Preparation method of medical hollow catheter with zebra stripe pattern

Abstract

The invention belongs to the technical field of medical catheter manufacturing, and particularly relates to a preparation method of a medical hollow catheter with a zebra stripe pattern, and the preparation method comprises the following steps: (1) coloring a thermoplastic polymer, carrying out extrusion molding, and cutting to obtain a strip with the width of 0.5-2mm; (2) selecting two strips with different colors, and uniformly winding the strips on the surface of the core rod under constant tension according to a spiral winding angle of 30-70 degrees to obtain a catheter with a zebra stripe pattern; (3) heating the catheter with the zebra stripe pattern; (4) shaping the heated conduit by using a scraping tool; (5) cooling the shaped catheter to cure and shape the zebra pattern; and (6) the zebra pattern is slipped off from the core rod, and the hollow catheter with the zebra pattern is obtained. By accurately controlling the winding angle and the strip width, the spatial frequency of the zebra pattern is matched with a sensing area which is most sensitive to human eyes, and the intraoperative visibility is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical catheter manufacturing, and particularly relates to a preparation method of a medical hollow catheter with a zebra pattern. Background Art

[0002] In the field of modern medical surgery, medical catheters, as a key auxiliary tool, are widely used in various complex surgical operations. However, the visual recognition problem of existing medical catheters during surgery has become increasingly prominent. Especially when facing complex internal passageways, it is difficult to quickly and accurately determine the position and direction of the catheter, which not only greatly affects the surgical efficiency but also may pose potential risks to surgical safety. In order to improve the visibility of the catheter, existing research has tried to use methods such as color marking or fluorescence treatment, but these methods have exposed many problems in practical applications, such as complex manufacturing processes, high costs, and poor durability, and are difficult to meet the high requirements of clinical catheter performance. Therefore, there is an urgent need for a catheter preparation method with clear structure, simple manufacturing, and good visual feedback.

[0003] Regarding the current application status of catheters, firstly, the preparation of catheter patterns mostly uses surface printing or dyeing treatment. Although the surface printing method can achieve diversified pattern design, in the actual use process, due to the frequent friction, bending and other complex movements of the catheter in the internal passageway, the pattern is extremely easy to wear, and its wear resistance and stability are seriously insufficient, and it is impossible to maintain a clear visual effect for a long time. And the dyeing treatment faces problems such as complex process and poor compatibility with catheter materials, and it is difficult to achieve a uniform and stable dyeing effect on catheters of different materials, thereby affecting the overall performance and quality of the catheter. Secondly, in traditional catheter design, as a common visual recognition pattern, the setting of the angle and width parameters of the zebra pattern is relatively arbitrary, lacking systematicness and theoretical basis. This arbitrariness makes it difficult for the zebra pattern to achieve the best visual effect, unable to fully play its function of assisting in judging the position and direction of the catheter during surgical operations, and at the same time bringing difficulties to the standardized production of catheters, and it is difficult to achieve large-scale and high-quality mass production.

[0004] In summary, there are many problems to be solved in the visual recognition of existing medical catheters, and their pattern preparation methods and zebra pattern designs are difficult to meet the requirements of efficient and safe operation of catheters in clinical surgery. Therefore, developing a catheter preparation method with a more stable structure, clearer pattern, better visual feedback and capable of mass production with a zebra structure has become an important research direction in the current field of medical engineering, and is of great significance for improving the surgical quality and ensuring patient safety. Summary of the Invention

[0005] In view of the problems and deficiencies in the prior art, the present invention aims to provide a method for preparing a medical hollow catheter with a zebra pattern.

[0006] To achieve the object of the present invention, the technical solution adopted by the present invention is as follows:

[0007] The present invention provides a method for preparing a medical hollow catheter with a zebra pattern, comprising the following steps:

[0008] (1) Color the thermoplastic polymer, extrude and cut it into thermoplastic polymer strips with a width of 0.5 - 2 mm;

[0009] (2) Select two thermoplastic polymer strips of different colors and evenly wind them onto the surface of the mandrel at a spiral winding angle of 30° - 70° under a constant tension to obtain a catheter with a zebra pattern;

[0010] (3) Heat-treat the catheter with a zebra pattern;

[0011] (4) Use a scraping tool to shape the heat-treated catheter to achieve compaction and flatness of the pattern;

[0012] (5) Cool the shaped catheter to solidify and fix the zebra pattern;

[0013] (6) Slide the solidified and fixed zebra pattern off the mandrel to obtain a medical hollow catheter with a zebra pattern.

[0014] Preferably, the width of the thermoplastic polymer strip in step (1) is 1.0 ± 0.3 mm.

[0015] Preferably, the winding angle in step (2) is 45° ± 15°.

[0016] Preferably, the tension in step (2) is 0.1 - 0.5 N and the winding speed is 10 - 50 rpm.

[0017] Preferably, the thermoplastic polymer in step (1) is one or more of polyurethane (PU), thermoplastic polyurethane elastomer (TPU), and polyether block amide (PEBA).

[0018] Preferably, the mandrel in step (2) is one of a stainless steel mandrel, a nitinol alloy mandrel, and a polyether ether ketone (PEEK) mandrel, and the diameter of the mandrel should match the inner diameter of the catheter.

[0019] Preferably, the thermoplastic polymer in step (1) is colored using a masterbatch, and the masterbatch used is a thermoplastic carrier-type masterbatch compatible with the thermoplastic polymer used, and the color is one of black, white, yellow, and blue to improve the visual contrast and recognition of the final catheter zebra pattern.

[0020] Preferably, the thickness of the thermoplastic polymer strip is 0.1 - 0.3 mm.

[0021] Preferably, the temperature of the heat treatment in step (3) is 90 - 160 °C, and the time is 1 - 3 min.

[0022] Preferably, the temperature of the shaping in step (4) is 50 - 80 °C, and the pressure is 1 - 3 N.

[0023] Preferably, the scraping tool in step (4) is a scraper.

[0024] Preferably, the cooling method in step (5) is water cooling or air cooling.

[0025] The present invention also provides a medical hollow catheter with a zebra pattern prepared by the above preparation method.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] (1) By using a two-color thermoplastic polymer strip to alternately wind around the core material to form a zebra pattern, the pattern is integrated with the catheter body, having good wear resistance and clarity, and avoiding the problems of unclear pattern printing and poor wear resistance in the traditional method.

[0028] (2) By setting the winding angle θ to 30° - 70° and the strip width d to 0.1 - 0.3 mm, the spatial frequency of the zebra pattern matches the most sensitive perception area of the human eye (the peak area of the human eye spatial contrast sensitivity curve CSF, 0.3 - 3 cycles / mm), so as to improve the visual clarity of the catheter during the operation and the visual feedback ability of the operator.

[0029] (3) The process of the present invention details the complete process flow from strip preparation, cutting, winding, heat treatment, scraper shaping to cooling and setting, with clear parameter control, applicable to various hollow catheter structures, and facilitating industrial promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a process flow chart of a medical hollow catheter with a zebra pattern;

[0031] Figure 2 is a preparation diagram of a medical hollow catheter with a zebra pattern, where 1 is a mandrel, 2 and 3 are strips of different colors, 4 is a heat treatment device, 5 is a scraper structure, and 6 is cooling and setting;

[0032] Figure 3 is a two-dimensional schematic diagram of the spiral winding structure of the zebra strip in Examples 1 - 6;

[0033] Figure 4Magnified view of the surface zebra stripe pattern structure of the finished catheter prepared in Example 1;

[0034] Figure 5 SEM image of the splicing joint of two different color thermoplastic polymer strips in Example 1;

[0035] Figure 6 Superposition diagram of the spatial frequency distribution map of the zebra stripe pattern of the vacuum catheter prepared in Example 4 and the human eye contrast sensitivity curve. The blue curve represents the spatial frequency energy distribution of the zebra stripe pattern of the catheter of the present invention under specific strip width and winding angle conditions, and the red curve represents the human eye CSF curve. Detailed implementation manners

[0036] Preparation of a medical hollow catheter with a zebra stripe pattern in Example 1

[0037] A preparation method of a medical hollow catheter with a zebra stripe pattern, and the process is as Figure 1 shown. The specific steps are as follows:

[0038] (1) Using thermoplastic polyurethane elastomer (TPU) as the matrix material, adding 1 wt% of black masterbatch (mainly composed of carbon black and polyester carrier system) and 1 wt% of yellow masterbatch (mainly composed of pigment yellow 93 and polyester carrier) respectively to make the TPU show black and yellow. Extrude and mold the colored thermoplastic polymer, and cut to obtain a black thermoplastic polymer strip A with a width of 1 mm and a thickness of 0.3 mm and a yellow thermoplastic polymer strip B;

[0039] (2) For the black thermoplastic polymer strip A and the yellow thermoplastic polymer strip B obtained in step (1), at a spiral winding angle of 30°, under the action of a tension control system, maintain a constant tension of 1.0 - 1.5 N, and wind the strips onto the surface of a stainless steel mandrel (outer diameter of 2.0 mm, surface finish Ra ≤ 0.2 μm) at a winding speed of 60 rpm to obtain a catheter with a zebra stripe pattern. The strips should closely adhere to the surface of the mandrel without overlapping or wrinkling, forming a visually regular and clear zebra stripe pattern. The process is as Figure 2 shown;

[0040] (3) Place the catheter with the zebra stripe pattern in a hot air furnace for heat treatment to soften and fuse the thermoplastic polymer strips and firmly adhere them to the surface of the mandrel. The heating temperature is 110 °C and the heating time is 1 - 3 min;

[0041] (4) Gently press the surface of the heat-treated catheter with a scraper mechanism to compact and level the strip structure, improving the pattern clarity and the consistency of the catheter surface. The temperature of the scraper is controlled at 90 °C and the applied pressure is 3.0 N;

[0042] (5) Cool the catheter after the scraper shaping using a water-cooling method to solidify and shape the molten polymer, and stably retain the zebra stripe pattern on the surface;

[0043] (6) Slip the zebra stripe pattern off the mandrel to obtain a medical hollow catheter with a zebra stripe pattern, which can be further processed such as cutting, sealing the ends, and sterilization.

[0044] Preparation of a medical hollow catheter with a zebra stripe pattern in Example 2

[0045] The content of Example 2 is basically the same as that of Example 1, and the differences are as follows: in step (1), the width of the thermoplastic polymer strip is 1 mm, and in step (2), the winding angle is 45°.

[0046] Preparation of a medical hollow catheter with a zebra stripe pattern in Example 3

[0047] The content of Example 3 is basically the same as that of Example 1, and the differences are as follows: in step (1), the width of the thermoplastic polymer strip is 1 mm, and in step (2), the winding angle is 70°.

[0048] Preparation of a medical hollow catheter with a zebra stripe pattern in Example 4

[0049] The content of Example 4 is basically the same as that of Example 1, and the differences are as follows: in step (1), the width of the thermoplastic polymer strip is 2 mm, and in step (2), the winding angle is 30°.

[0050] Preparation of a medical hollow catheter with a zebra stripe pattern in Example 5

[0051] The content of Example 5 is basically the same as that of Example 1, and the differences are as follows: in step (1), the width of the thermoplastic polymer strip is 2 mm, and in step (2), the winding angle is 45°.

[0052] Preparation of a medical hollow catheter with a zebra stripe pattern in Example 6

[0053] The content of Example 6 is basically the same as that of Example 1, and the differences are as follows: in step (1), the width of the thermoplastic polymer strip is 2 mm, and in step (2), the winding angle is 70°.

[0054] The two-dimensional schematic diagrams of the spiral winding structures of the zebra stripe strips in Examples 1 to 6 are as Figure 3 shown, where Figure 3 A corresponds to Example 1, Figure 3 B corresponds to Example 2, Figure 3 C corresponds to Example 3, Figure 3 D corresponds to Example 4, Figure 3 E corresponds to Example 5, Figure 3 F corresponds to Example 6.Figure 3 It shows a two-dimensional schematic diagram of the stripe composed of two thermoplastic polymers of different colors, with a width of 0.5 - 2 mm, helically wound around the surface of the mandrel at an angle of 30° - 70° under constant tension control, and the uniform arrangement of the zebra stripes on the catheter.

[0055] The finished product of the medical hollow catheter with zebra stripe pattern prepared in Example 1, the enlarged structure diagram is as Figure 4 shown, by Figure 4 it can be seen the regularity and continuity of the zebra stripe arrangement, and the clarity and uniformity of the pattern.

[0056] Test experiments

[0057] 1. Scanning electron microscope test

[0058] For the medical hollow catheter with zebra stripe pattern prepared in Example 1, scanning electron microscope test was carried out on the splicing joint of two thermoplastic polymer strips with different colors. The results are as Figure 5 shown, where Figure 5 A is the interface of two strips on the outer surface (pointed by the arrow), Figure 5 B is the interface of two strips on the inner surface (pointed by the arrow), Figure 5 C is the interface of two strips at the cross-section (pointed by the arrow). By Figure 5 it can be seen that the structure in the joint area is continuous, without obvious delamination or pores, and the material interface is well fused. This joint structure helps to maintain the continuity of the pattern and the overall structural stability, and ensures the reliability and consistency of the catheter product in clinical use.

[0059] 2. Fourier analysis verification

[0060] Fourier analysis verification was carried out on the catheter sample with zebra stripe pattern prepared in Example 4. The specific process is as follows:

[0061] (1) Sample preparation: Select typical winding parameters to prepare a catheter sample with zebra stripe pattern;

[0062] (2) Image acquisition: Use a high-resolution digital camera to take a frontal view of the catheter surface under uniform natural light conditions, ensure that the image is clear, in focus, and contains enough stripe periods;

[0063] (3) Image preprocessing: Convert the captured image into a grayscale image, crop the rectangular area containing the typical stripe area, and perform histogram equalization and high-pass filtering to enhance the texture edges;

[0064] (4) Frequency domain transformation: Use two-dimensional fast Fourier transform (2D-FFT) to transform the processed image into the frequency domain, obtain the power spectrum diagram, and extract the one-dimensional frequency intensity distribution curve from the center of the spectrum to the stripe arrangement direction;

[0065] (5) Unit conversion and analysis: Combining with the actual scale information of the image (calibrated by attaching a scale during shooting or a known-size area), convert the unit of the horizontal axis of the spectrum from pixel frequency (cycles / pixel) to spatial frequency (cycles / mm); it can be observed from the spectrum diagram that the frequency-domain energy is mainly concentrated in the range of 0.3 - 3 cycles / mm, and this frequency range corresponds to the human eye's contrast-sensitive area, indicating that the zebra stripe pattern on the catheter surface has good visual feedback characteristics.

[0066] Overlay and compare the spatial frequency distribution curve of the zebra stripe pattern of the vacuum catheter prepared in Example 4 of the present invention with the human eye contrast sensitivity curve (CSF). The results are as Figure 6 shown. The human eye contrast sensitivity curve describes the sensitivity of the human eye to detect the pattern contrast at different spatial frequencies. From Figure 6 it can be seen that the main frequency components of the zebra stripes exactly fall within the sensitive area of the CSF curve (usually the medium spatial frequency range of 3 - 10 cpd), indicating that the designed zebra stripes can provide a strong contrast and recognition in vision. This helps to improve the visual feedback and accuracy during surgical operations, and at the same time improves the tactile feedback and mechanical properties of the guide wire during operation.

[0067] Preparation of a medical hollow catheter with a zebra stripe pattern in Comparative Example 1

[0068] Comparative Example 1 is basically the same as Example 2, and the differences are as follows: in step (1), the width of the thermoplastic polymer strip is 3 mm, and in step (2), the winding angle is 45°.

[0069] Preparation of a medical hollow catheter with a zebra stripe pattern in Comparative Example 2

[0070] Comparative Example 2 is basically the same as Example 2, and the differences are as follows: in step (1), the width of the thermoplastic polymer strip is 1 mm, and in step (2), the winding angle is 15°.

[0071] Preparation of a medical hollow catheter with a zebra stripe pattern in Comparative Example 3

[0072] Comparative Example 3 is basically the same as Example 2, and the differences are as follows: in step (1), the width of the thermoplastic polymer strip is 1 mm, and in step (2), the winding angle is 80°.

[0073] Test the medical hollow catheters with zebra stripe patterns prepared in Example 2 and Comparative Examples 1 - 3. The results are shown in Table 1 below.

[0074] Table 1 Comparison of medical hollow catheters with zebra stripe patterns prepared in Example 2 and Comparative Examples 1 - 3

[0075]

[0076] As can be seen from Table 1, when the winding angle is lower than 30° or higher than 70°, or the strip width exceeds 2 mm or is less than 0.5 mm, the spatial frequency distribution of the obtained pattern deviates from the contrast sensitive frequency band of the human eye, resulting in a decrease in visual recognition ability, and the pattern is blurred or too dense or too sparse, making it difficult to achieve rapid intraoperative recognition. Through the collaborative optimization of the angle and width parameters in the embodiments of the present invention, the frequency domain energy is effectively concentrated in the visual sensitive area of 0.5 - 3 lines / mm, significantly improving the pattern recognition and operation controllability of the catheter.

[0077] The experimental results show that the zebra stripe structure design parameters proposed by the present invention can effectively make the stripe pattern on the catheter surface fall within the optimal frequency range perceived by the human eye in terms of spatial frequency, thereby significantly improving the visual visibility and recognition efficiency during clinical operations.

Claims

1. A preparation method of a medical hollow catheter with a zebra stripe pattern, characterized in that, It includes the following steps: (1) Color the thermoplastic polymer, extrude and shape it, and cut it to obtain a thermoplastic polymer strip with a width of 0.5 - 2 mm; (2) Select two thermoplastic polymer strips with different colors, and evenly wind them onto the surface of the mandrel at a spiral winding angle of 30° - 70° under a constant tension to obtain a catheter with a zebra pattern; (3) Heat-treat the catheter with a zebra pattern; (4) Use a scraping tool to shape the heat-treated catheter to achieve compaction and flatness of the pattern; (5) Cool the shaped catheter to solidify and fix the zebra pattern; (6) Slide the solidified and fixed zebra pattern off the mandrel to obtain a medical hollow catheter with a zebra pattern.

2. The preparation method according to claim 1, wherein The tension in step (2) is 0.1 - 0.5 N, and the winding speed is 10 - 50 rpm.

3. The preparation method according to claim 1, wherein, The thermoplastic polymer in step (1) is one of polyurethane, thermoplastic polyurethane elastomer, and polyether block amide.

4. The preparation method according to claim 3, wherein, The mandrel in step (2) is one of a stainless steel mandrel, a nitinol alloy mandrel, and a polyether ether ketone mandrel.

5. The preparation method according to claim 3, characterized in that The thickness of the thermoplastic polymer strip in step (1) is 0.1 - 0.3 mm.

6. The preparation method according to claim 5, characterized in that, The temperature of the heat treatment in step (3) is 90 - 160 °C, and the time is 1 - 3 min.

7. The preparation method according to claim 6, characterized in that, The temperature of the shaping in step (4) is 50 - 80 °C, and the pressure is 1 - 3 N.

8. A medical hollow catheter with a zebra pattern prepared by using the preparation method according to claims 1 - 7.

Images