Photoacoustic image generation apparatus and insert
Provided are a photoacoustic image generation apparatus and an insert that can evaluate whether a plurality of materials with different absorption wavelengths are present in the vicinity of a puncture needle, without preparing a plurality of light sources. A puncture needle is at least partially inserted into a subject. An optical fiber guides light with a first wavelength. A light emitting portion emits the light guided by the optical fiber. A light absorption/conversion member absorbs the light with the first wavelength emitted from the light emitting portion and converts the light with the first wavelength into light with a second wavelength. In addition, the light absorption/conversion member generates photoacoustic waves with the conversion into the light with the second wavelength.
1. An insert that is at least partially inserted into a subject, comprising:
an optical fiber that guides light with a first wavelength received from light sources emitting light of more than one wavelength;
a light emitting portion, formed by a leading end of the optical fiber, wherein the light emitting portion emits light guided by the optical fiber; and
a light absorption/conversion member that absorbs the light with the first wavelength emitted from the light emitting portion, wherein the light absorption/conversion member comprises a phosphor of a material selected according to an evaluation target material, wherein the phosphor:
absorbs the light with the first wavelength emitted from the light emitting portion,
converts the light with the first wavelength into light with a second wavelength different from the first wavelength,
based on the absorbing the light with the first wavelength emitted from the light emitting portion, generates photoacoustic waves with the conversion into the light with the second wavelength, and
emits the photoacoustic waves and the light with the second wavelength, and wherein the second wavelength is constant and is controlled by the material of the phosphor.
2. The insert according to claim 1 , wherein the light absorption/conversion member covers at least a part of a light emission surface of the light emitting portion.
3. The insert according to claim 1 , wherein the insert has an inner cavity, and the light absorption/conversion member functions as a fixing member that fixes the optical fiber to an inner wall of the inner cavity.
4. The insert according to any one of claim 1 , further comprising:
a transparent resin that transmits the light with the second wavelength, wherein the light absorption/conversion member is covered with the transparent resin.
5. The insert according to claim 4 , wherein the insert has an inner cavity, and the optical fiber and the light absorption/conversion member are fixed to an inner wall of the inner cavity by the transparent resin.
6. The insert according to claim 1 , wherein the insert is a puncture needle having an inner cavity, and the insert further includes a hollow tube in which the optical fiber is accommodated.
7. The insert according to claim 6 , wherein the puncture needle includes an inner needle and an outer needle, the inner needle includes the hollow tube, and the inner needle seals at least a portion of the inner cavity.
8. The insert according to claim 6 , wherein the light absorption/conversion member functions as a fixing member that fixes the optical fiber to an inner wall of the hollow tube.
9. The insert according to claim 6 , further comprising:
a transparent resin that transmits the light with the second wavelength, wherein the optical fiber and the light absorption/conversion member are fixed to an inner wall of the hollow tube by the transparent resin.
10. A photoacoustic image generation apparatus comprising:
light sources that emit light with a first wavelength, wherein the first wavelength is selected from a group of different wavelengths based on a light source of the light sources emitting the first wavelength;
an insert that is at least partially inserted into a subject, the insert comprising:
an optical fiber that guides the light with the first wavelength;
a light emitting portion, formed by a leading end of the optical fiber, wherein the light emitting portion emits light guided by the optical fiber; and
a light absorption/conversion member that absorbs the light with the first wavelength emitted from the light emitting portion, wherein the light absorption/conversion member comprises a phosphor of a material selected according to an evaluation target material, wherein the phosphor:
absorbs the light with the first wavelength emitted from the light emitting portion,
converts the light with the first wavelength into light with a second wavelength different from the first wavelength, and
based on the absorbing the light with the first wavelength emitted from the light emitting portion generates first photoacoustic waves with the conversion into the light with the second wavelength, wherein the second wavelength is constant and is controlled by the material of the phosphor;
an acoustic wave detection member, including a plurality of detector elements, that detects the first photoacoustic waves and second photoacoustic waves which are generated in the subject by the emission of the light with the second wavelength to the subject; and
a processor configured to generate a photoacoustic image based on the first photoacoustic waves and the second photoacoustic waves.
11. The photoacoustic image generation apparatus according to claim 10 , wherein the processor is further configured to detect one or more peaks having a larger signal value than the surroundings in the photoacoustic image.
12. The photoacoustic image generation apparatus according to claim 11 , wherein the processor is further configured to:
temporally track the signal value of the detected peak;
determine whether the insert is close to a material that generates the photoacoustic waves, based on a change in the tracked signal value; and
determine a determination result.
13. The photoacoustic image generation apparatus according to claim 12 , wherein, in a case in which the processor detects two peaks, the processor is further configured to determine that the insert is close to the material that generates the second photoacoustic waves.
14. The photoacoustic image generation apparatus according to claim 12 , wherein, in a case in which the change in the signal value is equal to or greater than a threshold value, the processor is further configured to determine that the insert is close to the material that generates the second photoacoustic waves.
15. The photoacoustic image generation apparatus according to claim 10 , wherein the second wavelength is a wavelength indicating absorptivity in light absorbance-wavelength characteristics of a material that is present at an insertion target position of the insert.
16. The photoacoustic image generation apparatus according to claim 10 , wherein the acoustic wave detection member further detects reflected acoustic waves with respect to acoustic waves transmitted to the subject, and the processor is further configured to generate a reflected acoustic image on the basis of the reflected acoustic waves.