Systems and methods for replacing signal artifacts in a glucose sensor data stream

Abstract

Systems and methods for minimizing or eliminating transient non-glucose related signal noise due to non-glucose rate limiting phenomenon such as ischemia, pH changes, temperatures changes, and the like. The system monitors a data stream from a glucose sensor and detects signal artifacts that have higher amplitude than electronic or diffusion-related system noise. The system replaces some or the entire data stream continually or intermittently including signal estimation methods that particularly address transient signal artifacts. The system is also capable of detecting the severity of the signal artifacts and selectively applying one or more signal estimation algorithm factors responsive to the severity of the signal artifacts, which includes selectively applying distinct sets of parameters to a signal estimation algorithm or selectively applying distinct signal estimation algorithms.

What is claimed is: 
     
         1 . A method for processing data from a continuous glucose sensor, the method comprising:
 monitoring a data stream generated by a working electrode of a continuous glucose sensor, the data stream comprising a glucose sensor data point;   monitoring an output of a counter electrode of the continuous glucose sensor;   detecting a signal artifact associated with the glucose sensor data point;   classifying the signal artifact based on the monitoring of the output of the counter electrode;   selectively applying one or more of a plurality of signal estimation algorithms based on the classification to generate an estimated sensor data point; and   replacing the sensor data point with the estimated sensor data point.   
     
     
         2 . The method of  claim 1 , wherein the data stream comprises a raw data stream. 
     
     
         3 . The method of  claim 1 , wherein the data stream comprises a calibrated data stream of glucose concentration values. 
     
     
         4 . The method of  claim 1 , wherein the signal artifact is a transient non-glucose related signal artifact. 
     
     
         5 . The method of  claim 1 , further comprising displaying or transmitting the estimated data point. 
     
     
         6 . The method of  claim 1 , wherein the detecting comprises identifying a drop in the output of the counter electrode and associating the output drop with the glucose sensor data point. 
     
     
         7 . The method of  claim 1 , wherein electronic circuitry is used to perform one or more of the monitoring of the data stream, the monitoring of the output, the detecting, the classifying, the selectively applying and the replacing. 
     
     
         8 . The method of  claim 1 , wherein the continuous glucose sensor is an implantable sensor comprising the working electrode, the counter electrode and a reference electrode. 
     
     
         9 . The method of  claim 1 , wherein the detecting comprises comparing the data stream with the output of the counter electrode. 
     
     
         10 . The method of  claim 1 , wherein the output of the counter electrode is measured in units of counts. 
     
     
         11 . The method of  claim 1 , wherein the classifying comprises classifying a severity of the signal artifact. 
     
     
         12 . A system for processing data from a continuous glucose sensor, the system comprising:
 a continuous glucose sensor comprising a working electrode configured to generate a data stream and a counter electrode configured to generate a counter electrode output; and   an artifact replacement module configured to:
 monitor the counter electrode output; 
 detect a signal artifact associated with a portion of the data stream; 
 classify the signal artifact based on the monitoring of the counter electrode output; 
 selectively apply one or more of a plurality of signal estimation algorithms based on the classification to generate an estimated data stream portion; and 
 replace the portion of the data stream with the estimated data stream portion. 
   
     
     
         13 . The system of  claim 12 , wherein the data stream comprises a raw data stream. 
     
     
         14 . The system of  claim 12 , wherein the data stream comprises a calibrated data stream of glucose concentration values. 
     
     
         15 . The system of  claim 12 , wherein the signal artifact is a transient non-glucose related signal artifact. 
     
     
         16 . The system of  claim 12 , further comprising an output module configured to display or transmit the information representative of the estimated data stream portion. 
     
     
         17 . The system of  claim 12 , wherein the artifact replacement module is configured to detect by identifying a drop in the counter electrode output and associating the output drop with the portion of the data stream. 
     
     
         18 . The system of  claim 12 , wherein the continuous glucose sensor is an implantable sensor and further comprises a reference electrode. 
     
     
         19 . The system of  claim 12 , wherein the artifact replacement module is configured to detect by comparing the data stream with the counter electrode output. 
     
     
         20 . The system of  claim 12 , wherein the counter electrode output is measured in units of counts.