JP2005312830A - Endoscope imaging system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To observe a fluorescent part and the living body of the other part with proper brightness without performing angle adjustment of the blue band pass filter of a light source. <P>SOLUTION: An endoscope imaging system 1 has a light source apparatus 2 capable of emitting illumination light from UV to visible light and a PDD endoscope 3 for observing a subject image. The light source apparatus 2 incorporates a blue band pass filter 11 which passes through a PDD exciting wavelength and whose angle is fixed. The PDD endoscope 3 incorporates a PDD filter 20. The spectral transmission characteristics of the blue band pass filter 11 and the PDD filter 20 are set to be transmission characteristics where two spectral characteristics are separated without providing a large superimposing part at the blue band pass filter 11 and the PDD filter 20. In the blue band pass filter 11, the blocking ratio of light is set to be low over the wide range of a wavelength from blue to green to generate leaked light. The part of the transmitted light form the superimposed part with the PDD filter 20. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention particularly relates to an endoscope imaging system that performs fluorescence observation by irradiating excitation light.

  2. Description of the Related Art Conventionally, endoscope imaging systems include those that perform fluorescence observation by irradiating excitation light in addition to normal endoscopic observation using visible light. Among such fluorescence observations, a method called PDD (Photodynamic Diagnosis), in which a tumor-sensitive photosensitizer is absorbed in advance in the tumor portion and irradiated with excitation light to diagnose the tumor by fluorescence. There is.

  In general, PDD fluoresces red when irradiated with blue excitation light. However, since fluorescence is weaker than excitation light, it is necessary to cut the excitation light on the light receiving side in order to obtain and observe a fluorescence image. . However, if the excitation light is completely cut off, the biological state other than the fluorescent part becomes invisible.

  Therefore, on the light receiving side, it is necessary to transmit a certain level of excitation light while balancing with fluorescence. However, the blue bandpass filter that transmits the excitation light provided in the light source has a problem that it is difficult to make the transmission amount of the excitation light constant because there are many variations in the wavelength of the emitted light.

Therefore, for example, as disclosed in German Patent No. 19902184, the wavelength of the emitted light is made constant by adjusting the angle of the blue bandpass filter of the light source device.
German Patent No. 19902184

  However, in the endoscope imaging system disclosed in Patent Document 1 described above, it is necessary to adjust the angle of the blue bandpass filter for each light source. This adjustment requires skill and takes time. Therefore, it is required to omit such adjustment.

  The present invention has been made in view of the above circumstances, and it is possible to observe a fluorescent part and a living body other than the fluorescent part with appropriate brightness without adjusting the angle of the blue bandpass filter of the light source. An object of the present invention is to provide an endoscope imaging system.

  The present invention provides an illuminating means capable of irradiating light having a visible light wavelength including at least blue excitation light, and a blue bandpass filter provided in the illuminating means that transmits blue excitation light and has a low transmission band in a preset range. An endoscope that emits blue excitation light from the illuminating means and receives reflected light from the subject; and light that has been cut by the low transmission band of the blue bandpass filter while cutting most of the blue excitation light. A cut filter provided in the transmissive endoscope; an imaging unit that captures a subject image by the endoscope; and an image processing unit that processes an imaging signal from the imaging unit and visualizes the image. It is characterized by.

  The endoscope imaging system according to the present invention can observe the fluorescent part and a living body other than the fluorescent part with appropriate brightness without adjusting the angle of the blue bandpass filter of the light source.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 and 2 show a first embodiment of the present invention, FIG. 1 is a schematic configuration diagram of an endoscope imaging system, and FIG. 2 is a spectral transmission of a blue bandpass filter of a light source device and a PDD filter of an endoscope. FIG.

  In FIG. 1, reference numeral 1 denotes an endoscope imaging system. The endoscope imaging system 1 includes a plurality of filters as illumination means that can irradiate illumination light having a wavelength from an ultraviolet light region to a visible light region. A light source device 2, a PDD endoscope 3 as an example of an endoscope that is inserted into a body cavity in order to observe the subject image by guiding illumination light to the subject and capturing the subject image; A single plate camera head 6 having a light guide 4 for transmitting illumination light to the PDD endoscope 3, a CCD 5 detachably connected to the eyepiece of the PDD endoscope 3; It is mainly composed of a camera control unit (hereinafter referred to as CCU) 7 that processes an image pickup signal from the CCD 5 and converts it into a standard video signal, and a monitor 8 that displays the video signal output from the CCU 7.

  The light source device 2 condenses illumination light, a lamp 10 such as a xenon lamp that emits light, a blue bandpass filter 11 that is provided on the illumination optical path of the lamp 10 and that transmits a PDD excitation wavelength and has a fixed angle. For example, a condensing lens 12 is provided. Here, the spectral transmission characteristics of the blue bandpass filter 11 will be described later.

  The PDD endoscope 3 includes a light guide fiber 16 that transmits illumination light from the light source device 2 to the distal end portion 15, an illumination lens 17 provided at the distal end portion 15, and an objective lens 18 that transmits an image from a subject. And an image guide 19 composed of a bundle of optical fiber cables for transmitting an image condensed by the objective lens 18, a PDD filter 20 as a cut filter provided at the end of the image guide 19, and the like. Yes. Here, the spectral transmission characteristics of the PDD filter 20 will be described later.

  The single plate camera head 6 is provided as an image pickup means, and mainly includes an imaging lens 22, an IR cut filter 23, and the CCD 5 as the image pickup element described above. The subject image transmitted from the PDD endoscope 3 is imaged by the imaging lens 22, supplied to the CCD 5 via the IR cut filter 23, and the imaging signal from the CCD 5 is sent to the CCU 7 to be imaged. .

  That is, the CCU 7 is provided as an image processing means for processing and imaging the image pickup signal from the single plate camera head 6, and image-processing the image pickup signal from the single plate camera head 6 to the monitor 8 as a video signal. Output and display video.

  Next, the spectral transmission characteristics of the blue bandpass filter 11 built in the light source device 2 and the PDD filter 20 built in the PDD endoscope 3 will be described with reference to FIG. For easy understanding, the spectral transmission characteristics of the conventional blue bandpass filter and the PDD filter are shown in FIG. 4 and will be described in comparison with the conventional spectral transmission characteristics.

  That is, as shown in FIG. 4, the spectral transmission characteristics of the conventional blue bandpass filter are mainly transmitted by limiting the blue wavelength. Further, the spectral transmission characteristic of the conventional PDD filter transmits light of blue to red wavelength so as to slightly overlap with the blue bandpass filter of the light source.

  Therefore, in the conventional endoscope imaging system using such a filter, when the PDD photosensitive material is irradiated with excitation light from the blue bandpass filter of the light source, it is fluorescent in red and the PDD of the PDD endoscope. The overlapping part with the filter becomes illumination light that illuminates a living body other than the fluorescent part. Here, the illumination light has a problem in that weak fluorescence cannot be seen when the amount of light is large, while a living body cannot be seen when the amount of light is small, and thus diagnosis and treatment cannot be performed.

  For this reason, the overlapping portion of the blue bandpass filter and the PDD filter should be strict, but the transmission band of the actual blue bandpass filter tends to have a large error. Therefore, in the conventional example, it is necessary to adjust the illumination light by adjusting the angle of the blue bandpass filter for each light source.

  On the other hand, the spectral transmission characteristics of the blue bandpass filter 11 and the PDD filter 20 according to the first embodiment of the present invention include a large overlapping portion between the blue bandpass filter 11 and the PDD filter 20, as shown in FIG. Not provided, the two spectral characteristics are set to separate transmission characteristics. The blue bandpass filter 11 is configured to generate leakage light by setting a low light rejection rate (setting a low transmission band) over a preset range, that is, a wide range of blue to green wavelengths. doing. In other words, this transmitted light portion forms an overlapping portion with the PDD filter 20. Although this overlapping portion has a low transmittance but covers a wide range, the transmission area is almost the same as that of the conventional overlapping portion.

  As described above, the blue band-pass filter 11 and the PDD filter 20 of the light source device 2 can set a low transmission band over a wide range of blue to green wavelengths of the blue band-pass filter 11 to obtain low transmitted light in a wide wavelength region. Therefore, even if an error occurs in the transmission region of the blue bandpass filter 11, the illumination light quantity is not greatly affected. Therefore, it is not necessary to adjust the angle of the blue bandpass filter and to strictly manage the overlapping portion as in the prior art.

  As described above, according to the first embodiment of the present invention, even if the transmission band wavelength varies in the blue bandpass filter 11 of the light source device 2, the illumination light is not greatly affected. Is no longer necessary. Therefore, the adjustment time and the adjustment jig at the time of shipment of the light source are not necessary, and the assembly cost can be reduced.

  In addition, setting the blue bandpass filter 11 to have a low blue to green light blocking rate also tends to loosen the specifications of the blue bandpass filter 11, which facilitates filter manufacture and is advantageous in terms of cost. It becomes. In addition, since the illumination light is a wide range of light from blue to green as compared with the conventional blue light alone, the color reproducibility other than the fluorescent part can be improved.

  Next, FIGS. 3 and 4 relate to a second embodiment of the present invention, FIG. 3 is a schematic explanatory diagram of the structure on the proximal end side of the special optical endoscope, and FIG. 4 is a spectral transmission characteristic of a blue bandpass filter. FIG. Note that the second embodiment is different from the first embodiment in that the endoscope is changed to a special light endoscope, and the same components are denoted by the same reference numerals, and the description of the same components is omitted. .

  That is, in the endoscope imaging system according to the second embodiment of the present invention, the blue bandpass filter 11 and the PDD filter 20 of the endoscope imaging system of the PDD endoscope according to the first embodiment shown in FIG. 1 are deleted. It has become.

  As shown in FIG. 3, the special optical endoscope 30 is provided with a light guide connection portion 31 that can be adjusted in angle, and a blue band that can be inserted and removed is provided at the end of the light guide fiber 16 at the entrance side. A pass filter 32 is provided.

  The spectral transmission characteristics of the blue bandpass filter 32 are set substantially the same as the spectral transmission characteristics of the conventional blue bandpass filter, as shown in FIG.

  In such an endoscope imaging system of the special light endoscope, the illumination light from the light source device 2 is transmitted through the blue bandpass filter 32 inserted in the special light endoscope 30, so that the blue color in FIG. The spectral characteristics are the same as those of the bandpass filter 32. Therefore, PDD fluorescence observation can be performed as in the conventional case.

  For the illumination light other than the fluorescent part at the time of PDD observation, the operator can change the angle of the light guide connection part 31 of the special optical endoscope 30 to shift the wavelength of the illumination light so that the brightness can be adjusted. It becomes. In transurethral resection used for PDD of bladder cancer, the operator usually holds the vicinity of the light guide connecting portion 31 of the special optical endoscope 30 with his hand, so that the angle can be adjusted without any problem. Further, the special optical endoscope 30 can be normally observed by removing the blue bandpass filter 32.

  That is, according to the second embodiment, since the surgeon can adjust the illumination light with the light guide connection portion 31, the light source device 2 does not need to adjust the angle of the blue bandpass filter. In addition, since the operator can adjust the brightness of the illumination light in this way, the balance between the fluorescence and the illumination light can be freely changed depending on the surgical procedure and the observation site.

1 is a schematic configuration diagram of an endoscope imaging system according to a first embodiment of the present invention. Same as above, spectral transmission characteristic diagram of blue bandpass filter of light source device and PDD filter of endoscope Schematic explanatory drawing of the structure of the base end side of the special optical endoscope according to the second embodiment of the present invention Same as above, spectral transmission characteristics of blue bandpass filter

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Endoscope imaging system 2 Light source device (illuminating means)
3 PDD endoscope 6 Single plate camera head 7 Camera control unit 11 Blue bandpass filter 20 PDD filter
Agent Patent Attorney Susumu Ito

Claims (3)

Illumination means capable of irradiating at least visible light wavelength including blue excitation light; and
A blue bandpass filter provided in the illumination means that transmits blue excitation light and has a low transmission band in a preset range;
An endoscope that receives blue excitation light from the illuminating means and receives reflected light of a subject;
A cut filter provided in the endoscope that cuts most of the blue excitation light and transmits light transmitted through the low transmission band of the blue bandpass filter;
Imaging means for imaging a subject image by the endoscope;
An endoscope imaging system comprising: an image processing unit that processes an imaging signal from the imaging unit to convert it into an image.   The endoscope imaging system according to claim 1, wherein the blue excitation light from the illuminating means is excitation light that causes the photosensitive material to fluoresce red.   The endoscope imaging system according to claim 1 or 2, wherein a low transmission band of the blue bandpass filter is set in a wavelength range of blue to green light.

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