Photoacoustic measurement device and probe for photoacoustic measurement device

Patent metadata

Field	Value
Publication number	US-9730588-B2
Application number	US-201414519809-A
Country	US
Kind code	B2
Filing date	Oct 21, 2014
Priority date	May 8, 2012
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

An object of the invention is to reduce the size of a probe for a photoacoustic measurement device. A light guide 71 is arranged such that one of a two side surfaces 71 a is closer to a probe axis C which faces a subject than the other side surface and a light emission end surface 71 c is closer to the probe axis C than a light incident end surface 71 b when the probe is used. When a refractive index of the light guide 71 with respect to the light is n1 and a refractive index of a medium around the light guide with respect to the light during photoacoustic measurement is n2 (n2<n1), the light emission end surface 71 c is obliquely formed such that an angle α[°] (where 90°−arcsin(n2/n1)<α<90°) is formed between the light emission end surface 71 c and the side surface 71 a.

First claim

What is claimed is:

1. A probe for a photoacoustic measurement device, comprising:
a light irradiation unit that emits light to be radiated to a subject; and
an acoustic wave detection unit that detects an acoustic wave which is emitted from the subject by the light irradiation,
wherein the light irradiation unit includes a light guide that has a parallel plate shape and includes two side surfaces which are parallel to each other, a light incident end surface on which the light is incident, and a light emission end surface which is opposite to the light incident end surface, with the side surfaces interposed therebetween, and from which the light is emitted,
the light guide is arranged such that one of the two side surfaces is closer to a probe axis which faces the subject than the other side surface and the light emission end surface is closer to the probe axis than the light incident end surface when the probe is used, and
when a refractive index of the light guide with respect to the light is n1 and a refractive index of a medium around the light guide with respect to the light during photoacoustic measurement is n2, an angle α is formed between the light emission end surface and the side surface which is closer to the probe axis, n2<n1 is satisfied, and 90°−arcsin(n2/n1)<α<90° is satisfied.

2. The probe for a photoacoustic measurement device according to claim 1 ,
wherein, when an incident angle of light, which travels in parallel to the two side surfaces in the light guide and is emitted from the light emission end surface, with respect to a plane perpendicular to the probe axis is β1 and an inclination angle of the light guide with respect to the probe axis is β2, the following expression is satisfied:

sin
⁡

(

90
⁢
°

-
α

)

sin
⁡

(

90
⁢
°

-
α
+

β
⁢

⁢
1

-

β
⁢

⁢
2

)

=

n
⁢

⁢
2

n
⁢

⁢
1

[

Expression
⁢

⁢
1

]

3. The probe for a photoacoustic measurement device according to claim 1 ,
wherein an arrangement angle of the light guide is changeable.

4. The probe for a photoacoustic measurement device according to claim 2 ,
wherein an arrangement angle of the light guide is changeable.

5. The probe for a photoacoustic measurement device according to claim 3 ,
wherein the arrangement angle of the light guide is changeable between a predetermined angle with respect to the probe axis and an angle which is parallel to the probe axis.

6. The probe for a photoacoustic measurement device according to claim 4 ,
wherein the arrangement angle of the light guide is changeable between a predetermined angle with respect to the probe axis and an angle which is parallel to the probe axis.

7. The probe for a photoacoustic measurement device according to claim 1 ,
wherein a plurality of the acoustic wave detection units are arranged in a line in a direction perpendicular to the probe axis, and
the light guide is arranged such that the light emission end surface extends in the arrangement direction of the plurality of acoustic wave detection units.

8. The probe for a photoacoustic measurement device according to claim 2 ,
wherein a plurality of the acoustic wave detection units are arranged in a line in a direction perpendicular to the probe axis, and
the light guide is arranged such that the light emission end surface extends in the arrangement direction of the plurality of acoustic wave detection units.

9. The probe for a photoacoustic measurement device according to claim 3 ,
wherein a plurality of the acoustic wave detection units are arranged in a line in a direction perpendicular to the probe axis, and
the light guide is arranged such that the light emission end surface extends in the arrangement direction of the plurality of acoustic wave detection units.

10. The probe for a photoacoustic measurement device according to claim 5 ,
wherein a plurality of the acoustic wave detection units are arranged in a line in a direction perpendicular to the probe axis, and
the light guide is arranged such that the light emission end surface extends in the arrangement direction of the plurality of acoustic wave detection units.

11. The probe for a photoacoustic measurement device according to claim 1 ,
wherein two light guides are provided, with the probe axis interposed therebetween.

12. The probe for a photoacoustic measurement device according to claim 2 ,
wherein two light guides are provided, with the probe axis interposed therebetween.

13. The probe for a photoacoustic measurement device according to claim 11 , further comprising:
shutters that are provided so as to correspond to the two light guides and control light transmission such that light which passes through the light guides is radiated to the subject for different periods.

14. The probe for a photoacoustic measurement device according to claim 1 , further comprising:
optical fibers through which light emitted from a light source is propagated,
wherein the optical fibers are optically coupled to the light incident end surface

Assignees

• Fujifilm Corp

Inventors

• Abe Takeya

Classifications

• G01N29/2418

  using optoacoustic interaction with the material, e.g. laser radiation, photoacoustics (photoacoustic cells G01N21/1702; measuring characteristics of vibrations by using radiation-sensitive means G01H9/00; acousto-optical conversion techniques for short-range imaging G01S15/8965; sound-producing devices using laser bundle G10K15/046) · CPC title

• A61B8/4416

  related to combined acquisition of different diagnostic modalities, e.g. combination of ultrasound and X-ray acquisitions · CPC title

• A61B8/463

  characterised by displaying multiple images or images and diagnostic data on one display · CPC title

• A61B8/5246

  combining images from the same or different imaging techniques, e.g. color Doppler and B-mode · CPC title

• G01N29/2462

  Probes with waveguides, e.g. SAW devices · CPC title