Photoacoustic device

A photoacoustic device comprising:

• an irradiation unit configured to generate a first acoustic wave from an object including a contrast agent by irradiating the object with a first light from a light source, and then bleach the contrast agent inside the object by irradiating the object including the contrast agent with a second light from the light source and generate a second acoustic wave from the object by irradiating the object with the first light from the light source after bleaching the contrast agent;
• a receiving unit configured to output a first electric signal upon receiving the first acoustic wave and output a second electric signal upon receiving the second acoustic wave;
• and
• an acquisition unit configured to acquire first property information on the object on the basis of the first electric signal, and acquire second property information on the object on the basis of the second electric signal,
• wherein the second light is pulsed light,
• wherein a pulse interval of the second light is a period of time shorter than a triplet excited state relaxation time of the contrast agent, and
• wherein where a value of a pulse width of the second light is denoted by τ and a value of a frequency of the second light is denoted by f, the τ and f fulfil the following relationship:
• (1−τ·f)/f<7×10−4.

A photoacoustic device comprising:

• an irradiation unit configured to generate a first acoustic wave from an object including a contrast agent by irradiating the object with a first light from a light source, and then bleach the contrast agent inside the object by irradiating the object including the contrast agent with a second light from the light source and generate a second acoustic wave from the object by irradiating the object with the first light from the light source after bleaching the contrast agent;
• a receiving unit configured to output a first electric signal upon receiving the first acoustic wave and output a second electric signal upon receiving the second acoustic wave;
• and
• an acquisition unit configured to acquire first property information on the object on the basis of the first electric signal, and acquire second property information on the object on the basis of the second electric signal,
• wherein the receiving unit has a plurality of conversion elements configured to receive the first and second acoustic waves and output the first and second electric signals, respectively, and a holding member configured to hold the plurality of conversion elements and having a substantially spherical crown shape, and
• wherein the irradiation unit is integrated with the receiving unit.

A photoacoustic device comprising:

• an irradiation unit configured to generate a first acoustic wave from an object including a contrast agent by irradiating the object with a first light from a light source, and then decrease an absorption coefficient of the contrast agent inside the object at wavelength of the first light by irradiating the object including the contrast agent with second light and generate a second acoustic wave from the object by irradiating the object with the first light from the light source after decreasing the absorption coefficient of the contrast agent;
• a receiving unit configured to output a first electric signal upon receiving the first acoustic wave and output a second electric signal upon receiving the second acoustic wave;
• and
• an acquisition unit configured to acquire first property information on the object on the basis of the first electric signal, and acquire second property information on the object on the basis of the second electric signal,
• wherein the second light is pulsed light, and
• wherein a pulse interval of the second light is a period of time shorter than a triplet excited state relaxation time of the contrast agent.