Method and system for investigating glucose metabolism

• US 20060253067A1
• Filed: 03/15/2006
• Published: 11/09/2006
• Est. Priority Date: 03/15/2005
• Status: Active Grant

• Current Assignee: Roche Diabetes Care Inc. (Roche Holding AG)
• Original Assignee: Roche Diagnostics Operations Incorporated (Roche Holding AG)
• Inventors: Hegger, Reiner, Staib, Arnulf, Pill, Johannes, Kotulla, Reinhard
• Granted Patent: US 8,131,474 B2
• Time in Patent Office: Days
• US Class Current: 604/67
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: G01N 33/66 involving blood sugars, e.g. galactose
• CPC Class Codes: Y10T 436/104998 Glucose, ketone, nitrate standard or control
• CPC Class Codes: Y10T 436/144444 Glucose

Abstract

The invention relates to a method for investigating the glucose metabolism of a human being for disease-relevant and/or disease-related particularities. The the glucose concentration g(t1) to g(tn) of a body fluid is measured at time points t1 to tn that are distributed over a period of at least six hours. The data points are then determined in phase space coordinates from the glucose concentration measuring values g(t1) to g(tn). The data points are then processed to highlight disease-relevant and/or disease-related particularities of the glucose metabolism of the investigated human being. The processing of the data points can be implemented by plotting them in a phase space representation or by determining from the data points a disturbance parameter that is correlated to the severity of a disturbance of glucose metabolism.

Claims

1. A Method for investigating a glucose metabolism of a human being for disease-relevant and/or disease-related particularities, the method comprising:

measuring a glucose concentration g(t1) to g(tn) of a body fluid at time points t1 to tn that are distributed over a period of at least six hours;

determining data points in a phase space coordinates from the glucose concentration g(t1) to g(tn); and

processing the data points to highlight disease-related particularities of the glucose metabolism of the investigated human being.

2. The method according to claim 1, wherein the body fluid is blood.

3. The method according to claim 1, wherein the time points t1 to tn are distributed over a period of at least four hours.

4. The method according to claim 1, wherein the time points t1 to tn are consecutive with time intervals of less than 20 minutes.

5. The method according to claim 1, wherein the time points t1 to tn are consecutive with time intervals of less than 10 minutes.

6. The method according to claim 1, wherein the time points t1 to tn are consecutive with time intervals of less than 5 minutes.

7. The method according to claim 1, wherein a two dimensional phase space coordinate system is used.

8. The method according to claim 1, wherein the data points are processed by plotting in a graphic phase space representation.

9. The method according to claim 8, wherein an increased density of data points in the graphic phase space representation is highlighted by coloring.

10. The method according to claim 9, wherein the data points are shown in a color that depends on the number of data points that are present in a pre-determined vicinity U of the respective data point.

11. The method according to claim 9, wherein different symbols are used in areas of increased data point density as compared to regions of lower density.

12. The method according to claim 8, wherein a trajectory described by the data points is displayed.

13. The method according to claim 1, wherein a function of the blood glucose concentration and/or at least one of its derivatives with respect to time are used as phase space coordinates.

14. The method according to claim 13, wherein the glucose concentration is one of the phase space coordinates.

15. The method according to claim 13, wherein a rate of change of the glucose concentration is one of the phase space coordinates.

16. The method according to claim 13, wherein delay coordinates are used as phase space coordinates.

17. The Method according to claim 16, wherein the delay time of between 10 minutes and 90 minutes, preferably between 15 minutes and 30 minutes, is selected for the delay coordinates.

18. The method according to claim 1, wherein the processing of the data points includes a step, in which the data points are used to determine a disturbance parameter that is correlated to the severity of a disturbance of glucose metabolism.

19. The method according to claim 18, wherein the disturbance parameter is determined by a statistical analysis of the data points.

20. The method according to claim 18, wherein the disturbance parameter is determined from the fraction of data points situated within a pre-determined vicinity U of a regulation point.

21. The method according to claim 18, wherein the disturbance parameter is determined from the ratio of the main axes of an ellipsoid of variance of the data points.

22. The method according to claim 18, wherein a trajectory in phase space described by a sequence of data points is analyzed in order to determine the disturbance parameter.

23. The method according to claim 18, wherein the disturbance parameter is determined from a curvature of a loop of the trajectory, preferably from the curvatures of multiple loops.

24. The method according to claim 23, wherein the loop of the trajectory is approximated by an ellipse and the disturbance parameter is determined from the ratio of the main axes of the ellipse.

25. The Method according to claim 18, wherein the disturbance parameter is determined by means of a cross-prediction.

26. The method according to claims 18, wherein the disturbance parameter is correlated to the probability of a diabetic disease.

27. The method according to claim 18, wherein the disturbance parameter indicates which stage of a disease of glucose metabolism is likely to be manifest.

28. A system for investigating the glucose metabolism of a human being for disease-relevant and/or disease-related particularities, the system comprising:

a measuring unit for measuring a blood glucose concentration g(t1) to g(tn) at time points t1 to tn that are distributed over a period of at least 6 hours; and

an analytical unit for determining data points in a phase space coordinates from the glucose concentration g(t1) to g(tn);

wherein the analytical unit is used to process the data points in order to highlight disease-related and/or disease-relevant particularities of the glucose metabolism of the investigated human being.

29. The system of claim 28, wherein the blood glucose concentration g(t1) to g(tn) at time points t1 to tn that are distributed over a period of at least 4 hours.

30. The system according to claim 28, wherein the system further comprises a display facility for displaying the data points thus determined in a phase space representation.

31. The system according to claim 28, wherein the analytical unit is used to determine from the data points a disturbance parameter that is correlated to the severity of a disturbance of glucose metabolism.

32. The system according to claim 31, wherein the disturbance parameter is used in conjunction with therapy data stored in a database to prepare and output a therapy recommendation.

33. The system according to claim 28, wherein the system comprises an implant with a storage reservoir for insulin and a micropump for the controlled release of insulin into the bloodstream of a patient, whereby the analytical unit triggers an alarm signal as soon as the disturbance parameter deviates by more than a pre-determined tolerance from a pre-determined nominal value.