Patent Description:
An endoscope that observes a lower digestive tract, such as the large intestine, is known. The lower digestive tract is intricately bent, unlike an upper digestive tract, such as an esophagus, which extends relatively linearly. Therefore, the endoscope, which is inserted into the lower digestive tract of a subject, such as a patient, an insertion part of the endoscope is also intricately bent. In order to grasp a shape of the insertion part of the endoscope inserted into the subject, an endoscope shape detection device that detects the shape of the insertion part of the endoscope in the subject (for example, see <CIT>) is known.

The endoscope shape detection device disclosed in <CIT> has a function of acquiring information for imaging the shape of the insertion part in the subject by using magnetism and imaging the shape of the insertion part based on the acquired information. For example, a plurality of magnetic field generation elements are disposed at intervals in the insertion part of the endoscope. The endoscope shape detection device detects a magnetic field generated by each magnetic field generation element in the insertion part by a magnetic field detection element disposed outside the subject. Since intensity of the magnetic field of each detected magnetic field generation element represents a position of each part of the insertion part with respect to the magnetic field detection element outside the subject, the endoscope shape detection device disclosed in <CIT> uses information on the intensity of the magnetic field of each magnetic field generation element as the information for imaging the shape of the insertion part to generate an image showing the shape of the insertion part. Further, the generated image is displayed on a monitor and presented to a user, such as an operator (for example, a doctor).

For example, <CIT> discloses an endoscope shape analysis apparatus, which includes a coordinates obtaining portion for obtaining coordinate values of an insertion portion; a storage portion for storing the coordinate values; a straight line setting portion for setting a first straight line and a second straight line, based on the coordinate values; a coordinate transformation portion for transforming coordinates of a previous second straight line, based on a positional relationship between a previous first straight line and the first straight line, to calculate a third straight line; a determination portion for determining whether there is an error in a position display from a positional relationship between the first straight line, the second straight line, and the third straight line; and a correction portion for correcting the second straight line.

An imaging procedure in the endoscope shape detection device of <CIT> is performed as follows, for example. First, the endoscope shape detection device disclosed in <CIT> specifies the position of each part of the insertion part to generate a three-dimension model of the insertion part based on the information for imaging the shape of the insertion part (for example, the information on the intensity of the magnetic field described above). Then, a rendering process is performed on the three-dimension model of the insertion part to generate a two-dimension image to be displayed on the monitor. The two-dimension image is an image showing the shape of the insertion part as viewed from one viewpoint in which the three-dimension model of the insertion part can be optionally set, and in the following, is referred to as a shape display image.

In a case in which the insertion part of the endoscope is bent in a loop shape in the subject, different portions of the insertion part intersect with each other in the shape display image depending on the set viewpoint. <CIT> discloses that a shade line process or a hidden surface process is performed in a case of the rendering process in order to express front and rear of the intersection portions.

However, depending on a display magnification of the shape display image, the insertion part of the endoscope may be displayed in a thin line shape in the shape display image. Therefore, there is a problem that it is difficult for the user to instantaneously determine the front and rear of the intersection portion even in a case in which the shade line process or the hidden surface process is performed on the intersection portion.

The present invention provides an endoscope shape display control device, an operation method of an endoscope shape display control device, and an operation program of the endoscope shape display control device with the features of the independent claims. The present invention is capable of displaying a shape display image in which an overlapping condition of an insertion part is easily visually recognized in the shape display image in which a shape of the insertion part of an endoscope in a state of being inserted into a subject is displayed.

An aspect of the present invention relates to an endoscope shape display control device comprising at least one processor, in which the processor acquires information for imaging a shape of an insertion part of an endoscope inserted in a subject, and displays, in a case of generating a shape display image in which the shape of the insertion part is displayed based on the acquired information, the insertion part with a pattern added on a surface thereof in the shape display image.

In the endoscope shape display control device according to the aspect described above, the pattern may be added to an entire region of the insertion part displayed in the shape display image.

In addition, in the endoscope shape display control device according to the aspect described above, the pattern may be a gradation in which a color is changed continuously or stepwise from one of a distal end side or a proximal end side of the insertion part to the other thereof. In this case, the gradation may be changed from green to blue.

According to a non-claimed example, the pattern may be a stripe pattern.

According to a non-claimed example, the pattern may be a wire frame pattern.

In addition, in the endoscope shape display control device according to the aspect described above, the processor may perform a shading process on the insertion part in addition to the pattern.

In addition, in the endoscope shape display control device according to the aspect described above, the information for imaging the shape of the insertion part may be information based on magnetic field measurement data obtained by using a plurality of magnetic field generation elements or a plurality of magnetic field detection elements provided in the insertion part.

Another aspect of the present invention relates to an operation method of an endoscope shape display control device, the method comprising an information acquisition step of acquiring information for imaging a shape of an insertion part of an endoscope inserted in a subject, and an image generation step of generating a shape display image in which the shape of the insertion part is displayed based on the acquired information and displaying the insertion part with a pattern added on a surface thereof in the shape display image.

Still another aspect of the present invention relates to an operation program of an endoscope shape display control device, the program causing a computer to function as an information acquisition unit that acquires information for imaging a shape of an insertion part of an endoscope inserted in a subject, and an image generation unit that generates a shape display image in which the shape of the insertion part is displayed based on the acquired information, the image generation unit displaying the insertion part with a pattern added on a surface thereof in the shape display image.

According to the technology of the present disclosure, it is possible to provide an endoscope shape display control device, an operation method of an endoscope shape display control device, and an operation program of the endoscope shape display control device capable of displaying a shape display image in which an overlapping condition of an insertion part is easily visually recognized in the shape display image in which a shape of the insertion part of an endoscope in a state of being inserted into a subject is displayed.

<FIG> is a schematic view showing an overall configuration of an endoscope system <NUM> comprising an endoscope shape display control device according to the technology of the present disclosure. As shown in <FIG>, the endoscope system <NUM> comprises an endoscope <NUM>, a light source device <NUM>, a navigation device <NUM>, a magnetic field generator <NUM>, a processor device <NUM>, and a monitor <NUM>. The endoscope system <NUM> is used for an endoscopic examination in a body of a subject H, such as a patient. The subject H is an example of a subject. The endoscope <NUM> is, for example, an endoscope inserted into the digestive tract, such as the large intestine, and is a soft endoscope having flexibility. The endoscope <NUM> has an insertion part <NUM> to be inserted into the digestive tract, an operating part <NUM> connected sequentially to a proximal end side of the insertion part <NUM> and gripped by an operator to perform various operations, and a universal cord <NUM> connected sequentially to the operating part <NUM>.

The endoscopic examination is performed, for example, in a state in which the subject H lies on an upper surface 16A of a bed <NUM>. In a case of a large intestine examination, the insertion part <NUM> of the endoscope <NUM> is inserted into the digestive tract from an anus by an operator OP who is the doctor. The light source device <NUM> supplies illumination light that illuminates an inside of the large intestine, which is an observation site, to the endoscope <NUM>. The processor device <NUM> generates an observation image <NUM> by processing an image captured by the endoscope <NUM>. The observation image <NUM> is displayed on the monitor <NUM>. The operator OP proceeds with the endoscopic examination while confirming the observation image <NUM>. The observation image <NUM> displayed on the monitor <NUM> is basically a motion picture, but it is also possible to display a still picture as the observation image <NUM> as needed.

In addition, the endoscope system <NUM> has a navigation function of navigating technique, such as an insertion operation of the endoscope <NUM> performed by the operator OP. Here, the navigation means supporting the technique of the endoscope <NUM> of the operator OP by presenting an insertion state including the position and the shape of the insertion part <NUM> of the endoscope <NUM> in the body of the subject H to the operator OP. By the navigation function, the insertion state of the insertion part <NUM> is detected using a magnetic field MF and the detected insertion state is presented.

The navigation function is realized by the navigation device <NUM>, the magnetic field generator <NUM>, and a magnetic field measurement device in the endoscope <NUM> described below. The magnetic field generator <NUM> generates the magnetic field MF. The magnetic field generator <NUM> is attached to, for example, a stand and is disposed beside the bed <NUM> on which the subject H lies. In addition, the magnetic field generator <NUM> is disposed within a range in which the generated magnetic field MF reaches the body of the subject H.

The magnetic field measurement device in the endoscope <NUM> detects the magnetic field MF generated by the magnetic field generator <NUM> and measures the intensity of the detected magnetic field MF. The navigation device <NUM> detects the insertion state of the insertion part <NUM> by deriving a relative position between the magnetic field generator <NUM> and the insertion part <NUM> based on a magnetic field measurement result by the magnetic field measurement device. The processor device <NUM> generates a shape display image <NUM>, which shows the insertion state detected by the navigation device <NUM>.

The monitor <NUM> displays the observation image <NUM> and the shape display image <NUM>. Note that the monitor <NUM> that displays the observation image <NUM> and the shape display image <NUM> may be provided separately.

As shown in <FIG>, the insertion part <NUM> is a tubular portion having a small diameter and a long length, and is configured by a soft part <NUM>, a bendable part <NUM>, and a distal end part <NUM>, which are connected sequentially from the proximal end side to the distal end side. The soft part <NUM> has flexibility. The bendable part <NUM> is a part that can be bent by the operation of the operating part <NUM>. An imaging apparatus <NUM> (see <FIG>) and the like are disposed at the distal end part <NUM>. In addition, although not shown in <FIG>, an illumination window <NUM> (see <FIG>) that illuminates the observation site with the illumination light, an observation window <NUM> (see <FIG>) on which subject light of the illumination light reflected by the subject is incident, a treatment tool outlet (not shown) for a treatment tool to protrude, and a cleaning nozzle (not shown) for cleaning the observation window <NUM> by injecting gas and water into the observation window <NUM> are provided on a distal end surface of the distal end part <NUM>.

Alight guide <NUM>, a signal cable <NUM>, an operation wire (not shown), and a pipe line for inserting the treatment tool (not shown) are provided in the insertion part <NUM>. The light guide <NUM> extends from the universal cord <NUM> and guides the illumination light supplied from the light source device <NUM> to the illumination window <NUM> at the distal end part <NUM>. The signal cable <NUM> is used for power supply to the imaging apparatus <NUM> in addition to communication of an image signal from the imaging apparatus <NUM> and a control signal for controlling the imaging apparatus <NUM>. Like the light guide <NUM>, the signal cable <NUM> also extends from the universal cord <NUM> and is arranged to the distal end part <NUM>.

The operation wire is a wire for operating the bendable part <NUM>, and is arranged from the operating part <NUM> to the bendable part <NUM>. The pipe line for inserting the treatment tool is a pipe line for inserting the treatment tool (not shown), such as forcep, and is arranged from the operating part <NUM> to the distal end part <NUM>. In addition, a fluid tube for air/water supply is provided in the insertion part <NUM>. The fluid tube supplies the distal end part <NUM> with gas and water for cleaning the observation window <NUM>.

In addition, in the insertion part <NUM>, a plurality of detection coils <NUM> are provided from the soft part <NUM> to the distal end part <NUM> at preset intervals. Each detection coil <NUM> corresponds to a magnetic field detection element which detects the magnetic field MF. Each detection coil <NUM> is affected by the magnetic field MF generated from the magnetic field generator <NUM>, so that an induced electromotive force is generated by an operation of electromagnetic induction, and an induced current is generated by the induced electromotive force. A value of the induced current generated from each detection coil <NUM> represents the intensity of the magnetic field MF detected by each detection coil <NUM>, which is the magnetic field measurement result. That is, the magnetic field measurement result refers to a value depending on the magnitude of the induced current, which represents the intensity of the magnetic field MF.

The operating part <NUM> is provided with various operation members operated by the operator. Specifically, the operating part <NUM> is provided with two types of bending operation knobs <NUM>, an air/water supply button <NUM>, and a suction button <NUM>. Each of the two types of bending operation knobs <NUM> is connected to the operation wire, and is used for a right-left bending operation and an up-down bending operation of the bendable part <NUM>. In addition, the operating part <NUM> is provided with a treatment tool inlet port <NUM> which is an inlet of the pipe line for inserting the treatment tool.

The universal cord <NUM> is a connection cord that connects the endoscope <NUM> to the light source device <NUM>. The universal cord <NUM> encompasses the signal cable <NUM>, the light guide <NUM>, and the fluid tube (not shown). In addition, a connector <NUM> connected to the light source device <NUM> is provided at an end part of the universal cord <NUM>.

By connecting the connector <NUM> to the light source device <NUM>, the light source device <NUM> supplies the power, the control signal, the illumination light, the gas, and the water necessary for operating the endoscope <NUM> to the endoscope <NUM>. In addition, the image signal of the observation site acquired by the imaging apparatus <NUM> (see <FIG>) of the distal end part <NUM> and the magnetic field measurement result based on a detection signal of each detection coil <NUM> are transmitted from the endoscope <NUM> to the light source device <NUM>.

The connector <NUM> is not electrically connected to the light source device <NUM> by wire using a metal signal line or the like, and instead, the connector <NUM> and the light source device <NUM> are connected to each other so as to be capable of optical communication (for example, non-contact type communication). The connector <NUM> transmits and receives the control signal exchanged between the endoscope <NUM> and the light source device <NUM> and transmits the image signal and the magnetic field measurement result from the endoscope <NUM> to the light source device <NUM> by optical communication. The connector <NUM> is provided with a laser diode (hereinafter, referred to as LD) <NUM> connected to the signal cable <NUM>.

The LD <NUM> is used for transmitting a large amount of data from the endoscope <NUM> to the light source device <NUM>, specifically, transmitting the image signal and the magnetic field measurement result. The LD <NUM> transmits the image signal and the magnetic field measurement result, which has been originally in a form of the electric signal, in a form of an optical signal to a photodiode (hereinafter, referred to as PD) <NUM> provided in the light source device <NUM>.

Note that, although not shown, apart from the LD <NUM> and the PD <NUM>, both the connector <NUM> and the light source device <NUM> are provided with a light transmission and reception unit that converts a small amount of the control signal exchanged between the endoscope <NUM> and the light source device <NUM> into the optical signal and transmits and receives the converted optical signal. Moreover, the connector <NUM> is provided with a power reception unit (not shown) that receives the power by wireless power supply from a power feed unit (not shown) of the light source device <NUM>.

The light guide <NUM> in the connector <NUM> is inserted into the light source device <NUM>. In addition, the fluid tube (not shown) in the connector <NUM> is connected to an air/water supply device (not shown) via the light source device <NUM>. As a result, the light source device <NUM> and the air/water supply device supply the illumination light, the gas, and the water to the endoscope <NUM>, respectively.

The light source device <NUM> supplies the illumination light to the light guide <NUM> of the endoscope <NUM> via the connector <NUM>, and supplies the gas and the water supplied from the air/water supply device (not shown) to the fluid tube (not shown) of the endoscope <NUM>. In addition, the light source device <NUM> receives the optical signal transmitted from the LD <NUM> by the PD <NUM>, converts the received optical signal into the original image signal, which is the electric signal, and the magnetic field measurement result, and then outputs the converted image signal and the magnetic field measurement result to the navigation device <NUM>.

The navigation device <NUM> outputs the image signal for generating the observation image <NUM> input from the light source device <NUM> to the processor device <NUM>. In addition, the navigation device <NUM> controls the drive of the magnetic field generator <NUM> described below, detects the shape and the like of the insertion part <NUM> in the body of the subject H, and outputs a detection result to the processor device <NUM> as the information for generating the shape display image <NUM>.

As described above, the endoscope <NUM> in the present embodiment is one-connector type having one connector <NUM> connected to the light source device <NUM>. The endoscope <NUM> is connected to each of the processor device <NUM> and the navigation device <NUM> so as to be capable of communication via the light source device <NUM> to which the connector <NUM> is connected.

The magnetic field generator <NUM> has a plurality of generation coils <NUM> corresponding to a plurality of magnetic field generation elements. Each generation coil <NUM> includes an X-axis coil, a Y-axis coil, and a Z-axis coil that generate, by applying a drive current, an alternating current magnetic field (in other words, an alternating current magnetic field) in directions corresponding to XYZ coordinate axes of an orthogonal coordinate system XYZ, respectively. Each generation coil <NUM> generates the magnetic field MF having the same frequency. The generation coils <NUM> generate the magnetic fields MF at different timings from each other under a control of the navigation device <NUM>, which will be described in detail below.

<FIG> is a block diagram showing an electric configuration of the endoscope system <NUM>. As shown in <FIG>, the endoscope <NUM> includes the light guide <NUM>, an irradiation lens <NUM>, the illumination window <NUM>, the observation window <NUM>, the imaging apparatus <NUM>, a magnetic field detection circuit <NUM>, an integrated control circuit <NUM>, the signal cable <NUM>, the LD <NUM>, and the fluid tube and the cleaning nozzle (which are not shown).

The light guide <NUM> is, for example, a large-diameter optical fiber or a bundle fiber.

An incident end of the light guide <NUM> is inserted into the light source device <NUM> via the connector <NUM>. The light guide <NUM> is inserted into the connector <NUM>, the universal cord <NUM>, and the operating part <NUM>, and an emission end faces the irradiation lens <NUM> provided in the distal end part <NUM> of the insertion part <NUM>. As a result, the illumination light supplied from the light source device <NUM> to the incident end of the light guide <NUM> is emitted to the observation site from the irradiation lens <NUM> through the illumination window <NUM> provided on the distal end surface of the distal end part <NUM>. Further, the illumination light reflected by the observation site is incident on an imaging surface of the imaging apparatus <NUM> as image light of the observation site through the observation window <NUM> provided on the distal end surface of the distal end part <NUM>.

Note that one end side of the fluid tube (not shown) described above is connected to the air/water supply device (not shown) through the connector <NUM> and the light source device <NUM>, and the other end side of the fluid tube (not shown) is connected to an air/water supply nozzle (not shown) provided on the distal end surface of the distal end part <NUM> through the insertion part <NUM> and the like. As a result, the gas or the water supplied from the air/water supply device (not shown) is injected into the observation window <NUM> from the air/water supply nozzle (not shown) to clean the observation window <NUM>.

The imaging apparatus <NUM> includes a condenser lens <NUM> and an imaging element <NUM>. The condenser lens <NUM> collects the image light of the observation site incident from the observation window <NUM>, and forms the collected image light of the observation site on the imaging surface of the imaging element <NUM>. The imaging element <NUM> is a complementary metal oxide semiconductor (CMOS) type or charge coupled device (CCD) type imaging element. The imaging element <NUM> is, for example, a color imaging element in which any of red (R), green (G), or blue (B) microfilter is assigned to each pixel. The imaging element <NUM> images the observation site, which is an observation target. More specifically, the imaging element <NUM> images the image light of the observation site imaged on the imaging surface (that is, converts the image light into the electric signal), and outputs the image signal of the observation site to the integrated control circuit <NUM>.

In addition, the imaging element <NUM> is provided with an oscillation unit 53a that outputs a reference signal (for example, a clock signal), such as a crystal oscillator, and the imaging element <NUM> outputs the image signal constituting the motion picture with the reference signal oscillated from the oscillation unit 53a as a reference. An interval of the reference signal defines a frame rate. The frame rate is, for example, <NUM> frames per second (fps).

The magnetic field detection circuit <NUM> is electrically connected to each detection coil <NUM> in the insertion part <NUM>. The magnetic field detection circuit <NUM> outputs magnetic field measurement data <NUM> including the magnetic field measurement result of each detection coil <NUM> depending on the magnetic field MF generated from the generation coil <NUM> of the magnetic field generator <NUM> to the integrated control circuit <NUM>.

The integrated control circuit <NUM> configured to include arithmetic circuits including various central processing units (CPU) and various memories, and controls the operations of the units of the endoscope <NUM> in an integrated manner. The integrated control circuit <NUM> functions as a signal processing unit <NUM>, a magnetic field measurement control unit <NUM>, and an image signal output unit <NUM> by executing a control program stored in a memory (not shown). The magnetic field detection circuit <NUM> and the magnetic field measurement control unit <NUM> are combined to configure a magnetic field measurement unit. The magnetic field measurement unit measures a plurality of the magnetic fields MF originating from the generation coils <NUM> corresponding to the plurality of magnetic field generation elements based on the detection signals output by the detection coils <NUM>, and outputs the magnetic field measurement result for each magnetic field MF. The magnetic field measurement unit and the detection coil <NUM> are combined to configure the magnetic field measurement device.

The signal processing unit <NUM> performs various signal processes on the image signals sequentially output from the imaging element <NUM>. The signal process includes, for example, an analog signal process, such as a sampling two correlation pile process and a signal amplification process, and an analog/digital (A/D) conversion process of converting an analog signal into a digital signal after the analog signal process. The image signal after the signal process is performed is called a frame image signal <NUM>. The signal processing unit <NUM> outputs the frame image signal <NUM> to the image signal output unit <NUM> depending on the frame rate. The frame image signal <NUM> is used as motion picture data of the observation site. As described above, a plurality of the frame image signals <NUM> are the image signals that are acquired by the imaging element <NUM> executing motion picture imaging and are output at preset time intervals.

The magnetic field measurement control unit <NUM> acquires the magnetic field measurement data <NUM> including a plurality of the magnetic field measurement results of the detection coils <NUM> via the magnetic field detection circuit <NUM>, and outputs the acquired magnetic field measurement data <NUM> to the image signal output unit <NUM>.

As shown in <FIG>, even in a case in which the intensity of the magnetic field generated by each generation coil <NUM> is the same, for example, the magnetic field measurement result of each detection coil <NUM> is changed depending on a distance and a direction between each generation coil <NUM> that generates the magnetic field MF and each detection coil <NUM>. For example, the first generation coil <NUM> shown in <FIG> has different distance and direction from each of the first to third detection coils <NUM>, as shown by a solid line. Therefore, the magnetic field measurement results of the first to third detection coils <NUM> for the magnetic field MF generated by one first generation coil <NUM> are different. A relationship between each of the second generation coil <NUM> and the third generation coil <NUM> and each of the first to third detection coils <NUM> is the same.

In addition, on the contrary, even in a case in which the intensity of the magnetic field MF generated by each of the first to third generation coils <NUM> is the same, the magnetic field measurement result of one first detection coil <NUM> for the magnetic field MF of each generation coil <NUM> is different. Here, for example, a case is considered in which the first to third generation coils <NUM> is the X-axis coil, the Y-axis coil, and the Z-axis coil, respectively. In this case, a three-dimension coordinate position of the first detection coil <NUM> corresponding to the XYZ coordinate axes can be detected based on the magnetic field measurement result of one first detection coil <NUM> for the magnetic field MF of each of the X-axis coil, the Y-axis coil, and the Z-axis coil. The same applies to the second detection coil <NUM> and the third detection coil <NUM>. In a case in which the three-dimension coordinate positions of the detection coils <NUM> provided in the insertion part <NUM> at preset intervals can be detected, the shape of the insertion part <NUM> can be detected.

Note that, actually, based on the magnetic field measurement result, an angle of each detection coil <NUM> is detected in addition to the three-dimension coordinate position of each detection coil <NUM>. The shape of the insertion part <NUM> is detected based on the information of the three-dimension coordinate position and the angle. In the following, in order to avoid complication, the description regarding the angle will be omitted and only the three-dimension coordinate position will be described.

<FIG> is an explanatory diagram for describing an example of the magnetic field measurement data <NUM> acquired by the magnetic field measurement control unit <NUM>. The magnetic field measurement control unit <NUM> detects the plurality of magnetic fields MF generated by the plurality of generation coils <NUM> by the plurality of detection coils <NUM> and acquires the magnetic field measurement data <NUM> including the plurality of magnetic field measurement results output from the detection coils <NUM>.

In <FIG>, (<NUM>) to (<NUM>) are data strings showing the magnetic field measurement results of the plurality of detection coils <NUM> with respect to the magnetic fields MF generated by the generation coils <NUM>, respectively. For example, "D11" is a magnetic field measurement result in which the magnetic field MF generated by the first generation coil <NUM> is detected by the first detection coil <NUM>. "D12" is a magnetic field measurement result in which the magnetic field MF generated by the first generation coil <NUM> is detected by the "second detection coil". Similarly, "D42" is a magnetic field measurement result in which the magnetic field MF generated by the fourth generation coil <NUM> is detected by the second detection coil <NUM>. "D43" is a magnetic field measurement result in which the magnetic field MF generated by the fourth generation coil <NUM> is detected by the third detection coil <NUM>.

The magnetic field measurement control unit <NUM> sequentially acquires the magnetic field measurement results of the detection coils <NUM> while synchronizing with a magnetic field generation timing of each generation coil <NUM> in the magnetic field generator <NUM>. The magnetic field measurement control unit <NUM> acquires, for example, the magnetic field measurement results of all of the detection coils <NUM> for the magnetic fields MF of all of the generation coils <NUM> in one magnetic field measurement period defined by a synchronization signal described below. As a result, the magnetic field measurement control unit <NUM> acquires the magnetic field measurement data <NUM> including the plurality of magnetic field measurement results relating to all of combinations of the generation coils <NUM> and the detection coils <NUM> in one magnetic field measurement period.

For example, in a case in which <NUM> generation coils <NUM> are provided in the magnetic field generator <NUM> and <NUM> detection coils <NUM> are provided in the insertion part <NUM>, <NUM> magnetic field measurement results are obtained for each generation coil <NUM>. Therefore, the magnetic field measurement control unit <NUM> acquires the magnetic field measurement data <NUM> including a total of <NUM> × <NUM> = <NUM> magnetic field measurement results in one magnetic field measurement period. The magnetic field measurement data <NUM> including the plurality of magnetic field measurement results relating to all of such combinations is referred to as total magnetic field measurement data. In the present embodiment, unless otherwise specified, the magnetic field measurement data <NUM> shall include the total magnetic field measurement data.

As shown in <FIG>, the image signal output unit <NUM> adds a frame start signal VD to each of the plurality of frame image signals <NUM> sequentially input from the signal processing unit <NUM>, and outputs the frame image signal <NUM>. In <FIG>, "frame <NUM>", "frame <NUM>", "frame <NUM>". are frame numbers indicating output order of the plurality of frame image signals <NUM>, which are shown for convenience. The frame start signal VD is a vertical synchronization signal, for example.

Moreover, the image signal output unit <NUM> adds the magnetic field measurement data <NUM> to the frame image signal <NUM> and outputs the frame image signal <NUM>. That is, the frame start signal VD and the magnetic field measurement data <NUM> are included in all of the frame image signals <NUM> output by the image signal output unit <NUM>. As shown in <FIG>, the magnetic field measurement data <NUM> is added to a signal invalid region ND between the frame image signals <NUM>, which corresponds to a blanking time of the imaging element <NUM>. The blanking time is a vertical blanking period, for example. As described above, the frame start signal VD is also the signal included in the vertical blanking period of the plurality of frame image signals <NUM>.

In <FIG>, the image signal output unit <NUM> outputs the frame image signal <NUM> to the LD <NUM> described above via the signal cable <NUM>. The LD <NUM> transmits the optical signal obtained by converting the frame image signal <NUM> into the optical signal to the PD <NUM> of the light source device <NUM>.

As described above, the image signal output unit <NUM> outputs the frame image signal <NUM> acquired from the imaging element <NUM> via the signal processing unit <NUM> to the outside of the endoscope <NUM>. In addition, by using the frame start signal VD included in the frame image signal <NUM> as the synchronization signal, the image signal output unit <NUM> functions as a synchronization signal generation unit.

The light source device <NUM> includes an illumination light source <NUM>, the PD <NUM>, a light source control unit <NUM>, a signal relay unit <NUM>, and a communication interface <NUM>. The illumination light source <NUM> is configured to include a semiconductor light source, such as the laser diode (LD) or a light emitting diode (LED), and is a white light source which emits white light having a wavelength range from a red region to a blue region as the illumination light. Note that, as the illumination light source <NUM>, in addition to the white light source, a special light source that emits special light, such as purple light and infrared light, may be used. The illumination light emitted from the illumination light source <NUM> is incident on the incident end of the light guide <NUM> described above.

The light source control unit <NUM> is configured to include various arithmetic circuits including the CPU and various memories, and controls the operation of each unit of the light source device <NUM>, such as the illumination light source <NUM>.

The PD <NUM> receives the optical signal transmitted from the LD <NUM>. The PD <NUM> converts the frame image signal <NUM> received in the form of the optical signal into the form of the original electric signal, and inputs the converted frame image signal <NUM> to the signal relay unit <NUM>. The signal relay unit <NUM> is configured by, for example, a field programmable gate array (FPGA). The FPGA is a processor of which a circuit configuration can be changed after manufacturing, and the circuit configuration includes various arithmetic circuits and various memory circuits.

The navigation device <NUM> includes an image signal acquisition unit <NUM>, an insertion state detection unit <NUM>, a magnetic field generation control unit <NUM>, a display output unit <NUM>, and an image generation unit <NUM>. Each unit of the navigation device <NUM> is configured by various arithmetic circuits (not shown) including one or a plurality of CPUs, and is operated by executing a control program stored in a memory (not shown).

The image signal acquisition unit <NUM> acquires the frame image signal <NUM> from the signal relay unit <NUM> via the communication interface <NUM>. Further, the image signal acquisition unit <NUM> outputs the acquired frame image signal <NUM> to the display output unit <NUM>.

In addition, the image signal acquisition unit <NUM> extracts the frame start signal VD and the magnetic field measurement data <NUM> included in the frame image signal <NUM>, and outputs the extracted frame start signal VD and the magnetic field measurement data <NUM> to the insertion state detection unit <NUM>. In addition, the image signal acquisition unit <NUM> extracts the frame start signal VD from the frame image signal <NUM>, and outputs the extracted frame start signal VD to the magnetic field generation control unit <NUM>.

The insertion state detection unit <NUM> detects the insertion state of the insertion part <NUM> of the endoscope <NUM> inserted into the body of the subject H based on the frame start signal VD and the magnetic field measurement data <NUM> acquired from the image signal acquisition unit <NUM>. The insertion state detection unit <NUM> includes a position detection unit <NUM> and an insertion part shape detection unit <NUM>.

The position detection unit <NUM> detects a position of each detection coil <NUM> based on the frame start signal VD and the magnetic field measurement data <NUM>. A determination unit 72A is provided in the position detection unit <NUM>.

As shown in <FIG>, the determination unit 72A determines the plurality of magnetic field measurement results included in the magnetic field measurement data <NUM> with reference to a correspondence relationship <NUM>. The correspondence relationship <NUM> is information indicating storage order of the plurality of magnetic field measurement results corresponding to a plurality of combinations of the generation coils <NUM> and the detection coils <NUM> included in the magnetic field measurement data <NUM>. The determination unit 72A determines which combination of each generation coil <NUM> and each detection coil <NUM> corresponds to each magnetic field measurement result included in the magnetic field measurement data <NUM> based on the correspondence relationship <NUM>.

Specifically, as will be described below, in the magnetic field measurement, generation order in which the generation coils <NUM> generate the magnetic field MF with the frame start signal VD as a reference and acquisition order of the magnetic field measurement results of the detection coils <NUM> for the magnetic field MF of one generation coil <NUM> are decided. The plurality of magnetic field measurement results corresponding to the combinations of the generation coils <NUM> and the detection coils <NUM> are stored in the magnetic field measurement data <NUM> depending on the generation order and the acquisition order. Therefore, the determination unit 72A can determine which combination of the plurality of magnetic field measurement results included in the magnetic field measurement data <NUM> (for example, "D11", "D12", "D13",. ) corresponds to each magnetic field measurement result by referring to the correspondence relationship <NUM> that defines the storage order with the frame start signal VD as a reference.

The position detection unit <NUM> detects, as coil position data, the position of each detection coil <NUM>, specifically, the three-dimension coordinate position based on the plurality of magnetic field measurement results determined by the determination unit 72A. The coil position data is a relative position with the magnetic field generator <NUM> as a reference. In <FIG>, for example, P1 indicates the three-dimension coordinate position (here, x1, y1, z1) of the first detection coil <NUM>. The same applies to P2, P3, P4, and the like.

In <FIG>, the position detection unit <NUM> outputs coil position data <NUM> to the insertion part shape detection unit <NUM>. The insertion part shape detection unit <NUM> detects the shape of the insertion part <NUM> in the body of the subject H based on the coil position data <NUM> input from the position detection unit <NUM>.

<FIG> is an explanatory diagram for describing an example of a shape detection process of the insertion part <NUM> by the insertion part shape detection unit <NUM>. As shown in <FIG>, the insertion part shape detection unit <NUM> performs an interpolation process of performing interpolation on each position with a curve based on the position (here, P1, P2,. ) of each detection coil <NUM> indicated by the coil position data <NUM>, derives a central axis C of the insertion part <NUM>, generates insertion part shape data <NUM> showing the shape of the insertion part <NUM>. The interpolation process of performing interpolation with a curve is, for example, Bezier curve interpolation. The insertion part shape data <NUM> includes a distal end position PT of the distal end part <NUM> of the insertion part <NUM>.

In <FIG>, the insertion part shape detection unit <NUM> outputs the insertion part shape data <NUM> to the image generation unit <NUM>. The insertion state detection unit <NUM> repeatedly performs a determination process by the determination unit 72A, a position detection process of detecting the coil position data <NUM> of each detection coil <NUM>, a shape detection process of the insertion part <NUM>, and an output of the insertion part shape data <NUM> each time the image signal acquisition unit <NUM> acquires new frame image signal <NUM>.

The image generation unit <NUM> generates the shape display image <NUM> based on the insertion part shape data <NUM>. As shown in <FIG>, a modeling unit 77A and a rendering unit 77B are provided in the image generation unit <NUM>. As will be described in detail below, in the image generation unit <NUM>, the modeling unit 77A generates a <NUM> dimension (D) model of the insertion part <NUM> based on the insertion part shape data <NUM>, and the rendering unit 77B performs a rendering process on the 3D model of the insertion part <NUM>, so that the <NUM> dimension (D) shape display image <NUM> showing the shape of the insertion part <NUM> is generated. The image generation unit <NUM> outputs data of the generated shape display image <NUM> to the processor device <NUM>.

The image generation unit <NUM> updates the shape display image <NUM> each time new insertion part shape data <NUM> is input. Further, the image generation unit <NUM> outputs the updated data of the shape display image <NUM> to the processor device <NUM> each time the shape display image <NUM> is updated.

The navigation device <NUM> is an example of an endoscope shape display control device according to the technology of the present disclosure that performs a display control of the shape display image <NUM>. As described above, the magnetic field measurement data <NUM> is data obtained by using the plurality of detection coils <NUM> which are an example of a plurality of magnetic field detection elements according to the technology of the present disclosure provided in the insertion part <NUM> of the endoscope <NUM>. The insertion part shape data <NUM> is information based on the magnetic field measurement data <NUM>, and is an example of information according to the technology of the present disclosure for imaging the shape of the insertion part <NUM> of the endoscope <NUM> inserted in the subject H, which is an example of the subject. The image generation unit <NUM> generates the shape display image <NUM> obtained by imaging the shape of the insertion part <NUM> based on the insertion part shape data <NUM>. That is, the image generation unit <NUM> is an example of an image generation unit according to the technology of the present disclosure, and is also an example of an information acquisition unit that acquires the information for imaging the shape of the insertion part.

The display output unit <NUM> outputs the frame image signal <NUM> previously input from the image signal acquisition unit <NUM> described above and the data of the shape display image <NUM> input from the image generation unit <NUM> to the processor device <NUM> via communication interfaces 80A and 80B. In this case, the display output unit <NUM> associates the frame image signal <NUM> with the data of the shape display image <NUM> that corresponds in time with the frame image signal <NUM>, and outputs the data to the processor device <NUM>.

The processor device <NUM> has a display input unit <NUM> and a display control unit <NUM>. The display input unit <NUM> sequentially outputs, to the display control unit <NUM>, the data of the frame image signal <NUM> and the shape display image <NUM> sequentially input from the display output unit <NUM> via the communication interfaces 80A and 80B.

The display control unit <NUM> receives the input of the frame image signal <NUM> from the display input unit <NUM>, and displays the observation image <NUM> (for example, the motion picture) based on the frame image signal <NUM> on the monitor <NUM> (see <FIG> and <FIG>). In addition, the display control unit <NUM> receives input of the data of the shape display image <NUM> from the display input unit <NUM> and displays the shape display image <NUM> (for example, the motion picture) on the monitor <NUM> (see <FIG> and <FIG>).

<FIG> is a flowchart for describing a flow of a generation process of the shape display image <NUM> by the image generation unit <NUM>.

The image generation unit <NUM> acquires the insertion part shape data (step S1). In the image generation unit <NUM>, the modeling unit 77A performs a modeling process of generating the 3D model of the insertion part <NUM> based on the insertion part shape data <NUM> (step S2).

As shown in <FIG>, in the modeling process, a cylindrical 3D model M having a diameter corresponding to a display scale of the insertion part <NUM> with the central axis C of the insertion part <NUM> in the insertion part shape data <NUM> as a central axis is generated.

Next, the rendering unit 77B executes a light source position setting process of setting the light source position in a case of rendering the 3D model M of the insertion part <NUM> (step S3). The light source position is set to a position with respect to the upper surface 16A of the bed <NUM> at which the light is emitted from an upper side in a virtual space in which the 3D model M is generated. Specifically, in a real space, in a case in which the magnetic field generator <NUM> and the bed <NUM> are installed on the same floor surface, a horizontal direction of the magnetic field generator <NUM> and the upper surface 16A of the bed <NUM> are in a parallel relationship. Therefore, in the virtual space, a plane parallel to the upper surface 16A of the bed <NUM> is set as an X-Y plane, and a Z-axis orthogonal to the X-Y plane is set. Further, in the virtual space, the light source position is set such that the light is emitted from an upper side of the set Z-axis to a lower side thereof.

Next, the rendering unit 77B executes a camera position setting process of setting a camera position (also referred to as a viewpoint position) in a case of rendering the 3D model M of the insertion part <NUM> (step S4). The camera position is set to a position with respect to the upper surface 16A of the bed <NUM> in the virtual space in which the 3D model M of the insertion part <NUM> is observed from the upper side of the Z-axis in the same manner as the light source position.

Next, the rendering unit 77B executes a texture setting process of finishing a surface of the 3D model M in a case of rendering the 3D model M of the insertion part <NUM> (step S5). In the texture setting process, a process of adding a pattern, which is a content of the texture, is performed on the surface of the insertion part <NUM>. Here, the pattern refers to a display aspect other than a plain single color. The pattern of the present embodiment is a gradation that is changed continuously from green to blue from the distal end side to the proximal end side of the insertion part <NUM>.

The definition of color will be described using a hue circle of a Munsell display system shown in <FIG>. The hue circle represents the classification of tint of chromatic color. For example, it is a Munsell hue circle divided into <NUM> colors. In <FIG>, symbols means red (R), yellow-red (YR), yellow (Y), green-yellow (GY), green (G), blue-green (BG), blue (B), purple-blue (PB), purple (P), and red purple (RP), respectively. In the hue circle shown in <FIG>, hues obtained by further dividing each of these <NUM> types of hues into two (for example, 5R and 10R for R) are displayed.

The green includes green-yellow (GY) and blue-green (BG) that are adjacent to each other on the right and left of green (G) in the hue circle. In the hue circle of <FIG>, colors from <NUM> GY to <NUM> BG correspond to green. Blue includes blue-green (BG) and purple-blue (PB) that are adjacent to each other on the right and left of blue (B) in the hue circle. In the hue circle of <FIG>, the colors from 5BG to 10PB correspond to blue. As described above, in the hue circle, green refers to a color containing a G element, and blue refers to a color containing a B element. The same applies to the definitions of other colors, such as red and yellow.

Finally, the rendering unit 77B adds a gradation pattern to the surface of the 3D model M based on the set light source position and the set camera position. In addition, the surface of the 3D model M added with the pattern is subjected to a shading process of performing shading corresponding to the light source. As described above, the rendering unit 77B performs the rendering process of generating the 2D shape display image <NUM> showing the shape of the insertion part <NUM> (step S6).

As a result, the shape display image <NUM> is generated, as shown in <FIG>. The shape display image <NUM> is configured to include an image showing the insertion part <NUM> and an image, which is a background thereof. In the following, the insertion part <NUM> in the shape display image <NUM>, or more accurately, the image of the insertion part <NUM> in the shape display image <NUM>, is simply referred to as the insertion part for simplification, and for distinguish from the actual insertion part <NUM>, a reference numeral <NUM> is added and is referred to as an insertion part <NUM> In the shape display image <NUM>, the surface of the insertion part <NUM> is displayed in the display aspect in which the gradation that is changed continuously from green to blue is added from the distal end side to the proximal end side of the insertion part <NUM>.

The generation process of the shape display image <NUM> is repeated each time the insertion part shape data <NUM> is updated.

In the large intestine examination, since a route of the large intestine is complicated, the insertion part <NUM> of the endoscope <NUM> may be bent in a loop shape in the body of the subject H. In this case, different portions of the insertion part <NUM> intersect with each other in the shape display image <NUM> depending on the camera position set in the rendering process.

In addition, depending on the display magnification of the shape display image <NUM>, the insertion part <NUM> may be displayed in a thin line shape in the shape display image <NUM>. Therefore, in a case in which the entire insertion part <NUM> is displayed in a plain single color (for example, black), there is a problem that it is difficult for a user to instantaneously determine the front and rear of an intersection portion 17GX even in a case in which the intersection portion 17GX shown in <FIG> is subjected to a shade line process or a hidden surface process.

On the other hand, in the endoscope system <NUM> according to the present disclosure, as described above, in the shape display image <NUM>, the insertion part <NUM> is displayed by being added with the gradation pattern which is changed continuously from green to blue from the distal end side to the proximal end side of the insertion part <NUM> As a result, the color of the insertion part <NUM> is different between the front and rear of the intersection portion 17GX, so that it is possible to easily determine the front and rear of the intersection portion 17GX. As described above, according to the technology of the present disclosure, it is easy to visually recognize an overlapping condition of the insertion parts <NUM> in the shape display image <NUM>.

In the present embodiment, the gradation pattern is added to the entire region of the insertion part <NUM> displayed on the shape display image <NUM>. Therefore, no matter where in the entire region of the displayed insertion part <NUM> is the intersection portion 17GX, it is possible to easily determine the front and rear of the intersection portion 17GX.

Note that in the present embodiment, the entire region of the displayed insertion part <NUM> is added with the gradation pattern, but the entire region does not necessarily have to be added with the gradation pattern. In a case in which the intersection portion 17GX is hardly generated on the distal end side and the proximal end side, it is not necessary to add the gradation pattern to a partial region of the distal end side and the proximal end side. For example, in the entire region of the insertion part <NUM> displayed on the shape display image <NUM>, a region having a length of <NUM>% from the distal end and a region having a length of <NUM>% from the proximal end may be used as regions without the gradation pattern.

In addition, by making the pattern added to the insertion part <NUM> the gradation pattern in which the color is changed continuously from the distal end side to the proximal end side of the insertion part <NUM>, the image can be more natural than a case in which the color is changed stepwise.

In addition, by displaying the insertion part <NUM> in the display aspect of the gradation that is changed continuously from green to blue, which is a combination of cold colors, the effect of suppressing irritation to the eyes can be expected as compared with a case in which the insertion part <NUM> is displayed by colors of a warm color system, such as red, orange, and yellow.

The embodiment described above is an example, and various modification examples are possible as shown below.

In the embodiment described above, the gradation that is changed from green to blue has been described as an example of the gradation, but a combination of a plurality of changing colors may be other than the colors of the example described above. For example, it may be a gradation that is changed from red to orange. In addition, the color of the gradation may be changed in accordance with the user's setting.

In the embodiment described above, the gradation pattern in which the color is changed continuously has been described as the pattern to be added to the surface of the insertion part <NUM> in the shape display image <NUM>, but the pattern may be other than the gradation.

In a case in which the surface of the insertion part <NUM> is displayed by being added with the pattern, it is possible to easily determine the front and rear of the intersection portion 17GX as compared with a case in which the surface of the insertion part <NUM> is displayed in a plain single color.

For example, as shown in <FIG>, the gradation pattern does not have to be an aspect in which the color is changed continuously, but an aspect in which the color is changed stepwise may be adopted.

In a shape display image 42A shown in <FIG>, the surface of the insertion part <NUM> is added with the gradation pattern that is changed stepwise to a different color from the distal end side to the proximal end side. Even in a case in which the color is not changed continuously, the colors of the insertion part <NUM> have different color scheme in the front and rear the intersection portion 17GX, so that it is possible to easily determine the front and rear of the intersection portion 17GX. It is needless to say that the gradation in which the color is changed continuously is preferable in that the color change is natural and the appearance is good.

In addition, the pattern may be a pattern other than the gradation, and may be a pattern in which a plurality of colors are combined. Here, a plurality of colors means, for example, a combination of colors in which at least one of lightness, chroma saturation, or hue is different from each other.

<FIG> shows a shape display image 42B according to a non-claimed example, wherein the pattern may be a vertical stripe pattern of a plurality of colors which extends in the longitudinal direction of the insertion part <NUM>. Even in this example, since the vertical stripes intersect with each other in the front and rear of the intersection portion 17GX, it is possible to easily determine the front and rear of the intersection portion 17GX.

<FIG> shows a shape display image 42C according to a non-claimed example, wherein the pattern may be a horizontal stripe pattern added in a ring shape around an axis of the insertion part <NUM>. Even in this example, since the horizontal stripes intersect with each other in the front and rear of the intersection portion 17GX, it is possible to easily determine the front and rear of the intersection portion 17GX.

Such a vertical stripe pattern and such a horizontal stripe pattern may be constituted by pinstripes, or the vertical stripe pattern and the horizontal stripe pattern may be constituted by a plurality of strip-shaped stripes having a width and the plurality of stripes are color-coded with different colors.

According to a non-claimed example, a wire frame pattern may be used as in a shape display image 42D shown in <FIG>. Note that the wire frame expresses a three-dimension object by connecting a plurality of points having three-dimension coordinates in accordance with a certain rule. The wire frame pattern is a display aspect in which the wire frame is displayed as the pattern on the surface of the insertion part <NUM>. Even with such a pattern, the same effect as in the example described above can be obtained.

In the embodiment described above, regarding the light source position and the camera position in a case of performing the rendering process, a case will be described in which, in a case in which the plane parallel to the upper surface 16A of the bed <NUM> is defined as the X-Y plane, a light irradiation direction and a viewpoint direction are set to a state of being from the upper side of the Z-axis to the lower side thereof. However, the light source position and the camera position are not limited to the above, and may be set in any direction based on an instruction input of the user. Examples of the direction in which the viewpoint direction is from the upper side of the Z-axis of the bed <NUM> to the lower side thereof include the following two directions. One direction is the viewpoint of observing the upper surface 16A of the bed <NUM> from directly above the bed <NUM>, that is, from a normal direction to the X-Y plane. The other direction is a viewpoint of a bird's-eye view of the upper surface 16A of the bed <NUM> from an oblique direction of the bed <NUM>. In addition to these, there may be an observation viewpoint on a side of the bed <NUM>, that is, parallel to the X-Y plane. In addition, a plurality of viewpoints may be switched and parallel viewpoints may be set.

In addition, in the embodiment described above, the example has been described in which each generation coil <NUM> generates the magnetic field MF having the same frequency, but the frequencies of the magnetic fields MF generated by the generation coils <NUM> may be different.

In addition, in the embodiment described above, the example has been described in which the magnetic field measurement unit including the magnetic field measurement control unit <NUM> is disposed in the endoscope <NUM> and the magnetic field generation control unit <NUM> is disposed in the navigation device <NUM>, on the contrary, the magnetic field generation control unit <NUM> may be disposed in the endoscope <NUM>, and the magnetic field measurement unit may be disposed in the navigation device <NUM>.

In the embodiment described above, for example, as a hardware structure of the processing unit that executes various processes, such as the image generation unit <NUM> which is an example of the information acquisition unit and the image generation unit, various processors in the following can be used. The various processors include the central processing unit (CPU) that is a general-purpose processor executing the software and functioning as the various processing units, as well as a programmable logic device (PLD) that is a processor of which a circuit configuration can be changed after manufacture, such as a field programmable gate array (FPGA) and/or a dedicated electric circuit that is a processor having a circuit configuration that is designed for exclusive use in order to execute a specific process, such as an application specific integrated circuit (ASIC).

One processing unit may be configured by one of the various processors, or may be a combination of two or more processors of the same type or different types (for example, a combination of a plurality of FPGAs and/or a combination of a CPU and an FPGA). In this way, as the hardware structure, various processing units are configured by one or more of various processors described above.

Moreover, as the hardware structure of these various processors, more specifically, it is possible to use an electrical circuit (circuitry) in which circuit elements such as semiconductor elements are combined.

An endoscope display control device having the information acquisition unit and the image generation unit may be realized by the computer of which the processor is the CPU.

A program for causing the CPU to function as the information acquisition unit and the image generation unit is an operation program of the endoscope display control device. The technology of the present disclosure extends to a computer-readable storage medium that stores the operation program non-transitorily, in addition to the operation program of the endoscope display control device.

In the present specification, "A and/or B" is synonymous with "at least one of A or B". That is, "A and/or B" means that it may be only A, only B, or a combination of A and B. In addition, in the present specification, in a case in which three or more matters are associated and expressed by "and/or", the same concept as "A and/or B" is applied.

Claim 1:
An endoscope shape display control device comprising:
at least one processor (<NUM>),
wherein the at least one processor (<NUM>) is configured
to acquire information detected by a navigation device (<NUM>) for imaging a shape of an insertion part (<NUM>) of an endoscope (<NUM>) inserted in a subject (H), and
to display on a monitor (<NUM>), in a case of generating a shape display image (<NUM>) in which the shape of the insertion part (<NUM>) is displayed based on the acquired information, the insertion part (<NUM>) with a pattern added on a surface thereof in the shape display image,
wherein the pattern is a gradation in which a color is changed continuously or stepwise from one of a distal end side or a proximal end side of the insertion part (<NUM>) to the other thereof, and
wherein the gradation is changed from green to blue.