Systems and methods for processing sensor data

• US 9,149,234 B2
• Filed: 06/13/2012
• Issued: 10/06/2015
• Est. Priority Date: 12/17/2007
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Kamath, Apurv Ullas, Mensinger, Michael Robert, Li, Ying, Mahalingam, Aarthi, Dobbles, John Michael
• Primary Examiner(s): D'ANGELO, MICHAEL J
• Application Number:
  US13/495,976
• Publication Number:
  US 20120302855A1
• Time in Patent Office: 1,210 Days
• Field of Search: 600/309, 600/316, 600345-347, 600/365
• US Class Current: 1/1
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 2560/04 Constructional details of apparatus
• CPC Class Codes: A61B 2562/085 combined with means for recording calibration data
• CPC Class Codes: A61B 5/0008 Temperature signals
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• 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 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• 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 5/4839 combined with drug delivery
• CPC Class Codes: A61B 5/6848 Needles
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/7221 Determining signal validity, reliability or quality A61B5/7207 and A61B5/7217 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 5/742 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: 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: G16H 15/00 : ICT specially adapted for medical reports, e.g. generation or transmission thereof
• CPC Class Codes: G16H 20/00 : ICT specially adapted for therapies or health-improving plans, e.g. for handling prescriptions, for steering therapy or for monitoring patient compliance
• CPC Class Codes: G16H 20/10 : relating to drugs or medications, e.g. for ensuring correct administration to patients
• CPC Class Codes: G16H 20/17 : delivered via infusion or injection
• CPC Class Codes: G16H 40/40 : for the management of medical equipment or devices, e.g. scheduling maintenance or upgrades
• CPC Class Codes: G16H 40/63 : for local operation
• CPC Class Codes: G16H 50/50 : for simulation or modelling of medical disorders
• 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 calibration of a continuous glucose sensor, the method comprising:

receiving a signal from a continuous glucose sensor;

determining a sensor performance during a sensor session based on determining an amount of drift on the signal over a period of time, wherein determining the amount of drift comprises monitoring a change in calibration information;

determining a time in the future when to request reference data responsive to the sensor performance determined, wherein the time is selected from a plurality of predetermined time periods based on sensor performance; and

displaying an indication on a display device representative of a request to obtain the reference data, wherein the displaying is responsive to the determined time; and

controlling delivery and/or insulin therapy instructions based on the sensor performance.

2. The method of claim 1, wherein the calibration information comprises one or more matched data pairs, a calibration set and/or a calibration line.

3. The method of claim 1, wherein the reference data is a reference value obtained using a blood glucose meter.

4. The method of claim 1, further comprising requesting reference data, using the display device, at predetermined time intervals during a sensor session of the sensor.

5. The method of claim 4, further comprising modifying the predetermined time intervals based on the determined sensor performance, and wherein the determined time is based on the predetermined intervals.

6. The method of claim 5, wherein the indication is representative of the time until a next reference value is needed.

7. The method of claim 1, wherein the determined time is greater when the amount of sensor drift is determined to be low than when the amount of sensor drift is determined to be high so as to minimize the number of reference data requests while ensuring a level of sensor performance.

8. The method of claim 1, wherein determining the time comprises applying the determined sensor performance to predefined criteria, wherein the time is greater when the sensor performance meets the predetermined criteria than when not meeting the predetermined criteria.

9. A system for processing continuous glucose sensor data, the system comprising:

a continuous analyte sensor configured to continuously measure a concentration of an analyte in a host;

a computer system configured to receive sensor data from the continuous analyte sensor, wherein the computer system is configured to determine a sensor performance during a sensor session and to process a signal from the sensor responsive to the evaluation, wherein the evaluation comprises monitoring a change in calibration information to determine an amount of drift on the signal over a period of time, wherein the computer system is configured to determine a time in the future when to request reference data based on the sensor performance, wherein the time is selected from a plurality of predetermined time periods based on sensor performance; and

a display device configured to display an indication representative of a request to obtain the reference data, wherein the displaying is responsive to the determined time,

wherein the computer system is further configured to control delivery and/or insulin therapy instructions based on the sensor performance.

10. The system of claim 9, wherein the calibration information comprises one or more matched data pairs, a calibration set and/or a calibration line.

11. The system of claim 9, wherein the computer system is configured to diagnose a sensor condition based on the sensor performance.

12. The system of claim 9, wherein the computer system is configured to control an alarm indicative of at least one of hypoglycemia, hyperglycemia, predicted hypoglycemia, or predicted hyperglycemia based on the sensor performance.

13. The system of claim 9, wherein the computer system is incorporated in a hand-held receiver device.

14. The system of claim 9, wherein the computer system is incorporated in sensor electronics configured to be physically coupled to the continuous analyte sensor.

15. The system of claim 9, wherein the reference data is a reference value obtained using a blood glucose meter.

16. The system of claim 9, wherein the display device is configured to request reference data at predetermined time intervals during a sensor session of the sensor.

17. The system of claim 16, wherein the computer system is configured to modify the predetermined time intervals based on the determined sensor performance, and wherein the determined time is based on the predetermined intervals.

18. The system of claim 17, wherein the indication is representative of the time until a next reference value is needed.

19. The system of claim 9, wherein the determined time is greater when the amount of sensor drift is determined to be low than when the amount of sensor drift is determined to be high so as to minimize the number of reference data requests while ensuring a level of sensor performance.

20. The system of claim 9, wherein the computer system is configured to determine a time when to request reference data based on the sensor performance by applying the determined sensor performance to predefined criteria, wherein the time is greater when the sensor performance meets the predetermined criteria than when not meeting the predetermined criteria.