Apparatus and method for internal ultra-fine coating of braided vascular prosthesis

Abstract

This invention provides an apparatus and method for applying an ultrafine coating to the interior of a braided artificial blood vessel. The apparatus includes an electrostatic spraying device, a storage box, a metal slide rod, a collection box, and an exhaust device on the collection box, connected in sequence. The storage box and collection box are equipped with connectors that horizontally fix the artificial blood vessel. A movable electrostatic metal ring connected to a grounding device is fitted onto the metal slide rod, and this electrostatic metal ring is also fitted onto the exterior of the artificial blood vessel. The collection box contains a metal wire extending into the interior of the artificial blood vessel and connected to an electrostatic generator. When the apparatus is used, the metal wire and the electrostatic metal ring create an electric field inside and outside the braided artificial blood vessel, causing the electrostatic spraying device to spray negatively charged droplets that move directionally towards the surface of the blood vessel from within. The horizontal movement of the electrostatic metal ring controls the droplets, achieving coating of the inner surface of the braided artificial blood vessel and obtaining a uniform ultrafine coating, providing a new approach for internal coating of braided artificial blood vessels.

Description

Technical Field

[0001] This invention relates to the field of artificial blood vessel coating technology, and in particular to an apparatus and method for an ultrafine coating inside a braided artificial blood vessel. Background Technology

[0002] With the improvement of people's quality of life, cardiovascular diseases have become common diseases threatening human health, and the incidence of a series of cardiovascular diseases is gradually increasing, ranking first among all diseases. At present, one of the most effective ways to treat cardiovascular diseases is vascular transplantation, which has led to an increasing demand for artificial blood vessels year by year. Artificial blood vessels woven from synthetic materials such as polyester, nylon, and polytetrafluoroethylene provide a new option for vascular transplantation. This type of woven artificial blood vessel has controllable dimensions and high mechanical properties. However, due to the large gaps between the yarns in the woven artificial blood vessel, bleeding is prone to occur when blood flows through it. In order to improve this phenomenon, a method of coating the inner wall of the woven artificial blood vessel has been proposed.

[0003] In the prior art, an invention patent (application number CN 202211380727.8) discloses an artificial blood vessel coating device and method. The device includes a pressure coating system and a control system. The pressure coating system includes a direct connector for holding the artificial blood vessel, a lifting plate, a guide rod, a supply pump, a return pump, a pressure stabilizing tank, a pressure sensor, a storage tank, and a heating device. The direct connector for holding the artificial blood vessel is mounted on the guide plate, which is mounted on the guide rod and can move up and down. The supply pump and the return pump form a pressure application device to realize the immersion and perfusion coating of the artificial blood vessel under a certain pressure / perfusion coating under a certain pressure. This invention ensures that the coating liquid can penetrate into the internal pores of the fabric yarn through the pressure coating method, ensuring the sealing of the artificial blood vessel after coating.

[0004] However, the yarns of braided artificial blood vessels have abundant pores and excellent permeability. During liquid permeation, there is almost no pressure difference between the inside and outside. Using the aforementioned method of pressurized perfusion to allow the coating liquid to penetrate the braided artificial blood vessel makes it difficult to control the degree of penetration. Furthermore, the impregnation method makes it difficult to adjust the coating thickness and coverage area, easily resulting in artificial blood vessels with excessively thick coatings, which is detrimental to their subsequent applications. In addition, existing coating equipment for artificial blood vessels suffers from problems such as uneven and incomplete coatings, difficulty in controlling coating thickness, and poor coating adhesion. Moreover, a large number of coating particles tend to accumulate inside the braided artificial blood vessel, thus affecting coating efficiency.

[0005] In view of this, it is necessary to design an improved device and method for ultrafine coating inside braided artificial blood vessels to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide an apparatus and method for ultrafine coating inside braided artificial blood vessels. By designing an apparatus with a special structure, an electric field is formed inside and outside the braided artificial blood vessel, causing negatively charged droplets inside the blood vessel to move directionally toward its surface. By controlling the electrostatic metal ring, the inner surface of the braided artificial blood vessel is coated to obtain a uniform ultrafine coating, providing a new approach for coating the inside of braided artificial blood vessels.

[0007] To achieve the above-mentioned objectives, this invention provides an apparatus for applying an ultrafine coating to the interior of a braided artificial blood vessel, comprising an electrostatic spraying device, a storage box, a metal slide bar, a collection box, and an exhaust device mounted on the collection box, connected in sequence; the storage box and the collection box have connectors on two opposite surfaces for horizontally fixing the artificial blood vessel; the two ends of the metal slide bar are respectively located directly above the connectors, and a movable electrostatic metal ring is fitted on the metal slide bar, which is also fitted on the outside of the artificial blood vessel;

[0008] The collection box also contains a metal wire that extends through the connector into the storage box and is located inside the artificial blood vessel. One end of the metal wire inside the collection box is connected to an electrostatic generator that provides a negative charge. The electrostatic metal ring is connected to a grounding device. The electrostatic spraying device is used to spray out negatively charged mist droplets. When the mist droplets pass through the storage box and the connector in sequence and reach the inside of the artificial blood vessel, the electrostatic metal ring controls the horizontal movement of the mist droplets to coat the artificial blood vessel.

[0009] As a further improvement of the present invention, the electrostatic spraying device includes a liquid storage tank, a press, an electrostatic spraying gun connected to the liquid storage tank, and a host computer connected to the electrostatic spraying gun via a signal. The output port of the electrostatic spraying gun is connected to the storage tank, and the press is connected to the liquid storage tank to provide pressure for the coating liquid in the liquid storage tank to enter the electrostatic spraying gun.

[0010] As a further improvement of the present invention, the metal slide bar is an insulating rod with a telescopic structure so that its length can be adapted to the length of the artificial blood vessel; the diameter of the metal wire is 0.1 to 0.5 mm; the metal wire and the electrostatic metal ring are made of conductive materials, including one of gold, copper, aluminum, and aluminum alloy.

[0011] As a further improvement of the present invention, fixing holes are provided on two opposite surfaces of the storage box and the collection box, and the connector is fixedly connected to the storage box or the collection box through the fixing holes.

[0012] As a further improvement of the present invention, a fixed connector is provided between the electrostatic spray gun and the storage box. One end of the fixed connector penetrates the surface of the storage box, and the other end is connected to the output port of the electrostatic spray gun, so as to realize the connection between the electrostatic spray gun and the storage box.

[0013] As a further improvement of the present invention, there are two metal slide rods, and the ends of the two metal slide rods are respectively fixed above and below the connector; the diameter of the metal slide rods is 0.5 to 1 mm.

[0014] As a further improvement of the present invention, the diameter of the fixing hole is 15-25 mm, and the diameter of the connector is the same as the inner diameter of the artificial blood vessel, which is 2-32 mm.

[0015] The present invention also provides a method for an ultrafine coating inside a braided artificial blood vessel, wherein the inner wall of the braided artificial blood vessel is coated using the equipment described in any one of the above-mentioned methods for an ultrafine coating inside a braided artificial blood vessel to obtain an ultrafine coating.

[0016] As a further improvement to the present invention, the following steps are included:

[0017] S1. Adjust the diameter of the connector and the length of the metal slide rod to match the inner diameter and length of the braided artificial blood vessel to be coated. Connect the two ends of the artificial blood vessel to the connectors on the storage box and the collection box respectively, and wrap the metal wire extending from the inside of the collection box inside the blood vessel. Place the electrostatic metal ring on the outside of the metal slide rod and the artificial blood vessel, and slide it to the end of the artificial blood vessel near the storage box.

[0018] S2. Start the press, the host and exhaust device connected to the electrostatic spray gun. The press sends the coating liquid in the storage tank into the electrostatic spray gun. The electrostatic spray gun electrostatically atomizes the coating liquid and sprays out negatively charged mist droplets at the output port. The mist droplets pass through the storage box and the connector in sequence and reach the inside of the braided artificial blood vessel.

[0019] S3. Start the electrostatic generator connected to the metal wire. The electrostatic generator provides negative charge to the metal wire. An electric field is formed between the negatively charged metal wire and the electrostatic metal ring connected to the grounding device, so that the negatively charged mist droplets move in a direction in the electric field and are coated from the inside of the braided artificial blood vessel to its inner surface.

[0020] S4. Control the horizontal movement of the electrostatic metal ring, thereby controlling the mist droplets to coat the inner wall of the braided artificial blood vessel in a range until an ultra-fine coating is formed inside the braided artificial blood vessel.

[0021] As a further improvement of the present invention, the electrostatic spray gun is also connected to an oil-free air compressor with a pressure set to 6-8 kPa, the pressure controller connected to the main unit is set to a pressure of 0.6-0.8 MPa, and the pressure of the press connected to the liquid storage tank is set to 0.1-0.4 MPa, so that the size range of the mist droplets is 0.1-0.3 mm and the flow rate is 0.03-0.06 mL / min; the moving speed of the electrostatic metal ring is 0.1-2.0 cm / s, and the moving speed of the electrostatic metal ring is adjusted to control the thickness of the ultrafine coating; the output voltage of the electrostatic generator is 50-80 kV and the current is 20-50 μA, and the output voltage and current of the electrostatic generator are adjusted to control the electric field strength between the metal wire and the electrostatic metal ring.

[0022] The beneficial effects of this invention are:

[0023] 1. An apparatus and method for applying an ultrafine coating to the interior of a braided artificial blood vessel, comprising an electrostatic spraying device, a storage box, a metal slide rod, a collection box, and an exhaust device mounted on the collection box, connected in sequence; the storage box and the collection box are equipped with connectors for horizontally fixing the artificial blood vessel; a movable electrostatic metal ring connected to a grounding device is fitted on the metal slide rod, and the electrostatic metal ring is also fitted on the outside of the artificial blood vessel; the collection box also contains a metal wire extending into the interior of the artificial blood vessel, and the metal wire is externally connected to an electrostatic generator. In application, the metal wire and the electrostatic metal ring create an electric field inside and outside the braided artificial blood vessel, causing the electrostatic spraying device to spray negatively charged droplets that move directionally towards the surface of the blood vessel from within. The horizontal movement of the electrostatic metal ring controls the droplets, achieving coating of the inner surface of the braided artificial blood vessel and obtaining a uniform ultrafine coating, providing a new approach for internal coating of braided artificial blood vessels.

[0024] 2. This invention utilizes an electrostatic spray gun to electrostatically atomize the coating liquid and controls the size and flow rate of the droplets, allowing small droplets to better penetrate the pores of the braided artificial blood vessel, resulting in an ultra-fine coating that ensures the sealing of the braided artificial blood vessel's interior. This invention uses the electric field formed inside and outside the artificial blood vessel to control the directional movement of negatively charged droplets, thus minimizing the impact force of the droplets on the yarn and preventing damage to the structure of the braided artificial blood vessel. Furthermore, this invention achieves precise control of the coating area through the horizontal movement of an electrostatic metal ring. It also utilizes the movement speed of the electrostatic metal ring in conjunction with the droplet flow rate, the output voltage and current of the electrostatic generator, and the diameter of the artificial blood vessel to control the coating thickness, meeting the different coating requirements of the braided artificial blood vessel. This equipment and method are highly applicable and have a wide range of applications.

[0025] 3. The device for ultrafine coating inside braided artificial blood vessels of the present invention has a simple structure, is easy to operate and implement, can flexibly and accurately adjust the coating thickness and coating range, and has high coating efficiency. The resulting ultrafine coating inside the braided artificial blood vessels is uniform, full and has good adhesion, which is beneficial to the subsequent application of artificial blood vessels. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the device for the ultrafine coating inside a braided artificial blood vessel according to the present invention.

[0027] Figure Labels

[0028] 100 - Equipment for ultra-fine coating inside braided artificial blood vessels; 110 - Electrostatic spraying device; 111 - Liquid storage tank; 112 - Press; 113 - Electrostatic spraying gun; 120 - Storage box; 121 - Fixing connector; 130 - Metal slide bar; 131 - Electrostatic metal ring; 132 - Grounding device; 140 - Collection box; 150 - Exhaust device; 160 - Connector; 170 - Metal wire; 171 - Electrostatic generator; 200 - Artificial blood vessel. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] It should also be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and / or processing steps closely related to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0031] Additionally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0032] Please see Figure 1As shown, a device 100 for ultra-fine coating inside a braided artificial blood vessel includes an electrostatic spraying device 110, a storage box 120, a metal slide bar 130, a collection box 140, and an exhaust device 150 installed on the collection box 140, connected in sequence. Connectors 160 for horizontally fixing the artificial blood vessel 200 are provided on two opposing surfaces of the storage box 120 and the collection box 140. The two ends of the metal slide bar 130 are respectively located directly above the connectors 160, and a movable electrostatic metal ring 131 is fitted onto the metal slide bar 130, which is also fitted onto the outside of the artificial blood vessel 200. Inside the collection box 140, a metal wire 170 extends through the connector 160 into the storage box 120 and is located inside the artificial blood vessel 200. One end of the metal wire 170 inside the collection box 140 is connected to an electrostatic generator 171 that provides a negative charge. The electrostatic metal ring 131 is connected to a grounding device 132. Thus, the electrostatic spraying device 110 sprays out negatively charged mist droplets. The mist droplets pass through the storage box 120 and the connector 160 in sequence. When they reach the inside of the artificial blood vessel 200, the electrostatic metal ring 131 controls the horizontal movement of the mist droplets to coat the artificial blood vessel 200.

[0033] Specifically, when the device is used, the metal wire 170 and the electrostatic metal ring 131 form an electric field inside and outside the braided artificial blood vessel 200, causing the electrostatic spraying device 110 to spray negatively charged mist droplets that move directionally from inside the blood vessel to its surface. The mist droplets are controlled by the horizontal movement of the electrostatic metal ring 131, thus achieving coating of the inner surface of the braided artificial blood vessel 200 and obtaining a uniform ultrafine coating, providing a new approach for the internal coating of the braided artificial blood vessel 200.

[0034] It should be noted that the metal wire 170 is located in the middle of the artificial blood vessel 200 and is equidistant from the inner wall of the artificial blood vessel 200 in all directions. This allows it to form a uniform electric field force in all directions with the electrostatic metal ring 131 outside the artificial blood vessel 200, thus preventing negatively charged mist droplets from accumulating in one direction.

[0035] Specifically, the electrostatic spraying device 110 includes a liquid storage tank 111, a press 112, an electrostatic spray gun 113 connected to the liquid storage tank 111, and a host computer connected to the electrostatic spray gun 113. The output port of the electrostatic spray gun 113 is connected to a storage tank 120. The press 112 is connected to the liquid storage tank 111 to provide pressure for the coating liquid in the liquid storage tank 111 to enter the electrostatic spray gun 113. The host computer connected to the electrostatic spray gun 113 can adjust the output parameters of the electrostatic spray gun 113 through the control of a pressure controller connected to the host computer. For example, the output voltage can adjust the spray rate, and the host current can adjust the charge of the spray droplets.

[0036] In some specific embodiments, the coating liquid in the storage tank 111 is a solution of collagen dissolved in acetic acid. In practical applications, the type of coating liquid can be adjusted according to the application environment and actual needs of the artificial blood vessel.

[0037] More specifically, the metal slide bar 130 is an insulated rod with a telescopic structure, allowing its length to adapt to the length of the artificial blood vessel 200; the diameter of the metal wire 170 is 0.1–0.5 mm; the metal wire 170 and the electrostatic metal ring 131 are made of conductive materials, including one of gold, copper, aluminum, or aluminum alloy. Fixing holes are respectively provided on two opposing surfaces of the storage box 120 and the collection box 140, and the connector 160 is fixedly connected to the storage box 120 or the collection box 140 through the fixing holes.

[0038] In some specific embodiments, there are two metal slide rods 130, with their ends fixed directly above and below the connector 160, respectively. The diameter of the metal slide rods 130 is 0.5–1 mm. The diameter of the fixing hole is 15–25 mm, and the diameter of the connector 160 is the same as the inner diameter of the artificial blood vessel 200, which is 2–32 mm. The inner diameter of the electrostatic metal ring 131 is determined according to the position of the artificial blood vessel 200 and the metal slide rods 130, with the standard being that the electrostatic metal ring 131 can fit the artificial blood vessel 200 and the metal slide rods 130 inside it.

[0039] A fixed connector 121 is provided between the electrostatic spray gun 113 and the storage box 120. One end of the fixed connector 121 penetrates the surface of the storage box 120, and the other end is connected to the output port of the electrostatic spray gun 113 to realize the connection between the electrostatic spray gun 113 and the storage box 120. The mist droplets with a certain impact force output by the electrostatic spray gun 113 enter the storage box 120, where the storage box 120 provides a buffering effect before entering the artificial blood vessel 200. This avoids the mist droplets having excessive penetrating power, which would affect the control of the mist droplets by the electrostatic metal ring 131, and also avoids the mist droplets damaging the structure of the artificial blood vessel 200.

[0040] The collection box 140 is used to collect excess fog droplets, and the exhaust device 150 on the collection box, in addition to discharging excess fog droplets, can also provide a certain power for the flow of fog droplets in the artificial blood vessel 200; through the continuous exhaust of the exhaust device 150, the flow of fog droplets from one end of the braided artificial blood vessel into the tail end is enhanced.

[0041] Preferably, the exhaust device 150 is located on the upper surface of the collection box 140, which is conducive to the discharge of mist droplets. The fixed base of the exhaust device 150 occupies 40-60% of the upper surface area of ​​the collection box 140, and the fan speed of the exhaust device 150 is 1000-2000 r / min.

[0042] In some specific embodiments, the storage box 120 and the collection box 140 are 10-25cm long, 9-21cm wide, and 30-40cm high; the connector 160 for fixing the artificial blood vessel 200 is placed in the middle area of ​​two opposing surfaces of the storage box 120 and the collection box 140. Both ends of the metal slide rod 130 are fixed 2-5cm from the upper end of the connector 160; if there are two metal slide rods 130, the lower metal slide rod 130 is fixed 2-5cm from the lower end of the connector 160. The inner diameter of the fixing connector 121 of the storage box 120 is the same as the outer diameter of the electrostatic spray gun 113, which is 35-45mm.

[0043] A method for applying an ultrafine coating to the interior of a braided artificial blood vessel, comprising the following steps: The method utilizes the aforementioned equipment 100 for applying an ultrafine coating to the interior of a braided artificial blood vessel to coat the inner wall of the vessel.

[0044] S1. Adjust the diameter of the connector 160 and the length of the metal slide bar 130 so that they match the inner diameter and length of the braided artificial blood vessel 200 to be coated. Connect the two ends of the artificial blood vessel 200 to the connector 160 on the storage box 120 and the collection box 140 respectively, and wrap the metal wire 170 extending from the inside of the collection box 140 inside the blood vessel. Place the electrostatic metal ring 131 on the outside of the metal slide bar 130 and the artificial blood vessel 200, and slide it to the end of the artificial blood vessel 200 near the storage box 120.

[0045] S2. Start the press 112, the host and exhaust device 150 connected to the electrostatic spray gun 113. The press 112 sends the coating liquid in the storage tank 111 into the electrostatic spray gun 113. The electrostatic spray gun 113 electrostatically atomizes the coating liquid and sprays out negatively charged mist droplets at the output port. The mist droplets pass through the storage box 120 and the connector 130 in sequence and reach the interior of the braided artificial blood vessel 200.

[0046] S3. Start the electrostatic generator 171 connected to the metal wire 170. The electrostatic generator 171 provides negative charge to the metal wire 170. An electric field is formed between the negatively charged metal wire 170 and the electrostatic metal ring 131 connected to the grounding device 132, so that the negatively charged mist droplets move in the electric field and are coated from the inside of the braided artificial blood vessel 200 to its inner surface.

[0047] S4. Control the horizontal movement of the electrostatic metal ring 131, thereby controlling the mist droplets to coat the inner wall of the braided artificial blood vessel 200 in a range until an ultra-fine coating is formed inside the braided artificial blood vessel 200.

[0048] Specifically, this invention utilizes an electrostatic spray gun 113 to electrostatically atomize the coating liquid and controls the size and flow rate of the droplets, allowing small droplets to better enter the pores of the braided artificial blood vessel 200, resulting in an ultra-fine coating and ensuring the sealing of the internal coating of the braided artificial blood vessel 200. Furthermore, the electric field formed inside and outside the artificial blood vessel 200 controls the directional movement of negatively charged droplets, thus minimizing the impact of the droplets on the yarn and preventing damage to the structure of the braided artificial blood vessel 200. In addition, this invention achieves accurate control of the coating area through the horizontal movement of the electrostatic metal ring 131. The moving speed of the electrostatic metal ring 131, in conjunction with the droplet flow rate, the output parameters of the electrostatic generator 171, and the diameter of the artificial blood vessel 200, controls the coating thickness to meet the different coating requirements of the braided artificial blood vessel 200. This equipment and method are highly applicable and have a wide range of applications.

[0049] Specifically, the electrostatic spray gun 113 is also connected to an oil-free air compressor with a pressure set to 6-8 kPa. The pressure controller connected to the main unit has a pressure set to 0.6-0.8 MPa, and the pressure of the press 112 connected to the liquid storage tank 111 is set to 0.1-0.4 MPa, so that the size range of the mist droplets is 0.1-0.3 mm and the flow rate is 0.03-0.06 mL / min. The moving speed of the electrostatic metal ring 131 is 0.1-2.0 cm / s. Adjusting the moving speed of the electrostatic metal ring 131 controls the thickness of the ultra-fine coating. The output voltage of the electrostatic generator 171 is 50-80 kV and the current is 20-50 μA. Adjusting the output voltage and current of the electrostatic generator 171 controls the electric field strength between the metal wire 170 and the electrostatic metal ring 131.

[0050] In some specific embodiments, the thickness of the inner coating of the braided artificial blood vessel 200 obtained by the above method and equipment is 0.05 to 0.5 mm, and the length of the inner coating of the artificial blood vessel 200 is 5 to 60 cm.

[0051] The device of this invention has a simple structure, is easy to operate and implement, and can flexibly and accurately adjust the coating thickness and coating range. It also has high coating efficiency, and the resulting woven artificial blood vessel has a uniform and full ultra-fine coating with good adhesion, which is beneficial to the subsequent application of artificial blood vessels.

[0052] Example 1

[0053] This embodiment provides a method for applying an ultrafine coating to the interior of a braided artificial blood vessel. The method involves using a device 100 for applying an ultrafine coating to the interior of the braided artificial blood vessel to coat the inner wall of the vessel. Specifically, the method includes the following steps:

[0054] S1. Adjust the diameter of connector 160 to 18mm, the length of metal slide rod 131 to 30cm, and the diameter to 0.5mm, so that they match the inner diameter and length (inner diameter 18mm, length 30cm) of the braided artificial blood vessel 200 to be coated. Connect the two ends of the artificial blood vessel 200 to connector 160 on storage box 120 and collection box 140 respectively, and wrap the metal wire 170 extending from the inside of collection box 140 inside the blood vessel. Slide the electrostatic metal ring 131 (made of copper, inner diameter 4cm) onto the outside of metal slide rod 130 and artificial blood vessel 200, and slide it to the end of artificial blood vessel 200 near storage box 120.

[0055] The storage box is 19cm long, 16cm wide, and 36cm high; the inner diameter of the fixing connector 121 of the storage box 120 and the outer diameter of the electrostatic spray gun 113 are 42.92mm.

[0056] S2. Start the press 112, the host connected to the electrostatic spray gun 113, and the exhaust device 150 (fan speed is 1000r / min). The press 112 sends the coating liquid in the storage tank 111 into the electrostatic spray gun 113. The electrostatic spray gun 113 electrostatically atomizes the coating liquid and sprays out negatively charged mist droplets (average size is 0.2mm, flow rate is 0.03mL / min) at the output port. The mist droplets pass through the storage box 120 and the connector 130 in sequence and reach the interior of the braided artificial blood vessel 200.

[0057] Among them, the pressure of the oil-free air compressor connected to the electrostatic spray gun 113 is set to 6.5 kPa, the pressure controller connected to the host is set to 0.6 MPa, and the pressure of the press connected to the liquid storage tank 111 is set to 0.2 MPa;

[0058] S3. Start the electrostatic generator 171 (voltage value 75kV, current value 30μA) connected to the metal wire 170. The electrostatic generator 171 provides negative charge to the metal wire 170. An electric field is formed between the negatively charged metal wire 170 and the electrostatic metal ring 131 connected to the grounding device 132, so that the negatively charged mist droplets move in a direction in the electric field and are coated from the inside of the braided artificial blood vessel 200 to its inner surface.

[0059] S4. Control the horizontal movement of the electrostatic metal ring 131 (moving speed is 0.5cm / s), thereby controlling the fog droplets to coat the inner wall of the braided artificial blood vessel 200 until an ultra-fine coating with a thickness of 0.5mm is formed inside the braided artificial blood vessel 200.

[0060] Comparative Example 1

[0061] Comparative Example 1 provides a method for applying an internal coating to a braided artificial blood vessel, wherein a coating solution is injected into the braided artificial blood vessel to obtain an internal coating for the braided artificial blood vessel.

[0062] Comparative Example 2

[0063] Comparative Example 2 provides a method for coating the inner layer of a braided artificial blood vessel, wherein the braided artificial blood vessel is immersed in a coating solution to obtain the inner layer of the braided artificial blood vessel.

[0064] Comparative Example 3

[0065] Comparative Example 3 provides a method for coating the interior of a braided artificial blood vessel. The difference from Example 1 is that the equipment is adjusted so that there is no metal wire 170 inside the artificial blood vessel. Otherwise, it is largely the same as Example 1 and will not be described again here.

[0066] Comparative Example 4

[0067] Comparative Example 4 provides a method for coating the interior of a braided artificial blood vessel. The difference from Example 1 is that the device is adjusted so that an electrostatic metal ring 131 is not fitted over the metal slide bar 130 and the outside of the artificial blood vessel. This will not be described in detail here.

[0068] The permeability of the artificial blood vessels obtained in Example 1 and Comparative Examples 1-4 was tested, and the results are shown in the table below.

[0069] Table 1. Performance characterization of artificial blood vessels in Examples 1 and 4 (Comparative Examples 1-4)

[0070] primitive artificial blood vessels 67 Example 1 3.7 Comparative Example 1 4.2 Comparative Example 2 3.5 Comparative Example 3 7.1 Comparative Example 4 8.4

[0071] Table 1 shows that the artificial blood vessel obtained using the coating method of Example 1 has low permeability parameters, indicating that a uniform ultrafine coating is formed inside the artificial blood vessel, which can prevent blood leakage during application. Comparative Examples 1 and 2, using perfusion and impregnation methods respectively, achieved a certain degree of sealing in the artificial blood vessel, but the coating thickness was difficult to control, resulting in a thicker coating inside the artificial blood vessel, affecting its subsequent application. Comparative Examples 3 and 4 did not create an electric field inside or outside the artificial blood vessel; they relied solely on the free movement of droplets into the gaps of the braided artificial blood vessel, making it difficult to form a coating.

[0072] Examples 2-4

[0073] Examples 2-4 provide a method for an ultrafine coating inside a braided artificial blood vessel. The difference from Example 1 is that the moving speed of the electrostatic metal ring 131 is 0.6 cm / s, 0.8 cm / s, and 1.0 cm / s, respectively. The rest is roughly the same as in Example 1 and will not be described again here.

[0074] Measurements showed that the thicknesses of the ultrafine coatings inside the braided artificial blood vessels prepared in Examples 2-4 were 0.34 mm, 0.15 mm, and 0.07 mm, respectively. This indicates that controlling the moving speed of the electrostatic metal ring 131 affects the thickness of the final braided artificial blood vessel inner wall coating. This is because controlling the moving speed of the electrostatic metal ring 131 is equivalent to the droplets being deposited on the inner wall of the braided artificial blood vessel of different areas at the same flow rate under the action of the electric field force within the same time period. Therefore, the slower the moving speed of the electrostatic metal ring 131, the smaller the total area deposited on the inner wall of the braided blood vessel, and the thicker the deposition thickness of the same volume of solution droplets on the inner wall of the braided blood vessel, resulting in inner wall coatings of different thicknesses.

[0075] Examples 5-7

[0076] Examples 5-7 provide a method for an ultrafine coating inside a braided artificial blood vessel. Compared with Example 1, the difference is that the inner diameter of the braided artificial blood vessel is 22mm, 26mm, and 30mm, respectively, and the connector 160 of the artificial blood vessel is replaced accordingly. The rest is roughly the same as Example 1, and will not be described again here.

[0077] Measurements showed that the thicknesses of the ultrafine coatings inside the braided artificial blood vessels prepared in Examples 2-4 were 0.35 mm, 0.27 mm, and 0.14 mm, respectively. It can be seen that under the same conditions, the different inner diameters of the artificial blood vessels resulted in different coating thicknesses. Therefore, in practical applications, the relevant parameters of the equipment can be adjusted according to the inner diameter of the artificial blood vessel to obtain a coating of appropriate thickness.

[0078] In summary, this invention provides an apparatus and method for ultrafine coating of the interior of braided artificial blood vessels. The apparatus utilizes a metal wire and an electrostatic metal ring to create an electric field inside and outside the braided artificial blood vessel. This causes an electrostatic spraying device to spray negatively charged droplets that move directionally towards the surface inside the blood vessel. The horizontal movement of the electrostatic metal ring controls the droplets, achieving coating of the inner surface of the braided artificial blood vessel and obtaining a uniform ultrafine coating. This invention utilizes an electrostatic spray gun to electrostatically atomize the coating liquid and controls the size and flow rate of the droplets, allowing small droplets to better penetrate the pores of the braided artificial blood vessel, resulting in an ultrafine coating and ensuring the sealing of the interior of the braided artificial blood vessel after coating. This invention utilizes the electric field formed inside and outside the artificial blood vessel to control the directional movement of negatively charged droplets, minimizing the impact on the yarn and preventing damage to the structure of the braided artificial blood vessel. Furthermore, this invention achieves precise control of the coating area through the horizontal movement of an electrostatic metal ring. It also utilizes the moving speed of the electrostatic metal ring in conjunction with the flow rate of the mist droplets, the output parameters of the electrostatic generator, and the diameter of the artificial blood vessel to control the coating thickness, thus meeting the different coating requirements of braided artificial blood vessels. This equipment and method are highly applicable and have a wide range of applications. The equipment for ultrafine coating inside braided artificial blood vessels of this invention has a simple structure, is easy to operate and implement, and can flexibly and accurately adjust the coating thickness and coating area. It also has high coating efficiency, resulting in a uniform, full, and well-adhesive ultrafine coating inside the braided artificial blood vessel, which is beneficial for subsequent applications of the artificial blood vessel.

[0079] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A device for applying an ultrafine coating to the interior of a braided artificial blood vessel, characterized in that, The device includes an electrostatic spraying device, a storage box, a metal slide bar, a collection box, and an exhaust device installed on the collection box, which are connected in sequence. Connectors for horizontally fixing the artificial blood vessel are provided on two opposite surfaces of the storage box and the collection box. The two ends of the metal slide bar are respectively located directly above the connectors. A movable electrostatic metal ring is fitted on the metal slide bar and is also fitted on the outside of the artificial blood vessel. The collection box also contains a metal wire that extends through the connector into the storage box and is located inside the artificial blood vessel. One end of the metal wire inside the collection box is connected to an electrostatic generator that provides a negative charge. The electrostatic metal ring is connected to a grounding device. The electrostatic spraying device is used to spray out negatively charged droplets. The droplets pass through the storage box and the connector in sequence. When they reach the inside of the artificial blood vessel, the electrostatic metal ring controls the droplets to coat the artificial blood vessel by moving horizontally. The moving speed of the electrostatic metal ring is 0.1~2.0 cm / s. Adjusting the moving speed of the electrostatic metal ring controls the thickness of the ultrafine coating. The metal slide bar is an insulated rod with a telescopic structure, so that its length can be adapted to the length of the artificial blood vessel; there are two metal slide bars, and the ends of the two metal slide bars are respectively fixed above and below the connector; the diameter of the connector is the same as the inner diameter of the artificial blood vessel, which is 2~32mm.

2. The device for ultrafine coating inside braided artificial blood vessels according to claim 1, characterized in that, The electrostatic spraying device includes a storage tank, a press, an electrostatic spray gun connected to the storage tank, and a host computer connected to the electrostatic spray gun via a signal. The output port of the electrostatic spray gun is connected to the storage tank, and the press is connected to the storage tank to provide pressure for the coating liquid in the storage tank to enter the electrostatic spray gun.

3. The device for ultrafine coating inside woven artificial blood vessels according to claim 1, characterized in that, The diameter of the metal wire is 0.1~0.5mm; the metal wire and the electrostatic metal ring are made of conductive materials, including one of gold, copper, aluminum, and aluminum alloy.

4. The device for ultrafine coating inside braided artificial blood vessels according to claim 1, characterized in that, The storage box and the collection box are respectively provided with fixing holes on two opposite surfaces, and the connector is fixedly connected to the storage box or the collection box through the fixing holes.

5. The device for ultrafine coating inside braided artificial blood vessels according to claim 2, characterized in that, A fixed connector is provided between the electrostatic spray gun and the storage box. One end of the fixed connector passes through the surface of the storage box, and the other end is connected to the output port of the electrostatic spray gun to realize the connection between the electrostatic spray gun and the storage box.

6. The apparatus for ultrafine coating inside braided artificial blood vessels according to claim 1, characterized in that, The diameter of the metal slide bar is 0.5~1mm.

7. The apparatus for ultrafine coating inside braided artificial blood vessels according to claim 4, characterized in that, The diameter of the fixing hole is 15~25mm.

8. A method for applying an ultrafine coating to the interior of a braided artificial blood vessel, characterized in that, The method of coating the inner wall of a braided artificial blood vessel with the equipment for ultrafine coating of the inner wall of a braided artificial blood vessel as described in any one of claims 1 to 7 to obtain an ultrafine coating includes the following steps: S1. Adjust the diameter of the connector and the length of the metal slide rod to match the inner diameter and length of the braided artificial blood vessel to be coated. Connect the two ends of the artificial blood vessel to the connectors on the storage box and the collection box respectively, and wrap the metal wire extending from the inside of the collection box inside the blood vessel. Place the electrostatic metal ring on the outside of the metal slide rod and the artificial blood vessel, and slide it to the end of the artificial blood vessel near the storage box. S2. Start the press, the host and exhaust device connected to the electrostatic spray gun. The press sends the coating liquid in the storage tank into the electrostatic spray gun. The electrostatic spray gun electrostatically atomizes the coating liquid and sprays out negatively charged mist droplets at the output port. The mist droplets pass through the storage box and the connector in sequence and reach the inside of the braided artificial blood vessel. S3. Start the electrostatic generator connected to the metal wire. The electrostatic generator provides negative charge to the metal wire. An electric field is formed between the negatively charged metal wire and the electrostatic metal ring connected to the grounding device, so that the negatively charged mist droplets move in a direction in the electric field and are coated from the inside of the braided artificial blood vessel to its inner surface. S4. Control the horizontal movement of the electrostatic metal ring, thereby controlling the mist droplets to coat the inner wall of the braided artificial blood vessel in a range until an ultra-fine coating is formed inside the braided artificial blood vessel.

9. The method for using an ultrafine coating inside a braided artificial blood vessel according to claim 8, characterized in that, The electrostatic spray gun is also connected to an oil-free air compressor with a pressure set to 6-8 kPa. The pressure controller connected to the main unit is set to a pressure of 0.6-0.8 MPa, and the pressure of the press connected to the liquid storage tank is set to a pressure of 0.1-0.4 MPa, so that the size of the mist droplets is 0.1-0.3 mm and the flow rate is 0.03-0.06 mL / min. The output voltage of the electrostatic generator is 50-80 kV and the current is 20-50 μA. Adjusting the output voltage and current of the electrostatic generator is used to control the electric field strength between the metal wire and the electrostatic metal ring.

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