In vivo image capturing system including capsule enclosing a camera

• US 8,773,500 B2
• Filed: 12/19/2006
• Issued: 07/08/2014
• Est. Priority Date: 01/18/2006
• Status: Active Grant

• Current Assignee: CapsoVision, Inc.
• Original Assignee: CapsoVision, Inc.
• Inventors: Wilson, Gordon, Wang, Kang-Huai
• Primary Examiner(s): Harrell, Robert B
• Application Number:
  US11/642,275
• Publication Number:
  US 20080143822A1
• Time in Patent Office: 2,758 Days
• Field of Search: 348/36, 600/160
• US Class Current: 348/36
• CPC Class Codes: A61B 1/00096 Optical elements
• CPC Class Codes: A61B 1/00179 for off-axis viewing
• CPC Class Codes: A61B 1/04 combined with photographic or television appliances
• CPC Class Codes: A61B 1/041 Capsule endoscopes for imaging
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/7232 involving compression of the physiological signal, e.g. to extend the signal recording period
• CPC Class Codes: G02B 13/06 Panoramic objectives; So-called "sky lenses" including panoramic objectives having reflecting surfaces
• CPC Class Codes: G02B 23/243 Objectives for endoscopes
• CPC Class Codes: G02B 3/08 with discontinuous faces, e.g. Fresnel lens diffractive Fresnel lenses G02B5/1876
• CPC Class Codes: H04N 23/51 Housings
• CPC Class Codes: H04N 23/555 for picking-up images in sites, inaccessible due to their dimensions or hazardous conditions, e.g. endoscopes or borescopes
• CPC Class Codes: H04N 23/698 for achieving an enlarged field of view, e.g. panoramic image capture

Abstract

An in vivo image capturing system includes a capsule, and a camera encased within the capsule and configured to capture through a transparent window of the capsule, a view outside the capsule. The system includes a light source enclosed within the capsule and a reflector configured to reflect a ray of light from the light source, away from the camera. Wherever incoming image rays and outgoing illuminating light rays intersect at a common point on any surface of the transparent window, an angle between an outgoing illuminating light ray and a surface normal exceeds an angle between an incoming image ray and the surface normal such that a reflection of the outgoing illuminating light ray from said any surface is not within a field of view (FOV) of the camera.

Claims

1. An in vivo image capturing system comprising:

a panoramic camera with a field of view (FOV) exceeding 180 degrees;

a capsule enclosing the panoramic camera, the capsule comprising a transparent window configured to pass light into the panoramic camera, the transparent window having an interior surface and an exterior surface;

a light source enclosed within the capsule;

a reflector configured within the capsule to reflect a ray of light from the light source, away from the panoramic camera;

wherein wherever incoming image rays and outgoing illuminating light rays intersect at a common point on any surface of the transparent window, an angle between an outgoing illuminating light ray and a surface normal exceeds an angle between an incoming image ray and the surface normal such that a reflection of the outgoing illuminating light ray from said any surface is not within the field of view (FOV) of the panoramic camera.

2. The in vivo image capturing system of claim 1 wherein the panoramic camera comprises an entrance pupil, and wherein a single image plane in the panoramic camera captures a panoramic image of a subject surface outside the capsule.

3. An in vivo image capturing system according to claim 2 wherein the capsule comprises a panoramic annular lens having a concentric axis of symmetry and two refractive surfaces and two reflective surfaces configured to allow incoming light to pass through a first refractive surface into a transparent medium, to be reflected by a first reflective surface, then reflected by a second reflective surface, and then to exit the transparent medium through a second refractive surface.

4. An in vivo image capturing system according to claim 3, wherein the two reflective surfaces and the two refractive surfaces are conicoid surfaces of revolution, and wherein a conic constant of the first reflective surface is in a range of −

0.6 to +2, where another conic constant of the second reflective surface is chosen to be less than that of the first.

5. An in vivo image capturing system according to claim 3, wherein each of the two reflective surfaces and the two refractive surfaces is one of a conicoid surface of revolution, a spheroidal surface, or an aspheroidal surface.

6. An in vivo image capturing system according to claim 2, wherein the capsule comprises a closed housing including the transparent window, and wherein the field of view (FOV) of the panoramic camera comprises a longitudinal field of view defined by a range of view angles relative to a longitudinal axis of the capsule and a latitudinal field of view defined by a panoramic range of azimuth angles about the longitudinal axis such that the panoramic camera can capture the panoramic image covering substantially a 360 deg latitudinal FOV and a longitudinal FOV ranging from some angle greater than 0 deg to another angle greater than 90 deg.

7. An in vivo image capturing system according to claim 6, wherein the capsule comprises a panoramic annular lens having a concentric axis of symmetry and two refractive surfaces and two reflective surfaces configured to allow incoming light to pass through a first refractive surface into a transparent medium.

8. An in vivo image capturing system according to claim 1, further comprising a data processor configured to generate a continuous image made up of multiple captured images.

9. An in vivo image capturing system according to claim 8, wherein the data processor is located outside the capsule.

10. The in vivo image capturing system of claim 1 wherein the reflector is configured to reflect the ray of light outside the capsule.

11. The in vivo image capturing system of claim 1 wherein several of the outgoing illuminating light rays pass from the light source into a material, reflect from a reflective surface of the material comprised in said reflector, and then pass to the exterior surface of the transparent window.

12. An in vivo image capturing system according to claim 1, further comprising:

a power source for providing power to the light source and the panoramic camera; and

a memory coupled to the panoramic camera to store at least one image captured by the panoramic camera.

13. A method for in vivo imaging with a camera encased within a capsule, comprising:

providing a capsule housing having a window at least partially transparent to electromagnetic radiation in a given wavelength range;

wherein the camera is a panoramic camera with a field of view exceeding 180 degrees;

ingesting said capsule by a patient;

emitting electromagnetic radiation in said given wavelength range through a first set of inner and outer transparent window surface regions of the window of said capsule housing;

detecting images from reflections of said electromagnetic radiation by a subject surface of said patient, through a second set of inner and outer transparent window surface regions of the window with an image sensor in the panoramic camera;

wherein the capsule comprises a reflector configured to reflect a ray of light from an illuminating light source, away from the panoramic camera;

wherein wherever incoming image rays and outgoing illuminating light rays intersect at a common point on any surface of the window, an angle between an outgoing illuminating light ray and a surface normal exceeds an angle between an incoming image ray and the surface normal such that a reflection of the outgoing illuminating light ray from said any surface is not within a field of view (FOV) of the panoramic camera.

14. A method according to claim 13, further comprising:

uploading the images to a computer for processing.

15. A method according to claim 14, wherein:

said uploading the images comprises retrieving the capsule housing and connecting the capsule to the computer.

16. A method according to claim 14, wherein:

said uploading the images comprises transmitting the images from the capsule to the computer.

17. A method according to claim 13, further comprising

performing compression on the images resulting from said detecting to produce compressed image data;

and

uploading the compressed image data.

18. A method according to claim 17, further comprising

after said performing and before said uploading, storing the compressed image data in a memory in the capsule.

19. A method according to claim 13, further comprising

uploading the images with a wireless signal.

20. A method according to claim 13, further comprising

performing compression on the images resulting from said detecting, to produce compressed image data;

and

uploading the compressed image data via a wireless communication signal.

21. A method according to claim 13, further comprising

performing compression on the images detected by the image sensor in the capsule to produce compressed image data;

storing the compressed image data in a memory in the capsule; and

uploading the compressed image data via a wireless communication signal.

22. A method according to claim 13 wherein:

at least a portion of said electromagnetic radiation passes from a light source comprised in the capsule into a material in the capsule, reflects from a reflective surface of the material comprised in said reflector, and then passes to an exterior surface of the window.

23. A method according to claim 13 further comprising generating a continuous image comprising multiple images resulting from said detecting.

24. A method according to claim 13, further comprising:

uploading image data from the image sensor to a receiver outside the patient.

25. An in vivo image capturing system comprising:

a capsule enclosing a camera, the capsule comprising a transparent window configured to pass light into the camera;

a light source enclosed within the capsule;

a reflector configured within the capsule to reflect at least one ray of light from the light source;

wherein wherever outgoing illuminating light rays after reflection by the reflector intersect with incoming image rays at a common point on a surface of the transparent window, an angle between an outgoing illuminating light ray reflected by the reflector and a surface normal exceeds an angle between an incoming image ray and the surface normal such that a reflection of the outgoing illuminating light ray from said surface is not within a field of view (FOV) of the camera.

26. The in vivo image capturing system of claim 25 wherein:

the reflector comprises another surface coated with a reflective coating that reflects said at least one ray of light from the light source.

27. The in vivo image capturing system of claim 26 wherein:

the reflective coating is a metal reflective coating.

28. The in vivo image capturing system of claim 26 wherein:

the reflective coating is a dielectric reflective coating.

29. The in vivo image capturing system of claim 25 wherein:

the field of view of the camera exceeds 180 degrees.

30. The in vivo image capturing system of claim 25 wherein:

the camera is panoramic; and

a single image plane in the camera is configured to capture a panoramic image of a subject surface outside the capsule.

31. The in vivo image capturing system of claim 25 wherein:

the reflector is configured to reflect said at least one ray of light away from the camera.

32. The in vivo image capturing system of claim 25 wherein:

the reflector is configured to reflect said at least one ray of light outside the capsule, through the transparent window.

33. A method for in vivo imaging with an ingestible capsule, the method comprising:

generating electromagnetic radiation at an illumination source in the ingestible capsule;

using a reflector within the ingestible capsule to reflect at least one ray of said electromagnetic radiation away from a camera in the ingestible capsule;

emitting through a transparent window of the ingestible capsule, at least one portion of said electromagnetic radiation including said at least one ray of said electromagnetic radiation; and

using an image sensor in the camera, to detect at least one image of a gastrointestinal tract, at least from reflections of said at least one portion outside the ingestible capsule that are received through the transparent window;

wherein wherever outgoing illuminating rays, after reflection by the reflector, intersect with incoming image rays at a common point on a surface of the transparent window, an angle between an outgoing illuminating ray reflected by the reflector and a surface normal exceeds an angle between an incoming image ray and the surface normal such that a reflection of the outgoing illuminating ray from said surface is not within a field of view (FOV) of the camera.

34. The method of claim 33 wherein:

the reflector comprises another surface coated with a reflective coating that reflects said at least one ray of said electromagnetic radiation from the illumination source.

35. The method of claim 34 wherein:

the reflective coating is a metal reflective coating.

36. The method of claim 34 wherein:

the reflective coating is a dielectric reflective coating.

37. The method of claim 33 wherein:

the field of view of the camera exceeds 180 degrees.

38. The method of claim 33 wherein:

said at least one image is a panoramic image detected in a single plane in the camera.

39. The method of claim 33 wherein:

the reflector is used to reflect said at least one ray of said electromagnetic radiation outside the ingestible capsule, through the transparent window.

40. An in vivo image capturing system comprising:

a capsule enclosing a camera, the capsule comprising a transparent window configured to pass light into the camera;

a light source enclosed within the capsule;

a reflector configured within the capsule to reflect at least one ray of light from the light source;

whereby the transparent window comprises a point P on an outer surface thereof, at which a ray A entering the capsule is captured at a largest field angle by an aperture of the camera, and the transparent window is adapted to refract the ray A at an angle α

₂ with respect to a surface normal;

wherein the reflector is positioned at a distance g measured;

(a) from an intersection of a line segment between the point P, at an angle −

α

₂ with the surface normal, and an inner wall of the transparent window;

(b) to an apex of the reflector; and

such that wherever outgoing illuminating light rays after reflection by the reflector intersect with incoming image rays at the point P on the outer surface of the transparent window, an angle between an outgoing illuminating light ray reflected by the reflector and the surface normal exceeds |α

₂|.

41. The in vivo image capturing system of claim 40 further comprising:

a data processor configured to generate a continuous image made up of multiple captured images.

42. The in vivo image capturing system of claim 41 wherein:

the data processor is located outside the capsule.

43. The in vivo image capturing system of claim 40 wherein:

the reflector comprises at least one of a prism or a ring of triangular cross section.

44. The in vivo image capturing system of claim 40 wherein:

the reflector is configured to reflect a ray of light (B) from the light source, away from the camera, which is a panoramic camera, such that scattering of said ray (B) outside the capsule results in a scattered ray (B′

) entering a field of view of the camera.

45. The in vivo image capturing system of claim 40 wherein:

the camera is a panoramic camera; and

the reflector is configured to reflect one or more of the outgoing illuminating light rays away from the panoramic camera in a manner that prevents stray light from directly entering a lens without being scattered by a subject surface.

46. The in vivo image capturing system of claim 40 wherein:

the camera is a panoramic camera configured to capture a panoramic image of an environment surrounding the panoramic camera; and

the panoramic image is captured on a single image plane.

47. The in vivo image capturing system of claim 40 wherein:

the capsule comprises a closed housing including the transparent window for passing light into the camera, which is a panoramic camera; and

the panoramic camera is configured with a longitudinal field of view defined by a range of view angles relative to a longitudinal axis of the capsule and a latitudinal field of view defined by a panoramic range of azimuth angles about the longitudinal axis such that the panoramic camera can capture a panoramic image covering a 360 deg latitudinal FOV and a longitudinal FOV ranging from some angle greater than 0 deg to another angle greater than 90 deg.

48. The in vivo image capturing system of claim 40 wherein:

the camera is a panoramic camera which includes a panoramic annular lens;

the panoramic annular lens has a concentric axis of symmetry and includes two refractive surfaces and two reflective surfaces configured to allow incoming light to pass through a first refractive surface into a transparent medium.

49. A method for in vivo imaging with an ingestible capsule, the method comprising:

providing a capsule having a window at least partially transparent to electromagnetic radiation in a given wavelength range;

ingesting said capsule by a patient;

emitting electromagnetic radiation in said given wavelength range from said capsule;

detecting images from reflections of said electromagnetic radiation with an image sensor using a camera;

whereby the window comprises a point P on an outer surface, at which a ray A entering the capsule is captured at a largest field angle by an aperture of the camera, and the window is adapted to refract the ray A at an angle α

₂ with respect to a surface normal;

wherein a reflector is positioned at a distance g measured;

(a) from an intersection of a line segment between the point P, at an angle −

α

₂ with the surface normal, and an inner wall of the window;

(b) to an apex of the reflector; and

such that wherever outgoing illuminating light rays after reflection by the reflector intersect with incoming image rays at the point P on the outer surface of the window, an angle between an outgoing illuminating light ray reflected by the reflector and the surface normal exceeds |α

₂|.

50. The method of claim 49 further comprising:

performing compression on images resulting from said detecting, to produce compressed image data.

51. The method of claim 50 further comprising:

storing the compressed image data in a memory in the capsule.

52. The method of claim 50 further comprising:

uploading the compressed image data via a wireless signal.

53. The method of claim 49 wherein:

the reflector comprises at least one of a prism or a ring of triangular cross section.

54. The method of claim 49 wherein:

the camera is a panoramic camera; and

the reflector is configured to reflect one or more of the outgoing illuminating light rays away from the panoramic camera in a manner that prevents stray light from directly entering a lens without being scattered by a subject surface.