Patent Application
20110164249
The present application claims priority from Japanese Application No. 2009-252959, filed on Nov. 4, 2009, the content of which is incorporated herein by reference.
The present invention relates to a method for obtaining spectroscopic data from an object and displaying or analyzing a form or function within or surface of the object from the obtained data.
For example, Japanese Unexamined Patent Application Publication No. 1998-309282 discloses a fluorescence observation device which performs accurate tissue characterization by using intensity of autofluorescence of the tissue. In this fluorescence observation device, a dark image, caused by extracting specific range of wavelengths, is brightened by extracting a certain wavelength range by means of a band pass filter dispersing fluorescence from a biological body and an image intensifier for amplifying a fluorescent image.
In spectrometry of a biological body such as autofluorescence observation, it is a problem that intensity of a detected signal may be weaken due to extraction of a certain wavelength range. Therefore, it is difficult to narrow a wavelength range of extraction in order to improve a contrast of an image or a possibility of selecting fluorescence materials. The above problem with respect to the detection signal can be solved by amplifying light to improve S/N ratio. However, in the fluorescence observation device disclosed in JP 1998309282A, it is not possible to obtain an image with good S/N ratio due to additive noise caused by the amplification of the fluorescence image using the image intensifier in an electron amplification process. Moreover, it is not possible to obtain an image with good N/S ratio without using a filter with high extinction factor, since the wavelength range is extracted only by a band pass filter. In view of this point, a method for amplifying signal intensity while suppressing deterioration of the spectroscopic data is provided according to the invention.
The first aspect of the invention of a method for detecting optical spectrum, which achieves the object described above, is characterized in that the optical spectrum of a light irradiated on an object, a spontaneous light emitted from within the object or a surface thereof, a scattered light, a transmitted light, a reflected light or a refracted light from within the object or a surface thereof generated by irradiating light on the object are resolved by amplifying said lights in a bandwidth narrower than the bandwidth of optical spectrum of said lights.
The second aspect of the invention of the method for detecting optical spectrum is characterized in that the object is irradiated with the light amplified in the bandwidth narrower than the bandwidth of the optical spectrum of a light source; and the optical spectrum of the scattered light, the transmitted light, the reflected light or the refracted light from within the object or the surface thereof generated by irradiating light on the object is resolved and detected at a photoelectric converter.
The third aspect of the invention of the method for detecting optical spectrum is characterized in that the light spectrum of the scattered light, the transmitted light, the reflected light or the refracted light from within the object or the surface thereof generated by irradiating light on the object is resolved by amplifying said lights in a bandwidth narrower than the bandwidth of the optical spectrum of said lights and detected at the photoelectric converter.
The fourth aspect of the invention of the method for detecting optical spectrum is characterized in that the light spectrum of the spontaneous light irradiated from within the object or a surface thereof is resolved by amplifying said light in the bandwidth narrower than bandwidth of the optical spectrum of said light and detected at the photoelectric converter.
The fifth aspect of the invention of the method for detecting optical spectrum is characterized in that the object is irradiated with the light amplified in the bandwidth narrower than the bandwidth of the optical spectrum of a light source; and the optical spectrum of the scattered light, the transmitted light, the reflected light or the refracted light from within the object or the surface thereof generated by irradiating light on the object is resolved by amplifying said lights in the bandwidth narrower than the bandwidth of the optical spectrum of said lights and detected at a photoelectric converter.
The sixth aspect of the invention of the method for detecting optical spectrum is characterized in that the light spectrum of the scattered light, the transmitted light, the reflected light or the refracted light from within the object or the surface thereof generated by irradiating light on the object is resolved by extracting a wavelength of said lights by means of a filter and detected at a photoelectric converter.
The seventh aspect of the invention of the method for detecting optical spectrum is characterized in that a wavelength of the light from the light source is extracted by the filter and the light with the extracted wavelength is irradiated on the object.
The eighth aspect of the invention of the method for detecting optical spectrum is characterized in that the wavelength of the amplified light is extracted by means of a filter and the light with the extracted wavelength is irradiated on the object or detected at the photoelectric converter.
The ninth aspect of the invention of the method for detecting optical spectrum is characterized in that the light irradiated on the object, the spontaneous light emitted from within the object or the surface thereof, the scattered light, the transmitted light, the reflected light or the refracted light from within the object or the surface thereof generated by irradiating light on the object is amplified after adjusting a mode.
According to the first aspect of the invention of a method for detecting optical spectrum, the optical spectrum of a light irradiated on the object, a spontaneous light emitted from within the object or a surface thereof, a scattered light, a transmitted light, a reflected light or a refracted light from within the object or a surface thereof generated by irradiating light on the object are resolved by amplifying said lights in a bandwidth narrower than the bandwidth of optical spectrum of said lights, so that even a light with weak intensity due to the narrowed bandwidth can be amplified and detected rapidly with low noise.
According to the second aspect of the invention of the method for detecting optical spectrum, the object is irradiated with the light amplified in the bandwidth narrower than the bandwidth of the optical spectrum of a light source; and the optical spectrum of the scattered light, the transmitted light, the reflected light or the refracted light from within the object or the surface thereof generated by irradiating light on the object is resolved and detected at a photoelectric converter, so that even a light with weak intensity due to the narrowed bandwidth can be amplified and a light source with a narrow bandwidth with enough intensity can be realized.
According to the third aspect of the invention of the method for detecting optical spectrum, that the light spectrum of the scattered light, the transmitted light, the reflected light or the refracted light from within the object or the surface thereof generated by irradiating light on the object is resolved by amplifying said lights in a bandwidth narrower than the bandwidth of the optical spectrum of said lights and detected at the photoelectric converter, so that even a light with weak intensity due to the narrowed bandwidth can be amplified and the light can detected rapidly with low noise relative to a case of using only a photoelectric converter.
According to the fourth aspect of the invention of the method for detecting optical spectrum, the light spectrum of the spontaneous light irradiated from within the object or a surface thereof is resolved by amplifying said light in the bandwidth narrower than the bandwidth of the optical spectrum of said light and detected at the photoelectric converter, so that even a light with weak intensity due to the narrowed bandwidth can be amplified and a luminescence of a biological body and the like can be detected rapidly with low noise.
According to the fifth aspect of the invention of the method for detecting optical spectrum, the object is irradiated with the light amplified in the bandwidth narrower than the bandwidth of the optical spectrum of a light source; and the optical spectrum of the scattered light, the transmitted light, the reflected light or the refracted light from within the object or the surface thereof generated by irradiating light on the object is resolved by amplifying said lights in the bandwidth narrower than the bandwidth of the optical spectrum of said lights and detected at a photoelectric converter, so that amplification effect of the light with weak intensity due to the narrowed bandwidth is further improved and the decrease of the intensity of the light to be detected is suppressed.
According to the sixth aspect of the invention of the method for detecting optical spectrum, the light spectrum of the scattered light, the transmitted light, the reflected light or the refracted light from within the object or the surface thereof generated by irradiating light on the object is resolved by extracting a wavelength of said lights by means of a filter and detected at a photoelectric converter, so that the optical spectrum can be detected with high wavelength resolution.
According to the seventh aspect of the invention of the method for detecting optical spectrum, a wavelength of the light from the light source is extracted by the filter and the light with the extracted wavelength is irradiated on the object, so that the light having a spectrum except for the wavelength range of the light to be detected is not detected, and thus the light can be detected with low noise.
According to the eighth aspect of the invention of the method for detecting optical spectrum, the wavelength of the amplified light is extracted by means of a filter and the light with the extracted wavelength is irradiated on the object or detected at the photoelectric converter, so that noisy light such as ASE generated by amplifying light can be blocked, and thus the light can be detected with low noise.
According to the ninth aspect of the invention of the method for detecting optical spectrum, the light irradiated on the object, the spontaneous light emitted from within the object or the surface thereof, the scattered light, the transmitted light, the reflected light or the refracted light from within the object or the surface thereof generated by irradiating light on the object is amplified after adjusting a mode, so that even a light detected with scattering or a disturbed waveform can be collected with high efficiency, and thus the light can be detected rapidly with high sensitivity.
Embodiments of the present invention will be now described with reference to the accompanying drawings.
The first embodiment: Referring to
Configuration: As shown in
An excitation light source 12 and a frame sequential filter 13 are integrated into the light source device 2. The excitation light source 12 is connected to a light source driver unit 11 and is driven by electric current generated at the light source driver unit 11. The light guide 16, the illumination lens 17, the objective lens 18 and the image guide 19 are integrated into the insertion unit 3. The insertion unit 3 is also detachably coupled to the light source device 2 and the optical detection device 4. An optical amplification unit 21 and a photoelectric converter 23 are integrated into the optical detection device 4. The frame sequential filter 13 is fixed to a filter driver unit 14 and rotated in accordance with the movement thereof. The optical amplification unit 21 is fixed to a driver unit 22 for optical amplification unit and rotated in accordance with the movement thereof.
A photoelectric converter 23 is connected to a driver unit 24 for the photoelectric converter and is driven by electric current generated at the driver unit 24. The image generator unit 5 is connected to the photoelectric converter 23 and converts an electric signal generated at the photoelectric converter 23 into an image signal by image processing. A not shown image memory for storing a series of obtained image signals is also integrated into the image generator unit 5. The image display unit 6 is connected to the image generator unit 5 and displays the image signal generated at the image generator unit 5.
The image generator unit 5, the image display unit 6, the light source driver unit 11, the filter driver unit 14, the driver unit 22 for the optical amplification unit and the driver unit 24 for the photoelectric converter are connected to the control unit 7 and are operationally controlled by the electric signals generated at the control unit 7.
Now, the light source device 2 is described in detail. The light source device 2 comprises the excitation light source 12, the frame sequential filter 13 and the frame sequential filter driver unit 14 and a condenser lens 15.
The excitation light source 12 generates excitation light by a xenon lamp, a halogen lamp, an LED, and LD (semiconductor laser) and the like. The excitation light source 12 is also coupled to the light source driver unit 11 which is connected to the control unit 7 and controls electric current, temperature, output light intensity and illumination duration by means of driving signals generated at the control unit 7. The frame sequential filter 13 is inserted between the excitation light source 12 and the condenser lens 15, and rotatably fixed to a rotational axis of the frame sequential filter driver unit 14 and controlled the rotation thereof at a predetermined speed by the control unit 7. The condenser lens 15 images the excitation light from the excitation light source 12 on a rear end face of the light guide 16 of the insertion unit 3.
As shown in
As shown in
Now, the insertion unit 3 is described in detail. The insertion unit 3 has an elongate shape to be inserted into a body cavity of a patient. The insertion unit 3 comprises a light guide 16, an illumination lens 17, objective lens 18 and an image guide 19. The insertion unit 3 is flexibly formed for a digestive tract, a bronchial tube, head and neck (throat) and a bladder and rigidly formed for an abdominal cavity, a chest cavity and a uterus.
The light guide 16 guides the excitation light from the light source device 2 to a tip of the insertion unit 3. The illumination lens 17 is mounted on the tip of the insertion unit 3 and arranged on the end face of the light guide 16. The excitation light guided from the light source device 2 by the light guide 16 is irradiated on the object via the illumination lens 15. The objective lens 18 images the light from the object onto the tip of the image guide 19. The image guide 19 guides the light imaged by the objective lens 18 to an optical detection device 4.
Now, the optical detection device 4 is described in detail. The optical detection device 4 comprises a collective lens 20, an optical amplification unit 21, a driver unit 22 for the optical amplification unit 21 and a photoelectric converter 23.
The collective lens 20 images the light coming from the object and transmitted the insertion unit 3 into the photoelectric converter 23. The optical amplification unit 21 is inserted between the collective lens 20 and the photoelectric converter 23 and rotatably fixed to a rotational axis of the driver unit 22 for the optical amplification unit 21 and controlled the rotation at a predetermined speed by the control unit 7. The photoelectric converter 23 converts the light intensity of a CCD, CMOS, PD, APD, PTM and the like arranged in an imaging position of the collective lens 20 into an electric signal. The photoelectric converter 23 is arranged in a vertical viewing position in
As shown in
As shown in
As shown in
As shown in
Now, usage of the endoscope device 1 according to the first embodiment is described.
When endoscopy is started, a surgeon connects an insertion unit 3 of a type corresponding to an observation part, out of a plurality of endoscopes with the light source device 2 and the optical detection device 4. Thereby, various data with respect to the insertion unit 3 contained in the image generator unit 5 is read by the control unit 7. Then, the frame sequential filter 13 and the optical amplification unit 21 to be used, having a respective wavelength for the normal light mode and a specific light mode (fluorescence observation) in accordance with the type of insertion unit, which is one of various data, are determined and correction setting for light detection, conversion and reading of the photoelectric conversion unit 23 is adjusted.
Now, effects of the normal light mode and the specific light mode (fluorescence observation) are described.
A surgeon inserts the insertion unit 3 into a body cavity of a patient such as bronchial tube, digestive tract, stomach, large intestine, abdominal cavity, bladder and uterus and the like for observation.
If the normal light observation (normal light mode) is performed, the frame sequential filter 13 is arranged on the illumination light path with the first filter set 30. The excitation light excited from the excitation light source 12 is transmitted by the filter set 30, resulting in the light of R(red), G(green) and B(blue) of the illumination light of the frame sequential filter being irradiated on the object, in this case, the vital tissue, from the illumination lens 17 via the light guide 16 of the insertion unit 3 in time series. If the normal light observation is performed, the optical amplification unit 21 is arranged to adjust the aperture set 32 on the light path from the object. The light is sequentially irradiated on the object in time series and the light coming from the object pass through aperture set 32 in the optical amplifier 21, so that the light from the object is incident on the photoelectric converter in a sequence of R(red), G(green), B(blue) in time series. The driver unit 24 for the photoelectric converter controls each exposure duration and the charge storage time of the reflected light from R, G, B at the photoelectric conversion 23 based on a synchronous signal of R, G, B in the normal light mode, which is input from the control unit 7.
If the fluorescence observation (specific light mode) is performed, the surgeon selects the specific light mode (for fluorescence observation) by switching from the normal light mode by means of an observation mode switching means. Following the selection of the mode, the second filter set 31 of the frame sequential filter 13 is arranged on the illumination light path by the frame sequential filter switching means. Further, following the selection of the mode, the optical amplifier set 33 of the optical amplifier unit 21 is arranged on the light path of the light coming from the object by the optical amplifier switching unit 21. The excitation light irradiated from the excitation light source 12 is transmitted by the filter set 31, resulting in the frame sequential illumination lights corresponding to EX1, EX2, EX3 being irradiated on the vital tissue in time series via the illumination lens 17 through light guide 16 of the insertion unit 3. The frame sequential illumination light is irradiated on the object in a sequence of EX1, EX2, EX3 during the fluorescence observation so that fluorescence having spectral characteristics of FL1, FL2, FL3 is accordingly generated from the object. For the fluorescence observation, the optical amplifier set 33 of the optical amplifier unit 21 is arranged on the light path from the object. The fluorescence FL1, FL2, FL3 from the object is incident on the optical amplifier set 33 of the optical amplifier unit 21 and is transmitted by the optical amplifiers 33A, 33B, 33C, respectively, so that the fluorescence from each object is amplified in a sequence of a narrow wavelength range FLA, FLB, FLC extracted from the wavelength range of incident fluorescence FL1, FL2, FL3 corresponding to the spectral property of the optical amplifiers 33A, 33B, 33C, and is sequentially incident on the photoelectric converter 23. The intensity of the autofluorescence is very weak relative to the intensity of the reflected light and the intensity ratio of the fluorescence and the reflected light is different depending on the parts of the object. The control unit 7 changes the intensity ratio of the fluorescence and the reflected light, which is different depending on the part of the object and the wavelength, as well as the light intensity of the excitation light source and the gain of the optical amplifier unit 21 to an adequate value, so that the display of the image display 6 unit is kept constant. The reflected light of the excitation light itself due to the irradiation of the excitation light onto the object (for example, EX1) and the autofluorescence (for example FL1) emitted from the object due to the excitation light are incident on the optical amplification unit 21. However, the excitation light itself (for example EX1) is cut by the dichroic mirror 41 and only the autofluorescence (for example FLA) amplified by the optical amplification unit 21 is incident on the light detection surface of the photoelectric converter 23. The mode adjustment means is arranged on the optical amplification unit 21 to modulate the optical amplification unit 21 in such a manner that the optical amplification unit 21 allows the multi-mode fluorescence to be incident on an incident side of the mode adjustment means and the energy distribution mode with high consistency substantially corresponding to amplifying spatial mode of the optical amplifiers 30A, 33B, 33C can be achieved downstream of the optical amplifier unit 21 on an exit side. Thus, the light from the object can be collected at high efficiency even though it is fluorescence. Therefore, the optical amplification unit 21 can amplify the fluorescence FL1, FL2, FL3 from the object with low loss.
The fluorescence and the reflected light from the object are sequentially incident on the photoelectric converter 23. The output signal corresponding to each wavelength from the photoelectric converter 23 is input into the image generation unit 5 in which signal processing and memorizing are performed and the fluorescence image is displayed at the image display unit 6 and a peripheral device such as a personal computer. A white balance adjustment at imaging of the fluorescence and the reflected light, a conversion of a setting value in the observation mode and a color conversion process and the like are performed at the image generation unit 5.
The autofluorescence having a peak in a green range can be obtained when the excitation light in a blue range is irradiated on the mucosa, and a characteristic that the intensity strength of the autofluorescence in an affected region is smaller than that of the normal region is used for the fluorescence observation. Furthermore, by means of the effect of blood, i.e., hemoglobin absorption wavelength band capturing a green reflected light and a red reflected light as reference light (a wavelength range unaffected by the blood), a composite image that can be obtained by imaging a part of the observation object is an image, in which the presence of an affected region without the influence of the inflammation (blood) can be acutely detected. For example, inflammation or hyperplasia is displayed with the same color as normal tissues and a part of adenoma or cancer is displayed with a different color from that of normal tissues. Thus, finding the affected neoplastic region is easier relative to the normal observation.
According to the first embodiment, overlapping of the wavelength ranges of the fluorescence from a plurality of objects can be avoided by the optical amplification unit 21, so that the difference of various autofluorescent materials in a fluorescent image can be imaged. Moreover, the intensity of fluorescence decreased by the extraction of the wavelength can be optically amplified with a good S/N ratio, so that presence of affected region can be acutely detected with less noise such as roughness and adequate lightness even though imaging with high sensitivity is performed.
The second embodiment:
In the description of the second embodiment of the invention shown in
Configuration: as shown in
The excitation light source 12 generates white excitation light by xenon lamp, halogen lamp, LED, LD (semiconductor laser) and the like. The excitation light filter 25 is a filter having a spectral property EX4 in the fluorescence observation mode and is interposed between the excitation light source 12 and the condenser lens 15. The excitation filter 25 is selectively moved onto the optical axis of the illumination light connecting the excitation light source 12 and the rear end face of the light guide 16 by a not shown switching mechanism for the excitation light filter. The excitation filter 25 is arranged outside of the illumination light path from the excitation light source 12 in the normal observation mode, and is arranged on the light path in the fluorescence observation mode. The excitation filter 25 can be a light amplifier.
In the fluorescence observation mode, the fluorescence FL4, FL5 from the object having a different wavelength range exits from the image guide 19 and is incident on the optical detection device 4B, and thereafter incident on the optical amplifier 33D. The optical amplifier 33D has a spectral property of amplifying the light intensity in the wavelength range of the fluorescence FL4 from the object and reflecting the light in the wavelength range of fluorescence FL5 from the object having a wavelength range different from the excitation light EX4 reflected on the object and the fluorescence FL4 from the object. The optical detection device 23A detects only the fluorescence FL4 coming from the object and amplified after transmitting the optical amplifier 33D. The band path filter 26A has a spectral property of transmitting the light in the wavelength range of fluorescence FL5 from the object. The optical amplifier 33E has a spectral property of amplifying the light intensity in the wavelength range of the fluorescence FL5 from the object. The optical detection device 23D detects only the fluorescence FL5 coming from the object and amplified after transmitting the optical amplifier 33E.
In the normal observation mode, the white detection light from the object exits from the image guide 19 and is incident on the optical detection device 4B, and thereafter it is incident on the optical amplifier 33D. The optical amplifier 33D has a spectral property of transmitting the light in the wavelength range of the detected light G (green) from the object and reflecting the light in the wavelength range of R (red) and B (blue). The band pass filter 26A has a spectral property of transmitting the light in the wavelength range of the detected light R (red) from the object, which is reflected at the optical amplifier 33D and reflecting the light in the wavelength range of B (blue). The optical amplifier 33E has a spectral property of reflecting the light in the wavelength range of the detected light R (red) from the object after the transmission of the band pass filter 26A. The photoelectric converters 23A, 23B, 23C detect the light G (green), B (blue), R (red) from the object, respectively.
As for the respective photoelectric converters 23A to 23 D, the band pass filter 26A and the optical amplifiers 33D, 33E, position, spectral property and the number of positioning are not limited to this.
As shown in
Now, usage of the endoscope device 100 according to the second embodiment is described. The surgeon inserts the insertion unit 3 into a body cavity of a patient for observation.
For the normal light observation, the white illumination light is irradiated on the vital tissue, which is an object, by the excitation light source 12 via the light guide 16 of the insertion unit 3. The white illumination light is irradiated on the object and the white detection light from the object is transmitted the optical amplifier 33D, the band pass filter 26A, and the optical amplifier 33E, so that the light G (green), B (blue), R(red) are incident on the photoelectric converter, respectively.
For the fluorescence observation, the excitation light having a wavelength range of the excitation light EX 4 is illuminated from the white light of the excitation light source 12 via the excitation filter 25 and irradiated on the vital tissue through the light guide 16 of the insert unit 3 and the illumination lens. Fluorescence FL4, FL 5 from the object passes the optical amplifier 33D, 33E, respectively and is extracted and amplified in a wavelength range FLB, FLC narrower than the fluorescence FL4, FL 5. Each amplified fluorescence FLB, FLC from the object is incident on the photoelectric converter.
According to the second embodiment, overlapping of the wavelength ranges of the fluorescence from a plurality of objects can be avoided by the optical amplifiers 33D, 33E, so that the difference of various autofluorescent materials in a fluorescence image can be imaged. Moreover, the intensity of fluorescence decreased by the extraction of the wavelength can be optically amplified with a good S/N ratio, so that presence of affected region can be acutely detected with less noise, such as roughness and adequate lightness and rapidly relative to the first embodiment even though imaging with high sensitivity is performed.
The third embodiment:
In the description of the third embodiment of the invention shown in
Configuration: As shown in
The objective lens 18 is mounted on the tip of the insertion unit 3C and provided on the side of the optical amplification unit 21 of the optical detection device 4C. The light from the object is imaged on the photoelectric converter 23 by the objective lens 18. The optical detection device 4C comprises the optical amplification unit 21 and the photoelectric converter 23 attached to each other and arranged on the tip of the insertion unit 3C with a surface of the optical amplification unit 21 and the objective lens 18 facing to each other. The photoelectric amplifier 23 is an element which converts the light intensity of a CCD, CMOS and the like provided in an imaging position of the objective lens 18 into an electric signal.
As shown in
As shown in
Now, usage of the endoscope device 110 according to the third embodiment is described. The surgeon inserts the insertion unit 3C into a body cavity of a patient for observation.
For the normal light observation (normal light mode), the first filter set 30 of the frame sequential filter 13 shown in
If the fluorescence observation (specific light mode) is performed, the surgeon selects the specific light mode (for fluorescence observation) by switching from the normal light mode at an observation mode switching unit. Following the selection of the mode, the second filter set 31 of the frame sequential filter 13 are arranged on the illumination light path by the frame sequential filter switching unit. The excitation light irradiated from the excitation light source 12 is transmitted by the filter set 31, resulting in the excitation light EX6, EX7 of the illumination light of the frame sequential filter being irradiated on the vital tissue in time series via the illumination lens 17 through light guide 16 of the insertion unit 3. The frame sequential illumination light is irradiated on the object in a sequence of EX6, EX7 during the fluorescence observation, so that fluorescence having a spectral property of FL6, FL7 is accordingly generated. For the fluorescence observation, the light amplification unit 21 sequentially lights up the excitation light sources 40H, 40I for the light amplifiers. Each of the light FL6, FL7 from the object is transmitted respective element of the optical amplification unit 21, so that the light from the object is extracted and amplified in time series in a wavelength range FLC, AFD narrower than the wavelength range of the incident fluorescence in accordance with the spectral property of each element of the optical amplification unit 21 and is sequentially incident on the photoelectric converter 23.
According to the third embodiment, the difference of various autofluorescent materials in the excitation light image can be imaged and the fluorescence intensity decreased by the extraction of the wavelength can be optically amplified with a good S/N ratio, so that presence of affected region can be acutely detected by mounting an relatively cheep imaging element on the tip of the endoscope instead of an expensive imaging element with high sensitivity.
The fourth embodiment:
In the description of the fourth embodiment of the invention shown in
Configuration: As shown in
Excitation light sources 12A, 12B, 12D, optical fibers 50A, 50B, 50C, 50D and optical couplers 51A, 51B are integrated into the light source device 2D. The illumination lens 17, an optical fiber 50E, an illumination scanning unit 52 and detection optical fiber 53 are integrated into the insertion unit 3D. The optical amplification units 21A, 21B, 21C, photoelectric converter 23, detection optical fibers 50F, 50G, 50H, 50I, 50J, 50K, 50L, 50M, optical couplers 51C, 51D and wavelength demultiplexer 54 are integrated into the optical detection device 4D.
Now, the light source device 2D is described in detail. Each of the excitation light sources 12A, 12B, 12C generates the excitation light consisting of LED, LD (semiconductor laser) and the like in the wavelength range of red (R), green (G), blue (B). The excitation light sources 12A, 12B, 12C are connected to the light source driver unit 11 and provided with electric current for lighting up. Furthermore, the light source driver unit 11 is connected to the control unit 7 to sequentially light up the excitation light source 12A, 12B, 12C by inputting a periodic signal from the control unit 7. Then the frame sequential illumination light of R (red), G(green), B(blue) is irradiated on the vital tissue through the illumination lens 17 via an optical scanning unit 52 of an insertion unit 3D and the like in time series. The optical fibers 50A, 50B, 50C guide the excitation light from the excitation light sources 12A, 12B, 12C to the optical couplers 51B, 51A, 51A, respectively, and the optical fiber 50D guides the excitation light from the light coupler 51A to the light coupler 51B. The optical coupler 51A outputs the excitation light of green (G) and blue (B) to the optical fiber 50D. The optical coupler 51B outputs the excitation light of green (G), blue (B), and red (R) to the rear end of the optical fiber 50E of the insertion unit 3D.
Now, the insertion unit 3D is described in detail. The optical fiber 50E guides the excitation light from the light source device 2D to the illumination scanning unit 52. The illumination scanning unit 52 comprises a light deflector such as a photoelectric element and a light deflection element such as acousto-optical element, as well as an optical fiber mechanically deformed by piezoelectric effect or electromagnetic force and the like, and deflects the excitation light from the optical fiber 50E. The illumination lens 17 is mounted on the tip of the insertion unit 3D and arranged on the side of the end face of the illumination scanning unit 52. The excitation light guided from the light source device 2 by the optical fiber 50E is deflected by the illumination scanning unit 52 and irradiated on the object via the illumination lens 17. The illumination scanning unit 52 is provided with electric current from a not shown driver unit for the illumination scanning unit and controlled thereby. The not shown illumination scanning driver unit is connected to the controller 7 and controlled by the electric signal generated at the control unit 7. Thus, the illumination scanning unit 52 scans the light irradiated on the object on the object surface by periodic drive by inputting the electric signal in a certain waveform from the control unit 7. The detection optical fiber 53 comprises a plurality of the optical fibers and is arranged from the tip to the rear end of the insertion unit 3 in the periphery of the insertion unit 3D. The detection optical fiber 53 receives the light from the object within an incident angle, which is determined by the structure and the composition of the optical fiber, from the tip of the optical fiber and guides it to the optical detection device 4D.
Now, the light source device 4D is described in detail. The optical fibers 50F, 50G, 50H guide the light of R (red), G (green), B (blue) from the wavelength demultiplexer 54 to the optical amplification units 21A, 21B, 21C, respectively; the optical fibers 50I, 50J, 50K guide the amplified light of R (red), G (green), B (blue) to the optical couplers 51C, 51C, 51D, respectively; the optical fiber 50L guides the amplified light R (red), G (green) to the optical coupler 51D; and the optical fiber 50M guides the amplified light of R (red), G (green), B (blue) to the photoelectric converter 23. The wavelength demultiplexer 54 comprises a diffraction grating and a light deflection element and the like and distributes the light incident on the detection optical fiber 53 to optical fiber 50F, 50G, 50H, respectively, depending on the wavelength range of R (red), G (green), B (blue). Furthermore, if the wavelength demultiplexer 54 comprises an active element such as a light deflection element, the wavelength demultiplexer 54 is connected to the control unit 7 and timing of the distribution of R (red), G (green), B (blue) is synchronized with the excitation light sources 12A, 12B, 12C by periodically inputting electric signals from the control unit 7. The optical coupler 51C outputs the light of R (red), G (green), B (blue) from the object to the optical fiber 50L. The optical coupler 51D outputs the light of R (red), G (green), B (blue) from the object to the optical fiber 50M. The photoelectric converter 23 is an element which converts the light intensity of PD, APD, PMT and the like into an electric signal.
As shown in
Furthermore, if an excitation light source, optical fibers, optical couplers, a wavelength demultiplexer, optical amplification unit, and a switching unit for the observation modes are provided for the fluorescence observation as in the case of the normal observation, the fluorescence observation can be performed by switching from the normal observation mode to the fluorescence observation mode.
Now, usage of the scanning endoscope device 8 according to the fourth embodiment is described. The surgeon inserts the insertion unit 3D into a body cavity of a patient for observation.
For the normal observation, frame sequential lights of R (red), G (green) and B (blue) from the excitation light source 12A, 12B, 12C are irradiated on the object, in this case, the vital tissue, through the illumination lens 17 via the illumination scanning unit 52 of the insertion unit 3 in time series. Furthermore, the frame sequential illumination light is irradiated on the object in time series, so that the lights of R (red), G (green), B (blue) from the object pass through the optical amplification unit 21A, 21B, 21C, respectively, and amplified in time series, and the amplified lights of R (red), G (green), B (blue) are sequentially incident on the photoelectric converter 23 after transmitting.
According to the fourth embodiment, the intensity of the reflected excitation light, which is decreased due to rapid illumination scanning and narrow incident angle of the detection optical fiber, is amplified at a good S/N ratio, so that an image with less noise such as roughness and adequate lightness can be achieved.
The fifth embodiment: The
In the description of the fifth embodiment of the invention shown in
Configuration: As shown in
The optical device 2E comprises an excitation light source 12D, 12E, collimator lenses 60A, 60B, mirror 61 and dichroic mirror 62A. Respective collimator lenses 60A, 60B substantially collimate the excitation light spread from the excitation light source 12D, 12E. The mirror 61 is interposed between the collimator lens 60A and the dichroic mirror 62A. The dichroic mirror 62A is disposed downstream of the collimator lens 60B at such an angle that the excitation light from the excitation light source 12D and the excitation light from the excitation light source 12E are coaxial. The dichroic mirror 62A also has a spectral property of transmitting the light in a wavelength range of the excitation light from the excitation light source 12C and reflecting the light in a wavelength range of the excitation light from the excitation light source 12E. The excitation light transmitted by and reflected at the dichroic mirror 62A exits the light source device 2E, and is incident on the dichroic mirror 62B.
The substantially parallel excitation light from the excitation light sources 12D, 12E exits the light source device 2E and is reflected at the dichroic mirror 62B and then passes the illumination scanning unit 63 and is transmitted and focused by the pupil objective lens 64. Then, the light is transmitted by the imaging lens 65 to be substantially parallel, and is subsequently transmitted by the objective lens 66 to be irradiated on a surface of the object. The illumination scanning unit 63 is supplied electric current form a not shown driver unit for an illumination scanning unit and controlled thereby. The illumination scanning unit 63 comprises a light deflector such as a photoelectric element and a light deflection element such as acousto-optical element, as well as a mirror mechanically deformed by piezoelectric effect or electromagnetic force and the like, and deflects the excitation light from the dichroic mirror 62. The not shown driver unit for an illumination scanning unit is connected to the control unit 7 and is controlled an electric signal generated at the control unit 7. Thus, the illumination scanning unit 63 is periodically driven by inputting the electric signal in any waveform from the control unit 7, so that it scans the excitation light irradiated on the object on the surface of the object. The objective lens 66 is arranged on an end of the scanning microscope device 9. The excitation light guided from the illumination light source 2 is deflected by the illumination scanning unit 63 and irradiated on the object via the objective lens 66.
The excitation light EX8 generated from the excitation light source 12D excites the fluorescent material in the object and emits fluoresce FL 8, FL9.
After the fluorescence FL8, FL9 from the object is collected at the objective lens 66 and exits as a substantially parallel light, and the light is transmitted and focused by the imaging lens 65, and the light is transmitted by the pupil objective lens 64 to be substantially parallel, and the light is subsequently transmitted by the dichroic mirror 62B and incident on the optical detection device 4E.
The optical detection device 4E comprises photoelectric converters 23E, 23F, 23G, optical amplifiers 33F, 33G, collective lenses 67A, 67B, 67C and confocal pinholes 68A, 68B, 68C. The substantially parallel fluorescence FL8, FL9 transmitted by the dichroic mirror 62B is incident on the light detection device 4E and then on the optical amplifier 33F. The optical amplifier 33F has a spectral property of amplifying the intensity of the light, extracted from the wavelength range of the fluorescence FL6 from the object, having a narrow wavelength range FLE, and reflecting the light having a wavelength range of the excitation light EX8 and the fluorescence FL9. Each of the confocal pinholes 68A, 68B, 68C has a not shown plurality of apertures with different diameter. The confocal pinholes 68A, 68B, 68C have a not shown driver unit for the confocal pinholes, the driver unit being connected to the control unit 7 (not shown), and selecting and arranging a diameter of the aperture of the confocal point by a control signal from the control unit 7. The collective lens 67A images the substantially parallel amplified fluorescence FLE onto the aperture of the confocal pinhole 68A. The confocal pinhole 68A is arranged in a conjugate position with the focusing point of the objective lens 66 and blocks scattered light and fluorescence generated around the focusing point of the objective lens 66 depending on the diameter of the aperture of the confocal pinhole. The photoelectric converter 23E detects only the amplified fluorescence FLE from the object, which has passed the aperture of the confocal pinhole 68A.
As shown in
Now, usage of the scanning microscope device 9 according to the fifth embodiment is described. A user arranges an object on the stage for observation.
For the fluorescence observation, the excitation light from the excitation light sources 12D, 12E is irradiated on the object via the illumination scanning unit 63 from the objective lens 66. Each of the fluorescence FL8 and FL9 is amplified and reflected at the optical amplifier 33F, and the amplified fluorescence FLE from the object is transmitted the confocal pinhole 68A and incident on the photoelectric converter 23E. The fluorescence FL9 from the object is also reflected at the optical amplifier 33F and amplified at the optical amplifier 33G. Then the amplified fluorescence FLF (not shown) from the object passes the confocal pinhole 68C and is incident on the photoelectric converter 23G.
According to the fifth embodiment, overlapping of the wavelength ranges of the fluorescence from a plurality of objects can be avoided by the optical amplifier 33, so that the difference of various fluorescence materials in a fluorescence image can be imaged. Furthermore, the intensity of fluorescence decreased by the extraction of the wavelength can be optically amplified with a good S/N ratio, so that presence of the fluorescent material can be acutely detected with less noise, such as roughness and adequate lightness.
The invention is not limited to the above embodiments, but many variations and modifications are possible. For example, optical amplification unit 21 and the optical amplifier 33 comprise a band pass filter 42 for extracting the light in the wavelength range narrower than the wavelength range of the detection light of the fluorescence from the object in the first to the fifth embodiments, but may also comprise the optical amplification medium 43 generating less noisy light in the wavelength range except for the wavelength range in which the light in the wavelength range narrower than that of the detection light or the fluorescence from the object are extracted and amplified. As an effect obtained from this configuration, the wavelength range of the band pass filter 42 on the exit side of the detection light or the fluorescence from the object, which is amplified at the optical amplifier 33 and the optical amplifier 42, can be broadened.
The optical amplification unit 21 and the optical amplifier 33 comprise a spectral property of having a single wavelength range of the light extracted from the detection light and the fluorescence from each object in the first to the fifth embodiments, but may comprise a spectral property allowing variable wavelength range (bandwidth) to be extracted and variable wavelength. As an effect of this configuration, it is possible to amplify the light at the optical amplifier 33 and the optical amplifier 42 by extracting a constant wavelength range of the light narrower than the detection light and the fluorescence from the object and sweeping the center wavelength of the constant wavelength range for amplifying. That is to say, it is possible to amplify the light by resolving spectrum of the detection light and the fluorescence from the object, so that a spectrometer with good wavelength resolution capacity, detection sensitivity and S/N ratio can be realized.
Furthermore, the optical amplification unit 21 and the optical amplifier 33 have a responsive property of completing rising and falling of the light amplification within a half time of the exposure duration for each frame sequential illumination light R (red), G (green), B (blue) in the normal observation in the first to the fifth embodiments. Moreover, the optical amplification unit 21 and the optical amplifier 33 have a responsive property of completing rising and falling of the light amplification within a half time of the exposure duration for each excitation lights EX 1 to EX 8 in the fluorescence observation in the first to the fifth embodiments.
While the autofluorescence is described as an example for scattering light in the above embodiment, the invention it is not limited to the autofluorescence, but can be applied for optical detection or image observation by fluorescent agent (such as fluorescent probe, fluorescent dye) which is supplied by directly splaying on the observation object by a nozzle or localized on the observation object within a body by means of drug delivery technique.
| Number | Date | Country | Kind |
|---|---|---|---|
| JP 2009-252959 | Nov 2009 | JP | national |
