JP2007244590A - Imaging system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging system reducing a time spent for treatment which is performed for a living tissue as compared with the conventional system. <P>SOLUTION: The imaging system has: a lighting means emitting a plurality of lighting light beams having wavelength bands different from one another to the living tissue; an imaging means for picking up the image of the living tissue illuminated by the plurality of lighting light beams, respectively; a luminance value comparison means for detecting luminance values of a plurality of images in accordance with the plurality of images of the living tissues and comparing differences between the image of a prescribed living tissue and the luminance value of images other than the prescribed living tissue in each of the plurality of images; an image extraction means for extracting an image in which a difference in luminance value is the largest out of the plurality of images; and a lighting selection means for selecting one lighting light beam which has a wavelength band obtaining an image whose difference in luminance value becomes the same as the image among the plurality of lighting light beams having different wavelength bands from one another. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an imaging system, and more particularly to an imaging system capable of obtaining a blood vessel running state.

  In recent years, by irradiating a living tissue with infrared light having a wavelength band corresponding to light absorption characteristics of blood vessels, blood, etc., as information related to the inside of the living tissue, for example, the number of hemoglobin in the blood, Devices that can obtain the state and the like have been proposed.

  As a device capable of obtaining information related to the inside of a living tissue as described above, for example, there is a blood vessel visualization method proposed in Patent Document 1.

The blood vessel visualization method proposed in Japanese Patent Application Laid-Open No. H10-260260 is based on the reflected light of illumination light having a predetermined band based on the absorption spectrum of hemoglobin, emitted from a living tissue present at a desired observation site. As the information about the inside of the living tissue is obtained by receiving the reflected light reflected by the CCD (charge coupled device) after reaching the blood vessel directly under the living tissue while eliminating the reflected light reflected on the tissue surface by the light shielding device. It is possible to obtain the state of blood vessel running.
Japanese Patent Laid-Open No. 2004-237051

  However, for example, in order to obtain a blood vessel running state of a blood vessel covered with fat, illumination light having a predetermined band based on the absorption spectrum of hemoglobin is emitted to a living tissue present at a desired observation site. In this case, the amount of reflected light reflected by the fat is relatively large, and the amount of reflected light reflected after reaching the blood vessel is relatively small, so that the blood vessel running state of the blood vessel is reduced. It becomes difficult to obtain.

  Therefore, the user uses the blood vessel visualization method proposed in Patent Document 1 to obtain the blood vessel running state of a blood vessel covered with fat inside the living tissue present in a desired observation site. If work such as fat removal around the blood vessel is not performed, the state of blood vessel running of the blood vessel cannot be sufficiently obtained. As a result, in the blood vessel visualization method proposed in Patent Document 1, there is a problem that the time spent for the treatment performed on the living tissue becomes longer.

  The present invention has been made in view of the above-described points, and an object of the present invention is to provide an imaging system capable of reducing the time spent for a treatment performed on a living tissue as compared with the conventional art.

  The first imaging system according to the present invention includes an illuminating unit capable of emitting a plurality of illumination lights each having a different wavelength band in a wavelength band of at least 1000 nm or more to a living tissue, and sensitivity in a wavelength band of at least 1000 nm or more. And imaging means for capturing images of the biological tissue respectively illuminated by the plurality of illumination lights, and brightness values of the plurality of images corresponding to the plurality of biological tissue images captured by the imaging means. A plurality of luminance value comparing means for detecting a difference in luminance value between an image of a predetermined biological tissue and an image other than the predetermined biological tissue in each of the plurality of images based on the detection result; Image extraction means for extracting one image having the largest difference in luminance value, and each having a different wavelength band based on information on the one image. Illumination selection means for selecting one illumination light having one wavelength band, which enables obtaining an image having a difference in luminance value similar to that of the one image among the plurality of illumination lights. It is characterized by having.

  The second imaging system according to the present invention is characterized in that, in the first imaging system, the predetermined living tissue is a blood vessel.

  In a third imaging system according to the present invention, in the first or second imaging system, the plurality of illumination lights have at least a wavelength at which a light transmittance of the predetermined biological tissue is equal to or less than a light transmittance of fat. It is characterized by having light.

  According to a fourth imaging system of the present invention, in the first to third imaging systems, the illumination unit can emit illumination light having a wavelength band from 1400 nm to 1500 nm.

  According to a fifth imaging system of the present invention, in the first to third imaging systems, the illumination unit can emit illumination light having a wavelength band from 1900 nm to 2000 nm.

  According to the imaging system of the present invention, the time spent for the treatment performed on the living tissue can be shortened compared to the conventional case.

  1 to 13 relate to an embodiment of the present invention. FIG. 1 is a diagram illustrating an example of a configuration of a main part of an imaging system according to the present embodiment. FIG. 2 is a perspective view showing the configuration of the distal end side of the illumination unit and the endoscope body of FIG. FIG. 3 is a front view illustrating a configuration of an illumination unit included in the illumination unit of FIG. 1. FIG. 4 is a diagram showing the transmissivity characteristics of blood vessels and fat in living tissue. FIG. 5 is a diagram illustrating an example when the slide detection switch is turned on in the imaging system of FIG. 1. FIG. 6 is a block diagram showing an internal configuration of a camera control unit (hereinafter referred to as CCU) in the imaging system of FIG. FIG. 7 is a schematic diagram showing optical paths of illumination light and reflected light when a blood vessel running state is obtained using the imaging system of FIG. FIG. 8 is a schematic diagram showing images of living tissue and blood vessels illuminated by the first illumination light when the blood vessel running state is obtained using the imaging system of FIG. FIG. 9 is a schematic diagram showing images of living tissue and blood vessels illuminated by the second illumination light when the blood vessel running state is obtained using the imaging system of FIG. FIG. 10 is a schematic diagram illustrating images of living tissue and blood vessels illuminated with the third illumination light when the blood vessel running state is obtained using the imaging system of FIG. FIG. 11 is a diagram illustrating an example of a luminance value detection result in the image of the biological tissue and blood vessels illustrated in FIG. FIG. 12 is a diagram illustrating an example of a luminance value detection result in the image of the biological tissue and blood vessel illustrated in FIG. FIG. 13 is a diagram illustrating an example of a luminance value detection result in the image of the biological tissue and blood vessel illustrated in FIG.

  As shown in FIG. 1, the imaging system 1 captures an image of a biological tissue 101 as a subject, outputs an image of the captured biological tissue 101 as an imaging signal, and is output from the endoscope 2. Image processing is performed on the captured image signal, and the image of the living tissue 101 is displayed based on the CCU 3 that outputs the image signal after the image processing is performed as a video signal and the analog video signal output from the CCU 3. It has a monitor 4 as a main part.

  The endoscope 2 is driven based on a drive signal output from the CCU 3, and includes an illumination unit 5 that emits illumination light including at least an infrared region band to the living tissue 101, and an illumination unit 5. The endoscope body 6 is configured to form and capture an image of the illuminated living tissue 101 and output it as an imaging signal, and an adapter 7 to which the endoscope body 6 can be attached and detached.

  As shown in FIG. 1, the illumination unit 5 having a function as illumination means is a cylindrical slide that is slidable by being fitted to the outer peripheral surface of the outer tube forming the insertion portion 61 of the endoscope body 6. Portion 51, support rod 52 extending from the distal end side of slide portion 51, annular illumination portion 53 provided integrally fixed to the distal end side of support rod 52, slide portion 51 and support rod And a signal line 54 that is provided through the interior of 52 and transmits a drive signal output from the CCU 3 to the illumination unit 53.

  More specifically, the slide part 51, the support bar 52, and the illumination part 53 have, for example, configurations as shown in FIG. The slide part 51 has a configuration in which the objective lens 63 of the endoscope body 6 can slide in the direction of the optical axis O shown in FIG. Further, the inner diameter of the annular portion of the illumination portion 53 is configured to be larger than the outer diameter of the distal end portion 61 a of the insertion portion 61. Therefore, the distal end portion 61 a of the insertion portion 61 can be passed inside the annular portion of the illumination portion 53.

  As shown in FIG. 1, the illumination unit 53 enters either a driving state or a stopped state based on a driving signal output from the CCU 3 via the signal line 54. Further, for example, as shown in FIG. 3, the illumination unit 53 includes LEDs 53a, 53b, and 53c that emit illumination light having a wavelength band of at least 1000 nm as a predetermined wavelength band in the driving state. It is configured. In the present embodiment, the illumination unit 53 includes three LEDs 53a, 53b, and 53c, as shown in FIG.

  The LEDs 53a, 53b, and 53c emit illumination light in different wavelength bands including at least a wavelength at which the light transmittance of fat is larger than the light transmittance of blood vessels. Specifically, the first illumination light emitted from the LED 53a, the second illumination light emitted from the LED 53b, and the third illumination light emitted from the LED 53c are indicated by, for example, a symbol A in FIG. Each wavelength included in the wavelength band from 1000 nm to 1600 nm, or each wavelength included in the wavelength band from 1850 nm to 2200 nm indicated by the symbol B in FIG. Each has a different wavelength band. In the present embodiment, λ1 is the center wavelength of the wavelength band of the first illumination light, λ2 is the center wavelength of the wavelength band of the second illumination light, and the wavelength of the third illumination light is When the center wavelength of the band is λ3, it is assumed that the relationship of λ1 <λ2 <λ3 holds.

  Furthermore, as shown in FIG. 1, the convex portion 51 a of the slide portion 51 is disposed, for example, inside the cylindrical portion 71 of the adapter 7. A coil spring 72 is disposed in a space sandwiched between the convex portion 51 a of the slide portion 51 and the inner peripheral surface of the cylindrical body portion 71. The illumination unit 5 is biased forward of the insertion portion 61 by the coil spring 72. In addition, a convex portion for retaining is formed at the front end portion 71 a of the cylindrical body portion 71 with which both ends of the coil spring 72 abut so as to engage with the convex portion 51 a of the slide portion 51.

  Further, a slide lever 55 for sliding the slide part 51 is provided on the rear end side of the slide part 51. With such a configuration, for example, when the slide lever 55 is operated in the direction of the arrow shown in FIG. 1, the illumination unit 5 slides in the axial direction of the insertion portion 61.

  The adapter 7 also has a slide detection switch 73 for detecting the slide state of the slide portion 51.

  The slide detection switch 73 is disposed inside the cylindrical body portion 71 of the adapter 7 and is turned off when not pressed by the rear end portion 51b of the slide portion 51, for example, as shown in FIG. At the same time, as shown in FIG. 5, when the slide portion 51 is pressed by the rear end portion 51 b, it is turned on. Then, the slide detection switch 73 outputs to the CCU 3 a switch state signal for indicating whether the state of the slide detection switch 73 is the off state or the on state.

  The endoscope main body 6 has passed through the rigid hood 62, which is configured with a shape and size that can be inserted into a body cavity, a transparent hood 62 disposed at the distal end portion 61 a of the insertion portion 61, and the transparent hood 62. An objective lens 63 that collects and forms an image of the biological tissue 101 and an imaging element 64 that captures an image of the biological tissue 101 imaged by the objective lens 63 and outputs the image as an imaging signal. Yes. The insertion portion 61 is configured to be detachable from the cylindrical portion 71 of the adapter 7 at the endoscope body rear end portion 61b.

  The imaging element 64 having a function as an imaging unit is formed of a semiconductor detection element (photovoltaic semiconductor detection element) such as InAs that has sensitivity in a wavelength band of at least 1000 nm or more.

  The CCU 3 includes an LED drive circuit 31, a signal processing circuit 32, and an image sensor drive circuit 33 that supplies power for driving the image sensor 74 of the adapter 7. And the LED drive circuit 31 and the signal processing circuit 32 which CCU3 has have a structure as shown, for example in FIG.

  As shown in FIG. 6, the LED drive circuit 31 includes a state detection circuit 31a, an illumination control circuit 31b, and LED drivers 31c, 31d, and 31e.

  The state detection circuit 31a detects the state of the slide detection switch 73 based on the switch state signal output from the slide detection switch 73 of the adapter 7, and outputs the detection result to the signal processing circuit 32 as a state detection signal. .

  The illumination control circuit 31b sends a driver control signal for controlling the operation state of the LED drivers 31c, 31d and 31e to the LED drivers 31c, 31d and 31e based on the contrast control signal output from the signal processing circuit 32. Output each. The illumination control circuit 31b indicates an LED driver that is turned on by outputting the driver control signal among the LED drivers 31c, 31d, and 31e at substantially the same timing as the timing at which the driver control signal is output. The driver driving state signal is output to the signal processing circuit 32.

  The LED driver 31c outputs a drive signal to the LED 53a provided in the illumination unit 53 based on the driver control signal output from the illumination control circuit 31b. Then, the LED 53a shifts from the stop state to the drive state by the drive signal, and emits the first illumination light to the living tissue 101 in the drive state.

  The LED driver 31d outputs a drive signal to the LED 53b provided in the illumination unit 53 based on the driver control signal output from the illumination control circuit 31b. Then, the LED 53b shifts from the stop state to the drive state by the drive signal, and emits the second illumination light to the living tissue 101 in the drive state.

  The LED driver 31e outputs a drive signal to the LED 53c provided in the illumination unit 53 based on the driver control signal output from the illumination control circuit 31b. Then, the LED 53c shifts from the stop state to the drive state by the drive signal, and emits the third illumination light to the living tissue 101 in the drive state.

  As shown in FIG. 6, the signal processing circuit 32 is a process circuit 32 a that performs processing such as noise removal on the imaging signal output from the endoscope 2, and the imaging signal output from the process circuit 32 a is a digital image. An A / D converter 32b that converts the signal, a digital image processing circuit 32c that performs image processing on the digital image signal output from the A / D converter 32b, a selector 32d, and a timing control circuit 32e. It is configured.

  Further, the signal processing circuit 32 includes memories 32f, 32g and 32h, a contrast control circuit 32i, a luminance comparison circuit 32j, an image composition circuit 32k, and a D / A converter 32l.

  The timing control circuit 32e is a timing for setting the processing timing of each part of the process circuit 32a, the A / D converter 32b, the digital image processing circuit 32c, and the selector 32d based on the driver driving state signal output from the illumination control circuit 31b. Output a signal. Specifically, when the timing control circuit 32e detects that the LED driver 31c is driven based on the driver driving state signal output from the illumination control circuit 31b, the timing control circuit 32e outputs a first timing signal to the respective units. . Further, when the timing control circuit 32e detects that the LED driver 31d is driven based on the driver driving state signal output from the illumination control circuit 31b, the timing control circuit 32e outputs a second timing signal to the respective units. Further, when the timing control circuit 32e detects that the LED driver 31e is driven based on the driver drive state signal output from the illumination control circuit 31b, the timing control circuit 32e outputs a third timing signal to the respective units.

  The selector 32d outputs the digital image signal output from the digital image processing circuit 32c to any one of the memories 32f, 32g, and 32h based on the timing signal output from the timing control circuit 32e. . Specifically, the selector 32d outputs the digital image signal output from the digital image processing circuit 32c to the memory 32f based on the first timing signal output from the timing control circuit 32e. The selector 32d outputs the digital image signal output from the digital image processing circuit 32c to the memory 32g based on the second timing signal output from the timing control circuit 32e. Further, the selector 32d outputs the digital image signal output from the digital image processing circuit 32c to the memory 32h based on the third timing signal output from the timing control circuit 32e.

  The memories 32f, 32g, and 32h temporarily store the digital image signal output from the selector 32d and store the digital image signal at substantially the same timing based on the reading timing of the luminance comparison circuit 32j. Output for.

  The contrast control circuit 32i controls each part of the illumination control circuit 31b and the luminance comparison circuit 32j based on the state detection signal output from the state detection circuit 31a and the luminance value comparison information signal output from the luminance comparison circuit 32j. Then, a contrast control signal is output to each unit.

  The luminance comparison circuit 32j is based on each digital image signal read from each memory of the memories 32f, 32g, and 32h and a contrast control signal output from the contrast control circuit 32i, in each image corresponding to each digital image signal. Contrast comparison processing is performed. Then, the luminance comparison circuit 32j outputs information obtained based on the comparison result in the comparison processing to the contrast control circuit 32i as a luminance value comparison information signal. The luminance comparison circuit 32j outputs a digital image signal corresponding to the comparison result to the image synthesis circuit 32k among the digital image signals output from the memories 32f, 32g, and 32h.

  The image composition circuit 32k converts each digital image signal output from the luminance comparison circuit 32j into a digital video signal, and outputs the digital video signal to the D / A converter 32l.

  The D / A converter 32 l converts the digital video signal output from the image synthesis circuit 32 k into an analog video signal and outputs the analog video signal to the monitor 4.

  Next, the operation of the imaging system 1 will be described.

  First, for example, as shown in FIG. 1, the user keeps the slide detection switch 73 not pressed by the rear end portion 51 b of the slide portion 51, and in the vicinity of the living tissue 101 existing at a desired observation site in the body cavity. The lighting unit 5 and the insertion portion 61 are inserted until the first time. Thereafter, the user presses the illumination unit 53 of the illumination unit 5 against the living tissue 101 to bring it into contact therewith.

  Since the slide detection switch 73 is not pressed by the rear end portion 51b of the slide portion 51, the slide detection switch 73 outputs a switch state signal to the CCU 3 to indicate that it is in an off state.

  Based on the switch state signal output from the slide detection switch 73 of the adapter 7, the state detection circuit 31 a outputs a state detection signal for indicating that the slide detection switch 73 is in the OFF state to the signal processing circuit 32. .

  When the contrast control circuit 32i detects that the slide detection switch 73 is off based on the state detection signal output from the state detection circuit 31a, the contrast control circuit 32i sends the contrast control signal corresponding to the off state to the illumination control circuit 31b and the luminance. It outputs to the comparison circuit 32j.

  Based on the contrast control signal output from the contrast control circuit 32i, the illumination control circuit 31b sequentially and continuously outputs, for example, pulsed driver control signals to the LED drivers 31c, 31d, and 31e. Thus, the drivers are intermittently driven. The illumination control circuit 31b is turned on by outputting the pulsed driver control signal among the LED drivers 31c, 31d, and 31e at substantially the same timing as the timing of outputting the pulsed driver control signal. A driver driving state signal for indicating the LED driver is output to the signal processing circuit 32.

  Based on the driver control signal output from the illumination control circuit 31b, the LED driver 31c outputs a drive signal to the LED 53a provided in the illumination unit 53 at substantially the same timing as the input timing of the driver control signal. .

  The LED 53a shifts from the stop state to the drive state by the drive signal, and emits the first illumination light to the living tissue 101 in the drive state. Then, the image of the living tissue 101 illuminated by the first illumination light passes through the transparent hood 62, is imaged by the objective lens 63, is imaged by the imaging element 64, and is then processed by the CCU 3 as an imaging signal. Input to the circuit 32a.

  Based on the driver control signal output from the illumination control circuit 31b, the LED driver 31d outputs a drive signal to the LED 53b provided in the illumination unit 53 at substantially the same timing as the timing at which the driver control signal is input. .

  The LED 53b shifts from the stop state to the drive state by the drive signal, and emits the second illumination light to the living tissue 101 in the drive state. Then, the image of the biological tissue 101 illuminated by the second illumination light passes through the transparent hood 62, is imaged by the objective lens 63, is imaged by the imaging element 64, and is then processed by the CCU 3 as an imaging signal. Input to the circuit 32a.

  Based on the driver control signal output from the illumination control circuit 31b, the LED driver 31e outputs a drive signal to the LED 53c provided in the illumination unit 53 at substantially the same timing as the driver control signal is input. .

  Then, the LED 53c shifts from the stop state to the drive state by the drive signal, and emits the third illumination light to the living tissue 101 in the drive state. Then, the image of the living tissue 101 illuminated by the third illumination light passes through the transparent hood 62, is imaged by the objective lens 63, is imaged by the imaging element 64, and is then processed by the CCU 3 as an imaging signal. Input to the circuit 32a.

  The imaging signal based on the image of the living tissue 101 illuminated by the first illumination light is processed at the timing based on the first timing signal output from the timing control circuit 32e, the process circuit 32a, the A / D converter 32b, and the digital image. Processing is performed in each part of the processing circuit 32c and the selector 32d. Then, the imaging signal based on the image of the living tissue 101 illuminated by the first illumination light subjected to the processing in each unit is converted into a digital image signal, and is sent to the memory 32f by the selector 32d. Is output.

  In addition, the imaging signal based on the image of the living tissue 101 illuminated with the second illumination light is processed at the timing based on the second timing signal output from the timing control circuit 32e, the process circuit 32a, the A / D converter 32b, Processing is performed in each part of the digital image processing circuit 32c and the selector 32d. Then, the imaging signal based on the image of the living tissue 101 illuminated by the second illumination light subjected to the processing in each unit is converted into a digital image signal by the selector 32d to the memory 32g. Is output.

  Furthermore, the imaging signal based on the image of the living tissue 101 illuminated by the third illumination light is processed at the timing based on the third timing signal output from the timing control circuit 32e, the process circuit 32a, the A / D converter 32b, Processing is performed in each part of the digital image processing circuit 32c and the selector 32d. Then, the imaging signal based on the image of the living tissue 101 illuminated by the first illumination light that has been subjected to the processing in each unit is converted into a digital image signal by the selector 32d to the memory 32h. Is output.

  The luminance comparison circuit 32j reads from each memory 32f, 32g, and 32h based on each digital image signal read from each memory 32f, 32g, and 32h and the contrast control signal output from the contrast control circuit 32i. However, without comparing the contrast for each digital image signal, each digital image signal is output through.

  The image synthesis circuit 32k synthesizes each image based on each digital image signal output from the luminance comparison circuit 32j, converts the image into a digital video signal, and outputs the digital video signal to the D / A converter 32l.

  The D / A converter 32 l converts the digital video signal output from the image synthesis circuit 32 k into an analog video signal and outputs the analog video signal to the monitor 4.

  By the action described above, the monitor 4 has the image of the living tissue 101 illuminated with the first illumination light, the image of the living tissue 101 illuminated with the second illumination light, and the third illumination light. An image obtained by combining the image of the living tissue 101 illuminated by the above is displayed.

  Further, when the illumination unit 5 and the insertion unit 61 arrive at a location on the surface of the living tissue 101 where the blood vessel 103 that is a target of blood vessel traveling is present, in addition to the illumination unit 53 of the illumination unit 5, the insertion unit The distal end portion 61a of 61 is pressed against the living tissue 101 and brought into contact therewith. By performing such an operation, the user places the LEDs of the illumination unit 53 and the transparent hood 62 of the endoscope body 6 at a position as shown in FIG. Deploy. In FIG. 7, for simplicity of explanation, it is assumed that any one of the LEDs 53 a, 53 b, and 53 c is indicated as an LED 53 i. 7 is a state immediately before the slide detection switch 73 is pressed by the rear end portion 51b of the slide portion 51.

  When the LED 53i in FIG. 7 is an LED 53a, most of the first illumination light emitted from the LED 53a has, for example, a fat 102 present in the vicinity of the surface layer of the living tissue 101 having an optical path as indicated by a dashed line in FIG. The reflected light is reflected at. Then, the images of the living tissue 101 and the blood vessel 103 illuminated by the first illumination light based on the reflected light are imaged by the objective lens 63 after passing through the transparent hood 62 and are respectively imaged by the image sensor 64. After that, it is input to the process circuit 32a of the CCU 3 as an imaging signal.

  When the LED 53i in FIG. 7 is an LED 53b, most of the second illumination light emitted from the LED 53b has, for example, a fat 102 present in the middle layer of the living tissue 101 having an optical path as indicated by a two-dot chain line in FIG. The reflected light is reflected at. Then, the images of the living tissue 101 and the blood vessel 103 illuminated by the second illumination light based on the reflected light are imaged by the objective lens 63 after passing through the transparent hood 62 and are respectively imaged by the imaging element 64. After that, it is input to the process circuit 32a of the CCU 3 as an imaging signal.

  When the LED 53i in FIG. 7 is an LED 53c, most of the third illumination light emitted from the LED 53c is reflected by, for example, the blood vessel 103 existing in the deep layer of the living tissue 101 having an optical path as shown by the dotted line in FIG. Reflected light. Then, the images of the living tissue 101 and the blood vessel 103 illuminated by the third illumination light based on the reflected light are imaged by the objective lens 63 after passing through the transparent hood 62 and are respectively imaged by the imaging element 64. After that, it is input to the process circuit 32a of the CCU 3 as an imaging signal.

  The imaging signal based on the image of the living tissue 101 illuminated by the first illumination light is processed at the timing based on the first timing signal output from the timing control circuit 32e, the process circuit 32a, the A / D converter 32b, and the digital image. Processing is performed in each part of the processing circuit 32c and the selector 32d. Then, the imaging signal based on the image of the living tissue 101 illuminated by the first illumination light subjected to the processing in each unit is converted into a digital image signal, and is sent to the memory 32f by the selector 32d. Is output.

  In addition, the imaging signal based on the image of the living tissue 101 illuminated with the second illumination light is processed at the timing based on the second timing signal output from the timing control circuit 32e, the process circuit 32a, the A / D converter 32b, Processing is performed in each part of the digital image processing circuit 32c and the selector 32d. Then, the imaging signal based on the image of the living tissue 101 illuminated by the second illumination light subjected to the processing in each unit is converted into a digital image signal by the selector 32d to the memory 32g. Is output.

  Furthermore, the imaging signal based on the image of the living tissue 101 illuminated by the third illumination light is processed at the timing based on the third timing signal output from the timing control circuit 32e, the process circuit 32a, the A / D converter 32b, Processing is performed in each part of the digital image processing circuit 32c and the selector 32d. Then, the imaging signal based on the image of the living tissue 101 illuminated by the first illumination light that has been subjected to the processing in each unit is converted into a digital image signal by the selector 32d to the memory 32h. Is output.

  Thereafter, the slide part 51 is further slid to the proximal end side of the endoscope 2. For example, when the slide detection switch 73 is pressed by the rear end part 51 b of the slide part 51 as shown in FIG. The detection switch 73 outputs to the CCU 3 a switch state signal for indicating that the detection switch 73 is turned on.

  Based on the switch state signal output from the slide detection switch 73 of the adapter 7, the state detection circuit 31 a outputs a state detection signal for indicating that the slide detection switch 73 is on to the signal processing circuit 32. .

  When the contrast control circuit 32i detects that the slide detection switch 73 is in the on state based on the state detection signal output from the state detection circuit 31a, the contrast control circuit 32i sends a contrast control signal corresponding to the on state to the luminance comparison circuit 32j. Output.

  When the luminance comparison circuit 32j serving as the luminance value comparison means detects that the slide detection switch 73 is on based on the contrast control signal output from the contrast control circuit 32i, for example, a memory 32f as described below is used. , 32g, and 32h, the luminance value is detected by a method of sequentially detecting the luminance value of a pixel existing at a substantially central position in the vertical direction of each image according to each digital image signal read from each memory. While using the result, a contrast comparison process is performed between the images.

  Specifically, when the image read from the memory 32f is the image shown in FIG. 8, the luminance comparison circuit 32j sequentially applies the luminance values of the pixels existing at the position substantially at the center in the vertical direction of the image in the horizontal direction. By detecting, for example, a detection result as shown in FIG. 11 is obtained.

  When the image read from the memory 32g is the image shown in FIG. 9, the luminance comparison circuit 32j sequentially detects the luminance values of the pixels present at the approximate center in the vertical direction of the image in the horizontal direction. By moving, for example, a detection result as shown in FIG. 12 is obtained.

  Further, when the image read from the memory 32h is the image shown in FIG. 10, the luminance comparison circuit 32j sequentially detects the luminance values of the pixels present at the approximate center in the vertical direction of the image in the horizontal direction. By moving, for example, a detection result as shown in FIG. 13 is obtained.

  Then, the luminance comparison circuit 32j as the luminance value comparison means, based on the detection result of the luminance value in each image, the image of the blood vessel 103 in each image read from each memory of the memories 32f, 32g, and 32h, and other than the blood vessel 103 The difference in luminance value with the image of is compared. Then, the luminance comparison circuit 32j serving as an image extraction unit calculates the image of the blood vessel 103 and the image other than the blood vessel 103 among the images read from the memories 32f, 32g, and 32h. One image with the largest difference in luminance values is extracted. Thereafter, the luminance comparison circuit 32j outputs information on the one image to the contrast control circuit 32i as a luminance value comparison information signal.

  Specifically, for example, when the luminance comparison circuit 32j obtains the detection result of the luminance value in each image as shown in FIGS. An image shown in FIG. 10 is extracted, which is an image in which the difference in luminance value between the image 103 and an image other than the blood vessel 103 is maximum. Then, the luminance comparison circuit 32j outputs information relating to the image shown in FIG. 10 to the contrast control circuit 32i as a luminance value comparison information signal.

  In the present embodiment, the luminance comparison circuit 32j performs the luminance value comparison process until it detects that the slide detection switch 73 has been turned on again from the off state after performing the luminance value comparison process described above. Without performing the comparison process, the digital image signals read from the memories 32f, 32g, and 32h are passed through and output.

  Thereafter, the contrast control circuit 32i converts the image shown in FIG. 10 into the image of the blood vessel 103 and the image other than the blood vessel 103 in the image of the living tissue 101 based on the luminance value comparison information signal output from the luminance comparison circuit 32j. It is determined that the image has the maximum contrast. And the contrast control circuit 32i which has a function as an illumination selection means obtains the image which has the difference of the same luminance value as said one image among each illumination light radiate | emitted from each LED which the illumination part 53 has. One illumination light having one wavelength band is selected. Further, the contrast control circuit 32i outputs a contrast control signal for performing control according to the selection result to the illumination control circuit 31b.

  The illumination control circuit 31b continuously turns on the LED driver 31e by outputting a driver control signal to the LED driver 31e based on the contrast control signal output from the contrast control circuit 32i, and the LED driver 31c. LED drivers 31c and 31d are turned off by stopping the output of the driver control signals to and 31d.

  When the LED driver 31e is in an on state and the LED drivers 31c and 31d are in an off state, illumination light is emitted only from the LED 53c of the illumination unit 53, and no illumination light is emitted from the LEDs 53a and 53b. Therefore, an image of the living tissue 101 and the blood vessel 103 illuminated with the third illumination light is formed on the objective lens 63.

  The images of the living tissue 101 and the blood vessel 103 illuminated by the third illumination light are imaged by the objective lens 63, captured by the imaging element 64, and then input to the process circuit 32a as an imaging signal.

  The imaging signal based on the images of the living tissue 101 and the blood vessel 103 illuminated with the third illumination light is processed at the timing based on the third timing signal output from the timing control circuit 32e, and the process circuit 32a and the A / D converter 32b. Processing is performed in each part of the digital image processing circuit 32c and the selector 32d. Then, the imaging signal based on the image of the living tissue 101 illuminated by the third illumination light subjected to the processing in each unit is converted into a digital image signal by the selector 32d, and the memories 32f, 32g, and Is output for 32h.

  The luminance comparison circuit 32j reads from each memory 32f, 32g, and 32h based on each digital image signal read from each memory 32f, 32g, and 32h and the contrast control signal output from the contrast control circuit 32i. However, the luminance value comparison processing for each digital image signal is not performed, and each digital image signal is output through.

  The image synthesis circuit 32k synthesizes each image based on each digital image signal output from the luminance comparison circuit 32j, converts the image into a digital video signal, and outputs the digital video signal to the D / A converter 32l.

  The D / A converter 32 l converts the digital video signal output from the image synthesis circuit 32 k into an analog video signal and outputs the analog video signal to the monitor 4.

  By the operation described above, for example, the image shown in FIG. 10 is displayed on the monitor 4 as an image of the living tissue 101 and the blood vessel 103 illuminated by the third illumination light.

  As described above, the imaging system 1 according to the present embodiment performs operations such as removing fat around a blood vessel in a blood vessel running state of a blood vessel covered with fat that is present in a living tissue at a desired observation site. Can be obtained without doing. As a result, the imaging system 1 of the present embodiment can reduce the time spent for the treatment performed on the living tissue compared to the conventional art.

  In addition, the imaging system 1 of the present embodiment has a wavelength band corresponding to the depth at which the blood vessel exists in the living tissue with respect to the blood vessel covered with fat that exists in the living tissue at a desired observation site. Illumination light can be emitted. As a result, the imaging system 1 of the present embodiment can obtain an image in which the contrast between the image of the blood vessel that is the target of blood vessel travel and the image other than the blood vessel is high in the image of the biological tissue of the desired observation site. it can.

  The difference between the light transmittance of fat in the living tissue 101 and the light transmittance of blood vessels (blood vessel walls) is maximized in the wavelength band of the illumination light emitted from each of the LEDs 53a, 53b and 53c. When the predetermined wavelength band is set, the imaging system 1 of the present embodiment can obtain an image with higher contrast between an image of a blood vessel to be obtained for blood vessel travel and an image other than the blood vessel. More specifically, the predetermined wavelength band is, for example, a wavelength band of 1450 nm ± 50 nm indicated by reference numeral A1 in FIG. 4 or a wavelength band of 1950 nm ± 50 nm indicated by reference numeral B1 in FIG. , Any one wavelength band.

  In addition, this invention is not limited to embodiment mentioned above, Of course, a various change and application are possible in the range which does not deviate from the meaning of invention.

The figure which shows an example of a structure of the principal part of the imaging system which concerns on this embodiment. The perspective view which shows the structure of the front end side of the illumination unit of FIG. 1, and an endoscope main body. The front view which shows the structure of the illumination part which the illumination unit of FIG. 1 has. The figure which shows the permeability | transmittance characteristic of the blood vessel and fat in a biological tissue. The figure which shows an example when the slide detection switch will be in an ON state in the imaging system of FIG. The block diagram which shows the structure inside CCU in the imaging system of FIG. The schematic diagram which shows the optical path of illumination light and reflected light when obtaining the state of blood vessel running using the imaging system of FIG. The schematic diagram which shows the image of the biological tissue and blood vessel illuminated by the 1st illumination light, when obtaining the state of blood-vessel running using the imaging system of FIG. The schematic diagram which shows the image of the biological tissue and blood vessel illuminated with the 2nd illumination light, when obtaining the state of blood-vessel running using the imaging system of FIG. The schematic diagram which shows the image of the biological tissue and blood vessel illuminated with the 3rd illumination light, when obtaining the state of blood-vessel running using the imaging system of FIG. The figure which shows an example of the detection result of a luminance value in the image of the biological tissue and blood vessel image shown in FIG. The figure which shows an example of the detection result of a luminance value in the image of the biological tissue and blood vessel image shown in FIG. The figure which shows an example of the detection result of a luminance value in the image of the biological tissue and blood vessel image shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Imaging system, 2 ... Endoscope, 3 ... CCU, 4 ... Monitor, 5 ... Illumination unit, 6 ... Endoscope main body, 7 ... Adapter, 31 ... Drive circuit, 31a ... State detection circuit, 31b ... Lighting control circuit, 31c, 31d, 31e ... LED driver, 32 ... Signal processing circuit, 32a ... Process circuit, 32b ..A / D converter, 32c... Digital image processing circuit, 32d... Selector, 32e... Timing control circuit, 32f, 32g, 32h. ..Luminance comparison circuit, 32k ... Image composition circuit, 32l ... D / A converter, 33 ... Image sensor drive circuit, 51 ... Slide part 51a ... Convex part, 51b ... After End, 52 ... Support 53... Illumination section, 54... Signal line, 55... Slide lever, 61... Insertion section, 61 a... Tip section, 61 b. .. Transparent hood, 63... Objective lens, 64... Image sensor, 71... Cylindrical body portion, 71 a. ... Image sensor, 101 ... Living tissue, 102 ... Fat, 103 ... Blood vessel

Claims (5)

Illuminating means capable of emitting a plurality of illumination lights each having a different wavelength band to a living tissue in a wavelength band of at least 1000 nm or more;
An imaging unit that has sensitivity in a wavelength band of at least 1000 nm or more, and that captures an image of the biological tissue illuminated by each of the plurality of illumination lights;
In addition to detecting luminance values of a plurality of images according to the plurality of images of the biological tissue imaged by the imaging means, based on the detection result, an image of a predetermined biological tissue in each of the plurality of images, and A luminance value comparing means for comparing a difference in luminance value with an image other than a predetermined biological tissue;
Image extracting means for extracting one image having the largest difference in luminance value among the plurality of images;
One wavelength that makes it possible to obtain an image in which the difference in luminance value is the same as that of the one image among a plurality of illumination lights each having a different wavelength band based on the information related to the one image Illumination selection means for selecting one illumination light having a band;
An imaging system comprising:   The imaging system according to claim 1, wherein the predetermined living tissue is a blood vessel.   3. The imaging system according to claim 1, wherein the plurality of illumination lights are light having at least a wavelength at which a light transmittance of the predetermined living tissue is equal to or less than a light transmittance of fat.   The imaging system according to any one of claims 1 to 3, wherein the illumination unit can emit illumination light having a wavelength band from 1400 nm to 1500 nm.   The imaging system according to any one of claims 1 to 3, wherein the illumination unit is capable of emitting illumination light having a wavelength band from 1900 nm to 2000 nm.

Images