Analyzing device, sensor testing device, testing method and computer-readable storage medium

• US 9,297,777 B2
• Filed: 02/02/2012
• Issued: 03/29/2016
• Est. Priority Date: 02/03/2011
• Status: Active Grant

• Current Assignee: ARKRAY, Inc
• Original Assignee: ARKRAY, Inc
• Inventors: Sekimoto, Shinjiro
• Primary Examiner(s): Van, Luan
• Assistant Examiner(s): ROSENWALD, STEVEN ERIC
• Application Number:
  US13/365,054
• Publication Number:
  US 20120199496A1
• Time in Patent Office: 1,517 Days
• Field of Search: 205/791.5, 204/401, 20440301-40315, 204/406, 600/345, 600/347
• US Class Current: 1/1
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/1486 using enzyme electrodes, e.g. with immobilised oxidase
• 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

There is provided a sensor testing method including: applying at least one of a first voltage that obtains a response caused by a substance and a second voltage that either obtains no response or substantially no response caused by the substance across a first electrode and a second electrode of a sensor; measuring current flowing between the first electrode and the second electrode; and determining whether or not there is a defect present in the sensor based on a quantity related to an amount of change per specific period of time of a current measured when the first voltage and/or the second voltage have been applied.

Claims

1. An analyzing device comprising:

a sensor section comprising

a reagent layer comprising a reagent capable of reacting with a target substance in a sample liquid,

an electrode section comprising a first electrode and a second electrode for applying a voltage to the reagent layer, and an external layer membrane for contacting the reagent layer;

a voltage application unit configured to apply at least one of a first voltage across the first electrode and the second electrode, resulting in a response current, caused by the target substance, flowing between the first electrode and the second electrode, and a second voltage resulting in no or substantially no response current;

a current measurement unit configured to measure the response current flowing between the first electrode and the second electrode; and

a computer programmed to compute at least one of

a time required for an amount of change of the response current per specific amount of change in time resulting from the application of the first voltage to reach a value in a predetermined first specific range prior to when the response current reaches a steady state for determining whether there is a defect present in the external layer membrane or

a time required for an amount of change of the response current per specific amount of change in time resulting from the application of the second voltage to reach a value in a predetermined second specific range prior to when the response current reaches a steady state for determining whether there is a defect present in the external layer membrane.

2. The analyzing device of claim 1 further comprising:

a storage unit configured to store

a first relationship between the time required for an amount of change of the response current per specific amount of change in time resulting from the application of the first voltage to reach a value in a predetermined first specific range and a set of defect ratios corresponding to the time required for the response current resulting from the application of the first voltage, and

a second relationship between the time required for an amount of change of the response current per specific amount of change in time resulting from the application of the second voltage to reach a value in a predetermined second specific range and a set of defect ratios corresponding to the time required for the response current resulting from the application of the second voltage; and

a correction unit configured to correct the response current value measured by the current measurement unit when a defect is determined by the determination unit to have occurred in the external layer membrane,

wherein the correction is based on at least one of the first relationship stored by the storage unit or the second relationship stored by the storage unit.

3. The analyzing device of claim 2 wherein the correction unit is configured to estimate the defect ratios based on at least one of the first relationship and the second relationship, and to correct the response current value measured by the current measurement unit based on a relationship between the defect ratio of the external layer membrane and the response current value measured from the sensor section provided with an external layer membrane having defects corresponding to the defect ratio.

4. The analyzing device of claim 3 wherein the defect ratio based on both the first relationship and the second relationship is computed as the average value, the maximum value or the minimum value of a first defect ratio estimated based on the first relationship and a second defect ratio estimated based on the second relationship.

5. The analyzing device of claim 1 further comprising an output unit that is configured to output a signal indicating that a defect has occurred in the sensor section when a defect is determined to have occurred in the external layer membrane by the determination unit.

6. The analyzing device of claim 1 wherein the voltage application unit is configured to apply the first voltage and the second voltage alternately.

7. The analyzing device of claim 1 wherein the current measurement unit is configured to continuously measure the current flowing between the first electrode and the second electrode.

8. The analyzing device of claim 1 wherein the sensor section is configured to be disposed under the skin of a user of the analyzing device and the reagent layer is configured to react to a composition to be tested present under the skin.

9. The analyzing device of claim 1 wherein the reagent layer is configured to extract electrons from the composition to be tested and to supply the extracted electrons to the electrode.

10. The analyzing device of claim 1 wherein the reagent layer includes an enzyme portion for extracting electrons from the composition to be tested.