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1. WO2019118060 - PROCÉDÉS ET SYSTÈMES DE SURVEILLANCE CONTINUE DU GLUCOSE

Note: Texte fondé sur des processus automatiques de reconnaissance optique de caractères. Seule la version PDF a une valeur juridique

[ EN ]

WHAT IS CLAIMED IS:

1. A method for optional external calibration of a calibration-free glucose sensor for measuring the level of glucose in a body of a user, said glucose sensor including physical sensor electronics, a microcontroller, and a working electrode, the method comprising:

periodically measuring, by said physical sensor electronics, electrode current (Isig) signals for the working electrode;

performing, by said microcontroller, an Electrochemical Impedance Spectroscopy (EIS) procedure to generate ElS-related data for the working electrode;

based on said Isig signals and ElS-related data and a plurality of calibration-free SG-predictive models, calculating, by said microcontroller, a respective sensor glucose (SG) value for each of the SG-predictive models;

calculating, by said microcontroller, a SG variance estimate for each respective SG value; determining, by said microcontroller, whether an external blood glucose (BG) value is available and, when available, incorporating said BG value into said calculation of the SG value; fusing, by said microcontroller, said respective SG values from the plurality of SG-predictive models to obtain a single, fused SG value;

applying, by said microcontroller, an unscented Kalman filter to said fused SG value; and calculating, by said microcontroller, a calibrated SG value to be displayed to the user.

2. The method of claim 1, wherein the sensor electronics further measure voltage values of a counter electrode (Vcntr) of said glucose sensor.

3. The method of claim 2, wherein the microcontroller further preprocesses said Isig signals and Vcntr values prior to calculation of said respective SG values.

4. The method of claim 3, further including applying a low-pass filter to said Isig signals.

5. The method of claim 3, wherein said preprocessing comprises down-sampling Isig signals that are close together in time.

6. The method of claim 1, wherein said plurality of SG-predictive models are machine learning models.

7. The method of claim 6, wherein said machine learning models include at least one of a genetic programming algorithm, a regression decision tree, and a bagged decision tree.

8. The method of claim 1, wherein said plurality of SG -predictive models are analytical models.

9. The method of claim 1, wherein each SG variance estimate for each respective SG value is calculated empirically from training data.

10. The method of claim 1, wherein one or more of said respective SG values are modulated for a period of time prior to said fusion.

11. The method of claim 10, wherein, when a BG value is available, said BG value is compared to a respective SG value, and said modulation is performed when a difference between said respective SG value and BG value exceeds a threshold.

12. The method of claim 1, wherein said Kalman filter contains one set of measurement functions for when an external BG value is available, and one set of measurement functions for when an external BG value is not available.

13. The method of claim 1, wherein, when an external BG value is available, said BG value is incorporated into said calculation of the SG value prior to said fusion.

14. The method of claim 1, wherein, when an external BG value is available, said BG value is used to adjust said single, fused SG value.

15. The method of claim 1, wherein the sensor includes a plurality of working electrodes.

16. A glucose monitoring system comprising:

a glucose sensor device for determining the concentration of glucose in a body of a user during a total sensor-device wear time, said total sensor-device wear time including a first time window, a subsequent second time window, and a transition period between said first time window and said second time window, said glucose sensor device comprising:

a first glucose sensor; and

a second glucose sensor, said first and second glucose sensors having disparate characteristics in at least one of hydration, stabilization, and durability; and

sensor electronics, said sensor electronics including at least one physical microprocessor that is configured to:

(a) periodically receive from the first glucose sensor respective first output signals indicative of glucose concentration levels in the user’ body;

(b) calculate glucose concentration levels in the user’s body based entirely on the first output signals during said first time window;

(c) periodically receive from the second glucose sensor respective second output signals indicative of glucose concentration levels in the user’ body;

(d) calculate glucose concentration levels in the user’s body based on both the first and second output signals during said transition period; and

(e) calculate glucose concentration levels in the user’s body based entirely on the second output signals during said second time window.

17. The system of claim 16, wherein at least one of the first glucose sensor and the second glucose sensor is a calibration-free sensor.

18. The system of claim 17, wherein at least one of the first glucose sensor and the second glucose sensor is a calibrated sensor.

19. The system of claim 16, wherein the sensor device is either implanted or subcutaneously disposed in the user’s body.

20. The system of claim 16, wherein at least one of the first and second sensors is calibrated with an optional reference blood glucose (BG) value.

21. The system of claim 16, wherein each of the first and second sensors is calibrated with at least one of: the output signal (Isig) from the other sensor, the voltage from a counter electrode (Vcntr) in each respective sensor, an electrochemical impedance spectroscopy (ElS)-related parameter, and diagnostic outputs for each respective sensor.

22. The system of claim 16, wherein, based on said hydration, stabilization, and durability characteristics of the first and second glucose sensors, the microprocessor determines a beginning time and an end time for each of the first time window, the transition period, and the second time window.

23. The system of claim 22, wherein the microprocessor periodically fuses said first and second output signals to calculate a single, fused glucose value during the transition period.

24. The system of claim 16, wherein, during the transition period, the microprocessor compares said first and second output signals to diagnose whether each respective glucose sensor is functioning properly.

25. The system of claim 24, wherein, based on said comparison and diagnosis, the microprocessor assigns respective weights to said first and second output signals to generate respective weighted first and second signals.

26. The system of claim 25, wherein the microprocessor periodically calculates a single, fused glucose value based on said weighted first and second signals.

27. The system of claim 16, wherein both of the first and second glucose sensors are calibration-free sensors.

28. The system of claim 27, wherein the microprocessor uses said first output signals from the first glucose sensor to calibrate said second glucose sensor.

29. The system of claim 28, wherein the microprocessor uses said second output signals from the second glucose sensor to calibrate said first glucose sensor.

30. The system of claim 27, wherein at least one of the first and second glucose sensors is optionally calibrated with a reference blood glucose (BG) value.

31. The system of claim 16, further including a transmitter, wherein the transmitter is worn on the user’s body.

32. The system of claim 31, further including a handheld monitor.

33. The system of claim 32, further including an insulin pump.

34. The system of claim 33, wherein said glucose monitoring system is a closed-loop system.