US 2013/0199299 A1 · QUANTIFICATION OF OPTICAL ABSORPTION COEFFICIENTS USING ACOUSTIC SPECTRA IN PHOTOACOUSTIC TOMOGRAPHY

Abstract

Accurately quantifying optical absorption coefficient using acoustic spectra of photoacoustic signals. Optical absorption is closely associated with many physiological parameters, such as the concentration and oxygen saturation of hemoglobin, and it can be used to quantify the concentrations of non-fluorescent molecules. A sample is illuminated by, for example, a pulsed laser and following the absorption of optical energy, a photoacoustic pressure is generated via thermo-elastic expansion. The acoustic waves then propagate and are detected by a transducer. The optical absorption coefficient of the sample is quantified from spectra of the measured photoacoustic signals. Factors, such as system bandwidth and acoustic attenuation, may affect the quantification but are canceled by dividing the acoustic spectra measured at multiple optical wavelengths.

Claims20

Dependent claims

A method of determining an optical absorption coefficient of an object, said method comprising:

focusing a first light pulse emitted by a light source into a volume of the object, wherein the first light pulse has a first wavelength;
detecting a first photoacoustic spectrum using an acoustic transducer, wherein the first acoustic spectrum is emitted by the object in response to receiving the first light pulse;
focusing a second light pulse emitted by the light source into the volume of the object, wherein the second light pulse has a second wavelength;
detecting a second acoustic spectrum using an acoustic transducer, wherein the second acoustic spectrum is emitted by the object in response to receiving the second light pulse;
and
determining the absorption coefficient of the volume of the object as a function of the first acoustic spectrum and the second acoustic spectrum.

3 more elements

A system for determining an optical absorption coefficient of a volume of an object, said system comprising:

a light source for emitting a first light pulse having a first wavelength and a second light pulse having a second wavelength;
a focusing element for focusing the first light pulse and the second light pulse into a volume of the object;
an acoustic transducer for detecting a first acoustic spectrum emitted by the object in response to the volume of the object absorbing the first light pulse and a second acoustic spectrum emitted by the object in response to the volume of the object absorbing the second light pulse;
and
a controller for determining the absorption coefficient of the volume of the object as a function of the first acoustic spectrum and the second acoustic spectrum.

2 more elements

A system for generating an image of an object and determining an optical absorption coefficient of a volume of an object, said system comprising:

a light source for emitting a first light pulse having a first wavelength and a second light pulse having a second wavelength;
a focusing element for focusing the first light pulse and the second light pulse into a volume of a plurality of volumes of the object;
an acoustic transducer for detecting a first acoustic spectrum produced by the object in response to the volume of the object absorbing the first light pulse and a second acoustic spectrum produced by the object in response to the volume of the object absorbing the second light pulse;
a controller for determining the absorption coefficient of the volume of the object as a function of the first acoustic spectrum and the second acoustic spectrum and for reconstructing an image from acoustic spectra detected from the plurality of volumes of the object;
and
a scanner for altering a spatial relationship between the object and the focusing element after the first acoustic spectrum and the second acoustic spectrum are detected by the acoustic transducer for the volume such that the first light pulse and the second light pulse are focused into another volume of the plurality of volumes of the object.

3 more elements

Dependencies are inferred from the claim text.

Quantification of optical absorption coefficients using acoustic spectra in photoacoustic tomography

Life of this patent

Quantification of optical absorption coefficients using acoustic spectra in photoacoustic tomography

Life of this patent

Abstract

Claims20