Microcatheter and microcatheter bending control method

Abstract

The present invention discloses a microcatheter and a microcatheter bending control method, which comprises: an inner tube; an outer tube, the outer tube is concentrically arranged on the outside of the inner tube; a developing ring, an annular accommodation space is formed between the inner tube and the outer tube, the developing ring is at least arranged at the distal end of the accommodation space, and the developing ring connects the inner tube and the outer tube respectively; an operating wire, the operating wire is arranged in the accommodation space, and the distal end of the operating wire is fixed relative to the developing ring. This structural improvement can enable the microcatheter to have the ability to control bending, avoid the current situation where the microcatheter needs to be pre-shaped, and reduce the complexity of the operation of the microcatheter. At the same time, the radial size of the microcatheter can also meet the requirements.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a microcatheter and a microcatheter bending control method. Background Art

[0002] As medical device-related products are gradually improved, related vascular intervention technologies continue to mature. However, for smaller blood vessels and blood vessels with more complex pathways, such as intracranial blood vessels, coronary blood vessels and peripheral small blood vessels (organs such as the liver and kidneys), more complex procedures such as TACE (transcatheter hepatic arterial chemoembolization) and the treatment of peripheral and intracranial vascular aneurysms require the delivery of embolic microspheres and coils, all of which require microcatheters as key interventional tools. The defects of existing interventional microcatheters on the market are as follows: Due to the small diameter of the microcatheter, it is difficult to arrange structures such as bend control to adjust the shape of the catheter inside the microcatheter. Therefore, for complex access procedures, not only does it require repeated pre-shaping of the microcatheter, resulting in complicated operations, but it also places high professional requirements on medical staff. Doctors need to have many years of interventional experience. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the defect of complicated operation of microcatheter in the prior art and to provide a microcatheter and a microcatheter bending control method.

[0004] The present invention solves the above technical problems through the following technical solutions:

[0005] A microcatheter, comprising:

[0006] Inner tube;

[0007] An outer tube, the outer tube is concentrically arranged outside the inner tube;

[0008] A developing ring, which forms an annular accommodation space between the inner tube and the outer tube, the developing ring being arranged at least at the distal end of the accommodation space, and the developing ring is respectively connected to the inner tube and the outer tube;

[0009] An operating wire is arranged in the accommodating space, and a distal end of the operating wire is fixed relative to the developing ring.

[0010] By arranging the inner tube and the outer tube concentrically with each other, a accommodating space for accommodating a developing ring and an operating wire is formed between the inner tube and the outer tube, wherein the developing ring is respectively connected to the inner tube and the outer tube to fix the distal end of the entire microcatheter, and the developing ring is used as a fixing object for the operating wire, and there is no need to set a wire pull ring.

[0011] This connection scheme requires a smaller space along the radial direction of the microcatheter, so that the radial dimensions of the developing ring and the accommodating space can be further reduced, so that when an operating wire is arranged, the radial dimensions of the microcatheter can also meet the requirements, so that the microcatheter has the ability to control bending, avoiding the current situation where the microcatheter needs to be pre-shaped to cope with more complex access procedures, thereby reducing the complexity of microcatheter operation.

[0012] Preferably, the micro-catheter further comprises a bending radius adjusting member, and the elastic modulus of the bending radius adjusting member is smaller than the elastic modulus of the inner tube and the outer tube;

[0013] The bending radius adjusting member extends along the axial direction of the microcatheter and extends from the proximal end of the microcatheter to a first preset distance from the distal end of the microcatheter. The bending radius adjusting member can move along the axial direction of the microcatheter relative to the inner tube and the outer tube.

[0014] By setting a bending radius adjusting member with an elastic modulus smaller than that of the inner tube and the outer tube in the microcatheter, the local elasticity of the microcatheter is changed by adjusting the position of the bending radius adjusting member relative to the inner tube and the outer tube, thereby achieving the purpose of adjusting the bending radius.

[0015] Specifically, the bending radius adjusting member extends along the axial direction of the microcatheter and extends from the proximal end to a first preset distance from the distal end of the microcatheter. The elasticity of the microcatheter in the area where the bending radius adjusting member is set is reduced, so that the distal end of the bending radius adjusting member is the starting point of the microcatheter bending control action.

[0016] At the same time, the other end of the bending radius adjusting member extends to the proximal end and can move along the axial direction of the microcatheter relative to the inner tube and the outer tube, so as to adjust the relative position by operating the proximal end of the bending radius adjusting member, change the position of the distal end of the bending radius adjusting member, and thus change the starting point of the microcatheter bending action, so as to achieve the purpose of changing the bending radius through the movement of the bending radius adjusting member.

[0017] Preferably, the cross-sectional shape of the bending radius adjusting member along the axial direction of the micro-catheter is circular, and the bending radius adjusting member is arranged between the inner tube and the outer tube;

[0018] Or, the cross-sectional shape of the bending radius adjusting member along the axial direction of the microcatheter is C-shaped, and the bending radius adjusting member is coaxially arranged between the inner tube and the outer tube or coaxially arranged on the inner side of the inner tube;

[0019] Alternatively, the cross-sectional shape of the bending radius adjusting member along the axial direction of the micro-catheter is O-shaped, and the bending radius adjusting member is coaxially arranged on the inner side of the inner tube.

[0020] The above structural setting scheme provides three relatively preferred specific setting schemes for the bending radius adjusting member.

[0021] Preferably, the microcatheter further comprises an operation wire sleeve, the operation wire sleeve is arranged in the accommodating space, and the operation wire sleeve is respectively connected to the inner tube and the outer tube;

[0022] The operation wire is correspondingly inserted into the operation wire sleeve.

[0023] An operating wire sleeve fixed between the inner tube and the outer tube is provided to accommodate the operating wire, so as to guide and direct the operating wire and prevent the operating wire from moving randomly in the accommodating space.

[0024] Preferably, the microcatheter further comprises a first structural layer, the first structural layer is located outside the inner tube, and the operation wire sheath is connected to the inner tube via the first structural layer.

[0025] The first structural layer is wrapped on the outer surface of the inner tube so as to improve the torsion control and bending resistance of the microcatheter through the multi-layer structure.

[0026] Preferably, the inner tube is made of a medical polymer material, and the first structural layer is made of a medical metal material.

[0027] In the case of a multi-layer structure, the inner tube is made of medical polymer materials to have good compatibility with other devices contained in the microcatheter (such as spring coils, embolic microspheres, etc.). At the same time, the first structural layer is made of medical metal materials to further improve the torsion control and bending resistance of the microcatheter.

[0028] Preferably, along the axial direction of the micro-catheter, the first structural layer covers the entire outer side of the inner tube.

[0029] Preferably, the microcatheter further comprises a second structural layer, the second structural layer is located on the inner side of the outer tube, and the operation wire sheath is connected to the outer tube via the second structural layer.

[0030] The second structural layer is wrapped on the inner surface of the outer tube so as to improve the torsion control and bending resistance of the microcatheter through the multi-layer structure.

[0031] Preferably, the outer tube is made of a medical polymer material, and the first structural layer is made of a medical metal material.

[0032] In the case of a multi-layer structure, the outer tube is made of medical polymer materials to have good compatibility with other devices in contact with the outside of the microcatheter. At the same time, the second structural layer is made of medical metal materials to further improve the torsion control and bending resistance of the microcatheter.

[0033] Preferably, the microcatheter also includes a third structural layer, which is located on the inner side of the outer tube, and the operation wire sheath is connected to the outer tube through the second structural layer and the third structural layer. The third structural layer extends from the proximal end of the microcatheter to a second preset distance from the distal end of the microcatheter, and the third structural layer is made of medical metal material.

[0034] The second structural layer and the third structural layer are respectively wrapped on the inner surface of the outer tube, so as to improve the torsion control and bending resistance of the microcatheter through the multi-layer structure. The third structural layer extends from the proximal end of the microcatheter to a second preset distance from the distal end of the microcatheter, so as to keep a certain distance between the third structural layer and the distal end of the microcatheter, so that the distal end diameter of the microcatheter will not be too large.

[0035] Preferably, there are multiple operation wires, and the multiple operation wires are evenly arranged around the circumference of the microcatheter.

[0036] The operating wires are evenly arranged along the circumferential direction to reduce the difficulty of controlling the microcatheter to bend in a specific direction by pulling the corresponding operating wires.

[0037] Preferably, the developing ring has a first fixing hole and a second fixing hole which are arranged close to each other along the circumferential direction of the microcatheter and penetrate the developing ring along the axial direction of the microcatheter, and the distal end of each of the operating wires passes through the corresponding first fixing hole and the second fixing hole in sequence to be fixed relative to the developing ring.

[0038] The solution of fixing the operating wire by back-threading takes up less space and requires fewer steps to complete the fixation than other solutions such as bonding, screw connection or welding.

[0039] By setting a plurality of operating wires to connect the developing ring, the distal end of the microcatheter can be completely directed in different directions by pulling different operating wires, thereby achieving the purpose of multi-directional bending control.

[0040] Preferably, the distance between the axis of the first fixing hole and the axis of the second fixing hole is defined as D, the diameter of the operating wire is defined as d, and 2d≤D≤4d.

[0041] A microcatheter bending control method, which uses the microcatheter as described above, wherein the number of the operating wires of the microcatheter is multiple, and the distal ends of the multiple operating wires are respectively fixed on the developing ring;

[0042] The microcatheter bending control method specifically comprises the following steps:

[0043] By pulling at least two operating wires simultaneously, the distal end of the microcatheter is bent to a preset angle by using the at least two operating wires to act on the vector components of the developing ring; and / or,

[0044] By pulling at least two operating wires simultaneously, the at least two operating wires are used to act on the component vectors of the developing ring to make the distal end of the microcatheter deflect to a preset angle.

[0045] By pulling a plurality of operating wires at the same time, the distal end of the microcatheter is bent to a preset angle by utilizing the plurality of operating wires to act on the vector components of the developing ring, thereby meeting the bending requirement.

[0046] At the same time, by pulling a plurality of operating wires simultaneously, the distal end of the microcatheter is deflected to a preset angle by utilizing the plurality of operating wires to act on the component vectors of the developing ring, so that the angle does not need to be adjusted by rotating the microcatheter.

[0047] Preferably, the preset angle of the distal end of the microcatheter is defined as A, and the preset angle of the deflection of the distal end of the microcatheter is defined as B. The microcatheter bending control method specifically includes the following steps:

[0048] By pulling two operating wires simultaneously, the distal end of the microcatheter is bent to a preset angle A by using at least two operating wires to act on the vector components of the developing ring, wherein the preset bending angle A is between the bending angle A1 of pulling one of the operating wires alone and the bending angle A2 of pulling the other operating wire alone; and / or,

[0049] By pulling two operating wires at the same time, the distal end of the microcatheter is caused to swing to a preset angle B by using at least two operating wires to act on the component vector of the developing ring, wherein the preset angle B of the swing is between the swing angle B1 when one of the operating wires is pulled alone and the swing angle B2 when the other operating wire is pulled alone.

[0050] The positive and progressive effects of the present invention are:

[0051] (1) By placing an operating wire between the inner tube and the outer tube of the microcatheter, the microcatheter is given the ability to control bending, avoiding the need for pre-shaping of the current microcatheter to cope with more complex access procedures, thereby reducing the complexity of microcatheter operation.

[0052] (2) The developing ring in the microcatheter is used as the fixing object of the operating wire, and there is no need to set a wire pull ring, thereby reducing the number of parts required for the microcatheter.

[0053] (3) Provide a solution for changing the bending radius of the microcatheter by moving the bending radius adjusting member, so that the bending radius of the microcatheter can be adjusted in real time as needed to cope with more complex access procedures.

[0054] (4) A connection scheme between the developing ring and the operating wire is provided. This connection scheme requires a smaller space along the radial direction of the microcatheter, so that the radial dimensions of the developing ring and the accommodating space can be further reduced, so that when the operating wire is arranged, the radial dimensions of the microcatheter can also meet the requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 Schematic diagram of the internal structure of the microcatheter according to Example 1 of the present invention.

[0056] Figure 2 It is a schematic structural diagram of the microcatheter according to Example 1 of the present invention, wherein the outer tube is partially hidden.

[0057] Figure 3 Schematic diagram of the connection relationship between the developing ring and the operating wire of Example 1 of the present invention.

[0058] Figure 4a This is a schematic diagram of the use status of the microcatheter of Example 1 of the present invention (I).

[0059] Figure 4b This is a schematic diagram of the use status of the microcatheter of Example 1 of the present invention (II).

[0060] Figure 5 It is a schematic diagram of the three-dimensional structure of the microcatheter according to Example 1 of the present invention, wherein the outer tube is partially hidden.

[0061] Figure 6 It is a schematic structural diagram of a bending radius adjusting member of a microcatheter according to Example 1 of the present invention.

[0062] Figure 7a This is a schematic diagram of the use status of the bending radius adjusting member of Example 1 of the present invention (I).

[0063] Figure 7b This is a schematic diagram of the use status of the bending radius adjusting member of Example 1 of the present invention (I).

[0064] Figure 8 It is a schematic structural diagram of a bending radius adjusting member of a microcatheter in another embodiment of the present invention.

[0065] Figure 9aThis is a schematic diagram of the setting position of the bending radius adjusting member of Example 1 of the present invention.

[0066] Figure 9b Schematic diagram of the setting position of the bending radius adjusting member in other embodiments of the present invention (I).

[0067] Fig.9c Schematic diagram of the setting position of the bending radius adjusting member in other embodiments of the present invention (II).

[0068] Figure 9d Schematic diagram of the setting position of the bending radius adjusting member in other solutions of the present invention (III).

[0069] Fig.9e Schematic diagram (IV) of the setting position of the bending radius adjusting member in other solutions of the present invention.

[0070] Fig.10 This is a schematic diagram of the use status of the microcatheter of Example 2 of the present invention.

[0071] Fig.11 This is a schematic diagram of the use status of the microcatheter of Example 3 of the present invention.

[0072] Fig.12 This is a schematic diagram of the use status of the microcatheter of Example 4 of the present invention.

[0073] Description of reference numerals:

[0074] Microcatheter 100, circumferential direction X, radial direction Y, axial direction Z;

[0075] Inner tube 1;

[0076] The first structural layer 2;

[0077] Operating lines 31, 32, 33, 34;

[0078] Operating wire sleeves 310, 320;

[0079] The second structural layer 4;

[0080] The third structural layer 5;

[0081] Outer tube 6;

[0082] Development ring 7, first fixing hole 71, second fixing hole 72;

[0083] Accommodation space 8;

[0084] Bending radius adjusting member 9; DETAILED DESCRIPTION

[0085] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples. The terms "proximal end" and "distal end" used in this text are relative to the clinician who manipulates the microcatheter. The term "proximal end" refers to the portion of the microcatheter that is relatively close to the clinician, and the term "distal end" refers to the portion of the microcatheter that is relatively far away from the clinician. For example, the in vitro portion is at the proximal end, and the in vivo portion that is intervened is at the distal end.

[0086] Example 1

[0087] This embodiment provides a microcatheter, wherein, Figure 1 and Figure 2 As shown, the circumferential direction of the microcatheter 100 is defined as X, the radial direction is defined as Y, and the axial direction is defined as Z. The microcatheter 100 at least includes an inner tube 1, an outer tube 6, a developing ring 7, and two operating wires 31, 32. The outer tube 6 is concentrically arranged on the outside of the inner tube 1 to form an annular accommodation space 8 between the outer tube 6 and the inner tube 1, and the developing ring 7 and the two operating wires 31, 32 are arranged in the accommodation space 8. The developing ring 7 is arranged at the distal end of the accommodation space 8, and the developing ring 7 is fixedly connected to the inner tube 1 and the outer tube 6, respectively. By mutually concentrically arranging the inner tube 1 and the outer tube 6, an accommodation space 8 for accommodating the developing ring 7 and the operating wires is formed between the inner tube 1 and the outer tube 6, wherein the developing ring 7 is connected to the inner tube 1 and the outer tube 6, respectively, to fix the distal end of the entire microcatheter 100.

[0088] like Figure 3 As shown, the developing ring 7 has a first fixing hole 71 and a second fixing hole 72 which are arranged close to each other along the circumferential direction X of the microcatheter 100 and penetrate the developing ring 7 along the axial direction Z of the microcatheter 100. Taking the operating wire 31 as an example, the distal end of the operating wire 31 passes through the first fixing hole 71 and the second fixing hole 72 in sequence to be fixed relative to the developing ring 7. By providing the first fixing hole 71 and the second fixing hole 72 which are arranged along the circumferential direction X and penetrate along the axial direction Z on the developing ring 7, the connection between the operating wire 31 and the developing ring 7 is achieved by the distal end of the operating wire 31 passing back through the first fixing hole 71 and the second fixing hole 72, so that the developing ring 7 is used as the fixing object of the operating wire, and there is no need to set a wire pull ring. Among them, the fixing method of the operating wire 32 relative to the developing ring 7 is the same as that of the operating wire 31, and the fixing of the operating wire 32 is achieved by providing the first fixing hole 71 and the second fixing hole 72 corresponding to the operating wire 32.

[0089] This connection scheme requires a smaller space along the radial direction Y of the microcatheter 100, so that the radial dimensions of the developing ring 7 and the accommodating space 8 can be further reduced, so that when an operating wire is arranged, the radial dimension of the microcatheter 100 can also meet the requirements, so that the microcatheter 100 has the ability to control bending, avoiding the current situation where the microcatheter 100 needs to be pre-shaped, and reducing the complexity of the operation of the microcatheter 100.

[0090] Of course, in other embodiments, the operating wire may be fixed to the developing ring 7 by other means, such as by bonding, screw connection or welding. Among them, the back-penetration method used in this embodiment to fix the operating wire occupies less space than other fixing schemes, and requires fewer steps to complete the fixing, which is relatively better.

[0091] Specifically, there can be multiple developing rings 7, which are distributed at different positions of the microcatheter 100 to achieve the purpose of developing at different positions, but at least one of these developing rings 7 must be set at the distal end of the microcatheter 100, so that the microcatheter 100 can have the ability to control bending through the fixation of this developing ring 7 and each operating wire.

[0092] Among them, Figure 3 As shown, the distance between the axis of the first fixing hole 71 and the axis of the second fixing hole 72 is D, and the diameter of the operating wire 31 is d. Therefore, in order to improve the ability of the first fixing hole 71 and the second fixing hole 72 to fix the operating wire 31, the distance D between the axes of the first fixing hole 71 and the second fixing hole 72 should be controlled within the range between 2 times the diameter d of the operating wire 31 and 4 times the diameter d of the operating wire 31.

[0093] Specifically, if Figure 4a As shown, by applying a certain pulling force to the operating wire 31 along the axial direction Z at the proximal end of the microcatheter 100, the operating wire 31 will drive the microcatheter 100 to bend in the direction where the operating wire 31 is located. Figure 4b As shown, a certain pulling force is applied to the operating wire 32 along the axial direction Z at the proximal end of the microcatheter 100, and the operating wire 32 will also drive the microcatheter 100 to move in the direction of the operating wire 32, thereby realizing the bending of the microcatheter 100. In this embodiment, by pulling the two operating wires 31 and 32 respectively, the two bending angles of the microcatheter 100 are 180°. Of course, based on the change of the pulling force applied to the two operating wires 31 and 32, the microcatheter 100 can be bent at different angles through different pulling degrees.

[0094] In the present embodiment, two operating wires 31 and 32 are used to realize the bending control operation of the microcatheter 100. In other embodiments, only one operating wire may be used, or more than three operating wires may be used to realize the bending control operation of the microcatheter 100. When more operating wires are used, the adjustable bending angle of the microcatheter 100 is also increased accordingly, but too many operating wires will occupy the space of the microcatheter 100, resulting in the overall diameter size of the microcatheter 100 not meeting the requirements. Among them, when three or more operating wires are set in the microcatheter 100, these operating wires should be evenly arranged around the circumference with the axis of the microcatheter 100 as the center. By evenly arranging the operating wires in the circumferential direction, the control difficulty of pulling the corresponding operating wire to make the microcatheter 100 bend in a specific direction can be reduced.

[0095] like Figure 1 and Figure 2 As shown, in this embodiment, the microcatheter 100 further includes two operation wire sleeves 310 and 320 respectively corresponding to the two operation wires 31 and 32, the two operation wire sleeves 310 and 320 are arranged in the accommodation space 8, and the two operation wire sleeves 310 and 320 are respectively connected to the inner tube 1 and the outer tube 6, and the two operation wires 31 and 32 are correspondingly passed through the two operation wire sleeves 310 and 320. By setting the operation wire sleeve fixed between the inner tube 1 and the outer tube 6 to accommodate the operation wire, the operation wire can be guided and guided to prevent the operation wire from moving randomly in the accommodation space 8.

[0096] In addition, if Figure 1 and Figure 2 As shown, in this embodiment, the microcatheter 100 further includes a first structural layer 2, which is wrapped on the outer surface of the inner tube 1, and the two operation wire sleeves 310 and 320 are connected to the inner tube 1 through the first structural layer 2. By wrapping the first structural layer 2 on the outer surface of the inner tube 1, the torsion control and bending resistance of the microcatheter 100 are improved through the multi-layer structure.

[0097] At the same time, the microcatheter 100 also includes a second structural layer 4 and a third structural layer 5. The second structural layer 4 is wrapped on the inner surface of the outer tube 6, and the two operating wire sleeves 310 and 320 are connected to the outer tube 6 through the second structural layer 4. By wrapping the second structural layer 4 on the inner surface of the outer tube 6, the torsion control and bending resistance of the microcatheter 100 are improved through the multi-layer structure. At the same time, the third structural layer 5 is also wrapped on the inner surface of the outer tube 6, and the two operating wire sleeves 310 and 320 are also connected to the outer tube 6 through the third structural layer 5.

[0098] like Figure 5As shown, along the axial direction Z of the microcatheter 100, the second structural layer 4 extends from the proximal end to the distal end of the microcatheter 100, and the third structural layer 5 is located on the outer peripheral side of the second structural layer 4, and extends from the proximal end of the microcatheter 100 to a position at a second preset distance F2 from the distal end of the microcatheter 100. By keeping a certain distance between the third structural layer 5 and the distal end of the microcatheter 100, the diameter of the distal end of the microcatheter 100 will not be too large. Of course, in other embodiments, other structural layers such as the fourth structural layer and the fifth structural layer can be further arranged on the outer peripheral side of the third structural layer 5. These structural layers need to maintain a certain distance from the distal end of the microcatheter 100, and the distance gradually increases with the increase in the number of structural layers, so as to ensure that the diameter of the distal end of the microcatheter 100 will not be too large.

[0099] Specifically, in this embodiment, the first structural layer, the second structural layer and the third structural layer are all woven mesh structures, and the polymer material is infiltrated into the meshes of the first structural layer, the second structural layer and the third structural layer by pouring, so as to form the tube body structure of the microcatheter 100 after the polymer material is completely solidified. Under this process scheme, the outer surface of the tube body formed after the polymer material is solidified is the outer tube 6, and the inner surface of the tube body is the inner tube 1. Of course, in other embodiments, other processes in the prior art can also be used to form the tube body structure of the microcatheter 100.

[0100] like Figure 6 As shown, in this embodiment, the microcatheter 100 further includes a bending radius adjusting member 9 , and the elastic modulus of the bending radius adjusting member 9 is smaller than the elastic modulus of the inner tube 1 and the outer tube 6 .

[0101] The bending radius adjusting member 9 extends along the axial direction Z of the microcatheter 100 and extends from the proximal end of the microcatheter 100 to a first preset distance F1 from the distal end of the microcatheter 100. The bending radius adjusting member 9 can move along the axial direction Z of the microcatheter relative to the inner tube and the outer tube.

[0102] like Figure 7a and Figure 7b As shown, by setting a bending radius adjustment member 9 with an elastic modulus smaller than that of the inner tube 1 and the outer tube 6 in the microcatheter 100, the local elasticity of the microcatheter 100 is changed by adjusting the position of the bending radius adjustment member 9 relative to the inner tube 1 and the outer tube 6, thereby achieving the purpose of adjusting the bending radius.

[0103] Specifically, the bending radius adjusting member 9 extends along the axial direction Z of the microcatheter 100, and extends from the proximal end to a first preset distance F1 from the distal end of the microcatheter 100. In the area where the bending radius adjusting member 9 is set, the elasticity of the microcatheter 100 is reduced, so that the distal end of the bending radius adjusting member 9 is the starting point of the bending control action of the microcatheter 100. At the same time, the other end of the bending radius adjusting member 9 extends to the proximal end, and can move along the axial direction Z of the microcatheter 100 relative to the inner tube 1 and the outer tube 6, so as to adjust the relative position by operating the proximal end of the bending radius adjusting member 9, change the position of the distal end of the bending radius adjusting member 9, and then change the starting point of the bending control action of the microcatheter 100, so as to achieve the purpose of changing the bending radius through the activity of the bending radius adjusting member.

[0104] Specifically, Figure 7a As shown, the first preset distance F1 between the bending radius adjusting member 9 and the distal end of the microcatheter 100 is relatively small. At this time, the bending radius of the microcatheter 100 is R2. Figure 7b As shown, by pulling the bending radius adjusting member 9 at the proximal end, the first preset distance F1 between the bending radius adjusting member 9 and the distal end of the microcatheter 100 is relatively large. Therefore, the bending radius of the microcatheter 100 becomes R1, and the purpose of changing the bending radius is achieved through the movement of the bending radius adjusting member 9.

[0105] In this embodiment, if Figure 6 and Figure 9a As shown in FIG. 1 , the cross-sectional shape of the bending radius adjusting member 9 along the axial direction Z of the microcatheter 100 is circular, and is disposed between the inner tube 1 and the outer tube 6, and is arranged relatively close to the operating wire 31. However, it should be clearly stated that the arrangement position of the bending radius adjusting member 9 is not limited to this, and can also be as follows: Figure 9b As shown, the bending radius adjusting member 9 is arranged on the inner side of the inner layer tube 1 so as to achieve the purpose of changing the bending radius through the movement of the bending radius adjusting member 9 .

[0106] In addition, the structural form of the bending radius adjusting member 9 is also diverse and is not limited to the circular cross-section of the present application.

[0107] For example Figure 8 As shown, the cross section of the bending radius adjusting member 9 can also be C-shaped and coaxially arranged between the inner layer tube and the outer layer tube (see Fig.9c ), or it can also be coaxially arranged on the inner side of the inner tube (see Figure 9d ). And from Fig.9cIt can be seen that the number of the bending radius adjusting member 9 is not limited to one, and two or more bending radius adjusting members 9 can be provided to jointly adjust the bending radius of the microcatheter 100. If two bending radius adjusting members are provided to jointly adjust the bending radius of the microcatheter 100, the two bending radius adjusting members can be symmetrically arranged with the axis of the microcatheter as the center; if more bending radius adjusting members are provided to jointly adjust the bending radius of the microcatheter 100, these bending radius adjusting members can be arranged circumferentially with the axis of the microcatheter as the center.

[0108] In addition, the cross section of the bending radius adjusting member 9 can also be O-shaped and coaxially arranged on the inner side of the inner tube (see Fig.9e ). In this embodiment, the cross-sectional shape and the setting position of the bending radius adjusting member 9 are only for explaining the distance, and the cross-sectional shape and the position that can be actually set are not limited thereto.

[0109] In this embodiment, from the inside to the outside of the micro-catheter 100, the materials of the components are selected as follows:

[0110] (1) The wall thickness of the inner tube 1 is 0.0005”-0.0015” inch, and the selected material is a polymer material, such as fluorine-containing polymer materials PTFE / FEP, amide polymer materials polyamide (PA) / polyether block polyamide (Pebax), general plastic polyethylene (PE) / polyimide (PI), etc.

[0111] (2) The first structural layer 2 may be a braided layer, a coil layer, a hypotube layer, etc., and may be made of any medical metal material, such as SS304V / nickel titanium, etc., or any medical polymer material, such as PA / polyethylene terephthalate (PET) / PE, etc. Specifically, in the present embodiment, the first structural layer 2 is a braided SS304V material.

[0112] (3) The two operating wires 31 and 32 can be made of any medical metal material, such as SS304V / nickel titanium, or any medical polymer material, such as PA / polyethylene terephthalate (PET) / PE.

[0113] (4) The two operating wire sleeves 310 and 320 can be selected to have a structure and material similar to that of the inner layer tube 1 .

[0114] (5) The second structural layer 4 can be a braided layer, a coil layer, a hypotube layer, etc., and can be made of any medical metal material, such as SS304V / nickel titanium, etc., or any medical polymer material, such as PA / polyethylene terephthalate (PET) / PE, etc.

[0115] (6) The third structural layer 5 may be a braided layer, a coil layer, a hypotube layer, etc., and may be made of any medical metal material, such as SS304V / nickel titanium, etc., or may be made of any medical polymer material, such as PA / polyethylene terephthalate (PET) / PE, etc.

[0116] (7) The outer tube 6 is the outermost layer of the microcatheter 100. The selected material can be all medical polymer materials, such as PA / Pebax / polyurethane (TPU) and the like. Its hardness includes the hardness of all polymer materials, such as Shore A: 20-99A.

[0117] (8) The optional material of the developing ring 7 is all medical metal materials that can be developed, such as platinum-iridium alloy, etc., and can also be all medical polymer materials that can be developed, such as PA / Pebax with added barium sulfate, etc.

[0118] Example 2

[0119] This embodiment also provides a microcatheter 100, whose structure is substantially the same as that of the microcatheter 100 provided in Embodiment 1, except that: in this embodiment, Fig.10 As shown, the microcatheter 100 has three operating wires 31, 32, and 33. By pulling the corresponding operating wires respectively, the microcatheter 100 is bent toward the corresponding directions.

[0120] Example 3

[0121] This embodiment also provides a microcatheter 100, whose structure is substantially the same as that of the microcatheter 100 provided in Embodiment 1, except that: in this embodiment, Fig.11 As shown, the microcatheter 100 has four operating wires 31, 32, 33, and 34. By pulling the corresponding operating wires respectively, the microcatheter 100 is bent toward the corresponding directions.

[0122] Example 4

[0123] This embodiment provides a bending control solution for a microcatheter 100 , which is for the above-mentioned microcatheter 100 and must be for a microcatheter 100 with more than three operating wires as in Embodiment 2 or Embodiment 3.

[0124] The bending control method of the microcatheter 100 specifically includes the following steps:

[0125] By pulling at least two of the operating wires simultaneously, the at least two operating wires are used to act on the component vectors of the developing ring 7 so that the distal end of the microcatheter 100 is bent to a preset angle, and by pulling at least two of the operating wires simultaneously, the at least two operating wires are used to act on the component vectors of the developing ring 7 so that the distal end of the microcatheter 100 is deflected to a preset angle.

[0126] by Fig.12 Taking the microcatheter 100 shown as an example, the microcatheter 100 in this embodiment has three operating wires evenly distributed on the circumference, and the angle between the three operating wires is 120°. By pulling at least two operating wires at the same time, the distal end of the microcatheter 100 is bent and deflected by using the components of these operating wires acting on the developing ring 7. Taking the distal deflection of the microcatheter 100 as an example, by pulling the first operating wire 31 and the second operating wire 32, and at the same time, not pulling the third operating wire 33, the distal end of the microcatheter 100 is bent toward the area between the first operating wire 31 and the second operating wire 32. At the same time, the degree of pulling the second operating wire 32 is greater than the degree of pulling the first operating wire 31, so that the microcatheter 100 is slightly closer to the position C where the microcatheter 100 is located when the second operating wire 32 is pulled alone.

[0127] In addition, pulling multiple operating wires simultaneously can also change the bending angle of the microcatheter 100. The actual bending angle of the microcatheter 100 is the superposition of the component vectors of the multiple operating wires pulled.

[0128] Here, the example of pulling two operating wires (operating wire 31 and operating wire 32) at the same time is taken as follows. Fig.12 As shown, the preset angle for adjusting the bend of the distal end of the microcatheter 100 is defined as A, and the preset angle for deflecting the distal end of the microcatheter 100 is defined as B.

[0129] By pulling the operating wire 31 and the operating wire 32 at the same time, and utilizing the components of the operating wire 31 and the operating wire 32 acting on the developing ring 7, the distal end of the microcatheter 100 is bent to a preset angle A, wherein the preset bending angle A should be between the bending angle A1 of pulling the operating wire 31 alone and the bending angle A2 of pulling the operating wire 32 alone.

[0130] Meanwhile, the preset angle B of the deflection of the distal end of the microcatheter 100 should also be between the deflection angle B1 of the separate traction operation wire 31 and the deflection angle B2 of the separate traction operation wire 32 .

[0131] When three operating wires (operating wire 31, operating wire 32 and operating wire 33) are pulled at the same time, the bending angle and deflection angle of the distal end of the microcatheter 100 are also affected by the three operating wires at the same time, and the final position is the result of the superposition of the vector components of the three operating wires. This bending control method can not only achieve multi-directional bending, but also meet the purpose of reaching any required position without rotating the microcatheter 100. It makes it possible to meet the bending requirements even when the number of operating wires is small, thereby further reducing the diameter of the microcatheter 100.

[0132] In addition, this embodiment uses a microcatheter 100 with three operating wires as an example to illustrate the specific principles of the bending method, but the bending method is not limited to three-way bending. Four-way bending or even multi-way bending can also adopt the bending method provided in this embodiment, so that the microcatheter 100 can achieve the purpose of bending in more directions than the number of operating wires.

[0133] Specifically, in this embodiment, the stretched lengths of the three operating wires, the bending angle of the distal end of the microcatheter 100, and the angle of the position N where the microcatheter 100 is located have the following relationship:

[0134] ΔL=-rAcos(B+C·2Π / 3);

[0135] in:

[0136] A: is the bending angle of the microcatheter 100;

[0137] B: is the deflection angle of the microcatheter 100;

[0138] C: is the position coefficient of the three operating lines. For operating line 31, C=0; for operating line 32, C=1; for operating line 33, C=2;

[0139] ΔL: The difference in the stretched length of the operating line;

[0140] r: is the radius of the catheter;

[0141] The corresponding relationship between the difference in the stretched lengths of the three operating wires and the bending angle A and the swing angle B of the microcatheter 100 is as follows:

[0142] When the microcatheter 100 is at position N, the bending angle of the microcatheter 100 is A, and the corresponding deflection angle of the end of the microcatheter 100 is B. At this time, the corresponding stretching changes of the three operating wires at the proximal end are:

[0143] Operating line 31: ΔL1=-rAcos(B);

[0144] Operating line 32: ΔL2=-rAcos(B+2Π / 3);

[0145] Operating line 33: ΔL3=-rAcos(B+4Π / 3);

[0146] That is, when the microcatheter 100 needs to reach a designated position at a specific angle A / B during actual clinical applications, the microcatheter 100 can reach the designated position by stretching or extending the three operating wires by ΔL1, ΔL2, and ΔL3 at the proximal end.

[0147] Although the specific embodiments of the present invention are described above, it should be understood by those skilled in the art that this is only for illustration and the protection scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. A microcatheter, characterized in that: It includes: Inner tube; An outer tube, the outer tube being arranged concentrically on the outer side of the inner tube; A developing ring, which forms an annular accommodation space between the inner tube and the outer tube, the developing ring being arranged at least at the distal end of the accommodation space, and the developing ring is respectively connected to the inner tube and the outer tube; an operating wire, the operating wire being arranged in the accommodating space, and a distal end of the operating wire being fixed relative to the developing ring; A bending radius adjusting member, wherein the elastic modulus of the bending radius adjusting member is smaller than the elastic modulus of the inner tube and the outer tube; The bending radius adjusting member extends along the axial direction of the microcatheter and continuously extends from the proximal end of the microcatheter to a first preset distance from the distal end of the microcatheter. The bending radius adjusting member can reciprocate along the axial direction of the microcatheter relative to the inner tube and the outer tube.

2. The microcatheter according to claim 1, characterized in that: The cross-sectional shape of the bending radius adjusting member along the axial direction of the micro-catheter is circular, and the bending radius adjusting member is arranged between the inner tube and the outer tube; Or, the cross-sectional shape of the bending radius adjusting member along the axial direction of the microcatheter is C-shaped, and the bending radius adjusting member is coaxially arranged between the inner tube and the outer tube or coaxially arranged on the inner side of the inner tube; Alternatively, the cross-sectional shape of the bending radius adjusting member along the axial direction of the micro-catheter is O-shaped, and the bending radius adjusting member is coaxially arranged on the inner side of the inner tube.

3. The microcatheter according to claim 1, characterized in that: The microcatheter further comprises an operation wire sleeve, which is arranged in the accommodation space and is respectively connected to the inner tube and the outer tube; The operation wire is correspondingly inserted into the operation wire sleeve.

4. The microcatheter according to claim 3, characterized in that: The microcatheter further comprises a first structural layer, the first structural layer is located outside the inner tube, and the operation wire sleeve is connected to the inner tube via the first structural layer.

5. The microcatheter according to claim 4, characterized in that: The inner tube is made of medical polymer materials, and the first structural layer is made of medical metal materials; And / or, along the axial direction of the micro-catheter, the first structural layer covers the entire outer side of the inner tube.

6. The microcatheter according to claim 4, characterized in that: The microcatheter further comprises a second structural layer, which is located on the inner side of the outer tube, and the operation wire sleeve is connected to the outer tube via the second structural layer.

7. The microcatheter according to claim 6, characterized in that: The outer tube is made of medical polymer material, and the second structural layer is made of medical metal material; And / or, the microcatheter also includes a third structural layer, the third structural layer is wrapped on the inner surface of the outer tube, the operation wire sheath is connected to the outer tube through the second structural layer and the third structural layer, the third structural layer extends from the proximal end of the microcatheter to a second preset distance from the distal end of the microcatheter, and the third structural layer is made of medical metal material.

8. The microcatheter according to any one of claims 1 to 7, characterized in that: There are multiple operation wires, and the multiple operation wires are evenly arranged around the circumference of the microcatheter with the axis of the microcatheter as the center.

9. The microcatheter according to claim 8, characterized in that: The developing ring has a first fixing hole and a second fixing hole which are arranged close to each other along the circumferential direction of the microcatheter and penetrate the developing ring along the axial direction of the microcatheter. The distal end of each operating wire passes through the corresponding first fixing hole and the second fixing hole in sequence to be fixed relative to the developing ring.

10. The microcatheter according to claim 9, characterized in that The distance between the axis of the first fixing hole and the axis of the second fixing hole is defined as D, the diameter of the operation wire is defined as d, and 2d≤D≤4d.

11. A method for controlling the bending of a microcatheter, characterized in that: It uses a microcatheter as described in any one of claims 1 to 10, wherein the number of the operating wires of the microcatheter is multiple, and the distal ends of the multiple operating wires are respectively fixed on the developing ring; The microcatheter bending control method specifically comprises the following steps: By pulling at least two operating wires simultaneously, the distal end of the microcatheter is bent to a preset angle by using the at least two operating wires to act on the vector components of the developing ring; and / or, By pulling at least two operating wires simultaneously, the at least two operating wires are used to act on the component vectors of the developing ring to make the distal end of the microcatheter deflect to a preset angle.

12. The microcatheter bending control method according to claim 11, characterized in that: The preset angle of the distal end of the microcatheter is defined as A, and the preset angle of the deflection of the distal end of the microcatheter is defined as B. The microcatheter bending control method specifically includes the following steps: By pulling two operating wires simultaneously, the distal end of the microcatheter is bent to a preset angle A by using at least two operating wires to act on the vector components of the developing ring, wherein the preset bending angle A is between the bending angle A1 of pulling one of the operating wires alone and the bending angle A2 of pulling the other operating wire alone; and / or, By pulling two operating wires at the same time, the distal end of the microcatheter is caused to swing to a preset angle B by using at least two operating wires to act on the component vector of the developing ring, wherein the preset angle B of the swing is between the swing angle B1 when one of the operating wires is pulled alone and the swing angle B2 when the other operating wire is pulled alone.

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