JP4475966B2 - Endoscope device - Google Patents

Description

  The present invention relates to an endoscope apparatus, and more particularly, to an endoscope apparatus that performs photodynamic diagnosis (PDD) and photodynamic therapy (PDT).

  In an endoscopic device that observes and examines a body cavity, a photosensitive substance that has a tumor affinity and is sensitive to excitation light with a short wavelength is administered to a living body in advance, and laser light that can be used as excitation light is then applied. Photodynamic Diagnosis (hereinafter referred to as Photodynamic Diagnosis), which diagnoses tumors by irradiating the surface of biological tissues with relatively weak output and observing the fluorescence emitted by photosensitizers whose concentrations are high at the lesions of tumors such as cancer And a device capable of photodynamic therapy (hereinafter abbreviated as PDT) for treating a tumor such as cancer by irradiating a surface of a living tissue with a laser beam having a relatively short wavelength with a relatively strong output. Proposed.

Patent Document 1 discloses an endoscope apparatus including at least one laser oscillator for diagnosis (PDD) and one or more laser oscillators for treatment (PDT).
JP 2000-189527 A

  However, in this apparatus, it is necessary to prepare a laser oscillator for PDD and a laser oscillator for PDT separately, and the apparatus is large.

  Accordingly, an object of the present invention is to provide a laser light source device that is suitable for both PDD and PDT and does not increase in size.

  An endoscope apparatus according to the present invention collects a laser light source unit having a plurality of laser oscillators that emit laser light that can be used as excitation light for photodynamic diagnosis, and laser light emitted from the plurality of laser oscillators In the case of the first mode for performing the condensing unit and the photodynamic diagnosis, the living tissue can be observed by the laser beam irradiated through the condensing unit among a plurality of laser oscillators, and the laser beam irradiated to the living tissue In the second mode in which the first number of laser oscillators determined so that the output does not damage the living tissue and the photodynamic therapy is performed, the number of laser oscillators greater than the first number among the plurality of laser oscillators and the laser A laser output control unit that drives a second number of laser oscillators capable of treating living tissue with light.

  As a result, a common laser oscillator can be used for photodynamic diagnosis (PDD) and photodynamic therapy (PDT), and the size can be reduced as compared with a conventional apparatus that prepares a laser oscillator suitable for each of PDD and PDT. It becomes possible. In addition, since the number of laser oscillators that emit light can be adjusted according to the application, the irradiation output is too strong and damages the living tissue on the observation surface, or conversely, the irradiation output is too weak than the irradiation output required for treatment. There is no problem that it cannot be fully cured.

Preferably, the first number is determined such that the output per unit area of the laser light irradiated to the living tissue in the first mode is 30 mW / cm ² or less, and the second number is the second mode. In this case, the output per unit area of the laser light applied to the living tissue is determined to be at least 150 mW / cm ² .

  Preferably, when the laser output control unit is in the first mode and diagnoses a shallow region from the surface of the living tissue, the wavelength of the relatively short laser beam among the plurality of laser oscillators is the first wavelength. When a laser oscillator is preferentially used and a deep region is diagnosed, a laser oscillator having a relatively long second wavelength of laser light among a plurality of laser oscillators is preferentially used. This makes it possible to select a laser oscillator to be used according to the depth of the site to be diagnosed from the surface of the biological tissue.

  More preferably, the first wavelength is a value between 360 nm and 420 nm, and the second wavelength is a value between 630 nm and 1070 nm.

  Preferably, a white light source unit that emits white light and a light source switching unit that serves as a light source for irradiating at least one of the white light source unit and the laser light source unit are provided. Thereby, irradiation of the observation surface by white light in normal observation becomes possible as necessary.

  More preferably, in the first mode, first and second image memory units for temporarily recording first and second image signals obtained by irradiation from the white light source unit and the laser light source unit, And an image synthesis unit for synthesizing the second image signal. As a result, a clear image of the surface of the living tissue that improves the diagnostic accuracy by combining the image of fluorescence obtained by irradiation with laser light as excitation light from the laser light source and the image of white light irradiation from the white light source. It becomes possible to obtain.

  More preferably, in the case of the second mode, the living tissue is observed by white light irradiation from the white light source unit, the part to be irradiated with the laser light from the laser light source unit is specified, and the white light irradiation is maintained. Laser beam irradiation from the laser light source unit is performed on the site to be irradiated. As a result, it becomes easy to observe and identify the lesion site to which the laser beam should be irradiated during treatment.

  More preferably, the white light source unit includes a discharge lamp, and the light source switching unit includes a shutter that blocks white light emitted from the discharge lamp as necessary. As a result, it is possible to switch on and off the white light irradiation as necessary while keeping the discharge lamp that generates a time lag during on / off switching on.

  Preferably, the condensing unit includes a rod lens and a light guiding member that guides laser light from a plurality of laser oscillators to the rod lens. This makes it possible to collect laser light from several laser oscillators that are turned on among the plurality of laser oscillators as one light.

  As described above, according to the present invention, it is possible to provide a laser light source device that is suitable for both PDD and PDT and does not increase in size.

  Hereinafter, an embodiment of the present invention will be described with reference to FIG. FIG. 1 shows a configuration diagram of an endoscope apparatus. The endoscope apparatus according to the present embodiment includes an electronic scope 10, a color processor (electronic endoscope processor) 20, and a color monitor 40. The electronic scope 10 images the subject under the control of the color processor 20. The image signal obtained by imaging is converted by the color processor 20 into a video signal that can be output (screen display) on the color monitor 40. The converted video signal is transmitted to the color monitor 40 as an analog signal. The transmitted video signal is output by the color monitor 40. The user can observe the subject image captured by the electronic scope based on the output result from the color monitor 40.

  The electronic scope 10 includes an imaging unit 11 and an illumination unit 12, and the imaging unit 11 captures an image of the subject while the illumination unit 12 gives an appropriate amount of light to the subject.

  The imaging unit 11 includes an objective lens 11a and an imaging element 11b such as a CCD. The objective lens 11a is provided with excitation light cut coating in order to observe fluorescence. The electric charge accumulated in the image sensor 11b by imaging the subject is transferred to the video signal processing unit 21 as an image signal for each field.

  The illumination unit 12 supplies light from the laser light source unit 27 and the white light source unit 28 that irradiate the living tissue via the light guiding member 12b and the light distribution lens 12a. The electronic scope 10 and the color processor 20 are electrically and optically connected by a connector portion (not shown).

  The color processor 20 includes a video signal processing unit 21, a main control circuit 24, a laser light source unit 27, a white light source unit 28, and a light source switching unit 30. The color processor 20 captures an image signal that has been captured and transferred by the electronic scope 10. Then, it is converted into a video signal that can be output by the color monitor 40.

  The video signal processing unit 21 performs A / D conversion, gamma correction, contour enhancement, and amplification on the image signal for each field sent from the electronic scope 10 by the previous stage video signal processing circuit 21a, and via the memory switching unit 21b. The first and second image memory units 21c and 21d are temporarily recorded sequentially. The memory switching unit 21b switches a memory for temporarily recording an image signal obtained by imaging for each field.

  When only normal observation is performed, the first and second image memory units 21c and 21d respectively receive the first and second image signals by the white light supplied from the white light source unit 28 in the first and second fields of one frame. Record. When only PDD is performed, the first and second image memory units 21c and 21d are based on fluorescence obtained by irradiation with laser light as excitation light supplied from the laser light source unit 27 in the first and second fields of one frame. First and second image signals are recorded. In the case of performing PDT, the first and second image memory units 21c and 21d are laser light emitted from the laser light source unit 27 in the first and second fields of one frame and white light supplied from the white light source unit 28. First and second image signals are recorded respectively. The first and second image signals temporarily recorded in the first and second image memory units 21c and 21d are transferred to the subsequent video signal processing circuit 21e. The post-stage video signal processing circuit 21e converts the first and second image signals into first and second video signals such as a video composite signal and a Y / C separation signal, respectively, and converts them into analog signals at the D / A converter 21f. Then, the data is output to the color monitor 40 as needed.

  When performing normal observation and PDD, the first image memory unit 21c temporarily records a first image signal based on white light supplied from the white light source unit 28 in the first field of one frame. The second image memory unit 21d temporarily records a second image signal by fluorescence obtained by irradiation with laser light as excitation light supplied from the laser light source unit 27 in the second field of one frame. The first and second image signals temporarily recorded in the first and second image memory units 21c and 21d are transferred to the subsequent video signal processing circuit 21e. The post-stage video signal processing circuit 21e synthesizes the transferred first and second image signals, converts them to video signals such as a video composite signal and a Y / C separation signal, and converts them into analog signals by the D / A converter 21f. After the conversion, the data is output to the color monitor 40.

  The main control circuit 24 includes a CPU and a RAM (not shown), and controls each part of the endoscope apparatus and temporarily records signals.

Laser light source 27, first to m sub-control circuit 27a ₁ through 27a _m, first to m laser oscillator 27b ₁ through 27b _m, such as a laser diode (LD) that emits blue laser light available for excitation light a, first to m laser light guide member 27c ₁ through 27c _m, such as an optical fiber, a rod lens 27d, and a laser beam focusing lens 27e. The first to m sub-control circuit 27a ₁ through 27a _m under the control of the main control circuit 24 drives the first to m laser oscillator 27b ₁ through 27b _m, respectively. First to m laser oscillator 27b ₁ through 27b _m emits blue laser light available for excitation light, a rod lens 27d, respectively, via the first through m laser light guide member 27c ₁ through 27c _m, the laser beam focusing It is condensed on the optical lens 27e.

The wavelength of the laser beam emitted from the first through n laser oscillator 27b ₁ through 27b _n of the first to m laser oscillator 27b ₁ through 27b _m is set to a relatively short 360～420Nm. The wavelengths of the laser beams emitted from the ( _{n + 1)} -th to _{m- th} laser oscillators 27b _{n + 1 to} 27b _m are set between 630 to 1070 nm, which is relatively long. m is a natural number of 2 or more, and n is a natural number of less than m and 1 or more.

The main control circuit 24 has a laser output control function for controlling which one of the _first to m-th laser oscillators 27b _{1 to} 27b _m is driven with what output according to the purpose of use. Specifically, it is selectively used according to the distance from the surface of the living tissue of the site to be irradiated, or it is properly used for PDD and PDT.

If the site desired to be irradiated shallow area from the biological tissue surface, the wavelength of laser light to use a shorter first to n laser oscillator 27b ₁ through 27b _n preferentially. If the site desired to be irradiated is a deep region from the biological tissue surface, the wavelength of the laser light is preferentially use long first n +. 1 to m th laser oscillator 27b n + ₁ ~27b _m.

For PDD, for purposes of weakening the irradiation light amount, of the first to m laser oscillator 27b ₁ through 27b _m, it performed using the laser oscillator of the first number. On the other hand, in the case of PDT, the second number of laser oscillators are used for the purpose of increasing the amount of light. Since the light output width that can be adjusted within the range that individual laser oscillators can maintain light emission is narrow, considering that the adjustment range of the amount of irradiation light is wider than the adjustment of output, the number of laser oscillators to drive is increased or decreased It is.

Here, the first number refers to the laser beam irradiated through the rod lens 27d, the laser beam condensing lens 27e, the light source switching unit 30, and the illumination unit 12 among the _first to m-th laser oscillators 27b _{1 to} 27b _m. In other words, the number of living tissue can be observed by fluorescence obtained by illumination of laser light as excitation light, and the living tissue is not damaged. The second number refers to the laser beam irradiated through the rod lens 27d, the laser beam condensing lens 27e, the light source switching unit 30, and the illumination unit 12 among the _first to m-th laser oscillators 27b _{1 to} 27b _m. Thus, the number is such that the active oxygen is generated in the lesioned part of the living tissue and the lesion cell is necrotized to burn out the necessary part. Thus, the first number is less than the second number.

As a specific guideline, the output per unit area of the irradiation laser light that does not damage the living tissue is 30 mW / cm ² or less, and the output per unit area of the irradiation laser light required for PDT is at least 150 mW / cm ^2. (Or more). At present, there is an output of 30 to 60 mW per laser oscillator, and the optical transmission efficiency when irradiated from the light distribution lens 12a of the illumination unit 12 is 20 to 30%. Therefore, for example, the output of the laser oscillator is set to 30 mW, the optical transmission efficiency is set to 20%, and the predetermined laser light in consideration of the distance and the light distribution angle between the tip of the electronic scope 10 and the laser light irradiation surface. According to the irradiation conditions, 17 corresponds to the first number of laser oscillators required in the case of PDD, and 83 corresponds to the second number of laser oscillators required in the case of PDT.

  Therefore, it is possible to use a laser oscillator common to PDD and PDT, and it is possible to reduce the size of the conventional apparatus that prepares a laser oscillator suitable for each of PDD and PDT. In addition, the laser oscillator that emits light can be selected and the output amount can be adjusted according to the application, so the irradiation output is too strong and damages the living tissue on the observation surface, or conversely too weak than the irradiation output required for treatment. Therefore, there is no problem that the lesion cannot be fully cured.

  The white light source unit 28 includes a discharge lamp 28a that starts discharge by applying a high voltage pulse such as a xenon lamp that emits white light and emits white light, and a white light condensing lens 28b that collects the emitted light. . White light from a discharge lamp is broadband light having a wide wavelength band from a short wavelength to a long wavelength.

  The emitted white light and laser light are applied to the living tissue (observation surface) that is the subject through the light source switching unit 30, the light guiding member 12b such as an optical fiber, and the light distribution lens 12a.

  The light source switching unit 30 includes a shutter 30a, a white light reflecting mirror 30b, a half mirror 30c, and a condenser lens 30d. The shutter 30a transmits or blocks white light by opening and closing. In the case of normal observation in which white light is irradiated on the observation surface, the shutter 30a is opened to transmit white light from the white light source unit 28. Meanwhile, the laser light source 27 that emits the laser light is turned off. The transmitted white light is reflected by the white light reflecting mirror 30b and the half mirror 30c, and is irradiated on the observation surface through the condenser lens 30d, the light guiding member 12b, and the light distribution lens 12a. In the case of a PDD that irradiates the observation surface with laser light as excitation light, the shutter 30a is closed to block white light from the white light source unit 28. In the case of PDT that irradiates the observation surface (lesion part) with laser light, the shutter 30a remains open and does not transmit white light from the white light source part 28 and is not blocked, and is the same as normal observation in parallel with the PDT treatment. Can be observed. In both cases of PDD and PDT, the laser light source unit 27 that emits laser light is turned on during that time, and the blue laser light emitted from the laser light source unit 27 is transmitted through the half mirror 30c, the condensing lens 30d, and the light. The observation surface is irradiated through the guide member 12b and the light distribution lens 12a. The main control circuit 24 performs the opening / closing control of the shutter 30a and the on / off control of the laser light source unit 27.

  The color monitor 40 is a commercially available color monitor that can capture and display a video signal, and outputs (screen display) the video signal that is captured by the electronic scope 10 and converted by the color processor 20.

  When white light is irradiated onto the living tissue via the light distribution lens 12a, the broadband light reflected or scattered by the living tissue is collected by the objective lens 11a and received by the imaging device 11b. When the living tissue is irradiated with laser light as excitation light through the light distribution lens 12a, the narrow band light reflected or scattered by the living tissue, the fluorescence emitted by the photosensitive substance, and the excited living tissue itself The autofluorescence emitted from the light is condensed on the objective lens 11a, and the fluorescence emitted from the photosensitive substance and the autofluorescence are received by the image sensor 11b. However, since autofluorescence is weak light, it does not greatly affect the imaging result.

  The degree of the light reaching the tissue in the body cavity in the depth direction depends on the wavelength. That is, light having a short wavelength reaches only a shallow region from the surface of the living tissue, and light having a long wavelength reaches the deep region from the surface of the living tissue.

  White light from a discharge lamp with a wide wavelength band reaches the deep region from the surface of the living tissue, and reflects from the reach depth range. It becomes possible to project. Therefore, it is easy to grasp the entire image of the observation surface of the living tissue in normal observation and PDT.

  As will be described later, by synthesizing an image obtained by narrowband light with a normal observation image obtained by white light broadband light, a clear PDD synthesized observation image relating to the observation surface of the subject can be obtained and diagnostic ability can be improved.

  Hereinafter, embodiments of the present invention in PDD and PDT will be described with reference to flowcharts. In any case, after the operation of the endoscope apparatus is started (step S11 in FIG. 2 and step S31 in FIG. 3), the discharge lamp 28a of the white light source unit 28 is maintained in the lighting state, and light is irradiated onto the observation surface. Whether or not it is operated by the shutter 30a.

  First, the case of performing normal observation and PDD will be described with reference to FIG. When the endoscope operation is started in step S11, the shutter 30a is opened in step S12. In step S13, white light is emitted from the white light source unit 28 toward the observation surface in the first field of one frame. At this time, the laser light source unit 27 is turned off. In step S14, broadband light is reflected by the reflected white light, and the first image signal is temporarily recorded in the first image memory unit 21c as a normal observation image.

In step S15, the shutter 30a to the closed state, in step S16, only the first number of laser oscillators of the first to m laser oscillator 27b ₁ through 27b _m of the laser light source unit 27 in the second field of a frame Drive or turn on, other laser oscillators turn off. The laser oscillator to be turned on is determined according to the distance from the surface of the living tissue of the site to be irradiated. In step S17, laser light as excitation light from the laser oscillator turned on is irradiated toward the observation surface. In step S18, narrowband light due to reflection of fluorescence generated by the irradiated laser light as excitation light is imaged and temporarily recorded in the second image memory unit 21d as a PDD narrowband light image. In step S19, the laser light source unit 27 is turned off and the light emission of the first number of laser oscillators is also stopped. In step S20, the first image signal and the second image signal temporarily recorded in the first and second image memory units 21c and 21d are synthesized. In step S21, the synthesized image signal is converted into a video signal and displayed on the color monitor 40 as a PDD synthesized observation image to perform PDD. In step S22, it is determined whether to continue observation for PDD, that is, whether to continue imaging. When continuing observation, it returns to step S12 and starts the imaging procedure of the next frame. When ending without continuing observation, the process ends in step S22.

  Next, a case where PDT is performed will be described with reference to FIG. When the endoscope operation is started in step S31, the shutter 30a is opened in step S32. In step S33, white light is emitted from the white light source unit 28 toward the observation surface. At this time, the laser light source unit 27 is turned off. In step S34, broadband light by reflection of the white light irradiated in the first and second fields of one frame is imaged and displayed on the color monitor 40 corresponding to the captured first and second image signals as needed. While observing the first and second video signals, a lesion portion diagnosed by PDD is found.

In step S35, to the first to drive or ON state for a second number of laser oscillator of the m laser oscillator 27b ₁ through 27b _m laser light source unit 27. At this time, in order to continue observation to identify the location of the lesion to be treated by irradiating the laser beam, the white light source unit 28 emits the discharge lamp 28a and the shutter 30a remains open. In step S36, imaging is performed for each field, and while observing the video signal displayed on the color monitor 40 in response to the captured image signal, the laser light from the laser oscillator turned on is directed toward the lesion. To perform PDT. In step S37, the shutter 30a is closed. In step S38, only the first number of laser oscillators among the first to m-th laser oscillators 27b _{1 to} 27b _m are kept on, and the other laser oscillators are turned off. Narrowband light due to reflection of fluorescence generated by laser light as excitation light irradiated by the first number of laser oscillators turned on is imaged for each field, and corresponds to the captured PDD narrowband light image. Then, PDD is performed by observing the video signal displayed on the color monitor 40. In step S39, it is determined whether or not the lesion has been completely cured as a result of PDD. If it is not completely cured, the process returns to step S32 to repeat PDT. If it is completely cured, the laser light source unit 27 is turned off in step S40, and the light emission of the first number of laser oscillators is stopped, and the process ends in step S41.

The on / off timing of the laser light source unit 27 and the white light source unit 28 in the case of performing these normal observation, PDD, and PDT will be described with reference to the timing chart of FIG. When only normal observation by white light irradiation of the white light source unit 28 is performed (t11 to t13 in FIG. 4), the white light source unit 28 in any field in one frame (t11 to t12, t12 to t13 in FIG. 4). The discharge lamp 28a is turned on, the shutter 30a is opened, and the laser light source 27 is turned off (steps S32 to S34 in FIG. 3). When only PDD is performed by irradiating laser light as excitation light of the laser light source unit 27 (t13 to t15 in FIG. 4), the laser is used in any field (t13 to t14, t14 to t15 in FIG. 4) in one frame. only the first to the first number of laser oscillator of the m laser oscillator 27b ₁ through 27b _m of the light source unit 27 is turned on. Although the white light source unit 28 is in the on state, when the shutter 30a is in the closed state, the observation surface is effectively turned off so that white light is not irradiated (steps S37 to S39 in FIG. 3). In FIG. 4, the first and second laser oscillators 27b ₁ and 27b ₂ having a short wavelength are driven to observe the vicinity of the surface of the living tissue as an example.

When performing normal observation and PDD described in the flowchart of FIG. 2 (t15 to t17 in FIG. 4), the discharge lamp 28a of the white light source unit 28 is turned on in the first field (t15 to t16 in FIG. 4) in one frame. In this state, the shutter 30a is opened and white light irradiation is performed, and the first image signal captured at this time is recorded in the first image memory unit 21c (steps S12 to S14 in FIG. 2). In the first field, the laser light source unit 27 is turned off. Only the first number of laser oscillators of the first to m laser oscillator 27b ₁ through 27b _m of the laser light source unit 27 in the second field (t16 to t17 in FIG. 4) is turned on in the next same frame . Although the white light source unit 28 is in the on state, when the shutter 30a is in the closed state, the observation surface is turned off so that white light is not irradiated. The second image signal captured at this time is recorded in the second image memory unit 21d (steps S15 to S18 in FIG. 2). An image signal obtained by combining the first and second image signals is converted into a video signal and displayed on the color monitor 40 (steps S19 to S21 in FIG. 2). In FIG. 4, the first and second laser oscillators 27b ₁ and 27b ₂ having a short wavelength are driven to observe the vicinity of the surface of the living tissue as an example. By performing laser light irradiation with a weak light amount as excitation light using the first number of laser oscillators, PDD can be performed without damaging the surface of the living tissue as the observation surface and its surroundings. Further, by synthesizing with a normal image in the case of white light irradiation, it becomes possible to diagnose a lesion near the surface of a living tissue while grasping the entire image of the observation surface that improves the diagnostic ability.

When the PDT described in the flowchart of FIG. 3 is performed (t17 to t19 in FIG. 4), after the observation of a lesion by normal observation and PDD (step S34 in FIG. 3), any field in one frame (in FIG. 4) t17 to t18, the discharge lamp 28a of the white light source unit 28 even t18~t19), and the first to the second laser oscillator drive or oN state of the number of the m laser oscillator 27b ₁ through 27b _m laser light source unit 27 (Steps S35 to S36 in FIG. 3). The shutter 30a is opened. By performing laser beam irradiation using the second number of laser oscillators, it becomes possible to necrotize and burn out the lesion area to be treated by laser beam irradiation with a strong light amount. Moreover, since white light irradiation is performed at the same time, it is possible to perform PDT while grasping the position of the lesion with the color monitor 40. FIG. 4 shows an example in which all the laser oscillators 27b _{1 to} 27b _m are turned on as the second number.

  The light source switching unit 30 that switches the light source to irradiate the living tissue to either white light or laser light has been described as using the shutter 30a, but this is instantly turned on by an on / off signal like a discharge lamp. This is effective when the lamp cannot be turned off. As long as the white light source can be turned on and off instantaneously, such as an LED, the shutter 30a may not be used, and the light source switching unit 30 includes a laser light source unit 27 that emits laser light and an LED that emits white light. Any function that can perform on / off switching control alternately with the light source is sufficient.

Further, although the wavelengths of the _first to mth laser oscillators 27b _{1 to} 27b _m are set in two types, they are set in three or more types in order to further adjust the depth of the site to be irradiated from the biological tissue surface. May be.

The block diagram of the endoscope apparatus in this embodiment is shown. The flowchart which performs normal observation and PDD is shown. The flowchart which performs PDT is shown. The timing chart showing the on-off state of each light source part at the time of performing normal observation, PDD, and PDT is shown.

Explanation of symbols

10 electronic endoscope 20 color processor 21 the image signal processing unit 24 main control circuit 27 laser light source unit 27a ₁ through 27a _m first to m sub-control circuit 27b ₁ through 27b _n shorter wavelength first to n laser oscillator 27b _n + 1 through 27b _m relatively long first n +. 1 to m th laser oscillator 27c ₁ through 27c _m laser light guide member 28 white light source unit 30 light source switching unit 40 a color monitor wavelength

Claims (7)

A laser light source unit having a plurality of laser oscillators that emit laser light that can be used as excitation light for photodynamic diagnosis;
A light collecting unit that collects laser light emitted from the plurality of laser oscillators;
In the case of the first mode for performing the photodynamic diagnosis, the laser light that can be observed in the living tissue by the laser light irradiated through the condensing unit among the plurality of laser oscillators and that is irradiated onto the living tissue. In the second mode in which the first number of laser oscillators determined so that the output of the laser beam does not damage the living tissue and photodynamic therapy is performed, the first number of the plurality of laser oscillators A laser output controller that drives a second number of laser oscillators that are more capable of treating the living tissue with the laser light ;
A white light source that emits white light;
A light source switching unit having at least one of the white light source unit and the laser light source unit as a light source of irradiation light;
First and second image memory units for temporarily recording first and second image signals obtained by irradiation from at least one of the white light source unit and the laser light source unit in the first mode;
An endoscope apparatus comprising: an image synthesis unit that synthesizes the first and second image signals . The first number is determined such that an output per unit area of the laser light irradiated to the living tissue in the first mode is 30 mW / cm ² or less, and the second number is The endoscope apparatus according to claim 1, wherein an output per unit area of the laser light applied to the living tissue in the second mode is determined to be at least 150 mW / cm ² .   In the first mode and when diagnosing a shallow region from the surface of the living tissue, the laser output control unit has a first wavelength in which the wavelength of the laser light is relatively short among the plurality of laser oscillators. In the case of diagnosing a deep region, the laser oscillator having a relatively long second wavelength among the plurality of laser oscillators should be used preferentially. The endoscope apparatus according to claim 1.   The endoscope apparatus according to claim 3, wherein the first wavelength is a value between 360 nm and 420 nm, and the second wavelength is a value between 630 nm and 1070 nm. In the case of the second mode, the living tissue is observed by irradiating white light from the white light source unit, the part to be irradiated with the laser light from the laser light source unit is specified, and while maintaining the white light irradiation, The endoscope apparatus according to claim 1 , wherein the laser light irradiation from a laser light source unit is performed on the part. The endoscope apparatus according to claim 1 , wherein the white light source unit includes a discharge lamp, and the light source switching unit includes a shutter that blocks white light emitted from the discharge lamp as necessary.   The endoscope apparatus according to claim 1, wherein the condensing unit includes a rod lens and a light guiding member that guides the laser light from the plurality of laser oscillators to the rod lens.

Images