JP2013039224A - Smoke detecting method and device, and image pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a smoke detector for detecting smoke generated in a part to be observed on the basis of an image picked up by irradiating the part with a light, wherein highly precise smoke detection is executed by suppressing erroneous smoke detection.SOLUTION: First images based on a light emitted from the part to be observed by irradiating the part to be observed with a first light having a first wavelength band are acquired in time series. Second images based on light emitted from the part to be observed by irradiating the part to be observed with a second light having a wavelength band longer than the first wavelength band are acquired in time series. If the time-series change amount of the first images acquired in time series becomes not less than a predetermined amount and then the time-series change amount of the second images acquired in series becomes not less than a predetermined amount, it is determined that smoke is generated in a vicinity of the part to be observed.

Description

  The present invention relates to a smoke detection method and apparatus for detecting smoke generated in an observed part based on an image acquired by irradiating light to the observed part, and an image pickup apparatus.

  Conventionally, endoscope systems for observing tissue in a body cavity are widely known, and a normal image is obtained by imaging a portion to be observed in a body cavity by irradiation with white light, and this normal image is displayed on a monitor screen. Electronic endoscope systems have been widely put into practical use.

  Further, as an endoscope system as described above, for example, together with a normal image, an autofluorescence image emitted from an observed part by irradiation of excitation light is captured to obtain an autofluorescence image, and these images are displayed on a monitor screen. A fluorescence endoscope system for displaying on the screen has been proposed.

  In addition, as a fluorescence endoscope system, for example, ICG (Indocyanine Green) is introduced into the body in advance, and the fluorescence image of the blood vessel is detected by irradiating the observation part with excitation light and detecting the fluorescence of ICG in the blood vessel. Some have also been proposed.

  Here, during the operation using the endoscope system as described above, a part of the tissue in the body cavity may be extracted with an electric knife, or a cauterization treatment may be performed for hemostasis. When such a treatment is performed, smoke or mist is generated from the tissue, and the field of view of the displayed normal image or fluorescent image is deteriorated, or the lens at the tip of the endoscope is soiled. Further, particularly in a fluorescence endoscope system, when the field of view is deteriorated due to smoke as described above, it is not preferable from the viewpoint of safety to continuously irradiate the observation part with the excitation light as it is.

  Therefore, when smoke or the like is generated as described above, it is necessary to operate the smoke evacuation device to perform smoke evacuation in the body cavity, to wash the tip of the endoscope, or to stop the excitation light. In a situation where an endoscope is inserted into a body cavity and a surgical operation is performed using an electric knife, it is very difficult to perform a smoke exhausting operation, an endoscope cleaning operation, or an excitation light stopping operation. is there.

  Therefore, for example, in Patent Document 1, a concentration measuring device for measuring the concentration of smoke or mist is provided at the tip of an endoscope, and the concentration of smoke or mist measured by the concentration measuring device is higher than a predetermined threshold value. It has been proposed to automatically operate the smoke evacuation device when it becomes. Patent Document 1 also proposes acquiring smoke and mist density information based on the result of edge extraction processing and pattern processing performed on an image signal captured by an endoscope.

  Patent Document 2 proposes a method for detecting smoke by detecting movement and color in an image captured by an endoscope.

JP-A-11-309156 JP 11-318909 A

  However, for example, when a concentration measuring device is provided as in Patent Document 1, the cost is increased and the diameter of the distal end of the endoscope becomes large, which is not preferable. In addition, if smoke is detected by the edge of an image captured by an endoscope, it can be distinguished whether the edge is blurred due to smoke or the subject itself is highly smooth. Therefore, there is a possibility that smoke is erroneously detected.

  In addition, as in Patent Document 2, when smoke is detected by detecting movement and color in an image captured by an endoscope, the movement of smoke or the movement of an imaging target itself such as an internal organ is not detected. In addition, there is a possibility that the subject to be photographed is whitish in color detection, and smoke may be erroneously detected.

  In view of the above problems, the present invention suppresses false detection in a smoke detection method and apparatus and an image imaging apparatus that detect smoke generated in an observed part based on an image captured by an endoscope or the like, An object of the present invention is to provide a smoke detection method and apparatus capable of performing highly accurate smoke detection and an image pickup apparatus.

  The smoke detection device of the present invention acquires the first image based on the light emitted from the observed part by irradiating the observed part with the first light having the first wavelength band. And a second image based on the light emitted from the observed part by irradiating the observed part with the second light having a wavelength band longer than the first wavelength band. The second image acquired in time series by the second image acquisition unit after the temporal change amount of the first image acquired in time series by the acquisition unit and the first image acquisition unit exceeds a predetermined amount. And a smoke generation determination unit that determines that smoke has been generated around the observed portion when the amount of change with time of the image exceeds a predetermined amount.

  In the smoke detection device of the present invention, the smoke generation determination unit can acquire the temporal change amount of the color component of the first or second image.

  In addition, the smoke generation determination unit can acquire the temporal change amount of the first wavelength component and the second wavelength component including the shorter wavelength component than the first wavelength component as the temporal change amount of the color component.

  In addition, the first wavelength component can be a red component and the second wavelength component can be a white component.

  Further, the smoke generation determination unit can acquire the temporal change amount of the frequency component of the first or second image.

  Further, the smoke generation determination unit can acquire the temporal change amount of the ratio between the frequency component on the high frequency side and the frequency component on the low frequency side as the temporal change amount of the frequency component.

  In addition, the first image acquisition unit can acquire a visible image based on reflected light emitted from the observed portion by irradiation with visible light as the first light as the first image.

  Further, the second image acquisition unit can acquire, as the second image, a fluorescence image based on the fluorescence emitted from the observed unit by irradiation with excitation light as the second light.

  Moreover, near infrared light can be used as excitation light.

  In addition, the smoke generation determination unit can switch detection or non-detection of the generation of smoke according to the irradiation or non-irradiation of the first and second lights.

  The smoke detection method of the present invention acquires, in time series, a first image based on light emitted from an observed part by irradiating the observed part with first light having a first wavelength band. A second image based on the light emitted from the observed part by irradiating the observed part with the second light having a wavelength band longer than the wavelength band of 1 is acquired in time series, and the time series After the amount of change over time of the acquired first image becomes equal to or greater than a predetermined amount, when the amount of change over time of the second image acquired in time series becomes equal to or greater than a predetermined amount, smoke is generated around the observed portion. It is characterized by determining that it has occurred.

  The image pickup apparatus of the present invention emits light from the observed portion by irradiating the smoke detecting device, the light irradiating portion that irradiates the observed portion with the first and second lights, and the first light to the observed portion. A first imaging unit that captures a first image based on the emitted light, and a second image that captures a second image based on the light emitted from the observed unit by irradiation of the second light onto the observed unit And an imaging unit.

  The image pickup apparatus of the present invention further includes an insertion portion that is inserted into the body and guides light emitted from the observed portion by irradiation of the first and second lights to the observed portion. I can do it.

  According to the smoke detection method and apparatus and the image pickup apparatus of the present invention, the first image is acquired in time series by irradiating the observed portion with the first light having the first wavelength band, and the first image The second image is acquired in time series by irradiating the observed portion with the second light having a wavelength band longer than the wavelength band, and the temporal change amount of the first image acquired in the time series is given. When the amount of change over time of the second image acquired in the above time series becomes equal to or greater than a predetermined amount after the amount exceeds the fixed amount, it is determined that smoke has been generated around the observed portion. The generation of smoke can be determined based on the amount of change over time of two images due to irradiation of light having different wavelength bands. For example, when the generation of smoke is determined based on only one image feature as in the prior art Compared to , It is possible to perform highly accurate smoke detection.

  Here, as described above, the generation of smoke is determined based on the amount of change over time of two images by irradiation of light having different wavelength bands. This is because the smoke is more likely to be scattered than the second light, that is, the smoke image is more likely to appear in the first image than in the second image. That is, when smoke is generated around the observed portion, the timing at which the smoke image appears in the first image is later than the timing at which the smoke image appears in the second image. In the present invention, the occurrence of smoke is determined based on the amount of change over time of two images due to the irradiation of light having different wavelength bands by utilizing the occurrence of such a timing difference.

Schematic configuration diagram of a rigid endoscope system using an embodiment of the smoke detection device of the present invention Schematic configuration diagram of body cavity insertion part Schematic configuration diagram of the imaging unit The block diagram which shows schematic structure of an image processing apparatus and a light source device Block diagram showing schematic configuration of smoke detector The flowchart for demonstrating the effect | action of the rigid endoscope system using one Embodiment of the smoke detection apparatus of this invention.

  Hereinafter, a rigid endoscope system using an embodiment of a smoke detection device of the present invention will be described in detail with reference to the drawings. The rigid endoscope system of the present embodiment is characterized by a method for detecting smoke generated during an operation on the observed portion. First, the configuration of the entire rigid endoscope system will be described. FIG. 1 is a diagram showing a schematic configuration of a rigid endoscope system 1 of the present embodiment.

  As shown in FIG. 1, the rigid endoscope system 1 of the present embodiment includes a light source device 2 that emits normal light of white light and excitation light of near infrared light, and normal light emitted from the light source device 2 and excitation. While irradiating the observed part with light, a normal image based on the reflected light reflected from the observed part by white light irradiation and a fluorescent image based on the fluorescence emitted from the observed part by irradiating excitation light are captured. The rigid endoscope imaging device 10, a processor 3 that performs predetermined processing on the image signal imaged by the rigid endoscope imaging device 10, and outputs a control signal to the light source device 2 and an air / water supply device 5 described later, and the processor 3 The monitor 4 that displays the fluorescent image and the normal image of the observed portion based on the display control signal generated in step S3, and physiological saline and carbon dioxide are supplied to the rigid endoscope imaging device 10 in accordance with the control signal from the processor 3. The air and water supply device 5, and an electric knife control device 6 for controlling the output of the electric knife 7 on the basis of a control signal output from the processor 3.

  As shown in FIG. 1, the rigid endoscope imaging apparatus 10 includes a body cavity insertion unit 30 that is inserted into a body cavity, and an imaging unit 20 that captures a normal image and a fluorescence image of the observed portion guided by the body cavity insertion unit 30. And.

  As shown in FIGS. 1 and 2, the rigid endoscope imaging apparatus 10 has a body cavity insertion unit 30 and an imaging unit 20 that are detachably connected. The body cavity insertion portion 30 includes a connection member 30a, an insertion member 30b, a cable connection port 30c, an irradiation window 30d, an imaging window 30e, and a washing nozzle 30f.

  The connection member 30a is provided on one end side 30X of the body cavity insertion part 30 (insertion member 30b). For example, the connection member 30a is fitted into an opening 20a formed on the imaging unit 20 side, whereby the imaging unit 20 and the body cavity insertion part 30 are connected. Are detachably connected.

  The insertion member 30b is inserted into the body cavity when photographing inside the body cavity, and is formed of a hard material and has, for example, a cylindrical shape with a diameter of about 5 mm. A lens group for forming an image of the observed portion is accommodated in the insertion member 30b, and the normal image and the fluorescent image of the observed portion incident from the imaging window 30e on the other end side 30Y are lenses. The light is emitted to the imaging unit 20 side of the one end side 30X through the group.

  A cable connection port 30c is provided on the side surface of the insertion member 30b, and the optical cable LC is mechanically connected to the cable connection port 30c. Thereby, the light source device 2 and the insertion member 30b are optically connected via the optical cable LC. The optical cable LC is formed from a bundle fiber that guides normal light and excitation light.

  The irradiation window 30d is provided on the other end side 30Y of the body cavity insertion part 30, and irradiates the observed part with normal light and excitation light guided by the optical cable LC. A bundle fiber that guides normal light and excitation light from the cable connection port 30c to the irradiation window 30d (not shown) is accommodated in the insertion member 30b, and the tip of the bundle fiber is polished. An irradiation window 30d is formed.

  The cleaning nozzle 30f provided at the tip of the insertion member 30b discharges physiological saline and carbon dioxide supplied from the air / water supply device 5 to the irradiation window 30d and the imaging window 30e, and cleans them. Although not shown in FIG. 2, the body cavity insertion portion 30 is provided with a tube or the like for guiding physiological saline or carbon dioxide supplied from the air / water supply device 5 to the cleaning nozzle 30f. To do.

  FIG. 3 is a diagram illustrating a schematic configuration of the imaging unit 20. The imaging unit 20 includes a first imaging system that captures a fluorescent image of the observed part imaged by the lens group in the body cavity inserting unit 30 and generates a fluorescent image signal of the observed part, and the body cavity inserting unit 30 And a second imaging system that generates a normal image signal by capturing a normal image of the observed portion formed by the lens group. These imaging systems are divided into two optical axes orthogonal to each other by a dichroic prism 21 having a spectral characteristic that reflects a normal image and transmits a fluorescent image.

  The first imaging system cuts light having a wavelength equal to or less than the wavelength of the excitation light reflected at the observed portion and transmitted through the dichroic prism 21 and from the excitation light cut filter 22 that transmits the fluorescent image L4 and the body cavity insertion portion 30. A first imaging optical system 23 that forms a fluorescent image L4 that is emitted and transmitted through the dichroic prism 21 and the excitation light cut filter 22, and a high image that captures the fluorescent image L4 formed by the first imaging optical system 23. And a sensitivity image sensor 24.

  The second imaging system includes a second imaging optical system 25 that forms a normal image L3 emitted from the body cavity insertion unit 30 and reflected by the dichroic prism 21, and a normal image formed by the second imaging optical system 25. An image sensor 26 that captures the image L3 is provided.

  The high-sensitivity imaging element 24 detects light in the wavelength band of the fluorescent image L4 with high sensitivity, converts it into a fluorescent image signal, and outputs it. In the present embodiment, an image sensor that captures a monochrome image is used as the high-sensitivity image sensor 24.

  The image sensor 26 detects light in the wavelength band of the normal image, converts it into a normal image signal, and outputs it. On the image pickup surface of the image pickup element 26, color filters of three primary colors red (R), green (G) and blue (B), or cyan (C), magenta (M) and yellow (Y) are arranged in a Bayer array or a honeycomb. It is provided in an array.

  In addition, the imaging unit 20 includes an imaging control unit 27. The imaging control unit 27 performs CDS / AGC (correlated double sampling / automatic gain control) processing and A / A processing on the fluorescence image signal output from the high-sensitivity imaging device 24 and the normal image signal output from the imaging device 26. D conversion processing is performed and output to the processor 3 via a cable.

  As shown in FIG. 4, the processor 3 includes a normal image input controller 31, a fluorescence image input controller 32, an image processing unit 33, a memory 34, a video output unit 35, an operation unit 36, a TG (timing generator) 37, a CPU 38, and smoke. A detection unit 39 is provided.

  The normal image input controller 31 and the fluorescence image input controller 32 include a line buffer having a predetermined capacity, and the normal image input controller 31 receives the normal image signal for each frame output from the imaging control unit 27 of the imaging unit 20. The fluorescent image input controller 32 temporarily stores fluorescent image signals. Then, the normal image signal stored in the normal image input controller 31 and the fluorescent image signal stored in the fluorescent image input controller 32 are stored in the memory 34 via the bus.

  The image processing unit 33 receives a normal image signal and a fluorescence image signal for each frame read from the memory 34, performs predetermined image processing on these image signals, and outputs them to the bus.

  The video output unit 35 receives the normal image signal and the fluorescence image signal output from the image processing unit 33 via the bus, performs predetermined processing to generate a display control signal, and outputs the display control signal to the monitor 4. Output.

  The operation unit 36 receives input by the operator such as various operation instructions and control parameters. The TG 37 outputs a driving pulse signal for driving the high-sensitivity imaging device 24, the imaging device 26 of the imaging unit 20, and the LD driver 45 of the light source device 2 described later. The CPU 38 controls the entire system.

  The smoke detection unit 39 is picked up by the electric scalpel 7 or the like when the observed part in the body cavity is treated based on the normal image signal and the fluorescence image signal which are imaged by the rigid endoscope imaging device 10 and sequentially input in time series. It detects the generated smoke.

  FIG. 5 is a diagram illustrating a specific configuration of the smoke detection unit 39. As shown in FIG. 5, the smoke detection unit 39 includes a color component calculation unit 50, a frequency component calculation unit 51, a reference information storage unit 52, and a smoke generation determination unit 53.

  The color component calculation unit 50 analyzes the normal image signal input in time series and sequentially calculates the information of the color component included in the normal image signal. In the present embodiment, specifically, The information on the red component and the information on the white component included in the normal image signal is calculated, and the information is output to the reference information storage unit 52 and the smoke generation determination unit 53.

  Here, the information of the red component and the information of the white component are acquired because when the smoke is not generated in the observed portion, the red component such as the internal organ is relatively included in the normal image signal. On the other hand, when smoke is generated in the observed portion, since the normal image signal contains a relatively larger white component than a red component, these color components This is because the ratio included in the normal image signal is an index for determining the presence or absence of smoke. In the present embodiment, the red component is calculated in addition to the white component representing smoke. However, the present invention is not limited to this, and other color components may be calculated. For example, the skin color component is calculated. It may be. Alternatively, in addition to the ratio between the red component and the white component, the ratio between the other first wavelength component and the second wavelength component including a component having a shorter wavelength than the first wavelength component is acquired. It may be.

  The frequency component calculation unit 51 analyzes the normal image signal and the fluorescence image signal input in time series, and sequentially calculates information on the frequency components included in the normal image signal and the fluorescence image signal. Specifically, the normal image signal and the fluorescence image signal are subjected to Fourier transform to calculate the spatial frequency component distribution, and the information is output to the reference information storage unit 52 and the smoke generation determination unit 53. Is.

  Here, the information of the frequency component included in the normal image signal and the fluorescent image signal is calculated because the normal image signal and the fluorescent image signal are not included in the normal image signal and the fluorescent image signal when smoke is not generated in the observed portion. If there is a relatively large amount of high-frequency component image signals representing the contours and blood vessels of the human body, while smoke is generated in the observed part, the internal organs and blood vessels are blurred by the smoke, so that the normal image Since the signal contains a relatively large amount of low-frequency component image signals, the ratio between the high-frequency side frequency component and the low-frequency side frequency component is an index for determining the presence or absence of smoke. Because.

  The reference information storage unit 52 uses the color component information of the normal image signal and the frequency component information of the normal image signal and the fluorescent image signal calculated at the start of imaging of the normal image and fluorescent image of the observed portion as the reference color component information. And stored as reference frequency component information. The reference color component information and the reference frequency component information serve as a reference for calculating the temporal change amount of the color component information and the frequency component information of the normal image signal and the fluorescence image signal that are currently captured. In the present embodiment, the color component information and the frequency component information calculated at the start of imaging are used as the reference color component information and the reference frequency component information. Alternatively, the color component information and the frequency component information calculated at the time may be used as the reference color component information and the reference frequency component information.

  The smoke generation determination unit 53 acquires a first time at which smoke is assumed to be generated in the normal image based on the temporal change amount of the color component information and the frequency component information of the normal image signal input in time series. And a second time when smoke is assumed to be generated in the fluorescent image based on the temporal change amount of the frequency component information of the fluorescent image signal input in time series, and from the first time When the second time is late, it is finally determined that smoke is generated around the observed portion.

  Here, as described above, the smoke is generated using both the first time at which smoke is assumed to be generated in the normal image and the second time at which smoke is assumed to be generated in the fluorescent image. The presence / absence determination is performed, for example, when the presence / absence of smoke is determined only based on the temporal change in the color component and frequency component information of the normal image. The ratio of the low-frequency component of the signal is not increased, but the ratio of the low-frequency component may be increased because the organ with high smoothness is simply taken as an object to be photographed. In some cases, the white component of the image signal does not increase, but the white component increases because the target is simply a whitish organ. In such a case, there is a possibility of false detection of smoke. Because there is.

  Furthermore, since normal light (white light) irradiated to the observed part when capturing a normal image is light in a wide wavelength band that is relatively shorter than the excitation light, scattering by smoke is more than that of the excitation light. That is, the smoke image is more likely to appear in the normal image than in the fluorescent image. Therefore, when smoke is generated around the observed portion, the time at which the smoke image appears in the fluorescent image is later than the time at which the smoke image appears in the normal image. The smoke detection unit 39 of the present embodiment uses the phenomenon in which this time difference is generated, and it is assumed that smoke is generated in the first time when the smoke is generated in the normal image and the fluorescence image. The second time is acquired, and when the second time is later than the first time, it is finally determined that smoke has occurred, so that more accurate smoke detection is performed. It is a thing.

  When the smoke generation determination unit 53 determines that smoke is present around the observed portion, the smoke generation determination unit 53 outputs a smoke detection signal to the CPU 38 of the processor 3. The CPU 38 outputs a predetermined control signal to the light source device 2, the air / water supply device 5, and the electric knife control device 6 in accordance with the input smoke detection signal.

  Returning to FIG. 4, the light source device 2 collects the normal light source 40 that emits normal light (white light) L <b> 1 having a broadband wavelength of about 400 to 700 nm and the normal light L <b> 1 emitted from the normal light source 40. The optical lens 42 and the dichroic mirror that transmits the normal light L1 collected by the condenser lens 42, reflects the excitation light L2 described later, and makes the normal light L1 and the excitation light L2 enter the incident end of the optical cable LC. 43. For example, a xenon lamp is used as the normal light source 40. A diaphragm 41 is provided between the normal light source 40 and the condenser lens 42, and the amount of the diaphragm is controlled based on a control signal from an ALC (Automatic light control) 48.

  The light source device 2 includes a near-infrared LD light source 44 that emits near-infrared light of 750 to 830 nm as excitation light L2, an LD driver 45 that drives the near-infrared LD light source 44, and a near-infrared LD light source 44. A condensing lens 46 that condenses the excitation light L2 emitted from the light source, and a mirror 47 that reflects the excitation light L2 collected by the condensing lens 46 toward the dichroic mirror 43.

  Then, the LD driver 45 of the present embodiment stops the emission of the excitation light L2 from the near-infrared LD light source 44 according to the control signal output from the CPU 38 by the smoke detection signal output from the smoke detection unit 39. Is.

  In addition, as excitation light L2, the wavelength of a narrow band is used rather than the normal light which consists of a broadband wavelength. And as excitation light L2, it is not limited to the light of the said wavelength range, It determines suitably according to the kind of fluorescent pigment | dye, or the kind of biological tissue made to autofluoresce.

The air / water supply device 5 includes a CO ₂ cylinder in which carbon dioxide gas is stored, a liquid storage tank in which physiological saline is stored, an air / water supply control unit that controls air / water supply of carbon dioxide gas and physiological chlorine, and the like. I have. The air / water supply control unit supplies air / water and supplies carbon dioxide gas or physiological saline to the body cavity insertion unit 30 when an instruction to supply air or water is received in the operation unit 36 of the processor 3, for example. In addition, air or water is supplied according to the control signal output from the CPU 38 by the smoke detection signal output from the smoke detector 39.

  The electric knife control device 6 outputs a control signal to the electric knife 7 in accordance with the output of the electric knife 7 set and inputted by the user, and controls the output of the electric knife 7. Further, the smoke detector 39 The control signal is output to the electric knife 7 so as to lower the currently set output of the electric knife 7 in accordance with the control signal output from the CPU 38 in accordance with the smoke detection signal output from.

  In the present embodiment, as described above, when smoke is detected by the smoke detection unit 39, the emission of the excitation light L2 from the light source device 2 is stopped, or the air / water supply device 5 performs the air / water supply. In this case, carbon dioxide gas or physiological saline is discharged from the washing nozzle 30f of the body cavity insertion unit 30 and the output of the electric knife 7 is lowered by the electric knife control device 6. However, the present invention is not limited to this. A smoke exhaust device that injects carbon dioxide into the body cavity and sucks gas in the body cavity may be provided, and this smoke exhaust device may be operated when smoke is detected by the smoke detector 39.

  Next, the operation of the rigid endoscope system of the present embodiment will be described with reference to the flowchart shown in FIG.

  First, the body cavity insertion part 30 is inserted into the body cavity by the operator, and the tip of the body cavity insertion part 30 is installed in the vicinity of the observed part (S10).

  Then, the normal light L1 emitted from the normal light source 40 of the light source device 2 is incident on the body cavity insertion unit 30 via the condenser lens 42, the dichroic mirror 43, and the optical cable LC, and is irradiated from the irradiation window 30d of the body cavity insertion unit 30. Irradiate the observation part. On the other hand, the excitation light L2 emitted from the near-infrared LD light source 44 of the light source device 2 is incident on the body cavity insertion part 30 via the condenser lens 46, the mirror 47, and the optical cable LC, and the irradiation window 30d of the body cavity insertion part 30 To the portion to be observed simultaneously with the normal light L1.

  Then, a normal image based on the reflected light reflected from the observed portion by the irradiation of the normal light L1 is captured, and a fluorescent image based on the fluorescence emitted from the observed portion by the irradiation of the excitation light L2 is captured ( S12). It should be noted that ICG is administered to the observed part in advance, and fluorescence emitted from the ICG is imaged.

  Specifically, when capturing the normal image, the normal image L3 based on the reflected light reflected from the observed portion by the irradiation of the normal light L1 is incident from the distal end 30Y of the insertion member 30b, and the inside of the insertion member 30b. The light is guided by the lens group and emitted toward the imaging unit 20.

  The normal image L3 incident on the imaging unit 20 is reflected by the dichroic prism 21 in the direction perpendicular to the imaging element 26, and is imaged on the imaging surface of the imaging element 26 by the second imaging optical system 25. 26 sequentially captures images at a predetermined frame rate.

  The normal image signals sequentially output from the image sensor 26 are subjected to CDS / AGC (correlated double sampling / automatic gain control) processing and A / D conversion processing in the imaging control unit 27, and then the processor 3 through the cable. Are output sequentially.

  The normal image signal input to the processor 3 is temporarily stored in the normal image input controller 31 and then stored in the memory 34. Then, the normal image signal for each frame read from the memory 34 is subjected to gradation correction processing and sharpness correction processing in the image processing unit 33 and then sequentially output to the video output unit 35 and smoke detection. The data are sequentially output to the unit 39.

  Then, the video output unit 35 performs a predetermined process on the input normal image signal to generate a display control signal, and sequentially outputs the display control signal for each frame to the monitor 4. Then, the monitor 4 displays a normal image based on the input display control signal (S14).

  The normal image signal input to the smoke detection unit 39 is input to the color component calculation unit 50 and the frequency component calculation unit 51. Then, the color component calculation unit 50 analyzes the input normal image signal, calculates a red component and a white component included in the normal image signal, and the red of the normal image signal of the frame that is first captured at the start of imaging. The component and the white component are output and stored in the reference information storage unit 52 (S16), and the red component and the white component of the normal image signal of the subsequent frames are sequentially output to the smoke generation determination unit 53. The frequency component calculation unit 51 calculates the distribution of the spatial frequency component by performing Fourier transform on the input normal image signal, and calculates the spatial frequency component of the normal image signal of the frame first captured at the start of imaging. The distribution is output and stored in the reference information storage unit 52 (S16), and the distribution of the spatial frequency components of the normal image signals of the subsequent frames is sequentially output to the smoke generation determination unit 53.

  On the other hand, when the fluorescent image is picked up, a fluorescent image L4 based on the fluorescence emitted from the observed portion by the irradiation of the excitation light is incident from the tip 30Y of the insertion member 30b and guided by the lens group in the insertion member 30b. And emitted toward the imaging unit 20.

  The fluorescent image L4 incident on the imaging unit 20 passes through the dichroic prism 21 and the excitation light cut filter 22, and is then imaged on the imaging surface of the high-sensitivity imaging element 24 by the first imaging optical system 23, and has high sensitivity. Images are taken at a predetermined frame rate by the image sensor 24.

  Fluorescent image signals sequentially output from the high-sensitivity imaging device 24 are subjected to CDS / AGC (correlated double sampling / automatic gain control) processing and A / D conversion processing in the imaging control unit 27, and then via a cable. The data is sequentially output to the processor 3.

  The fluorescence image signal input to the processor 3 is temporarily stored in the fluorescence image input controller 32 and then stored in the memory 34. The fluorescence image signal for each frame read from the memory 34 is subjected to predetermined image processing in the image processing unit 33 and then sequentially output to the video output unit 35 and sequentially to the smoke detection unit 39. Is output.

  The video output unit 35 performs a predetermined process on the input fluorescent image signal to generate a display control signal, and sequentially outputs the display control signal for each frame to the monitor 4. Then, the monitor 4 displays a fluorescent image based on the input display control signal (S14).

  The fluorescence image signal input to the smoke detection unit 39 is input to the frequency component calculation unit 51. The frequency component calculation unit 51 performs a Fourier transform on the input fluorescent image signal to calculate the spatial frequency component distribution, and calculates the spatial frequency component distribution of the fluorescent image signal of the frame first captured at the start of imaging. The data is output to the reference information storage unit 52 and stored (S16), and the distribution of the spatial frequency components of the fluorescence image signals of the subsequent frames is sequentially output to the smoke generation determination unit 53.

  Then, in a state where the normal image and the fluorescence image are displayed on the monitor 4 as described above, the smoke detection unit 39 monitors the temporal change amount of the color component information and the frequency component information of the normal image signal sequentially input. At the same time (S18), by monitoring the amount of change over time in the frequency component information of the fluorescence image signals that are sequentially input (S20), the presence or absence of smoke in the vicinity of the observed portion is detected.

  Specifically, first, the smoke generation determination unit 53 of the smoke detection unit 39 reads the reference color component information and the reference frequency component information of the past normal image stored in the reference information storage unit 52, and the fluorescent image. The reference frequency component information is read out.

  Then, the smoke generation determination unit 53 calculates the amount of change over time of the color component information and the frequency component information calculated based on the normal image signal currently captured. Specifically, the smoke generation determination unit 53 calculates the ratio of the white component to the red component included in the currently captured normal image signal, and the red component based on the reference color component information of the past normal image. The ratio of the white component is calculated. Then, the temporal change amount of the color component information is calculated by subtracting the ratio calculated based on the reference color component information from the ratio calculated based on the normal image signal currently captured.

  The smoke generation determination unit 53 calculates the ratio of the spatial frequency component on the low frequency side to the spatial frequency component on the high frequency side based on the distribution of the spatial frequency component of the normal image signal currently captured, Based on the reference frequency component information of the normal image, the ratio of the spatial frequency component on the low frequency side to the spatial frequency component on the high frequency side is calculated. Then, the temporal change amount of the frequency component information of the normal image is calculated by subtracting the ratio calculated based on the reference frequency component information from the ratio calculated based on the normal image signal currently captured.

  Then, the smoke generation determination unit 53 determines that both the temporal change amount of the color component information and the temporal change amount of the frequency component information of the normal image calculated as described above are equal to or greater than a predetermined threshold set in advance. It is monitored whether or not (S18).

  On the other hand, the smoke generation determination unit 53 calculates the ratio of the spatial frequency component on the low frequency side to the spatial frequency component on the high frequency side based on the distribution of the spatial frequency component of the fluorescent image signal currently captured, Based on the reference frequency component information of the fluorescent image, the ratio of the spatial frequency component on the low frequency side to the spatial frequency component on the high frequency side is calculated. Then, the temporal change amount of the frequency component information of the fluorescent image is calculated by subtracting the ratio calculated based on the reference frequency component information from the ratio calculated based on the fluorescent image signal currently captured.

  Then, the smoke generation determination unit 53 monitors whether or not the temporal change amount of the frequency component information of the fluorescent image calculated as described above is equal to or greater than a predetermined threshold value set in advance (S20).

  Here, as described above, when smoke is generated by the observed portion, the smoke image appears more easily in the normal image than in the fluorescence image, and the smoke image appears in the fluorescence image than the time when the smoke image appears in the normal image. The time when the image appears will be later.

  Therefore, the smoke generation determination unit 53 uses this property to acquire the first time when both the temporal change amount of the color component information and the temporal change amount of the frequency component information of the normal image are equal to or greater than a predetermined threshold. In addition, the second time when the temporal change amount of the frequency component information of the fluorescent image is equal to or greater than a predetermined threshold is acquired (S24), and the second time is later than the first time. (S26, YES), it is determined that smoke is generated around the observed portion (S28).

  When the smoke generation determination unit 53 determines that smoke has been generated around the observed portion, it outputs a smoke detection signal to the CPU 38. The CPU 38 outputs a control signal to the air / water supply device 5 according to the input smoke detection signal, and the air / water supply device 5 performs air supply or water supply according to the input control signal (S30). The CPU 38 also outputs a control signal to the electric knife control device 6 in accordance with the input smoke detection signal, and the electric knife control device 6 sets the currently set electric signal in accordance with the input control signal. A control signal is output to the electric knife 7 so as to reduce the output of the knife 7. Further, as described above, the smoke exhausting function may be operated at this time.

  In the rigid endoscope system of the above embodiment, the first time when the temporal change amount of the normal image becomes equal to or greater than a predetermined threshold value and the second time when the temporal change amount of the fluorescent image becomes equal to or greater than the predetermined threshold value. However, it is not always necessary to acquire these times. In short, after the amount of change with time of the normal image exceeds a predetermined threshold, the amount of change with time of the fluorescent image exceeds the predetermined threshold. What is necessary is just to be able to determine that it became. For example, a flag is set when the amount of change over time of the normal image exceeds a predetermined threshold, and smoke is generated when the amount of change over time of the fluorescent image exceeds the predetermined threshold with the flag set. You may make it determine with having carried out.

  In the rigid endoscope system of the above embodiment, only the frequency component information is calculated without calculating the color component information as the temporal change amount of the fluorescent image. In the present embodiment, this is the fluorescence image. For example, when a fluorescent image is captured as a color image, color component information is also calculated for the fluorescent image, and the amount of change over time of the color component information is the same as that of a normal image. You may make it monitor.

  In the rigid endoscope system of the above embodiment, the temporal change in the color component information and the frequency component information in the image is monitored. However, the present invention is not limited to this, and information that changes on the image due to the generation of smoke. If there is, you may make it monitor the amount of time-dependent change of other information.

  Further, in the rigid endoscope system of the above embodiment, the start and end of irradiation of the normal light and the excitation light to the observed part are linked with the start and end of the smoke detection operation in the smoke detection unit 39. Also good. That is, the operation of smoke detection may be started at the start of irradiation with the normal light and the excitation light to the observed portion, and the operation of smoke detection may be ended at the end of the irradiation of the normal light and the excitation light to the observed portion. .

  In the above-described embodiment, normal light and excitation light are simultaneously irradiated onto the observed part to capture the normal image and the fluorescence image simultaneously. However, the present invention is not limited to this. For example, normal light and excitation light are used. May be configured to alternately irradiate a portion to be observed in a time-division manner to capture a normal image and a fluorescence image in a time-division manner.

  In the above embodiment, the fluorescent image is picked up by the first image pickup system. However, the present invention is not limited to this, and an image based on the light absorption characteristic of the observed part by special light irradiation to the observed part is picked up. You may make it do.

  In the above-described embodiment, the smoke detection device of the present invention is applied to a rigid endoscope system. However, the present invention is not limited to this. For example, the present invention can be applied to other endoscope systems having a flexible endoscope device. Good. Further, the present invention is not limited to an endoscope system, and may be applied to a so-called video camera type medical image capturing apparatus that does not include an insertion portion that is inserted into the body.

DESCRIPTION OF SYMBOLS 1 Hard endoscope system 2 Light source device 3 Processor 4 Monitor 5 Air supply / water supply device 6 Electric knife control device 7 Electric knife 10 Rigid mirror imaging device 20 Imaging unit 24 High sensitivity imaging device 26 Imaging device 30 Body cavity insertion part 30d Irradiation window 30e Imaging window 30f Cleaning nozzle 39 Smoke detection unit 40 Normal light source 44 Near-infrared LD light source 50 Color component calculation unit 51 Frequency component calculation unit 52 Reference information storage unit 53 Smoke generation determination unit

Claims (13)

A first image acquisition unit that acquires a first image based on light emitted from the observed portion by irradiating the observed portion with first light having a first wavelength band;
Second image acquisition for acquiring a second image based on light emitted from the observed portion by irradiating the observed portion with second light having a wavelength band longer than the first wavelength band And
After the amount of change over time of the first image acquired in time series by the first image acquisition unit becomes a predetermined amount or more, the second image acquired in time series by the second image acquisition unit A smoke detection device comprising: a smoke generation determination unit that determines that smoke has been generated around the observed portion when the amount of change with time is equal to or greater than a predetermined amount.   The smoke detection apparatus according to claim 1, wherein the smoke generation determination unit acquires a temporal change amount of a color component of the first or second image.   The smoke generation determination unit acquires a temporal change amount of a second wavelength component including a first wavelength component and a shorter wavelength component than the first wavelength component as the temporal change amount of the color component. The smoke detection device according to claim 2.   The smoke detection apparatus according to claim 3, wherein the first wavelength component is a red component, and the second wavelength component is a white component.   5. The smoke detection device according to claim 1, wherein the smoke generation determination unit acquires a temporal change amount of a frequency component of the first or second image.   The said smoke generation | occurrence | production determination part acquires the time-dependent change amount of the ratio of the frequency component of a high frequency side and the frequency component of a low frequency side as a time-dependent change amount of the said frequency component. Smoke detection device.   The first image acquisition unit acquires, as the first image, a visible image based on reflected light emitted from the observed portion by irradiation with visible light as the first light. The smoke detection device according to any one of claims 1 to 6.   The second image acquisition unit acquires, as the second image, a fluorescence image based on fluorescence emitted from the observed portion by irradiation with excitation light as the second light. The smoke detection device according to any one of claims 1 to 7.   The smoke detection apparatus according to claim 8, wherein the excitation light is near infrared light.   The smoke generation determination unit switches detection or non-detection of the generation of smoke according to irradiation or non-irradiation of the first and second lights. The smoke detection device according to item. A first image based on light emitted from the observed portion by irradiating the observed portion with the first light having the first wavelength band is acquired in time series,
Acquiring a second image based on light emitted from the observed part by irradiating the observed part with the second light having a wavelength band longer than the first wavelength band in time series;
When the amount of change over time of the second image acquired in time series becomes equal to or greater than a predetermined amount after the amount of change over time of the first image acquired in time series exceeds the predetermined amount, A smoke detection method comprising determining that smoke is generated around an observation unit. A smoke detection device according to any one of claims 1 to 10,
A light irradiation unit that irradiates the observed portion with the first and second lights;
A first imaging unit that captures a first image based on light emitted from the observed part by irradiation of the first light to the observed part;
An image capturing apparatus comprising: a second image capturing unit configured to capture a second image based on light emitted from the observed unit by irradiation of the second light to the observed unit.   13. The image according to claim 12, further comprising an insertion part that is inserted into the body and guides light emitted from the observed part by irradiation of the first and second light to the observed part. Imaging device.

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