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.

1 . A method for processing data from a glucose sensor, the method comprising:
 receiving sensor data corresponding to a time period from the glucose sensor, the sensor data representative of glucose values of a host for the time period;   processing and displaying a graphical representation of the sensor data on a hand-held unit; and   post-processing and re-displaying a graphical representation of the sensor data corresponding to the time period on the handheld unit, whereby the post-processed and re-displayed graphical representation more closely represents the actual glucose values of the host for the time period.   
     
     
         2 . The method of  claim 1 , wherein post-processing is conducted responsive to a request. 
     
     
         3 . The method of  claim 1 , wherein post-processing is conducted automatically. 
     
     
         4 . The method of  claim 1 , further comprising determining whether a signal artifact event has occurred, wherein the post-processing is based at least in part upon whether the signal artifact event has occurred. 
     
     
         5 . The method of  claim 4 , wherein a signal artifact event is determined to have occurred if a residual associated with the sensor data exceeds a threshold value. 
     
     
         6 . The method of  claim 1 , wherein the displaying comprises displaying calibrated sensor data, and wherein the post-processing comprises re-calibrating the sensor data corresponding to the time period, and wherein the re-displaying comprises displaying a graphical representation of the recalculated sensor data corresponding to the time period. 
     
     
         7 . The method of  claim 1 , wherein post-processing comprises filtering the data to recalculate data corresponding to the time period. 
     
     
         8 . The method of  claim 1 , wherein the post-processing comprises recalculating the sensor data corresponding to the time period, wherein a time lag induced by real-time filtering is substantially removed from the sensor data corresponding to the time period. 
     
     
         9 . The method of  claim 1 , wherein post-processing the data comprises algorithmically smoothing the sensor data over a moving window, wherein the moving window comprises time points before and after each sensor data point is obtained. 
     
     
         10 . A system configured to process data from an analyte sensor, the system comprising:
 a data receiving module configured to receive sensor data corresponding to a time period from the analyte sensor, the sensor data representative of glucose values of a host for the time period;   an output module configured to display a substantially real-time numerical value corresponding to a most recently received sensor data point and a graphical representation of sensor data corresponding to the time period; and   a processor module configured to post-process the sensor data corresponding to the time period, wherein the output module is configured to re-display a graphical representation of the post-processed sensor data corresponding to the time period, whereby the graphical representation of the post-processed sensor data more closely represents the actual glucose values of the host for the time period.   
     
     
         11 . The system of  claim 10 , wherein processor module is configured to post-process the displayed data responsive to a request. 
     
     
         12 . The system of  claim 10 , wherein processor module is configured to post-process substantially automatically. 
     
     
         13 . The system of  claim 10 , wherein the processor module is configured to determine whether a signal artifact event has occurred, wherein the post-processing is based at least in part upon whether the signal artifact event has occurred. 
     
     
         14 . The system of  claim 13 , wherein the processor module is configured determining whether a signal artifact has occurred by comparing the received data with filtered data to obtain at least one residual, wherein a signal artifact event is determined to have occurred if the residual is exceeds a threshold value. 
     
     
         15 . The system of  claim 10 , wherein the processor module is configured to post-process the sensor data by filtering and recalculate the data corresponding to the time period, whereby the output module displays the graphical representation of the recalculated data corresponding to the time period. 
     
     
         16 . The system of  claim 10 , wherein the processor module is configured to post-process the sensor data by recalculating the sensor data corresponding to the time period, wherein a time lag induced by real-time filtering is substantially removed from the sensor data corresponding to the time period, and wherein the output module is further configured to display a graphical representation of the recalculated data corresponding to the time period. 
     
     
         17 . The system of  claim 10 , wherein processor module is configured to post-process the sensor data by algorithmically smoothing a plurality of sensor data points of the sensor data over a moving window, wherein the moving window comprises time points before and after each smoothed data point was obtained.