A device for preventing a puncture guide wire from entering a dilator

Abstract

This invention relates to the field of medical device technology and discloses a device for preventing a puncture guidewire from accidentally entering a dilator. The device includes: a dilator with a groove at its end; a resistance triggering unit disposed within the groove; a guidewire capable of passing through the dilator and contacting the resistance triggering unit, the guidewire's surface having a positively charged coating on at least a portion within the dilator; the resistance triggering unit includes: a negatively charged substrate, a hydrophobic film wrapped around the substrate surface, and a trigger layer wrapped around the outer surface of the hydrophobic film, the trigger layer having directional cracks on its surface; the trigger layer has an intact state and a torn state. When the guidewire moves in the forward direction, the trigger layer is intact; when the guidewire moves in the retraction direction, the trigger layer and the hydrophobic film tear, exposing the negatively charged substrate. The substrate and the guidewire coating generate electrostatic adsorption, creating resistance to the guidewire's movement. This provides accurate warning without interfering with normal operation, ensuring safety and ease of use.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and more specifically, to a device for preventing the puncture guidewire from accidentally entering the dilator. Background Technology

[0002] In percutaneous vascular puncture and interventional procedures (such as coronary intervention, neurointervention, etc.), the standard operating procedure is to first establish a channel with a puncture needle, then insert a guidewire, and then advance an dilator / sheath along the guidewire to establish a stable working channel. In this process, there is a serious clinical safety hazard: because the surface of the traditional guidewire is extremely smooth, and the inner wall of the dilator is also smooth, the guidewire has almost no resistance to movement in the dilator. If the operator is negligent or lacks experience, the guidewire may accidentally retract into the dilator under slight external force. In severe cases, this can damage the blood vessel and lead to surgical failure, or even completely slip into the blood vessel.

[0003] When the guidewire accidentally retracts, the operator usually has no tactile feedback and cannot detect it in time. If the guidewire slips too deep, it can directly puncture the blood vessel wall, causing fatal bleeding. Even if no damage is caused, the guidewire stuck in the blood vessel may become a source of thrombosis or cause long-term complications. In the current technology, some guidewires only have visual markings, which cannot fundamentally prevent misoperation, while other mechanical locking structures are often more complex, more expensive, or may interfere with the normal smooth operation feel.

[0004] Therefore, it is necessary to propose a device to prevent the puncture guidewire from accidentally entering the dilator, so as to at least partially solve the problems existing in the prior art. Summary of the Invention

[0005] The summary section introduces a series of simplified concepts, which will be further explained in detail in the detailed description section. The summary section of this invention is not intended to limit the key features and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0006] To at least partially solve the above problems, the present invention provides a device for preventing the puncture guidewire from accidentally entering the dilator, comprising: An expander, with a groove inside its end; A resistance triggering unit is disposed within the groove; A guide wire that can pass through the expander and contact the resistance triggering unit, wherein the surface of the guide wire is provided with a positively charged coating on at least a portion of its portion located within the expander; The resistance triggering unit includes: a negatively charged substrate, a hydrophobic film wrapped around the surface of the substrate, and a triggering layer wrapped around the outer surface of the hydrophobic film, wherein the surface of the triggering layer is provided with directional cracks. The trigger layer has an intact state and a torn state. When the guidewire moves in the forward direction, the trigger layer is in the intact state. When the guidewire moves in the backward direction, the trigger layer is torn and the hydrophobic film is torn simultaneously, exposing the negatively charged substrate. The exposed substrate and the coating of the guidewire generate electrostatic adsorption, which creates resistance to the movement of the guidewire.

[0007] Preferably, the expander has at least two grooves inside its end, and each groove has at least one resistance triggering unit.

[0008] Preferably, the size of the resistance triggering unit is larger than the gap distance between the guidewire and the dilator.

[0009] Preferably, the resistance triggering unit is in the form of a circular particle.

[0010] Preferably, the resistance triggering unit is block-shaped, with the side near the guide wire being an arc-shaped surface, and the directional crack is correspondingly disposed on the arc-shaped surface.

[0011] Preferably, the directional crack includes solid lines and dashed lines, with one end of the solid lines connected to the front end of the dashed lines; wherein the end of the dashed lines closer to the direction of the guide wire's advance is the front end.

[0012] Preferably, the matrix uses carboxylated silicon dioxide as the substrate.

[0013] Preferably, the trigger layer is formed of a blend of polylactic acid and polycaprolactone.

[0014] Preferably, the thickness of the trigger layer is 5 μm to 10 μm.

[0015] Preferably, the positively charged coating on the guide wire surface is chitosan-NH3. + .

[0016] Compared with the prior art, the present invention has at least the following beneficial effects: The device for preventing the puncture guidewire from accidentally entering the dilator described in this invention uses the relationship between the guidewire's movement direction and the directional crack to control the triggering of electrostatic adsorption. This ensures that significant resistance is generated only when the guidewire undergoes a potentially dangerous retraction movement, achieving precise early warning without interfering with normal operation, thus guaranteeing safety and ease of operation. The present invention has a simple structure, requiring only a resistance triggering unit fixed inside the end of the expander, eliminating the need for complex mechanical or electronic components, thus reducing the failure rate and manufacturing cost. The total resistance designed in this invention is greater than the conventional surgical force, ensuring that the surgeon can clearly perceive it, while it is far below the safety threshold for vascular tissue damage in the prior art. While providing effective early warning, it avoids new risks caused by excessive resistance itself. All functional materials of this invention have excellent biocompatibility, and the resistance triggering unit is permanently fixed inside the end of the expander, structurally eliminating the possibility of entering the bloodstream. At the end of the operation, all materials can be completely removed with the instrument. The working principle of this invention is based on the physical interaction between materials. It does not change the shape and size of the dilator and guidewire or the basic operating feel. Operators do not need to learn new operating techniques, making it easy to promote.

[0017] The device for preventing the puncture guidewire from accidentally entering the dilator according to the present invention, other advantages, objectives and features of the present invention will be apparent in part from the following description, and in part will be understood by those skilled in the art through study and practice of the invention. Attached Figure Description

[0018] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 A schematic diagram of the existing technology for inserting a guidewire into a dilator / sheath; Figure 2 This is a schematic diagram of the first structure of the device for preventing the puncture guide wire from accidentally entering the dilator according to the present invention; Figure 3 This is a cross-sectional schematic diagram of a first structure of the device for preventing the puncture guidewire from accidentally entering the dilator according to the present invention. Figure 4 This is a schematic cross-sectional view of another structure of the first type of the device for preventing the puncture guidewire from accidentally entering the dilator according to the present invention; Figure 5 This is a schematic diagram of a second structure of the device for preventing the puncture guidewire from accidentally entering the dilator according to the present invention; Figure 6 This is a cross-sectional schematic diagram of the second structure of the device for preventing the puncture guidewire from accidentally entering the dilator according to the present invention; Figure 7 This is a schematic diagram of the first type of directional crack in the device for preventing the puncture guide wire from accidentally entering the dilator according to the present invention; Figure 8 This is a schematic diagram of the second type of directional crack in the device for preventing the puncture guide wire from accidentally entering the dilator according to the present invention; Figure 9 This is a schematic diagram of the third type of directional crack in the device for preventing the puncture guide wire from accidentally entering the dilator according to the present invention; Figure 10 This is a schematic diagram of the structure of the first type of directional crack on the circular granular resistance triggering unit in the device for preventing the puncture guide wire from accidentally entering the dilator according to the present invention. Figure 11 This is a schematic diagram of the structure of the second type of directional crack on the circular granular resistance triggering unit in the device for preventing the puncture guide wire from accidentally entering the dilator according to the present invention. Figure 12 This is a schematic diagram of the structure of the third type of directional crack on the circular granular resistance triggering unit in the device for preventing the puncture guide wire from accidentally entering the dilator according to the present invention. Figure 13 This is a schematic diagram of the structure of the first type of directional crack on the block-shaped resistance triggering unit in the device for preventing the puncture guide wire from accidentally entering the dilator according to the present invention. Figure 14 This is a schematic diagram of the structure of the second type of directional crack on the block-shaped resistance triggering unit in the device for preventing the puncture guide wire from accidentally entering the dilator according to the present invention. Figure 15 This is a schematic diagram of the structure of the third type of directional crack on the block-shaped resistance triggering unit in the device for preventing the puncture guide wire from accidentally entering the dilator according to the present invention. Figure 16 The device for preventing the puncture guide wire from accidentally entering the dilator according to the present invention, under scenario B, considering the Debye shielding effect, calculates the electrostatic adsorption force decay curve of two charged surfaces as the gap changes from 0.1 nm to 10 nm.

[0019] In the attached figures, 1 is the expander, 2 is the groove, 3 is the resistance triggering unit, 31 is the substrate, 32 is the triggering layer, 4 is the guide wire, 5 is the coating, 6 is the directional crack, 61 is the solid line pattern, 62 is the dashed line pattern, and 7 is the sheath. Detailed Implementation

[0020] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments, so that those skilled in the art can implement it based on the description.

[0021] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0022] like Figure 1 The diagram shows a guide wire being inserted into the dilator 1 and sheath 7 in the prior art. The guide wire 4 has no resistance to movement within the dilator 1.

[0023] like Figures 2-15 As shown, the present invention provides a device for preventing the puncture guidewire from accidentally entering the dilator, comprising: Expander 1, with a groove 2 inside its end; The resistance triggering unit 3 is disposed in the groove 2; The guide wire 4 is able to pass through the expander 1 and contact the resistance triggering unit 3. The surface of the guide wire 4 is provided with a positively charged coating 5 on at least a portion of its portion located within the expander 1. The resistance triggering unit 3 includes: a negatively charged substrate 31, a hydrophobic film wrapped around the surface of the substrate 31, and a triggering layer 32 wrapped around the outer surface of the hydrophobic film. The surface of the triggering layer 32 is provided with directional cracks 6. The trigger layer 32 has an intact state and a torn state. When the guide wire 4 moves in the forward direction, the trigger layer 32 is in the intact state. When the guide wire 4 moves in the retraction direction, the trigger layer 32 is torn and the hydrophobic film is torn simultaneously, exposing the negatively charged substrate 31. The exposed substrate 31 and the coating 5 of the guide wire 4 generate electrostatic adsorption, forming a resistance to the movement of the guide wire 4.

[0024] Furthermore, the hydrophobic film on the surface of the substrate 31 is a nano-hydrophobic fluorocarbon film with a thickness of 10nm~50nm; the trigger layer 32 is coated on the outside of the nano-hydrophobic fluorocarbon film. The directional crack 6 is formed by etching on the surface of the trigger layer 32 using an excimer laser cold processing process. It has a geometry that causes stress concentration when the guide wire 4 retracts to guide the tearing. In addition, the directional crack 6 can also penetrate the trigger layer 32 to reach the nano-hydrophobic fluorocarbon film to ensure the tearing effect.

[0025] When the guidewire 4 moves in the retraction direction, the trigger layer 32 tears and exposes the negatively charged substrate 31. The nano-hydrophobic fluorocarbon film ruptures simultaneously, forming a local micro-drying area between the exposed substrate 31 and the coating 5 of the guidewire 4, effectively dissipating electrolyte liquids such as blood. The exposed substrate 31 and the coating 5 of the guidewire 4 generate electrostatic adsorption, creating resistance to the movement of the guidewire 4.

[0026] The total length of the dilator 1 is 165 mm (including the tube inserted into the blood vessel), and its inner diameter is 1.2 mm. It is made of medical polymer material. The guide wire 4 has a total length of 450 mm and an outer diameter of 0.9 mm. At least in the section from 390 mm to 450 mm at its end, a positively charged coating 5 is provided. The resistance trigger unit 3 is integrated into the end of the expander 1. The resistance trigger unit 3 with directional cracks 6 is placed into the groove 2 in a preset direction. The resistance trigger unit 3 is fixed in the groove 2. The two can be fixed by applying medical-grade UV glue in the groove 2, and after curing, the particles are firmly embedded in the groove 2. Alternatively, the groove 2 and the resistance trigger unit 3 can be fixed by mechanical snap-fit ​​to prevent the resistance trigger unit 3 from coming out when subjected to force.

[0027] When a channel is established using a puncture needle, and then guidewire 4 is inserted, with part of guidewire 4 inside the blood vessel and the other part outside the skin, dilator 1 and sheath 7 are then advanced along guidewire 4. During this process, guidewire 4 remains stationary while dilator 1 and sheath 7 move, and guidewire 4 advances relative to dilator 1 (e.g., ...). Figure 2 When the guide wire 4 moves to the right relative to the expander 1 (i.e., in the forward direction) and passes through the resistance trigger unit 3, the coating 5 on the surface of the guide wire 4 and the trigger layer 32 of the resistance trigger unit 3 experience sliding friction. Since the directional crack 6 is parallel to the grain when the guide wire 4 moves in the forward direction, the friction force will not cause the directional crack 6 to expand and tear. The trigger layer 32 remains intact, and the internal substrate 31 is not exposed. At this time, there is no electrostatic adsorption between the positively charged coating 5 and the trigger layer 32, and the resistance is <0.2N, resulting in a relatively smooth feel. When guidewire 4 retracts relative to dilator 1 due to unforeseen circumstances (e.g.) Figure 2 When the guidewire 4 moves to the left relative to the expander 1 (i.e., in the retraction direction), its movement direction makes the directional crack 6 reverse, causing the trigger layer 32 to tear along the directional crack 6. The nano-hydrophobic fluorocarbon film ruptures simultaneously, forming a local micro-drying area between the exposed substrate 31 and the coating 5 of the guidewire 4. This effectively drains electrolyte liquids such as blood, exposing the negatively charged substrate 31. Then, the positively charged coating 5 on the surface of the substrate 31 and the surface of the guidewire 4 immediately undergo electrostatic adsorption. It should be noted that the electrostatic adsorption force is a normal force perpendicular to the contact surface. Its function is to press the coating 5 of the guidewire 4 against the surface of the substrate 31. When the guidewire 4 retracts, the "sticking" or "dragging" sensation felt by the surgeon is the sliding friction force that prevents the guidewire 4 from sliding. Its magnitude is determined by the sliding friction force = electrostatic adsorption force × coefficient of friction. For the direct contact between the PLA / PCL blend coating 5 and the exposed carboxylated silica substrate 31 in the micro-drying zone, its static friction coefficient is approximately 0.9~1.0. According to simulation calculations, assuming... Assuming the electrostatic attraction force of a single resistance trigger unit 3 is approximately 0.23N, multiplied by the friction coefficient of 0.9~1.0, the retraction resistance generated by a single resistance trigger unit 3 is approximately 0.21N~0.23N; when 16 resistance trigger units 3 are set, the total retraction resistance can reach 3.3N~3.7N (calculated value is approximately 3.52N). This resistance manifests as a clear "sticking" or "dragging" sensation for the operator holding the guidewire 4, forming a strong tactile alarm that enables the operator to immediately stop the action and conduct an examination. Once an adsorption warning occurs, the operator does not need to forcibly separate the components. Since both the coating 5 and the trigger layer 32 have good biocompatibility and the adsorption force is within a safe range, the operator can apply force stably and withdraw the guidewire 4 and the dilator 1 as a whole from the patient's body simultaneously. All the resistance trigger units 3 are fixed inside the end of the dilator 1 and will be taken out of the body along with the dilator 1, ensuring that no material remains in the patient's blood vessels.

[0028] The design objectives of this device are based on existing data and mechanical calculations: Normal operating force: In the prior art, the normal operating force, i.e. the propulsion force, of the expander 1 and the sheath 7 is 1.9N~2.4N; Clinical safety threshold: the risk threshold for vascular injury > 4.84N, and the upper limit of safe operation is recommended to be ≤ 6N; The device is designed to withstand a total resistance of 3.52N (this value is obtained by multiplying the electrostatic adsorption force as the normal force by the friction coefficient of 0.9~1.0 to obtain the sliding friction force). This value is significantly greater than the normal operating force, ensuring a clear warning, while being far below the safety threshold, ensuring that the warning action itself will not cause tissue damage. In addition, 3.52N is also above the resistance range (0.5N~3N) that can be clearly perceived by the human hand.

[0029] In one embodiment, the surface of the substrate 31 is further coated with a nano-hydrophobic fluorocarbon film, the thickness of which is 10 nm to 50 nm; the trigger layer 32 is coated on the outside of the nano-hydrophobic fluorocarbon film. The directional crack 6 is formed by etching on the surface of the trigger layer 32 using an excimer laser cold processing process. It has a geometry that causes stress concentration when the guide wire 4 retracts to guide the tearing. In addition, the directional crack 6 can also penetrate the trigger layer 32 to reach the nano-hydrophobic fluorocarbon film to ensure the tearing effect.

[0030] When the guidewire 4 moves in the retraction direction, the trigger layer 32 tears and exposes the negatively charged substrate 31. The nano-hydrophobic fluorocarbon film ruptures simultaneously, forming a local micro-drying area between the exposed substrate 31 and the coating 5 of the guidewire 4, effectively dissipating electrolyte liquids such as blood. The exposed substrate 31 and the coating 5 of the guidewire 4 generate electrostatic adsorption, creating resistance to the movement of the guidewire 4.

[0031] In one embodiment, the expander 1 has at least two grooves 2 inside its end, and each groove 2 has at least one resistance triggering unit 3.

[0032] The resistance generated by each resistance triggering unit 3 can be calculated in advance. Then, based on the goal of a total resistance of not less than 3.52N, the number of resistance triggering units 3 is set to ensure effective prevention of guide wire 4 retraction.

[0033] In one embodiment, the size of the resistance triggering unit 3 is greater than the gap distance between the guide wire 4 and the expander 1.

[0034] The resistance triggering unit 3 is fixed in the groove 2 and will not flow into the blood vessel from the gap between the guidewire 4 and the dilator 1, ensuring safety.

[0035] like Figure 2As shown, in one embodiment, the resistance triggering unit 3 is in the form of a circular particle.

[0036] When the resistance trigger unit 3 is in the form of a circular particle, its diameter is 1.3 mm. The basic adsorption force (normal force) of a single circular particle-shaped resistance trigger unit 3 is 0.13~0.15 N (for example, with a contact area of ​​0.05 mm²). 2 (The adsorption force per unit area is 2.6 N / mm²–3.0 N / mm²). The side of the circular granular resistance trigger unit 3 that contacts the guide wire 4 can be set as an arc surface to optimize the adsorption force of the resistance trigger unit 3, for example, by increasing the contact area to 0.08 mm². 2 ~0.09 mm 2 Then the adsorption force of a single resistance trigger unit 3 can be increased to no less than 0.22N. This electrostatic adsorption force acts as a normal force to press the coating 5 against the surface of the substrate 31. When the guide wire 4 retracts, the retraction resistance generated by a single resistance trigger unit 3 is about 0.21N~0.23N. When 16 resistance trigger units 3 are set, the total retraction resistance can reach 3.3N~3.7N (calculated value is about 3.52N).

[0037] like Figure 3 As shown, the resistance triggering unit 3 can be set in two symmetrical rows, or it can be set in four rows evenly distributed along the circumference of the guide wire 4. The number of resistance triggering units 3 is at least 16, so as to ensure the resistance generated when the guide wire 4 is retracted.

[0038] like Figure 4 As shown, the resistance triggering unit 3 can be set into two symmetrical groups, each group consisting of two rows, with a minimum of 16 resistance triggering units 3, thereby ensuring the resistance generated when the guide wire 4 retracts.

[0039] like Figure 5 As shown, in one embodiment, the resistance triggering unit 3 is block-shaped, with an arc-shaped surface on the side near the guide wire 4, and the directional crack 6 is correspondingly disposed on the arc-shaped surface.

[0040] Compared to the circular granular resistance trigger unit 3, the block-shaped resistance trigger unit 3 can generate a better resistance effect when the guide wire 4 retracts. Moreover, the block-shaped resistance trigger unit 3 is better fixed in the groove 2. In order to avoid excessive resistance when the guide wire 4 advances, it can be set to contact a part of the arc surface with the resistance trigger unit 3. For example, the lowest point of the arc surface is in contact with the resistance trigger unit 3. When the guide wire 4 retracts unexpectedly, the trigger layer 32 on the entire arc surface can be torn and peeled off by the directional crack 6, exposing the substrate 31, which can form a greater resistance effect on the guide wire 4.

[0041] like Figures 7-9As shown, in one embodiment, the directional crack 6 includes: solid line crack 61 and dashed line crack 62, one end of the solid line crack 61 is connected to the front end of the dashed line crack 62; wherein, the end of the dashed line crack 62 closer to the advancing direction of the guide wire 4 is the front end.

[0042] like Figure 7 , Figure 10 and Figure 13 As shown, solid line 61 and dashed line 62 form a reclining L-shape. Solid line 61 is perpendicular to the direction of movement of guidewire 4, and dashed line 62 is parallel to the direction of movement of guidewire 4. One end of solid line 61 is connected to the front end of dashed line 62. When guidewire 4 moves in the forward direction, i.e. Figure 10 and Figure 13 As indicated by the left arrow, when the coating 5 on the surface of the guidewire 4 comes into contact with the solid lines 61, the directional crack 6 will not tear because the dashed lines 62 are at the rear end; when the guidewire 4 moves in the retraction direction, i.e. Figure 10 and Figure 13 As indicated by the right arrow in the diagram, the coating 5 on the surface of the guidewire 4 comes into contact with the trigger layer 32, exerting a force to the left on the solid line pattern 61. The connection between the solid line pattern 61 and the dashed line pattern 62 will be torn by the force, tearing along the dashed line pattern 62, causing the trigger layer 32 to tear and exposing the substrate 31.

[0043] like Figure 8 , Figure 11 and Figure 14 As shown, solid lines 61 and dashed lines 62 form a rectangle with a notch on the left. Solid lines 61 are perpendicular to the direction of movement of guidewire 4, and dashed lines 62 are parallel to the direction of movement of guidewire 4. The two ends of solid lines 61 are connected to the front ends of the two dashed lines 62 respectively. When guidewire 4 moves in the forward direction, i.e. Figure 11 and Figure 14 As indicated by the left arrow, when the coating 5 on the surface of guidewire 4 contacts the solid lines 61, the directional crack 6 will not tear because both dashed lines 62 are at the rear end; when guidewire 4 moves in the retraction direction, i.e. Figure 11 and Figure 14 As indicated by the right arrow in the diagram, the coating 5 on the surface of the guidewire 4 comes into contact with the trigger layer 32, exerting a force to the left on the solid line pattern 61. The connection between the solid line pattern 61 and the dashed line pattern 62 will be torn by the force, tearing along the two dashed lines 62, causing the trigger layer 32 to tear and exposing the substrate 31.

[0044] like Figure 9 , Figure 12 and Figure 15 As shown, solid lines 61 and dashed lines 62 form an arrowhead shape, with the tip of the arrowhead being solid line 61 and the two extensions of the arrowhead being dashed lines 62; when the guidewire 4 moves in the forward direction, that is... Figure 12 and Figure 15As indicated by the left arrow, when the coating 5 on the surface of the guidewire 4 comes into contact with the solid line 61, the directional crack 6 will not tear because both dashed lines 62 are at the rear end of the solid line 61; when the guidewire 4 moves in the retraction direction, i.e. Figure 12 and Figure 15 As indicated by the right arrow in the diagram, the coating 5 on the surface of the guidewire 4 comes into contact with the trigger layer 32, exerting a force to the left on the solid line pattern 61. The connection between the solid line pattern 61 and the dashed line pattern 62 will be torn by the force, tearing along the two dashed lines 62, causing the trigger layer 32 to tear and exposing the substrate 31.

[0045] In one embodiment, the substrate 31 uses carboxylated silicon dioxide as the substrate.

[0046] Carboxylated silica (SiO2-COOH) is commonly used in coronary stent coatings in existing technologies, and therefore can be used as a medical material.

[0047] In one embodiment, the trigger layer 32 is formed of a blend of polylactic acid and polycaprolactone.

[0048] Furthermore, the thickness of the trigger layer 32 is 5μm to 10μm.

[0049] The mass ratio of polylactic acid to polycaprolactone is 50:50, which is a commonly used implant material in existing technology, and therefore can be used as a medical material.

[0050] In one embodiment, the positively charged coating 5 on the surface of the guide wire 4 is chitosan-NH3. + .

[0051] Chitosan-NH3 + It is commonly used in hemostatic materials and stent coatings in existing technologies, and therefore can be used as a medical material.

[0052] To verify the feasibility of the core technical solution under physiological conditions, the present invention also conducted the following three simulation analyses: The first simulation analysis: Feasibility analysis of electrostatic adsorption force under physiological conditions; (1) Simulation model and parameter settings: In order to quantitatively evaluate the electrostatic adsorption force between oppositely charged surfaces in a simulated blood environment, the following simulation model was established: Geometric model, with chitosan-NH3 on the surface of guide wire 4 + The contact between coating 5 and substrate 31 is simplified to two parallel flat plate models, with the effective contact area set to 0.05mm²~0.09mm² (consistent with the arc surface contact area of ​​the circular granular resistance triggering unit 3). Physical field coupling: An electrostatic field-fluid field coupling model was established, and the 0.9% NaCl solution (simulating the blood environment, 37℃) was regarded as a homogeneous electrolyte with an ionic strength of approximately 0.15M. Key physical parameters: Debye length is introduced as the core parameter. In physiological saline with an ionic strength of 0.15M, the Debye length is about 0.7nm~0.8nm. The Debye length reflects the attenuation distance of the electrostatic field in the electrolyte solution. That is, beyond this distance, the electrostatic attraction between opposite charges will be shielded by the redistribution of counterions in the solution (Debye shielding effect). Referring to existing literature, chitosan-NH3 + The surface charge characteristics of coating 5 and carboxylated silica at physiological pH were determined. The surface charge density of substrate 31 was set to -40 C / m² to -50 C / m², and the surface charge density of coating 5 was set to +30 C / m² to +40 C / m².

[0053] (2) Simulate computational scenarios and compare two computational scenarios: Scenario A (ideal dry environment, control group): without electrolyte shielding, the electrostatic attraction between oppositely charged plates is calculated solely based on Coulomb's law. In scenario B (physiological environment, experimental group), considering the Debye shielding effect, the electrostatic adsorption force decay curves of two charged surfaces are calculated as the gap changes from 0.1 nm to 10 nm.

[0054] like Figure 16 The figure shows the curve of adsorption force as a function of gap distance. The formula for calculating adsorption force is as follows: F(d) = F0·exp(-d / λ) D ); Where F(d) is the adsorption force; d is the interstitial distance; F0 is the adsorption force when the interstitial distance is 0, F0 = 3.7 N; exp is an exponential function with base e; λ D λ is the Debye length. D =0.8nm.

[0055] (3) Simulation results: According to the results of scenario A, under ideal conditions without electrolyte shielding, when the contact area is 0.08 mm², the theoretical value of electrostatic adsorption force can reach approximately 4.2 N to 5.1 N. Scenario B result, such as Figure 16 As shown, when two charged surfaces come into physical contact (gap → 0), since the electric double layer has not yet been fully formed, electrostatic attraction still dominates, and the theoretical value of the adsorption force can reach about 3.4N~4.0N. When the gap increases to 1 nm (approximately equal to the Debye length), the adsorption force decreases to approximately 0.8 N~1.2 N; When the gap increases to 5 nm, the adsorption force decreases to about 0.01 N to 0.05 N, which can be ignored. When the gap increases to more than 10 nm, the adsorption force approaches zero.

[0056] Comparison between scenario A and scenario B: The Debye shielding effect causes the electrostatic adsorption force to decrease sharply after the gap exceeds 1 nm, but under zero-distance contact conditions, the adsorption force can still be maintained at the order of 3 N or higher.

[0057] (4) Simulation conclusions: The simulation results show that electrostatic adsorption is not completely ineffective in electrolyte environments such as blood, but its effectiveness is highly dependent on whether sub-nanometer-level close contact can be achieved between the contact surfaces. Once there is a liquid gap of more than a few nanometers, the adsorption force will disappear rapidly due to Debye shielding. Therefore, this invention introduces a nano-hydrophobic fluorocarbon film. When the trigger layer 32 is torn, the hydrophobic fluorocarbon film breaks simultaneously. Its strong hydrophobicity instantly dissipates the electrolyte solution between the contact surfaces, forming a local micro-dry area, maintaining the effective contact distance at the sub-nanometer level, thereby ensuring the effective generation of electrostatic adsorption force under physiological conditions.

[0058] The second simulation analysis: mechanical simulation of directional crack tearing behavior; (1) Simulation model and parameter setting: In order to verify the controllable tearing behavior of directional cracks of different shapes under reverse shear force, the following simulation model was established: Material model: Trigger layer 32 (polylactic acid / polycaprolactone blend, PLA / PCL, mass ratio 50:50) adopts an elastoplastic material model; referring to existing literature and material databases, the following parameters are set: tensile strength 15MPa~20MPa, elastic modulus approximately 1.0GPa~3.5GPa, elongation at break 200%~350%; Crack modeling: Three types of directional cracks 6 were modeled in detail on the surface of the trigger layer 32: L-shaped (solid lines 61 and dashed lines 62 connected at 90°), rectangular notch type (double dashed lines arranged symmetrically), and arrow-shaped (tip pointing in the direction of travel). The crack depth was set to 60%~80% of the thickness of the trigger layer 32, that is, for a 7µm thick trigger layer 32, the crack depth was 4.2µm~5.6µm, and the radius of curvature of the crack tip was set to 1µm~3µm (simulating the processing accuracy of excimer laser etching). Load and boundary conditions: A uniform shear force is applied along the retraction direction on the contact surface between the coating 5 of the guide wire 4 and the trigger layer 32. The load gradually increases from 0 to 2.0N, and the bottom of the substrate 31 is set as a fixed constraint. Analysis method: The extended finite element method was used to analyze and simulate the stress intensity factor variation at the crack tip and the crack propagation path.

[0059] (2) Simulation results: Stress distribution characteristics: The maximum stress concentration of the L-shaped crack occurs at the junction of the solid line 61 and the dashed line 62. When the shear force reaches about 0.9N~1.1N, the stress intensity factor exceeds the fracture toughness of the material, and the crack propagates along the direction of the dashed line 62. The rectangular notch-type crack has stress symmetrically concentrated at the front end of the two dashed lines 62, with a trigger threshold of approximately 0.8N~1.0N and a large tearing area. Arrow-shaped cracks exhibit the lowest trigger threshold (approximately 0.5N~0.8N) due to the tip effect. Furthermore, the tearing path extends stably along the dotted lines 62 on both sides, resulting in optimal controllability.

[0060] Tearing dynamic process: All three crack morphologies can achieve controllable tearing along the designed path, verifying the unidirectional triggering logic of the directional crack 6 design. That is, when the guide wire 4 moves forward (with the grain), the friction is insufficient to cause stress concentration, and the trigger layer 32 remains intact; when the guide wire 4 retracts (against the grain), the shear force is concentrated at a specific position under the guidance of the crack geometry, driving the trigger layer 32 to tear along the predetermined path.

[0061] (3) Simulation conclusions: The simulation results show that directional cracks 6 with specific geometric shapes can be formed by etching on the surface of the trigger layer 32 through excimer laser cold processing, which can achieve unidirectional mechanical triggering. The triggering threshold of the crack (0.5N~1.2N) can be precisely designed by adjusting the crack depth, material fracture strength and crack geometry. Among them, the arrow-shaped crack has the lowest and most stable triggering threshold due to the stress concentration effect at the tip, and is the preferred solution.

[0062] The third simulation analysis: Simulation of the role of nano-hydrophobic fluorocarbon film in the formation of the micro-drying zone; (1) Simulation model: To verify whether the nano-hydrophobic fluorocarbon film can effectively displace the electrolyte solution and form a micro-dry zone after the trigger layer 32 is torn, the following simulation model was established: A geometric model was used to simulate the microscopic scenario where the nano-hydrophobic fluorocarbon film on the surface of the substrate 31 was exposed and came into contact with the coating 5 of the guide wire 4 after the trigger layer 32 was torn. The diameter of the contact area was set to 200µm~400µm (corresponding to a contact area of ​​0.03mm²~0.13mm²). The physical model uses computational fluid dynamics to simulate the interfacial behavior between the hydrophobic fluorocarbon membrane (contact angle >120°) and the electrolyte solution (0.9% NaCl). Under the condition that the guide wire 4 and the substrate 31 are squeezed (contact pressure of about 0.1MPa~0.5MPa), the discharge efficiency of the liquid in the contact area is calculated.

[0063] (2) Simulation results: When compressed, the nano-hydrophobic fluorocarbon membrane can form a "three-phase contact line" at the edge of the contact area, and the liquid is discharged outward. Under a contact pressure of 0.3 MPa, a micro-dry zone can be formed in the contact center region (approximately 100 µm to 150 µm in diameter), with a residual liquid film thickness of <5 nm; The effective duration of this micro-dry zone is approximately 50ms to 200ms, which is sufficient to generate electrostatic adsorption at the moment of triggering and provide tactile feedback to the surgeon (human hand perception response time is approximately 100ms to 300ms).

[0064] (3) Simulation conclusions: The simulation results show that the nano-hydrophobic fluorocarbon film can effectively form a local micro-drying area between the contact surface of the guide wire 4 and the substrate 31 after the trigger layer is torn, and maintain the contact gap at the level of Debye length (about 0.8 nm) or smaller, thereby overcoming the Debye shielding effect in the blood environment and enabling the electrostatic adsorption force to be effectively generated.

[0065] The materials used in each component of this invention are all materials that have been successfully applied in the biomedical field. Their specific preparation processes can be implemented with reference to existing technologies, which are described below: (1) Materials and preparation of matrix 31: The substrate 31 uses carboxylated silicon dioxide as the base material. Carboxylated silicon dioxide (SiO2-COOH) is a functionalized material prepared by introducing carboxyl functional groups onto the surface of silicon dioxide nanoparticles through surface chemical modification. Its surface modification process (such as the silane coupling agent method) is a mature technology in this field. Carboxylated silicon dioxide has been widely used in biomedical applications such as coronary stent coatings and drug delivery systems, exhibiting good biocompatibility and stable surface negative charge properties. The preparation method of the substrate 31 includes the following steps: S11. Select spherical silica microspheres with a particle size of 0.8µm~1.5µm as the substrate; S12. The surface of silica microspheres is modified by amylation using a silane coupling agent (e.g., 3-aminopropyltriethoxysilane, APTES) to form aminated silica (SiO2-NH2); this amylation modification process is a conventional technique in the field. S13. Then, through the acylation reaction of amino groups with succinic anhydride, carboxyl groups are introduced onto the surface of aminated silica to obtain carboxylated silica (SiO2-COOH). S14. Carboxylated silica microspheres and polytetrafluoroethylene (PTFE) nanopowder are mixed at a mass ratio of 90:10 to 95:5 and then subjected to high-voltage corona discharge treatment (discharge voltage 15kV to 25kV, treatment time 30s to 120s) to make the surface of the substrate 31 carry a stable negative charge, with a surface charge density of -40 C / m² to -50 C / m².

[0066] (2) Preparation of nano-hydrophobic fluorocarbon membranes: The nano-hydrophobic fluorocarbon film is coated onto the surface of the substrate 31 by dip coating or vapor deposition. Specifically: S21. Immerse the corona-treated substrate 31 into a fluoropolymer solution (such as polytetrafluoroethylene dispersion or fluorinated ethylene propylene copolymer solution) and control the immersion time to be 5s~15s. S22. Dry and cure at 60℃~80℃ for 10min~30min to form a uniform hydrophobic fluorocarbon film with a thickness of 10nm~50nm; S23. The water contact angle of this hydrophobic fluorocarbon membrane can reach 110°~130°, and it has excellent hydrophobic drainage performance.

[0067] Fluoropolymers have been widely used in the surface treatment of medical devices, and their biocompatibility and chemical inertness have been fully verified.

[0068] (3) Materials and fabrication of trigger layer 32: The trigger layer 32 is formed of a blend of polylactic acid (PLA) and polycaprolactone (PCL), and is directly coated onto the outer surface of the nano-hydrophobic fluorocarbon film using a solution casting method. Because the nano-hydrophobic fluorocarbon film has high hydrophobicity (contact angle 110°~130°), the PLA / PCL solution is difficult to spread evenly on an untreated surface. Therefore, a mild surface activation treatment is required on the surface of the nano-hydrophobic fluorocarbon film before casting the trigger layer 32. The specific process is as follows: S31. Substrate Pretreatment: The substrate 31 coated with the nano-hydrophobic fluorocarbon film is placed in a low-power argon plasma treatment device. The radio frequency power is set to 5W~15W, the treatment time is 10s~30s, and the gas flow rate is 10sccm~20sccm. This low-power plasma treatment only introduces trace amounts of oxygen-containing polar groups (such as -OH, -COOH) on the surface of the nano-hydrophobic fluorocarbon film, which moderately reduces the surface water contact angle from 120°~130° to 80°~95°, thereby improving the wettability and spreadability of PLA / PCL solution on its surface, without damaging the overall hydrophobic structure and film integrity of the nano-hydrophobic fluorocarbon film (film thickness loss <2nm). S32. Preparation of coating solution: Dry polylactic acid (PLA) and polycaprolactone (PCL) separately in a vacuum drying oven at 40℃~55℃ for 12h~24h to remove moisture. Then weigh and mix them at a mass ratio of 50:50 (i.e., 50 parts PLA and 50 parts PCL), dissolve them in dichloromethane, and prepare a PLA / PCL solution with a concentration of 5wt%~10wt%. S33, Solution Casting Coating: The plasma-treated substrate 31 is immersed in a PLA / PCL solution and coated using a dip-coating method. The pulling speed is controlled at 0.5 mm / s to 2 mm / s. To achieve a target film thickness of 5 µm to 10 µm, the coating needs to be repeated 3 to 5 times. After each coating, the substrate is allowed to stand at room temperature for 5 to 10 minutes to allow the solvent to fully evaporate before the next coating is applied. By controlling the solution concentration and the number of coatings, the final film thickness can be precisely controlled. S34. Drying and curing: The coated substrate 31 is placed in a vacuum drying oven and dried at 40℃~50℃ for 12h~24h to allow the residual solvent to evaporate completely, forming a dense PLA / PCL trigger layer 32 with a thickness of 5µm~10µm. The interface bonding between the obtained trigger layer 32 and the nano-hydrophobic fluorocarbon film is as follows: After plasma activation, the trace polar groups on the surface of the nano-hydrophobic fluorocarbon film form intermolecular forces (van der Waals forces and hydrogen bonds) with the PLA / PCL molecular chains. At the same time, during the solution casting process, the PLA / PCL molecular chains penetrate into the micro-rough structure on the surface of the nano-hydrophobic fluorocarbon film, forming a mechanical interlock. The synergistic effect of the two makes the interface peel strength reach 0.5N / cm~2.0N / cm, which is sufficient to ensure that the trigger layer 32 does not delaminate during normal use. At the same time, when the guide wire 4 is retracted, the trigger layer 32 can drive the nano-hydrophobic fluorocarbon film to tear synchronously. S35. Performance verification: The fracture strength of the obtained trigger layer 32 is 15MPa~20MPa, the elongation at break is 200%~350%, and the elastic modulus is 1.0GPa~3.5GPa, which meets the mechanical performance requirements for directional crack 6 triggering tearing.

[0069] The low-power argon plasma treatment is a mature surface modification technology in the field of medical device coatings. Its treatment conditions are mild and will not damage the functionality of the nano-hydrophobic fluorocarbon film. Moreover, no additional adhesives or intermediate layers are required after treatment, which simplifies the manufacturing process.

[0070] (4) Processing technology for directional crack 6: The directional crack 6 is formed on the surface of the trigger layer 32 by excimer laser cold processing. Excimer lasers (such as argon fluoride (ArF) excimer lasers with a wavelength of 193nm) have been successfully applied in the field of interventional medical device manufacturing. Their cold processing characteristics (high photon energy and extremely small heat-affected zone) are particularly suitable for the precision micromachining of polymer films. The specific processing technology is as follows: S41. Fix the formed trigger layer 32 film onto a precision motion platform; S42. An ArF excimer laser (wavelength 193nm) is used, with the laser energy density set to 1.0J / cm²~3.0J / cm² and the pulse frequency to 50Hz~200Hz. S43. By using mask projection or direct writing scanning, directional cracks 6 of a preset shape (L-shaped, rectangular notch-shaped or arrow-shaped) are etched on the surface of the trigger layer 32. S44. The etching depth is controlled to be 60%~80% of the trigger layer thickness, that is, for a 7µm thick trigger layer, the etching depth is 4.2µm~5.6µm; S45. The V-groove opening angle formed by etching is 45°~75°, and the radius of curvature of the crack tip is 1µm~3µm to ensure stress concentration effect.

[0071] This laser processing technology can precisely control the depth, angle, and geometry of the crack, ensuring that the directional crack 6 has the unidirectional triggering performance required by the design.

[0072] (5) Preparation of coating 5 on the surface of guide wire 4: The positively charged coating 5 on the surface of the guide wire 4 is chitosan-NH3. + Chitosan is a natural cationic polysaccharide that, under physiological pH conditions, its amino groups are protonated to form -NH3. + Carrying a positive charge, chitosan has been widely used in biomedical fields such as hemostatic materials, coronary stent coatings, and drug delivery carriers in existing technologies, exhibiting excellent biocompatibility and antibacterial properties; the preparation method of coating 5 is as follows: S51. Dissolve chitosan in a 1%~2% acetic acid aqueous solution to prepare a chitosan solution with a concentration of 1wt%~3wt%. S52. Immerse the end section (390mm~450mm) of guidewire 4 into the chitosan solution and coat it using the dip-coating method, controlling the lifting speed to be 1mm / s~5mm / s. S53. After natural drying at room temperature, the coating is cross-linked with glutaraldehyde vapor or genipin to stabilize the coating structure and surface charge. S54. The thickness of the resulting coating 5 is 1µm~3µm, and the surface charge density is +30 C / m²~+40 C / m² under physiological pH conditions.

[0073] Based on the foregoing, in a specific embodiment of the present invention, the parameters of each component are as follows: Expander 1: Total length 165mm, inner diameter 1.2mm, made of medical-grade polyurethane; Guide wire 4: Total length 450mm, outer diameter 0.9mm, with chitosan-NH3 coated on the surface of the 390mm~450mm section at its end. + Coating 5, with a coating thickness of 2µm, was prepared by dip coating and cross-linked with glutaraldehyde to stabilize the charge, with a surface charge density of +35C / m². Resistance triggering unit 3: consists of 16 spherical particles with a diameter of 1.3 mm, arranged in two rows and symmetrically embedded in the groove 2 at the end of the expander 1; Matrix 31: Carboxylated silica microspheres doped with polytetrafluoroethylene nanopowder (mass ratio 93:7) were prepared by high voltage corona discharge treatment, with a surface charge density of -45 C / m². Nano-hydrophobic fluorocarbon film: The film is coated onto the surface of substrate 31 by dip coating. The material is polytetrafluoroethylene dispersion. The film thickness is about 30 nm and the water contact angle is 125°. Trigger layer 32: is a film of polylactic acid and polycaprolactone (mass ratio 50:50) blend, with a thickness of 7µm, which is hot-pressed after melt blending (195℃, 8min); Directional crack 6: It is arrow-shaped and formed by etching with an ArF excimer laser (wavelength 193nm, energy density 2.0J / cm²) with an etching depth of 5.2µm (approximately 74% of the trigger layer thickness), a V-shaped opening angle of 60°, and a crack tip curvature radius of approximately 2µm.

[0074] In this embodiment, when the guidewire 4 moves in the forward direction, the resistance is <0.2N, and the operation feels smooth; when the guidewire 4 moves in the retraction direction, the trigger layer 32 tears along the directional crack 6, and the nano-hydrophobic fluorocarbon film ruptures simultaneously, forming a local micro-dry area at the contact surface between the substrate 31 and the coating 5, generating electrostatic adsorption (normal force). This electrostatic adsorption force is converted into sliding friction force through the friction coefficient, and the total retraction resistance is about 3.45N~3.60N, which meets the design requirements of being greater than the normal operating force (1.9N~2.4N) and less than the vascular injury threshold (>4.84N).

[0075] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0076] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0077] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. Other modifications can be easily made by those skilled in the art. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A device for preventing the puncture guidewire from accidentally entering the dilator, characterized in that, include: Expander (1), with a groove (2) inside its end; A resistance triggering unit (3) is disposed in the groove (2); The guide wire (4) is able to pass through the expander (1) and contact the resistance triggering unit (3). The surface of the guide wire (4) is provided with a positively charged coating (5) on at least a portion of its portion located within the expander (1). The resistance triggering unit (3) includes: a negatively charged substrate (31), a hydrophobic film wrapped around the surface of the substrate (31), and a triggering layer (32) wrapped around the outer surface of the hydrophobic film. The surface of the triggering layer (32) is provided with directional cracks (6). The trigger layer (32) has an intact state and a torn state. When the guide wire (4) moves in the forward direction, the trigger layer (32) is in an intact state. When the guide wire (4) moves in the backward direction, the trigger layer (32) is torn and the hydrophobic film is torn simultaneously, exposing the negatively charged substrate (31). The exposed substrate (31) and the coating (5) of the guide wire (4) generate electrostatic adsorption, forming a motion resistance on the guide wire (4).

2. The device for preventing the puncture guidewire from accidentally entering the dilator according to claim 1, characterized in that, The expander (1) has at least two grooves (2) inside its end, and each groove (2) has at least one resistance triggering unit (3).

3. The device for preventing the puncture guidewire from accidentally entering the dilator according to claim 1, characterized in that, The size of the resistance triggering unit (3) is greater than the gap distance between the guide wire (4) and the expander (1).

4. The device for preventing the puncture guidewire from accidentally entering the dilator according to claim 1, characterized in that, The resistance triggering unit (3) is in the form of round particles.

5. The device for preventing the puncture guidewire from accidentally entering the dilator according to claim 1, characterized in that, The resistance triggering unit (3) is block-shaped, and the side of it close to the guide wire (4) is an arc-shaped surface. The directional crack (6) is correspondingly set on the arc-shaped surface.

6. The device for preventing the puncture guidewire from accidentally entering the dilator according to claim 1, characterized in that, The directional crack (6) includes: solid line crack (61) and dashed line crack (62), one end of the solid line crack (61) is connected to the front end of the dashed line crack (62); wherein, the end of the dashed line crack (62) closer to the direction of travel of the guide wire (4) is the front end.

7. The device for preventing the puncture guidewire from accidentally entering the dilator according to claim 6, characterized in that, The substrate (31) uses carboxylated silicon dioxide as the substrate.

8. The device for preventing the puncture guidewire from accidentally entering the dilator according to claim 1, characterized in that, The trigger layer (32) is formed of a blend of polylactic acid and polycaprolactone.

9. The device for preventing the puncture guidewire from accidentally entering the dilator according to claim 1, characterized in that, The thickness of the trigger layer (32) is 5μm~10μm.

10. The device for preventing the puncture guidewire from accidentally entering the dilator according to claim 1, characterized in that, The positively charged coating (5) on the surface of the guide wire (4) is chitosan-NH3. + .

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