JP2022076799A - Simulated blood vessel - Google Patents

Abstract

To provide a simulated blood vessel similar to an actual blood vessel, the simulated blood vessel allowing a user to feel that a guide wire is penetrating into an inner membrane and also feel that a guide wire is moving forward from an inner membrane to a middle membrane.SOLUTION: The simulated blood vessel is formed of a gel of polyvinyl alcohol and is in the shape of a tube with a hollow part. The simulated blood vessel has a specific structure having a first part, a second part, and a third part, the first part being located on a virtual straight line in a lateral cross surface of the simulated blood vessel and having the value of a penetration force which is larger than a first value, the second part being located on the outside wall side of the first part and having the value of a penetration force which is larger than a second value, and the third part being located between the first part and the second part and having the value of a penetration force which is smaller than a third value smaller than the first value and the second value.SELECTED DRAWING: Figure 2

Description

The techniques disclosed herein relate to simulated blood vessels.

Percutaneous angioplasty (hereinafter referred to as "PTA") or percutaneous coronary angioplasty (hereinafter referred to as "PTA") to restore blood flow in a stenosis or obstruction (hereinafter referred to as "lesion") in a blood vessel. "PTCA") is widely used. In PTA and PTCA (hereinafter referred to as "PTA and the like"), for example, various techniques such as a balloon expansion method are adopted.

The procedure by the balloon expansion method is performed by, for example, the following procedure. That is, the guide wire is inserted into the blood vessel and pushed forward until the guide wire passes through the lesion in the blood vessel. Next, the guide wire is used as a rail to advance the balloon catheter to the lesion. Then, by expanding the balloon of the balloon catheter, the blood vessel wall of the lesion is expanded from the inside. These procedures secure blood passages and restore blood flow.

In the procedure by PTA or the like, it is not easy to learn the procedure by PTA or the like because the technician is required to perform delicate operations and the position and condition of the lesion in the blood vessel varies from patient to patient. Therefore, various simulated blood vessels that imitate blood vessels have been proposed for training to improve procedures such as PTA.

Here, the actual blood vessel generally has a relatively elastic tubular intima, an intima surrounding the outside of the intima, and an adventitia surrounding the outside of the media. Further, in an actual blood vessel, an inner elastic plate is further present between the intima and the media, and an outer elastic plate is present between the media and the outer membrane.

On the other hand, for training to improve procedures such as incision of blood vessels, anastomosis of incisions, and anastomosis between blood vessels in surgery, simulations of the intima, media, and adventitia of actual blood vessels are simulated. Blood vessels have been proposed (see, for example, Patent Document 1). Specifically, the simulated blood vessel has an intima layer, a media layer arranged outside the media layer, and an adventitia layer arranged outside the media layer. The simulated blood vessel further includes a mesh layer between the intima layer and the media layer and between the media layer and the adventitia layer, respectively. The intima layer, the media layer, and the outer membrane layer are formed of silicone rubber or the like. The mesh layer is a flexible sheet-like member having a plurality of through holes formed therein, and is composed of a sheet-like member formed of a synthetic resin such as polyethylene terephthalate, polyurethane, or polypropylene.

Further, a technique using polyvinyl alcohol as a material for forming simulated blood vessels has been proposed (see, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 2017-53897 Japanese Unexamined Patent Publication No. 2011-8213

As described above, the condition of the actual lesion is various, and for example, there may be a lesion such as a chronic complete occlusion in the actual blood vessel. In such a case, it is difficult to adopt a technique of pushing the guide wire to the lesion. Therefore, after penetrating the blood vessel wall (intima) with a guide wire traveling in the blood vessel, the guide wire is advanced between the intima and the media to pass through the position of the lesion and balloon. A catheter may be used to push the space between the intima and media. This is because the guide wire can be advanced between the intima and the media with a lower load than the film thickness portion of the intima or the media. By such a procedure, a blood passage is secured between the intima and the media, and blood flow is restored.

In order to practice such a procedure, it is desired to provide a simulated blood vessel having a layered structure similar to that of an actual blood vessel. More specifically, a simulated blood vessel similar to an actual blood vessel, which has a sensation when the guide wire penetrates the intima and a sensation when the guide wire advances between the intima and the media. Is desired.

The above tasks are not limited to simulated blood vessels used for training to improve procedures such as PTA, but are vascular lesion models including simulated blood vessels and simulated lesions that imitate lesions, and organ models having a layered structure. This is a common issue for biological models such as.

This specification discloses a technique capable of solving the above-mentioned problems.

The techniques disclosed herein can be realized, for example, in the following forms.

(1) The simulated blood vessel disclosed in the present specification is a tubular simulated blood vessel formed of a gel of polyvinyl alcohol and having a hollow portion, and the simulated blood vessel is a virtual straight line in a cross section of the simulated blood vessel. The value of the penetrating force is the first on a virtual straight line that passes through a specific point on the inner wall of the simulated blood vessel and the distance between the specific point and the outer wall of the simulated blood vessel is the shortest distance. A first portion that exceeds the value, a second portion that is located on the outer wall side with respect to the first portion and has a penetration force value that exceeds the second value, and the first portion. And the third part, which is located between the second part and the penetrating force value is less than or equal to the third value smaller than either the first value or the second value. , With a specific structure.

This simulated blood vessel is made of PVA gel. Therefore, this simulated blood vessel can have good elasticity and flexibility similar to those of an actual blood vessel. Further, the simulated blood vessel is arranged between the first portion and the second portion having a relatively high penetrating force value and the first portion and the second portion, and the penetrating force value is the first. It has a third portion that is smaller than either value of the portion and the second portion. Therefore, for example, the first portion located inside the simulated blood vessel and the second portion located on the outer wall side with respect to the first portion are each relatively elastic intima of the actual blood vessel. And the media can be simulated, and the third part can simulate the space between the intima and the media of the actual blood vessel. In this way, according to this simulated blood vessel, a simulated blood vessel that simulates the sensation when the guide wire is advanced between the intima and the media while simulating the sensation when the guide wire penetrates the intima. Can be provided.

(2) In the simulated blood vessel, the first portion, the second portion, and the third portion may each be formed of a polyvinyl alcohol gel. That is, the first portion, the second portion, and the third portion are formed of a single forming material. Therefore, the affinity between the adjacent portions becomes good, and it becomes possible to integrally configure the parts as a whole. Therefore, according to this simulated blood vessel, it is possible to provide a simulated blood vessel that simulates an actual blood vessel more effectively.

(3) In the simulated blood vessel, the maximum value of the penetrating force in the third portion may be a value of 40% or less of the maximum value of the penetrating force in the first portion. According to this simulated blood vessel, when the guide wire is advanced between the intima and the media, the third portion makes it easier to advance the guide wire as compared with the first portion. It is possible to provide a simulated blood vessel that more effectively simulates the sensation of.

(4) In the simulated blood vessel, the value of the penetrating force in the first portion and the second portion is more than 50 g, and the value of the penetrating force in the third portion is 50 g or less. May be. According to this simulated blood vessel, the guide wire is set to the intima and the media while the penetrating force values of the first part and the second part are approximated to the penetrating force values of the intima and the media of the actual blood vessel. It is possible to provide a simulated blood vessel that more effectively simulates the sensation of progressing between and.

(5) In the simulated blood vessel, the third portion of the total length of the length of the first portion, the length of the second portion, and the length of the third portion on the virtual straight line. The ratio of the length of the portion may be 30% or less. According to this simulated blood vessel, the length (thickness) of the third portion is smaller than the length (thickness) of the first portion and the length (thickness) of the second portion, so that the actual blood vessel It is possible to provide a simulated blood vessel that more effectively simulates the intima and media of the intima and the space between the intima and the media.

(6) In the simulated blood vessel, the first portion and the second portion may each be configured to be chemically crosslinked. According to this simulated blood vessel, since the first part and the second part are each composed of chemically crosslinked chemical crosslinked sites, the suppleness and high penetrating power of the actual blood vessel are more effective. It is possible to provide a simulated blood vessel simulated.

(7) In the simulated blood vessel, the simulated blood vessel has a fourth portion located on the outer wall side with respect to the second portion, and the fourth portion is composed of only a chemically crosslinked site that is chemically crosslinked. The value of the penetrating force in the fourth portion may be smaller than the maximum value of the second portion and larger than the third value of the third portion. According to this simulated blood vessel, for example, it is possible to provide a simulated blood vessel that more effectively simulates the layer structure of an actual blood vessel provided with an adventitia.

The techniques disclosed in the present specification can be realized in various forms, for example, in the form of a biological model, a training kit including a biological model, a simulator including a biological model, a method for manufacturing the same, and the like. It can be realized.

Explanatory drawing which shows schematic appearance composition of simulated blood vessel 100 in 1st Embodiment Explanatory drawing which enlarges and shows composition of the cross section of simulated blood vessel 100 in 1st Embodiment A flowchart showing a method of manufacturing the simulated blood vessel 100 in the first embodiment. Explanatory drawing which conceptually shows the manufacturing method of the simulated blood vessel 100 in 1st Embodiment Explanatory drawing which enlarges and shows composition of the cross section of simulated blood vessel 100a in 2nd Embodiment Explanatory drawing which enlarges and shows composition of the cross section of simulated blood vessel 100b in 3rd Embodiment Explanatory drawing which enlarges and shows composition of the cross section of simulated blood vessel 100c in 4th Embodiment

A. First Embodiment:
A-1. Configuration of simulated blood vessel 100:
FIG. 1 is an explanatory diagram schematically showing the appearance configuration of the simulated blood vessel 100 in the first embodiment, and FIG. 2 is an explanatory diagram showing an enlarged configuration of a cross section of the simulated blood vessel 100 in the first embodiment. be. FIG. 2 shows the YZ cross-sectional configuration of the simulated blood vessel 100 at the position II-II of FIG. Each figure shows XYZ axes that are orthogonal to each other to identify the direction. In the present specification, for convenience, the Z-axis positive direction is referred to as an upward direction, and the Z-axis negative direction is referred to as a downward direction, but the simulated blood vessel 100 is actually installed or installed in a direction different from such an orientation. It may be used. The same applies to FIGS. 3 and later.

The simulated blood vessel 100 is a device that imitates an actual blood vessel. The simulated blood vessel 100 is used alone, in combination with other simulated blood vessels or simulated lesions, or as a part of a training kit or simulator, for example, a guide wire used for training for improving a procedure such as PTA, PTA, or the like. Used for performance evaluation of medical equipment in Japan.

As shown in FIG. 1, the simulated blood vessel 100 is a circular tubular member extending in the X-axis direction and has a hollow portion H. The simulated blood vessel 100 has an inner wall S1 and an outer wall S2 that define the hollow portion H. The outer diameter ED of the simulated blood vessel 100 is, for example, 10 to 50 mm (preferably 20 to 40 mm), and the inner diameter ID (diameter of the hollow portion H) is, for example, 5 to 45 mm (preferably 15 to 35 mm). Further, the simulated blood vessel 100 is formed of a PVA gel obtained by gelling polyvinyl alcohol (hereinafter, also referred to as “PVA”). Therefore, the simulated blood vessel 100 has good flexibility like an actual blood vessel. More specifically, the simulated blood vessel 100 contains a chemically crosslinked gel obtained by gelling PVA by chemical crosslinking. Here, in the present specification, the term "gel" means that it is in the form of a gel at room temperature or at the operating temperature of the simulated blood vessel 100 (for example, 20 ° C to 50 ° C). The PVA that is the material for forming the simulated blood vessel 100 is a PVA homopolymer obtained by saponification of polyvinyl acetate, or PVA obtained by saponification of a copolymer of vinyl acetate and another monomer copolymerizable therewith. Examples thereof include a copolymer and a PVA modified product in which some hydroxyl groups contained in PVA are substituted with other substituents. The other monomer used in the PVA copolymer is not particularly limited, and examples thereof include conventionally known monomers such as vinyl formate, vinyl propionate, vinyl benzoate, and vinyl t-butyl benzoate. The other substituent used in the PVA modified product is not particularly limited, and examples thereof include a carboxyl group, a sulfonic acid group, an acetoacetyl group, and an amine group. The PVA is preferably a polymer in which the total of the polymerization units based on vinyl acetate and the polymerization units based on vinyl alcohol is 90 mol% or more, more preferably 95 mol% or more, and further preferably. It is a PVA homopolymer. This is because it is easy to handle as a biological model because it exhibits physical characteristics that are closer to those of actual blood vessels in terms of shape stability, flexibility, etc., and is safe for living organisms. The PVA may be used alone or in combination of two or more.

In the present embodiment, the average degree of polymerization of PVA is, for example, about 500 or more and 3000 or less. When the average degree of polymerization is less than 500, the obtained gel becomes soft and it tends to be difficult to maintain an independent shape as a simulated blood vessel. On the other hand, when the average degree of polymerization exceeds 3000, the solubility of PVA in a solvent (for example, water) decreases, and it becomes difficult to form a uniform gel shape. Therefore, the PVA is formed into a desired shape. It tends to be difficult to do. The average degree of polymerization is more preferably 1000 or more and 2000 or less, and further preferably 1500 or more and 1800 or less. The saponification degree of PVA is, for example, about 80 mol% or more. If the degree of saponification is less than 80 mol%, it tends to be difficult to form a PVA gel. The saponification degree is more preferably 90 mol% or more, still more preferably 98 mol% or more.

The PVA gel is classified into a "physically crosslinked gel" and a "chemically crosslinked gel". The "physically crosslinked gel" is a gel that is crosslinked by a non-covalent bond such as a hydrogen bond or an ionic bond, and means a gel in which a crosslinked point is reversibly generated and disappears by an external force such as a temperature change. On the other hand, the "chemically crosslinked gel" is a gel that is crosslinked by a covalent bond, and means a gel in which the crosslinked point does not disappear due to an external force such as a temperature change. The degree of chemical cross-linking in the PVA gel affects the hardness of the PVA gel. More specifically, the higher the formation ratio of the chemical crosslinks in the PVA gel, the higher the hardness of the PVA gel, and the higher the degree of the chemical crosslinks in the PVA gel, the higher the hardness of the PVA gel. That is, the hardness of the PVA gel increases as the chemical cross-linking in the PVA gel progresses.

Here, the "degree of chemical cross-linking" in the PVA gel can be expressed by a conventionally known method, for example, the intensity of the spectrum indicated by the substituents formed by the chemical cross-linking in the PVA gel. The intensity of the spectrum indicated by the substituent formed by the chemical cross-linking in the PVA gel can be evaluated by a conventionally known method, for example, by the following method. For example, when PVA is chemically cross-linked by using glutaraldehyde as a chemical cross-linking agent, an ester group is formed in the PVA gel. Using nuclear magnetic resonance spectroscopy (NMR spectroscopy) or infrared spectroscopy (IR spectroscopy), the spectrum (chemical shift or peak) peculiar to this ester group is identified, and the intensity of the identified spectrum is calculated. ..

As shown in FIG. 2, the simulated blood vessel 100 of the present embodiment has a four-layer structure. More specifically, the inner hard layer 10, the soft layer 30, the outer hard layer 20, and the outer lubricating layer 40 are provided in this order from the inner wall S1 side. Each layer is formed of PVA gel. The composition of the PVA gel forming each layer may be the same as or different from each other. The inner hard layer 10 is an example of the first part in the claims, and the outer hard layer 20 is an example of the second part in the claims. Further, the soft layer 30 is an example of the third part in the claims, and the outer lubricating layer 40 is an example of the fourth part in the claims.

The inner hard layer 10 is a relatively hard PVA gel layer and is composed of a chemically crosslinked gel. The layer thickness T1 of the inner hard layer 10 may be, for example, 0.5 mm or more and 20 mm or less, and may be 3 mm or more and 15 mm or less. Further, the value of the penetrating force in the inner hard layer 10 is, for example, more than 30 g, more than 40 g, and more than 50 g. As described above, since the inner hard layer 10 contains the chemically crosslinked gel, it has a relatively high penetration force value. Therefore, the inner hard layer 10 can exhibit properties (relatively high elasticity and flexibility) similar to those of the endometrium in an actual blood vessel. The penetration force values of 30 g, 40 g and 50 g in the inner hard layer 10 are examples of the first values in the claims, respectively.

The outer hard layer 20 is located on the outer wall S2 side with respect to the inner hard layer 10. Like the inner hard layer 10, the outer hard layer 20 is a relatively hard PVA gel layer and is composed of a chemically crosslinked gel. The layer thickness T2 of the outer hard layer 20 may be, for example, 0.5 mm or more and 20 mm or less, and may be 3 mm or more and 15 mm or less. Further, the value of the penetrating force in the outer hard layer 20 is, for example, more than 30 g, more than 40 g, and more than 50 g. In the present embodiment, the values of the layer thickness T2 and the penetrating force of the outer hard layer 20 are equivalent to the values of the layer thickness T1 and the penetrating force of the inner hard layer 10, respectively. As described above, since the outer hard layer 20 contains the chemically crosslinked gel like the inner hard layer 10, it has a relatively high penetrating force value. Therefore, the outer hard layer 20 can exhibit properties (relatively high elasticity and flexibility) similar to those of the media in an actual blood vessel. The penetration force values of 30 g, 40 g and 50 g in the outer hard layer 20 are examples of the second values in the claims, respectively.

The soft layer 30 is located between the inner hard layer 10 and the outer hard layer 20. The soft layer 30 is a PVA gel layer that is relatively fragile and contains some chemically crosslinked gel. The degree of chemical cross-linking in the soft layer 30 is lower than the degree of chemical cross-linking in the inner hard layer 10, the outer hard layer 20, and the outer lubricating layer 40. The layer thickness T3 of the soft layer 30 may be, for example, 0.01 mm or more and 3 mm or less, and may be 0.05 mm or more and 1 mm or less. In the present embodiment, the layer thickness T3 of the soft layer 30 is smaller than the layer thickness T1 of the inner hard layer 10 and the layer thickness T2 of the outer hard layer 20, and further, the layer thickness T1, the layer thickness T2, and the layer thickness T3 The ratio of the layer thickness T3 to the total thickness (layer thickness T3 / (layer thickness T1 + layer thickness T2 + layer thickness T3) × 100) is 30% or less, and further is 15% or less. Further, the value of the penetrating force in the soft layer 30 is smaller than either the value of the penetrating force in the inner hard layer 10 or the value of the penetrating force in the outer hard layer 20. In the present embodiment, the maximum value of the penetrating force in the soft layer 30 is smaller than the maximum value of the penetrating force in the inner hard layer 10, and further, the maximum value of the penetrating force in the soft layer 30 is the penetrating force in the inner hard layer 10. It is 40% or less of the maximum value of, and further, 20% or less. In the present embodiment, the value of the penetrating force in the soft layer 30 is, for example, 50 g or less, 40 g or less, and further 30 g or less. As described above, the soft layer 30 has a relatively low penetration value because the degree of chemical cross-linking is low. Therefore, the soft layer 30 can exhibit properties (relatively low elasticity and flexibility) that are close to the gap between the intima and the media in an actual blood vessel. The penetration force values of 30 g, 40 g, and 50 g in the soft layer 30 are examples of the third value in the claims, respectively.

The outer lubricating layer 40 is located on the outer wall S2 side with respect to the outer hard layer 20. The outer lubricating layer 40 is a relatively flexible PVA gel layer and is composed only of chemically crosslinked gel. The layer thickness T4 of the outer lubricating layer 40 may be, for example, 0.5 mm or more and 20 mm or less, and may be 3 mm or more and 15 mm or less. In the present embodiment, the layer thickness T4 of the outer lubricating layer 40 is equivalent to the layer thickness T1 of the inner hard layer 10 and the layer thickness T2 of the outer hard layer 20. Further, in the present embodiment, the value of the penetrating force in the outer lubricating layer 40 is smaller than the maximum value of the penetrating force in the outer hard layer 20 and larger than the value of the penetrating force in the soft layer 30. As described above, the outer lubricating layer 40 has a relatively high penetrating force value because it contains the chemically crosslinked gel like the inner hard layer 10 and the outer hard layer 20. Therefore, the outer lubricating layer 40 can exhibit properties (relatively high elasticity and flexibility) similar to those of the adventitia in an actual blood vessel. In the present embodiment, the degree of chemical cross-linking in the outer lubricating layer 40 is lower than the degree of chemical cross-linking in the inner hard layer 10 and the outer hard layer 20.

As an example of the simulated blood vessel 100, the penetrating force values of the inner hard layer 10 and the outer hard layer 20 are each more than 30 g, and the maximum value is 80 g or more (and 100 g or more, further 120 g or more), and the soft layer. Examples thereof include layer structures of 30 g or less and 35 g or more and less than 120 g (and less than 100 g, further less than 80 g, and 70 g or less) in the outer lubricating layer 40. Further, as another example of the simulated blood vessel 100, the value of the penetrating force is more than 50 g in the inner hard layer 10 and the outer hard layer 20, respectively, and the maximum value is 80 g or more (and 100 g or more, further 120 g or more). There is a layer structure of 50 g or less in the soft layer 30 and 35 g or more and less than 120 g (and less than 100 g, further less than 80 g, and 70 g or less) in the outer lubricating layer 40.

The above-mentioned "value of penetrating force in the inner hard layer 10" means, for example, in the cross section of the simulated blood vessel 100 shown in FIG. 2, the penetrating force of the inner hard layer 10 is measured in the circumferential direction centered on the center point PO. It can be an average value when measured at five points at equal intervals (for example, two points on both sides in the circumferential direction from the center point with the point on the virtual straight line VL in FIG. 2 as the center point). Further, the above-mentioned "maximum value of penetration force in the inner hard layer 10" means, for example, the penetration force (the above average value) of the inner hard layer 10 on the virtual straight line VL of FIG. 2 in the radial direction from P1. It can be the maximum value when measured in order in the direction of. The same applies to the "penetration force value" or the "maximum penetration force value" in the other layers.

In the present specification, the value of penetration force can be measured by, for example, the following method. A Texture Analyzer manufactured by Stable Micro Systems and a needle-shaped measuring probe are used. The measuring probe was lowered to the measurement point of the penetrating force in the cross section of the simulated blood vessel 100 at a speed of 2 mm / sec, and the maximum load when the measuring probe entered the simulated blood vessel 100 was taken as the penetrating force.

In the present specification, each of the above layers can be specified by, for example, the following method. As shown in FIG. 2, on the virtual straight line VL in the cross section of the simulated blood vessel 100, the penetrating force at a plurality of points is measured from the inner wall S1 side to the outer wall S2 side. For example, when the penetrating force values of the inner hard layer 10 and the outer hard layer 20 are more than 50 g, the measurement points where the measured penetrating force values are continuously more than 50 g starting from the specific point P1 of the inner wall S1. The measurement point farthest from the start point is set as the end point, and the area from the start point to the end point can be specified as the inner hard layer 10. Among the measurement points where the measured penetration force value exceeds 50 g, the measurement point closest to the outer wall S2 side from the end point of the inner hard layer 10 is set as the starting point, and the highest penetration force is measured from the start point to the outer wall S2 side. The end point can be specified as the outer hard layer 20 from the start point to the end point. The soft layer 30 can be specified from the end point of the inner hard layer 10 to the start point of the outer hard layer 20. From the end point of the outer hard layer 20 to the specific point P2 of the outer wall S2 can be specified as the outer lubricating layer 40. In the above, the virtual straight line VL is a straight line passing through the specific point P1 of the inner wall S1 of the simulated blood vessel 100 and the specific point P2 of the outer wall S2. The specific point P2 is a point where the distance between the specific point P1 and the outer wall S2 of the simulated blood vessel 100 is the shortest distance. In the present embodiment, the virtual straight line VL passes through the center point PO of the simulated blood vessel 100.
In the above, the case where the penetrating force values of the inner hard layer 10 and the outer hard layer 20 are more than 50 g has been described, but when the penetrating force values are more than 40 g and more than 30 g, each layer is similarly used. Can be identified. The same applies to the embodiments described later.

A-2. Method for manufacturing simulated blood vessel 100:
Next, a method for manufacturing the simulated blood vessel 100 in the first embodiment will be described. FIG. 3 is a flowchart showing a method of manufacturing the simulated blood vessel 100 in the present embodiment. Further, FIG. 4 is an explanatory diagram conceptually showing the method for manufacturing the simulated blood vessel 100 in the present embodiment. In the right column of FIG. 4, a partially enlarged view of the X1 portion shown in the left column is shown.

First, a first tubular body CB1 formed of a physically crosslinked gel PG impregnated with an acid catalyst AC is prepared (see S110, FIG. 4A). More specifically, a first cylindrical body CB1 having a diameter substantially the same as the diameter of the hollow portion H of the simulated blood vessel 100 is prepared. More specifically, the physically crosslinked gel PG can be produced by a known method such as a cast dry method or a freeze-thaw method. The cast dry method is a method in which a PVA aqueous solution having a predetermined concentration is prepared by adding PVA to water and heat treatment is performed, and the PVA aqueous solution is dried to obtain a physically crosslinked gel. Further, the freeze-thaw method is a method for obtaining a physically crosslinked gel by repeating a freeze treatment and a thaw treatment a predetermined number of times with respect to the same PVA aqueous solution as described above. When producing the physically cross-linked gel PG, the degree of physical cross-linking can be increased by increasing the concentration of PVA constituting the physically cross-linked gel PG, and the hardness and elasticity of the simulated blood vessel 100 can be increased. Then, the physically crosslinked gel PG obtained by the above-mentioned known method is molded into a tubular shape, and the molded tubular body is immersed in the acid catalyst AC to prepare the first tubular body CB1. The acid catalyst AC is not particularly limited, and examples thereof include citric acid and hydrochloric acid. The concentration of the acid catalyst AC is, for example, 0.01 mol / L or more and 1.0 mol / L or less, and more preferably 0.1 mol / L or more and 0.3 mol / L or less. The first tubular body CB1 can be obtained, for example, by immersing the tubular body in a 0.5 N citric acid aqueous solution at 25 ° C. for 10 minutes under 1 atm.

Next, a cross-linking agent CL-containing PVA solution PS (hereinafter referred to as “PVA solution PS”) and a cross-linking agent CL-containing aqueous solution AS (hereinafter referred to as “aqueous solution AS”) are prepared (S120, S130). The cross-linking agent CL is not particularly limited, and examples thereof include dialdehydes such as glutaraldehyde, glyoxal, formalin, and terephthalaldehyde. Here, the dialdehyde is an aldehyde having two aldehyde groups (formyl groups). The concentration of dialdehyde is, for example, 0.01 mol / L or more and 1.0 mol / L or less, and more preferably 0.1 mol / L or more and 0.3 mol / L or less.

Next, the hollow portion H of the first tubular body CB1 is filled with the aqueous solution AS, and the first tubular body CB1 is immersed in the PVA solution PS (see S140, FIG. 4B). In the step S140, for example, the first tubular body CB1 in which the hollow portion H is filled with a 25% aqueous solution of glutaraldehyde is immersed in a 25% PVA solution of glutaraldehyde at 1 atm at 25 ° C. for 10 minutes. Can be done by. By performing step S140, a coexistence system of the physically crosslinked gel PG and the chemically crosslinked gel CG is formed around the inner wall S1 and the outer wall S2p of the first tubular body CB1.

The catalyst exchange reaction will be described with reference to the right column of FIG. 4 (B). In FIG. 4B, citric acid as the acid catalyst AC is schematically shown by “Δ”, and dialdehyde as the cross-linking agent CL is schematically shown by “◯”. On the inner wall S1 side of the first tubular body CB1, the acid catalyst AC contained in the first tubular body CB1 reacts with the cross-linking agent CL contained in the aqueous solution AS to form a physical cross-linking gel PG and a chemical cross-linking gel CG. Coexistence system is formed (formation of the inner hard layer 10P before treatment). Further, on the outer wall S2p side of the first tubular body CB1, a catalyst exchange reaction proceeds between the first tubular body CB1 containing the acid catalyst AC and the PVA solution PS containing the cross-linking agent CL. .. As a result, chemical crosslinks are newly formed around the outer wall S2p of the first tubular body CB1 and outside the outer wall S2p. As a result, a coexistence system of the physically crosslinked gel PG and the chemically crosslinked gel CG was formed around the outer wall S2p of the first tubular body CB1 (formation of the outer hard layer 20P before treatment), and PVA outside the outer wall S2p. A chemically crosslinked gel CG is formed from PVA in the solution PS (formation of the outer lubricating layer 40). Further, a portion between the inner wall S1 and the outer wall S2p containing the physically cross-linked gel PG and having an extremely low degree of chemical cross-linking is formed as the pre-treatment soft layer 30P. In this way, a second cylindrical body CB2 including the pre-treatment inner hard layer 10P, the pre-treatment soft layer 30P, the pre-treatment outer hard layer 20P, and the outer lubricating layer 40 is produced (FIG. 4 (FIG. 4). See C).

The chemical cross-linking reaction is carried out from the inner wall S1 of the first tubular body CB1 toward the outer wall S2p side, or from the outer wall S2p toward the inner wall S1 side, or outside the first tubular body CB1. It progresses step by step toward it. Therefore, in the second tubular body CB2, the chemical cross-linking density is high in the inner hard layer 10 and the outer hard layer 20 near the inner wall S1 and the outer wall S2p, and the chemical cross-linking density is high in the soft layer 30 away from the inner wall S1 and the outer wall S2p. Will be low. As mentioned above, the penetration force of the PVA gel increases as the degree of chemical cross-linking increases. Therefore, in the second tubular body CB2, the penetrating force of the inner hard layer 10 and the outer hard layer 20 is high, and the penetrating force of the soft layer 30 is low. The degree of formation of the chemically crosslinked gel CG can be changed by adjusting the amount of the crosslinking agent CL and the acid catalyst AC added, the pH of the acid catalyst AC, the reaction pressure, the reaction temperature, the reaction time, and the like. Further, the reaction of forming a chemical crosslink may be stopped by immersing the second tubular body CB2 in an alkaline solution such as sodium carbonate.

The outer lubricating layer 40 forms a chemical crosslink by utilizing the acid catalyst AC contained in the physical cross-linking gel PG, which is not consumed by the chemical cross-linking in the inner hard layer 10 and the outer hard layer 20. Therefore, the chemical cross-linking density in the outer lubricating layer 40 is lower than the chemical cross-linking density of the inner hard layer 10 and the outer hard layer 20. Further, the inner hard layer 10 and the outer hard layer 20 form a coexistence system of the physical cross-linking gel PG and the chemical cross-linking, while the outer lubricating layer 40 forms the chemical cross-linking from PVA in the PVA solution PS. In other words, in the portion where the physically cross-linked gel PG exists, the PVA molecular chains are already bonded to each other by physical cross-linking, so that a chemically cross-linked gel CG in which the PVA molecules are more densely formed is formed. On the other hand, in PVA in PVA solution PS, since the PVA molecular chains are not in a bonded state, a chemically crosslinked gel CG in which PVA molecules are relatively sparse is formed. Therefore, in the manufacturing method of the present embodiment, the value of the penetrating force of the outer lubricating layer 40 is lower than the value of the penetrating force of the inner hard layer 10 and the outer hard layer 20.

Next, the second tubular body CB2 is treated with hot water HW to prepare a simulated blood vessel 100 (see S150, FIG. 4D). The hot water HW is, for example, hot water having a temperature of 80 ° C. to 100 ° C. The step of step S150 can be performed, for example, by boiling the second cylindrical body CB2 at 80 ° C. for 10 minutes under 1 atm. By performing step S150, the physical cross-linking of the physical cross-linking gel PG in the pre-treatment inner hard layer 10P, the pre-treatment soft layer 30P and the pre-treatment outer hard layer 20P disappears, and the soft layer 30 is formed. The degree of disappearance of the physical cross-linking of the simulated blood vessel 100 can be changed by adjusting the temperature, time, etc. of the hot water HW. As a result, a simulated blood vessel 100 including an inner hard layer 10, a soft layer 30, an outer hard layer 20, and an outer lubricating layer 40 can be produced (see FIG. 4E).

A-3. Effect of the first embodiment:
As described above, the simulated blood vessel 100 of the present embodiment includes a layer structure having an inner hard layer 10, an outer hard layer 20, and a soft layer 30. Further, the value of the penetrating force of the soft layer 30 is smaller than the value of the penetrating force of the inner hard layer 10 and the outer hard layer 20.

The simulated blood vessel 100 of this embodiment is formed of PVA gel. Therefore, the simulated blood vessel 100 of the present embodiment can have good elasticity and flexibility similar to those of an actual blood vessel. Further, the simulated blood vessel 100 of the present embodiment is arranged between the inner hard layer 10 and the outer hard layer 20 having a relatively high penetrating force value, and the inner hard layer 10 and the outer hard layer 20, and has a penetrating force value. Has a soft layer 30 smaller than any of the inner hard layer 10 and the outer hard layer 20. Therefore, for example, the inner hard layer 10 located inside the simulated blood vessel 100 and the outer hard layer 20 located on the outer wall S2 side with respect to the inner hard layer 10 are relatively elastic actual blood vessels, respectively. The intima and the media can be simulated, and the soft layer 30 can simulate the space between the intima and the media of an actual blood vessel. As described above, according to the simulated blood vessel 100 of the present embodiment, while simulating the sensation when the guide wire penetrates the intima, the sensation when the guide wire advances between the intima and the media is simulated. It is possible to provide the simulated blood vessel 100.

Further, in the simulated blood vessel 100 of the present embodiment, the inner hard layer 10, the outer hard layer 20, and the soft layer 30 are each formed of a polyvinyl alcohol gel. That is, the inner hard layer 10, the outer hard layer 20, and the soft layer 30 are formed of a single forming material. Therefore, the affinity between adjacent layers becomes good, and it becomes possible to integrally configure the layers as a whole. Therefore, according to the simulated blood vessel 100 of the present embodiment, it is possible to provide a simulated blood vessel 100 that more effectively simulates an actual blood vessel.

Further, in the simulated blood vessel 100 of the present embodiment, the maximum value of the penetrating force in the soft layer 30 is 40% or less of the maximum value of the penetrating force in the inner hard layer 10. According to the simulated blood vessel 100 of the present embodiment, the soft layer 30 makes it easier to advance the guide wire as compared with the inner hard layer 10, so that the guide wire is placed between the intima and the media. It is possible to provide a simulated blood vessel 100 that more effectively simulates the sensation of progress. Although the simulated blood vessel 100 of the present embodiment has been described above, in the simulated blood vessel of the present invention, the maximum value of the penetrating force in the soft layer is 30% or less of the maximum value of the penetrating force in the inner hard layer. Well, it may be a value of 20% or less.

Further, in the simulated blood vessel 100 of the present embodiment, the value of the penetrating force in the inner hard layer 10 and the outer hard layer 20 is more than 50 g, and the value of the penetrating force in the soft layer 30 is 50 g or less. According to the simulated blood vessel 100 of the present embodiment, the guide wire is inserted while the values of the penetrating force of the inner hard layer 10 and the outer hard layer 20 are approximated to the values of the penetrating force of the intima and the media of the actual blood vessel. It is possible to provide a simulated blood vessel 100 that more effectively simulates the sensation of progressing between the membrane and the media. Although the simulated blood vessel 100 of the present embodiment has been described above, in the simulated blood vessel of the present invention, the value of the penetrating force in the inner hard layer and the outer hard layer may be more than 40 g or more than 30 g. .. Further, the value of the penetrating force in the soft layer 30 may be 40 g or less, or 30 g or less.

Further, in the simulated blood vessel 100 of the present embodiment, the soft layer 30 occupies the total length of the layer thickness T1 of the inner hard layer 10, the layer thickness T2 of the outer hard layer 20, and the layer thickness T3 of the soft layer 30. The ratio of the layer thickness T3 is 30% or less. According to the simulated blood vessel 100 of the present embodiment, the layer thickness T3 of the soft layer 30 is smaller than the layer thickness T1 of the inner hard layer 10 and the layer thickness T2 of the outer hard layer 20, and therefore the intima of the actual blood vessel. And it is possible to provide a simulated blood vessel 100 that more effectively simulates the media and the space between the intima and the media. Although the simulated blood vessel 100 of the present embodiment has been described above, in the simulated blood vessel of the present invention, the layer thickness T1 of the inner hard layer 10, the layer thickness T2 of the outer hard layer 20, and the layer thickness T3 of the soft layer 30 are described. The ratio of the layer thickness T3 of the soft layer 30 to the total length may be 15% or less, 10% or less, and further may be 5% or less.

Further, in the simulated blood vessel 100 of the present embodiment, the inner hard layer 10 and the outer hard layer 20 are each composed of a chemically crosslinked gel CG. According to the simulated blood vessel 100 of the present embodiment, since the inner hard layer 10 and the outer hard layer 20 are each composed of the chemically crosslinked gel CG, the suppleness and the high penetration force of the actual blood vessel can be further improved. It is possible to provide a simulated blood vessel 100 that is effectively simulated. Further, in the simulated blood vessel 100 of the present embodiment, the soft layer 30 is composed of an inner hard layer 10 and a chemically cross-linked gel having a lower degree of chemical cross-linking than the outer hard layer 20.

Further, the simulated blood vessel 100 of the present embodiment has an outer lubricating layer 40 composed only of the chemically crosslinked gel CG, and the value of the penetrating force in the outer lubricating layer 40 is higher than the maximum value of the penetrating force of the outer hard layer 20. It is small and larger than the value of the penetrating force of the soft layer 30. According to the simulated blood vessel 100 of the present embodiment, for example, it is possible to provide a simulated blood vessel 100 that more effectively simulates the layer structure of an actual blood vessel provided with an adventitia.

B. Second embodiment:
FIG. 5 is an explanatory diagram schematically showing the configuration of the simulated blood vessel 100a in the second embodiment. FIG. 5 shows the YZ cross-sectional configuration of the simulated blood vessel 100a of the second embodiment at the same position as FIG. 2 (position II-II in FIG. 1). Hereinafter, among the configurations of the simulated blood vessel 100a of the second embodiment, the description thereof will be omitted as appropriate for the same configuration as the simulated blood vessel 100 of the first embodiment described above.

The simulated blood vessel 100a of the second embodiment has a four-layer structure like the simulated blood vessel 100 of the first embodiment. The simulated blood vessel 100a is different from the simulated blood vessel 100 of the first embodiment in that it does not have the outer lubricating layer 40 and has the inner lubricating layer 50.

As described above, the simulated blood vessel 100a has a four-layer structure. More specifically, the inner lubricating layer 50, the inner hard layer 10, the soft layer 30, and the outer hard layer 20 are provided in this order from the inner wall S1 side. The values of the forming material, layer thickness, and penetrating force of each layer are the same as those of the simulated blood vessel 100. Further, similarly to the simulated blood vessel 100, the outer diameter EDa of the simulated blood vessel 100a is, for example, 10 to 50 mm (preferably 20 to 40 mm), and the inner diameter IDa (diameter of the hollow portion H) is, for example, 5 to 45 mm (). It is preferably 15 to 35 mm).

The inner lubricating layer 50 is located on the inner wall S1 side with respect to the inner hard layer 10. The inner lubricating layer 50 is a relatively flexible PVA gel layer, a relatively flexible PVA gel layer, and is composed only of a chemically crosslinked gel. The layer thickness T5 of the inner lubricating layer 50 may be, for example, 0.5 mm or more and 20 mm or less, and may be 3 mm or more and 15 mm or less. In the present embodiment, the layer thickness T5 of the inner lubricating layer 50 is equivalent to the layer thickness T1 of the inner hard layer 10 and the layer thickness T2 of the outer hard layer 20. Further, in the present embodiment, the value of the penetrating force in the inner lubricating layer 50 is equivalent to the value of the penetrating force in the outer lubricating layer 40 of the first embodiment. That is, the value of the penetrating force in the inner lubricating layer 50 is smaller than the maximum value of the penetrating force in the inner hard layer 10 and the outer hard layer 20, and is larger than the value of the penetrating force in the soft layer 30. As described above, the inner lubricating layer 50 has a relatively high penetrating force value because it contains the chemically crosslinked gel like the inner hard layer 10 and the outer hard layer 20. Therefore, the inner lubricating layer 50, together with the outer hard layer 20, can exhibit properties (relatively high elasticity and flexibility) similar to those of the endometrium in an actual blood vessel.

As an example of the simulated blood vessel 100a, the value of the penetrating force is more than 30 g in each of the inner hard layer 10 and the outer hard layer 20, and the maximum value is 80 g or more (and 100 g or more, further 120 g or more), and the soft layer. Examples thereof include a layer structure of 30 g or less in 30 and 35 g or more and less than 120 g (and less than 100 g, further less than 80 g, and 70 g or less) in the inner lubricating layer 50. Further, as another example of the simulated blood vessel 100a, the value of the penetrating force is more than 50 g in the inner hard layer 10 and the outer hard layer 20, respectively, and the maximum value is 80 g or more (and 100 g or more, further 120 g or more). There is a layer structure of 50 g or less in the soft layer 30 and 35 g or more and less than 120 g (and less than 100 g, further less than 80 g, and 70 g or less) in the inner lubricating layer 50.

In the present embodiment, each of the above layers can be specified by, for example, the following method. As shown in FIG. 5, on the virtual straight line VL in the cross section of the simulated blood vessel 100a, the penetrating force at a plurality of points is measured from the inner wall S1 side to the outer wall S2 side. For example, when the penetrating force values of the inner hard layer 10 and the outer hard layer 20 are more than 50 g, the measurement points where the measured penetrating force values are continuously more than 50 g starting from the specific point P2 of the outer wall S2. The measurement point farthest from the start point is set as the end point, and the area from the start point to the end point can be specified as the outer hard layer 20. Among the measurement points where the measured penetration force value exceeds 50 g, the measurement point closest to the inner wall S1 side from the end point of the outer hard layer 20 is set as the starting point, and the highest penetration force is measured from the start point to the inner wall S1 side. The end point can be specified as the inner hard layer 10 from the start point to the end point. From the end point of the outer hard layer 20 to the start point of the inner hard layer 10, the soft layer 30 can be specified. From the end point of the inner hard layer 10 to the specific point P1 of the inner wall S1, the inner lubricating layer 50 can be specified. In the above, the virtual straight line VL is a straight line passing through the specific point P1 of the inner wall S1 of the simulated blood vessel 100 and the specific point P2 of the outer wall S2. The specific point P2 is a point where the distance between the specific point P1 and the outer wall S2 of the simulated blood vessel 100 is the shortest distance. In the present embodiment, the virtual straight line VL passes through the center point PO of the simulated blood vessel 100.

The simulated blood vessel 100a in the present embodiment can be manufactured by modifying a part of the steps of the method for manufacturing the simulated blood vessel 100 in the first embodiment. Specifically, the simulated blood vessel 100a can be manufactured, for example, by replacing step S140 of the first embodiment with the following step.

That is, in the method for producing the simulated blood vessel 100a, the hollow portion of the first tubular body is filled with the PVA solution PS, and the first tubular body is immersed in the aqueous solution AS. By performing this step, a chemically crosslinked gel CG is formed from the physically crosslinked gel PG around the inner wall and the outer wall of the first tubular body. More specifically, on the inner wall side of the first tubular body, a catalyst exchange reaction proceeds between the first tubular body containing the acid catalyst AC and the PVA solution PS containing the cross-linking agent CL. do. As a result, chemical crosslinks are newly formed around the inner wall of the first tubular body and inside the inner wall. As a result, a coexistence system of the physically crosslinked gel PG and the chemically crosslinked gel CG was formed around the inner wall of the first tubular body (formation of the inner hard layer 10P before treatment), and inside the inner wall, in the PVA solution PS. A chemically crosslinked gel CG is formed from the PVA of the above (formation of the inner lubricating layer 50). Further, on the outer wall side of the first tubular body, the acid catalyst AC contained in the first tubular body reacts with the cross-linking agent CL contained in the aqueous solution AS, and the physical cross-linking gel PG and the chemical cross-linking gel CG are formed. A coexistence system is formed (formation of the outer hard layer 20P before treatment). Further, a portion between the inner wall and the outer wall containing the physically cross-linked gel PG and having an extremely low degree of chemical cross-linking is formed as the pre-treatment soft layer 30P. In this way, a second tubular body including the inner lubricating layer 50, the pre-treatment inner hard layer 10P, the pre-treatment soft layer 30P, and the pre-treatment outer hard layer 20P is produced.

The second tubular body produced in the above step is treated with hot water HW in the same manner as in step S150 of the first embodiment to produce a simulated blood vessel 100a. Thereby, a simulated blood vessel 100a including the inner lubricating layer 50, the inner hard layer 10, the soft layer 30, and the outer hard layer 20 can be produced.

The simulated blood vessel 100a of the present embodiment having the above configuration has the same effect as the simulated blood vessel 100 of the first embodiment except for the effect of providing the outer lubricating layer 40.

C. Third embodiment:
FIG. 6 is an explanatory diagram schematically showing the configuration of the simulated blood vessel 100b in the third embodiment. FIG. 6 shows the YZ cross-sectional configuration of the simulated blood vessel 100b of the third embodiment at the same position as that of FIG. 2 (position of II-II in FIG. 1). Hereinafter, among the configurations of the simulated blood vessels 100b of the third embodiment, the same configurations as those of the simulated blood vessels 100 and 100a of the first and second embodiments described above will be omitted as appropriate.

The simulated blood vessel 100b of the third embodiment is different from the simulated blood vessel 100 of the first embodiment in that it further includes an inner lubricating layer 50. That is, the simulated blood vessel 100b has a five-layer structure.

As described above, the simulated blood vessel 100b has a five-layer structure. More specifically, the inner lubricating layer 50, the inner hard layer 10, the soft layer 30, the outer hard layer 20, and the outer lubricating layer 40 are provided in this order from the inner wall S1 side. The values of the forming material, layer thickness, and penetrating force of each layer are the same as those of the simulated blood vessels 100 and 100a. The outer diameter and inner diameter of the simulated blood vessel 100b are the same as those of the simulated blood vessels 100 and 100a.

As an example of the simulated blood vessel 100b, the value of the penetrating force is more than 30 g in each of the inner hard layer 10 and the outer hard layer 20, and the maximum value is 80 g or more (and 100 g or more, further 120 g or more), and the soft layer. Examples thereof include layer structures of 30 g or less and 35 g or more and less than 120 g (and less than 100 g, further less than 80 g, and 70 g or less) in the outer lubricating layer 40 and the inner lubricating layer 50, respectively. Further, as another example of the simulated blood vessel 100b, the value of the penetrating force is more than 50 g in the inner hard layer 10 and the outer hard layer 20, respectively, and the maximum value is 80 g or more (and 100 g or more, further 120 g or more). The layer structure is 50 g or less in the soft layer 30, and 35 g or more and less than 120 g (and less than 100 g, further less than 80 g, and 70 g or less) in the outer lubricating layer 40 and the inner lubricating layer 50. can.

The simulated blood vessel 100b in the present embodiment can be manufactured by modifying a part of the steps of the method for manufacturing the simulated blood vessel 100 in the first embodiment. Specifically, the simulated blood vessel 100b can be manufactured, for example, by replacing step S140 with the following step without requiring step S130 (preparation of the aqueous solution AS) of the first embodiment. That is, the first tubular body is immersed in the PVA solution PS. As a result, a coexistence system of the physically crosslinked gel PG and the chemically crosslinked gel CG is formed both around the inner wall and the outer wall of the first tubular body (pre-treatment inner hard layer 10P and pre-treatment outer hard layer 20P). Formation). Further, a chemically crosslinked gel CG is formed from PVA in the PVA solution PS both on the outside of the outer wall and the inside of the inner wall of the first tubular body (formation of the outer lubricating layer 40 and the inner lubricating layer 50). In this way, a second tubular body including the inner lubricating layer 50, the pre-treatment inner hard layer 10P, the pre-treatment soft layer 30P, the pre-treatment outer hard layer 20P, and the outer lubricating layer 40 is produced. Lubrication.

The second tubular body produced in the above step is treated with hot water HW in the same manner as in step S150 of the first embodiment to produce a simulated blood vessel 100b. As a result, a simulated blood vessel 100b including an inner lubricating layer 50, an inner hard layer 10, a soft layer 30, an outer hard layer 20, and an outer lubricating layer 40 can be produced.

The simulated blood vessel 100b of the present embodiment having the above configuration has the same effect as the simulated blood vessel 100 of the first embodiment.

D. Fourth Embodiment:
FIG. 7 is an explanatory diagram schematically showing the configuration of the simulated blood vessel 100c in the fourth embodiment. FIG. 7 shows the YZ cross-sectional configuration of the simulated blood vessel 100c of the fourth embodiment at the same position as FIG. 2 (position II-II in FIG. 1). In the following, among the configurations of the simulated blood vessel 100c of the fourth embodiment, the description of the same configuration as the simulated blood vessel 100 of the first embodiment described above will be omitted as appropriate.

The simulated blood vessel 100c of the fourth embodiment is different from the simulated blood vessel 100 of the first embodiment in that it does not include the outer lubricating layer 40. That is, the simulated blood vessel 100c has a three-layer structure.

As described above, the simulated blood vessel 100c has a three-layer structure. More specifically, the inner hard layer 10, the soft layer 30, and the outer hard layer 20 are provided in this order from the inner wall S1 side. The values of the forming material, layer thickness, and penetrating force of each layer are the same as those of the simulated blood vessel 100. The outer diameter and inner diameter of the simulated blood vessel 100c are the same as those of the simulated blood vessel 100.

As an example of the simulated blood vessel 100c, the value of the penetrating force is more than 30 g in each of the inner hard layer 10 and the outer hard layer 20, and the maximum value is 80 g or more (and 100 g or more, further 120 g or more). A layer structure of 30 g or less in the soft layer 30 can be mentioned. Further, as another example of the simulated blood vessel 100c, the penetration force value is more than 50 g in the inner hard layer 10 and the outer hard layer 20, respectively, and the maximum value is 80 g or more (and 100 g or more, further 120 g or more). There is a layered structure that weighs less than 50 g in the soft layer 30.

The simulated blood vessel 100c in the present embodiment can be manufactured by modifying a part of the steps of the method for manufacturing the simulated blood vessel 100 in the first embodiment. Specifically, the simulated blood vessel 100c can be manufactured, for example, by replacing step S140 with the following step without requiring step S120 (preparation of PVA solution PS) of the first embodiment. That is, the first tubular body is immersed in the aqueous solution AS. As a result, a coexistence system of the physically crosslinked gel PG and the chemically crosslinked gel CG is formed both around the inner wall and the outer wall of the first tubular body (pre-treatment inner hard layer 10P and pre-treatment outer hard layer 20P). Formation). In this way, a second tubular body including the pre-treatment inner hard layer 10P, the pre-treatment soft layer 30P, and the pre-treatment outer hard layer 20P is produced.

The second tubular body produced in the above step is treated with hot water HW in the same manner as in step S150 of the first embodiment to produce a simulated blood vessel 100c. Thereby, a simulated blood vessel 100c including the inner hard layer 10, the soft layer 30, and the outer hard layer 20 can be produced.

The simulated blood vessel 100c of the present embodiment having the above configuration has the same effect as the simulated blood vessel 100 of the first embodiment except for the effect of providing the outer lubricating layer 40.

E. Modification example:
The technique disclosed in the present specification is not limited to the above-described embodiment, and can be transformed into various forms without departing from the gist thereof, and for example, the following modifications are also possible.

In the above embodiment, the simulated blood vessel 100 is a circular tube, but the simulated blood vessel 100 is not limited to this. For example, the cross section may be a polygonal cylinder.

In the above embodiment, the simulated blood vessel 100 has a structure having a layered structure, but the simulated blood vessel 100 is not limited to this. For example, a part of the cross section of the simulated blood vessel 100 may have the above configuration. That is, in one cross section of the simulated blood vessel 100, the first portion and the second portion corresponding to the inner hard layer 10, the outer hard layer 20, the soft layer 30, and the outer lubricating layer 40, respectively. , A configuration having a third portion and a fourth portion may be used.

In the above embodiment, the inner hard layer 10 and the outer hard layer 20 are composed of a chemically crosslinked gel, but the present invention is not limited thereto. For example, at least one of the inner hard layer 10 and the outer hard layer 20 may have a physically crosslinked gel. Further, in the above embodiment, the soft layer 30 is configured to include a small amount of chemically crosslinked gel, but the present invention is not limited to this. For example, the soft layer 30 may be configured not to contain a chemically crosslinked gel.

In the above embodiment, the degree of chemical cross-linking between the inner hard layer 10, the outer hard layer 20, the soft layer 30, and the outer lubricating layer 40 is substantially uniform, but is not limited thereto. For example, the degree of chemical cross-linking may be partially different in the at least one layer.

In the above embodiment, the layer thickness of each layer can be changed as appropriate. Further, in the above embodiment, the layer thickness T1 of the inner hard layer 10 and the layer thickness T2 of the outer hard layer 20 may be different from each other. Further, in the above embodiment, the ratio of the layer thickness T3 to the total thickness of the layer thickness T1, the layer thickness T2, and the layer thickness T3 (layer thickness T3 / (layer thickness T1 + layer thickness T2 + layer thickness T3) × 100) is It may be more than 30% or more than 15%. The lower limit of the ratio of the layer thickness T3 to the total thickness of the layer thickness T1, the layer thickness T2, and the layer thickness T3 is not particularly limited and may be appropriately set. May be.
In the above embodiment, the ratio of the thickness of the soft layer 30 (layer thickness T3) to the thickness of the simulated blood vessel ((outer diameter-inner diameter) / 2) is 30% or less, 15% or less, or 10% or less. It may be 5% or less. The ratio of the thickness of the soft layer 30 (layer thickness T3) to the thickness of the simulated blood vessel ((outer diameter-inner diameter) / 2) may be 1% or more, or 2% or more.

In the above embodiment, the value of the penetration force of each layer can be changed as appropriate. Further, in the above embodiment, the value of the penetrating force of the inner hard layer 10 and the value of the penetrating force of the outer hard layer 20 may be different from each other. Further, in the above embodiment, the value of the penetrating force of the inner hard layer 10 and the outer hard layer 20 may be 30 g or less, 40 g or less, or 50 g or less. Further, in the above embodiment, the value of the penetrating force of the soft layer 30 may be more than 50 g, more than 40 g, or more than 30. Further, in the above embodiment, the maximum value of the penetrating force of the soft layer 30 may be more than 40%, more than 30%, or more than 20% of the maximum value of the penetrating force of the inner hard layer 10.

In the above embodiment, the layer thickness T4 of the outer lubricating layer 40, the layer thickness T1 of the inner hard layer 10, and the layer thickness T2 of the outer hard layer 20 may be different from each other. Further, in the above embodiment, the value of the penetrating force of the outer lubricating layer 40 may be greater than or equal to the maximum value of the penetrating force of the outer hard layer 20 or less than the value of the penetrating force of the soft layer 30.

In the above embodiment, the layer thickness T5 of the inner lubricating layer 50, the layer thickness T1 of the inner hard layer 10, and the layer thickness T2 of the outer hard layer 20 may be different from each other. Further, in the above embodiment, the value of the penetrating force of the inner lubricating layer 50 may be greater than or equal to the maximum value of the penetrating force of the outer hard layer 20 or less than the value of the penetrating force of the soft layer 30.

In the above embodiment, the inner hard layer 10 may have a change in the value of the penetrating force in the layer. For example, the inner hard layer 10 penetrates stepwise from the soft layer 30 side toward the hollow portion H side of the simulated blood vessel 100. The power may be increased. Further, since the inner hard layer 10 can exhibit properties (relatively high elasticity and flexibility) more similar to those of the media in an actual blood vessel, the maximum value of the penetrating force is preferably 80 g or more. , 90 g or more is more preferable, and 100 g or more is further preferable.
As for the outer hard layer 20, the value of the penetrating force may change in the layer as in the inner hard layer 10. For example, the penetrating force gradually increases from the soft layer 30 side toward the outer wall S2 side. It may be larger.

In the above embodiment, the degree of chemical cross-linking in the inner hard layer 10 and the outer hard layer 20 may be substantially uniform or may vary within the layer. For example, in the inner hard layer 10, the degree of chemical cross-linking may be gradually increased from the soft layer 30 side toward the hollow portion H side of the simulated blood vessel 100. Regarding the outer hard layer 20, the degree of chemical cross-linking may be substantially uniform, or the value of the penetrating force may change within the layer. For example, from the soft layer 30 side toward the outer wall S2 side. , The degree of chemical cross-linking may be gradually increased.

The method for producing the simulated blood vessel 100 according to the above embodiment is an example, and is not limited to this, as long as it is a manufacturing method capable of realizing the layered structure of the simulated blood vessel 100.

10: Inner hard layer 20: Outer hard layer 30: Soft layer 30P: Untreated soft layer 40: Outer lubrication layer 50: Inner lubrication layer 100: Simulated blood vessel 100a: Simulated blood vessel 100b: Simulated blood vessel 100c: Simulated blood vessel ED: Outer diameter EDa: Outer diameter H: Hollow part ID: Inner diameter IDa: Inner diameter P1: Specific point P2: Specific point PO: Center point S1: Inner wall S2: Outer wall T1: Layer thickness T2: Layer thickness T3: Layer thickness T4: Layer thickness T5: Layer thickness VL: Virtual straight line

Claims (7)

A tubular simulated blood vessel formed of polyvinyl alcohol gel and having a hollow portion.
The simulated blood vessel is a virtual straight line in the cross section of the simulated blood vessel, passes through a specific point on the inner wall of the simulated blood vessel, and the distance between the specific point and the outer wall of the simulated blood vessel is the shortest distance. On a virtual straight line
The first part where the value of the penetration force exceeds the first value, and
A second portion located on the outer wall side with respect to the first portion and having a penetration force value exceeding the second value.
It is located between the first portion and the second portion, and the value of the penetration force is less than or equal to a third value smaller than either of the first value and the second value. With a third part,
With a specific structure,
Simulated blood vessel. In the simulated blood vessel according to claim 1,
The first portion, the second portion, and the third portion are each formed of a gel of polyvinyl alcohol.
Simulated blood vessel. In the simulated blood vessel according to claim 1 or 2.
The maximum value of the penetrating force in the third portion is a value of 40% or less of the maximum value of the penetrating force in the first portion.
Simulated blood vessel. In the simulated blood vessel according to any one of claims 1 to 3.
The value of the penetrating force in the first portion and the second portion is more than 50 g.
The value of the penetrating force in the third portion is 50 g or less.
Simulated blood vessel. In the simulated blood vessel according to claim 4,
On the virtual straight line, the ratio of the length of the third portion to the total length of the length of the first portion, the length of the second portion, and the length of the third portion is , 30% or less,
Simulated blood vessel. In the simulated blood vessel according to any one of claims 1 to 5.
The first portion and the second portion are each composed of chemically crosslinked chemical cross-linking sites.
Simulated blood vessel. In the simulated blood vessel according to any one of claims 1 to 6.
It has a fourth portion located on the outer wall side with respect to the second portion.
The fourth part is composed of only the chemically crosslinked site which is chemically crosslinked.
The value of the penetration force in the fourth portion is smaller than the maximum value of the second portion and larger than the third value of the third portion.
Simulated blood vessel.

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