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 interfering species, ischemia, pH changes, temperatures changes, known or unknown sources of mechanical, electrical and/or biochemical noise, 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 processes some or the entire data stream continually or intermittently based at least in part on whether the signal artifact event has occurred.

What is claimed is: 
     
         1 . A method of analyzing data from an analyte sensor, the method comprising:
 receiving data from the analyte sensor, the data comprising at least one sensor data point;   determining whether a signal artifact event has occurred; and   processing the received data, wherein the processing is based at least in part upon whether the signal artifact event has occurred.   
     
     
         2 . The method of  claim 1 , further comprising filtering the received data to generate filtered data. 
     
     
         3 . The method of  claim 2 , wherein determining whether a signal artifact has occurred comprises comparing the received data with the filtered data to obtain at least one residual. 
     
     
         4 . The method of  claim 3 , wherein a signal artifact event is determined to have occurred if the residual is exceeds a threshold value. 
     
     
         5 . The method of  claim 4 , further comprising determining whether another signal artifact event has occurred, wherein another signal artifact event has occurred if the residual exceeds a second threshold value. 
     
     
         6 . The method of  claim 3 , wherein a signal artifact event is determined to have occurred if the residual is exceeds a threshold value for a predetermined period of time or for a predetermined amount of data. 
     
     
         7 . The method of  claim 6 , wherein determining whether a signal artifact has occurred further comprises determining whether a predetermined number of residuals exceeds a threshold over a predetermined period of time, or whether a predetermined amount of data exceeds a threshold. 
     
     
         8 . The method of  claim 3 , wherein determining whether a signal artifact event has occurred further comprises determining a differential between a first residual at a first time point and a second residual at a second time point. 
     
     
         9 . The method of  claim 8 , wherein determining whether a signal artifact event has occurred further comprises determining whether a predetermined number of differentials exceeds a threshold over a predetermined period of time, or whether an amount of data exceeds a threshold. 
     
     
         10 . The method of  claim 1 , further comprising receiving reference data from a reference analyte monitor, the reference data including at least one reference data point. 
     
     
         11 . The method of  claim 10 , wherein processing the received data further comprises determining a reliability of the received data, wherein processing is conducted if the signal artifact event is determined to have not occurred. 
     
     
         12 . The method of  claim 10 , further comprising matching the reference data to substantially time corresponding received data to form a matching data pair, wherein the reference data is matched if the signal artifact event is determined to have not occurred. 
     
     
         13 . The method of  claim 10 , further comprising including the reference data in a calibration factor for use in calibrating the glucose sensor, wherein the reference data is included if the signal artifact event is determined to have not occurred. 
     
     
         14 . The method of  claim 1 , further comprising prompting a user for a reference glucose value, wherein prompting is conducted if the signal artifact event is determined to have not occurred. 
     
     
         15 . The method of  claim 1 , wherein processing the received data comprises displaying a graphical representation of the received data. 
     
     
         16 . The method of  claim 1 , wherein processing the received data comprises filtering the received data, wherein filtering is conducted if the signal artifact event is determined to have occurred. 
     
     
         17 . The method of  claim 1 , further comprising filtering the received data, wherein processing the received data comprises displaying a graphical representation of the filtered data, wherein processing is conducted if the signal artifact event is determined to have occurred. 
     
     
         18 . The method of  claim 1 , further comprising filtering the received data to generate filtered data, wherein determining whether a signal artifact event has occurred further comprises comparing the received data with the filtered data to obtain a residual, and wherein processing the received data comprises utilizing the residual to modify the filtered data. 
     
     
         19 . The method of  claim 1 , further comprising filtering the received data to generate filtered data, wherein determining whether a signal artifact event has occurred further comprises comparing the received data with the filtered data to obtain a residual and deriving a differential of the residual by calculating a first derivative of the residual, and wherein processing the received data comprises utilizing the differential to modify the filtered data. 
     
     
         20 . A system configured to process data from an analyte sensor, the system comprising:
 a data receiving module configured to receive sensor data from the analyte sensor, the data comprising at least one sensor data point;   a signal artifacts module configured to detect a signal artifact in the sensor data; and   a processor module configured to process the sensor data, wherein processing is dependent at least in part upon whether the signal artifact is detected.