CN219721653U - Guide wire and extension catheter system - Google Patents

Abstract

The utility model belongs to the field of medical instruments, and particularly relates to a guide wire and an extension catheter system. Because the guide wire comprises a hollow tubular spiral supporting structure, the guide wire is easier to pass through a tortuous vessel by utilizing the spiral supporting structure, and strong support is provided for the extension catheter, so that the extension catheter can conveniently enter the tortuous and narrow branch vessels, and the extension catheter can smoothly and efficiently reach a lesion position.

Description

Guide wire and extension catheter system

Technical Field

The utility model relates to the technical field of medical instruments, in particular to a guide wire and an extension catheter system.

Background

Percutaneous coronary intervention (percutaneous transluminal coronary intervention, PCI) refers to techniques for delivering a balloon catheter or other related instrument using percutaneous puncture techniques, relieving coronary stenosis or obstruction, and reestablishing coronary blood flow. With the continuous development of medicine, medical intervention operations have also been greatly developed. Minimally invasive interventional procedures for treating diseases such as heart and blood vessels by inserting a catheter into the blood vessel are widely practiced. In interventional procedures, a guide catheter is used to guide a catheter device (e.g., balloon catheter, stent delivery catheter, etc.) for treatment to a lesion.

The guiding catheter supports the delivery of the catheter device by a reaction force generated by the pressure on the vessel wall. However, the guiding catheter alone does not provide sufficient back support and in some cases the catheter device cannot pass through the stenosis and reach the lesion. Thus, in addition to the guide catheter, a guide extension catheter is used to obtain additional back support.

The existing extension catheter can slide and even slip due to fit clearance when the guide catheter is placed in an inner cavity, so that the operation time is prolonged, and larger damage is caused to a patient. The extension guide wire in the related art can not provide effective support for the extension catheter because of factors such as unreasonable size and structural design when guiding the extension catheter to enter the coronary artery branch, so that the extension catheter can not smoothly and quickly reach the lesion position and is difficult to reach the lesion position, the operation difficulty is greatly increased, and the operation efficiency is reduced.

Disclosure of Invention

The embodiment of the utility model provides a guide wire and an extension catheter system, which aim to provide powerful support for the extension catheter and enable the extension catheter to smoothly and efficiently enter a vascular lesion position.

To this end, according to one aspect of the present utility model, there is provided a guide wire comprising a push wire, a helical support structure and a guide head sequentially connected from a proximal end to a distal end, the helical support structure having a hollow tubular shape, the helical support structure being supported on an inner wall of a tube body of an extension catheter when the guide wire is placed in the extension catheter.

Optionally, the outer diameter of the spiral supporting structure decreases from the middle to one end of the seeker and from the middle to one end of the pushing wire, and the decreasing trend of the outer diameter of the spiral supporting structure from the middle to one end of the seeker is smaller than the decreasing trend from the middle to one end of the pushing wire.

Optionally, the coil spacing of the helical support structure increases gradually from the proximal end to the distal end.

Optionally, the introducer comprises an outer spring and an inner spring, the proximal end of the outer spring being connected to the distal end of the helical support structure, the inner spring being fixed inside the outer spring.

Optionally, the seeker further comprises a safety wire made of a memory material, the safety wire is arranged inside the distal end of the outer layer spring, and the proximal end of the safety wire is fixedly connected to the distal end of the inner layer spring.

Optionally, the guide head further comprises a developing spring made of medical developing material, and the developing spring is alternately wound on the distal end of the outer layer spring and fixedly connected to the distal end of the inner layer spring.

Optionally, the distal end of the helical support structure is in smooth transition with the proximal end of the outer spring; and/or, the proximal end of the spiral supporting structure is in smooth transition connection with the distal end of the pushing wire.

According to another aspect of the present utility model there is provided an elongate catheter system comprising an elongate catheter comprising from proximal end to distal end, and a guidewire as described above

The medical device comprises a pushing rod and a tube body, wherein the pushing rod and the tube body are sequentially connected with the distal end of the pushing rod, the tube body is provided with a channel for conveying medical devices, and a device guide-in port is formed in the proximal end of the channel.

Optionally, the inner wall of the tube body is provided with a reinforcing wire along the axial direction.

Optionally, after the guide wire is placed in the channel, the helical support structure is always located within the channel during axial movement of the guide wire relative to the tube.

The guide wire and the extension catheter system provided by the utility model have the beneficial effects that: compared with the prior art, the guide wire comprises the pushing wire, the spiral supporting structure and the guide head which are sequentially connected from the proximal end to the distal end, and the spiral supporting structure is in a hollow tubular shape, so that the guide wire is easier to pass through a tortuous vessel, and provides powerful support for the extension catheter, the extension catheter can conveniently enter the tortuous and narrow branch vessel, and the extension catheter can smoothly and efficiently reach a lesion position. The extension catheter system can avoid inconvenient operation caused by repeatedly pushing the extension catheter in operation, shorten operation time, improve operation efficiency and reduce pain of patients.

Drawings

In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the utility model, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Wherein:

FIG. 1 is a schematic view of an elongate catheter system according to an embodiment of the present utility model;

FIG. 2 is a schematic view of the overall structure of a guidewire according to an embodiment of the present utility model;

FIG. 3 is a schematic cross-sectional view of a guidewire according to an embodiment of the utility model;

FIG. 4 is a schematic cross-sectional view of a seeker in a guidewire according to an embodiment of the present utility model;

FIG. 5 is a schematic view of the structure of an extension catheter in an extension catheter system according to an embodiment of the present utility model;

FIG. 6 is a schematic view of the cross-sectional structure of A-A in FIG. 5;

FIG. 7 is a schematic cross-sectional view of the proximal end of the body of an elongate catheter system according to an embodiment of the present utility model.

Description of main reference numerals:

10. a guide wire;

110. pushing the wire;

120. a helical support structure;

130. a guide head; 131. an outer layer spring; 132. an inner layer spring; 133. a safety wire; 134. a developing spring; 135. a protective cap;

20. extending the catheter;

210. a push rod;

220. a tube body; 2201. a channel; 22011. an instrument introduction port; 221. an inner layer; 222. in (a)

A middle reinforcing layer; 223. an outer layer;

230. a handle;

240. reinforcing wires;

250. and a developing ring.

Detailed Description

In order that the utility model may be readily understood, a more complete description of the utility model will be rendered by reference to the appended drawings. Preferred embodiments of the present utility model are shown in the drawings. This utility model may, however, be embodied in many other different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Reference in the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the utility model. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is to be expressly and implicitly understood by those of ordinary skill in the art that the described embodiments of the utility model can be combined with other embodiments without conflict.

It will be understood that when an element is referred to as being "connected to," "fixed to," or "disposed on" another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element. Furthermore, in the description of the present utility model, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this utility model belongs. The terminology used herein in the description of the utility model is for the purpose of describing particular embodiments only and is not intended to be limiting of the utility model. The terms "a," "an," "the," and similar referents in the context of the utility model are not to be construed as limiting the quantity, but rather as singular or plural. The terms "comprising," "including," "having," and any variations thereof, are intended to cover a non-exclusive inclusion. The term "and/or" as used herein describes an association relationship of associated objects, meaning that there may be three relationships, e.g., "a and/or B" may mean: a exists alone, A and B exist together, and B exists alone.

The "proximal" and "distal" as used herein are defined in terms of the position of the operator and the instrument, and the end near the operator is the "proximal" and the end far from the operator is the "distal".

Embodiments of the present utility model provide an elongate catheter system for guiding a catheter device (e.g., balloon catheter, stent delivery catheter, etc.) for treatment to a lesion during interventional procedures.

As shown in FIG. 1, the elongate catheter system includes a guidewire 10 and an elongate catheter 20, the guidewire 10 being 100mm to 1000mm longer than the elongate catheter 20. The extension catheter 20 includes a push rod 210 and a tube 220 connected in sequence from a proximal end to a distal end, the tube 220 having a channel 2201 for delivering a medical device, the proximal end of the channel 2201 being provided with a device introduction port 22011.

Because the existing extension guide wire can not provide effective support for the extension guide tube due to factors such as unreasonable size and structural design when the extension guide tube is guided to enter the coronary artery branch, the extension guide tube can not smoothly and rapidly reach the lesion position, the operation difficulty is greatly increased, and the operation efficiency is reduced.

In this regard, the elongate catheter system of the present embodiment provides improved design of the structure of the guidewire 10 so that it provides a strong support for the elongate catheter 20 and allows the elongate catheter 20 to be smoothly and efficiently advanced into the vascular lesion site.

In the embodiment of the present utility model, as shown in fig. 2 and 3, the guide wire 10 includes a push wire 110, a spiral supporting structure 120 and a guide head 130 sequentially connected from a proximal end to a distal end, wherein the spiral supporting structure 120 is hollow and tubular, and as shown in fig. 1, when the guide wire 10 is placed in the extension catheter 20, the spiral supporting structure 120 is supported on the inner wall of the tube body 220 of the extension catheter 20.

Because the guide wire 10 comprises the hollow tubular spiral supporting structure 120, the guide wire 10 is easier to pass through a tortuous vessel by utilizing the spiral supporting structure 120, and strong support is provided for the extension catheter 20, so that the extension catheter 20 can conveniently enter the tortuous and narrow branch vessels, and the extension catheter 20 can smoothly and efficiently reach a lesion position.

Wherein the outer diameter of the helical support structure 120 is larger than the outer diameter of the push wire 110 and the outer diameter of the introducer 130. The pushing wire 110 may be made of metal, preferably nickel titanium or stainless steel, and the pushing wire 110 may be coated or uncoated.

Further, it will be appreciated that to ensure that the guidewire 10 can be inserted into the elongate catheter 20, the maximum outer diameter of the helical support structure 120 of the guidewire 10 is less than the inner diameter of the body 220 of the elongate catheter 20.

After the guidewire 10 is placed into the channel 2201 in the body 220 of the elongate catheter 20, the helical support structure 120 is always positioned within the channel 2201 during axial movement of the guidewire 10 relative to the body 220 to prevent damage to the vessel by exposure of the helical support structure 120.

In one embodiment, as shown in fig. 1-3, the outer diameter of the helical support structure 120 decreases from the middle to one end of the introducer head 130 and from the middle to one end of the push wire 110, and the decreasing trend of the outer diameter of the helical support structure 120 from the middle to one end of the introducer head 130 is less than the decreasing trend from the middle to one end of the push wire 110.

Through the above reducing design, the degree of change of the distal diameter of the spiral supporting structure 120 is slower than that of the proximal end, so that the guide wire 10 can be drilled into the blood vessel more easily, the extension catheter 20 can conveniently enter the tortuous and narrow branch blood vessel, and good tracking performance of the extension catheter 20 can be satisfied, so that the vascular lesion position can be reached smoothly and efficiently.

In one embodiment, the coil spacing of the helical support structure 120 increases gradually from the proximal end to the distal end.

By designing as above to impart further flexibility to the distal end of the helical support structure 120, the ability of the helical support structure 120 to pass through tortuous vessels is enhanced.

Here, it should be noted that the coil pitch of the spiral supporting structure 120 gradually increases from the proximal end to the distal end, and the coil pitch of the whole spiral supporting structure 120 may gradually increase from the proximal end to the distal end, or the coil pitch of the whole portion of the spiral supporting structure 120 may gradually increase from the proximal end to the distal end.

In one embodiment, the hardness of the introducer 130 in the guidewire 10 is less than the hardness of the pusher wire 110, and the introducer 130 and the pusher wire 110 are of equal diameter. Through the design, the distal end of the guide wire 10 is softer than the proximal end, so that the damage of the guide wire 10 to the blood vessel is reduced, and the trafficability of the guide wire 10 in the blood vessel of a human body is improved.

Specifically, the hardness can be controlled by selecting different materials, which is not limited herein.

In one embodiment, as shown in fig. 4, the seeker 130 includes an outer spring 131 and an inner spring 132, the proximal end of the outer spring 131 being connected to the distal end of the helical support structure 120, the inner spring 132 being secured within the outer spring 131.

Specifically, the inner diameter of the outer layer spring 131 is equal to the outer diameter of the inner layer spring 132, and the outer layer spring 131 is fixedly connected to the proximal end of the inner layer spring 132 to form a connection portion. The outer layer spring 131 may be made of stainless steel.

Further, in order to avoid the damage to the inner wall of the blood vessel caused by the distal end of the outer spring 131, the distal end of the outer spring 131 is provided with a protective cap 135 made of polymer material and having a hemispherical shape.

Since the spiral supporting structure 120 is of a loose structure, the wall thickness is large and can be firmer, the guide head 130 is of a compact structure, the wall thickness can be thin, the pushing wire 110 is used as a pushing component, and the diameter is large and convenient to operate. Accordingly, the wall thickness of the helical support structure 120 should be greater than the outer diameter of the outer layer spring 131 and less than the outer diameter of the push wire 110.

In a specific embodiment, as shown in fig. 4, the seeker 130 further includes a safety wire 133 made of a memory material, the safety wire 133 being disposed inside the distal end of the outer spring 131, and the proximal end of the safety wire 133 being fixedly connected to the distal end of the inner spring 132.

The safety wire 133 has good shape memory, and can be restored to an initial state after the introducer 130 passes through the curved portion, so that it is easy to pass through the curved blood vessel, and convenient to operate.

In a specific embodiment, with continued reference to fig. 4, the introducer 130 further includes a developer spring 134 made of a medical developer material, the developer spring 134 being interlaced around the distal end of the outer spring 131 and fixedly attached to the distal end of the inner spring 132.

By providing the developing spring 134, an operator can clearly judge the position of the guide wire 10 in the blood vessel of the human body under rays in the operation process, so that the safety of the extension catheter system in the process of entering the human body is improved.

Specifically, the developing spring 134 has the same pitch and inner and outer diameters as the outer layer spring 131, but the length of the developing spring 134 is smaller than the length of the outer layer spring 131. The medical developing material can be platinum iridium alloy, platinum nickel alloy, platinum tungsten alloy, tungsten and the like. In the present embodiment, the developing spring 134 is a platinum-tungsten spring, which is fixedly connected to the distal end of the inner spring 132 and forms a connection portion. The platinum tungsten spring is also fixedly connected with the safety wire 133.

In a specific embodiment, referring to fig. 2 and 3, the distal end of the helical support structure 120 is in smooth transition with the proximal end of the outer spring 131; and/or the proximal end of the helical support structure 120 is smoothly transitioned to the distal end of the push wire 110. So designed, the flexibility of the guidewire 10 is improved.

The tangent line of the coil in the spiral support structure 120 of the guide wire 10 forms an angle (shown as beta) of 0 deg. to 90 deg. with the axis of the spiral support structure 120, and the spiral support structure 120 forms a smooth transition section with the outer layer spring 131 and is fixedly connected with the proximal end of the outer layer spring 131 to form a connection part. The proximal end of the spiral support structure 120 is fixedly connected with the pushing wire 110 and forms a connecting part, the spiral support structure 120 is transited from the position with the largest inner diameter to the proximal end, the inner diameter of the tube is 10-100% of the largest inner diameter, and the distance from the pushing wire 110 is 1-10 mm.

To reduce the friction on the surface of the guide wire, to improve the interaction between instruments (ball/guide wire, stent/guide wire), to improve the tracking of the guide wire in the blood vessel, coating is often applied to the surface of the guide wire. Currently, guide wire coatings of various companies are divided into two main categories, hydrophilic coatings and hydrophobic coatings. Hydrophilic coating (hydro coat) guidewires attract water molecules to form a "gel-like" surface on their surface, reducing the resistance of the guidewire to passage. Hydrophobic coating (Microglide) guide wires resist water molecules to form a 'staggered' surface, so that friction is reduced, and the tracking performance of the guide wires is improved.

Thus, in some embodiments of the present utility model, the distal end of the guidewire 10 (i.e., the introducer 130) is provided with a hydrophilic coating. The hydrophilic coating has a lubricating effect, and can reduce the friction force of the guide wire 10 passing through the human blood vessel, thereby improving the trafficability of the guide wire 10 in the human blood vessel.

In the extension duct system, as shown in fig. 5, the inner wall of the tube body 220 of the extension duct 20 is provided with a reinforcing wire 240 in the axial direction. The cross-sectional shape of the reinforcing wire 240 may be circular, elliptical or square, and is not limited herein.

By providing an axial stiffening wire 240, the pushing force of the extension catheter 20 is increased. Preferably, the stiffness of the reinforcement wire 240 tapers from the proximal end to the distal end, which makes it easier for the tube 220 to pass over tortuous lesions.

The proximal end of the tube 220 is fixedly connected with the distal end of the push rod 210 and forms a connection portion with smooth transition of hardness to promote the trafficability of the extension tube in the blood vessel, and the length of the connection portion is 1mm-5mm. Specifically, as shown in fig. 5 and 7, the proximal end of the reinforcement wire 240 within the tube 220 is integrally formed with the distal end of the push rod 210.

Wherein the pushing rod 210 has flexibility to bend following the curved shape of the blood vessel, and is made of a metal material such as stainless steel material, mild steel, nickel-containing alloy, or metal-polymer composite material. The radial cross-section of the pushing rod 210 is one of elliptical, circular and semi-arc, and preferably, the pushing rod 210 adopts a hypotube, and the hypotube has a structure that improves the kink resistance and the feasibility of the operation of the extension catheter 20 in the medical process.

For ease of manipulation, the elongate catheter 20 further includes a handle 230 coupled to the proximal end of the push rod 210, and the handle 230 may be coupled to the push rod 210 by one or more of welding, soldering, or glue bonding. Preferably, the handle 230 is of a flat design to facilitate finger gripping and rotation.

In one embodiment, the proximal end of the tube 220 has a hardness that is greater than the hardness of the distal end of the tube 220.

The hardness of the tube 220 is gradually reduced in the proximal to distal direction, so that not only deformation is avoided, but also the wound is easier to pass through the lesion.

In particular, the setting may be by material distribution or by wall thickness variation. For example, from the proximal end to the distal end of the tube 220, the inner diameter of the tube 220 remains constant, and the stiffness of the tube 220 is adjusted by the material distribution.

In a specific embodiment, as shown in fig. 6, the pipe body 220 is a composite structure, and includes an inner layer 221, an intermediate reinforcing layer 222 and an outer layer 223 in this order from inside to outside, which can provide strong support, pressure resistance and fracture resistance.

The inner layer 221 is made of polytetrafluoroethylene or linear low density polyethylene to provide low friction for the passage of other instruments.

The middle reinforcement layer 222 is a stainless steel woven mesh layer or a spring layer, which provides the tube 220 with strong negative pressure resistance and strong support. The middle reinforcing layer 222 of the stainless steel woven mesh layer or the spring layer and the distal end connection of the pushing rod 210 made of metal materials can be connected in a laser welding mode, and the connection part design of the metal materials is hidden in the middle of the materials, so that damage to blood vessels is avoided.

The outer layer 223 is made of one or more of polyether block polyamide, nylon 12 and polyurethane elastomer, and has smoother appearance and hand feeling, so that the blood vessel is fully protected, and thrombus, interlayer and the like are not easy to generate. Further, the hardness of the material of the outer layer 223 is sequentially reduced from the proximal end to the distal end of the tube 220, so that the design is not abrupt, the requirement of pushing the tube 220 in the blood vessel of a human body is better met, a doctor can operate more accurately and conveniently, and the pain of a patient in the operation process can be reduced.

In a specific embodiment, the inner diameter of the tube 220 decreases from the proximal end to the distal end of the tube 220, and is designed such that the inner diameter of the tube 220 is designed to decrease upward due to the small diameter of the distal vessel, allowing the tube 220 to enter deeper into the smaller vessel. Of course, the inner diameter of the tube 220 may not be the diameter-changing design, but may be constant.

In a specific embodiment, the tube 220 has a diameter-changing design with the same inner diameter as the outer diameter, i.e., the inner diameter is changed to the same extent as the outer diameter. By the design, the pipe body 220 is smoothly transited, and the pushing acting force is ensured to be uniform.

Of course, in other embodiments, the inner diameter and the outer diameter of the tube 220 may be designed with different degrees of diameter variation, i.e., the degree of diameter variation of the inner diameter is different from the degree of diameter variation of the outer diameter.

Specifically, the decreasing trend of the inner diameter of the tube 220 is smaller from the proximal end to the distal end than the decreasing trend of the outer diameter of the tube 220, i.e., the wall thickness of the tube 220 increases from the proximal end to the distal end of the tube 220; the decreasing trend of the inner diameter of the tube 220 is greater than the decreasing trend of the outer diameter of the tube 220, i.e., the wall thickness of the tube 220 decreases from the proximal end to the distal end of the tube 220.

The distal (tip) end of the tube 220 is flexible and does not easily damage the blood vessel.

In one embodiment, as shown in fig. 1, 5 and 7, instrument input port 22011 is designed in a bezel configuration.

The bevel-structured instrument guide port 22011 provides for improved pushability delivery of the elongate catheter 20.

The end of the bevel structure facing away from the push rod 210 forms a circular arc transition with the outer layer 223 of the tube 220, and the end of the bevel structure facing towards the push rod 210 is tangential to the surface of the push rod 210 facing the inner layer 221 of the tube 220, thus being designed such that the proximal end of the channel 2201 forms a fast exchange port resembling the shape of a water drop.

As shown in fig. 7, the projection of the instrument guide port 22011 on the radial direction of the tube 220 is a circular arc concave inward toward the distal end, the circular arc is tangent to the surface of the push rod 210 facing the inner layer 221, and the angle (shown as α in the figure) between the tangent point of the circular arc and the intersection point of the circular arc with the surface of the outer layer 223 of the tube 220 is 25 ° -35 °.

In one embodiment, both the distal and proximal ends of the tube 220 are provided with a development mark or development coating. As shown in fig. 5, the developing mark or developing coating is a developing ring 250 disposed circumferentially inside the tube 220.

In one embodiment, the outer surfaces of the tube 220 and the push rod 210 are provided with an anticoagulant coating.

The anticoagulant coating is made of a bioactive material. Specifically, the anticoagulation coating can be a hydrophilic coating of negative charge/heparinoid polymer, can be a polyethylene glycol layer grafted with anticoagulation conformation, can be a multi-layer composite layer formed by heparin/dopamine and heparin/collagen, and can also be a magnetic layer formed by magnetic materials.

Further, the anticoagulant coating can also be prepared by carrying out surface modification on the metal surface. Specifically, the metal surface may be subjected to a chemical passivation treatment, such as a mixed acid passivation treatment, or may be subjected to a physical passivation treatment, such as a high-temperature heat treatment passivation.

In summary, in percutaneous coronary intervention, the method of using the extension catheter system is as follows: the guide wire 10 is placed into the extension catheter 20 and then placed into the guide catheter (not shown in the figure), the handle 230 of the extension catheter 20 is positioned outside the guide catheter, the extension catheter 20 is easier to enter a designated position under the guidance of the guide wire 10 with strong supporting property, and the reinforcing wire 240 is axially arranged in the tube body 220 of the extension catheter 20, so that the reinforcing wire 240 can be used for enabling the extension catheter 20 to easily enter a branch vessel and a narrow vessel, avoiding the inconvenience of operation caused by repeatedly pushing the extension catheter 20 in the operation, greatly shortening the operation time, simplifying the complex operation and reducing the pain of patients.

The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

Claims (10)

1. The guide wire is characterized by comprising a pushing wire, a spiral supporting structure and a guide head which are sequentially connected from a proximal end to a distal end, wherein the spiral supporting structure is hollow and tubular, and when the guide wire is placed into an extension catheter, the spiral supporting structure is supported on the inner wall of a catheter body of the extension catheter.

2. The guidewire of claim 1, wherein the outer diameter of the helical support structure decreases from the middle to one end of the seeker and from the middle to one end of the pusher wire, and the decreasing trend of the outer diameter of the helical support structure from the middle to one end of the seeker is less than the decreasing trend from the middle to one end of the pusher wire.

3. The guidewire of claim 1 or 2, wherein the coil spacing of the helical support structure increases gradually from the proximal end to the distal end.

4. The guidewire of claim 1, wherein the introducer comprises an outer spring and an inner spring, the proximal end of the outer spring being connected to the distal end of the helical support structure, the inner spring being secured within the outer spring.

5. The guidewire of claim 4, wherein the introducer further comprises a safety wire made of a memory material, the safety wire disposed inside the distal end of the outer spring, the proximal end of the safety wire fixedly attached to the distal end of the inner spring.

6. The guidewire of claim 4 or 5, wherein the introducer further comprises a development spring made of a medical development material, the development spring being interlaced around the distal end of the outer spring and fixedly attached to the distal end of the inner spring.

7. The guidewire of claim 4, wherein the distal end of the helical support structure is in smooth transition with the proximal end of the outer spring; and/or, the proximal end of the spiral supporting structure is in smooth transition connection with the distal end of the pushing wire.

8. An elongate catheter system comprising an elongate catheter and a guidewire according to any one of claims 1-7, the elongate catheter comprising a push rod and a tube connected in sequence from a proximal end to a distal end, the tube having a passageway for delivering a medical device, the proximal end of the passageway being provided with a device introduction port.

9. The elongate catheter system according to claim 8 wherein the inner wall of the tube is provided with reinforcing wires in the axial direction.

10. The elongate catheter system as recited in claim 8 or 9 wherein the helical support structure is always located within the channel during axial movement of the guidewire relative to the tube after the guidewire is placed into the channel.