Bolus calculator with probabilistic glucose measurements

• US 10,518,031 B2
• Filed: 03/04/2016
• Issued: 12/31/2019
• Est. Priority Date: 03/04/2016
• Status: Active Grant

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Inventors: Duke, David L.
• Primary Examiner(s): Sims, Jason M
• Application Number:
  US15/061,526
• Publication Number:
  US 20170252514A1
• Time in Patent Office: 1,397 Days
• Field of Search: None
• CPC Class Codes: A61M 2205/3584 using modem, internet or bluetooth
• CPC Class Codes: A61M 2205/52 with memories providing a history of measured variating parameters of apparatus or patient
• 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 20/17 delivered via infusion or injection
• CPC Class Codes: G16H 20/40 relating to mechanical, radiation or invasive therapies, e.g. surgery, laser therapy, dialysis or acupuncture
• CPC Class Codes: G16H 40/63 for local operation

Abstract

Methods and devices involving using a bolus calculator for calculating a correction insulin dose accounting for continuous glucose monitoring noise. More specifically, methods and devices using an algorithm executed by a processor of the bolus calculator and using a glucose measurement and uncertainty of the glucose measurement to determine if a standard correction dose should be adjusted once calculations are performed for the standard correction dose and hypoglycemia-averse correction insulin dose and the two doses are compared.

Claims

1. A method of adjusting a standard correction insulin bolus administered to a user to reduce hypoglycemia risk after consuming a corresponding meal via accounting for continuous glucose monitoring noise of a sensor imbedded in the user, the method comprising:

coupling a bolus calculator to a database, the bolus calculator containing therewithin a processor that when activated executes an algorithm;

activating the processor to execute the algorithm;

calculating, via the algorithm, a standard correction insulin dose (I_g) utilizing an insulin sensitivity factor (IS) of a user and a pre-set target glucose level;

receiving by the bolus calculator a glucose measurement from the sensor imbedded in the user;

calculating, via the algorithm, a hypoglycemia-averse correction insulin dose (I_hypo(x)%) using the insulin sensitivity factor, the received glucose measurement of the user, and a measure of an uncertainty of the glucose measurement from the sensor, wherein the algorithm accounts for past uncertainty regarding at least one of a calibration routine of the user, a day of use for the sensor, and a sensor lot via the database; and

adjusting the standard correction insulin bolus administered to the user for the corresponding meal via selecting the minimum value between the hypoglycemia-averse correction insulin dose and the standard correction insulin dose to reduce hypoglycemia risk of the user after consuming the corresponding meal.

2. A method of adjusting a standard correction insulin bolus administered to a user to reduce hypoglycemia risk after consuming a corresponding meal via accounting for continuous glucose monitoring noise of a sensor imbedded in the user, the method comprising:

coupling a bolus calculator to a database, the bolus calculator containing therewithin a processor that when activated executes an algorithm defining a pre-set target glucose level (g_t), a threshold percentage defining a probability of hypoglycemia (P_hypo), and a standard deviation (σ

_g) defining an uncertainty of a glucose measurement (g) received from the sensor imbedded in the user;

activating the processor to execute the algorithm;

receiving by the bolus calculator the glucose measurement from the sensor of the user;

calculating, using the glucose measurement, the standard deviation, and a parameter on a normal cumulative distribution, a level (g_x%), wherein x corresponds to the threshold percentage defining the probability of hypoglycemia, wherein the algorithm accounts for past uncertainty regarding at least one of a calibration routine of the user, a day of use for the sensor, and a sensor lot via the database;

calculating a standard correction insulin dose (I_g) utilizing an insulin sensitivity factor (IS) of a user and the pre-set target glucose level;

calculating a hypoglycemia-averse correction insulin dose (I_hypo(x)%) using the insulin sensitivity factor of the user and the calculated level on the cumulative frequency distribution;

comparing the standard correction insulin dose with the hypoglycemia-averse correction insulin dose; and

selecting the minimum of the correction insulin doses; and

adjusting the standard correction insulin bolus administered to the user for the corresponding meal via the selected insulin dose to reduce hypoglycemia risk of the user after consuming the corresponding meal.

3. The method of claim 2 further comprising defining the (g_x%) as (g_50%) and performing the following calculation:

g_5%=g−

1.6449·

σ

_g.

4. The method of claim 2 further comprising setting the (g_t) as shown below:

5. The method of claim 2 further comprising setting a hypoglycemia threshold as shown below,

6. The method of claim 2 further comprising calculating the standard correction insulin dose by:

7. The method of claim 2 further comprising defining the (g_x%) as (g_50%), designating the (I_hypo(x)%) as (I_hypo5%) and calculating the hypoglycemia-averse correction insulin dose by:

8. The method of claim 2 further comprising removing the standard correction insulin bolus administered to the user for the corresponding meal when the selected insulin dose is negative.

9. The method of claim 2 further comprising providing a carbohydrate suggestion when the selected insulin dose is negative.

10. The method of claim 2 further comprising setting the (g_x%) as at least one of (g_10%), (g_15%) and (g_20%).

20. The method of claim 2, wherein the processor automatically selects the threshold percentage.

21. The method of claim 2, wherein the standard correction insulin bolus is administered to the user via an insulin pump or by injection.

22. The method of claim 2, further comprises accounting for active insulin recently injected into the user, via the bolus calculator shifting:

the glucose target (ĝ

) by a glucose equivalent for the active insulin (g_i), where ĝ

_t=g_t+g_i;

the hypoglycemia threshold ({circumflex over (T)}_hypo) by the glucose equivalent for the active insulin (g_i), where {circumflex over (T)}_hypo=T_hypo+g_i, and

wherein the standard correction insulin dose is then calculated by;

11. A bolus calculator to adjust a standard correction insulin bolus administered to a user to reduce hypoglycemia risk after consuming a corresponding meal via an account for continuous glucose monitoring noise of a sensor imbedded in the user, the bolus calculator comprising:

a processor that when activated is configured to;

couple the bolus calculator to a database;

receive a glucose measurement (g) from the sensor embedded in the user;

execute an algorithm defining a pre-set target glucose level (g_t), a threshold percentage defining a probability of hypoglycemia (P_hypo), and a standard deviation (σ

_g) defining an uncertainty of the glucose measurement (g) from the sensor of the user;

calculate a level (g_x%), wherein x corresponds to the threshold percentage defining the probability of hypoglycemia, via use of the glucose measurement, the standard deviation, and a parameter on a normal cumulative distribution, wherein the algorithm accounts for past uncertainty regarding at least one of a calibration routine of the user, a day of use for the sensor, and a sensor lot via the database;

calculate a standard correction insulin dose (I_g) utilizing an insulin sensitivity factor (IS) of a user and the pre-set target glucose level;

calculate a hypoglycemia-averse correction insulin dose (I_hypo(x)%) using the insulin sensitivity factor of the user and the calculated level on the cumulative frequency distribution;

compare the standard correction insulin dose with the hypoglycemia-averse correction insulin dose;

select the minimum of the correction insulin doses; and

adjust the standard correction insulin bolus administered to the user for the corresponding meal via the selected insulin dose to reduce hypoglycemia risk of the user after consuming the corresponding meal.

12. The bolus calculator of claim 11 wherein the algorithm is configured to define the (g_x%) as (g_50%) and perform the calculation below:

g_5%=g−

1.6449·

σ

_g.

13. The bolus calculator of claim 11 wherein the algorithm is configured to set the (g_t) as shown below:

14. The bolus calculator of claim 11 wherein the algorithm is configured to set a hypoglycemia threshold as shown below,

15. The bolus calculator of claim 11 wherein the algorithm is configured to calculate the standard correction insulin dose by:

16. The bolus calculator of claim 11 wherein the algorithm is configured to define the (g_x%) as (g_5%), designate the I_hypo(x)% as I_hypo5%, and calculate the hypoglycemia-averse correction insulin dose by:

17. The bolus calculator of claim 11 wherein the algorithm is configured to remove a corresponding meal bolus when the selected insulin dose is negative.

18. The bolus calculator of claim 11 wherein the algorithm is configured to provide a carbohydrate suggestion when the selected insulin dose is negative.

19. The bolus calculator of claim 11, wherein the algorithm is configured to set the level (g_x%) as at least one of (g_10%), (g_15%) and (g_20%).

23. The bolus calculator of claim 19, wherein the processor automatically selects between percentages (x %) to set the level (g_x%).