METHOD OF MEASURING BLOOD COMPONENT, SENSOR USED IN THE METHOD, AND MEASURING DEVICE

• US 20100270177A1
• Filed: 07/01/2010
• Published: 10/28/2010
• Est. Priority Date: 12/04/2003
• Status: Active Grant

• Current Assignee: PHC Holdings Corporation
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: FUJIWARA, Masaki, SHINNO, Teppei, IKEDA, Shin
• Granted Patent: US 8,540,864 B2
• Time in Patent Office: Days
• US Class Current: 205/777.500
• CPC Class Codes: C12Q 1/001 Enzyme electrodes
• CPC Class Codes: C12Q 1/006 for glucose
• CPC Class Codes: G01N 27/3274 Corrective measures, e.g. error detection, compensation for temperature or hematocrit, calibration coding of calibration information G01N33/48771
• CPC Class Codes: G01N 33/66 involving blood sugars, e.g. galactose
• CPC Class Codes: G01N 33/728 Bilirubin; including biliverdin

Abstract

The present invention provides a method of measuring a component in blood, by which an amount of the component can be corrected accurately by measuring a hematocrit (Hct) value of the blood with high accuracy and high reliability and also provides a sensor used in the method. The sensor for measuring a component in blood has a first analysis portion and a second analysis portion. The first analysis portion has a first electrode system (11,12) and a reagent layer (14), and the reagent layer (14) has an oxidoreductase that acts on the component and a mediator. In the first analysis portion, the component in the blood is measured by causing a redox reaction of the component with the oxidoreductase in the presence of the mediator and detecting a redox current caused when a voltage is applied by the first electrode (11,12). The second analysis portion has a working electrode and a counter electrode, and a mediator is provided on the counter electrode but not on the working electrode. In the second analysis portion, a Hct value of the blood is measured by supplying the blood to the electrode system, applying a voltage to cause a current to flow, and detecting a value of the current. Using this Hct value, the amount of the component is corrected.

Claims

1. A method of measuring a component in blood, comprising:

causing a redox reaction between the component in the blood and an oxidoreductase in the presence of a mediator;

detecting an oxidation current or a reduction current caused through the redox reaction by an electrode system; and

calculating an amount of the component based on a value of the detected current,

wherein the method further comprises measuring a Hct value of the blood and correcting the amount of the component using this Hct value, the measurement of the Hct value comprising;

supplying the blood to an electrode system comprising a working electrode and a counter electrode, with a mediator being present on the counter electrode but not on the working electrode;

applying a voltage to electrode system in this state to cause an oxidation current or a reduction current to flow between the electrodes;

detecting the oxidation current or the reduction current; and

calculating the Hct value based on a value of the detected current.

2. The method according to claim 1, wherein the mediator used for the measurement of the Hct value is a ferricyanide.

3. The method according to claim 1, wherein the mediator used for the measurement of the Hct value is potassium ferricyanide.

4. The method according to claim 1, wherein, in the measurement of the Hct value, the working electrode on which the mediator is not provided is coated with a polymeric material.

5. The method according to claim 1, wherein in the measurement of the Hct value, the working electrode on which the mediator is not provided is coated with carboxymethylcellulose.

6. The method according to claim 1, wherein the voltage applied in the measurement of the Hct value is equal to or higher than a voltage causing electrolysis of water.

7. The method according to claim 1, wherein the voltage applied in the measurement of the Hct value is 1 to 10 V.

8. The method according to claim 1, wherein the voltage applied in the measurement of the Hct value is 1 to 6.5 V.

9. The method according to claim 1, wherein the correction using the Hct value is carried out based on one of a calibration curve and a calibration table that have been prepared previously for showing a relationship between a Hct value and an amount of the component.

10. The method according to claim 1, wherein the Hct value is measured after the amount of the component has been measured.

12. The method according to claim 1, further comprising measuring a temperature of a measurement environment,

wherein the amount of the component is corrected using the measured temperature.

13. The method according to claim 1, further comprising measuring a temperature of a measurement environment,

wherein the amount of the component is corrected using the measured temperature and the correction using the temperature is carried out based on one of a calibration curve and a calibration table that have been prepared previously for showing a relationship between a blood temperature and an amount of the component.

14. The method according to claim 1, wherein the component to be measured is at least one selected from the group consisting of glucose, lactic acid, uric acid, bilirubin, and cholesterol.

11. (canceled)

15. The method according to claim 1, wherein the component to be measured is glucose, and the oxidoreductase is at least one of glucose oxidase and glucose dehydrogenase. 16-43. (canceled)