JPH0924023A - Fluorescent endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To pick up a fluorecent image with high sensitivity by long time continuous exposure while the condition of a living body can be confirmed. SOLUTION: The excitation light L1 from an excitation light source 10 and the illuminating light L2 from an illuminating light source 15 are applied to a region 23 of the interior of a living body through a light transmitting optical fiber 14. At this time, the radiation of the excitation light L1 and the illumination light L2 to the region 23 is switched to be pulse-like and alternate by a rotating shutter. Fluorescent light L3 emitted from the region 23 by the irradiation of excitation light L1 is detected by a third image pickup means 31 to form a fluorescent image, and the illuminating light L2 reflected on the region 23 is detected by a second image pickup means 35 to form a normal image. At this time, the drive of the rotating shutter 36 is controlled by a motor drive control circuit 20, whereby when the excitation light L1 is applied to the region 23, the fluorescent light L3 is guided to the first image pickup means 31 in which long time exposure is performed, and when the illuminating light L2 is applied to the region 23, the illuminating light L2 reflected on the region 23 is guided to the second image pickup means 35.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endoscope for observing the inside of a living body, and more particularly, to irradiating excitation light to a site inside the living body that absorbs a photosensitizer that emits fluorescence. The present invention relates to a fluorescence endoscope that captures an image with fluorescence emitted from the photosensitizer.

[0002]

2. Description of the Related Art Conventionally, PDD (Photodynamic
Various studies have been made on photodynamic diagnosis called "diagnosis". This PDD has tumor affinity,
A photosensitizer that emits fluorescence when excited by light is previously absorbed in a tumor portion of a living body, and the portion is irradiated with excitation light in the excitation wavelength region of the photosensitizer to generate fluorescence, and the fluorescence is generated. This is a technique for diagnosing a tumor part by displaying an image.

For example, Japanese Patent Publication No. 63-9464, Japanese Patent Application Laid-Open No. 1-133630, and Japanese Patent Application Laid-Open No. 7-59783 disclose a fluorescent image diagnostic apparatus for performing this PDD. Basically, this kind of fluorescent image diagnostic apparatus basically includes an excitation light irradiating means for irradiating a living body with excitation light in an excitation wavelength region of a photosensitive substance, and a fluorescent image of the living body by detecting fluorescence emitted from the photosensitive substance. As one form of such a device, a fluorescent endoscope that is incorporated into an endoscope inserted into a living body is widely known.

[0004] In addition to the above means, in addition to the above means, means for irradiating the living body with illumination light, which is usually white light when a fluorescent image is not captured, and detecting illumination light reflected from the living body, There are provided imaging means for capturing a normal image of a living body, and image display means for receiving the output of the imaging means and displaying the normal image (generally also serving as a fluorescent image display). It is possible to observe the state of the living body indicated by, and monitor the positional relationship between the living body and the tip of the light irradiation and imaging means.

[0005]

By the way, since the fluorescence emitted from the above-mentioned photosensitizer is generally extremely weak, it is difficult for many conventional fluorescence endoscopes to pick up a fluorescence image with high sensitivity. .

In the above-mentioned Japanese Patent Publication No. 63-9464, an excimer die laser that emits high-intensity laser light is used as an excitation light source, and an image intensifier (image intensifying tube) is used as a fluorescence image pickup means. Shows a fluorescence endoscope that enables high-sensitivity imaging.
Since the excimer dye laser and the image intensifier are very expensive, the fluorescent endoscope using them is inevitably expensive.

Even if the above-mentioned special excitation light source and fluorescent image pickup means are not used, a fluorescent image can be picked up with high sensitivity if continuous exposure is possible for a long time. However, all conventional fluorescent endoscopes use illumination light. Excitation light is emitted to the living body in a pulse while the light is turned off, and a fluorescent image is captured at the video rate of the NTSC standard (field period 1/60 seconds: the actual imaging time is shorter than that) even at the longest time. However, continuous exposure for a long time is impossible. This is because the illumination light cannot be emitted while the fluorescence image is being captured, and therefore the state of the living body and the positional relationship between the light irradiation and the tip portion of the imaging means and the living body cannot be confirmed, and such a state continues for a long time. This is because there is a circumstance that it must be avoided to ensure the safety of the living body.

The present invention has been made in view of the above circumstances, and a fluorescent image can be formed by long-time exposure while confirming the state of the living body and the positional relationship between the living body and the tip of the imaging means and the living body. An object of the present invention is to provide a fluorescence endoscope capable of capturing an image with high sensitivity.

[0009]

The fluorescent endoscope according to the present invention is so constructed that a normal image can be picked up at the same time as picking up a fluorescent image. For parts inside the body that are absorbing sensitive substances,
Excitation light irradiation means for irradiating the excitation light in the excitation wavelength region of the photosensitizer, illumination light irradiation means for irradiating the inside of the living body with the illumination light, and irradiation of the excitation light and the illumination light to the above-mentioned portion , Light irradiation switching means for switching in a pulsed and alternating manner, a first shutter arranged at a position where the fluorescence emitted from the above portion is incident to limit the passage of the fluorescence, and a reflection at the above portion The second shutter arranged at a position where the illumination light enters and limiting the passage of the illumination light, and the excitation light drives the first and second shutters in synchronization with the operation of the light irradiation switching means. Shutter control means for controlling the first shutter to open when the site is illuminated and the second shutter to open when the illumination light is illuminated to the site; and the fluorescence through the first shutter. To detect the A first image capturing unit that captures a fluorescent image of a living body with a plurality of exposure times during a period in which the shutter is open, and a second image capturing unit that captures a normal image of a living body by detecting illumination light through a second shutter. And an image pickup means.

As the first image pickup means, it is desirable to use one that can change the exposure time as described in claim 2.

Further, as described in claim 3, it is preferable that the second image pickup means picks up a normal image of a living body for a plurality of exposure times during a period in which the second shutter is open.

On the other hand, in the fluorescence endoscope of the present invention, as described in claim 4, as the excitation light irradiation means and the illumination light irradiation means, those which emit excitation light and illumination light continuously can be used. In that case, as the light irradiation switching means, it is possible to preferably use one having a configuration in which the shutters respectively arranged in the optical paths of the excitation light and the illumination light are alternately opened.

Further, in the fluorescence endoscope of the present invention, as described in claim 5, as the light irradiation switching means, each light source constituting the excitation light irradiation means and the illumination light irradiation means is alternately turned on in a pulsed manner. A thing can also be used.

Further, in the fluorescence endoscope of the present invention, as described in claim 6, when the excitation light irradiating means and the illuminating light irradiating means respectively emit excitation light and illuminating light continuously, The light irradiation switching means is fixed to the rotating body, a rotating body, an exciting light reflecting mirror that is fixed to the rotating body and reflects the exciting light in a direction toward the portion when the rotating body is at a predetermined rotation position. When the rotating body is at a rotation position different from the predetermined rotation position, the illumination light reflecting mirror for reflecting the illumination light in the direction toward the portion is provided, and the first shutter and the second shutter are provided. The shutter and the shutter control means are fixed to the rotating body and the rotating body, and when the rotating body is in a rotation position where the excitation light reflecting mirror reflects the excitation light, the fluorescence is directed to the first imaging means. Counter to direction And a fluorescent reflection mirror to be rotated, and fixed to the rotating body, the illumination light reflected by the portion when the rotating body is in a rotation position for reflecting the illumination light by the illumination light reflection mirror for light transmission is second imaging means. It can be configured by an illumination light reflection mirror for receiving light that reflects the light in a direction toward.

[0015]

In the fluorescence endoscope of the present invention having the above-mentioned structure, the fluorescence emitted from the site inside the living body is incident on the first image pickup means by the action of the light irradiation switching means and the shutter control means. The state and the state in which the illumination light reflected by the above portion is incident on the second image pickup means can be switched alternately at short time intervals. Therefore, the second image pickup means can repeat the image pickup of the reflected illumination light, that is, the normal image at short time intervals, and the output thereof can be used to display the part inside the living body in real time.

In parallel with this, a fluorescent image of a living body can be picked up by the first image pickup means. At this time, the first image pickup means is exposed for a plurality of exposure times during the period in which the first shutter is open. Since it is designed to capture an image in a strict sense, it is not a continuous exposure, but the total exposure time is long and a fluorescent image can be captured with high sensitivity.

When the fluorescent image is taken,
As described above, since the normal image of the living body can be displayed in real time by using the second image pickup means, the operator or the like observes the normal image to check the state of the living body, the light irradiation and the tip portion of the image pickup means. The positional relationship with the living body can be confirmed. If so, the safety of the living body is ensured even if the fluorescent image is taken for a long time.

As described above, the fluorescent endoscope of the present invention enables high-sensitivity imaging of a fluorescent image by long-time exposure, and is expensive such as the above-mentioned excimer dye laser and image intensifier. Since the means is basically unnecessary, it can be formed relatively inexpensively.

The appropriate exposure time of the first image pickup means may vary depending on the type of the photosensitizer mentioned above. Therefore, if the first image pickup means capable of changing the exposure time is used, an appropriate exposure time can be set corresponding to the change of the photosensitizer used.

Further, it is desirable that the irradiation switching between the excitation light and the illumination light by the light irradiation switching means is performed in a cycle in which no flicker is felt, that is, in a cycle generally shorter than 1/60 seconds. Even if the irradiation switching cycle is set to be considerably short as described above, in that case, if the second image pickup means is configured to image for a plurality of exposure times during the period in which the second shutter is open, it is normal. The image can be picked up with high sensitivity.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a fluorescence endoscope according to a first embodiment of the present invention. This fluorescence endoscope reflects, for example, an excitation light source 10 that continuously emits excitation light L1 in a blue region, a collimator lens 11 that makes the excitation light L1 parallel, and an excitation light L1 that is made parallel. A dichroic mirror 12 and a condenser lens 13 for condensing the excitation light L1 reflected by the dichroic mirror 12.
And a light-transmitting optical fiber 14 arranged so that the collected excitation light L1 is incident.

Further, an illumination light source 15 which continuously emits illumination light L2 which is white light, a collimator lens 16 which collimates the illumination light L2, and a mirror 17 which reflects the collimated illumination light L2. And are provided. The dichroic mirror 12 transmits the illumination light L2. The mirror 17 is arranged so that the illumination light L2 reflected there passes through the dichroic mirror 12 and then follows the same optical path as the excitation light L1.

A shutter 18 is inserted in the optical path of the excitation light L1 between the collimator lens 11 and the dichroic mirror 12 and the optical path of the illumination light L2 between the collimator lens 16 and the mirror 17. It has become. The shutter 18 has a plurality of slits (not shown), and is driven by a motor 19 rotating at high speed to rotate. The driving of the motor 19 is controlled by a motor drive control circuit 20 which constitutes a light irradiation switching means together with the motor 19 and the shutter 18.

The plurality of slits of the shutter 18 are such that when one of them reaches a position where the excitation light L1 passes.
No slit is located in the optical path of the illumination light L2 (that is, the shutter 18 blocks the illumination light L2), and conversely, the slit 1
Excitation light L when one comes to a position where the illumination light L2 passes.
No slit is located in the optical path of 1 (that is, the shutter 18
Block the excitation light L1). The shutter 18 in each optical path of the excitation light L1 and the illumination light L2
The opening and closing timings of the above are shown in (a) and (b) of FIG. 2, respectively. In this example, the opening / closing cycle of the shutter 18 is 1/120.
Seconds.

The diagnostic site 23 inside the living body 22 has a tumor 24, and the diagnostic site 23 is pre-absorbed with a photosensitizer having a tumor affinity and emitting fluorescence when excited by light. . As the photosensitizer, for example, a porphyrin-based substance is used. When the excitation light L1 or the illumination light L2 is applied to the diagnostic site 23, the light is reflected by the diagnostic site 23, and particularly when the excitation light L1 is applied, the photosensitizer emits fluorescence L3. . In order to detect such light, a condenser lens 25 and a light receiving optical fiber 26 are provided. The light receiving optical fiber 26 and the tip of the light transmitting optical fiber 14 are integrated and held by the probe 21 inserted into the living body 22.

Lights L3 and L1 that are condensed by the condenser lens 25 and are incident on one end of the light receiving optical fiber 26 into the fiber.
(Or L2) propagates through the optical fiber 26 and exits from the other end. The light emitted from the light receiving optical fiber 26 is collimated by the collimator lens 27,
A part is reflected at the beam splitter 28, and the rest is transmitted therethrough.

The light reflected by the beam splitter 28 is condensed by the condenser lens 29 and is incident on the first image pickup means 31 via the excitation light cut filter 30. The first image pickup means 31 provided for picking up a fluorescent image is composed of, for example, a CCD image pickup plate having a charge storage function capable of long-time exposure, and its output is input to an image display means 32 such as a CRT. It

On the other hand, the light transmitted through the beam splitter 28 is reflected by the mirror 33, is condensed by the condenser lens 34, and is incident on the second image pickup means 35. The second image pickup means 35 provided for picking up a normal image is composed of, for example, a color CCD image pickup plate, and the output thereof is also input to the image display means 32.

The beam splitter 28 and the condenser lens 29 are also provided.
A shutter 36 is inserted in the optical path between the mirror 33 and the condenser lens 34.
This shutter 36 has a plurality of slits (not shown),
It rotates by being driven by a motor 37 that rotates at high speed. The drive of the motor 37 is controlled by the motor drive control circuit 20 described above.

The plurality of slits of the shutter 36, like the shutter 18 described above, shutter the light reflected by the mirror 33 when one of them reaches a position where the light reflected by the beam splitter 28 passes. The shutter 36 is arranged so as to block the light reflected by the beam splitter 28 when one of the slits comes to a position where the light reflected by the mirror 33 passes, on the contrary, when the slit 36 blocks.

Here, the motor drive control circuit 20 drives the motor 19 and the motor 37 in synchronization with each other, so that the opening / closing timing of the shutter 36 in the optical path of the light reflected by the beam splitter 28 is as shown in FIG. The opening / closing timing of the shutter 18 in the optical path of the excitation light L1 shown in (a) is the same, and the opening / closing timing of the shutter 36 in the optical path of the light reflected by the mirror 33 is the illumination light L2 shown in (b) of FIG. It is assumed to be the same as the opening / closing timing of the shutter 18 in the optical path.

The operation of the fluorescent endoscope having the above structure will be described below. By rotating the shutter 18 as described above, the excitation light L1 and the illumination light L2 are alternately incident on the light transmitting optical fiber 14 at short time intervals. So the diagnostic site
The excitation light L1 and the illumination light L2, which are respectively emitted from the optical fiber 14 for light transmission in a pulse shape, are alternately applied to the light source 23.

Since the opening / closing timings of the shutter 18 and the shutter 36 are set as described above, the excitation light L
When 1 is irradiated to the diagnostic region 23, the optical path to the first imaging means 31 is opened and the optical path to the second imaging means 35 is closed,
On the other hand, when the diagnostic light 23 is irradiated with the illumination light L2, the second
The optical path to the image pickup means 35 is opened and the optical path to the first image pickup means 31 is closed.

Therefore, the fluorescent light L3 emitted from the diagnostic part 23 when the excitation light L1 is irradiated passes through the condenser lens 25, the light receiving optical fiber 26, the condenser lens 27, and the beam splitter 28 as described above, After passing through the slit of the shutter 36 and condensed by the condenser lens 29, the first image pickup means
It is incident on 31. Then, the fluorescent image of the diagnostic region 23 is picked up by the first image pickup means 31, and the fluorescent image A is displayed on the image display means 32. Since the photosensitizer has a tumor affinity, basically only the tumor portion is shown as the fluorescence image A.

Here, the operation timing of the charge accumulation of the first image pickup means 31 is as shown in FIG. 2 (c). That is, the first imaging unit 31 continues to accumulate electric charges for a relatively long time T (for example, about 1 second to several seconds) over a plurality of periods (1/240 seconds) during which the optical path of the fluorescence L3 toward the first imaging unit 31 is opened. . Therefore, the first image pickup means 31 detects the fluorescence L3 that is incident in a pulse shape at a cycle of 1/120 second in total for a long time, and the fluorescence image A can be imaged with high sensitivity.

While the first image pickup means 31 continues to accumulate electric charges in this way, the diagnostic region 23 is irradiated with the illumination light L2 several times, and the illumination light L2 reflected by the diagnostic region 23 at that time.
Part of is reflected by the beam splitter 28. However, since the optical path of the light toward the first image pickup means 31 is closed by the shutter 36 during the period in which the diagnostic region 23 is irradiated with the illumination light L2, the first image pickup means 31 detects the reflected illumination light L2. Only the fluorescence L3 is continuously detected. The excitation light L1 reflected by the diagnostic region 23 and traveling toward the first imaging means 31 is cut by the excitation light cut filter 30.

On the other hand, the illumination light L2 reflected by the diagnostic portion 23 when the illumination light L2 is irradiated is, as described above, the condensing lens.
After passing through 25, the light receiving optical fiber 26, the condenser lens 27, the beam splitter 28, and the mirror 33, the light passes through the slit of the shutter 36, is condensed by the condenser lens 34, and enters the second image pickup means 35. Then, the normal color image of the diagnostic region 23 is picked up by the second image pickup means 35, and the normal image B is displayed on the image display means 32.

Here, the operation timing of the charge accumulation of the second image pickup means 35 is as shown in FIG. 2 (d). That is, the second image pickup means 35 picks up the normal image B at the video rate of the NTSC standard whose field period is 1/60 second. Therefore, the normal image B of the diagnostic region 23 is displayed on the image display means 32 in real time. Therefore, the operator or the assistant observes the normal image B to determine the state of the diagnostic region 23, the probe 21 and the diagnostic region 23, and the like.
It is possible to confirm the positional relationship with. If so, the safety of the living body 22 is ensured even if the fluorescent image A is imaged for a long time as described above.

The first image pickup means 31 and the second image pickup means 35.
The operation timing of the charge accumulation of the motor drive control circuit 20
Is synchronized with the operation timings of the shutters 18 and 36 on the basis of the synchronization signal output by.

Further, in this example, the irradiation switching period of the excitation light L1 and the illumination light L2 is set sufficiently short as 1/120 seconds so that flicker is not felt in the displayed image. As described above, even if the irradiation switching cycle is short, the second image capturing unit 35 captures one image with the exposure time (1/80 seconds) over a plurality of periods during which the diagnostic region 23 is irradiated with the illumination light L2. Therefore, the normal image B is also captured with high sensitivity.

Further, while the second image pickup means 35 continues to accumulate electric charges, the diagnostic region 23 is irradiated with the excitation light L1 once,
At that time, the excitation light L1 and the fluorescence L reflected by the diagnostic region 23
Part of 3 passes through the beam splitter 28. However, since the shutter 36 closes the optical path of the light directed to the second image pickup means 35 during the period in which the diagnostic region 23 is irradiated with the excitation light L1, the second image pickup means 35 causes the reflected excitation light L1 and fluorescence L3 to be reflected. Is not detected, and only the illumination light L2 is detected.

In the embodiment described above, the drive of one shutter 36 is controlled by the motor drive control circuit 20 which constitutes the shutter control means.
A first shutter that restricts the passage of the fluorescent light L3 toward the 31 and a second shutter that restricts the passage of the illumination light L2 toward the second imaging unit 35 are provided separately.
The drive of one shutter may be controlled by the shutter control means.

Fluorescence L3 toward the first image pickup means 31
A first shutter for restricting the passage of light and a second image pickup means 35.
A second shutter that limits the passage of the illumination light L2 toward
Further, the shutter for switching the irradiation of the excitation light L1 and the illumination light L2 is not limited to a mechanically operated shutter, but a PLZ
It is also possible to use one made of T, PLHT, or the like.

Next, with reference to FIG. 3, a fluorescent endoscope according to a second embodiment of the present invention will be described. In FIG. 3, the same elements as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted unless necessary (the same applies hereinafter).

Compared with the fluorescent endoscope of the first embodiment, the fluorescent endoscope of the second embodiment has a structure for switching irradiation of excitation light and illumination light, and switching of this light irradiation. The configuration for controlling the drive of the shutter 36 in synchronism with is different. That is, in the second embodiment, the excitation light source 10 and the illumination light source 15 that emit the excitation light L1 and the illumination light L2 in pulses are used. And these excitation light source 10 and illumination light source 15
Is controlled by the light source drive control circuit 40 so that the other is turned on while one is turned off and the other is turned on when the other is turned off. These excitation light source 10 and illumination light source 15
The drive timings of the above are shown in (a) and (b) of FIG. 4, respectively. In the figure, ON indicates lighting and OFF indicates turning off.

The light source drive control circuit 40 and the motor drive control circuit 20 operate based on the synchronization signal input from the synchronization control circuit 41, so that the shutter 36 is opened / closed in the optical path of the light reflected by the beam splitter 28. The timing is the same as the ON-OFF timing of the excitation light source 10 shown in FIG. 4A, and the opening / closing timing of the shutter 36 in the optical path of the light reflected by the mirror 33 is shown in FIG. 4B. The timing is the same as the ON-OFF timing of the illumination light source 15.

Also in the above configuration, when the excitation light L1 is applied to the diagnostic region 23, the optical path to the first image pickup means 31 is opened and the optical path to the second image pickup means 35 is closed, while the illumination is illuminated. When the light L2 is applied to the diagnostic region 23, the optical path to the second image pickup means 35 is opened and the optical path to the first image pickup means 31 is closed.

The operation timings of the charge accumulation of the first image pickup means 31 and the second image pickup means 35 are (c) of FIG.
As shown in (d), the fluorescent image A and the normal image B are photographed and displayed in the same manner as in the first embodiment.

Next, with reference to FIGS. 5 and 6, a third embodiment of the fluorescence endoscope of the present invention will be described. In the fluorescence endoscope according to the third embodiment, what is generally called a shutter drum is used to switch irradiation between the excitation light L1 and the illumination light L2. The shutter drum 50 has a rotating body 52 which is rotationally driven in a fixed direction around a rotating shaft 51 by a driving unit (not shown). The rotation axis 51 is arranged in a direction orthogonal to the traveling directions of the excitation light L1 and the illumination light L2. 5 and 6 show a state in which the rotational positions of the rotating body 52 differ from each other by 90 °.

Two mirrors 53a and 53b are arranged on the rotating body 52 so that their height positions (direction parallel to the rotating shaft 51) are aligned with each other.
Similarly, the two beam traps 54a and 54b are fixed. The mirrors 53a and 53b are arranged at an angle of 180 ° around the rotary shaft 51 at positions where the distance from the rotary shaft 51 is equal to each other. Beam trap 54a, 54b
Also at positions where the distances from the rotation axis 51 are equal to each other,
It is arranged at an angle of 180 ° around the rotating shaft 51. The mirror 53a and the beam trap 54a have a rotating shaft.
They are arranged around 51 with a 90 ° angle offset from each other.

The rotating body 52 has the above-mentioned mirrors 53a and 53b.
The two mirrors 55a and 55b and the two beam traps 56a and 56b are fixed at the height positions different from those of the beam traps 54a and 54b with their height positions aligned with each other. The mirrors 55a and 55b are arranged at an angle of 180 ° around the rotary shaft 51 at positions where the distances from the rotary shaft 51 are equal to each other. Beam trap 56a, 56b
Also at positions where the distances from the rotation axis 51 are equal to each other,
It is arranged at an angle of 180 ° around the rotating shaft 51. The mirror 55a and the beam trap 56a are arranged around the rotating shaft 51 with a 90 ° angle offset from each other.

The lower mirrors 53a, 53b and the upper mirrors 55a, 55b in the figure are arranged around the rotating shaft 51 with a 90 ° angle offset from each other. Beam trap 54 in the lower part of the figure
a, 54b and the upper beam traps 56a, 56b are also rotating shafts.
There is a 90 ° angle offset around 51.
In addition, the lower mirrors 53a and 53b and the upper mirrors 55a and 55b
b is disposed at a position where the distance from the rotation shaft 51 is equal to each other. The lower beam traps 54a and 54b and the upper beam traps 56a and 56b in the figure are also arranged at positions where the distances from the rotating shaft 51 are equal to each other. The lower beam traps 54a and 54b are arranged closer to the rotary shaft 51 than the upper mirrors 55a and 55b.

In the above structure, both the excitation light source 10 and the illumination light source 15 are continuously driven. The rotating body 52 is shown in FIG.
When it reaches the rotational position shown in (1), the excitation light L1 is reflected by the mirror 53a and enters the condenser lens 13, where it is condensed and enters the light transmitting optical fiber 14. At this time, the illumination light L2 is absorbed by the beam trap 56a and does not enter the light transmitting optical fiber 14. Therefore, in this case, only the excitation light L1 is applied to the diagnosis region 23.

The fluorescent light L3 emitted from the diagnostic region 23 is reflected by the mirror 53b via the condenser lens 25, the light receiving optical fiber 26, and the condenser lens 27, and is condensed by the condenser lens 29, so that the first Is incident on the image pickup means 31. Then, the fluorescent image of the diagnostic region 23 is picked up by the first image pickup means 31, and the fluorescent image A is displayed on the image display means 32.

On the other hand, from the state shown in FIG.
When rotated, the state shown in FIG. 6 is obtained. In this state, the illumination light L2 is reflected by the mirror 55a and enters the condenser lens 13, where it is condensed and enters the light transmitting optical fiber 14. At this time, the excitation light L1 is absorbed by the beam trap 54a and does not enter the light transmitting optical fiber 14. Therefore, in this case, only the illumination light L2 is applied to the diagnosis region 23.

At this time, the illumination light L2 reflected by the diagnostic region 23
Is a condenser lens 25, an optical fiber 26 for receiving light, a condenser lens
After passing through 27, the light is reflected by the mirror 55b, is condensed by the condenser lens 34, and is incident on the second image pickup means 35. So this second
The color normal image of the diagnostic region 23 is picked up by the image pickup means 35 and the normal image B is displayed on the image display means 32.

From the state shown in FIG. 6, the rotary body 52 is further rotated by 90 °.
When rotated, the diagnostic region 23 is irradiated with the excitation light L1 and the fluorescence image A is captured. However, in this case, the excitation light L1 is reflected by the mirror 53b and the fluorescence L3 is reflected by the mirror 53a.
Will be reflected at.

When the rotator 52 further rotates by 90 ° from there, the diagnostic part 23 is illuminated with the illumination light L2 and the normal image B is captured. However, at this time, the illumination light L2 before entering the light transmitting optical fiber 14 is reflected by the mirror 55b, and the illumination light L2 reflected by the diagnostic portion 23 and emitted from the light receiving optical fiber 26 is reflected by the mirror 55a.

As described above, the fluorescent image A and the normal image B are alternately imaged as the rotator 52 rotates.

In this embodiment, the mirrors 53a, 53a
Although each of b acts as both an excitation light reflection mirror and a fluorescence reflection mirror, dedicated excitation light reflection mirrors and fluorescence reflection mirrors may be used. For example, in the structure shown in FIGS. 5 and 6, the mirrors 53a and 53b may be fixed to the rotating body 52 while changing their height positions.

Further, in this embodiment, the mirrors 55a, 55a
Each of the b's acts as both a light-transmitting illumination light reflection mirror and a light-receiving illumination light reflection mirror, and the same applies to them.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a fluorescence endoscope which is a first embodiment of the present invention.

FIG. 2 is a graph showing an opening / closing timing of a shutter for switching irradiation of excitation light and illumination light and an exposure timing of an image pickup unit in the first embodiment.

FIG. 3 is a schematic view showing a fluorescence endoscope which is a second embodiment of the present invention.

FIG. 4 is a graph showing lighting timings of an excitation light source and an illumination light source in the fluorescent endoscope of the second embodiment, and exposure timings of an imaging unit.

FIG. 5 is a schematic diagram showing a fluorescence endoscope which is a third embodiment of the present invention.

FIG. 6 is a schematic view showing a state different from that of FIG. 5 of the fluorescence endoscope of the third embodiment.

[Explanation of symbols]

 10 Excitation light source 11, 16, 27 Collimator lens 12 Dichroic mirror 13, 25, 29, 34 Condenser lens 14 Optical fiber for light transmission 15 Illumination light source 17, 33 Mirror 18, 36 Shutter 19, 37 Motor 20 Motor drive control circuit 21 Probe 22 Living body 23 Diagnostic site 26 Receiving optical fiber 28 Beam splitter 30 Excitation light cut filter 31 First imaging means 32 Image display means 35 Second imaging means 40 Light source drive control circuit 41 Synchronization control circuit 50 Shutter drum 51 Rotation axis 52 Rotating body 53a, 53b, 55a, 55b Mirror 54a, 54b, 56a, 56b Beam trap L1 Excitation light L2 Illumination light L3 Fluorescence

Claims (6)

[Claims] 1. Excitation light irradiating means for irradiating a site inside a living body absorbing a photosensitizer that emits fluorescence with excitation light in an excitation wavelength region of the photosensitizer, and a part inside the living body. Illumination light irradiating means for irradiating the irradiating light, and light irradiation switching means for switching the irradiation of the excitation light and the illuminating light to the site so as to be pulsed and alternately, and at a position where the fluorescence is incident. A first shutter arranged to limit the passage of the fluorescent light; a second shutter arranged to a position where the illumination light reflected by the site enters to limit the passage of the illumination light; and the light irradiation switching means. The driving of the two shutters is synchronized with the operation of the first shutter, and the first shutter is opened when the excitation light is applied to the part, and the second shutter is opened when the illumination light is applied to the part. Control to open Shutter control means, first imaging means for detecting the fluorescence through the first shutter, and capturing a fluorescence image of a living body for a plurality of exposure times during a period in which the shutter is open; And a second image pickup means for picking up a normal image of a living body by detecting the illumination light through the second shutter. 2. The fluorescent endoscope according to claim 1, wherein the first image pickup means is one that can change the exposure time. 3. The image pickup device according to claim 1, wherein the second image pickup device picks up the normal image for a plurality of exposure times during a period in which the second shutter is open. Fluorescent endoscope. 4. The excitation light irradiating means and the illumination light irradiating means continuously emit the excitation light and the illumination light, respectively, and the light irradiation switching means respectively in the optical paths of the excitation light and the illumination light. The fluorescence endoscope according to any one of claims 1 to 3, wherein the arranged shutters are opened alternately. 5. The light irradiation switching means is for illuminating each of the light sources constituting the excitation light irradiation means and the illumination light irradiation means alternately in a pulsed manner. The fluorescent endoscope according to item 1. 6. The excitation light irradiating means and the illumination light irradiating means continuously emit the excitation light and the illuminating light, respectively, and the light irradiation switching means is fixed to the rotating body and the rotating body. And an excitation light reflection mirror that reflects the excitation light in a direction toward the portion when the rotating body is at a predetermined rotation position, and the rotation body is fixed to the rotation body and the rotation body is different from the predetermined rotation position. An illumination light reflection mirror for transmitting light that reflects the illumination light in a direction toward the portion when in the position, wherein the first shutter, the second shutter, and shutter control means include the rotating body and the rotating body. A fluorescent reflection mirror fixed to a rotating body and configured to reflect the fluorescence in a direction toward the first imaging unit when the rotating body is in a rotation position where the excitation light reflecting mirror reflects the excitation light; Is fixed to the rotary body and is in a rotation position where the illuminating light reflecting mirror for transmitting light reflects the illuminating light, the illuminating light reflected by the portion is reflected in a direction toward the second imaging means. The fluorescence endoscope according to any one of claims 1 to 3, comprising an illumination light reflection mirror.