Concentration measuring method and concentration measuring apparatus

• US 7,491,310 B2
• Filed: 10/09/2002
• Issued: 02/17/2009
• Est. Priority Date: 10/12/2001
• Status: Active Grant

• Current Assignee: ARKRAY, Inc
• Original Assignee: ARKRAY, Inc
• Inventors: Okuda, Hisashi, Kado, Kotaro, Oura, Yoshimi
• Primary Examiner(s): NOGUEROLA, ALEXANDER STEPHAN
• Application Number:
  US10/492,432
• Publication Number:
  US 20040232009A1
• Time in Patent Office: 2,323 Days
• Field of Search: 204/412, 20440301-403, 204/15, 204/400, 204/403, 205/775, 205/778, 205/777.5, 205/792
• US Class Current: 205/777.5
• 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 relates to a technique for measuring the concentration of a particular component in a sample liquid using a test tool (2). The test tool (2) includes a first through a third detection elements (31a-33a) arranged in the mentioned order in the moving direction of the sample liquid for measuring an electro-physical quantity. The present invention provides a concentration measuring method which includes a first detection step for detecting whether or not liquid conduction is established between the first and the second detection elements (31a, 32a), a second detection step for detecting whether or not liquid conduction is established between the second and the third detection elements (31a, 33a), a measurement step for measuring an electro-physical quantity by using the first through the third detection elements (31a-33a), and a concentration computation step for computing the concentration of the particular component based on the electro-physical quantity. The present invention also provides a concentration measuring apparatus (1) for realizing the concentration measuring method.

Claims

1. A concentration measuring method for measuring concentration of a particular component in a sample liquid using a test tool;

the test tool comprising;

a capillary for moving the sample liquid, an operative electrode, a first counterpart electrode arranged upstream from the operative electrode in a moving direction of the sample liquid, a second counterpart electrode arranged downstream from the operative electrode in the moving direction of the sample liquid;

wherein the method comprises;

a first detection step for detecting whether or not liquid conduction is established between the operative electrode and the first counterpart electrode by detecting a response current between these two electrodes under voltage application;

a second detection step performed after conduction is detected in the first detection step for detecting whether or nor liquid conduction is established between the operative electrode and the second counterpart electrode by detecting the response current between these two electrodes for detecting a response current under voltage application;

a measurement step performed after conduction is detected in the second detection step for measuring a response current between the operative electrode and the first counterpart electrode or between the operative electrode and the second counterpart electrode under voltage application; and

a concentration computation step for computing the concentration of the particular component based on the response current measured in the measurement step, the computation of the concentration being also based on a lapse time between conduction detection in the first detection step and conduction detection in the second detection step.

2. The concentration measuring method according to claim 1, wherein the concentration computation step includes data processing operation for correcting, based on a correction value, the response current measured in the measurement step or a computed value obtained based on the measured response current;

and

wherein the correction value is obtained by computation based on data showing a relationship between the lapse time and the correction value.

3. The concentration measuring method according to claim 1, wherein the sample liquid contains a coexisting component which causes an error in the concentration measurement of the particular component;

and

wherein the lapse is figured out as a reflection of influence of the coexisting component.

4. The concentration measuring method according to claim 3, wherein the sample liquid is blood containing blood cell components as the coexisting component.

5. The concentration measuring method according to claim 3, wherein the particular component is glucose.

6. A concentration measuring apparatus for measuring concentration of a particular component in a sample liquid using a test tool;

the test tool comprising;

a capillary for moving the sample liquid, an operative electrode, a first counterpart electrode arranged upstream from the operative electrode in a moving direction of the sample liquid, a second counterpart electrode arranged downstream from the operative electrode in the moving direction of the sample liquid;

wherein the apparatus comprises;

a voltage application unit for applying a voltage between the operative electrode and the first counterpart electrode as well as between the operative electrode and the second counterpart electrode;

a current measurer for measuring a response current between the operative electrode and the first counterpart electrode under voltage application, the current measurer also measuring a response current between the operative electrode and the second counterpart electrode under voltage application;

a detector for detecting whether or not liquid conduction is established between the operative electrode and the first counterpart electrode by detecting the response current between these two electrodes under voltage application, the detector also detecting whether or not liquid conduction is established between the operative electrode and the second counterpart electrode by detecting the response current between these two electrodes under voltage application after conduction is detected between the operative electrode and the first counterpart electrode; and

a computation unit for computing the concentration of the particular component based on a response current measured under voltage application between the operative electrode and the first counterpart electrode or between the operative electrode and the second counterpart electrode after conduction is detected between the operative electrode and the second counterpart electrode, the concentration computation being also based on a lapse time from conduction detection between the operative electrode and the first counterpart electrode to conduction detection between the operative electrode and the second counterpart electrode.