Endoscope system and operation method thereof

Abstract

To provide an endoscope system for calculating a region of a subject with a high degree of recognition precision while performing endoscopic observation, and to provide an operation method thereof.SOLUTION: An endoscope system 10 includes an endoscope 11, an air supply device 16, and a processor. The processor controls emission of illumination light for illuminating a subject S and measurement light for measuring a distance between a plurality of places of the subject S and the endoscope 11. The measurement light is emitted with a first air supply amount, the subject S is imaged by emitting or turning off the illumination light with a light amount suppressed with respect to the measurement light, and a region of the subject S is calculated from acquired first distance information. The measurement light is emitted with a second air supply amount, the subject S is imaged by emitting or turning off the illumination light with a light amount suppressed with respect to the measurement light, and a region of the subject S is calculated from acquired second distance information.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to an endoscopic system and a method of operation thereof. [Background technology]

[0002] In recent years, diagnoses using endoscope systems have become common in the medical field, and there are methods for diagnosing functional diseases of the digestive tract using endoscope systems. Functional diseases of the digestive tract include functional dyspepsia (FD) and irritable bowel syndrome (IBS), and in these diseases, the digestive tract is less likely to expand than in healthy people. Observing the digestive tract and measuring the ease of expansion can assist in the diagnosis of functional diseases.

[0003] Various observation methods have been proposed for diagnosis of the digestive tract using an endoscope system. For example, there is a three-dimensional measurement method in which a pattern is projected onto the subject using measurement light different from the illumination light that illuminates the subject. Measurement of the ease with which the digestive tract spreads can be achieved by blowing air into the digestive tract from an endoscope equipped with an air blowing function and observing before and after the air blowing. An example of an endoscope device in Patent Document 1 that measures the size of a subject using an endoscope that performs a three-dimensional measurement method while normally observing the subject, which is the affected area.

[0004] The endoscopic device in Patent Document 1 has a technology in which an endoscope having an air / water nozzle emits pulsed measurement assist light at specific frame intervals relative to imaging using only illumination light to capture an image of a subject and measure the observation distance of the subject. The size of the subject is measured from the image captured using the measurement assist light. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-187598 A Summary of the Invention [Problem to be solved by the invention]

[0006] In measuring the size of a subject using the auxiliary measurement light of Patent Document 1, the auxiliary measurement light is emitted together with the illumination light, so that the mucous membrane reflection and halation of the illumination light become disturbances, and the recognition accuracy of the pattern light by the auxiliary measurement light decreases. When the recognition accuracy decreases, the reliability of the measurement results of the size of the subject, especially the change in size, decreases.

[0007] An object of the present invention is to provide an endoscope system and an operating method thereof that calculates the area of ​​a subject with high recognition accuracy while observing with an endoscope. [Means for solving the problem]

[0008] The endoscopic system of the present invention includes an endoscope that images a subject, an air supply device connected to the endoscope and that supplies air at multiple stages of air supply volumes through the tip of the endoscope, and a processor, wherein the processor controls the emission of illumination light that illuminates the subject and measurement light for measuring distances between multiple points on the subject and the endoscope, acquires a first imaging signal from the endoscope that images the subject by irradiating the measurement light at a first air supply volume and irradiating the illumination light at a reduced light volume relative to the measurement light or turning it off, acquires a second imaging signal from the endoscope that images the subject by irradiating the measurement light and irradiating the illumination light at a reduced light volume relative to the measurement light or turning it off at a second air supply volume that is a volume different from the first air supply volume, calculates the area of ​​the subject from first distance information obtained by measuring the distance between the multiple points on the subject and the endoscope based on the first imaging signal, and calculates the area of ​​the subject from second distance information obtained by measuring the distance between the multiple points on the subject and the endoscope based on the second imaging signal.

[0009] It is preferable that the endoscope divides the subject into images at specific angles corresponding to the field of view, and the processor measures first distance information based on a plurality of first divided imaging signals obtained by imaging the subject at each specific angle, and measures second distance information based on a plurality of second divided imaging signals obtained by imaging the subject at each specific angle.

[0010] It is preferable that the processor determine a specific part of the subject, calculate a region of the specific part from the first distance information, and calculate a region of the specific part from the second distance information.

[0011] The measurement light is preferably a pattern light in which spot lights are arranged in a lattice pattern.

[0012] The area is preferably at least one of a length, which is a one-dimensional area, a surface area, which is a two-dimensional area, and a volume, which is a three-dimensional area.

[0013] When the endoscope applies a light intensity threshold, which is a threshold value for the light intensity in the emission of a predetermined measurement light and illumination light, and irradiates the measurement light and irradiates the illumination light with a suppressed light intensity relative to the measurement light, it is preferable to perform measurement irradiation in which the measurement light is irradiated with an intensity equal to or greater than the light intensity threshold and the illumination light is irradiated with an intensity less than the light intensity threshold.

[0014] It is preferable that the endoscope continuously images the subject by switching between measurement illumination and observation illumination, in which illumination light is irradiated at an amount of light equal to or greater than a light amount threshold, and that the processor displays on a screen an observation endoscopic image generated by imaging the subject using the observation illumination.

[0015] It is preferable that the endoscope continuously images the subject by switching between measurement illumination and measurement location confirmation illumination, in which illumination light and measurement light are irradiated at an amount of light equal to or greater than a light intensity threshold, and that the processor displays on a screen a two-light endoscopic image generated by imaging the subject using measurement location confirmation illumination.

[0016] It is preferable that the processor displays on a screen a measurement light image generated by imaging the subject using measurement illumination.

[0017] It is preferable that the processor performs a different screen display for each type of generated image.

[0018] The endoscope continuously images the subject by switching between measurement illumination, observation illumination in which illumination light is irradiated at an intensity equal to or greater than a light intensity threshold, and measurement location confirmation illumination in which illumination light and measurement light are irradiated at an intensity equal to or greater than a light intensity threshold, and it is preferable that the processor displays on different screens an observation endoscopic image generated by imaging the subject with observation illumination and a two-type light endoscopic image generated by imaging the subject with measurement location confirmation illumination.

[0019] The endoscopic system of the present invention includes an endoscope that images a subject, an air supply device connected to the endoscope and that supplies air at multiple stages of air supply volumes through the tip of the endoscope, and a processor, wherein the processor controls the emission of illumination light that illuminates the subject and measurement light for measuring distances between multiple locations on the subject and the endoscope, and acquires a first imaging signal from the endoscope that images the subject by irradiating the measurement light at a first air supply volume and irradiating the illumination light at a reduced light volume relative to the measurement light or by turning the illumination light off, and acquires a second imaging signal from the endoscope that images the subject by irradiating the measurement light and irradiating the illumination light at a reduced light volume relative to the measurement light or by turning the illumination light off, at a second air supply volume that is a volume different from the first air supply volume, and calculates and outputs an index value representing the amount of extension of the subject using the difference between first distance information obtained by measuring the distance between the multiple locations on the subject and the endoscope based on the first imaging signal and second distance information obtained by measuring the distance between the multiple locations on the subject and the endoscope based on the second imaging signal.

[0020] The processor preferably calculates the volume of the subject based on the index value.

[0021] The operation method of the endoscopic system of the present invention includes the steps of: an air supply device supplying air at multiple levels of air supply volumes through the tip of an endoscope that images a subject; controlling the emission of illumination light for illuminating the subject and measurement light for measuring distances between multiple locations on the subject and the endoscope; acquiring a first imaging signal from the endoscope that images the subject by irradiating the measurement light at a first air supply volume and irradiating the illumination light at a reduced light volume relative to the measurement light or turning it off; acquiring a second imaging signal from the endoscope that images the subject by irradiating the measurement light and irradiating the illumination light at a reduced light volume relative to the measurement light or turning it off at a second air supply volume that is a volume different from the first air supply volume; calculating the area of ​​the subject from first distance information obtained by measuring the distance between the multiple locations on the subject and the endoscope based on the first imaging signal; and calculating the area of ​​the subject from second distance information obtained by measuring the distance between the multiple locations on the subject and the endoscope based on the second imaging signal. Effect of the Invention

[0022] According to the present invention, the area of ​​a subject can be calculated with high recognition accuracy while observing with an endoscope. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a schematic diagram of an endoscope system. [Diagram 2] FIG. 2 is an explanatory diagram of the tip portion of the endoscope as viewed from the front. [Diagram 3] 2 is a block diagram showing the functions of the endoscope system. FIG. [Figure 4] FIG. 1 is an explanatory diagram of a method for inflating the stomach by supplying air to a barostat bag. [Diagram 5] FIG. 1 is an explanatory diagram of a method for inflating the stomach by inflating air using an endoscope. [Figure 6] FIG. 1 is an explanatory diagram of an endoscope for performing observation while supplying air. [Figure 7] FIG. 13 is an explanatory diagram of (A) a measurement light image captured with measurement light, (B) an observation endoscopic image captured with illumination light, and (C) a dual-light endoscopic image captured with measurement light and illumination light, obtained during observation in measurement mode. [Figure 8] FIG. 1 is an explanatory diagram showing the relationship between the internal pressure and volume of the gastric fundus in healthy subjects and patients with functional gastrointestinal disorders. [Figure 9] FIG. 11 is an explanatory diagram for determining a specific part of a subject. [Figure 10] FIG. 2 is an explanatory diagram illustrating imaging of a subject using a first observation pattern. [Figure 11] FIG. 13 is an explanatory diagram illustrating imaging of a subject using a second observation pattern. [Figure 12] FIG. 13 is an explanatory diagram illustrating imaging of a subject using a third observation pattern. [Figure 13] FIG. 13 is an explanatory diagram for capturing an image of a subject using a fourth observation pattern. [Figure 14] FIG. 13 is an explanatory diagram for capturing an image of a subject using a fifth observation pattern. [Figure 15] FIG. 13 is an explanatory diagram for capturing an image of a subject using a sixth observation pattern. [Figure 16] FIG. 13 is an explanatory diagram for capturing an image of a subject using a seventh observation pattern. [Figure 17] 5 is an explanatory diagram of a projection pattern by measurement light. FIG. [Figure 18] 1 is a flowchart showing a sequence of steps for three-dimensional measurement according to the present invention. [Figure 19] 13 is an explanatory diagram of a light source device according to a modified example. [Figure 20] 13A and 13B are explanatory diagrams of projection patterns by measurement light in a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] As shown in Fig. 1, an endoscope system 10 according to an embodiment of the present invention includes an endoscope 11, a light source device 12, a processor device 13, a display 14, a user interface (UI) 15, an air supply device 16, and a pressure gauge 17. The endoscope 11 is optically connected to the light source device 12 and electrically connected to the processor device 13. The light source device 12 supplies illumination light to the endoscope 11. The endoscope 11 is also physically connected to the air supply device 16 and the pressure gauge 17. The air supply device 16 supplies measurement gas to the endoscope 11.

[0025] The endoscope 11 illuminates with illumination light, captures an image of a subject, and obtains an endoscopic image. The endoscope 11 has an insertion section 11a that is inserted into a subject such as the digestive tract, and an operation section 11b that is provided at the base end of the insertion section 11a. A bending section 11c and a tip section 11d are provided at the tip side of the insertion section 11a. The bending section 11c is bent in a desired direction by operating the operation section 11b. The tip section 11d irradiates illumination light toward the subject and receives reflected light from the subject to capture an image of the subject. The operation section 11b is provided with a mode changeover switch 11e that is used for switching between modes, and an air supply switch 11f that controls air supply from the air supply device 16.

[0026] The processor device 13 is electrically connected to the display 14 and the user interface 15. The processor device 13 receives an image signal from the endoscope 11 and performs various processes based on the image signal. An external recording unit (not shown) for recording images and image information, etc. may be connected to the processor device 13. The display 14 outputs and displays images and image information of a subject that have been image-processed by the processor device 13. The user interface 15 has a keyboard, a mouse, a touchpad, a microphone, a foot pedal, etc., and has a function of accepting input operations such as function settings.

[0027] 2, the tip 11d of the endoscope 11 viewed from the front is substantially circular, and includes an illumination lens 21 for irradiating illumination light supplied from the light source device 12, an objective lens 22 for receiving light from the subject, a measurement light emitting section 23 for emitting measurement light supplied from the light source device 12 in an arbitrary pattern, an air supply nozzle 24 for supplying measurement gas supplied from the air supply device 16, and a tip forceps port 25 connected to the main body forceps port 11g by a forceps channel. The measurement light emitting section 23 may be used as a separate body from the endoscope 11. In this case, the measurement light is emitted by a probe that has the function of the measurement light emitting section 23 and can be inserted and removed from the forceps port.

[0028] The gas supply device 16 supplies the measurement gas to the endoscope 11 in response to pressing of the gas supply switch 11f. The measurement gas is supplied from the gas supply nozzle 24 into the living body via the gas supply channel passing through the inside of the endoscope 11. The measurement gas is, for example, carbon dioxide or air, and the gas supply expands the digestive tract. The gas supply device 16 may also be electrically connected to the processor device 13, and may set a gas supply pattern that controls the gas supply timing and gas supply output, etc., to automatically supply gas. The gas supply output, which is the amount of gas supplied per unit time, is also controlled. Unless otherwise specified, gas is supplied at an arbitrary fixed output.

[0029] The pressure gauge 17 measures the pressure of the gas transmitted by a tube connected to the main body forceps port 11g. The transmitted gas passes through a forceps channel inside the insertion section 11a from the tip forceps port 25 to the main body forceps port 11g. When the tip section 11d of the endoscope 11 is inserted into a specific digestive tract, the pressure gauge 17 can measure the internal pressure of the specific digestive tract. The pressure transmitted to the pressure gauge 17 changes depending on the amount of measurement gas sent into the digestive tract and the state of the specific digestive tract. The pressure gauge 17 is electrically connected to the processor device 13 and transmits measured internal pressure information to the processor device 13 as needed.

[0030] As shown in FIG. 3, in the endoscopic system 10, the light source device 12 transmits emitted illumination light to the endoscope 11 via the light guide 36, and the endoscope 11 transmits an image signal captured using the illumination light to the processor device 13, and the processor device 13 generates an image to be displayed on the display 14.

[0031] The light source device 12 includes an illumination light source 30 that emits illumination light having a plurality of different dominant wavelengths or illumination light that is white light, a measurement light source 32 that emits measurement light that has a wavelength different from that of the illumination light source 30 and is used for measurement, and an emission control unit 34 that controls the emission timing and emission amount of the illumination light source 30 and the measurement light source 32. The measurement light source 32 is preferably a laser light source. The measurement light source 32 may be provided in the illumination light source 30, in the endoscope 11, or in another device such as a measurement light source device different from the light source device 12.

[0032] The function of the light emission control unit 34 is realized by a light source control processor (not shown) provided in the light source device 12, and controls the illumination light emitted by the illumination light source 30 and the measurement light emitted by the measurement light source 32. When the light source device 12 and the processor device 13 are electrically connected, the function of the light source control processor may be realized by a central control unit instead of the light source control processor. The light emission control unit 34 adjusts the drive current based on a preset light emission pattern.

[0033] The illumination light and measurement light are incident on the light guide 36. The light guide 36 is built into the endoscope 11 and a universal cord (a cord that connects the endoscope 11 with the light source device 12 and the processor device 13). The light guide 36 propagates light from the light source device 12 to the tip 11d of the endoscope 11.

[0034] The tip portion 11d is provided with an illumination optical system 38 and an imaging optical system 40. The illumination light propagated by the light guide 36 is irradiated onto the subject via the illumination lens 21 of the illumination optical system 38. The measurement light propagated by the light guide 36 is irradiated onto the subject via the measurement light emitting section 23 of the illumination optical system 38. The imaging optical system 40 has an objective lens 42 and an imaging sensor 44. The illumination light and the reflected light of the measurement light returning from the subject are incident on the imaging sensor 44 via the objective lens 42. As a result, an image of the subject is formed on the imaging sensor 44, which is a color imaging sensor.

[0035] The measurement light is used to measure the distance to multiple points at once, and a pattern is irradiated onto the subject to acquire distance information. For example, the measurement light may be a pattern of spot light repeated in an arbitrary pattern, arranged in a lattice pattern.

[0036] The imaging control unit 45 drives and controls the imaging sensor 44 in response to instructions from the mode changeover switch 11e and the user interface 15 via the processor device 13, and signals from the light emission control unit 34, and controls mode switching among observation modes and imaging in each mode. In controlling imaging, the imaging control unit 45 adjusts the exposure period by setting the shutter speed of an electronic shutter (not shown) of the imaging sensor 44, and the like.

[0037] Unless otherwise specified, the image sensor 44 has a fixed image frame length, and is controlled to alternate between an accumulation period and a readout period at a predetermined interval, for example, 60 fps (frames per second), i.e., every 1 / 60 seconds. The image frame length may be adjusted by changing the shutter speed of the electronic shutter.

[0038] The imaging sensor 44 may be a photoelectric conversion element such as a CCD (Charge Coupled Device) sensor or a CMOS (Complementary Metal-Oxide Semiconductor) sensor. The imaging sensor 44 performs, for example, a storage operation of photoelectrically converting received light and storing a signal charge according to the amount of received light for each pixel within an acquisition period of one frame, and a readout operation of reading out the stored signal charge. The signal charge for each pixel read out from the imaging sensor 44 is converted into a voltage signal and input to a CDS / AGC (Correlated Double Sampling / Automatic Gain Control) circuit 46. The light source device 12 generates illumination light in accordance with the timing of the storage operation of the imaging sensor 44, and causes the illumination light to enter the light guide 36.

[0039] Each pixel of the image sensor 44 is provided with either a B pixel (blue pixel) having a B (blue) color filter, a G pixel (green pixel) having a G (green) color filter, or an R pixel (red pixel) having an R (red) color filter. For example, the image sensor 44 is preferably a color image sensor with a Bayer array in which the ratio of the number of B pixels, G pixels, and R pixels is 1:2:1.

[0040] The B color filter transmits mainly light in the blue band, specifically light with a wavelength band of 380 to 560 nm (blue transmission band). The peak wavelength at which the transmittance is maximum is around 460 to 470 nm. The G color filter transmits mainly light in the green band, specifically light with a wavelength band of 450 to 630 nm (green transmission band). The R color filter transmits mainly light in the red band, specifically light with a wavelength band of 580 to 760 nm (red transmission band).

[0041] Also, a complementary color image sensor equipped with complementary color filters of C (cyan), M (magenta), Y (yellow) and G (green) may be used instead of the primary color image sensor 44. When a complementary color image sensor is used, image signals of four colors, CMYG, are output, and by converting the four color image signals of CMYG into three color image signals of RGB by complementary color-primary color conversion, image signals of each color of RGB similar to those of the image sensor 44 can be obtained.

[0042] The CDS / AGC circuit 46 performs correlated double sampling (CDS) and automatic gain control (AGC) on the analog image signal obtained from the image sensor 44. The image signal passed through the CDS / AGC circuit 46 is converted into a digital image signal by an A / D (Analog / Digital) converter 48. The digital image signal after A / D conversion is input to the processor device 13.

[0043] Programs for each process are incorporated in a program memory (not shown) in the processor device 13. A central control unit (not shown) constituted by a processor executes the programs in the program memory to realize the functions of an image signal acquisition unit 50, a DSP (Digital Signal Processor) 51, a noise reduction unit 52, an image processing unit 53, and an output control unit 54.

[0044] The image signal acquisition unit 50 receives an image signal input from the endoscope 11 driven and controlled by the imaging control unit 45, and transmits the received image signal to the DSP 51. The output control unit 54 transmits the image signal of the image to be displayed, acquired from the image processing unit 53, to the display 14.

[0045] The DSP 51 performs various signal processing such as defect correction, offset processing, gain correction, linear matrix processing, gamma conversion, demosaic processing, and YC conversion processing on the received image signal. In the defect correction processing, signals from defective pixels of the imaging sensor 44 are corrected. In the offset processing, dark current components are removed from the image signal that has been subjected to the defect correction processing, and an accurate zero level is set. In the gain correction processing, the signal level of each image signal is adjusted by multiplying the image signal of each color after the offset processing by a specific gain. The image signal of each color after the gain correction processing is subjected to linear matrix processing to improve color reproducibility.

[0046] Then, the brightness and saturation of each image signal are adjusted by gamma conversion processing. The image signals after the linear matrix processing are subjected to demosaic processing (also called isotropic processing or synchronization processing), and signals of the missing colors of each pixel are generated by interpolation. Through the demosaic processing, all pixels have signals of each of the RGB colors. The DSP 51 performs YC conversion processing on each image signal after the demosaic processing, and outputs a luminance signal Y and color difference signals Cb and Cr to the noise reduction unit 52.

[0047] The noise reduction unit 52 performs noise reduction processing, for example, by a moving average method, a median filter method, etc., on the image signal that has been subjected to demosaic processing, etc. by the DSP 51. The image signal with the noise reduced is input to the image processing unit 53.

[0048] The image processing unit 53 further performs color conversion processing such as 3×3 matrix processing, tone conversion processing, and 3D LUT (Look Up Table) processing on the input image signal for one frame. Then, various color enhancement processes are performed on the RGB image data that has been color converted. The RGB image data that has been color enhanced is subjected to structure enhancement processing such as spatial frequency enhancement. The image processing unit 53 outputs the RGB image data that has been subjected to structure enhancement processing as an image to the output control unit 54 or the distance measurement processing unit 60. Instead of the distance measurement processing unit 60, the RGB image data may be output to another device that is different from the processor device 13 and has at least the functions of the distance measurement processing unit 60 described later.

[0049] The output control unit 54 sequentially acquires the measurement light image, the observation endoscope image, or the dual-light endoscope image, and converts them into a video signal that enables full-color display on the display 14. The converted video signal is output and displayed on the display 14. This allows the doctor or other person to observe the subject using still or moving images of the observation endoscope images.

[0050] The distance measurement processing unit 60 measures the distance (distance) to the subject using the measurement light image, observation endoscope image, or dual-light endoscope image acquired by the image processing unit 53, and calculates the surface area and volume of the subject based on the measured distance information. The distance measurement processing unit 60 has the functions of a distance measurement unit 62, a specific part discrimination unit 64, an area calculation unit 66, and an air supply control unit 68.

[0051] The distance measurement unit 62 measures the distance in an image acquired by imaging using the measurement light, and acquires distance information between the tip 11d and the subject at a measurement position according to the projection pattern of the measurement light.

[0052] The specific part discrimination unit 64 discriminates the range of the specific part in the image, which is the part to be subjected to region calculation. In discriminating the specific part, image recognition is performed using pixel information of the image captured with illumination light.

[0053] Image recognition may be performed using a trained model optimized for image recognition processing. In this case, the specific part discrimination unit 64 includes a recognizer (not shown) having a trained model required for image recognition, and the recognizer includes a CNN (Convolutional Neural Network), which is a computer algorithm consisting of a neural network that performs machine learning, and learns in advance with data such as an image group including images including the specific part to be discriminated and images not including the specific part, discriminates the specific part for the input image, and outputs position information of the specific part in the input image.

[0054] In addition, in determining a specific part, if an image captured with measurement light acquires distance information at a number and position of measurement positions that enable estimation of the shape of the subject, an estimated shape determination may be performed in which the three-dimensional shape of the captured subject is estimated and a specific part is determined from the characteristics of the estimated shape.

[0055] The area calculation unit 66 calculates the area of ​​the subject using the measured distance information. The area is calculated in association with the time series when the imaging signal was acquired and information on the amount of air supply, and the amount of progress of the area in the same place on the subject is obtained. The amount of progress is calculated and output as an index value based on the enlargement rate of the area, etc. The area calculation unit 66 calculates at least one of the length, which is a one-dimensional area, the surface area, which is a two-dimensional area, and the volume, which is a three-dimensional area, as the area.

[0056] The area is a value calculated using the actual measured value of the surface area of ​​the specific part, for example, the surface area of ​​the stomach or the volume of the stomach is calculated from the surface area of ​​the dome. Therefore, when the specific part is the dome, a table is stored in advance to calculate the stomach volume from the size ratio of the dome to the stomach and the surface area of ​​the dome. When the length is measured as the area, the amount of elongation is calculated from the change in the length of the dome.

[0057] The air supply control unit 68 controls air supply in response to observation of the subject by the endoscope 11. Air supply is controlled in stages based on the passage of time, internal pressure information, or user operation. Air supply may be automatically suppressed when no increase in the volume of the digestive tract is observed in response to air supply. For example, the air supply control unit 68 is electrically connected to the pressure gauge 17, and when the increase in internal pressure is large compared to the amount of air supply, the air supply amount is controlled to be reduced or maintained.

[0058] As shown in Figure 4, the barostat method is a conventional method for measuring changes in gastrointestinal pressure and volume for diagnosing diseases. In the barostat method, the patient swallows a balloon BS with a tube attached, and the gastrointestinal tract D is pushed out by the internal pressure of the balloon BS, which is inflated evenly as shown by the arrow, by supplying air through the tube, and the upper part of the stomach is inflated in the direction of the arrow. The volume of the balloon BS is calculated using the amount of air supplied and the internal pressure. On the other hand, the barostat method requires dedicated equipment, causes pain to the patient due to the balloon BS, and makes it difficult to grasp the position of the balloon BS. It is highly invasive, and the gastrointestinal tract cannot be observed directly. Therefore, the burden on the patient can be reduced by using a method in which gas is directly supplied to the gastrointestinal tract D to inflate it without using a balloon.

[0059] As shown in Fig. 5, the endoscope 11 connected to the air supply device 16 has the insertion section 11a inserted into the digestive tract D and supplies air from the air supply nozzle 24. By capturing an image during air supply, it is possible to observe the process of the digestive tract D expanding in the direction of the arrow and the digestive tract D at any internal pressure. The internal pressure is measured by the pressure of gas transmitted from the tip forceps port 25 to the pressure gauge 17. Because the digestive tract D is expanded by supplying a measurement gas, it is possible to measure the internal pressure of the digestive tract and changes in the volume and surface area of ​​the digestive tract D with minimal invasiveness without the medical device such as the endoscope 11 coming into contact with the subject.

[0060] Digestive tract observation using the endoscope system 10 to measure the internal pressure and area of ​​the digestive tract will be described using a stomach inflated by air as the subject S and the fundus as the specific area to be observed and measured.

[0061] The endoscope system 10 of this embodiment performs observation by arbitrarily switching between a normal observation mode in which the illumination light is continuously turned on and the measurement mode in which the illumination light and the measurement light, which have two different wavelengths, are turned on and off frame by frame, and the distance to the subject and the volume are calculated. The observation mode is switched by a user operation such as pressing the mode selector switch 11e.

[0062] As shown in FIG. 6, an endoscope 11 is used to observe a subject S in the digestive tract D. The subject S captured by the imaging range R is captured as an endoscopic image. When the imaging range of a single endoscopic image of a subject, such as a specific region, is insufficient because the imaging range of the subject is wider than the imaging range R, or when the three-dimensional structure of the subject S needs to be accurately grasped, the curved portion 11c of the insertion portion 11a inserted into the subject is rotated to divide the subject S into specific angles according to the field of view, and imaging is performed. For example, the curved portion 11c is rotated along a rotation axis Ax set based on an arbitrary viewpoint H, and an endoscopic image of a field of view according to the number of divisions or the field of view angle is captured. The rotation axis Ax is set arbitrarily based on the positional relationship between the tip portion 11d and the specific region, or the shape of the specific region.

[0063] The bending of the bending portion 11c may be used to rotate the tip portion 11d, which is the imaging position, based on a rotation axis Ax set with respect to an arbitrary viewpoint H relative to the subject S, to capture 360-degree images. In this case, the endoscope 11 with an angle of view of 120 degrees or more can obtain an endoscopic image in which the subject S can be observed at 360 degrees using divided imaging signals in which the field of view is divided into three for each 120 degrees set at a specific angle. In addition, when the angle of view is 90 degrees or more and 120 degrees or less, an endoscopic image in which the field of view is divided into four for each 90 degrees set at a specific angle may be captured. An endoscopic image in which the subject S is captured over a wider range than the imaging range R can be created by combining divided imaging signals acquired continuously or at specific intervals with the imaging timing close to each other, such as within 3 seconds.

[0064] In normal observation mode, an endoscopic image is generated and displayed on the screen by illuminating the subject S with illumination light suitable for observation. In normal observation, the illumination light is continuously turned on during observation, and the exposure period is adjusted by opening and closing the shutter, etc. In normal observation mode, the digestive tract can be observed as it expands with air of any output.

[0065] In the measurement mode, the air supply device 16 connected to the endoscope 11 that images the subject supplies air at multiple levels of volume from the tip 11d, and controls the emission of illumination light that illuminates the subject S and measurement light for measuring the distance between multiple points on the subject S and the endoscope 11 to capture an endoscopic image.

[0066] The multiple-stage gas supply volume is the total amount of gas supplied to the digestive tract at any time point when the gas supply output is fixed at any output. For example, if the measurement mode is performed at 5-second intervals from the start of gas supply, the gas supply volume at 5 seconds after the start of gas supply is the first gas supply volume, and the gas supply volume at 10 seconds after the start of gas supply is the second gas supply volume. Similarly, imaging may be performed at the third gas supply volume at 15 seconds and the fourth gas supply volume at 20 seconds. In addition, the measurement time points do not need to be at equal intervals, and the speed of spread can be measured more accurately by measuring the start of spread at small intervals.

[0067] As shown in FIG. 7, in the measurement mode, the following endoscopic images are acquired: a measurement light image 70 for calculating the distance and volume of the subject S, an observation endoscopic image 72 for observing the subject S, and a two-light endoscopic image 74 for confirming and observing the measurement location of the subject S. A measurement light pattern 80 is projected onto the subject S by irradiating the measurement light. FIG. 7(A) shows a measurement light image 70 generated by the processor device 13 after imaging the subject S with the first irradiation in which the measurement light is irradiated by the endoscope 11 and the illumination light is irradiated with a light amount suppressed relative to the measurement light or is turned off. The measurement light will be described using a projection pattern in which a dot pattern is repeated at equal intervals, but it may be set arbitrarily, such as a line pattern or a cross pattern. In addition, the pattern intervals do not have to be equal. FIG. 7(B) shows an image of the subject S with the second irradiation in which the illumination light is irradiated by the endoscope 11, and an observation endoscopic image 72 is generated by the processor device 13 and used for subject observation. As shown in Figure 7 (C), the subject S is imaged using a third irradiation in which the endoscope 11 irradiates illumination light and measurement light, and a two-light endoscopic image 74 is generated by the processor device 13 and used to confirm the measurement location and observe the subject S.

[0068] The suppressed amount of illumination light is an amount of light that does not interfere with distance measurement using the measurement light, and is controlled according to a preset threshold value. This prevents disturbance of the measurement point caused by the measurement light due to mucous membrane reflection of the illumination light or halation in the measurement light image 70, and allows the position and shape of the captured subject to be confirmed.

[0069] In the measurement mode, the illumination light and the measurement light are controlled to capture an image. In addition, air supply is controlled together with the emission. In the first irradiation, at least a first imaging signal and a second imaging signal, which are imaging signals at a plurality of different stages of air supply volume, are acquired. That is, in a state where the air supply device 16 supplies air at a first air supply volume, which is an arbitrary stage of air supply volume, the measurement light is irradiated, and the illumination light is irradiated at a light volume suppressed relative to the measurement light or is turned off to acquire a first imaging signal in which an image of the subject S is captured. In addition, in a state where the air supply device 16 supplies air at a second air supply volume different from the first air supply volume, the measurement light is irradiated, and the illumination light is irradiated at a light volume suppressed relative to the measurement light or is turned off to acquire a second imaging signal in which an image of the subject S is captured.

[0070] The first and second imaging signals are obtained by imaging the subject S using a measurement light pattern 80 that can obtain distance information of multiple measurement points on the subject S. The area of ​​the subject S is calculated from first distance information obtained by measuring the distance between the multiple points on the subject S and the endoscope 11 based on the first imaging signal, and the area of ​​the subject S is calculated from second distance information obtained by measuring the distance between the multiple points on the subject S and the endoscope 11 based on the second imaging signal. The area includes a one-dimensional area that is a length, a two-dimensional area that is a surface area, and a three-dimensional area that is a volume, and the ease of expansion of the digestive tract is obtained by calculating both of them. The first distance information and the second distance information are distance information for specific parts at the same position that have different amounts of air sent.

[0071] In the measurement mode, the subject S is divided into specific angles according to the field of view, and a plurality of divided imaging signals obtained by imaging are used to perform distance measurement. Under imaging conditions where the field of view in the imaging range R is 120 degrees or more, the curved portion 11c is rotated to obtain divided imaging signals divided into three parts every 120 degrees, and distance measurement is performed based on each of the three divided imaging signals. Distance measurement is also performed in a similar manner under imaging conditions where divided imaging signals are obtained by dividing the field of view into four parts every 90 degrees. The specific range determination described later may be performed for each divided imaging signal, or may be performed after integrating distance information obtained from the divided imaging signals.

[0072] In the first air supply amount, the first distance information is measured based on a plurality of first divided image pickup signals obtained by imaging the subject S at each specific angle, and in the second air supply amount, the second distance information is measured based on a plurality of second divided image pickup signals obtained by imaging the subject S at each specific angle. Note that the number of divisions and whether or not to perform division are determined according to the shooting conditions of the subject S, which change according to the air supply amount.

[0073] Patients with a disease in the function of the digestive tract may experience symptoms in which the digestive tract, such as the fundus of the stomach, is less likely to expand than healthy individuals with normal digestive tract function. Specifically, the upper limit of the stomach volume that increases with an increase in internal pressure is small, and the pace of increase in volume in response to an increase in internal pressure is slow. As shown in Figure 8, the presence or absence of an abnormality in the function of the digestive tract is determined using the relationship between the volume and internal pressure of the digestive tract, and it is expected that the relationship between the internal pressure and the change in the volume of the stomach of a healthy individual will show a difference in the healthy curve 76, and the relationship between the internal pressure and the change in the volume of the stomach of a patient with functional dyspepsia will show a difference in the functional disease curve 78.

[0074] When the digestive tract is inflated by insufflation or the like from a reference internal pressure value P0 and a reference volume value V0 when the digestive tract is not inflated, the volume increase stops at a volume value V1 at an internal pressure value P1 in the functional disease curve 78. On the other hand, in the healthy curve 76, the volume increases even if the internal pressure increases further than the internal pressure value P1. Also, in the functional disease curve 78, the volume value V1 at which the volume increase stops is realized at an internal pressure value P2 in the healthy curve 76, which is a pressure lower than the internal pressure value P1.

[0075] In addition, since the patient feels pain when there is no or only a small increase in volume relative to the increase in internal pressure, it is preferable to terminate air supply or reduce the amount of air supply when the increase rate of volume relative to internal pressure is calculated to be equal to or less than a preset rate during volume observation using air supply. The volume width W can be obtained by comparing the difference in volume between the two curves at the same internal pressure. In addition to the volume width W, comparing the functional disease curve 78, which shows the relationship between volume and internal pressure obtained by measurement, with the healthy curve 76, which shows the relationship between volume and internal pressure in the gastric fundus of a general healthy person measured in advance, can lead to understanding the state of functional disease.

[0076] As shown in FIG. 9, the specific part discrimination unit 64 discriminates a specific part in the subject S captured using illumination light as a specific range 82. When the specific part is a vault, the specific range 82 is discriminated as an area occupied by the vault by image recognition of the observation endoscope image 72 using a recognition device, for example. The discriminated area is associated with the observation endoscope image 72 as specific range information, such as position information. The specific range information is applied to the measurement light image 70 of a frame captured before or after the observation endoscope image 72 used for discrimination, and the measurement light image 70 uses distance information of a measurement point included in the specific range 82. When the vault is divided into a plurality of images captured under the same imaging conditions and imaged, the specific range is detected using the divided captured images, and the specific part is discriminated.

[0077] In addition, in the measurement light image 70, when a lattice-shaped measurement light pattern is projected onto the entire image and the density of measurement points in the image is high, the three-dimensional shape of the subject S may be calculated based on the distance information to specify the vault. When the projection range of the measurement light pattern is limited or the density of measurement points in the image is low, the specific range 82 may be detected using the measurement light image 70 illuminated with suppressed illumination light or the two-type light endoscope image 74. In this case, the area of ​​the pattern light is not used for measurement or is weighted relatively low in image recognition to reduce the influence of the measurement light.

[0078] In the measurement mode, the change in the area of ​​a specific part is measured from the difference in distance information acquired at multiple air supply volume stages, and the amount of progress, which is the amount of expansion of the subject S, is calculated. The difference between the first distance information and the second distance information acquired at at least two stages, the first and second air supply volume stages, is used. In the case of the air supply volume stage set in the calculation of the amount of progress, for example, the air supply volume according to a time series, an index value indicating the rate of change of the observation distance over time can be calculated. In the case of division by internal pressure, an index value indicating the rate of change of the area with the change in internal pressure can be calculated. When the subject expands, the observation distance indicated by the distance information of the measurement point at the same position becomes longer.

[0079] The stages of the air supply amount include an initial stage immediately after the start of air supply or an initial stage where no air supply is made and the amount of air supply can be ignored, an expansion stage where the subject expands as the amount of air supply increases, and an upper limit stage where the internal pressure increases after a predetermined amount of air supply or more and the expansion of the subject stops. At least the region of the specific part where the amount of air supply is at the upper limit stage is used for comparison with a healthy state. It is preferable to determine the measurement interval in imaging based on a time series or the internal pressure.

[0080] The amount of progress is calculated using at least two stages of the subject's expansion, for example, the areas of the specific parts in the initial stage and the upper limit stage. For example, if the amount of air supply in the initial stage is the first air supply amount and the amount of air supply in the upper limit stage is the second air supply amount, the minimum distance information of the subject S is calculated from the first distance information, and the maximum distance information of the subject S is calculated from the second distance information, so that the maximum amount of progress of the subject S can be obtained. The area of ​​the subject S calculated from the index value is at least either the surface area or the volume. The difference between the average distance in the first distance information and the average distance in the second distance information may be calculated and used as the index value representing the maximum amount of progress.

[0081] In addition, by measuring distance information at arbitrarily set equal intervals of air supply during the expansion stage and measuring the internal pressure at each air supply volume, the volume of the subject S can be calculated and an index value indicating the subject's progress over time can be obtained.

[0082] In addition, by using the pressure gauge 17 to set the first air supply volume, the second air supply volume, and the nth air supply volume based on the changes in the internal pressure at equal intervals, distance information corresponding to the internal pressure can be obtained, and this can be calculated as an index value indicating the amount of progress between any internal pressures.

[0083] In the measurement mode, distance measurement is performed using an active stereo method that actively emits measurement light to perform three-dimensional measurement. The active stereo method uses the projection of measurement light and the principle of triangulation using a camera. Measurement may also be performed in combination with an optical radar method that uses the time difference or phase difference of measurement light measured by a TOF (Time of Flight) sensor. For example, in the active stereo method, the projected measurement light is observed by the camera function of the endoscope 11, but the measurement light is observed using a TOF sensor provided on the measurement light emission unit 23 or a tool inserted into the forceps port. When using a TOF sensor by inserting it into the forceps port, a method that does not interfere with pressure measurement is adopted, such as using an endoscope 11 equipped with multiple forceps ports.

[0084] The spot light, which is the return light of the measurement light in the measurement light image 70, is extracted by binarization processing based on the light amount and comparison with a predetermined threshold. The predetermined threshold is a preset extraction threshold applied to the illumination light and the return light of the measurement light, for example, in terms of brightness or luminance. When emitting the measurement light with a suppressed light amount, the measurement light is emitted with a light amount that makes the return light equal to or greater than the extraction threshold that is extracted in the binarization processing, and the suppressed illumination light is emitted with a light amount that makes the return light less than the extraction threshold that is not extracted in the binarization processing, and the measurement light image 70 is acquired.

[0085] Therefore, the light emission control unit 34 transmits to the endoscope 11 a light amount to which a light amount threshold, which is a preset light amount threshold, is applied in the emission of the measurement light and the suppressed illumination light. In the measurement irradiation in which the endoscope 11 emits the measurement light and emits the illumination light with a suppressed light amount with respect to the measurement light, the endoscope 11 emits the measurement light with a light amount equal to or greater than the light amount threshold, and the illumination light with a light amount less than the light amount threshold. For example, in a binarization process using 256 gradations such as luminance values ​​of "0" to "255", a luminance value of "128" is set as the extraction threshold, the measurement light is emitted with a light amount at which the return light has a luminance value of "128" or more, and the suppressed illumination light is emitted with a light amount at which the return light has a luminance value less than "128". When only the measurement light is emitted, control is performed to emit a light amount at which the return light of the measurement light is equal to or greater than the extraction threshold. The light amount threshold is set to a value that takes into account errors such as attenuation in the return light into the extraction threshold. The emitted light amount is the integral light amount per unit area.

[0086] In order to reduce errors due to return light and perform binarization more reliably, the amount of measurement light may be controlled to be higher than the threshold by a predetermined percentage, and the amount of suppressed illumination light may be controlled to be lower than the threshold by a predetermined percentage. For example, the emission of measurement light is controlled so that the luminance value of "254", which is 20% higher than the threshold, becomes the average luminance value, and the amount of suppressed illumination light is controlled so that the luminance value of "102", which is 20% lower than the threshold, becomes the average luminance value.

[0087] Distance measurement is performed based on the brightness of each measurement point extracted by extraction processing on the measurement light image 70. For example, in the case of 256 gradations, the distance of the subject S to the endoscope at each measurement point is measured at 128 levels in the extracted brightness levels of "128" to "255". Distance information of each measurement point obtained by distance measurement is associated with the measurement light image 70.

[0088] In endoscopic observation performed together with air supply control, it is preferable to use a plurality of observation patterns. Observation frames are acquired by switching between at least one of the measurement light image 70, the observation endoscope image 72, and the two-light endoscope image 74, and volume measurement and image display are performed. For example, the first to seventh observation patterns are switched.

[0089] 10, in the first observation pattern, a measurement light image 70 and an observation endoscopic image 72 are acquired by switching between them at an arbitrary ratio, and the measurement light image 70 and the observation endoscopic image 72 are switched and displayed on the display 14. In addition, area calculations such as distance measurement and volume calculation are performed from the acquired measurement light image 70.

[0090] 11, in the second observation pattern, a measurement light image 70 and a dual-light endoscopic image 74 are acquired by switching between them at an arbitrary ratio, and the measurement light image 70 and the dual-light endoscopic image 74 are switched and displayed on the display 14. In addition, area calculations such as distance measurement and volume calculation are performed from the acquired measurement light image 70.

[0091] 12, in the third observation pattern, the measurement light image 70 and the observation endoscope image 72 are acquired by switching at an arbitrary ratio, and the observation endoscope image 72 is continuously displayed on the screen. Since the measurement light image 70 for performing area calculation such as distance measurement and volume calculation is not displayed on the screen, the screen does not flicker.

[0092] 13, in the fourth observation pattern, a measurement light image 70 and a dual-light endoscopic image 74 are acquired by switching between them at an arbitrary ratio, and the dual-light endoscopic image 74 is continuously displayed on the display 14. The measurement light image 70 used for area calculation such as distance measurement and volume calculation is not displayed on the screen, so the screen does not flicker.

[0093] 14, in the fifth observation pattern, the measurement light image 70 and the observation endoscope image 72 are acquired by switching between them at an arbitrary ratio, and the measurement light image 70 and the observation endoscope image 72 are successively displayed on two screens. For example, the observation endoscope image 72 is displayed on the first screen, and the measurement light image 70 is displayed on the second screen. In addition, area calculations such as distance measurement and volume calculation are performed from the measurement light image 70 displayed on the second screen.

[0094] The display of two screens may be realized by electrically connecting a second display (not shown) different from the display 14 to the processor device 13 and realizing the first screen and the second screen on each display, or by dividing the screen of the display 14 into two to realize the first screen and the second screen. Furthermore, distance measurement in each frame of the measurement light image 70 displayed on the second screen may be performed after the screen display is switched to the next frame, or may be performed while the second screen is being displayed.

[0095] 15, in the sixth observation pattern, a measurement light image 70 captured by measurement irradiation and a dual-light endoscopic image 74 are acquired by switching at an arbitrary ratio, and the measurement light image 70 and the dual-light endoscopic image 74 are successively displayed on two screens. In the sixth observation pattern, two-screen display and area calculations such as distance measurement and volume calculation are performed in the same manner as in the fifth observation pattern.

[0096] In the first to sixth observation patterns, two frames of the observation endoscopic image 72 or the dual-light endoscopic image 74 and one frame of the measurement light image 70 are alternately acquired, but this is not limited to this and the same number of frames may be alternately captured, or the number of continuous captures of the observation endoscopic image 72 or the dual-light endoscopic image 74 and the measurement light image 70 may each be arbitrarily set and alternately captured.

[0097] In the third to sixth observation patterns, the observation endoscopic image 72 or the dual-light endoscopic image 74 may be displayed on the screen in accordance with the frame rate at which the images were captured, but the frame rate at which the images are displayed on the screen may be adjusted in accordance with the shooting ratio. For example, when the ratio of the observation endoscopic image 72 or the dual-light endoscopic image 74 to the measurement light image 70 is 2:1 and the images are captured at a frame rate of 60 fps, the observation endoscopic image 72 or the dual-light endoscopic image 74 may be displayed on the screen at 40 fps. Furthermore, the display of the measurement light image 70 in the fifth to sixth observation patterns may also be adjusted in accordance with the shooting ratio.

[0098] 16, in the seventh observation pattern, a measurement light image 70 captured with measurement illumination, an observation endoscopic image 72 captured with observation illumination, and a dual-light endoscopic image 74 captured with measurement location confirmation illumination are acquired by switching at an arbitrary ratio, and the generated observation endoscopic image 72 and dual-light endoscopic image 74 are displayed on two screens. In the seventh observation pattern, an image is displayed in which illumination light is always irradiated with a predetermined amount or more of light, and the measurement location can be confirmed.

[0099] Each observation pattern may be set in advance so that it can be switched by a user operation during an examination. For example, it may be switched by further pressing the mode switching switch 11e used for switching the observation mode, or by pressing an observation pattern switching switch (not shown) provided on the endoscope 11 or the user interface 15. In addition, the observation pattern may be divided into an imaging pattern that is a pattern for acquiring each imaging signal, and a display pattern that controls the display of each acquired imaging signal, and set so that it can be switched to any combination of imaging pattern and display pattern.

[0100] As shown in Fig. 17, the projection pattern, which is the shape when projected by the measurement light, may be set arbitrarily instead of a dot pattern arranged in a grid. For example, in addition to dot patterns, there are line patterns, cross patterns, stripe patterns, scale patterns, and combination patterns, and shapes such as dots and lines may be projected in any number and arrangement. When using lines, it is preferable to use dashed lines or dotted lines in addition to solid lines. For example, when projecting multiple lines side by side, a mode in which solid and dotted lines are repeated is used.

[0101] In a dot pattern, as shown in Fig. 7(A), dots or small circles are projected onto the subject S. Distance measurement is performed at the positions (spots) of each dot, which is the measurement light. As with a line pattern and a cross pattern, a shape in which multiple lines are projected that cross or do not cross may be used depending on the subject S.

[0102] There are also types such as a single type, a repeating type, a circular type, a central dot type, a projection in which each shape is asymmetric or random, and a special type that does not fit any of the above. In volume measurement, it is necessary to obtain multiple pieces of distance information, so in the single type, it is necessary to associate multiple measurement images 71. Therefore, it is preferable to adopt a projection pattern that provides multiple measurement locations for one measurement light image.

[0103] A sequence of operations for performing three-dimensional measurement of a subject in the measurement mode in the endoscope system 10 will be described with reference to the flowchart shown in Fig. 18. The insertion section 11a of the endoscope 11 is inserted into the digestive tract, which is the subject (step ST110). The endoscope system 10 sets the observation mode to the measurement mode by a user operation on any of the endoscope 11, the light source device 12, or the processor device 13 (step ST120). In response to starting the measurement mode by switching the observation mode, etc., air supply is started with an arbitrary air supply output, such as a preset air supply output (step ST130). With the start of air supply, an image of the subject is captured with an arbitrary observation pattern (step ST140).

[0104] Regardless of the observation pattern, the measurement light image 70 is obtained by imaging the subject with the measurement light irradiated and the illumination light irradiated with a reduced amount of light relative to the measurement light or turned off (step ST150). A specific part, which is the observation part, is identified from at least one of the measurement light image 70, the observation endoscope image 72, and the two-light endoscope image 74 (step ST160). Distance measurements are performed at multiple points from the spot light projected onto the specific part of the measurement light image 70 (step ST170). A two-dimensional or three-dimensional area of ​​the specific part is calculated based on the distance measurement results of the specific part (step ST180).

[0105] In the measurement mode, the subject S is observed at multiple stages of air supply amount, and the area of ​​the specific part is observed. If the area of ​​the specific part at multiple stages of air supply amount is calculated (Y in step ST190), the amount of progress of the digestive tract is calculated (step ST200) using multiple distance information. If the area of ​​the specific part at multiple stages of air supply amount is not calculated (N in step ST190), imaging is performed at different stages of air supply amount, and measurement light image 70 is obtained (step ST150).

[0106] After the amount of progression of the digestive tract is calculated, the measurement mode is switched to the normal observation mode, and the series of steps is completed. Note that the endoscopic observation may be ended directly without switching to the normal observation mode.

[0107] Although the light source device 12 equipped with the measurement light source 32 that emits measurement light, which is pattern light, has been described as an embodiment, a light source device 12 that emits measurement light of multiple colors may also be used. For example, a measurement mode may be implemented in a light source device 12 equipped with three types of measurement light sources that emit light of different wavelength bands. Below, a description is given of a projection pattern of measurement light using three types of measurement light sources as a modified example. The contents other than the measurement light are the same as those of the above embodiment, so description is omitted.

[0108] 19, in the case of emitting three types of measurement light emitting light of different wavelengths, for example, a measurement light source 32 having a first measurement light source 32a emitting green light as a first measurement light, a second measurement light source 32b emitting red light as a second illumination light, and a third measurement light source 32c emitting blue light as a third measurement light is provided in light source device 12. Emission control unit 34 transmits drive currents to illumination light source 30 and first measurement light source 32a, second measurement light source 32b, and third measurement light source 32c in measurement light source 32, independently controlling light intensity, turn-off timing, and the like.

[0109] As shown in Fig. 20, in the projection pattern by a plurality of measurement lights, different measurement lights are projected onto the subject by distinguishing based on components such as single points, lines, and stripes. In the projection pattern composed of two types of measurement light by the first measurement light and the second measurement light, in the cross pattern, vertical lines are projected with green light projection portions 80a by the first measurement light, and horizontal lines are projected with red light projection portions 80b by the second measurement light. In addition, in the striped pattern, odd-numbered stages such as the first and third stages counting from the top are projected with green light projection portions 80a, and even-numbered stages such as the second stage are projected with red light projection portions 80b.

[0110] In the projection pattern composed of three kinds of measurement light by the first measurement light, the second measurement light, and the third measurement light, the dot pattern is projected in order from a single point on the left side with a green light projection portion 80a by the first measurement light, a red light projection portion 80b by the second measurement light, and a blue light projection portion 80c by the third measurement light. Similarly, in the stripe pattern, the green light projection portion 80a, the red light projection portion 80b, and the blue light projection portion 80c are projected from the left side.

[0111] The number of different measurement light beams having different wavelengths is not limited to three, and four or more types of light sources may be used. In addition, it is preferable to appropriately change the shape of the emitted projection pattern and the color-coding method according to the application.

[0112] In the above embodiment, the hardware structure of the processing units that execute various processes, such as the light emission control unit 34, the imaging control unit 45, the image signal acquisition unit 50, the DSP 51, the noise reduction unit 52, the image processing unit 53, the output control unit 54, and the distance measurement processing unit 60, is various processors as shown below. The various processors include a CPU (Central Processing Unit), which is a general-purpose processor that executes software (programs) and functions as various processing units, a GPU (Graphical Processing Unit), a programmable logic device (PLD), which is a processor whose circuit configuration can be changed after manufacture such as an FPGA (Field Programmable Gate Array), and a dedicated electric circuit, which is a processor having a circuit configuration designed exclusively for executing various processes.

[0113] One processing unit may be configured with one of these various processors, or may be configured with a combination of two or more processors of the same type or different types (for example, multiple FPGAs, a combination of a CPU and an FPGA, or a combination of a CPU and a GPU, etc.). Also, multiple processing units may be configured with one processor. As an example of configuring multiple processing units with one processor, first, as represented by a computer such as a client or a server, there is a form in which one processor is configured with a combination of one or more CPUs and software, and this processor functions as multiple processing units. Second, as represented by a system on chip (SoC), there is a form in which a processor is used that realizes the functions of the entire system including multiple processing units with one IC (Integrated Circuit) chip. In this way, the various processing units are configured using one or more of the above various processors as a hardware structure.

[0114] Furthermore, the hardware structure of these various processors is, more specifically, an electric circuit (Circuitry) in the form of a combination of circuit elements such as semiconductor elements. The hardware structure of the storage unit is a storage device such as a hard disk drive (HDD) or a solid state drive (SSD). From the above description, the endoscope systems described in the following supplementary notes 1 to 13 can be understood.

[0115] [Appendix 1] an endoscope for imaging a subject; an air supply device connected to the endoscope and supplying air at a plurality of levels of air supply volume through a tip portion of the endoscope; a processor; The processor, controlling emission of illumination light for illuminating an object and measurement light for measuring distances between a plurality of points on the object and the endoscope; acquiring a first image capture signal from the endoscope which captures an image of the subject while irradiating the measurement light and irradiating the illumination light with a light amount suppressed relative to the measurement light or while turning the illumination light off when the air supply amount is a first air supply amount; a second image capturing signal is acquired from the endoscope which captures an image of the subject by irradiating the measurement light and irradiating the illumination light with a light amount suppressed relative to the measurement light or by turning off the illumination light at a second air supply amount which is a step different from the first air supply amount; calculating a region of the subject from first distance information obtained by measuring distances between a plurality of points of the subject and an endoscope based on the first imaging signal; an endoscope system that calculates the area of ​​the subject from second distance information obtained by measuring distances between multiple points on the subject and an endoscope based on the second imaging signal; [Appendix 2] The endoscope includes: The subject is divided into specific angles according to a field of view and imaged, The processor, measuring the first distance information based on a plurality of first divided image pickup signals obtained by capturing images of the subject at each of the specific angles; The endoscope system according to claim 1, wherein the second distance information is measured based on a plurality of second divided image signals obtained by imaging the subject at each of the specific angles. [Appendix 3] The processor, Identifying a specific part of the subject; Calculating a region of the specific portion from the first distance information; 3. An endoscope system according to claim 1, further comprising: a controller for controlling said first distance information; [Appendix 4] 4. The endoscope system according to claim 1, wherein the measurement light is a pattern light in which spot lights are arranged in a grid pattern. [Appendix 5] An endoscopic system according to any one of appendices 1 to 4, wherein the region is at least one of a length, which is a one-dimensional region, a surface area, which is a two-dimensional region, and a volume, which is a three-dimensional region. [Appendix 6] The endoscope includes: A light intensity threshold is applied, which is a threshold value for the amount of light emitted by the measurement light and the illumination light that has been set in advance. An endoscopic system described in any one of Appendices 1 to 5, wherein when the measurement light is irradiated and the illumination light is irradiated at a light intensity that is suppressed relative to the measurement light, measurement irradiation is performed in which the measurement light is irradiated at a light intensity equal to or greater than the light intensity threshold and the illumination light is irradiated at an intensity less than the light intensity threshold. [Appendix 7] The endoscope includes: continuously capturing images of the subject by switching between the measurement illumination and observation illumination in which the illumination light is irradiated at an amount of light equal to or greater than the light amount threshold; The processor, 7. The endoscope system according to claim 6, wherein an endoscopic image for observation generated by imaging the subject using the observation illumination is displayed on a screen. [Appendix 8] The endoscope includes: continuously capturing images of the subject by switching between the measurement illumination and a measurement location confirmation illumination in which the illumination light and the measurement light are irradiated at an amount of light equal to or greater than the light amount threshold; The processor, An endoscope system as described in Appendix 6, which displays on a screen a two-type light endoscope image generated by imaging the subject using the measurement location confirmation irradiation. [Appendix 9] The processor, 9. The endoscope system according to claim 7 or 8, wherein a measurement light image generated by imaging the subject using the measurement irradiation is displayed on a screen. [Appendix 10] The processor, 10. An endoscope system according to claim 9, which displays different images on a screen depending on the type of image generated. [Appendix 11] The endoscope includes: continuously capturing images of the subject by switching between the measurement illumination, observation illumination in which the illumination light is irradiated at an amount of light equal to or greater than the light amount threshold, and measurement location confirmation illumination in which the illumination light and the measurement light are irradiated at an amount of light equal to or greater than the light amount threshold; The processor, An endoscopic system as described in Appendix 6, which displays on different screens an observation endoscopic image generated by imaging the subject using the observation illumination and a two-type light endoscopic image generated by imaging the subject using the measurement location confirmation illumination. [Appendix 12] an endoscope for imaging a subject; an air supply device connected to the endoscope and supplying air from a tip of the endoscope at a plurality of levels of air supply volume; A processor is provided. The processor, controlling emission of illumination light for illuminating an object and measurement light for measuring a distance between the object and the endoscope; a first image capturing signal is acquired from the endoscope which captures an image of the subject by irradiating the measurement light and irradiating the illumination light with a light amount suppressed relative to the measurement light or by turning off the illumination light while the air supply device is supplying air at a first air supply amount; a second image capturing signal is acquired from the endoscope which captures an image of the subject by irradiating the measurement light and irradiating the illumination light with a light amount suppressed relative to the measurement light or by turning the illumination light off in a state where the air supply device supplies air at a second air supply amount which is different from the first air supply amount; An endoscopic system that calculates and outputs an index value representing the amount of extension of the subject, using the difference between first distance information obtained by measuring the distance between multiple points on the subject and an endoscope based on the first imaging signal, and second distance information obtained by measuring the distance between multiple points on the subject and an endoscope based on the second imaging signal. [Appendix 13] The processor, 13. The endoscope system according to claim 12, further comprising: a volume of the subject calculated based on the index value. [Explanation of symbols]

[0116] 10 Endoscope System 11 Endoscopy 11a Insertion part 11b Operation section 11c Curved section 11d Tip 11e Mode switch 11f Air supply switch 11g Main body forceps mouth 12 Light source device 13 Processor unit 14 Display 15 User Interface 16 Air supply device 17 Pressure gauge 21 Lighting Lens 22 Objective Lens 23 Measurement light output section 24 Air outlet 25 Tip forceps opening 30 Light source for lighting 32 Measurement light source 32a First measurement light source 32b Second measurement light source 32c Third measurement light source 34 Light emission control unit 36 Light Guide 38 Illumination optical system 40 Imaging Optical System 44 Image sensor 45 Imaging control section 46 CDS / AGC circuit 48 A / D Converter 50 Image signal acquisition unit 51 DSP 52 Noise reduction section 53 Image processing section 54 Output control section 60 Measurement mode control section 62 Distance measurement unit 64 Specific part discrimination section 66 Area calculation part 68 Air supply control unit 70 Measurement light image 72 Endoscopic images for observation 74 2-type light endoscope images 76 Healthy People Curve 78 Functional disease patient curve 80 Measurement light pattern 80a green light projection part 80b Red light projection part 80c blue light projection part 82 Specific parts Ax Rotation axis BS Balloon D Gastrointestinal tract H Perspective P0 Reference internal pressure value P1 internal pressure value P2 internal pressure value R Image Range S Subject ST110~ST200 Step V0 Reference volume value V1 Volume value W volume width

Claims

1. an endoscope for imaging a subject; an air supply device connected to the endoscope and supplying air at a plurality of levels of air supply volume through a tip portion of the endoscope; a processor; The processor, controlling emission of illumination light for illuminating an object and measurement light for measuring distances between a plurality of points on the object and the endoscope; acquiring a first image capture signal from the endoscope which captures an image of the subject by irradiating the measurement light and irradiating the illumination light with a light amount suppressed relative to the measurement light or by turning off the illumination light when the air supply amount is a first air supply amount; a second image capturing signal is acquired from the endoscope which captures an image of the subject by irradiating the measurement light and irradiating the illumination light with a light amount suppressed relative to the measurement light or by turning off the illumination light at a second air supply amount which is a step different from the first air supply amount; calculating a region of the subject from first distance information obtained by measuring distances between a plurality of points of the subject and the endoscope based on the first imaging signal; An endoscope system that calculates a region of the subject from second distance information obtained by measuring distances between multiple points on the subject and the endoscope based on the second imaging signal.

2. The endoscope includes: The subject is divided into specific angles according to a field of view and imaged, The processor, measuring the first distance information based on a plurality of first divided imaging signals obtained by imaging the subject at each of the specific angles; The endoscope system according to claim 1 , wherein the second distance information is measured based on a plurality of second divided image pickup signals obtained by picking up an image of the subject at each of the specific angles.

3. The processor, Identifying a specific part of the subject; Calculating a region of the specific portion from the first distance information; The endoscope system according to claim 1 , wherein the area of ​​the specific portion is calculated from the second distance information.

4. 2. The endoscope system according to claim 1, wherein the measurement light is a pattern light in which spot lights are arranged in a lattice pattern.

5. 5. The endoscope system according to claim 1, wherein the region is at least one of a length which is a one-dimensional region, a surface area which is a two-dimensional region, and a volume which is a three-dimensional region.

6. The endoscope includes: applying a preset light intensity threshold value which is a threshold value of the light intensity in the emission of the measurement light and the illumination light; The endoscopic system according to claim 1, wherein when the measurement light is irradiated and the illumination light is irradiated at a light amount that is suppressed relative to the measurement light, measurement irradiation is performed in which the measurement light is irradiated at a light amount equal to or greater than the light amount threshold and the illumination light is irradiated at a light amount less than the light amount threshold.

7. The endoscope includes: continuously capturing images of the subject by switching between the measurement illumination and observation illumination in which the illumination light is irradiated at an amount of light equal to or greater than the light amount threshold; The processor, The endoscope system according to claim 6, further comprising: an endoscopic image for observation generated by imaging the subject using the illumination for observation and displayed on a screen.

8. The endoscope includes: continuously capturing images of the subject by switching between the measurement illumination and a measurement location confirmation illumination in which the illumination light and the measurement light are irradiated at an amount of light equal to or greater than the light amount threshold; The processor, The endoscope system according to claim 6, wherein a two-light endoscopic image generated by imaging the subject using the measurement location confirmation irradiation is displayed on a screen.

9. The processor, 9. The endoscope system according to claim 7, further comprising a measuring light image generated by imaging the subject with the measurement irradiation and displayed on a screen.

10. The processor, 10. The endoscope system according to claim 9, wherein different screen displays are performed for each type of generated image.

11. The endoscope includes: continuously capturing images of the subject by switching between the measurement illumination, observation illumination in which the illumination light is irradiated at an amount of light equal to or greater than the light amount threshold, and measurement location confirmation illumination in which the illumination light and the measurement light are irradiated at an amount of light equal to or greater than the light amount threshold; The processor, An endoscopic system as described in claim 6, wherein an observation endoscopic image generated by imaging the subject using the observation illumination and a two-type light endoscopic image generated by imaging the subject using the measurement location confirmation illumination are displayed on different screens.

12. an endoscope for imaging a subject; an air supply device connected to the endoscope and supplying air from a tip of the endoscope at a plurality of levels of air supply volume; A processor is provided. The processor, controlling emission of illumination light for illuminating an object and measurement light for measuring a distance between the object and the endoscope; a first image capturing signal is acquired from the endoscope which captures an image of the subject by irradiating the measurement light and irradiating the illumination light with a light amount suppressed relative to the measurement light or by turning off the illumination light while the air supply device is supplying air at a first air supply amount; a second image capturing signal is acquired from the endoscope which captures an image of the subject by irradiating the measurement light and irradiating the illumination light with a reduced light amount relative to the measurement light or by turning off the illumination light in a state where the air supply device supplies air at a second air supply amount which is different from the first air supply amount; An endoscopic system that calculates and outputs an index value representing the amount of extension of the subject using the difference between first distance information obtained by measuring the distance between multiple points of the subject and the endoscope based on the first image capture signal and second distance information obtained by measuring the distance between multiple points of the subject and the endoscope based on the second image capture signal.

13. The processor, The endoscope system according to claim 12 , wherein the volume of the subject is calculated based on the index value.

14. A step in which an air supply device supplies air at a plurality of levels of air supply amount through a tip portion of an endoscope that captures an image of a subject; a step of controlling emission of illumination light for illuminating an object and measurement light for measuring distances between a plurality of points on the object and the endoscope; acquiring a first image capture signal from the endoscope which captures an image of the subject while irradiating the measurement light and irradiating the illumination light with a light amount suppressed relative to the measurement light or while turning the illumination light off when the air supply amount is a first air supply amount; a step of acquiring a second image pickup signal from the endoscope which captures an image of the subject by irradiating the measurement light and irradiating the illumination light with a light amount suppressed relative to the measurement light or by turning off the illumination light at a second air supply amount which is a stage different from the first air supply amount; calculating a region of the subject from first distance information obtained by measuring distances between a plurality of points of the subject and the endoscope based on the first imaging signal; A method for operating an endoscope system comprising the step of calculating an area of ​​the subject from second distance information obtained by measuring the distance between multiple points of the subject and the endoscope based on the second imaging signal.

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