An adjustable-bend catheter structure and corresponding interventional medical device

Abstract

The present invention discloses an adjustable curved catheter structure and a corresponding interventional medical device. The adjustable curved catheter structure includes a catheter body, which includes an inner tube, an intermediate tube and an outer tube which are sequentially sleeved; wherein a part of the intermediate tube close to the proximal end of the catheter body includes a first braided layer, a winding layer and a second braided layer which are sequentially arranged from the inside to the outside, and another part of the intermediate tube close to the distal end of the catheter body includes a first braided layer and a winding layer; a wire drawing tube, which is arranged between the first braided layer and the winding layer and is provided with a wire drawing; a developing ring, which is arranged at the distal end of the catheter body and connected to the first end of the wire drawing; a handle adjuster, which is arranged at the proximal end of the catheter body and connected to the second end of the wire drawing to drive the second end of the wire drawing to reciprocate, thereby driving the distal end of the catheter body to bend to a set angle or restore to its original state. The adjustable curved catheter structure can meet the needs of interventional surgery by arranging a special braided structure in the catheter body.

Description

Technical Field

[0001] The invention relates to an adjustable curved catheter structure and also to an interventional medical device comprising the adjustable curved catheter structure, belonging to the technical field of medical devices. Background Art

[0002] Interventional surgery is less harmful to the human body and can effectively shorten the operation time. It is a medical technology that has rapidly emerged and been promoted in recent years. As an auxiliary device for interventional surgery, microcatheters are mainly used for super-selective angiography and transarterial embolization, such as hepatic hemangioma arterial embolization (TAE), arteriovenous malformation (AVM), prostate artery embolization (PAE) and gastrointestinal bleeding. However, traditional microcatheters have a predetermined shape that cannot be changed in the patient's body. Adjustable microcatheters can be used for controlled and selective injection into blood vessels, including diagnostic, embolic, or therapeutic materials.

[0003] At present, most of the microcatheters used in coronary arteries, nerves and peripherals require doctors to pre-shape them to accurately guide the instruments or drugs in the catheter to specific parts, but this increases the number of surgical steps and requires a guidewire for guidance during the operation. Some microcatheters have been shaped before leaving the factory. The above two types of microcatheters may not be able to reach the lesion during surgery due to abnormal blood vessel course, blood vessel torsion, vascular lumen stenosis and other reasons.

[0004] The diameter of existing adjustable bend catheters is generally between 4F and 15F. They generally have the following problems: during the bending process, the winding wire of the bending section of the catheter will be offset, and the offset will be more obvious as the bending angle increases and the number of bending times increases. This will result in inaccurate bending angles, excessive loss of bending stroke, and a short number of available bending times, making it difficult for the catheter to reach the designated target position, or unable to smoothly deliver the instrument to the target site, affecting the smooth progress of the interventional surgery. Summary of the invention

[0005] The primary technical problem to be solved by the present invention is to provide an adjustable curved conduit structure.

[0006] Another technical problem to be solved by the present invention is to provide an interventional medical device using the adjustable curved catheter structure.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] According to a first aspect of an embodiment of the present invention, there is provided an adjustable curved conduit structure, comprising:

[0009] A catheter body, the catheter body comprising an inner tube, an intermediate tube and an outer tube which are sequentially sleeved from the inside to the outside; wherein a portion of the intermediate tube close to the proximal end of the catheter body comprises a first braided layer, a winding layer and a second braided layer which are sequentially arranged from the inside to the outside, and another portion of the intermediate tube close to the distal end of the catheter body comprises the first braided layer and the winding layer which are sequentially arranged from the inside to the outside;

[0010] A wire drawing tube, arranged between the first braided layer and the winding layer, wherein a wire drawing tube is provided with a wire drawing wire;

[0011] A developing ring is disposed at the distal end of the catheter body and connected to the first end of the drawing wire;

[0012] A handle adjuster is arranged at the proximal end of the catheter body and is connected to the second end of the wire drawing. The handle adjuster can drive the second end of the wire drawing to move back and forth, so as to drive the wire drawing to move back and forth in the wire drawing tube, thereby driving the distal end of the catheter body to bend to a set angle or restore to its original state.

[0013] Preferably, on another part of the intermediate tube close to the distal end of the catheter body, a limit point is provided at the position where the braiding node of the first braided layer intersects the winding layer, so as to limit the relative position of the first braided layer and the winding layer and adjust the flexibility of the distal end of the catheter body.

[0014] Preferably, the setting of the limit point is determined based on the lesion location, the hardness of the outer tube and the number of turns of the winding layer.

[0015] Preferably, when the lesion is located at a distal arterial branch;

[0016] If the outer tube has a first hardness t1 and the winding layer has a first number of turns n1, a plurality of continuous and non-interval limiting points are provided on both sides of the distal end of the intermediate tube;

[0017] If the outer tube has a second hardness t2 and the winding layer has a second number of turns n2, a plurality of continuous and non-interval limiting points are provided on one side of the distal end of the intermediate tube, and a plurality of interval limiting points are provided on the other side of the distal end of the intermediate tube;

[0018] If the outer tube has a third hardness t3 and the winding layer has a third number of turns n3, a plurality of spaced limiting points are provided on both sides of the distal end of the intermediate tube;

[0019] Among them, t1<t2<t3, n1≤n2≤n3.

[0020] Preferably, when the lesion is located at a proximal thick branch of the artery;

[0021] If the outer tube has a fourth hardness t4 and the winding layer has a fourth number of turns n4, a plurality of continuous and non-interval limiting points are provided on both sides of the distal end of the intermediate tube;

[0022] If the outer tube has a fifth hardness t5 and the winding layer has a fifth number of turns n5, a plurality of continuous and non-interval limiting points are provided on one side of the distal end of the intermediate tube, and a plurality of interval limiting points are provided on the other side of the distal end of the intermediate tube;

[0023] If the outer tube has a sixth hardness t6 and the winding layer has a sixth number of turns n6, a plurality of spaced limiting points are provided on both sides of the distal end of the intermediate tube;

[0024] Among them, t1<t2<t3<t4<t5<t6, n1≤n2≤n3≤n4≤n5≤n6.

[0025] Preferably, the first braided layer has a preset braiding pitch L, where L=C / 2P; wherein C is the total number of spindles in the first braided layer, and P is the number of crosses per inch on the first braided layer;

[0026] The winding layer has a preset turn distance D, D=xL; wherein x is a positive integer greater than or equal to 2.

[0027] Preferably, the catheter body has a variable hardness, so that the hardness of the catheter body gradually increases from the distal end of the catheter body to the proximal end of the catheter body.

[0028] Preferably, the limiting points include at least any one of welding points, bonding points or wire binding points.

[0029] Preferably, a recessed portion is formed on the outer side of the first braided layer and / or the inner side of the winding layer, and the wire drawing tube is clamped in the recessed portion to limit the relative position of the wire drawing tube.

[0030] Preferably, at the distal end of the intermediate tube, an end of the winding layer close to the developing ring has a preset distance from the developing ring.

[0031] According to a second aspect of an embodiment of the present invention, an interventional medical device is provided, comprising the above-mentioned adjustable curved catheter structure.

[0032] Compared with the prior art, the present invention has the following technical effects:

[0033] (1) By setting three layers of special braided structures at the proximal end of the catheter body and by setting two layers of special braided structures at the distal end of the catheter body, it is ensured that the proximal end of the catheter body has corresponding rigidity and the distal end of the catheter body has corresponding flexibility, which can meet the needs of interventional surgery.

[0034] (2) By fixing the winding layer in the bending section and the first braided layer to form a limit point, and performing heat treatment on the entire winding to eliminate stress, the winding layer is not easily offset during use, and each bending adjustment will not change, making each bending adjustment more precise and having better fatigue performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A schematic structural diagram of an adjustable curved conduit structure in an unbent state provided by the first embodiment of the present invention;

[0036] Figure 2 A schematic diagram of the structure of an adjustable curved conduit structure in a bent state provided by the first embodiment of the present invention;

[0037] Figure 3 It is a schematic diagram of a partial structure of a catheter body in the first embodiment of the present invention;

[0038] Figure 4 This is a schematic structural diagram of the proximal end of the intermediate tube in the first embodiment of the present invention;

[0039] Figure 5 This is a schematic structural diagram of the distal end of the intermediate tube in the first embodiment of the present invention;

[0040] Figure 6 A braided structure of a first braided layer and a second braided layer in the first embodiment of the present invention;

[0041] Figure 7 Another braided structure of the first braided layer and the second braided layer in the first embodiment of the present invention;

[0042] Figure 8 A schematic structural diagram of the distal end of the intermediate tube provided in the second embodiment of the present invention. DETAILED DESCRIPTION

[0043] The technical content of the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0044] Figure 1 The figure shows an adjustable curved catheter structure provided by an embodiment of the present invention. By setting a special braided structure in the catheter body, it can be ensured that the proximal end of the catheter body has corresponding rigidity and the distal end of the catheter body has corresponding flexibility to meet the needs of interventional surgery. For the convenience of description, in one embodiment of the present invention, a three-layer braided structure is set at the proximal end of the catheter body and a two-layer braided structure is set at the distal end of the catheter body as an example for explanation, but this does not constitute a limitation of the present invention. Therefore, the special braided structure in the present invention can also be a similar structural form in which a four-layer braided structure is set at the proximal end of the catheter body and a three-layer braided structure is set at the distal end of the catheter body.

[0045] <First Embodiment>

[0046] Figures 1 to 7 The figure shows the structure of an adjustable curved catheter in the first embodiment of the present invention, which includes a catheter body 1, a wire drawing tube 2, a wire drawing 3, a developing ring 4 and a handle adjuster 5.

[0047] like Figure 3 As shown, the catheter body 1 includes an inner tube 11, an intermediate tube 12 and an outer tube 13 which are sequentially sleeved from the inside to the outside. Figure 4 and Figure 5 As shown, the intermediate tube 12 is close to the proximal end of the catheter body (i.e. Figure 1 The portion of the A end in the middle tube 12 includes a first braided layer 121, a winding layer 122 and a second braided layer 123 arranged in sequence from the inside to the outside, and the middle tube 12 is close to the distal end of the catheter body (i.e. Figure 1 The other part of the B end in FIG. 1 includes a first braided layer 121 and a winding layer 122 (such as Figure 5 ). The wire drawing tube 2 is arranged between the first braided layer 121 and the winding layer 122, and a wire drawing 3 is passed through the wire drawing tube 2. The developing ring 4 is arranged at the distal end of the catheter body 1, and the developing ring 4 is connected to the first end 31 of the wire drawing 3. The handle regulator 5 is arranged at the proximal end of the catheter body 1, and the handle regulator 5 is connected to the second end 32 of the wire drawing 3. The handle regulator 5 can drive the second end of the wire drawing 3 to move back and forth, so as to drive the wire drawing 3 to move back and forth in the wire drawing tube 2, thereby driving the distal end of the catheter body 1 to bend to a set angle or restore to its original state.

[0048] In one embodiment of the present invention, there are two drawing tubes 2, which are symmetrically arranged on both sides of the intermediate tube 12. Accordingly, there are two drawing wires 3, and the first ends of the two drawing wires 3 are respectively connected to the position C and the position D of the developing ring 4 (such as Figure 5 As shown in Figure 1 As shown, the adjusting gear 51 on the handle adjuster 5 can drive the second end of the wire drawing 3 to move back and forth in the X direction, and the two wire drawing 3 are independently controlled. Figure 5 As shown, when the adjusting gear 51 drives the wire 3' to move along the X direction and keeps the wire 3" stationary, the wire 3' will apply a pulling force to the position C of the developing ring 4, thereby driving the distal end of the catheter body 1 to bend clockwise (as shown in FIG. Figure 2The specific bending angle is determined based on the adjustment position of the adjustment gear 51. When the bending angle is determined, the adjustment gear 51 can be locked to keep the distal end of the catheter body 1 in a bent state. On the contrary, when the adjustment gear 51 drives the wire drawing 3' to move in the opposite direction of the X direction and keeps the wire drawing 3' stationary, the distal end of the catheter body 1 returns to its original state. Similarly, when the adjustment gear 51 drives the wire drawing 3' to move in the X direction and keeps the wire drawing 3' stationary, the wire drawing 3' will apply a pulling force to the position D of the developing ring 4, thereby driving the distal end of the catheter body 1 to bend counterclockwise; on the contrary, when the adjustment gear 51 drives the wire drawing 3' to move in the opposite direction of the X direction and keeps the wire drawing 3' stationary, the distal end of the catheter body 1 returns to its original state. Among them, the handle adjuster 5 is a conventional structure in this field, so only the working principle of its bending adjustment is explained here, and its internal composition is not described in detail.

[0049] In the above embodiment, the first braided layer 121 and the second braided layer 123 have the same braided structure, and the braided layers on multiple sections can be braided and wound with braided wires of the same or different materials, and the performance of the product can be changed by using the braided material, braiding method, and braiding warp and weft density. In one embodiment of the present invention, two upper and one lower (such as Figure 6 ) or two up and two down (as shown Figure 7 The braiding form of the structure (as shown) makes the entire catheter body 1 have better toughness, tracking and torsion control.

[0050] In addition, in one embodiment of the present invention, the braiding ppi (picks per inch) of the first braided layer 121 is 120-200, and the braiding ppi of the second braided layer 123 is 50-80, and the overall hardness of the catheter body 1 can be changed by changing the braiding density. The first braided layer 121 and the second braided layer 123 are both composed of flat wires or round wires with a wire diameter of 0.01-0.02 mm, and the materials of the flat wires or round wires include but are not limited to 304 stainless steel, 316 stainless steel, platinum-iridium alloy or platinum-tungsten alloy.

[0051] The winding density of the winding layer 122 at the proximal end is 10 to 30 turns per 10 mm, and the winding density at the distal end is 50 to 80 turns per 10 mm. The winding wire used in the winding layer 122 needs to be heat treated to eliminate stress. Depending on the different metal wires, the tempering temperature is 240°C to 340°C, and the insulation time is 20 to 50 minutes, so as to achieve the purpose of eliminating processing stress and ensuring the strength, hardness and toughness of the material.

[0052] In the above embodiment, the wire drawing tube 2 is a polytetrafluoroethylene tube, the length range of the catheter body 1 is set to 85cm~180cm, the outer diameter range is set to within 3F, and the wall thickness range of the polytetrafluoroethylene tube 2 is set to 0.01mm~0.05mm, so that the wire drawing 3 can slide freely in the polytetrafluoroethylene tube 2.

[0053] In the above embodiment, the material of the wire drawing 3 is stainless steel or nickel-titanium alloy. The wire drawing 3 is processed into a strand by multiple filaments, thereby increasing the toughness of the wire drawing 3 and preventing it from breaking easily. The wire drawing 3 is connected and fixed to the developing ring 4 at the far end, and the preferred connection method is soldering.

[0054] In the above embodiment, the material used for the inner tube 11 is polytetrafluoroethylene, which has excellent corrosion resistance and heat resistance, and is generally used as a lining, and then matched with a casing, so that the lining layer of the entire inner tube 11 is both corrosion-resistant and high and low temperature-resistant, and the surface is pressure-resistant, and has sufficient strength and rigidity. The material used for the outer tube 13 includes but is not limited to polyether block amides of different hardness, nylon, or a material obtained by mixing the above materials in a certain proportion.

[0055] Therefore, combined with the toughness of the first braided layer 121, the winding layer 122 and the second braided layer 123 and the hardness of the outer layer polyether block amide and nylon, the entire catheter body 1 can form segments of different hardness from the distal end to the proximal end (that is, the hardness of the catheter body 1 gradually increases from the distal end to the proximal end), so that when entering the human body for surgical observation, it can avoid visual and operational blind spots, meet the requirements that each segment can be deformed in a different bending order without being easily broken, and make the entire tube body have good flexibility, tracking and torque control, as well as precise bending accuracy.

[0056] In the above embodiment, preferably, a recessed portion (not shown in the figure) is formed on the outside of the first braided layer 121 and / or the inside of the winding layer 122, and the wire drawing tube 2 is clamped in the recessed portion to limit the relative position of the wire drawing tube 2. Thus, the wire drawing tube 2 can be limited and fixed by the recessed portion to avoid the position of the wire drawing tube 2 being offset after multiple bending, thereby affecting the bending angle of the catheter body 1. The recessed portion is preferably arc-shaped and matches the outer diameter of the wire drawing tube 2, but the shape of the recessed portion can also be adaptively adjusted as needed.

[0057] <Second Embodiment>

[0058] like Figure 8As shown, the second embodiment of the present invention provides another adjustable bend catheter structure. Compared with the first embodiment, the difference of the second embodiment is that, on another part of the intermediate tube 12 near the distal end of the catheter body 1, a limit point 6 is provided at the position where the braiding node of the first braided layer 121 intersects with the winding layer 122, so as to limit the relative position of the first braided layer 121 and the winding layer 122 and adjust the flexibility of the distal end of the catheter body 1. By fixing the winding layer 122 and the first braided layer 121 in the bending section and heat-treating the entire winding to eliminate stress, the winding layer 122 is not easy to deviate during use, and there will be no change each time the bending is adjusted, so that each bending is more accurate and the fatigue performance is better.

[0059] Specifically, the setting of the limit point 6 is determined based on the lesion location, the hardness of the outer tube 13, and the number of turns of the winding layer 122. In one embodiment of the present invention, when the lesion location is located at the distal arterial thin branch, if the outer tube has a first hardness t1 and the winding layer has a first number of turns n1, then both sides of the distal end of the intermediate tube are provided with a plurality of continuous and non-interval limit points 6; if the outer tube has a second hardness t2 and the winding layer has a second number of turns n2, then one side of the distal end of the intermediate tube is provided with a plurality of continuous and non-interval limit points 6, and the other side of the distal end of the intermediate tube is provided with a plurality of interval-arranged limit points 6; if the outer tube has a third hardness t3 and the winding layer has a third number of turns n3, then both sides of the distal end of the intermediate tube are provided with a plurality of interval-arranged limit points 6; wherein, t1<t2<t3, n1≤n2≤n3.

[0060] It can be understood that in the embodiment of the present invention, the plurality of continuous non-interval limiting points refer to: for one side of the distal end of the intermediate tube, a limiting point is set at the position where each turn of the winding layer intersects with the first braided layer, for example: a limiting point is set at the position where the first turn of the winding layer intersects with the first braided layer, a limiting point is set at the position where the second turn of the winding layer intersects with the first braided layer, a limiting point is set at the position where the third turn of the winding layer intersects with the first braided layer, and so on, forming a plurality of continuous non-interval limiting points. The plurality of interval-set limiting points refer to: for one side of the distal end of the intermediate tube, after each turn or each few turns, a limiting point is set at the position where the next turn of the winding layer intersects with the first braided layer, for example: a limiting point is set at the position where the first turn of the winding layer intersects with the first braided layer, a limiting point is set at the position where the third turn of the winding layer intersects with the first braided layer, a limiting point is set at the position where the fifth turn of the winding layer intersects with the first braided layer, and so on, forming a plurality of interval-set limiting points.

[0061] Similarly, when the lesion is located at the proximal thick branch of the artery, if the outer tube has a fourth hardness t4 and the winding layer has a fourth number of turns n4, then both sides of the distal end of the intermediate tube are provided with a plurality of continuous and uninterrupted limit points; if the outer tube has a fifth hardness t5 and the winding layer has a fifth number of turns n5, then one side of the distal end of the intermediate tube is provided with a plurality of continuous and uninterrupted limit points, and the other side of the distal end of the intermediate tube is provided with a plurality of spaced limit points; if the outer tube has a sixth hardness t6 and the winding layer has a sixth number of turns n6, then both sides of the distal end of the intermediate tube are provided with a plurality of spaced limit points; wherein, t1<t2<t3<t4<t5<t6, n1≤n2≤n3≤n4≤n5≤n6.

[0062] Therefore, in one embodiment of the present invention, by fixing the winding layer 122 and the first braided layer 121 at the distal end at the intersection, the winding layer 122 and the first braided layer 121 will not be offset when the distal end of the catheter body 1 is bent, the adjustment is more precise, the number of adjustable bends is greater, and the complex human lumen structure can be better met, reducing the operation time and risk. In addition, in one embodiment of the present invention, the adjustable bend catheter structure can be divided into 6 specifications to adapt to different usage conditions to improve the applicability of the catheter structure.

[0063] In the above embodiment, the first braided layer 121 has a preset braiding pitch L, L=C / 2P, in inches; wherein C is the total number of spindles of the first braided layer 121, and P is the number of crosses per inch ppi on the first braided layer 121. The winding layer 122 has a preset turn pitch D. Preferably, in one embodiment of the present invention, D=xL, wherein x is a positive integer greater than or equal to 2, so that the turn pitch of the winding layer 122 is an integer multiple of the braiding pitch of the first braided layer 121, so that the winding layer 122 can intersect with the braiding node of the first braided layer 121, which is beneficial to the setting of the limit point, which not only improves the convenience of setting the limit point 6, but also can improve the connection strength between the first braided layer 121 and the winding layer 122.

[0064] In the above embodiment, the first braided layer 121 at the distal end of the catheter body 1 and the limiting point 6 of the winding layer 122 are connected by laser welding. The laser welding weld is small, the welding effect is smooth and flat, and the weld is delicate and fine; non-contact processing does not produce external force on welding, and is suitable for welding parts that are difficult to contact; and the energy density is highly concentrated, the heating and cooling speeds during welding are extremely fast, the heat-affected zone is small, and the welding stress and deformation are very small; automatic welding, no welding wire or solder is required, no pollution, environmental protection and hygiene; the welding process is stable, the weld surface and internal quality are good, and the performance is high; it is not disturbed and does not require vacuum protection. In addition, pulsed laser welding uses a laser beam with alternating power for welding. Each laser pulse forms a weld on the weldment, which is mainly used for welding micro-precision components and microelectronic components. The size of the heating spot of pulsed laser welding is only a few thousand microns, so it is suitable for welding metal sheets, films, and metal filaments. It satisfies the formula p=4EΠd 2 t, where p is the power density on the laser spot (W / cm 2 ), E is the energy of the laser pulse (J), d is the spot diameter (cm), and t is the pulse width (s). There is a linear relationship between pulse energy and pulse width. At the same time, as the thickness of the weld increases, the laser pulse energy increases accordingly. The parameters of this laser welding are E of 1 to 5j, t of 2 to 5ms, and d of 0.01 to 0.05cm.

[0065] In another embodiment, the limiting point 6 of the first braided layer 121 and the winding layer 122 is fixed with an adhesive. Specifically, an instant adhesive containing α-cyanoacrylate adhesive, UV glue, and a cured adhesive film with good toughness, strong impact and shear resistance, and good weather resistance. A 0.01 cm needle can be used for dispensing, and the amount of dispensing is also adjusted to the minimum, so that the fixed wire is not woven at the same time, the thickness of the adhesive surface is small, the joint stress distribution is uniform, the fatigue resistance is good, the process is simple, and the production efficiency is high.

[0066] In another embodiment, the limiting points 6 of the first braided layer 121 and the winding layer 122 are fixed with metal wires such as stainless steel or nickel-titanium wires, and the wire diameter is 0.01 to 0.05 cm, which will not affect the overall thickness of the catheter. The specific fixing method is wire binding or forging, which can achieve a fixing effect without affecting other properties of the material, and is simple to operate and easy to implement.

[0067] Through the above three fixing methods, the winding layer 122 and the first braided layer 121 at the distal end of the catheter body 1 (i.e., the adjustable bending section) are fixed together, and the winding layer 122 will not be offset due to the continuous pulling of the wire drawing 3, thereby affecting the accuracy of the bending adjustment. By fixing the winding layer 122, the force of the winding layer 122 on the first braided layer 121 will not change each time the catheter body 1 is bent, and it is easier and more accurate to adjust, which can better meet the complex human lumen structure and reduce the operation time and risk.

[0068] In the above embodiment, at the distal end of the intermediate tube 12, the end of the winding layer 122 close to the developing ring 4 has a preset distance from the developing ring. Specifically, the preset distance is preferably 20 to 50 mm, so as to avoid the limit point 6 being too close to the developing ring 4, which causes the distal end of the catheter body 1 to bend unsmoothly.

[0069] It should be noted that the technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0070] Based on the above embodiments, the present invention further provides an interventional medical device, which includes the adjustable curved catheter structure described in any one of the first embodiment or the second embodiment. Thus, the adjustable curved catheter structure can be used to conveniently perform curved adjustment.

[0071] To summarize, the adjustable bend catheter structure provided in the embodiment of the present invention, by setting three layers of special braiding structure at the proximal end of the catheter body 1 and by setting two layers of special braiding result at the distal end of the catheter body 1, ensures that the proximal end of the catheter body has corresponding rigidity and the distal end of the catheter body has corresponding flexibility, which can meet the needs of interventional surgery.

[0072] In addition, by fixing the winding layer 122 in the bending section to the first braided layer 121 and heat treating the entire winding to eliminate stress, the winding layer 122 is less likely to shift during use and will not change each time the bending is adjusted, making each bending more precise and having better fatigue performance.

[0073] The above is a detailed description of the adjustable curved catheter structure and the corresponding interventional medical device provided by the present invention. For those skilled in the art, any obvious changes made to it without departing from the essence of the present invention will constitute an infringement of the patent right of the present invention and will bear the corresponding legal liability.

Claims

1. An adjustable curved conduit structure, characterized in that include: A catheter body, the catheter body comprising an inner tube, an intermediate tube and an outer tube which are sequentially sleeved from the inside to the outside; wherein a part of the intermediate tube near the proximal end of the catheter body comprises a first braided layer, a winding layer and a second braided layer which are sequentially arranged from the inside to the outside, and another part of the intermediate tube near the distal end of the catheter body comprises the first braided layer and the winding layer which are sequentially arranged from the inside to the outside; wherein on another part of the intermediate tube near the distal end of the catheter body, a limit point is provided at a position where a braiding node of the first braided layer intersects with the winding layer, so as to limit the relative position of the first braided layer and the winding layer and adjust the flexibility of the distal end of the catheter body; the braiding structure of the first braided layer and the second braided layer is the same, and the braided layers on multiple segments are braided and wound with braided wires of the same or different materials, so as to adjust the performance of the catheter body by using the braiding material, braiding method and braiding warp and weft density; the winding density of the winding layer at the proximal end is 10 to 30 turns per 10 mm, and the winding density at the distal end is 50 to 80 turns per 10 mm; the winding wire used in the winding layer is stress-relieved by heat treatment; A wire drawing tube, arranged between the first braided layer and the winding layer, wherein a wire drawing tube is provided with a wire drawing wire; A developing ring is disposed at the distal end of the catheter body and connected to the first end of the drawing wire; A handle adjuster is arranged at the proximal end of the catheter body and is connected to the second end of the wire drawing. The handle adjuster can drive the second end of the wire drawing to move back and forth, so as to drive the wire drawing to move back and forth in the wire drawing tube, thereby driving the distal end of the catheter body to bend to a set angle or restore to its original state.

2. The adjustable curved conduit structure according to claim 1, characterized in that: The setting of the limit point is determined based on the lesion location, the hardness of the outer tube and the number of turns of the winding layer.

3. The adjustable curved conduit structure according to claim 2, characterized in that When the lesion is located at a distal arterial branch; If the outer tube has a first hardness t1 and the winding layer has a first number of turns n1, a plurality of continuous and non-interval limiting points are provided on both sides of the distal end of the intermediate tube; If the outer tube has a second hardness t2 and the winding layer has a second number of turns n2, a plurality of continuous and non-interval limiting points are provided on one side of the distal end of the intermediate tube, and a plurality of interval limiting points are provided on the other side of the distal end of the intermediate tube; If the outer tube has a third hardness t3 and the winding layer has a third number of turns n3, a plurality of spaced limiting points are provided on both sides of the distal end of the intermediate tube; Among them, t1<t2<t3, n1≤n2≤n3.

4. The adjustable curved conduit structure according to claim 3, characterized in that When the lesion is located at a proximal thick arterial branch; If the outer tube has a fourth hardness t4 and the winding layer has a fourth number of turns n4, a plurality of continuous and non-interval limiting points are provided on both sides of the distal end of the intermediate tube; If the outer tube has a fifth hardness t5 and the winding layer has a fifth number of turns n5, a plurality of continuous and non-interval limiting points are provided on one side of the distal end of the intermediate tube, and a plurality of interval limiting points are provided on the other side of the distal end of the intermediate tube; If the outer tube has a sixth hardness t6 and the winding layer has a sixth number of turns n6, a plurality of spaced limiting points are provided on both sides of the distal end of the intermediate tube; Among them, t1<t2<t3<t4<t5<t6, n1≤n2≤n3≤n4≤n5≤n6.

5. The adjustable curved conduit structure according to claim 1, characterized in that: The first braided layer has a preset braiding pitch L, L=C / 2P, in inches; wherein C is the total number of spindles in the first braided layer, and P is the number of crosses per inch on the first braided layer; The winding layer has a preset turn distance D, D=xL; wherein x is a positive integer greater than or equal to 2.

6. The adjustable curved conduit structure according to claim 1, characterized in that: The catheter body has a variable hardness such that the hardness of the catheter body gradually increases from the distal end of the catheter body to the proximal end of the catheter body.

7. The adjustable curved conduit structure according to any one of claims 1 to 6, characterized in that: A recessed portion is formed on the outer side of the first braided layer and / or the inner side of the winding layer, and the wire drawing tube is clamped in the recessed portion to limit the relative position of the wire drawing tube.

8. The adjustable curved conduit structure according to any one of claims 1 to 6, characterized in that: At the distal end of the intermediate tube, an end of the winding layer close to the developing ring has a preset distance from the developing ring.

9. An interventional medical device, characterized in that The invention comprises the adjustable curved conduit structure as described in any one of claims 1 to 7.

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