Systems and methods for processing sensor data

• US 9,717,449 B2
• Filed: 01/15/2013
• Issued: 08/01/2017
• Est. Priority Date: 10/25/2007
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Mahalingam, Aarthi, Dobbles, John Michael, Kamath, Apurv Ullas
• Primary Examiner(s): Natnithithadha, Navin
• Assistant Examiner(s): MESSERSMITH, ERIC J
• Application Number:
  US13/742,178
• Publication Number:
  US 20130150692A1
• Time in Patent Office: 1,659 Days
• CPC Class Codes: A61B 5/0004 characterised by the type of physiological signal transmitted
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/1477 non-invasive
• 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 5/6833 Adhesive patches
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/725 using specific filters therefor, e.g. Kalman or adaptive filters A61B5/316 take precedence
• 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 5/7278 Artificial waveform generation or derivation, e.g. synthesising signals from measured signals A61B5/327 takes precedence
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: A61B 5/743 Displaying an image simultaneously with additional graphical information, e.g. symbols, charts, function plots
• CPC Class Codes: G16H 40/40 for the management of medical equipment or devices, e.g. scheduling maintenance or upgrades
• 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 processing sensor data are provided. In some embodiments, systems and methods are provided for calibration of a continuous analyte sensor. In some embodiments, systems and methods are provided for classification of a level of noise on a sensor signal. In some embodiments, systems and methods are provided for determining a rate of change for analyte concentration based on a continuous sensor signal. In some embodiments, systems and methods for alerting or alarming a patient based on prediction of glucose concentration are provided.

Claims

1. A method for generating analyte measurements of a host, the method comprising:

generating sensor data during a first time period using an analyte sensor coupled to a sensor electronics unit, wherein the sensor electronics unit is adhered to a body of a host;

receiving, using a receiver in wireless communication with the sensor electronics unit, a reference analyte value generated by a reference analyte monitor;

responsive to receiving the reference analyte value, determining a first estimated analyte concentration value to display using an immediate calibration algorithm that includes matching the reference analyte value to a sensor data point closest with respect to time, wherein the first estimated analyte concentration value is associated with the analyte concentration of the host at a point in time;

determining a second estimated analyte concentration value to display using the reference analyte value and the sensor data for the first time period in a standard calibration algorithm that is different from the immediate calibration algorithm, wherein the standard calibration algorithm includes re-matching the reference analyte value to an optimal sensor data point or points, and wherein the second estimated analyte concentration value is associated with the analyte concentration of the host at the same point in time as the first estimated analyte concentration value; and

displaying, on a display of the receiver, a numerical analyte value selected from the first estimated analyte value and the second estimated analyte value, wherein the first estimated analyte concentration value is selected as the displayed numerical value until the second estimated analyte concentration is available, and subsequently selecting the second estimated analyte concentration value to be the displayed numerical value.

2. The method of claim 1, wherein the sensor data for the first time period is not used to determine the first estimated analyte concentration value.

5. The method of claim 1, wherein determining the second estimated analyte concentration value to display is performed responsive to determining that both the sensor data for the first time period and the reference analyte value are available for calibration.

6. The method of claim 5, further comprising periodically establishing wireless communication between the sensor electronics unit and the receiver, wherein the receiver sends the reference analyte value to the sensor electronics unit during the periodically established wireless communication and wherein the sensor electronics unit sends the first estimated analyte value to the receiver during the periodically established wireless communication.

7. The method of claim 6, wherein the second estimated analyte concentration value is not available due to the communication between the sensor electronics and the receiver.

8. The method of claim 1, wherein the second estimated analyte concentration value is not available until both the reference analyte value and the sensor data generated during the first time period are available to be used in the standard calibration algorithm.

9. The method of claim 1, wherein the standard calibration algorithm is performed by the sensor electronics module.

10. The method of claim 1, wherein the immediate calibration algorithm is performed by the receiver.

11. The method of claim 1, wherein receiving the reference analyte value comprises receiving user input using a user interface of the receiver or wirelessly receiving the reference analyte value using the receiver from the reference analyte monitor.

12. The method of claim 1, wherein the reference analyte monitor is a single-point blood glucose monitor.

13. The method of claim 1, where the analyte is glucose and wherein the sensor is a continuous glucose sensor.

14. The method of claim 1, wherein the standard calibration algorithm comprises a conversion function, wherein the conversion function is based on a matching of the reference analyte value to sensor data.

15. The method of claim 1, wherein displaying the first estimated analyte value is performed within 1 minute of receiving the reference analyte value and displaying the second estimated analyte value is performed subsequent to the reference analyte value and the sensor data being available for matching.

16. The method of claim 1, further comprising displaying a graphical representation of estimated analyte data over a time period simultaneously with the numerical analyte value.

17. The method of claim 1, wherein the optimal sensor data point or points includes an average of a plurality of sensor data points in a timeframe associated with the reference analyte value.

3. A method for generating analyte measurements of a host, the method comprising:

generating sensor data during a first time period using an analyte sensor coupled to a sensor electronics unit, wherein the sensor electronics unit is adhered to a body of a host;

receiving, using a receiver in wireless communication with the sensor electronics unit, a reference analyte value generated by a reference analyte monitor;

responsive to receiving the reference analyte value, determining a first estimated analyte concentration value associated with a point in time to display using an immediate calibration algorithm that includes matching the reference analyte value to a sensor data point closest with respect to time;

projecting an analyte concentration value, wherein using the immediate calibration algorithm comprises comparing the projected analyte concentration value to the reference data value;

determining a second estimated analyte concentration value associated with the point in time to display using the reference analyte value and the sensor data for the first time period in a standard calibration algorithm that is different from the immediate calibration algorithm, wherein the standard calibration algorithm includes matching the reference analyte value to an optimal sensor data point or points; and

displaying, on a display of the receiver, a numerical analyte value selected from the first estimated analyte value and the second estimated analyte value, wherein the first estimated analyte concentration value is selected as the displayed numerical value until the second estimated analyte concentration is available, and subsequently selecting the second estimated analyte concentration value to be the displayed numerical value.

4. The method of claim 3, wherein the projected analyte value is projected based on sensor data generated by the analyte sensor during a second time period that is prior to the first time period.