Fluorescent endoscope system enabling simultaneous normal light observation and fluorescence observation in infrared spectrum

• US 6,293,911 B1
• Filed: 11/19/1997
• Issued: 09/25/2001
• Est. Priority Date: 11/20/1996
• Status: Expired due to Term

• Current Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Original Assignee: Olympus Optical Corporation Limited (Olympus Corporation)
• Inventors: Nakamura, Kazunari, Imaizumi, Katsuichi
• Primary Examiner(s): Leubecker, John P.
• Application Number:
  US08/974,531
• Time in Patent Office: 1,406 Days
• Field of Search: 600/109, 600/160, 600/178, 600/407, 600/476, 600/478, 600/473
• US Class Current: 600/160
• CPC Class Codes: A61B 1/000094 extracting biological structures
• CPC Class Codes: A61B 1/000095 for image enhancement
• CPC Class Codes: A61B 1/0005 combining images e.g. side-by-side, superimposed or tiled
• CPC Class Codes: A61B 1/00186 with imaging filters
• CPC Class Codes: A61B 1/043 for fluorescence imaging
• CPC Class Codes: A61B 1/0646 with illumination filters
• CPC Class Codes: A61B 5/0071 by measuring fluorescence emission
• CPC Class Codes: A61B 5/0084 for introduction into the body, e.g. by catheters A61B5/1459 takes precedence

Abstract

Excitation light for normal light observation with wavelengths in the visible spectrum, which is output from a lamp, and excitation light with wavelengths in the infrared spectrum for exciting a fluorescent substance characteristic of being accumulated readily in a lesion are irradiated simultaneously to a living tissue, to which the fluorescent substance has been administered, through an endoscope. Fluorescence components are separated from light stemming from the living tissue by means of a separator such as a dichroic mirror, introduced to a first imaging device, and then imaged. Light components with wavelengths in the visible spectrum are introduced to a second imaging device and then imaged. Signals representing the images are subjected to signal processing, whereby a video signal is produced. For better diagnosis, two images are displayed while, for example, one of the images is superimposed on the other.

Claims

1. An endoscope system, comprising:

an endoscope having an elongated insertion part capable of being inserted into a living body;

an administering means for use in administering a fluorescent substance to the inside of a living body, said fluorescent substance emitting a fluorescence with wavelengths in a first infrared spectrum which is transmitted by a living tissue more efficiently than light with wavelengths in the visible and ultraviolet spectra, said fluorescent substance being apt to be accumulated in a lesion;

an excitation light irradiating means for irradiating excitation light to said living tissue inside said living body to which said fluorescent substance has been administered, said excitation light having wavelengths in a second infrared spectrum different from said first infrared spectrum, said excitation light irradiating means irradiates said excitation light intermittently to said living body;

an imaging means incorporated in said endoscope, for cutting off said excitation light and producing a fluorescence image using fluorescence with wavelengths in said first infrared spectrum emanating from said florescent substance, said imaging means being responsive to said excitation light intermittently irradiated to said living body to output a first image signal when said excitation light is irradiated and a second image signal when said excitation light is not irradiated;

a first memory for storing said first image signal output from said imaging means when said excitation light is irradiated;

a second memory for storing said second image signal output from said imaging means when said excitation light is not irradiated;

a subtracting means for subtracting said second image signal stored in said second memory from said first image signal stored in said first memory;

a signal processing means for processing an output signal of said subtracting means and for producing a video signal; and

a display means for displaying an image represented by said video signal.

2. An endoscope system, comprising:

an endoscope having an elongated insertion part capable of being inserted into a living body;

a light source means for simultaneously irradiating excitation light with wavelengths in a first infrared spectrum and irradiating visible light with wavelengths in the visible spectrum, said excitation light exciting a fluorescent substance administered to living tissue, wherein upon excitation, said fluorescent substance emits fluorescence in a second infrared spectrum with wavelengths longer than said wavelengths in said first infrared spectrum;

a separating means for separating said fluorescence with wavelengths in said second infrared spectrum, from light stemming from said living tissue;

a first imaging means for imaging said fluorescence with wavelengths in said second infrared spectrum separated by said separating means; and

a second imaging means for imaging light with wavelengths in the visible spectrum.

3. An endoscope system according to claim 2, wherein said fluorescent substance is an antibody labeled by indocyanine green.

4. An endoscope system according to claim 2, wherein said separating means is a dichroic mirror, and said second imaging means includes at least three imaging devices different from one of said first imaging means.

5. An endoscope system according to claim 2, wherein said separating means is a mosaic filter, and said first imaging means and second imaging means are realized with a common imaging means.

6. An endoscope system according to claim 5, wherein said endoscope is an electronic endoscope having said separating means and common imaging means located in a distal part of said insertional part.

7. An endoscope system according to claim 5, wherein said endoscope is an optical endoscope having an eyepiece unit and an image guide, and wherein said separating means, first imaging means, and second imaging means are located in a camera mounted on the eyepiece unit.

8. An endoscope system according to claim 2, wherein said separating means includes a dichroic mirror, and said first imaging means includes an image intensifier.

9. An endoscope system comprising:

an endoscope having an elongated insertion part capable of being inserted into a living body;

an administering means for use in administering a fluorescent substance, which emits fluorescence with wavelengths in a first infrared spectrum to be transmitted by a living tissue more efficiently than light with wavelengths in the visible and ultraviolet spectra, and which is apt to be accumulated in a lesion, to the inside of a living body;

an excitation light irradiating means for irradiating excitation light with wavelengths in a second infrared spectrum longer than the visible spectrum and shorter than the first infrared spectrum to the living tissue inside the living body to which the fluorescent substance has been administered;

a visible light irradiating means for irradiating light with wavelengths in the visible spectrum to the living tissue through said endoscope;

a first imaging means, incorporated in said endoscope, for cutting off excitation light with wavelengths in the second infrared spectrum and forming a fluorescence image using fluorescence with wavelengths in the first infrared spectrum emanating from said fluorescent substance;

a second imaging means, incorporated in said endoscope, for imaging light with wavelengths in the visible spectrum;

a signal processing means for processing signals output from said first and second imaging means and producing a video signal;

a display means for displaying an image represented by the video signal; and

a control means for controlling an output level of said first imaging means on the basis of an output signal of said second imaging means.

10. An endoscope system according to claim 9, wherein said control means includes an amount-of-light control means for controlling amounts of light output from said excitation light irradiating means and visible light irradiating means.

11. An endoscope system comprising:

an endoscope having an elongated insertional part capable of being inserted into a living body;

an administering means for use in administering a fluorescent substance to an inside of said living body, said fluorescent substance emitting fluorescence with wavelengths in a first infrared spectrum that is transmitted by a living tissue more efficiently than light with wavelengths in the visible and ultraviolet spectra and that is apt to be accumulated in a lesion;

an excitation light irradiating means for irradiating excitation light to said living tissue inside said living body to which the fluorescent substance has been administered, said excitation light having wavelengths in a second infrared spectrum different from the first infrared spectrum;

a visible light irradiating means for irradiating light with wavelengths in the visible spectrum to the living tissue through said endoscope;

a first imaging means, incorporated in said endoscope, for cutting off excitation light and forming a fluorescence image using fluorescence with wavelengths in the first infrared spectrum emanating from said fluorescent substance;

a second imaging means, incorporated in said endoscope, for imaging light with wavelengths in the visible spectrum;

a control means for controlling an output level of said first imaging means on the basis of an output signal of said second imaging means, said control means includes a gain control means for controlling a gain to be provided by an amplifying means for amplifying an image signal produced by said first imaging means;

a signal processing means for processing signals output from said first and second imaging means and producing a video signal; and

a display means for displaying an image represented by said video signal.

12. An endoscope system comprising:

an endoscope having an elongated insertional part capable of being inserted into a living body;

an administering means for use in administering a fluorescent substance to an inside of said living body, said fluorescent substance emitting fluorescence with wavelengths in a first infrared spectrum that is transmitted by a living tissue more efficiently than light with wavelengths in the visible and ultraviolet spectra and that is apt to be accumulated in a lesion;

an excitation light irradiating means for irradiating excitation light to said living tissue inside said living body to which the fluorescent substance has been administered, said excitation light having wavelengths in a second infrared spectrum different from the first infrared spectrum;

a visible light irradiating means for irradiating light with wavelengths in the visible spectrum to the living tissue through said endoscope;

a first imaging means, incorporated in said endoscope, for cutting off excitation light and forming a fluorescence image using fluorescence with wavelengths in the first infrared spectrum emanating from said fluorescent substance;

a second imaging means, incorporated in said endoscope, for imaging light with wavelengths in the visible spectrum;

an image normalizing means for extracting a reference image depicted by light with wavelengths of 600 nm or longer from an image formed by said second imaging means, and normalizing a fluorescence image formed by said first imaging means relative to the reference image;

a signal processing means for processing signals output from said first and second imaging means and producing a video signal; and

a display means for displaying an image represented by said video signal.

13. An endoscope system comprising:

an endoscope having an elongated insertional part capable of being inserted into a living body;

an administering means for use in administering a fluorescent substance to an inside of said living body, said fluorescent substance emitting fluorescence with wavelengths in a first infrared spectrum that is transmitted by a living tissue more efficiently than light with wavelengths in the visible and ultraviolet spectra and that is apt to be accumulated in a lesion;

an excitation light irradiating means for irradiating excitation light to said living tissue inside said living body to which the fluorescent substance has been administered, said excitation light having wavelengths in a second infrared spectrum different from the first infrared spectrum;

a visible light irradiating means for irradiating light with wavelengths in the visible spectrum to the living tissue through said endoscope;

a first imaging means, incorporated in said endoscope, for cutting off excitation light and forming a fluorescence image using fluorescence with wavelengths in the first infrared spectrum emanating from said fluorescent substance;

a second imaging means, incorporated in said endoscope, for imaging light with wavelengths in the visible spectrum;

a signal processing means for processing signals output from said first and second imaging means and producing a video signal;

a display means for displaying an image represented by said video signal;

a marker producing means for producing markers to be displayed at positions on said display means which are determined on the basis of the luminance levels of a fluorescence image formed by said first imaging means and associated with regions concerned; and

an image superimposing means for superimposing the markers on a visible light image formed by said second imaging means.

14. An endoscope system comprising:

an endoscope having an elongated insertional part capable of being inserted into a living body;

an administering means for use in administering a fluorescent substance to an inside of said living body, said fluorescent substance emitting fluorescence with wavelengths in a first infrared spectrum that is transmitted by a living tissue more efficiently than light with wavelengths in the visible and ultraviolet spectra and that is apt to be accumulated in a lesion;

an excitation light irradiating means for irradiating excitation light to said living tissue inside said living body to which the fluorescent substance has been administered, said excitation light having wavelengths in a second infrared spectrum different from the first infrared spectrum;

a visible light irradiating means for irradiating light with wavelengths in the visible spectrum to the living tissue through said endoscope;

a first imaging means, incorporated in said endoscope, for cutting off excitation light and forming a fluorescence image using fluorescence with wavelengths in the first infrared spectrum emanating from said fluorescent substance;

a second imaging means, incorporated in said endoscope, for imaging light with wavelengths in the visible spectrum;

a signal processing means for processing signals output from said first and second imaging means and producing a video signal;

a display means for displaying an image represented by said video signal, wherein at least one color is assigned to said fluorescence image formed by said first imaging means, at least one color is assigned to a visible light image formed by said second imaging means, and wherein the images are displayed on said display means.

15. An endoscope system comprising:

an endoscope having an elongated insertion part capable of being inserted into a living body;

an administering means for use in administering a fluorescent substance to an inside of said living body, said fluorescent substance emitting florescence with wavelengths in a first infrared spectrum that is transmitted by a living tissue more efficiently than light with wavelengths in the visible and ultraviolet spectra and that is apt to be accumulated in a lesion;

an excitation light irradiating means for irradiating excitation light to said living tissue inside said living body to which the fluorescent substance has been administered said excitation light having wavelengths in a second infrared spectrum different from the first infrared spectrum;

a visible light irradiating means for irradiating light with wavelengths in the visible spectrum to said living tissue;

an imaging device having a first imaging means, incorporated in said endoscope, for cutting off said excitation light and forming a fluorescence image using fluorescence with wavelengths in the first infrared spectrum emanating from said fluorescent substance and having a second imaging means, incorporated in said endoscope, for forming a visible light image using light with wavelengths in the visible spectrum;

a diaphragm means inserted to an optical path linking said living tissue and said imaging device, wherein said diaphragm means having a visible light transmission area of a first predetermined size for transmitting visible light and having a visible light non-transmission area of a second predetermined size that does not transmit visible light but transmits light with wavelengths in said first infrared spectrum said second predetermined size being larger than said first predetermined size;

a signal processing means for processing signals output from said imaging device and for producing a video signal; and

a display means for displaying an image represented by said video signal.

16. An endoscope system comprising:

an endoscope having an elongated insertional part capable of being inserted into a living body;

an administering means for use in administering a fluorescent substance to an inside of said living body, said fluorescent substance emitting fluorescence with wavelengths in a first infrared spectrum that is transmitted by a living tissue more efficiently than light with wavelengths in the visible and ultraviolet spectra and that is apt to be accumulated in a lesion;

an excitation light irradiating means for irradiating excitation light to said living tissue inside said living body to which the fluorescent substance has been administered, said excitation light having wavelengths in a second infrared spectrum different from the first infrared spectrum;

a visible light irradiating means for irradiating light with wavelengths in the visible spectrum to the living tissue through said endoscope;

a first imaging means, incorporated in said endoscope, for cutting off excitation light and forming a fluorescence image using fluorescence with wavelengths in the first infrared spectrum emanating from said fluorescent substance;

a second imaging means, incorporated in said endoscope, for imaging light with wavelengths in the visible spectrum;

a signal processing means for processing signals output from said first and second imaging means and producing a video signal wherein an image signal representing a fluorescence image formed by said first imaging means and an image signal representing a visible light image formed by said second imaging means are switched and then input to said signal processing means, and wherein said signal processing means controls the gain of an image signal synchronously with the switching of the inputted fluorescence image and visible light image; and

a display means for displaying an image represented by said video signal.

17. An endoscope system comprising:

an endoscope having an elongated insertion part capable of being inserted into a living body;

an administering means for use in administering a fluorescent substance, which emits fluorescence with wavelengths in a first infrared spectrum to be transmitted by a living tissue more efficiently than light with wavelengths in the visible and ultraviolet spectra, and which is apt to be accumulated in a lesion, to the inside of a living body;

an excitation light irradiating means for irradiating excitation light with wavelengths in a second infrared spectrum longer than the visible spectrum and shorter than the first infrared spectrum to the living tissue inside the living body to which the fluorescent substance has been administered;

a visible light irradiating means for irradiating light with wavelengths in the visible spectrum to the living tissue through said endoscope;

a first imaging means, incorporated in said endoscope, for cutting off excitation light with wavelengths in the second infrared spectrum and forming a fluorescence image using fluorescence with wavelengths in the first infrared spectrum emanating from said fluorescent substance;

a second imaging means, incorporated as an imaging device common to said first imaging means in said endoscope, for imaging light with wavelengths in the visible spectrum;

a signal processing means for processing signals output from said first and second imaging means and producing a video signal;

a display means for displaying an image represented by the video signal;

a switching means for switching excitation light and visible light and irradiating selected light to the living tissue; and

a variable diaphragm means inserted to an optical path linking the living tissue and said imaging device, wherein an amount of light to be passed by said variable diaphragm means is controlled according to the switching.

18. An endoscope system comprising:

an endoscope having an elongated insertion part capable of being inserted into a living body;

an administering means for use in administering a fluorescent substance, which emits fluorescence with wavelengths in a first infrared spectrum to be transmitted by a living tissue more efficiently than light with wavelengths in the visible and ultraviolet spectra, and which is apt to be accumulated in a lesion, to the inside of a living body;

an excitation light irradiating means for irradiating excitation light with wavelengths in a second infrared spectrum longer than the visible spectrum and shorter than the first infrared spectrum to the living tissue inside the living body to which the fluorescent substance has been administered;

a visible light irradiating means for irradiating light with wavelengths in the visible spectrum to the living tissue through said endoscope;

a first imaging means, incorporated in said endoscope, for cutting off excitation light with wavelengths in the second infrared spectrum and forming a fluorescence image using fluorescence with wavelengths in the first infrared spectrum emanating from said fluorescent substance;

a second imaging means, incorporated as an imaging device common to said first imaging means in said endoscope, for imaging light with wavelengths in the visible spectrum;

a signal processing means for processing signals output from said first and second imaging means and producing a video signal;

a display means for displaying an image represented by the video signal;

a switching means for switching excitation light and visible light and irradiating selected light to the living tissue; and

an integrating means for integrating a current level of an image signal produced by said imaging device and a level thereof attained during an immediately preceding frame, wherein the integration is controlled according to the switching.

19. An endoscope system comprising:

an endoscope having an elongated insertional part capable of being inserted into a living body;

an administering means for use in administering a fluorescent substance to an inside of said living body, said fluorescent substance emitting fluorescence with wavelengths in a first infrared spectrum that is transmitted by a living tissue more efficiently than light with wavelengths in the visible and ultraviolet spectra and that is apt to be accumulated in a lesion;

an excitation light irradiating means for irradiating excitation light to said living tissue inside said living body to which the fluorescent substance has been administered, said excitation light having wavelengths in a second infrared spectrum different from the first infrared spectrum;

a visible light irradiating means for irradiating light with wavelengths in the visible spectrum to the living tissue through said endoscope;

a first imaging means, incorporated in said endoscope, for cutting off excitation light and forming a fluorescence image using fluorescence with wavelengths in the first infrared spectrum emanating from said fluorescent substance;

a second imaging means, incorporated in said endoscope, for imaging light with wavelengths in the visible spectrum, wherein said first imaging means and second imaging means share a common imaging device;

a switching means for switching said excitation light and said visible light and irradiating selected light to the living tissue, wherein control is provided so that;

when an image signal representing a fluorescence image is output from said imaging device according to switching by said switching means, said image signal is passed to a first filter circuit for smoothening; and

when an image signal representing a visible light image is output from said imaging device, the image signal is passed to a second filter circuit for contour enhancement;

a signal processing means for processing signals output from said first and second imaging means and producing a video signal; and

a display means for displaying an image represented by said video signal.

20. An endoscope system comprising:

an endoscope having an elongated insertional part capable of being inserted into a living body;

an administering means for use in administering a fluorescent substance to an inside of said living body, said fluorescent substance emitting fluorescence with wavelengths in a first infrared spectrum that is transmitted by a living tissue more efficiently than light with wavelengths in the visible and ultraviolet spectra and that is apt to be accumulated in a lesion;

an excitation light irradiating means for irradiating excitation light to said living tissue inside said living body to which the fluorescent substance has been administered, said excitation light having wavelengths in a second infrared spectrum different from the first infrared spectrum;

a visible light irradiating means for irradiating light with wavelengths in the visible spectrum to the living tissue through said endoscope,

wherein said excitation light irradiating means and visible light irradiating means irradiate light output from a lamp, which glows in a spectrum including the first infrared spectrum and visible spectrum, as color sequential light to the living tissue, said excitation light irradiating means and said visible light irradiating means including;

a first filter and second filter for transmitting light with wavelengths in two spectra within the visible spectrum, and a third filter for transmitting excitation light with wavelengths in one spectrum different from the two spectra within the visible spectrum and in the first infrared spectrum, said first, second and third filters being arranged successively on an optical path;

a first imaging means, incorporated in said endoscope, for cutting off excitation light and forming a fluorescence image using fluorescence with wavelengths in the first infrared spectrum emanating from said fluorescent substance;

a second imaging means, incorporated in said endoscope, for imaging light with wavelengths in the visible spectrum, wherein said first imaging means and second imaging means share a common imaging device;

a signal processing means for processing signals output from said first and second imaging means and producing a video signal; and

a display means for displaying an image represented by said video signal.

21. An endoscope system according to claim 20, wherein said signal processing means produces a video signal representing a fluorescence image during one frame required for production of a video signal representing a color image of one frame under irradiation of color sequential light.

22. An endoscope system comprising:

an endoscope having an elongated insertion part capable of being inserted into a living body;

an administering means for use in administering a fluorescent substance, which emits fluorescence with wavelengths in a first infrared spectrum to be transmitted by a living tissue more efficiently than light with wavelengths in the visible and ultraviolet spectra, and which is apt to be accumulated in a lesion, to the inside of a living body;

an excitation light irradiating means for irradiating excitation light with wavelengths in a second infrared spectrum longer than the visible spectrum and shorter than the first infrared spectrum to the living tissue inside the living body to which the fluorescent substance has been administered;

a visible light irradiating means for irradiating light with wavelengths in the visible spectrum to the living tissue through said endoscope;

a first imaging means, incorporated in said endoscope, for cutting off excitation light with wavelengths in the second infrared spectrum and forming a fluorescence image using fluorescence with wavelengths in the first infrared spectrum emanating from said fluorescent substance;

a second imaging means, incorporated as an imaging device common to said first imaging means in said endoscope, for imaging light with wavelengths in the visible spectrum;

a signal processing means for processing signals output from said first and second imaging means and producing a video signal; and

a display means for displaying an image represented by the video signal, wherein the excitation light and visible light are irradiated simultaneously to the living tissue.

23. An endoscope system according to claim 22, wherein said first and second imaging means simultaneously produce a fluorescence image and a visible light image depicted by light with wavelengths in the visible spectrum.

24. An endoscope system comprising:

an endoscope having an elongated insertion part capable of being inserted into a living body;

a light source for irradiating illumination light containing excitation light with wavelengths in a first infrared spectrum which causes a fluorescent substance administered to a living tissue to fluoresce;

a first imaging means for producing a fluorescence image depicted by light with wavelengths in a second infrared spectrum different from the first infrared spectrum;

a second imaging means for forming a reflected light image using reflected excitation light stemming from the living tissue; and

a display means for displaying the fluorescence image and reflected light image formed by said first and second imaging means while superimposing the fluorescence image on the reflected light image.

25. An endoscope system comprising:

an endoscope having an elongated insertion part capable of being inserted into a living body;

a light source for irradiating illumination light containing excitation light with wavelengths in a first infrared spectrum which causes a fluorescent substance administered to a living tissue to fluoresce;

a first imaging means for producing a fluorescence image depicted by light with wavelengths in a second infrared spectrum different from the first infrared spectrum;

a second imaging means for forming a reflected light image depicted by reflecting light of the illumination light stemming from the living tissue; and

a display means for displaying the fluorescence image and reflected light image formed by said first and second imaging means while superimposing the fluorescence image on the reflected light image, wherein said second imaging means forms the reflected light image simultaneously with a fluorescence image formed by said first imaging means.

26. An endoscope system comprising:

an endoscope having an elongated insertion part capable of being inserted into a living body;

an administering means for use in administering a fluorescent substance, which emits fluorescence with wavelengths in a first infrared spectrum to be transmitted by a living tissue more efficiently than light with wavelengths in the visible and ultraviolet spectra, and which is apt to be accumulated in a lesion, to the inside of a living body;

an excitation light irradiating means for irradiating excitation light with wavelengths in a second infrared spectrum longer than the visible spectrum and shorter than the first infrared spectrum to the living tissue inside the living body to which the fluorescent substance has been administered;

a visible light irradiating means for irradiating light with wavelengths in the visible spectrum to the living tissue through said endoscope;

a first imaging means, incorporated in said endoscope, for forming a fluorescence image using fluorescence with wavelengths in the first infrared spectrum emanating from said fluorescent substance via a filter for cutting of the excitation light with wavelengths in the second spectrum;

a second imaging means, incorporated as an imaging device common to said first imaging means for imaging light with wavelengths in the visible spectrum via said filter;

a signal processing means for processing signals output from said first and second imaging means and producing a video signal; and

a display means for displaying an image represented by the video signal.