Endoscope shape display control device, operating method of endoscope shape display control device, and computer readable medium

Abstract

The endoscope shape display control device of the present invention comprises at least one processor, which acquires information for imaging the shape of an insertion portion of an endoscope, generates a shape display image of the shape of the insertion portion based on the acquired information, and when the shape display image is reduced as a whole at a first reduction ratio, executes a first control for setting the diameter of the insertion portion in the shape display image to a second reduction ratio greater than the first reduction ratio.

Description

Technical Field

[0001] The present invention relates to an endoscope shape display control device, an operating method of the endoscope shape display control device, and an execution program of the endoscope shape display control device. Background Art

[0002] An endoscope for observing the lower digestive tract such as the large intestine is known. The lower digestive tract is different from the upper digestive tract such as the esophagus which extends relatively straight, and is complicatedly curved. Therefore, the insertion portion of the endoscope inserted into the lower digestive tract of a subject such as a patient is also complicatedly curved. In order to grasp the shape of the insertion portion of the endoscope inserted into the subject, an endoscope shape detection device is known that detects the shape of the insertion portion of the endoscope in the subject (for example, refer to Japanese Patent Publication No. 2004-551).

[0003] The endoscope shape detection device described in Japanese Patent Application Laid-Open No. 2004-551 has the function of acquiring information for imaging the shape of an insertion portion in a subject by using magnetism, and imaging the shape of the insertion portion based on the acquired information. For example, a plurality of magnetic field generating sources are arranged at intervals in the insertion portion of an endoscope. The endoscope shape detection device detects the magnetic field generated by each magnetic field generating source in the insertion portion using a magnetic field detection element arranged outside the subject. The intensity of the magnetic field of each magnetic field generating source detected shows the position of each part of the insertion portion relative to the magnetic field detection element outside the subject, so the endoscope shape detection device described in Japanese Patent Application Laid-Open No. 2004-551 uses the information of the intensity of the magnetic field of each magnetic field generating source as the information for imaging the shape of the insertion portion, and generates an image representing the shape of the insertion portion. Then, the generated image is displayed on a display and presented to a user such as a surgeon (e.g., a doctor). Summary of the invention

[0004] The imaging sequence in the endoscope shape detection device of Japanese Patent Publication No. 2004-551 is performed as follows, for example. First, the endoscope shape detection device of Japanese Patent Publication No. 2004-551 determines the positions of the various parts of the insertion part based on the information for imaging the shape of the insertion part (for example, the strength information of the magnetic field), thereby generating a three-dimensional model of the insertion part. Next, the three-dimensional model of the insertion part is rendered to generate a two-dimensional image for display on a display. The two-dimensional image is an image of the shape of the insertion part of the three-dimensional model of the insertion part observed from one viewpoint that can be arbitrarily set, and is hereinafter referred to as a shape display image.

[0005] When the insertion portion of the endoscope is bent into a ring shape in the subject, different parts of the insertion portion intersect each other in the shape display image according to the set viewpoint. Japanese Patent Publication No. 2004-551 states that in order to express the front and back of the intersecting parts, hatching or hidden surface processing is performed during the drawing process.

[0006] However, in the method of implementing the hatching or hidden surface processing described in Japanese Patent Application Publication No. 2004-551, it is sometimes difficult to visually recognize the front-back relationship of the intersection, that is, the overlapping state of the insertion portion. That is, the insertion portion of the endoscope is in the shape of a long and thin tube. If the shape display image is reduced as a whole for display, not only the length of the insertion portion becomes thinner, but also the diameter of the insertion portion becomes thinner at the same ratio.

[0007] In this way, there is a situation where the insertion portion becomes too thin due to the reduction ratio, resulting in a situation where it is displayed in a linear form. In this case, if the insertion portion is bent into a ring shape, only two lines can be observed to intersect. Even if the linear portion is subjected to shadow processing and hidden surface processing, the effect of improving the visual recognition of the overlapping condition of the insertion portion cannot be expected. Therefore, there is a problem that it is difficult for the user to instantly judge the front and back of the intersection portion (in other words, the overlapping condition of the insertion portion), etc., and it is difficult to visually recognize the overlapping condition of the insertion portion.

[0008] The technical purpose of the present invention is to provide an endoscope shape display control device, an operating method of the endoscope shape display control device, and a program for the endoscope shape display control device, which can display a shape display image that allows the overlapping condition of the insertion portion to be easily visually recognized even when the shape display image showing the shape of the insertion portion of an endoscope inserted into a subject is displayed in a reduced size.

[0009] Means for solving technical problems

[0010] An endoscope shape display control device involved in one embodiment of the present invention comprises at least one processor, which performs the following processing: obtaining information for imaging the shape of an insertion portion of an endoscope inserted into a subject, generating a shape display image showing the shape of the insertion portion based on the acquired information, and when reducing the displayed shape display image, controlling the reduction rate of the reduced size relative to a preset reference size, and when reducing the shape display image as a whole at a first reduction rate, executing a first control for setting the diameter of the insertion portion in the shape display image to a second reduction rate greater than the first reduction rate.

[0011] In the endoscope shape display control device of the above aspect, the processor may set the reduction rate to the first reduction rate for the length of the insertion portion and set the reduction rate to the second reduction rate for the diameter of the insertion portion.

[0012] Furthermore, in the endoscope shape display control device of the above-mentioned method, the processor can execute the second control of setting the first reduction ratio and the second reduction ratio to the same value when the first reduction ratio is greater than a predetermined threshold value, and can execute the first control when the first reduction ratio is less than the threshold value.

[0013] A working method of an endoscope shape display control device involved in one embodiment of the present invention comprises: an information acquisition step of acquiring information for imaging the shape of an insertion portion of an endoscope inserted into a subject; an image generation step of generating a shape display image showing the shape of the insertion portion based on the acquired information; and a reduction ratio control step of controlling the reduction ratio of the reduced size relative to a preset reference size when reducing the displayed shape display image, and executing a first control of setting the diameter of the insertion portion in the shape display image to a second reduction ratio greater than the first reduction ratio when reducing the entire shape display image at a first reduction ratio.

[0014] An execution program of an endoscope shape display control device involved in one embodiment of the present invention causes a computer to function as the following three parts: an information acquisition unit that acquires information for imaging the shape of an insertion portion of an endoscope inserted into a subject; an image generation unit that generates a shape display image that displays the shape of the insertion portion based on the acquired information; and a reduction ratio control unit that controls the reduction ratio of the reduced size relative to a preset reference size when reducing the displayed shape display image, and when reducing the entire shape display image at a first reduction ratio, executes a first control to set the diameter of the insertion portion in the shape display image to a second reduction ratio that is greater than the first reduction ratio.

[0015] Effects of the Invention

[0016] According to the technology of the present invention, it is possible to provide an endoscope shape display control device, an operating method of the endoscope shape display control device, and a program for the endoscope shape display control device, which can display a shape display image that allows the overlapping condition of the insertion portion to be easily visually identified even when the shape display image showing the shape of the insertion portion of an endoscope inserted into a subject is displayed in a reduced size. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is an explanatory diagram showing a state of endoscopic inspection using an endoscope system.

[0018] Figure 2 It is a schematic diagram showing the overall structure of an endoscope system.

[0019] Figure 3 This is a block diagram showing the electrical configuration of an endoscope system.

[0020] Figure 4 This is an explanatory diagram showing a state in which a plurality of detection coils detect magnetic fields generated by a plurality of generation coils.

[0021] Figure 5 It is an explanatory diagram showing an example of magnetic field measurement data.

[0022] Figure 6 It is an explanatory diagram for explaining the determination processing by the determination unit and the position detection processing by each detection coil of the position detection unit.

[0023] Figure 7 It is an explanatory diagram showing an example of the shape detection processing of the insertion portion.

[0024] Figure 8 This is a functional block diagram of the image generation unit.

[0025] Fig. 9 This is a flowchart for explaining the flow of a process of generating a shape display image at the time of equal-size display by the image generating unit.

[0026] Fig.10 This is a flowchart for explaining the flow of the modeling process performed by the image generation unit.

[0027] Fig.11 It is an explanatory diagram showing an example of the 3D model generation process of the insertion portion.

[0028] Fig.12 This is a diagram showing an example of a shape display image.

[0029] Fig.13 This is a functional block diagram of the image generation unit and the information storage unit.

[0030] Fig.14 This is a diagram for explaining the content of the first control.

[0031] Fig.15 It is an explanatory diagram showing an example of the 3D model generation process of the insertion portion.

[0032] Fig.16 This is a diagram showing an example of a shape display image.

[0033] Fig.17 A diagram showing an example of a conventional shape display image.

[0034] Fig.18 This is a flowchart for explaining the flow of the modeling process performed by the image generation unit. DETAILED DESCRIPTION

[0035] [Overall structure of the endoscope system]

[0036] Figure 1 Schematic diagram showing the overall structure of an endoscope system 9 including an endoscope shape display control device according to the present invention. Figure 1 As shown, the endoscope system 9 includes an endoscope 10, a light source device 11, a navigation device 12, a magnetic field generator 13, a processor device 14, and a display 15. The endoscope system 9 is used for endoscopic examination in the body of a subject H such as a patient. The subject H is an example of a subject. The endoscope 10 is, for example, an endoscope inserted into a digestive tract such as a large intestine, and is a flexible soft endoscope. The endoscope 10 includes: an insertion portion 17 inserted into the digestive tract, an operating portion 18 connected to the base end side of the insertion portion 17 and for the operating doctor OP to hold and perform various operations, and a universal cord 19 connected to the operating portion 18.

[0037] Endoscopic examination is performed, for example, with the examinee H lying on the top surface 16A of the bed 16. In the case of a large intestine examination, the operating doctor OP, who is a doctor, inserts the insertion portion 17 of the endoscope 10 from the anus into the lower digestive tract. The light source device 11 provides the endoscope 10 with illumination light for illuminating the large intestine as the observation site. The processor device 14 generates an observation image 41 by processing the image captured by the endoscope 10. The observation image 41 is displayed on the display 15. The operating doctor OP performs the endoscopic examination while confirming the observation image 41. The observation image 41 displayed on the display 15 is basically a dynamic image, but a still image can also be displayed as the observation image 41 as needed.

[0038] In addition, the endoscope system 9 has a navigation function for navigating finger operations such as the insertion operation of the endoscope 10 performed by the operating doctor OP. Here, navigation refers to assisting the operating doctor OP in finger operations of the endoscope 10 by prompting the operating doctor OP with the insertion state including the position and shape of the insertion portion 17 of the endoscope 10 in the body of the subject H. The navigation function detects the insertion state of the insertion portion 17 using the magnetic field MF, and prompts the detected insertion state.

[0039] The navigation function is realized by the navigation device 12, the magnetic field generator 13, and the magnetic field measuring device in the endoscope 10 described later. The magnetic field generator 13 generates a magnetic field MF. The magnetic field generator 13 is arranged at a preset position within a range where the generated magnetic field MF reaches the body of the subject H. The magnetic field generator 13 is an example of a magnetic field device involved in the technology of the present invention.

[0040] The magnetic field measuring device in the endoscope 10 detects the magnetic field MF generated by the magnetic field generator 13 and measures the intensity of the detected magnetic field MF. The navigation device 12 detects the insertion state of the insertion portion 17 by deriving the relative position of the magnetic field generator 13 and the insertion portion 17 based on the magnetic field measurement result of the magnetic field measuring device. The processor device 14 generates a shape display image 42 showing the insertion state detected by the navigation device 12.

[0041] The display 15 displays the observation image 41 and the shape display image 42. In addition, the display 15 that displays the observation image 41 and the shape display image 42 may be provided separately.

[0042] like Figure 2 As shown, the insertion portion 17 is a thin and long tubular portion, which is composed of a soft portion 21, a bending portion 22 and a front end portion 23 connected in sequence from the base end side to the front end side. The soft portion 21 is flexible. The bending portion 22 is a portion that can be bent by operating the operating portion 18. The front end portion 23 is provided with a camera device 48 (refer to Figure 3 ) etc. And, in Figure 2 Although not shown in the figure, an illumination window 46 is provided on the front end surface of the front end portion 23 to illuminate the observation area (reference Figure 3 ); observation window 47, the incident illumination light is reflected by the subject light (reference Figure 3 ); a disposal tool outlet for protruding the disposal tool (not shown); and a cleaning nozzle for cleaning the observation window 47 by spraying gas and water onto the observation window 47 (not shown).

[0043] The insertion portion 17 is provided with a light guide 33, a signal cable 32, an operation wire (not shown), and a conduit (not shown) for inserting and penetrating a treatment instrument. The light guide 33 is extended from the universal cord 19 to guide the illumination light supplied from the light source device 11 to the illumination window 46 of the distal end portion 23. The signal cable 32 is used for communication of image signals from the imaging device 48 and control signals for controlling the imaging device 48, and also for supplying power to the imaging device 48. The signal cable 32 is also extended from the universal cord 19 and is provided to the distal end portion 23, similarly to the light guide 33.

[0044] The operation wire is a wire for operating the bending portion 22, and is arranged between the operation portion 18 and the bending portion 22. The pipeline for inserting and penetrating a treatment instrument is a pipeline for inserting and penetrating a treatment instrument (not shown) such as forceps, and is arranged from the operation portion 18 to the front end portion 23. In addition, a fluid hose for supplying air and water is provided in the insertion portion 17. The fluid hose supplies gas and water for cleaning the observation window 47 to the front end portion 23.

[0045] Furthermore, a plurality of detection coils 25 are provided at predetermined intervals from the soft portion 21 to the front end portion 23 in the insertion portion 17. Each detection coil 25 is equivalent to a magnetic field detection element that detects the magnetic field MF. Each detection coil 25 generates an induced electromotive force under the action of electromagnetic induction by being affected by the magnetic field MF generated by the magnetic field generator 13, and generates an induced current by the induced electromotive force. The value of the induced current generated by each detection coil 25 shows the strength of the magnetic field MF detected by each detection coil 25, which becomes a magnetic field measurement result. That is, the magnetic field measurement result refers to a value corresponding to the magnitude of the induced current that shows the strength of the magnetic field MF.

[0046] The operation portion 18 is provided with various operation components operated by the operating doctor OP. Specifically, the operation portion 18 is provided with two types of bending operation knobs 27, an air and water supply button 28, and a suction button 29. The two types of bending operation knobs 27 are respectively connected to the operation wires and are used for the left and right bending operation and the up and down bending operation of the bending portion 22. In addition, the operation portion 18 is provided with a treatment instrument introduction port 31 as an entrance for inserting a treatment instrument into the penetration conduit.

[0047] The universal cord 19 is a connection cord for connecting the endoscope 10 to the light source device 11. The universal cord 19 includes a signal cable 32, a light guide 33, and a fluid hose (not shown). In addition, a connector 34 connected to the light source device 11 is provided at the end of the universal cord 19.

[0048] By connecting the connector 34 to the light source device 11, the power, control signal, illumination light, gas, and water required for the operation of the endoscope 10 are supplied from the light source device 11 to the endoscope 10. Figure 2 ) The image signal of the observation part acquired and the magnetic field measurement result based on the detection signal of each detection coil 25 are sent from the endoscope 10 to the light source device 11.

[0049] The connector 34 and the light source device 11 are not connected by wired electrical connection using a metal signal line or the like, but are connected to each other by optical communication (e.g., contactless communication). The connector 34 transmits and receives control signals exchanged between the endoscope 10 and the light source device 11 and transmits image signals and magnetic field measurement results from the endoscope 10 to the light source device 11 by optical communication. The connector 34 is provided with a laser diode (hereinafter referred to as LD) 36 connected to the signal cable 32.

[0050] LD36 is used to send large-volume data, specifically, image signals and magnetic field measurement results, from the endoscope 10 to the light source device 11. LD36 sends the image signals and magnetic field measurement results, which are originally in the form of electrical signals, to a photodiode (PD) 37 provided in the light source device 11 in the form of optical signals.

[0051] Although not shown in the figure, an optical transceiver is provided in both the connector 34 and the light source device 11 separately from the LD 36 and the PD 37, and the optical transceiver converts the small-capacity control signal exchanged between the endoscope 10 and the light source device 11 into an optical signal for transmission and reception. In addition, a power receiving unit (not shown) is provided on the connector 34 to receive power from the power supply unit (not shown) of the light source device 11 through wireless power supply.

[0052] The light guide 33 in the connector 34 is inserted into the light source device 11. Furthermore, a fluid hose (not shown) in the connector 34 is connected to an air and water supply device (not shown) via the light source device 11. Thus, illumination light and gas and water are supplied to the endoscope 10 from the light source device 11 and the air and water supply device, respectively.

[0053] The light source device 11 supplies illumination light to the light guide 33 of the endoscope 10 via the connector 34, and supplies gas and water supplied from an air and water supply device (not shown) to a fluid hose (not shown) of the endoscope 10. In addition, the light source device 11 receives the optical signal sent from the LD 36 using the PD 37, converts the received optical signal into the original image signal and magnetic field measurement result as an electrical signal, and outputs the result to the navigation device 12.

[0054] The navigation device 12 outputs the image signal for generating the observation image 41 input from the light source device 11 to the processor device 14. In addition, the navigation device 12 controls the driving of the magnetic field generator 13 described later, detects the shape of the insertion portion 17 in the body of the subject H, and outputs the detection result to the processor device 14 as information for generating the shape display image 42.

[0055] As described above, the endoscope 10 in this example is of a single connector type having one connector 34 connected to the light source device 11. The endoscope 10 is communicably connected to the processor device 14 and the navigation device 12 via the light source device 11 to which the connector 34 is connected.

[0056] The magnetic field generator 13 has a plurality of generating coils 39 corresponding to a plurality of magnetic field generating source elements. Each generating coil 39 includes, for example, an X-axis coil, a Y-axis coil, and a Z-axis coil that generate an alternating magnetic field (in other words, an alternating magnetic field) in directions corresponding to the XYZ coordinate axes of the orthogonal coordinate system XYZ by applying a driving current. Each generating coil 39 generates a magnetic field MF of the same frequency. Each generating coil 39 generates a magnetic field MF at different times from each other under the control of the navigation device 12, and the details will be described later.

[0057] <Endoscope>

[0058] Figure 3 is a block diagram showing the electrical configuration of the endoscope system 9. Figure 3 As shown, the endoscope 10 has a light guide 33, an irradiation lens 45, an illumination window 46, an observation window 47, an imaging device 48, a magnetic field detection circuit 49, a general control circuit 50, a signal cable 32, an LD 36, and a fluid hose and a cleaning nozzle not shown.

[0059] The light guide 33 is a large-diameter optical fiber or a bundled optical fiber. The incident end of the light guide 33 is embedded in the light source device 11 via the connector 34. The light guide 33 is inserted through the connector 34, the universal cord 19, and the operation portion 18, and the emission end protrudes toward the irradiation lens 45 provided in the front end portion 23 of the insertion portion 17. Thus, the illumination light supplied from the light source device 11 to the incident end of the light guide 33 is illuminated from the irradiation lens 45 through the illumination window 46 on the front end surface of the front end portion 23 and is photographed on the observation area. Then, the illumination light reflected on the observation area is incident on the imaging surface of the imaging device 48 as the image light of the observation area through the observation window 47 provided on the front end surface of the front end portion 23.

[0060] In addition, one end side of the aforementioned fluid hose (not shown) is connected to the air and water supply device (not shown) through the connector 34 and the light source device 11, and the other end side of the fluid hose (not shown) is connected to the air and water supply nozzle (not shown) provided on the front end surface of the front end portion 23 through the insertion portion 17. Thus, gas or water is supplied from the air and water supply device (not shown) and sprayed from the air and water supply nozzle (not shown) toward the observation window 47, thereby cleaning the observation window 47.

[0061] The imaging device 48 has a focusing lens 52 and an imaging element 53. The focusing lens 52 focuses the image light of the observation part incident from the observation window 47, and images the focused image light of the observation part on the imaging surface of the imaging element 53. The imaging element 53 is a CMOS (complementary metal oxide semiconductor) type or a CCD (Charge Coupled Device) type imaging element. The imaging element 53 is, for example, a color imaging element in which a microfilter of any one of R (Red), G (Green), and B (Blue) is assigned to each pixel. The imaging element 53 photographs the observation part as the observation object. More specifically, the imaging element 53 photographs the image light of the observation part imaged on the imaging surface (i.e., converts it into an electrical signal), and outputs the image signal of the observation part to the overall control circuit 50.

[0062] In addition, the imaging element 53 is provided with an oscillator 53a that outputs a reference signal (e.g., a clock signal) such as a crystal oscillator, and the imaging element 53 outputs an image signal constituting a dynamic image based on the reference signal oscillated from the oscillator 53a. The interval of the reference signal determines the frame rate. The frame rate is, for example, 30fps (frames per second).

[0063] The magnetic field detection circuit 49 is electrically connected to each detection coil 25 in the insertion portion 17. The magnetic field detection circuit 49 outputs magnetic field measurement data 55 including each magnetic field measurement result of each detection coil 25 corresponding to the magnetic field MF generated by the generating coil 39 of the magnetic field generator 13 to the overall control circuit 50.

[0064] The overall control circuit 50 includes various computing circuits including a CPU (Central Processing Unit) and various memories, and overall controls the actions of various parts of the endoscope 10. The overall control circuit 50 performs the functions of the signal processing unit 57, the magnetic field measurement control unit 58, and the image signal output unit 59 by executing a control program stored in a memory not shown in the figure. The magnetic field detection circuit 49 and the magnetic field measurement control unit 58 are combined to form a magnetic field measurement unit. The magnetic field measurement unit measures multiple magnetic fields MF generated by each of the generating coils 39 corresponding to multiple magnetic field generating sources based on the detection signal output by the detection coil 25, thereby outputting the magnetic field measurement results of each magnetic field MF. The magnetic field measurement unit and the detection coil 25 are combined to form a magnetic field measurement device.

[0065] The signal processing unit 57 performs various signal processing on the image signals sequentially output from the imaging element 53. As the signal processing, for example, analog signal processing such as correlated double sampling processing and signal amplification processing, A / D (Analog / Digital) conversion processing for converting the analog signal into a digital signal after the analog signal processing, etc. The image signal after the signal processing is performed is called a frame image signal 61. The signal processing unit 57 outputs the frame image signal 61 to the image signal output unit 59 at a frame rate. The frame image signal 61 is used as dynamic image data of the observation part. In this way, a plurality of frame image signals 61 are image signals acquired by performing dynamic image capture by the imaging element 53 and output at a preset time interval.

[0066] The magnetic field measurement control unit 58 acquires the magnetic field measurement data 55 including a plurality of magnetic field measurement results of each detection coil 25 via the magnetic field detection circuit 49 , and outputs the acquired magnetic field measurement data 55 to the image signal output unit 59 .

[0067] like Figure 4 As shown, the magnetic field measurement results of each detection coil 25 vary depending on the distance and direction between each generating coil 39 generating the magnetic field MF and each detection coil 25, for example, even if the strength of the magnetic field generated by each generating coil 39 is the same. Figure 4 In the first generating coil 39 shown, as indicated by the solid line, the distance and orientation to the first to third detection coils 25 are different. Therefore, regarding the magnetic field MF generated by one first generating coil 39, each of the first to third detection coils 25 has a different magnetic field measurement result. The relationship between each of the second generating coil 39 and the third generating coil 39 and the first to third detection coils 25 is also the same.

[0068] Furthermore, conversely, even if the intensity of the magnetic field MF generated by each of the first to third generating coils 39 is the same, the magnetic field measurement results of one first detection coil 25 for each magnetic field MF of each generating coil 39 are different. Here, for example, consider a case where each of the first to third generating coils 39 is an X-axis coil, a Y-axis coil, and a Z-axis coil, respectively. In this case, based on the magnetic field measurement results of one first detection coil 25 for each magnetic field MF of each coil of the X-axis, Y-axis, and Z-axis, the three-dimensional coordinate position of the first detection coil 25 corresponding to the XYZ coordinate axis can be detected. The same is true for the second detection coil 25 and the third detection coil 25. As long as the three-dimensional coordinate positions of each detection coil 25 set at a predetermined interval in the insertion portion 17 can be detected, the shape of the insertion portion 17 can be detected.

[0069] In fact, according to the magnetic field measurement results, in addition to the three-dimensional coordinate position of each detection coil 25, the angle of each detection coil 25 can also be detected. The shape of the insertion portion 17 is detected based on the information of the three-dimensional coordinate position and the angle. In the following, in order to avoid complication, the angle is omitted and only the three-dimensional coordinate position is described.

[0070] Figure 5 1 is an explanatory diagram for explaining an example of magnetic field measurement data 55 acquired by the magnetic field measurement control unit 58. The magnetic field measurement control unit 58 acquires the magnetic field measurement data 55, which includes a plurality of magnetic field measurement results outputted from each of the plurality of detection coils 25, each of which detects each of the plurality of magnetic fields MF generated by the plurality of generation coils 39.

[0071] exist Figure 5 In the data, (1) to (4) are data columns of the magnetic field measurement results of each of the multiple detection coils 25 regarding the magnetic field MF generated by each generating coil 39. For example, "D11" is the magnetic field measurement result obtained by detecting the magnetic field MF generated in the first generating coil 39 through the first detection coil 25. "D12" is the magnetic field measurement result obtained by detecting the magnetic field MF generated in the first generating coil 39 through the "second detection coil". Similarly, "D42" is the magnetic field measurement result obtained by detecting the magnetic field MF generated in the fourth generating coil 39 through the second detection coil 25. "D43" is the magnetic field measurement result obtained by detecting the magnetic field MF generated in the fourth generating coil 39 through the third detection coil 25.

[0072] The magnetic field measurement control unit 58 sequentially obtains the magnetic field measurement results of each detection coil 25 while synchronizing with the magnetic field generation timing of each generating coil 39 in the magnetic field generator 13. For example, the magnetic field measurement control unit 58 obtains the magnetic field measurement results of each detection coil 25 for each magnetic field MF of all generating coils 39 during one magnetic field measurement period specified by a synchronization signal described later. Thus, the magnetic field measurement control unit 58 obtains the magnetic field measurement data 55 including a plurality of magnetic field measurement results related to all combinations of each generating coil 39 and each detection coil 25 during one magnetic field measurement period.

[0073] For example, when 9 generating coils 39 are provided in the magnetic field generator 13 and 17 detecting coils 25 are provided in the insertion part 17, 17 magnetic field measurement results are obtained for each generating coil 39. Therefore, the magnetic field measurement control unit 58 obtains a total of 9x17=153 magnetic field measurement data 55 including magnetic field measurement results during one magnetic field measurement. The magnetic field measurement data 55 including a plurality of magnetic field measurement results involved in all of these combinations is referred to as full magnetic field measurement data. In this example, the magnetic field measurement data 55 includes full magnetic field measurement data unless otherwise specified.

[0074] like Figure 6 As shown, the image signal output unit 59 adds a frame start signal VD to each of the plurality of frame image signals 61 sequentially input from the signal processing unit 57, thereby outputting the frame image signals 61. Figure 6 In the figure, for ease of understanding, "frame 1", "frame 2", "frame 3", ... are frame numbers indicating the output order of the plurality of frame image signals 61. The frame start signal VD is, for example, a vertical synchronization signal.

[0075] Furthermore, the image signal output unit 59 adds the magnetic field measurement data 55 to the frame image signal 61, thereby outputting the frame image signal 61. That is, all the frame image signals 61 output by the image signal output unit 59 include the frame start signal VD and the magnetic field measurement data 55. Figure 6 As shown, the magnetic field measurement data 55 is added to the signal invalid area ND between each frame image signal 61 corresponding to the blanking period of the imaging element 53. The blanking period is, for example, the vertical blanking period. As described above, the frame start signal VD is also a signal included in the vertical blanking period of multiple frame image signals 61.

[0076] exist Figure 3 In the example, the image signal output unit 59 outputs the frame image signal 61 to the LD 36 described above via the signal cable 32. The LD 36 transmits the optical signal obtained by converting the frame image signal 61 into an optical signal to the PD 37 of the light source device 11.

[0077] In this way, the image signal output unit 59 outputs the acquired frame image signal 61 from the imaging element 53 to the outside of the endoscope 10 via the signal processing unit 57. In addition, by using the frame start signal VD included in the frame image signal 61 as a synchronization signal, the image signal output unit 59 functions as a synchronization signal generation unit.

[0078] <Light source device>

[0079] The light source device 11 includes an illumination light source 63, a PD 37, a light source control unit 64, a signal relay unit 62, and a communication interface 65. The illumination light source 63 is composed of a semiconductor light source such as an LD (Laser Diode) or a light emitting diode (Light Emitting Diode: LED), and is a white light source that emits white light with a wavelength from the red region to the cyan region as illumination light. In addition, as the illumination light source 63, in addition to the white light source, a special light source that emits special light such as purple light and infrared light can also be used. The illumination light emitted from the illumination light source 63 is incident on the incident end of the aforementioned light guide 33.

[0080] The light source control unit 64 is configured to include various calculation circuits including a CPU and various memories, and controls the operation of various components of the light source device 11 such as the illumination light source 63 .

[0081] PD37 receives the optical signal sent from LD36. PD37 converts the frame image signal 61 received in the form of an optical signal into the original form of an electrical signal, and inputs the converted frame image signal 61 to the signal relay unit 62. The signal relay unit 62 is composed of, for example, an FPGA (Field Programmable Gate Array). FPGA is a processor whose circuit structure can be changed after manufacturing, and the circuit structure includes various operation circuits and various memory circuits.

[0082] <Navigation device>

[0083] The navigation device 12 includes an image signal acquisition unit 68, an insertion state detection unit 70, a magnetic field generation control unit 71, a display output unit 74, an image generation unit 77, a command input unit 80, and an information storage unit 81. Each unit of the navigation device 12 is composed of various operation circuits (not shown) including one or more CPUs, and operates by executing a control program stored in a memory not shown.

[0084] The image signal acquisition section 68 acquires the frame image signal 61 from the signal relay section 62 via the communication interface 65. Then, the image signal acquisition section 68 outputs the acquired frame image signal 61 to the display output section 74.

[0085] Furthermore, the image signal acquisition unit 68 extracts the frame start signal VD and the magnetic field measurement data 55 included in the frame image signal 61, and outputs the extracted frame start signal VD and the magnetic field measurement data 55 to the insertion state detection unit 70. Furthermore, the image signal acquisition unit 68 extracts the frame start signal VD from the frame image signal 61, and outputs the extracted frame start signal VD to the magnetic field generation control unit 71.

[0086] The insertion state detector 70 detects the insertion state of the insertion portion 17 of the endoscope 10 inserted into the body of the subject H based on the frame start signal VD and the magnetic field measurement data 55 acquired from the image signal acquisition unit 68 . The insertion state detector 70 includes a position detector 72 and an insertion portion shape detector 73 .

[0087] The position detection unit 72 detects the position of each detection coil 25 based on the frame start signal VD and the magnetic field measurement data 55. The position detection unit 72 is provided with a determination unit 72A.

[0088] like Figure 6 As shown, the determination unit 72A refers to the correspondence 75 to determine the multiple magnetic field measurement results included in the magnetic field measurement data 55. The correspondence 75 is information showing the storage order of the multiple magnetic field measurement results corresponding to the multiple combinations of the generating coils 39 and the detecting coils 25 included in the magnetic field measurement data 55. The determination unit 72A determines which combination of the generating coils 39 and the detecting coils 25 each magnetic field measurement result included in the magnetic field measurement data 55 corresponds to based on the correspondence 75.

[0089] Specifically, in the magnetic field measurement, the generation order of the magnetic field MF generated by each generating coil 39 and the acquisition order of the magnetic field measurement results of each detection coil 25 for the magnetic field MF of one generating coil 39 are determined based on the frame start signal VD. A plurality of magnetic field measurement results corresponding to the combination of each generating coil 39 and each detection coil 25 are stored in the magnetic field measurement data 55 according to the generation order and the acquisition order. Therefore, the determination unit 72A can determine which combination (for example, "D11", "D12", "D13" ...) the plurality of magnetic field measurement results included in the magnetic field measurement data 55 correspond to by referring to the prescribed storage order correspondence relationship 75 based on the frame start signal VD.

[0090] The position detection unit 72 detects the position of each detection coil 25, specifically, the three-dimensional coordinate position, as coil position data 76 based on the plurality of magnetic field measurement results determined by the determination unit 72A. The coil position data is a relative position with respect to the magnetic field generator 13. Figure 6 In , for example, P1 represents the three-dimensional coordinate position (here, x1, y1, z1) of the first detection coil 25. The same applies to P2, P3, P4, and so on.

[0091] exist Figure 3 In the embodiment, the position detection unit 72 outputs the coil position data 76 to the insertion portion shape detection unit 73. The insertion portion shape detection unit 73 detects the shape of the insertion portion 17 in the body of the subject H based on the coil position data 76 input from the position detection unit 72.

[0092] Figure 71 is an explanatory diagram for explaining an example of the shape detection process of the insertion portion 17 by the insertion portion shape detection unit 73. Figure 7 As shown, the insertion portion shape detection unit 73 performs interpolation processing of interpolating each position with a curve based on the position of each detection coil 25 represented by the coil position data 76 (here, P1, P2, ...), derives the central axis C of the insertion portion 17, and generates the insertion portion shape data 78 representing the shape of the insertion portion 17. The interpolation processing of interpolating with a curve is, for example, Bezier curve interpolation. The insertion portion shape data 78 includes the front end position PT of the front end portion 23 of the insertion portion 17.

[0093] exist Figure 3 In the process, the insertion portion shape detection unit 73 outputs the insertion portion shape data 78 to the image generation unit 77. Every time the image signal acquisition unit 68 acquires a new frame image signal 61, the insertion state detection unit 70 repeatedly performs the discrimination processing by the discrimination unit 72A, the position detection processing of detecting the coil position data 76 of each detection coil 25, the shape detection processing of the insertion portion 17, and the output of the insertion portion shape data 78.

[0094] The image generation unit 77 generates the shape display image 42 based on the insertion portion shape data 78. Figure 8 As shown, a modeling unit 77A and a rendering unit 77B are provided in the image generating unit 77. The details will be described later. In the image generating unit 77, the modeling unit 77A generates a 3D (Dimension) model of the insertion unit 17 based on the insertion unit shape data 78, and the rendering unit 77B performs rendering processing on the 3D model of the insertion unit 17, thereby generating a 2D (Dimension) shape display image 42 representing the shape of the insertion unit 17. The image generating unit 77 outputs the data of the generated shape display image 42 to the processor device 14.

[0095] The image generating unit 77 updates the shape display image 42 every time new insertion portion shape data 78 is input. Then, every time the shape display image 42 is updated, the image generating unit 77 outputs the data of the updated shape display image 42 to the processor device 14.

[0096] The command input unit 80 is an interface for the user to use the navigation device 12. The command input unit 80 is composed of, for example, a display having a touch panel that can be touched by the user, and operation buttons, etc. The command input unit 80 is provided so that commands to various parts of the navigation device 12, such as a display magnification change command, can be input.

[0097] The information storage unit 81 is constituted by a non-volatile memory such as a flash memory, for example. The non-volatile memory can retain the data stored in the memory even when the power of the navigation device 12 is turned off.

[0098] The navigation device 12 is an example of an endoscope shape display control device that performs display control related to the shape display image 42 involved in the technology of the present invention. As described above, the magnetic field measurement data 55 is data obtained by using a plurality of detection coils 25 as an example of a plurality of magnetic field detection elements provided in the insertion portion 17 of the endoscope 10 involved in the technology of the present invention. The insertion portion shape data 78 is information based on the magnetic field measurement data 55, and is an example of information that images the shape of the insertion portion 17 of the endoscope 10 embedded in the subject H as an example of the subject involved in the technology of the present invention. The image generation unit 77 generates a shape display image 42 that images the shape of the insertion portion 17 based on the insertion portion shape data 78. In addition, the image generation unit 77 controls the reduction ratio of the size of the shape display image 42 when the display magnification of the shape display image 42 is changed. That is, the image generation unit 77 is an example of the information acquisition unit, the image generation unit, and the reduction ratio control unit involved in the technology of the present invention.

[0099] The display output unit 74 outputs the frame image signal 61 previously input from the image signal acquisition unit 68 and the data of the shape display image 42 input from the image generation unit 77 to the processor device 14 via the communication interfaces 90A and 90B. At this time, the display output unit 74 establishes a correspondence relationship between the frame image signal 61 and the data of the shape display image 42 corresponding to the frame image signal 61 in time, and outputs them to the processor device 14.

[0100] <Processor device>

[0101] The processor device 14 includes a display input unit 92 and a display control unit 93. The display input unit 92 sequentially outputs the frame image signal 61 and the data of the shape display image 42 sequentially input from the display output unit 74 via the communication interfaces 90A and 90B to the display control unit 93.

[0102] The display control unit 93 receives an input of the frame image signal 61 from the display input unit 92, and displays an observation image 41 (for example, a moving image) based on the frame image signal 61 on the display 15 (see Figure 1 and Figure 2 ). In addition, the display control unit 93 receives input of data of the shape display image 42 from the display input unit 92, and displays the shape display image 42 (for example, a dynamic image) on the display 15 (refer to Figure 1 and Figure 2 ).

[0103] [Flow of shape display image generation process]

[0104] Fig. 9 This is a flowchart for explaining the flow of the process of generating the shape display image 42 by the image generating unit 77 . Fig.10This is a flowchart for explaining the flow of the modeling process by the image generating unit 77. First, the case where the shape display image 42 is displayed at the same magnification will be explained.

[0105] like Fig. 9 As shown in the flowchart of , the image generation unit 77 performs an insertion portion shape data acquisition process of acquiring the insertion portion shape data 78 from the insertion state detection unit 70 (step S1). Next, in the image generation unit 77, the modeling unit 77A performs a modeling process of generating a 3D model of the insertion portion 17 based on the insertion portion shape data 78 (step S2).

[0106] Fig.10 As shown in the flowchart of , in the modeling process, first, the modeling unit 77A determines whether a display magnification change command has been received (step S11 ).

[0107] In step S11, if it is determined that no display magnification change command has been received (the determination result is No), Fig.11 As shown, the modeling unit 77A performs general control to set the display magnification of the entire shape display image 42 and the display magnification of the diameter of the insertion portion 17 to the same value (step S15). In the case of equal magnification display, the display magnification of the entire shape display image 42 and the display magnification of the diameter of the insertion portion 17 are both 100% (an example of a reference size).

[0108] Next, the modeling unit 77A performs a formal modeling process to generate a cylindrical 3D model M with a preset reference diameter D0, using the central axis C of the insertion unit 17 in the insertion unit shape data 78 as the central axis (step S16). Here, the length of the preset portion of the 3D model M of the insertion unit 17 is set as the reference length L0. Strictly speaking, the reference length L0 is the length of the preset portion of the central axis C of the insertion unit 17. When the insertion unit 17 is curved, it is the length of the curve, but in the case of a curved insertion unit 17, it is the length of the curve. Fig.11 In the figure, a straight line is used for convenience.

[0109] Back to Fig. 9 , then, the drawing unit 77B performs a light source position setting process, which sets the light source position when drawing the 3D model M of the insertion unit 17 (step S3). The light source position is set to a position where light is irradiated from above to the top surface 16A of the bed 16 in the virtual space for generating the 3D model M. Specifically, in the real space, when the magnetic field generator 13 and the bed 16 are arranged on the same floor surface, the horizontal direction of the magnetic field generator 13 is parallel to the top surface 16A of the bed 16. Therefore, in the virtual space, the surface parallel to the top surface 16A of the bed 16 is set as the XY plane, and the Z axis orthogonal to the XY plane is set. Then, in the virtual space, the light source position is set in such a way that light is irradiated from above the set Z axis toward below.

[0110] Next, the rendering unit 77B performs a camera position setting process for setting a camera position (also referred to as a viewpoint position) when rendering the 3D model M of the insertion unit 17 (step S4). The camera position is set to a position in the virtual space at which the 3D model M of the insertion unit 17 is viewed from above the Z axis relative to the top surface 16A of the bed 16, similarly to the light source position.

[0111] Next, the rendering unit 77B executes a texture setting process for finishing the surface of the 3D model M when rendering the 3D model M of the insertion unit 17 (step S5 ). In the texture setting process, a texture of a solid color pattern is processed on the surface of the insertion unit 17 , for example.

[0112] Finally, the rendering unit 77B adds a pattern to the surface of the 3D model M according to the set light source position, camera, and texture. In addition, a shadow process is performed to add a shadow corresponding to the light source to the surface of the 3D model M to which the pattern is added. The rendering unit 77B thus performs a rendering process to generate a 2D shape display image 42 representing the shape of the insertion portion 17 (step S6).

[0113] Therefore, if Fig.12 As shown, a shape display image 42 is generated for equal magnification display. The shape display image 42 is composed of an image representing the insertion portion 17 and an image serving as its background. Hereinafter, for simplicity, the insertion portion 17 in the shape display image 42, or more accurately, the image of the insertion portion 17 in the shape display image 42, is referred to as the insertion portion, and in order to distinguish it from the actual insertion portion 17, it is marked with a symbol 17G and referred to as the insertion portion 17G.

[0114] The process of generating the shape display image 42 is repeated every time the insertion portion shape data 78 is updated.

[0115] Next, a case where a command to change the display magnification of the shape display image 42 is issued will be described. Fig.13 It is a functional block diagram of the image generation unit 77 and the information storage unit 81.

[0116] The display magnification change command is input by the user through the command input unit 80. The display magnification change command includes the display magnification of the entire shape display image 42. The display magnification information is stored in the information storage unit 81 as display magnification information 82. Every time a new display magnification change command appears, the display magnification information 82 is updated to the content included in the new display magnification change command.

[0117] When the display magnification is 100%, the shape display image 42 is displayed at the same magnification as a whole (here, it is displayed at the reference size). When the display magnification exceeds 100%, the shape display image 42 is displayed in an enlarged manner as a whole (here, it is displayed in an enlarged manner relative to the reference size). The display magnification and the enlargement ratio in this case have the same meaning. When the display magnification is less than 100%, the shape display image 42 is displayed in a reduced manner as a whole (here, it is displayed in a reduced manner relative to the reference size). The display magnification and the reduction ratio in this case have the same meaning. The reduction ratio corresponds to the first reduction ratio R1 involved in the technology of the present invention. Hereinafter, the display magnification (here, the reduction ratio) when the display magnification represented by the display magnification information 82 is less than 100% will be described as the first reduction ratio R1. The first reduction ratio R1 is, for example, 50%.

[0118] Regarding the processing when a display magnification change command is issued, only Fig. 9 The processing contents of the modeling process S2 in the flowchart of are different. First, execute Fig. 9 The insertion part shape data acquisition process (step S1) and the modeling setting process (step S2) of the flowchart.

[0119] Fig.10 As shown in the flowchart of , in the modeling process, first, the modeling unit 77A determines whether a display magnification change command has been received (step S11). In step S11, if it is determined that a display magnification change command has been received (the determination result is yes), the modeling unit 77A executes a display magnification information acquisition process of acquiring the display magnification information 82 from the information storage unit 81 (step S12).

[0120] Next, the modeling unit 77A determines whether the display magnification indicated by the display magnification information 82 is less than 100%, that is, whether the shape display image 42 is displayed in a reduced size relative to the same size (step S13). In step S13, if it is determined that the display magnification is less than 100% (that is, the shape display image 42 is displayed in a reduced size) (the determination result is yes), the modeling unit 77A performs a first control of setting the second reduction ratio R2, which is the reduction ratio of the diameter of the insertion portion 17 in the shape display image 42, to a value greater than the first reduction ratio R1 (step S14).

[0121] Fig.14 FIG. 7 is a diagram for explaining the content of the first control executed by the modeling unit 77A. Fig.14, for the sake of convenience, the insertion portion 17 is displayed as a straight line. The first reduction ratio R1 is the reduction ratio of the entire shape display image 42, and is the same value as the ratio of the reduced length L1 of the predetermined portion of the insertion portion 17 of the reduced shape display image 42 to the reference length L0 of the predetermined portion of the insertion portion 17 when displayed at the same scale (i.e., L1 / L0). The second reduction ratio R2 is the ratio of the reduced diameter D1 of the insertion portion 17 of the reduced shape display image 42 to the reference diameter D0 of the insertion portion 17 when displayed at the same scale (i.e., D1 / D0). The first control is a control for setting the second reduction ratio R2 to a value greater than the first reduction ratio R1. As a result of the first control, the ratio of the reduced diameter D1 to the reduced length L1 is greater than the ratio of the reference diameter D0 to the reference length L0, and therefore the insertion portion 17 is displayed thicker than the thickness corresponding to the first reduction ratio R1.

[0122] Specifically, the modeling unit 77A calculates the second reduction ratio R2, for example, by the following formula. Here, the units of the first reduction ratio R1 and the second reduction ratio R2 are %. When the first reduction ratio R1 is, for example, 50%, the second reduction ratio R2 is set to 75% of the value greater than the first reduction ratio R1 (here, 50%) as calculated by the following formula.

[0123] R2={(100-R1) / 2}+R1

[0124] Fig.15 3D model generation processing of the insertion part in the reduced display. Fig.15 and the following Fig.16 and Fig.17 For illustration purposes, exact dimensions are not shown. Fig.15 As shown, the modeling unit 77A performs the modeling formal processing to generate a cylindrical 3D model M with the central axis C of the insertion portion 17 in the insertion portion shape data 78 as the central axis (step S16). In the processing up to step S14, the first reduction rate R1, which is the reduction rate of the entire shape display image 42, is set to 50%, and the second reduction rate R2, which is the reduction rate of the diameter of the insertion portion 17 in the shape display image 42, is set to 75%. In addition, Fig.15 The area E indicated by the dotted line in the figure represents the display range when displayed at the same scale.

[0125] Therefore, if Fig.15As shown, the modeling unit 77A reduces the length of the entire insertion portion 17 so that the reduced length L1 of the predetermined portion of the insertion portion 17 in the reduced shape display image 42 becomes 50% of the reference length L0 of the predetermined portion of the insertion portion 17 when displayed at the same scale. In addition, the modeling unit 77A reduces the diameter of the insertion portion 17 so that the reduced diameter D1 of the insertion portion 17 becomes 75% of the reference diameter D0.

[0126] Back to Fig. 9 , the drawing unit 77B sequentially performs the light source position setting process (step S3), the camera position setting process (step S4), and the texture setting process (step S5). The drawing unit 77B performs the same setting process as that in the equal-size display in each setting process. Finally, the drawing unit 77B performs the drawing process (step S6).

[0127] Therefore, if Fig.16 As shown, a shape display image 42A is generated by reducing the shape display image 42 as a whole to 50%. The shape display image 42A is composed of an image of the insertion portion 17 and an image that serves as its background. Hereinafter, for convenience, the insertion portion 17 in the shape display image 42A, more precisely, the image of the insertion portion 17 in the shape display image 42A is simply referred to as the insertion portion, and in order to distinguish it from the actual insertion portion 17, it is marked with a symbol 17G and is referred to as the insertion portion 17G.

[0128] The process of generating the shape display image 42A is repeated every time the insertion portion shape data 78 is updated.

[0129] In addition, when the display magnification is 100% or more, Fig.10 In step S13 of the flowchart, it is determined that the display magnification is not less than 100% (i.e., the shape display image 42 is displayed at the same magnification or enlarged) (the result of determination is No). In this case, the modeling unit 77A performs a general control to set the display magnification of the shape display image 42 as a whole and the display magnification of the diameter of the insertion portion 17 to the same value (step S15), and transfers to step S16. Thus, an image in which the shape display image 42 is displayed at the same magnification or enlarged is obtained.

[0130] [Effects]

[0131] In the endoscope system 9 of the present invention, as described above, when the shape display image 42 is displayed in a reduced size, in the modeling unit 77A, a first control is performed to set the second reduction rate R2, which is the reduction rate of the diameter of the insertion portion 17 within the shape display image 42, to a value greater than the first reduction rate R1, which is the reduction rate of the shape display image 42 as a whole.

[0132] As a result, in the shape display image 42A reduced to 50%, compared with the shape display image 42 displayed at the same scale, the reduced length GL1 is 50% of the reference length GL0, whereas the reduced diameter GD1 is 75% of the reference diameter GD0.

[0133] As a comparative example, Fig.17 4B is a shape display image 42B generated by a conventional technique of uniformly reducing the entire shape display image 42. The shape display image 42B is an image in which the entire display area is uniformly reduced by 50%. In the shape display image 42B reduced by 50%, compared with the shape display image 42 displayed at the same magnification, the reduced length GLn is 50% of the reference length GL0, and the reduced diameter GDn is also 50% of the reference diameter GD0.

[0134] When the shape display image 42 is reduced at the same reduction ratio, the reduced diameter GD1 of the shape display image 42A generated by the technology of the present invention is larger than the reduced diameter GDn of the shape display image 42B generated by the prior art. Therefore, the front and rear of the intersection 17GX of the insertion portion 17G can be easily determined. In this way, according to the technology of the present invention, even when the shape display image 42 is reduced and displayed, the shape display image 42A that allows easy visual recognition of the overlapping state of the insertion portion 17G can be displayed.

[0135] [Modifications]

[0136] The above-described embodiment is merely an example, and various modifications are possible as described below.

[0137] For example, in the above-described embodiment, when the shape display image 42 is displayed in a reduced form, the modeling unit 77A is always executed to perform the first control of setting the second reduction ratio R2, which is the reduction ratio of the diameter of the insertion portion 17 in the shape display image 42, to a value greater than the first reduction ratio R1, which is the reduction ratio of the entire shape display image 42. In contrast, when the shape display image 42 is displayed in a reduced form, the modeling unit 77A may execute the first control only when the first reduction ratio is smaller than a preset threshold value.

[0138] The flow of the processing in this case will be described. As described above, the overall flow of the generation process of the shape display image 42 is as follows: Fig. 9 In this method, only Fig. 9 The processing contents of the modeling process S2 in the flowchart are different. Fig.18 This is a flowchart for explaining the flow of the modeling process of this embodiment. The threshold value can be set to any reduction ratio.

[0139] like Fig.18 As shown in the flowchart of , in the modeling process, first, the modeling unit 77A determines whether a display magnification change command has been received (step S21). In step S21, if it is determined that a display magnification change command has been received (the determination result is yes), the modeling unit 77A executes a display magnification information acquisition process of acquiring the display magnification information 82 from the information storage unit 81 (step S22).

[0140] Next, the modeling unit 77A determines whether the display magnification indicated by the display magnification information 82 is less than 100%, that is, whether the shape display image 42 is displayed in a reduced size relative to the same size (step S23). In step S23, if it is determined that the display magnification is less than 100% (that is, the shape display image 42 is displayed in a reduced size) (the determination result is yes), the modeling unit 77A determines whether the first reduction ratio R1 is less than a threshold value (step S24).

[0141] In step S24 , when it is determined that the first reduction ratio R1 is smaller than the threshold value (the determination result is YES), the modeling unit 77A performs a first control of setting the second reduction ratio R2 , which is the reduction ratio of the diameter of the insertion portion 17 in the shape display image 42 , to a value larger than the first reduction ratio R1 (step S26 ).

[0142] For example, when the first reduction ratio R1 is 50% and the threshold value is 80%, the modeling unit 77A calculates the second reduction ratio R2 by the following formula. Here, the units of the first reduction ratio R1 and the second reduction ratio R2 are %. As a result of the calculation by the following formula, the second reduction ratio R2 is set to a value greater than the first reduction ratio R1 (here, 50%), that is, 65%.

[0143] R2={(80-R1) / 2}+R1

[0144] In step S24, when it is determined that the first reduction ratio R1 is not less than the threshold value (the determination result is No), the modeling unit 77A performs a second control to set the second reduction ratio R2, which is the reduction ratio of the diameter of the insertion portion 17 in the shape display image 42, to the same value as the first reduction ratio R1 (step S27).

[0145] Next, the modeling unit 77A performs a formal modeling process of generating a cylindrical 3D model M with the central axis C of the insertion portion 17 in the insertion portion shape data 78 as the central axis (step S28), and then transfers to the step S29. Fig. 9 Step S3 of the flowchart.

[0146] In addition, Fig.18In step S21 of the flowchart, if it is determined that no display magnification change command has been received (the result of determination is No), and in step S23, if it is determined that the display magnification is not less than 100% (i.e., the shape display image 42 is displayed at the same magnification or enlarged display) (the result of determination is No), the process proceeds to step S25. The modeling unit 77A performs a general control to set the display magnification of the entire shape display image 42 and the display magnification of the diameter of the insertion portion 17 to the same value (step S25), and then proceeds to step S28. Thus, an image in which the entire shape display image 42 is displayed at the same magnification or enlarged display is acquired.

[0147] If the first control is executed when the shape display image 42 is displayed in reduced size, the reduced diameter GD1 of the insertion portion 17G is displayed thicker than the actual insertion portion 17 in the reduced shape display image 42A. However, in the present embodiment, the second control is executed when the first reduction ratio R1 is equal to or greater than the threshold value, and the first control is executed only when the first reduction ratio R1 is less than the threshold value.

[0148] As a result, when the reduction ratio is large and the insertion portion 17 cannot be displayed too thin, the diameter of the insertion portion 17G can be displayed with a thickness corresponding to the first reduction ratio R1, and only when the reduction ratio is small and the insertion portion 17 is displayed thin, the diameter of the insertion portion 17G can be displayed thicker than the thickness corresponding to the first reduction ratio R1. Therefore, a natural reduced image with little sense of incongruity can be displayed.

[0149] Furthermore, in the above embodiment, the method for determining the second reduction ratio R2 in the first control is not limited to the method of determining using the above formula, and any determination method may be used as long as the second reduction ratio R2 is greater than the first reduction ratio R1. For example, it may be determined using a formula different from the above formula, or it may be determined by referring to a table showing the relationship between the value of the first reduction ratio R1 and the value of the second reduction ratio R2.

[0150] Furthermore, in the above-mentioned embodiment, the process of generating the shape display image 42 after the display magnification is changed is not limited to the method of changing the length and diameter of the insertion portion 17 during modeling described above in accordance with the display magnification, thereby fixing the camera position during drawing, and any method may be used. For example, the method may be as follows: the length of the insertion portion 17 during modeling is fixed, only the diameter is changed in accordance with the display magnification, and the camera position during drawing is changed in accordance with the display magnification.

[0151] Furthermore, in the above-described embodiment, an example in which each generating coil 39 generates the magnetic field MF of the same frequency has been described. However, the frequencies of the magnetic field MF generated by each generating coil 39 may be different.

[0152] Furthermore, in the above-mentioned embodiments, an example is given in which a magnetic field measuring unit including a magnetic field measuring control unit 58 is configured in the endoscope 10, and a magnetic field generating control unit 71 is configured in the navigation device 12. However, conversely, the magnetic field generating control unit 71 may be configured in the endoscope 10, and the magnetic field measuring unit may be configured in the navigation device 12.

[0153] Furthermore, in the above-mentioned embodiment, for example, as a hardware structure of a processing unit (Processing Unit) that executes various processes such as an information acquisition unit, an image generation unit, and an image generation unit 77 as an example of a reduction ratio control unit, various processors (Processors) shown below can be used. The various processors include a common processor that executes software to perform the functions of various processing units, namely a CPU (Central Processing Unit), and also include a processor that can change the circuit structure after manufacturing, such as a FPGA (Field Programmable Gate Array), i.e., a programmable logic device (PLD), and / or a processor that has a circuit structure specially designed for executing specific processing, such as an ASIC (Application Specific Integrated Circuit), i.e., a dedicated circuit.

[0154] A processing unit may be composed of one of these various processors, or may be composed of a combination of two or more processors of the same type or different types (for example, a combination of multiple FPGAs and / or a combination of a CPU and an FPGA). In this way, various processing units are composed of one or more of the above-mentioned various processors as a hardware structure.

[0155] Furthermore, as the hardware configuration of these various processors, more specifically, a circuit (Circuitry) in which circuit elements such as semiconductor elements are combined can be used.

[0156] An endoscope display control device having an information acquisition unit, an image generation unit, and a reduction ratio control unit can be realized by a computer whose processor is composed of a CPU. A program for causing the CPU to function as the information acquisition unit and the image generation unit is an execution program of the endoscope display control device. The technology of the present invention relates to a computer-readable storage medium that non-temporarily stores the execution program in addition to the execution program of the endoscope display control device.

[0157] From the above description, the invention described in the following supplementary notes can be grasped.

[0158] "Supplementary Item 1"

[0159] An endoscope shape display control device, comprising:

[0160] an information acquisition processor that acquires information for imaging the shape of an insertion portion of an endoscope inserted into a subject;

[0161] an image generation processor that generates a shape display image showing the shape of the insertion portion based on the acquired information; and

[0162] The reduction ratio control processor controls the reduction ratio of the reduced size relative to a preset reference size when reducing the displayed shape display image, and performs a first control on the diameter of the insertion portion in the shape display image to be set to a second reduction ratio greater than the first reduction ratio when reducing the entire shape display image at a first reduction ratio.

[0163] In this specification, "A and / or B" has the same meaning as "at least one of A and B". That is, "A and / or B" may mean only A, only B, or a combination of A and B. Furthermore, in this specification, the same idea as "A and / or B" applies to the case where three or more cases are connected and expressed with "and / or".

[0164] The recorded contents and illustrated contents shown above are detailed descriptions of the parts involved in the technology of the present invention, which are only an example of the technology of the present invention. For example, the descriptions related to the above-mentioned structure, function, action and effect are descriptions related to an example of the structure, function, action and effect of the parts involved in the technology of the present invention. Therefore, without departing from the scope of the purpose of the technology of the present invention, it is of course possible to delete unnecessary parts of the recorded contents and illustrated contents shown above, or to add or replace new elements. In addition, in order to avoid complicated situations and to make it easy to understand the parts involved in the technology of the present invention, the descriptions related to the technical common sense that does not particularly need to be explained in terms of enabling the implementation of the technology of the present invention are omitted in the recorded contents and illustrated contents shown above.

[0165] The entire disclosure of Japanese patent application No. 2019-141387 filed on July 31, 2019 is incorporated into this specification by reference. All documents, patent applications, and technical standards described in this specification are incorporated into this specification by reference to the same extent as if each document, patent application, and technical standard was specifically and individually described as being incorporated by reference.

Claims

1. An endoscope shape display control device, comprising at least one processor, The processor performs the following processing: acquiring information for imaging the shape of an insertion portion of an endoscope inserted into a subject, generating a shape display image showing the shape of the insertion portion based on the acquired information, When the displayed shape display image is reduced, a reduction ratio of the reduced size relative to a preset reference size is controlled, and when the entire shape display image is reduced at a first reduction ratio, a first control is performed in which a second reduction ratio greater than the first reduction ratio is set for the diameter of the insertion portion in the shape display image. When the first reduction ratio is equal to or larger than a preset threshold, the second control is performed to set the first reduction ratio and the second reduction ratio to the same value, and when the first reduction ratio is smaller than the threshold, the first control is performed.

2. The endoscope shape display control device according to claim 1, wherein: The processor sets the reduction ratio to the first reduction ratio for the length of the insertion portion and sets the reduction ratio to the second reduction ratio for the diameter of the insertion portion.

3. A working method of an endoscope shape display control device, the method comprising: an information acquisition step of acquiring information for imaging the shape of an insertion portion of the endoscope inserted into the subject; an image generating step of generating a shape display image showing the shape of the insertion portion according to the acquired information; A reduction rate control step, when reducing the displayed shape display image, controls the reduction rate of the reduced size relative to a preset reference size, and when reducing the shape display image as a whole at a first reduction rate, executes a first control, in which a diameter of the insertion portion in the shape display image is set to a second reduction rate greater than the first reduction rate, and when the first reduction rate is greater than a preset threshold, executes a second control of setting the first reduction rate and the second reduction rate to the same value, and when the first reduction rate is less than the threshold, executes the first control.

4. A computer-readable medium having recorded thereon an execution program of an endoscope shape display control device, the execution program causing a computer to function as the following three parts: an information acquisition unit that acquires information for imaging the shape of an insertion portion of an endoscope inserted into a subject; an image generating unit, which generates a shape display image showing the shape of the insertion unit according to the acquired information; and The reduction ratio control unit controls the reduction ratio of the size after reduction relative to a preset reference size when reducing the displayed shape display image, and executes a first control when reducing the shape display image as a whole at a first reduction ratio, wherein a second reduction ratio greater than the first reduction ratio is set for the diameter of the insertion portion in the shape display image, and when the first reduction ratio is greater than a preset threshold value, a second control is executed to set the first reduction ratio and the second reduction ratio to the same value, and when the first reduction ratio is less than the threshold value, the first control is executed.

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