Low oxygen in vivo analyte sensor

Abstract

The present invention relates generally to systems and methods for measuring an analyte in a host. More particularly, the present invention relates to systems and methods for transcutaneous and subcutaneous measurement of glucose in a host.

What is claimed is: 
     
         1 . An analyte sensor system comprising:
 a transcutaneous analyte sensor body comprising an electrode configured to measure a glucose level in a host;   a membrane disposed over the electrode, the membrane comprising:
 a first layer configured to limit transport of glucose to the electrode; and 
 a second layer comprising an enzyme to catalyze a reaction of glucose and oxygen as a co-reactant; and 
   a sensor electronics unit operably connected to the electrode and configured to measure a current produced by the electrode, wherein the sensor electronics unit is configured to measure glucose concentration with substantial linearity at glucose concentrations of up to about 400 mg/dL at an oxygen concentration of 0.6 mg/L.