Method for performing correction of blood glucose assay bias using blood hemoglobin concentration

• US 20080248581A1
• Filed: 03/26/2008
• Published: 10/09/2008
• Est. Priority Date: 04/06/2007
• Status: Abandoned Application

• Current Assignee: Bayer Healthcare LLC (Bayer AG)
• Original Assignee: Bayer Healthcare LLC (Bayer AG)
• Inventors: Warchal-Windham, Mary Ellen, Chu, Amy H.
• Application Number:
  US12/079,363
• Publication Number:
  US 20080248581A1
• Time in Patent Office: Days
• US Class Current: 436/66
• CPC Class Codes: G01N 33/66 involving blood sugars, e.g. galactose
• CPC Class Codes: G01N 33/721 Haemoglobin

Abstract

A device and method for determining a correction factor for correcting the blood glucose assay bias based on sample hematocrit interference in a testing device using the blood hemoglobin concentration. The hemoglobin assay and the glucose assay may be performed using a single combination monitoring device.

Claims

1. A method for correcting the blood glucose assay bias in a testing device or system that measures glucose and hemoglobin concentrations in a blood sample, the method comprising the acts of:

measuring the total hemoglobin concentration, Hb, of the blood sample as part of a hemoglobin A_1C assay;

measuring the glucose concentration, Glu_uncor, of the blood sample;

calculating the percent hematocrit, % Hct, of the blood sample based on an empirical relationship between the total hemoglobin concentration, Hb, and the percent hematocrit, % Hct;

calculating a correction factor, % Correction, based on an empirical relationship between the percent hematocrit, % Hct and the correction factor, % Correction; and

correcting the glucose concentration, Glu_uncor, of the blood sample using the % Correction to provide a corrected gluclose concentration, Glu_cor.

2. The method of claim 1, wherein the empirical relationship between the correction factor, % Correction, and the percent hematocrit, % Hct, is represented by the formula % Correction=(% Hct×

C3)+C4, wherein C3 and C4 are constants which are glucose-concentration dependent.

3. The method of claim 1, wherein the empirical relationship between the percent hematocrit, % Hct, and the total hemoglobin concentration, Hb, is represented by the formula % Hct=(C1 ×

Hb)+C2, wherein Hb is in g/dL, and C1 and C2 are constants.

4. The method of claim 1, wherein, if the percent hematocrit, % Hct, is within a defined normal range, the corrected glucose concentration, Glu_cor is calculated according to the relationship Glu_cor=Glu_uncor.

5. The method of claim 4, wherein the normal range is from about 35% to about 45%.

6. The method of claim 1 wherein, if the percent hematocrit, % Hct, is outside of a defined normal range, the corrected glucose concentration, Glu_cor is calculated according to the relationship Glu_cor=Glu_uncor−

(Glu_uncor×

% Correction).

7. The method of claim 6, wherein the normal range is less than about 35% and greater than about 45%.

8. The method of claim 1, wherein the glucose concentration is performed using an optical testing method.

9. The method of claim 1, wherein the glucose concentration is performed using an electrochemical testing method.

10. The method of claim 1, wherein the testing device or system that measures glucose and hemoglobin concentrations in a blood sample includes a single combination monitoring device.

11. The method of claim 1, wherein the method further calculates the percentage hemoglobin A_1C, % HbA_1C, as a ratio of the concentration of hemoglobin A_1C to the concentration of total hemoglobin according to the relationship % HbA_1C=(HbA_1C/Hb)×

100.

12. A testing device or system for measuring the blood glucose concentration and total hemoglobin concentration in a blood sample and correcting the measured glucose concentration for a glucose assay bias effect, the testing device or system comprising:

a reagent system adapted to measure the blood glucose concentration, Glu_uncor of the blood sample;

a reagent system adapted to measure the total hemoglobin concentration, Hb, of the blood sample as part of a hemoglobin A_1C assay;

a processor adapted to calculate

a percent hematocrit, % Hct, of the blood sample based on an empirical relationship using the total hemoglobin concentration, Hb,

a correction factor, % Correction, based on an empirical relationship using the percent hematocrit, % Hct,

a corrected glucose concentration, Glu_cor, of the blood sample based on the correction factor, % Correction; and

a display adapted to display the corrected glucose concentration, Glu_cor, to a user.

13. The testing device of claim 12, wherein the empirical relationship between the correction factor, % Correction, and the percent hematocrit, % Hct, is represented by the formula % Correction=(% Hct×

C3)+C4, wherein C3 and C4 are constants which are glucose-concentration dependent.

14. The testing device of claim 12, wherein the empirical relationship between the percent hematocrit, % Hct, and the total hemoglobin concentration, Hb, is represented by the formula % Hct=(C1 ×

Hb)+C2, wherein Hb is in mmole/L and C1 and C2 are constants.

15. The testing device of claim 12, wherein, if the percent hematocrit, % Hct, is within a defined normal range, the corrected glucose concentration, Glu_cor. is calculated according to the relationship Glu_cor=Glu_uncor.

16. The testing device of claim 15, wherein the normal range is from about 35% to about 45%.

17. The testing device of claim 12, wherein, if the percent hematocrit, % Hct, is outside of a defined normal range, the corrected glucose concentration, Glu_cor is calculated according to the relationship Glu_cor=Glu_uncor−

(Glu_uncor×

% Correction).

18. The testing device of claim 17, wherein the normal range is less than about 35% and greater than about 45%.

19. The testing device of claim 12, wherein the glucose concentration is performed using an optical testing method.

20. The testing device of claim 12, wherein the glucose concentration is performed using an electrochemical testing method.

21. A single combination testing device adapted for measuring blood glucose concentration and total hemoglobin concentration in a blood sample, the total hemoglobin concentration being measured as part of a hemoglobin A_1C assay.