Specimen information acquisition apparatus and method therefor

A method used for an apparatus which includes a memory in communication with a processor, the memory storing instructions that, when executed by the processor, causes the processor to perform the method comprising the steps of:

• calculating a first optical characteristic value distribution in a specimen on the basis of a signal obtained through detection of an acoustic wave that is produced by irradiating the specimen with light, the first optical characteristic value distribution being an initial sound pressure distribution or an optical energy absorption density distribution which represents the product of an absorption coefficient distribution and a local fluence distribution;
• determining, based on a designation by an operator within the first optical characteristic value distribution, two or more regions of a vessel in the specimen;
• determining, from the first optical characteristic value distribution, the initial sound pressure distribution or the optical energy absorption density distribution of the determined two or more regions of the vessel;
• calculating, by using the initial sound pressure distribution or the optical energy absorption density distribution of the determined two or more regions of the vessel, an average optical constant of a background region which surrounds the two or more regions of the vessel;
• calculating, by using the calculated average optical constant of the background region, the local fluence distribution in the specimen;
• and
• calculating, by dividing the first optical characteristic value distribution by the local fluence distribution, a second optical characteristic value distribution in which the first optical characteristic value distribution is corrected.

A non-transitory computer-readable storage medium storing thereon a program that causes a computer to execute the steps of:

• calculating a first optical characteristic value distribution in a specimen on the basis of a signal obtained through detection of an acoustic wave that is produced by irradiating the specimen with light, the first optical characteristic value distribution being an initial sound pressure distribution or an optical energy absorption density distribution which represents the product of an absorption coefficient distribution and a local fluence distribution;
• determining, based on a designation by on operator within the first optical characteristic value distribution, two or more regions of a vessel in the specimen;
• determining, from the first optical characteristic value distribution, the initial sound pressure distribution or the optical energy absorption density distribution of the determined two or more regions of the vessel;
• calculating, by using the initial sound pressure distribution or the optical energy absorption density distribution of the determined two or more regions of the vessel, an average optical constant of a background region which surrounds the two or more regions of the vessel;
• calculating, by using the calculated average optical constant of the background region, the local fluence distribution in the specimen;
• and
• calculating, by dividing the first optical characteristic value distribution by the local fluence distribution, a second optical characteristic value distribution in which the first optical characteristic value distribution is corrected.

An apparatus for obtaining an optical characteristic value distribution in a specimen on the basis of a signal obtained by detection of an acoustic wave generated by irradiation of the specimen with light, comprising:

• a memory in communication with a processor, the memory storing instructions that, when executed by the processor, causes the processor to:
• calculate, by using the signal, a first optical characteristic value distribution in the specimen, the first optical characteristic value distribution being an initial sound pressure distribution or an optical energy absorption density distribution which represents the product of an absorption coefficient distribution and a local fluence distribution;
• determine, based on a designation by an operator within the first optical characteristic value distribution, two or more regions of a vessel in the specimen;
• determine from the first optical characteristic value distribution, the initial sound pressure distribution or the optical energy absorption density distribution of the determined two or more regions of the vessel;
• calculate, by using the initial sound pressure distribution or the optical energy absorption density distribution of the determined two or more regions of the vessel, an average optical constant of a background region which surrounds the two or more regions of the vessel;
• calculate, by using the calculated average optical constant of the background region, the local fluence distribution in the specimen;
• and
• calculate, by dividing the first optical characteristic value distribution by the local fluence distribution, a second optical characteristic value distribution.

An apparatus for obtaining an optical characteristic value distribution in a specimen on the basis of a signal obtained by detection of an acoustic wave generated by irradiation of the specimen with light, comprising:

• a memory in communication with a processor, the memory storing instructions that, when executed by the processor, cause the processor to:
• calculate, by using the signal, a first optical characteristic value distribution in the specimen, the first optical characteristic value distribution being an initial sound pressure distribution or an optical energy absorption density distribution which represents the product of an absorption coefficient distribution and a local fluence distribution;
• determine, on the basis of the first optical characteristic value distribution, two or more regions of a vessel in the specimen;
• determine, from the first optical characteristic value distribution, the initial sound pressure distribution or the optical energy absorption density distribution of the determined two or more regions of the vessel;
• calculate, by using the initial sound pressure distribution or the optical energy absorption density distribution of the determined two or more regions of the vessel, an average optical constant of a background region which surrounds the two or more regions of the vessel;
• calculate, by using the calculated average optical constant of the background region, the local fluence distribution in the specimen;
• and
• calculate, by dividing the first optical characteristic value distribution by the local fluence distribution, a second optical characteristic value distribution.

An apparatus for obtaining an optical characteristic value distribution in a specimen on the basis of a signal obtained by detection of an acoustic wave generated by irradiation of the specimen with light, comprising:

• a memory in communication with a processor, the memory storing instructions that, when executed by the processor, cause the processor to:
• calculate, using the signal, a first optical characteristic value distribution in the specimen, the first optical characteristic value distribution being an initial sound pressure distribution or an optical energy absorption density distribution which represents the product of an absorption coefficient distribution and a local fluence distribution;
• determine, based on a designation by an operator, two or more regions of a vessel in the specimen;
• determine from the first optical characteristic value distribution, the initial sound pressure distribution or the optical energy absorption density distribution of the determined two or more regions of the vessel;
• calculate, by using the initial sound pressure distribution or the optical energy absorption density distribution of the determined two or more regions of the vessel, an average optical constant of a background region which surrounds the two or more regions of the vessel;
• calculate, by using the calculated average optical constant of the background region, a local fluence distribution in the specimen;
• and
• calculate, by dividing the first optical characteristic value distribution by the local fluence distribution, a second optical characteristic value distribution.