Method of screening for disorders of glucose metabolism

• US 20030054428A1
• Filed: 08/13/2002
• Published: 03/20/2003
• Est. Priority Date: 05/30/2000
• Status: Active Grant

• Current Assignee: GLT Acquisition Corporation
• Original Assignee: Sensys Medical, Inc. (Sensys Medical Limited)
• Inventors: Cone, Andrew, Hockersmith, Linda, Monfre, Stephen L., Hazen, Kevin H., Hetzel, Donald
• Granted Patent: US 7,395,158 B2
• Time in Patent Office: Days
• US Class Current: 435/14
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/7264 Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems neural networks per se G06N3/00; expert systems per se G06N5/00
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems
• CPC Class Codes: Y10T 436/144444 Glucose

Abstract

A method of screening for disorders of glucose metabolism such as impaired glucose tolerance and diabetes allows prevention, or early detection and treatment of diabetic complications such as cardiovascular disease, retinopathy, and other disorders of the major organs and systems. A mathematical algorithm evaluates the shape of a subject'"'"'s glucose profile and classifies the profile into one of several predefined clusters, each cluster corresponding either to a normal condition or one of several abnormal conditions. The series of blood glucose values making up the glucose tolerance curve may be measured using any glucose analyzer including: invasive, minimally invasive and noninvasive types. The method is executed on a processing device programmed to perform the steps of the method. Depending on the outcome of the screening, a subject may be provided with additional information concerning their condition and/or counseled to consult further with their health care provider.

Claims

1. A method of screening a subject for disorders of glucose metabolism, comprising the steps of:

providing at least a portion of a glucose profile, said profile comprising a plurality of blood glucose values from before and after a glucose challenge;

evaluating shape of said profile based on one or more parameters of said shape; and

classifying said subject into at least one predetermined cluster based on evaluation of said shape.

2. The method of claim 1, wherein said plurality of blood glucose values comprises a time series.

3. The method of claim 1, wherein said blood glucose values are actual values.

4. The method of claim 1, wherein said blood glucose values are relative values.

5. The method of claim 1, wherein said parameters include any of:

initial fasting glucose concentration; and

glucose concentration after elapse of a predetermined time interval.

6. The method of claim 5, wherein said evaluating step comprises:

comparing any of said parameters with corresponding predetermined values and/or ranges of values indicative of either a normal condition or one of a plurality of abnormal conditions.

7. The method of claim 6, wherein said predetermined clusters correspond to said conditions, said clusters comprising:

normal;

impaired glucose tolerance;

diabetic; and

low glucose tolerance.

8. The method of claim 1, wherein said evaluation step comprises:

determining a weight for each of said parameters according to a fuzzy algorithm.

9. The method of claim 8, wherein said step of determining a weight comprises the steps of:

assigning each parameter a value on either a linear or non-linear scale, according to value of said parameter, said assigned value comprising said weight.

10. The method of claim 9, wherein minimum and maximum of said scale correspond to predetermined threshold values for a normal condition and a diabetic condition, respectively.

11. The method of claim 9, wherein minimum and maximum of said scale correspond to predetermined threshold values for a low glucose tolerance and a normal condition, respectively.

12. The method of claim 9, wherein minimum and maximum of said scale correspond to predetermined threshold values for a low glucose tolerance and a diabetic condition, respectively.

13. The method of claim 9, wherein ranges of values represented by said scale are established according to standard diagnostic criteria.

14. The method of claim 9, wherein missing parameters are assigned a weight of zero.

15. The method of claim 9, wherein missing data are supplied from historical data.

16. The method of claim 9, further comprising the step of calculating one or more screening factors based on actual or relative values of said parameters and said weights.

17. The method of claim 16, wherein said step of calculating screening factors comprises the step of calculating a weighted average of said weighted parameters according to:

18. The method of claim 16, wherein said step of calculating screening factors comprises the steps of:

calculating a weighted average of a first set of selected weighted parameters according to;

${\mathrm{SF}}_1=\frac{\left(P_1<br><br>W_1+P_6<br><br>W_6\right)}{\left(W_1+W_6\right)},$

wherein SF₁=a first screening factor; and

calculating a weighted average of a second set of selected weighted parameters according to;

${\mathrm{SF}}_2=\frac{\left(P_2<br><br>W_2+P_3<br><br>W_3+P_4<br><br>W_4+P_5<br><br>W_5\right)}{\left(W_2+W_3+W_4+W_5\right)},$

wherein SF₂=a second screening factor.

19. The method of claim 16, further comprising the step of establishing threshold screening limits based on said screening factors.

20. The method of claim 1, wherein said parameters include any of:

initial fasting glucose concentration;

rate of increase of glucose concentration following said glucose challenge;

peak monitored glucose concentration;

duration glucose remains elevated;

rate of decrease of glucose concentration following said peak concentration; and

minimum glucose concentration following said peak concentration.

21. The method of claim 1, further comprising the step of advising said subject of screening results.

22. The method of claim 1, further comprising the step of advising said subject of health risks from complications likely to result from subject'"'"'s condition.

23. The method of claim 1, wherein said values are obtained using any of:

a noninvasive blood glucose analyzer;

a minimally invasive blood glucose analyzer; and

an invasive blood glucose analyzer.

24. The method of claim 1, wherein a processing device so programmed executes said steps.