Probe, transducer unit, and subject information acquisition apparatus
To provide a photoacoustic probe capable of acquiring subject information for reducing generation of artifacts without increasing the number of wires connected to the outside. Provided is a probe including a plurality of ultrasonic transducers, wherein the ultrasonic transducers are divided into a plurality of groups, two adjoining ultrasonic transducers belong to different groups, and the probe includes a group selection unit configured to switch signals of the ultrasonic transducers to be outputtable for each of the groups.
1. A probe, comprising:
a plurality of ultrasonic transducers divided into a plurality of groups and configured to receive photoacoustic waves from a subject irradiated by a light source;
a plurality of receiving circuits connected to the plurality of ultrasonic transducers and configured to generate detection signals based on the received photoacoustic waves; and
a group selection unit configured to switch signals corresponding to the received photoacoustic waves to be output for each of the groups based on a selection signal,
wherein the receiving circuits are provided respectively for the groups,
wherein a first ultrasonic transducer belonging to a first group of the plurality of groups is surrounded by other ultrasonic transducers belonging to different groups of the plurality of groups that are different from the first group, and
wherein the group selection unit outputs a signal for stopping operation of the receiving circuit that corresponds to the group that does not output the signals.
2. The probe according to claim 1 , wherein the signals of the ultrasonic transducers are output via wires.
3. The probe according to claim 1 , wherein distances between the first ultrasonic transducer and closest ultrasonic transducers belonging to the different groups are substantially the same for each group.
4. The probe according to claim 1 , wherein two ultrasonic transducers belonging to the same group are separated from each other, and an ultrasonic transducer belonging to another group is disposed between the two ultrasonic transducers belonging to the same group.
5. The probe according to claim 1 , wherein the plurality of ultrasonic transducers are disposed on a curved surface.
6. The probe according to claim 1 , wherein the ultrasonic transducer is provided with a plurality of cells each having a pair of electrodes formed with a space therebetween.
7. The probe according to claim 6 , further comprising a voltage generating unit configured to apply a voltage between the pair of electrodes of the cell,
wherein the group selection unit is disposed between the ultrasonic transducer and the voltage generating unit, and
wherein the group selection unit operates such that there is no potential difference between the electrodes of the cell of the ultrasonic transducer belonging to the group that does not output the signals.
8. The probe according to claim 1 , wherein a region of a group selected by the group selection unit overlaps with a region of another group.
9. The probe according to claim 1 , wherein:
the plurality of ultrasonic transducers is constituted by a first subelement region, a second subelement region which adjoins to the upper and lower sides of the first subelement region, a third subelement region which adjoins to the left and right sides of the first subelement region, and a fourth subelement region which adjoins to a corner of the first subelement region;
the group selection unit is capable of selecting an arbitrary element for each of the first subelement region, the second subelement region, and the third subelement region; and
the probe is capable of selecting signals from the second subelement region, the third subelement region and the fourth subelement region, adding the signals to a signal from the first subelement region, and outputting to a wire,
wherein an adder circuit sums the detection signals outputted from the receiving circuits connected respectively to the first subelement region, the second subelement region, the third subelement region and the fourth subelement region.
10. The probe according to claim 1 , wherein the group selection unit includes a transmission selection unit that has a movable film and a support member and causes one of the received photoacoustic waves to reflect on the movable film or to penetrate through the support member according to the selection signal.
11. A subject information acquisition apparatus comprising:
the probe according to claim 1 ;
an image information generating apparatus to generate reproduction image information from signals received from the probe; and
a display to display an image in accordance with the reproduction image information.
12. The subject information acquisition apparatus according to claim 11 , wherein the probe is capable of transmitting an ultrasonic wave.
13. The probe according to claim 1 , wherein the plurality of transducers are disposed on a hemispherical housing.
14. The probe according to claim 1 wherein the group selection unit switches the signals in synchronization with a light-emitting timing of the light source.