# US 8,540,864 B2 · Method of measuring blood component, sensor used in the method, and measuring device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,540,864 B2 - Document ID: US8540864B2 - Status: Granted - Kind: B2 - Application number: 12/829,077 - Filed: 2010-07-01 - Published: 2010-10-28 - Granted: 2013-09-24 - Earliest claimed: 2003-12-04 - Assignees: Panasonic Corporation - Applicants: Masaki Fujiwara; Teppei Shinno; Shin Ikeda - Inventors: Masaki Fujiwara; Teppei Shinno; Shin Ikeda - Web page: https://patentgrep.com/patent/US8540864B2 ## CPC - G01N 27/3274: {Corrective measures, e.g. error detection, compensation for temperature or hematocrit, calibration (coding of calibration information G01N33/48771)} - C12Q 1/001: {Enzyme electrodes} - C12Q 1/006: {for glucose} - G01N 33/66: involving blood sugars, e.g. galactose - G01N 33/728: {Bilirubin; including biliverdin} - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - C12Q: MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS (immunoassay G01N33/53); COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES ## 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 ### Claim 1 A method of measuring a component in a blood sample, comprising: causing a redox reaction between the component in the blood sample and an oxidoreductase in the presence of a mediator; detecting a first oxidation current or a reduction current caused by the redox reaction with an electrode system for measuring the component; calculating an amount of the component based on a value of the detected current; and measuring a Hct value of the blood sample and correcting the amount of the component using the measured Hct value, the measurement of the Hct value comprising: applying a voltage in the presence of the blood sample to a second electrode system for Hct value measurement that comprises a counter electrode and a working electrode to cause an oxidation current or a reduction current to flow between the counter electrode and the working electrode for the Hct value measurement, the oxidoreductase and the mediator used for the redox reaction with the component in the blood sample being present on the counter electrode for the Hct value measurement, the counter electrode for the Hct value measurement being part of the first electrode system for detecting the oxidation or reduction current for measuring the component in the blood sample, and a mediator for the Hct value measurement being present on the counter electrode for Hct value measurement and not on the working electrode for Hct value measurement; detecting the oxidation current or the reduction current from applying the voltage to the electrode system for Hct measurement; and calculating the Hct value based on a value of the detected current. ### Claim 2 (depends on 1) The method according to claim 1, wherein the mediator used for the measurement of the Hct value is a ferricyanide. ### Claim 3 (depends on 2) The method according to claim 2, wherein the ferricyanide is potassium ferricyanide. ### Claim 4 (depends on 1) The method according to claim 1, wherein the working electrode for measuring the Hct value is coated with a polymeric material. ### Claim 5 (depends on 4) The method according to claim 4, wherein the polymeric material is carboxymethylcellulose. ### Claim 6 (depends on 1) 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. ### Claim 7 (depends on 6) The method according to claim 6, wherein the voltage applied in the measurement of the Hct value is 1 to 10 V. ### Claim 8 (depends on 7) The method according to claim 7, wherein the voltage applied in the measurement of the Hct value is 1 to 6.5 V. ### Claim 9 (depends on 1) 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 prepared previously for showing a relationship between a Hct value and an amount of the component. ### Claim 10 (depends on 1) The method according to claim 1, wherein the Hct value is measured after the amount of the component has been measured. ### Claim 11 (depends on 1) 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. ### Claim 12 (depends on 1) 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. ### Claim 13 (depends on 1) 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. ### Claim 14 (depends on 13) The method according to claim 13, wherein the component to be measured is glucose, and the oxidoreductase is at least one of glucose oxidase and glucose dehydrogenase. ### Claim 15 (depends on 1) The method according to claim 1, wherein the application of voltage for the Hct measurement is carried out for a time period of 0.01 to 10 seconds. ### Claim 16 (depends on 1) The method according to claim 1, wherein the working electrode for the Hct value measurement is not affected by the mediator on the counter electrode during the Hct value measurement.