Calibrator configured for use with noninvasive analyte-concentration monitor and employing traditional measurements

• US 6,678,542 B2
• Filed: 11/02/2001
• Issued: 01/13/2004
• Est. Priority Date: 08/16/2001
• Status: Expired due to Fees

• Current Assignee: OptiScan Biomedical Corporation
• Original Assignee: OptiScan Biomedical Corporation
• Inventors: Gable, Jennifer H., Braig, James R., Sterling, Bernhard B., Rule, Peter, Cortella, Julian M., Smith, Heidi M.
• Primary Examiner(s): Winakur, Eric F.
• Assistant Examiner(s): KREMER, MATTHEW
• Application Number:
  US10/015,932
• Publication Number:
  US 20030036688A1
• Time in Patent Office: 802 Days
• Field of Search: 600/310, 600/316, 600/322, 600/331, 600/326, 600/365, 600/309
• US Class Current: 600/316
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters
• CPC Class Codes: A61B 5/1491 Heated applicators
• CPC Class Codes: A61B 5/1495 Calibrating or testing of in-vivo probes

Abstract

A method calibrates a monitor that comprises a non-invasive blood constituent monitor and a traditional measurement system. The non-invasive blood constituent monitor includes a thermal gradient inducing element an analyzer window. A traditional monitor output representing a property of a blood constituent is generated by the traditional measurement system. A non-invasive monitor output representing the property of the whole blood constituent is generated by the non-invasive constituent monitor. The traditional monitor output and the non-invasive monitor output are compared to estimate an amount of error. The non-invasive monitor output is corrected by the amount of error.

Claims

1. A method for calibrating a non-invasive blood constituent monitor connected to a traditional measurement system via a data link, the non-invasive monitor having an analyzer window, the method comprising:

determining whether there is a restricted period in effect;

selecting a first measurement location distal of a wrist or a second measurement location other than distal of the wrist based on whether a restricted period is in effect;

performing a traditional measurement of a blood constituent at the selected measurement location using the traditional measurement system;

generating a traditional monitor output representing a property of the blood constituent;

placing the analyzer window of the non-invasive blood constituent monitor in contact with the skin of a patient;

analyzing the blood constituent in blood within the patient with the non-invasive blood constituent monitor;

generating a non-invasive monitor output representing the property of the blood constituent;

comparing the traditional monitor output and the non-invasive monitor output to estimate an error; and

correcting the non-invasive monitor output based on said error.

2. The method of claim 1, wherein placing the analyzer window of the non-invasive blood constituent monitor in contact with the skin of the patient comprises placing the analyzer window in contact with the skin of the patient at said first measurement location or said second measurement location based on whether a restricted period is in effect.

3. The method of claim 1, wherein placing an analyzer window of the non-invasive blood constituent monitor in contact with the skin of the patient further comprises placing a thermal gradient inducing element of said non-invasive blood constituent monitor in contact with the skin of the patient.

4. The method of claim 1, further comprising correcting subsequent non-invasive monitor outputs based on said error.

5. The method of claim 1, wherein performing a traditional measurement comprises:

withdrawing an amount of whole blood from the patient, and

analyzing the blood constituent in the amount of whole blood with the traditional measurement system.

6. The method of claim 1 wherein generating a traditional monitor output representing a property of the blood constituent comprises generating a traditional monitor output representing the concentration of blood glucose.

7. The method of claim 1 wherein performing a traditional comprises performing an electro-chemical analysis of the whole blood withdrawn.

8. The method of claim 1 wherein determining whether there is a restricted period in effect comprises measuring an amount of time since the patient has eaten.

9. The method of claim 8 wherein the amount of time measured is from about 0.5 hour to about 3 hours.

10. The method of claim 8, wherein the amount of time measured s from about 1 hours to about 2 hours.

11. The method of claim 8, wherein the amount of time measured is from about 1.5 hours to about 2 hours.

12. The method of claim 8, wherein the amount of time measured is about 2 hours.

13. A method for calibrating a non-invasive blood constituent monitor, the method comprising:

selecting a first measurement location distal of a wrist or second measurement location other than distal of the wrist;

performing an invasive measurement of a blood constituent at the selected measurement location using an invasive blood constituent monitor;

generating an invasive monitor output representing a property of the blood constituent;

performing a non-invasive measurement of the blood constituent at the selected measurement location using the non-invasive blood constituent monitor;

generating a non-invasive monitor output representing the property of the blood constituent;

comparing the invasive monitor output and the non-invasive monitor output to estimate an error;

correcting the non-invasive monitor output based on said error; and

determining whether there is a restricted period in effect;

wherein selecting a first measurement location distal of the wrist or a second measurement location other than distal of the wrist comprises selecting the first or second measurement location based on whether there is a restricted period in effect.

14. The method of claim 13, further comprising correcting subsequent non-invasive monitor outputs based on said error.

15. The method of claim 13, wherein determining whether there is a restricted period in effect comprises measuring an amount of time since a subject has eaten.

16. The method of claim 15, wherein the amount of time measured is from about 0.5 hour to about 3 hours.

17. The method of claim 15, wherein the amount of time measured is from about 1 hours to about 2 hours.

18. The method of claim 15, wherein the amount of time measured is from about 1.5 hours to about 2 hours.

19. The method of claim 15, wherein the amount of time measured is about 2 hours.

20. A method foil calibrating a non-invasive blood constituent monitor, the method comprising:

selecting, based on patient-specific parameters, a first measurement location distal of a wrist or a second measurement location other than distal of the wrist;

performing an invasive measurement of a blood constituent at the selected measurement location using an invasive blood constituent monitor;

generating an invasive monitor output representing a property of the blood constituent;

performing a non-invasive measurement of the blood constituent at the selected measurement location using the non-invasive blood constituent monitor;

generating a non-invasive monitor output representing the property of the blood constituent;

comparing the invasive monitor output and the non-invasive monitor output to estimate an error; and

correcting the non-invasive monitor output based on said error;

wherein selecting based on patient-specific parameters comprising determining whether there is a restricted period in effect.

21. The method of claim 20, further comprising correcting subsequent non-invasive monitor outputs based on said error.

22. The method of claim 20, wherein determining whether there is a restricted period in effect comprises measuring an amount of time since a subject has eaten.

23. The method of claim 22 wherein the amount of time measured is from about 0.5 hour to about 3 hours.

24. The method of claim 22, wherein the amount of time measured is from about 1 hours to about 2 hours.

25. The method of claim 22 wherein the amount of time measured is from about 1.5 hours to about 2 hours.

26. The method of claim 22, wherein the amount of time measured is about 2 hours.