JP2680052B2 - Radiation detection endoscope - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a radiation detection endoscope capable of detecting radiation.

[Prior art] In recent years, by inserting an elongated insertion portion into a body cavity,
2. Description of the Related Art Endoscopes capable of observing organs in a body cavity and the like and performing various treatments using a treatment tool inserted into a treatment tool channel as necessary are widely used.

Also, various electronic endoscopes using a solid-state imaging device such as a charge-coupled device (CCD) as an imaging unit have been proposed.

By the way, as a means for detecting and diagnosing cancer, a substance that specifically aggregates in cancer cells is marked with a radioactive substance, and radiation emitted from the cancer cells is detected to determine the presence, invasion range, or metastasis of cancer. Is being done.

Further, for example, Japanese Utility Model Publication No. 47-5168 discloses an endoscope in which a radiation detecting element is provided at the tip. The endoscope shown in this prior art example uses a light guide body made of a flexible thin wire, that is, a fiber bundle as an observation means. Providing a detection element is also conceivable. Also,
As shown in the specification of Japanese Patent Application No. 63-126588 filed by the applicant of the present application, the solid-state imaging device for observation itself may be used as the radiation detecting means. In this case, when radiation such as γ-rays is incident on the solid-state image sensor, it is displayed as a bright spot on the monitor screen.

[Problems to be Solved by the Invention] However, during normal observation, when a pixel signal containing a lot of noise generated by radiation incident on a solid-state image sensor is displayed as it is, bright spots appear on the screen, making it difficult to see. is there.

[Object of the Invention] The present invention has been made in view of the above circumstances, and provides a radiation detection endoscope capable of obtaining an easily observable image in which noise on the screen due to radiation is reduced during normal observation. The purpose is to do.

[Means for Solving the Problems] A radiation detection endoscope of the present invention is an endoscope that uses a solid-state image sensor as an image pickup unit and a radiation detection unit, and compares a signal obtained from the solid-state image sensor with a reference value. And a means for replacing the signal of the signal portion with a predetermined value when the signal portion exceeding the reference value is detected by the comparing means.

[Operation] In the present invention, at the time of normal observation, a signal obtained from the solid-state image sensor, for example, each pixel signal is compared with a reference value by the comparison means, and a signal exceeding the reference value is given a predetermined value, for example, a pixel adjacent to that pixel By substituting the value of the signal of ## EQU1 ## for the radiation, an image in which noise due to radiation is reduced can be obtained.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

1 and 2 relate to an embodiment of the present invention. FIG. 1 is an explanatory view showing a configuration of an endoscope apparatus, and FIG. 2 shows an endoscope distal end portion in a modified example of the present embodiment. FIG.

As shown in FIG. 1, the endoscope 1 includes an elongated and flexible insertion portion 2, for example, and a large-diameter operation portion 3 is connected to the rear end of the insertion portion 2. A flexible universal cord 4 is laterally extended from the operation portion 3, and a connector 6 detachably connected to the processing device 5 is provided at an end portion of the universal cord 4.

An observation window, an illumination window, and a treatment tool channel opening are provided at the distal end portion 10 of the insertion portion 2. A cylindrical collimator 11 made of a radiopaque material such as lead is mounted inside the observation window, and an objective lens system 12 is mounted in the collimator 11. In addition, a solid-state image sensor, for example, a CCD 15 is arranged at the image forming position of the objective lens system 12 at the back of the collimator 11.

In addition, when the simultaneous type is used as the color imaging method,
On the front surface of the CCD 15, there is provided a color filter array in which filters for transmitting respective color lights of R (red), G (green), B (blue) and the like are arranged in a mosaic pattern.

A signal line 26 is connected to the CCD 15 and the signal line 26
Is inserted into the insertion portion 2, the operation portion 3 and the universal cord 4 and connected to the connector 6.

In addition, a light distribution lens is provided inside the illumination window of the distal end portion 10.
31 is arranged, and a light guide 32 is connected to the rear end side of the light distribution lens 31. The light guide 32 is inserted into the insertion portion 2, the operation portion 3 and the universal cord 4, and the incident end portion is connected to the connector 6.

In addition, a treatment instrument channel 35 is formed in the insertion portion 2, the distal end side of the treatment instrument channel 35 is opened by the treatment instrument channel opening of the distal end portion 10, and the proximal end side of the operation portion 3 is formed. An insertion opening 36 is formed so as to open laterally.

On the other hand, the treatment device 5 includes a lamp 41 that emits illumination light.
The illumination light emitted from the lamp 41 is incident on the incident end of the light guide 32. The treatment device 5 also includes a drive unit 42 connected to the CCD 15 via the signal line 26 and the connector 6, and a comparator 43. The CCD 15 is driven by the driving unit 42, and the pixel signal read from the CCD 15 is input to the comparator 43. This pixel signal is passed through the comparator 43, and the A / D
A / D conversion is performed by the converter 44, and the converted data is input to the memory 45.

The comparator 43 can be set to be switched between a normal observation mode and a radiation detection mode. In the normal observation mode, the comparator 43 compares each input pixel signal with a reference value, and stores a signal below the reference value at a predetermined address of the memory 45 as it is, For a signal exceeding the value, the same value as the signal immediately before the signal is stored in a predetermined address of the memory 45. If two or more pixel signals continuously exceed the reference value and the immediately preceding signal also exceeds the reference value, the value of the signal of the reference value or less in the previous pixel is stored in the memory 45. This is, for example, provided with storage means for holding a signal below the latest reference value, and for a signal exceeding the reference value, instead of the signal, outputs a signal below the latest reference value stored in the storage means. It can be realized by doing. On the other hand, in the radiation detection mode, the comparator 43 outputs each input pixel signal as it is.

The memory 45, by the memory address instruction unit 46,
Addresses for writing and reading are designated. The timing and the like of the memory address designating section 46 and the driving section 42 are controlled by the control section 47.

When one frame of pixel signal is stored in the memory 45, the memory 45 is read out, D / A converted by the D / A converter 48, input to the signal processing circuit 49, and video signal processed. It has become. Then, the video signal output from the signal processing circuit 49 is input to the display unit 50 such as a monitor,
A subject image is displayed on the display unit 50.

 Next, the operation of the present embodiment will be described.

When a cancer or the like is examined using the endoscope 1 of the present embodiment, a cancer antibody marked with a radioisotope, deoxyoxyglucose, etc., which easily collects in the cancer, are intravenously injected at a predetermined time before the examination. And inject it into the body. In a cancer, these reagents gather and the cancer emits radiation, for example, gamma rays.

When the insertion portion 2 of the endoscope 1 is inserted into the body cavity and the lamp 41 in the processing device 5 is caused to emit light, the illumination light emitted from the lamp 41 is incident on the light guide 32 of the endoscope 1. Incident on. This light is transmitted to the tip 10 by the light guide 32.
, And irradiate the subject through the light distribution lens 31.

The optical image of this subject is captured by the objective lens system 12 at CC
Imaged on D15.

Further, when the distal end portion 10 of the endoscope 1 is located at a position facing the cancer, γ-rays emitted from the cancer enter the collimator 11 through the opening of the collimator 11. Then, the γ-ray hits the PN junction of the CCD 15 to generate a signal, and the γ-ray is detected.

The CCD 15 is driven by the driving unit 42, and the read pixel signal is input to the comparator 43. In the normal observation mode, the comparator 43 compares each input pixel signal with a reference value, and stores a signal below the reference value at a predetermined address of the memory 45 as it is, For signals that exceed the value, set the same value as the signal immediately before that signal and below the reference value in the memory 45.
Stored at a predetermined address of. When one frame of pixel signal is stored in the memory 45, the memory 45 is read out, D / A converted by the D / A converter 48, and video signal processed by the signal processing circuit 49. The video signal output from 49 is input to the display unit 50. And this display unit 50
The subject image is displayed on. In this case, for a pixel whose signal level becomes equal to or higher than the reference value due to the noise caused by the radiation, the signal value of the pixel in the vicinity is replaced. No, it is easy to observe.

On the other hand, in the radiation detection mode, the comparator 43
Outputs each input pixel signal as it is. Therefore, in this case, a bright spot due to the radiation appears in the image displayed on the display unit 50, and thus the radiation can be detected. Note that the illumination light may be dimmed or turned off when the radiation is detected.

Thus, according to the present embodiment, during normal observation, the observation image of the endoscope 1 does not show bright spots due to radiation, and an image that is easy to see and easy to observe can be obtained.

In the above embodiment, the CCD 15 serves both as the image pickup means and the radiation detection means, but as shown in FIG. 2, a semiconductor is provided at the distal end portion 10 of the insertion portion 2 of the endoscope 1 separately from the CCD 15. A radiation detecting means such as the radiation detector 51 may be provided. The semiconductor radiation detector 51 is connected to a signal processing circuit (not shown) via a signal line 52, and radiation information from this signal processing circuit is displayed on the display unit 50 or a display different from the display unit 50. It is supposed to be displayed in the means.

It should be noted that the present invention is not limited to the above embodiment, and for example, for a pixel having a signal exceeding the reference value, it is not the pixel immediately preceding the pixel but the pixel having a signal having the reference value or less in the vicinity of the pixel It may be replaced with a signal value. In this case CCD1
The pixel signal of 5 may be stored in the memory once, and the above process may be performed while being read from this memory and stored again in another memory.

Further, the value to be replaced with the signal exceeding the reference value is not limited to the value of the neighboring pixels, but may be a value obtained by reducing the signal to a predetermined ratio, a value obtained by subtracting a constant value from the signal, or a constant value. Is also good.

Alternatively, the pixel signal from the CCD 15 may be subjected to video signal processing to be converted into a video signal, the video signal may be compared with a reference value, and the signal of the signal portion equal to or higher than the reference value may be replaced with a predetermined value. In this case, a signal having a reference value or more may be clipped.

Further, the color imaging system is not limited to the simultaneous system, but may be a frame sequential system in which illumination light is sequentially switched to R, G, B and the like.

Further, the radiation is not limited to γ rays, but may be α rays or β rays.

As described above, according to the present invention, the signal from the solid-state image sensor is compared with the reference value, and the signal in the signal portion exceeding the reference value can be replaced with a predetermined value. At the time of observation, there is an effect that an easily observable image in which noise on the screen due to radiation is reduced can be obtained.

[Brief description of the drawings]

1 and 2 relate to an embodiment of the present invention. FIG. 1 is an explanatory view showing a configuration of an endoscope apparatus, and FIG. 2 shows an endoscope distal end portion in a modified example of the present embodiment. FIG. 1 ... Endoscope, 2 ... Insertion part 10 ... Tip part, 11 ... Collimator 12 ... Objective lens system, 15 ... CCD 43 ... Comparator, 45 ... Memory 49 ... Signal processing part, 50 ...... Display

 ─────────────────────────────────────────────―― ─── Continuation of the front page (72) Mutsumi Yoshikawa 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Co., Ltd. (72) Inventor Motoyuki Tagawa 2-43 Hatagaya, Shibuya-ku, Tokyo No. Olympus Optical Industry Co., Ltd. (72) Inventor Makoto Inaba 2-43-2 Hatagaya, Shibuya-ku, Tokyo Olympus Optical Industry Co., Ltd. (72) Masaaki Hayashi 2-43-2 Hatagaya, Shibuya-ku, Tokyo No. Olympus Optical Industry Co., Ltd. (56) Reference JP-A-64-74489 (JP, A)

Claims (1)

(57) [Claims] 1. An endoscope using a solid-state image sensor as an image pickup means and a radiation detection means, comparing means for comparing a signal obtained from the solid-state image sensor with a reference value, and the reference value by the comparing means. A radiation detecting endoscope, which is provided with a means capable of replacing the signal of the exceeding portion with a predetermined value when the signal portion is detected.