Method for preparing artificial blood vessel with valve

Abstract

The present invention relates to a method for preparing a valved artificial blood vessel. The valved artificial blood vessel is a tubular fabric with a valve inside, comprising an outer tube and an inner tube connected to each other. The outer tube is a cylindrical tube. When the inner tube is unfolded, it is composed of three identical quasi-rectangular shapes, the quasi-rectangular shapes differing from rectangles only in that the upper and lower edges are curved edges. The upper edges of the three quasi-rectangular shapes are free edges, while the lower edges and straight edges are respectively fixed to the inner wall of the outer tube. First, a pattern image of the valved artificial blood vessel is input into weaving CAD software, and then the design is set according to the fabric density. Then, a process is performed to match each part of the valved artificial blood vessel pattern image with the tissue in a needle organization table, thereby generating a pattern pattern in the weaving CAD software. Finally, the pattern pattern is imported into a loom system of a jacquard loom for integrated weaving to obtain the product. The seamless valved artificial blood vessel of the present invention does not suffer from stress concentration at the suture site, thereby greatly improving tear resistance.

Description

Technical Field

[0001] The invention belongs to the technical field of artificial blood vessels and relates to a method for preparing an artificial blood vessel with a valve. Background Art

[0002] Congenital heart disease is the leading cause of early infant mortality. Most patients with congenital heart disease have abnormalities in the right ventricular outflow tract, a section of blood vessels in the human heart's anatomical structure that connects the right ventricle and the pulmonary artery. Right ventricular outflow tract reconstruction is an applicable surgical method for correcting a variety of congenital heart diseases.

[0003] Initially, homografts were used to reconstruct the right ventricular outflow tract, which is the gold standard for right ventricular outflow tract reconstruction. However, due to the limited supply of homografts and their inappropriate size for the right ventricular outflow tract of infants and young children, there is no available treatment material for infants, which increases the early mortality rate of infant patients.

[0004] To address this issue, attempts have been made to replace the lack of homologous grafts with xenografts. Among them, glutaraldehyde-treated bovine jugular vein (BJV) has been used to reconstruct the right ventricular outflow tract since 1999. However, most BJVs do not meet the vascular size requirements of infant patients and can cause complications, making it difficult to achieve long-term durability. The most common complications are ductal stenosis, which often requires surgical re-intervention, and a high incidence of endocarditis in the late stage of implantation. Calcification, functional insufficiency, and other problems may occur in the later stages. In addition, the distal anastomosis of the bovine jugular vein may show early fibrotic cortical formation, as well as severe ductal dilatation and reflux.

[0005] Later, scholars began to use polymer materials, such as polyester and expanded polytetrafluoroethylene (ePTFE), to replace the human body's right ventricular outflow tract vascular conduits to save children in urgent need of surgery. However, at present, there are no valved conduit products suitable for the blood vessel size of infants and young children. Some right ventricular outflow tract abnormalities involve valve abnormalities, such as pulmonary valve stenosis, pulmonary valve atresia, and tetralogy of Fallot. Under normal circumstances, the pulmonary valve closes after the right ventricle contracts to prevent blood backflow. Artificial blood vessels with valves can help reduce the workload of the right ventricle. In the absence of a valve, the right ventricle needs to pump blood more forcefully to overcome the backflow of blood and flow resistance, which increases the workload of the heart and may lead to heart failure. Therefore, artificial blood vessels used for the right ventricular outflow tract need to have valves to prevent blood backflow and ensure normal blood flow.

[0006] Clinicians typically use ePTFE membranes to manually sew valved conduits during surgery. However, this method prolongs the operation and increases the risk of infection during surgery. For example, patent US20230404751A1 discloses a double-valve valved conduit that uses ePTFE to form the conduit and valve, and uses polypropylene sutures to sew the valve to the conduit. However, polypropylene sutures can cause an immune response, potentially leading to inflammation or fibrotic tissue formation, which can affect the long-term function of the valve.

[0007] Patent CN105142574B sews bovine and porcine pericardial leaflets to an artificial blood vessel; Patent CN106794065B sews cut and trimmed leaflets to an artificial blood vessel; and Patent CN 109549751 A sews a three-leaflet valve integrated into the animal pericardium, with the tubular body sewn along its sides. However, suturing the leaflets after trimming them to the artificial blood vessel is prone to bleeding and stress concentration at the suture site, significantly reducing the durability of the valved conduit in vivo.

[0008] In addition, the existing technology also uses a valve ring (CN117120001A, the valve ring is made of nickel-titanium alloy) or a sewing ring (CN105142574B) to fix and support the valve leaflets. Patent CN114173713A uses a support ring to deliver and secure the valve to the surrounding tissue for reinforcement (the adjustable stabilization ring engages the cardiovascular valve). However, the presence of the sewing ring will increase the overall rigidity of the valve, thereby reducing the compliance and flexibility of the valve, which will cause stress concentration problems at the contact point between the valve and the sewing ring, causing the valve to wear long-term or even fail. At the same time, the rigid structure of the sewing ring may be more prone to calcification over time, and calcification will make the valve harder, reduce valve function, and ultimately lead to valve failure.

[0009] Patent US2024156593A1 uses a compressible layer of material to radially expand to form a support structure and adjust the valve diameter; Patent US2022226109A1 applies pressure to the frame elements supporting the valve to achieve radial expansion of the frame to fix and support the leaflets. However, using a compressible layer of material to radially expand to form a support structure and adjust the valve diameter makes it difficult to accurately expand the support structure to the appropriate valve diameter.

[0010] To address these challenges, sutureless closure technology emerged. Current research on sutureless closure technology includes thermal bonding and 3D knitting. While progress has been made, these technologies are primarily applied to common artificial blood vessels, rather than complex valved structures.

[0011] For example, patent US2023165675A1 seamlessly attaches the leaflet to the tube through thermal bonding. However, thermal bonding requires precise control of process parameters such as temperature and cooling rate during melt recrystallization, as well as material formulation (such as the addition of toughening agents) to minimize or avoid the impact of thermal bonding on the toughness of the suture between the leaflet and the tubular portion.

[0012] Therefore, it is of great significance to study a method for preparing a valved artificial blood vessel to solve the problems existing in the prior art. Summary of the Invention

[0013] The purpose of the present invention is to solve the problems existing in the prior art and provide a method for preparing a valved artificial blood vessel.

[0014] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0015] A method for preparing a valved artificial blood vessel. The valved artificial blood vessel is a tubular fabric with a valve inside, comprising an outer tube and an inner tube connected to each other. The outer tube is a cylindrical tube. When the inner tube is unfolded, it is composed of three identical quasi-rectangular shapes. The quasi-rectangular shapes differ from rectangles only in that their upper and lower edges are curved. The upper edges of the three quasi-rectangular shapes are free edges, while the lower edges and straight edges are respectively fixed to the inner wall of the outer tube.

[0016] First, input the pattern of the artificial blood vessel with valve into the weaving CAD software, and then make the design settings, including density, size and number of grids. The density settings in the design settings are all set according to the density of one layer of fabric. The warp density of one layer of fabric is actually 4 times the warp density of four layers of fabric. 1 Then the process is carried out, including shuttle setting, fabric structure design, needle organization table setting and sample card setting (based on the configuration of the jacquard machine used, the total number of warp yarns of the artificial blood vessel with valve, and each wire of the jacquard machine controlling a single warp yarn to make the sample card and set the functional needle organization table in the sample card), the various parts of the artificial blood vessel with valve pattern and the organization are matched to the needle organization table, thereby generating a pattern pattern in the weaving CAD software, and finally the pattern pattern is imported into the loom system of the jacquard machine for integrated weaving to obtain the artificial blood vessel with valve.

[0017] As the preferred technical solution:

[0018] In the method for preparing a valved artificial blood vessel as described above, the height h of the straight side of the rectangular shape is D is the outer tube diameter.

[0019] In the method for preparing a valved artificial blood vessel as described above, the upper and lower sides of the rectangular shape are both arc sides, the arc α of the upper side is 90-180°, and the arc β of the lower side is 90-180°.

[0020] In the preparation method of a valved artificial blood vessel as described above, multiple coils of rigid wire are woven into the outer tube to provide a fixed support. The rigid wire is made of stainless steel wire, nickel-titanium alloy wire, cobalt-chromium alloy wire or glass fiber yarn. The woven area is located 0 to 10 cm below the lowest point of the lower side of the rectangle.

[0021] The preparation method of a valved artificial blood vessel as described above determines the machine parameters according to the diameter of the patient's right ventricular outflow tract. The weaving machine parameters are: fabric machine tube diameter 8-40 mm, warp density 100-1000 yarns / 10 cm, weft density 50-800 yarns / 10 cm, machine weaving shrinkage rate 1-10%, total number of warp yarns 200-1000 yarns, and machine reed number 40-400 / 10 cm.

[0022] Designing the machine parameters according to the patient's blood vessel size and adjusting the warp and weft density to obtain valved artificial blood vessels of corresponding sizes will overcome the problem of blood vessel size mismatch in patients with congenital heart disease, especially infants and young children.

[0023] According to the method for preparing a valved artificial blood vessel as described above, the valved artificial blood vessel is regarded as four layers of fabric during weaving, wherein the first and fourth layers of fabric are symmetrical structures (i.e., the two layers have the same shape and size), the second and third layers of fabric are symmetrical structures (i.e., the two layers have the same shape and size), the second and third layers of fabric are connected to form the outer tube of the valved artificial blood vessel, and the first and fourth layers of fabric are connected to form the inner tube of the valved artificial blood vessel, i.e., the valve; when the artificial blood vessel is put on the loom for weaving, the valve is designed to be outside, i.e., the first and fourth layers are the woven valve, and the second and third layers are the woven tube body. The advantage of this design is that the structure of the valve can be clearly seen during weaving, so as to facilitate judgment as to whether the woven structure is the desired valved structure; after weaving is completed, the valved artificial blood vessel is manually flipped over to obtain the valved artificial blood vessel;

[0024] The first fabric layer and the fourth fabric layer have the same weave structure, which is plain weave, twill weave, satin weave, double plain weave, basket weave, reinforced twill weave, composite twill weave or reinforced satin weave;

[0025] The second fabric layer and the third fabric layer have the same weave structure, which is plain weave, twill weave, satin weave, double plain weave, basket weave, reinforced twill weave, composite twill weave or reinforced satin weave;

[0026] The first fabric layer, the second fabric layer, the third fabric layer, and the fourth fabric layer have the same weave structure as the consolidation parts, which are plain weave, twill weave, satin weave, double plain weave, basket weave, reinforced twill weave, composite twill weave, or reinforced satin weave.

[0027] Since the jacquard machine's harness can control each warp yarn individually, the structure of each layer of the four-layer fabric can be designed separately. The total number of warp threads is divided into four equal parts in the loom system. The lifting order of each layer of yarn is controlled by designing the structure. The lifted yarn is interwoven with the input weft yarn to form a fabric structure, thereby forming a specific structure with valved pipes.

[0028] During weaving, the order in which each yarn is lifted is controlled according to the pattern pattern generated in the weaving CAD software; the generated pattern pattern represents the interwoven structure of the warp and weft yarns in each layer of the four-layer fabric. According to the pattern pattern, the jacquard machine will control the lifting of each warp yarn, and the weft yarn is manually inserted to form the fabric.

[0029] The design of the consolidation structure at the valve-tube connection involves consolidating the first and second fabric layers by knotting the warp yarns of the second fabric layer with the weft yarns of the first fabric layer. Similarly, knotting the warp yarns of the third fabric layer with the weft yarns of the fourth fabric layer consolidates the third and fourth fabric layers. In the unconsolidated areas, the valve leaflets and the outer tube form a flap pocket. A first layer of woven valve-like fabric, a second, third, and fourth layers of woven tubular fabric, are provided. Knotted structures are applied to specific consolidation areas of the first and second fabric layers to connect the valves of the first layer and the tube of the second layer. The same applies to the third and fourth layers.

[0030] The depth of the valve cuff is determined based on the minimum length of the line connecting the two upper end points of the valve leaflet on the outer tube.

[0031] In the method for preparing a valved artificial blood vessel as described above, the material of the valved artificial blood vessel is polyester, polypropylene, polytetrafluoroethylene or ultra-high molecular weight polyethylene.

[0032] According to the method for preparing a valved artificial blood vessel as described above, the tear resistance of the valved artificial blood vessel is 25 to 1500 N / mm, which is significantly improved compared with the existing hand-sewn valved artificial blood vessels.

[0033] Principle of the invention:

[0034] The present invention utilizes the structural design of woven fabrics to integrate the valve and vascular conduit, connecting the valve and vascular conduit through the fixed points between the fabric structures. The ideal structure of valve and conduit integration can be achieved on a jacquard loom through the coordination of the loom system and the structural design.

[0035] The present invention prepares a valved artificial blood vessel by seamlessly integrating molding on a loom. Compared with the existing method of suturing valves and artificial blood vessels using suture technology, it is easier to keep the tension of the artificial blood vessel consistent. Due to the large difference in mechanical properties between the suture thread and the artificial blood vessel material, such as elastic modulus and strength, the suture thread is usually harder or softer than the artificial blood vessel material. This inconsistency can easily cause uneven stress in the artificial blood vessel, thereby forming stress concentration at the contact interface; and local protrusions are easily formed at the suture site, and these areas will also form stress concentration. Moreover, it is impossible to achieve perfect symmetry and uniform distribution of the valved pipe during the suturing process. The unevenness in the spacing, depth and tightness between the suture points will lead to local stress concentration. The method of the present invention prepares a valved artificial blood vessel by seamlessly integrating molding on a loom. The material of the consolidation site is consistent with the artificial blood vessel material, which can avoid the problem of inconsistent tension caused by the inconsistency between the suture thread and the blood vessel material. Secondly, the fabric formed by the valve-shaped pipe on the loom is smooth at the consolidation point, and no local bulge is formed, which can avoid the stress concentration problem caused by the bulge at the suture part; and in the weaving CAD software, the consolidation points in the pattern pattern can be designed as a symmetrical structure and the consolidation points can be evenly distributed to ensure that the consolidation points will not cause stress concentration problems due to symmetry problems.

[0036] Beneficial effects:

[0037] (1) The method for preparing a valved artificial blood vessel of the present invention does not cause stress concentration at the suture site due to the seamless suture process, thereby improving the tear resistance of the valved artificial blood vessel.

[0038] (2) The present invention provides a method for preparing a valved artificial blood vessel, wherein valved tubes of various specifications are integrally formed on a loom, without the need for suturing, thereby shortening the operation time and reducing the risk of infection for the patient; and the valved artificial blood vessel has a rigid-flexible structure, which facilitates fixation of the connection between the blood vessel and the heart;

[0039] (3) The method for preparing a valved artificial blood vessel of the present invention can design the machine parameters according to the patient's blood vessel size and adjust the warp and weft density to obtain a valved artificial blood vessel of corresponding size, thereby overcoming the problem of mismatch with the blood vessel size of infants and young children. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 The present invention is a flow chart of a method for preparing a valved artificial blood vessel;

[0041] Figure 2 This is a frontal plan view of a valved vascular graft;

[0042] Figure 3 This is the main view of the valved vascular graft installed on the machine;

[0043] Figure 4is a pattern diagram; in the diagram, a is the width of the petal, b is the depth of the petal pocket, c is the length of the free edge, and d is the length of the fixed edge;

[0044] Among them, 1-outer tube, 2-petal, 3-consolidation part, 4-rigid wire, 5-free edge. DETAILED DESCRIPTION

[0045] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0046] The test methods involved in the performance indicators of the present invention are as follows:

[0047] Tear Resistance: ISO 7198 is a standard developed by the International Organization for Standardization (ISO) specifically for evaluating the mechanical and physical properties of artificial blood vessels (including tubular vascular grafts and vascular patches), including tear resistance testing. This standard specifies a tear strength test method, typically performed using a tensile testing machine to measure the maximum force a material can withstand when it tears. Test Method: Fabric tear resistance testing is performed using a multifunctional strength tester for medical textiles (YG(B)026G-500). First, determine the test conditions: set the clamp distance to 7 mm, the tensile direction upward, and the tensile rate to 20 mm / min. To begin testing, clamp the sample at both ends in the fixture, with one end of the clamp clamped to the valve of the valved conduit and the other end clamped to the conduit of the valved conduit, ensuring a secure, non-slip fit. At the start of the experiment, gradually apply tensile force until the sample tears, and record the maximum load at which the tear occurs. For each example, calculate the average of multiple test data sets, and take the average of the maximum loads for each sample as the tear strength for that example.

[0048] Example 1

[0049] A valved artificial blood vessel is a tubular polyester fabric with a valve inside, comprising an outer tube and an inner tube connected to each other; the outer tube is a cylindrical tube, and the inner tube is composed of three identical quasi-rectangular tubes when unfolded, the only difference between the quasi-rectangular tubes and the rectangles being that the upper and lower sides are arc-shaped; the arc α of the upper side is 90°, and the arc β of the lower side is 90°; the upper sides of the three quasi-rectangular tubes are free sides, and the lower sides and straight sides are respectively fixed to the inner wall of the outer tube; at the unfixed part, the leaflets (quasi-rectangular tubes) form a valve pocket with the outer tube; the height h of the straight side of the quasi-rectangular tube is D is the outer tube diameter, D = 7 mm; the longitudinal length of the outer tube is 80 mm; the width a of a single leaflet is 8 mm, the depth b of the leaflet is 10 mm, the length c of the free edge is 10 mm, and the length d of the fixed edge is 10 mm;

[0050] Ten turns of stainless steel wire are woven on the outer tube for fixing and supporting, and the woven area is located 3 cm below the lowest point of the lower side of the rectangle.

[0051] The tear strength of the valved artificial blood vessel is 26.6N / mm.

[0052] The method for preparing the above-mentioned valved artificial blood vessel comprises the following specific steps:

[0053] (1) Input the pattern of the valved vascular graft into the weaving CAD software;

[0054] (2) Design settings, including fabric density, size, and number of grids;

[0055] According to the design of one layer of fabric, the warp density is 75 pieces / 10cm, the fabric width is 1.3cm, the warp grid number is 70, the weft density is 50 pieces / 10cm, the fabric length is 8cm, and the weft grid number is 60;

[0056] (3) Performing process treatment;

[0057] (3.1) Shuttle setting;

[0058] The valved artificial blood vessel is made of four layers of fabric, with the shuttle set according to the color blocks of the pattern, and the shuttle is set from left to right in the order of the layers during weaving;

[0059] (3.2) Fabric structure design;

[0060] During weaving, the valved artificial blood vessel is regarded as four layers of fabric, the first layer of fabric and the fourth layer of fabric are symmetrical structures, the second layer of fabric and the third layer of fabric are symmetrical structures, the second layer of fabric and the third layer of fabric are connected to form the outer tube of the valved artificial blood vessel, and the first layer of fabric and the fourth layer of fabric are connected to form the inner tube of the valved artificial blood vessel;

[0061] The first layer of fabric and the fourth layer of fabric have the same structure, which is plain weave.

[0062] The second and third fabrics have the same structure, which is plain weave;

[0063] The first fabric layer and the second fabric layer as well as the third fabric layer and the fourth fabric layer have the same weave structure as the consolidation part, which is plain weave;

[0064] (3.3) Setting of needle organization table;

[0065] According to the different color blocks of the pattern, the corresponding organization of each layer is input into the needle organization table;

[0066] (3.4) Sample card setting;

[0067] Each grid in the sample card corresponds to each harness on the jacquard machine. Select the pattern needles to be weaved. The number of pattern needles corresponds to the total number of warp yarns.

[0068] (4) Corresponding each part of the valved artificial blood vessel pattern to the tissue in the needle organization table, thereby generating a pattern pattern in the weaving CAD software;

[0069] (5) The pattern pattern is imported into the loom system of the jacquard machine for integrated weaving. Ten turns of stainless steel wire are woven into the outer tube to serve as a fixed support. The woven area is located 3 cm below the lowest point of the lower side of the rectangular shape. Finally, the artificial blood vessel with a valve is obtained by manual flipping.

[0070] The specific weaving process is as follows: when the loom is on, shuttle weaving is carried out from bottom to top according to the pattern pattern, and the lifting order of each yarn is controlled by the pattern pattern; the fabric is woven from top to bottom, the first and fourth layers are woven into petals, and the second and third layers are woven into tubes; the tube part is woven first, and at the beginning, according to the set pattern needle organization table, the warp yarns on the tube are lifted, and the weft yarns are put in to weave the tube; when weaving to the consolidation part, the petals and tubes are woven together, and according to the organization structure entered in the pattern needle organization table, the warp yarns on the tube and the petals are lifted respectively, and the weft yarns are put in to weave in the order of lifting the warp yarns of the first layer, the fourth layer, the second layer, and the third layer; when the weaving of the petal part is completed, the tubular part is woven separately, and at this time, according to the design of the pattern needle organization table, only the warp yarns on the tube are lifted and interwoven with the weft yarns to form a tube, and finally a four-layer fabric with a flap artificial blood vessel is formed;

[0071] The weaving parameters are as follows: the warp density is determined according to the warp density range of the artificial blood vessel, which is 300 yarns / 10 cm; the total number of warp yarns is determined to be 150 yarns based on the patient's blood vessel diameter; the fabric tube diameter is 8 mm, the weft density is 200 yarns / 10 cm, the weaving shrinkage is 1%, the reed number is 75 / 10 cm; and the fabric fold diameter is 12.56 mm.

[0072] The above-mentioned valved artificial blood vessel with the same shape and structure prepared by hand sewing has a tear strength of 12.4 N / mm.

[0073] Example 2

[0074] A valved artificial blood vessel is a tubular polyester fabric with a valve inside, comprising an outer tube and an inner tube connected to each other;

[0075] The outer tube is a cylindrical tube. When the inner tube is unfolded, it is composed of three identical quasi-rectangular shapes. The only difference between the quasi-rectangular shapes and the rectangular shapes is that the upper and lower edges are arc-shaped. The arc α of the upper edge is 180°, and the arc β of the lower edge is 180°. The upper edges of the three quasi-rectangular shapes are free edges, and the lower edges and straight edges are respectively fixed to the inner wall of the outer tube. At the unfixed part, the leaflets (quasi-rectangular) form a flap with the outer tube.

[0076] The height h of the straight side of the rectangular shape is D, where D is the diameter of the outer tube, D=18 mm; the longitudinal length of the outer tube is 120 mm;

[0077] The width of a single leaflet is 21 mm, the depth of the leaflet is 8 mm, the length of the free edge is 24 mm, and the length of the fixed edge is 24 mm.

[0078] The outer tube is woven with 20 loops of nickel-titanium alloy wire for fixed support, and the woven area is located 10 cm below the lowest point of the lower side of the rectangle.

[0079] The tear strength of the valved artificial blood vessel is 53.5N / mm.

[0080] The method for preparing the above-mentioned valved artificial blood vessel comprises the following specific steps:

[0081] (1) Input the pattern of the valved vascular graft into the weaving CAD software;

[0082] (2) Design settings, including fabric density, size, and number of grids;

[0083] According to the design of one layer of fabric, the warp density is 175 pieces / 10cm, the fabric width is 3.1cm, the warp grid number is 220, the weft density is 150 pieces / 10cm, the fabric length is 12cm, and the weft grid number is 210;

[0084] (3) Performing process treatment;

[0085] (3.1) Shuttle setting;

[0086] The valved artificial blood vessel is made of four layers of fabric, with the shuttle set according to the color blocks of the pattern, and the shuttle is set from left to right in the order of the layers during weaving;

[0087] (3.2) Fabric structure design;

[0088] During weaving, the valved artificial blood vessel is regarded as four layers of fabric, the first layer of fabric and the fourth layer of fabric are symmetrical structures, the second layer of fabric and the third layer of fabric are symmetrical structures, the second layer of fabric and the third layer of fabric are connected to form the outer tube of the valved artificial blood vessel, and the first layer of fabric and the fourth layer of fabric are connected to form the inner tube of the valved artificial blood vessel;

[0089] The first and fourth fabric layers have the same weave structure, which is satin weave.

[0090] The second and third fabrics have the same structure, which is plain weave;

[0091] The first fabric layer and the second fabric layer as well as the third fabric layer and the fourth fabric layer have the same weave structure as the consolidation part, which is twill weave;

[0092] (3.3) Setting of needle organization table;

[0093] According to the different color blocks of the pattern, the corresponding organization of each layer is input into the needle organization table;

[0094] (3.4) Sample card setting;

[0095] Each grid in the sample card corresponds to each harness on the jacquard machine. Select the pattern needles to be weaved, and the number of pattern needles corresponds to the total number of warp yarns.

[0096] (4) Corresponding each part of the valved artificial blood vessel pattern to the tissue in the needle organization table, thereby generating a pattern pattern in the weaving CAD software;

[0097] (5) The pattern pattern is imported into the loom system of the jacquard machine for integrated weaving. Twenty turns of nickel-titanium alloy wire are woven into the outer tube to provide a fixed support. The weaving area is located 10 cm below the lowest point of the lower side of the rectangular shape. Finally, the artificial blood vessel with a valve is obtained by manual flipping.

[0098] The specific weaving process is as follows: when the loom is on, shuttle weaving is carried out from bottom to top according to the pattern pattern, and the lifting order of each yarn is controlled by the pattern pattern; the fabric is woven from top to bottom, the first and fourth layers are woven into petals, and the second and third layers are woven into tubes; the tube part is woven first, and at the beginning, according to the set pattern needle organization table, the warp yarns on the tube are lifted, and the weft yarns are put in to weave the tube; when weaving to the consolidation part, the petals and tubes are woven together, and according to the organization structure entered in the pattern needle organization table, the warp yarns on the tube and the petals are lifted respectively, and the weft yarns are put in to weave in the order of lifting the warp yarns of the first layer, the fourth layer, the second layer, and the third layer; when the weaving of the petal part is completed, the tubular part is woven separately, and at this time, according to the design of the pattern needle organization table, only the warp yarns on the tube are lifted and interwoven with the weft yarns to form a tube, and finally a four-layer fabric with a flap artificial blood vessel is formed;

[0099] The weaving machine parameters are as follows: the warp density is determined according to the warp density range of the artificial blood vessel, which is 1000 yarns / 10 cm; the total number of warp yarns is determined according to the patient's blood vessel diameter, which is 1256 yarns; the fabric tube diameter is 20 mm, the weft density is 800 yarns / 10 cm, the weaving shrinkage is 10%, the reed number is 250 / 10 cm; and the fabric fold diameter is 31.4 mm.

[0100] The tear strength of the artificial blood vessel with a valve of the same shape and structure prepared by hand sewing is 32.4N / mm.

[0101] Example 3

[0102] A valved vascular prosthesis, such as Figure 2 As shown, a tubular polyester fabric with a valve inside includes an outer tube and an inner tube connected to each other;

[0103] like Figure 3 As shown, the outer tube 1 is a cylindrical tube, and the inner tube, after being unfolded, is composed of three identical quasi-rectangular shapes. The only difference between the quasi-rectangular shapes and the rectangular shapes is that the upper and lower edges are arc-shaped edges; the arc α of the upper edge is 120°, and the arc β of the lower edge is 120°; the upper edges of the three quasi-rectangular shapes are free edges 5, and the lower edges and straight edges are respectively fixed to the inner wall of the outer tube to form fixed portions 3; at the unfixed portion, the leaflets 2 (quasi-rectangular) form a flap with the outer tube;

[0104] The height h of the straight side of the quasi-rectangle is D is the outer tube diameter, D = 14 mm; the longitudinal length of the outer tube is 100 mm;

[0105] like Figure 4 As shown, the width a of a single leaflet is 16 mm, the depth b of the leaflet is 6 mm, the length c of the free edge is 18 mm, and the length d of the fixed edge is 18 mm;

[0106] The outer tube is woven with 30 turns of rigid wire 4, i.e., cobalt-chromium alloy wire, which plays a role of fixing and supporting. The woven area is located 6 cm below the lowest point of the lower side of the rectangular shape.

[0107] The tear strength of the valved artificial blood vessel is 45.3N / mm.

[0108] The preparation method of the above-mentioned artificial blood vessel with valve is as follows: Figure 1 The specific steps are as follows:

[0109] (1) Figure 4 The pattern of the valved vascular graft shown is input into the weaving CAD software;

[0110] (2) Design settings, including fabric density, size, and number of grids;

[0111] According to the design of one layer of fabric, the warp density is 150 pieces / 10cm, the fabric width is 2.4cm, the warp grid number is 142, the weft density is 125 pieces / 10cm, the fabric length is 10cm, and the weft grid number is 125;

[0112] (3) Performing process treatment;

[0113] (3.1) Shuttle setting;

[0114] The valved artificial blood vessel is a four-layer fabric, which is set according to the color blocks of the pattern. When weaving, the shuttle is set from left to right in the order of the number of layers.

[0115] (3.2) Fabric structure design;

[0116] During weaving, the valved artificial blood vessel is regarded as four layers of fabric, the first layer of fabric and the fourth layer of fabric are symmetrical structures, the second layer of fabric and the third layer of fabric are symmetrical structures, the second layer of fabric and the third layer of fabric are connected to form the outer tube of the valved artificial blood vessel, and the first layer of fabric and the fourth layer of fabric are connected to form the inner tube of the valved artificial blood vessel;

[0117] The first and fourth fabric layers have the same weave structure, which is twill weave.

[0118] The second and third fabrics have the same structure, which is plain weave;

[0119] The first fabric layer and the second fabric layer as well as the third fabric layer and the fourth fabric layer have the same weave structure as the consolidation part, which is twill weave;

[0120] (3.3) Setting of needle organization table;

[0121] According to the different color blocks of the pattern, the corresponding organization of each layer is input into the needle organization table;

[0122] (3.4) Sample card setting;

[0123] Each grid in the sample card corresponds to each harness on the jacquard machine. Select the pattern needles to be weaved, and the number of pattern needles corresponds to the total number of warp yarns.

[0124] (4) Corresponding each part of the valved artificial blood vessel pattern to the tissue in the needle organization table, thereby generating a pattern pattern in the weaving CAD software;

[0125] (5) The pattern pattern is imported into the loom system of the jacquard machine for integrated weaving. Thirty turns of cobalt-chromium alloy wire are woven into the outer tube to provide a fixed support. The woven area is located 6 cm below the lowest point of the lower side of the rectangular shape. Finally, the artificial blood vessel with a valve is obtained by manual flipping.

[0126] The specific weaving process is as follows: when the loom is on, shuttle weaving is carried out from bottom to top according to the pattern pattern, and the lifting order of each yarn is controlled by the pattern pattern; the fabric is woven from top to bottom, the first and fourth layers are woven into petals, and the second and third layers are woven into tubes; the tube part is woven first, and at the beginning, according to the set pattern needle organization table, the warp yarns on the tube are lifted, and the weft yarns are put in to weave the tube; when weaving to the consolidation part, the petals and tubes are woven together, and according to the organization structure entered in the pattern needle organization table, the warp yarns on the tube and the petals are lifted respectively, and the weft yarns are put in to weave in the order of lifting the warp yarns of the first layer, the fourth layer, the second layer, and the third layer; when the weaving of the petal part is completed, the tubular part is woven separately, and at this time, according to the design of the pattern needle organization table, only the warp yarns on the tube are lifted and interwoven with the weft yarns to form a tube, and finally a four-layer fabric with a flap artificial blood vessel is formed;

[0127] The weaving machine parameters are as follows: the warp density is determined according to the warp density range of the artificial blood vessel, which is 600 yarns / 10 cm; the total number of warp yarns is determined to be 565 yarns based on the patient's blood vessel diameter; the fabric tube diameter is 15 mm, the weft density is 500 yarns / 10 cm, the weaving shrinkage is 3%, the reed number is 150 / 10 cm; and the fabric fold diameter is 23.55 mm.

[0128] The tear strength of the artificial blood vessel with a valve of the same shape and structure prepared by hand sewing is 25.4N / mm.

Claims

1. A method for preparing a valved artificial blood vessel, wherein the valved artificial blood vessel is a tubular fabric with a valve inside, comprising an outer tube and an inner tube connected to each other, wherein the outer tube is a cylindrical tube, and wherein: After the inner tube is unfolded, it is composed of three identical quasi-rectangular shapes. The only difference between the quasi-rectangular shapes and the rectangular shapes is that the upper and lower edges are curved edges. The upper edges of the three quasi-rectangular shapes are free edges, and the lower edges and straight edges are respectively fixed to the inner wall of the outer tube. First, the pattern of the valved artificial blood vessel is input into the weaving CAD software. Then, the design is set, including the fabric density, size, and number of grids. Then, the process is processed, including the shuttle setting, the fabric structure design, the needle structure table setting, and the sample card setting. The various parts of the valved artificial blood vessel pattern and the structure are matched to the needle structure table, and the pattern pattern is generated in the weaving CAD software. Finally, the pattern pattern is imported into the loom system of the jacquard machine for integrated weaving to obtain the valved artificial blood vessel. During weaving, the valved artificial blood vessel is regarded as four layers of fabric, wherein the first and fourth layers of fabric are symmetrically structured, and the second and third layers of fabric are symmetrically structured. The second and third layers of fabric are connected to form the outer tube of the valved artificial blood vessel, and the first and fourth layers of fabric are connected to form the inner tube of the valved artificial blood vessel. After weaving is completed, the valved artificial blood vessel is flipped over to obtain the valved artificial blood vessel. Regarding the design of the consolidation tissue at the junction of the valve and tube, the first and second fabric layers are consolidated by the warp yarns of the second fabric layer of the tissue structure node and the weft yarns of the first fabric layer, and the third and fourth fabric layers are consolidated by the warp yarns of the third fabric layer of the node and the weft yarns of the fourth fabric layer; at the unconsolidated part, the valve leaflet and the outer tube form a valve pocket; A first layer of woven petal fabric, a second and third layers of woven tubular fabric, and a fourth layer of woven petal fabric are provided. The petals of the first layer and the tubes of the second layer are connected by providing a nodular tissue structure on the consolidated parts of the first and second layers of fabric. The petals of the fourth layer and the tubes of the third layer are connected by providing a nodular tissue structure on the consolidated parts of the third and fourth layers of fabric.

2. The method for preparing a valved artificial blood vessel according to claim 1, characterized in that: The height h of the straight side of the quasi-rectangle is , D is the outer tube diameter.

3. The method for preparing a valved artificial blood vessel according to claim 1, characterized in that: The upper and lower sides of the quasi-rectangle are both arc sides, the arc α of the upper side is 90~180°, and the arc β of the lower side is 90~180°.

4. The method for preparing a valved artificial blood vessel according to claim 1, characterized in that: Multiple turns of rigid wire are woven into the outer tube for fixed support. The rigid wire is stainless steel wire, nickel-titanium alloy wire, cobalt-chromium alloy wire or glass fiber yarn. The woven area is located 0 to 10 cm below the lowest point of the lower side of the rectangle.

5. The method for preparing a valved artificial blood vessel according to claim 1, characterized in that: The weaving machine parameters are: fabric tube diameter 8~40mm, warp density 100~1000 pieces / 10cm, weft density 50~800 pieces / 10cm, weaving shrinkage 1~10%, total number of warp yarns 200~1000 pieces, and reed number 40~400 / 10cm.

6. The method for preparing a valved artificial blood vessel according to claim 1, characterized in that: The first fabric layer and the fourth fabric layer have the same weave structure, which is plain weave, twill weave, satin weave, double plain weave, basket weave, reinforced twill weave, composite twill weave or reinforced satin weave; The second fabric layer and the third fabric layer have the same weave structure, which is plain weave, twill weave, satin weave, double plain weave, basket weave, reinforced twill weave, composite twill weave or reinforced satin weave; The first fabric layer, the second fabric layer, the third fabric layer, and the fourth fabric layer have the same weave structure as the consolidation parts, which are plain weave, twill weave, satin weave, double plain weave, basket weave, reinforced twill weave, composite twill weave, or reinforced satin weave.

7. The method for preparing a valved artificial blood vessel according to claim 1, characterized in that: The materials of valved artificial blood vessels are polyester, polypropylene, polytetrafluoroethylene or ultra-high molecular weight polyethylene.

8. The method for preparing a valved artificial blood vessel according to claim 7, characterized in that: The tear strength of valved artificial blood vessels is 25~1500N / mm.

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