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US 7,623,907 B2Granted
Endoscope for observing scattered light from living body tissue and method of observing scattered light from living body tissue
AssigneeOlympus Corporation
InventorsHideyuki Takaoka, Mamoru Tamura
Life of this patent
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Abstract
An endoscope apparatus and method are disclosed wherein first and second light beams, each having different center wavelengths, illuminate an object. A detector and a light receiver optical system are provided that receive back-scattered light from first and second illumination devices. A processor is provided that calculates a value corresponding to the size of particles that back-scatter light of the first and second light beams that are incident onto the object, with the calculated value being independent of the concentration of the particles. The first illumination device and the second illumination device are arranged in a specified manner so that a specified condition is satisfied.
Claims26
An endoscope apparatus having an insertable portion for examining an object within a living body using scattered light, said endoscope apparatus comprising:
- a light source;
- a first illumination device that directs light from the light source and illuminates the object from the insertable portion of the endoscope apparatus with a first light beam having a center ray and a first wavelength;
- a second illumination device that directs light from the light source and illuminates the object from the insertable portion of the endoscope apparatus with a second light beam having a center ray and a second wavelength;
- a detector;
- a light receiver optical system having a field of view and an optical axis, and that receives light from the first and second illumination devices that has been back-scattered from the object and guides it to the detector;
- and
- a processor that calculates a value that corresponds to the size of particles of an object that scatter light;
- wherein
- at least two of the first illumination device, the second illumination device, and the light receiver optical system include a positive or negative lens having a lateral offset relative to an optical axis of light that is incident onto the positive or negative lens;
- the center ray of the first light beam and the center ray of the second light beam intersect the optical axis of the light receiver optical system at substantially the same point;
- and
- the first illumination device and the second illumination device are arranged so that the following condition is satisfied
- α1<α2
- where
- α1 is the angle formed by the optical axis of the light receiver optical system and the center ray of the first light beam, which is defined as a line that is included in the first light beam and is substantially in the center of the bundle of rays that are emitted from the first illumination device and intersect at a point where the optical axis of the light receiver optical system intersects the surface of an object;
- and
- α2 is the angle formed by the optical axis of the light receiver optical system and the center ray of the second light beam, which is defined as a line that is included in the second light beam and is substantially in the center of the bundle of rays that are emitted from the second illumination device and intersect at a point where the optical axis of the light receiver optical system intersects the surface of an object.
14 more elements
An endoscope apparatus having an insertable portion for examining an object within a living body using scattered light, said endoscope apparatus comprising:
- a light source;
- a first illumination device that directs light from the light source and illuminates the object from an insertable portion of the endoscope apparatus with a first light beam having a center ray and a first wavelength;
- a second illumination device that directs light from the light source and illuminates the object from an insertable portion of the endoscope apparatus with a second light beam having a center ray and a second wavelength;
- an objective optical system having an optical axis;
- an image pickup device that receives an image formed by the objective optical system;
- a processor that calculates a difference of a first image signal being output from the image pickup device when an object is illuminated by the first illumination device versus a second image signal being output from the image pickup device when the object is illuminated by the second illumination device, or that calculates a ratio of the first image signal divided by the second image signal;
- wherein
- at least two of the first illumination device, the second illumination device, and the light receiver optical system include a positive or negative lens having a lateral offset relative to an optical axis of light that is incident onto the positive or negative lens;
- the first and second illumination devices are so arranged that a center line of a light beam emitted from the first illumination device and a center line of a light beam emitted from the second illumination device intersect at substantially the same point on said optical axis;
- the first and second illumination devices are so arranged that the angle formed by the illumination light at the time of illumination by the first illumination device and the scattered light detected from the object by the light receiver optical system, that is, at the angle 180° minus α1, is within the range of 176°-180°, and that the angle of the illumination light that is incident onto the object at the time of illumination by the second illumination device and the scattered light detected from the object with the light receiver optical system, that is, at the angle 180°minus α2, is greater than or equal to 176°;
- and
- the first illumination device and the second illumination device are arranged so that the following condition is satisfied
- α1<α2
- where
- α1 is the angle formed by the optical axis of the image pickup device and the center ray of the first light beam, which is defined as a line that is included in the first light beam and is substantially in the center of the bundle of rays that are emitted from the first illumination device and intersect at a point where the optical axis of the objective optical system intersects the surface of an object;
- and
- α2 is the angle formed by the optical axis of the image pickup device and the center ray of the center light beam, which is defined as a line that is included in the second light beam and is substantially in the center of the bundle of rays that are emitted from the second illumination device and intersect at a point where the optical axis of the objective optical system intersects the surface of an object.
14 more elements
An endoscope apparatus having an insertable portion for examining an object within a living body using scattered light, said endoscope apparatus comprising:
- a light source;
- a first illumination device that directs light from the light source and illuminates the object from the insertable portion of the endoscope apparatus with a first light beam having a center ray and a first wavelength;
- a second illumination device that directs light from the light source and illuminates the object from the insertable portion of the endoscope apparatus with a second light beam having a center ray and a second wavelength;
- an objective optical system having an optical axis;
- an image pickup device having an optical axis that receives an image formed by the objective optical system;
- and
- a processor that calculates the difference between a first image signal being output from the image pickup device when the object is illuminated by the first illumination device versus a second image signal being output from the image pickup device when the object is being illuminated by the second illumination device, or that calculates the ratio of said first image signal divided by said second image signal;
- wherein
- at least two of the first illumination device, the second illumination device, and the light receiver optical system include a positive or negative lens having a lateral offset relative to an optical axis of light that is incident onto the positive or negative lens;
- the first illumination device and the second illumination device are so arranged that a center line of a light beam emitted from the first illumination device and a center line of a light beam emitted from the second illumination device intersect at substantially the same point on said optical axis;
- the first illumination device and the second illumination device are arranged so that the following condition is satisfied
- α1<α2
- where
- α1 is the angle formed by the optical axis of the image pickup device and the center ray of the first light beam, which is defined as a line that is included in the first light beam and is substantially in the center of the bundle of rays that are emitted from the first illumination device and intersect at a point where the optical axis of the image pickup device intersects the surface of an object;
- α2 is the angle formed by the optical axis of the image pickup device and the center ray of the second light beam, which is defined as a line that is included in the second light beam and is substantially in the center of the bundle of rays that are emitted from the second illumination device and intersect at a point where the optical axis of the image pickup device intersects the surface of an object;
- and
- the first light beam and the second light beam each have a narrow bandwidth centered in the wavelength region of 500 nm or shorter.
14 more elements
Dependencies are inferred from the claim text.