Observation apparatus and method for a vascular 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 Art

[0002] In the evaluation of catheters inserted into blood vessels, and in the technical training and evaluation of endovascular surgery, it is necessary to observe the shape of the 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, visible light cameras and X-ray projection devices are often used. A method of forming a blood vessel model from a transparent material and filling the lumen of the blood vessel model (hereinafter referred to as "lumen region") with a liquid colored with a dye or the like to observe the blood vessel shape and the catheter inserted into the blood vessel model visually or with a visible light camera is simple. However, in this case, the catheter cannot be fluoroscoped, and the position and state of a guide wire or the like constituting the catheter cannot be confirmed, so the reproducibility of endovascular surgery is low. This problem can be solved by using X-rays, but its use is not easy from the viewpoints of radiation exposure and management.

[0003] Generally, a catheter has a multilayer structure in which wires (those having a treatment function such as a balloon, a coil, a stent, etc., a drug (a liquid such as a contrast agent or a thrombolytic agent), and other sheaths) are inserted into a thin cylindrical sheath. In observation using visible light, the tip position and state of the wires inserted multilayerly inside the sheath cannot be detected. In actual treatment using a catheter, information on the tip position and state of the wires in the sheath is required. In addition, in a practical catheter, in order to specify specific positions of the sheath and the wires, a material that does not transmit X-rays (X-ray non-permeable marker) is attached to the tip and intermediate portions thereof, and in the X-ray projection device used during treatment, the relative positions of each can be confirmed.

[0004] To observe the position and condition of wire tips within a sheath while avoiding X-ray exposure, an observation method combining fluorescence observation technology and image processing technology has been proposed (Non-Patent Literature 1). Furthermore, a lubricating fluid to ensure lubrication between the vascular model and the catheter is proposed in Patent Document 1. [Prior art documents] [Patent Documents]

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

[0006] [Non-Patent Document 1] Kazuaki Fukusaku et al., "Enabling Endovascular Treatment Training Anytime, Anywhere - Development of an Endovascular Treatment Simulation that Does Not Expose Physicians to X-rays," [online], February 19, 2022, 51st Annual Meeting of the Japanese Society of Neuroradiology https: / / www.u-ryukyu.ac.jp / news / 32074 / [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] According to the observation method described in Non-Patent Document 1, it is necessary to attach fluorescent material to the parts of the catheter sheath and wires that you want to visualize. In other words, you cannot use the actual catheter as is. Furthermore, in order to visualize the vascular model, it is necessary to introduce a contrast agent (a liquid containing a fluorescent dye) into the fluid that fills the lumen region of the vascular model.

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

[0009] The inventors of this invention have conducted extensive research to solve the above problems and have discovered that by using near-infrared light, which has higher material penetration than visible light and whose light absorption rate varies in diverse ways depending on the material and wavelength compared to visible light, it is possible to simultaneously or selectively visualize the shape of blood vessels and the state inside the catheter without using contrast agents or the like. In other words, it is not necessary to attach contrast agents or fluorescent materials to the catheter sheath or wires, which were required in conventional technology.

[0010] Near-infrared absorptivity varies greatly depending on the type of substance and the wavelength of near-infrared light used. This characteristic allows near-infrared spectroscopy to measure changes in absorptivity in the near-infrared region and identify the substance's components by comparing the measurement results with a spectral table showing its absorption characteristics. Furthermore, for many substances, the absorptivity changes significantly between the visible light region and the near-infrared region. This property of near-infrared light allows for the observation of liquids containing dyes that appear opaque in the visible light region as transparent in the near-infrared region. Similarly, various soft polymers such as silicone rubber, various hard polymers such as acrylic resins, and various liquids such as water and oil, which appear transparent in the visible light region, can be observed as different colors (shades) in the near-infrared region without the use of contrast agents (hereinafter referred to as "near-infrared spectroscopic observation"). Moreover, since the near-infrared absorptivity (i.e., near-infrared transmittance) of each substance changes drastically by varying the wavelength in the near-infrared region, this characteristic can be used to identify differences in the shape and material of various parts of a composite structure composed of different materials.

[0011] The inventors have discovered that, due to the characteristics of near-infrared light, near-infrared spectroscopy allows for the observation of various parts of a vascular model, which appear completely transparent in the visible light region (both inside and out), as images that distinguish differences in shape and material, without the use of contrast agents or the like. They also discovered that by changing the wavelength and intensity of the near-infrared light used (light source intensity and exposure settings of the observation device), the balance of the contrast of various parts of the vascular model can be altered without physically manipulating the object being observed. Furthermore, they found that by changing the wavelength and intensity of the near-infrared light, it is possible to selectively visualize or conceal the vascular shape while keeping the fluoroscopic image of the catheter visible 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 near-infrared radiography (hereinafter referred to as "near-infrared radiography"). As a simpler and safer method than X-ray observation, it is used for non-destructive testing of semiconductors and for detecting foreign objects in liquids.

[0013] While visible light observation provides a three-dimensional (3D) view of the vascular model, near-infrared fluoroscopy yields a two-dimensional (2D) image due to its transparency. This two-dimensional image closely resembles the X-ray fluoroscopic images obtained in catheter-based endovascular surgery, making it suitable for simulating such procedures. Furthermore, even when the various parts of the vascular model intersect three-dimensionally, i.e., in front of and behind the direction of near-infrared irradiation, a two-dimensional fluoroscopic image similar to that obtained in X-ray observation can be obtained.

[0014] Actual catheters share the common characteristic of having a thin-film, multilayer structure, but the constituent materials and film thickness of the sheath are not uniform depending on the type (various soft resins such as polyester, polyethylene, polyamide (nylon), polyurethane, and silicone rubber are used as sheath constituent materials). Furthermore, catheters and wires incorporate complex structures such as metal structures like meshes and radiopaque markers, and mechanical structures like balloons and coil release mechanisms. For catheters with these characteristics, the inventors have found that by performing observations that incorporate both near-infrared fluoroscopy and near-infrared spectroscopy, it is possible to reproduce the catheter as an image close to the X-ray observation image during actual surgery, and even as a functionally enhanced observation image that includes information not obtainable from X-ray observation alone.

[0015] By using near-infrared light, catheters can be observed fluoroscopically, and observational images that can distinguish differences in their structure and material can be obtained. Furthermore, by changing the wavelength and intensity of the near-infrared light used, the contrast balance of the observational image can be altered without physically manipulating the vascular model. For example, a specific region of the vascular model to be observed can be selected, and the contrast balance of the selected region can be changed or reversed, or the specific region can be made visible or invisible.

[0016] The first aspect of this invention is defined as follows: An observation device for observing a vascular model into which a catheter has been inserted, wherein a material having near-infrared absorption properties different from the constituent materials of the vascular model is placed inside the vascular model, and the catheter comprises 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 capable of receiving 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 defined as above, since the substance disposed in the blood vessel model has near-infrared absorption specificity different from the constituent material of the blood vessel model, in near-infrared spectroscopic observation, it is possible to visually recognize 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. At this time, since the catheter inserted into the blood vessel model has permeability different from the constituent material of the blood vessel model and the substance with respect to near-infrared rays, the catheter can be observed separately from the blood vessel model and the substance.

[0017] The second aspect of this invention is defined as follows. An observation method for an observation target using the observation device according to the first aspect, causing the first light source to emit the first near-infrared ray toward the observation target, and causing the first light receiving unit to receive the first near-infrared ray transmitted through the observation target; causing the first image generation unit to generate the first image based on the first near-infrared ray received by the first light receiving unit; causing the display to display the first image; An observation method for the observation target, which, if necessary, adjusts the light amount of the first near-infrared ray used for generating the first image so that the sheath of the catheter, the wires in the sheath, and the blood vessel model can be visually recognized simultaneously.

[0018] As described in the first aspect, it is possible to separately observe the blood vessel model and the catheter inserted therein by near-infrared spectroscopic observation. If necessary, by adjusting the light amount of the first infrared ray used for generating the first image, a perspective image of the catheter can be displayed together with the blood vessel model on the image of the display. That is, near-infrared fluoroscopy is possible by adjusting the light amount of near-infrared rays. Here, "if necessary" means that if the blood vessel model and the catheter constituting the observation target are standardized, the light amount can be adjusted in advance so that adjustment of the light amount is not required during observation (hereinafter the same in this specification).

[0019] Since it is a prerequisite for catheter simulation to be able to visually recognize the catheter sheath, the wires inside the sheath, and the blood vessel model simultaneously, the method for observing the blood vessel model defined in the second aspect is practical. By adjusting the amount of near-infrared light, it is also possible to selectively display only the outer contour image (non-fluoroscopic image) of the catheter, the outer contour image of the catheter and the image of the blood vessel model, only the fluoroscopic image of the catheter, or only the blood vessel model on the image of the display.

[0020] In the above, as an adjustment device for adjusting the amount of near-infrared light, those attached to the near-infrared light source to adjust the amount of near-infrared light emitted from the light source, an aperture attached to the light receiving part such as a camera to adjust the amount of light collected by the camera, those that process the image taken by the camera and adjust the amount of light, etc. can be used.

[0021] The third aspect of this invention utilizes near-infrared reflection observation. Near-infrared light has different reflection characteristics depending on the material it irradiates. For example, there are differences in reflection characteristics between iron (stainless steel) and platinum. Among the wires constituting the catheter, there is one in which platinum is attached in the middle of a stainless steel wire to serve as an X-ray non-permeable marker. Since both stainless steel and platinum do not transmit near-infrared light, neither near-infrared spectroscopic observation nor near-infrared fluoroscopic observation is effective for such wires.

[0022] On the other hand, since the near-infrared reflection characteristics are different between stainless steel and platinum, by irradiating near-infrared light from a second near-infrared light source and condensing the reflected light from the object (in the above example, the wire equipped with a platinum marker) onto the light receiving part, it is possible to distinguish and observe the stainless steel, which is the base metal of the wire, and the platinum, which is the marker. And this observation can be carried out in combination with the near-infrared spectroscopic observation and near-infrared fluoroscopic observation described in the second aspect.

[0023] Therefore, the third aspect of this invention is defined as follows. That is, A first-phase observation apparatus further comprising a second light source emitting second near-infrared light, a second light receiving unit capable of receiving the second near-infrared light, a second image generating unit and an image synthesis unit that generate a second image based on the second near-infrared light captured by the second light receiving unit, The image synthesis unit is used to superimpose the first image and the second image to form a composite image. The composite image is displayed on the aforementioned display.

[0024] The observation method using the observation device for the third phase, as defined in this way, is as follows: The third aspect is a method of observing an object using a prescribed observation device, The first light source emits the first near-infrared light toward the object to be observed, and the first near-infrared light that has passed through the object to be observed is received by the first light receiving unit. The first image generation unit generates a first image based on the first near-infrared light received by the first light receiving unit. The second light source emits the second near-infrared light toward the object to be observed, and the second near-infrared light reflected by the object to be observed is received by the second light receiving unit. The second image generation unit generates a second image based on the second near-infrared light received by the second light receiving unit. The image synthesis unit generates a composite image by superimposing the first image and the second image. The composite image is displayed on the aforementioned display. Here, by adjusting the amount of first near-infrared light used to generate the first image as needed, and / or adjusting the amount of second near-infrared light used to generate the second image as needed, the sheath of the catheter, the wires inside the sheath, the radiopaque markers on the wires, and the vascular model can be visualized simultaneously.

[0025] The observation apparatus of the fifth aspect of this invention is defined as follows: In the observation apparatus defined in the third aspect, a grayscale image generation unit that converts the first image and the second image into grayscale, The system comprises an image inversion unit that generates a second-first image by inverting the gradation of the grayscale image of the second image.

[0026] The observation method using the observation device for the fifth phase, as defined in this way, is as follows: An observation method using a prescribed observation device in the fifth phase, The grayscale image generation unit converts the first image and the second image into grayscale. The image inversion unit inverts the gradation of the grayscaled second image to form the second-first image. The image synthesis unit superimposes the grayscaled first image and the second-1 image, and then calculates the value of each pixel in each image to synthesize them.

[0027] The seventh observation apparatus of this invention is defined as follows. That is, in the observation apparatus specified in the fifth phase, A first polarization unit that polarizes the first near-infrared light in a first direction, A second polarization unit that polarizes the aforementioned second near-infrared light in a second direction, The device further comprises a housing for housing the first light-receiving unit and the second light-receiving unit, wherein the first light-receiving unit is capable of receiving first near-infrared light polarized in the first direction, and the second light-receiving unit is capable of receiving second near-infrared light polarized in the second direction. The first image generation unit generates the first image based on the first near-infrared light polarized in the first direction, The second image generation unit is instructed to generate the second image based on the second near-infrared light polarized in the second direction.

[0028] The observation method using the observation device for the seventh phase, as defined in this way, is as follows: The seventh stage is a method of observing an object using a prescribed observation device, The grayscale image generation unit converts the first image and the second image into grayscale. The image inversion unit inverts the gradation of the grayscaled second image to form the second-first image. The aforementioned image synthesis unit superimposes the grayscaled first image and the second-1 image, and then calculates and synthesizes the values ​​for each pixel of each image to obtain the object to be observed.

[0029] In the above, the near-infrared wavelengths from the first and second light sources can be excluded from the 1300nm to 1550nm range, allowing the use of near-infrared wavelengths that are less affected by absorption by water. Because the amount of water transmitted by the first near-infrared light from the first light source and the amount of water transmitted by the second near-infrared light from the second light source are different, using near-infrared wavelengths that have a large effect on light absorption makes it difficult to simultaneously produce clear images of both the transmitted image from the first light source and the reflected image from the second light source. It is preferable to form the second light source using LEDs with a wavelength of 1300 nm or less, which are readily available industrially and have relatively little effect from absorption by water.

[0030] In the above, it is preferable to use monochromatic light for the first and second near-infrared rays. By installing the second near-infrared rays at multiple locations and emitting them towards the object of observation from multiple directions, the visibility of the X-ray opaque markers on the wires can be observed stably regardless of their position. Instead of installing multiple second near-infrared rays, mirrors or half-mirrors can also be used in combination. By using mirrors or half-mirrors, the number of installation locations for the second near-infrared rays can be reduced. In particular, when observing the object of observation while it is immersed in liquid, when the second near-infrared rays are emitted towards the object of observation, they are reflected (including total internal reflection) / refracted by the liquid surface or the surface of the liquid container, making irradiation from a specific direction difficult or impossible. In such cases, this problem can be avoided by installing mirrors or half-mirrors in the liquid to reflect the second near-infrared rays and then irradiating the object of observation. Regardless of whether or not the object is immersed in liquid, mirrors or half-mirrors can also be included as part of the structure of the object of observation, including the blood vessel model. This reduces the constraints on the installation location of the second near-infrared light source and also allows for the addition of functions such as polarization state adjustment (e.g., polarization state reversal). Multiple monochromatic lights of different wavelengths may be used for the second near-infrared light. In this case, each of these monochromatic lights is polarized to a different state and emitted toward the object to be observed. By combining them optically or numerically in the second light receiving unit or the image synthesis unit, the visibility of the X-ray opaque markers of the wires in near-infrared reflection observation can be improved. Even in the near-infrared range, devices with a wide range of wavelengths (e.g., near-infrared lamps) require adjustment for wavelength-dependent chromatic aberration. By using a lens with a focus shift correction function in the near-infrared region, the lens's focus can be set to the same position for different wavelengths. This method eliminates the need to adjust for chromatic aberration for each wavelength, simplifying the equipment configuration and improving workability during use. By using a polarizing camera equipped with a polarizing filter for each pixel in a specific direction, the first and second light-receiving units can be integrated into a single camera. This method eliminates the need to adjust the relative position and magnification of the image, simplifying the equipment configuration and improving workability during use. Here, monochromatic near-infrared radiation includes near-infrared radiation emitted from the LEDs that make up the light source. The wavelength of near-infrared radiation from an LED light source is based on the LED's band gap, so if the band gap is wide due to impurities in the LED, near-infrared radiation with a wavelength range corresponding to that band gap will be emitted from the LED light source. Near-infrared light emitted from a near-infrared lamp can be monochromatized by passing it through a filter that selectively transmits wavelengths. [Brief explanation of the drawing]

[0031] [Figure 1] Figure 1 shows the spectra of water and silicone rubber, illustrating their near-infrared absorption characteristics. [Figure 2] Figure 2 is a schematic diagram showing the observation device of this invention. [Figure 3] In Figure 3, 3A shows the observation image in visible light, and 3B shows the observation image using near-infrared light at 1450 nm. [Figure 4] Figure 4 is a graph showing the relationship between particle radius, wavelength, and Rayleigh observation. [Figure 5] Figure 5 shows an observation image of an embodiment of this invention. [Figure 6] Figure 6 shows an observation image obtained by near-infrared reflection observation. [Figure 7] Figure 7 is a block diagram showing an observation apparatus of another embodiment of the present invention. [Figure 8] Figure 8 shows an example of the first image obtained from the first near-infrared light using the apparatus shown in Figure 7. [Figure 9] Figure 9 shows an example of a second image obtained from the second near-infrared light source using the apparatus shown in Figure 7. [Figure 10] Figure 10 shows an example of Image 2-1, which is created by inverting the color tones of Image 2. [Figure 11] Figure 11 shows a composite image of the first image and the second-first image. [Figure 12] Figure 12 shows the image from Figure 11 with density correction to highlight the radiopaque markers. [Figure 13] Figure 13 is a block diagram showing an observation apparatus of another embodiment of the present invention. [Figure 14] Figure 14 shows an example of an image output from the device shown in Figure 13. [Modes for carrying out the invention]

[0032] Near-infrared generally refers to light with wavelengths between 780 nm and 2500 nm. The absorption rate of near-infrared light varies depending on its wavelength and the material (see Figure 1). It can be seen that the infrared absorption rate of water changes significantly depending on the wavelength in the near-infrared region. The lumen of vascular models is often filled with fluid to mimic blood, and this fluid is typically an aqueous solution consisting mainly of water, similar to blood, with lubricating components added as needed. To enable simultaneous and effective observation of both near-infrared fluoroscopy and near-infrared spectroscopy, 1450 nm was selected as the wavelength in the near-infrared region where water has a significantly high absorption rate and which is easily differentiated from the absorption rates of air and silicone rubber. Observation of the vascular model and the catheter inserted into the vascular model was performed using this wavelength.

[0033] Figure 2 shows the structure of the observation device 10. In the figure, reference numeral 1 indicates a catheter. This catheter 1 comprises a sheath 2 and wires 3 inserted into the sheath 2. Reference numeral 5 indicates a blood vessel model, and the lumen of the blood vessel model 5 is filled with a lubricating fluid 6. This lubricating fluid may be circulated to give it fluidity. The area surrounding the blood vessel model 5 is filled with an immersion fluid 7 that does not contain lubricating components. The observation device 10 comprises a first near-infrared light source 11, a light intensity adjustment device 13, a first near-infrared camera 15, and a display 17.

[0034] The vascular models are made of silicone rubber provided by Fine Biomedical Co., Ltd., with a film thickness of 0.3 mm to 3.0 mm and a lumen of 1 mm to 15 mm. The lumen region of the vascular models is filled with a lubricating fluid, which is a mixture of water and lubricating components. This lubricating fluid is a substance with near-infrared absorption properties different from those of the constituent materials of the vascular models. The catheter used was the Excelsior Microcatheter manufactured by Stryker Japan Ltd. The wires used were GDC coils manufactured by Stryker Japan Ltd. For the first near-infrared light source 11, an infrared illuminator (model number: TH2-100X100IR145) manufactured by CCS Corporation was used. For the light intensity adjustment device 13, a power supply (model number: PD-3024) equipped with a function to adjust the output of the light source 11, i.e., the amount of near-infrared light emitted from the light source 11 was used. For the near-infrared camera 15, a near-infrared camera (model number: ABA-013VIR) manufactured by AVAL DATA Co., Ltd. and a polarizing camera (model number: XCG-CP510) manufactured by Sony Corporation were used, and for the camera lens, a near-infrared compatible lens (model number: LM35HC-SW and model number: LM35HC-VIS-SW) manufactured by Kowa Optronics Co., Ltd. was used.

[0035] As shown in Figure 2, the 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 its light intensity is adjusted by the light intensity adjustment device 13. The near-infrared light irradiated from the light source 11 onto 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.

[0036] In the above setup, Figure 3(A) shows a monochrome image of the vascular model and the catheter inserted into the vascular model as observed by a visible light optical camera. Figure 3(B) shows an image of the vascular model and the catheter inserted into the vascular model as observed by camera 15 (with the aperture of the camera lens set to F2.8) using a 1450nm light source 11 (with the light intensity set to maximum using the light intensity adjustment device attached to the light source).

[0037] The tip positions of wires placed inside the catheter can be observed from reference numerals 6, 7, and 8 in Figure 3(B). According to the inventors' studies, by adjusting the light intensity, structures such as metal mesh incorporated inside the catheter could also be observed fluoroscopically. The state inside the catheter sheath and the internal structure cannot be confirmed by visible light observation as shown in Figure 3(A) (reference numeral 3 is an external image of an X-ray opaque marker exposed on the surface of the sheath). Furthermore, the following can be seen from the comparison between reference numerals 10 and 5 in the same figure. In visible light observation, the lumen region, wall cross-sectional region, and perivascular region of the blood vessel model appear to be the same color (transparent). In near-infrared observation, each of the above regions can be clearly distinguished by differences in density.

[0038] As can be seen from reference numeral 9 in the figure, even when multiple vascular branches included in the vascular model intersect in three dimensions, the visibility of both vessels is not reduced, and both can be clearly observed as planar (2D) images. In the visible light image, as shown by reference numeral 4, the outline of the vascular lumen is partially visible, but this outline is not an image of the wall cross-section region observed as shown by reference numeral 9, but rather a reflected image produced by the reflection of ambient light from the surface of the lumen region or the outer surface of the vascular model. Since this reflected image is viewed three-dimensionally (3D), the visualized image of the vascular lumen visualized by this method differs from the planar (2D) image obtained by X-ray observation.

[0039] The reflected image appears as a density distribution on the lumen region, leading to a decrease in the visibility of the lumen region. This method is less suitable compared to the method for visualizing the wall cross-section region of the present invention. In methods using visible light, part or all of the vascular model can be seen in three dimensions (3D) due to reflection of ambient light, and all opaque objects, including catheters and wires, can also be observed in three dimensions (3D).

[0040] Since near-infrared light is invisible to the naked eye (and does not cause glare even when the light intensity is increased), using near-infrared light does not interfere with the operator's work in any way. In other words, adjusting the light intensity of the near-infrared light source to obtain optimal observation conditions does not place any burden on the operator.

[0041] In the above, a water-soluble polymer was dissolved in the lubricating liquid 6 filling the inside of the blood vessel model 5 and the immersion liquid 7 filling the area around the blood vessel model 5. This water-soluble polymer is thought to be particles with a diameter of several nanometers in the aqueous solution, and as shown in Figure 4, it causes Rayleigh scattering. As a result, near-infrared light from the light source 11 is scattered in the liquid and efficiently irradiated onto the object of observation. Furthermore, by using such a liquid, scattering occurs when the near-infrared light passes through the surface of the blood vessel model or is reflected from the outer surface, and image information such as the surrounding environment contained in the irradiated near-infrared light is lost. In addition to this method, a similar effect can also be obtained by mixing particles that cause Rayleigh scattering into the material forming the blood vessel model, thereby scattering near-infrared light inside the structure of the blood vessel model.

[0042] As a result, compared to the case where a liquid that does not produce Rayleigh scattering was used, the obtained observed image was more planar (2D), with each part being closer to the image observed by X-ray. This effect was particularly noticeable in the wall cross-section region of the blood vessel model, where, when a liquid that produces Rayleigh scattering was used, the wall cross-section region was observed as a uniform color region without any pattern. On the other hand, with a liquid that does not produce Rayleigh scattering, images of the surrounding environment were projected onto the wall cross-section region, resulting in variations in density and patterns, and sometimes the image appeared somewhat three-dimensional.

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

[0044] According to the inventors' studies, when near-infrared light with a wavelength of 1300 to 1550 nm is used, differences in infrared absorption rates occur between water placed in the lumen region of a blood vessel model and polymer materials such as silicone rubber and acrylic resin, as well as gases such as air. This makes near-infrared spectroscopy easier, and the lumen region can be clearly visualized. Since the near-infrared absorption rate of water is lower than that of catheters and wires, the resulting image of the lumen region can be reduced in visibility or completely eliminated on the observation image without significantly affecting the fluoroscopic image of the catheter. This can be achieved by using near-infrared light with a shorter wavelength (such as 1200 nm in this configuration), adjusting the light intensity by adjusting the light source or the light intensity adjustment device attached to the camera, or adjusting the contrast balance of the observation image using the image processing device attached to the camera.

[0045] This method allows for easy and instantaneous selection and reproduction of X-ray images from actual surgical procedures, showing both images with and without contrast agent administration, without requiring any physical manipulation of the object being observed, such as the administration of contrast agents. As an example, Figure 5 shows observation images when the lumen region is selectively visualized and obscured by adjusting the light intensity. Figure 5(B) is an observation image obtained when using a 1450nm light source 11 (with the light intensity set to maximum using the adjustment device attached to the light source) and setting the aperture of the lens attached to the camera 15 to F2.8. Under these conditions, the fluoroscopic image of the catheter and the lumen region (wall cross-section region) of the vascular model are visualized in a way that allows for identification. Figure 5(C) is an observation image obtained when using the same light source 11 but setting the aperture of the lens attached to the camera 15 to F1.8. Under these conditions, the fluoroscopic image of the catheter is observed, but the lumen region (wall cross-section region) of the vascular model disappears. Figure 5(A) is an observation image obtained when using the same light source 11 but setting the aperture of the lens attached to the camera 15 to F5.0. Under these conditions, the entire observation image becomes dark, making it difficult to see the state inside the catheter, so these observation conditions are not suitable.

[0046] The amount of light required to obtain Figures 5(B) and 5(C) varies depending on the amount of water, the thickness and material of the sheath 2 of catheter 1, and the presence or absence of particles that cause Rayleigh scattering. For example, when the diameter of the blood vessel model is large, or when the depth of the immersion fluid 7 surrounding the blood vessel model is large, the amount of infrared absorption by water becomes excessively large at wavelengths of 1300 to 1550 nm, resulting in a generally darker image, thus requiring a high light intensity from the light source. To reduce the infrared absorption rate by water and clearly visualize the shape of blood vessels, near-infrared light with wavelengths shorter than 1300 nm (such as near-infrared light 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 contrast value decreases only in the areas containing water, thereby creating conditions suitable for near-infrared radiography and near-infrared spectroscopy.

[0047] During catheter treatment simulations, it is necessary to adjust observation conditions such as the light intensity and wavelength of the light source while observing the image displayed on the screen, depending on the catheter and vascular model being used. When there are significant differences in elevation of the object being observed, such as when the blood vessel model is three-dimensionally curved, it may be necessary to adjust the light intensity and focus according to the distance from the light source to the object being observed.

[0048] As described above, near-infrared spectroscopy and near-infrared transmission observation allow for simultaneous observation of a vascular model, enabling identification of the luminal region of the vascular model, and a fluoroscopic image of the catheter. On the other hand, by mixing particles that interfere with near-infrared light into the material forming the blood vessel model and / or the liquid filling the blood vessel model, the opacity of the area where the particles are present during near-infrared observation can be increased, thereby forcibly visualizing the region containing the particles, i.e., the lumen region of the blood vessel model. As particles that interfere with near-infrared light, particles that absorb near-infrared light, particles that scatter near-infrared light, or particles that reflect near-infrared light can be used. For example, aluminum nanoparticles or India ink (carbon-based nanoparticles) can be used. In the near-infrared region, if the particle size is larger than approximately 100 nm, Mie scattering occurs, making the observed image unclear and significantly reducing transmittance, which is undesirable. When fluoroscopic observation is required, it is preferable to use particles with a particle size of less than 100 nm, more preferably 0.5 nm to 50 nm, to induce Rayleigh scattering, thereby maintaining the clarity of the observed image and, for the reasons mentioned above, exhibiting the effect of improving near-infrared fluoroscopic observation ability compared to when no particles are added. Furthermore, particles larger than 100 nm are used to visualize areas where fluoroscopic observation of the interior is unnecessary, such as pseudo-thrombi placed in the lumen region of a vascular model.

[0049] In the above, the light source is not particularly limited as long as it can emit near-infrared light of sufficient intensity to observe a fluoroscopic image of the catheter. From the perspective of near-infrared spectroscopic observation, the contrast balance of 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 performed on the camera side. This can be done by placing a wavelength-selective filter in front of the camera, or by selecting wavelengths during image processing after the camera has focused the light. When using light sources with different wavelengths, it is possible to form images by switching wavelengths. Furthermore, by simultaneously emitting light from light sources with different wavelengths and preparing cameras and displays corresponding to each wavelength, it is possible to simultaneously form images corresponding to each wavelength.

[0050] By using a first light source that emits near-infrared light with wavelengths of 1300nm to 1550nm, which has a high absorption rate by water, and a second light source with wavelengths of 780nm to 1250nm, which has a relatively low absorption rate by water, it is possible to selectively visualize or obscure only the lumen region while maintaining the fluoroscopic image of the catheter with a simple switching operation. Alternatively, wavelengths can be selected to produce appropriate density depending on the diameter of the vascular model and the depth of the surrounding immersion fluid. Alternatively, wavelengths exhibiting 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 evenly irradiates a desired area of ​​the vascular model being observed with near-infrared light. A parallel light source may be used for purposes such as clearly observing the contour of the object being observed, or a diffuse light source may be used to facilitate fluoroscopic observation by irradiating the object from multiple directions. It is also possible to use a line light source or a point light source to observe only a part of the object being observed, or to pass near-infrared light from a line light source or a point light source through a light diffusion circuit to evenly irradiate a desired area of ​​the vascular model.

[0052] The light source can also illuminate the object being observed from multiple directions. Near-infrared light, in particular, has low penetration through metals. Therefore, in a configuration where a vascular model is placed between the light source and the camera for observation, if the object being observed includes a thick metal structure, the near-infrared light will be completely blocked by that metal structure. As a result, it becomes impossible to distinguish between stainless steel delivery wires of aneurysm embolization coils, for example, that have partially platinum radiopaque markers attached to them.

[0053] The inventors realized that near-infrared light exhibits different reflectivity depending on the type and wavelength of the metal material. By performing observations using near-infrared reflection, they found that it is possible to obtain observation images that allow for the identification of structures made of different metal materials, as shown in Figure 6. In Figure 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 generating near-infrared reflection is placed on the side of the blood vessel model (in a direction perpendicular to the axis of the first light source and camera used for near-infrared fluoroscopy observation, or diagonally upward) to irradiate the blood vessel model with near-infrared light. A third light source can also be added to irradiate additionally from a different direction than the first light source. In near-infrared reflection observation, the wavelengths of the first light source, the second light source, and even the third light source can be arbitrarily selected, but in order to suppress chromatic aberration, it is preferable to make the wavelengths of each light source the same.

[0054] The camera is not particularly limited as long as it can receive near-infrared light from the light source. Multiple cameras can be used depending on the light source. The display visualizes the output from the camera. It is preferable that the light source and the camera's light intensity adjustment device be positioned in a location that allows adjustment while viewing the display, so that the amount of light entering the camera can be adjusted while viewing the image on the display.

[0055] We have been conducting extensive research to enable even clearer imaging of radiopaque markers. Figure 7 shows the configuration of such imaging device 100. In Figure 7, elements identical to those in Figure 2 are denoted by the same reference numerals, and their descriptions are omitted. A 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 a first direction by the first changing plate 103. This polarized first near-infrared light is received by the first light receiving unit 111. Second near-ultraviolet light with a wavelength of 850 nm is emitted from the second light source 105 and polarized in a second direction by the second polarizing plate 107. This polarized second near-infrared light 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 generation unit, and the first image is converted to grayscale. Figure 8 shows an example of the first image.

[0057] The second image forming unit 122 forms a second image using the second near-infrared light received by the second light receiving unit 112. The second image forming unit 122 includes a grayscale image generation unit, and the second image is converted to grayscale. Figure 9 shows an example of the second image.

[0058] The second image has its color tone inverted in the image inversion unit 128. Here, inversion means inverting the gradation value of each pixel around the grayscale center value. For example, in the case of a 265-gradation grayscale, if the center value is 133 and the value is 160 (=133+27), then after inversion it becomes 106 (=133-27). The reversed 2-1 image is shown in Figure 10.

[0059] Image 2-1 and Image 1 are combined in the image combining unit 130. In this combining process, the values ​​of corresponding pixels in both images are multiplied. As a result, black is emphasized to the black side, and white is emphasized to the white side. The alignment of Image 2-1 and Image 1 will be performed using a well-known method. The image synthesized in this way is shown in Figure 11. Figure 12 shows the image after density correction, highlighting the position of the radiopaque marker.

[0060] Figure 13 shows another embodiment of the observation apparatus 200. In Figure 13, elements identical to those in Figure 7 are denoted by the same reference numerals, and their descriptions are omitted. The observation device 200 in Figure 13 includes a background image storage unit 210, an image evaluation unit 220, and a guidance generation unit 221. The background image storage unit 210 stores images of bones and other tissues, and these images can be displayed in conjunction with the composite image by the image synthesis unit 130.

[0061] The image evaluation unit 220 evaluates the composite image shown in Figure 12 using, for example, photoelastic stress observation or AI. As shown in Figure 14, when evaluating the stress generated in the blood vessel model using photoelastic stress observation, the guidance display unit 221 can display the stress distribution as color (gradation) information superimposed on the composite image as guidance. It can also display text information.

[0062] In actual catheter-based endovascular surgery, the administered contrast agent is washed away by the bloodstream, so the blood vessels are only visualized for a few seconds. Furthermore, due to toxicity, there is a limit to the amount of contrast agent that can be used, and it cannot be administered repeatedly. Therefore, a technique (vascular roadmap method) is used in which the vascular visualization image at the moment of contrast agent administration is saved as a still image and superimposed onto an observational image in which only the catheter is visualized. In near-infrared observation according to the present invention, it was confirmed that the vascular roadmap method can be reproduced by saving a still image of the vascular lumen in a visualized state, then changing the observation conditions to make the image of the vascular lumen disappear so that only the catheter is visible, and then performing image processing to overlay the still image as needed. In order to reproduce the vascular roadmap method, it is preferable to further equip the observation device of the present invention with hardware interfaces such as a foot pedal or joystick so that various operations associated with the image processing can be performed in a manner similar to actual catheter endovascular surgery.

[0063] The blood vessel model can be made from cross-linked soft polymer materials such as silicone rubber, urethane rubber, soft polyvinyl chloride, and soft photocurable resin, or from hard polymer materials such as acrylic resin and hard photocurable resin, or from combinations thereof, that transmit near-infrared light. In the lumen region of the blood vessel model, it is necessary to place a substance that exhibits infrared absorption characteristics different from the material forming the blood vessel model, so that the region can be identified during near-infrared spectroscopy observation. For example, if 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 fluid mainly composed of water, or the lumen of the blood vessel model can be coated with a lubricating fluid and then filled with air.

[0064] In this invention, the blood vessel models that can be used include blood vessel models having a membrane structure similar to that of living blood vessels (hereinafter referred to as "membrane blood vessel models"), blood vessel models in which a cavity simulating the lumen of a blood vessel is formed inside a block body such as a rectangular parallelepiped, cylinder, or sphere (hereinafter referred to as "block-shaped blood vessel models"), or blood vessel models that combine both. In the membrane blood vessel model, liquids, gases, and solids (especially gel-like solids) 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 membrane blood vessel model, it is possible to visualize not only the lumen region of the blood vessel model but also the wall cross-section region of the blood vessel model so that they can be identified. In the block-shaped blood vessel model, various substances can be selectively placed in the lumen region, depending on the situation.

[0065] As constituent materials for such blood vessel models, various materials can be used, as long as they are near-infrared transparent, such as soft materials like silicone rubber, urethane rubber, soft polyvinyl chloride, and soft photocurable resins; gels made of polyvinyl alcohol, etc.; and hard photocurable resins, etc. Since near-infrared light does not harm the human eye, it is preferable that such polymer materials also transmit visible light so that an operator can visually observe a vascular model irradiated with near-infrared light using visible light.

[0066] Examples of crosslinked polymer materials include crosslinked soft polymer materials such as silicone rubber, urethane rubber, soft polyvinyl chloride, and soft photocurable resins, as well as hard polymer materials such as acrylic resins and hard photocurable resins, and materials combining these. The material used to form the blood vessel model and the liquid filling the lumen of the blood vessel model may be colored with dyes that are distinguishable in the visible light region. Many dyes used in the visible light region exhibit high transmittance in the near-infrared region, so they hardly affect 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. It is also possible to form blood vessel models from gel-like substances such as polyvinyl alcohol. Because polyvinyl alcohol blood vessel models have high lubricity due to their physical properties, the only substance required to fill the lumen of the blood vessel model is water or air. Of course, this does not preclude the addition of lubrication-enhancing agents such as surfactants.

[0067] The vascular model can be pre-attached with lesion models that simulate thrombi and plaque, or they can be movably installed. In performing near-infrared spectroscopy observation according to the present invention, it is preferable to form the lesion model using a material that exhibits different near-infrared absorption characteristics from the forming material of the vascular model and the material placed in the lumen region, in order to selectively enhance the visibility of the lesion model. By observing the simulation process of catheter angioplasty and thrombectomy using plaques and thrombi made of such materials, it is possible to clearly observe how plaque is crushed by balloons and stents within the lumen of the vascular model, and how thrombi are captured by stents and collected while moving through the blood vessel together with the stent.

[0068] Furthermore, in this invention, a single light-receiving unit can simultaneously receive a first near-infrared light transmitted through the object of observation and a second near-infrared light reflected from the object of observation, and an image can be directly formed based on this received light without 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 is equipped with a focus shift correction function. When using a single light-receiving unit, it is also possible to receive the first near-infrared light transmitted through the object of observation and the second near-infrared light reflected from the object with a time difference, and then process and combine the images generated from each. In this case, the second image generated from the first near-infrared light can also have its color tone inverted, and then process and combine it with the first image generated from the first near-infrared light.

[0069] This invention is not limited in any way to the embodiments and examples described above. Various modifications that do not depart from the scope of the claims and are easily conceivable by those skilled in the art are also included in this invention. The following information is disclosed. (20) A cassette used in an observation device that observes a vascular model into which a catheter has been inserted, the vascular model being incorporated The aforementioned vascular model, A housing that holds the blood vessel model, The system includes an immersion liquid that fills the space between the outer surface of the blood vessel model and the inner surface of the housing, The immersion liquid is a cassette containing a material that produces Rayleigh scattering. (21) A cassette used in an observation device for observing a vascular model into which a catheter has been inserted, the cassette incorporating the vascular model, The aforementioned vascular model, A housing that holds the blood vessel model, The system further comprises an immersion liquid that fills the space between the outer surface of the blood vessel model and the inner surface of the housing, The cassette according to (20), wherein the immersion liquid contains a material that causes Rayleigh scattering. (22) The cassette according to (20), wherein the material that produces Rayleigh scattering is a water-soluble polymer material.

[0070] Furthermore, the following matters will be disclosed. (1) An observation device for observing a vascular model into which a catheter has been inserted, wherein a material having near-infrared absorption properties different from the constituent materials of the vascular model is placed inside the vascular model, and the catheter comprises a sheath and wires inserted into the sheath. The system comprises a first light source that emits first near-infrared light, a first light receiving unit capable of receiving 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. The first near-infrared light is an observation device capable of penetrating the blood vessel model, the materials within the blood vessel model, and the sheath of the catheter. (2) (1) A method for observing an object using the observation apparatus described above, The first light source emits the first near-infrared light toward the object to be observed, and the first near-infrared light that has passed through the object to be observed is received by the first light receiving unit. The first image generation unit generates the first image based on the first near-infrared light received by the first light receiving unit. The first image is displayed on the aforementioned display, An observation method that allows simultaneous visualization of the catheter sheath, the wires within the sheath, and the vascular model by adjusting the amount of first near-infrared light used to generate the first image. (3) The system further comprises a second light source that emits a second near-infrared light reflected by the catheter, a second light-receiving unit capable of receiving the second near-infrared light, and a second image generation unit that generates a second image based on the second near-infrared light 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 on the display overlaid on the first image. (1) The observation apparatus described above. (4) (3) A method for observing an object using the observation apparatus described above, The first light source emits the first near-infrared light toward the object to be observed, and the first near-infrared light that has passed through the object to be observed is received by the first light receiving unit. The first image generation unit generates the first image based on the first near-infrared light received by the first light receiving unit. The second light source emits the second near-infrared light toward the object to be observed, and the second near-infrared light reflected by the object to be observed is received by the second light receiving unit. The second image generation unit generates the second image based on the second near-infrared light received by the second light receiving unit. The image synthesis unit generates a composite image by superimposing the first image and the second image. The composite image is displayed on the aforementioned display. An observation method that allows simultaneous visualization of the catheter sheath, the wires within the sheath, the radiopaque markers on the wires, and the vascular model by adjusting the amount of first near-infrared light used to generate the first image and / or adjusting the amount of second near-infrared light used to generate the second image. (5) A first polarization unit that polarizes the first near-infrared light in a first direction, A second polarization unit that polarizes the aforementioned second near-infrared light in a second direction, A grayscale image generation unit that converts the first image and the second image into grayscale, The observation apparatus according to (3), comprising: a tone inversion unit that inverts the tone of the grayscale image of the second image to generate the second-first image. (6) An observation device for observing a vascular model into which a catheter has been inserted, wherein a material having near-infrared absorption properties different from the constituent materials of the vascular model is placed inside the vascular model, and the catheter comprises a sheath and wires inserted into the sheath. The system comprises a first light source that emits first near-infrared light, a first light receiving unit capable of receiving the first near-infrared light, and a first image generating unit that generates a first image based on the first near-infrared light captured by the first light receiving unit. The first near-infrared light is capable of penetrating the blood vessel model, the materials within the blood vessel model, and the sheath of the catheter. A second light source that emits a second near-infrared light reflected by the catheter, a second light receiving unit capable of receiving the second near-infrared light, and a second image generating unit that generates a second image based on the second near-infrared light captured by the second light receiving unit, Furthermore, an observation method for an object to be observed using an observation device equipped with a first polarization unit, a second polarization unit, a grayscale image generation unit, a grayscale inversion unit, an image synthesis unit, and a display, The first polarization unit polarizes the first near-infrared light in a first direction, and the first image generation unit generates the first image based on the first near-infrared light that has been polarized in the first direction and transmitted through the object being observed. The second polarization unit polarizes the second near-infrared light in a second direction, and the second image generation unit generates the second image based on the second near-infrared light that has been polarized in the second direction and reflected by the object being observed. The grayscale image generation unit converts the first image and the second image into grayscale. The tone inversion unit inverts the tone of the grayscale image of the second image to generate the second-first image. An observation method for an object to be observed, wherein the image synthesis unit generates a composite image by superimposing the grayscale first image and the second-1 image so that the sheath of the catheter, the wires inside the sheath, the radiopaque markers on the wires, and the vascular model can be viewed simultaneously, and displays the composite image on the display. (7) The observation method according to (6), wherein the density correction of the composite image is performed so that the X-ray opaque marker is emphasized. (8) The image evaluation unit evaluates the composite image synthesized by the image synthesis unit, The system further includes a guidance forming unit that forms guidance based on the evaluation results of the image evaluation unit, The observation apparatus according to (3), wherein the guidance is displayed on the display. (9) An observation device for observing a vascular model into which a catheter has been inserted, wherein a material having near-infrared absorption properties different from the constituent materials of the vascular model is placed inside the vascular model, and the catheter comprises a sheath and wires inserted into the sheath. The system comprises a first light source that emits first near-infrared light, a first light receiving unit capable of receiving the first near-infrared light, and a first image generating unit that generates a first image based on the first near-infrared light captured by the first light receiving unit. The first near-infrared light is capable of penetrating the blood vessel model, the materials within the blood vessel model, and the sheath of the catheter. A second light source that emits a second near-infrared light reflected by the catheter, a second light receiving unit capable of receiving the second near-infrared light, and a second image generating unit that generates a second image based on the second near-infrared light captured by the second light receiving unit, An observation method for an object to be observed using an observation device equipped with an image synthesis unit, an image evaluation unit, and a display, The first light source emits the first near-infrared light toward the object to be observed, and the first near-infrared light that has passed through the object to be observed is received by the first light receiving unit. The first image generation unit generates the first image based on the first near-infrared light received by the first light receiving unit. The second light source emits the second near-infrared light toward the object to be observed, and the second near-infrared light reflected by the object to be observed is received by the second light receiving unit. The second image generation unit generates the second image based on the second near-infrared light received by the second light receiving unit. The image synthesis unit is instructed to superimpose the first image and the second image to generate a composite image. The image evaluation unit is made to evaluate the composite image. The guidance formation unit is made to form guidance based on the evaluation results of the image evaluation unit. The composite image and the guidance are displayed on the aforementioned display. The method of observing the subject of observation. (10) The observation apparatus described in (1), wherein the first near-infrared light is monochromatic light. (11) The observation method according to (4), wherein a material having near-infrared absorption characteristics different from those of the constituent material of the blood vessel model is included in the material that causes Rayleigh scattering upon 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 according to (4), wherein the constituent material of the blood vessel model includes a material that produces Rayleigh scattering upon 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 apparatus according to (1), wherein the material having near-infrared absorption characteristics different from those of the constituent materials of the blood vessel model contains a material that causes Rayleigh scattering upon receiving the first near-infrared light. (14) The observation apparatus according to (1), wherein the constituent material of the blood vessel model includes a material that produces Rayleigh scattering upon receiving the first near-infrared light. (15) The observation apparatus 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 vascular model into which a catheter has been inserted, wherein the inside of the vascular model is filled with lubricating fluid, the area around the vascular model is filled with immersion fluid, and the catheter comprises a sheath and wires inserted into the sheath. The system comprises a first light source that emits first near-infrared light, a first light receiving unit capable of receiving 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. The lubricating fluid and / or the immersion fluid contains a material that causes Rayleigh scattering. The first near-infrared light is an observation device capable of penetrating the blood vessel model, the materials within the blood vessel model, and the sheath of the catheter. (17) The observation apparatus 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 apparatus according to (1), wherein the synthesized image is displayed on the display. [Explanation of symbols]

[0071] 1 Catheter 2 sheaths 3 Wires 5. Vascular Models 10 Observation device 20 wires 30 Markers

Claims

1. An observation device for observing a catheter, wherein the catheter comprises a sheath and wires inserted into the sheath, The system comprises a first light source that emits first near-infrared light, a first light receiving unit capable of receiving 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. The first near-infrared light is an observation device capable of penetrating the sheath of the catheter.

2. A method for observing an object using the observation apparatus described in Claim 1, The first light source emits the first near-infrared light toward the object to be observed, and the first near-infrared light that has passed through the object to be observed is received by the first light receiving unit. The first image generation unit generates a first image based on the first near-infrared light received by the first light receiving unit. The first image is displayed on the aforementioned display. An observation method that allows simultaneous visualization of the sheath of the catheter and the wires inside the sheath by adjusting the amount of first near-infrared light used to generate the first image.

3. The observation apparatus according to claim 1, wherein the first near-infrared light is monochromatic light.

4. The observation apparatus according to claim 1, wherein the first near-infrared light has a wavelength of 1300 nm to 1550 nm.

Images