SYSTEMS AND METHODS FOR REPLACING SIGNAL ARTIFACTS IN A GLUCOSE SENSOR DATA STREAM

• US 20120215086A1
• Filed: 04/05/2012
• Published: 08/23/2012
• Est. Priority Date: 08/22/2003
• Status: Abandoned Application

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Kamath, Apurv, Brauker, James H., Mahalingam, Aarthi, Li, Ying
• Application Number:
  US13/440,971
• Publication Number:
  US 20120215086A1
• Time in Patent Office: Days
• US Class Current: 600/365
• CPC Class Codes: A61B 2560/0252 using ambient temperature
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 5/145 Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissuemeasuring of blood pressure or blood flow A61B5/02; non-radiation detecting or locating of foreign bodies in blood A61B5/06
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14539 for measuring pH
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• CPC Class Codes: A61B 5/14865 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors
• CPC Class Codes: A61B 5/6848 Needles
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/7225 Details of analog processing, e.g. isolation amplifier, gain or sensitivity adjustment, filtering, baseline or drift compensation A61B5/30, A61B5/316 take precedence; transformers for specific applications H01F38/00; amplifiers H03F
• CPC Class Codes: A61B 5/7239 using differentiation including higher order derivatives
• CPC Class Codes: A61B 5/7257 using Fourier transforms
• CPC Class Codes: A61B 5/726 using Wavelet transforms
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems
• CPC Class Codes: Y02A 90/10 Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

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.

Claims

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.