Method, system, and computer program product for calculating daily weighted averages of glucose measurements (or derived quantities) with time-based weights

• US 20090326357A1
• Filed: 06/25/2008
• Published: 12/31/2009
• Est. Priority Date: 06/25/2008
• Status: Active Grant

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Roche Diagnostics Operations Incorporated (Roche Holding AG)
• Inventors: Weinert, Stefan, Thukral, Ajay
• Granted Patent: US 8,175,812 B2
• Time in Patent Office: Days
• US Class Current: 600/365
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: C12Q 1/00 Measuring or testing processes involving enzymes, nucleic acids or microorganisms measuring or testing apparatus with condition measuring or sensing means, e.g. colony counters, C12M1/34; Compositions therefor; Processes of preparing such compositions
• CPC Class Codes: G16H 20/17 delivered via infusion or injection
• CPC Class Codes: G16H 40/63 for local operation

Abstract

A method and system for calculating daily weighted averages of glucose measurements (or derived quantities) with time-based weights are disclosed. The present invention computes an average daily glucose value using the time based weights based on only consecutive glucose measurements in the plurality of glucose measurements with acceptable time intervals that do not exceed a predefined maximum time interval. The invention further relates to a computer program for implementing the method for calculating daily weighted averages of spot monitoring glucose measurements (or derived quantities) with the time-based weights.

Claims

1. A method for calculating daily weighted averages of glucose measurements with time-based weights comprising:

providing a plurality of glucose measurements each collected at a different time;

determining whether each time interval between two consecutive glucose measurements in the plurality of glucose measurements exceeds a predefined maximum time interval value;

computing electronically an average daily glucose value, which represents the daily weighted average of the glucose measurements, using time based weights based on only consecutive glucose measurements in the plurality of glucose measurements with acceptable time intervals that do not exceed the predefined maximum time interval; and

providing the computed daily weighted average of the glucose measurements.

2. The method according to claim 1 wherein the average daily glucose value is computed also by using a glucose value for each acceptable time interval represented by an arithmetic average of the two consecutive glucose measurements.

3. The method according to claim 1 wherein each of the time based weights is the length of the time interval between the two consecutive glucose measurements divided by the sum of all such time intervals used in calculating the time-weighted sum of glucose measurements.

4. The method according to claim 1 wherein each of the time based weights is the length of the time interval between the two consecutive glucose measurements divided by the sum of all such time intervals used in calculating the time-weighted sum of glucose measurements., and the method further comprises setting equal to zero the weight assigned to the time interval between the two consecutive glucose measurements if exceeding the predefined maximum time interval.

5. The method according to claim 1 wherein computing electronically the average daily glucose value when a next glucose measurement is assigned a date later than a previous glucose measurement.

6. The method according to claim 1 further comprises storing the computed daily weighted average, and using stored daily weighted averages to calculate a long term weighted average.

7. The method according to claim 6 where the weights used for calculating a long term average decline over time.

8. The method of claim 1 wherein the average daily glucose value is calculated according to:

9. The method of claim 1 wherein if the average daily glucose value avg_bG_k will not give a not_a_number result, and a time interval between a last bG measurement (bG_Nk−

1,<sup>k−

1</sup>t<sub>Nk−

1</sub><sup>k−

1</sup>) of a previous day k−

1 and a first bG measurement in day k in the plurality of glucose measurement is less than or equal to the predefined maximum time interval, and the time interval between a last glucose measurement on the day k and a first measurement after the day k is more than the predefined maximum time interval, then the average daily glucose value for the day k is calculated according to;

10. The method of claim 1 wherein if the average daily glucose value avg_bG_k will not give a not_a_number result, and either no glucose (bG) measurements for a previous day k−

1 exist in the plurality of glucose measurements or a time interval between a last bG measurement result of the previous day k−

1 and a first bG measurement in day k in the plurality of glucose measurement is greater than the predefined maximum time interval, and a time interval between a last bG measurement of the day k and a first bG measurement (bG_1,^k+1t₁^k+1) after the day k in the plurality of glucose measurements is not more than the predefined maximum time interval, then the average daily glucose value for D_k is calculated according to;

11. The method of claim 1 wherein if the average daily glucose value avg_bG_k will not give a not_a_number result, and a time interval between a last bG measurement (bG_Nk−

1,<sup>k−

1</sup>t<sub>Nk−

1</sub><sup>k−

1</sup>) of a previous day k−

1 and a first bG measurement in day k in the plurality of glucose measurement is no more than the predefined maximum time interval, and a time interval between a last bG measurement of the day k and a first bG measurement (bG_1,^k+1t₁^k+1) after the day k in the plurality of glucose measurements is not more than the predefined maximum time interval, then the average daily glucose value for D_k is calculated according to;

22. A computer program comprising code that when executed by a processor based system performs the steps of method claim 1.

12. A system for calculating daily weighted averages of glucose measurements with time-based weights comprising:

a processor programmed to;

receive a plurality of glucose measurements each collected at a different time;

determine whether each time interval between two consecutive glucose measurements in the plurality of glucose measurements exceeds a predefined maximum time interval length;

compute an average daily glucose value, which represents the daily weighted average of the glucose measurements, using time based weights based on only consecutive glucose measurements in the plurality of glucose measurements with acceptable time intervals that do not exceed the predefined maximum time interval; and

provide the computed daily weighted average of the glucose measurements.

13. The system according to claim 12 wherein the processor is programmed to compute the average daily glucose value also by using a glucose value for each acceptable time interval represented by an arithmetic average of the two consecutive glucose measurements.

14. The system according to claim 12 wherein the processor is programmed to compute the weighted sum by adding the products of the arithmetic average and the length of the time interval between consecutive glucose measurements.

15. The system according to claim 12 wherein the processor is programmed to compute the weighted sum by adding the products of the arithmetic average and the length of the time interval between consecutive glucose measurements, and setting equal to zero the weight assigned to the time interval between two consecutive glucose measurements if exceeding the predefined maximum time interval.

16. The method according to claim 12 wherein the processor is further programmed to capture glucose measurements, to store captured glucose measurements in memory, and to compute the average daily glucose value when one of the captured glucose measurements is assigned a date later than a previous one of the captured glucose measurements.

17. The system according to claim 12 wherein the processor is further programmed to store the computed daily weighted average, and to stored daily weighted averages to calculate a long term weighted average.

18. The method according to claim 17 wherein weights used to calculate the long term weighted average decline over time.

19. The system according to claim 12, wherein the processor is provided in a glucose meter.

20. The system of claim 12, wherein the processor is programmed to receive the plurality of glucose measurements from memory.

21. The system of claim 12, wherein the plurality of glucose measurement are received by the processor being programmed to capture results from spot measured glucose measurements.