Plasma device and method for functional deposition treatment of inner and outer walls of catheter
Through plasma devices and methods, ultrahydrophobic and superhydrophilic films are formed, which solves the problem of insufficient wettability of the catheter material, improves the resistance and biocompatibility, and achieves efficient and environmentally friendly modification effects.
Patent Information
- Application Number
- CN202510455400.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-11
- Publication Date
- 2025-07-11
AI Technical Summary
The existing catheter materials have shortcomings in the hydrophobicity of the inner wall and the hydrophilicity of the outer wall, resulting in problems of urine residue, bacterial adhesion and tissue friction, and the existing modification technology is costly or unstable.
Using plasma devices and methods, during the deposition process of the inner and outer walls of the catheter, a plasma device composed of quartz glass tubes and high-voltage electrodes is used to form an ultra-hydrophilic and super-hydrophilic film through a mixed gas of argon and HMDSO, and the deposition process is optimized with nanosecond pulse power parameters.
It realizes ultra-hydrophoreticity and anti-adhesion of the inner wall of the urethra catheter, ultra-hydrophilicity and biocompatible of the outer wall, high film stability, excellent anti-aging performance, simplifies the production process and is environmentally friendly and non-toxic.
Smart Images
Figure CN120291065A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a urinary catheter, and particularly to a plasma device and method for functional deposition treatment on the inner / outer walls of a urinary catheter. Background Art
[0002] A urinary catheter is inserted into the bladder through the urethra to relieve urinary incontinence and is a key instrument for maintaining the health of the urinary system. For the urinary catheter material, its inner wall needs to have low-polarity hydrophobicity to enhance the anti-adhesion performance; the outer wall, due to contact with the human body, should have high polarity and hydrophilicity to achieve good biocompatibility. In this way, the attachment of bacteria to form a biofilm on the inner wall can be avoided, as well as the inflammation problem caused by the friction between the outer wall and body tissues. At present, most urinary catheters use PVC (polyvinyl chloride) material. After staying in the bladder for a long time, this material has the problems of poor hydrophobicity on the inner wall and difficulty in maintaining it persistently, resulting in the inability to discharge urine in time, the easy settlement of impurities in urine on the inner wall, and then the formation of residual scale, stone deposition, and bacterial adhesion to form a biofilm in the catheter, increasing the risk of catheter blockage and infection. Its outer wall has poor hydrophilicity and high friction, which will increase the friction and irritation to the urethral tissue, increasing the possibility of injury and infection. At the same time, the existing hydrophilic modification technologies generally have an aging phenomenon and are difficult to maintain a super-hydrophilic state for a long time. Therefore, improving the super-hydrophobicity and anti-adhesion of the inner wall of the urinary catheter, as well as the super-hydrophilicity and biocompatibility of the outer wall, and extending the anti-aging performance are of crucial significance for the safe application of the urinary catheter.
[0003] The main existing methods for improving the wettability of the inner and outer walls of urinary catheters include: 1) Physical modification method: Using laser etching or 3D printing technology to construct a series of regular rough structures on the inner and outer walls, increasing the physical roughness, and using the Wenzel model to improve the wettability of the surface of the urinary catheter. This method has a lasting effect and good biocompatibility, but the cost is high and it may affect the mechanical properties of the urinary catheter.
[0004] 2) Surface graft polymerization: Introducing active sites on the material surface through chemical initiators or ultraviolet irradiation, enabling monomer molecules to undergo polymerization reactions on the surface, thereby introducing specific polymers or functional groups on the surface to form stable polymer chains. This technology has a high cost and is not conducive to large-scale industrial production.
[0005] 3) Chemical coating technology: Preparing the required wettability of the inner and outer walls by changing the types of solutions in which the urinary catheter is soaked, and improving the wettability by surface coating or microfluidic technology for the inner and outer walls. Although such methods are simple to operate and have a low cost, the coating is prone to peeling off and it is difficult to uniformly cover the inner wall.
[0006] In summary, improving the wettability of the inner and outer walls of the catheter by physical methods is difficult to achieve large-scale industrial production due to the high precision requirements of the instruments required in the preparation process, which easily affect the mechanical properties and other disadvantages. Improving the wettability of the inner and outer walls of the catheter by chemical methods is difficult to control the reaction conditions and is prone to chemical contamination. Most of the currently widely used chemical methods will cause a series of irreversible damages to the catheter, so there are certain requirements and limitations on the operability of the equipment. In addition, the wettability of the inner and outer walls improved by existing methods mostly cannot meet the requirement of uniform treatment of the inner wall of the catheter. Summary of the Invention
[0007] 1. Technical problems to be solved: How to improve the superhydrophobicity and anti-adhesion of the inner wall of the catheter, as well as the superhydrophilicity and biocompatibility of the outer wall, and extend the anti-aging performance.
[0008] 2. Technical solutions: To solve the above problems, the present invention provides a plasma device for functional deposition treatment of the inner and outer walls of a catheter, including a quartz glass tube. The first high-voltage electrode is located inside the quartz glass tube. The first ground electrode is in the shape of a metal cylinder and is tightly connected to the outer wall of the quartz glass tube. The catheter is located inside the quartz glass tube. Insulating devices are provided at both the left and right ends of the first high-voltage electrode. One end of the first high-voltage electrode is connected and fixed to the center position of the insulating device at the left end. Two coaxial circular grooves are provided in the insulating device at the left end. The first circular groove is used to fix the catheter. A third circular groove corresponding to the second circular groove is provided in the insulating device at the right end. One end of the quartz glass tube is located in the second circular groove, and the other end passes through the third circular groove. The second circular groove and the third circular groove fix the quartz glass tube. A hole with the same diameter as the catheter is opened at the center position of the insulating device at the right end. A semi-circular tray is provided in the hole to hold the catheter. Inner wall air inlets are opened in the first circular groove; outer wall air inlets are opened between the first circular groove and the second circular groove, and outer wall air outlets are provided at the position between the third circular groove and the hole.
[0009] The first ground electrode is tightly connected to the outer wall of the left section of the quartz glass tube. It also includes a second ground electrode, which is a copper foil. The copper foil is wound around the outer wall of the other section of the quartz glass tube and is in contact with the first ground electrode. The length of the copper foil wound around the quartz glass tube is 30%-40% of the length of the quartz glass tube. A cylindrical second high-voltage electrode is provided on a part of the outer wall of the second ground electrode and is connected to it. The right end of the second high-voltage electrode is flush with the right end of the second ground electrode. The length of the second high-voltage electrode is 85%-90% of the length of the second ground electrode. An insulator with an equilateral trapezoid cross-section is provided at the first circular groove to assist in fixing the catheter.
[0010] The inner wall air inlet and the outer wall air inlet pass through Ar gas and HMDSO mixed gas with different concentrations.
[0011] The present invention also provides a plasma method for functional deposition treatment of the inner and outer walls of a catheter. Using the plasma device for functional deposition treatment of the inner and outer walls of a catheter, it includes the following steps: Step S01: Accurately place the high-voltage electrode 3 at the geometric center position of the first insulator 1. Subsequently, place the catheter 1 in the first circular groove, and place the other end in the circular hole of the second insulating device. Seal both ends of the quartz glass tube 10 and insert it into the second circular groove and the third circular groove for fixation. Set the ground electrode 2 and the third electrode 4 in the quartz glass tube 10 to complete the assembly.
[0012] Step S02: Check the flowmeter. If it is in the on state, it needs to be closed and the flow rates of each gas path are set. Open the gas valve of the Ar gas cylinder in the gas cylinder storage unit, and then open the gas path of the HMDSO medium bottle. Ventilate to fully mix Ar gas and HMDSO solution in the first mixing gas cylinder.
[0013] Step S03: The high-voltage pulse unit uses a nanosecond pulse power supply. High-purity argon gas is introduced into the main gas path at a flow rate of 1 L / min; the medium is introduced into the auxiliary gas path. The HMDSO is respectively brought into the mixing gas path by the bubbling method. Control the flow rates of HMDSO in the auxiliary gas paths of the inner wall and the outer wall of the catheter, so that the final HMDSO on the inner wall reaches 1.34 ppm and is introduced into the inside of the catheter through the inner wall air inlet 5, and the HMDSO on the outer wall reaches 1.1 ppm and is introduced into the space between the inner wall of the quartz glass tube 10 and the outer wall of the catheter 1 through the outer wall air inlet 7; under the action of the air flow, the position of the filament continuously changes, prompting the deposited film to cover the entire area.
[0014] Step S04: Close the outer wall HMDSO auxiliary gas path, and only introduce 1 L / min of pure argon for outer wall activation. Keep the inner wall gas path unchanged and continue deposition. Ground the ground electrode 2, connect the high-voltage electrode 3 to the high-voltage power supply, check the motor rotation button, and close it if it is not closed. Open the power supply unit, set the parameters of the nanosecond pulse power supply, and start plasma modification.
[0015] Step S05: After the modification is completed, turn off the power supply, and then turn off the power supply unit: sequentially close the pure Ar gas path and the HMDSO medium bottle gas path, then close the gas valve of the Ar gas cylinder in the gas cylinder storage unit, draw out the catheter from the right side, initialize the gas flowmeter parameters through the human-computer interaction control unit, and finally turn off the power of the human-computer interaction control unit.
[0016] 3. Beneficial effects: The present invention uses plasma to improve the wettability of materials. Starting from both the chemical composition and physical morphology of the material surface, the preparation efficiency is improved, and the plasma treatment temperature is relatively low with a mild effect, which can ensure the normal use of the catheter. The method of the present invention can treat both the inner and outer walls of the catheter simultaneously and prepare surfaces with different wettabilities. It has high efficiency and low manufacturing cost. Only by changing the type of medium is required, and there is no need for multiple layers of coatings. Treating the catheter with plasma is a green and environmentally friendly modification technology that does not produce toxic substances and does not require a specific waste liquid recovery treatment system, greatly simplifying the modification process. The method of the present invention uses adjustable plasma treatment parameters to prepare different super-hydrophobic and hydrophilic films. At the same time, the wettable film has high stability, and the anti-aging days of the hydrophilic film can reach 35 days. Description of the Drawings
[0017] Figure 1 is a schematic structural diagram of the present invention.
[0018] Figure 2 is a schematic diagram of the discharge area.
[0019] Figure 3 is a side view of the second insulator.
[0020] Figure 4 is a cross-sectional view of the inner wall air inlet and the outer wall air inlet in the present invention.
[0021] Figure 5 is a schematic diagram of the plasma reaction process.
[0022] Figure 6 is a water contact angle diagram of the inner / outer wall of the catheter.
[0023] Figure 7 is the initial aging days of the hydrophilic film on the outer wall of the catheter under different operating parameters.
[0024] Figure 8 is the water contact angle change curve of the wettability of the inner / outer wall of the catheter.
[0025] Description of the reference numerals: 1 catheter, 2 first ground electrode, 3 first high-voltage electrode, 4 second high-voltage electrode, 5 second ground electrode, 6 semi-circular tray, 7 inner wall air inlet, 8 outer wall air inlet, 9 outer wall air outlet, 10 insulating device, 11 quartz tube. Detailed Description of the Invention
[0026] The present invention will be described in detail below with reference to the drawings and embodiments.
[0027] As Figure 1As shown in the figure, the present invention provides a plasma device for functional deposition treatment on the inner and outer walls of a catheter, including a quartz glass tube 11, a first high-voltage electrode 3 located inside the quartz glass tube 11, the first ground electrode 2 being in the shape of a metal cylinder and tightly connected to the outer wall of the quartz glass tube 11. The catheter 1 is located inside the quartz glass tube 11. Insulating devices 10 are provided at both the left and right ends of the first high-voltage electrode 3. One end of the first high-voltage electrode 3 is connected and fixed to the center position of the insulating device 9 at the left end. Two coaxial circular grooves are provided in the insulating device 10 at the left end. The first circular groove is used to fix the catheter 11. A third circular groove corresponding to the second circular groove is provided in the insulating device 10 at the right end. One end of the quartz glass tube 11 is located inside the second circular groove, and the other end passes through the third circular groove. The second circular groove and the third circular groove fix the quartz glass tube 1.
[0028] A hole having the same diameter as the catheter 1 is opened at the center position of the insulating device 10 at the right end. A semi-circular tray 6 is provided in the hole for supporting the catheter 1, as Figure 3 shown. Inner wall air inlet holes 7 are opened in the first circular groove; outer wall air inlet holes 8 are opened between the first circular groove and the second circular groove, and outer wall air outlet holes 9 are provided between the positions of the third circular groove and the hole.
[0029] As Figure 4 shown, inner wall air inlet holes 5 are opened in the first circular groove; outer wall air inlet holes 7 are opened between the first circular groove and the second circular groove, and outer wall air outlet holes 8 are provided between the positions of the third circular groove and the hole.
[0030] In one embodiment, the first ground electrode 2 is tightly connected to a section of the outer wall on the left side of the quartz glass tube 11. A second ground electrode 5 is further included. The second ground electrode 5 is a copper foil, which is wound around the outer wall of another section of the quartz glass tube 11 and contacts the first ground electrode 2. The length of the copper foil wound around the quartz glass tube 11 is 30%-40% of the length of the quartz glass tube 11. A cylindrical second high-voltage electrode 4 connected thereto is provided on a part of the outer wall of the second ground electrode 5. The right end of the second high-voltage electrode 4 is flush with the right end of the second ground electrode 5. The length of the second high-voltage electrode 4 is 85%-90% of the second ground electrode 5.
[0031] The first high-voltage electrode 3, between the first high-voltage electrode 3 and the second high-voltage electrode 4, and the third high-voltage electrode 4 divide the discharge into three regions, namely: the first region, the second region, and the third region, as Figure 2 shown.
[0032] In the first region, by combining the coaxial DBD discharge and adjusting the operating parameters, the wettability of the inner and outer walls of the catheter 1 can be simultaneously processed, resulting in super hydrophobicity and anti-adhesion of the inner wall, super hydrophilicity of the outer wall and improved biocompatibility.
[0033] In the second zone, the surface discharge and the coaxial DBD discharge can be combined to treat the inner wall to improve the super hydrophobicity and anti-adhesion. At the same time, there is a preliminary ionization medium, which is conducive to further complete ionization in the third zone to treat the inner wall.
[0034] In the third region, the coaxial discharge is formed, which can deposit the pre-treated ionized particles and the medium on the inner wall more thoroughly and effectively, thereby improving the super hydrophobicity and anti-adhesion properties.
[0035] In one embodiment, the gas cylinder uses an argon gas cylinder, which is divided into two gas channels to enter different media, and a human-machine interactive control unit is used to control a gas flow meter to monitor and adjust the gas flow of each gas channel in real time.
[0036] The gas circuit is divided into a main gas circuit with working gas as the main gas and an auxiliary gas circuit for introducing precursors. The medium gas circuit is divided into an HMDSO medium gas circuit, and the two constitute the total gas circuit. The main gas circuit is mainly responsible for providing working gas, while the auxiliary gas circuit provides reaction medium through bubbling method.
[0037] The plasma method for functional deposition treatment of the inner and outer walls of a urinary catheter of the present invention uses the plasma device for functional deposition treatment of the inner and outer walls of a urinary catheter, and comprises the following steps: First, the first high-voltage electrode 3 is precisely placed at the geometric center of the gas distributor to ensure discharge uniformity. Subsequently, the catheter 1 is fixed to the center of the insulating device 10 at the left end with the help of an insulator with an equilateral trapezoidal cross section. The first grounding electrode 2 is connected to the insulating device on the other side to construct a coaxial electrode for processing the inner and outer walls of the catheter. The quartz glass tube 11 is inserted into the groove of the insulating device 10 on the left side and fixed, and copper foil is wrapped around the outside to form the second grounding electrode 5, thus completing the equipment assembly.
[0038] Prepare to connect the gas line. Check the flow meter. If it is open, close it and set the flow rate of each gas line. Open the gas valve of the Ar gas cylinder in the gas cylinder storage unit, then open the HMDSO medium bottle gas line and ventilate for 1 min to fully mix the Ar gas and HMDSO solution in the mixing bottle. Introduce HMDSO gas of different concentrations from the inner and outer wall vents of the left insulating device to prepare for deposition.
[0039] The high-voltage pulse unit uses a nanosecond pulse power supply, and its power supply parameters are set as follows: voltage amplitude 12 kV, repetition frequency 5 kHz, rise time 100 ns, pulse width 800 ns, and fall time 100 ns.
[0040] The power supply is a nanosecond pulse power supply for the high-voltage pulse unit. The high-voltage terminal is connected to the high-voltage electrode of the discharge device to control the discharge power supply parameters and the connection circuit. The plasma generated by the high voltage deposits on the inner and outer walls of the catheter; a coaxial discharge is formed using the ground electrode and the high-voltage electrode. At the same time, two gas path devices are used to process the inner and outer walls of the catheter. Argon is selected as the working gas for the main gas path during deposition, and HMDSO is introduced into the auxiliary gas path to deposit a thin film on the inner / outer wall of the catheter to improve the hydrophobicity of the inner / outer wall; when activating, the auxiliary gas path leading to the outer wall of the catheter is closed, and only Ar is introduced for activation treatment to improve the hydrophilicity of the outer wall; at this time, the gas path leading to the inner wall of the catheter remains unchanged, argon is selected as the working gas for the main gas path, and HMDSO is introduced into the auxiliary gas path to still deposit a hydrophobic thin film on the inner wall of the catheter.
[0041] High-purity argon is introduced into the main gas path at a flow rate of 1 L / min; a medium is introduced into the auxiliary gas path, and HMDSO is carried into the mixed gas path by the bubbling method respectively. The flow rate of HMDSO in the auxiliary gas path for processing the inner / outer wall is such that the final HMDSO on the inner wall reaches 1.34 ppm and is introduced into the inside of the catheter through the inner wall air inlet 7, and the HMDSO on the outer wall reaches 1.1 ppm and is introduced into the inside of the ground electrode through the outer wall air inlet 8. The discharge air gap of the coaxial electrode is set to 1.0 mm to form a mixed-mode discharge with both filament and diffuse plasmas.
[0042] Under the action of the air flow, the position of the filaments continuously changes, prompting the deposited thin film to cover the entire area. The discharge treatment duration is 10 min, aiming to prepare thin films with different wettabilities on the inner and outer walls of the catheter. After that, the HMDSO auxiliary gas path for the outer wall is closed, and only 1 L / min of pure argon is introduced for outer wall activation. The inner wall gas path remains unchanged, and deposition continues.
[0043] After completion, ground the grounding electrode, connect the high-voltage electrode to the high-voltage power supply, check the motor rotation button, and turn it off if it is not already off. Turn on the power unit, set the parameters of the nanosecond pulse power supply: voltage amplitude 12 kV, repetition frequency 5 kHz, rise time 100 ns, pulse width 800 ns, fall time 100 ns, and start the plasma modification. After the modification is completed, turn off the power supply, and then turn off the power unit. Sequentially close the pure Ar gas line and the HMDSO medium bottle gas line. Subsequently, close the Ar gas cylinder valve of the gas cylinder storage unit and draw out the catheter from the right side. Initialize the gas flowmeter parameters through the human-machine interaction control unit. Finally, turn off the human-machine interaction control unit. After processing, if the storage time is within 1 month, it can be used directly. If it exceeds one month, reactivation is required. In this regard, the power supply needs to be re-added.
[0044] In the present invention, plasma hydrophobic deposition is carried out on the inner wall of the catheter to introduce carbon-containing groups to improve hydrophobicity and thus enhance anti-adhesion. On the other hand, deposition + activation is carried out on the outer wall of the catheter to increase the oxygen-silicon ratio to prepare a quasi-inorganic SiO2 film and introduce hydrophilic groups such as -OH to prepare a hydrophilic film, thereby improving lubricity and biocompatibility.
[0045] In the molecular chain of PVC, there are mainly C-C and C-Cl. The polarity of the overall molecule is weak. According to the "like dissolves like" principle, the intermolecular force between the weakly polar PVC molecules and the strongly polar water molecules is weak, thus showing hydrophobicity. Plasma polymerization deposition will apply high-energy particles on the surface of the catheter, and the medium HMDSO will decompose into methyl groups in it and react with the inner wall PVC surface to form a new oxide film attached to the inner wall. The Ar plasma will react with the outer wall PVC to form -OH oxygen-containing groups and remove the excess methyl groups to form a quasi-inorganic SiO2 film, providing a prerequisite for the hydrophilic film. The schematic diagram of the chemical action is as Figure 5 shown. Argon, as the carrier gas, can not only maintain the stability of the plasma but also react with the medium to form more functional groups to participate in the reaction. At the same time, plasma activation can increase the surface roughness of the material. According to the Wenzel model, it can further promote the transformation of the inner wall film from hydrophobic to superhydrophobic and the outer wall film from hydrophilic to superhydrophilic.
[0046] To prove the stable anti-aging performance of the present invention, the water contact angle (WCA) of the surface of the catheter after two-step plasma treatment was measured.
[0047] The water contact angle test was carried out on the plasma-treated catheter after 24 hours of placement, as Figure 6 shown. The results show that for the untreated catheter, as Figure 6 shown in a, the water contact angle is 67.5 ± 1.2°; after the inner wall is treated with hydrophobic deposition, as Figure 6As shown in Fig. b, the contact angle is significantly increased to 134.7±1.3°; while for the super-hydrophilic thin film formed on the outer wall by a two-step process, as Figure 6 shown in Fig. c, the contact angle is as low as 1.3±0.7°. This treatment process realizes the differential functional design of anti-adhesion on the inner wall and biocompatibility on the outer wall of the catheter, and constructs the surface of medical devices with specific biological interface characteristics by regulating the surface wettability of the material.
[0048] To optimize the anti-aging performance of the hydrophilic outer wall, parameter optimization experiments were carried out by regulating the HMDSO concentration and deposition time, as Figure 7 shown. The results show that when the HMDSO concentration increases from 0.93 ppm to 1.34 ppm, the initial aging days first increase and then decrease, and the concentration of 1.1 ppm is the optimal value; when the deposition time extends from 6 min to 10 min, the initial aging days also show a trend of first rising and then falling, and 10 min is the optimal treatment duration. Based on the above rules, the combination of 1.1 ppm HMDSO concentration and 10 min deposition time is determined as the optimal process parameters. At the same time, users can also customize the preparation of hydrophilic thin films with different anti-aging cycles by adjusting the operating parameters according to actual application requirements.
[0049] Through Figure 8 water contact angle (WCA) curve analysis, it is shown that the WCA of the hydrophobic thin film on the inner wall is stably maintained at 130.1±1.2° after 30 days of storage; the super-hydrophilic thin film directly activated on the outer wall ages after only 1 day and the WCA rises to 32.1±0.9°, and stabilizes at 62.2±1.1° after 7 days; while the super-hydrophilic thin film on the outer wall using the deposition + activation process can maintain a super-hydrophilic state with WCA < 5° for 35 days, and the WCA suddenly rises to 118.3±0.8° after aging, presumably caused by the reorganization of polar groups. This result verifies that the present invention can effectively improve the wettability of the inner and outer walls of the catheter, thereby promoting the biocompatibility of the outer wall of the catheter and the anti-adhesion of the inner wall of the catheter. The hydrophobic recovery of the outer wall after one month of use can regenerate the super-hydrophilic performance through secondary activation, providing technical feasibility for the maintenance of clinical devices.
Claims
1. A plasma device for functional deposition treatment of the inner and outer walls of a catheter, comprising a quartz glass tube (11), a first high-voltage electrode (3) located inside the quartz glass tube (11), the first ground electrode (2) being in the shape of a metal cylinder and being tightly connected to the outer wall of the quartz glass tube (11), characterized in that: The catheter (1) is located inside the quartz glass tube (11). Insulating devices (10) are provided at both the left end and the right end of the first high-voltage electrode (3). One end of the first high-voltage electrode (3) is connected and fixed to the center position of the insulating device (9) at the left end. Two coaxial circular grooves are provided in the insulating device (10) at the left end. The first circular groove is used to fix the catheter (11). A third circular groove corresponding to the second circular groove is provided in the insulating device (10) at the right end. One end of the quartz glass tube (11) is located inside the second circular groove, and the other end passes through the third circular groove. The second circular groove and the third circular groove fix the quartz glass tube (1). A hole with the same diameter as the catheter (1) is opened at the center position of the insulating device (10) at the right end. A semi-circular tray (6) is provided in the hole to hold the catheter (1). An inner wall air inlet hole (7) is opened in the first circular groove; an outer wall air inlet hole (8) is opened between the first circular groove and the second circular groove, and an outer wall air outlet hole (9) is provided at the position between the third circular groove and the hole.
2. The plasma device for functional deposition treatment on the inner and outer walls of the catheter according to claim 1, characterized in that: The first ground electrode (2) is closely connected to the outer wall of the left section of the quartz glass tube (11). A second ground electrode (5) is further included. The second ground electrode (5) is a copper foil. The copper foil is wound around the outer wall of the other section of the quartz glass tube (11) and is in contact with the first ground electrode (2). The length of the copper foil wound around the quartz glass tube (11) is 30%-40% of the length of the quartz glass tube (11). A cylindrical second high-voltage electrode (4) connected thereto is provided on a part of the outer wall of the second ground electrode (5). The right end of the second high-voltage electrode (4) is flush with the right end of the second ground electrode (5). The length of the second high-voltage electrode (4) is 85%-90% of the second ground electrode (5).
3. The plasma device for functional deposition treatment on the inner and outer walls of a catheter as claimed in claim 1, characterized in that: An insulator with an equilateral trapezoid cross-section is provided at the first circular groove to assist in fixing the catheter (1).
4. The plasma device for functional deposition treatment of the inner and outer walls of a urinary catheter according to any one of claims 1-3, characterized in that: An air cylinder is further included. The air cylinder uses an argon cylinder and is divided into two gas path channels to enter different media. At the same time, the human-computer interaction control unit is used to control the gas flowmeter to monitor and adjust the gas flow of each gas path channel in real time.
5. The plasma device for functional deposition treatment on the inner and outer walls of a urinary catheter according to claim 4, characterized in that: The gas path includes a main gas path mainly for working gas and an auxiliary gas path for introducing a precursor. The medium gas path is divided into an HMDSO medium gas path, and the two constitute the total gas path. The main gas path is mainly responsible for providing the working gas, and the auxiliary gas path provides the reaction medium through the bubbling method.
6. The plasma device for the functional deposition treatment of the inner and outer walls of a urinary catheter according to claim 5, characterized in that: The inner wall air inlet (7) and the outer wall air inlet (8) are mixed with Ar gas and HMDSO with different concentrations.
7. A plasma method for functional deposition treatment on the inner and outer walls of a catheter, using the plasma device for functional deposition treatment on the inner and outer walls of a catheter according to any one of claims 1-6, including the following steps: Step S01: Precisely place the first high-voltage electrode (3) at the geometric center of the insulator (10) on the left end. Subsequently, place the catheter (1) in the first annular groove, and place the other end in the circular hole of the insulating device on the right end. Seal both ends of the quartz glass tube (10) and insert it into the second annular groove and the third annular groove for fixation. Set up the first ground electrode (2) and the second ground electrode (5) on the quartz glass tube (11) to complete the assembly; Step S02: Check the flowmeter. If it is in the on state, turn it off and set the flow rates of each gas path. Open the gas valve of the Ar gas cylinder in the gas cylinder storage unit, and then open the gas path of the HMDSO medium bottle. Ventilate to fully mix the Ar gas and the HMDSO solution in the first mixing gas cylinder; Step S03: The high-voltage pulse unit uses a nanosecond pulse power supply. High-purity argon is introduced into the main gas path at a flow rate of 1 L / min; the medium is introduced into the auxiliary gas path. The HMDSO is brought into the mixed gas path by the bubbling method respectively. Control the flow rates of HMDSO in the auxiliary gas paths on the inner wall and the outer wall of the catheter, so that the final HMDSO on the inner wall reaches 1.34 ppm and is introduced into the inside of the catheter through the inner wall air inlet (7), and the HMDSO on the outer wall reaches 1.1 ppm and is introduced between the inner wall of the quartz glass tube (10) and the outer wall of the catheter (1) through the outer wall air inlet (8). Under the action of the air flow, the position of the filament continuously changes, prompting the deposited film to cover the entire area; Step S04: Close the HMDSO auxiliary gas path on the outer wall, and only introduce pure argon at 1 L / min for outer wall activation. Keep the inner wall gas path unchanged and continue deposition. Ground the first ground electrode (2), connect the first high-voltage electrode (3) to the high-voltage power supply, check the motor rotation button, and turn it off if it is not closed. Open the power supply unit, set the parameters of the nanosecond pulse power supply, and start the plasma modification; Step S05: After the modification is completed, turn off the power supply, and then turn off the power supply unit. Close the pure Ar gas path and the HMDSO medium bottle gas path in sequence, and then close the Ar gas cylinder valve of the gas cylinder storage unit. Withdraw the catheter from the right side, initialize the gas flowmeter parameters through the human-machine interaction control unit, and finally turn off the power of the human-machine interaction control unit.
8. The plasma method for functional deposition treatment of inner and outer walls as claimed in claim 7, characterized in that: The parameters of the nanosecond pulse power supply used in the high-voltage pulse unit are set as follows: voltage amplitude 12 kV, repetition frequency 5 kHz, rising edge 100 ns, pulse width 800 ns, falling edge 100 ns.
9. The plasma method for functional deposition treatment of inner and outer walls as described in claim 7, characterized in that: The discharge air gap of the coaxial electrode is set to 1.0 mm to form a hybrid-mode discharge with both filaments and diffuse plasma.
10. The plasma method for functional deposition treatment of inner and outer walls according to claim 7, characterized in that: The discharge treatment duration is 10 min, aiming to prepare films with different wettabilities on the inner and outer walls of the catheter.