JP2004305382A - Special light observation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a special light observation system which can obtain an endoscope observation image in a proper imaging mode according to various biomedical observation sites. <P>SOLUTION: A filter rotary plate 22 equipped with filters respectively for the visible light (ordinary observation), for the absorption wavelength of ICG as a medicine and for the excitation wavelength is provided on the side of a light source unit 5 and a filter mounting plate 34 having the filters respectively for the ordinary observation, the fluorescent observation and the absorption light observation mounted thereon is provided in front of a CCD 32 of a TV camera 3 mounted on an optical type endoscope 2. An observation is made possible under the absorption characteristics of the ICG by operating a changeover lever 36 and this also makes the observations adaptable to various biomedical observation sites, for example, the observation utilizing the fluorescent emission characteristics when the pulmonary tissue with the coal powder deposited is observed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a special light observation system capable of observing at an absorption wavelength and a fluorescence wavelength of a drug such as indocyanine green in addition to observation using visible light.
[0002]
[Prior art]
In recent years, endoscope apparatuses are widely used in the medical field and the industrial field. The endoscope apparatus is capable of diagnosing a site to be examined such as an affected part in a body cavity without an incision by inserting an elongated endoscope insertion portion into the body cavity, or a treatment tool as necessary. Can be inserted for therapeutic treatment. The endoscope apparatus captures a subject image of a subject to be inspected from the distal end portion of the endoscope insertion unit by an objective optical system, and transmits the captured image to a hand-side eyepiece unit by a subject image transmission unit such as an image guide. It can be magnified by an eyepiece optical system.
[0003]
In such an endoscope apparatus, a television camera is detachably attached to an eyepiece of an endoscope as an imaging apparatus, and a signal from an imaging element such as a CCD (charge-coupled device) built in the television camera is used for camera control. A signal can be processed by a unit (hereinafter, CCU) and an endoscope image can be displayed on a monitor.
[0004]
In recent years, some endoscope apparatuses perform special light observation using ultraviolet light, infrared light, or the like in addition to normal endoscope observation using visible light, and perform observation and diagnosis.
For example, in Japanese Patent Application Laid-Open No. 2001-87221, when infrared observation is selected in addition to normal endoscopic observation using visible light, an infrared image and a visible image are displayed as parent-child images, This makes it easy to identify each part and provides an observation image that is easy to diagnose.
[0005]
In a conventional example of performing infrared light observation, for example, a drug called indocyanine green (ICG; Indocyanine Green) having an absorption peak at near infrared light near 805 nm in a living body is used as a contrast agent. Some observers perform infrared light observation at a wavelength of.
[0006]
By utilizing the tendency of the lymph nodes / lymphatic vessels into which ICG has been injected to become darker (blacker) than other parts, blood vessel running and detection accuracy of lymph nodes / lymphatic vessels are enhanced.
[0007]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2001-87221
[Problems to be solved by the invention]
However, in the above-described conventional example, for example, when observing lung tissue in which charcoal powder has been deposited, the darkness due to charcoal powder deposition causes the detection accuracy of lymph nodes and the like to decrease. That is, in the above conventional example, an endoscope observation image cannot be obtained in an appropriate imaging mode according to various living body observation sites.
[0009]
In other words, for example, when a drug such as ICG used for observation of a living tissue is used, the observation is performed in the absorption wavelength range of the drug. There is a disadvantage that cannot be done.
[0010]
(Object of the invention)
The present invention has been made in view of the above points, and has as its object to provide a special light observation system capable of obtaining an endoscopic observation image in an appropriate imaging mode according to various living body observation sites.
[0011]
More specifically, when a drug such as ICG used for observation of a living tissue is used, it can be observed in an absorption wavelength range of the drug, and in an environment where the same tendency is caused by other coal powder or the like. It is an object of the present invention to provide a special light observation system which enables fluorescence observation by a medicine and obtains an endoscopic observation image in a state in which a part containing a medicine and the like can be easily identified even under the influence of charcoal powder or the like. I do.
[0012]
[Means for Solving the Problems]
Visible light, an absorption wavelength of a drug used for living body observation, and a light source device incorporating a plurality of irradiation filters capable of selectively irradiating an excitation wavelength,
A plurality of filters capable of selectively imaging visible light, an absorption wavelength of the drug, and a fluorescence wavelength are arranged switchably in front of an imaging element provided in an imaging unit, and a light source is provided in accordance with the switching operation of the filters. By switching a plurality of irradiation filters in the apparatus, an endoscope observation image can be obtained in an appropriate imaging mode according to various living body observation sites.
[0013]
More specifically, when a drug such as ICG is used, it can be observed in the absorption wavelength range of the drug, and in an environment where the same tendency is caused by other charcoal powder or the like, fluorescence observation by the drug is selected. Thus, an endoscope observation image can be obtained in a state where a portion containing a medicine or the like can be easily identified even in a state where there is an influence of coal powder or the like.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First Embodiment)
FIGS. 1 to 4 relate to a first embodiment of the present invention. FIG. 1 shows an entire configuration of a special light observation system according to the first embodiment. FIG. 2 shows a filter configuration of a filter rotating plate of a light source device. FIG. 3 shows a filter configuration of a filter mounting plate provided in the television camera, and FIG. 4 shows absorption characteristics and fluorescence emission characteristics by ICG.
[0015]
As shown in FIG. 1, a special light observation system 1 according to a first embodiment of the present invention includes a television camera (camera head) 3 having a built-in image pickup means in, for example, an optical endoscope 2 inserted into a body cavity. A TV camera external endoscope 4 mounted thereon, a light source device 5 for supplying illumination light to the optical endoscope 2, and a camera control unit (CCU for short) which performs signal processing on image pickup means built in the TV camera 3. ) 6 and a monitor 7 for displaying an endoscope image captured by the imaging means by receiving a standard video signal output from the CCU 6.
[0016]
The optical endoscope 2 includes, for example, a rigid insertion portion 11, a grip portion 12 provided at a rear end of the insertion portion 11, and an eyepiece portion 13 provided at a rear end of the grip portion 12. The light guide cable 14 is connected to the base of the grip 12.
A light guide 15 for transmitting illuminating light is inserted into the insertion portion 11, and the light guide 15 is provided at an end portion of the light guide cable 14 via a light guide cable 14 connected to a base on a side of the grip portion 12. The base 16 is detachably connected to the light source device 5.
[0017]
A lamp 21 such as a xenon lamp which is lit by a lamp lighting power supply supplied from a lamp lighting circuit (not shown) is provided in the light source device 5, and this lamp 21 emits illumination light in a blue wavelength range from infrared to visible. Generates light.
[0018]
This light is attached to a filter rotating plate (turret plate) 22, passes through one of filters 23A, 23B, and 23C (see FIG. 2) arranged on the illumination optical path, and is condensed by a condenser lens 24 to be illuminated. The light is incident on the incident end face of the light guide 15 in the guide base 16, and is transmitted to the distal end side of the insertion portion 11 by the light guide 15. In other words, the light is transmitted to the distal end face of the light guide attached to the illumination window at the distal end of the insertion section 11, is emitted from the distal end face, and illuminates the subject side such as the affected part.
[0019]
The filter rotating plate 22 is rotatably held by a motor 25, and a filter arranged on the illumination light path is selectively set by a motor control circuit (or a rotating plate control circuit) 26 for controlling the driving of the motor 25.
[0020]
As shown in FIG. 2, the filter rotating plate 22 has, for example, a normal light irradiation filter 23A, an excitation light irradiation filter 23B, and an absorption light irradiation filter that transmit visible light through three windows provided in a rotation direction of a light-shielding disk, for example. 23C is attached.
[0021]
The normal light irradiation filter 23A is a filter that transmits a visible light wavelength range of approximately 380 nm to 700 nm. The excitation light irradiation filter 23B is a filter that transmits an ICG excitation wavelength of 790 nm. The absorption light irradiation filter 23C is a filter that transmits the ICG absorption wavelength of 805 nm.
[0022]
An objective lens 27 is attached to the observation window provided adjacent to the illumination window at the distal end of the insertion section 11, and forms an optical image of the illuminated subject such as a diseased part. The formed optical image is transmitted to the rear end face side by a relay lens system 28 serving as an image guide.
[0023]
This optical image can be magnified and observed by an eyepiece lens 29 provided in the eyepiece unit 13. When the television camera 3 is mounted on the eyepiece 13, an imaging unit is formed such that an optical image transmitted via the imaging lens 31 in the television camera 3 is formed on an imaging element. I have.
[0024]
That is, for example, a charge-coupled device (abbreviated as CCD) 32 is disposed as an image pickup device at an image forming position where an optical image is formed. A color separation filter 33 such as a mosaic filter is arranged on the imaging surface of the CCD 32, and an image color-separated by the color separation filter 33 is formed on the imaging surface of the CCD 32. Note that at least one of the color separation filters 33 has a characteristic of transmitting light in the infrared region.
[0025]
A filter mounting plate 34 is disposed between the imaging lens 31 and the CCD 32 so as to be rotatable around an axis. The filter mounting plate 34 has a substantially fan shape as shown in FIG. Are provided with three filters 35A, 35B, 35C.
[0026]
That is, the filter 35A for normal observation, the filter 35B for fluorescence observation and the filter 35C for absorption light observation are attached to both sides thereof, so that the normal observation mode, the fluorescence observation mode, and the absorption light observation mode can be selected and set. I have.
The normal light observation filter 35A has the same characteristics as the normal light irradiation filter 23A on the light source device 5, that is, a filter that transmits a visible light wavelength range of approximately 380 nm to 700 nm.
[0027]
Further, the fluorescence observation filter 35B is a filter set so that the excitation light irradiating filter 23B on the side of the light source device 5 irradiates the excitation light for exciting the ICG and transmits 835 nm which is the wavelength of the fluorescence emitted from the ICG. In addition, the filter transmits 820 nm or more so that 805 nm, which is the absorption wavelength of ICG, cannot be transmitted.
The absorption light observation filter 35C is a filter that transmits light having a wavelength of 805 nm transmitted through the absorption light irradiation filter 23C on the light source device 5 side and can transmit visible light to near-infrared light.
[0028]
In addition, the filter mounting plate 34 can select and set a filter arranged on the imaging optical path by operating a switching lever 36 provided outside the television camera 3 so that an observation mode (imaging mode) can be selected. I have.
[0029]
As shown in FIG. 3, the filter mounting plate 34 is provided with a number of holes for identifying the filters arranged on the imaging optical path, the number corresponding to the filters, and the light emitting element and the light receiving element are sandwiched between the holes. A signal for identifying a filter arranged on the imaging optical path is output to the CCU 6 based on outputs of the light receiving elements by the three arranged photo interrupters 38.
[0030]
The connector 39 at the end of the camera cable of the television camera 3 is detachably connected to the CCU 6.
A CCD driver 41 for driving the CCD 32 is provided in the CCU 6. When a CCD drive signal from the CCD driver is applied to the CCD 32, an image signal photoelectrically converted by the CCD 32 is sent to a pre-processing circuit 42 in the CCU 6. Is entered. Then, after being amplified, a correlated double sampling process or the like is performed, a baseband signal component is extracted from the imaging signal, and further converted by the A / D conversion circuit 43 into a digital signal.
[0031]
This signal is input to a color separation circuit 44, where it is color-separated into Y / C and converted into R, G, B signals by a color matrix circuit therein, and then image data of color components is temporarily stored in a memory 45. Is done. The operations of the color separation circuit 44 and the memory 45 are controlled by the CPU 46.
[0032]
In this case, when the normal light observation filter 35A is selected and the visible light illumination and the imaging state are set, the memory 45 stores the R, G, and B image data separately for the color components. Is controlled by the CPU 46.
[0033]
When fluorescence and absorption light are selected, the color matrix circuit responds to the characteristics and arrangement of the color separation filters 33 arranged on the imaging surface of the CCD 32, and outputs signals from pixels having sensitivity to fluorescence and absorption light. The CPU 46 controls such that only components are extracted by setting matrix coefficients.
[0034]
When fluorescence and absorption light are selected, the CPU 46 controls writing to the memory 45 so as to simply generate image data of luminance (brightness) information. For example, the same image data is written in each of the color component memories constituting the memory 45, and a monochrome video signal is output to the monitor 7 side. Of course, the color signal to be assigned may be changed according to the luminance level and displayed in a pseudo color.
[0035]
The memory 45 is read out at a predetermined timing, subjected to processing such as contour enhancement and γ correction by a post-processing circuit 47, converted into a standard video signal, output to the monitor 7, and displayed on the monitor 7. The image captured by the CCD 32 is displayed as an endoscope image.
[0036]
In the present embodiment, while making it possible to obtain a normal endoscopic observation image by visible light, so as to obtain an appropriate endoscopic observation image according to various living body observation sites, so that it can be selected I have.
[0037]
In other words, as shown in FIG. 1, when the filter arranged on the imaging optical path is switched by the switching lever 36, the switching operation causes the filter arranged on the imaging optical path to be identified by the photointerrupter 38 as the filter identifying means. The output is sent to the CPU 46, which controls the operation of the signal processing system in the CCU 6, and the CPU 46 sends a control signal to the rotating plate control circuit 26 of the light source device 5.
[0038]
The rotating plate control circuit 26 receives the control signal from the CPU 46 and controls the motor 25 so that a filter corresponding to the filter arranged on the imaging optical path is arranged on the illumination optical path.
[0039]
For example, when the normal observation mode is selected on the television camera 3 side and the normal observation filter 35A is set on the imaging optical path, the normal light irradiation filter 23A is arranged on the illumination optical path on the light source device 5 side, and When the fluorescence observation mode is selected on the camera 3 side and the fluorescence observation filter 35B is set on the imaging optical path, the excitation light irradiation filter 23B is arranged on the illumination optical path on the light source device 5 side, and the television camera 3 side When the absorption light observation mode is selected and the absorption light observation filter 35C is set on the imaging optical path, the absorption light irradiation filter 23C is arranged on the illumination light path on the light source device 5 side.
[0040]
The operation of the present embodiment having such a configuration will be described.
After setting as shown in FIG. 1, the optical endoscope 2 is inserted into a site to be observed in the body cavity.
Light emitted from a lamp 21 provided in the light source device 5 passes through a filter provided on a filter rotating plate 22, and is condensed by a condenser lens 24, and guided to a light guide 15 of a light guide cable 14. You.
[0041]
Further, light is irradiated into the body cavity by the light guide 15 in the endoscope 2. The illuminated optical image of the observation target site in the body cavity is captured by the CCD 32 through the filter provided in the television camera 3 via the image guide 28.
The television camera 3 is provided with a switching lever 36, and the filter rotating plate 22 in the light source device 5 is controlled by the rotating plate control circuit 26 via the CCU 6 according to the filter selected by the operation of the switching lever 36. The corresponding filter provided on the filter rotating plate 22 is selected.
[0042]
For example, when the normal observation filter 35A is selected, the normal light irradiation filter 23A is selected, and when the fluorescence observation filter 35B is selected, the excitation light irradiation filter 23B is selected, and the absorption light observation filter 35C is selected. When this is done, the absorption light irradiation filter 23C is selected.
[0043]
For this reason, it can be inserted into, for example, the stomach or large intestine, and the inspection target site can be observed with normal visible light by the normal observation filter 35A. When it is desired to observe the blood vessel running and the lymph nodes and lymph vessels in more detail, for example, the ICG is injected into the examination target site through a channel (not shown) of the endoscope 2 and the switching lever 36 is operated to absorb the ICG. The light observation mode, that is, the absorption light observation filter 35C is selected to be arranged on the imaging optical path.
[0044]
FIG. 4 shows absorption characteristics and fluorescence emission characteristics by ICG, wherein the horizontal axis represents wavelength and the vertical axis represents absorption and emission intensities. The absorption peak is around 805 nm, and the fluorescence emission peak is around 835 nm.
[0045]
By selecting the absorption light mode, the absorption light irradiation filter 23C is selected on the light source device 5 side, and the blood vessel portion, the lymph node, the sentinel lymph node, etc., into which the ICG has been injected are subjected to the light absorption characteristics by the ICG as shown in FIG. By observing in a darkened state, it is possible to obtain an endoscope observation image that allows a clearer observation or identification of the running state of blood vessels and the like.
[0046]
In addition, when the blood vessel is inserted into the lung or the like for observation, the blood vessel running, the lymph nodes, and the lymph vessels can be similarly observed in more detail.
In this case, in the case where the coal powder is deposited, the portion becomes dark due to the deposition of the coal powder, and when the blood vessel running and the detection of the lymph nodes are reduced, the switching lever 36 is operated. The fluorescence observation mode, that is, the fluorescence observation filter 35B is selected.
[0047]
Then, by this selection, the excitation light irradiation filter 23B is selected on the light source device 5 side, and the ICG is excited by the excitation light from the excitation light irradiation filter 23B, and the television camera 3 is (excited) by the fluorescence observation filter 35B. The image is picked up by the CCD 32 after transmitting the fluorescence wavelength emitted by the ICG.
[0048]
In this case, the part that emits fluorescence by the ICG becomes a fluorescent image that is displayed brightly, so that the blood vessel part and the lymph nodes containing the ICG are observed brighter by the fluorescent image, whereas the part where the coal powder is deposited becomes dark. Therefore, it is possible to obtain an endoscopic observation image by fluorescence in a state that can be distinguished from the darkened portion of the coal powder deposit.
[0049]
As described above, according to the present embodiment, in addition to the normal observation image using visible light according to the observation site of the living body, observation can be performed at the absorption wavelength of the drug, or observation can be performed at the fluorescence wavelength of the drug. it can. That is, an appropriate endoscope observation image can be obtained according to various observation sites of the living body.
[0050]
Further, in the present embodiment, when observing a living tissue such as a lymph node into which normal ICG is injected, identification of the injected lymph node or the like is performed in an absorption light observation mode, and further, a fluorescence observation mode is set. Thus, the lymph node into which ICG has been injected can also be identified in this fluorescence observation mode.
[0051]
In this case, the identification of the lymph nodes and the like can be performed more accurately than in the conventional example in which only one of them is used. Further, even when the tumor tissue has a characteristic of high affinity for ICG, more detailed or highly reliable image information can be obtained by performing observation or imaging using both the absorption light observation mode and the fluorescence observation mode. It is also possible to provide an environment in which diagnosis can be performed more easily.
[0052]
Further, as a modified example of the first embodiment, there is provided a correlation amount evaluation unit (or calculation unit) for evaluating a correlation amount between both images obtained by using both the absorption light observation mode and the fluorescence observation mode. It is also possible to perform a process of converting the obtained result to a portion having a particularly high correlation amount in a pseudo color to display a pseudo color on the monitor 7.
[0053]
By doing so, the portion having a high correlation amount is displayed in color by both images, so that the tissue into which ICG has been injected can be displayed in a more prominent or easily identifiable manner.
[0054]
When the correlation amount is evaluated, the correlation amount may be evaluated by a process of dividing an image signal obtained in the fluorescence observation mode by an image signal obtained in the absorption light observation mode. Thus, the evaluation result of the correlation amount may be obtained.
[0055]
(Second embodiment)
Next, a second embodiment of the present invention will be described. This embodiment has almost the same configuration as the first embodiment. In the present embodiment, for example, each of the color separation filters 33 of the CCD 32 is set to have a characteristic of transmitting an infrared wavelength in addition to the color transmission characteristics of the R, G, and B filters.
In this case, in consideration of the color transmission characteristics of the R, G, and B filters and the transmission characteristics of wavelengths in the infrared region, the CPU 46 controls the coefficients so that the color matrix of the color separation circuit in the observation mode is optimized. I do.
[0056]
By changing the color matrix of the signal processing means according to the observation mode selected according to the filter switching, it is possible to set a signal processing state appropriate for the selected imaging state, and to obtain an image that is easy to observe. ing.
[0057]
Therefore, according to the present embodiment, by selecting the observation mode, the sensitivity is obtained in the observation mode in consideration of the transmission characteristics of the color separation filter disposed in front of the CCD 32 according to the selected observation mode. Since the coefficients of the color matrix are appropriately set in consideration of the characteristics of the filter, an image that can be more easily observed is obtained.
[0058]
In another embodiment, for example, the color separation filter 33 in front of the CCD 32 may not be provided. In this case, a monochrome image is formed as an image using visible light, but sensitivity in fluorescence observation or absorption light observation can be further increased.
In the above description, the case of using ICG as the medicine has been described, but the present invention can be applied to the case where another medicine is used.
[0059]
Further, in the above description, the television endoscope 4 having the imaging unit is provided by mounting the television camera 3 having the imaging unit (imaging unit) on the optical endoscope 2 having the rigid insertion unit. However, the television camera 3 may be attached to an optical endoscope having a flexible insertion portion.
[0060]
[Appendix]
1. In claim 1, there is provided an evaluation means for evaluating the correlation amount of the image obtained at each of the absorption wavelength and the fluorescence wavelength of the drug.
2. In Supplementary Note 2, a pseudo-coloring unit that displays the evaluation result by the evaluating unit in a pseudo color at a portion having a high correlation amount is provided.
[0061]
【The invention's effect】
As described above, according to the present invention, in addition to normal observation with visible light, illumination and imaging using a drug absorption wavelength and a fluorescence wavelength can be selectively performed. , An endoscope observation image is obtained in an appropriate imaging mode.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of a special light observation system according to a first embodiment of the present invention.
FIG. 2 is a diagram illustrating a filter configuration of a filter rotating plate of the light source device.
FIG. 3 is a diagram showing a filter configuration of a filter mounting plate provided in the television camera.
FIG. 4 is a diagram showing absorption characteristics and fluorescence emission characteristics by ICG.
[Explanation of symbols]
1. Special light observation system 2. Optical endoscope 3. Television camera (camera head)
4: Telescope camera endoscope 5: Light source device 6: CCU
7 Monitor 11 Insertion part 14 Light guide cable 15 Light guide 21 Lamp 22 Filter rotating plate 23A Normal light irradiation filter 23B Excitation light irradiation filter 23C Absorption light irradiation filter 25 Motor 26 Rotary plate control Circuit 32: CCD
33 ... Color separation filter 34 ... Filter mounting plate 35A ... Filter for normal observation 35B ... Filter for fluorescence observation 35C ... Filter for absorption light observation 36 ... Switching lever 41 ... CCD driver 44 ... Color separation circuit 45 ... Memory 46 ... CPU

Claims (3)

Visible light, an absorption wavelength of a drug used for living body observation, and a light source device incorporating a plurality of irradiation filters capable of selectively irradiating an excitation wavelength,
A plurality of filters capable of selectively imaging visible light, an absorption wavelength of the drug, and a fluorescence wavelength are arranged switchably in front of an imaging element provided in an imaging unit, and a light source is provided in accordance with the switching operation of the filters. A special light observation system, wherein a plurality of irradiation filters in the apparatus are switched. The special light observation system according to claim 1, wherein the medicine is indocyanine green. The special light observation according to claim 1, wherein a color matrix in a signal processing unit that performs signal processing on the imaging unit can be changed so as to be optimal according to a filter switching operation in the imaging unit. system.

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