CN211560260U - Sectional type adjustable bending micro-catheter - Google Patents

Abstract

The utility model provides a sectional adjustable-bending micro-catheter, which comprises a catheter body and a traction mechanism, wherein the catheter body comprises an inner membrane tube, a first reinforced layer and a second reinforced layer which are sleeved outside the inner membrane tube, and an outer layer which wraps and is welded with the inner membrane tube, the first reinforced layer and the second reinforced layer; the far end of the tube body is an adjustable bending section, and the rest part is a main body section; the first reinforcing layer extends axially in the corresponding adjustable bending section, the second reinforcing layer extends axially in the corresponding main body section, and the rigidity of the second reinforcing layer is larger than that of the first reinforcing layer. When the adjustable bending section is bent, the main body section is less influenced by the bending of the adjustable bending section due to the support of the second reinforcing layer on the main body section, so that the main body section is prevented from being subjected to unexpected bending deformation, and the main body section has less influence on the adjustable bending section, so that the adjustable bending section can keep an ideal bending state.

Description

Segmented Bendable Microcatheter

technical field

The utility model relates to the technical field of medical devices, in particular to a segmented adjustable bendable micro-catheter.

Background technique

Chronic Total Occlusion of Coronary Artery (CTO) refers to the complete occlusion of the original coronary artery, confirmed by coronary angiography with a blood flow rating of 0 for thrombolysis in myocardial infarction (TIMI), and its occlusion time is greater than or equal to 3 months of disease.

Clinically, percutaneous coronary intervention (PCI) is mainly used to treat CTO lesions. The general steps of PCI include insertion of a guide wire, balloon dilation, stent placement and necessary posterior expansion, wherein the guide wire needs to be movably inserted into the microcatheter and passed through the vascular occlusion segment under the support of the microcatheter. If the distal end of the microcatheter does not have a bending function, the distal end of the microcatheter may abut against the vessel wall, which makes it easy for the guidewire to enter the false lumen of the diseased vessel, resulting in complications such as coronary dissection or perforation. If the distal end of the microcatheter has a bending function, the distal end of the microcatheter can be used to control the advancing direction of the guide wire to prevent the guide wire from adhering to the vessel wall and entering the false lumen, thereby reducing the probability of complications such as coronary dissection or perforation.

The following technical problems generally exist in the bendable microcatheter in the prior art: the microcatheter tube body includes a main body section at the proximal end and a bendable section at the distal end, and the bendable section is a continuation of the main body section, and the bendable section There is a uniform and continuous integral braided mesh reinforcement layer in the main body section, so when the adjustable bending section is bent, it will inevitably affect the main body section, causing the main body section to undergo undesired bending deformation, and then The body segment will in turn influence the bendable segment to deviate from the ideal bend state.

Utility model content

The purpose of the present invention is to overcome the deficiencies of the prior art and provide a segmented adjustable bendable micro-catheter, the adjustable bendable segment at the distal end of which has less influence on the main body segment when bent, and the adjustable bendable segment can maintain a relatively The ideal bent state.

In order to solve the above technical problems, the utility model provides a segmented adjustable bendable micro-catheter, which includes a tube body and a traction mechanism, the tube body includes an endometrial tube, a first reinforcing layer and a second reinforcing layer sleeved outside the endometrial tube. The reinforcement layer, and the outer layer wrapping and welding the inner membrane tube, the first reinforcement layer and the second reinforcement layer; the distal end of the tube body is the bendable section, and the rest is the main body section; the first reinforcement layer corresponds to the bendable section The inner part of the segment extends in the axial direction, the second reinforcement layer extends axially in the corresponding main body segment, and the rigidity of the second reinforcement layer is greater than that of the first reinforcement layer; The anchoring ring is fixed in the distal end of the adjustable bendable segment, one end of the traction wire is fixed with the anchoring ring, and the other end protrudes from the proximal end of the main body segment.

The pipe body of the segmented adjustable bendable micro-catheter of the present invention includes an adjustable bendable section and a main body section, a first reinforcement layer is arranged in the bendable section, a second reinforcement layer is arranged in the main body section, and the second reinforcement layer is arranged in the main body section. The stiffness of the layer is greater than the stiffness of the first reinforcement layer. When the pulling wire is pulled toward the proximal end to drive the bendable segment to bend, due to the support of the second reinforcing layer to the main body segment, the main body segment is less affected by the bending of the adjustable bendable segment, thereby avoiding undesired bending deformation of the main body segment, and vice versa. The main body segment has less influence on the adjustable segment, so that the adjustable segment can maintain an ideal bending state and improve the success rate of the operation.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the implementation manner. Obviously, the accompanying drawings in the following description are some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

FIG. 1 is a schematic structural diagram of a segmented adjustable bendable microcatheter according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of the tubular body of the segmented bendable microcatheter of FIG. 1 .

FIG. 3 is a schematic cross-sectional view taken along line III-III in FIG. 2 .

FIG. 4 is a schematic cross-sectional view taken along the line IV-IV in FIG. 2 .

FIG. 5 is a schematic cross-sectional view taken along the line V-V in FIG. 2 .

FIG. 6 is a schematic cross-sectional view taken along line VI-VI in FIG. 2 .

FIG. 7 is a partial side view of the tubular body of the segmented bendable microcatheter in FIG. 2 with the outer layer removed.

Fig. 8 is a partial side view of the second embodiment of the tubular body of the segmented bendable microcatheter after removing the outer layer.

FIG. 9 is a partial side view of the tubular body of the segmented bendable microcatheter after removing the outer layer of the third embodiment.

FIG. 10 is a partial side view of the tube body of the segmented bendable microcatheter after removing the outer layer of the fourth embodiment.

FIG. 11 is a partial side view of the tube body of the segmented bendable microcatheter after removing the outer layer of the fifth embodiment.

FIG. 12 is a partial side view of the tube body of the segmented bendable microcatheter after removing the outer layer of the sixth embodiment.

FIG. 13 is a schematic cross-sectional view taken along line XIII-XIII in FIG. 12 .

FIG. 14 is a schematic cross-sectional view taken along line XIV-XIV in FIG. 12 .

FIG. 15 is a schematic cross-sectional view taken along line XV-XV in FIG. 12 .

16 is a schematic side view of the tube body of the segmented bendable micro-catheter provided by the present invention in a bending state.

FIG. 17 is a schematic three-dimensional structural diagram of the tube body of the segmented adjustable bendable micro-catheter provided by the present invention in a bend-adjusted state.

FIG. 18 is a schematic diagram of the segmented bendable microcatheter provided by the present invention when it is used for the treatment of chronic total occlusive coronary artery disease.

Detailed ways

The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the implementations. example. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

In addition, the following descriptions of the various embodiments refer to the accompanying drawings to illustrate specific embodiments in which the present invention may be practiced. The directional terms mentioned in the present utility model, such as "up", "down", "front", "rear", "left", "right", "inside", "outside", "side", etc., Only refer to the orientation of the attached drawings, therefore, the directional terms used are for better and clearer description and understanding of the present invention, rather than indicating or implying that the referred device or element must have a specific orientation, a specific orientation, and a specific orientation. Therefore, it should not be construed as a limitation on the present invention.

Orientation definition: For the sake of clarity, the end close to the operator is referred to as the "proximal end" and the end away from the operator is referred to as the "distal end" during the operation. This definition is only for the convenience of expression, and should not be construed as a limitation of the present invention. "Axial" refers to the direction of the axis of the pipe body.

Please refer to FIG. 1 and FIG. 2 , the present invention provides a segmented adjustable bendable microcatheter 100 , which includes a tube body 20 , a handle 40 disposed at the proximal end of the tube body 20 , and a handle 40 disposed in the tube body 20 and the handle 40 . traction mechanism. The distal end of the tube body 20 is the adjustable bendable section 22 , and the tube body 20 is the main body section 24 except the adjustable bendable section 22 . The adjustable bendable section 22 can be bent by operating the traction mechanism and maintain an ideal bending state. The segmented adjustable bendable microcatheter 100 of the present invention is especially suitable for treating CTO lesions.

As shown in FIG. 2 , the tube body 20 includes an intima tube 201 , a first reinforcement layer 204 and a second reinforcement layer 205 sheathed outside the intima tube 201 , wrapping and welding the intima tube 201 , the first reinforcement layer 204 and The outer layer 202 of the second reinforcing layer 205 and the connecting ring 206 welded in the outer layer 202 . The first reinforcing layer 204 extends axially corresponding to the adjustable bendable segment 22 ; the second reinforcing layer 205 extends axially corresponding to the main body segment 24 , and the rigidity of the second reinforcing layer 205 is greater than that of the first reinforcing layer 204 , The adjustable bendable section 22 is easy to bend, while the main body section 24 is less bendable. The connecting ring 206 is sleeved on the outer periphery of the proximal end of the first reinforcement layer 204 and the distal end of the second reinforcement layer 205 . The distal portion of the tubular body 20 at the connecting ring 206 is the bendable section 22 , and the proximal portion of the tubular body 20 at the connecting ring 206 is the main body section 24 . The traction mechanism includes an anchoring ring 61 disposed at the distal end of the adjustable bendable segment 22 and at least one traction wire 63 movably inserted into the tube body 20. The distal end of the traction wire 63 is fixedly connected to the anchoring ring 61, and the traction wire 63 It is slidably passed through the tube body 20 along the extending direction of the tube body 20 , and the proximal end of the pulling wire 63 protrudes from the proximal end of the main body section 24 . Driving the traction wire 63 to pull the anchor ring 61 toward the proximal end can drive the adjustable bendable section 22 provided with the first reinforcing layer 204 to bend, and the first reinforcing layer 204 elastically deforms until the adjustable bendable section 22 is bent in place; When the pulling wire 63 pulls the anchoring ring 61 , the first reinforcing layer 204 is elastically reset to drive the adjustable bending section 22 to reset.

The tube body 20 of the segmented adjustable bendable microcatheter 100 in the present invention includes an adjustable bendable section 22 , a main body section 24 and a connection welded in the outer layer 202 and located between the adjustable bendable section 22 and the main body section 24 Ring 206, a first reinforcing layer 204 is arranged in the adjustable bendable section 22, and a second reinforcing layer 205 is arranged in the main body section 24. The rigidity of the second reinforcing layer 205 is greater than that of the first reinforcing layer 204, and the pulling wire 63 is pulled towards the proximal end It can drive the bendable section 22 to bend, but due to the support of the main body section 24 by the second reinforcement layer 205 with greater rigidity, the force generated by the bending of the bendable section 22 is not enough to change the strength of the second reinforcement layer 205 and the main body section 24. Therefore, the main body section 24 is less affected by the bending of the adjustable bending section 22, so that undesired bending deformation of the main body section 24 can be avoided. The curved segment 22 can approach and maintain an ideal curved state, thereby improving the success rate of the operation.

The first reinforcement layer 204 and the second reinforcement layer 205 are independent of each other, and the connecting ring 206 is sleeved on the outer periphery of the proximal end of the first reinforcement layer 204 and the outer periphery of the distal end of the second reinforcement layer 205 . The intimal tube 201 axially forms a tube lumen 2011 for threading a guide wire. The outer layer 202 thermally fuses the connecting ring 206 , the first reinforcing layer 204 , the second reinforcing layer 205 and the inner membrane tube 201 into one. Specifically, the first reinforcement layer 204 and the second reinforcement layer 205 are in axial contact, and the proximal end of the first reinforcement layer 204 and the distal end of the second reinforcement layer 205 can be shaped by a high temperature heat treatment above 100° C. or a polymer heat shrinkable film heat shrinking to prevent the proximal end of the first reinforcement layer 204 and the distal end of the second reinforcement layer 205 from spreading apart; the connecting ring 206 is sleeved on the periphery of the contact point between the first reinforcement layer 204 and the second reinforcement layer 205, More reliably prevent the first reinforcement layer 204 and the second reinforcement layer 205 from spreading apart at the contact point; the outer layer 202 is thermally fused on the first reinforcement layer 204, the second reinforcement layer 205 and the connection ring 206, which can prevent the connection ring 206 . The first reinforcement layer 204 and the second reinforcement layer 205 are moved to further strengthen the connection reliability of the first reinforcement layer 204 and the second reinforcement layer 205 , and ensure the strength of the connection between the bendable section 22 and the main body section 24 .

As shown in FIG. 2 and FIG. 3 , in this embodiment, the pulling mechanism 60 includes four pulling wires 63 , the distal end of each pulling wire 63 is fixedly connected to the anchoring ring 61 , and the proximal end of each pulling wire 63 is along the tube body The extension direction of 20 extends and protrudes from the proximal end of the main body section 24 , and the pulling wire 63 can slide in the axial direction in the tubular body 20 . The four pulling wires 63 are arranged in a circumferential array of the anchoring ring 61 , that is, the central angle corresponding to the two adjacent pulling wires 63 is 90 degrees. Pulling different traction wires 63 toward the proximal end can bend the adjustable section 22 in four different directions, that is, pull one of the traction wires 63 toward the proximal end, and the adjustable section 22 faces where the one of the traction wires 63 is located. Side bend.

Of course, in other implementations, the pulling mechanism 60 may include two pulling wires 63, or three pulling wires 63, or more than four pulling wires 63, all of which are arranged along the circumferential array of the anchoring ring 61, so as to correspondingly make The adjustable bendable section 22 can be bent in two, or three, or four or more different directions.

In some embodiments, the anchoring ring 61 is sleeved on the intima tube 201 , and the inner peripheral surface of the anchoring ring 61 is attached to the outer peripheral surface of the intimal tube 201 , the inner peripheral surface of the first reinforcing layer 204 and the second The inner peripheral surface of the reinforcing layer 205 is all attached to the outer peripheral surface of the intima tube 201 to reduce the overall thickness of the tube body 20 .

As shown in FIG. 2, FIG. 4 to FIG. 6, the outer layer 202 is provided with a wire threading tube 65 equal to the number of the traction wires 63 on the outer side of the intimal tube 201 along the extending direction of the tube body 20, and the anchoring ring 61 is disposed at the distal end of the wire threading tube 65 . The inner cavity of the wire threading tube 65 forms a pulling wire cavity 650 along the extending direction of the tube body 20 . The outer layer 202 fuses the first reinforcement layer 204 , the second reinforcement layer 205 , the connecting ring 206 , the wire threading tube 65 and the inner membrane tube 201 into one body. In this embodiment, the outer peripheral surface of the wire threading tube 65 is attached to the outer peripheral surface of the intima tube 201 to reduce the thickness of the tube body 20;

In other embodiments, the wire threading tube 65 may also be located between the intima tube 201 and the first reinforcing layer 204 and the second reinforcing layer 205 .

In this embodiment, the number of the pulling wires 63 is four, and the number of the corresponding threading tubes 65 is also four. The four wire threading tubes 65 are arranged in a circumferential array around the anchoring ring 61 , a pulling wire 63 is axially passed through the pulling wire cavity 650 of each wire threading tube 65 , and the distal end of each pulling wire 63 is fixedly connected on the anchor ring 61 . The central angle corresponding to the two adjacent wire threading tubes 65 is 90 degrees. The pulling wires 63 can slide in the corresponding wire threading tubes 65, and pulling the pulling wires 63 in different wire threading tubes 65 toward the proximal end can bend the adjustable bendable section 22 in four different directions.

Of course, in other implementations, two, or three, or more than four wire threading tubes 65 may be correspondingly provided according to the number of the pulling wires 63 included in the pulling mechanism 60 .

In some other embodiments, the inner peripheral surfaces of the first reinforcement layer 204 and the second reinforcement layer 205 may fit the outer peripheral surface of the wire threading tube 65 to reduce the thickness of the tube body 20 .

Specifically, the inner membrane tube 201 is a flexible tube body with an inner diameter of 0.1 mm-1.0 mm, and the inner membrane tube 201 can be made of thermoplastic plastics such as polytetrafluoroethylene (PTFE), nylon, and fluorinated ethylene propylene copolymer (FEP). to make.

The inner diameter of the connecting ring 206 ranges from 0.4mm to 1mm, and its material can be selected from metal rings such as stainless steel, platinum, gold, tungsten, tantalum, etc., or can be selected from polyimide (PI), polytetrafluoroethylene (PTFE) , Polyethylene terephthalate (PET) and other polymer material rings. When the connecting ring 206 adopts a developing material such as platinum, gold, tantalum, etc., the connecting ring 206 also has a developing function, so as to observe the bending starting position of the adjustable bending section 22 .

The outer layer 202 can be selected from thermoplastic materials such as polyurethane polymer, block polyamide, nylon, etc. The outer layer 202 is covered and welded with the first reinforcement layer 204, the second reinforcement layer 205 and the connecting ring 206 through a hot-melting process, and is connected to the outer layer 204. The outer peripheral surfaces of the intimal tube 201 and the threading tube 65 are combined to form the tube body 20 .

The wire threading tube 65 can be a pipe body with an inner diameter of 0.05mm-0.3mm, and the wire threading tube 65 can be made of polytetrafluoroethylene (PTFE), polyethylene terephthalate (PET), polyimide (PI) It can also be made of stainless steel, nickel titanium and other metal materials. The distal end of the pulling wire 63 and the anchoring ring 61 can be fixed by bonding, welding or overlapping.

In this embodiment, the anchoring ring 61 is sleeved on the outer peripheral surface of the distal end of the intimal tube 201 , the inner diameter of the anchoring ring 61 can be 0.4mm-1.0mm, and the anchoring ring 61 can be made of stainless steel, platinum, gold, tungsten , tantalum and other metals or their alloys. Preferably, the anchoring ring 61 is made of radiopaque metal material such as tantalum, so that the anchoring ring 61 also has a developing function, so as to observe the bending end position of the adjustable bendable segment 22 and determine the adjustable bendable segment 22 Whether the bending state is as expected.

The traction wire 63 can be made of stainless steel, nickel-titanium and other alloy wires with a diameter of 0.05mm-0.25mm, and can also be made of nylon, polytetrafluoroethylene and other polymer material wires.

The first reinforcement layer 204 is made of a first wire material, and the second reinforcement layer 205 is made of a second wire material, and at least one of the cross-sectional area, density, and material stiffness of the second wire material is greater than the Corresponding cross-sectional area, density, and material stiffness of the first filaments make the stiffness of the second reinforcing layer 205 greater than the stiffness of the first reinforcing layer 204 .

Preferably, the first reinforcement layer 204 has a spiral structure (similar to a spring shape) or a woven mesh structure, and the second reinforcement layer 205 has a spiral structure or a woven mesh structure.

Specifically, please refer to FIG. 2 to FIG. 7 together. In the first embodiment of the segmented adjustable bendable microcatheter, the first wire material of the first reinforcing layer 204 is sleeved on the outer circumference of all the wire threading tubes 65 The second wire of the second reinforcing layer 205 is a helical structure that is sheathed on the outer peripheral surface of all wire threading tubes 65 and is located at the proximal side of the connecting ring 206 . The helical structure of the first reinforcement layer 204 and the helical structure of the second reinforcement layer 205 have the same density and material stiffness, and the density of the helical structure refers to the number of turns of the helix per unit length in the axial direction. The first wire is a round wire, the second wire is a round wire, and the diameter of the second wire is larger than the diameter of the first wire, so that the cross-sectional area of the second wire is larger than that of the first wire The cross-sectional area of the material is adjusted so that the stiffness of the second reinforcement layer 205 is greater than that of the first reinforcement layer 204 .

Preferably, the wire diameter of the second wire material is 1.5 times to 4 times the wire diameter of the first wire material; more preferably, the ratio of the wire diameter of the first wire material to the wire diameter of the second wire material 1:2 or 1:3.

As shown in FIG. 8 , the structure of the second embodiment of the segmented bendable microcatheter is similar to that of the first embodiment, except that the wire diameter of the first wire of the first reinforcing layer 204 is the same as that of the first embodiment. The second wires of the second reinforcing layer 205 have the same wire diameter (ie: cross-sectional area) and the same material stiffness, and the density of the helical structure of the first wire is smaller than the density of the helical structure of the second wire, so that the first The stiffness of the reinforcement layer 204 is smaller than that of the second reinforcement layer 205 .

As shown in FIG. 9 , the structure of the third embodiment of the segmented adjustable bendable microcatheter is similar to the first embodiment, except that the first wire and the second reinforcing layer of the first reinforcing layer 204 are different. The second filaments of 205 have the same material stiffness and the same density, the first filaments of the first reinforcing layer 204 are round filaments, the second filaments of the second reinforcing layer 205 are flat filaments, and the cross-section of the flat filaments is the same. The thickness is greater than or equal to the wire diameter of the round wire, the width of the cross section of the flat wire is greater than the wire diameter of the round wire, so that the cross-sectional area of the second wire material is greater than the cross-sectional area of the first wire material, so that the stiffness of the first reinforcement layer 204 is smaller than that of the second reinforcement layer 205 . Preferably, the ratio of the width to the thickness of the cross-section of the flat wire ranges from 1.5 to 4; more preferably, the ratio of the width to the thickness of the cross-section of the flat wire is 2 or 3.

As shown in FIG. 10 , the structure of the fourth embodiment of the segmented adjustable bendable microcatheter is similar to that of the first embodiment, except that the first wire of the first reinforcing layer 204 is a helical structure, and the first The second wire material of the second reinforcing layer 205 is a woven mesh structure, and the rigidity of the woven mesh structure is greater than that of the helical structure.

Specifically, the first wire material of the first reinforcing layer 204 is a helical structure sleeved on the outer peripheral surface of all the wire threading tubes 65 and located at the far side of the connecting ring 206, and the helical structure can be a round wire or a flat wire; The second wire material of the second reinforcing layer 205 is a braided mesh structure sleeved on the outer peripheral surface of all the wire threading tubes 65 and located near the connection ring 206 , and the braided mesh structure adopts a round wire or a flat wire. The first wire and the second wire have the same cross-sectional area and the same material stiffness, but the density of the second wire is greater than that of the first wire, so that the stiffness of the second reinforcing layer 205 is greater than that of the first reinforcing layer 204 stiffness. The density of the helical structure refers to the number of turns of the helix per unit length in the axial direction, and the density of the woven mesh structure refers to the number of wires cut out per unit length in the axial direction.

As shown in FIG. 11 , the structure of the fifth embodiment of the segmented adjustable bendable microcatheter is similar to that of the first embodiment, except that the first wire material of the first reinforcing layer 204 is a woven mesh structure, The second wire material of the second reinforcing layer 205 is a helical structure, and the rigidity of the helical structure is greater than that of the woven mesh structure.

Specifically, the first wire material of the first reinforcing layer 204 is a braided mesh structure sleeved on the outer peripheral surfaces of all the wire threading tubes 65 and located at the far side of the connecting ring 206 , and the braided mesh structure can be a round wire or a flat wire. Wire; the second reinforcing layer 205 is a helical structure sleeved on the outer peripheral surface of all wire threading tubes 65 and located at the proximal side of the connecting ring 206, and the helical structure can be round wire or flat wire. Under the condition of the same material stiffness and the same density, the cross-sectional area of the second wire material is larger than the cross-sectional area of the first wire material, so that the stiffness of the second reinforcing layer 205 is greater than that of the first reinforcing layer 204 . Under the condition of the same material stiffness and the same cross-sectional area, the density of the second filaments is greater than the density of the first filaments, so that the stiffness of the second reinforcement layer 205 is greater than that of the first reinforcement layer 204 ; In the case of the same cross-sectional area and the same density, the first wire and the second wire are made of different materials, and the material stiffness of the second wire is greater than that of the first wire, such as the first wire Stainless steel wire is used as the wire material, and nickel-titanium wire is used as the second wire material, so that the stiffness of the second reinforcement layer 205 is greater than that of the first reinforcement layer 204 .

As shown in FIGS. 12 to 15 , the structure of the sixth embodiment of the segmented adjustable bendable microcatheter is similar to that of the first embodiment, except that the first wire of the first reinforcing layer 204 is the first Woven mesh structure, the second wire material of the second reinforcing layer 205 is a second woven mesh structure, the first wire material and the second wire material have the same material stiffness and the same density, the first wire material and the second wire material They are all round wires, but the wire diameter of the second wire is larger than that of the first wire, that is, the cross-sectional area of the second wire is larger than the cross-sectional area of the first wire, so that the stiffness of the second reinforcing layer 205 is greater than that of the first wire. Stiffness of reinforcement layer 204 .

In other embodiments, both the first wire material and the second wire material may adopt a woven mesh structure. Under the condition of the same material stiffness and the same cross-sectional area, the density of the second wire material is greater than that of the second wire material. The density of the first wires can make the stiffness of the second reinforcing layer 205 greater than the stiffness of the first reinforcing layer 204. Preferably, the density of the second wires is 1.5 times the density of the first wires -3 In the case of the same cross-sectional area and the same density, the first wire and the second wire are made of different materials, and the material stiffness of the second wire is greater than that of the first wire, such as The first wire material is made of stainless steel wire, and the second wire material is made of nickel-titanium wire, so that the stiffness of the second reinforcement layer 205 is greater than that of the first reinforcement layer 204 .

The above embodiment only enumerates that the first wire and the second wire have the same three parameters of material stiffness, cross-sectional area and density, and the corresponding two parameters are the same, and the other parameter is that the second wire is larger than the first wire. The wire material makes the stiffness of the second reinforcement layer 205 greater than the stiffness of the first reinforcement layer 204 . It is not difficult to understand that in other embodiments, one parameter corresponding to the second wire material and the second wire material can also be set to be the same, and the other two parameters are that the second wire material is larger than the first wire material, or even the second wire material is larger than the first wire material. The three parameters of the second wire material are all corresponding to greater than the three parameters of the first wire material, so that the stiffness of the second reinforcement layer 205 is significantly greater than that of the first reinforcement layer 204 .

Further, in some embodiments, the stiffness of the outer layer 202 of the main body section 24 is greater than the stiffness of the outer layer 202 of the adjustable bending section 22. The specific implementation method is: the outer layer 202 of the main body section 24 adopts a higher stiffness than the adjustable bending section. The outer layer 202 of the 22 has a higher hardness material, for example, the outer layer 202 of the adjustable bending section 22 is made of block polyamide with a shore hardness of 35D, and the outer layer 202 of the main body section 24 is made of a block polyamide with a shore hardness of 72D. amide; or the outer layer 202 of the main body segment 24 heat-melts more thermoplastic material than the outer layer 202 of the adjustable bendable segment 22, thereby ensuring that the rigidity of the outer layer 202 of the main body segment 24 is greater than that of the outer layer 202 of the adjustable bendable segment 22 stiffness.

As shown in FIG. 1 , the proximal end of the handle 40 is provided with a Luer connector 43 , the middle of the handle 40 is provided with a drive mechanism 45 that can move in the axial direction, the drive mechanism 45 includes several sliders 450 , and the proximal end of the traction wire 63 is fixed Connected to the corresponding sliding block 450 , each sliding block 450 sliding along the axial direction can drive the corresponding pulling wire 63 to slide. Specifically, a plurality of guide grooves 42 are axially defined in the middle of the housing of the handle 40 , and the guide grooves 42 are arranged in an array along the circumferential direction of the handle 40 . The distal end of each pulling wire 63 is fixedly connected to the anchoring ring 61 , and the proximal end is fixedly connected to the corresponding slider 450 . By pulling the sliding block 450 in the axial direction to make the corresponding pulling wire 63 pull the anchoring ring 61 , the bending function of the adjustable bending section 22 can be realized. Since the stiffness of the second reinforcing layer 205 is greater than that of the first reinforcing layer 204, the stiffness of the main body section 24 is greater than that of the adjustable bending section 22. When the pulling wire 63 is pulled to bend the adjustable bending section 22, the adjustable bending section 22 can be bent. The influence of the bending section 22 on the main body section 24 is small, and the main body section 24 can basically remain in a straight state, so that the main body section 24 will not adversely affect the adjustable bending section 22, so that the adjustable bending section 22 can achieve and maintain a relatively ideal bent state.

As shown in FIG. 1 and FIG. 17 , different sliders 450 are pulled toward the proximal end to drive the corresponding pulling wire 63 to move toward the proximal end, so that the adjustable bendable sections 22 can be bent in four different directions respectively.

Please refer to FIG. 18 , when the segmented bendable microcatheter 100 of the present invention is actually applied to the treatment of chronic total occlusive disease of coronary artery (CTO), the tube body 20 enters the target blood vessel 82 through the branch blood vessel 81 and can be bent After the segment 22 is adjusted and bent to the ideal state, the guide wire 90 is pierced from the distal end of the tube body 20, and can penetrate the vascular occlusion segment 80 from the middle position of the blood vessel, preventing the guide wire 90 from entering between the intima 83 and the adventitia 85 of the blood vessel. The vascular false lumen 84 is formed.

The above are the implementations of the embodiments of the present invention. It should be pointed out that for those skilled in the art, without departing from the principles of the embodiments of the present invention, several improvements and modifications can also be made. These improvements and Retouching is also regarded as the protection scope of the present invention.

Claims (12)

1. A sectional type bending-adjustable microcatheter is characterized by comprising a tube body and a traction mechanism;

the pipe body comprises an inner film pipe, a first reinforcing layer and a second reinforcing layer which are sleeved outside the inner film pipe, and an outer layer which wraps and is welded with the inner film pipe, the first reinforcing layer and the second reinforcing layer; the far end of the tube body is an adjustable bending section, and the rest part of the tube body is a main body section; the first reinforcing layer extends axially in the corresponding adjustable bending section, the second reinforcing layer extends axially in the corresponding main body section, and the rigidity of the second reinforcing layer is greater than that of the first reinforcing layer;

the traction mechanism comprises an anchoring ring and at least one traction wire movably arranged in the tube body in a penetrating mode, the anchoring ring is fixed in the far end of the adjustable bending section, one end of the traction wire is fixed with the anchoring ring, and the other end of the traction wire extends out of the near end of the main body section.

2. The segmented tunable curved microcatheter of claim 1, wherein a connecting ring is further fused within the outer layer, the connecting ring surrounding the outer periphery of the proximal end of the first reinforcing layer and the distal end of the second reinforcing layer.

3. The segmented tunable curved microcatheter of claim 2, wherein the connecting ring is made of a radiopaque metallic material.

4. The segmented tunable curved microcatheter of claim 1, wherein the first reinforcement layer is fabricated from a first wire and the second reinforcement layer is fabricated from a second wire, the second wire having at least one of a cross-sectional area, a density, a material stiffness greater than the corresponding cross-sectional area, density, material stiffness of the first wire such that the stiffness of the second reinforcement layer is greater than the stiffness of the first reinforcement layer.

5. The segmented tunable curved microcatheter of claim 4, wherein the first reinforcing layer is in a helical or woven mesh configuration and the second reinforcing layer is in a helical or woven mesh configuration.

6. The segmented tunable curved microcatheter of claim 5, wherein the first reinforcement layer and the second reinforcement layer are both in a helical structure or a woven mesh structure, the first wire and the second wire are the same in density and material stiffness, the first wire is a round wire, the second wire is a round wire, and the diameter of the second wire is greater than the diameter of the first wire; or the first wire material is a round wire, the second wire material is a flat wire, the thickness of the section of the second wire material is larger than or equal to the diameter of the first wire material, and the width of the section of the second wire material is larger than the diameter of the second wire material.

7. The segmented tunable curved microcatheter of claim 5, wherein the first reinforcement layer and the second reinforcement layer are each in a helical or woven mesh structure, the first wires and the second wires have the same cross-sectional area and material stiffness, and the second wires are more dense than the first wires.

8. The segmented tunable curved microcatheter of claim 5, wherein the first wire and the second wire have the same cross-sectional area and material stiffness, the first reinforcing layer is in a helical configuration, the second reinforcing layer is in a woven mesh configuration, and the second wire is denser than the first wire.

9. The segmented tunable curved microcatheter of claim 5, wherein the first reinforcement layer and the second reinforcement layer are each in a helical or woven mesh structure, the first wire and the second wire are of the same cross-sectional area and density, and the second wire has a material stiffness greater than the first wire.

10. The segmented tunable curved microcatheter of claim 1, wherein said pulling mechanism comprises a plurality of pulling wires, a plurality of threading tubes are fusion bonded within said outer layer, said plurality of threading tubes are arranged in a circumferential array around said anchoring ring, and a corresponding pulling wire is threaded within a corresponding one of said threading tubes.

11. The segmented tunable curved microcatheter according to any of claims 1-10, wherein the proximal end of the first reinforcing layer and the distal end of the second reinforcing layer are both shaped.

12. The segmented, adjustable bend microcatheter of claim 1, further comprising a handle attached to the proximal end of said body, wherein a drive mechanism is disposed within said handle, said drive mechanism comprising at least one slide that slides axially, a proximal end of said pull wire being correspondingly attached to said slide.

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