Alert System for Hypo and Hyperglycemia Prevention based on Clinical Risk

• US 20130109944A1
• Filed: 10/26/2012
• Published: 05/02/2013
• Est. Priority Date: 10/26/2011
• Status: Active Grant

• Current Assignee: DexCom Incorporated
• Original Assignee: Universita' Degli Studi Di Padova (Repubblica Italiana)
• Inventors: Cobelli, Claudio, Guerra, Stefania, Facchinetti, Andrea, Sparacino, Giovanni, Schiavon, Michele
• Granted Patent: US 9,439,602 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: 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 alerting a patient of hypoglycemia and hyperglycemia risk, comprising:

(a) a continuous glucose monitoring (CGM) device configured to determine periodically a glucose level in the patient, thereby generating a series of glucose levels;

(b) a dynamic risk estimation module that is configured to;

(i) evaluate a differential change in glucose level over time (dg/dt) based on the series of glucose levels;

(ii) generate a smoothed glucose level that is indicative of the series of glucose levels; and

(iii) estimate a dynamic risk based on the smoothed CGM and dg/dt;

(c) a comparison circuit that compares the dynamic risk to a predetermined threshold; and

(d) a device monitor that is configured to generate a display representative of the smoothed CGM and that is also configured to generate a perceptible alarm when the dynamic risk is greater than the predetermined threshold.

2. The system of claim 1, wherein the system evaluates a differential change in glucose level over time (dg/dt) based on the series of glucose levels by employing a regularized deconvolution algorithm.

3. The system of claim 1, further comprising a circuit that is configured to calculate an angle α

that is a function of dg/dt and wherein the device monitor is also configured to display an arrow that is angled from horizontal by the angle α

.

4. The system of claim 1, wherein the perceptible alarm comprises an alarm selected from a list consisting of:

a blinking display, a brightly colored display, a vibratory alarm, an audible alarm, and combinations thereof.

5. The system of claim 1, wherein the display is configured to show different smoothed CGM values as corresponding different colors.

6. The system of claim 1, wherein the display is further configured to display a trend box that indicates a CGM data trend.

7. A method of monitoring glucose in a patient, comprising the steps of:

(a) receiving from a continuous glucose monitoring (CGM) device a periodic series of glucose levels in the patient;

(b) evaluating a differential change in glucose level over time (dg/dt) based on the series of glucose levels;

(c) generating a smoothed glucose level that is indicative of the series of glucose levels;

(d) estimating a dynamic risk based on the smoothed CGM and dg/dt;

(e) comparing the dynamic risk to a predetermined threshold; and

(f) generating a display representative of the smoothed CGM and generating a perceptible alarm when the dynamic risk is greater than the predetermined threshold.

8. The method of claim 7, further comprising the step of displaying an arrow, such as a colored arrow, indicative of a dg/dt trend.

9. The method of claim 8, further comprising the steps of:

(a) calculating an angle α

that is a function of dg/dt; and

(b) displaying the arrow so that it is angled from horizontal by the angle α

,

10. The method of claim 7, wherein the perceptible alarm comprises an alarm selected from a list consisting of:

a blinking display, a brightly colored display, a vibratory alarm, an audible alarm, and combinations thereof.

11. The method of claim 7, wherein the display shows different smoothed CGM values as corresponding different colors.

12. The method of claim 7, further comprising the step of displaying a trend box that indicates a CGM data trend.