Signal processing for continuous analyte sensor

• US 9,192,328 B2
• Filed: 09/23/2009
• Issued: 11/24/2015
• Est. Priority Date: 12/09/2003
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Brauker, James H., Carr-Brendel, Victoria, Goode, Paul V., Kamath, Apurv U., Thrower, James P., Xavier, Ben
• Primary Examiner(s): Natnithithadha, Navin
• Application Number:
  US12/565,173
• Publication Number:
  US 20100016687A1
• Time in Patent Office: 2,253 Days
• Field of Search: 600/309, 600345-366
• US Class Current: 1/1
• 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 5/14503 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors A61B5/1459, A61B5/1464, A61B5/1473, A61B5/1482, A61B5/14865 take precedence
• CPC Class Codes: A61B 5/1451 for interstitial fluid
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/1468 using chemical or electrochemical methods, e.g. by polarographic means A61B5/1486 takes precedence
• CPC Class Codes: A61B 5/1473 invasive, e.g. introduced into the body by a catheter A61B5/1482 takes precedence
• CPC Class Codes: A61B 5/1486 using enzyme electrodes, e.g. with immobilised oxidase
• 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 5/1495 Calibrating or testing of in-vivo probes
• CPC Class Codes: A61B 5/7257 using Fourier transforms
• CPC Class Codes: A61B 5/726 using Wavelet transforms
• CPC Class Codes: A61B 5/7264 Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems neural networks per se G06N3/00; expert systems per se G06N5/00
• CPC Class Codes: A61B 5/7275 Determining trends in physiological measurement data; Predicting development of a medical condition based on physiological measurements, e.g. determining a risk factor
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: A61B 5/7455 characterised by tactile indication, e.g. vibration or electrical stimulation
• CPC Class Codes: A61B 5/746 Alarms related to a physiological condition, e.g. details of setting alarm thresholds or avoiding false alarms alarms per se G08B
• CPC Class Codes: A61B 5/7475 User input or interface means, e.g. keyboard, pointing device, joystick
• CPC Class Codes: A61M 5/1723 using feedback of body parameters, e.g. blood-sugar, pressure measurement of body parameters A61B5/00
• CPC Class Codes: G16Z 99/00 Subject matter not provided for in other main groups of this subclass
• 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 dynamically and intelligently estimating analyte data from a continuous analyte sensor, including receiving a data stream, selecting one of a plurality of algorithms, and employing the selected algorithm to estimate analyte values. Additional data processing includes evaluating the selected estimative algorithms, analyzing a variation of the estimated analyte values based on statistical, clinical, or physiological parameters, comparing the estimated analyte values with corresponding measure analyte values, and providing output to a user. Estimation can be used to compensate for time lag, match sensor data with corresponding reference data, warn of upcoming clinical risk, replace erroneous sensor data signals, and provide more timely analyte information encourage proactive behavior and preempt clinical risk.

Claims

1. A method for estimating analyte values from a continuous analyte sensor, the method comprising:

receiving a data stream from a continuous analyte sensor for a time period; and

estimating, using a processor module, one or more analyte values for a future time period, wherein estimating comprises predicting one or more analyte values for the future time period based on the data stream, applying one or more physiological parameters to the predicted one or more analyte values, and obtaining the estimated one or more analyte values based on the application of the one or more physiological parameters to the predicted one or more analyte values.

2. The method of claim 1, wherein the one or more physiological parameters include a predetermined rate of change.

3. The method of claim 2, wherein the predetermined rate of change is at least 4 mg/dL/min.

4. The method of claim 1, wherein the one or more physiological parameters include a predetermined acceleration.

5. The method of claim 4, wherein the predetermined acceleration is at least 0.1 mg/dL/min².

6. The method of claim 1, further comprising providing output based on the estimated one or more analyte values.

7. The method of claim 6, wherein providing output comprises displaying information on a display device based on the estimated one or more analyte values.

8. The method of claim 6, wherein providing output comprises alarming responsive to the estimated one or more analyte values meeting one or more criteria.

9. The method of claim 1, wherein estimating is responsive to an event trigger.

10. The method of claim 1, wherein the application of the one or more physiological parameters to the predicted one or more analyte values comprises determining physiological boundaries based on the one or more physiological parameters and determining whether the predicted one or more analyte values fall within the physiological boundaries.

11. The method of claim 10, wherein only predicted values that fall within the physiological boundaries are used to obtain the one or more estimated values.

12. A system for estimating analyte values from a continuous analyte sensor, the system comprising:

an input module operably connected to a continuous analyte sensor and configured to receive a data stream from the continuous analyte sensor for a time period; and

a processor module comprising programming configured to estimate one or more analyte values for a future time period, wherein the programming configured to estimate is configured to predict one or more analyte values for the future time period based on the data stream and obtain the estimated one or more analyte values based on an application of one or more physiological parameters to the predicted one or more analyte values.

13. The system of claim 12, wherein the one or more physiological parameters include a predetermined rate of change.

14. The system of claim 13, wherein the predetermined rate of change is at least 4 mg/dL/min.

15. The system of claim 12, wherein the one or more physiological parameters include a predetermined acceleration.

16. The system of claim 15, wherein the predetermined acceleration is at least 0.1 mg/dL/min².

17. The system of claim 12, wherein the processor module further comprises programming configured to provide output based on the estimated one or more analyte values.

18. The system of claim 17, wherein the programming configured to provide output is configured to display information on a display device based on the estimated one or more analyte values.

19. The system of claim 17, wherein the programming configured to provide output is configured provide an alarm responsive to the estimated one or more analyte values meeting one or more criteria.

20. The system of claim 12, wherein the programming configured to estimate is responsive to an event trigger.

21. The system of claim 12, wherein the application of the one or more physiological parameters to the predicted one or more analyte values comprises determining physiological boundaries based on the one or more physiological parameters and determining whether the predicted one or more analyte values fall within the physiological boundaries.

22. The system of claim 21, wherein only predicted values that fall within the physiological boundaries are used to obtain the one or more estimated values.