Medical guide wire and medical system

Abstract

The invention provides a medical guide wire and a medical system. The medical guide wire comprises a far-end part and a pushing rod which are sequentially connected from far to near in the axial direction of the medical guide wire. The pushing rod is provided with an inner hole extending in the axial direction in a penetrating mode. The far end part comprises at least one magnetic positioning sensor; the magnetic positioning sensor comprises a magnetic core and an induction coil wound on the outer surface of the magnetic core; at least two wires are led out from the induction coil, penetrate through an inner hole of the pushing rod and extend to the near end of the pushing rod. The medical system comprises a medical guide wire and a medical catheter; the medical catheter is provided with a guide wire passage which penetrates through the medical catheter in the axial direction of the medical catheter; the medical guide wire is used for movably penetrating through the guide wire passageway. By means of the configuration, visualization of the medical guide wire can be achieved, then visualization of the tissue structure and the medical catheter can be achieved through the medical guide wire, the passing ability of the catheter can be improved, the operation safety is improved, and the operation complexity is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to a medical guide wire with three-dimensional magnetic positioning function and a medical system comprising the medical guide wire and a medical catheter. BACKGROUND

[0002] Interventional therapy is a new treatment method between surgery and internal medicine. Interventional therapy is a minimally invasive treatment method of making a few millimeter micro-channel on blood vessels or skin, or treating the local lesion through the original pipeline of human body under the guidance of imaging equipment (such as DSA, CT, MR and B-ultrasound) without exposing the lesion by surgery. With the increasing aging, the number of patients with cardiovascular and cerebrovascular diseases and peripheral vascular diseases is continuously increasing, and the demand for vascular interventional medical devices is continuously expanding. Interventional surgery has been increasingly widely applied in the diagnosis and treatment of current malignant tumors, cardiovascular diseases and the like due to its advantages of small trauma to human body, short recovery time and low cost.

[0003] In the field of vascular interventional therapy, catheters and guide wires are essential consumables. Since the shape of human body lumen such as heart cavity, blood vessels and digestive tract is curved and variable, or even has many branches, it is difficult for the operator to push the catheter to the target position. Especially in the blood vessel blind area with small radius of curvature, the operator needs to use an X-ray machine or other image contrast equipment to prevent path deviation and damage to blood vessels during the pushing process. The guide wire has the functions of exploration and guidance, which helps to improve the positioning and operation safety of the catheter. Therefore, people have developed whole exchange type catheters and quick exchange catheters, that is, the guide wire is first guided to the target position through the narrow area of the lumen, and then the catheter sleeved outside the guide wire is introduced along the guide wire, which greatly improves the operability and safety of the clinical lumen interventional technology.

[0004] However, during the catheter switching process using the guide wire, the distal end of the guide wire has displacement and vibration, which may cause damage to the blood vessels. Therefore, the imaging equipment is still needed to position the guide wire and the catheter and observe the structure of the blood vessels during the operation. In the related art, some catheters are also provided with three-dimensional magnetic positioning sensors to realize three-dimensional magnetic positioning and track the position and direction of the catheter. However, the main problem of the three-dimensional magnetic positioning sensor installed on the existing catheter is that the size is large, especially the distal end of the catheter needs to integrate many functions, which will greatly increase the design difficulty of the distal end of the catheter.

[0005] It should be noted that the information disclosed in the background section of the present application is only intended to deepen the understanding of the general background of the present application, and should not be regarded as acknowledging or implying in any form that the information constitutes prior art known to those skilled in the art. SUMMARY

[0006] The application aims to provide a medical guide wire and a medical system to solve the problem of blood vessel injury caused by displacement and vibration of the distal end of the guide wire during the process of switching the catheter using the guide wire in the prior art.

[0007] To achieve the above-mentioned purpose, the application provides a medical guide wire, which comprises a distal end part and a push rod connected in sequence from the distal end to the proximal end along the axial direction of the medical guide wire; the push rod has an inner hole extending through along the axial direction of the push rod; the distal end part comprises at least one magnetic positioning sensor; the magnetic positioning sensor comprises a magnetic core and an induction coil wound on the outer surface of the magnetic core; the induction coil leads out at least two wires, and the at least two wires extend through the inner hole of the push rod to the proximal end of the push rod.

[0008] Optionally, the distal end part further comprises a head cap, a sheath structure and an inner structure; the head cap is fixed at the distal end of the sheath structure; the sheath structure is sleeved on the outside of the inner structure; the inner structure comprises a core structure, the proximal end of the core structure is connected with the distal end of the push rod, and at least part of the core structure forms the magnetic core and is wound with the induction coil, and the induction coil leads out the at least two wires at the proximal end thereof.

[0009] Optionally, at least part of the core structure forms the magnetic core, and the core structure comprises a magnetic core, a variable diameter section and a constant diameter section connected in sequence from the distal end to the proximal end along the axial direction of the core structure; the proximal end of the constant diameter section is connected with the distal end of the push rod; the variable diameter section and the constant diameter section both have an inner hole extending through along the axial direction thereof; the inner hole of the variable diameter section, the inner hole of the constant diameter section and the inner hole of the push rod are connected in sequence; a part of the length of the magnetic core is embedded in the inner hole of the variable diameter section to be fixed from the distal end of the variable diameter section; the outer diameter of the variable diameter section gradually increases from the distal end to the proximal end in the whole length thereof; the maximum outer diameter of the variable diameter section is the same as the outer diameter of the constant diameter section; the outer diameter of the constant diameter section is smaller than the outer diameter of the push rod; the at least two wires extend into the inner hole of the variable diameter section from the distal end of the variable diameter section, and then extend along the inner hole of the variable diameter section, the inner hole of the constant diameter section and the inner hole of the push rod to the proximal end of the push rod.

[0010] Optionally, a conical transition section is arranged between the proximal end of the core structure and the distal end of the push rod, and the outer diameter of the conical transition section gradually increases from the distal end to the proximal end in the whole length thereof.

[0011] Optionally, all of the core structures form one magnetic core; or, part or all of the core structures form multiple magnetic cores, which are arranged in sequence in the axial direction of the core structures, and each magnetic core is provided with an induction coil around its outer surface, and each induction coil is independent of each other, and each induction coil has at least two wires leading out from its proximal end, and all the wires extend through the same inner hole of the push rod to the proximal end of the push rod.

[0012] Optionally, the distal end portion further comprises a shaping structure, which is located inside the sheath structure and is connected to the proximal end of the head cap and the distal end of the core structure respectively.

[0013] Optionally, the entire outer surface of the tapered transition section is provided with a glue coating layer, the outer diameter of the glue coating layer gradually increases from the distal end to the proximal end, and the maximum outer diameter of the glue coating layer is less than or equal to the outer diameter of the push rod.

[0014] Optionally, the head cap is a visible structure, or the head cap is a gel ball formed by gel making or a melt ball formed by melting.

[0015] Optionally, any induction coil leads out two wires, and the two wires form a twisted pair structure.

[0016] Optionally, the proximal end of the push rod is provided with a socket, the induction coil is connected to the socket through at least two wires leading out, and the socket can filter the induction signal output by the induction coil.

[0017] Optionally, the proximal end of the push rod is provided with a fastening position, the distance from the fastening position to the distal end of the medical guide wire is the same as the distance from the distal end of the medical catheter to the proximal end of the guide wire inlet; the medical guide wire is used to detachably connect the fastening position and the proximal end of the medical catheter; when the medical guide wire is connected to the medical catheter at the fastening position, the distal end portion is accommodated inside the distal end of the medical catheter.

[0018] Optionally, a positioning mark is arranged at the fastening position; the distal end of the push rod is provided with a tapered transition section, the outer surface of the tapered transition section is provided with a first glue coating section along a part of the circumferential direction and a second glue coating section along another part of the circumferential direction, the outer diameter of the first glue coating section gradually decreases from the distal end to the proximal end and forms a bayonet at the proximal end, the second glue coating section has a constant outer diameter from the distal end to the proximal end; the positioning mark is arranged on the same side as the first glue coating section.

[0019] Optionally, the magnetic positioning sensor has at least one of the following characteristics:

[0020] An outer surface of the magnetic core is provided with a texture to accommodate a wire for winding the induction coil;

[0021] The length of the induction coil accounts for 75%-90% of the length of the magnetic core;

[0022] The wire diameter of the induction coil is 20-30 μm;

[0023] The number of winding layers of the induction coil is not more than 2, and the number of winding turns of the induction coil is not more than 280 turns;

[0024] The outer diameter of the magnetic core is 0.15-0.18 mm, and the length of the magnetic core is 4-4.4 mm;

[0025] The magnetic core is of a solid structure or a hollow structure;

[0026] The magnetic core is made of an amorphous material.

[0027] Optionally, the medical guide wire has a specification of 0.014-0.038 inch.

[0028] In addition, based on the same inventive concept, the application further provides a medical system, comprising: a medical guide wire according to any one of the embodiments and a medical guide catheter; the medical guide catheter has a guide wire passage arranged along an axial direction of the medical guide catheter; the medical guide wire is used to movably pass through the guide wire passage.

[0029] Optionally, the medical guide catheter comprises a bendable section, and the guide wire passage comprises a guide wire cavity arranged in the bendable section; a proximal end of the guide wire cavity is provided with a retraction limiting part; the retraction limiting part has an initial state and a limiting state, and can be switched between the initial state and the limiting state;

[0030] In the initial state, the retraction limiting part can allow a distal end part of the medical guide wire and a push rod to pass through;

[0031] In the limiting state, the retraction limiting part is deformed under the action of a force of the medical guide wire retraction, thereby preventing the connection between the distal end part of the medical guide wire and the push rod from passing through, so that the connection between the distal end part of the medical guide wire and the push rod is limited in the retraction limiting part, thereby preventing the push rod from staying in the bendable section.

[0032] Optionally, the retraction limiting part is an annular wall, one end of the annular wall is connected with the guide wire cavity, and the other end is a free end; in the initial state, the other end of the annular wall extends obliquely towards the distal end of the bendable section, so that the annular wall forms a tapered structure with a small distal end inner diameter and a large proximal end inner diameter, and the minimum inner diameter of the annular wall is greater than the diameter of the medical guide wire; in the limiting state, the free end of the annular wall is bent and deformed towards the proximal end of the bendable section under the action of the retraction force of the medical guide wire, and then the inner diameter of the annular wall is smaller than the diameter of the medical guide wire;

[0033] Alternatively, the retraction limiting part consists of a barb, one end of the barb is connected with the guide wire cavity, and the other end is a free end; in the initial state, the other end of the barb extends obliquely towards the distal end of the bendable section, the distance from the end of the barb connected with the guide wire cavity to the inner wall of the guide wire cavity on the opposite side is greater than the outer diameter of the push rod, and the distance from the free end of the barb to the inner wall of the guide wire cavity on the opposite side is smaller than the outer diameter of the push rod; in the limiting state, the free end of the barb is bent and deformed towards the proximal end of the bendable section under the action of the retraction force of the medical guide wire, and then the free end of the barb is clamped into the distal end of the push rod to limit the medical guide wire.

[0034] Optionally, the proximal end of the medical catheter is provided with a connecting valve, and the proximal end of the medical guide wire is provided with a fastening position; when the distal end part of the medical guide wire enters the inside of the distal end of the medical catheter, the connecting valve detachably connects the proximal end of the medical guide wire at the fastening position.

[0035] Optionally, the medical system further comprises a signal processing device in communication connection with the medical guide wire, and the signal processing device can amplify and filter the induction signal output by the induction coil.

[0036] The medical guide wire provided above comprises: a distal end part and a push rod connected in sequence from distal to proximal along the axial direction of the medical guide wire; the push rod has an inner hole extending through along the axial direction of the push rod; the distal end part comprises at least one magnetic positioning sensor; the magnetic positioning sensor comprises a magnetic core and an induction coil wound on the outer surface of the magnetic core; the induction coil leads out at least two wires, and the at least two wires extend through the inner hole of the push rod to the proximal end of the push rod.

[0037] In this way, the medical guide wire itself has a three-dimensional magnetic positioning function, realizing the visualization of the medical guide wire, and the movement and tremor of the medical guide wire can be monitored in real time during the operation to prevent the blood vessel from being damaged during the exchange process, thereby increasing the safety of the operation. When the medical guide wire is used in cooperation with the medical catheter, the visualization of the tissue structure and the medical catheter can be realized through the medical guide wire, which is conducive to improving the catheter passability, improving the safety of the operation, and reducing the complexity of the operation and the radiation dose during the operation.

[0038] It should be noted that the medical system provided in the present application belongs to the same inventive concept as the medical guide wire provided in the present application, and therefore the medical system provided in the present application has at least all the beneficial effects of the medical guide wire provided in the present application. For details, please refer to the relevant description of the beneficial effects of the medical guide wire provided in the present application. Therefore, the beneficial effects of the medical system provided in the present application will not be described one by one here. BRIEF DESCRIPTION OF DRAWINGS

[0039] Those skilled in the art will understand that the provided drawings are for better understanding of the present application and do not constitute any limitation on the scope of the present application.

[0040] Figure 1 is a schematic view of the medical guide wire of the present application penetrating the medical catheter.

[0041] Figure 2 is a schematic view of the medical catheter of the present application being pushed in the renal artery by the medical guide wire.

[0042] Figure 3 is a schematic view of the medical catheter of the present application being in place and abutting in the renal artery.

[0043] Figure 4 is a schematic view of the structure of the medical guide wire of the present application.

[0044] Figure 5 is a schematic view of the bendable section of the medical catheter of the present application and the internal structure of the guide wire lumen thereof.

[0045] Figure 6 is a schematic view of the structure of the medical guide wire of another embodiment of the present application.

[0046] Figure 7 is a schematic view of the structure of the medical guide wire of another embodiment of the present application.

[0047] Figure 8 is a schematic view of the bendable section of the medical catheter of another embodiment of the present application and the internal structure of the guide wire lumen thereof.

[0048] Figure 9 is a schematic view of the distal end of the push rod of the medical guide wire of the present application being coated with glue.

[0049] In the drawings:

[0050] 1 - medical guide wire; 2 - distal part; 3 - push rod; 4 - magnetic core; 5 - induction coil; 6 - wire; 7 - head cap; 8 - sheath structure; 9 - core structure; 91 - variable diameter section; 92 - constant diameter section; 11 - shaping structure; 12 - tapered transition section; 13 - connecting tube; 14 - first glue coating section; 15 - second glue coating section; 20 - medical catheter; 21 - electrode section; 22 - transition connecting section; 23 - bendable section; 24 - catheter body; 25 - handle; 26 - guide wire lumen; 27 - withdrawal limiting part; 271 - annular wall; 272 - barb. DETAILED DESCRIPTION

[0051] To make the purposes, advantages and features of the present application clearer, the present application is further described in detail below in combination with the drawings and specific embodiments. It should be noted that the drawings are all very simplified and not drawn in proportion, and are only used to facilitate and clarify the purpose of assisting the description of the embodiments of the present application. In addition, the structures shown in the drawings are often part of the actual structures. In particular, the emphasis shown in each drawing is different, and sometimes different proportions are used.

[0052] As used in this application, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. The term “or” is generally employed in its sense including “and / or” unless the context clearly dictates otherwise. The term “plurality” is generally employed in its sense including “two or more” unless the context clearly dictates otherwise. The term “first,” “second,” and the like, are used merely as labels to aid description and do not imply or suggest relative importance or a quantity of the specified features. Thus, features with “first,” “second,” etc. designations can include one or at least two of such features, either expressly or implicitly. The terms “proximal” and “distal” generally refer to two portions of a medical catheter or guidewire having one end for insertion into a human body and a handle end extending out of the body. The term “proximal” refers to a location closer to the handle end of the medical catheter or guidewire, and the term “distal” refers to a location closer to the insertion end of the medical catheter or guidewire and thus further away from the handle end of the medical catheter or guidewire. Alternatively, in a manual or hand-operated application, the terms “proximal” and “distal” are defined herein with respect to an operator such as a surgeon or clinician. The term “proximal” refers to a location closer to the operator, and the term “distal” refers to a location closer to a patient’s affliction and thus further away from the operator. Furthermore, as used in this application, “mounted,” “connected,” “coupled,” one element “disposed” on another element, should be broadly interpreted, generally to mean that two elements are in any kind of relationship, either directly or indirectly, connected, coupled, engaged, or driving, and cannot be understood to indicate or imply a spatial positional relationship between the two elements, i.e., one element can be inside, outside, above, below, or to the side of the other element, unless the context clearly dictates otherwise. The specific meaning of the above terms in this application can be understood by those of ordinary skill in the art according to the specific circumstances. Furthermore, directional terms such as above, below, up, down, upward, downward, left, right, etc. are used with respect to the exemplary embodiments as they are shown in the figures, upward or up direction is toward the top of the corresponding figure, and downward or down direction is toward the bottom of the corresponding figure. As used in this application, the term “axial” refers to a direction along a central axis of the entire medical instrument or corresponding structural component, the term “circumferential” refers to a direction around the central axis, and the term “radial” refers to a direction perpendicular to the axial direction, e.g., diametrically.

[0053] The medical guide wire and the medical system can be used in combination, and the medical guide wire is movably arranged in the guide wire channel of the medical guide catheter. The medical guide catheter can be easily positioned in a blood vessel, especially in a blood vessel with a special structure, and the operation difficulty is reduced.

[0054] In particular, the medical guide wire has a three-dimensional magnetic positioning function, realizes visualization of the medical guide wire, and can monitor movement and vibration of the medical guide wire in real time during an operation to prevent damage to a blood vessel during exchange and increase safety of the operation. Meanwhile, the medical guide wire can realize visualization of a blood vessel structure and a catheter during an operation, which is beneficial to improving catheter passability, improving safety of the operation, and reducing complexity of the operation and a radiation dose during the operation. The following is described with reference to the accompanying drawings.

[0055] First, referring to Figures 1-3 , the medical system provided by the embodiments of the present application comprises a medical guide wire 1 and a medical guide catheter 20, and the medical guide wire 1 is used in combination with the medical guide catheter 20. The medical guide catheter 20 herein can be various medical devices through which the medical guide wire 1 can pass, such as an electrode catheter or a non-electrode catheter such as a balloon catheter and an ultrasonic catheter. In general, the specific structure and specific type of the medical guide catheter 20 are not limited. For ease of understanding, the following is exemplarily described by taking an electrode catheter.

[0056] Specifically, referring to Figure 1 , the electrode catheter can comprise, from far to near, an electrode segment 21, a transition connection segment 22, a bendable segment 23, a catheter main body 24, and a handle 25.

[0057] The electrode segment 21 has at least one electrode, and preferably comprises at least a distal end head electrode. The electrode is used for mapping or ablation. In addition, when the electrode segment 21 comprises a plurality of electrodes, the electrodes are connected by an insulating member and achieve electrical isolation. It should be understood that a single electrode can perform monopolar stimulation and ablation, a plurality of electrodes can perform bipolar stimulation and ablation, i.e., inter-electrode stimulation and ablation, and can also perform multi-electrode simultaneous ablation. The material of the electrode can be a metal material such as platinum-iridium alloy that can be visualized and conductive, or a conductive material such as stainless steel and gold. The specific structure of the electrode segment 21 can be adjusted and changed according to the function of the catheter. For example, a plurality of holes can be arranged in the electrode segment 21 to allow placement of a saline tube, and a wire, a temperature measurement and positioning sensor, and other accessories can also be installed. The electrode segment 21 can have different shapes, such as a straight line type, a ring type, a claw type, a flower type, and various shapes that can be positioned and operated.

[0058] The transition connecting section 22 is used to connect the electrode section 21 and the bendable section 23. The transition connecting section 22 is generally a single-lumen tube, and the bendable section 23 is a multi-lumen tube. The bendable section 23 is controlled to bend by the pull wires, so as to realize the bending control of the medical catheter 20, especially the bidirectional bending control, and effectively improve the adhesion of the medical catheter 20.

[0059] The pull wires are at least two, and the at least two pull wires are symmetrically distributed in the medical catheter 20. Generally, all the pull wires are arranged from the distal end of the bendable section 23, then pass through the catheter body 24 to the handle 25, and are controlled to bend under the control of the handle 25. The pull wires are mostly round wire structures. In some cases, the distal end of the pull wire can be welded with a flat wire, the proximal end of the flat wire is cut off in the bendable section 23, and the parallel opposite sides of the flat wire with a larger size improve the symmetry of the bending directions of the two sides. Then, from the bendable section 23, the two pull wires and the corresponding flat wires are respectively arranged in two symmetric wire lumen, so that the bidirectional bending, positioning and adhesion functions can be realized by the two pull wires, and the bending directions of the two sides can be flexibly controlled by adjusting the installation direction of the flat wire, such as 180° two-side symmetric bending or 90° vertical distribution.

[0060] In some cases, the bendable section 23 is a four-lumen tube, and contains four chambers inside; two symmetric chambers are used as pull wire lumens to realize bidirectional bending control; and the other two chambers are internally provided with polymer tube materials, and are respectively used for passing saline and a medical guide wire 1; various wires are distributed along the gap between the inner wall of the four lumens and the outer wall of the polymer tube material.

[0061] Further, the catheter body 24 is an elongated tube body, which is used to connect the multi-lumen tube of the bendable section 23 and the handle 25. Generally, the catheter body 24 includes a braided layer, which can enhance the strength of the proximal end of the catheter, improve the support of the catheter, prevent the deformation of the catheter, and also provide the function of transmitting the torque of the catheter in proportion.

[0062] In addition, the handle 25 can provide various functions, such as providing the pull wire bending control function, providing a saline perfusion port, a guide wire inlet, an electrical stimulation energy interface, a radio frequency energy interface, etc. Specifically, the handle 25 needs to be set according to the functions of the electrode catheter itself. For the electrode catheter, the proximal end of the handle 25 is usually provided with an electrical stimulation energy-radio frequency energy interface to realize electrical stimulation and radio frequency energy ablation, and the proximal end of the handle 25 can also be provided with a guide wire inlet and a saline perfusion port, and the medical guide wire 1 and the perfusion saline can be connected to the electrode catheter from the corresponding ports. In addition, the handle 25 is internally provided with a pull wire system to control the pull wires.

[0063] It should also be understood that the electrode catheter is provided with a guide wire passage penetrating along the axial direction of the electrode catheter, and the guide wire passage extends from the electrode section 21, the transition connecting section 22, the bendable section 23, the catheter body 24, and the handle 25, so that the guide wire can be positioned in the blood vessel.

[0064] With reference back to Figures 1-3 , the cooperation between the medical guide wire 1 and the medical guide catheter 20 will be further described by taking the medical guide catheter 20 of the whole exchange type as an example. According to the application scenario described in the figure, the medical guide catheter 20 is designed in the whole exchange type, which can be cooperated with the medical guide wire 1 to push, position and withdraw in the renal artery.

[0065] Taking the transcatheter renal sympathetic denervation as an example, the surgical process is roughly as follows: after the transfemoral puncture and angiography are completed, the medical guide catheter 20 is placed, and the specific operation process is as follows:

[0066] Firstly, as shown in Figure 1 , the medical guide wire 1 is sent into the medical guide catheter 20 along the guide wire channel of the medical guide catheter 20 outside the body, but the distal end of the medical guide wire 1 does not leak out of the distal end of the guide wire channel outside;

[0067] Then, as shown in Figure 2 , the medical guide catheter 20 is sent into the sheath, and then the medical guide wire 1 is pushed to the distal end of the renal artery;

[0068] Then, as shown in Figure 3 , the medical guide catheter 20 is made to cross the renal artery orifice and the tortuous part of the blood vessel along the medical guide wire 1, enter the renal artery, and reach the target position. After the medical guide wire 1 is withdrawn, the bending control is implemented by the handle 25 to make the bendable section 23 bend, so that the distal end of the catheter is attached to the blood vessel wall, and then stimulation and ablation are performed.

[0069] As can be seen, in actual use, the medical guide catheter 20 is pushed along the medical guide wire 1, which is more likely to cross the renal artery orifice and the tortuous part to reach the target position and achieve rapid attachment through bidirectional bending control. It should also be understood that if the medical guide catheter 20 needs to be replaced, the medical guide catheter 20 in the body is withdrawn, the medical guide wire 1 is not withdrawn, and the medical guide catheter 20 to be used is sent into the body along the medical guide wire 1, which can reduce the damage to the blood vessel during the process of using the guide wire to replace the catheter.

[0070] Then, with reference to Figure 4 , the embodiment of the present application provides a medical guide wire 1, which comprises: a distal end part 2 and a push rod 3 connected in sequence from distal to proximal along the axial direction of the medical guide wire 1; the push rod 3 has an inner hole extending through along the axial direction of the medical guide wire 1; the distal end part 2 comprises at least one magnetic positioning sensor; the magnetic positioning sensor comprises a magnetic core 4 and an induction coil 5 wound on the outer surface of the magnetic core 4; the induction coil 5 leads out at least two wires 6, and the at least two wires 6 extend through the inner hole of the push rod 3 to the proximal end of the push rod 3.

[0071] Thus configured, since the distal end portion 2 of the medical guide wire 1 is provided with the magnetic positioning sensor, the presence of the magnetic positioning sensor enables the medical guide wire 1 to have a three-dimensional magnetic positioning function, based on which the visualization of the medical guide wire 1 can be realized. Furthermore, when the medical guide wire 1 is used in cooperation with the medical catheter 20, in addition to directly displaying the three-dimensional structure of the blood vessel tissue, the bending state of the medical catheter 20 during use can also be displayed in real time, and the medical catheter 20 can be presented to the medical staff in a visual state, which not only improves the passability of the catheter and makes the positioning of the catheter more flexible, but also reduces the difficulty of the operation and the radiation dose during the operation, and increases the safety and efficiency of the operation.

[0072] Optionally, the medical guide wire 1 has a specification of 0.014 inch to 0.038 inch. The most commonly used guide wire specifications are 0.014 inch, 0.035 inch and 0.038 inch, which can accommodate the most commonly used medical catheter 20. Here, the guide wire specification refers to the diameter of the guide wire. In this embodiment, the diameter of the guide wire refers to the outer diameter of the push rod 3.

[0073] It should be understood that the material, shape and size of the magnetic core 4 can be adjusted and changed as needed. The magnetic core 4 can have various shapes. Optionally, the shape of the magnetic core 4 can be cylindrical, square, ring-shaped or other shapes. Preferably, the magnetic core 4 is cylindrical. The material of the magnetic core 4 is not limited. Commonly used magnetic core materials include amorphous material, ferrite, permalloy and the like. In view of the applicable frequency band and initial magnetic permeability, preferably, the magnetic core 4 is made of amorphous material with high magnetic permeability, small temperature influence and small eddy current loss. The magnetic core 4 can be solid or hollow, and more preferably is solid.

[0074] When the magnetic core 4 is installed, at least two copper wires with an insulating outer skin can be wound on the outer surface of the magnetic core 4 to form an induction coil 5. The induction coil 5 is preferably led out of at least two wires 6 at the proximal end thereof for signal transmission. In some cases, the induction coil 5 can be led out of at least two wires 6 at the proximal end of the magnetic core 4.

[0075] After the induction coil 5 is led out of at least two wires 6, the two wires 6 can adopt various structural forms, such as the coaxial cable structure, the parallel and parallel cable structure or the twisted pair structure. Preferably, any induction coil 5 is led out of two wires 6, and the two wires 6 form a twisted pair structure, i.e. Figure 4 As shown. It can be understood that when the cable transmits data, there is current passing through the wire core, which will generate some electromagnetic signals that are harmful "noise" to other wire cores. The twisted pair is a paired structure, and the "noise" emitted by the twisted wires 6 will cancel each other out, thereby increasing the transmission efficiency. In addition, compared with the coaxial cable, the twisted pair has a smaller outer diameter and stronger resistance to entanglement, pressure and bending.

[0076] The lead wire 6 led out from the induction coil 5 is finally connected to the proximal end of the push rod 3. The proximal end of the push rod 3 can be provided with a socket, and the lead wire 6 is connected to the socket by welding or other means, specifically, the proximal end of the lead wire 6 is connected to the corresponding pin of the socket, so as to realize the transmission of the induction signal to the three-dimensional magnetic positioning device. Preferably, the socket can filter the induction signal output by the induction coil 5 to reduce signal interference and improve magnetic positioning accuracy.

[0077] In order to obtain high-quality magnetic positioning induction signals, the medical system preferably further comprises a signal processing device in communication with the medical guide wire 1, which can amplify and filter the induction signal output by the induction coil 5 to obtain more accurate induction signals and increase the magnetic positioning accuracy.

[0078] Further preferably, the distal portion 2 can include a head cap 7, a sheath structure 8 and an internal structure; the head cap 7 is fixed at the distal end of the sheath structure 8; the sheath structure 8 is sleeved outside the internal structure; the proximal end of the sheath structure 8 is connected to the distal end of the push rod 3, which can be directly connected or indirectly connected; the internal structure includes a core structure 9, the proximal end of the core structure 9 is connected to the distal end of the push rod 3, and at least part of the core structure 9 forms the magnetic core 4 and is provided with the induction coil 5, and the induction coil 5 preferably leads out at least two lead wires 6 at its proximal end.

[0079] The entire outer surface of the head cap 7 is smooth, which can better protect the blood vessels. The main function of the head cap 7 is to increase the softness of the distal end of the guide wire, provide support, enhance tactile feedback, improve tracking, reduce friction, protect blood vessels, etc. For example, in some cases, the head cap 7 can also be developed under X-ray to increase visibility. Optionally, the head cap 7 is a visible structure made of a suitable visible metal material, such as platinum-iridium, etc. Optionally, the head cap 7 is a gel ball made of gel or a molten ball formed by melting. The gel ball is soft and less likely to damage blood vessels and other tissue structures.

[0080] The outer diameter of the sheath structure 8 is usually less than or equal to the outer diameter of the push rod 3. The proximal end of the sheath structure 8 can be connected to the distal end of the push rod 3 or to the proximal end of the core structure 9. In addition, a gap is reserved between the inner side of the sheath structure 8 and the outer side of the core structure 9 to facilitate the arrangement of the induction coil 5. The size of the induction coil 5 in the radial direction is mainly determined according to the specifications of the medical guide wire 1. If the gap between the inner side of the sheath structure 8 and the outer side of the core structure 9 is large enough, more layers and more turns of the induction coil 5 can be arranged to increase the magnetic positioning accuracy.

[0081] The sheath structure 8 can have various structural forms, such as a spring coil, or a non-spring coil structure such as a plastic sheath structure, a polymer sheath structure, etc., which are not limited in the present application. Preferably, the sheath structure 8 can be developed under X-ray. In the present embodiment, the sheath structure 8 is a spring coil, the entire spring coil can be developed, and the wire material for winding the spring coil can be platinum alloy or other developable metal materials. The sheath structure 8 increases the softness of the distal end of the guide wire, and especially when the sheath structure 8 can be developed, it also increases the visibility of the distal end of the guide wire, facilitating the passage of the guide wire and the catheter through the tortuous structure. The outer surface of the sheath structure 8 can also have a coating, such as a hydrophilic coating or a hydrophobic coating. Preferably, the base body of the sheath structure 8 is processed to have a hydrophilic or hydrophobic coating, and then applied to the medical guide wire 1.

[0082] At the same time, the internal structure is mainly used to make a magnetic positioning sensor, which is entirely wrapped inside the sheath structure 8 and is not exposed, so that the entire magnetic positioning sensor has a small size and does not increase the overall diameter of the guide wire, and the difficulty of setting the magnetic positioning sensor at the distal end of the catheter is low. In practice, one or more magnetic positioning sensors can be installed between the distal end of the push rod 3 and the head cap 7.

[0083] It should be understood that such a magnetic positioning sensor can be configured in many commonly used guide wires, so that the medical guide wire 1 is more flexible and safe in clinical application, can monitor the in-place condition of the guide wire and the catheter in real time, and can cope with various complex vascular structures and lesions.

[0084] Preferably, the distal end portion 2 further comprises a shaping structure 11, which is located inside the sheath structure 8 and is connected to the proximal end of the head cap 7 and the distal end of the core structure 9, respectively. The shaping structure 11 is an elongated structure with certain toughness and softness, and is usually made of metal. The setting of the shaping structure 11, on the one hand, increases the softness of the distal end of the guide wire and reduces the damage to the tissue, and on the other hand, the medical staff can shape the distal end of the guide wire according to the lesion site and morphology to adapt to the anatomical structure. The outer diameter of the shaping structure 11 can be smaller than the outer diameter of the magnetic core 4. Optionally, the shaping structure 11 is composed of a thin wire.

[0085] Next, in the actual manufacturing process, one or more magnetic cores 4 can be made through the core structure 9.

[0086] Please refer to Figure 4In some embodiments, the core structure 9 forms a part of the magnetic core 4, and the core structure 9 includes the magnetic core 4, a variable diameter section 91 and a constant diameter section 92 connected in sequence along the axial direction of the core structure 9. The proximal end of the constant diameter section 92 is connected to the distal end of the push rod 3. The variable diameter section 91 and the constant diameter section 92 each have an inner hole extending through the axial direction of the section. The inner hole of the variable diameter section 91, the inner hole of the constant diameter section 92 and the inner hole of the push rod 3 are connected in sequence. In this embodiment, there is only one magnetic core 4, and a part of the length of the magnetic core 4 is embedded in the inner hole of the variable diameter section 91 to be fixed. The variable diameter section 91 has a gradually increasing outer diameter from the distal end to the proximal end of the variable diameter section 91, which is a gradually changing design. The maximum outer diameter of the variable diameter section 91 is the same as the outer diameter of the constant diameter section 92, and the outer diameter of the constant diameter section 92 is smaller than the outer diameter of the push rod 3. In this embodiment, the variable diameter section 91 is provided to provide good support, torque transmission and pushability to the distal end of the guide wire. In addition, the inductive coil 5 wound on the magnetic core 4 has at least two wires 6 drawn out from the proximal end of the magnetic core 4. The wires 6 can directly enter the inner hole of the variable diameter section 91 from the distal end of the variable diameter section 91 at the proximal end of the magnetic core 4, and then extend along the inner hole of the variable diameter section 91, the inner hole of the constant diameter section 92 and the inner hole of the push rod 3 to the proximal end of the push rod 3.

[0087] It can be understood that the remaining part of the core structure 9 (including the variable diameter section 91 and the constant diameter section 92) other than the magnetic core 4 is a non-magnetic structure. In this case, the magnetic core 4 and the remaining part of the core structure 9 can be formed separately and then assembled. Specifically, a part of the length of the magnetic core 4 is embedded in the inner hole of the variable diameter section 91 to be fixed. The fixing method can be a combination of one or more fixing methods such as glue bonding and welding. It should be understood that in other embodiments, the remaining part of the core structure 9 can be all constant diameter sections 92, such as one or more constant diameter sections 92 with different diameters.

[0088] Preferably, a tapered transition section 12 is provided between the proximal end of the core structure 9 and the distal end of the push rod 3. In this embodiment, the tapered transition section 12 is between the proximal end of the constant diameter section 92 and the distal end of the push rod 3. The tapered transition section 12 has a gradually increasing outer diameter from the distal end to the proximal end of the tapered transition section 12 to the outer diameter of the push rod 3. The tapered transition section 12 can be linearly tapered or non-linearly tapered. Optionally, the length of the tapered transition section 12 is 2mm-4mm.

[0089] The remaining part of the core structure 9 other than the magnetic core 4 can be integrally formed or assembled by multiple sections. For example, the constant diameter section 92 and the variable diameter section 91 are integrally formed, or the constant diameter section 92 and the variable diameter section 91 are formed separately and then assembled together by welding or other suitable methods. Similarly, the remaining part of the core structure 9 and the push rod 3 can be integrally formed, or the remaining part of the core structure 9 and the push rod 3 are formed separately and then assembled together. The assembly method can be welding or other connection methods.

[0090] Optionally, the entire outer surface of the push rod 3 is provided with a hydrophilic coating or a hydrophobic coating to achieve good maneuverability. Preferably, the entire outer surface of the push rod 3 is provided with a PTFE hydrophobic coating. The push rod 3 is generally an elongated rod member, which needs to meet certain mechanical performance requirements. The push rod 3 and the remaining part of the core structure 9 except the magnetic core 4 can be made of various commonly used medical metal materials such as nickel-titanium alloy or stainless steel.

[0091] In Figure 6 , as a variant, the entire structure of the core structure 9 is provided with the magnetic core 4, and the magnetic core 4 is one, and the induction coil 5 is one. Compared with the foregoing embodiment, the length of the magnetic core 4 of this embodiment is the length of the entire core structure 9, and therefore, the lengths of the magnetic core and the induction coil are both increased. Preferably, the outer diameter of the core structure 9 remains unchanged from far to near in its entire length.

[0092] As another variant, part or all of the structure of the core structure 9 can form a plurality of magnetic cores 4, which are distributed in sequence in the axial direction of the core structure 9, for example, continuously or discretely or both. An induction coil 5 is wound around the outer surface of each magnetic core 4, and each induction coil 5 is independent of each other, and each induction coil 5 leads out at least two wires 6, and all the wires 6 converge at the proximal end of the core structure 9 and then extend through the same inner hole of the push rod 3 to the proximal end of the push rod 3. In this embodiment, each magnetic core 4 is functionally independent, and an induction coil 5 is wound around the outer surface of each magnetic core 4, and each induction coil 5 is also independent of each other and not connected. In this way, it is equivalent to providing a plurality of independent magnetic positioning sensors in the distal end portion 2 of the medical guide wire 1, and each magnetic positioning sensor includes an induction coil 5 and a corresponding magnetic core 4. In this way, the same medical guide wire 1 can accommodate a plurality of high-sensitivity magnetic positioning sensors at the distal end, making the magnetic positioning more accurate and reliable.

[0093] Here, the exemplary embodiments described in Figure 7 are explained. As Figure 7As shown, part of the core structure 9 forms, for example, three independent magnetic cores 4, and the magnetic cores 4 are connected by connecting tubes 13. The connecting tubes 13 can be provided with wires 6, or the wires 6 are provided outside the connecting tubes 13. In this embodiment, each connecting tube 13 is also provided with wires 6 (preferably twisted wires), so that the wires 6 of the induction coils 5 on some magnetic cores 4 can be routed through the connecting tubes 13 between adjacent magnetic cores 4. In some cases, the wires 6 can also be routed through the inner holes of some magnetic cores 4. In this embodiment, the wires 6 are provided outside the magnetic cores 4 after exiting the connecting tubes 13. The connecting tubes 13 can be sleeved on one end of the magnetic cores 4 or the one end of the magnetic cores 4 is embedded in the connecting tubes 13, and then fixed by welding or gluing, etc. Preferably, the magnetic cores 4 and the connecting tubes 13 are fixed by pouring glue into the connecting tubes 13. It should be understood that a plurality of magnetic cores 4 can also be connected as a whole by one connecting tube 13, which is not limited by the present application.

[0094] The magnetic positioning design of the medical guide wire 1 is further described below.

[0095] Since the self-made magnetic positioning sensor needs to be installed at the distal end of the guide wire with a small space, the voltage sensitivity of the induction coil 5 should be higher than that of the hollow induction coil μ c times. c The calculation formula is as follows:

[0096]

[0097] In formula (1), N d is the demagnetization factor, which is determined by the shape of the magnetic core 4; for example, for an oblong body, μ r is the initial permeability of the magnetic core 4; l is the length of the magnetic core 4; d is the diameter (i.e. the outer diameter) of the magnetic core 4; ln is the logarithm, and ln2l is the logarithm of 2l.

[0098] According to formula (1), μ c can be calculated, and according to the calculated μ c , it can be known whether the voltage sensitivity of the induction coil 5 meets the product requirements. Conversely, according to the voltage sensitivity, the shape and size of the magnetic core 4 can also be optimized, and finally the appropriate shape and size of the magnetic core 4 are selected to achieve the optimal magnetic positioning effect.

[0099] It should be understood that the magnetic permeability is a property of the material itself, so when the material of the magnetic core 4 is determined, the shape and size (including diameter and length) of the magnetic core 4 are the key to the magnetic induction design. Therefore, in the actual research and development process, the shape and size of the magnetic core 4 are adjusted to meet the requirements of the magnetic positioning in precision, sensitivity, signal strength, etc. As for the problem of the reduction of the magnetic positioning precision caused by other noise introduced by the magnetic core 4, as mentioned above, circuit compensation can be taken to solve it, such as filtering, amplification, etc.

[0100] Optionally, the outer diameter of the magnetic core 4 is 0.15mm-0.18mm, such as 0.15mm, 0.16mm, 0.17mm, 0.18mm, etc., and the length of the magnetic core 4 is 4mm-4.4mm, such as 4.0mm, 4.1mm, 4.2mm, 4.3mm, 4.4mm, etc.; this size is especially suitable for a medical guide wire 1 of 0.014inch specification, for example, the outer diameter of the distal end portion 2 is 0.26mm-0.33mm, such as 0.26mm, 0.27mm, 0.28mm, 0.29mm, 0.30mm, 0.31mm, 0.32mm, 0.33mm, etc., and the inner diameter of the sheath structure 8 is not less than (i.e. greater than or equal to) 0.2mm.

[0101] In addition, considering that the magnetic induction intensity of the magnetic core 4 is the largest at the center and the sensitivity is the highest, therefore, the length of the induction coil 5 accounts for 75%-90% of the length of the magnetic core 4, such as 75%, 80%, 85% or 90%. For example, in the embodiment, the length of the magnetic core 4 embedded in the variable diameter section 91 accounts for 10%-25% of the length of the magnetic core 4, such as 10%, 15%, 20% or 25%, which guarantees firm fixation of the magnetic core 4 while taking into account the sensitivity. In a specific example, when the specification of the medical guide wire 1 is 0.014inch, the length of the magnetic core 4 is 4mm, in order to avoid edge effect, the induction coil 5 can be wound in the range of 3mm-3.5mm of the center of the magnetic core 4, that is, the length of the induction coil 5 accounts for 75%-90% of the length of the magnetic core 4, such as 75%, 80%, 85%, 90%, which guarantees the sensitivity of the magnetic positioning.

[0102] In the case of ensuring that the magnetic field changes more obviously and the coil copper wire will not be burned out, the wire diameter of the induction coil 5 is preferably 20-30 μm, such as 20 μm, 25 μm or 30 μm, etc. In addition, the winding layer number and the winding turn number of the induction coil 5 can be adjusted according to the coil wire diameter, the inner diameter of the sheath structure 8 and the outer diameter of the magnetic core 4. Optionally, the winding layer number of the induction coil 5 is not more than 2 layers, and the winding turn number of the induction coil 5 is not more than 280 turns. At this time, preferably, the wire diameter is 20-30 μm, such as 20 μm, 25 μm, 30 μm, the gap between the inner side of the sheath structure 8 and the outer side of the magnetic core 4 is 20-50 μm, such as 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm.

[0103] Preferably, the outer surface of the magnetic core 4 is provided with a texture, which can accommodate the wire 6 for winding the induction coil 5, thereby defining the position of the induction coil 5, and further ensuring the magnetic positioning accuracy and sensitivity. The shape and size of the texture are set according to the winding shape and size of the wire 6. Optionally, the diameter of the texture is consistent with the wire diameter of the wire 6, the depth of the texture is equal to the radius of the wire 6, and the interval between the textures is the interval between the windings. Optionally, the texture interval accuracy reaches 1 μm, which can ensure the winding accuracy of the induction coil 5 during assembly.

[0104] It should be understood that another key of the magnetic induction design also lies in the inductance value. For example, the length of the induction coil 5 and the length of the magnetic core 4 are in the ratio of 0.1-0.8. When the value of β is 0.1-0.8, the inductance calculation formula is:

[0105]

[0106] In formula (2), L is the inductance value; μ0 is the vacuum permeability; μr is the relative permeability of the magnetic core; A is the cross-sectional area of the coil; l is the length of the magnetic core; N is the total number of turns of the coil; b is the length of the coil. c c w

[0107] According to formula (2), the inductance value of the induction coil 5 can be calculated to know the sensitivity. Conversely, based on the inductance value, the shape and size of the induction coil 5 can be further optimized, and finally the appropriate shape and size of the induction coil 5 are selected to achieve the best magnetic positioning effect.

[0108] Further research shows that when the medical guide wire 1 is withdrawn, if the push rod 3 of the medical guide wire 1 is in the bendable section 23 of the medical catheter 20, the adjustable bending deformation ability of the medical catheter 20 will be weakened, the bending control force will be increased, and the bending control difficulty will be increased.

[0109] Therefore, on the one hand, as shown in FIG. 1, the push rod 3 of the medical guide wire 1 is provided with a guide structure 7, which is in the form of a guide groove. Figure 4 ​​​As shown, the connection between the proximal end of the core structure 9 and the distal end of the push rod 3 is provided with a glue layer, specifically, the glue layer is provided on the outer surface of the tapered transition section 12, and the outer diameter of the glue layer is less than or equal to the outer diameter of the push rod 3. The glue layer is designed to gradually increase from the distal end to the proximal end, and the maximum outer diameter is less than or equal to the outer diameter of the push rod 3. In a specific example, the maximum outer diameter of the glue layer is less than or equal to 0.014 inch. The glue layer is formed by glue coating and has a certain viscosity, which can increase the withdrawal resistance of the connection between the proximal end of the core structure 9 and the distal end of the push rod 3 when the medical guide wire 1 is withdrawn, so as to limit the medical guide wire 1.

[0110] On the other hand, as Figure 5 As shown, the medical catheter 20 includes a bendable section 23, and the guide wire passage includes a guide wire lumen 26 provided in the bendable section 23, and the proximal end of the guide wire lumen 26 is provided with a withdrawal limiting part 27. The withdrawal limiting part 27 has an initial state and a limiting state, and can be switched between the initial state and the limiting state.

[0111] In the initial state, the withdrawal limiting part 27 can normally pass the medical guide wire 1 without increasing the pushing resistance, that is, when the medical guide wire 1 is pushed in the guide wire passage from the proximal end to the distal end, the distal end part 2 of the medical guide wire 1 and the push rod 3 can smoothly pass through the withdrawal limiting part 27.

[0112] And in the limiting state, the withdrawal limiting part 27 is deformed under the action of the force of the medical guide wire 1 being withdrawn, and then prevents the connection between the distal end part 2 of the medical guide wire 1 and the push rod 3 from passing through, so that the connection between the distal end part 2 and the push rod 3 is limited in the withdrawal limiting part 27, and then the push rod 3 does not stay in the bendable section 23, and does not affect the bending control of the medical catheter 20.

[0113] Specifically, in the limiting state, the withdrawal limiting part 27 prevents the connection between the proximal end of the core structure 9 and the distal end of the push rod 3 from passing through, so that the connection between the proximal end of the core structure 9 and the distal end of the push rod 3 is limited in the withdrawal limiting part 27, and especially after the glue layer is provided at the connection, the glue layer increases the resistance of the connection when being withdrawn, so that the connection is easily blocked by the withdrawal limiting part 27.

[0114] The retreat limiting portion 27 is made of a high polymer material with good toughness and flexibility. The retreat limiting portion 27 can be achieved by various measures. Although the embodiment is described in combination with the annular wall 271 in the drawings, it should be understood that other limiting ways can also be adopted. Although the annular wall 271 of the embodiment has a simpler structure, is more convenient to use, and has less influence on the performance of the bendable section 23, the embodiment should not be limited to this structure. Therefore, in addition to the structure of the retreat limiting portion 27 listed in the drawings, those skilled in the art can find other alternative ways to achieve the functions / achieve the effects described in the present application based on the description in the present application, not just including the scheme disclosed in the embodiment.

[0115] Preferably, as described in the Figure 5 The retreat limiting portion 27 is an annular wall 271, one end of which is connected to the inner wall of the guide wire cavity 26, and the other end is a free end. In the initial state (natural opening), the other end of the annular wall 271 extends obliquely towards the distal end of the bendable section 23, so that the annular wall 271 forms a tapered structure with a small distal end inner diameter (D2) and a large proximal end inner diameter (D1). However, the minimum inner diameter (D2) of the annular wall 271 is still larger than the diameter of the medical guide wire 1, so that the distal end portion 2 and the push rod 3 can pass normally. Further, in the limiting state, the free end of the annular wall 271 is bent and deformed towards the proximal end of the bendable section 23 under the action of the force of the medical guide wire 1 retreat, and then the inner diameter (D3) of the annular wall 271 is smaller than the diameter of the medical guide wire 1, thereby hindering the retreat of the medical guide wire 1, and finally limiting the connection between the proximal end of the core structure 9 and the distal end of the push rod 3 to the proximal end of the bendable section 23.

[0116] The retreat limiting portion 27 can be a continuous annular wall 271 or an annular wall 271 defined by a plurality of discrete barbs 272. Here, the continuous annular wall 271 refers to an entire annular wall shown in the drawings, and the discrete annular wall 271 refers to a plurality of independent barbs 272, which are arranged along a circumferential direction of the guide wire cavity 26, one end of each barb 272 is connected to the inner wall of the guide wire cavity 26, and the other end is a free end, which extends obliquely towards the distal end of the bendable section 23 in the natural opening. In the embodiment, the retreat limiting portion 27 is composed of a plurality of independent barbs 272; from the proximal end to the distal end, the arrangement direction of each barb 272 is just in line with the pushing direction of the medical guide wire 1, and does not hinder the pushing of the medical guide wire 1; from the distal end to the proximal end, the arrangement direction of each barb 272 is just against the retreat direction of the medical guide wire 1, so that the medical guide wire 1 can be limited at this position when it retreats, without affecting the adjustable bending of the medical guide tube 20, and the medical guide wire 1 also will not move or vibrate randomly.

[0117] For example, to ensure the smooth passage of the medical guidewire 1 during push-out and its positioning function during retraction, the thickness of the barbs 272 is set to d, where D1 = D-2d > 0.014 inch, D2 = D-3d > 0.014 inch, and D3 = D-4d < 0.014 inch, where D is a fixed value and 0.014 inch is the diameter of the medical guidewire 1. Based on this, when pushing the medical guidewire 1, the pushing force is along the direction of the barbs 272, allowing both the distal portion 2 and the push rod 3 to pass through; during retraction, the push rod 3 can retract normally through the barbs 272, especially when the surface of the push rod 3 is coated with a PTFE slip coating, making it easier for the push rod 3 to retract through the barbs 272. It should be understood that the adhesive coating (i.e., the adhesive layer) at the connection between the core structure 9 and the push rod 3 is sticky, and the resistance is large when retracting. Moreover, the retraction force is opposite to the direction of the barb, and the barb is easy to bend in the proximal direction. The inner diameter D3 after bending can prevent the medical guide wire 1 from continuing to retract, thereby limiting the connection between the core structure 9 and the push rod 3 to the proximal end of the flexible section 23.

[0118] like Figure 8 and Figure 9 As shown, in another embodiment, the retraction limiting part 27 consists of only one barb 272. Specifically, a barb 272 is provided on the inner wall near the outer side of the catheter in the proximal end of the guidewire cavity 26 of the flexible section 23. The barb 272 extends partially circumferentially along the inner wall of the guidewire cavity 26, and is not arranged in a complete circle. The barb 272 occupies approximately 1 / 4 to 1 / 2 of the circumference of the inner wall of the guidewire cavity 26. In this embodiment, one end of the barb 272 is connected to the inner wall of the guidewire cavity 26, and the other end is a free end. When naturally opened, the other end of the barb 272 extends obliquely towards the distal end of the flexible section 23, and the distance D4 from the end of the barb 272 connected to the guidewire cavity 26 to the inner wall of the opposite guidewire cavity 26 is greater than the outer diameter of the push rod 3. When the barb 272 is naturally opened, the distance D5 from the free end of the barb 272 to the inner wall of the opposite guidewire cavity 26 is less than the outer diameter of the push rod 3.

[0119] Meanwhile, when the distal end of the push rod 3 is circumferentially coated, a first coating section 14 is arranged on a part of the outer surface of the tapered transition section 12 in the circumferential direction, and a second coating section 15 is arranged on another part of the outer surface of the tapered transition section 12 in the circumferential direction. The outer diameter of the first coating section 14 gradually decreases from the distal end to the proximal end, and a bayonet hole similar to a V shape is formed at the proximal end. The coating range of the first coating section 14 along the circumferential direction of the outer surface of the tapered transition section 12 is substantially consistent with the extension range of the barb 272 along the circumferential direction of the inner wall of the guide wire lumen 26, for example, about 1 / 4 to 1 / 2 of the circumference of the outer surface of the tapered transition section 12. Therefore, the first coating section 14 and the second coating section 15 are arranged opposite to each other on the outer surface of the tapered transition section 12, so that a part of the outer surface of the tapered transition section 12 in the circumferential direction forms the first coating section 14, and the remaining part is the second coating section 15. The second coating section 15 has a constant outer diameter from the distal end to the proximal end, and the outer diameter is consistent with the outer diameter of the sheath structure 8. Based on this, when the medical guide wire 1 is withdrawn, the free end of the barb 272 will be subjected to the action force of the withdrawal of the medical guide wire 1, and then be bent and deformed towards the proximal end of the bendable section 23, and then be clamped into the bayonet hole at the distal end of the push rod 3 to limit the medical guide wire 1.

[0120] In addition, when the proximal end of the medical guide wire 1 is provided with a fastening position, preferably, the positioning mark at the fastening position is arranged on the same side of the medical guide wire 1 as the first coating section 14, and can be kept on the same side as the barb 272 during withdrawal to play an indicating role. Specifically, when the medical guide wire 1 is pushed from the proximal end to the distal end of the medical catheter 20, the positioning mark at the proximal end of the medical guide wire 1 is away from the outside of the medical catheter 20, that is, the first coating section 14 is located on the opposite side of the barb 272, and then passes through the guide wire lumen 26, so that the second coating section 15 can smoothly slide through the barb 272, ensuring that the medical guide wire 1 can normally pass through. Conversely, when the medical guide wire 1 is withdrawn, the positioning mark at the proximal end of the medical guide wire 1 is directed towards the outside of the medical catheter 20, so that the first coating section 14 is located on the same side of the barb 272, and then passes through the guide wire lumen 26, so that the barb 272 in the guide wire lumen 26 can be clamped into the bayonet hole at the proximal end of the first coating section 14 to limit the medical guide wire 1.

[0121] In another aspect, when three-dimensional modeling is performed, the position of the medical guide wire 1 in the blood vessel fluctuates greatly, and cannot always maintain the state of adhering to the blood vessel wall, which will affect the accuracy of modeling.

[0122] To this end, in a further improved embodiment, the proximal end of the push rod 3 is provided with a fastening position, the distance from the fastening position to the distal end of the medical guide wire 1 is the same as the distance from the distal end of the medical catheter 20 to the proximal guide wire inlet. In this way, during the operation, the medical guide wire 1 can be detachably connected to the proximal end of the medical catheter 20 at the fastening position, thereby limiting the position of the medical guide wire 1 so that the medical guide wire 1 cannot move or vibrate at will. And when the medical guide wire 1 is connected to the medical catheter 20 at the fastening position, it can be ensured that the distal end portion 2 of the medical guide wire 1 is exactly accommodated inside the distal end of the medical catheter 20, so that the high-precision three-dimensional modeling can be realized by the abutment of the distal end of the medical catheter 20 and the blood vessel wall. It can be understood that during three-dimensional modeling, it is necessary to ensure that the magnetic positioning sensor at the distal end of the medical guide wire 1 is inside the distal end of the medical catheter 20. At this time, by virtue of the abutment of the distal end of the medical catheter 20 and the blood vessel wall, the magnetic positioning data of the catheter distal end is obtained, and then when the magnetic positioning calculation is performed, only the position compensation of the catheter radius size is needed to realize the three-dimensional modeling of the catheter and the blood vessel tissue.

[0123] Preferably, a positioning mark is arranged at the fastening position, which can be arranged in various ways, for example, laser marking, printing, etching, etc. In this way, medical staff can quickly determine the position of the medical guide wire 1 according to the positioning mark. When three-dimensional modeling is needed, after the position of the medical guide wire 1 is determined, the proximal end of the medical guide wire 1 is connected to the medical catheter 20 at the fastening position to prevent the medical guide wire 1 from moving, so as to realize high-precision modeling. Since the proximal end of the medical catheter 20 is provided with a connection valve, such as a Y-shaped hemostatic valve, when the distal end portion 2 of the medical guide wire 1 enters the inside of the distal end of the medical catheter 20, the proximal end of the medical guide wire 1 can be detachably connected to the connection valve on the proximal end of the catheter to limit the position of the medical guide wire 1.

[0124] Therefore, the blood vessel can be three-dimensionally modeled and displayed in real time during the movement of the medical guide wire 1 in the blood vessel in the body, making the operation more intuitive and visual. At the same time, the handle 25 of the medical catheter 20 can also control the bendable section 23 during the operation, and the distal end of the catheter can be bidirectionally deflected, thereby improving the abutment force and the flexibility of the bending direction control. The three-dimensional modeling method is understood by those skilled in the art, and therefore will not be described in detail.

[0125] In summary, according to the technical scheme provided by the embodiment of the present application, the magnetic positioning sensor can be self-made on the medical guide wire 1, so that the medical guide wire 1 has a three-dimensional magnetic positioning function, the visualization of the medical guide wire 1 is realized, and then the movement and tremor of the medical guide wire 1 can be monitored in real time during the operation, so as to prevent the blood vessel from being damaged during the exchange process and increase the safety of the operation. Especially when the medical guide wire 1 is used in cooperation with the medical catheter 20 during the operation, in addition to directly showing the three-dimensional structure of the blood vessel tissue, the curved state of the catheter during use can also be displayed in real time, and the catheter is presented in a visible state, which is beneficial to improve the passability of the catheter, improve the safety of the operation, and reduce the complexity of the operation and the radiation dose during the operation.

[0126] Finally, it should be further pointed out that although the ablation of the renal artery is taken as an example for description in the foregoing, it is not limited thereto, and the medical catheter 20 provided by the embodiment can also be used for ablation of different parts such as cardiac ablation and bronchial ablation. Moreover, the medical catheter 20 is not limited to an ablation catheter, but can also be various medical catheters. In practice, as long as the medical catheter 20 can be used in cooperation with the medical guide wire 1 for intervention in the blood vessel, the medical guide wire 1 can be used to guide the medical catheter 20 to reach the target position, and the visualization of the blood vessel tissue structure, the guide wire and the catheter can be realized by means of the medical guide wire 1.

[0127] It should be pointed out that the above several embodiments can be combined with each other. The above description is only a description of the preferred embodiments of the present application, and does not limit the scope of the present application in any way, and any modification or modification of the above-mentioned disclosure by a person skilled in the art falls within the protection scope of the present application.

Claims

1. A medical guidewire, characterized in that, include: A distal portion and a push rod are connected sequentially from far to near along their own axial direction; the push rod has an inner hole extending through it along its own axial direction; the distal portion includes at least one magnetic positioning sensor; the magnetic positioning sensor includes a magnetic core and an induction coil wound on the outer surface of the magnetic core; at least two wires are led out from the induction coil, and the at least two wires extend through the inner hole of the push rod to the proximal end of the push rod.

2. The medical guidewire according to claim 1, characterized in that, The distal portion further includes a head cap, a sheath structure, and an internal structure; the head cap is fixed to the distal end of the sheath structure; the sheath structure is sleeved on the outside of the internal structure; the internal structure includes a core structure, the proximal end of which is connected to the distal end of the push rod, and at least a portion of the core structure forms a magnetic core around which the induction coil is wound, and at least two wires are led out from the proximal end of the induction coil.

3. The medical guidewire according to claim 2, characterized in that, A portion of the core structure forms a magnetic core, and the core structure includes a magnetic core, a variable-diameter section, and a constant-diameter section connected sequentially from far to near along its own axial direction; the proximal end of the constant-diameter section is connected to the distal end of the push rod; both the variable-diameter section and the constant-diameter section have an inner hole extending through their own axial direction; the inner holes of the variable-diameter section, the constant-diameter section, and the push rod are sequentially connected; a portion of the length of the magnetic core is fixedly embedded in the inner hole of the variable-diameter section from the distal end of the variable-diameter section; the outer diameter of the variable-diameter section gradually increases from far to near along its entire length; the maximum outer diameter of the variable-diameter section is the same as the outer diameter of the constant-diameter section; the outer diameter of the constant-diameter section is smaller than the outer diameter of the push rod; at least two wires extend from the distal end of the variable-diameter section into the inner hole of the variable-diameter section, and then extend along the inner holes of the variable-diameter section, the constant-diameter section, and the push rod to the proximal end of the push rod.

4. The medical guidewire according to claim 2, characterized in that, A tapered transition section is provided between the proximal end of the core structure and the distal end of the push rod, and the outer diameter of the tapered transition section gradually increases from the distal end to the proximal end along its entire length.

5. The medical guidewire according to claim 2, characterized in that, The entire structure of the core structure forms one magnetic core; or, part or all of the structure of the core structure forms multiple magnetic cores, which are distributed sequentially along the axial direction of the core structure. An induction coil is wound on the outer surface of each magnetic core. Each induction coil is independent of the others. At least two wires are led out from the proximal end of each induction coil. All the wires extend through the same inner hole of the push rod to the proximal end of the push rod.

6. The medical guidewire according to claim 2, characterized in that, The distal portion also includes a shaping structural member located inside the sheath structure and connecting the proximal end of the head cap and the distal end of the core structure, respectively.

7. The medical guidewire according to claim 4, characterized in that, An adhesive layer is provided on the entire outer surface of the tapered transition section. The outer diameter of the adhesive layer gradually increases from far to near, and the maximum outer diameter of the adhesive layer is less than or equal to the outer diameter of the push rod.

8. The medical guidewire according to claim 2, characterized in that, The head cap is a developable structure, or the head cap is a gel ball formed by gel production or a molten ball formed by melting.

9. The medical guidewire according to claim 1 or 2, characterized in that, Two wires are led out from any of the induction coils, and the two wires form a twisted pair structure.

10. The medical guidewire according to claim 1 or 2, characterized in that, A socket is provided at the near end of the push rod, and the induction coil is connected to the socket through at least two lead wires, and the socket can filter the induction signal output by the induction coil.

11. The medical guidewire according to claim 1 or 2, characterized in that, The push rod has a fastening position at its proximal end, and the distance from the fastening position to the distal end of the medical guidewire is the same as the distance from the distal end of the medical catheter to the proximal guidewire inlet; the medical guidewire is used to detachably connect to the proximal end of the medical catheter at the fastening position. When the medical guidewire is connected to the medical catheter at the fastening position, the distal portion is accommodated inside the distal end of the medical catheter.

12. The medical guidewire according to claim 11, characterized in that, A positioning mark is provided at the fastening position; a tapered transition section is provided at the far end of the push rod, and a first adhesive section is provided on a portion of the outer surface of the tapered transition section along the circumferential direction, and a second adhesive section is provided on another portion. The outer diameter of the first adhesive section gradually decreases from far to near and forms a notch at the near end. The second adhesive section has a constant outer diameter from far to near. The positioning mark is located on the same side as the first adhesive section.

13. The medical guidewire according to claim 1 or 2, characterized in that, The magnetic positioning sensor has at least one of the following characteristics: The outer surface of the magnetic core is textured to accommodate the wires wound around the induction coil; The length of the induction coil accounts for 75%-90% of the length of the magnetic core; The wire diameter of the induction coil is 20μm-30μm; The number of winding layers of the induction coil does not exceed 2 layers, and the number of turns of the induction coil does not exceed 280 turns; The outer diameter of the magnetic core is 0.15mm-0.18mm, and the length of the magnetic core is 4mm-4.4mm; The magnetic core can be a solid structure or a hollow structure; The magnetic core is made of amorphous material.

14. The medical guidewire according to claim 1 or 2, characterized in that, The specifications of the medical guidewire are 0.014 inch to 0.038 inch.

15. A medical system, characterized in that, include: A medical catheter and a medical guidewire as described in any one of claims 1-14; the medical catheter has a guidewire passage extending through it along its own axial direction; The medical guidewire is used to movably pass through the guidewire pathway.

16. The medical system according to claim 15, characterized in that, The medical catheter includes a flexible section, and the guidewire passage includes a guidewire lumen disposed within the flexible section; a retraction limiting part is provided at the proximal end of the guidewire lumen; the retraction limiting part has an initial state and a limiting state, and can switch between the initial state and the limiting state. In the initial state, the retraction limiting part allows the distal portion of the medical guidewire and the push rod to pass through; In the limited position, the retraction limiting part deforms after being subjected to the retraction force of the medical guidewire, thereby preventing the connection between the distal part of the medical guidewire and the push rod from passing through, so that the connection between the distal part of the medical guidewire and the push rod is limited by the retraction limiting part, thereby preventing the push rod from staying in the flexible section.

17. The medical system according to claim 16, characterized in that, The retraction limiting part is an annular wall, one end of which is connected to the guidewire cavity, and the other end is a free end. In the initial state, the other end of the annular wall extends obliquely towards the distal end of the flexible section, so that the annular wall forms a conical structure with a small inner diameter at the distal end and a large inner diameter at the proximal end, and the minimum inner diameter of the annular wall is greater than the diameter of the medical guidewire. In the limiting state, the free end of the annular wall is bent and deformed towards the proximal end of the flexible section after being subjected to the retraction force of the medical guidewire, thereby making the inner diameter of the annular wall smaller than the diameter of the medical guidewire. Alternatively, the retraction limiting part is composed of a barb, one end of which is connected to the guide wire cavity, and the other end is a free end; In the initial state, the other end of the barb extends obliquely toward the distal end of the flexible section. The distance from the end of the barb connected to the guidewire cavity to the inner wall of the guidewire cavity on the opposite side is greater than the outer diameter of the push rod, and the distance from the free end of the barb to the inner wall of the guidewire cavity on the opposite side is less than the outer diameter of the push rod. In the limiting state, the free end of the barb is bent and deformed toward the proximal end of the flexible section after being subjected to the retraction force of the medical guidewire, and then gets stuck in the slot at the distal end of the push rod to limit the medical guidewire.

18. The medical system according to claim 15, characterized in that, The medical catheter is provided with a connecting valve at its proximal end, and the medical guidewire is provided with a fastening position at its proximal end; when the distal portion of the medical guidewire enters the distal interior of the medical catheter, the connecting valve is detachably connected to the proximal end of the medical guidewire at the fastening position.

19. The medical system according to claim 15, characterized in that, It also includes a signal processing device that is communicatively connected to the medical guidewire, the signal processing device being able to amplify and filter the induction signal output by the induction coil.

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