Fluorescence endoscopy and endoscopic device therefor

• US 5,092,331 A
• Filed: 08/24/1989
• Issued: 03/03/1992
• Est. Priority Date: 01/30/1989
• Status: Expired due to Term

• Current Assignee: Olympus Optical Company Ltd. (Olympus Corporation)
• Original Assignee: Olympus Optical Company Ltd. (Olympus Corporation)
• Inventors: Nakamura, Kazunari, Nonami, Tetsuo, Tsuruoka, Takao, Hiyama, Keiichi
• Primary Examiner(s): Kamm, William E.
• Assistant Examiner(s): Pontius, Kevin
• Application Number:
  US07/397,812
• Time in Patent Office: 922 Days
• Field of Search: 128/6, 128/634, 128/665, 436/172
• US Class Current: 600/342
• CPC Class Codes: H04N 23/125 Colour sequential image capture, e.g. using a colour wheel
• 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 23/56 provided with illuminating means
• CPC Class Codes: H04N 23/63 by using electronic viewfinders
• CPC Class Codes: H04N 23/84 for processing colour signals
• CPC Class Codes: H04N 25/131 including elements passing infrared wavelengths

Abstract

A fluorescence endoscopy and an endoscopic device therefor, wherein, to an object to be examined containing a fluorescent substance, light rays in a plurality of wavelength ranges whose degrees of exciting the fluorescent substance are different from one another and which can constitute a color images are sequentially irradiated; images of the object are obtained by the respective wavelength ranges; a color image of the object is constituted using the images obtained by the respective wavelength ranges and information based on fluorescence emitted by the fluorescent substance, is obtained using at least an image obtained by a wavelength whose degree of exciting the fluorescent substance is largest out of the images obtained by the respective wavelength ranges.

Claims

1. A fluorescence endoscopy comprising the steps of:

sequentially irradiating, to an object to be examined containing a fluorescent substance, light rays in a plurality of wavelength ranges whose degrees of exciting said fluorescent substance are different from one another and which can constitute a color image;

obtaining images of said object to be examined to which said light rays have been irradiated by said respective wavelength ranges;

constituting a color image of said object to be examined using said images obtained of said object;

obtaining a color picture image as first light information about said object to be examined by the light rays of the wavelength range having a largest degree of exciting said fluorescent substance among said light rays irradiated, said first light information including a fluorescence information component other than a reflected light information component of said object;

obtaining said reflected light information component of said object as second light information about said object to be examined by the light rays of the wavelength ranges other than the wavelength range for obtaining said first light information among said light rays irradiated; and

obtaining fluorescence-based information about said object to be examined based on said first light information and said second light information by a) comparing said first and second light information and b) making said fluorescence information component conspicuous in said reflected light information component of said object which is to be examined in said first light information.

2. A fluorescence endoscopy according to claim 1, wherein at least one of said light rays in said plurality of wavelength ranges to be irradiated by said step of irradiating light rays includes a light ray which excites said fluorescent substance in wavelength ranges other than a wavelength range of visible light.

3. A fluorescence endoscopy according to claim 1, wherein said step of obtaining fluorescence-based information includes a step of adjusting said first light information level and said second light information level so as to be equal to each other at a reference time and obtaining said fluorescence-based information at a predetermined time by the difference between said levels adjusted by said adjusting step.

4. A fluorescence endoscopy according to claim 1, wherein said step of obtaining fluorescence-based information includes a step of adjusting said first light information level and said second light information level so as to be equal to each other at a reference time and said difference expanding step expands the difference between said levels adjusted by said adjusting step.

5. A fluorescence endoscopy according to claim 1 further comprising a step of switching between said color image obtained by said step of constituting a color image and said fluorescence-based information obtained by said step of obtaining fluorescence-based information and forming an output thereof.

6. A fluorescence endoscopy according to claim 1 wherein said step of obtaining fluorescence-based information includes a step of continuously displaying said fluorescence-based information so that a variation with a lapse of time of the fluorescence-based information may be recognized.

7. A fluorescence endoscopy according to claim 1 includes a step of displaying light information obtained by said step of comparing and calculating.

8. A fluorescence endoscopy according to claim 1 wherein said step of comparing and calculating includes a step of calculating a difference between respective levels of said first and second light information.

9. A fluorescence endoscopy according to claim 8 wherein said step of comparing and calculating includes a step of calculating and expanding said difference between the levels.

10. A fluorescence endoscopy according to claim 1 wherein said step of comparing and calculating includes a step of expanding a negative correlation between said first and second light information.

11. A fluorescence endoscopy according to claim 10 wherein said step of expanding can vary an expanding level.

12. A fluorescence endoscopy according to claim 11 wherein said step of expanding is carried out by a matrix converting means supplied with the first and second light information.

13. A fluorescence endoscopy according to claim 1 wherein said step of irradiating sequentially irradiates light of three colors of red, green and blue.

14. A fluorescence endoscopy according to claim 13 wherein said first light information is obtained when an examined object is irradiated by a blue light as a light ray and said second light information obtained when the examined object is irradiated by a green light as a light ray.

15. A fluorescence endoscopy according to claim 1 wherein said step of comparing and calculating further normalizes said fluorescence information by information of a quantity of blood obtained when the object is irradiated by a red light as said light ray for canceling an effect of a large or small quantity of blood from said fluorescence information.

16. A fluorescence endoscopy according to claim 15 wherein said information of the quantity of blood is supplemented by said second light information.

17. A fluorescence endoscopic device for obtaining information about fluorescence comprising:

an endoscopy body having a thin, long inserting portion including an observing window at a tip thereof and an image forming optical system which forms an image by receiving a light ray entered from said observing window;

an irradiating means for sequentially irradiating, to an object to be examined containing a florescent substance, light rays in a plurality of wavelength ranges whose degrees of exciting said fluorescent substance are difference from one another and which can constitute a color image;

an imaging means for receiving an image formed by said image forming optical system, and for obtaining images of said object to be examined to which said light rays have been irradiated by said irradiating means, by said respective wavelength ranges;

a signal processing means for constituting a color image of said object to be examined using said images by said respective wavelength ranges obtained by said imaging means;

a first detecting means for obtaining first light information about said examined object by light of the wavelength range having a largest degree of exciting said fluorescent substance among said light irradiating by said irradiating means, said first light information including a fluorescence information component other than a reflected light information component of said object;

a second detecting means for obtaining said reflected light information component of said object as second light information about said examined object by the light of the wavelength ranges other than the wavelength range for obtaining said first light information among said light irradiated by said irradiating means; and

a comparing and calculating means for comparing levels of said first and second light information obtained by said first and second detecting means and for calculating to make said fluorescence information component conspicuous.

18. A fluorescence endoscopic device according to claim 17 further comprising means for switching between said color image obtained by said signal processing means and said fluorescence information component obtained by said comparing and calculating means and forming an output thereof.

19. A fluorescence endoscopic device according to claim 17 wherein said comparing and calculating means detects a difference between said first and second light information.

20. A fluorescence endoscopic device according to claim 19 wherein said comparing and calculating means has a function expanding said difference.

21. A fluorescence endoscopic device according to claim 20 wherein a means for expanding said difference comprises a matrix converting means which can control a degree of emphasizing.

22. A fluorescence endoscopic device according to claim 21, wherein said matrix converting means expands a negative correlation between said first and second light information.

23. A fluorescence endoscopic device according to claim 19 wherein said comparing and calculating means can control a relative level between said first and second light information which detects said difference.

24. A fluorescence endoscopic device according to claim 23, wherein said comparing and calculating means further includes an adjusting means for adjusting said first light information level and said second light information level to be equal to each other at a reference time, whereas said means for detecting a difference detects a difference between said levels adjusted by said adjusting means.

25. A fluorescence endoscopic device according to claim 17 wherein said first light information can be obtained when the object is irradiated by a blue light as a light ray and said second light information can be obtained when the object is irradiated by a green light as a light ray.

26. A fluorescence endoscopic device according to claim 17 said comparing and calculating means normalizes said fluorescence information by information of quantity of blood obtained when the object is irradiated by a red light as a light ray for canceling an effect of a large or small quantity of blood from said fluorescence information.

27. A fluorescence endoscopic device according to claim 26 wherein said information of the quantity of blood is supplemented by said second light information.

28. An endoscopic device, used with a fluorescent substance emitting fluorescence information having a color of longer wavelength ranges than blue light by receiving blue light, said endoscopic device comprising:

irradiating means for sequentially irradiating, to an object to be examined, three color irradiating light of red, green and blue;

detecting means for sequentially detecting reflected light of said object;

obtaining means for obtaining picture images corresponding to respective irradiating light and for obtaining a color picture image by composing said images;

emphasizing means for calculating and emphasizing said fluorescence information by comparing blue picture image information, corresponding to said blue irradiating light, with green picture image information corresponding to said green irradiating light; and

a display means for displaying emphasized blue picture image information.

29. An endoscopic device according to claim 28 wherein said emphasizing means reduces a component other than a fluorescence component from the picture image corresponding to said blue irradiating light by detecting a difference of the picture image corresponding to the blue irradiating light from the picture image corresponding to the green irradiating light and makes a fluorescence information component conspicuous.

30. An endoscopic device according to claim 28 wherein said displaying means displays said emphasized blue picture image information by a single color.

31. An endoscopic device according to claim 28 wherein said displaying means displays color by overlapping said emphasized blue picture image information with said green picture image information and red picture image information corresponding to a red irradiating light.

32. A method for displaying fluorescence information by an endoscope comprising the steps of:

receiving a blue light and injecting a fluorescent substance emitting fluorescence, of a higher wavelength than blue light, into a body;

bringing an endoscopic device into a body cavity, said endoscopic device comprising an irradiating means for sequentially irradiating red, green and blue irradiating light into the body cavity and a receiving light means for receiving a light from an irradiated part;

supplementing signals from said receiving light means by reducing a component other than a fluorescence component from a blue light by considering a signal when said green or red irradiating light irradiates compared with a blue signal when said blue irradiating light irradiates; and

displaying a projected image relating to supplemented signals of said step of supplementing.

33. A method according to claim 32 wherein said step of supplementing reduces a component other than the fluorescence component by subtracting a signal at a time of irradiating the green or red light from the blue signal.