Photoacoustic apparatus

• US 8,397,573 B2
• Filed: 09/02/2009
• Issued: 03/19/2013
• Est. Priority Date: 09/10/2008
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Kobayashi, Shuichi
• Primary Examiner(s): Macchiarolo, Peter
• Assistant Examiner(s): Shah, Samir M
• Application Number:
  US12/552,391
• Publication Number:
  US 20100058870A1
• Time in Patent Office: 1,294 Days
• Field of Search: 736/42, 735/96, 735/87, 735/97, 736/02, 736/09, 736/17, 359/305, 356/432
• US Class Current: 73/596
• CPC Class Codes: G01N 21/1702 with opto-acoustic detection, e.g. for gases or analysing solids

Abstract

A photoacoustic apparatus includes an acoustic lens configured to collect a acoustic wave, an acoustic detector configured to detect the acoustic wave collected by the acoustic lens, a driver configured to move at least one of the acoustic detector and the acoustic lens so as to measure the acoustic wave generated from an object to be measured due to a photoacoustic effect, and a controller configured to output a first measurement signal resulting from the acoustic wave that is generated from a first position in the object, and to eliminate a second measurement signal resulting from the acoustic wave that is generated from a second position different from the first position in the object.

Claims

1. A photoacoustic apparatus comprising:

an acoustic lens configured to collect an acoustic wave generated by a photoacoustic effect;

an acoustic detector configured to detect the acoustic wave collected by said acoustic lens; and

a controller configured to obtain an estimated value of arrival time when the acoustic wave generated from a first position in an object arrives at said acoustic detector based on positions of said acoustic detector and said acoustic lens, to output a first measurement signal resulting from the acoustic wave that is generated from the first position in the object, and to eliminate a second measurement signal resulting from the acoustic wave that is generated from a second position different from the first position in the object based on the estimated value.

2. The photoacoustic apparatus according to claim 1, wherein the first position is conjugate with a position of said acoustic detector with respect to said acoustic lens.

3. The photoacoustic apparatus according to claim 1, wherein said controller eliminates the second measurement signal based on positions of said acoustic detector and said acoustic lens.

4. The photoacoustic apparatus according to claim 1, further comprising a shutter arranged between the object and said acoustic detector,

wherein opening and closing of said shutter is controlled so as to prevent the acoustic wave generated from the second position from arriving at said acoustic detector and to transmit the acoustic wave generated from the first position to said acoustic detector.

5. The photoacoustic apparatus according to claim 1, wherein said acoustic detector detects both the acoustic wave generated from the first position and the acoustic wave generated from the second position, and

wherein said controller provides a process that eliminates the second measurement signal based on the acoustic wave generated from the second position based on a detection result provided by said acoustic detector.

6. The photoacoustic apparatus according to claim 1, further comprising a light source to illuminate the object and a unit configured to change a wavelength of light generated by said light source.

7. The photoacoustic apparatus according to claim 1, further having an impedance matching solution between said acoustic lens and said acoustic detector.

8. The photoacoustic apparatus according to claim 1, further comprising a driver configured to move at least one of said acoustic detector and said acoustic lens.

9. The photoacoustic apparatus according to claim 8, wherein said acoustic lens includes an array of two-dimensionally arranged acoustic lenses, and

wherein the photoacoustic apparatus includes a plurality of said acoustic detectors and a plurality of said drivers, both the number of acoustic detectors and the number of drivers being equal to the number of acoustic lenses.

10. A photoacoustic apparatus comprising:

an acoustic lens configured to collect an acoustic wave generated by a photoacoustic effect;

an acoustic detector configured to detect the acoustic wave collected by said acoustic lens;

a controller configured to output a first measurement signal resulting from the acoustic wave that is generated from a first position in an object, and to eliminate a second measurement signal resulting from the acoustic wave that is generated from a second position different from the first position in the object; and

a shutter arranged between the object and said acoustic detector,

said controller configured to control opening and closing of said shutter so as to transmit the acoustic wave generated from the first position in the object to said acoustic detector, and to prevent the acoustic wave generated from the second position different from the first portion in the object from arriving at said acoustic detector.

11. The photoacoustic apparatus according to claim 10, wherein the first position is conjugate with a position of said acoustic detector with respect to said acoustic lens.

12. The photoacoustic apparatus according to claim 10, wherein said controller eliminates the second measurement signal based on positions of said acoustic detector and said acoustic lens.

13. The photoacoustic apparatus according to claim 10, wherein said acoustic detector detects both the acoustic wave generated from the first position and the acoustic wave generated from the second position, and

wherein said controller provides a process that eliminates the second measurement signal based on the acoustic wave generated from the second position based on a detection result provided by said acoustic detector.

14. The photoacoustic apparatus according to claim 10, further comprising a light source to illuminate the object and a unit configured to change a wavelength of light generated by said light source.

15. The photoacoustic apparatus according to claim 10, further having an impedance matching solution between said acoustic lens and said acoustic detector.

16. The photoacoustic apparatus according to claim 10, further comprising a driver configured to move at least one of said acoustic detector and said acoustic lens.

17. The photoacoustic apparatus according to claim 16, wherein said acoustic lens includes an array of two-dimensionally arranged acoustic lenses, and

wherein the photoacoustic apparatus includes a plurality of said acoustic detectors and a plurality of said drivers, both the number of acoustic detectors and the number of drivers being equal to the number of acoustic lenses.