Photoacoustic Wave Detector and Photoacoustic Imaging Device

• US 20170258333A1
• Filed: 08/21/2015
• Published: 09/14/2017
• Est. Priority Date: 08/28/2014
• Status: Abandoned Application

• Current Assignee: PreXion Corporation (Funai Electric Holdings Company Limited)
• Original Assignee: PreXion Corporation (Funai Electric Holdings Company Limited)
• Inventors: SHIGETA, Yusuke
• Application Number:
  US15/506,773
• Publication Number:
  US 20170258333A1
• Time in Patent Office: Days
• CPC Class Codes: A61B 5/0084 for introduction into the body, e.g. by catheters A61B5/1459 takes precedence
• CPC Class Codes: A61B 5/0095 by applying light and detecting acoustic waves, i.e. photoacoustic measurements
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00
• CPC Class Codes: A61B 8/13 Tomography A61B8/10, A61B8/12 take precedence; tomography for radiation diagnosis A61B6/02
• CPC Class Codes: A61B 8/445 Details of catheter construction
• CPC Class Codes: A61B 8/4483 characterised by features of the ultrasound transducer

Abstract

This photoacoustic wave detector is provided with: an internal light source (212) that comprises an LED element (212a) to be inserted into the interior of a subject (P) and that irradiates an object to be detected (Q) within the subject with light emitted from the LED element; and an internal acoustoelectric conversion unit (22) that detects a photoacoustic wave generated at the object to be detected in the interior of the subject (150) and generates an internal detection signal that is based on the detection result of the photoacoustic wave (AW).

Claims

1. A photoacoustic wave detector comprising:

an internal light source including a light-emitting element to be inserted into a test object, the internal light source applying light emitted from the light-emitting element to a detection target in the test object; and

an internal detecting portion that detects a photoacoustic wave inside the test object and generates an internal detection signal based on a result of detection of the photoacoustic wave, the photoacoustic wave being generated at the detection target.

2. The photoacoustic wave detector according to claim 1, wherein

the internal light source and the internal detecting portion are both provided near the tip of an inserted part to be inserted into the test object.

3. The photoacoustic wave detector according to claim 1, wherein

the internal detecting portion is provided at a lateral surface of the inserted part to be inserted into the test object, the lateral surface extending in a direction conforming to a direction of insertion of the inserted part,

the lateral surface is formed of a curved surface or a plurality of planes and includes a mounting surface on which the light-emitting element is mounted, and

the light-emitting element is arranged to be pointed outward of a direction of a normal to the mounting surface of the inserted part.

4. The photoacoustic wave detector according to claim 3, wherein

the mounting surface is formed of a circular curved surface,

the internal detecting portion is provided along the outer periphery of the lateral surface of the inserted part as viewed in the direction of insertion of the inserted part, and

the light-emitting element is configured to emit light outward of the direction of the normal so as to cover the entire periphery of the mounting surface as viewed in the direction of insertion of the inserted part.

5. The photoacoustic wave detector according to claim 3, further comprising a reflective member that reflects light emitted from the light-emitting element outward of the direction of the normal.

6. The photoacoustic wave detector according to claim 1, further comprising a reflective member that reflects light emitted from the light-emitting element outward of a direction of a normal to a lateral surface of the inserted part to be inserted into the test object, the lateral surface extending in a direction conforming to a direction of insertion of the inserted part, wherein

the internal detecting portion is provided at the lateral surface,

the light-emitting element is mounted on a mounting surface pointed in the direction of insertion, and

the reflective member has a reflective surface facing the mounting surface.

7. The photoacoustic wave detector according to claim 1, wherein

the inserted part to be inserted into the test object is rotatable about the direction of insertion of the inserted part as an axis.

8. The photoacoustic wave detector according to claim 1, wherein

the internal light source includes at least one of a light-emitting diode element, a semiconductor laser element, and an organic light-emitting diode element to function as the light-emitting element.

9. The photoacoustic wave detector according to claim 1, wherein

the internal detecting portion has a detection surface provided near the internal light source and used for detecting a photoacoustic wave,

the photoacoustic wave detector further comprising a reflective portion having a reflective surface on which light generated from the light-emitting element is reflected toward a direction of the detection target facing the detection surface.

10. The photoacoustic wave detector according to claim 9, wherein

the reflective portion includes a side wall arranged lateral to the internal detecting portion and the internal light source, and

the reflective surface is provided on a surface of the side wall adjacent to the internal detecting portion and the internal light source.

11. The photoacoustic wave detector according to claim 9, further comprising a light guide portion that guides light from the internal light source to the test object, wherein

the internal light source includes a sealing portion that seals the light-emitting element, and

the light guide portion is arranged closer to the detection target than the sealing portion.

12. The photoacoustic wave detector according to claim 11, wherein

the sealing portion has an outer surface formed into a lens-like shape that collects light from the light-emitting element and directs the collected light toward the light guide portion.

13. The photoacoustic wave detector according to claim 11, wherein

the internal detecting portion includes a piezoelectric element that allows transmission of light, and

the piezoelectric element is arranged in the light guide portion and is arranged to overlap the light-emitting element in a plan view.

14. The photoacoustic wave detector according to claim 9, wherein

the internal light source includes a plurality of the light-emitting elements, and

the reflective surface is provided to surround the light-emitting elements.

15. The photoacoustic wave detector according to claim 14, wherein

the reflective surface is provided in an annular shape to surround the entire peripheries of the light-emitting elements.

16. A photoacoustic imaging apparatus comprising:

a photoacoustic wave detector including an internal light source and an internal detecting portion, the internal light source including a light-emitting element to be inserted into a test object, the internal light source applying light emitted from the light-emitting element to a detection target in the test object, the internal detecting portion detecting a photoacoustic wave inside the test object and generating an internal detection signal based on a result of detection of the photoacoustic wave, the photoacoustic wave being generated at the detection target;

an internal detection image generating portion that generates an internal detection tomographic image of the test object based on the internal detection signal; and

an image forming portion that forms a photoacoustic image using the internal detection tomographic image.

17. The photoacoustic imaging apparatus according to claim 16, further comprising an external light source that emits light from the outside of the test object to the detection target, wherein

timing of emission of light from the external light source is synchronized with timing of emission of light from the internal light source.

18. The photoacoustic imaging apparatus according to claim 16, further comprising:

an external detecting portion that detects a photoacoustic wave outside the test object and generates an external detection signal based on a result of detection of the photoacoustic wave, the photoacoustic wave being generated at the detection target in the test object; and

an external detection image generating portion that generates an external detection tomographic image of the test object based on the external detection signal, wherein

the image forming portion further uses the external detection tomographic image for forming the photoacoustic image.

19. The photoacoustic imaging apparatus according to claim 18, wherein

the internal detecting portion has a detection surface provided near the internal light source and used for detecting a photoacoustic wave, and

the photoacoustic wave detector further includes a reflective portion a reflective surface on which light generated from the light-emitting element is reflected toward a direction of the detection target facing the detection surface.

20. The photoacoustic imaging apparatus according to claim 19, further comprising a signal processing portion, wherein

the signal processing portion is configured to superimpose photoacoustic images based on corresponding photoacoustic waves detected by the internal detecting portion and the external detecting portion respectively.