Component concentration measuring device

Patent metadata

Field	Value
Publication number	US-12408840-B2
Application number	US-201917417556-A
Country	US
Kind code	B2
Filing date	Dec 11, 2019
Priority date	Dec 25, 2018
Publication date	Sep 9, 2025
Grant date	Sep 9, 2025

Abstract

A light emitting unit irradiates a measurement site of a measurement subject with a light beam having a wavelength that is absorbed by a measurement target substance. A detection unit detects a photoacoustic signal generated in the measurement site irradiated with the light beam emitted from the light emitting unit. A resonator is arranged so as to clamp the measurement site, and causes the above-described photoacoustic signal to resonate. The resonator is constituted by a first reflection unit and a second reflection unit. The first reflection unit is arranged between the light irradiation unit and the measurement site. Also, the light beam passes through the first reflection unit. The second reflection unit is arranged between the detection unit and the measurement site.

First claim

The invention claimed is:

1. A component concentration measuring device comprising:
a light emitting device configured to irradiate a measurement site of a measurement subject with a light beam having a wavelength that is absorbed by a measurement target substance;
a detector configured to detect a photoacoustic signal generated in the measurement site irradiated with the light beam; and
a resonator that is arranged with the measurement site in between, and is configured to cause the photoacoustic signal to resonate, wherein the resonator includes:
a first reflector between the light emitting device and the measurement site and has a first reflection surface configured to reflect the photoacoustic signal while allowing the light beam to pass;
a second reflector between the detector and the measurement site and has a second reflection surface configured to reflect the photoacoustic signal, wherein the first reflection surface and the second reflection surface are parallel to each other; and
a gap between the first reflection surface and the second reflection surface is a gap at which the photoacoustic signal resonates.

2. The component concentration measuring device according to claim 1 , further comprising:
a material filling a gap between the second reflector and the measurement site, wherein the material has a predetermined acoustic impedance.

3. The component concentration measuring device according to claim 1 , wherein:
the first reflection surface faces the measurement site; and
the first reflector includes:
a first contact surface that faces the light emitting device and is in contact with a light emitting end of the light emitting device; and
a void between the first reflection surface and the first contact surface.

4. The component concentration measuring device according to claim 1 , wherein:
the second reflection surface faces the measurement site; and
the second reflector includes:
a second contact surface that faces the detector and is in contact with a detection face of the detector that faces the measurement site; and
a void between the second reflection surface and the second contact surface.

5. The component concentration measuring device according to claim 1 , wherein a concentration of the measurement target substance is obtained based on the photoacoustic signal.

6. The component concentration measuring device according to claim 1 , wherein
the measurement target substance is glucose, and
the light emitting device is configured to emit the light beam having a wavelength that is absorbed by glucose.

Assignees

• Nippon Telegraph & Telephone

Inventors

• Tanaka Yujiro
• Nakamura Masahito
• Matsunaga Daichi
• Seyama Michiko

Classifications

• A61B5/14532 Primary

  for measuring glucose, e.g. by tissue impedance measurement · CPC title

• A61B5/0095 Primary

  by applying light and detecting acoustic waves, i.e. photoacoustic measurements · CPC title

• G01N29/28

  providing acoustic coupling {, e.g. water (impedance matching G10K11/02)} · CPC title

• A61B8/13

  Tomography (A61B8/10, A61B8/12 take precedence) · CPC title

• G01N29/48

  by amplitude comparison · CPC title