Method and apparatus for predicting the risk of hypoglycemia

• US 6,923,763 B1
• Filed: 08/21/2000
• Issued: 08/02/2005
• Est. Priority Date: 08/23/1999
• Status: Expired due to Term

• Current Assignee: University of Virginia Patent Foundation (University of Virginia)
• Original Assignee: University of Virginia Patent Foundation (University of Virginia)
• Inventors: Straume, Martin, Kovatchev, Boris P., Clarke, William L., Moorman, J. Randall
• Primary Examiner(s): Hindenburg, Max F.
• Assistant Examiner(s): ASTORINO, MICHAEL C
• Application Number:
  US10/069,674
• Time in Patent Office: 1,807 Days
• Field of Search: 600300-301, 600/309, 600/316, 600/322, 600/365, 125/898, 125/920, 125/925, 706/924, 702/19, 235375-385, 435/236, 708131-132
• US Class Current: 600/300
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/4035 Evaluating the autonomic nervous system
• 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: G16H 10/60 for patient-specific data, e.g. for electronic patient records
• CPC Class Codes: G16H 20/17 delivered via infusion or injection
• CPC Class Codes: G16H 40/67 for remote operation
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems
• CPC Class Codes: G16H 50/30 for calculating health indices; for individual health risk assessment
• CPC Class Codes: G16H 50/50 for simulation or modelling of medical disorders
• CPC Class Codes: Y10S 128/92 Computer assisted medical diagnostics

Abstract

The invention relates to a method which utilizes blood glucose (“BG”) sampling, insulin infusion/injection records, heart rate (“HR”) information and heart rate varability (“HRV”) information to estimate BG in the near future and to estimate of the risk of the onset of hypoglycemia. The invention also relates to an apparatus for predicting BG levels and for assessing the risk of the onset of hypoglycemia in the near future. The invention is based on two predetermined bio-mathematical routines: a network model of BG fluctuations and a BG profile for assessment of the risk of hypoglycemia.

Claims

1. A method for predicting a near future BG profile and the onset of hypoglycemia comprising the steps of:

monitoring and recording a BG history profile;

monitoring and recording an insulin infusion and/or injection history profile;

monitoring and recording a HR history profile as an estimate of physical activity;

monitoring and recording a HRV history profile as an estimate of sympathetic nervous system activity;

determining a predicted near future BG profile using a first predetermined bio-mathematical routine; and

evaluating the near future BG profile to predict the onset of hypoglycemia in the near future based on an assessed risk of hypoglycemia, wherein the assessed risk of hypoglycemia is determined using a second predetermined bio-mathematical routine using a computerized processor.

2. The method of claim 1 further including the step of adjusting insulin infusion and/or injection rates based on the predicted near future BG profile and the predicted onset of hypoglycemia.

3. The method of claim 1 wherein the step of monitoring and recording HRV history profiles further includes the step of using an EKG to measure and evaluate the power spectra of RR time series as an estimate of HRV.

4. The method of claim 1 wherein the second predetermined bio-mathematical routine assesses the risk of hypoglycemia based on a Low BG Index which is determined using a BG Risk Function.

5. The method of claim 1 wherein the second predetermined bio-mathematical routine comprises the steps of:

receiving and recording a BG history profile;

transforming the BG history profile scale to obtain a symmetrical distribution scale;

introducing a BG Risk Function to obtain a Low BG Index; and

determining the assessed risk of hypoglycemia based on the Low BG Index.

6. A method for predicting a near future BG profile and the onset of hypoglycemia in the near future comprising the steps of:

receiving data input regarding BG history, insulin infusion/injection history, HR history, and HRV history;

evaluating the data input received using a first predetermined bio-mathematical routine to predict a near future BG profile; and

evaluating the near future BG profile to predict the onset of hypoglycemia in the near future based on an assessed risk of hypoglycemia, wherein the assessed risk of hypoglycemia is determined using a second predetermined bio-mathematical routine using a computerized processor.

7. The method of claim 6 wherein the second predetermined bio-mathematical routine assesses the risk of hypoglycemia based on a Low BG Index which is determined using a BG Risk Function.

8. The method of claim 6 wherein the second predetermined bio-mathematical routine comprises the steps of:

transforming the BG history profile scale to obtain a symmetrical distribution scale;

introducing a BG Risk Function to obtain a Low BG Index; and

determining the assessed risk of hypoglycemia based on the Low BG Index.

9. An apparatus for predicting a near future BG profile and the onset of hypoglycemia comprising:

a BG history profile recording mechanism;

an insulin infusion and/or injection history profile recording mechanism;

a HR history profile recording mechanism;

a HRV history profile recording mechanism;

a near future BG profile prediction module for predicting the near future BG profile using a first predetermined bio-mathematical routine; and

a hypoglycemia prediction module for predicting the onset of hypoglycemia based on an assessed risk of hypoglycemia, wherein the assessed risk of hypoglycemia is determined by a computer processor using a second predetermined bio-mathematical routine.

10. The apparatus of claim 9 further comprising an BG monitoring module associated with the BG history profile recording mechanism.

11. The apparatus of claim 9 further comprising an HRV determination module associated with the HRV history profile recording module, wherein the HRV determination module comprises an EKG which evaluates the power spectra of RR time series as an estimate of HRV.

12. The apparatus of claim 9 further comprising an insulin infusion module associated with the insulin infusion and/or injection history profile recording module, and an insulin-regulation module which adjusts insulin infusion based on the predicted near future BG profile and the predicted onset of hypoglycemia.

13. The apparatus of claim 9 further comprising a hypoglycemia risk assessment module which determines the assessed risk of hypoglycemia using the second predetermined bio-mathematical routine.

14. The apparatus of claim 13 wherein the hypoglycemia risk assessment module comprises:

an interface for receiving data regarding a BG history profile;

a scale transformation module for transforming the BG history profile scale to obtain a symmetrical distribution scale;

a BG Risk Function module for determining a Low BG Index; and

a hypoglycemia risk classification module for determining the assessed risk of hypoglycemia based on the Low BG Index.

15. An apparatus for predicting a near future BG profile and the onset of hypoglycemia comprising:

an interface for receiving data regarding BG history, insulin infusion and/or injection history, HR history, and HRV history profiles;

a BG prediction module for predicting a near future BG profile using a first predetermined bio-mathematical routine; and

a hypoglycemia prediction module for predicting the onset of hypoglycemia in the near future based on an assessed risk of hypoglycemia, wherein the assessed risk of hypoglycemia is determined by a computer processor using a second predetermined bio-mathematical routine.

16. The apparatus of claim 15 further including a hypoglycemia risk assessment module for determining the assessed risk of hypoglycemia using the second predetermined bio-mathematical routine.