Alert system for hypo and hyperglycemia prevention based on clinical risk

• US 9,439,602 B2
• Filed: 10/26/2012
• Issued: 09/13/2016
• Est. Priority Date: 10/26/2011
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: DexCom Incorporated
• Inventors: Guerra, Stefania, Sparacino, Giovanni, Cobelli, Claudio, Facchinetti, Andrea, Schiavon, Michele
• Primary Examiner(s): Natnithithadha, Navin
• Assistant Examiner(s): MESSERSMITH, ERIC J
• Application Number:
  US13/661,393
• Publication Number:
  US 20130109944A1
• Time in Patent Office: 1,418 Days
• Field of Search: 600/345, 600/347, 600/365
• US Class Current: 1/1
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• 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 5/7405 using sound
• CPC Class Codes: A61B 5/743 Displaying an image simultaneously with additional graphical information, e.g. symbols, charts, function plots
• 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: G16H 50/30 for calculating health indices; for individual health risk assessment

Abstract

A device for generating alerts for Hypo and Hyperglycemia Prevention from Continuous Glucose Monitoring (CGM) determines a dynamic risk based on both information of glucose level and a trend obtainable from a CGM signals. The device includes a display whose color depends on the DR (for example, red for high DR, green for low risk). When DR exceeds a certain threshold, alerts are generated to suggest the patient to pay attention to the current glucose reading and to its trend, both of which are shown on the display in numbers and symbols (e.g. an arrow with different slope or color).

Claims

1. A system for communicating glycemic risk to a patient, comprising:

a continuous glucose monitoring device that generates a series of data points indicative of a glucose level in the patient; and

processing circuitry configured to iteratively;

calculate a glucose level and a rate of change of the glucose level based on the series of data points;

determine a dynamic risk score based a nonlinear transformation that converts the current glucose level and the rate of change of the current glucose level to a dynamic risk score; and

select a color from a color scale based on the dynamic risk score, the color scale comprising a plurality of colors, each color indicative of one of a plurality of risk levels of the patient; and

display, on a user interface, the current glucose level, the rate of change, and the color indicative of one of a plurality of risk levels of the patient so that glycemic risk is communicated.

2. The system of claim 1, wherein the glucose level is a present or current glucose level.

3. The system of claim 1, wherein the glucose level is a predicted or future glucose level.

4. The system of claim 1, wherein the series of data points are smoothed.

5. The system of claim 1, wherein the nonlinear transformation amplifies the dynamic risk score as the current glucose level and the rate of change approach a clinically critical region.

6. The system of claim 1, wherein the nonlinear transformation is logarithmic transformation.

7. The system of claim 1, wherein the nonlinear transformation is a hyperbolic transformation.

8. The system of claim 1, wherein the nonlinear transformation is an arctangent transformation.

9. The system of claim 1, wherein the scale of colors is defined by a color map that represents the nonlinear transformation.

10. The system of claim 1, wherein the color map defines colors that can be mapped to different glucose levels along a first axis and rate of change values along a second axis.

11. The system of claim 1, wherein the processing circuitry is configured to generate a perceptible alarm when the dynamic risk is greater than a predetermined threshold.

12. The system of claim 1, wherein the color is displayed as a background color.

13. The system of claim 1, wherein the color is displayed with or on the glucose level.

14. The system of claim 1, wherein the color is displayed with or on the trend arrow.

15. The system of claim 1, wherein the continuous glucose monitoring device is further configured to generate additional data points indicative of the glucose concentration level in the patient, wherein the circuitry is configured to repeat the calculating, determining and displaying for each of the additional data points generated by the continuous glucose monitoring device.

16. A method for communicating glycemic risk to a patient, comprising:

generating, by a continuous glucose monitoring device, a series of data points indicative of a glucose level in the patient;

iteratively calculating a glucose level and a rate of change of the glucose level based on the series of data points;

iteratively determining a dynamic risk score based a nonlinear transformation that converts the current glucose level and the rate of change of the current glucose level to a dynamic risk score;

iteratively selecting a color from a color scale based on the dynamic risk score, the color scale comprising a plurality of colors, each color indicative of one of a plurality of risk levels of the patient; and

iteratively displaying, on a user interface, the current glucose level, the rate of change, and the color indicative of one of a plurality of risk levels of the patient so that glycemic risk is communicated.

17. The method of claim 16, wherein the glucose level is a present or current glucose level.

18. The method of claim 16, wherein the glucose level is a predicted or future glucose level.

19. The method of claim 16, wherein the series of data points are smoothed.

20. The method of claim 16, wherein the nonlinear transformation amplifies the dynamic risk score as the current glucose level and the rate of change approach a clinically critical region.

21. The method of claim 16, wherein the nonlinear transformation is logarithmic transformation.

22. The method of claim 16, wherein the nonlinear transformation is a hyperbolic transformation.

23. The method of claim 16, wherein the nonlinear transformation is an arctangent transformation.

24. The method of claim 16, wherein the scale of colors is defined by a color map that represents the nonlinear transformation.

25. The method of claim 16, wherein the color map defines colors that can be mapped to different glucose levels along a first axis and rate of change values along a second axis.

26. The method of claim 16, comprising generating a perceptible alarm when the dynamic risk is greater than a predetermined threshold.

27. The method of claim 16, wherein the color is displayed as a background color.

28. The method of claim 16, wherein the color is displayed with or on the glucose level.

29. The method of claim 16, wherein the color is displayed with or on the trend arrow.

30. The method of claim 16, generating, by the continuous glucose monitoring device, additional data points indicative of the glucose concentration level in the patient, and repeating the calculating, determining and displaying for each of the additional data points generated by the continuous glucose monitoring device.