Vivo CAMERA WITH MULTIPLE SOURCES TO ILLUMINATE TISSUE AT DIFFERENT DISTANCES

• US 20140128675A1
• Filed: 01/15/2014
• Published: 05/08/2014
• Est. Priority Date: 06/09/2008
• Status: Active Grant

• Current Assignee: CapsoVision, Inc.
• Original Assignee: CapsoVision, Inc.
• Inventors: Wilson, Gordon C.
• Granted Patent: US 8,956,281 B2
• Time in Patent Office: Days
• US Class Current: 600/109
• CPC Class Codes: A61B 1/00006 of control signals
• CPC Class Codes: A61B 1/00009 of image signals during a use of endoscope
• CPC Class Codes: A61B 1/00016 using wireless means
• CPC Class Codes: A61B 1/0002 provided with data storages
• CPC Class Codes: A61B 1/00032 internally powered
• CPC Class Codes: A61B 1/00114 Electrical cables in or with an endoscope
• CPC Class Codes: A61B 1/00177 for 90 degrees side-viewing
• CPC Class Codes: A61B 1/041 Capsule endoscopes for imaging
• CPC Class Codes: A61B 1/0607 for annular illumination
• CPC Class Codes: A61B 1/0623 for off-axis illumination
• CPC Class Codes: A61B 1/0625 for multiple fixed illumination angles
• CPC Class Codes: A61B 1/0661 Endoscope light sources
• CPC Class Codes: A61B 1/0684 using light emitting diodes [LED]

Abstract

An in vivo endoscope illuminates tissue using multiple sources. Light from a short-range source exits a tubular wall of the endoscope through a first illumination region that overlaps an imaging region, and the light returns through the imaging region after reflection by tissue, to form an image in a camera. Light from a long-range source exits the tubular wall through a second illumination region that does not overlap the imaging region. The endoscope of some embodiments includes a mirror, and light from an emitter for the short-range source is split and reaches the first illumination region from both sides of an optical axis of the camera. Illuminating the first illumination region with split fractions of light results in greater uniformity of illumination, than illuminating directly with an un-split beam. The energy generated by each source is changed depending on distance of the tissue to be imaged.

Claims

1. An endoscope comprising:

a housing sufficiently small to travel through a gastrointestinal tract of a human;

a transmitter enclosed within said housing, to transmit image data to an external device;

a set of one or more sensors enclosed within said housing and coupled to said transmitter, said set supplying said image data to said transmitter;

a first source enclosed within said housing, to generate first electromagnetic radiation exiting said housing;

wherein said first source is positioned at a location whereby said first electromagnetic radiation passes through a first region of the housing defined by a first intersection of said first electromagnetic radiation with a surface of the housing;

a second source enclosed within said housing, to generate second electromagnetic radiation exiting said housing;

wherein said second source is positioned at a location whereby said second electromagnetic radiation passes through a second region of the housing defined by a second intersection of said second electromagnetic radiation with the surface of the housing;

wherein the first region is larger than the second region;

wherein a third electromagnetic radiation forms said image data;

wherein at least a portion of said third electromagnetic radiation arises from reflection of at least a fraction of said first and said second electromagnetic radiation;

wherein a third region of the housing is defined by an intersection of a surface of the housing with said third electromagnetic radiation;

wherein at least a majority of the second electromagnetic radiation passes through a fourth region not overlapping the third region; and

wherein the first region and the second region are on a curved surface.

2. The endoscope of claim 1 wherein:

all or almost all of the second electromagnetic radiation passes through the fourth region.

3. The endoscope of claim 1 wherein:

said set is coupled to said transmitter by a processor comprised in the endoscope and enclosed within said housing;

additional electromagnetic radiation forms additional data also supplied by said set to said processor; and

said processor excludes said additional data to obtain said image data supplied to said transmitter.

4. The endoscope of claim 3 wherein:

at least a portion of said additional electromagnetic radiation arises from reflection by said housing, of a fourth electromagnetic radiation from at least one of the first source or the second source.

5. The endoscope of claim 1 wherein:

the endoscope further comprises an additional wall enclosed within the housing;

a plurality of paths correspond to a plurality of rays originating from a specific source in a group consisting of the first source and the second source, the plurality of paths pass through the additional wall to reach the housing and reflect therefrom to form within said housing, a mirror image of the specific source, in the absence of the additional wall; and

wherein the additional wall is opaque and positioned adjacent to the specific source to block passage of the plurality of rays along said paths to prevent said formation of said mirror image by said plurality of rays.

6. The endoscope of claim 5 wherein:

the additional wall is annular.

7. The endoscope of claim 1 wherein:

a majority of the first electromagnetic radiation exiting the housing passes through the third region.

8. The endoscope of claim 1 wherein:

the first region is at least 1.2 times larger than the second region.

9. The endoscope of claim 1 wherein:

the first region is at least 1.5 times larger than the second region.

10. The endoscope of claim 1 wherein:

the first region is at least 2 times larger than the second region.

11. The endoscope of claim 1 wherein:

the housing has an aspect ratio greater than one;

a longitudinal plane passes through a longitudinal axis of the housing;

the longitudinal plane passes through each of said first source and said second source; and

said first source is offset from said second source in a direction of said longitudinal axis.

12. The endoscope of claim 1 wherein:

a portion of the first electromagnetic radiation is reflected by a mirror in the endoscope before passing through the first region of the housing; and

another portion of the first electromagnetic radiation passes through the first region of the housing without reflection by said mirror.

13. The endoscope of claim 12 wherein:

a sensor in said set is comprised in a camera configured to capture at least a portion of the third electromagnetic radiation entering the housing; and

a first distance between the first source and an optical axis of the camera is smaller than a second distance between the first source and the mirror.

14. The endoscope of claim 1 further comprising:

a mirrored surface oriented to reduce angular divergence of a portion of the first electromagnetic radiation incident thereon.

15. The endoscope of claim 1 further comprising:

a baffle and a lens enclosed within the housing;

wherein a first virtual image of the baffle blocks a line-of-sight between a pupil and a second virtual image of at least one of the first source and the second source, the second virtual image being formed within a field of view of the lens in the absence of the first virtual image.

16. The endoscope of claim 1 further comprising:

a baffle enclosed within the housing;

wherein the baffle is positioned to block rays originating in at least one of the first source and the second source from forming a virtual image that can be captured by the set of sensors.

17. The endoscope of claim 1 wherein:

said image data represents a diagnosable image at a specific location in a gastrointestinal tract and excludes additional data which represents an unduly bright region.

18. The endoscope of claim 1 wherein:

the first source and the second source generate different amounts of energy relative to each other depending on a distance of tissue from the endoscope.

19. The endoscope of claim 1 wherein:

the third region at least partially overlaps the first region; and

the third region does not overlap the second region, whereby the fourth region is identical to the second region.

20. The endoscope of claim 1 wherein:

the first source comprises an emitter and an optical element that splits electromagnetic radiation received from the emitter.

21. The endoscope of claim 1 wherein said fraction is hereinafter a first fraction, the endoscope further comprising:

an optical element;

wherein the optical element reduces angular dispersion of at least a second fraction of the first electromagnetic radiation.

22. The endoscope of claim 1 wherein said fraction is hereinafter a third fraction, the endoscope further comprising:

an optical element located between the first source and the housing;

wherein;

at least a first fraction of the first electromagnetic radiation from the first source is incident on the first region after reflection by the optical element;

at least a second fraction of the first electromagnetic radiation from the first source is incident on the first region without reflection by the optical element; and

said first fraction is greater than said second fraction.

23. The endoscope of claim 22 wherein:

a sensor in said set is comprised in a camera configured to capture at least a portion of the third electromagnetic radiation entering the housing; and

a first distance between the first source and an optical axis of the camera is smaller than a second distance between the first source and the mirror.

24. The endoscope of claim 1 wherein:

a majority of the first region overlaps the third region.

25. A method of in vivo imaging comprising:

an endoscope emitting first electromagnetic radiation exiting a housing from a first source to illuminate a gastrointestinal tract;

wherein said first electromagnetic radiation exits the endoscope from a first region of said housing to illuminate a gastrointestinal tract;

wherein the first region is defined by a first intersection of said first electromagnetic radiation with a surface of said housing;

said endoscope emitting second electromagnetic radiation exiting said housing from a second source to further illuminate said gastrointestinal tract;

wherein said second electromagnetic radiation exits the endoscope from a second region of said housing;

wherein the second region is defined by a second intersection of said second electromagnetic radiation with said surface of said housing;

wherein a third region, located within the first region and at least partially outside the second region, is larger than said second region; and

said endoscope storing inside a memory at least a portion of an image formed by reflections, received through said first region, of said first electromagnetic radiation and said second electromagnetic radiation by said gastrointestinal tract.

26. The method of claim 25 wherein:

said emittings and said storing are performed when said endoscope is at a first location relative to the gastrointestinal tract, the method further comprising;

in response to movement of said endoscope to a second location at which a first increase Δ

d1 resulting from said movement, in a first distance d1 of the first region from the gastrointestinal tract is greater than a second increase Δ

d2 resulting from said movement, in a second distance d2 of the second region from the gastrointestinal tract when measured in a common direction, said endoscope automatically increasing radiant energy E2 emitted in the second electromagnetic radiation from said second region by a second amount Δ

E2 while increasing radiant energy emitted in the first electromagnetic radiation by a first amount Δ

E1, said first amount Δ

E1 being smaller than said second amount Δ

E2; and

subsequent to said increasings, said endoscope storing in said memory another portion of another image of said tract from said second location.

27. The method of claim 25 wherein:

the first region is at least 1.2 times larger than the second region.

28. The method of claim 25 wherein:

the first region is at least 1.5 times larger than the second region.

29. The method of claim 25 wherein:

the first region is at least 2 times larger than the second region.

30. The method of claim 25 further comprising:

at least a first fraction of the first electromagnetic radiation from the first source being incident on the first region after reflection by an optical element located in the housing and at least a second fraction of the first electromagnetic radiation from the first source being incident on the first region without reflection by the optical element, said first fraction being greater than said second fraction;

wherein an input aperture of the optical element is on a first side of a plane and the first source is on a second side of said plane and all electromagnetic radiation from the first source is emitted on the second side of said plane; and

a majority of the second electromagnetic radiation from the second source being incident on the second region without reflection between the second source and the housing;

wherein each source comprises a pair of terminals with current passing therebetween and at least one emitter of electromagnetic radiation powered through said pair of terminals.

31. The method of claim 25 wherein:

said endoscope transmits a majority of the first electromagnetic radiation after reflection by an optical element within said endoscope;

wherein an input aperture of the optical element is on a first side of a plane and a first source of the first electromagnetic radiation is on a second side of said plane and all electromagnetic radiation from the first source is emitted on the second side of said plane; and

said endoscope transmits a majority of the second electromagnetic radiation without reflection.

32. The method of claim 25 further comprising:

said endoscope calculating an average luminance value for each sector in a plurality of sectors used to sense said image;

said endoscope calculating a difference between the average luminance value calculated for each sector and a target luminance value for said each sector; and

said endoscope computing a drive current for generating the second electromagnetic radiation, based at least partially on said difference.

33. The method of claim 32 wherein:

a change in said drive current is obtained based on a linear combination of a plurality of said differences individually calculated for each sector in said plurality of sectors.

34. The method of claim 25 wherein:

at least a first fraction of the first electromagnetic radiation from the first source is incident on the first region after reflection by an optical element located between the first source and the housing and at least a second fraction of the first electromagnetic radiation from the first source is incident on the first region without reflection by the optical element, said first fraction being greater than said second fraction.

35. The method of claim 34 wherein:

a majority of the second electromagnetic radiation from the second source is incident on the second region without reflection between the second source and the housing.

36. The method of claim 25 wherein:

said endoscope transmits a majority of the first electromagnetic radiation after reflection by at least one optical element within said endoscope; and

said endoscope transmits a majority of the second electromagnetic radiation without reflection by said at least one optical element.