BIOSENSOR SYSTEM, SENSOR CHIP, AND METHOD OF MEASURING ANALYTE CONCENTRATION IN BLOOD SAMPLE

• US 20110027816A1
• Filed: 04/02/2009
• Published: 02/03/2011
• Est. Priority Date: 04/07/2008
• Status: Active Grant

• Current Assignee: PHC Holdings Corporation
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Fujiwara, Masaki
• Granted Patent: US 8,940,138 B2
• Time in Patent Office: Days
• US Class Current: 435/25
• CPC Class Codes: C12Q 1/26 involving oxidoreductase
• CPC Class Codes: G01N 27/3273 Devices therefor, e.g. test element readers, circuitry details not specific to biochemical electrodes G01N33/4875
• CPC Class Codes: G01N 27/3274 Corrective measures, e.g. error detection, compensation for temperature or hematocrit, calibration coding of calibration information G01N33/48771

Abstract

The present invention provides a biosensor system that can prevent a measurement error caused by the temperature of the environment in use from occurring. A biosensor system 100 includes a measuring instrument 101 having an operation part 306, and a sensor chip 200 that is insertable into and removable from the measuring instrument 101 and into which a blood sample is introduced. The sensor chip 200 includes a measurement part 41 (a measurement part A) that acquires Data a related to the concentration of an analyte in a blood sample based on the amount of electric current that flows in the blood sample due to a reaction in which an oxidoreductase with the analyte used as a substrate is involved, and a measurement part 42 (a measurement part B) that acquires, from the blood sample, Data b for temperature correction of Data a. The operation part 306 has a function of determining the concentration of the analyte in the blood sample, with the concentration having been corrected according to the temperature of the blood sample based on Data a and Data b.

Claims

1. A biosensor system, comprising:

a measuring instrument having an operation part, and

a sensor chip that is insertable into and removable from the measuring instrument and into which a blood sample is introduced,

wherein the sensor chip includes a measurement part A that acquires Data a related to the concentration of an analyte in the blood sample based on the amount of electric current that flows in the blood sample due to a reaction in which an oxidoreductase with the analyte used as a substrate is involved, and a measurement part B that acquires, from the blood sample, Data b for temperature correction of the Data a, and

the operation part has a function of determining the concentration of the analyte in the blood sample, with the concentration having been corrected according to the temperature of the blood sample based on the Data a and the Data b.

2. The biosensor system according to claim 1, wherein the measurement part B comprises electrodes for applying voltage to the blood sample.

3. The biosensor system according to claim 2, wherein the Data b is related to the amount of electric current that flows in the blood sample according to oxidation or reduction of a redox substance other than the analyte.

4. The biosensor system according to claim 1, wherein the measuring instrument has a control circuit that provides the measurement part A with a signal that indicates acquisition of the Data a within a range of at least 0.5 second but less than 2.5 seconds from the time when the blood sample has been introduced into the sensor chip.

5. The biosensor system according to claim 1, wherein the sensor chip has a reaction reagent layer containing the oxidoreductase,

the reaction reagent layer contains no water-soluble polymer or contains less than 0.2 mass % of water-soluble polymer, and

the measuring instrument has a control circuit that provides the measurement part A with a signal that indicates acquisition of the Data a within a range of at least 0.5 second but less than 2.5 seconds from the time when the blood sample has been introduced into the sensor chip.

6. The biosensor system according to claim 1, wherein the sensor chip has a reaction reagent layer containing the oxidoreductase,

the reaction reagent layer contains at least 0.2 mass % of water-soluble polymer, and

the measuring instrument has a control circuit that provides the measurement part A with a signal that indicates acquisition of the Data a after a lapse of at least 2.5 seconds from the time when the blood sample has been introduced into the sensor chip.

7. The biosensor system according to claim 3, wherein the operation part has a conversion table in which Data c, Data d, and the concentration of an analyte in a blood sample corresponding to the Data c and the Data d are described, where the Data c is related to the amount of electric current that flows in the blood sample due to a reaction in which an oxidoreductase with the analyte used as a substrate is involved and the Data d is related to the amount of electric current that flows in the blood sample according to oxidation or reduction of a redox substance other than the analyte, and the operation part determines the concentration of the analyte in the blood sample based on the Data a and the Data b with referring to the conversion table.

8. The biosensor system according to claim 7, wherein in the conversion table, one converted value based on the Data c and the Data d is described instead of the Data c and the Data d.

9. The biosensor system according to claim 3, wherein the measuring instrument further comprises an environmental temperature measurement part for measuring the temperature of a measurement environment.

10. The biosensor system according to claim 3, wherein the operation part has a first conversion table and a second conversion table, the first conversion table is a conversion table in which Data c, Data d, and the concentration of an analyte in a blood sample corresponding to the Data c and the Data d are described, where the Data c is related to the amount of electric current that flows in the blood sample due to a reaction in which an oxidoreductase with the analyte used as a substrate is involved and the Data d is related to the amount of electric current that flows in the blood sample according to oxidation or reduction of a redox substance other than the analyte, and the second conversion table has the Data c and Data e for correcting the Data c according to the temperature of a measurement environment.

11. The biosensor system according to claim 10, wherein the measuring instrument further comprises an environmental temperature measurement part for measuring the temperature of the measurement environment, and a control circuit for providing the environmental temperature measurement part with a signal that indicates implementation of first temperature measurement before acquisition of the Data a and the Data b and a signal that indicates implementation of second temperature measurement after acquisition of the Data a and the Data b, and

when the temperatures measured in the first temperature measurement and the second temperature measurement are indicated as a first temperature and a second temperature, respectively, the operation part determines:

i) the concentration of the analyte in the blood sample based on the Data a and the Data b with referring to the first conversion table when the first temperature and the second temperature satisfy the following relational expression (1);

2.5°

C.≦

|(Second Temperature)−

(First Temperature)| 

 

(1), and

ii) the concentration of the analyte in the blood sample based on the Data a and data related to the first temperature and/or the second temperature instead of the Data b with referring to the second conversion table when the first temperature and the second temperature satisfy the following relational expression (2);

|(Second Temperature)−

(First Temperature)|<

2.5°

C. 

 

(2).

12. The biosensor system according to claim 11, wherein the control circuit provides the environmental temperature measurement part with a signal that indicates implementation of the second temperature measurement after a lapse of at least 5 seconds from the first temperature measurement.

13. A sensor chip that is used in a biosensor system according to claim 1 and into which a blood sample is introduced,

wherein the sensor chip comprises a measurement part A that acquires Data a related to the concentration of an analyte in the blood sample based on the amount of electric current that flows in the blood sample due to a reaction in which an oxidoreductase with the analyte used as a substrate is involved, and a measurement part B that acquires, from the blood sample, Data b for temperature correction of the Data a.

14. The biosensor system according to claim 13, wherein the measurement part B has electrodes for applying voltage to the blood sample.

15. A method of measuring the concentration of an analyte in a blood sample, comprising:

a step of acquiring Data a related to the concentration of the analyte based on the amount of electric current that flows in the blood sample due to a reaction in which an oxidoreductase with the analyte used as a substrate is involved, a step of acquiring, from the blood sample, Data b for temperature correction of the Data a, and a step of determining the concentration of the analyte in the blood sample, with the concentration having been corrected according to the temperature of the blood sample based on the Data a and the Data b,

wherein the step of acquiring the Data b includes a step of applying voltage to a pair of electrodes that have been brought into contact with the blood sample and measuring the amount of electric current that flows in the blood sample according to oxidation or reduction of a redox substance other than the analyte.

16. The method according to claim 15, wherein the concentration of an analyte in a blood sample is determined based on the Data a and the Data b with referring to a conversion table in which Data c, Data d, and the concentration of the analyte in the blood sample corresponding to the Data c and the Data d are described, where the Data c is related to the amount of electric current that flows in the blood sample due to a reaction in which an oxidoreductase with the analyte used as a substrate is involved and the Data d is related to the amount of electric current that flows in the blood sample according to oxidation or reduction of a redox substance other than the analyte.

17. The method according to claim 16, wherein in the conversion table, one converted value based on the Data c and the Data d is described instead of the Data c and the Data d.

18. The method according to claim 15, further comprising a step of measuring environmental temperature around the blood sample,

wherein the step comprises a first temperature measurement step of measuring the environmental temperature before acquisition of the Data a and the Data b and a second temperature measurement step of measuring the environmental temperature after acquisition of the Data a and the Data b, and

when the temperatures measured by the first temperature measurement step and the second temperature measurement step are indicated as a first temperature and a second temperature, respectively,

i) the concentration of an analyte in a blood sample is determined based on the Data a and the Data b with referring to the first conversion table in which Data c, Data d, and the concentration of the analyte in the blood sample corresponding to the Data c and the Data d are described, where the Data c is related to the amount of electric current that flows in the blood sample due to a reaction in which an oxidoreductase with the analyte used as a substrate is involved and the Data d is related to the amount of electric current that flows in the blood sample according to oxidation or reduction of a redox substance other than the analyte when the first temperature and the second temperature satisfy the following relational expression (1):

2.5°

C.≦

|(Second Temperature)−

(First Temperature)| 

 

(1), and

ii) the concentration of the analyte in the blood sample is determined based on the Data a and data related to the first temperature and/or the second temperature instead of the Data b with referring to the second conversion table that has the Data c and Data e for correcting the Data c according to the temperature of a measurement environment when the first temperature and the second temperature satisfy the following relational expression (2);

|(Second Temperature)−

(First Temperature)|<

2.5°

C. 

 

(2).

19. The method according to claim 18, wherein the second temperature measurement step is carried out after a lapse of at least 5 seconds from the first temperature measurement step.