Photoacoustic measurement probe and probe unit and photoacoustic measurement apparatus including the same

1. A photoacoustic measurement probe, comprising: a light emitting unit including a light guide plate that emits measurement light toward a subject; an optical fiber that guides the measurement light to the light emitting unit; an acoustic wave detector including a transducer array that detects an acoustic wave emitted from a part of the subject that has absorbed the measurement light and that includes a plurality of electroacoustic conversion elements arranged in at least a first direction; a preamplifier that amplifies an output of the acoustic wave detector; a housing including a tubular member having a quadrangular tubular shape and four side plates, the four side plates surrounding the tubular member, wherein the housing houses the light emitting unit, the optical fiber, the acoustic wave detector, and the preamplifier; a first heat conductive member including a heat transfer plate that is in direct contact with at least one of two side plates, an inner surface of each of the two side plates facing each other in the first direction, and the preamplifier to transfer heat generated by the preamplifier to the at least one side plate; and a second heat conductive member including a second heat transfer plate that is in direct contact with at least one of two side plates different from the at least one of two side plates with which the first heat conductive member is in contact and the side plate having the inner surface facing the inner surface of the side plate that is in contact with the first heat conducting member and the acoustic wave detector to transfer heat generated by the acoustic wave detector to the at least one of two side plates different from the at least one of two side plates with which the first heat conductive member is in contact and the side plate having the inner surface facing the inner surface of the side plate that is in contact with the first heat conducting member.

2. The photoacoustic measurement probe according to claim 1 ,

wherein a width of each of the two side plates with which the second heat conductive member is in contact is larger than a width of each of the two side plates with which the first heat conductive member is in contact.

3. The photoacoustic measurement probe according to claim 1 ,

wherein a plurality of the optical fibers extend in a tube axis direction of the tubular member and are arranged to be aligned in a direction parallel to the first direction, and

the second heat conductive member has a portion disposed around the plurality of optical fibers.

4. The photoacoustic measurement probe according to claim 1 , further comprising: a fiber fixing member including a plurality of grooves that fixes the plurality of optical fibers to the housing, wherein the second heat conductive member is in contact with at least one of two side plates different from the at least one of the two side plates with which the first heat conducting member is in contact on a proximal end side of at least one of two side plates different from the at least one of the two side plates with which the first heat conducting member rather than the fiber fixing member.

5. The photoacoustic measurement probe according to claim 1 ,

wherein the second heat conductive member also serves as a fiber fixing member including a plurality of grooves that fixes the plurality of optical fibers to the housing.

6. The photoacoustic measurement probe according to claim 1 , wherein the second heat conductive member is in contact with an inner surface of at least one of two side plates different from the at least one of the two side plates with which the first heat conducting member through a holding member.

7. The photoacoustic measurement probe according to claim 1 ,

wherein two light emitting units are provided,

the acoustic wave detector is disposed on a distal end side of the tubular member, and

on the distal end side of the tubular member, the two light emitting units are disposed with the acoustic wave detector interposed therebetween in a second direction crossing the first direction.

8. A probe unit, comprising:

the photoacoustic measurement probe according to claim 1 ;

a light source that outputs measurement light; and

a connection unit that optically connects the measurement light to the light emitting unit of the photoacoustic measurement probe.

9. A photoacoustic measurement apparatus, comprising:

the photoacoustic measurement probe according to claim 1 ; and

a signal processing unit that generates a photoacoustic image based on a photoacoustic wave detection signal output from the photoacoustic measurement probe.