Apparatus and method for observing blood vessel model

Abstract

To provide a cassette with a built-in blood vessel model suitable for an observation apparatus capable of simultaneously observing a fluoroscopic image of a catheter inserted into the blood vessel model and the blood vessel model itself, without use of an X-ray.SOLUTION: A cassette with a built-in blood vessel model is used for an observation apparatus in which the vessel model subjected to insertion of a catheter is set as an observation object. The cassette has the blood vessel model, a housing for holding the blood vessel model, and a lubricating liquid for filling the inside of the blood vessel model. The lubricating liquid includes a material that causes Rayleigh scattering.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] When evaluating a catheter to be inserted into a blood vessel, or when performing technical training or 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. In order to observe the blood vessel shape and the state of the catheter inserted into the blood vessel model, in addition to direct visual observation, a visible light camera and an X-ray projection device are often used. It is easy to form a blood vessel model from a transparent material and fill the lumen of the blood vessel model (hereinafter referred to as the "lumen region") with a liquid colored with a dye or the like, and then observe the blood vessel shape and the catheter inserted into the blood vessel model visually or with a visible light camera. However, in this case, the catheter cannot be seen through, and the position and condition of the guide wire and other components that make up the catheter cannot be confirmed, so the reproducibility of intravascular surgery is low. This problem can be solved by using X-rays, but their use is not easy due to radiation exposure and management considerations.

[0003] Catheters generally have a multi-layer structure with wires (including balloons, coils, stents and other devices with therapeutic functions, drugs (liquids such as contrast agents and thrombolytic agents) and other sheaths) inserted into a thin, tubular sheath, and observation using visible light does not allow for detection of the position or condition of the tips of the wires inserted into the sheath in multiple layers. In actual treatment using catheters, information on the tip position and condition of wires inside the sheath is necessary. In addition, in practical catheters, in order to clearly indicate the specific positions of the sheath and wires, materials that do not transmit X-rays (X-ray opaque markers) are attached to the tips and middle parts of the catheters, making it possible to confirm their relative positions using the X-ray projection device used during treatment.

[0004] In order to observe the tip position and condition of wires within a sheath while avoiding exposure to X-rays, an observation method has been proposed that combines fluorescent observation technology and image processing technology (Non-Patent Document 1). Furthermore, Patent Document 1 proposes a lubricating liquid that ensures lubricity between the blood vessel model and the catheter. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 5992031 [Non-patent literature]

[0006] [Non-Patent Document 1] Kazuaki Fukasaku et al. “Intravascular treatment training is now possible anytime, anywhere – Development of an endovascular treatment simulation that does not expose doctors to X-rays”, [online], February 19, 2022, 51st Japanese Society of Neuroradiology https: / / www.u-ryukyu.ac.jp / news / 32074 / Summary of the Invention [Problem to be solved by the invention]

[0007] According to the observation method introduced in Non-Patent Document 1, it is necessary to attach a fluorescent material to the catheter sheath and the parts of the wires that are to be visualized. In other words, the actual catheter cannot be used as is. Furthermore, in order to visualize the blood vessel model, it is necessary to introduce a contrast agent (a liquid containing a fluorescent dye) into the liquid filling the lumen region of the blood vessel model.

[0008] For example, if the vascular model is made of a gel material such as polyvinyl alcohol, there is a risk that the contrast agent will seep into the material from which the vascular model is made or adhere to the inner surface of the vascular model, making it difficult for the model to withstand long-term use. On the other hand, when the blood vessel model is made of a cross-linked polymer material such as silicone rubber, the lumen of the blood vessel model needs to be filled with a lubricating liquid to ensure lubrication between the catheter and the blood vessel model (see Patent Document 1). When a contrast agent is mixed into the lubricating liquid, the lubricating function of the lubricating liquid may be reduced. [Means for solving the problem]

[0009] The inventors of the present invention have conducted extensive research to solve the above problems, and have found that by using near-infrared light, which has a higher material permeability than visible light and a more diverse light absorption rate depending on the material and wavelength than visible light, it is possible to simultaneously or selectively visualize the blood vessel shape and the state inside the catheter without using contrast agents, etc. In other words, there is no need to attach contrast agents or fluorescent materials to the catheter sheath or wires, as was necessary in the prior art.

[0010] Near-infrared absorptivity varies in various ways depending on the type of substance and the wavelength of the near-infrared used. Due to this characteristic, in near-infrared spectroscopy, the change in absorptivity in the near-infrared region is measured, and the components of the substance are identified by comparing the measurement results with a spectrum table showing the absorption characteristics. In addition, in many substances, the absorptivity changes greatly between the visible light region and the near-infrared region. Due to this characteristic of near-infrared light, liquids containing pigments that appear opaque in the visible light region can be observed transparently in the near-infrared region, and various soft polymers such as silicone rubber, various hard polymers such as acrylic resin, and various liquids such as water and oil that appear transparent in the visible light region can be observed as different colors (shades) in the near-infrared region without using contrast agents (hereinafter referred to as "near-infrared spectroscopic observation"). Furthermore, the near-infrared absorptivity (i.e., near-infrared transmittance) of each substance varies in various ways by changing the wavelength in the near-infrared region, so by utilizing this characteristic, differences in the shapes and materials of each part of a composite structure composed of different substances can be identified.

[0011] The inventors have found that, due to the characteristics of near-infrared light, by performing near-infrared spectroscopic observation, each part of a blood vessel model, which appears completely transparent in the visible light region, including the inside and outside, can be observed as an image in which the difference in shape and material can be distinguished, without using a contrast agent or the like. In addition, by changing the wavelength and light quantity of the near-infrared light used (the intensity of the light source and the exposure setting of the observation device), the balance of the light and shade of each part of the blood vessel model can be changed without performing any physical manipulation on the observation target. In addition, by changing the wavelength and light quantity of the near-infrared light, it has been found that the blood vessel shape can be selectively visualized or disappeared while the fluoroscopic image of the catheter is visualized on the observation screen.

[0012] On the other hand, near-infrared light, like X-rays, has the property of easily penetrating various materials, making it possible to perform fluoroscopic observation of objects (hereinafter referred to as "near-infrared fluoroscopic observation"). As a method that is simpler and safer than X-ray observation, it is used for non-destructive testing of semiconductors and foreign body inspection in liquids.

[0013] When observed with visible light, the blood vessel model is observed three-dimensionally (3D), but when observed with near-infrared fluoroscopy, a planar (2D) image like a shadow puppet is obtained due to its transparency. Such planar (2D) images are close to X-ray fluoroscopy images obtained in catheter intravascular surgery, and are suitable for reproducing a simulation of the same surgery. Furthermore, even when each part of the blood vessel model is three-dimensional, i.e., crosses in front of or behind the direction of near-infrared irradiation, a planar (2D) fluoroscopy image similar to an X-ray observation image can be obtained.

[0014] Actual catheters all have a common feature of a thin-film multi-layer structure, but the sheath material and film thickness are not uniform depending on the type (sheath materials include various soft resins such as polyester, polyethylene, polyamide (nylon), polyurethane, and silicone rubber). Catheters and wires also incorporate complex metal structures such as meshes and X-ray opaque markers, and mechanical structures such as balloons and coil detachment mechanisms. The inventors have found that by observing catheters with such features using both near-infrared fluoroscopy and near-infrared spectroscopy, the catheter can be reproduced as an image similar to an X-ray image observed during an actual operation, and further as an expanded observation image including information that cannot be obtained by X-ray observation.

[0015] By using near-infrared light, it is possible to observe the catheter through the fluoroscopic view, and to obtain an observation image that can distinguish differences in its structure and material. Furthermore, by changing the wavelength and light intensity of the near-infrared light used, it is possible to change the shading balance of the observation image without physically manipulating the blood vessel model. For example, it is possible to select a specific area of ​​the blood vessel model to be observed, change or reverse the shading balance of the selected specific area, or make the specific area visible or disappear.

[0016] A first aspect of the present invention is defined as follows. An observation device for observing a blood vessel model into which a catheter is inserted, the observation device comprising: a substance having near-infrared absorption characteristics different from a constituent material of the blood vessel model disposed inside the blood vessel model; the catheter including a sheath and wires inserted into the sheath; An observation device comprising: a first light source that emits first near-infrared light; a first light receiving unit that can receive the first near-infrared light; a first image generating unit that generates a first image based on the first near-infrared light captured by the first light receiving unit; and a display that displays the first image. According to the blood vessel model observation device of the first aspect thus defined, since the substance placed in the blood vessel model has a near-infrared absorption specificity different from that of the constituent material of the blood vessel model, it becomes possible to visually confirm the boundary between the blood vessel wall cross-sectional area of ​​the blood vessel model (hereinafter referred to as "wall cross-sectional area") and the substance in near-infrared spectroscopic observation. At this time, since the catheter inserted in the blood vessel model has a permeability to near-infrared rays different from that of the constituent material of the blood vessel model and the substance, the catheter can be observed separately from the blood vessel model and the substance.

[0017] A second aspect of the present invention is defined as follows. A method for observing an observation object using the observation device according to the first aspect, comprising: The first light source is caused to emit the first near-infrared light toward the observation object, and the first light receiving unit is caused to receive the first near-infrared light that has passed through the observation object; causing the first image generating unit to generate the first image based on the first near-infrared light received by the first light receiving unit; causing the display to display the first image; A method for observing an object to be observed, which enables the sheath of the catheter, the wires within the sheath, and the blood vessel model to be simultaneously viewed by adjusting the amount of the first near-infrared light used to generate the first image as necessary.

[0018] As explained in the first aspect, the blood vessel model and the catheter inserted therein can be clearly distinguished and observed by near-infrared spectroscopic observation. If necessary, the amount of the first infrared light used to generate the first image can be adjusted to display a fluoroscopic image of the catheter together with the blood vessel model on the image on the display. That is, by adjusting the amount of near-infrared light, near-infrared fluoroscopic observation is possible. Here, "as necessary" means that if the vascular model or catheter constituting the object of observation is standardized, then by adjusting the amount of light in advance, there is no need to adjust the amount of light during observation (the same applies throughout the rest of this specification).

[0019] Since the catheter simulation is premised on being able to simultaneously view the catheter sheath, the wires inside the sheath, and the blood vessel model, the observation method of the blood vessel model defined in the second aspect is practical. By adjusting the amount of near-infrared light, it is possible to selectively display on the display image only the outer contour image (non-transparent image) of the catheter, an image of the outer contour image of the catheter and the blood vessel model, only a fluoroscopic image of the catheter, or only the blood vessel model.

[0020] In the above, examples of the adjustment device for adjusting the amount of near-infrared light that can be used include a device attached to a near-infrared light source and adjusting the amount of near-infrared light emitted from the light source, a diaphragm attached to a light receiving unit of a camera or the like and adjusting the amount of light collected by the camera, and a device that processes an image captured by a camera and adjusts the amount of light.

[0021] A third aspect of the invention utilizes near-infrared reflectance observation. Near-infrared rays have different reflection characteristics depending on the material they are irradiated with. For example, the reflection characteristics of iron (stainless steel) and platinum are different. Among the wires that make up catheters, there are some that are made of stainless steel wires with platinum attached to the middle to serve as X-ray opaque markers. Since neither stainless steel nor platinum transmits near-infrared light, neither near-infrared spectroscopic observation nor near-infrared fluoroscopic observation is effective for such wires.

[0022] On the other hand, since stainless steel and platinum have different near-infrared reflection characteristics, by irradiating near-infrared light from a second near-infrared light source and collecting the reflected light from the target (the wire with a platinum marker in the above example) on the light receiving section, it is possible to clearly distinguish and observe the stainless steel, which is the base metal of the wire, from the platinum, which is the marker. This observation can be performed in conjunction with the near-infrared spectroscopic observation and near-infrared fluoroscopic observation described in the second aspect.

[0023] Therefore, the third aspect of the present invention is defined as follows: An observation device according to the first aspect, further comprising 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 synthesis unit; causing the image synthesis unit to superimpose the first image and the second image to form a synthetic image; The display is caused to display the composite image.

[0024] The observation method using the observation device of the third aspect thus defined is as follows. A method for observing an object to be observed using an observation device according to a third aspect, comprising: The first light source is caused to emit the first near-infrared light toward the observation target, and the first light receiving unit is caused to receive the first near-infrared light that has transmitted through the observation target; causing the first image generating unit to generate the first image based on the first near-infrared light received by the first light receiving unit; The second light source is caused to emit the second near-infrared light toward the observation target, and the second light receiving unit is caused to receive the second near-infrared light reflected by the observation target; causing the second image generating unit to generate the second image based on the second near-infrared light received by the second light receiving unit; causing the image synthesis unit to generate a synthetic image by superimposing the first image and the second image; The display is caused to display the composite image. Here, by adjusting the amount of the first near-infrared light used to generate the first image as needed, and / or by adjusting the amount of the second near-infrared light used to generate the second image as needed, it becomes possible to simultaneously view the sheath of the catheter, the wires within the sheath, the X-ray opaque markers on the wires, and the vascular model.

[0025] The observation device according to a fifth aspect of the present invention is defined as follows: That is, in the observation device defined in the third aspect, the observation device further includes a grayscale image generating unit that converts the first image and the second image into grayscale images; and an image inversion unit that inverts the gradation of the grayscale image of the second image to generate a 2-1 image.

[0026] The observation method using the observation device of the fifth aspect thus defined is as follows. A method of observation using an observation device as defined in a fifth aspect, comprising: causing the grayscale image generating unit to grayscale the first image and the second image; The image inversion unit inverts the gradation of the grayscaled second image to form a 2-1 image; The image synthesis unit superimposes the grayscaled first image and the grayscaled second image, and synthesizes the images by calculating the pixel values ​​of each image.

[0027] The observation device according to the seventh aspect of the present invention is defined as follows. That is, in the observation device prescribed in the fifth aspect, A first polarizing unit that polarizes the first near-infrared light in a first direction; A second polarizing unit that polarizes the second near-infrared light in a second direction; a housing that houses the first light receiving unit and the second light receiving unit, wherein the first light receiving unit is capable of receiving a first near-infrared ray polarized in the first direction, and the second light receiving unit is capable of receiving a second near-infrared ray polarized in the second direction; causing the first image generating unit to generate the first image based on the first near-infrared light polarized in the first direction; The second image generating unit generates the second image based on the second near-infrared light polarized in the second direction.

[0028] The observation method using the observation device of the seventh aspect thus defined is as follows. A method for observing an object to be observed using an observation device as defined in the seventh aspect, comprising: causing the grayscale image generating unit to grayscale the first image and the second image; The image inversion unit inverts the gradation of the grayscaled second image to form a 2-1 image; The image synthesis unit superimposes the grayscaled first image and the grayscaled second-1 image, and calculates the values ​​of each image for each pixel to synthesize the images.

[0029] In the above, the wavelengths of the near-infrared rays from the first light source and the second light source are outside the range of 1300 nm to 1550 nm, and near-infrared rays of a wavelength that is less affected by absorption by water can be used. Since the amount of water through which the first near-infrared rays from the first light source transmit and the amount of water through which the second near-infrared rays from the second light source transmit are different, if near-infrared rays of a wavelength that is more affected by light absorption are used, it becomes difficult to clearly display a transmitted image by the first light source and a reflected image by the second light source at the same time. It is preferable to form the second light source using an LED having a wavelength of 1300 nm or less, which is easily available industrially and is relatively less susceptible to absorption by water.

[0030] In the above, it is preferable to use monochromatic light for the first and second near-infrared rays. The second near-infrared rays are installed at multiple positions and radiated from multiple directions toward the observation target, so that the visibility of the X-ray opaque markers of the wires can be stably observed regardless of the position. Instead of installing multiple second near-infrared rays, a mirror or a half mirror can be used in combination. By using a mirror or a half mirror, the number of installation positions of the second near-infrared rays can be reduced. In particular, when the observation target is observed while immersed in liquid, when the second near-infrared rays are radiated toward the observation target, they are reflected (including total reflection) / refracted on the liquid surface or the surface of the liquid container, making it difficult or impossible to irradiate from a specific direction. In such a case, this problem can be avoided by installing a mirror or a half mirror in the liquid and irradiating the second near-infrared rays to the observation target after reflecting them. Regardless of whether the observation target is immersed in liquid, a mirror or a half mirror can be included as part of the structure of the observation target including the blood vessel model. In addition to reducing restrictions on the installation position of the second near-infrared light source, it can also be given a function such as adjusting the polarization state (such as inverting the polarization state). The second near-infrared ray may be a plurality of monochromatic rays having different wavelengths. In this case, the monochromatic rays are polarized in different states and emitted toward the object of observation, and are then synthesized by the second light receiving unit or the image synthesis unit through optical or numerical calculation, thereby improving the visibility of the X-ray opaque marker of the wire in near-infrared reflection observation. For near-infrared light with a wide range of wavelengths (such as near-infrared lamps), it is necessary to adjust chromatic aberration, which depends on the wavelength. By using a lens with a focus shift correction function in the near-infrared region, it is possible to set the lens focus to the same position for different wavelengths. This method eliminates the need to adjust chromatic aberration for each wavelength, simplifying the equipment configuration and improving workability during use. By using a polarized camera with a polarizing filter in a specific direction for each pixel, the first light receiving unit and the second light receiving unit can be integrated into a single camera. This method eliminates the need to adjust the relative position of the image, the magnification ratio, etc., simplifying the equipment configuration and improving workability during use. Here, monochromatic near-infrared light includes near-infrared light emitted from the LED that constitutes the light source. The wavelength of near-infrared light from an LED light source is based on the band gap of the LED, so 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 that width will be emitted from the LED light source. Near-infrared light emitted from a near-infrared lamp can be made monochromatic by passing it through a filter that selectively transmits wavelengths. [Brief description of the drawings]

[0031] [Figure 1] FIG. 1 is a spectrum showing the near-infrared absorption characteristics of water and silicone rubber. [Diagram 2] FIG. 2 is a schematic diagram showing an observation device according to the present invention. [Diagram 3] In FIG. 3, 3A shows an image observed using visible light, and 3B shows an image observed using near-infrared light of 1450 nm. [Figure 4] FIG. 4 is a graph showing the relationship between particle radius, wavelength, and Rayleigh observation. [Diagram 5] FIG. 5 shows an image of an embodiment of the present invention. [Figure 6] FIG. 6 shows an image observed by near-infrared reflection observation. [Figure 7] FIG. 7 is a block diagram showing an observation device according to another embodiment of the present invention. [Figure 8] FIG. 8 shows an example of a first image obtained from the first near-infrared light in the device of FIG. [Figure 9] FIG. 9 shows an example of a second image obtained from the second near-infrared light in the device of FIG. [Figure 10] FIG. 10 shows an example of image 2-1 in which the color tone of image 2 is inverted. [Figure 11] FIG. 11 shows a composite image of the first image and the second image. [Figure 12] FIG. 12 shows an image in which the image in FIG. 11 has been density-corrected to emphasize the X-ray opaque markers. [Figure 13] FIG. 13 is a block diagram showing an observation device according to another embodiment of the present invention. [Figure 14] FIG. 14 shows an example of an image output from the device of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] Near infrared generally refers to light with wavelengths between 780nm and 2500nm. The absorption rate of near-infrared rays varies depending on the wavelength and the material (see Figure 1). It can be seen that the infrared absorption rate of water varies greatly depending on the wavelength in the near-infrared region. The lumen of the blood vessel model is often filled with liquid to mimic blood, and such liquid is generally an aqueous solution made of a liquid whose main component is water, like blood, with a lubricant mixed in as necessary. In order to simultaneously and effectively perform both near-infrared fluoroscopy and near-infrared spectroscopy observations, we selected 1450 nm as a wavelength in the near-infrared range where the absorption rate of water is significantly high and can be easily differentiated from the absorption rates of air, silicone rubber, etc., and observed the blood vessel model and the catheter inserted into the blood vessel model.

[0033] FIG. 2 shows the structure of the observation device 10. In the figure, reference numeral 1 denotes a catheter. This catheter 1 includes a sheath 2 and wires 3 inserted into the sheath 2. Reference numeral 5 denotes a blood vessel model, and the lumen of the blood vessel model 5 is filled with a lubricating liquid 6. This lubricating liquid may be circulated to give it fluidity. The surroundings of the blood vessel model 5 are 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 amount adjustment device 13 , a first near-infrared camera 15 , and a display 17 .

[0034] The blood vessel model is made of silicone rubber provided by Fine Biomedical LLC, with a membrane thickness of 0.3mm to 3.0mm and a lumen of 1mm to 15mm. The lumen area of ​​the blood vessel model is filled with a lubricating liquid made by mixing water with a lubricating component. This lubricating liquid is a substance with near-infrared absorption characteristics different from the constituent material of the blood vessel model. The catheter used was an Excelsior microcatheter manufactured by Japan Stryker Corp. The wires used were GDC coils manufactured by Japan Stryker Corp. The first near-infrared light source 11 was an infrared illuminator (model number: TH2-100X100IR145) manufactured by CCS Inc. The light amount adjustment device 13 was a power supply (model number: PD-3024) equipped with a function of adjusting the output of the light source 11, i.e., the amount of near-infrared light emitted from the light source 11. The near-infrared camera 15 was a near-infrared camera (model number: ABA-013VIR) manufactured by Aval Data Inc. and a polarized camera (model number: XCG-CP510) manufactured by Sony Corporation, and the camera lens was a near-infrared compatible lens (model number: LM35HC-SW and model number: LM35HC-VIS-SW) manufactured by Kowa Optronics Co., Ltd.

[0035] 2, an object to be observed is set between the light source 11 and the camera 15. Near-infrared light with a wavelength of 1450 nm is emitted from the light source 11, and the amount of light is adjusted by a light amount 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 and is received by the camera 15, and the image is displayed on the display 17.

[0036] Fig. 3(A) shows a monochrome image of the blood vessel model and the catheter inserted into the blood vessel model observed with a visible light optical camera under the above settings. Fig. 3(B) shows an image of the blood vessel model and the catheter inserted into the blood vessel model observed with a camera 15 (with the aperture of the camera lens set to F2.8) using a 1450 nm light source 11 (with the light intensity adjustment device attached to the light source set to maximum).

[0037] The tip positions of the wires arranged inside the catheter can be observed from symbols 6, 7, and 8 in Fig. 3(B). According to the inventors' study, by adjusting the amount of light, it was possible to fluoroscopically observe structures such as metal meshes incorporated inside the catheter. The state and internal structure inside the catheter sheath cannot be confirmed by visible light observation as shown in Fig. 3(A) (symbol 3 is an external image of an X-ray opaque marker exposed on the surface of the sheath). Furthermore, the following can be seen by comparing symbols 10 and 5 in the same figure. When observed with visible light, the lumen region, wall cross-sectional region, and peripheral region of the blood vessel model appear to be the same color (transparent). When observed with near-infrared light, the above-mentioned regions can be clearly distinguished by their shading.

[0038] As can be seen from reference number 9 in the figure, even when multiple vascular branches included in the vascular model intersect three-dimensionally, the visibility of both blood vessels is not reduced, and both can be clearly observed as planar (2D) images. In the image using visible light, as shown by reference number 4, the contour of the vascular lumen is partially visible, but this contour is not an image of the wall cross-sectional area as shown by reference number 9, but a reflected image of environmental light reflected on the surface of the lumen area and the outer surface of the vascular model. Because this reflected image is visible three-dimensionally (3D), the visualized image of the vascular lumen visualized by this method looks different from the planar (2D) image obtained by X-ray observation.

[0039] The reflected image appears as a light and dark distribution on the lumen area, which reduces the visibility of the lumen area, and is therefore not preferable compared to the method of visualizing the wall cross-sectional area of ​​the present invention. When using visible light, part or all of the vascular model appears three-dimensional (3D) due to the reflection of ambient light, and all opaque objects, including catheters and wires, are observed in three dimensions.

[0040] Near-infrared light is not visible to the naked eye (it is not dazzling even if the light intensity is increased), so using near-infrared light does not impede the operator's work in any way. In other words, even if the light intensity of the near-infrared light source is arbitrarily adjusted to obtain optimal observation conditions, no burden is placed on the operator.

[0041] In the above, a water-soluble polymer is dissolved in the lubricating liquid 6 that fills the inside of the blood vessel model 5 and in the immersion liquid 7 that fills the periphery of the blood vessel model 5. Such a water-soluble polymer is considered to be a particle having a diameter of several nm in an aqueous solution, and generates Rayleigh scattering as shown in FIG. 4. As a result, the near-infrared light from the light source 11 is scattered in the liquid and efficiently irradiated onto the observation target. In addition, if such a liquid is used, scattering occurs when the near-infrared light passes through the surface of the blood vessel model or is reflected by the outer surface, and image information such as the surrounding environment image contained in the irradiated near-infrared light is lost. In addition to this method, a similar effect can be obtained by mixing particles that generate Rayleigh scattering into the material that forms the blood vessel model, thereby scattering the near-infrared light inside the structure of the blood vessel model.

[0042] As a result, compared to when a liquid that does not cause Rayleigh scattering was used, each part of the obtained observation image was a more planar (2D) image closer to that observed using X-rays. This effect was particularly noticeable in the wall cross-sectional region of the blood vessel model, where when a liquid that causes Rayleigh scattering was used, the wall cross-sectional region was observed as a uniformly colored region without any pattern. On the other hand, when a liquid that does not cause Rayleigh scattering was used, images of the surrounding environment were projected onto the wall cross-sectional region, resulting in shading and patterns, and the image was sometimes observed to be somewhat three-dimensional.

[0043] As can be seen from Figure 1, in the near infrared wavelength region of 1300nm to 1550nm, the infrared absorption rate of water is higher than that of the wavelength region of 780nm to 1200nm. The infrared absorption characteristics of silicone rubber vary depending on the type, but silicone rubber (model number: SYLGARD 182, manufactured by The Dow Chemical Company) having the characteristics shown in Figure 1 has lower absorption rates than water in the main wavelength region of near infrared (particularly at a wavelength of 1200nm, it shows an absorption rate close to that of water, and at a wavelength of 1450nm, it shows a significantly higher absorption rate than water).

[0044] According to the study by the present inventors, when near-infrared rays with a wavelength of 1300 to 1550 nm are used, the infrared absorptivity of polymeric materials such as silicone rubber and acrylic resin, and gases such as air, differs from that of water placed in the lumen region of the blood vessel model, making it easier to perform near-infrared spectroscopic observation, and the lumen region can be clearly visualized. Since the near-infrared absorptivity of water is lower than that of catheters and wires, the image of the obtained lumen region can be weakened or completely disappeared on the observation image without affecting the fluoroscopic image of the catheter by using near-infrared rays with a shorter wavelength (such as 1200 nm in the configuration of this embodiment), increasing the amount of light by adjusting the light source and the light amount adjustment device attached to the camera, or adjusting the shading balance of the observation image by the image processing device attached to the camera.

[0045] According to this method, it is possible to easily and instantly select and reproduce X-ray images taken during actual surgery when a contrast agent is administered and when it is not, without performing any physical manipulation of the observation subject, such as administering a contrast agent. As an example, FIG. 5 shows an observation image in which the lumen region is selectively visualized and disappeared by adjusting the light intensity. FIG. 5(B) is an observation image obtained when the aperture of the lens attached to the camera 15 is set to F2.8 using a 1450 nm light source 11 (the light intensity is set to maximum by the adjustment device attached to the light source). Under these conditions, the lumen region (wall cross-sectional region) of the blood vessel model is visualized in a identifiable state together with the fluoroscopic image of the catheter. FIG. 5(C) is an observation 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 these conditions, the fluoroscopic image of the catheter is observed, but the lumen region (wall cross-sectional region) of the blood vessel model has disappeared. FIG. 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 these conditions, the entire observation image becomes dark, making it difficult to visually recognize the state inside the catheter, and is therefore not suitable as an observation condition.

[0046] The light intensity conditions for obtaining Figure 5(B) and Figure 5(C) vary depending on the amount of water, the thickness and material of the sheath 2 of the catheter 1, and even the presence or absence of particles that cause Rayleigh scattering. 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 amount of infrared absorption by the water becomes excessive at wavelengths of 1300 to 1550 nm, and the obtained image becomes dark overall, so a high light intensity is required for the light source. In order to reduce the infrared absorption rate by water and clearly visualize the shape of blood vessels, near-infrared rays with wavelengths shorter than 1300 nm (such as near-infrared rays with wavelengths of 780 nm to 1250 nm) can be used. In this case, it is effective to adjust the amount of near-infrared light so that the shading value of only the area containing water is reduced, thereby creating conditions suitable for near-infrared fluoroscopic observation or near-infrared spectroscopic observation.

[0047] When simulating catheter treatment, it is necessary to adjust observation conditions such as the light intensity and wavelength of the light source while observing the image on the display each time, depending on the catheter and blood vessel model used. When the blood vessel model is curved in three dimensions, or when there is a large difference in height between the object being observed, it may be necessary to adjust the amount of light and the focus according to the distance from the light source to the object being observed.

[0048] As described above, near-infrared spectroscopic observation and near-infrared transmittance observation make it possible to simultaneously observe an observation image of the blood vessel model in which the lumen region of the blood vessel model can be identified and a fluoroscopic image of the catheter. On the other hand, by mixing particles that interfere with near-infrared rays into the material for forming the blood vessel model and / or the liquid that fills the blood vessel model, the opacity of the part where the particles are present during near-infrared observation can be increased, and the region containing the particles, i.e., the lumen region of the blood vessel model, can be forcibly visualized. 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 fine particles and India ink (fine particles mainly composed of carbon). In the near-infrared region, if the particle diameter is larger than about 100 nm, Mie scattering occurs, making the observed image unclear and the transmittance is also greatly reduced, which is not preferable. When fluoroscopic observation is required, it is preferable to maintain the clarity of the observed image by using particles with a particle diameter of less than 100 nm, more preferably about 0.5 nm to 50 nm, to create a state in which Rayleigh scattering occurs, and to exhibit the effect of improving the near-infrared fluoroscopic observation ability compared to when no particles are added, for the above-mentioned reasons. Particles larger than 100 nm are used to visualize areas where fluoroscopic observation of the inside is not required, such as a pseudo-thrombus placed in the lumen region of a blood vessel model.

[0049] In the above, the light source is not particularly limited as long as it can emit near-infrared light with an intensity that allows a fluoroscopic image of the catheter to be observed. From the viewpoint of near-infrared spectroscopic observation, the balance of shading in each part of the observation target can be adjusted by using multiple light sources with different wavelengths or by preparing a light source with a variable wavelength. Wavelength selection can also be done on the camera side by placing a wavelength-selective filter in front of the camera, or by selecting wavelengths during image processing after light is collected by the camera. When light sources with different wavelengths are used, images can be formed by switching between the wavelengths. It is also possible to simultaneously emit light from light sources with different wavelengths and prepare cameras and displays corresponding to each wavelength to simultaneously form images corresponding to each wavelength.

[0050] By using 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, it is possible to selectively visualize or erase only the lumen area while maintaining the fluoroscopic image of the catheter by a simple switching operation. Alternatively, the wavelength can be selected to produce appropriate shading depending on the diameter of the blood vessel model and the depth of the surrounding immersion liquid. Alternatively, the wavelength that shows the optimal absorption and transmission characteristics can be selected depending on the type and material of the catheter used.

[0051] The light source is preferably a surface light source that uniformly irradiates a desired region of the blood vessel model as the observation target with near-infrared rays. A parallel light source may be used for the purpose of clearly observing the contour of the observation target, or a diffuse light source may be used for the purpose of irradiating the observation target from multiple directions to facilitate fluoroscopic observation. A line light source or a point light source may be used to enable observation of only a portion of the observation target, or near-infrared rays from the line light source or point light source may be passed through a light diffusion circuit to uniformly irradiate a desired region of the blood vessel model.

[0052] The light source can also irradiate the observation target from multiple directions. In particular, near-infrared light has low permeability to metals, so in a configuration in which a blood vessel model is placed between the light source and the camera for observation, if the observation target includes a thick metal structure, the near-infrared light is completely blocked by the metal structure. For this reason, when platinum X-ray-opaque markers are partially attached to the stainless steel delivery wire of the aneurysm embolization coil, they cannot be identified.

[0053] The inventors realized that near-infrared light has a characteristic that shows different reflectance depending on the type and wavelength of metal material, and discovered that by performing observations using near-infrared light reflection in addition, it is possible to obtain observation images that allow the identification of structures made of different metal materials, as shown in Figure 6. In FIG. 6, reference numeral 20 denotes the stainless steel delivery wire, and reference numeral 30 denotes the platinum X-ray opaque marker. In near-infrared reflection observation, a second light source for reflecting near-infrared light is disposed in the lateral direction of the blood vessel model (in a direction perpendicular to the axis of the first light source and the camera used in near-infrared fluoroscopic observation, or obliquely upward) and near-infrared light is irradiated onto the blood vessel model. A third light source can be added to additionally irradiate from a direction different from the first light source. In near-infrared reflection observation, the wavelengths of the first light source, second light source, and even third light source can be selected arbitrarily, but in order to suppress chromatic aberration, it is preferable to use the same wavelength for each light source.

[0054] The camera is not particularly limited as long as it can receive near-infrared light from the light source. A plurality of cameras can be used depending on the light source. The display images the output from the camera, and preferably the light source and the camera's associated light adjustment device are positioned so that the amount of light entering the camera can be adjusted while viewing the display, so that the amount of light entering the camera can be adjusted while viewing the display.

[0055] We have been researching ways to capture X-ray opaque markers even more clearly. Fig. 7 shows the configuration of such an imaging device 100. In Fig. 7, the same elements as those in Fig. 2 are given the same reference numerals and their explanation will be omitted. A first near-infrared ray having a wavelength of 940 nm is emitted from a first light source of the image capturing device 100 and is polarized in a first direction by the first polarizing plate 103. The first near-infrared ray polarized in this manner is received by the first light receiving unit 111. A second near-ultraviolet ray having a wavelength of 850 nm is emitted from the second light source 105 and is polarized in a second direction by the second polarizing plate 107. The second near-infrared ray polarized in this manner is reflected by the object to be measured and received by the second light receiving unit 112.

[0056] The first image forming unit 121 forms a first image using the first near-infrared light received by the first light receiving unit 111. The first image forming unit 121 includes a grayscale image generating unit, and the first image is converted to a grayscale image. FIG. 8 shows an example of the first image.

[0057] The second image forming section 122 forms a second image using the second near-infrared light received by the second light receiving section 112. The second image forming section 122 includes a grayscale image generating section, and the second image is grayscaled. FIG. 9 shows an example of the second image.

[0058] The color tone of the second image is inverted in the image inversion unit 128. Here, inversion means inverting the gradation value of each pixel around the grayscale center value, and for example, in the case of a grayscale with 265 gradations, if the value is 160 (=133+27) with the center value 133 as the center, after inversion it becomes 106 (=133-27). The thus inverted 2-1 image is shown in FIG.

[0059] The 2-1 image and the 1st image are combined in the image combining unit 130. In the combining here, the values ​​of corresponding pixels in both images are multiplied together. As a result, black is emphasized toward the black side, and white is emphasized toward the white side. The alignment between the 2-1 image and the 1st image is performed by a known method. The image synthesized in this way is shown in FIG. In FIG. 12, density correction has been performed to emphasize the positions of the X-ray opaque markers.

[0060] Fig. 13 shows an observation device 200 according to another embodiment. In Fig. 13, the same elements as those in Fig. 7 are given the same reference numerals and their description will be omitted. The observation device 200 in FIG. 13 includes a background image storage unit 210, an image evaluation unit 220, and a guidance generation unit 221. A background image store 210 stores images of bones and other tissues, which can be displayed by the image combiner 130 along with the composite image.

[0061] The image evaluation unit 220 evaluates the composite image shown in Fig. 12, for example, using a photoelastic stress observation method or AI. When evaluating the stress generated in the blood vessel model by the photoelastic stress observation method, as shown in Fig. 14, the guidance display unit 221 displays the stress distribution as color (gradation) information superimposed on the composite image as guidance. At the same time, text information can also be displayed.

[0062] In actual catheter-based intravascular surgery, the administered contrast agent is washed away by the bloodstream, so blood vessels are only visible for a few seconds. In addition, due to toxicity, there is a limit to the amount of contrast agent that can be used, and it cannot be administered multiple times. For this reason, a method is used in which the blood vessel visualization image at the moment the contrast agent is administered is saved as a still image and then superimposed on an observation image in which only the catheter is visualized (vascular roadmapping method). It was confirmed that the vascular roadmapping method can be reproduced by storing a still image in which the vascular lumen is visualized in the near-infrared observation of the present invention, changing the observation conditions to eliminate the image of the vascular lumen so that only the catheter is visualized, and then performing image processing to overlay and present the still image as necessary. In reproducing the vascular roadmapping method, it is preferable to further provide the observation device of the present invention with a hardware interface such as a foot pedal or joystick so that various operations associated with the image processing can be performed in a manner similar to that of actual catheter intravascular surgery.

[0063] The blood vessel model can be made of a crosslinked soft polymer material such as silicone rubber, urethane rubber, soft polyvinyl chloride, and soft photocurable resin, or a hard polymer material such as acrylic resin or hard photocurable resin, or a combination of these materials that transmit near-infrared rays. In the lumen region of the blood vessel model, a substance that exhibits infrared absorption characteristics different from the material forming the blood vessel model must be placed so that the region can be identified during near-infrared spectroscopic observation. For example, when silicone rubber is used as the material forming the blood vessel model, the lumen of the blood vessel model can be filled with a lubricating liquid whose main component is water, or the lubricating liquid can be applied to the lumen surface of the blood vessel model and then the lumen can be filled with air.

[0064] The blood vessel model in the present invention may be a blood vessel model having a membranous structure similar to that of a biological blood vessel (hereinafter referred to as a "membranous blood vessel model"), a blood vessel model in which a cavity simulating a blood vessel lumen is formed inside a block body such as a rectangular parallelepiped, a cylinder, or a sphere (hereinafter referred to as a block-shaped blood vessel model), or a blood vessel model combining both of them. In the membranous blood vessel model, liquid, gas, or solid (particularly gel-like solid) can be selectively placed in the lumen region and the surrounding region of the blood vessel model depending on the situation (for example, water can be placed in the lumen region and water or air can be placed in the surrounding region). As a result, in the membranous blood vessel model, not only the lumen region of the blood vessel model but also the wall cross-sectional region of the blood vessel model can be visualized so as to be distinguishable. In the block-shaped blood vessel model, various substances can be selectively placed in the lumen region depending on the situation.

[0065] As materials for constructing such a vascular model, various materials can be used as long as they are near-infrared transparent, such as soft materials such as silicone rubber, urethane rubber, soft polyvinyl chloride, and soft photocurable resins, gels made of polyvinyl alcohol, acrylic resins, and hard photocurable resins. Since near-infrared rays do not damage the human eye, it is preferable that such a polymeric material is also transparent to visible light so that an operator can visually observe the blood vessel model irradiated with near-infrared rays using visible light.

[0066] Examples of crosslinked polymeric materials include crosslinked soft polymeric materials such as silicone rubber, urethane rubber, soft polyvinyl chloride, and soft photocurable resin, hard polymeric materials such as acrylic resin and hard photocurable resin, and combinations of these materials. The material forming the blood vessel model and the liquid filling the lumen of the blood vessel model may be colored with a dye that can be identified in the visible light region. Many of the dyes used in the visible light region have high transmittance in the near-infrared region, so they have almost no effect on the near-infrared spectroscopic observation image, and the conditions for the image observed in the visible light region and the image observed in the near-infrared region can be set separately. A blood vessel model can also be made from a gel-like substance such as polyvinyl alcohol. Since a blood vessel model made of polyvinyl alcohol has high lubricity due to its physical properties, the material to be filled into the lumen of the blood vessel model can be only water or air. Of course, this does not prevent the addition of a drug that enhances lubricity, such as a surfactant.

[0067] A lesion model simulating a thrombus or plaque can be attached to the blood vessel model in advance or movably installed. In performing near-infrared spectroscopic observation in the present invention, it is preferable to form the lesion model using a material that exhibits near-infrared absorption characteristics different from the material forming the blood vessel model or the substance placed in the lumen region in order to selectively increase the visibility of the lesion model. By observing the simulation process of catheter angioplasty or thrombus using plaque or thrombus made of such a material, it is possible to clearly observe, in the lumen of the blood vessel model, how the plaque is crushed by a balloon or stent, how the thrombus is captured by the stent and is collected while moving in the blood vessel together with the stent.

[0068] In the present invention, a single light receiving unit can be used to simultaneously receive the first near-infrared light transmitted through the object to be observed and the second near-infrared light reflected by the object to be observed, and an image can be formed directly based on the received light without performing any calculations. In forming such an image, when the first near-infrared light and the second near-infrared light have different wavelengths, it is preferable that the lens provided in the light receiving unit has a focus shift correction function. When one light receiving unit is used, the first near-infrared light that has passed through the object to be observed and the second near-infrared light that has been reflected by the object to be observed can be received with a time difference, and the images generated from each can be calculated and combined. In this case, the second image generated from the first near-infrared light can be inverted in color tone, and this can be calculated and combined with the first image generated from the first near-infrared light.

[0069] The present invention is not limited to the above-mentioned embodiment and examples. Various modifications within the scope of the claims and within the scope that can be easily conceived by a person skilled in the art are also included in the present invention. The following items are disclosed: (20) A cassette used in an observation device for observing a blood vessel model into which a catheter is inserted, the cassette incorporating the blood vessel model, The vascular model; A housing for holding the blood vessel model; an immersion liquid filling a gap between an outer peripheral surface of the blood vessel model and an inner peripheral surface of the housing, The immersion fluid includes a material that produces Rayleigh scattering. (21) A cassette used in an observation device for observing a blood vessel model into which a catheter is inserted, the cassette incorporating the blood vessel model, The vascular model; A housing for holding the blood vessel model; an immersion liquid filling a gap between an outer peripheral surface of the blood vessel model and an inner peripheral surface of the housing, The cassette of (20), wherein the immersion liquid contains a material that produces Rayleigh scattering. (22) The cassette according to (20), wherein the material that causes Rayleigh scattering is a water-soluble polymer material.

[0070] In addition, the following is disclosed: (1) An observation device for observing a blood vessel model into which a catheter is inserted, the observation device comprising: a substance having near-infrared absorption characteristics different from a constituent material of the blood vessel model disposed inside the blood vessel model; the catheter including a sheath and wires inserted into the sheath; 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; An observation device in which the first near-infrared light can penetrate the blood vessel model, materials in the blood vessel model, and a sheath of the catheter. (2) A method for observing an object using the observation device according to (1), comprising: The first light source is caused to emit the first near-infrared light toward the observation target, and the first light receiving unit is caused to receive the first near-infrared light that has transmitted through the observation target; causing the first image generating unit to generate the first image based on the first near-infrared light received by the first light receiving unit; causing the display to display the first image; An observation method that enables the sheath of the catheter, the wires within the sheath, and the blood vessel model to be simultaneously viewed by adjusting the amount of the first near-infrared light used to generate the first image. (3) The catheter further includes a second light source that emits a second near-infrared ray reflected by the catheter, 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, an image synthesis unit that superimposes the first image and the second image; the second image is displayed over the first image on the display; The observation device described in (1). (4) A method for observing an object using the observation device according to (3), The first light source is caused to emit the first near-infrared light toward the observation target, and the first light receiving unit is caused to receive the first near-infrared light that has passed through the observation target; causing the first image generating unit to generate the first image based on the first near-infrared light received by the first light receiving unit; The second light source is caused to emit the second near-infrared light toward the observation target, and the second light receiving unit is caused to receive the second near-infrared light reflected by the observation target; causing the second image generating unit to generate the second image based on the second near-infrared light received by the second light receiving unit; causing the image synthesis unit to generate a synthetic image by superimposing the first image and the second image; Displaying the composite image on the display; An observation method that enables the sheath of the catheter, the wires within the sheath, X-ray opaque markers on the wires, and the blood vessel model to be simultaneously viewed by adjusting the amount of the first near-infrared light used to generate the first image and / or adjusting the amount of the second near-infrared light used to generate the second image. (5) A first polarizing unit that polarizes the first near-infrared light in a first direction; A second polarizing unit that polarizes the second near-infrared light in a second direction; a grayscale image generating unit that converts the first image and the second image into grayscale images; The observation device according to (3), further comprising: a tone inversion unit that inverts the tone of a grayscale image of the second image to generate a 2-1 image. (6) An observation device for observing a blood vessel model into which a catheter is inserted, the observation device comprising: a substance having near-infrared absorption characteristics different from a constituent material of the blood vessel model disposed inside the blood vessel model; the catheter including a sheath and wires inserted into the sheath; The camera includes 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, the first near-infrared light is capable of penetrating the blood vessel model, a substance in the blood vessel model, and a sheath of the catheter; a second light source that emits a second near-infrared ray reflected by the catheter, 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; Further, there is provided a method for observing an object using an observation device including a first polarizing unit, a second polarizing unit, a grayscale image generating unit, a tone inversion unit, an image synthesis unit, and a display, comprising: causing the first polarizing unit to polarize the first near-infrared light in a first direction, and causing the first image generating unit to generate the first image based on the first near-infrared light polarized in the first direction and transmitted through the observation target; causing the second polarizing unit to polarize the second near-infrared light in a second direction, and causing the second image generating unit to generate the second image based on the second near-infrared light polarized in the second direction and reflected by the object to be observed; causing the grayscale image generating unit to grayscale the first image and the second image; causing the tone inversion unit to invert the tone of the grayscale image of the second image to generate a 2-1 image; A method for observing an object, in which the image synthesis unit overlays the grayscaled first image and the 2-1 image to generate a composite image and displays it on the display so that the sheath of the catheter, the wires inside the sheath, the X-ray opaque markers on the wires, and the blood vessel model can be simultaneously viewed. (7) The observation method according to (6), further comprising performing density correction on the composite image so that the X-ray opaque marker is emphasized. (8) an image evaluation unit that evaluates a composite image generated by the image synthesis unit; A guidance forming unit that forms guidance based on the evaluation result of the image evaluation unit, The observation device according to (3), wherein the guidance is displayed on the display. (9) An observation device for observing a blood vessel model into which a catheter is inserted, the observation device comprising: a substance having near-infrared absorption characteristics different from a constituent material of the blood vessel model disposed inside the blood vessel model; the catheter including a sheath and wires inserted into the sheath; The camera includes 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, the first near-infrared light is capable of penetrating the blood vessel model, a substance in the blood vessel model, and a sheath of the catheter; a second light source that emits a second near-infrared ray reflected by the catheter, 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; A method for observing an object using an observation device including an image synthesis unit, an image evaluation unit, and a display, comprising: The first light source is caused to emit the first near-infrared light toward the observation target, and the first light receiving unit is caused to receive the first near-infrared light that has passed through the observation target; causing the first image generating unit to generate the first image based on the first near-infrared light received by the first light receiving unit; The second light source is caused to emit the second near-infrared light toward the observation target, and the second light receiving unit receives the second near-infrared light reflected by the observation target; causing the second image generating unit to generate the second image based on the second near-infrared light received by the second light receiving unit; causing the image synthesis unit to superimpose the first image and the second image to generate a synthetic image; causing the image evaluation unit to evaluate the composite image; causing a guidance forming unit to form guidance based on the evaluation result of the image evaluating unit; displaying the composite image and the guidance on the display; The method of observing the subject. (10) The observation device according to (1), wherein the first near-infrared light is monochromatic light. (11) The observation method described in (4), wherein a material having near-infrared absorption characteristics different from the constituent material of the blood vessel model is contained in a material that generates Rayleigh scattering when receiving the first near-infrared light from the first light source and the second near-infrared light from the second light source. (12) The observation method described in (4), wherein the constituent material of the blood vessel model includes a material that generates Rayleigh scattering when receiving the first near-infrared light from the first light source and the second near-infrared light from the second light source. (13) The observation device according to (1), wherein a material that receives the first near-infrared light and causes Rayleigh scattering is contained in a substance having near-infrared absorption characteristics different from a constituent material of the blood vessel model. (14) The observation device according to (1), wherein a constituent material of the blood vessel model contains a material that receives the first near-infrared light and generates Rayleigh scattering. (15) The observation device according to (14), wherein the first near-infrared light has a wavelength of 1300 nm to 1550 nm. (16) An observation device for observing a blood vessel model into which a catheter is inserted, the blood vessel model being filled with a lubricating liquid and the blood vessel model being surrounded by an immersion liquid, the catheter comprising a sheath and wires inserted into the sheath; 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; the lubricating liquid and / or the immersion liquid contains a material that produces Rayleigh scattering; An observation device in which the first near-infrared light can penetrate the blood vessel model, materials in the blood vessel model, and a sheath of the catheter. (17) The observation device according to (16), wherein the first near-infrared light has a wavelength of 1300 nm to 1550 nm. (18) A background image storage unit and an image synthesis unit are further provided, The image synthesis unit synthesizes the background image stored in the background image storage unit with the first image generated by the first image generation unit, The observation device according to (1), wherein the synthesized image is displayed on the display. [Explanation of symbols]

[0071] 1 Catheter 2 Sheath 3 Wires 5. Vascular model 10 Observation equipment 20 Wire 30 Marker

Claims

1. A cassette used in an observation device for observing a blood vessel model into which a catheter is inserted, the cassette incorporating the blood vessel model, The vascular model; A housing for holding the blood vessel model; A lubricating liquid filling the inside of the blood vessel model, The lubricating liquid comprises a material that produces Rayleigh scattering.

2. 2. The cassette according to claim 1, wherein an immersion liquid containing a material that causes Rayleigh scattering in the blood vessel model is provided between an outer peripheral surface of the three-dimensional model and an inner peripheral surface of the housing.

3. 2. The cassette of claim 1, wherein the material that produces Rayleigh scattering is a water-soluble polymeric material.

4. ） 2. A cassette according to claim 1, wherein a lesion model made of a material having near-infrared absorbing properties different from those of the constituent material of the blood vessel model or the lubricating liquid is attached to the blood vessel model.

5. 5. The cassette according to claim 4, wherein the lesion model is movably attached to the blood vessel model.

Images