WO2019116947A1

WO2019116947A1 - Electronic endoscope system

Info

Publication number: WO2019116947A1
Application number: PCT/JP2018/044409
Authority: WO
Inventors: 池谷　浩平
Original assignee: Hoya株式会社
Priority date: 2017-12-15
Filing date: 2018-12-03
Publication date: 2019-06-20
Also published as: JP7211971B2; JPWO2019116947A1

Abstract

This electronic endoscope system includes: a light source unit for emitting illumination light; an imaging element that is provided on an electronic endoscope and is for capturing an image of biological tissue illuminated with the illumination light; and a control unit. The control unit is provided in a processor and includes: a determination unit for determining whether an image color component of the image of the biological tissue repeatedly captured by the imaging element satisfies determination conditions that use a ratio of different image color component values in each pixel of the image; and a light amount changing unit for changing the amount of light as a result of the determination and according to the light absorptivity of a substance within a body cavity, the light for which the amount is subject to control being at least a portion of a light component of the illumination light.

Description

Electronic endoscope system

The present invention relates to an electronic endoscope system for imaging a living tissue in a body cavity.

2. Description of the Related Art An electronic endoscope system that uses images and information of living tissue in a body cavity captured by an imaging device for diagnosis and treatment is generally known. In diagnosis and treatment using an electronic endoscope system, in order to obtain an image emphasizing a special part in living tissue, special light of a specific wavelength band different from white light which is ordinary light illuminates living tissue. It is used as light. For example, in order to obtain an image in which a portion of a blood vessel in a living tissue is emphasized, special light whose light intensity distribution is set to correspond to the absorptivity of the blood vessel is used. An endoscope system capable of capturing a special image using such special light, that is, special light having a spectral intensity characteristic different from that of white light is known (Patent Document 1).

The light source device of the known endoscope system includes a first light source unit that emits light of a first wavelength band, a second light source unit that emits light of a second wavelength band, and first and second light source units. It is comprised from the optical path synthetic | combination means which synthesize | combines the optical path of the light inject | emitted from 2 light source units, and the light source control means which carries out light emission control of each light source unit separately. When each light source unit is driven to emit light in the first mode, the light in each wavelength band is emitted at a first intensity ratio, and is synthesized to be ordinary light and supplied to the endoscope. Further, when each light source unit is driven to emit light in the second mode, light in each wavelength band is emitted and synthesized at a second intensity ratio at which light in the second wavelength band is relatively low. As a result, it is supplied to the endoscope as special light with high absorbance for a specific living tissue.

International Publication No. 2017/142097

In the above endoscope system, when illuminating living tissue with special light for diagnosis and treatment, the wavelength of the special light has a high absorptivity of blood in the blood vessel in order to emphasize the image of the blood vessel in living tissue In many cases, special light in which the peak of the light intensity is matched to the wavelength band corresponding to the wavelength band is set. Further, in the above light source device, since a light emitting diode is used, the light intensity is strong in a narrow wavelength band compared to special light obtained by transmitting only a part of the wavelength band of white light emitted by a conventional halogen lamp or the like. can do. For this reason, a special light can be used to display a captured image in which an image of blood having a high absorptivity is emphasized more than in the past. Such display of a captured image is used not only for diagnosis of a living tissue but also for treatment of living tissue. For example, special light may be used to search for concentrated lesions in blood vessels of a living tissue, such as a tumor, and perform a treatment to remove the tumor. When excising the tumorous part, insert the excision treatment tool from the operation part of the endoscope system and project it from the tip surface provided with the illumination window from which the illumination light is emitted and the observation window that receives the light of the image of the imaging subject. While looking at the image taken by the endoscope system, the tumor part is scratched and marked, and then the tumor part is excised using a resection treatment tool.

However, in the cut portion at this time, a large amount of blood may flow out and adhere to the illumination window or the observation window. Since the image of the blood adhering to the observation window is displayed on the captured image, the blood adhered to the observation window is discharged from the air supply port or water supply port provided at the tip end surface to make the observation window It can be washed. On the other hand, when blood adheres to the illumination window, the illumination of the living tissue is rapidly darkened or completely dark, and the captured image displayed on the monitor screen is rapidly darkened or sharply darkened for observation or It may not be possible to diagnose.

Furthermore, when a living tissue is illuminated with special light of high light intensity using a light emitting diode, a part of the special light has a light intensity distribution set according to the wavelength band where the absorptivity of blood is high, The blood adhering to the illumination window may absorb the part of the light to become heat and warm up, and may be dried on the surface of the illumination window and fixed as a film. When the blood adheres, even if the fluid is discharged to the illumination window, it is not possible to wash the film adhered to the surface. For this reason, the blood adhering to the illumination window needs to be washed before it is fixed. The substance that adheres to the surface of the illumination window is not limited to blood that has flowed into the body cavity, but is a biological substance that is secreted from living tissue, or a body cavity such as a residue of an external substance introduced from outside the body into the body cavity and remaining in the body cavity. There is also an inner substance.

Therefore, according to the present invention, when the living tissue is treated while imaging the living tissue in the body cavity, the substance in the body cavity adheres to the illumination window on the distal end surface of the endoscope and the captured image can not be seen and diagnosis and treatment become difficult It is an object of the present invention to provide an electronic endoscope system capable of suppressing the

One aspect of the present invention is an electronic endoscope system comprising an electronic endoscope and a processor configured to image living tissue in a body cavity. The electronic endoscope system is
A light source configured to emit illumination light;
An imaging device provided in the electronic endoscope and configured to image the living tissue illuminated by the illumination light;
It is provided in the processor, and it is determined whether a captured image of the living tissue captured by the imaging device satisfies a determination condition using a ratio of values of different image color components in pixels of the captured image. The light source unit is controlled to change a light amount per unit time of a light component of a part of the light components included in the illumination light according to a determination unit configured to perform and a result of the determination. And a control unit including the light amount change unit configured in the above.
The determination is a determination as to whether the captured image captured by the imaging element is a captured image including an image of a body cavity material different from the living tissue in the body cavity based on the ratio.
The ratio used for the determination condition is the image color component of interest with respect to the value of the image color component of interest of the captured image including the wavelength at which the light reflectance of the body cavity material is highest in the sensitivity wavelength band of the imaging element. It is a ratio of values of image color components other than
The light amount changing unit is configured to change the light amount of the light component, with the light component of the illumination light determined according to the absorptivity of the substance in the body cavity as a light amount control target light.

The illumination light is combined light obtained by combining a plurality of lights as the light component,
The light amount changing unit is configured to reduce the light amount of the first light component by dividing it into a first light component for reducing the light amount among the illumination light as the light amount control target light and a second light component for which the light amount is not reduced. Preferably, the absorptivity of the body cavity substance that absorbs the first light component is larger than the absorptivity of the body cavity substance that absorbs the second light component.
Further, it is preferable that the wavelength of the light quantity control target light includes a wavelength at which the absorptivity of the substance in the body cavity is maximum.

It is preferable that the determination condition includes a condition whether or not the number of pixels whose ratio is smaller than a predetermined threshold value is larger than a predetermined number as an allowable limit value in the captured image.

The imaging device is configured to image the biological tissue in time series;
It is preferable that the determination condition includes a condition whether or not the number of pixels of which the temporal change of the ratio has become larger than a predetermined range in the captured image is larger than a predetermined number as an allowable limit value. .

The imaging device is configured to image the biological tissue in time series;
The determination condition is whether or not the duration in which the number of pixels whose ratio is smaller than a predetermined threshold value is larger than a predetermined number is longer than the predetermined time as the allowable limit value in the captured image. Is preferred.

The imaging device is configured to image the biological tissue in time series;
The determination condition is that, in the captured image, the duration time in which the number of pixels whose temporal change of the ratio is increased beyond a predetermined range is larger than a predetermined number continues as an allowable limit value. It is preferable that the condition be long or not.

The light quantity changer divides the light quantity of the light quantity control target light into a plurality of light quantity levels and sequentially changes them in stages.
The determination unit includes a reference table in which the light amount is associated with the allowable limit value in order to change the allowable limit value used in the determination condition according to the light amount after the change of the light amount control target light. Is preferred.

When the determination condition is satisfied, the light amount changing unit is configured to control the light source unit to reduce a relative ratio of the light amount of the light amount control target light to the total light amount of the illumination light. Is preferred.

The control unit is configured to automatically control the light source unit such that the amount of light of the entire illumination light emitted by the light source unit is increased according to a decrease in an average value of luminance components of the captured image. It has a light quantity adjustment unit,
The determination unit is further configured to determine whether or not the light amount of the entire illumination light increased by the automatic light amount adjustment unit exceeds a predetermined amount.
The light amount change unit controls the light source unit to change the light amount of the light amount control target light when the determination condition is satisfied and the light amount of the entire illumination light exceeds a predetermined amount. Preferably, it is configured in

The electronic endoscope includes an illumination window for illuminating the illumination light toward the living tissue, an observation window for capturing an image of the living tissue, and a surface of the illumination window and the observation window. Having a tip surface with a fluid discharge port configured to discharge fluid;
The electronic endoscope is connected with a fluid delivery mechanism configured to supply the fluid to eject the fluid from the fluid ejection port;
The control unit includes a fluid operation control unit configured to control the operation of the fluid delivery mechanism so as to discharge the fluid from the fluid discharge port;
The fluid operation control unit controls the operation of causing the fluid to be discharged from the fluid discharge port before the determination unit determines whether the increased total amount of illumination light has exceeded a predetermined amount. Preferably, it is configured to do.

The electronic endoscope includes an illumination window for illuminating the illumination light toward the living tissue, an observation window for capturing an image of the living tissue, and a surface of the illumination window and the observation window. Having a tip surface with a fluid discharge port configured to discharge fluid;
The electronic endoscope is connected with a fluid delivery mechanism configured to supply the fluid to eject the fluid from the fluid ejection port;
The control unit is configured to control the operation of the fluid delivery mechanism so as to discharge the fluid from the fluid discharge port when the light amount changing unit changes the light amount of the light amount control target light Preferably, an operation control unit is provided.
The illumination window is provided at each of two places sandwiching the observation window,
Preferably, the fluid discharge port is provided with a discharge nozzle configured to discharge fluid to each of the illumination window and the observation window.

It is preferable that the control unit is configured to change the light amount per unit time of the light amount control target light by changing the light intensity of the light amount control target light.

The processor includes an image processing unit configured to perform image processing on the captured image;
The image processing unit is configured to adjust a gain adjustment amount for an image color component of a wavelength band including the wavelength band of the light amount control target light in the captured image captured by the imaging device after changing the light amount of the light amount control target light. It is preferable that it is configured to change according to the amount of change of the light quantity of the light quantity control target light.

The image color component A, which is one of the image color components of the captured image, is a wavelength of at least one other light in addition to the wavelength band of the light quantity control target light among the plurality of lights emitted from the light source unit A band is included as a wavelength band of the image color component A,
The light quantity changing unit is configured to change the light quantity per unit time of the other light in order to suppress a change in the value of the image color component A when the light quantity of the light quantity control target light is changed. Is preferred.

The electronic endoscope system includes a monitor connected to the processor and configured to display the captured image. The control unit determines that the image color component of the captured image satisfies the determination condition. In the case, the monitor is configured to transmit the information to notify information indicating that the intracavitary substance may be attached to an illumination window for illuminating the illumination light toward the living tissue. It is preferable that the information control unit be provided.

It is preferable that the light amount change unit is configured to change the light amount of the light amount control target light after a predetermined time has elapsed from the information notification by the notification control unit.

According to the above-mentioned electronic endoscope system, when the living tissue is treated while imaging the living tissue in the body cavity, the substance in the body cavity adheres to the illumination window of the distal end surface of the endoscope and the captured image disappears and diagnosis or It can control that treatment becomes difficult.

FIG. 1 is an external perspective view of an electronic endoscope system according to an embodiment. It is a block diagram showing composition of an electronic endoscope system which is one embodiment. It is a figure which illustrates typically the structure of the light source part of the endoscope system shown in FIG. It is a figure which shows an example of the front end surface of the front-end | tip part of the electronic endoscope of one Embodiment. It is a figure which shows an example of the spectrum waveform of the special light used with the electronic endoscope system shown in FIG. It is a figure which shows an example of the spectrum waveform of the white light used with the electronic endoscope system shown in FIG. It is a block diagram explaining the structure of the system controller of the electronic endoscope system shown in FIG. It is a figure which shows an example of the spectrum waveform of the transmittance | permeability of the primary color filter provided in the solid-state image sensor of the electronic endoscope system shown in FIG. It is a figure which shows the spectrum waveform of the absorptivity of the blood. It is a block diagram showing an example of composition of a system controller of an electronic endoscope system of one embodiment. It is a block diagram showing an example of composition of a system controller of an electronic endoscope system of one embodiment.

Hereinafter, the electronic endoscope system of the embodiment will be described with reference to the drawings.
FIG. 1 is an external perspective view of an electronic endoscope system 1 according to an embodiment, and FIG. 2 is a block diagram showing the configuration of the electronic endoscope system 1. The electronic endoscope system 1 shown in FIG. 1 is a system specialized for medical use, and mainly includes an electronic endoscope (hereinafter referred to as an electronic scope) 100, a processor 200, a light source device 300, and a monitor 400. . The electronic scope 100, the light source device 300, and the monitor 400 are connected to the processor 200, respectively. Although the light source device 300 and the processor 200 are separately provided, the light source device 300 may be integrally provided in the processor 200.

The processor 200 includes a system controller 21 and a timing controller 22 as shown in FIG. The system controller 21 is a control unit that executes various programs stored in a memory (not shown) and integrally controls the entire electronic endoscope system 1, and is configured by software or hardware. Further, the system controller 21 is connected to the operation panel 24. The system controller 21 changes each operation of the electronic endoscope system 1 and parameters for each operation according to an instruction from the operator input to the operation panel 24. The input instruction by the operator includes, for example, an instruction to switch the observation mode of the electronic endoscope system 1. The observation modes include a normal observation mode in which white light is observed as illumination light and a special observation mode in which special light is observed as illumination light.
The timing controller 22 outputs clock pulses for adjusting the timing of operation of each unit to each circuit in the electronic endoscope system 1.

The light source device 300 includes a light source unit 310 and a condenser lens 350, as shown in FIG. FIG. 3 is a diagram schematically illustrating the configuration of the light source unit 310. As shown in FIG. As shown in FIG. 3, the light source unit 310 includes four light source units 312 to 315, three optical elements 333 to 335, collimating lenses 322 to 325, and a light source driving circuit 340.
The light source drive circuit 340 generates a drive current for driving the light source units 312 to 315 with the controlled light intensity in accordance with the control signal of the system controller 21 and sends it to each light source unit.

The light source units 312 to 315 include light emitting diodes (LEDs: Light Emitting Diodes) that emit light of a wavelength band of a predetermined color.
The collimator lenses 322 to 325 are disposed on the light path of the emitted light on the front surface of each of the light source units 312 to 315, and convert the emitted light into parallel light.

The optical elements 333 to 335 have a function of transmitting or reflecting incident light. The optical elements 332 to 335 use, for example, a dichroic mirror or a dichroic prism. The optical elements 333 to 335 reflect the light component of the wavelength band set as the wavelength characteristic in each of the optical elements 333 to 335 among the incident light, and transmit the light components of the remaining wavelength bands. The optical elements 333 to 335 have wavelength characteristics set according to the wavelength bands of the light emitted from the light source units 312 to 315, so that the light of the wavelength band set by the optical elements 333 to 335 is multiplexed. It becomes one illumination light. The light source unit 312 is, for example, a red LED that emits light in a red wavelength band (for example, a wavelength of 620 to 680 nm), and the light source unit 313 is light in a blue wavelength band (for example, a wavelength of 430 to 470 nm) And a green phosphor 313b. The green phosphor 313b is excited by the blue LED light emitted from the blue LED 313a, and emits fluorescence in a green wavelength band (for example, a wavelength of 470 to 600 nm). The light source unit 314 includes a blue LED that emits light in a blue wavelength band (for example, a wavelength of 430 to 470 nm). The light source unit 315 includes a purple LED that emits light in a purple wavelength band (eg, a wavelength of 395 to 435 nm). The purple wavelength band at least includes the wavelength 415 nm.

The transmitted light and the reflected light are combined at each position of the optical elements 333 to 335 having wavelength characteristics set according to such a wavelength band of light. Therefore, in the light source unit 310, the light emitted from the plurality of light source units is combined with the light having a desired wavelength band and emitted from the light source unit 310 as illumination light. The light source drive circuit 340 changes the light intensity of the light emitted from the light source units 312 to 315 in the case where the white light used in the normal observation mode is the illumination light and the special light used in the special observation mode is the illumination light. Configured to
Although the light source unit 310 has a configuration in which the optical elements 333 to 335 are arranged in series as shown in FIG. 3, the present invention is not limited to this configuration. As long as light emitted from the four light source units 312 to 315 is combined into one illumination light, the configuration of the arrangement of the light source units 312 to 315 and the optical elements 333 to 335 is not particularly limited.
Thus, illumination light is synthetic light which compounded a plurality of lights as a light component.

As shown in FIG. 2, the illumination light L emitted from the light source unit 310 is condensed by the condenser lens 350 on the incident end face of a light carrying bundle (LCB) 11 described later, which is formed of a bundle of plural optical fibers. And enter the LCB 11.

As shown in FIG. 1, the electronic scope 100 mainly includes a connection portion 50, an operation portion 52, an insertion portion 54, and a cable 51 connecting the connection portion 50 and the operation portion 52. The insertion portion 54 includes a flexible tube 58 connecting the operation portion 52 and the distal end portion 56 of the insertion portion 50. Inside the flexible tube 58, an LCB 11, an air / water tube for sending a fluid such as water or air, a treatment instrument introduction tube, a signal line and the like are provided. The treatment instrument introduction tube is a tube for inserting a treatment instrument for treating (for example, cutting and removing) living tissue from the operation unit 52 and projecting it from the tip portion 56 to treat the living tissue. . The signal line includes a transmission line for transmitting a captured image signal from a solid-state imaging device 14 described later and a control line for transmitting a control signal from the processor 200 to the solid-state imaging device 14.
The distal end portion of the operation unit 52 of the electronic scope 100 is a flexible insertion portion 54 for insertion into the human body. In the vicinity of the distal end of the insertion portion 54, a bending portion 60 connected to the proximal end of the insertion portion 54 is provided, and the bending portion 60 bends in response to the remote control in the operation portion 52. The bending mechanism of the bending portion 60 is a known mechanism incorporated in a general endoscope. The bending structure is to bend the bending portion 60 by pulling the operation wire interlocked with the rotation operation of the bending operation knob provided in the operation portion 52. At the tip of the bending portion 60, a tip portion 56 provided with a solid-state imaging device 14 is provided.

The distal end portion 56 of the electronic scope 100 has an illumination light emitting end of the LCB 11 disposed over substantially the entire length from the connection portion 50 to the distal end portion 56.
As shown in FIG. 2, the light distribution lens is provided in front of the illumination light emission end of the LCB 11 at the distal end portion 56, and the front surface on the living tissue side of the light distribution lens is the illumination window 12 for emitting illumination light. ing. Further, the distal end portion 56 is provided with an objective lens for forming an image of a living tissue, and the front surface on the living tissue side of the objective lens is an observation window 13 for receiving light of the image of the living tissue. Further, the tip end portion 56 is provided with a solid-state imaging device 14 for receiving the formed image, and an amplifier (not shown) for amplifying an image signal output from the solid-state imaging device 14.

The illumination light that has entered the LCB 11 propagates in the LCB 11, exits from the illumination light output end of the LCB 11, and illuminates the subject of the biological tissue as illumination light through the illumination window 12 configured with a light distribution lens. The return light from the subject of the illumination light emitted from the illumination window 12 forms an optical image on the light receiving surface of the solid-state imaging device 14 through the observation window 13 constituted by the objective lens.
The light source unit 310 of the light source device 300 may be embedded in the tip end portion 56 of the electronic scope 100 when the configuration is compact. In this case, the LCB 11 and the condenser lens 350 for guiding the illumination light from the light source unit 310 to the distal end portion 56 are unnecessary.

FIG. 4 is a view showing an example of the distal end surface 57 of the distal end portion 56. As shown in FIG. On the front end surface 57, two illumination windows 12 composed of light distribution lenses provided in front of the tip of the LCB 11 are provided, and further, they are composed of objective lenses so as to be sandwiched between the illumination windows 12 An observation window 13 is provided. In addition, a treatment tool opening 62 for causing the treatment tool to protrude from the tip end surface 57, and an air / water supply port 64 (a fluid discharge port for discharging a fluid for cleaning the illumination window 12 and the observation window 13) ). The air / water supply port 64 is a portion that receives the supply of fluid from the fluid delivery mechanism (see FIG. 10) connected to the operation unit 52 via the air / water supply pipe in the flexible tube 58 and discharges the fluid. . Specifically, the air / water supply port 64 has three discharge nozzles, and the discharge nozzles are configured to spray and wash water and air on each of the two illumination windows 12 and one observation window 13. It is done.
Further, instead of the end face 57 shown in FIG. 4, the air / water supply port 64 may be provided separately from the air supply port for discharging air and the water supply port for discharging water.

The solid-state imaging device 14 is a single-plate color imaging device having a Bayer-type pixel arrangement. The solid-state imaging device 14 accumulates an optical image formed by each pixel on the light receiving surface as an electric charge according to the light quantity, and generates image signals of R (Red), G (Green), and B (Blue). Output. The solid-state imaging device 14 is a charge coupled device (CCD) image sensor or a complementary metal oxide semiconductor (CMOS) image sensor. Alternatively, an imaging device other than the image sensor may be used. A color filter that defines a wavelength band in an image color component of a captured image of the solid-state imaging device 14 is provided in front of each light receiving position of the solid-state imaging device 14. As color filters, for example, primary color filters of red (R), green (G) and blue (B) are used. The solid-state imaging device 14 repeatedly images the living tissue at timing according to the clock pulse transmitted from the timing controller 22. That is, the solid-state imaging device 14 is configured to image a living tissue in time series. In other words, the solid-state imaging device 14 is configured to obtain a moving image of a living tissue.

In the connection unit 50 of the electronic scope 100, a driver signal processing circuit 15 and a memory 16 are provided as shown in FIG. The driver signal processing circuit 15 receives an image signal of a living tissue from the solid-state imaging device 14 in a frame cycle. The frame period is, for example, 1/30 seconds. The driver signal processing circuit 15 performs predetermined processing on the image signal input from the solid-state imaging device 14, and outputs the processed signal to the pre-stage signal processing circuit 26 of the processor 200.

The driver signal processing circuit 15 also accesses the memory 16 to read out the unique information of the electronic scope 100. The unique information of the electronic scope 100 recorded in the memory 16 includes, for example, the number of pixels and sensitivity of the solid-state imaging device 14, an operable frame rate, and a model number. The driver signal processing circuit 15 outputs the unique information read from the memory 16 to the system controller 21.

The system controller 21 performs various operations based on the unique information of the electronic scope 100 to generate a control signal. The system controller 21 controls the operation and timing of various circuits in the processor 200 so that processing suitable for the electronic scope 100 connected to the processor 200 is performed using the generated control signal.

The timing controller 22 supplies clock pulses to the driver signal processing circuit 15 according to the timing control by the system controller 21. The driver signal processing circuit 15 drives and controls the solid-state imaging device 14 at timing synchronized with the frame rate of the image processed on the processor 200 side according to the clock pulse supplied from the timing controller 22.

The pre-stage signal processing circuit 26 performs predetermined image processing such as demosaicing, matrix calculation, gain adjustment, and color balance processing on the image signal of the captured image input from the driver signal processing circuit 15 in one frame cycle, It is output to the image memory 27.

The image memory 27 buffers an image signal input from the front stage signal processing circuit 26, and outputs the image signal to the rear stage signal processing circuit 28 in accordance with timing control by the timing controller 22.

The post-stage signal processing circuit 28 processes the image signal input from the image memory 27 to generate screen data for monitor display, and converts the generated screen data for monitor display into a predetermined video format signal. The converted video format signal is output to the monitor 400. As a result, the moving image of the biological tissue taken in time series by the electronic scope 100 is displayed on the display screen of the monitor 400.

The electronic endoscope system 1 has a plurality of observation modes including a normal observation mode and a special observation mode for observing a living tissue. Each observation mode is switched manually or automatically according to the living tissue to be observed. For example, when it is desired to illuminate and observe a living tissue with white light, the observation mode is switched to the normal observation mode by, for example, an input instruction through the operation panel 24. In addition to light having a flat spectral intensity distribution in the visible light band, white light includes pseudo white light in which light of a plurality of wavelength bands is mixed, not having a flat spectral intensity distribution. When it is desired to obtain a photographed image in which a specific biological tissue such as a blood vessel is emphasized by illuminating the biological tissue with special light, the observation mode is switched to the special observation mode by, for example, an input instruction through the operation panel 24. Be

FIG. 5 is a diagram showing an example of a spectral waveform of special light used in the special observation mode. FIG. 6 is a diagram showing an example of a spectral waveform of white light used in the normal observation mode, specifically, pseudo white light. As shown in FIGS. 5 and 6, purple light Lv having a wavelength band of 395 to 435 nm, blue light Lb having a wavelength band of 430 to 470 nm, and green light Lg having a wavelength band of 470 to 600 nm , And illumination light obtained by combining red light Lr having a wavelength band of 620 to 680 nm. In the special light shown as an example in FIG. 5, the light intensity of the purple light Lv is overwhelmingly stronger than the light intensities of the other lights. This makes it possible to emphasize blood (hemoglobin) having a large absorptivity at 410 to 420 nm, particularly at 415 nm, contained in blood vessels, ie, to enhance the image of a blood vessel.
On the other hand, in the pseudo white light shown as an example in FIG. 6, the light intensity of the purple light Lv is lower than the light intensity of the purple light Lv in the special light, and instead, the light intensity of the blue light Lb is high The light intensity of the special light is higher than the light intensity of the blue light Lb. The light of the spectral waveform shown in FIG. 6 has substantially the same red, green and blue signal levels obtained when the solid-state imaging device 14 receives the light transmitted through the color filter provided in the solid-state imaging device 14 Thus, the light intensity of each light is adjusted.
Such special light or pseudo white light can be changed by adjusting the amount of light emitted from the light source units 312 to 315 per unit time. The adjustment of the light amount per unit time is performed, for example, by adjusting the light intensity, or by adjusting the irradiation time when the illumination light is pulse lighting.

When imaging a living tissue in a body cavity using such an electronic scope 100 to observe and treat the living tissue, a body cavity material may adhere to the illumination window 12 and be fixed. In the following description, blood is described as a representative example of a substance in a body cavity.
For example, when using the electronic endoscope system 1 to find and observe the position of a tumor portion where blood vessels are concentrated in a body cavity, and treat the tumor portion using a treatment tool, special observation using special light as illumination light The mode is used. In the special observation mode, special light that can distinguish between a normal part and a lesion part (tumor part) of a living tissue is used as illumination light. At this time, since the living tissue is treated, for example, by excision, blood easily flows into the body cavity and adheres to the distal end surface 57 of the distal end portion 56. The blood adhering to the observation window 13 of the distal end surface 57 is reflected on the captured image, so it is possible to judge the presence or absence of the blood adhesion. When it is confirmed that the blood adheres to the observation window 13, it is possible to discharge the fluid such as water or air from the air / water supply port 64 immediately to wash the surface and remove the blood. However, when blood adheres to the illumination window 12, it is difficult to confirm the adhesion of the blood, so the blood may be left until it coagulates and adheres on the surface of the illumination window 12. Once the blood has condensed, even if the fluid such as water or air is discharged from the air / water supply port 64 to wash the surface of the illumination window 12, the coagulated blood can not be removed. In particular, the special light used in the special observation mode often makes the light intensity of the purple light Lv having the wavelength band where the light absorption of blood is the highest the light intensity of the purple light Lv in the pseudo white light, The blood adhering to the illumination window 12 absorbs purple light Lv and tends to coagulate earlier than the blood adhering to the observation window 13. For this reason, when the possibility of adhering to the illumination window 12 is high, it is preferable to determine early that the possibility that blood has adhered to the illumination window 12 and to wash the surface of the illumination window 12.

The electronic endoscope system 1 has a high possibility that blood may adhere to the illumination window 12 so that blood can be removed early even if blood adheres to the surface of the illumination window 12 It has a configuration that can be determined. That is, when imaging the living tissue in the body cavity while treating the living tissue, the electronic endoscope system 1 adheres and adheres the blood which is the body cavity material to the illumination window 12 of the distal end surface 57, thereby capturing the captured image. It has the composition which controls becoming defective.

FIG. 7 is a diagram for explaining the configuration of the system controller 21 of the processor 200.
As shown in FIG. 7, the system controller (control unit) 21 generates a control signal for controlling and managing the operation of each part of the electronic endoscope system 1 and transmits it to each part, in addition to the system operation control unit 21A A determination unit 21B and a light amount change unit 21C are provided.

The determination unit 21B is a portion that determines whether or not the image color component of the captured image of the biological tissue repeatedly captured at predetermined time intervals by the solid-state imaging device 14 satisfies the set determination condition. The determination condition is a condition using a ratio of values of different image color components in each pixel of the captured image. Specifically, the determination unit 21B determines the determination condition in order to make the above determination on a captured image including an image of a substance in the body cavity different from the living tissue in the body cavity, for example, a captured image including an image of blood. The determination is performed by calculating the ratio of the values of image color components other than the target image color component to the value of the target image color component of the captured image as the above ratio used for. Here, the target image color component of the captured image is an image color component of the captured image including the wavelength at which the light reflectance of blood (subjacent substance) is the highest in the sensitivity wavelength band of the solid-state imaging device 14. The target image color component of the captured image including the wavelength with the highest light reflectance is the red light component most reflected in the case of blood, so the target image color component is the image of the image captured by the solid-state imaging device 14 It is a red image color component.

FIG. 8 is a diagram showing an example of a spectral waveform of the transmittance of the primary color filter provided on the front surface of each light receiving position of the solid-state imaging device 14. In the spectral waveform of the transmittance of the color filter shown in FIG. 8, the wavelength band where the transmittance is greater than 0 is the sensitivity wavelength band in the solid-state imaging device 14. Thus, the determination unit 21B calculates the ratio of the value of the target image color component of the captured image to the value of the other image color components. In this case, the target image color component is the red color component R of the wavelength band indicated by R shown in FIG. Therefore, assuming that the value of the blue color component is Db, the value of the green color component is Dg, and the value of the red color component that is the target image color component is Dr, the ratio calculated by the determination unit 21B is Db / Dr or Dg / Dr. Thus, the reason for using the ratio of image color components in the same pixel is to eliminate the influence of the luminance which is different for each pixel. Therefore, instead of Db / Dr or Dg / Dr, it is also possible to use the ratio of the value of Dr to the luminance component in the same pixel.
Using such a ratio, the determination unit 21B determines whether the image color component of the captured image satisfies the determination condition. The determination condition is, for example, when there are a large number of pixels for which the value of Db / Dr or Dg / Dr is equal to or less than the threshold in the captured image, that is, when there are many images of blood in the captured image It is a condition for determining that blood is likely to have flowed out and the blood has adhered to the illumination window 12. Such determination conditions will be described later.

The light amount changing unit 21C changes the light amount per unit time of some of the plurality of lights emitted by the light source device 300 according to the determination result of the determining unit 21B, for example, a light source to reduce the light amount. The device 300 is controlled. In one embodiment, reducing the light intensity reduces the amount of light per unit time. In another embodiment, when the light intensity is reduced, the period during which the solid-state imaging device 14 performs imaging by photoelectric conversion is removed while the light intensity is kept constant, or the light emission is continuously performed for a certain period or By switching off intermittently, the amount of light per unit time is changed (decreased). Specifically, the light quantity changing unit 21C changes the light quantity by using the light component of the illumination light determined according to the absorptivity of the substance in the body cavity as the light quantity control target light so that the light absorption of the substance in the body cavity is reduced. More specifically, the light quantity change unit 21C sets the light quantity control target as the light quantity control target light whose light absorptivity of blood is higher than a predetermined value, for example, the highest light among the lights emitted by the light source device 300. The operation of the light source drive circuit 340 is controlled to change the amount of light.
FIG. 9 is a diagram showing a spectral waveform of blood absorptivity. As shown in FIG. 9, the absorptivity of blood is maximized in the range of 410 to 420 nm, particularly at 415 nm. For this reason, the light amount control target light whose light intensity is reduced becomes purple light Lv emitted from the light source unit 315.

Thus, according to the result determined by the determination unit 21B, the light amount changing unit 21C converts the light component of the illumination light determined according to the absorptivity of the body cavity substance so that the light absorption of the body cavity substance is reduced. The light quantity is changed as the control target light. Further, according to one embodiment, the light amount changing unit 21C divides the illumination light L into a first light component for reducing the light amount and a second light component not for reducing the light amount as the light amount control target light. It is configured to reduce the amount of light of one light component. In this case, it is preferable that the absorptivity of the body cavity material that absorbs the first light component is larger than the absorptivity of the body cavity material that absorbs the second light component.
Further, according to one embodiment, the light quantity control target light is, for example, a light component in which the absorptivity of the substance in the body cavity is higher than a predetermined value, and more preferably a light component having the maximum absorptivity. is there. In other words, it is preferable that the wavelength of light subject to light quantity control includes a wavelength at which the absorptivity of the substance in the body cavity is maximum.

The light intensity of the light quantity control target light does not have to be reduced to the level of the light intensity of the purple light Lv in the pseudo white light as indicated by the dotted line in FIG. 5, for example. It may be reduced to the light intensity of the purple light Lv at.
Note that the light amount changing unit 21C may reduce the relative ratio of the light amount of the light amount control target light to the light amount of the entire illumination light, instead of reducing the light intensity.

According to one embodiment, the determination unit 21B determines that the possibility of blood adhering to the illumination window 12 is high, according to one embodiment, in the captured image, the above-mentioned ratio Db / Dr or Dg / Dr is a predetermined threshold value. It is preferable to include the condition A whether or not the smaller number of pixels is larger than a predetermined number as the allowable limit value. In the captured image, when the ratio is smaller than a predetermined threshold, for example, when the number of pixels of the image of blood is large, it can be said that blood is likely to be attached to the illumination window 12. As the above-mentioned allowable limit value of the number of pixels of the image of blood, the upper limit of the predetermined allowable occupancy rate of the number of pixels of the image of blood occupied in all pixels of the captured image, and the number of all pixels of the captured image The pixel in the specific area (for example, a rectangular or circular area smaller than the image size of the captured image and including the central position of the captured image) in the captured image may be used. .Times..times..times..times..times..times..times..times..times..times..times..times..times..times..times.

Further, according to one embodiment, in the captured image obtained in time series, the determination condition is predetermined as the allowable limit value of the number of pixels of which the temporal change of the above-mentioned ratio increases beyond a predetermined range. It is preferable to include the condition B which is larger than the number. The temporal change of the ratio is, for example, the ratio of the above-mentioned ratio in two captured images adjacent to each other among the captured images of moving images obtained in time series divided by the difference between the captured times of the two captured images. is there. In the captured image, when blood flows out to a living tissue, the time change of the above ratio (when the time change is negative, it means the absolute value of the time change) becomes larger than the predetermined range (the change of the ratio is large Therefore, when such a number of pixels is large, it means that blood has flowed out on the living tissue, and it can be said that there is a high possibility that the blood has adhered to the illumination window 12. The upper limit of the predetermined allowable occupancy rate of the number of pixels changing to the image of blood occupied in all the pixels of the captured image as the above-mentioned allowable limit value of the number of pixels changed from the image of living tissue to the image of blood in this way Alternatively, a product obtained by multiplying the number of all pixels of the captured image may be used, or a specific area near the center position in the captured image (for example, smaller than the image size of the captured image, including the center position of the captured image) The number of pixels in the rectangular or circular area) may be multiplied by the upper limit of the predetermined allowable occupancy rate of the number of pixels changing to the image of blood occupied in this specific area. It is also preferable that the determination conditions include condition A and condition B simultaneously.
In this case, when the number of pixels under condition A, condition B, or condition A and condition B is larger than a predetermined number, the light quantity changing unit 21C controls the light source device 300 to reduce the light quantity of light subject to light quantity control. Is also preferred.

Further, according to one embodiment, the determination condition is that, in the captured image obtained in time series, the duration for which the number of pixels whose ratio is smaller than the predetermined threshold is larger than the predetermined number continues to be permitted. It is preferable to include the condition C as to whether the value is longer than a predetermined time. In the captured image, the number of pixels whose ratio is smaller than a predetermined threshold value is continuously present for a predetermined time, for example, when the image of blood is continuously present for a predetermined time, blood may be attached to the illumination window 12 It can be said that the sex is high.

According to one embodiment, the determination condition is that, in the captured images obtained in time series, the state in which the number of pixels whose temporal change of the above-mentioned ratio increases beyond a predetermined range is larger than a predetermined number continues It is preferable to include the condition D whether the duration is longer than a predetermined time as an allowable limit value. The number of pixels in which the temporal change of the ratio is increased beyond a predetermined range, for example, the number of pixels which has been rapidly changed from an image of a living tissue to an image of blood continuously exists for a predetermined time. Is rapidly increasing and continuously existing for a predetermined time, it is highly likely that blood has flowed into the body cavity and blood has adhered to the illumination window 12.

The determination unit 21B may make a determination using a combination of at least two of the above conditions A to D as the determination condition.
According to one embodiment, when the conditions A and B are satisfied and the conditions C and D are satisfied, the light quantity control unit 21B may control the light source device 300 to reduce the light quantity of the light quantity control target light. preferable.

According to one embodiment, the light quantity changing unit 21B may divide the light quantity per unit time of the light quantity control target light into a plurality of light quantity levels and sequentially change the light quantity in a stepwise manner. In this case, for example, when the light intensity of the light amount control target light is divided into a plurality of intensity levels and sequentially changed in stages, the determination unit 21B determines the light intensity (light amount) after the change of the light amount control target light. It is preferable to provide a reference table for changing the allowable limit values of the above-mentioned conditions A to D, that is, the predetermined number or the above-mentioned predetermined time, which is used in the judgment condition. The reference table is information in which the light intensity of the light amount control target light and the above-described allowable limit value used in the determination condition are stored in association with each other. When the light intensity of the light quantity control target light is lowered stepwise, when the intensity level of the light quantity control object light is high, the above predetermined number used as the allowable limit value or the above predetermined time is the light quantity control target Different from the tolerance limits used when the light intensity level is low. It is preferable to change the allowable limit value according to the intensity level of the light quantity control target light in order to make the determination with high accuracy.

FIG. 10 is a diagram illustrating an example of the configuration of the system controller 21 according to an embodiment. According to one embodiment, the operation unit 52 of the electronic scope 100 is a fluid delivery mechanism 70 (for example, a syringe pump or the like) that supplies air or water to discharge air or water (fluid) from the air / water supply port 64. Connected with The fluid delivery mechanism is connected to the operation unit 52 through a pipe for supplying air or water. In this case, in addition to the system operation control unit 21A, the determination unit 21B, and the light quantity change unit 21C, the system controller 21 preferably includes a fluid operation control unit 21D that controls the operation of the fluid delivery mechanism. When the light quantity changing unit 21C changes the light quantity of the light quantity control target light, it is preferable that the fluid operation control unit 21D perform the control of the operation of the fluid delivery mechanism 70 from the point of removing blood adhering early.

FIG. 11 is a diagram showing an example of the configuration of a system controller 21 according to still another embodiment. According to one embodiment, in addition to the system operation control unit 21A, the determination unit 21B, and the light amount change unit 21C, the system controller (control unit) 21 determines the light source device according to the decrease in the average value of the luminance components of the captured image. The automatic light amount adjustment unit 21E may be provided to control the light source drive circuit 340 of the light source device 300 such that the light amount of the entire illumination light emitted by the light source 300 increases (so that the light amount increases uniformly in the entire wavelength band). The automatic light quantity adjustment unit 21E is generally used to suppress fluctuations in the luminance of a captured image due to the length (short distance) of the distance (imaging distance) between the living tissue as the subject and the distal end surface 57. However, the automatic light amount adjustment unit 21E can be effectively used also in the determination by the determination unit 21B. That is, in addition to the determination using the determination condition, the determination unit 21B further determines whether the increased light amount of the entire illumination light (light amount per unit time) exceeds a predetermined amount. It is preferable to control the light source device 300 so as to change the light quantity of the light quantity control target light when the light quantity of the entire illumination light exceeds a predetermined quantity. When blood adheres to the illumination window 12, it absorbs part of the illumination light L and the illumination light becomes dark rapidly, so the automatic light amount adjustment unit 21E increases the light amount so that the brightness of the illumination light becomes constant. Do. However, even if the automatic light quantity adjustment unit 21E increases the light quantity of the illumination light, the improvement of the average value of the luminance components of the captured image is not sufficient, and if the average value is still small, the possibility of blood adhering to the illumination window 12 Is high. In this case, the light quantity of the entire illumination light is larger than usual. Therefore, when the above-described determination condition is satisfied, and the light amount of the increased total illumination light in the illumination light exceeds a predetermined amount, for example, the upper limit of the light amount that increases when blood is not attached to the illumination window 12 In addition, controlling the light source device 300 to change the light amount of the light amount control target light more reliably determines that the blood adheres to the illumination window 12 and suppresses the blood from adhering to the illumination window 12 It is preferable from the point which can be done.
The automatic light quantity adjustment unit 21E can acquire information on the light quantity of the present illumination light L emitted from the light source device 300 from the control signal that the automatic light quantity adjustment unit 21E sends to the light source drive circuit 340.
Furthermore, in another embodiment, the system controller 21 shown in FIG. 11 may be provided with a fluid operation control unit 21D shown in FIG. In this case, before the determination unit 21B determines whether the light amount of the increased total illumination light in the illumination light exceeds a predetermined amount, the fluid operation control unit 21D receives air or water from the air / water supply port 64 ( It is preferable to control the operation of discharging the fluid. Since the illumination window 12 is cleaned before the determination of the light amount of the illumination light in the determination unit 21B, the cleaned illumination window 12 can be used as the determination target.

As shown in FIG. 2, the processor 200 includes a pre-processing circuit 26 (image processing unit) that performs image processing on a captured image. The pre-processing circuit 26 adjusts the gain of the image signal of the captured image. In this case, the pre-processing circuit 26 generates an image color component of a wavelength band including the wavelength band of the light amount control target light in the captured image captured by the solid-state imaging device 14 after changing the light amount of the light amount control target light It is preferable to change the gain adjustment amount for the color component in accordance with the change amount of the light quantity of the light quantity control target light. In the above-mentioned example, the light quantity control target light is purple light Lv, and this purple light Lv is included in the blue (B) wavelength band as shown in FIG. , According to the amount of change of the light quantity of the purple light Lv. Specifically, when the light amount of the purple light Lv is reduced, the gain for increasing the value of the blue image color component is increased as the light amount of the purple light Lv is decreased.
Thereby, even when the light amount of the light to be controlled is reduced, the color balance of the captured image displayed on the monitor 400 is maintained before and after the change of the light amount, and the operator does not stress the captured image of the living tissue. It can be observed.

According to one embodiment, as shown in FIGS. 5 and 8, the wavelength band of blue (B) also includes the wavelength band of blue light Lb emitted from the light source unit 314. Therefore, when the light amount of the purple light Lv is decreased, it is also preferable to increase the light amount of the blue light Lb and maintain the color balance of the captured image displayed on the monitor 400 before and after the change of the light amount. That is, an image color component A (for example, a blue image color component) which is one of the image color components of the captured image is a light quantity control target light (for example, violet light) among a plurality of lights emitted from the light source device 300 In addition to the wavelength band of Lv), the wavelength band of at least one other light (for example, blue light Lb) is included as the wavelength band of the image color component A. At this time, when the light quantity changing unit 21C changes (for example, reduces) the light quantity of the light quantity control target light (for example, purple light Lv), the change of the value of the image color component A (blue image color component) In order to suppress, it is preferable to change (increase) the light amount per unit time of another light (for example, blue light Lb). Such an embodiment may be performed in combination with the above-described change in gain adjustment amount. Thereby, even when the light amount of the light to be controlled is reduced, the color balance of the captured image displayed on the monitor 400 is maintained before and after the change of the light amount, and the operator observes the captured image of the living tissue without stress. can do.

In addition, when the image color component of the captured image satisfies the determination condition, the system controller 21 (control unit) information that blood may be attached to the illumination window 12 for illuminating the illumination light toward the living tissue. It is also preferable to include a notification control unit 21F that transmits the above information to the monitor 400, as shown in FIG. Thus, the operator can manually clean the illumination window 12 at an early stage. For this reason, it can suppress that blood adheres to the illumination window 12. Furthermore, it is preferable that the notification control unit 21F transmit information so that the monitor 400 can notify that the observation in the body cavity in the special observation mode can be continued.
In this case, after a predetermined time has elapsed from notification of information indicating that blood may be attached to the illumination window 12, for example, after 10 seconds, the light quantity change unit 21C changes the light quantity of the light quantity control target light It is preferred to do. By transmitting information to the operator and notifying in advance, the operator can prepare for the possibility of color change of the captured image, and can continue stable observation, diagnosis or treatment.
When blood is removed by cleaning the illumination window 12, for example, when the average value of the luminance components of the captured image is recovered, the light intensity of the light quantity control target light may be returned to the original light intensity.

In the above-described embodiment, the body cavity material is described for blood that has flowed into the body cavity, but the body cavity material is a biological material that is secreted from living tissue and is introduced from outside the body into the body cavity and remains in the body cavity. It contains substances in the body cavity such as residues of external substances (food). In this case, the light quantity control target light is not limited to purple light and changes according to the absorptivity of the substance in the body cavity. In addition, the type of the target image color component of the captured image used for the determination condition also changes according to the reflection characteristic of the substance in the body cavity.
Note that, as described above, the light amount changing unit 21C causes at least one of the illumination light to be reduced according to the absorptivity of the body cavity material so that the light absorption of the body cavity material is reduced according to the result determined by the determining unit 21B. The light component is configured to change the light quantity as the light quantity control target light. Specifically, the light quantity of light having a high absorptivity of the substance in the body cavity is configured to be reduced. However, the light quantity control target light may increase the light quantity of light having a low absorptivity.

As mentioned above, although the electronic endoscope system of the present invention was explained in detail, the electronic endoscope system of the present invention is not limited to the above-mentioned embodiment, In the range which does not deviate from the main point of the present invention, various improvement or change Of course it is good.

1 Electronic Endoscope System 11 LCB (Light Carrying Bundle)
12 illumination window 13 observation window 14 solid-state imaging device 15 driver signal processing circuit 21 system controller 21A system operation control unit 21B determination unit 21C light amount change unit 21D fluid operation control unit 21E automatic light amount adjustment unit 21F notification control unit 22 timing controller 23, 16 Memory 24 Operation panel 26 Pre-stage signal processing circuit 27 Image memory 28 Post-stage signal processing circuit 50 Connector part 51 Cable 52 Operation part 54 Insertion part 56 Tip part 57 Tip surface 58 Flexible tube 60 Bend part 62 Treatment tool opening 64 Air supply water Port 70 Fluid delivery mechanism 100 Electronic scope 200 Processor 300 Light source device 310

Light source units

312, 313, 314, 315

Light source units

322, 323, 324, 325

Collimating lenses

333, 334, 335 Optical element 340 Light source drive circuit 350 collection Light lens

Claims

An electronic endoscope system comprising an electronic endoscope and a processor configured to image living tissue in a body cavity, the electronic endoscope system comprising:
A light source configured to emit illumination light;
An imaging device provided in the electronic endoscope and configured to image the living tissue illuminated by the illumination light;
It is provided in the processor, and it is determined whether a captured image of the living tissue captured by the imaging device satisfies a determination condition using a ratio of values of different image color components in pixels of the captured image. The light source unit is controlled to change a light amount per unit time of a light component of a part of the light components included in the illumination light according to a determination unit configured to perform and a result of the determination. A control unit including the light amount change unit configured in
The determination is determination based on the ratio as to whether or not the captured image captured by the imaging element is a captured image including an image of a body cavity material different from the living tissue in the body cavity.
The ratio used for the determination condition is the image color component of interest with respect to the value of the image color component of interest of the captured image including the wavelength at which the light reflectance of the body cavity material is highest in the sensitivity wavelength band of the imaging element. It is a ratio of values of image color components other than
The light amount changing unit is configured to change the light amount of the light component, with the light component of the illumination light determined according to the absorptivity of the substance in the body cavity as a light amount control target light. Electronic endoscope system.
The illumination light is combined light obtained by combining a plurality of lights as the light component,
The light amount changing unit is configured to reduce the light amount of the first light component by dividing it into a first light component for reducing the light amount among the illumination light as the light amount control target light and a second light component for which the light amount is not reduced. The electronic endoscopy according to claim 1, wherein the absorptivity of the body cavity substance configured to absorb the first light component is greater than the absorptivity of the body cavity substance absorbing the second light component. Mirror system.
The electronic endoscope system according to claim 1, wherein a wavelength of the light quantity control target light includes a wavelength at which the absorptivity of the substance in the body cavity is maximum.
The method according to any one of claims 1 to 3, wherein the determination condition includes a condition as to whether or not the number of pixels whose ratio is smaller than a predetermined threshold value is larger than a predetermined number as an allowable limit value in the captured image. The electronic endoscope system according to the item.
The imaging device is configured to image the biological tissue in time series;
The determination condition includes a condition as to whether or not the number of pixels of the captured image where the temporal change of the ratio has increased beyond a predetermined range is larger than a predetermined number as an allowable limit value. The electronic endoscope system according to any one of to 4.
The imaging device is configured to image the biological tissue in time series;
The determination condition is whether or not the duration in which the number of pixels whose ratio is smaller than a predetermined threshold value is larger than a predetermined number is longer than the predetermined time as the allowable limit value in the captured image. The electronic endoscope system according to any one of claims 1 to 5, which comprises
The imaging device is configured to image the biological tissue in time series;
The determination condition is that, in the captured image, the duration time in which the number of pixels whose temporal change of the ratio is increased beyond a predetermined range is larger than a predetermined number continues as an allowable limit value. The electronic endoscope system according to any one of claims 1 to 6, which includes a long or not long condition.
The light quantity changer divides the light quantity of the light quantity control target light into a plurality of light quantity levels and sequentially changes them in stages.
The determination unit includes a reference table in which the light amount is associated with the allowable limit value in order to change the allowable limit value used in the determination condition according to the light amount after the change of the light amount control target light. The electronic endoscope system according to any one of claims 4 to 7.
When the determination condition is satisfied, the light amount changing unit is configured to control the light source unit so as to reduce a relative ratio of the light amount of the light amount control target light to the total light amount of the illumination light. Item 9. The electronic endoscope system according to any one of Items 1 to 8.
The control unit is configured to control the light source unit so as to increase the light amount of the entire illumination light emitted from the light source unit according to a decrease in an average value of luminance components of the captured image. Equipped with an adjustment unit,
The determination unit is further configured to determine whether or not the light amount of the entire illumination light increased by the automatic light amount adjustment unit exceeds a predetermined amount.
The light amount change unit controls the light source unit to change the light amount of the light amount control target light when the determination condition is satisfied and the light amount of the entire illumination light exceeds a predetermined amount. The electronic endoscope system according to any one of claims 1 to 9, which is configured as follows.
The electronic endoscope includes an illumination window for illuminating the illumination light toward the living tissue, an observation window for capturing an image of the living tissue, and a surface of the illumination window and the observation window. Having a tip surface with a fluid discharge port configured to discharge fluid;
The electronic endoscope is connected with a fluid delivery mechanism configured to supply the fluid to eject the fluid from the fluid ejection port;
The control unit includes a fluid operation control unit configured to control the operation of the fluid delivery mechanism so as to discharge the fluid from the fluid discharge port;
Before the determination unit determines whether the light amount of the entire illumination light increased by the automatic light amount adjustment unit exceeds a predetermined amount, the fluid operation control unit causes the fluid to be discharged from the fluid discharge port. 11. The electronic endoscope system according to claim 10, wherein the electronic endoscope system is configured to perform control of an ejection operation.
The electronic endoscope includes an illumination window for illuminating the illumination light toward the living tissue, an observation window for capturing an image of the living tissue, and a surface of the illumination window and the observation window. Having a tip surface with a fluid discharge port configured to discharge fluid;
The electronic endoscope is connected with a fluid delivery mechanism configured to supply the fluid to eject the fluid from the fluid ejection port;
The control unit is configured to control the operation of the fluid delivery mechanism so as to discharge the fluid from the fluid discharge port when the light amount changing unit changes the light amount of the light amount control target light The electronic endoscope system according to any one of claims 1 to 10, comprising an operation control unit.
The controller according to any one of claims 1 to 12, wherein the control unit is configured to change the light amount per unit time of the light amount control target light by changing the light intensity of the light amount control target light. The electronic endoscope system according to claim 1.
The processor includes an image processing unit configured to perform image processing on the captured image;
The image processing unit is configured to adjust a gain adjustment amount for an image color component of a wavelength band including the wavelength band of the light amount control target light in the captured image captured by the imaging device after changing the light amount of the light amount control target light. The electronic endoscope system according to any one of claims 1 to 13, wherein the electronic endoscope system is configured to change according to the amount of change of the light amount of the light to be controlled.
The image color component A, which is one of the image color components of the captured image, is a wavelength of at least one other light in addition to the wavelength band of the light quantity control target light among the plurality of lights emitted from the light source unit A band is included as a wavelength band of the image color component A,
The light quantity changing unit is configured to change the light quantity per unit time of the other light in order to suppress a change in the value of the image color component A when the light quantity of the light quantity control target light is changed. The electronic endoscope system according to any one of claims 1 to 14.
The electronic endoscope system includes a monitor connected to the processor and configured to display the captured image. The control unit determines that the image color component of the captured image satisfies the determination condition. The monitor is configured to transmit the information to notify information indicating that the intracavitary substance may be attached to an illumination window for illuminating the illumination light toward the living tissue; The electronic endoscope system according to any one of claims 1 to 15, further comprising a notification control unit.
17. The electronic endoscope system according to claim 16, wherein the light amount change unit is configured to change the light amount of the light amount control target light after a predetermined time has elapsed from notification of the information by the notification control unit. .