Endoscope system for fluorescent observation

Abstract

An endoscope system is disclosed for detecting fluorescent light emitted in the near-infrared region by a plurality of fluorescent labeling materials introduced into a living tissue. An illumination system generates illumination light in the wavelength range 600 nm-2000 nm which serves as excitation light for the plurality of fluorescent labeling materials, and a detection system that can separately detect different ones of the plurality of fluorescent light emissions that are emitted at different wavelengths from among the plurality of fluorescent labeling materials is provided. The endoscope system may include a conventional-type endoscope having an insertion section, or a capsule endoscope that wirelessly transmits image data. By superimposing the image data obtained using reflected light in the visible region and fluorescent light emitted by the fluorescent labeling materials, improved diagnostic capabilities are provided.

1 . An endoscope system for detecting fluorescent light emitted in the near-infrared region by a plurality of fluorescent labeling materials introduced into a living tissue, comprising: 
 an endoscope that has an elongated insertion section and an eyepiece section;    an illumination system for generating illumination light that includes an excitation light for said plurality of fluorescent labeling materials;    a detection system that includes an optical element having a transmission wavelength that can be varied so as to separate fluorescent light emissions that are emitted at different wavelengths from among the plurality of fluorescent labeling materials, said optical element located in the eyepiece section; and    a controller that controls the transmission wavelength of said optical element so as to scan for different fluorescent light emissions.    
     
     
         2 . An endoscope system for detecting fluorescent light emitted in the near-infrared region by a plurality of fluorescent labeling materials introduced into a living tissue, comprising: 
 an endoscope that has an elongated insertion section;    an illumination system for generating illumination light that includes an excitation light for said plurality of fluorescent labeling materials;    a detection system that includes an optical element having a transmission wavelength that can be varied so as to separate fluorescent light emissions that are emitted at different wavelengths from among the plurality of fluorescent labeling materials, said optical element located in a distal end part of said elongated insertion section; and    a controller that controls the transmission wavelength of said optical element so as to scan for different fluorescent light emissions.    
     
     
         3 . The endoscope system according to  claim 2 , wherein said excitation light includes wavelengths in the wavelength range of 600 nm≦λ≦2000 nm.  
     
     
         4 . An endoscope system for detecting fluorescent light emitted in the near-infrared region by a plurality of fluorescent labeling materials introduced into a living tissue, comprising: 
 an endoscope having an insertion section and an eyepiece section;    an illumination system for generating illumination light that includes an excitation light for the plurality of fluorescent labeling materials;    a detection system that includes an electronic camera head adapted to be optically connected to said eyepiece section and an optical element which separates fluorescent light emissions that are emitted at different wavelengths from among the plurality of fluorescent labeling materials, said optical element located in the camera head; and    a plurality of sensors that receive the respective separated fluorescent light emissions that are emitted at different wavelengths.    
     
     
         5 . The endoscope system according to  claim 4 , wherein said excitation light includes wavelengths in the wavelength range of 600 nm≦λ≦2000 nm.  
     
     
         6 . The endoscope system according to  claim 1 , the detection system further including a filter that cuts off the excitation light.  
     
     
         7 . The endoscope system according to  claim 2 , the detection system further including a filter that cuts off the excitation light.  
     
     
         8 . The endoscope system according to  claim 2 , the detection system further including an objective optical system and a filter that cuts off the excitation light, said objective optical system and said filter located in a distal end portion of the insertion section.  
     
     
         9 . The endoscope system according to  claim 4 , the detection system further including an objective optical system and a filter that cuts off the excitation light, said objective optical system and said filter located in a distal end portion of the insertion section.  
     
     
         10 . The endoscope system according to  claim 1 , wherein said optical element is an etalon.  
     
     
         11 . The endoscope system according to  claim 2 , wherein said optical element is an etalon.  
     
     
         12 . The endoscope system according to  claim 1 , wherein: 
 the illumination system comprises a light source device that includes a plurality of wavelength selection filters that are insertable into, and removable from, an optical path of the illumination light; and    the illumination system has at least two illumination modes, namely, mode 1 and mode 2, that are selectable by inserting, and/or removing, one or more of the plurality of filters;    where    in mode 1, illumination light is emitted only within the visible region; and    in mode 2, illumination light having a wavelength component λ within the range 600 nm≦λ≦2000 nm is emitted.    
     
     
         13 . The endoscope system according to  claim 12 , wherein said optical element has its transmission wavelength varied by changing a voltage applied to said optical element only in mode  2 .  
     
     
         14 . The endoscope system according to  claim 2 , wherein: 
 the illumination system includes a light source device having a plurality of wavelength selection filters that are insertable into, and removable from, an optical path of the illumination light; and    the illumination system has at least two illumination modes, namely, mode  1  and mode  2 , that are selectable by inserting, and/or removing, one or more of the plurality of filters;    where    in mode 1, illumination light is emitted only within the visible region; and    in mode 2, illumination light having a wavelength λ component within the range 600 nm≦λ≦2000 nm is emitted.    
     
     
         15 . The endoscope system according to  claim 14 , wherein said optical element has its transmission wavelength varied by changing a voltage applied thereto only in the mode  2 .  
     
     
         16 . The endoscope system according to  claim 4 , wherein: 
 the illumination system comprises a light source device that includes a wavelength selection filter that is insertable into, and removable from, an optical path of the illumination light, said wavelength selection filter transmits or reflects, at least a part, wavelengths of illumination light in the range of approximately 600 nm-2000 nm, and    the fluorescence separation optical element is configured so as to separate the fluorescences only when a specified filter is inserted into the illumination light path.    
     
     
         17 . An endoscope system for detecting fluorescences in the near-infrared region by a plurality of fluorescent labeling materials that have previously been introduced into a living tissue, comprising: 
 an illumination system for generating illumination light that includes light for excitation of the plurality of fluorescent labeling materials, or visible light;    a detection system that includes an excitation light cut-off filter, a wavelength separation filter that separates the fluorescences emitted from the plurality of fluorescent labeling materials, and a sensor that detects sequentially each of the separated fluorescences; and    a observation system that includes an objective optical system and an image sensor for receiving an image of an object formed by the objective optical system.    
     
     
         18 . The endoscope system according to  claim 17 , wherein said excitation light includes wavelengths in the wavelength range of 600 nm≦λ2000 nm.  
     
     
         19 . The endoscope system according to  claim 17 , wherein the sensor serves as both a fluoresence detector and an image sensor.  
     
     
         20 . An endoscope system for detecting fluorescences emitted in the near-infrared region by a plurality of fluorescent labeling materials introduced in a living tissue, comprising: 
 an illumination system;    an observation system; and    a TV camera unit;    wherein    the illumination system includes a light source device which generates illumination light that includes light for excitation of the plurality of fluorescent labeling materials;    the observation system includes an objective optical system, an image transmitting optical system that transmits an image formed by the objective optical system, and an ocular optical system; and    the TV camera unit includes a coupling optical system adapted to be optically connectable to the ocular optical system for forming an image of the image transmitted by the transmission optical system, an excitation light cut-off filter, a wavelength separation filter that separates the fluorescences emitted from the plurality of fluorescent labeling materials, and an image sensor.    
     
     
         21 . The endoscope system according to  claim 20 , wherein said excitation light includes wavelengths in the wavelength range of 600 nm≦λ≦2000 nm.  
     
     
         22 . An endoscope system for detecting fluorescences emitted in the near-infrared region by a plurality of fluorescent labeling materials introduced into living tissue, comprising: 
 an illumination system;    an observation system; and    a TV camera unit;    wherein    the illumination system includes a light source device which generates illumination light that includes light for excitation of the plurality of fluorescent labeling materials;    the observation system includes an objective optical system, an image transmitting optical system that transmits an image formed by the objective optical system, and an ocular optical system that includes an excitation light cut-off filter; and    the TV camera unit includes a coupling optical system adapted to be optically connectable to the ocular optical system for forming an image of the image transmitted by the transmission optical system, a wavelength separation filter that separates the fluorescences emitted from the plurality of fluorescent labeling materials, and an image sensor.    
     
     
         23 . The endoscope system according to  claim 22 , wherein said excitation light includes wavelengths in the wavelength range of 600 nm≦λ≦2000 nm.  
     
     
         24 . An endoscope system for detecting fluorescences emitted in the near-infrared region by a plurality of fluorescent labeling materials introduced into living tissue, comprising: 
 an endoscope; and    a light source device;    wherein    the light source device generates illumination light that includes light for excitation of the plurality of fluorescent labeling materials;    the endoscope comprises an objective optical system, an image transmission optical system that transmits an image formed by the objective optical system, a coupling optical system that forms an image of the image transmitted by the transmission optical system, an image sensor, an excitation light cut-off filter, and a wavelength separation filter that separates the fluorescences emitted by the plurality of fluorescent labeling materials; and    both the excitation light cut-off filter and the wavelength separation filter are arranged between the transmission optical system and the image sensor.    
     
     
         25 . The endoscope system according to  claim 24 , wherein said excitation light includes wavelengths in the wavelength range of 600 nm≦λ≦2000 nm.  
     
     
         26 . A capsule endoscope apparatus for detecting fluorescences emitted in the near-infrared region by a plurality of fluorescent labeling materials introduced into living tissue, the capsule endoscope apparatus comprising: 
 an illumination unit that includes a red band light source, a green band light source, a blue band light source, and a near-infrared band light source; and    an imaging unit that includes an objective optical system, an excitation light cut-off filter, a transmission wavelength separation filter which separates different fluorescences emitted from different fluorescent labeling materials, and an image sensor.    
     
     
         27 . A capsule endoscope system that includes the capsule endoscope apparatus according to  claim 26 , wherein 
 the capsule endoscope apparatus further includes a transmitter; and    a receiver is provided outside the capsule endoscope apparatus for receiving an image signal transmitted by the transmitter.    
     
     
         28 . The capsule endoscope system according to  claim 27 , and further including an image display device positioned outside the capsule endoscope apparatus that displays an endoscopic image using reflected visible wavelength light and on which marks, that indicate positions where the fluorescences are emitted by the living tissue, are superimposed.  
     
     
         29 . The capsule endoscope system according to  claim 28 , wherein the displayed marks are different colors, each different color corresponding to a different fluorescent labeling material.  
     
     
         30 . An endoscope system for detecting fluorescences emitted by a plurality of different fluorescent labeling materials introduced into living tissue, comprising: 
 an illumination system; and    an observation system;    wherein    the illumination system includes illumination optics and a light source device that generates at least light for normal observation and light for excitation of the fluorescent labeling materials;    the observation system includes an objective optical system, an excitation light cut-off filter, a wavelength tunable filter, and a detector; and    the wavelength tunable filter is a tunable etalon that has an average transmittance in the visible region that enables a sufficient intensity of light to transmit through the wavelength tunable filter for normal observation, and has a narrow passband in the infrared region with the passband, as well as the passband wavelength peak, being variable in wavelength.    
     
     
         31 . An endoscope system for detecting fluorescences emitted by a plurality of fluorescent labeling materials introduced into living tissue, comprising: 
 an illumination system; and    an observation system;    wherein    the illumination system generates an excitation light for the fluorescent labeling materials;    the observation system includes an objective optical system, an excitation light cut-off filter, a wavelength tunable filter and a detector;    the tunable filter is formed as an etalon that includes a plurality of transparent substrates arranged so as to form a gap therebetween, the surfaces of the substrates that face each other across the gap have semi-transparent films, at least two of which have a spectral transmittance and the following conditions are satisfied:    T1≧80% and    T2≦35%,    where    T1 is the average transmittance in the wavelength region of 400 nm≦λ≦650 nm, and    T2 is a transmittance in the wavelength band having a lower boundary that is 50 nm shorter than the peak transmittance wavelength of the shortest fluorescence wavelength, and an upper boundary that is 50 nm longer than the peak transmittance wavelength of the longest fluorescence wavelength.    
     
     
         32 . An endoscope for detecting fluorescence emitted by a plurality of fluorescent labeling materials introduced into living tissue, comprising: 
 an illumination unit; and    an observation unit;    wherein    the illumination unit generates near-infrared illumination light that includes a wavelength band for excitation of the fluorescent labeling materials;    the observation unit includes an objective optical system, an excitation light blocking filter, a wavelength tunable filter, and a detector;    the combination of the excitation light blocking filter and the tunable filter passes light in the visible region, and has a passband in the infrared region which allows the fluorescence emitted from the fluorescent labeling material that is under observation to pass through;    wherein the spectral transmittance of said combination satisfies the following conditions:    T3≧60%    T4≦0.01%    T5≧65%    5 nm≦d5≦35 nm    where    T3 is the average transmittance within the visible wavelength range of 400 nm≦λ≦650 nm,    T4 is the transmittance for the wavelengths within a range 20 nm above and 20 nm below the wavelength range of the excitation light generated by the illumination unit,    T5 is the transmittance at the peak transmittance wavelength for an infrared passband,    d5 is the infrared passband's full width as measured at 50% of the peak transmittance, and    λ is the wavelength of light incident onto the filter.    
     
     
         33 . The endoscope system according to  claim 30 , wherein the tunable etalon includes at least three semi-transparent base substrates.  
     
     
         34 . The endoscope system according to  claim 31 , wherein the etalon includes at least three semi-transparent base substrates.  
     
     
         35 . The endoscope system according to  claim 32 , wherein the tunable filter includes at least three semi-transparent base substrates.  
     
     
         36 . The endoscope system according to  claim 1 , and further comprising an image display device that displays an endoscopic image of the living tissue on which marks, that indicate the positions on the living tissue from which fluorescences are detected, are superimposed.  
     
     
         37 . The endoscope system according to  claim 2 , and further comprising an image display device that displays an endoscopic image of the living tissue on which marks, that indicate the positions on the living tissue from which fluorescences are detected, are superimposed.  
     
     
         38 . The endoscope system according to  claim 4 , and further comprising an image display device that displays an endoscopic image of the living tissue on which marks, that indicate the positions on the living tissue from which fluorescences are detected, are superimposed.  
     
     
         39 . The endoscope system according to  claim 17 , and further comprising an image display device that displays an endoscopic image of the living tissue on which marks, that indicate the positions on the living tissue from which fluorescences are detected, are superimposed.  
     
     
         40 . The endoscope system according to  claim 20 , and further comprising an image display device that displays an endoscopic image of the living tissue on which marks, that indicate the positions on the living tissue from which fluorescences are detected, are superimposed.  
     
     
         41 . The endoscope system according to  claim 22 , and further comprising an image display device that displays an endoscopic image of the living tissue on which marks, that indicate the positions on the living tissue from which fluorescences are detected, are superimposed.  
     
     
         42 . The endoscope system according to  claim 24 , and further comprising an image display device that displays an endoscopic image of the living tissue on which marks, that indicate the positions on the living tissue from which fluorescences are detected, are superimposed.  
     
     
         43 . The endoscope according to  claim 1 , wherein said excitation light includes wavelengths in the wavelength range of 600 nm≦λ≦2000 nm.