surface-treated with a polymer containing hydrophilic moieties 
     
     
         17 . The glucose sensor of  claim 12 , wherein the outer domain comprises at least about 15 wt. % of a hydrophilic component. 
     
     
         18 . The glucose sensor of  claim 12 , wherein the outer domain comprises at least about 25 wt. % of a hydrophilic component. 
     
     
         19 . The glucose sensor of  claim 12 , wherein the glucose sensor has a sensitivity to glucose of from about 25 pA/mg/dL to about 500 pA/mg/dL. 
     
     
         20 . The glucose sensor of  claim 12 , wherein the glucose sensor has a sensitivity to glucose of from about 25 pA/mg/dL to about 100 pA/mg/dL.