Acoustic wave detection probe and photoacoustic measurement apparatus provided with the same

• US 9,282,900 B2
• Filed: 08/11/2014
• Issued: 03/15/2016
• Est. Priority Date: 02/29/2012
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: Irisawa, Kaku
• Primary Examiner(s): Chen, Tse
• Assistant Examiner(s): NGUYEN, HIEN NGOC
• Application Number:
  US14/456,568
• Publication Number:
  US 20140350368A1
• Time in Patent Office: 582 Days
• Field of Search: 600/476
• US Class Current: 1/1
• CPC Class Codes: A61B 2090/306 using optical fibres
• CPC Class Codes: A61B 2576/00 Medical imaging apparatus involving image processing or analysis A61B1/00009, A61B6/52 and A61B8/52 take precedence; image processing per se G06T; details of algorithms for analysing medical images G06T7/0012
• CPC Class Codes: A61B 5/0095 by applying light and detecting acoustic waves, i.e. photoacoustic measurements
• CPC Class Codes: A61B 5/0097 by applying acoustic waves and detecting light, i.e. acoustooptic measurements
• CPC Class Codes: A61B 90/30 Devices for illuminating a surgical field, the devices having an interrelation with other surgical devices or with a surgical procedure
• CPC Class Codes: G01N 2291/02466 Biological material, e.g. blood
• CPC Class Codes: G01N 29/2418 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 Class Codes: G01N 29/2462 Probes with waveguides, e.g. SAW devices

Abstract

In an acoustic wave detection probe provided with a light guide section that guides measuring light such that the measuring light is outputted toward a subject and an acoustic wave transducer that detects a photoacoustic wave generated in the subject by the projection of the measuring light, the light guide section includes a homogenizer that flat-tops an energy profile of the measuring light entered from the upstream side of the optical system, a light condensing member that condenses the measuring light transmitted through the homogenizer, and a bundle fiber which includes a plurality of optical fibers and is disposed such that the measuring light transmitted through the light condensing member enters from an entrance end of the bundle fiber.

Claims

1. An acoustic wave detection probe provided with a light guide section, and an acoustic wave transducer, wherein the light guide section comprises:

a homogenizer that flat-tops an energy profile of high energy measuring light entered the light guide section;

a light condensing member that condenses the high energy measuring light transmitted through the homogenizer; and

a bundle fiber which includes a plurality of optical fibers and is disposed such that the high energy measuring light transmitted through the light condensing member enters from an entrance end of the bundle fiber, wherein

the homogenizer further diffuses the high energy measuring light;

when the focal length of the light condensing member, the spread angle of the high energy measuring light when entering the homogenizer, and the diffusion angle of the homogenizer are taken as f, φ

, and θ

respectively, the light condensing member condenses the high energy measuring light such that a minimum beam diameter D defined by Formula 1 below satisfies Formula 2 below in relation to a diameter d of the bundle fiber; and

the bundle fiber is disposed such that the high energy measuring light enters the bundle fiber with the beam diameter D being 0.8 d to 1.2 d;

2. The probe as claimed in claim 1, wherein the entrance end of the bundle fiber is fusion processed.

3. The probe as claimed in claim 1, wherein the outer circumferences of the plurality of optical fibers are covered with a material having high durability against optical energy at the entrance end.

4. The probe as claimed in claim 3, wherein the material having high durability against optical energy is silica.

5. The probe as claimed in claim 1, wherein exit ends of optical fibers in each of a plurality of divided areas divided in an end face arrangement of the entrance end are disposed according to a relative magnitude with respect to each divided area to which the exit ends belong such that an energy profile when the high energy measuring light exits from the exit ends of all optical fibers becomes homogeneous as a whole.

6. The probe as claimed in claim 5, wherein the plurality of divided areas is divided according to the distance from the center of the bundle fiber.

7. The probe as claimed in claim 1, wherein the light guide section comprises at least one light guide plate having a connection surface to which at least some of the exit ends of the plurality of optical fibers are connected and an exit surface from which the high energy measuring light entered from the connection surface exits.

8. The probe as claimed in claim 7, wherein the light guide plate is provided in plurality and disposed across the acoustic wave transducer.

9. The probe as claimed in claim 1, wherein the probe comprises a holding section that holds the entrance end so as to cover the entrance face of the bundle fiber and has a window section at a portion where the high energy measuring light enters.

10. The probe as claimed in claim 9, wherein the window section comprises an ND filter.

11. A photoacoustic measurement apparatus, comprising:

the probe of claim 1; and

a signal processor that processes a photoacoustic signal of the photoacoustic wave detected by the acoustic wave transducer.

12. The photoacoustic measurement apparatus as claimed in claim 11, wherein the apparatus comprises:

a light source that outputs the high energy measuring light;

an equipment housing having a mounting section optically connected to the light source and holding the homogenizer; and

a holding section that integrally holds the light condensing member and the bundle fiber,

wherein the mounting section and the holding section have connector structures removably attachable to each other.

13. The photoacoustic measurement apparatus as claimed in claim 11, wherein the apparatus comprises:

a light source that outputs the high enemy measuring light;

an equipment housing having a mounting section optically connected to the light source and holding the homogenizer and the light condensing member; and

a holding section that holds the entrance end so as to cover the entrance face of the bundle fiber and has a window section at a portion where the high enemy measuring light enters,

wherein the mounting section and the holding section have connector structures removably attachable to each other.

14. The photoacoustic measurement apparatus as claimed in claim 11, wherein the signal processor comprises an acoustic image generator that generates a photoacoustic image based on the photoacoustic signal.

15. The photoacoustic measurement apparatus as claimed in claim 14, wherein:

the acoustic wave transducer detects a reflected acoustic wave of a transmitted acoustic wave to the subject; and

the acoustic image generator generates a reflected acoustic wave image based on a signal of the reflected acoustic wave.