Skin model

Abstract

This invention provides a skin model that has a tactile feel similar to human skin and can also be used for practicing skin incision and suturing. [Solution] A skin model having an epidermal layer, a subcutaneous tissue layer, and a muscle layer in that order, wherein the epidermal layer contains 100 parts by mass of (component A1) hydrogenated block copolymer with an MFR (measured at a temperature of 230°C and a load of 2.16 kg) of 1 g / 10 min. or less, and (component A2) oil in an amount of 150 parts by mass or more and 450 parts by mass or less, and (component A3) surface modifier in an amount of 5% by mass or more and 30% by mass or less in the total amount of the raw material resin composition of the epidermal layer, the subcutaneous tissue layer contains 100 parts by mass of (component B1) hydrogenated block copolymer with an MFR (measured at a temperature of 230°C and a load of 2.16 kg) of 1 g / 10 min. or less, and (component B2) oil in an amount of more than 450 parts by mass and 1100 parts by mass or less, and the muscle layer contains (component C1) hydrogenated block copolymer.

Description

Technical Field

[0001] The present disclosure relates to a skin model.

Background Art

[0002] Conventionally, since living bodies cannot be used for practicing human surgeries, animal organs such as pigs have generally been used. However, freshness is required for animal organs. In addition, when a person practicing a surgical technique is injured, there is a risk of infection by pathogenic bacteria etc. contained in the animal organ from the wound, and a great deal of cost is required for the hygiene management of surgical cutting tools and the disposal of used organs. Although it has been considered to perform surgical technique practice using konjac instead of living body organs, since the incision feeling and touch feeling of konjac are quite different from those of the human body, it cannot be said to be suitable for surgical technique practice. Therefore, it has been considered to use a biological model such as an organ model similar to a living body organ instead of a living body organ (Patent Documents 1 to 3).

[0003] In addition, with the progress of chemotherapy, the number of cases using subcutaneous implantable medical devices has been increasing. Subcutaneous implantable medical devices have advantages such as a reduced risk of infection and a reduced possibility of spontaneous removal, in addition to the certainty of administration, compared with conventional blood vessel securing, and the generalization of the implantation technique of subcutaneous implantable medical devices has been promoted.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, there were no skin models that had a texture similar to human skin and could be used for practicing skin incision and suturing. Therefore, there is a need for the development of a skin model that has a texture similar to human skin and can also be used for practicing skin incision and suturing.

[0006] The objective of this disclosure is to provide a skin model that has a tactile feel similar to human skin and can also be used for practicing skin incision and suturing. [Means for solving the problem]

[0007] The present inventors, after considering various means, have found a skin model having an epidermal layer, a subcutaneous tissue layer, and a muscle layer in that order, wherein the epidermal layer contains 100 parts by mass of (component A1) hydrogenated block copolymer with an MFR (measured at a temperature of 230°C and a load of 2.16 kg) of 1 g / 10 min. or less, and 150 parts by mass or more and 450 parts by mass or less of (component A2) oil, and the total amount of the raw material resin composition of the epidermal layer contains 5% by mass or more and 30% by mass or less of (component A3) surface modifier, and the We have found that a skin model can be created in which the subcutaneous tissue layer contains 100 parts by mass of (component B1) hydrogenated block copolymer with an MFR (measured at a temperature of 230°C and a load of 2.16 kg) of 1 g / 10 min. or less, and (component B2) oil in amounts between 450 parts by mass and 1100 parts by mass or less, and the muscle layer contains (component C1) hydrogenated block copolymer, thereby providing a skin model that has a tactile feel similar to human skin and can also be used for practicing skin incision and suturing, and with this discovery, we have completed this disclosure.

[0008] This disclosure includes the following aspects: [1] A skin model having the epidermal layer, subcutaneous tissue layer, and muscle layer in this order, The surface layer contains 100 parts by mass of (component A1) hydrogenated block copolymer with an MFR (measured at a temperature of 230°C and a load of 2.16 kg) of 1 g / 10 min. or less, and 150 parts by mass or more and 450 parts by mass or less of (component A2) oil, and the total amount of (component A3) surface modifier in the raw material resin composition of the surface layer contains 5% by mass or more and 30% by mass or less. The subcutaneous tissue layer contains 100 parts by mass of (component B1) hydrogenated block copolymer with an MFR (measured at a temperature of 230°C and a load of 2.16 kg) of 1 g / 10 min. or less, and (component B2) oil in amounts between 450 parts by mass and 1100 parts by mass or less. A skin model in which the muscle layer contains (component C1) hydrogenated block copolymer. [Effects of the Invention]

[0009] According to this disclosure, it is possible to provide a skin model that has a texture similar to human skin and can also be used for practicing skin incision and suturing. [Brief explanation of the drawing]

[0010] [Figure 1] This figure shows a cross-section of a skin model according to the first embodiment of this disclosure. [Figure 2] This figure shows a cross-section of a skin model according to the first embodiment of this disclosure. [Figure 3] This figure shows the method for measuring tackiness in this disclosure. [Figure 4] This figure shows the method for measuring intensity in this disclosure. [Modes for carrying out the invention]

[0011] One embodiment of the present disclosure will be described in detail below, but the scope of the present disclosure is not limited to the embodiment described herein, and various modifications can be made without departing from the spirit of the present disclosure. Each embodiment disclosed herein can be combined with any other features disclosed herein. If multiple upper and lower limits are given for a particular parameter, any combination of these upper and lower limits can be used to create a suitable numerical range. The lower and / or upper limits of the numerical ranges described herein may be replaced with numerical values ​​within that range, as shown in the examples. The expression "X~Y" indicating a numerical range means "X or greater and Y or less". If a particular description given for one embodiment also applies to other embodiments, that description may be omitted in the other embodiments.

[0012] [First Embodiment] Figure 1 shows a skin model according to the first embodiment of this disclosure. In this embodiment, the skin model has an epidermal layer, a subcutaneous tissue layer, and a muscular layer in that order.

[0013] (epidermal layer) The epidermis is the uppermost layer and is joined to the upper surface of the subcutaneous tissue layer at its lower surface. The shape of the epidermis is preferably flat or resembles the shape of a human chest or abdomen. In this embodiment, the surface layer contains 100 parts by mass of (component A1) hydrogenated block copolymer (hereinafter sometimes simply referred to as "hydrogenated block copolymer") with an MFR (measured at a temperature of 230°C and a load of 2.16 kg) of 1 g / 10 min. or less, and (component A2) oil, and contains 5% by mass or more and 30% by mass or less of (component A3) surface modifier in the total amount of the raw material resin composition of the surface layer.

[0014] In one embodiment, the skin layer contains a resin component mainly composed of a hydrogenated block copolymer. Here, "mainly composed of" means containing more than 50% by mass based on the total amount of the resin component, preferably 60% by mass or more, 70% by mass or more, 80% by mass or more, or 90% by mass or more, and more preferably 100% by mass. In one embodiment, the content of the hydrogenated block copolymer contained in the raw material resin composition of the skin layer is preferably 10 to 40% by mass, more preferably 10 to 38% by mass, and even more preferably 10 to 35% by mass based on the total mass of the raw material resin composition of the skin layer.

[0015] (Component A1) Hydrogenated block copolymer The hydrogenated block copolymer preferably contains one or more hydrogenated products (hydrogenated products or hydrides) of an aromatic vinyl-conjugated diene block copolymer containing a block polymerization unit (X) derived from an aromatic vinyl and a block polymerization unit (Y) derived from a conjugated diene.

[0016] The form of the aromatic vinyl-conjugated diene block copolymer having such a structure is represented by, for example, X(YX)n or (XY)n [n is an integer of 1 or more]. Among these, those in the form of X(YX)n, particularly those in the form of X-Y-X, are preferred. As those in the form of X-Y-X, one or more copolymers selected from the group consisting of polystyrene-polybutadiene-polystyrene block copolymer, polystyrene-polyisoprene-polystyrene block copolymer, and polystyrene-polyisoprene·butadiene-polystyrene block copolymer are preferred.

[0017] In such an aromatic vinyl-conjugated diene block copolymer, the aromatic vinyl block unit (X) which is a hard segment exists as a crosslinking point of the conjugated diene rubber block unit (Y) to form a pseudo crosslinking (domain). The conjugated diene rubber block unit (Y) existing between the aromatic vinyl block units (X) is a soft segment and has rubber elasticity.

[0018] Aromatic vinyls that form block polymerization units (X) include styrene, α-methylstyrene, 3-methylstyrene, p-methylstyrene, 4-propylstyrene, 4-dodecylstyrene, 4-cyclohexylstyrene, 2-ethyl-4-benzylstyrene, 4-(phenylbutyl)styrene, 1-vinylnaphthalene, and 2-vinylnaphthalene. Among these, styrene is preferred.

[0019] Examples of conjugated dienes that form block polymerization units (Y) include butadiene, isoprene, pentadiene, 2,3-dimethylbutadiene, and combinations thereof. Among these, one or more conjugated dienes selected from the group consisting of butadiene, isoprene, and combinations of butadiene and isoprene (butadiene-isoprene copolymerization) are preferred. One or more of these conjugated dienes can also be used in combination. The conjugated diene block polymerization unit (Y) consisting of butadiene-isoprene copolymerization units may be random copolymerization units of butadiene and isoprene, block copolymerization units, or tapered copolymerization units.

[0020] In the aromatic vinyl-conjugated diene block copolymer described above, the content of aromatic vinyl block polymerization units (X) is preferably 5% by mass or more and 50% by mass or less, and more preferably 20% by mass or more and 40% by mass or less. The content of these aromatic vinyl units can be measured by conventional methods such as infrared spectroscopy and NMR spectroscopy.

[0021] The aromatic vinyl-conjugated diene block copolymer described above can be produced by various methods. Examples of production methods include: (1) a method in which an alkyllithium compound such as n-butyllithium is used as an initiator to sequentially polymerize aromatic vinyl, and then conjugated diene; (2) a method in which aromatic vinyl, and then conjugated diene, are polymerized and coupled with a coupling agent; and (3) a method in which a lithium compound is used as an initiator to sequentially polymerize conjugated diene, and then aromatic vinyl.

[0022] Hydrogenated block copolymers are obtained by hydrogenating (hydrogenating or hydridizing) an aromatic vinyl-conjugated diene block copolymer as described above using a known method, with a preferred hydrogenation rate of 90 mol% or more. This hydrogenation rate is the value when the total amount of carbon-carbon double bonds in the conjugated diene block polymerization unit (Y) is taken as 100 mol%. "Hydrogenation rate of 90 mol% or more" indicates that 90 mol% or more of the carbon-carbon double bonds are hydrogenated. The hydrogenation rate is measured by a known method such as nuclear magnetic resonance spectroscopy (NMR). Examples of such hydrogenated block copolymers include polystyrene-poly(ethylene / propylene) block (SEP), polystyrene-poly(ethylene / propylene) block-polystyrene (SEPS), polystyrene-poly(ethylene / butylene) block-polystyrene (SEBS), and polystyrene-poly(ethylene-ethylene / propylene) block-polystyrene (SEEPS). More specifically, examples include SEPTON (manufactured by Kuraray Co., Ltd.), Kraton (manufactured by Shell Chemical Co., Ltd.), Kraton G (manufactured by Shell Chemical Co., Ltd.), and ToughTec (manufactured by Asahi Kasei Corporation) (all are product names).

[0023] In this embodiment, the melt flow rate (MFR (temperature 230°C, load 2.16 kg)) of the hydrogenated block copolymer is 1 g / 10 min. or less. In one embodiment, it is more preferable that the melt flow rate (MFR (temperature 230°C, load 2.16 kg)) of the hydrogenated block copolymer is less than 0.1 g / 10 min. Examples of resins with an MFR (measured at temperature 230°C, load 2.16 kg) of 1 g / 10 min. or less include SEEPS. MFR (temperature 230°C, load 2.16 kg) refers to the MFR measured under conditions of temperature 230°C and load 2.16 kg in accordance with JIS K7210.

[0024] (Component A2) Oil Preferably, the oils include paraffinic process oils, naphthenic process oils, aromatic process oils, mineral oils such as liquid paraffin, silicone oils, castor oil, linseed oil, olefin waxes, and mineral waxes. Among these, paraffinic and / or naphthenic process oils are preferred. Examples of process oils include the Diana Process Oil series (manufactured by Idemitsu Kosan Co., Ltd.) and JOMO Process P (manufactured by Japan Energy Co., Ltd.). In addition, various ester-based plasticizers such as phthalic acid, trimellitic acid, pyromellitic acid, adipic acid, or citric acid can also be used. These may be used alone or in combination. By including oil, the softness can be adjusted to create a softer resin composition. As a result, a resin composition can be made that gives a model with softness and physical properties similar to human skin. In terms of workability, it is preferable to pre-absorb the oil into resin A. For this purpose, the shape of resin A is preferably the aforementioned powder or amorphous (crumb) form, which easily absorbs oil.

[0025] The oil has a kinematic viscosity of 0.1 to 100 mm at 37.8°C or 40°C. 2 It is preferable that the value be / s, and the range is 0.1 to 50 mm. 2 It is more preferable that the value be / s, and the range is 0.1 to 15 mm. 2 It is even more preferable that the kinematic viscosity is / s. By keeping it within the above range, it becomes easier to obtain a resin composition that provides a bio-model with high flexibility and physical properties similar to the blood vessels and / or skin of animals, including humans. The kinematic viscosity can be measured by using a Cannon-Fenske viscometer at a test temperature of 37.8°C or 40°C, in accordance with "5. Kinematic Viscosity Test Method" of JIS K 2283:2000.

[0026] In one embodiment, it is preferable that the lowest temperature peak in the generated gas analysis by heated gas generation analysis (EGA-MS method) is oil at 100°C or higher. The lowest temperature peak in the generated gas analysis using the EGA-MS method can be measured as follows. Under a non-atmospheric exposure environment, perform the EGA-MS method within the range of 0 to 200 °C to examine the detection level. The measurement conditions of the EGA-MS method are as follows. <Pyrolysis conditions> Apparatus: Double-shot pyrolyzer ("PY-3030D", manufactured by Frontier Lab Co., Ltd.) Sample amount: 10 - 20 mg is used Heating conditions: Hold at 40 °C for 5 min, increase the temperature to 200 °C at 5 °C / min, and set the holding time at 200 °C to 0 min. Atmosphere: He <GC / MS conditions> Apparatus: "7890A", manufactured by Agilent Technologies / "JMS-T100GC" (manufactured by JEOL Ltd.) Column: Ultra ALLOY-DTM (2.5 m, I.D. 0.15 mmφ) Oven temperature: 300 °C Inlet temperature: 300 °C Split ratio: 50:1 Detector voltage: 2100 V Ionization method: EI

[0027] In this embodiment, the content of the oil (Component A2) in the raw material resin composition of the skin layer is 150 to 450 parts by mass with respect to 100 parts by mass of Resin A. In one embodiment, the content of the oil (Component A2) in the raw material resin composition of the skin layer is more preferably 150 to 400 parts by mass, and even more preferably 150 to 350 parts by mass, with respect to 100 parts by mass of the hydrogenated block copolymer. By setting the content of the oil (Component A2) to 150 parts by mass or more with respect to 100 parts by mass of Resin A, it becomes easier to reproduce the softness of the skin. By setting the content of the oil (Component A2) to 450 parts by mass or less with respect to 100 parts by mass of Resin A, it is possible to suppress a decrease in strength when molded into a sheet.

[0028] (Component A3) Surface modifier As the surface modifier, an antioxidant, an inorganic filler, a paint, etc. can be used.

[0029] Examples of antioxidants include phenolic compounds (4,4-thiobis(3-methyl-6-t-butylphenol), 2,5-di-t-butylhydroquinone, 2,6-di-t-butyl-p-cresol, etc.), phosphorus compounds (diphenylnonylphenyl phosphite, triphenyl phosphite, tris(nonylphenyl) phosphite, etc.), and sulfur compounds (bis(2-methyl-4-(3-n-alkylthiopropionyloxy)-5-t-butylphenyl) sulfide, 2,2-thiodiethylenebis(3-(3,5-t-butyl-4-hydroxyphenyl)propionate, dilaurylthiopropionate, etc.). Among these, phenolic antioxidants are preferred, and hindered phenolic antioxidants are more preferred, from the viewpoint of suppressing oxidation of natural rubber contained in adhesives in high-temperature environments. Examples of hindered phenol antioxidants include octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, ethylene-bis(oxyethylene)-bis-(3-(5-t-butyl-4-hydroxy-m-tolyl)propionate, and pentaerythritol-tetrakis-(3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate). Furthermore, commercially available hindered phenol antioxidants may be used. Examples of such commercially available products include "Irganox® 1076," "Irganox 1010," and "Irganox 245" (all trade names) manufactured by BASF Japan Ltd. These antioxidants may be used individually or in combination of two or more.

[0030] When an antioxidant is used as a surface modifier (component A3), the amount of (component A3) surface modifier added is preferably 5 to 50% by mass, more preferably 5 to 25% by mass, and even more preferably 8 to 25% by mass, relative to the raw resin composition of the surface layer. By setting the content of (component A3) surface modifier to 5% by mass or more relative to the resin composition, it is possible to suppress the increase in tackiness when the sheet is molded. (Component A3) By limiting the content of the surface modifier to 50% by mass or less relative to the resin composition, it is possible to suppress the powdery surface, deterioration of tactile feel, and generation of foreign matter when the sheet is formed.

[0031] Examples of inorganic fillers include silica, carbon black, talc, alumina, sodium silicate, calcium silicate, calcium sulfate, calcium carbonate, magnesium carbonate, magnesium oxide, zinc oxide, titanium oxide, boehmite, bentonite, and hydrotalcite. Of these, silica, alumina, and calcium carbonate are preferred, and silica is particularly preferred from an economic standpoint. These inorganic fillers may be used individually or in combination of two or more.

[0032] Examples of paints include silicone-based paints, polyether-modified paints, acrylic resin-based paints, acrylic group-modified paints, and fluorine-modified paints. These paints may be used individually or in combination of two or more types.

[0033] When an inorganic filler or paint is used as the (component A3) surface modifier, the content of the (component A3) surface modifier in the raw material resin composition of the epidermal layer is preferably 0.05 to 1% by mass, more preferably 0.05 to 0.5% by mass, and even more preferably 0.05 to 0.2% by mass, based on the total amount of the raw material resin composition of the epidermal layer. Inorganic fillers and coatings are preferably applied after the resin composition has been molded.

[0034] In one embodiment, the raw material resin composition for the surface layer may contain additives other than oil and surface modifiers, as long as they do not hinder the effects of the present invention. Examples of additives include pigments, surfactants, viscosity modifiers, and antioxidants. The amount of additives is not particularly limited as long as it provides the effects of the present invention, but is preferably 10% by mass or less relative to the total mass of the raw material resin composition.

[0035] In one embodiment, the thickness of the epidermal layer is preferably 1 to 3 mm, more preferably 1.2 to 2.8 mm, and even more preferably 1.5 to 2.5 mm.

[0036] By satisfying the above composition, the raw material resin composition for the epidermal layer makes it easier to achieve the following parameters. In one embodiment, the tackiness of the raw material resin composition for the epidermal layer is preferably 0.60 N or less, more preferably 0.05 N to 0.60 N, even more preferably 0.05 N to 0.40 N, and particularly preferably 0.05 N to 0.30 N. If the tackiness of the raw material resin composition for the epidermal layer is 0.60 N or less, it becomes easier to approximate the tactile sensation when the skin model is incised to that of human skin. The tackiness of the raw resin composition for the surface layer can be measured by preparing a 70mm x 70mm, 10mm thick sheet using the raw resin composition, and using a force gauge, pressing a circular jig for the force gauge (φ12mm) downwards until a load of 20N is applied, then returning the depth to 0mm, and measuring the load when the jig is pulled upwards.

[0037] In one embodiment, the hardness of the raw material resin composition for the epidermal layer is preferably 3.0 N or more and 25 N or less, more preferably 3.3 N or more and 25 N or less, even more preferably 5.0 N or more and 25 N or less, and particularly preferably 10 N or more and 25 N or less. If the hardness of the raw material resin composition for the epidermal layer is 3.0 N or more and 25 N or less, it becomes easier to make the tactile sensation when the skin model is cut closer to the tactile sensation when human skin is cut. The hardness of the raw resin composition for the surface layer can be measured, for example, by preparing a 70mm x 70mm, 10mm thick sheet using the raw resin composition, and measuring the load applied when a circular force gauge fixture (φ12mm) is pressed against the sheet to a depth of 1mm using a force gauge. In addition to the above method, the hardness can also be measured using a Type E rubber hardness tester according to the method described in JIS K 6253-3 "Vulcanized rubber and thermoplastic rubber - Method for determining hardness - Part 3: Durometer hardness".

[0038] In one embodiment, the strength of the raw material resin composition for the epidermal layer is preferably 3.0 N or more and 12.0 N or less. More preferably, the strength of the raw material resin composition for the epidermal layer is 3.1 N or more and 11.5 N or less, and even more preferably 3.3 N or more and 11.0 N or less. If the strength of the raw material resin composition for the epidermal layer is 3.0 N or more, it will be less likely to tear during suturing technique practice. If it is 12.0 N or less, it will be easier to approximate the tactile feel of human skin when it is incised. The strength of the raw resin composition for the epidermal layer can be measured, for example, by preparing a 70mm x 70mm, 10mm thick sheet using the raw resin composition, passing a polydioxanone suture thread with a thickness of 4-0 and an inverted angle suture needle through the sheet to a depth of 5mm, then pulling the suture thread upward using a force gauge, and measuring the load at which the sheet breaks.

[0039] (subcutaneous tissue layer) The subcutaneous tissue layer is the intermediate layer, and its upper surface is joined to the lower surface of the epidermis, and its lower surface is joined to the upper surface of the muscular layer. The shape of the subcutaneous tissue layer is preferably flat or a shape that mimics the human chest or abdomen. In this embodiment, the subcutaneous tissue layer contains 100 parts by mass of (component B1) hydrogenated block copolymer (hereinafter sometimes simply referred to as "hydrogenated block copolymer") with an MFR (measured at a temperature of 230°C and a load of 2.16 kg) of 1 g / 10 min. or less, and (component B2) oil, in amounts of more than 450 parts by mass and up to 1100 parts by mass.

[0040] (Component B1) Hydrogenated block copolymer In one embodiment, the raw material resin composition for the subcutaneous tissue layer includes a resin component mainly composed of a hydrogenated block copolymer. The resin component content in the raw material resin composition for the subcutaneous tissue layer is preferably 5 to 30% by mass, more preferably 6 to 25% by mass, and even more preferably 7 to 20% by mass, based on the total mass of the raw material resin composition for the subcutaneous tissue layer. In one embodiment, the hydrogenated block copolymer content in the raw material resin composition for the subcutaneous tissue layer is preferably 5 to 30% by mass, more preferably 6 to 25% by mass, and even more preferably 7 to 20% by mass, based on the total mass of the raw material resin composition for the subcutaneous tissue layer.

[0041] (Component B2) Oil In this embodiment, the content of (component B2) oil in the raw material resin composition for the subcutaneous tissue layer is more than 450 parts by mass and 1100 parts by mass or less per 100 parts by mass of hydrogenated block copolymer. In one embodiment, the content of (component B2) oil in the raw material resin composition for the subcutaneous tissue layer is preferably 750 parts by mass or more and 1050 parts by mass or less, and more preferably 450 parts by mass or more and 1000 parts by mass or less per 100 parts by mass of hydrogenated block copolymer.

[0042] (Component B3) Surface modifier When an antioxidant is used as a surface modifier (component B3), the content of the surface modifier (component B3) is preferably 5 to 50% by mass, more preferably 5 to 25% by mass, and even more preferably 8 to 25% by mass, relative to the raw material resin composition of the subcutaneous tissue layer, as an external addition. When an inorganic filler or paint is used as the (component B3) surface modifier, the content of the (component B3) surface modifier in the raw material resin composition of the subcutaneous tissue layer is preferably 0.05 to 1.0% by mass, more preferably 0.05 to 0.5% by mass, and even more preferably 0.05 to 0.2% by mass, relative to the total amount of the raw material resin composition of the subcutaneous tissue layer. Inorganic fillers and coatings are preferably applied after the raw resin composition has been molded.

[0043] In the subcutaneous tissue layer, the (component B1) hydrogenated block copolymer can be selected from those listed as (component A1) hydrogenated block copolymer. The (component B2) oil can be selected from those listed as (component A2) oil. The (component B3) surface modifier can be selected from those listed as (component A3) surface modifier.

[0044] Furthermore, in one embodiment, the raw material resin composition for the subcutaneous tissue layer may contain additives other than oil and surface modifiers, as long as they do not hinder the effects of the present invention. As additives, they can be selected and used from those listed as additives for the surface layer.

[0045] The subcutaneous tissue layer may be a single layer, as shown in Figure 1, or it may be composed of multiple layers, as shown in Figure 2. In one embodiment, the total thickness of the subcutaneous tissue layer is preferably 4 to 15 mm, more preferably 4 to 12 mm, and even more preferably 4 to 10 mm. When composed of multiple layers, the thickness of each layer is preferably 1 to 10 mm, preferably 1 to 8 mm, and preferably 1 to 7 mm. For example, if the subcutaneous tissue layer consists of two layers, the thickness of the first subcutaneous tissue layer is preferably 1 to 5 mm, more preferably 1 to 4 mm, and even more preferably 1 to 3 mm, while the thickness of the second subcutaneous tissue layer is preferably 3 to 10 mm, more preferably 3 to 8 mm, and even more preferably 4 to 7 mm.

[0046] By satisfying the above composition, the raw material resin composition for the subcutaneous tissue layer makes it easier to achieve the following parameters. In one embodiment, the tackiness of the raw material resin composition for the subcutaneous tissue layer is not particularly limited, but is preferably 0.10 N or more and 1.0 N or less, more preferably 0.12 N or more and 0.88 N or less, and even more preferably 0.13 N or more and 0.86 N or less. The tackiness of the raw material resin composition in the subcutaneous tissue layer can be measured using the same method as the tackiness of the raw material resin composition in the epidermal layer.

[0047] In one embodiment, the hardness of the raw material resin composition for the subcutaneous tissue layer is preferably lower than the hardness of the raw material resin composition for the epidermal layer, more preferably between 4.0 N and 8.0 N, even more preferably between 4.0 N and 7.8 N, and particularly preferably between 4.0 N and 7.6 N. If the hardness of the raw material resin composition for the subcutaneous tissue layer is lower than that of the raw material resin composition for the epidermal layer, it becomes easier to approximate the tactile sensation when the skin model is incised to that of human skin. The hardness of the raw material resin composition in the subcutaneous tissue layer can be measured using the same method as the hardness of the raw material resin composition in the epidermal layer.

[0048] In one embodiment, the strength of the raw material resin composition for the subcutaneous tissue layer is preferably 3.0N or more and 9.0N or less, more preferably 3.0N or more and 8.5N or less, even more preferably 3.0N or more and 8.0N or less, and particularly preferably 3.0N or more and 7.5N or less. If the strength of the raw material resin composition for the subcutaneous tissue layer is 3.0N or more, it becomes less likely to tear during suturing technique practice. Furthermore, if it is 9.0N or less, it not only becomes easier to approximate the tactile sensation of cutting human skin, but also makes it easier to approximate the tactile sensation of cutting the subcutaneous tissue layer with scissors to insert a tunneler in the implantation procedure for subcutaneous implantable medical devices to the tactile sensation of doing so on human skin. The strength of the raw material resin composition in the subcutaneous tissue layer can be measured using the same method as the strength of the raw material resin composition in the epidermal layer.

[0049] (Muscle layer) The muscle layer is the lowest layer and is joined to the lowest layer of the subcutaneous tissue at its upper surface. The muscle layer is preferably shaped like a flat plate or a shape that mimics the human chest or abdomen. In this embodiment, the muscle layer contains (component A1) hydrogenated block copolymer (hereinafter sometimes simply referred to as "hydrogenated block copolymer") with an MFR (measured at a temperature of 230°C and a load of 2.16 kg) of 1 g / 10 min. or less.

[0050] (Component C1) Hydrogenated Block Copolymer In one embodiment, the raw material resin composition for the muscle layer includes a resin component mainly composed of a hydrogenated block copolymer. In one embodiment, the content of the resin component in the raw material resin composition of the muscle layer is preferably 15 to 100% by mass, more preferably 15 to 70% by mass, and even more preferably 15 to 35% by mass, based on the total mass of the raw material resin composition of the muscle layer. In one embodiment, the content of resin B in the raw material resin composition of the muscle layer is preferably 15 to 100% by mass, more preferably 15 to 70% by mass, and even more preferably 15 to 35% by mass, based on the total mass of the raw material resin composition of the muscle layer.

[0051] (Component C2) Oil In one embodiment, the raw material resin composition for the muscle layer may contain (component C2) oil. The content of (component C2) oil in the raw material resin composition for the muscle layer is preferably 0 to 600 parts by mass, more preferably 1 to 450 parts by mass, and even more preferably 250 to 450 parts by mass, per 100 parts by mass of resin C.

[0052] (Component C3) Surface modifier In one embodiment, the raw material resin composition for the muscle layer may contain a surface modifier. The content of the surface modifier (component C3) in the raw material resin composition for the muscle layer is not particularly limited.

[0053] Resin C can be selected from those listed as Resin A. (Component C2) Oil can be selected from those listed as (Component A2) Oil. (Component C3) Surface modifier can be selected from those listed as (Component A3) Surface modifier.

[0054] Furthermore, in one embodiment, the raw material resin composition for the muscle layer may contain additives other than oil and surface modifiers, as long as they do not hinder the effects of the present invention. As additives, they can be selected and used from those listed as additives for the surface layer.

[0055] In one embodiment, the thickness of the muscle layer is preferably 10 mm or more, more preferably 10 mm to 30 mm, and even more preferably 10 mm to 20 mm.

[0056] By satisfying the above composition, the raw material resin composition for the muscle layer makes it easier to achieve the following parameters. The tackiness of the raw material resin composition for the muscle layer is not particularly limited, but is preferably 0.10 N or more and 1.0 N or less, more preferably 0.12 N or more and 0.90 N or less, and even more preferably 0.13 N or more and 0.80 N or less. The tackiness of the raw material resin composition for the muscle layer can be measured using the same method as the tackiness of the raw material resin composition for the epidermal layer.

[0057] In one embodiment, the hardness of the raw material resin composition for the muscle layer is preferably 3N or more and 25N or less, more preferably 4N or more and 24N or less, and even more preferably 5N or more and 23N or less. By setting the hardness of the raw material resin composition for the muscle layer to 3N or more, incision and suturing techniques are stabilized, and when a subcutaneous implantable medical device is placed in the subcutaneous fat layer, it contributes to the fixation of the subcutaneous implantable medical device, and the puncture technique for the subcutaneous implantable medical device is also made more stable and easier to perform. The hardness of the raw material resin composition for the muscle layer can be measured using the same method as the hardness of the raw material resin composition for the epidermal layer.

[0058] In one embodiment, the strength of the raw material resin composition for the muscle layer is not particularly limited, but is preferably 3.0N or more and 12N or less, more preferably 3.2N or more and 11N or less, and even more preferably 3.4N or more and 10N or less. The strength of the raw material resin composition for the muscle layer can be measured using the same method as the strength of the raw material resin composition for the epidermal layer.

[0059] Skin models can be molded using known molding methods. For example, a resin composition can be molded into individual layers by a heat-pressing method, and then the layers can be bonded together to complete the skin model. Alternatively, the material can be poured into any mold, heated, cooled, and solidified to create individual layers, and then bonded together to complete the skin model. Furthermore, each layer can be molded by injection molding or the like, and then bonded together to complete the skin model.

[0060] In one embodiment, the skin model can be used to practice skin incision and suturing techniques. It can also be used to practice implantation techniques for subcutaneously implantable medical devices.

[0061] A non-limiting list of exemplary embodiments and combinations of exemplary embodiments of this disclosure are disclosed below. [1] A skin model having the epidermal layer, subcutaneous tissue layer, and muscle layer in this order, The surface layer contains 100 parts by mass of (component A1) hydrogenated block copolymer with an MFR (measured at a temperature of 230°C and a load of 2.16 kg) of 1 g / 10 min. or less, and 150 parts by mass or more and 450 parts by mass or less of (component A2) oil, and the total amount of (component A3) surface modifier in the raw material resin composition of the surface layer contains 5% by mass or more and 30% by mass or less. The subcutaneous tissue layer contains 100 parts by mass of (component B1) hydrogenated block copolymer with an MFR (measured at a temperature of 230°C and a load of 2.16 kg) of 1 g / 10 min. or less, and (component B2) oil in amounts between 450 parts by mass and 1100 parts by mass or less. A skin model in which the muscle layer contains (component C1) hydrogenated block copolymer. [2] The skin model according to [1], wherein the muscle layer contains 100 parts by mass of (component C1) hydrogenated block copolymer with an MFR (measured at a temperature of 230°C and a load of 2.16 kg) of 1 g / 10 min. or less, and 1 part by mass or more and 450 parts by mass or less of (component C2) oil. [3] The skin model according to [1] or [2], wherein the surface modifier is a hindered phenol antioxidant. [4] A skin model as described in any of [1] to [3], wherein the thickness of the subcutaneous tissue layer is 4 to 15 mm. [5] A skin model as described in any of [1] to [4], wherein the thickness of the epidermal layer is 1 to 3 mm. [6] A skin model according to any one of [1] to [5], wherein the subcutaneous tissue layer is composed of multiple layers. [7] A skin model according to any one of [1] to [6], for practicing implantation procedures for subcutaneously implantable medical devices. Each configuration and its combination in each embodiment is an example, and additions, omissions, substitutions, and other modifications can be made as appropriate without departing from the spirit of this disclosure. This disclosure is not limited by the embodiments. [Examples]

[0062] The present disclosure will be further illustrated by the following examples, but these examples will not limit the interpretation of the present disclosure.

[0063] The various raw materials and manufacturing methods used in the examples are as follows. (1) Resin components • Hydrogenated block copolymer 1 (SEEPS: "SEPTON 4099", manufactured by Kuraray Co., Ltd.) (Number average molecular weight 400,000, MFR (temperature 230℃, load 2.16kg) 0.0g / 10min (0.0g / 10min means no flow), Styrene content 30% by mass, Hydrogenation rate 90 mol% or more) • Hydrogenated block copolymer 2 (SEEPS: "SEPTON J", manufactured by Kuraray Co., Ltd.) (Number average molecular weight 230,000, MFR (temperature 230°C, load 2.16 kg) 0.0 g / 10 min (0.0 g / 10 min means no flow)) (2) Oil • Oil 1 (Paraffin oil: "Pearlream EX", kinematic viscosity at 37.8℃: 10.6 mm) 2 (Manufactured by NOF Corporation) • Oil 2 (Paraffin oil: "PW90", kinematic viscosity at 40°C: 90.5 mm) 2 (Manufactured by Idemitsu Kosan Co., Ltd.) (Note that the kinematic viscosity was measured using a Cannon-Fenske viscometer at a test temperature of 37.8°C or 40°C, in accordance with "5. Kinematic Viscosity Test Method" of JIS K 2283:2000.) (3) Surface modifiers • Surface modifier 1 (Antioxidant: Hindered phenol antioxidant "Irganox 1010", manufactured by BASF Japan Ltd.)

[0064] [Preparation of resin composition 1] 100 parts by mass of hydrogenated block copolymer 1 and 1000 parts by mass of oil 1 were added, along with 20% by mass of surface modifier added externally to the total amount of hydrogenated block copolymer 1 and oil 1. The mixture was then stored for at least one hour to allow the resin to absorb the oil sufficiently. The mixture was then kneaded for 10 minutes at 180°C and a rotation speed of 100 revolutions per minute using a segment mixer (Laboplastmill KF70V2 model, manufactured by Toyo Seiki Co., Ltd.).

[0065] [Preparation of resin compositions 2-11] A resin composition was prepared in the same manner as resin composition 1, except that the materials listed in Table 1 were used and their content was as listed in Table 1.

[0066] (Measurement of tackiness) A 70mm x 70mm, 10mm thick sheet was prepared using the raw resin composition. A force gauge was used to press a circular jig (φ12mm) for the force gauge downwards until it reached a load of 20N. After returning the jig to a depth of 0mm, the load was measured when the jig was pulled upwards. Paper cloths were attached to the jig during the measurement. The test was performed three times, and the average value was defined as the tackiness.

[0067] (Hardness measurement) A 70mm x 70mm, 10mm thick sheet was prepared using the raw resin composition. A force gauge was used to measure the load applied when a circular force gauge jig (φ12mm) was pressed against the sheet to a depth of 1mm. The test was performed three times, and the average value was defined as the hardness.

[0068] (Measurement of intensity) A 70mm x 70mm, 10mm thick sheet was prepared using the raw resin composition. A polydioxanone suture thread with a thickness of 4-0 and an inverted-angle suture needle was used to thread the suture thread to a depth of 5mm. The suture thread was then pulled upward using a force gauge, and the load at which the sheet broke was measured. The test was performed three times, and the average value was taken as the strength.

[0069] [Table 1]

[0070] [Creating a skin model] (Example 1) Heat press method (180°C, 5 minutes, 50 kg / cm² pressure) 2 Using resin composition 8, an epidermal layer measuring 100 mm x 100 mm with a thickness of 2 mm was formed; using resin composition 5, a first subcutaneous tissue layer measuring 100 mm x 100 mm with a thickness of 5 mm was formed; using resin composition 5, a second subcutaneous tissue layer measuring 100 mm x 100 mm with a thickness of 5 mm was formed; and using resin composition 7, a muscle layer measuring 100 mm x 100 mm with a thickness of 20 mm was formed. These were then bonded together in this order to create a skin model. The prepared skin models were evaluated for tactile sensitivity, incisibility, and sutureability based on the following evaluation methods. The results are shown in Table 2.

[0071] (Example 2, Comparative Example 2) A skin model was prepared and evaluated in the same manner as in Example 1, except that the resin composition shown in Table 2 was used.

[0072] (Comparative Example 1) As a comparative example, commercially available product 1, "Suture Pad Pro" (manufactured by Japan Light Service Co., Ltd.), was used.

[0073] (1) Evaluation of tactile sensation The tactile sensation of pressing a finger against a skin model was evaluated. "Good" indicated no stickiness, "Acceptable" indicated stickiness but without a feeling of tackiness, and "Unacceptable" indicated stickiness to the point of feeling tacky.

[0074] (2) Evaluation of the reproducibility of the incision The reproducibility of incisions made to a skin model at a depth of approximately 5 mm by pressing a scalpel against it was evaluated. "Good" was defined as when incisions could be made with a scalpel and there was no resistance to the incision of the model; "Acceptable" was defined as when incisions could be made with a scalpel but slight resistance was felt during the incision; and "Unacceptable" was defined as when incisions were impossible or when incisions could be made but the resistance during the incision was significant and difficult to make.

[0075] (3) Evaluation of the reproducibility of sutures In the incision reproducibility evaluation test, the reproducibility of suturing was evaluated when an incised skin model was sutured from the outer layer of the epidermis to the subcutaneous tissue layer using polydioxanone sutures with a thickness of 4-0 and a reverse-angled suture needle. "Good" was rated if suturing was possible without damage, "Acceptable" if suturing was possible but partially damaged or difficult, and "Poor" if suturing was not possible.

[0076] [Table 2]

[0077] As shown in Table 2, the skin models of Examples 1 and 2 exhibited good tactile properties, reproducibility of incisions, and reproducibility of sutures, possessed a tactile feel similar to human skin, and could be used for practicing skin incisions and sutures. On the other hand, the skin model in Comparative Example 1 measured the strength of the layer corresponding to the epidermis at 4.08 N, which is lower than the strength required in the evaluation test for the reproducibility of the sutures, and there was a risk that the skin model would collapse due to the sutures. The skin model in Comparative Example 2 did not have a tactile feel similar to human skin. Furthermore, it offered significant resistance during incision, making it difficult to cut and unsuitable for practicing skin incision.

[0078] Furthermore, when the skin model from Example 1 was used to practice the implantation procedure for a 160mm x 160mm subcutaneous implantable medical device, it could be used without any problems. [Industrial applicability]

[0079] The skin model of this embodiment has a tactile feel similar to human skin and can also be used for practicing skin incision and suturing. Therefore, it is suitable for practicing skin incision and suturing techniques and thus has industrial applicability. [Explanation of Symbols]

[0080] 1. Skin model 2 Epidermal layer 3 Subcutaneous tissue layer 4 Muscle Layers 5 sheets 6. Jig 7 threads

Claims

1. A skin model having the epidermal layer, subcutaneous tissue layer, and muscle layer in this order, The surface layer contains 100 parts by mass of (component A1) hydrogenated block copolymer with an MFR (measured at a temperature of 230°C and a load of 2.16 kg) of 1 g / 10 min. or less, and 150 parts by mass or more and 450 parts by mass or less of (component A2) oil, and the total amount of (component A3) surface modifier in the raw material resin composition of the surface layer contains 5% by mass or more and 30% by mass or less. The subcutaneous tissue layer contains 100 parts by mass of (component B1) hydrogenated block copolymer with an MFR (measured at 230°C and a load of 2.16 kg) of 1 g / 10 min. or less, and (component B2) oil in amounts of more than 450 parts by mass and up to 1100 parts by mass. A skin model in which the muscle layer contains (component C1) hydrogenated block copolymer.

2. The skin model according to claim 1, wherein the muscle layer contains 100 parts by mass of a hydrogenated block copolymer with an MFR (measured at a temperature of 230°C and a load of 2.16 kg) of 1 g / 10 min. or less, and 1 to 450 parts by mass of oil (component C2).

3. The skin model according to claim 1 or 2, wherein the surface modifier is a hindered phenol antioxidant.

4. The skin model according to claim 1 or 2, wherein the thickness of the subcutaneous tissue layer is 4 to 15 mm.

5. The skin model according to claim 1 or 2, wherein the thickness of the epidermal layer is 1 to 3 mm.

6. The skin model according to claim 1 or 2, wherein the subcutaneous tissue layer is composed of a plurality of layers.

7. A skin model according to claim 1 or 2, for practicing the implantation procedure of a subcutaneously implantable medical device.

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