Vascular model observation device and method

Abstract

Provided are an observation device and an observation method with which it is possible to simultaneously observe a fluoroscopic image of a catheter inserted into a blood vessel model and the blood vessel model itself without using X-rays. A blood vessel model observation device for observing the shape of a blood vessel model and a catheter inserted into the blood vessel model, in which a substance having near-infrared absorption characteristics different from those of a constituent material of the blood vessel model is disposed inside the blood vessel model, and the catheter is provided with a sheath tube and a wire inserted into the sheath tube. The blood vessel model observation device is provided with a light source that emits near-infrared rays, a light quantity adjustment device that adjusts the light quantity of the near-infrared rays, a camera, and a display that displays an image captured by the camera.

Description

Technical Field

[0001] The present invention relates to an apparatus and a method for observing a blood vessel model and a catheter inserted into the blood vessel model. Background Art

[0002] In the evaluation of a catheter inserted into a blood vessel, or in the technical training or technical evaluation of intravascular surgery, it is necessary to observe the shape of a blood vessel model (hereinafter referred to as "blood vessel shape") and the state of the catheter inserted into the blood vessel model.

[0003] In order to observe the shape of a blood vessel and the state of a catheter inserted into a blood vessel model, a visible light camera or an X-ray projection device is often used in addition to direct observation by visual inspection.

[0004] The method of forming the vascular model from a transparent material and filling the inner cavity of the vascular model (hereinafter referred to as the "inner cavity area") with a colored liquid such as a pigment to visually or through a visible light camera to observe the shape of the blood vessel and the catheter inserted into the vascular model is simple and convenient. However, in this case, since the catheter cannot be seen through, the position and state of the guide wire constituting the catheter cannot be confirmed, so the reproducibility of the intravascular surgery is low. If X-rays are used, this problem is solved, but it is not easy to use from the perspective of radiation or management.

[0005] Generally, a catheter is a multi-layer structure in which wires (materials with therapeutic functions such as microbeads, coils, and stents, drugs (liquids such as contrast agents or thrombolytic agents, and other sheaths) are inserted into a thin cylindrical sheath. During observation using visible light, the front end position and status of the wires inserted in a multi-layer manner inside the sheath cannot be detected.

[0006] In actual treatment using a catheter, information on the position and status of the tip of the wire in the sheath is required. In addition, in practical catheters, in order to clearly indicate the specific positions of the sheath and wire, materials that do not allow X-rays to pass through (X-ray opaque markers) are attached to the tip and middle parts of the catheters, so that the relative positions of each can be confirmed in an X-ray projection device used in treatment.

[0007] In order to observe the tip position and state of the wires in the sheath while avoiding X-ray radiation, an observation method combining fluorescence observation technology and image processing technology has been proposed (Non-Patent Document 1). In addition, Patent Document 1 proposes a lubricating fluid that ensures lubricity between the blood vessel model and the catheter.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: Japanese Patent No. 5992031

[0011] Non-patent literature

[0012] Non-patent document 1: Fukasaku Kazuaki et al., "Development of an intravascular therapy simulation that enables endovascular therapy training anytime and anywhere without exposing physicians to X-ray radiation," [online], February 19, 2022, 51st Meeting of the Japanese Society of Neuroradiology https: / / www.u-ryukyu.ac.jp / news / 32074 / Summary of the invention

[0013] Problem that the invention aims to solve

[0014] According to the observation method described in Non-Patent Document 1, it is necessary to attach fluorescent materials to the sheath tube of the catheter and the wire portion to be visualized. In other words, the actual catheter cannot be used as it is.

[0015] Furthermore, in order to visualize the blood vessel model, it is necessary to introduce a contrast medium (a liquid containing a fluorescent dye) into the liquid filling the inner cavity region of the blood vessel model.

[0016] For example, when the blood vessel model is formed of a gel material such as polyvinyl alcohol, the contrast agent may seep into the blood vessel model forming material or be fixed to the inner surface of the blood vessel model, and thus it is difficult to withstand long-term use.

[0017] On the other hand, when the vascular model is formed of a cross-linked polymer material such as silicone rubber, in order to ensure the lubricity of the catheter and the vascular model, the lumen of the vascular model needs to be filled with a lubricating liquid (see Patent Document 1). When the contrast agent is mixed with the lubricating liquid, there is a risk that the lubricating function of the lubricating liquid will be reduced.

[0018] Means used to solve problems

[0019] The inventors of the present invention have repeatedly conducted intensive research to solve the above problems and have found that by using near infrared rays, which have a higher material permeability than visible light and whose light absorptivity varies in accordance with the material or wavelength compared to visible light, the shape of the blood vessels and the state inside the catheter can be visualized simultaneously or selectively without using contrast agents or the like. That is, there is no need to attach contrast agents or fluorescent materials required in the prior art to the sheath or wire of the catheter. The near infrared absorptivity varies in various ways depending on the type of substance and the wavelength of the near infrared used. Based on this characteristic, in near infrared spectroscopy, the change in absorptivity in the near infrared region is measured, and the composition of the substance is determined by comparing it with a spectrum table showing the measurement results and the absorption characteristics. In addition, in many substances, the absorptivity varies greatly in the visible light region and the near infrared region. According to the characteristics of near infrared rays, liquids containing pigments that appear opaque in the visible light region are observed as transparent in the near infrared region, or various soft polymers such as silicone rubber, various hard polymers such as acrylic resins, various liquids such as water or oil that appear transparent in the visible light region are observed as different colors (shades) in the near infrared region without using contrast agents, etc. (hereinafter referred to as "near infrared spectroscopic observation"). Furthermore, since the near infrared absorption rate (i.e., near infrared transmittance) of each substance changes in various ways in the near infrared region by changing the wavelength, it is possible to identify the differences in shape and material of each part of a composite structure composed of different substances by utilizing this characteristic.

[0020] The inventors have found that by performing near-infrared spectroscopic observation based on the characteristics of the near-infrared rays, it is possible to make each part of a blood vessel model that appears transparent both inside and outside in the visible light region different colors (shades) without using a contrast agent, and observe it as an image that can distinguish the difference in shape and material. It has also been found that by changing the wavelength and light amount of the near-infrared rays used (the intensity of the light source or the exposure setting of the observation device), the balance of the shades of each part of the blood vessel model can be changed without applying physical operations to the observation object. In addition, the inventors have found that by similarly changing the wavelength and light amount of the near-infrared rays, the blood vessel shape can be selectively visualized or disappeared while the perspective image of the catheter is visualized on the observation screen.

[0021] On the other hand, near-infrared rays, like X-rays, have the property of easily penetrating various materials, so they can perform perspective observation of objects (hereinafter referred to as "near-infrared perspective observation"). As a method that is simpler and safer than X-ray observation, it is used for non-destructive inspection of semiconductors, foreign body inspection in liquids, etc. In observation based on visible light, the vascular model is observed three-dimensionally (3D), but according to near-infrared perspective observation, due to its transmittance, a flat (2D) image like a movie is obtained. The above-mentioned flat (2D) image is close to the X-ray perspective image obtained by catheter intravascular surgery, and is preferred in reproducing the simulation of the same surgery. Furthermore, when the various parts included in the vascular model are crossed three-dimensionally, that is, in a front-to-back manner along the irradiation direction of the near-infrared rays, a flat (2D) perspective image similar to the X-ray observation image can also be obtained.

[0022] The real catheter has a thin film-like multilayer structure as a common feature, but the constituent material of the sheath and its film thickness vary depending on the type (various soft resins such as polyester, polyethylene, polyamide (nylon), polyurethane, and silicone rubber are used as the constituent material of the sheath). In addition, metal structures such as screens, X-ray opaque markers, and mechanical structures such as microbeads or coil detachment mechanisms are complexly loaded into the catheter or wire. For the catheter having the above characteristics, the inventors have found that by performing two side-introduced observations, namely near-infrared fluoroscopic observation and near-infrared spectroscopic observation, the catheter can be reproduced as an image close to the X-ray observation image during the actual operation, and further as a functionally expanded observation image containing information that cannot be obtained through X-ray observation.

[0023] By using near infrared rays, it is possible to observe the catheter through the catheter, and to obtain an observation image in which even the differences in structure and material can be identified. Furthermore, by changing the wavelength and light amount of the near infrared rays used, the light-darkness balance of the observation image can be changed without physically operating the blood vessel model. For example, a specific area of ​​the blood vessel model to be observed can be selected, and the light-darkness balance of the selected specific area can be changed or reversed, so that the specific area can be visualized or disappeared.

[0024] A first aspect of the invention is defined as follows.

[0025] An observation device is provided for observing a blood vessel model in which a catheter is inserted, wherein a substance having near-infrared absorption characteristics different from the constituent material of the blood vessel model is arranged inside the blood vessel model, and the catheter includes a sheath tube and a wire inserted into the sheath tube.

[0026] The observation device comprises: a first light source that emits a first near-infrared ray; a first light receiving unit that can receive the first near-infrared ray; a first image generating unit that generates a first image based on the first near-infrared ray captured by the first light receiving unit; and a display that displays the first image.

[0027] According to the blood vessel model observation device of the first aspect defined in this manner, since the substance disposed in the blood vessel model has near-infrared absorption specificity different from that of the constituent material of the blood vessel model, it is possible to visually confirm the boundary between the blood vessel wall cross-sectional area (hereinafter referred to as "wall cross-sectional area") of the blood vessel model and the substance in near-infrared spectroscopic observation. At this time, since the catheter inserted into the blood vessel model has a different transmittance to near-infrared rays than that of the constituent material of the blood vessel model and the substance, the catheter can be observed strictly distinguished from the blood vessel model and the substance.

[0028] A second aspect of the invention is defined as follows.

[0029] An observation method for an observation object, which is a method for observing an observation object using the observation device according to the first aspect, wherein:

[0030] The first light source emits the first near infrared ray toward the observation object, and the first light receiving unit receives the first near infrared ray after passing through the observation object.

[0031] causing the first image generating unit to generate the first image based on the first near infrared ray received by the first light receiving unit,

[0032] The first image is displayed on the display, and the light amount of the first near-infrared ray used for generating the first image is adjusted as needed, so that the sheath of the catheter, the wires in the sheath, and the blood vessel model can be visually confirmed at the same time.

[0033] The content that can be observed by strictly distinguishing the blood vessel model and the catheter inserted into the blood vessel model by near-infrared spectroscopic observation is as described in the first aspect. By adjusting the light amount of the first infrared ray used for generating the first image as needed, the perspective image of the catheter can be displayed together with the blood vessel model on the image of the display. That is, near-infrared perspective observation can be performed by adjusting the light amount of the near-infrared ray.

[0034] Here, as needed means that if the blood vessel model and the catheter constituting the observation object are standardized in advance, it is not necessary to adjust the light amount by adjusting the light amount in advance during observation (hereinafter, the same in this specification). Since it is a prerequisite for catheter simulation to be able to visually confirm the sheath of the catheter, the wires in the sheath, and the blood vessel model at the same time, the observation method of the blood vessel model specified in the second aspect is practical. It is also possible to selectively display only the outer contour image (non-perspective image) of the catheter on the image of the display by adjusting the light amount of near-infrared rays, selectively display only the outer contour image of the catheter and the image of the blood vessel model, the perspective image of the catheter, and selectively display only the blood vessel model.

[0035] In the above content, as an adjusting device for adjusting the amount of near-infrared light, it is possible to use an adjusting device that is attached to a near-infrared light source and adjusts the amount of near-infrared light released from the light source, an adjusting device that adjusts the aperture attached to a light receiving part such as a camera and focuses light for the camera, an adjusting device that processes the light amount of an image captured by a camera, etc.

[0036] The third aspect of the invention utilizes near-infrared reflection observation.

[0037] The reflection characteristics of near infrared rays differ depending on the material irradiated with the near infrared rays. For example, there is a difference in reflection characteristics between iron (stainless steel) and platinum.

[0038] Among the wires constituting the catheter, there are wires made of stainless steel with platinum attached as an X-ray opaque marker in the middle of the wire. Since stainless steel and platinum do not transmit near-infrared rays, near-infrared spectroscopic observation and near-infrared fluoroscopic observation are ineffective for these wires.

[0039] On the other hand, since stainless steel and platinum have different near-infrared reflection characteristics, by irradiating near-infrared rays from the second near-infrared light source and focusing the reflected light from the object (the wire with the platinum marker in the above example) to the light receiving part, the stainless steel as the base metal of the wire and the platinum as the marker can be strictly distinguished and observed. Moreover, this observation can be performed together with the near-infrared spectroscopic observation and near-infrared perspective observation described in the second aspect.

[0040] Therefore, the third aspect of the present invention is defined as follows. That is,

[0041] Based on the observation device defined in the first aspect, the observation device further comprises: a second light source that emits a second near-infrared ray; a second light receiving unit that can receive the second near-infrared ray; a second image generating unit that generates a second image based on the second near-infrared ray captured by the second light receiving unit; and an image synthesizing unit,

[0042] The image synthesis unit is caused to superimpose the first image and the second image to form a synthesized image, and the display is caused to display the synthesized image.

[0043] The observation method according to the observation device of the third aspect defined in this manner is as follows.

[0044] A method for observing an observation object, which is a method for observing an observation object using the observation device defined in the third aspect, wherein:

[0045] The first light source emits the first near infrared ray toward the observation object, and the first light receiving unit receives the first near infrared ray after passing through the observation object.

[0046] causing the first image generating unit to generate the first image based on the first near infrared rays received by the first light receiving unit, causing the second light source to emit the second near infrared rays toward the observation object, and causing the second light receiving unit to receive the second near infrared rays reflected by the observation object,

[0047] The second image generating unit generates the second image based on the second near infrared rays received by the second light receiving unit, the image synthesizing unit generates a synthesized image by overlapping the first image and the second image, and the display displays the synthesized image.

[0048] Here, by adjusting the amount of the first near-infrared light used for generating the first image as needed and / or adjusting the amount of the second near-infrared light used for generating the second image as needed, simultaneous visual confirmation of the sheath of the catheter, the wire type within the sheath, the X-ray opaque marker of the wire type, and the blood vessel model is achieved.

[0049] The observation device according to the fifth aspect of the present invention is defined as follows: That is, in addition to the observation device defined in the third aspect, the observation device comprises: a grayscale image generating unit that grayscales the first image and the second image; and

[0050] The image inverting unit inverts the grayscale of the grayscale image of the second image to generate the 2-1 image. The observation method of the observation device according to the fifth aspect defined in this manner is as follows.

[0051] An observation method of an observation object, which is an observation method using the observation device defined in the fifth aspect, wherein the grayscale image generating unit grayscales the first image and the second image,

[0052] The image inversion unit inverts the grayscale of the grayscaled second image to form a 2-1 image, and the image synthesis unit overlaps the grayscaled first image and the 2-1 image, and synthesizes them by calculating the value of each pixel of each image.

[0053] The observation device according to the seventh aspect of the present invention is defined as follows.

[0054] That is, based on the observation device specified in the fifth aspect,

[0055] The observation device also has:

[0056] a first polarizing unit, which polarizes the first near infrared ray in a first direction;

[0057] a second polarizing unit that polarizes the second near infrared ray in a second direction; and

[0058] A shell that accommodates the first light receiving unit and the second light receiving unit, wherein the first light receiving unit is capable of receiving the first near infrared rays polarized in the first direction, and the second light receiving unit is capable of receiving the second near infrared rays polarized in the second direction, so that the first image generating unit generates the first image based on the first near infrared rays polarized in the first direction, and the second image generating unit generates the second image based on the second near infrared rays polarized in the second direction.

[0059] The observation method of the observation device according to the seventh aspect defined in this manner is as follows.

[0060] A method for observing an observation object, which is a method for observing an observation object using the observation device defined in the seventh aspect, wherein:

[0061] causing the grayscale image generating unit to grayscale the first image and the second image,

[0062] The image inversion unit inverts the grayscale of the grayscaled second image to form a 2-1 image, and the image synthesis unit overlaps the grayscaled first image and the 2-1 image, and synthesizes them by calculating the value of each pixel of each image.

[0063] In the above, the near infrared rays from the first light source and the second light source can be near infrared rays of wavelengths other than 1300nm to 1550nm and having a small effect of water absorption. Since the amount of water through which the first near infrared rays from the first light source pass is different from the amount of water through which the second near infrared rays from the second light source pass, when using near infrared rays of wavelengths having a large effect of light absorption, it is difficult to clearly draw a transmission image based on the first light source and a reflection image based on the second light source at the same time.

[0064] The second light source is preferably formed of an LED having a wavelength of 1300 nm or less, which is easily available industrially and is less affected by water absorption.

[0065] In the above, monochromatic light is preferably used for the first near infrared ray and the second near infrared ray. The second near infrared ray is set at multiple positions and radiated toward the observation object from multiple directions, so that the visual confirmation of the X-ray non-transparent marker of the line type can be stably observed without relying on the position. It is also possible to simultaneously use a reflector and a half-reflector instead of setting multiple second near infrared rays. By using a reflector and a half-reflector, the setting position of the second near infrared ray can be reduced. In particular, when the observation object is observed in a state of being immersed in a liquid, when the second near infrared ray is radiated toward the observation object, it is difficult or impossible to irradiate from a specific direction due to reflection (including total reflection) / refraction by the surface of the liquid or the surface of the liquid storage container. In the above case, a reflector and a half-reflector can be set in the liquid and irradiated to the observation object on the basis of reflecting the second near infrared ray to avoid this problem. It is also possible to include a reflector and a half-reflector as part of the structure of the observation object including the blood vessel model regardless of whether it is immersed in the liquid. In addition to reducing restrictions on the installation position of the second near-infrared light source, it is also possible to provide functions such as adjustment of the polarization state (reversal of the polarization state, etc.).

[0066] For the second near infrared ray, a plurality of monochromatic lights with different wavelengths may also be used. In this case, these monochromatic lights are polarized in different states and released toward the observation object, and synthesized by the second light receiving unit or the image synthesizing unit through optical calculation or numerical calculation, so that the visual confirmation of the X-ray non-transparent marker of the line in the near infrared reflection observation can be improved.

[0067] In lamps that are near-infrared and have a wide wavelength (such as near-infrared lamps), it is necessary to adjust the chromatic aberration depending on the wavelength. By using a lens with a focus shift correction function in the near-infrared region, the focus of the lens can be set to the same position relative to different wavelengths. According to this method, it is no longer necessary to adjust the chromatic aberration according to the wavelength, which can simplify the structure of the machine and improve the operability during use. By using a polarizing camera that has a polarizing filter with a specific direction per pixel, the first light receiving unit and the second light receiving unit can be combined into one camera. According to this method, it is no longer necessary to adjust the relative position or magnification of the image, which can simplify the structure of the machine and improve the operability during use.

[0068] Here, the monochromatic near-infrared light also includes the near-infrared light emitted from the LED constituting the light source. Since the wavelength of the near-infrared light from the LED light source is based on the band gap of the LED, if there is a width in the band gap due to impurities contained in the LED, near-infrared light with a wavelength width corresponding to the width is emitted from the LED light source. The near-infrared light emitted from the near-infrared lamp can be monochromatized by passing through a filter that selects the wavelength to pass through. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Figure 1 This is a spectrum showing the absorption characteristics of water and silicone rubber to near infrared rays.

[0070] Figure 2 It is a schematic diagram showing the observation device of this invention.

[0071] exist Figure 3 3A shows an image observed under visible light, and 3B shows an image observed when using near-infrared light of 1450 nm.

[0072] Figure 4 This is a graph showing the relationship between particle radius, wavelength, and Rayleigh observation.

[0073] Figure 5 Observation images showing an embodiment of the present invention.

[0074] Figure 6 Indicates an observed image based on near-infrared reflection observation.

[0075] Figure 7 This is a block diagram showing an observation device according to another embodiment of the present invention.

[0076] Figure 8 Indicated in Figure 7 An example of a first image obtained based on a first near-infrared ray in a device.

[0077] Fig. 9 Indicated in Figure 7 An example of a second image obtained based on a second near-infrared ray in a device.

[0078] Fig.10 An example of the 2-1 image obtained by inverting the color tone of the 2nd image is shown.

[0079] Fig.11 This shows a composite image of the 1st image and the 2-1st image.

[0080] Fig.12 Express Fig.11 The image of the X-ray opaque marker is emphasized by performing density correction on the image.

[0081] Fig.13This is a block diagram showing an observation device according to another embodiment of the present invention.

[0082] Fig.14 Indicates from Fig.13 An example of an image output by the device. DETAILED DESCRIPTION

[0083] Near infrared generally refers to light with a wavelength of 780nm to 2500nm.

[0084] The absorption rate of near infrared rays varies depending on their wavelength and material (refer to Figure 1 ). It is known that the infrared absorption rate of water varies greatly depending on the wavelength in the near infrared region.

[0085] Since the inner cavity of the blood vessel model simulates blood, it is often filled with liquid. As the liquid, an aqueous solution in which a lubricating component is mixed with a liquid mainly composed of water like blood is generally used as needed. In order to simultaneously and effectively perform near-infrared fluoroscopic observation and near-infrared spectroscopic observation, 1450nm was selected as a wavelength at which the absorption rate of water is significantly high in the near-infrared region and is easily differentiated from the absorption rate of air, silicone rubber, etc., and observation of the blood vessel model and the catheter inserted into the blood vessel model was performed.

[0086] Figure 2 The structure of the observation device 10 is shown.

[0087] Reference numeral 1 in the figure indicates a catheter. The catheter 1 includes a sheath tube 2 and a wire 3 inserted into the sheath tube 2. Reference numeral 5 is a blood vessel model, and the inner cavity of the blood vessel model 5 is filled with a lubricating liquid 6. The lubricating liquid may be circulated to make it fluid. The periphery of the blood vessel model 5 is filled with an immersion liquid 7 that does not contain a lubricating component. The observation device 10 includes a first near-infrared light source 11, a light quantity adjustment device 13, a first near-infrared camera 15, and a display 17.

[0088] The blood vessel model is a silicone rubber blood vessel model provided by FAIN-Biomedical Co., Ltd., with a membrane thickness of 0.3mm to 3.0mm and an inner cavity of 1mm to 15mm. The inner cavity area of ​​the blood vessel model is filled with a lubricating liquid mixed with a lubricating component in water. The lubricating liquid is a substance with near-infrared absorption characteristics different from the constituent material of the blood vessel model.

[0089] As the catheter, an Excelsior microcatheter manufactured by Japan Stryker Co., Ltd. was used. As the wire, a GDC coil manufactured by Japan Stryker Co., Ltd. was used.

[0090] As the first near-infrared light source 11, an infrared illuminator (model: TH2-100X100IR145) manufactured by CCS Co., Ltd. was used. As the light quantity adjustment device 13, a power supply (model: PD-3024) having a function of adjusting the output of the light source 11, that is, the light quantity of the near-infrared rays emitted from the light source 11 was used. As the near-infrared camera 15, a near-infrared camera (model: ABA-013VIR) manufactured by Avaldata Co., Ltd. and a polarization camera (model: XCG-CP510) manufactured by Sony Corporation were used, and as the camera lens, near-infrared corresponding lenses (model: LM35HC-SW and model: LM35HC-VIS-SW) manufactured by Kowa Optronics Co., Ltd. were used.

[0091] like Figure 2 As shown in FIG. 1 , an observation object is set between the light source 11 and the camera 15. The light source 11 emits near infrared light with a wavelength of 1450 nm, and the light quantity is adjusted by the light quantity adjustment device 13. The near infrared light irradiated from the light source 11 to the blood vessel model 5 passes through the blood vessel model 5, is received by the camera 15, and the image is displayed on the display 17. In the above setting, the blood vessel model observed by the optical camera of visible light and the observation image of the catheter inserted into the blood vessel model are monochromatized as an image. Figure 3 (A) indicates. In addition, the light source 11 of 1450 nm (the light intensity is set to the maximum by the light intensity adjustment device attached to the light source) is used and the camera 15 (the aperture of the lens attached to the camera is set to F2.8) is used to observe Figure 3 (A) The blood vessel model and the observation image of the catheter inserted into the blood vessel model are shown in FIG. Figure 3 (B) indicates.

[0092] Can from Figure 3 (B) 6, 7, and 8 are used to observe the tip of the wires placed inside the catheter. According to the research of the inventors, by adjusting the light intensity, the metal mesh installed inside the catheter can also be observed through the perspective. Figure 3 (A) It cannot be confirmed in the visible light observation (reference numeral 3 is the appearance image of the X-ray opaque marker exposed on the surface of the sheath tube). In addition, the following can be understood from the comparison between reference numerals 10 and 5 in the same figure. In the observation based on visible light, the inner cavity area, wall section area and blood vessel surrounding area of ​​the blood vessel model appear to be the same color (transparent). In the observation based on near infrared rays, the above-mentioned areas can be clearly identified by shades.

[0093] As can be confirmed from the reference numeral 9 of the same figure, even when a plurality of vascular branches included in the vascular model intersect in three dimensions, the visual confirmation of both blood vessels is not reduced, and both can be clearly observed as a plane (2D) image. In the image based on visible light, as shown in the reference numeral 4, a part of the contour of the vascular lumen is visually confirmed, but this contour is not an image observed in the wall section area as shown in the reference numeral 9, but a reflection image generated by the reflection of ambient light on the surface of the lumen area and the outer surface of the vascular model. Since this reflection image is visually confirmed in three dimensions (3D), the visualization image of the vascular lumen visualized by this method is different from the plane (2D) image obtained by X-ray observation.

[0094] Since the reflected image appears as a light-dark distribution in the inner cavity region, the visibility of the inner cavity region is reduced, which is not preferable compared to the method of visualizing the wall cross-section region of the present invention.

[0095] In the method using visible light, a part or the entire blood vessel model appears three-dimensional (3D) due to reflection of ambient light, and all opaque observation objects including catheters and wires are observed three-dimensionally (3D).

[0096] Since near infrared rays cannot be visually confirmed (even if the light intensity is increased, it is not dazzling), the use of near infrared rays will not hinder the operator's work. In other words, even if the light intensity of the near infrared light source is arbitrarily adjusted to obtain the optimal observation conditions, it will not cause any burden to the operator.

[0097] In the above, the water-soluble polymer is dissolved in the lubricating liquid 6 filling the blood vessel model 5 and the immersion liquid 7 filling the periphery of the blood vessel model 5. The water-soluble polymer is considered to be a particle having a diameter of several nanometers in the aqueous solution. Figure 4 As shown, Rayleigh scattering occurs. As a result, the near infrared light from the light source 11 is scattered in the liquid and efficiently irradiated to the object of observation. In addition, if the above-mentioned liquid is used, the near infrared light is scattered when it passes through the surface of the blood vessel model or is reflected on the outer surface, and the image information of the surrounding environment image contained in the irradiated near infrared light disappears. In addition to this method, by mixing particles that produce Rayleigh scattering into the material forming the blood vessel model, the near infrared light can be scattered inside the structure of the blood vessel model to obtain the same effect.

[0098] As a result, each part of the observed image obtained becomes a more planar (2D) image that is close to an X-ray-based observed image, compared to the case where a liquid that does not generate Rayleigh scattering is used. The effect is particularly evident in the wall section area of ​​the blood vessel model, which is observed as a uniform color area without patterns when a liquid that generates Rayleigh scattering is used. On the other hand, in a liquid that does not generate Rayleigh scattering, an image of the surrounding environment is projected on the wall section area, generating shades and patterns, and is observed slightly three-dimensionally.

[0099] As from Figure 1 It has been confirmed that in the near infrared region of 1300nm to 1550nm, the infrared absorption rate of water is higher than that of 780nm to 1200nm. The infrared absorption characteristics of silicone rubber vary depending on the type. Figure 1 In the silicone rubber (manufactured by Dow Chemical Company, model: SYLGARD 182) with the characteristics shown, the absorption rate is lower than that of water in the main wavelength region of near-infrared rays (particularly, at a wavelength of 1200nm, it shows an absorption rate close to that of water, and at a wavelength of 1450nm, it shows an absorption rate significantly higher than that of water).

[0100] According to the research of the present inventors, when near infrared rays with a wavelength of 1300 to 1550 nm are used, the infrared absorption rates of polymer materials such as silicone rubber and acrylic resin, and gases such as air are different from those of water disposed in the lumen area of ​​the blood vessel model, making it easier to perform near infrared spectroscopic observation, and the lumen area can be clearly visualized. In addition, since the near infrared absorption rate of water is lower than that of catheters and wires, the image of the lumen area obtained is reduced in the observation image or completely eliminated by using near infrared rays with a shorter wavelength (a wavelength of 1200 nm in the configuration of this embodiment, etc.), adjusting the light source, the light intensity adjustment device attached to the camera, etc., or adjusting the light balance of the observation image by the image processing device attached to the camera, so as to hardly affect the perspective image of the catheter.

[0101] According to this method, it is possible to easily and instantly select and reproduce the images of the X-ray observation images of the actual surgery when the contrast agent is injected and when the contrast agent is not injected, without performing physical operations such as injecting contrast agent into the observation object. As an example, the observation image of the case where the inner cavity area is selectively visualized and disappeared by adjusting the light amount is used as Figure 5 express. Figure 5(B) is an observation image obtained when the light source 11 of 1450 nm is used (the light intensity is set to the maximum by the adjustment device attached to the light source) and the aperture of the lens attached to the camera 15 is set to F2.8. Under this condition, the lumen area (wall section area) of the blood vessel model is visualized in a state where it can be recognized together with the fluoroscopic image of the catheter. Figure 5 (C) is an observed image obtained when the aperture of the lens attached to the camera 15 is set to F1.8 while using the same light source 11. Under this condition, a fluoroscopic image of the catheter is observed, but the inner cavity region (wall cross-section region) of the blood vessel model disappears. Figure 5 (A) is an observation image obtained when the aperture of the lens attached to the camera 15 is set to F5.0 while using the same light source 11. Under this condition, the observation image becomes dark as a whole, making it difficult to visually confirm the state inside the catheter, and therefore is not suitable as an observation condition.

[0102] According to the amount of water, the thickness and material of the sheath tube 2 of the catheter 1, and further according to the presence or absence of particles that generate Rayleigh scattering, the Figure 5 (B) or Figure 5 (C) The light intensity conditions change. For example, when the diameter of the blood vessel model is large or the depth of the immersion liquid 7 around the blood vessel model is large, the infrared absorption of water at a wavelength of 1300 to 1550 nm becomes excessive, and the obtained image becomes dark as a whole, so a high light intensity is required for the light source.

[0103] In order to reduce the infrared absorption rate of water and clearly visualize the shape of blood vessels, near infrared rays with a wavelength shorter than 1300nm (such as near infrared rays with a wavelength of 780nm to 1250nm) can be used. In this case, in order to reduce the shading value of the area containing only water, it is effective to adjust the light amount of near infrared rays to create a state suitable for near infrared fluoroscopic observation and near infrared spectroscopic observation.

[0104] In the simulation of catheter treatment, it is necessary to adjust observation conditions such as the light intensity and wavelength of the light source each time while observing the image projected on the monitor, depending on the catheter and blood vessel model used.

[0105] When the blood vessel model is three-dimensionally curved or when there is a large height difference in the observation target, the light intensity and focus may need to be adjusted according to the distance from the light source to the observation target.

[0106] As described above, by near-infrared spectral observation and near-infrared transmission observation, the observation image of the blood vessel model capable of identifying the inner cavity region of the blood vessel model and the fluoroscopic image of the catheter can be simultaneously observed.

[0107] On the other hand, it is also possible to increase the opacity of the part where the particles exist during near-infrared observation by mixing particles that interfere with near-infrared rays into the forming material of the vascular model and / or the liquid that fills the vascular model, and to forcibly visualize the area containing the particles, that is, the lumen area of ​​the vascular model. As particles that interfere with near-infrared rays, particles that absorb near-infrared rays, particles that scatter near-infrared rays, or particles that reflect near-infrared rays can be used, for example, aluminum particles or ink (carbon-based particles) can be used. In addition, in the near-infrared region, if the particle diameter is larger than about 100nm, Mie scattering occurs and the observed image becomes unclear, and the transmittance is greatly reduced, so it is not preferred. In the case where perspective observation is required, it is preferred that Rayleigh scattering is generated by using particles with a particle diameter of less than 100nm, more preferably about 0.5nm to 50nm, thereby maintaining the clarity of the observed image, and based on the above reasons, the effect of improving the near-infrared perspective observation ability is shown compared to the case where no particles are added.

[0108] In addition, particles larger than 100 nm are used to match a suspected thrombus or the like provided in the inner cavity region of the blood vessel model and to visualize an area where transparent observation of the interior is unnecessary.

[0109] In the above, the light source is not particularly limited as long as it can emit near infrared light of sufficient intensity to observe the catheter's fluoroscopic image. From the perspective of near infrared spectroscopic observation, the light and dark balance of each part of the observation object can be adjusted by using multiple light sources with different wavelengths or preparing a light source with a variable wavelength.

[0110] The wavelength selection can also be performed on the camera side. A wavelength-selective filter can be placed in front of the camera or the wavelength selection can be performed during image processing after the camera has focused the light.

[0111] When using light sources with different wavelengths, the wavelengths can be switched to form an image. Alternatively, light sources with different wavelengths can be made to emit light simultaneously, and cameras and displays corresponding to the respective wavelengths can be prepared to simultaneously form images corresponding to the respective wavelengths.

[0112] By having a first light source that emits near-infrared light with a wavelength of 1300nm to 1550nm, which has a high water absorption rate, and a second light source with a wavelength of 780nm to 1250nm, which has a relatively low water absorption rate, coexist, it is possible to selectively visualize or eliminate only the inner cavity area while maintaining the perspective image of the catheter through a simple switching operation. Alternatively, the wavelength can be selected in a manner that produces appropriate shades according to the diameter of the blood vessel model and the depth of the surrounding immersion fluid. Alternatively, the wavelength that represents the optimal absorption and transmission characteristics can be selected according to the type and material of the catheter used.

[0113] The light source preferably uses a surface light source that evenly irradiates near-infrared rays to a desired area of ​​the blood vessel model as the observation object. A parallel light source may be used for the purpose of clearly observing the outline of the observation object, or a diffuse light source may be used for the purpose of facilitating perspective observation by irradiating light to the observation object from multiple directions. In addition, it is also possible to observe only a part of the observation object using a line light source or a point light source, or to evenly irradiate the near-infrared rays from the line light source or the point light source to a desired area of ​​the blood vessel model via a light diffusion circuit.

[0114] The light source can also irradiate the observation object from multiple directions. In particular, near-infrared rays have low permeability to metals. Therefore, in a configuration where a blood vessel model is arranged between the light source and the camera for observation, if the observation object includes a thick metal structure, the near-infrared rays are completely blocked by the metal structure. Therefore, in the case where a platinum X-ray opaque marker is attached to a part of the stainless steel transmission wire of the aneurysm embolization coil, it is impossible to identify them.

[0115] The inventors of the present invention have noticed that near infrared rays have different reflectance characteristics depending on the type and wavelength of the metal material. They have found that by observing the reflection of near infrared rays simultaneously, it is possible to obtain a method for identifying the metal material. Figure 6 Observation images of structures composed of different metal materials are shown.

[0116] exist Figure 6 In the figure, reference numeral 20 is the aforementioned stainless steel conveyor wire, and reference numeral 30 is the aforementioned platinum X-ray opaque marker. In near-infrared reflection observation, a second light source for generating near-infrared reflection is arranged in a lateral direction of the blood vessel model (in a direction orthogonal to the axis of the first light source and the camera for near-infrared perspective observation or obliquely upward) to irradiate the blood vessel model with near-infrared rays. A third light source can also be added to irradiate from a direction different from that of the first light source. In near-infrared reflection observation, the wavelengths of the first light source, the second light source, and further, the third light source can be arbitrarily selected, but in order to suppress chromatic aberration, it is preferred that the wavelengths of the light sources be the same.

[0117] The camera is not particularly limited as long as it can receive near infrared rays from the light source, and a plurality of cameras may be used in accordance with the light source.

[0118] The display images the output from the camera. In order to adjust the amount of light incident on the camera while visually checking the image on the display, it is preferable to arrange a light source or a light amount adjustment device attached to the camera at a position where the display can be adjusted while visually checking the image on the display.

[0119] In order to be able to photograph X-ray opaque markers more clearly, repeated research has been conducted.

[0120] Figure 7 2 shows the structure of the above-mentioned imaging device 100. Figure 7 In, with Figure 2 The same elements are denoted by the same reference numerals, and description thereof will be omitted.

[0121] The first near infrared light with a wavelength of 940 nm is emitted from the first light source of the imaging device 100, and is polarized in the first direction by the first change plate 103. The first near infrared light polarized in this way is received by the first light receiving unit 111. The second near ultraviolet light with a wavelength of 850 nm is emitted from the second light source 105, and is polarized in the second direction by the second polarizing plate 107. The second near infrared light polarized in this way is reflected by the measurement object and is received by the second light receiving unit 112.

[0122] The first image forming unit 121 forms a first image using the first near infrared rays received by the first light receiving unit 111. The first image forming unit 121 includes a grayscale image generating unit, and grayscales the first image.

[0123] Figure 8 An example of the first image is shown.

[0124] The second image forming unit 122 forms a second image using the second near infrared rays received by the second light receiving unit 112 .

[0125] The second image forming unit 122 includes a grayscale image generating unit, and the second image is converted into grayscale.

[0126] Fig. 9 This shows an example of the second image.

[0127] The second image has its tone inverted in the image inverting unit 128. Here, inversion means inverting the grayscale value of each pixel around the grayscale center value. For example, in the case of a grayscale of 265 grayscales, if the center value 133 is taken as the center and the value is 160 (=133+27), the inverted value is 106 (=133-27).

[0128] The 2-1 image after the inversion is Fig.10 express.

[0129] The 2-1st image and the first image are combined by the image combining unit 130. In this combination, the values ​​of corresponding pixels in the two images are multiplied. As a result, black is emphasized to be darker and white is emphasized to be whiter.

[0130] In addition, the alignment between the 2-1st image and the first image is performed by a known method.

[0131] The synthesized image is Fig.11 express.

[0132] Fig.12 This is a diagram in which the position of the X-ray opaque marker is emphasized after performing density correction.

[0133] Fig.13 FIG. 2 shows an observation device 200 according to another embodiment. Fig.13 For Figure 7 The same elements are denoted by the same reference numerals, and description thereof is omitted.

[0134] Fig.13 The observation device 200 includes a background image storage unit 210 , an image evaluation unit 220 , and a guide generation unit 221 .

[0135] The background image storage unit 210 stores images of bones and other tissues, and these images can be displayed together with the synthesized image by the image synthesis unit 130 .

[0136] The image evaluation unit 220 evaluates the image by using, for example, photoelastic stress observation or AI. Fig.12 The composite image shown. Fig.14 As shown, when evaluating the stress generated in the blood vessel model by the photoelastic stress observation method, the guide display unit 221 acts as a guide to display the stress distribution as color (grayscale) information superimposed on the synthesized image. At the same time, text information can also be displayed.

[0137] In actual catheter-based endovascular surgery, the injected contrast agent flows away through the bloodstream, so the blood vessels are only visualized for a few seconds. In addition, due to its toxicity, there is an upper limit on the amount of contrast agent used, and it cannot be injected multiple times. Therefore, a technique (vascular route mapping method) is used to save the blood vessel visualization image at the moment the contrast agent is injected as a still image and superimpose it on the observation image where only the catheter is visualized.

[0138] In the near-infrared observation of the present invention, it was confirmed that the above-mentioned blood vessel route mapping method can be reproduced by performing image processing such that the image of the blood vessel lumen disappears and only the catheter is visualized after a still image of the state in which the lumen of the blood vessel is visualized is changed after a still image is saved, and the still image is superimposed and presented as needed. In terms of reproducing the blood vessel route mapping method, it is preferred that the observation device of the present invention further includes a hardware interface such as a foot pedal and a joystick, so that various operations accompanying the image processing can be performed in the same manner as in actual catheter intravascular surgery.

[0139] For the blood vessel model, a material formed by a cross-linked soft polymer material such as silicone rubber, polyurethane rubber, soft polyvinyl chloride, and soft photocurable resin, a hard polymer material such as acrylic resin, hard photocurable resin, or a material formed by combining these materials and allowing near infrared rays to pass through can be used. In the inner cavity area of ​​the blood vessel model, in order to be able to identify the area during near infrared spectroscopy observation, it is necessary to configure a substance that exhibits infrared absorption characteristics different from the material forming the blood vessel model. For example, when silicone rubber is used as the material forming the blood vessel model, the inner cavity of the blood vessel model can be filled with a lubricating liquid mainly composed of water, or the inner cavity can be filled with air after the lubricating liquid is applied to the inner cavity surface of the blood vessel model.

[0140] As the blood vessel model in the present invention, a blood vessel model having the same thin film structure as a biological blood vessel (hereinafter referred to as a "thin film blood vessel model"), or a blood vessel model having a cavity portion simulating the lumen of a blood vessel formed inside a block such as a rectangular parallelepiped, a cylinder, or a sphere (hereinafter referred to as a block blood vessel model), or a blood vessel model formed by combining the two, etc. can be used. In the thin film blood vessel model, liquid, gas, solid (particularly gel-like solid) can be selectively arranged in the lumen area and the surrounding area of ​​the blood vessel model according to the situation (for example, water can be arranged in the lumen area, and water and air can be arranged in the surrounding area). Thus, in the thin film blood vessel model, not only the lumen area of ​​the blood vessel model but also the wall section area of ​​the blood vessel model can be visualized in a manner that allows identification. In the block blood vessel model, various substances can be selectively arranged in the lumen area according to the situation.

[0141] As the constituent material of the above-mentioned blood vessel model, various materials such as silicone rubber, polyurethane rubber, soft polyvinyl chloride, soft photocurable resin, gel composed of polyvinyl alcohol, acrylic resin, hard photocurable resin, etc. can be used as long as they are materials with near-infrared transmittance.

[0142] Since near infrared rays do not hinder human eyes, the polymer material preferably has transparency to visible light in order to allow the operator to visually observe the blood vessel model after irradiation with near infrared rays.

[0143] As cross-linked polymer materials, cross-linked soft polymer materials such as silicone rubber, polyurethane rubber, soft polyvinyl chloride, and soft photocurable resins, hard polymer materials such as acrylic resins and hard photocurable resins, and materials obtained by combining them can be listed. The material for forming the vascular model, the liquid filling the inner cavity of the vascular model, etc. can also be colored with a pigment that can be identified in the visible light region. Since most of the pigments used in the visible light region show high transmittance in the near-infrared region, it is possible to set conditions for the image observed in the visible light region and the image observed in the near-infrared region in a manner that has almost no effect on the near-infrared spectroscopic observation image.

[0144] The blood vessel model can also be formed from a gel-like substance such as polyvinyl alcohol. Since the blood vessel model made of polyvinyl alcohol has high lubricity in its physical properties, the substance filled in the inner cavity of the blood vessel model can also be only water or air. Of course, it does not interfere with the addition of a drug that enhances lubricity, such as a surfactant.

[0145] In the blood vessel model, a lesion model simulating a thrombus or plaque can be pre-attached or movably arranged. On the basis of the near-infrared spectroscopic observation of the present invention, in order to selectively improve the visual confirmation of the lesion model, it is preferred to form the lesion model using a material that exhibits near-infrared absorption characteristics different from the forming material of the blood vessel model and the material arranged in the inner cavity area. By using plaques and thrombi made of the above materials to observe the simulation process of catheter angioplasty or thrombus retrieval, in the inner cavity of the blood vessel model, it is possible to clearly observe the plaque being squeezed by microbeads and stents, the thrombus being captured by the stent and being recovered while moving in the blood vessel together with the stent, etc.

[0146] In addition, in the present invention, a single light receiving unit can be used to simultaneously receive the first near infrared rays that have passed through the observation object and the second near infrared rays that have been reflected by the observation object, and an image can be directly formed based on the received light without performing any operation. In the formation of the above image, preferably, when the first near infrared rays and the second near infrared rays have different wavelengths, the lens provided in the light receiving unit is a lens having a focus shift correction function.

[0147] When a single light receiving unit is used, the first near infrared ray that has passed through the observation object and the second near infrared ray that has been reflected by the observation object can be received with a time difference, and the images generated by each can be calculated and synthesized. In this case, the second image generated from the first near infrared ray can have its color tone inverted, and the second image with the inverted color tone can be calculated and synthesized with the first image generated from the first near infrared ray.

[0148] This invention does not limit the description of the above-mentioned embodiments and examples of the invention in any way. Various modifications within the scope that can be easily conceived by those skilled in the art without departing from the description of the technical solution are also included in this invention.

[0149] Description of Reference Numerals

[0150] 1: catheter;

[0151] 2: sheath;

[0152] 3: Line type;

[0153] 5: Blood vessel model;

[0154] 10: Observation device;

[0155] 20: line;

[0156] 30: Identifier.

Claims

1. An observation device, which is an observation device for observing a blood vessel model in which a catheter is inserted, wherein: A substance having near infrared absorption characteristics different from that of a constituent material of the blood vessel model is arranged inside the blood vessel model, and the catheter includes a sheath tube and a wire inserted into the sheath tube. The observation device comprises: a first light source that emits a first near infrared ray; a first light receiving unit that can receive the first near infrared ray; and a first image generating unit that generates a first image based on the first near infrared ray captured by the first light receiving unit. and a display that displays the first image.

2. An observation method, which is a method of observing an observation object using the observation device according to claim 1, wherein: The first light source emits the first near infrared ray toward the observation object, and the first light receiving unit receives the first near infrared ray after passing through the observation object. causing the first image generating unit to generate the first image based on the first near infrared rays received by the first light receiving unit, causing the display to display the first image, By adjusting the light amount of the first near-infrared ray used for generating the first image as needed, it is possible to visually confirm the sheath of the catheter, the wires in the sheath, and the blood vessel model at the same time.

3. The observation device according to claim 1, wherein: The observation device further comprises: a second light source that emits a second near infrared ray; a second light receiving unit that can receive the second near infrared ray; and a second image generating unit that generates a second image based on the second near infrared ray captured by the second light receiving unit. as well as an image synthesis unit that superimposes the first image and the second image, The first image and the second image are displayed on the display so as to overlap with the first image.

4. An observation method, which is a method of observing an observation object using the observation device according to claim 3, wherein: The first light source emits the first near infrared ray toward the observation object, and the first light receiving unit receives the first near infrared ray after passing through the observation object. causing the first image generating unit to generate the first image based on the first near infrared rays received by the first light receiving unit, causing the display to display the first image, The second light source emits the second near infrared ray toward the observation object, and the second light receiving unit receives the second near infrared ray reflected by the observation object. causing the second image generating unit to generate the second image based on the second near infrared rays received by the second light receiving unit, causing the image synthesis unit to generate a synthesized image by superimposing the first image and the second image, causing the display to display the composite image, By adjusting the amount of the first near-infrared light used for generating the first image as needed and / or adjusting the amount of the second near-infrared light used for generating the second image as needed, simultaneous visual confirmation of the sheath of the catheter, the wires within the sheath, the X-ray opaque markers of the wires, and the blood vessel model is achieved.

5. The observation device according to claim 3, wherein: The observation device comprises: a first polarizing unit, which polarizes the first near infrared ray in a first direction; a second polarizing unit, which polarizes the second near infrared ray in a second direction; a grayscale image generating unit that converts the first image and the second image into grayscale; and The grayscale inverting unit inverts the grayscale of the grayscale image of the second image to generate a 2-1 image.

6. A method for observing an observation object, the method using the observation device according to claim 5, wherein: causing the first image generating unit to generate the first image based on the first near infrared rays polarized in the first direction, causing the second image generating unit to generate the second image based on the second near infrared rays polarized in the second direction, causing the grayscale image generating unit to grayscale the first image and the second image, causing the grayscale inverting section to invert the grayscale of the grayscaled second image to form a 2-1 image, The image synthesis unit superimposes the grayscaled first image and the 2-1 image, and synthesizes them by calculating the value of each pixel of each image.

7. The observation method according to claim 4, wherein: A concentration correction is performed to emphasize the radiopaque markers.

8. The observation device according to claim 3, wherein: The observation device also has: an image evaluating unit that evaluates the synthesized image synthesized by the image synthesizing unit; and a guide forming unit that forms a guide based on the evaluation result of the image processing unit, The guide is displayed on the display.

9. A method for observing an observation object, the method comprising using the observation device according to claim 8, wherein: causing the image evaluation unit to evaluate the synthesized image, causing the guide forming unit to form a guide based on the evaluation result of the image evaluating unit, The display is caused to display the guidance.

10. An observation device for observing a blood vessel model into which a catheter is inserted, wherein: A substance having near infrared absorption characteristics different from that of a constituent material of the blood vessel model is arranged inside the blood vessel model, and the catheter includes a sheath tube and a wire inserted into the sheath tube. The observation device comprises: a first light source that emits a first near-infrared ray; a first light receiving unit that can receive the first near-infrared ray after passing through the observation object; a first image generating unit that generates a first image based on the first near-infrared ray captured by the first light receiving unit; and a display that displays the first image. The light amount of the first near-infrared ray used for generating the first image is adjusted.

11. An observation device for observing a blood vessel model into which a catheter is inserted, wherein: A substance having near infrared absorption characteristics different from that of a constituent material of the blood vessel model is arranged inside the blood vessel model, and the catheter includes a sheath tube and a wire inserted into the sheath tube. The observation device comprises: a second light source that emits a second near-infrared ray; a second light receiving unit that can receive the second near-infrared ray reflected from the observation object; a second image generating unit that generates a second image based on the second near-infrared ray captured by the second light receiving unit; and a display that displays the second image. The light amount of the second near-infrared ray used for generating the second image is adjusted.

12. The observation device according to claim 3, wherein: The first near infrared ray and the second near infrared ray are monochromatic lights.

13. The observation method according to claim 4, wherein: The material having near-infrared absorption characteristics different from the constituent material of the blood vessel model contains a material that receives near-infrared light from the light source and generates Rayleigh scattering.

14. The observation method according to claim 4, wherein: The constituent material of the blood vessel model contains a material that receives near infrared light from the light source and generates Rayleigh scattering.

Images