US 7,732,784 B2 · Wavelength-tunable light generator and optical coherence tomography device

Abstract

An OCT technique that permits tomographic observation of biological body parts that are difficult to restrain, and also provides a tomographic observation technique for the observation of a constrainable part that does not require constraint and thus removes a burden on the biological body. A wavelength-tunable light generator (wavelength-tunable light source) is employed as the light source of the optical coherence tomography device. The wavelength-tunable light generator has a wave number tunable range width of at least 4.7×10−2 μm−1 and an emitted-light frequency width of no more than 13 GHz, for example, and is capable of changing the wave number stepwise at wave number intervals of no more than 3.1×10−4 μm−1 and time intervals of no more than 530 μs.

Claims10

Dependent claims

A wavelength-tunable light generator for optical coherence tomography, comprising:

a light-emitting section that combines and outputs the outputs of a plurality of wavelength-tunable light sources of different wave number sweep ranges;
and
a control device that permits a wave number sweep in excess of the wave number sweep range of individual wavelength-tunable light sources by sweeping said wavelength-tunable light sources one at a time, wherein the wave number is changed stepwise.

An optical coherence tomography device comprising:

a wavelength-tunable light generator including
a light-emitting section that combines and outputs the outputs of a plurality of wavelength-tunable light sources of different wave number sweep ranges, and
a control device that permits a wave number sweep in excess of the wave number sweep range of individual wavelength-tunable light sources by sweeping said wavelength-tunable light sources one at a time;
means for dividing output light of said wavelength-tunable fight generator into measurement light and reference light;
means for irradiating a measurement object with said measurement light and for collecting signal light produced as a result of said measurement light being reflected or backscattered by said measurement object;
means for combining said signal light and said reference light;
means for measuring intensity of the output light combined by said combining means for each wave number of said wavelength-tunable light generator;
and
means for specifying, in a depth direction of said measurement object, a position at which said measurement light is reflected or backscattered by said measurement object and a reflection or backscatter intensity, from a set of intensities of said combined output light measured for each of the wave numbers by said measuring means,
wherein said specifying means subjects a combination of real numbers comprising said intensity of the output light combined by said combining means and said wave number to a Fourier transform,
wherein said specifying means corrects said intensity of the output light combined by said combining means so as to eliminate the effect of fluctuations in the intensity with respect to the wave number of the output light of said wavelength-tunable light generator, and
wherein said correction is performed by multiplying a reciprocal number of a value that is obtained by sequentially measuring the intensity of the output light of said wavelength-tunable light generator each time said wave number is changed during the measurement by said optical coherence tomography device, or a numerical value that is proportional to said reciprocal number, by said intensity of the output light combined by said combining means.

9 more elements

An optical coherence tomography device comprising:

a wavelength-tunable light generator including
a light-emitting section that combines and outputs the outputs of a plurality of wavelength-tunable light sources of different wave number sweep ranges, and
a control device that permits a wave number sweep in excess of the wave number sweep range of individual wavelength-tunable light sources by sweeping said wavelength-tunable light sources one at a time;
means for dividing output light of said wavelength-tunable light generator into measurement light and reference light;
means for irradiating a measurement object with said measurement light and for collecting signal light produced as a result of said measurement light being reflected or backscattered by said measurement object;
means for combining said signal light and said reference light;
means for measuring intensity of the output light combined by said combining means for each wave number of said wavelength-tunable light generator;
and
means for specifying, in a depth direction of said measurement object, a position at which said measurement light is reflected or backscattered by said measurement object and a reflection or backscatter intensity, from a set of intensities of said combined output light measured for each of the wave numbers by said measuring means,
wherein said specifying means subjects a combination of real numbers comprising said intensity of the output light combined by said combining means and said wave number to a Fourier transform,
wherein said specifying means corrects said intensity of the output light combined by said combining means so as to eliminate the effect of fluctuations in the intensity with respect to the wave number of the output light of said wavelength-tunable light generator, and
wherein said correction is performed by multiplying a reciprocal number of a value that is obtained by pre-measuring, for each of said wave numbers, the intensity of the output light of said wavelength-tunable light generator, or a numerical value that is proportional to said reciprocal number, by the intensity of said combined output light.

9 more elements

An optical coherence tomography device, comprising:

a wavelength-tunable light generator including
a light-emitting section that combines and outputs the outputs of a plurality of wavelength-tunable light sources of different wave number sweep ranges, and
a control device that permits a wave number sweep in excess of the wave number sweep range of individual wavelength-tunable light sources,
wherein the outputs of said wavelength-tunable light sources are sequentially output in chronological order;
means for dividing output light of said wavelength-tunable light generator into measurement light and reference light;
means for irradiating a measurement object with said measurement light and for collecting signal light produced as a result of said measurement light being reflected or backscattered by said measurement object;
means for combining said signal light and said reference light;
means for measuring intensity of the output light combined by said combining means for each wave number of said wavelength-tunable light generator;
and
means for specifying, in a depth direction of said measurement object, a position at which said measurement light is reflected or backscattered by said measurement object and a reflection or backscatter intensity, from a set of intensities of said combined output light measured for each of the wave numbers by said measuring means,
wherein said specifying means subjects a combination of real numbers comprising said intensity of the output light combined by said combining means and said wave number to a Fourier transform,
wherein said specifying means corrects said intensity of the output light combined by said combining means so as to eliminate the effect of fluctuations in the intensity with respect to the wave number of the output light of said wavelength-tunable light generator, and
wherein said correction is performed by multiplying a reciprocal number of a value that is obtained by sequentially measuring the intensity of the output light of said wavelength-tunable light generator each time said wave number is changed during the measurement by said optical coherence tomography device, or a numerical value that is proportional to said reciprocal number, by said intensity of the output light combined by said combining means.

10 more elements

An optical coherence tomography device, comprising:

a wavelength-tunable light generator including
a light-emitting section that combines and outputs the outputs of a plurality of wavelength-tunable light sources of different wave number sweep ranges, and
a control device that permits a wave number sweep in excess of the wave number sweep range of individual wavelength-tunable light sources,
wherein the outputs of said wavelength-tunable light sources are sequentially output in chronological order;
means for dividing output light of said wavelength-tunable light generator into measurement light and reference light;
means for irradiating a measurement object with said measurement light and for collecting signal light produced as a result of said measurement light being reflected or backscattered by said measurement object;
means for combining said signal light and said reference light;
means for measuring intensity of the output light combined by said combining means for each wave number of said wavelength-tunable light generator;
and
means for specifying, in a depth direction of said measurement object, a position at which said measurement light is reflected or backscattered by said measurement object and a reflection or backscatter intensity, from a set of intensities of said combined output light measured for each of the wave numbers by said measuring means,
wherein said specifying means subjects a combination of real numbers comprising said intensity of the output light combined by said combining means and said wave number to a Fourier transform,
wherein said specifying means corrects said intensity of the output light combined by said combining means so as to eliminate the effect of fluctuations in the intensity with respect to the wave number of the output light of said wavelength-tunable light generator, and
wherein said correction is performed by multiplying a reciprocal number of a value that is obtained by pre-measuring, for each of said wave numbers, the intensity of the output light of said wavelength-tunable light generator, or a numerical value that is proportional to said reciprocal number, by the intensity of said combined output light.

10 more elements

Dependencies are inferred from the claim text.

Facts

Application

11/867,732Filed 5 Oct 2007 · division

Priority

JP 2003-33520726 Sep 2003

Published

US 2008/0031410 A17 Feb 2008

Granted

8 Jun 2010

Term ends

Not estimatedThe source records don’t support an estimate.

Classification15 codes

G01N 21/4795
Scattering, i.e. diffuse reflection: spatially resolved investigating of object in scattering medium
A61B 5/0066
Arrangements for scanning: optical coherence imaging
A61B 5/0073
Using light, e.g. diagnosis by transillumination, diascopy, fluorescence: by tomography, i.e. reconstruction of 3D images from 2D projections
A61B 5/0088
Adapted for particular medical purposes: for oral or dental tissue

Family

PCT/JP2004/014302Parent of this division · filed 22 Sep 2004

US 2008/0031410 A1Pre-grant publication · published 7 Feb 2008

Application10/573,113Parent of this division

US 2008/0252901 A1Published application

US 7,732,784 B2This patent

From the US filing history. Foreign family members aren’t listed.

Wavelength-tunable light generator and optical coherence tomography device

Life of this patent

Wavelength-tunable light generator and optical coherence tomography device

Life of this patent

Abstract

Claims10