Photoacoustic apparatus and method for controlling the same

• US 9,173,633 B2
• Filed: 12/08/2010
• Issued: 11/03/2015
• Est. Priority Date: 12/11/2009
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Sudo, Yoshiaki, Sato, Akira
• Primary Examiner(s): SAINT SURIN, JACQUES M
• Application Number:
  US13/514,925
• Publication Number:
  US 20120285248A1
• Time in Patent Office: 1,791 Days
• Field of Search: 736/43, 736/55, 736/02, 600/437
• US Class Current: 1/1
• CPC Class Codes: A61B 2560/0233 Optical standards
• 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 5/0059 using light, e.g. diagnosis by transillumination, diascopy, fluorescence A61B5/0093, A61B5/1455, A61B5/02416 and A61B5/0261 take precedence
• CPC Class Codes: A61B 5/0095 by applying light and detecting acoustic waves, i.e. photoacoustic measurements
• CPC Class Codes: A61B 8/08 Detecting organic movements or changes, e.g. tumours, cysts, swellings A61B8/02 - A61B8/06 take precedence

Abstract

A photoacoustic apparatus capable of recognizing variation in reception characteristic among a plurality of receiving elements that detect an acoustic wave in the photoacoustic apparatus with a simple configuration unique to the photoacoustic apparatus. A detecting unit including a plurality of receiving elements is configured to detect an acoustic wave that is generated when an analyte is irradiated with light. A signal processing unit is configured to acquire information about the inside of the analyte from a detected signal acquired from the detecting unit. An optical absorber is configured to absorb the irradiation light; and a reception characteristic calculation unit is configured to calculate reception characteristic information of the plurality of receiving elements on the basis of detected signals when the plurality of receiving elements receive an acoustic wave that is generated from the optical absorber.

Claims

1. A photoacoustic apparatus comprising:

a detecting unit including a plurality of receiving elements configured to detect an acoustic wave that is generated when an analyte is irradiated with light;

a signal processing unit configured to acquire information about the inside of the analyte from a detected signal acquired from the detecting unit;

a plurality of optical absorbers configured to absorb the irradiation light; and

a reception characteristic calculation unit configured to calculate reception characteristic information of the plurality of receiving elements on the basis of detected signals when the plurality of receiving elements receive an acoustic wave that is generated from the optical absorbers; and

plates configured to fix the analyte from both sides,

wherein the optical absorbers are arranged in at least one of the plates or on a surface of the at least one plate such that the optical absorbers are separated from each other and a movable mechanism configured to move the at least one plate on which the optical absorbers are arranged to a position at which the optical absorbers are not irradiated with the light when the analyte is measured.

2. The photoacoustic apparatus according to claim 1, wherein the reception characteristic calculation unit calculates sensitivity characteristic information of the plurality of receiving elements.

3. The photoacoustic apparatus according to claim 2, wherein the signal processing unit revises the detected signal when the detecting unit receives the acoustic wave generated in the analyte to reduce a difference in sensitivity among the plurality of receiving units recognized from the calculated sensitivity characteristic information.

4. The photoacoustic apparatus according to claim 1, wherein the reception characteristic calculation unit calculates frequency characteristic information of the plurality of receiving elements.

5. The photoacoustic apparatus according to claim 4, wherein the signal processing unit revises the detected signal when the detecting unit receives the acoustic wave generated in the analyte to reduce a difference in frequency-dependent sensitivity among the plurality of receiving units recognized from the calculated frequency characteristic information.

6. The photoacoustic apparatus according to claim 1, further comprising:

plates configured to fix the analyte from both sides, the plates including a first plate and a second plate facing the first plate, and wherein the optical absorbers are arranged in the first plate or on a surface of the first plate.

7. The photoacoustic apparatus according to claim 1, wherein the optical absorbers are arranged in a region of the plate provided with the optical absorbers other than a measurement region for the analyte.

8. The photacoustic apparatus according to claim 1, wherein the optical absorbers are made of a material having a higher light absorptance than the plates.

9. The photoacoustic apparatus according to claim 1, wherein the optical absorbers are made of a material that exhibits a photoacoustic characteristic different from a photoacoustic characteristic of the analyte.

10. The photoacoustic apparatus according to claim 1, wherein the plurality of optical absorbers has a same size.

11. The photoacoustic apparatus according to claim 1, wherein the plurality of optical absorbers is made of a same material.

12. The photoacoustic apparatus according to claim 1, wherein the plurality of optical absorbers has a same size as a tissue of the subject.

13. The photoacoustic apparatus according to claim 1, wherein the plurality of optical absorbers has a size in a range from 1 mm to 20 mm.

14. The photoacoustic apparatus according to claim 1, wherein the plurality of optical absorbers is spherical.

15. The photoacoustic apparatus according to claim 1, wherein the plurality of optical absorbers is arranged in at least one of the plates on a center point of the plurality of receiving elements.

16. A method for controlling a photoacoustic apparatus comprising the steps of:

irradiating a plurality of optical absorbers with light, the optical absorbers being provided in at least one plate of plates for fixing an analyte from both sides or on a surface of the at least one plate such that the optical absorbers are separate from each other;

receiving an acoustic wave that is generated from the optical absorber when the optical absorbers receives the light, by a detecting unit including a plurality of receiving units; and

calculating reception characteristic information of the plurality of receiving elements on the basis of detected signals of the plurality of receiving elements and moving the at least one plate on which the optical absorbers are provided to a position at which the optical absorbers are not irradiated with the light when the analyte is measured.