Methods and systems for analyzing glucose data measured from a person having diabetes

• US 10,617,363 B2
• Filed: 04/02/2015
• Issued: 04/14/2020
• Est. Priority Date: 04/02/2015
• Status: Active Grant

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Inventors: Diebold, Eric R, Greenburg, Alan, Duke, David L
• Primary Examiner(s): Berhanu, Etsub D
• Assistant Examiner(s): Catina, Michael A
• Application Number:
  US14/677,148
• Publication Number:
  US 20160287184A1
• Time in Patent Office: 1,839 Days
• CPC Class Codes: A61B 5/0022 Monitoring a patient using a global network, e.g. telephone networks, internet
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/4839 combined with drug delivery
• 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 5/7246 using correlation, e.g. template matching or determination of similarity
• CPC Class Codes: A61B 5/725 using specific filters therefor, e.g. Kalman or adaptive filters A61B5/316 take precedence
• CPC Class Codes: A61B 5/7275 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 5/7282 Event detection, e.g. detecting unique waveforms indicative of a medical condition A61B5/4094, A61B5/4818, A61B5/349, A61B5/0823 take precedence
• CPC Class Codes: A61B 5/7405 using sound
• 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: G16H 40/63 for local operation

Abstract

Methods and systems are disclosed analyzing a glucose level of a person having diabetes. The method, in at least one example, comprises receiving into a computing device a plurality of measured glucose values from a continuous glucose monitoring system coupled to a person having diabetes, analyzing the plurality of measured glucose values with a probability analysis tool on the computing device to determine a glucose threshold (g_I0), and a boundary glucose value (g_ρ) at a probability threshold where the person having diabetes requires at least a predetermined insulin dose, and comparing, with the computing device, the boundary glucose value (g_ρ) to the glucose threshold (g_I0), wherein if the boundary glucose value (g_ρ) is greater than the glucose threshold (g_I0) then the computing device performs an alert on a user interface.

Claims

1. A method of administering a safety insulin bolus for alerting a person having diabetes, the method comprising:

receiving into a computing device a plurality of measured glucose values from a continuous glucose monitoring system with a glucose sensor coupled to a person having diabetes;

calculating with the computing device a glucose threshold (g_Io) based upon a maximum allowable glucose, a correction factor, and a minimum insulin dose;

calculating with the computing device variance of the plurality of measured glucose values;

calculating by the computing device a boundary glucose value (g_p) based upon a probability threshold where the person having diabetes requires at least a predetermined insulin dose, a glucose value from the plurality of measured glucose values, and the variance calculated;

executing, by the computing device, an alert via a user interface, wherein the alert indicates that a glucose measurement should be taken and the alert is executed when the computing device compares the boundary glucose value (g_p) to the glucose threshold (g_Io) and determines that the boundary glucose value (g_p) is greater than the glucose threshold (g_Io), and

administering a safety insulin bolus to the person having diabetes upon executing the alert that a glucose measurement should be taken and the computing device determining that the glucose measurement has not been performed and a correction dose has not been administered, wherein the safety insulin bolus is determined by the computing device using the boundary glucose value.

2. The method of claim 1, further comprising determining a maximum safe insulin bonus.

3. The method of claim 2, further comprising producing an alarm on the user interface if a manual bolus request exceeds the maximum safe insulin bolus.

4. The method of claim 1, wherein calculating the boundary glucose value (g_ρ

) is according to;

g_ρ

=√

{square root over (2σ

_g²)}erf<sup>−

1</sup>(2ρ

−

1)+g,

wherein

σ

_g² is a variance of glucose measurement,

ρ

is the probability threshold that the person having diabetes requires at least a predetermined insulin dose, and

g is a glucose value from the plurality of measured glucose values.

5. The method of claim 1, wherein calculating the glucose threshold (g_I0) is according to:

g_I0=g_m+cI₀,

wherein,

g_m is the maximum allowable glucose,

c is the correction factor, and

I₀ is the minimum insulin dose.

6. The method of claim 5, wherein at least one of the maximum allowable glucose, the minimum insulin dose, and the correction factor are supplied by a bolus calculator.

7. The method of claim 1, wherein the predetermined insulin dose is 1 unit.

8. The method of claim 1, wherein the glucose threshold is dependent on the time of day.

9. The method of claim 1, wherein the probability threshold is selected from a group consisting of 99%, 98%, 90%, 75%, and 50%.

10. The method of claim 1, wherein a day is broken into a plurality of time blocks, at least one of the plurality of time blocks having a different glucose threshold than the remaining time blocks.

11. The method of claim 1, wherein the predetermined insulin dose is higher during a period of sleep than a waking period.

12. The method of claim 1, wherein the plurality of measured glucose values comprise periodic glucose measurements taken approximately every one minute.

13. The method of claim 1, wherein the alert may be a display, sound, vibration, or any combination thereof.

14. The method of claim 1 wherein the glucose measurement is a self-monitored blood glucose measurement.

15. The method of claim 1, wherein the glucose measurement is an additional measurement taken by the continuous glucose monitoring system and triggered by a user.

16. The method of claim 1, further comprising determining an insulin bolus dose with the computing device using a glucose measurement.

17. The method of claim 16, wherein the determining of the insulin bolus dose uses at least one of a rate of change measurement of the plurality of measured glucose values, a trend in the plurality of measured glucose values, and a pattern in the plurality of measured glucose values.

18. The method of claim 16, wherein the determining of the insulin bolus dose uses at least one rate of change measurement of the plurality of measured glucose values, and a predicted glucose value, wherein the correction dose is

19. The method of claim 18, wherein time t is about 20 minutes to about 60 minutes.

20. The method of claim 1, further comprising determining by the computing device normal functioning of the glucose sensor of the continuous glucose monitoring system by using a probability analysis tool configured to calculate a probability of glucose sensor accuracy (PA) based on changes in the received measured glucose values, and said method further comprises weighting the received measured glucose values with the calculated probability of glucose sensor accuracy (PA), and calculating an estimated glucose level of the person by using the weighted received measured glucose values in a recursive filter which minimizes at least effect of a malfunction in the glucose sensor, wherein the probability analysis tool is selected from a state machine and a hidden Markov model, and the recursive filter is selected from a Kalman filter and an Extended Kalman filter.

21. A system for administering a safety insulin bolus to a person having diabetes upon a probability of needing insulin exceeding a threshold level, the system comprising:

a controller, a user interface, and a computer readable medium having computer executable instructions which upon execution by the controller causes the controller to;

receive a plurality of measured glucose values from a glucose sensor coupled to a person having diabetes,

calculate a glucose threshold (g_I0) based upon a maximum allowable glucose, a correction factor, and a minimum insulin dose,

calculate variance of the plurality of measured glucose values,

calculate a boundary glucose value (g_ρ

) based upon a probability threshold where the person having diabetes requires at least a predetermined insulin dose, a glucose value from the plurality of measured glucose values, and the variance calculated,

execute an alert, via the user interface, wherein the alert indicates that a glucose measurement should be taken and the alert is executed when the controller compares the boundary glucose value (g_p) to the glucose threshold (g_Io) and determines that the boundary glucose value (g_ρ

) is greater than the glucose threshold (g_I0), and

administer a safety insulin bolus to the person having diabetes upon executing the alert that a glucose measurement should be taken and determine the glucose measurement has not been performed and a correction dose has not been administered, wherein the safety insulin bolus is determined by use of the boundary glucose value; and

a bolus calculator in communication with the controller, wherein the bolus calculator is configured to determine an insulin bolus based on the plurality of measured glucose values.

22. The system of claim 21, wherein the controller is configured to calculate a maximum safe insulin bolus.

23. The system of claim 21, wherein the controller is configured to produce an alarm on the user interface if a manual bolus request entered in the user interface exceeds the maximum safe insulin bolus.

24. The system of claim 21, wherein the computer executable instructions further cause the controller to determine a glucose rate of change of the plurality of measured glucose values, wherein the glucose rate of change is used by the bolus calculator to modify the insulin bolus.

25. The system of claim 24, wherein the controller displays on the user interface the modified insulin bolus.

26. The system of claim 24, wherein the computer executable instructions further cause the controller to utilize the rate of change to predict a glucose level at a future time for use by the bolus calculator.

27. The system of claim 21, wherein the computer executable instructions further cause the controller to:

calculate a probability of glucose sensor accuracy (PA) based on changes in the received measured glucose values using a probability analysis tool, weight the received measured glucose values with the calculated probability of glucose sensor accuracy (PA), and calculate an estimated glucose level of the person by use of the weighted received measured glucose values in a recursive filter which minimizes at least effect of a malfunction in the glucose sensor, wherein the probability analysis tool is selected from a state machine and a hidden Markov model, and the recursive filter is selected from a Kalman filter and an Extended Kalman filter.

28. The system of claim 21, wherein:

the boundary glucose value (g_ρ

) is calculated according to;

g_ρ

=√

{square root over (2σ

_g²)}erf<sup>−

1</sup>(2ρ

−

1)+g,

wherein

σ

_g² is a variance of glucose measurement,

ρ

is the probability threshold that the person having diabetes requires at least a predetermined insulin dose, and

g is a glucose result from the plurality of measured glucose values,

the glucose threshold (g_I0) is calculated according to;

g_I0=g_m+cI₀,

wherein,

g_m is the maximum allowable glucose,

c is the correction factor, and

I₀ is the minimum insulin dose;

the probability threshold is selected from a group consisting of 99%, 98%, 90%, 75%, and 50%; and

at least one of the maximum allowable glucose, the minimum insulin dose, and the correction factor are supplied by the bolus calculator.