Medical hypotube and hypotube manufacturing method

Abstract

The invention provides a hypotube and a preparation method thereof, and belongs to the field of medical instruments. Comprising the steps that nickel-titanium alloy serves as a raw material and is subjected to heat treatment till the inner wall of the nickel-titanium alloy pipe becomes black; a near-end cutting area and a far-end cutting area which are formed are sequentially connected in the axis direction of the wave tube, a plurality of notch grooves are formed in the tube body of the wave tube, the distance between the notch grooves is gradually increased from the near-end cutting area to the far-end cutting area in the axis direction, and the width of the inner side of a notch of each notch groove is larger than the width of the outer side of the notch of each notch groove; and pickling the laser-cut pipe body. The defect that in the prior art, the bending radius is insufficient is overcome, and the medical accident risk that the hypotube is bent and broken in the intravascular conveying process is effectively reduced. According to the invention, the overall durability of the hypotube can be ensured while the production efficiency is improved.

Description

Technical Field

[0001] The present invention belongs to the field of medical devices, and more specifically, relates to a medical hypotube. The present invention also relates to a method for manufacturing the hypotube. Background Art

[0002] Medical devices refer to various tools and equipment used to prevent, diagnose, treat or alleviate diseases. They can be divided into multiple categories, such as diagnostic equipment (such as X-ray machines, ultrasound machines, etc.), treatment equipment (such as surgical knives, laser instruments, medical intervention guidewires, etc.), monitoring equipment (such as electrocardiographs, blood pressure monitors, etc.) and support equipment (such as ventilators, wheelchairs, etc.). Medical devices play a key role in medical intervention. Through precise technology and design, they help medical staff perform various treatments and surgical operations, improve treatment effects and patients' quality of life.

[0003] Among them, medical interventional guidewires are generally divided into the following parts: guidewire tip, guidewire body, guidewire core wire and coating lubricant. Among them, the design of the guidewire tip plays a more important role in the overall mechanical properties of the guidewire. For example, it guides and passes the entire guidewire in blood vessels and tissues, and guides the guidewire tip to position the guidewire to a specific target location, such as at the lesion site or treatment area. The shape and markings of the guidewire tip can help doctors navigate accurately and avoid any potential dangers. The guidewire tip helps doctors advance the guidewire to the target location by supporting the guidewire body and providing propulsion, which is crucial for passing through complex vascular anatomical structures and lesion locations. The guidewire tip is mainly composed of a hypotube, which has the following functions: 1. Provide stable support for the guidewire to prevent it from bending or twisting, and ensure accurate navigation and operation of the guidewire in the blood vessel; 2. The material and structural design of the hypotube can increase the strength and durability of the guidewire, enabling it to withstand the pressure and torsional force in the blood vessel and reduce the risk of breakage and deformation; 3. The design of the hypotube can balance the hardness and flexibility of the guidewire, allowing the guidewire to flexibly pass through the blood vessel while maintaining sufficient rigidity for precise operation; 4. Guidance: The support and guidance functions provided by the hypotube can help doctors accurately position and operate the guidewire, improving the accuracy and success rate of the operation.

[0004] In the prior art, due to the limitation of the manufacturing process of the hypotube, the bending radius of the hypotube is insufficient, the elasticity is poor, and the fatigue resistance is poor. Due to the problem of fatigue resistance, the tip of the guide wire (i.e., the hypotube) is easily bent and broken during the intravascular delivery of the hypotube, thus causing medical accidents. Summary of the invention

[0005] The main purpose of the present application is to provide a medical hypotube to make up for the defect of insufficient bending radius in the prior art, and to have good anti-fatigue performance, so as to effectively reduce the risk of medical accidents such as bending and rupture of the hypotube during intravascular delivery.

[0006] Another object of the present application is to provide a method for manufacturing the above-mentioned medical hypotube to improve production efficiency while ensuring the overall durability of the hypotube.

[0007] In order to achieve the above-mentioned purpose, the present application proposes a medical hypotube, comprising: a proximal cutting area and a distal cutting area connected in sequence along the axis direction of the hypotube, a plurality of grooves are provided on the body of the hypotube, the spacing of the grooves gradually increases from the proximal cutting area to the distal cutting area along the axis direction, and the inner width of the groove opening is greater than the outer width.

[0008] Furthermore, the grooves are arranged in a spiral shape along the axis of the tube body.

[0009] Furthermore, the interval between two adjacent grooves gradually changes from the proximal cutting area to the distal cutting area along the axis in the range of 0.03 to 0.3 um.

[0010] Furthermore, the width of the groove is 0.01-0.03 um.

[0011] Furthermore, the diameter of the hypotube is 0.28-0.40 mm.

[0012] Furthermore, the wall thickness of the hypotube is 0.048-0.053 mm.

[0013] Furthermore, the material of the hypotube is a nickel-titanium alloy tube.

[0014] The present application also proposes a method for manufacturing a hypotube, comprising the following steps: A nickel-titanium alloy tube with a nearly equal atomic ratio is used as a raw material, and the raw material is heat-treated until the inner surface of the nickel-titanium alloy tube turns black; Laser cutting is performed on the heat-treated tube body: a groove is formed by spiral cutting along the axial direction of the tube body, and the groove is cut along a direction inclined to the tube body so that the inner width of the groove is greater than the outer width; The tube body after laser cutting is pickled, and the pickling time is not less than 240s.

[0015] Furthermore, during the heat treatment, argon or nitrogen is first introduced into the heat treatment equipment as a protective gas, the air in the heat treatment equipment is exhausted, and then oxygen is introduced into the inner cavity of the nickel-titanium alloy tube until the inner surface of the nickel-titanium alloy tube turns black.

[0016] Furthermore, the process parameters of the heat treatment are: heat treatment time is 10 to 40 seconds, temperature is 700 to 900°C; The laser cutting process parameters are: femtosecond laser 1000-1100nm, spot diameter 10-40um, focal length ±0.1mm, single pulse energy 1.0-6.0uJ, repetition frequency: 100k-600kHz; The pickling solution is a mixed solution of 3% to 5% hydrofluoric acid, 18% to 22% nitric acid, and 73% to 79% ionized water by volume.

[0017] The medical hypotube proposed by the present invention has the following beneficial effects: The hypotube provided by the present invention can make up for the defect of insufficient bending radius in the prior art, and has good anti-fatigue performance, which can effectively reduce the risk of medical accidents such as bending and rupture of the hypotube during intravascular delivery.

[0018] The method for manufacturing a hypotube proposed in the present invention has the following beneficial effects: The method for manufacturing a hypotube provided by the present invention can improve production efficiency while ensuring the overall durability of the hypotube. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the structure of a medical hypotube of the present invention; Figure 2 A diagram showing the positional relationship between the wedge-shaped structure of the present invention and the inner and outer surfaces of the hypotube; Figure 3 This is a standard tensile curve diagram of the original nickel-titanium alloy tube of the present invention; Figure 4 is a standard tensile curve diagram of the nickel-titanium alloy of the present invention after heat treatment; Figure 5 This is a light microscope image of the hypotube of the present invention without heat treatment; Figure 6 This is an optical microscope image of the hypotube of the present invention after heat treatment.

[0020] In the figure, 1, hypotube, 11, proximal cutting area, 12, distal cutting area, 13, groove, 131, wedge-shaped structure, 14, inner surface of hypotube, 15, outer surface of hypotube. DETAILED DESCRIPTION

[0021] The embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

[0022] The following describes the embodiments of the present disclosure through specific examples, and those skilled in the art can easily understand other advantages and effects of the present disclosure from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all of the embodiments. The present disclosure can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present disclosure. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present disclosure.

[0023] Example refer to Figure 1-2 As shown, the hypotube includes: a proximal cutting area 11 and a distal cutting area 12 which are cut and formed in sequence along the axis direction of the hypotube 1, and the length of the distal cutting area 12 is less than the length of the proximal cutting area 11. Among them, a plurality of grooves 13 distributed in a spiral shape along the axis are cut on the body of the hypotube 1, and the spacing between two adjacent grooves 13 gradually increases from the proximal cutting area 11 to the distal cutting area 12 along the axis direction, and the gradient range is 0.03 to 0.3um. By changing the spacing between the grooves 13, the strength of the proximal end of the hypotube is ensured and the distal end meets the bending radius requirements. The body of the hypotube 1 is a hollow tubular structure.

[0024] Specifically, refer to Figure 2 , the cross section of the groove 13 is a wedge-shaped structure 131. The wedge-shaped structure 131 is a notch cut by the groove 13, and the spacing of the notches is larger at one end close to the inner surface 14 of the sea wave tube 1 than at one end close to the outer surface 15 of the sea wave tube 1, that is, the overall structure is roughly a trapezoidal structure. The transverse wedge-shaped structure 131 enhances the bending performance of the tube body, and can ensure that the tube body has good durability and shape retention. Cutting the entire tube body achieves a softer and proximal strong support effect, providing better anti-fatigue performance. The grooves are arranged in a spiral shape along the axial direction of the sea wave tube 1, and its spiral cutting pattern makes the laser processing have high production efficiency.

[0025] In this embodiment, since the hypotube 1 travels in the blood vessel, the length of the hypotube 1 should not be too short or too long. After many experiments and tests, it is concluded that the diameter of the hypotube 1 is 0.28-0.40 mm, which is the best and reasonable range. In order to reduce the friction between the hypotube 1 and the blood vessel wall and the friction between the hypotube 1 and the catheter wall, a hypotube 1 with a wall thickness of 0.048-0.053 mm is selected. Figure 5The structure of the hypotube 1 under the electron microscope photo. In this embodiment, the main reasons for selecting nickel-titanium alloy pipes for the hypotube 1 are as follows: First, nickel-titanium alloy has excellent superelasticity, can withstand frequent bending and expansion in medical equipment, and can quickly restore its original shape and is not easy to deform permanently. Secondly, nickel-titanium alloy has good corrosion resistance and can resist the erosion of liquids and chemical and biological elements in the body, which makes it have strong stability. In addition, nickel-titanium alloy can also maintain its excellent mechanical properties at body temperature and is suitable for application scenarios in contact with the human body. After many experimental tests, the end of the notch close to the inner surface 14 of the hypotube 1 is at an obtuse angle to the tangent of the inner surface 14 of the hypotube 1. When the obtuse angle is less than or equal to 120°, its mechanical properties achieve the best effect, that is, the anti-fatigue performance is in the best state. It should be noted that after many experimental tests, when the width of the groove 13 is in the range of 0.01 to 0.03um, it can ensure that the hypotube 1 has a sufficient bending radius.

[0026] In order to facilitate the production of the above-mentioned hypotube and improve production efficiency, the present invention also proposes a method for manufacturing a hypotube, comprising the following steps: Step 1: Using nickel-titanium alloy tubes with nearly equal atomic ratios as raw materials, the raw materials are subjected to heat treatment process. The specific process steps are as follows: First, argon or nitrogen is introduced into the heat treatment equipment as a protective gas, and the air in the heat treatment equipment is exhausted. Then, oxygen is introduced into the inner cavity of the nickel-titanium alloy tube for oxidation treatment, that is, oxygen is injected into the wall of the nickel-titanium alloy tube using a micro-injector until the inner surface of the nickel-titanium alloy tube turns black (such as Figure 6 The heat treatment process parameters are as follows: heat treatment time is 10 to 40 seconds and temperature is 700 to 900 °C.

[0027] In this step, the purpose of oxidation is to make it easier to cut at the internal oxide layer during subsequent laser cutting, thereby eventually forming a trapezoidal notch structure. After this heat treatment process, the mechanical properties and thermal stability of the nickel-titanium alloy tube are significantly improved, and its tensile strength, yield strength and other mechanical performance indicators are improved.

[0028] Step 2: Laser cutting the heat-treated tube body: spiral cutting along the axial direction of the tube body to form a groove, and cutting along the direction inclined to the tube body so that the inner width of the groove is greater than the outer width. The cutting angle range is 1° to 10°, and the laser cutting process parameters are: femtosecond laser 1000 to 1100nm, spot diameter 10 to 40um, focal length ±0.1mm, single pulse energy 1.0 to 6.0uJ, repetition frequency: 100k to 600kHz.

[0029] In this step, a groove is formed by spiral cutting along the axial direction of the tube body, and the inner width of the groove is greater than the outer width. This special design enables the groove to disperse stress more effectively when subjected to external force, thereby improving the overall strength and toughness of the tube body. By precisely controlling the single pulse energy (1.0~6.0uJ) and repetition frequency (100k~600kHz), the heat-affected zone during the cutting process can be minimized to avoid unnecessary damage to the tube body material. In addition, the non-contact processing method of laser cutting also reduces the mechanical stress and vibration generated during the cutting process, further improving the cutting quality.

[0030] Step 3: The laser-cut tube body is pickled to obtain a finished product, wherein the pickling solution is a mixed solution of 3% to 5% hydrofluoric acid, 18% to 22% nitric acid, and 73% to 79% ionized water by volume, and the pickling time is not less than 240 seconds.

[0031] In this step, pickling can remove carbides and tiny metal particles generated during laser cutting, making the surface of the tube smoother and cleaner. This not only improves the aesthetics of the tube, but more importantly, reduces the adverse effects of surface defects on the performance of the tube, such as reducing the friction coefficient and improving corrosion resistance. Among them, nitric acid mainly plays the role of oxidation and dissolution in the pickling solution, which can further remove impurities and uneven parts on the metal surface, and work together with hydrofluoric acid to significantly improve the cleaning ability of the pickling solution. Deionized water, as a solvent, can dilute the concentration of hydrofluoric acid and nitric acid, making the pickling solution milder while maintaining the stability and uniformity of the pickling solution. Among them, the preferred volume percentage of the pickling solution is: a mixed solution of 4% hydrofluoric acid, 20% nitric acid, and 76% deionized water. At this time, the tube body of the hypotube 1 is pickled with the above-mentioned pickling solution, and the metal surface is cleaner and more uniform, which is conducive to the attachment of subsequent coatings or plating.

[0032] Experimental example In order to further illustrate that the hypotube manufactured by the hypotube manufacturing method of the present invention has better mechanical properties, the following mechanical property test experiment is hereby taken: like Figure 3-4 As shown, tensile tests were performed on the original nickel-titanium alloy tube and the heat-treated nickel-titanium alloy using a mechanical instrument, and tensile curves were drawn.

[0033] Figure 3 This is the standard tensile curve of the original nickel-titanium alloy tube. The first inflection point in the figure is the yield point of the alloy material. For nickel-titanium alloy materials, this is the area where pseudoplastic deformation of the material begins to occur. The deformation amount marked in the figure is %, and the platform represents the area of ​​plastic deformation of nickel-titanium alloy, which represents the elastic range of nickel-titanium alloy. After one cycle, it breaks after deforming to about 16% of its own shape, and its fracture strength is about 1243 Mpa.

[0034] Figure 4 is the standard tensile curve of nickel-titanium alloy after heat treatment, which is similar to Figure 3 Compared with the middle curve, the tensile stress corresponding to the yield point of the platform is lower than 400 MPa, and the fracture strength is about 923 MPa, which means that the material becomes softer after heat treatment. After one cycle, the tensile strain corresponding to the fracture strength increases to 43%. The toughness of the material is significantly increased after heat treatment.

[0035] Figure 5 This is a cross-sectional view of a nickel-titanium alloy tube that has not been heat treated (optical microscope image). Figure 6 This is a cross-sectional view (optical microscope view) of a heat-treated nickel-titanium alloy tube. Figure 6 and Figure 5 For comparison, Figure 6 The cross-sectional surface color is relatively dark, while the outer wall color is uniformly bright, which indicates that the method for manufacturing the hypotube provided by the present invention can make the inner wall uniformly oxidized while protecting the outer surface of the tube from oxidation.

[0036] The above is only for explaining the implementation mode of the present invention and is not intended to limit the present invention. For those skilled in the art, any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention without creative work should be included in the protection scope of the present invention.

Claims

1. A medical hypotube, characterized in that: include: The proximal cutting area and the distal cutting area are sequentially connected and formed along the axis direction of the sea wave tube. A plurality of grooves are arranged on the tube body of the sea wave tube. The spacing of the grooves increases gradually from the proximal cutting area to the distal cutting area along the axis direction. The inner width of the groove opening is greater than the outer width.

2. A medical hypotube according to claim 1, characterized in that: The grooves are arranged in a spiral shape along the axis direction of the tube body.

3. A medical hypotube according to claim 1, characterized in that: The interval between two adjacent grooves gradually changes from the proximal cutting area to the distal cutting area along the axis to a range of 0.03 to 0.3 um.

4. A medical hypotube according to claim 1, characterized in that: The width of the groove is 0.01-0.03 um.

5. A medical hypotube according to claim 1, characterized in that: The diameter of the hypotube is 0.28-0.40 mm.

6. A medical hypotube according to claim 1, characterized in that: The wall thickness of the hypotube is 0.048-0.053 mm.

7. A medical hypotube according to claim 1, characterized in that: The material of the hypotube is nickel-titanium alloy tube.

8. A method for manufacturing a hypotube, characterized in that: The steps include: Step 1: Using a nickel-titanium alloy tube with a nearly equal atomic ratio as a raw material, heat treating the raw material until the inner surface of the nickel-titanium alloy tube turns black; Step 2: Laser cutting the heat-treated tube body: cutting the tube body in a spiral along the axial direction to form a groove, and cutting in a direction inclined to the tube body so that the inner width of the groove is greater than the outer width; Step 3: Pickle the tube body after laser cutting for a period of not less than 240 seconds.

9. The method for manufacturing a hypotube according to claim 8, characterized in that: During the heat treatment, argon or nitrogen is first introduced into the heat treatment equipment as a protective gas, the air in the heat treatment equipment is exhausted, and then oxygen is introduced into the inner cavity of the nickel-titanium alloy tube until the inner surface of the nickel-titanium alloy tube turns black.

10. The method for manufacturing a hypotube according to claim 8, characterized in that: The process parameters of the heat treatment are: heat treatment time is 10 to 40 seconds, temperature is 700 to 900°C; The laser cutting process parameters are: femtosecond laser 1000-1100nm, spot diameter 10-40um, focal length ±0.1mm, single pulse energy 1.0-6.0uJ, repetition frequency: 100k-600kHz; The pickling solution is a mixed solution of 3% to 5% hydrofluoric acid, 18% to 22% nitric acid, and 73% to 79% ionized water by volume.

Images