A personalized laser-engraved medical composite catheter and a method of making the same

Abstract

The application discloses a kind of personalized laser engraving medical composite catheter and preparation method thereof, including inner layer, intermediate reinforcing layer and outer layer;The inner layer, intermediate reinforcing layer and outer layer are integrally formed by hot pressing;The outer layer is engraved with engraved patterns by laser engraving, and the engraved patterns correspond to the tortuosity of the catheter intervention path extracted from the CT data of the patient and the hardness requirement of the patient's CT data extraction.The application combines CT data processing system, and the hardness of each region of the catheter is accurately controlled by laser engraving on the outer layer of the high-strength composite catheter, which can quickly respond to the requirements of personalized treatment, meet the diversified needs of complex interventional surgery, and significantly improve the success rate and safety of surgery.

Description

Technical Field

[0001] This invention relates to the field of interventional medical device technology, specifically to a personalized laser-engraved medical composite catheter and its preparation method. Background Technology

[0002] Currently, with the development of interventional therapy technology, the requirements for medical composite catheters are becoming increasingly stringent. While traditional composite catheters exhibit excellent lubricity and mechanical properties, such as CN119838121A, a long-term implantable gel composite braided medical catheter and its molding method, which includes an inner membrane and a gel layer arranged sequentially from the inside out, with a braid embedded within the gel layer, this method introduces a PTFE inner layer, a reinforcing braided layer, and a polymer gel outer layer.

[0003] However, it has significant limitations when dealing with the winding blood vessels inside the human body: to accommodate the curvature and stenosis of blood vessels in different locations, the catheter needs to have different levels of stiffness and softness along its length. Traditional methods achieve this by changing the distribution of the reinforcing layer and creating specific structures, but this approach increases manufacturing complexity and makes precise control difficult.

[0004] While solutions such as splicing multiple outer materials or designing the reinforcing layer as a continuous gradient structure can solve the problem of softness and hardness control to some extent, they also bring new challenges, such as decreased interfacial bonding strength, increased production costs, and greater difficulty in quality control.

[0005] For example, CN116059508A discloses a multi-directional bending medical interventional device, including a handle and a catheter. The catheter is fixedly installed on the handle. The catheter body has several composite chambers inside. The handle has a through groove adapted to the composite chambers. The through groove communicates with the composite chambers and is used to input or output a medium into or out of the composite chambers. The bending direction of the catheter can be adjusted by adjusting the medium content in the composite chambers. By setting several composite chambers inside the catheter body and opening through grooves on the handle to communicate with the composite chambers, the medium content in the composite chambers can be adjusted through the through grooves. The catheter can be bent in multiple directions through the cooperation between the composite chambers, and it has a wide range of applications.

[0006] However, each patient's specific condition and anatomical structure are different, and existing standardized catheters cannot fully meet the needs of individualized treatment, especially in operations on complex lesion sites, which may affect the surgical outcome or even bring risks, thus leaving personalized needs unmet. Summary of the Invention

[0007] This invention addresses the problem of difficulty in precisely controlling the size of medical catheters and the inability to meet personalized needs by providing a laser-engraved medical composite catheter. This catheter is made of three layers integrally formed by hot pressing, with the outer layer laser-engraved according to the patient's scan data, thus realizing the customization of interventional catheters and meeting the diverse needs in complex interventional surgeries.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A personalized laser-engraved medical composite catheter includes an inner layer, a middle reinforcing layer, and an outer layer; the inner layer, the middle reinforcing layer, and the outer layer are integrally formed by hot pressing. The outer layer is laser-engraved with patterns that correspond to the tortuosity and hardness requirements of the catheter intervention path extracted from the patient's CT data.

[0009] This invention enables the production of catheters with adjustable hardness and softness characteristics in just two steps: first, a simple three-layer composite catheter is fabricated, and then laser engraving is performed as needed, significantly reducing production complexity. This invention overcomes the shortcomings of existing methods, such as increased manufacturing complexity, difficulty in precise control, decreased interfacial adhesion strength, increased production costs, greater difficulty in quality control, and inability to meet personalized needs.

[0010] The elastic modulus of the engraved pattern at point x on the outer layer of the medical composite catheter is calculated according to formula (1): (1) in, E x Let x be the elastic modulus at the location x of the conduit; E 0 The initial elastic modulus at point x of the conduit before carving. d x Let x be the engraving depth at the catheter. d max To the maximum permissible carving depth, w Let x be the engraving linewidth at the duct, and α, β, and r be material correction factors.

[0011] The engraving density gradient of the engraved pattern at position x of the medical composite catheter is calculated according to formula (2): (2) in, ▽S pattern (x) catheter x The engraving density gradient at the location, C vessel (x) The curvature function of the vessel to be intervened is extracted from the patient's CT data, where k is the catheter-vessel adaptation coefficient, with a value of 0.8 to 1.2. It is a partial differential operator. The partial differential represents the rate of change of the engraved linewidth along the axial direction (x direction) of the guide tube. By introducing the influence of the linewidth gradient, the gradual change in mechanical properties caused by the density of the engraved pattern can be more precisely controlled.

[0012] The inner layer is made of PTFE with a thickness of 0.05mm to 0.15mm; preferably, the intermediate reinforcing layer is made of medical-grade 316L stainless steel or a titanium-nickel alloy. 316L stainless steel has the advantages of low cost and high strength, making it suitable for catheters with relatively low flexibility requirements. Nickel-titanium alloys possess superelasticity and shape memory effect, providing excellent flexural strength and tracking ability in tortuous blood vessels, making them suitable for catheters with high flexibility requirements (such as nerve conduits).

[0013] Preferably, the thickness of the intermediate reinforcement layer is 0.03-0.3 mm. More preferably, the intermediate reinforcement layer is woven from metal wires with a diameter of 0.03 mm to 0.08 mm; the weaving density is 80 PPI to 120 PPI, and the weaving angle is 30° to 45° relative to the guide axis. Fine metal wires provide better flexibility, while coarser wires provide stronger support. High-density weaving enhances resistance to collapse and kinking, and the 30° to 45° weaving angle achieves a good balance between pushing force transmission and anti-rotation properties. PPI refers to the number of intersections per inch.

[0014] The outer layer is made of a high-molecular material that can be precisely laser-engraved, has good biocompatibility, and a certain degree of flexibility. Preferably, the outer layer material includes any one or more composite materials selected from polyurethane (PU), nylon (PA), polyethylene (PE), silicone rubber (SI), and thermoplastic polyolefin elastomer (TPE). The thickness of the outer layer is 0.2-0.5 mm, and the outer layer thickness is greater than the maximum allowable engraving depth + 0.05 mm, where 0.05 mm is a safety margin. For example, if the maximum engraving depth is designed to be 0.25 mm, then the outer layer thickness should be at least 0.30 mm to ensure that the engraving does not penetrate to the braided layer and damage the structural integrity.

[0015] Preferably, the outer surface is further provided with a hydrophilic layer, which is prepared on the outer surface after laser engraving; more preferably, the hydrophilic layer includes a polyvinylpyrrolidone (PVP) layer; the preparation process of the hydrophilic layer includes methods such as coating and curing or dip coating and curing. More preferably, the preparation of the hydrophilic layer includes: immersing the etched conduit in a PVP aqueous solution (concentration 5-10 wt%), and uniformly pulling it up (speed 2-5 mm / s) to ensure uniform coating; the resulting conduit is then dried in an oven at 60-80°C for 30-60 minutes to allow the coating to crosslink and cure. The dried hydrophilic layer has a thickness of approximately 1-5 μm, providing durable lubrication without significantly affecting the conduit size.

[0016] The present invention also provides a method for preparing the personalized laser-engraved medical composite catheter, comprising the following steps: Step 1: Place the inner tube on the braiding device, and use the traction device to pull the metal braided wires evenly around the inner layer to obtain the intermediate reinforcement layer. Step 2: The catheter obtained in Step 1 is extruded and coated so that the outer layer covers the middle reinforcing layer; Step 3: Based on the tortuosity and hardness requirements of the catheter intervention path extracted from the patient's CT data, design corresponding engraving patterns. Step 4: Laser engrave the outer layer of the catheter obtained in Step 2 according to the engraving pattern to obtain the medical composite catheter.

[0017] Laser engraving uses ultraviolet lasers for engraving. The process parameters include: power of 10W~30W, which can be adjusted according to the material and engraving depth; scanning speed of 100mm / s~1000mm / s; pulse frequency of 20kHz~80kHz; and 1~5 engraving passes to achieve the required depth.

[0018] In some implementations, ultraviolet lasers with wavelengths of 355±10nm or 266nm are used for engraving. 355nm±10nm is the most mainstream wavelength configuration in the current field of ultraviolet marking for medical catheters. Some high-end femtosecond-level devices use a wavelength of 266nm to obtain a smaller heat-affected zone (<1μm), which is suitable for processing implantable materials with extremely high requirements for thermal damage.

[0019] In the actual fabrication process, the specific process settings are as follows: First, calculate the required engraving depth and line width at point x of the guide tube. Then, conduct parameter simulation process experiments on the same material to establish a database of the correspondence between laser parameter combinations and the actual engraved depth and line width, as well as material correction coefficients α, β, and r. During processing, call the corresponding parameter combinations to achieve the target geometric features calculated by the formula.

[0020] The traction device includes at least two sets of transmission components and drive components; The transmission assembly includes a pair of main drive wheels and multiple auxiliary drive wheels, with the multiple auxiliary drive wheels located between the pair of main drive wheels. A transmission belt is wound around the pair of main drive wheels and the multiple auxiliary drive wheels. The two sets of transmission assemblies are arranged symmetrically up and down, and the pair of main drive wheels are connected to the drive assembly via a transmission shaft.

[0021] The transmission belt includes a wear-resistant layer and a transmission layer. The wear-resistant layer is made of a hard material, and the transmission layer is made of an elastic material. The upper center of the transmission layer is provided with a first mounting groove. Multiple detachable wear-compensating belts are located in the first mounting groove. Each wear-compensating belt has a protrusion at the top and a groove at the bottom that matches the protrusion. Multiple wear-compensating belts are stacked on top of each other, such that the protrusion of the lower wear-compensating belt is inserted into the groove of the upper wear-compensating belt. The top of the protrusion is an outwardly protruding arc surface. The outwardly protruding arc surface leaves more wear space, which allows the wear-compensating belt to be made thinner.

[0022] The lower center of the transmission layer is provided with a second mounting groove. The second mounting groove is provided with a plurality of first U-shaped elastic elements and a plurality of second U-shaped elastic elements adapted to the first U-shaped elastic elements. The outer side of the bow portion of the first U-shaped elastic element and the outer side of the bow portion of the second U-shaped elastic element abut against each other and are connected together. On the one hand, this allows the wear compensation belt to contact the guide tube upward, enhancing the friction between the belt and the guide tube. On the other hand, it also allows the wear-resistant layer to be tightly attached to the main drive wheel and the auxiliary drive wheel. The effect is more obvious, especially when the main drive wheel and the auxiliary drive wheel use friction transmission with the transmission belt, effectively preventing the transmission belt from slipping.

[0023] The top of the wear-resistant layer is provided with a groove, and the two ends of the second U-shaped elastic element are provided with sliders that are inserted into the groove.

[0024] This invention utilizes a hot-pressing integral molding process, resulting in higher mechanical properties and structural precision for the intermediate reinforcing layer. Currently, in traction devices, the metal braided belt causes severe wear after prolonged use, leading to localized loosening. This invention, with its wear-compensating belt, facilitates replacement of locally worn areas, avoiding the need for complete replacement, thus reducing production costs and simplifying replacement.

[0025] On the one hand, this invention utilizes finite element simulation technology and laser engraving to precisely control the changes in hardness and softness in each region of the catheter, enabling rapid response to individualized treatment requirements and meeting the diverse needs of complex interventional surgeries. On the other hand, during the fabrication of the three-layer composite tube, a traction device uniformly pulls the braided filaments to counteract the tension fluctuations caused by the spindle rotation, ensuring that each strand of braided filament is wound with uniform force on the surface of the inner tube, avoiding localized looseness or excessive tightness. The traction speed is dynamically matched with the spindle rotation speed, ensuring that the braided filaments precisely cover the inner tube at a preset angle and density, achieving consistency in the braided layer structure, further enhancing the mechanical properties and structural precision of the intermediate reinforcing layer, thereby realizing high mechanical performance and high-precision personalized customization of the composite medical catheter.

[0026] Compared with the prior art, the present invention has the following beneficial effects: This invention combines a CT data processing system with laser engraving on the outer layer of a high-strength composite catheter to precisely control the hardness and softness changes in each area of ​​the catheter. This allows for rapid response to personalized treatment requirements, meets the diverse needs of complex interventional surgeries, and significantly improves the success rate and safety of the procedure. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the personalized laser-engraved medical composite catheter structure of Example 1.

[0028] Figure 2 This is a schematic diagram of the traction device structure of the personalized laser-engraved medical composite catheter preparation method in Example 1.

[0029] Figure 3 This is a partial structural diagram of the wear compensation band of the traction device in the personalized laser-engraved medical composite catheter preparation method of Example 1.

[0030] Figure 4 yes Figure 3 Enlarged view of part A of the partial diagram of the wear compensation zone of the traction device.

[0031] Figure 5 This is a partial view of the wear compensation zone of the traction device in the personalized laser engraving method for preparing medical composite catheters with adjustable hardness and softness, as described in Example 2.

[0032] The labels for the attached figures are as follows: 1. Wear-resistant layer; 2. Transmission layer; 3. First mounting groove; 4. Wear-compensating strip; 5. Protrusion; 6. Groove; 7. Second mounting groove; 8. First U-shaped elastic element; 9. Second U-shaped elastic element; 10. Slide groove; 11. Slider; 12. Deformation strip; 21. Inner layer; 22. Intermediate reinforcing layer; 23. Outer layer; 100. Transmission assembly; 200. Drive assembly; 300. Main drive wheel; 400. Auxiliary drive wheel; 500. Transmission belt. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Modifications or equivalent substitutions made by those skilled in the art based on their understanding of the technical solutions of this invention, without departing from the spirit and scope of the invention, should be covered within the protection scope of this invention.

[0034] All raw materials used in the following specific implementation methods were purchased from the market.

[0035] In some implementations, the polymer outer layer (such as PU, PE, TPE, etc.) of medical catheters is commonly engraved using ultraviolet laser (UV laser) equipment. Ultraviolet lasers have short wavelengths (355nm or 266nm) and high photon energy, enabling them to directly break the molecular bonds of polymer materials through "photochemical action" (i.e., "cold processing"). This results in a minimal heat-affected zone, preventing material melting and deformation, making it particularly suitable for precision processing of medical catheters and other applications requiring stringent accuracy and surface quality.

[0036] In some implementations, the laser engraving equipment may be the YC-UVM300 (355nm, 3W / 5W / 10W optional, marking line width <40μm) from Keke Precision Machinery, the SYNEO Accu-Lase series UV laser workstation (dedicated to catheter drilling, cutting, and marking), the FOBA V.0020-UV UV marking laser (suitable for highly sensitive medical plastics such as catheters), as well as the Ruifengheng 3W / 5W UV laser and the Beyond Laser UV femtosecond laser equipment, etc.

[0037] In the following examples, the catheter tortuosity shape extracted from patient CT data follows the method described in CN117496173A. Alternatively, other methods can be used to obtain the tortuosity and stiffness requirements of the catheter interventional path, depending on clinical needs. The specific steps include: Step S1: Use a 3D optical scanner to scan the user's head and generate a 3D image of the user's head; use 3D modeling technology to perform 3D modeling on the user's head image to generate an initial 3D head model; perform model correction on the initial 3D head model to generate a standard 3D head model. Step S2: Obtain the user's cerebral vascular analysis area; use a CT scanner and the cerebral vascular analysis area to acquire cerebral vascular images of the target area of ​​the user, and generate target cerebral vascular images; extract cerebral vascular features from the target cerebral vascular images to obtain cerebral vascular feature images; Step S3: Transmit the cerebral vascular feature image to the standard head 3D model for cerebral vascular mapping processing, and extract the target region of the model according to the cerebral vascular analysis area to generate the target cerebral vascular model. Step S4: Use an ultrasonic sensor to collect blood flow velocity data of the user's cerebral blood vessels and generate blood flow velocity data; extract the cerebral blood vessel tortuosity nodes of the target cerebral blood vessel model and generate cerebral blood vessel tortuosity nodes of the target cerebral blood vessel model; collect deformation images of the tortuosity nodes of the cerebral blood vessels based on the blood flow velocity data and generate a set of deformation images of the cerebral blood vessel tortuosity nodes; perform real-time acquisition and processing of blood flow velocity data to generate real-time blood flow velocity data; predict blood vessel deformation features based on the deformation image set and real-time blood flow velocity data and generate cerebral blood vessel deformation feature data.

[0038] In this invention, the laser engraving equipment is installed at the end of the production line, receives engraving instructions from the computer-aided design system, and performs precise cutting on the outer surface of the guide tube.

[0039] In this invention, the finite element analysis software is connected to the design workstation to generate and verify the optimal carving scheme. The finite element analysis software used in this invention can be Abaqus (Dassault Systèmes).

[0040] In this invention, the CT data processing system is integrated into the entire process and used as the core of personalized customization to ensure that each catheter can be optimized for specific cases.

[0041] Example 1 like Figure 1 As shown, this invention discloses a medical composite catheter with personalized laser engraving and adjustable hardness, comprising: an inner layer 21, a middle reinforcing layer 22, and an outer layer 23. The inner layer, the middle reinforcing layer, and the outer layer are integrally formed by hot pressing. The outer layer is laser engraved with an engraved pattern, which corresponds to the tortuosity and hardness requirements of the catheter intervention path extracted from the patient's CT data.

[0042] Medical composite catheter x The elastic modulus of the engraved pattern at the location is calculated according to formula (1): (1) in, E x Let x be the elastic modulus at the location x of the conduit; E 0 The initial elastic modulus at point x of the conduit before carving. d x Let x be the engraving depth at the catheter. d max To the maximum permissible carving depth, w Let x be the engraving line width at the catheter, and α, β, and r be material correction coefficients. In this embodiment, α = 0.35, β = 1.2, and r = 0.05.

[0043] When catheter x At the bend, assuming the tortuosity requires the elastic modulus of the conduit to decrease to 40% of its original elastic modulus, then d(x) = 0.6*d max In this embodiment, the outer layer is made of medical-grade polyurethane with a thickness of 0.35mm. To ensure structural integrity, a maximum allowable engraving depth d is set. max The thickness is 0.20mm, with a safety margin of 0.15mm reserved to prevent damage to the intermediate reinforcement layer during engraving; W(x) = 20μm.

[0044] Medical composite catheter x The carving density gradient of the carved pattern is calculated according to formula (2): (2) in, ▽S pattern (x) catheter x The engraving density gradient at the location, C vessel (x) The curvature function of the vessel to be intervened is extracted from the patient's CT data. k is the catheter-vessel adaptation coefficient, with a value of 0.8. Since the coronary artery has high requirements for the passage of the catheter, the adaptation coefficient is set to a low value to increase the carving sensitivity. It is a partial differential operator.

[0045] In this invention, stress concentration occurs in the blood vessel wall at locations of abrupt curvature changes. For such stress concentration areas, the engraving density should be increased to improve the local flexibility of the catheter, thereby reducing the risk of blood vessel damage.

[0046] For the calibration of the coefficient k, this invention uses clinical data fitting (e.g., K=0.8 for coronary catheters, K=1.2 for neural catheters). For the calibration of the coefficient k, those skilled in the art use in vitro simulated vascular access bench tests for experimental calibration, specifically including: extracting the centerline curvature function of the vessel to be intervened from the patient's CT data and calculating its second derivative; constructing an in vitro simulated vascular access model consistent with the vascular path; conducting catheter pushing tests in the simulated vascular access, measuring the pushing force and minimum bending radius of the catheter under different engraving density gradients ▽Spattern(x); and determining the optimal value of the catheter-vessel adaptation coefficient k through regression fitting of experimental data, with the goal of minimizing pushing force and optimizing passability. In different clinical application scenarios, due to the systematic differences in vascular anatomy, the optimal value of the adaptation coefficient k varies: in coronary intervention, the catheter needs to balance pushing force transmission efficiency and compliance, and 0.8 is the preferred value after experimental calibration; in neural intervention, intracranial vessels are extremely tortuous, requiring higher local compliance of the catheter, and 1.2 is the preferred value after experimental calibration. The value of k is not limited to the above experimental calibration method, and those skilled in the art can adjust it in the range of 0.8 to 1.2 according to specific clinical needs.

[0047] In the generated sculpted pattern distribution map, high-density areas correspond to sharp bends in the blood vessels. For example, the rate of change of curvature at a point along the blood vessel path | 2 Cvessel x ) / x 2 |=0.3 / mm 2The engraving density gradient was calculated as follows: for coronary catheters, ▽Spattern(x) = 0.24 / mm (k = 0.8). The higher the vascular curvature, the higher the engraving density, improving the catheter's flexibility in curved areas.

[0048] Based on the formula above, and taking into account the tortuosity and stiffness requirements of the catheter intervention path extracted from the patient's CT data, the required engraving pattern for the entire catheter is calculated. The optimal engraving scheme is then generated and validated using the finite element analysis software Abaqus (Dassault Systèmes). This engraving scheme is then input into the laser engraving equipment for easy execution of engraving instructions.

[0049] The method for preparing the personalized laser-engraved medical composite catheter includes the following steps: Step 1: Place the PTFE inner tube (thickness 0.10mm) on the braiding device, and let the metal braided wires on each spindle (material is medical grade 316L stainless steel, wire diameter 0.05mm, braiding density 100 PPI, braiding angle 35°) be pulled evenly and wound on the surface of the inner tube by the traction device to obtain an intermediate reinforcing layer with a thickness of about 0.10mm. Step 2: The catheter obtained in Step 1 is passed through the extrusion device and coated by extrusion, so that the outer layer (material is medical grade polyurethane, such as Pellethane 2363-80A, extrusion thickness 0.35mm) is evenly coated on the middle reinforcing layer. After cooling and shaping, a three-layer composite catheter is obtained.

[0050] Step 3: Based on the tortuosity and hardness requirements of the catheter intervention path extracted from the patient's CT data, calculate the engraving pattern required for the entire catheter. Use the finite element analysis software Abaqus (Dassault Systèmes) to generate and verify the optimal engraving scheme. Input the engraving scheme into the laser engraving equipment to facilitate the execution of engraving instructions. Step 4: Laser engrave the outer layer of the catheter obtained in Step 2 according to the engraving pattern to obtain a medical composite catheter.

[0051] In step 3, ultraviolet laser was used for laser engraving. The process parameters included: power 15W, scanning speed 500mm / s, pulse frequency 40kHz, and engraving twice, thereby achieving the goal of engraving depth of 0.12mm and line width of 20μm.

[0052] In the actual fabrication process, the specific process settings are as follows: First, calculate the required engraving depth and line width at point x of the guide tube. Then, conduct parameter simulation process experiments on the same material to establish a database of the correspondence between laser parameter combinations and the actual engraved depth and line width, as well as material correction coefficients α, β, and r. During processing, call the corresponding parameter combinations to achieve the target geometric features calculated by the formula.

[0053] In this embodiment, the outer layer is medical-grade polyurethane. The process for obtaining the process parameters and material correction coefficients α, β, and r specifically includes the following: a. Sample Preparation: Medical-grade polyurethane tubing (0.3 mm thick) was selected, and a series of samples were prepared using a laser engraving system. Different engraving depths (dx: 0.05, 0.10, 0.15, 0.20 mm) and linewidth gradients were set for each group of samples. Wx / x: 0, 0.5, 1.0, 1.5 μm / mm).

[0054] b. Performance testing: Using a microcomputer-controlled electronic universal testing machine, a three-point bending test was performed on each specimen (span 20mm, loading speed 2mm / min), and its local elastic modulus (Ex) was calculated based on the load-displacement curve.

[0055] c. Data fitting: The measured Ex, dx, Wx / Substitute the x-data into the formula and use nonlinear regression analysis (such as the least squares method) to fit the data, and solve for the values ​​of α, β, and r that minimize the error between the fitted curve and the experimental data.

[0056] Based on the data fitting, for this specific polyurethane material, α = 0.35, β = 1.2, and r = 0.05. The goodness-of-fit coefficient R0 is... 2 A value > 0.99 indicates a highly accurate prediction of the elastic modulus after engraving. Further, by conducting parameter simulation process experiments on the same batch of polyurethane pipes, the actual engraving depth and linewidth under different laser parameter combinations were measured, thereby establishing a process database. Thus, in Example 1, the specific laser process parameters used were: power 15W, scanning speed 500mm / s, pulse frequency 40 kHz, and two engraving passes, achieving the target engraving depth of 0.12mm and linewidth of 20μm.

[0057] The outer surface is provided with a hydrophilic layer. In this embodiment, after laser engraving, a polyvinylpyrrolidone (PVP) hydrophilic coating is prepared on the outer surface of the conduit. The specific process is as follows: the engraved conduit is immersed in an 8 wt% PVP aqueous solution, and pulled at a uniform speed of 3 mm / s to ensure a uniform coating; after pulling, it is placed in a 70°C oven to dry for 45 minutes to allow the coating to crosslink and cure. After drying, the hydrophilic layer thickness is approximately 3 μm, providing durable lubrication without significantly affecting the conduit size.

[0058] The traction device used in step 1 is as follows: Figure 2 , Figure 3 and Figure 4As shown, the traction device includes two sets of transmission components 100 and a drive component 200. Each transmission component 100 includes a pair of main transmission pulleys 300 and multiple auxiliary transmission pulleys 400, with the auxiliary pulleys 400 positioned between the pair of main transmission pulleys 300. A transmission belt 500 is wound around the pair of main transmission pulleys 300 and the multiple auxiliary transmission pulleys 400. The two sets of transmission components are arranged symmetrically vertically to clamp the guide tube from both sides and pull it axially at a uniform speed through friction, ensuring stable guide tube speed and uniform tension of the braided yarns during the weaving process. The pair of main transmission pulleys are connected to the drive component 200 via a transmission shaft. The drive component includes a drive motor, which provides rotational power to the main transmission pulleys, thereby driving the transmission belt.

[0059] In this embodiment, the drive assembly is provided with multiple drive motors, and the output of the drive motors is directly connected to the drive shaft of the main drive wheel.

[0060] The transmission belt 500 is specifically as follows: Figure 3 and Figure 4 As shown, the system includes a wear-resistant layer 1 and a transmission layer 2. The wear-resistant layer is made of a hard material, and the transmission layer is made of an elastic material. The upper center of the transmission layer has a first mounting groove 3 containing multiple detachable wear-compensating strips 4. Each wear-compensating strip has a protrusion 5 at its top and a groove 6 at its bottom that matches the protrusion. The multiple wear-compensating strips are stacked vertically, such that the protrusion of the lower wear-compensating strip is inserted into the groove of the upper wear-compensating strip. The top of the protrusion is an outwardly protruding arc surface. The lower center of the transmission layer has a second mounting groove 7 containing multiple first U-shaped elastic elements 8 and multiple second U-shaped elastic elements 9 that match the first U-shaped elastic elements. The outer arc of the first U-shaped elastic element abuts against and connects with the outer arc of the second U-shaped elastic element. The top of the wear-resistant layer has a sliding groove 10, and the two ends of the second U-shaped elastic elements have sliders 11 that insert into the sliding groove. The second mounting groove is a bucket shape, narrower at the top and wider at the bottom. In this embodiment, the transmission wheel and auxiliary transmission wheel use friction transmission with the transmission belt.

[0061] Example 2 The difference between this embodiment and Embodiment 1 is that the conveyor belt in the traction device is as follows: Figure 5 As shown, the bottom of the protrusion is provided with a mounting groove, in which a deformation strip 12 made of a phase change material that deforms under heat is installed.

[0062] In this embodiment, when the temperature of the conveyor belt exceeds the phase change temperature of the deformation strip, the deformation strip changes from solid to liquid. This makes the protrusion of the wear compensation belt more elastic and the final deformation greater, allowing the wear compensation belt to grip the composite conduit better, resulting in a higher operating speed of the composite conduit and preventing slippage of the composite conduit.

[0063] The catheters from Example 1, after engraving and before engraving, were subjected to performance tests. The test methods included a three-point bending test (ASTM D790), a simulated blood vessel pushing friction test, and a minimum bending radius test. The results are shown in Table 1.

[0064] Table 1. Bending test of the conduit before and after engraving

[0065] As can be seen from the table, this invention can significantly reduce the bending stiffness of specific parts of the catheter through laser engraving, thereby greatly improving its passability and flexibility in tortuous blood vessels, verifying the effectiveness of personalized softness and stiffness control.

Claims

1. A personalized laser-engraved medical composite catheter, characterized in that, It includes an inner layer, an intermediate reinforcing layer, and an outer layer; the inner layer, intermediate reinforcing layer, and outer layer are integrally formed by hot pressing; The outer layer is laser-engraved with patterns that correspond to the tortuosity and hardness requirements of the catheter intervention path extracted from the patient's CT data.

2. The personalized laser-engraved medical composite catheter according to claim 1, characterized in that, The elastic modulus of the engraved pattern at point x on the outer layer of the medical composite catheter is calculated according to formula (1): （1） in, E x Let x be the elastic modulus at the location x of the conduit; E 0 The initial elastic modulus at point x of the conduit before carving. d x Let x be the engraving depth at the catheter. d max To the maximum permissible carving depth, w Let x be the engraving linewidth at the duct, and α, β, and r be material correction factors.

3. The personalized laser-engraved medical composite catheter according to claim 1, characterized in that, The engraving density gradient of the engraved pattern at position x on the outer layer of the medical composite catheter is calculated according to formula (2): （2） in, ▽S pattern (x) catheter x The engraving density gradient at the location, C vessel (x) The curvature function of the vessel to be intervened is extracted from the patient's CT data, where k is the catheter-vessel adaptation coefficient, with a value of 0.8 to 1.

2. It is a partial differential operator.

4. The personalized laser-engraved medical composite catheter according to claim 1, characterized in that, The inner layer is made of PTFE; the intermediate reinforcing layer is made of medical-grade stainless steel 316L or titanium-nickel alloy; the outer layer is made of any one or more composite materials selected from polyurethane, nylon, polyethylene, silicone rubber, and thermoplastic polyolefin elastomer. The inner layer has a thickness of 0.05~0.15mm; the middle reinforcing layer has a thickness of 0.03~0.3mm; and the outer layer has a thickness of 0.2~0.5mm. The outer layer thickness is greater than the maximum allowable engraving depth of the conduit + 0.05mm.

5. The personalized laser-engraved medical composite catheter according to claim 1, characterized in that, The outer surface is also provided with a hydrophilic layer of polyvinylpyrrolidone.

6. The personalized laser-engraved medical composite catheter according to claim 1, characterized in that, The intermediate reinforcing layer is made of woven metal wires with a diameter of 0.03mm to 0.08mm; the weaving density is 80 PPI to 120 PPI; and the weaving angle is 30° to 45° relative to the axis of the conduit.

7. The method for preparing a personalized laser-engraved medical composite catheter according to claim 1, characterized in that, Including the following steps: Step 1: Place the inner tube on the braiding device, and use the traction device to pull the metal braided wires evenly around the inner layer to obtain the intermediate reinforcement layer. Step 2: The catheter obtained in Step 1 is extruded and coated so that the outer layer covers the middle reinforcing layer; Step 3: Based on the tortuosity and hardness requirements of the catheter intervention path extracted from the patient's CT data, design corresponding engraving patterns. Step 4: Laser engrave the outer layer of the catheter obtained in Step 2 according to the engraving pattern to obtain the medical composite catheter.

8. The method for preparing a personalized laser-engraved medical composite catheter according to claim 7, characterized in that, The process parameters for laser engraving include: power 10W~30W, scanning speed 100mm / s~1000mm / s; pulse frequency 20kHz~80kHz; and engraving times 1~5 times.

9. The method for preparing a personalized laser-engraved medical composite catheter according to claim 1, characterized in that, The traction device includes at least two sets of transmission components and drive components; The transmission assembly includes a pair of main drive wheels and multiple auxiliary drive wheels, with the multiple auxiliary drive wheels located between the pair of main drive wheels. A transmission belt is wound around the pair of main drive wheels and the multiple auxiliary drive wheels. The two sets of transmission assemblies are arranged symmetrically up and down, and the pair of main drive wheels are connected to the drive assembly via a transmission shaft.

10. The method for preparing a personalized laser-engraved medical composite catheter according to claim 9, characterized in that, The transmission belt includes a wear-resistant layer and a transmission layer. The wear-resistant layer is made of a hard material, and the transmission layer is made of an elastic material. The upper center of the transmission layer is provided with a first mounting groove. In the first mounting groove, there are multiple detachable wear-compensating belts. The top of the wear-compensating belt is provided with a protrusion, and the bottom is provided with a groove that matches the protrusion. The multiple wear-compensating belts are stacked together, so that the protrusion of the lower wear-compensating belt is inserted into the groove of the upper wear-compensating belt. The top of the protrusion is an outwardly protruding arc surface. The lower center of the transmission layer is provided with a second mounting groove. The second mounting groove is provided with a plurality of first U-shaped elastic elements and a plurality of second U-shaped elastic elements adapted to the first U-shaped elastic elements. The outer side of the bow portion of the first U-shaped elastic element and the outer side of the bow portion of the second U-shaped elastic element abut against each other and are connected together. The top of the wear-resistant layer is provided with a groove, and the two ends of the second U-shaped elastic element are provided with sliders that are inserted into the groove.

Images