Method, apparatus, and program for processing tomographic images, and optical tomography system
View Patent ↗Deterioration of the resolution of tomographic images obtained by optical tomography measurement is prevented. Interference signals, which are obtained when a light beam L is emitted, are divided into a plurality of divided interference signals each having different wavelength bands. Spectral analysis is administered for each of the plurality of divided interference signals, to obtain a plurality of pieces of intermediate tomographic data. The plurality of pieces of intermediate tomographic data are employed to obtain tomographic data, a tomographic image is generated based on the tomographic data, then displayed.
1. A Fourier domain OCT tomographic image processing method, comprising the steps of:
emitting a light beam within a predetermined wavelength band;
dividing the emitted light beam in to a measuring light beam and a reference light beam;
combining reflected light beams, which are the measuring light beam reflected at various depth positions within a measurement target, with the reference light beam;
detecting interference light beams, formed by combining the reflected light beams and the reference light beam, as interference signals; and
generating a tomographic image from the interference signals; wherein:
the detected interference signals are divided into different wavelength bands, to generate a plurality of divided interference signals;
each of the plurality of divided interference signals is analyzed to obtain a plurality of pieces of tomographic data regarding each depth position of the measurement target, as intermediate tomographic data;
tomographic data are obtained employing the plurality of pieces of intermediate tomographic data; and
the tomographic image of the measurement target is generated employing the obtained tomographic data,
wherein the light beam is emitted while the wavelength thereof is periodically swept within the predetermined wavelength band; and
the plurality of divided interference signals are detected during a single period of the wavelength of the light beam being swept, and are divided into the divided interference signals for each of a plurality of different wavelength bands.
2. A Fourier-domain OCT tomographic image processing apparatus that emits a light beam within a predetermined wavelength band; divides the emitted light beam in to a measuring light beam and a reference light beam; combines reflected light beams, which are the measuring light beam reflected at various depth positions within a measurement target, with the reference light beam; detects interference light beams, formed by combining the reflected light beams and the reference light beam, as interference signals; and generates tomographic images from the interference signals; comprising:
interference signal dividing means, for dividing the detected interference signals into different wavelength bands, to generate a plurality of divided interference signals;
interference signal analyzing means, for analyzing each of the plurality of divided interference signals to obtain a plurality of pieces of tomographic data regarding each depth position of the measurement target, as intermediate tomographic data;
tomographic data obtaining means, for obtaining tomographic data employing the plurality of pieces of intermediate tomographic data; and
tomographic image generating means, for generating the tomographic images of the measurement target employing the obtained tomographic data,
wherein:
the light beam is emitted while the wavelength thereof is periodically swept within the predetermined wavelength band; and
the interference signal dividing means generates the plurality of divided interference signals, by dividing the interference signals, which are detected during a single period of the wavelength of the light beam being swept, into the divided interference signals for each of a plurality of different wavelength bands.
3. A tomographic image processing apparatus as defined in claim 2 , wherein:
the interference signal dividing means divides the interference signals such that the bandwidths of the divided interference signals are substantially uniform.
4. A tomographic image processing apparatus as defined in claim 2 , wherein:
the interference signal dividing means divides the interference signals such that the wavelength bands of the divided interference signals overlap with each other.
5. A tomographic image processing apparatus as defined in claim 2 , wherein:
the tomographic data obtaining means obtains the tomographic data by: calculating an average value of the plurality of intermediate tomographic data.
6. A tomographic image processing apparatus as defined in claim 2 , wherein:
the tomographic data obtaining means obtains the tomographic data by: calculating an average value of the plurality of intermediate tomographic data; excluding the intermediate tomographic data having the furthest value from the average value; and recalculating an average value of the remaining intermediate tomographic data.
7. A tomographic image processing apparatus as defined in claim 2 , wherein:
the tomographic data obtaining means obtains the tomographic data by: calculating an average value of the plurality of intermediate tomographic data; and weighting each piece of the intermediate tomographic data such that the weighting is greater the closer the value of the intermediate tomographic data is to the average value.
8. A tomographic image processing apparatus as defined in claim 2 , wherein:
the tomographic data obtaining means obtains the tomographic data by: calculating an average value and a variance of the plurality of intermediate tomographic data; extracting intermediate tomographic data having a difference from the average value smaller than the variance; and employing the extracted tomographic data.
9. A tomographic image processing apparatus as defined in claim 2 , further comprising:
interference signal converting means, for converting the interference signals or the divided interference signals so as to correspond to changes in wave numbers, when the wavelength of the light beam is swept.
10. A tangible computer readable medium, having recorded therein a Fourier-domain OCT tomographic image processing program, the program causing a computer to execute the procedures of:
emitting a light beam within a predetermined wavelength band;
dividing the emitted light beam in to a measuring light beam and a reference light beam;
combining reflected light beams, which are the measuring light beam reflected at various depth positions within a measurement target, with the reference light beam;
detecting interference light beams, formed by combining the reflected light beams and the reference light beam, as interference signals; and
generating a tomographic image from the interference signals; wherein:
the detected interference signals are divided into different wavelength bands, to generate a plurality of divided interference signals;
each of the plurality of divided interference signals is analyzed to obtain a plurality of pieces of tomographic data regarding each depth position of the measurement target, as intermediate tomographic data;
tomographic data are obtained employing the plurality of pieces of intermediate tomographic data; and
the tomographic image of the measurement target is generated employing the obtained tomographic data,
wherein:
the light beam is emitted while the wavelength thereof is periodically swept within the predetermined wavelength band; and
the plurality of divided interference signals are detected during a single period of the wavelength of the light beam being swept, and are divided into the divided interference signals for each of a plurality of different wavelength bands.
11. A Fourier-domain OCT optical tomography system, comprising:
a light source unit, for emitting a light beam within a predetermined wavelength band;
light dividing means, for dividing the emitted light beam in to a measuring light beam and a reference light beam;
combining means, for combining reflected light beams, which are the measuring light beam reflected at various depth positions within a measurement target, with the reference light beam;
interference light detecting means, for detecting interference light beams, formed by combining the reflected light beams and the reference light beam, as interference signals; and
tomographic data processing means, for generating a tomographic image from the interference signals; wherein the tomographic data processing means comprises:
interference signal dividing means, for dividing the detected interference signals into different wavelength bands, to generate a plurality of divided interference signals;
interference signal analyzing means, for analyzing each of the plurality of divided interference signals to obtain a plurality of pieces of tomographic data regarding each depth position of the measurement target, as intermediate tomographic data;
tomographic data obtaining means, for obtaining tomographic data employing the plurality of pieces of intermediate tomographic data; and
tomographic image generating means, for generating the tomographic images of the measurement target employing the obtained tomographic data,
wherein:
the light source unit emits the light beam while sweeping the wavelength thereof within the predetermined wavelength band; and
the interference signal dividing means generates the plurality of divided interference signals, by dividing the interference signals, which are detected during a single period of the wavelength of the light beam being swept, into the divided interference signals for each of a plurality of different wavelength bands.
12. A Fourier-domain OCT tomographic image processing method, comprising the steps of:
emitting a light beam within a predetermined wavelength band;
dividing the emitted light beam in to a measuring light beam and a reference light beam;
combining reflected light beams, which are the measuring light beam reflected at various depth positions within a measurement target, with the reference light beam;
detecting interference light beams, formed by combining the reflected light beams and the reference light beam, as interference signals; and
generating a tomographic image from the interference signals; wherein:
the detected interference signals are divided into different wavelength bands, to generate a plurality of divided interference signals;
each of the plurality of divided interference signals is analyzed to obtain a plurality of pieces of tomographic data regarding each depth position of the measurement target, as intermediate tomographic data;
tomographic data are obtained employing the plurality of pieces of intermediate tomographic data; and
the tomographic image of the measurement target is generated employing the obtained tomographic data,
wherein:
the divided interference signals are divided such that the wavelength bands of the divided interference signals overlap with each other.
13. A Fourier-domain OCT tomographic image processing apparatus that emits a light beam within a predetermined wavelength band; divides the emitted light beam in to a measuring light beam and a reference light beam; combines reflected light beams, which are the measuring light beam reflected at various depth positions within a measurement target, with the reference light beam; detects interference light beams, formed by combining the reflected light beams and the reference light beam, as interference signals; and generates tomographic images from the interference signals; comprising:
interference signal dividing means, for dividing the detected interference signals into different wavelength bands, to generate a plurality of divided interference signals;
interference signal analyzing means, for analyzing each of the plurality of divided interference signals to obtain a plurality of pieces of tomographic data regarding each depth position of the measurement target, as intermediate tomographic data;
tomographic data obtaining means, for obtaining tomographic data employing the plurality of pieces of intermediate tomographic data; and
tomographic image generating means, for generating the tomographic images of the measurement target employing the obtained tomographic data,
wherein:
the interference signal dividing means divides the interference signals such that the wavelength bands of the divided interference signals overlap with each other.
14. A tangible computer readable medium, having recorded therein a Fourier-domain OCT tomographic image processing program, the program causing a computer to execute the procedures of:
emitting a light beam within a predetermined wavelength band;
dividing the emitted light beam in to a measuring light beam and a reference light beam;
combining reflected light beams, which are the measuring light beam reflected at various depth positions within a measurement target, with the reference light beam;
detecting interference light beams, formed by combining the reflected light beams and the reference light beam, as interference signals; and
generating a tomographic image from the interference signals; wherein:
the detected interference signals are divided into different wavelength bands, to generate a plurality of divided interference signals;
each of the plurality of divided interference signals is analyzed to obtain a plurality of pieces of tomographic data regarding each depth position of the measurement target, as intermediate tomographic data;
tomographic data are obtained employing the plurality of pieces of intermediate tomographic data; and
the tomographic image of the measurement target is generated employing the obtained tomographic data, wherein:
the divided interference signals are divided such that the wavelength bands of the divided interference signals overlap with each other.
15. A Fourier-domain OCT tomography system, comprising:
a light source unit, for emitting a light beam within a predetermined wavelength band;
light dividing means, for dividing the emitted light beam in to a measuring light beam and a reference light beam;
combining means, for combining reflected light beams, which are the measuring light beam reflected at various depth positions within a measurement target, with the reference light beam;
interference light detecting means, for detecting interference light beams, formed by combining the reflected light beams and the reference light beam, as interference signals; and
tomographic data processing means, for generating a tomographic image from the interference signals; wherein the tomographic data processing means comprises:
interference signal dividing means, for dividing the detected interference signals into different wavelength bands, to generate a plurality of divided interference signals;
interference signal analyzing means, for analyzing each of the plurality of divided interference signals to obtain a plurality of pieces of tomographic data regarding each depth position of the measurement target, as intermediate tomographic data;
tomographic data obtaining means, for obtaining tomographic data employing the plurality of pieces of intermediate tomographic data; and
tomographic image generating means, for generating the tomographic images of the measurement target employing the obtained tomographic data, wherein:
the interference signal dividing means divides the interference signals such that the wavelength bands of the divided interference signals overlap with each other.