Patent Application
20130006109
1. Field of the Invention
The present invention relates to endoscope apparatuses, and more particularly, to an endoscope apparatus suitable for submucosal dissection.
2. Description of the Related Art
Conventionally, various minimally invasive inspections and operations using an endoscope are performed in a medical field. Operators can insert an endoscope into a body cavity, observe an object, images of which are picked up by an image pickup apparatus provided at a distal end portion of an endoscope insertion portion and perform treatment on a lesioned region as required using a treatment instrument inserted in a treatment instrument channel. Surgery using an endoscope does not require abdominal operation or the like, thus having an advantage of reducing a physical burden on a patient.
An endoscope apparatus is configured by including an endoscope, an image processing apparatus connected to the endoscope and an observation monitor. An image pickup device provided at the distal end portion of the endoscope insertion portion picks up an image of the lesioned region and the image is displayed on a monitor. The operator can perform diagnosis or necessary treatment while watching the image displayed on the monitor.
Furthermore, some endoscope apparatuses are able to perform special-light observation using special light such as infrared light not only for normal observation using white color light but also for observation of blood vessels inside.
In the case of an infrared endoscope apparatus, for example, indocyanine green (ICG) having an absorption peak characteristic in near-infrared light near a wavelength of 805 nm is injected as medicine into the blood of the patient. The object is then irradiated with infrared light near a wavelength of 805 nm and near 930 nm from a light source device by time sharing. A signal of an object image picked up by a CCD is inputted to a processor of the infrared endoscope apparatus. As disclosed, for example, in Japanese Patent Application Laid-Open Publication No. 2000-41942, regarding such an infrared endoscope apparatus, there is a proposal on an apparatus whose processor assigns an image near a wavelength of 805 nm to a green color signal (G), an image near a wavelength of 930 nm to a blue color signal (B), and outputs the signals to a monitor. Since the image of infrared light near 805 nm which is more absorbed by the ICG is assigned to the green color, the operator can observe the infrared image with good contrast when ICG is administered.
Furthermore, in recent years, endoscopic submucosal dissection (ESD) using an endoscope to dissect and peel off the submucosa where a lesioned region exists has been widespread. During ESD, in order to prevent the muscularis propria located deeper than the submucosa from being mistakenly perforated or prevent a relatively thick blood vessel in the mucous membrane from being cut, the operator needs to perform treatment such as dissection while checking the positions of the submucosa and the blood vessel.
For this reason, a method of avoiding the risk of mistakenly perforating the muscularis propria may be adopted by dyeing the submucosa with an aqueous solution which is a mixture of a pigment and a physiological saline solution before ESD to make stand out the boundary between the muscularis propria and the submucosa.
An endoscope apparatus according to an aspect of the present invention is provided with an illumination section that can switch between excitation light that excites a connective tissue in a submucosa of a tissue within a body cavity, first narrow-band light absorbed by a blood vessel running through the submucosa or a muscularis propria below the submucosa, and second narrow-band light absorbed by a substance locally injected into the submucosa, and radiate the selected light, an image pickup section that picks up an image of the tissue within the body cavity irradiated by the illumination section, and an image signal generation section that generates a plurality of image signals from an image pickup signal acquired through image pickup by the image pickup section.
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
As shown in
In the following description, since the normal-light observation mode of the endoscope apparatus 1 is the same as a conventional normal-light observation mode, the configuration of the normal-light observation mode will be described briefly and the ESD mode will be described mainly.
The CCD 2 constitutes an image pickup section or image pickup means that receives reflected light of the illuminating light radiated onto a tissue within a body cavity of an object to be examined and picks up an image of the tissue within the body cavity. The CCD 2 is a color image pickup device with a mosaic primary color filter arranged for each pixel. Instead of the CCD 2, the image pickup device may also be a CMOS image sensor that can perform analog-to-digital (A/D) conversion on a chip.
The light source device 4 is configured by including a power supply 11, an LED illumination section 12 that emits various illuminating light beams as illumination means, a control circuit 13, and a condensing lens 15 that condenses light on the plane of incidence of a light guide 14 disposed inside the endoscope 3. The LED illumination section 12 includes a light-emitting element group including a white color LED 16a, an excitation light LED 16b, a first narrow-band light LED 16c and a second narrow-band light LED 16d, and an optical system 17 such as a half mirror provided in correspondence with each light-emitting element. The optical system 17 condenses light from each LED which is a light-emitting element to the condensing lens 15.
In the present embodiment, the white color LED 16a is a light-emitting element that emits white color light of a wavelength band for normal-light observation.
The excitation light LED 16b is a light-emitting element that emits light near a wavelength of 400 nm as an excitation light EX to excite fluorescence. The excitation light EX is narrow-band light to excite a connective tissue in the submucosa of a tissue within a body cavity as will be described later and enable the connective tissue to emit auto fluorescence.
The narrow-band light LED 16c is a light-emitting element that emits narrow-band light NBa near a wavelength of 630 nm The narrow-band light NBa is light which is absorbed by a blood vessel to draw images of a relatively thick blood vessel running through the submucosa and muscularis propria as will be described later. The narrow-band light NBa is light of a wavelength band on the longer wavelength side than the narrow-band light NBb and less susceptible to influences of scattering or absorption on the surface of a tissue within a body cavity.
The narrow-band light LED 16d is a light-emitting element that emits narrow-band light NBb near a wavelength of 600 nm The narrow-band light NBb is light absorbed by indigo carmine which is a substance locally injected into the submucosa as will be described later. In particular, the narrow-band light NBb is narrow-band light corresponding to an absorption peak in a light absorption characteristic of indigo carmine
Here, in the case of light near a wavelength of 630 nm, “near” means that narrow-band light has a central wavelength of 630 nm and has a range of wavelengths on the order of a full width at half maximum ±10 nm centered on the wavelength of 630 nm The same applies to other wavelengths such as wavelength 600 nm and wavelength 550 nm which will be described later.
Therefore, the LED illumination section 12 of the light source device 4 constitutes illumination means or an illumination section that can switch between excitation light EX, narrow-band light NBa and NBb, and radiate the selected light. Furthermore, the light source device 4 is an illumination section that can illuminate an object with not only excitation light EX, narrow-band light NBa and NBb, but also white color light.
The control circuit 13 controls the power supply 11 and the LED illumination section 12 so that the light source device 4 emits illuminating light in accordance with each operating mode.
The processor 7 is configured by including a CCD drive circuit 21 which is a CCD driver, an amplifier 22, a process circuit 23, an analog digital (A/D) converter 24, a white balance circuit (hereinafter referred to as “W.B”) 25, a selector 26, synchronization memories 27, 28 and 29, an image processing circuit 30, digital analog (D/A) converters 31, 32 and 33, a coding circuit 34, a timing generator (hereinafter referred to as “T.G”) 35, a control circuit 36, a light-adjusting circuit 37 and a light adjustment control parameter switching circuit 38.
The endoscope 3 includes, in addition to the aforementioned CCD 2 and the light guide 14, a mode switchover switch 41, a lens 42 which is an optical system for illuminating light, a lens 43 which is an objective optical system for the CCD 2 and an excitation light cut filter 44. The light guide 14 is light guiding means for guiding the illuminating light emitted from the light source device 4 into a living tissue in the body cavity of an observation group. The lens 43 condenses fluorescence or reflected light from the tissue within the body cavity to the CCD 2 and the CCD 2 picks up an image of the tissue within the body cavity, which is the object, using the condensed light and outputs an image pickup signal. The excitation light cut filter 44 is a filter to intercept excitation light and has a passband for light having a wavelength of 430 to 690 nm
The CCD drive circuit 21 outputs a drive signal to drive the CCD 2 provided in the endoscope 3. The CCD 2 is a color CCD that is driven by the drive signal and outputs an image pickup signal. Furthermore, the amplifier 22 is intended to amplify the image pickup signal of the image of the tissue within the body cavity picked up by the CCD 2 via the objective optical system 43 provided at a distal end of the endoscope 3.
The process circuit 23 performs correlation double sampling and noise reduction or the like on the image pickup signal via the amplifier 22. The A/D converter 24 converts the analog image pickup signal that has passed through the process circuit 23 to a digital image signal.
The W.B 25 performs gain adjustment and white balance processing on the image signal digitized by the A/D converter 24 so that the R signal of the image signal has brightness equal to that of the B signal of the image signal with reference to the G signal of the image signal, for example.
The selector 26 classifies the image signal from the W.B 25 by color signal, that is, by wavelength and outputs the classified image signals. The image signals classified by color from the selector 26 are supplied to the synchronization memories 27, 28 and 29, each of which stores image signals.
The image processing circuit 30 reads the respective image signals stored in the synchronization memories 27, 28 and 29 and performs amplification processing, moving image color shift correction processing or the like. In a normal-light observation mode, one of the synchronization memories 27, 28 and 29 is used, whereas in an ESD mode, the synchronization memories 27, 28 and 29 are used. Image signals of fluorescence and two narrow band reflected light beams are stored in the synchronization memories 27, 28 and 29 respectively.
In the normal-light observation mode, the image processing circuit 30 outputs the respective image signals of RGB to their corresponding channels of RGB to display an object image with a predetermined color image. In the ESD mode, since the respective image signals of the fluorescence image and two narrow-band images are assigned to any one of the RGB channels beforehand, the image processing circuit 30 outputs the respective image signals generated to their corresponding channels of RGB.
Thus, the synchronization memories 27, 28 and 29 and the image processing circuit 30 constitute image signal generating means or an image signal generation section that generates an image signal from the signal picked up through the CCD 2 and outputs the image signal to the observation monitor 5.
The D/A converters 31, 32 and 33 convert the image signal from the image processing circuit 30 which is the image signal generation section to an analog video signal and output the image signal to the observation monitor 5 as a display apparatus. Furthermore, the outputs of the D/A converters 31, 32 and 33 are supplied to the coding circuit 34 and the digital filing apparatus 6 records endoscope images. Outputting to the observation monitor 5 and outputting to the digital filing apparatus 6 are performed according to the operator's operation on an operation panel (not shown) of the processor 7. Thus, the D/A converters 31, 32 and 33 and the observation monitor 5 constitute display means or a display section that synthesizes a plurality of image signals generated in the image signal processing circuit 30 and displays the composite image.
The T.G 35 is a circuit for controlling timing of illumination and image pickup. For this purpose, the T.G 35 receives a synchronization signal synchronized with the drive of each LED of the LED illumination section 12 from the control circuit 13 of the light source device 4 as input and outputs various timing signals to the respective circuits in the above-described processor 7.
The light-adjusting circuit 37 is a circuit that generates a light adjustment signal to adjust the amount of light emission of each LED of the LED illumination section 12 based on a light adjustment control parameter from the light adjustment control parameter switching circuit 38. The light adjustment control parameter switching circuit 38 is a circuit that switches between light adjustment control parameters to be outputted to the light-adjusting circuit 37 based on a control signal from the control circuit 36.
The light-adjusting circuit 37 is designed to control the LED illumination section 12 of the light source device 4 and perform appropriate brightness control based on the light adjustment control parameters from the light adjustment control parameter switching circuit 38 and the image pickup signal that has passed through the process circuit 23.
Furthermore, the endoscope 2 is provided with the mode switchover switch 41 for switching between the normal-light observation mode and ESD mode, and the output of the mode switchover switch 41 is outputted to the control circuit 36 in the processor 7. The control circuit 36 of the processor 7 is designed to output a control signal to the light adjustment control parameter switching circuit 38.
Each circuit in the processor 7 executes predetermined processing in accordance with a specified mode. Processing corresponding to the normal-light observation mode and the ESD mode is executed respectively and the observation monitor 5 displays a normal-light observation mode or ESD image.
During ESD, a physiological saline solution NS containing a pigment such as indigo carmine is locally injected into a submucosa 62 below a mucosal layer 61. A blood vessel 64 is a relatively thick blood vessel of 1 to 2 mm in diameter running through the submucosa 62 or muscularis propria 63. A lesioned region AA of the mucosal layer 61 is raised by the local injection of the physiological saline solution NS into the submucosa 62. With the lesioned region AA being raised, the operator dissects the submucosa 62 below the lesioned region AA using a treatment instrument SI such as an electric knife and peels off the mucosal layer 61 including the lesioned region AA.
In the ESD mode, the control circuit 36 of the endoscope apparatus 1 sequentially drives the excitation light LED 16b, two narrow-band light LEDs 16c and 16d in the LED illumination section 12 of the light source device 4 and supplies a control signal to the control circuit 13 so as to sequentially and repeatedly emit the excitation light EX, two narrow-band light beams NBa and NBb from the light source device 4. Furthermore, the control circuit 36 controls the image processing circuit 30 in the processor 7 so as to perform image processing for the ESD mode.
When the mode switchover switch 41 is operated and the normal-light observation mode is set, the white color LED 16a is driven and white color light WL is continuously emitted as shown in
When the ESD mode is set, the excitation light LED 16b, the first narrow-band light LED 16c and the second narrow-band light LED 16d are sequentially driven, and as shown in
Here, intensities of the excitation light EX and two narrow-band light beams NBa and NBb emitted from the light source 4 in the ESD mode will be described.
During ESD, a physiological saline solution NS containing a pigment substance is locally injected into the submucosa 62 below the mucosal layer 61 where the lesioned region exists. Here, indigo carmine is used as the pigment.
The auto fluorescence FL, and the reflected light beams of the narrow-band light NBa, NBb are received by the CCD 2. The CCD 2 outputs the respective image pickup signals of light and the respective image pickup signals are supplied to the selector 26 via the amplifier 22 or the like. The selector 26 stores the image of the auto fluorescence FL, the two images of the two reflected light beams of the narrow-band light NBa, NBb in the synchronization memories 27, 28 and 29 respectively in accordance with predetermined timing from the T.G 35. The respective images stored in the synchronization memories 27, 28 and 29 are divided into their respective RGB channels by the image processing circuit 30, then synthesized and outputted to the observation monitor 5.
The auto fluorescence FL and the reflected light beams of the respective narrow-band light NB a, NBb are generated using signals of pixels of specific color filters of the color filters of the CCD 2, and therefore the image processing circuit 30 performs interpolation processing for interpolation between necessary pixels.
As shown above, in the ESD mode, the operator can view a tissue within a body cavity with a composite image of the auto fluorescence FL and the reflected light beams of the narrow-band light NBa, NBb obtained by irradiating the tissue within the body cavity with the excitation light EX and two narrow-band light beams NBa and NBb.
Here, descriptions will be given about display states of an image of a tissue within a body cavity when the submucosa 62 is not removed as shown in
In the ESD mode, in the case as shown in
As shown in
In the case as shown in
Through the aforementioned assignment of the three image signals of FP, NAP and NBP to the three channels of R, B and G, in the composite image CP, the color tone of the tissue within a body cavity in the lower part changes from red to cyan as the observation point approximates from the submucosa 62 to the muscularis propria 63, and the relatively thick blood vessel 64 existing in the submucosa 62 or muscularis propria 63 is displayed in dark blue against the surrounding tissue within a body cavity which is drawn in red.
Here, although the auto fluorescence FL, narrow-band light NBa and narrow-band light NBb are assigned to the R, G and B channels respectively, other assignment methods may also be adopted. For example, the auto fluorescence FL, narrow-band light NBa, and narrow-band light NBb may be assigned to the G, B and R channels respectively.
This is because, the auto fluorescence FL emits strong fluorescence mainly in the submucosa 62, the narrow-band light NBb near a wavelength of 600 nm is more likely to be absorbed by indigo carmine, and therefore the reflected light thereof is weak. Furthermore, since the narrow-band light NBa near a wavelength of 630 nm is absorbed by the relatively thick blood vessel 64, the reflected light thereof is weaker and the submucosa 62, the muscularis propria 63 and the blood vessel 64 are drawn with different color tone differences as shown in
Therefore, when a comparison is made between
Furthermore, the narrow-band light NBa near a wavelength of 630 nm is used as light to increase visibility of the blood vessel and reduce the risk of hemorrhage and further the narrow-band light NBb near a wavelength of 600 nm increases the contrast between the submucosa 62 dyed with indigo carmine and the muscularis propria 63 therebelow, and therefore the physiological saline solution NS having a small indigo carmine content may be used.
In the aforementioned embodiment, the pigment contained in the physiological saline solution NS which is injected into the submucosa 62 is indigo carmine, but the pigment may be another pigment, for example, methylene blue. In that case, narrow-band light NBb that matches the light absorption spectrum characteristic of the pigment is selected.
As described above, according to the aforementioned embodiment, it is possible to realize an endoscope apparatus with improved visibility of blood vessels in the depth of the mucous membrane and improved visibility of the submucosa during ESD.
Next, modification examples of the aforementioned embodiment will be described.
The present modification example is a modification example of the light source device.
A light source device 4A is configured by including a xenon lamp 101 that emits illuminating light (white color light) as illumination means, a heat radiation cut filter 102 that intercepts heat radiation of the white color light, a diaphragm apparatus 103 that controls a light quantity of the white color light via the heat radiation cut filter 102, a rotation filter 104 that transforms illuminating light into frame sequential light as band limiting means, and a control circuit 13A that controls the rotation and position of the rotation filter 104. The frame sequential light that has passed through the rotation filter 104 is condensed by the condensing lens 15 onto the plane of incidence of the light guide 14 disposed in the electronic endoscope 3. The xenon lamp 101, the rotation filter 104 and the light guide 14 constitute an irradiation section or irradiating means that illuminates an object to be examined with illuminating light.
The filter 111 is a filter that allows light near a wavelength of 400 nm (=λ1) to pass therethrough as excitation light EX. The filter 112 is a filter that allows light near a wavelength of 630 nm (=λ2) to pass therethrough as narrow-band light NBa. The filter 113 is a filter that allows light near a wavelength of 600 nm (=λ3) to pass therethrough as narrow-band light NBb.
The rotation filter 104 is disposed on an optical path from the xenon lamp 101 which is the light emerging section of illuminating light to the image pickup surface of the CCD 2 and limits the illuminating light so as to narrow the illuminating light having a plurality of wavelength bands to light having at least three wavelength bands. The control circuit 13A controls the motor 105 for rotating the rotation filter 104 and thereby controls the rotation of the rotation filter 104.
A rack 106a is connected to the motor 105 and a motor (not shown) is connected to a pinion 106b and the rack 106a is attached to the pinion 106b so as to be screwed together. The control circuit 13A controls the rotation of the motor connected to the pinion 106b to move the rotation filter 104 in a direction shown by an arrow d, and can thereby change the position of the rotation filter 104.
Power is supplied to the xenon lamp 101, the diaphragm apparatus 103, the rotation filter motor 105, and the motor (not shown) connected to the pinion 19b from a power supply 11A.
When the operator operates the mode switchover switch 41 to select a normal-light observation mode, the rotation filter 104 moves out of the optical path, white color light emitted through the heat radiation cut filter 102 impinges on the lens 15 and the white color light is introduced into the light guide 14. Furthermore, when the operator operates the mode switchover switch 41 to select an ESD mode, the rotation filter 104 is disposed on the optical path and the excitation light EX and two narrow-band light beams NBa and NBb that have passed through the filters 111, 112 and 113 are sequentially introduced into the light guide 14 under the control of the control circuit 13A.
Therefore, operations similar to those of the aforementioned embodiment can also be obtained using the light source device 4A as shown in
In the aforementioned modification example, a color image pickup device is used as the image pickup device, but the image pickup device may also be a single-color image pickup device. In such a case, a rotation filter 104A has a configuration as shown in
On the outer circumference side of the rotation filter 104A, an R (red) filter section 114, a G (green) filter section 115, and a B (blue) filter section 116 constituting a set of filters to output frame sequential light having a spectral characteristic for normal-light observation are arranged along the circumferential direction as a first filter group. Furthermore, on the inner circumference side of the rotation filter 104A, two filters 111, 112 and 113 that allow light of three predetermined narrow-band wavelengths to pass therethrough are arranged along the circumferential direction as a second filter group.
The control circuit 13A controls the rotation of the motor connected to the pinion 106b so that the first filter group is disposed on the optical path in the normal-light observation mode, whereas in the ESD mode, the second filter group is disposed on the optical path.
RGB image signals from the CCD are stored in the three synchronization memories 27, 28 and 29 in synchronization with the rotation of the rotation filter 104A. That is, in the normal-light observation mode, the three RGB image signals are stored in the synchronization memories 27, 28 and 29 respectively, and in the ESD mode, the auto fluorescence FL and reflected light of the two narrow-band light beams NBa and NBb are stored in the synchronization memories 27, 28 and 29 respectively.
As described above, the configuration shown in the present modification example can also obtain operations and effects similar to those of the aforementioned embodiment.
In the aforementioned embodiment and modification example, the narrow-band light NBa near a wavelength of 630 nm is used to draw images of a relatively thick blood vessel, but when images of a finer blood vessel are preferred to be drawn, the narrow-band light NBc near a wavelength of 550 nm may be used. That is, the narrow-band light NBc near the wavelength of 550 nm is light of a wavelength band on the shorter wavelength side than the narrow-band light NBb near a wavelength of 600 nm and less susceptible to influences of scattering or absorption on the surface of a tissue within a body cavity.
The narrow-band light NBc near the wavelength of 550 nm has an advantage of being less susceptible to influences of indigo carmine and capable of drawing images of finer blood vessels.
As described above, the configuration shown in the present modification example can also obtain operations and effects similar to those of the aforementioned embodiment.
In the aforementioned embodiment, a composite image CP including a fluorescence image FP is displayed in the ESD mode, but the fluorescence image FP may not be displayed in the composite image CP in the ESD mode.
In the present modification example, the ESD mode further includes a fluorescence image display mode FM in which the fluorescence image FP is displayed in the composite image CP and a fluorescence image non-display mode NFM in which the fluorescence image FP is not displayed in the composite image CP.
In ESD, when a spark or the like occurs with the use of an electric knife or the like, a smear or halation may occur in an observed image displayed on the observation monitor 5. Since the auto fluorescence FL is originally weak light, the amplification rate of the auto fluorescence FL is high and when halation or the like occurs, the observed image displayed on the observation monitor 5 may be distorted considerably, making observation impossible.
Thus, in the ESD mode, when an output signal of a treatment instrument such as an electric knife is in on-state (case 1) or when a fluorescence image non-display mode NFM is selected by a predetermined operation switch (case 2) or when halation or the like is detected (case 3), the processor 7 controls the synthesis of images so as to select the fluorescence image non-display mode NFM in which the fluorescence image FP is not included in the composite image CP.
In case 1, as shown by a dotted line in
In case 2, one of the group of switches of the mode switchover switch 41 is a switch to select the fluorescence image display mode FM or fluorescence image non-display mode NFM, and the fluorescence image non-display mode NFM is selected according to the setting of the operator. Therefore, the fluorescence image non-display mode NFM is selected in accordance with a selection or an instruction of the operator and the occurrence of halation or the like on the screen can be suppressed.
In case 3, as shown by the dotted line in
As described above, the instruction of the fluorescence image non-display mode NFM is an instruction for not displaying the fluorescence image FL and that instruction is given based on the operation state of a predetermined switch, output state of the treatment instrument or state of halation included in the fluorescence image FL.
In the fluorescence image display mode FM in which the fluorescence image FP is displayed in the composite image CP, the image processing circuit 30 outputs the composite image CP resulting from synthesizing the fluorescence image FP and narrow-band images NAP and NBP.
In the fluorescence image non-display mode NFM, the image processing circuit 30 outputs the composite image CP resulting from synthesizing only the narrow-band images NAP and NBP.
In the fluorescence image non-display mode NFM in which the fluorescence image FP is not displayed, the red (R) channel component is missing, and therefore it may be possible to assign the narrow-band image NAP and NBP signals or another predetermined signal to the red (R) channel, multiply the narrow-band image NAP and NBP signals by predetermined weighting factors respectively and synthesize the signals so that the composite image CP as a whole is not tinged blue.
Furthermore, in the fluorescence image non-display mode NFM, instead of totally hiding the fluorescence image FP, the gain of the fluorescence image FP may be reduced by a predetermined amount. In other words, the endoscope apparatus 1 may also include a fluorescence image weak display mode in which the signal level of the fluorescence image FP is lowered and the fluorescence image FP is synthesized with another image so that the composite image is outputted.
That is, the image processing circuit 30 generates a first image signal by the auto fluorescence FL emitted from the connective tissue through the excitation light EX, a second image signal by the first narrow-band light NBa, and a third image signal by the second narrow-band light NBb, and when there is a predetermined instruction such as an instruction of the fluorescence image weak display mode, the image processing circuit 30 outputs a fluorescence image FP with the gain of each signal reduced by a predetermined amount and the narrow-band images NAP and NBP without the gain of each signal being reduced by a predetermined amount.
As described above, the configuration shown in the present modification example can also obtain operations and effects similar to those of the aforementioned embodiment and realize an observation without being distorted considerably by halation or the like.
In the aforementioned embodiment and modification examples, the operator switches between the normal-light observation mode and the ESD mode, but the light source device may time-sequentially and consecutively emit the white color light WL, excitation light EX, two narrow-band light beams NBa and NBb.
For example, by sequentially driving the white color LED 16a, the excitation light LED 16b, the first narrow-band light LED 16c and the second narrow-band light LED 16d in the LED illumination section 12 in
The image processing circuit 30 then generates a first image for normal-light observation based on the reflected light of the white color light WL, and generates the composite image CP generated from the auto fluorescence FL, the reflected light of the first narrow-band light NBa, and the reflected light of the second narrow-band light NBb as a second image. The image processing circuit 30 arranges the first image and the second image and simultaneously displays the images on the screen of the observation monitor 5.
That is, the image processing circuit 30 switches between the excitation light EX, the first narrow-band light NBa and the second narrow-band light NBb, and radiates the selected light, generates a first image resulting from synthesizing the three images picked up by the CCD 2, generates a second image from an image obtained by radiating the white color light WL and picked up by the CCD 2 and outputs the image signals of the two images. The first image and the second image are simultaneously displayed on the screen of the observation monitor 5.
According to the present modification example, it is possible to obtain operations and effects similar to those of the aforementioned embodiment, and both of the first image in the normal-light observation mode and the second image in the ESD mode are simultaneously displayed on the screen of the observation monitor 5, and the operator can thereby easily perform ESD.
In the aforementioned embodiment, white color light is radiated onto a tissue within a body cavity in the normal-light observation mode, whereas in the ESD mode, excitation light EX and two narrow-band light beams NBa and NBb are radiated. Thus, the tinge of an image displayed on the observation monitor 5 considerably differs between the normal-light observation mode and the ESD mode.
Thus, in the present modification example, the difference in tinge of an image displayed on the observation monitor 5 before and after mode switching is reduced.
For this, in the normal-light observation mode, the excitation light EX near a wavelength of 400 nm, the narrow-band light NBb near a wavelength of 600 nm and the white color light WL1 near a wavelength of 400 to 690 nm are sequentially and consecutively emitted.
The CCD 2 which is a color image pickup device picks up images of the sequentially emitted excitation light EX, narrow-band light NBb and white color light WL1, but since light of a wavelength band of 400 to 430 nm is lost in the excitation light cut filter 44, the image processing circuit 30 in the processor 7 converts the contrast to secure color reproducibility of the white color light image.
Furthermore, the image processing circuit 30 assigns the fluorescence image FL for the excitation light EX to the red (R) channel, assigns reflected light of the narrow-band light NBb to the green (G) channel and assigns reflected light of the white color light WL1 to the blue (B) channel to thereby generate composite image CP for normal-light observation.
In this case, in the processor 7, a ratio a between the fluorescence FL and the narrow-band light NBb, that is, a ratio of (intensity of fluorescence FL)/(intensity of narrow-band light NBb) is calculated. The signal of the blue (B) channel of the reflected light of the white color light WL1 is multiplied by the calculated ratio a and the resulting signal is outputted to the blue (B) channel.
That is, the observation monitor 5 displays a composite image CP resulting from synthesizing the image of the blue (B) channel of reflected light of the white color light WU multiplied by the ratio of (intensity of fluorescence FL)/(intensity of narrow-band light NBb), the image of the red (R) channel of the fluorescence image FL and the green (G) channel of the narrow-band light NBb.
The connective tissue of the submucosa 62 emits strong fluorescence FL through the excitation light EX, whereas the submucosa 62 dyed by indigo carmine absorbs the narrow-band light NBb and the reflected light thereof attenuates. Therefore, the ratio a of the fluorescence FL to the narrow-band light NBb considerably changes on the boundary between the mucosal layer 61 and the submucosa 62, and on the boundary between the muscularis propria 63 and the submucosa 62. Thus, by multiplying the blue (B) channel signal of reflected light of the white color light WL1 by the ratio a and synthesizing the three images, in the composite image CP in the normal-light observation mode, the submucosa 62 is displayed more with a tinge of blue than the other tissue within a body cavity.
Therefore, since only the submucosa 62 is drawn in a strong blue color also in the normal-light observation mode, the boundary between the submucosa 62 and the muscularis propria 63 is clearly displayed, allowing the operator to perform treatment while avoiding the risk of perforation in the muscularis propria 63.
Furthermore, when switching between the normal-light observation mode and the ESD mode, tinges of both images do not change considerably, and therefore the operator can perform observation without uncomfortable feeling.
As described above, the configuration shown in the present modification example can also obtain operations and effects similar to those of the aforementioned embodiment and can obtain an observed image without uncomfortable feeling at the time of switching between the normal-light observation mode and the ESD mode.
As described above, according to the aforementioned embodiment and modification examples, it is possible to obtain an endoscope apparatus that displays an image with high visibility of the blood vessel 64 in the depth of the mucous membrane during ESD and also improved visibility of the submucosa 62 on the observation monitor 5.
The ESD is a minimally invasive manipulation that peels off and removes an early-stage cancer or the like before submucosal invasion from the submucosa and thereby removes the lesioned region. According to the aforementioned embodiment and modification examples, the boundary between the submucosa and the muscularis propria is made clear and it is thereby possible to prevent the muscularis propria from being mistakenly removed or perforated. Furthermore, according to the aforementioned embodiment and modification examples, a relatively deep artery can be visualized clearly, preventing the risk of hemorrhage caused by arteriotomy. Thus, the operator can perform ESD safely.
The present invention is not limited to the aforementioned embodiment, but can be modified or altered in various ways without departing from the spirit and scope of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2011-087769 | Apr 2011 | JP | national |
This application is a continuation application of PCT/JP2012/055258 filed on Mar. 1, 2012 and claims benefit of Japanese Application No. 2011-087769 filed in Japan on Apr. 11, 2011, the entire contents of which are incorporated herein by this reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2012/055258 | Mar 2012 | US |
| Child | 13615973 | US |
