Concentration measuring instrument, concentration measuring contact apparatus, concentration measuring calculating apparatus, and concentration measuring method

• US 7,110,112 B2
• Filed: 03/05/2003
• Issued: 09/19/2006
• Est. Priority Date: 03/06/2002
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Uchida, Shinji, Shioi, Masahiko
• Primary Examiner(s): Lauchman, Layla G.
• Assistant Examiner(s): Punnoose, Roy M.
• Application Number:
  US10/479,758
• Publication Number:
  US 20040233433A1
• Time in Patent Office: 1,294 Days
• Field of Search: 356/364, 356/369, 356/370, 356/36, 356/445, 356/244
• US Class Current: 356/364
• CPC Class Codes: A61B 5/14558 by polarisation
• CPC Class Codes: G01N 2021/217 Measuring depolarisation or comparing polarised and depolarised parts of light
• CPC Class Codes: G01N 21/21 Polarisation-affecting properties G01N21/19 takes precedence
• CPC Class Codes: G01N 21/552 Attenuated total reflection

Abstract

To provide a concentration measuring method which enables a stable and highly accurate concentration measurement while avoiding the step of making a background measurement.

The concentration measuring apparatus includes: a concentration measuring contact that is brought into contact with a subject of measurement; a light source that emits light and enters the light into the concentration measuring contact; a polarizer that takes out p-polarized and s-polarized light components from the light which is passed through the concentration measuring contact into the subject of measurement, transmitted in the subject of measurement, and returned to the concentration measuring contact; a photodetector that determines at least the quantities of the p-polarized and s-polarized light components taken out by the polarizer; and calculating means that calculates the concentration of a specific component contained in the subject of measurement based on the determined results.

Claims

1. A concentration measuring apparatus, comprising:

a concentration measuring contact that is brought into contact with a subject of measurement;

a light source that emits light and enters the light into the concentration measuring contact;

a polarizer that takes out p-polarized and s-polarized light components from the light which is passed through the concentration measuring contact into the subject of measurement, transmitted in the subject of measurement, and returned to the concentration measuring contact;

a photodetector that determines at least the quantities of the p-polarized and s-polarized light components taken out by the photodetector; and

calculating means that calculates the concentration of a specific component contained in the subject of measurement based on the determined results.

2. The concentration measuring apparatus according to claim 1, wherein the calculating means calculates the concentration of the specific component utilizing correspondence information obtained in advance that allows the determined results to have a one-to-one correspondence with the concentrations of the specific component.

3. The concentration measuring apparatus according to claim 1, wherein the concentration measuring contact is an attenuated total reflection device and the light entered into the subject of measurement is evanescent light that oozes from the attenuated total reflection device.

4. The concentration measuring apparatus according to claim 1, wherein the subject of measurement is a living body tissue and the specific component is glucose, ethanol, cholesterol or a derivative of cholesterol.

5. The concentration measuring apparatus according to claim 1, wherein the calculating means carries out calculation according to the equation, log10 (Is/Ip) or log10 (Ip/Is), where Ip represents the measured value of the quantity of the p-polarized light component and Is represents the measured value of the quantity of the s-polarized light component, and obtains the concentration of the specific component based on the calculated value.

6. The concentration measuring apparatus according to claim 1, wherein the calculating means carries out calculation according to the equation, Ip/Is or Is/Ip, where Ip represents the measured value of the quantity of the p-polarized light component and Is represents the measured value of the quantity of the s-polarized light component and obtains the concentration of the specific component based on the calculated value.

7. The concentration measuring apparatus according to claim 1, wherein the photodetector measures the quantities of the p-polarized light component and the s-polarized light component alternately at least one time or more for each,

the calculating means selects, from among the measured values measured by the photo detector, the measured value of Ip, the quantity of the p-polarized light component, and the measured value of Is, the quantity of the s-polarized light component, the values being obtained at the respective measurement time points in immediate proximity to each other, carries out calculation using the selected Ip and Is values, and obtains the concentration of the specific component based on the calculated value.

8. A concentration measuring method of measuring a specific component contained in a subject of measurement comprising:

a contacting step of bringing the concentration measuring contact into contact with the subject of measurement;

a light entering step of entering light into the concentration measuring contact;

a measuring step of measuring at least the quantities of the p-polarized light component and the s-polarized light component of the light that is passed through the concentration measuring contact into the subject of measurement, transmitted in the subject of the measurement, and returned to the concentration measuring contact; and

a calculating step of calculating the concentration of the specific component contained in the subject of measurement based on the determined results in the measuring step.

9. A concentration measuring contact apparatus including:

a concentration measuring contact that is brought into contact with a subject of measurement;

a light source that emits light and enters the light into the concentration measuring contact;

a polarizer that takes out p-polarized and s-polarized light components of the light that is passed through the concentration measuring contact into the subject of measurement, transmitted in the subject of measurement, and returned to the concentration measuring contact; and

a photodetector that determines at least the quantities of the p-polarized light component and the s-polarized light component taken out by the polarizer, wherein the concentration of a specific component contained in the subject of measurement is calculated by calculating means based on the determined results.

10. A concentration measuring calculating apparatus including:

calculating means that calculates the concentration of a specific component contained in a subject of measurement based on determined results obtained by a concentration measuring contact apparatus which includes;

a concentration measuring contact that is brought into contact with the subject of measurement;

a light source that emits light and enters the light into the concentration measuring contact;

a polarizer that takes out p-polarized and s-polarized light components of the light that is passed through the concentration measuring contact into the subject of measurement, transmitted in the subject of measurement, and returned to the concentration measuring contact; and

a photodetector that determines at least the quantities of the p-polarized light component and the s-polarized light component taken out by the polarizer.