CN218944127U

CN218944127U - Tip assembly, interventional medical catheter and interventional medical guide wire

Info

Publication number: CN218944127U
Application number: CN202223203220.3U
Authority: CN
Inventors: 刘朝生; 张志军; 黄君仪; 李琴芳
Original assignee: Guangdong Bomai Medical Technology Co Ltd
Current assignee: Guangdong Bomai Medical Technology Co Ltd
Priority date: 2022-11-30
Filing date: 2022-11-30
Publication date: 2023-05-02
Anticipated expiration: 2032-11-30

Abstract

The application belongs to the field of medical instruments, and more particularly relates to a tip assembly, an interventional medical catheter and an interventional medical guide wire. The tip assembly includes a connecting section and a guide structure, a first end of the connecting section for connecting a distal end of a catheter or guidewire; the guide structure is arranged at the second end of the connecting section and is made of elastic materials; wherein the maximum dimension of the guide structure in the radial direction of the connecting section is 4mm-7mm. Before interventional operation, the first end of the connecting section can be connected with the distal end of the catheter or the guide wire, and when the catheter or the guide wire is pushed, the maximum size of the guide structure in the radial direction of the connecting section is larger than the diameter of the branch blood vessel and the size of the intimal tearing part of the blood vessel, so that the catheter or the guide wire cannot be pushed into the unintended branch blood vessel or the blood vessel interlayer in the blood vessel, and the risk of interventional operation is reduced.

Description

Tip assembly, interventional medical catheter and interventional medical guide wire

Technical Field

The application belongs to the field of medical instruments, and more particularly relates to a tip assembly, an interventional medical catheter and an interventional medical guide wire.

Background

With the continuous development of medicine, interventional surgery is widely applied, and compared with the traditional surgery, the interventional surgery has the advantages of less wound, less bleeding, rapid postoperative rehabilitation and the like. In the interventional operation, medical staff intervenes instruments such as a catheter or a guide wire into a blood vessel of a human body, reaches a lesion position along the blood vessel, and then performs operation treatment on the lesion position.

In the interventional operation, an image device such as a CT or an angiography machine is generally required to assist. When some emergency cases can only be used for interventional operations outside a hospital, medical staff can only push the catheter or the guide wire in a blind pushing mode, and the catheter or the guide wire is easy to push into an unintended branch vessel or a vessel interlayer in the vessel without the help of imaging equipment, so that a great operation risk exists.

Disclosure of Invention

An object of the embodiments of the present application is to provide a tip assembly, an interventional medical catheter and an interventional medical guidewire, which can effectively guide the catheter or the guidewire to a target position, and avoid pushing the catheter or the guidewire into an unintended branch vessel or a vessel dissection.

In order to achieve the above purpose, the technical scheme adopted in the embodiment of the application is as follows:

in one aspect, there is provided a tip assembly comprising:

a connecting section, a first end of the connecting section being used for connecting a distal end of a catheter or a guide wire;

the guide structure is arranged at the second end of the connecting section and is made of elastic materials;

wherein the maximum dimension of the guide structure in the radial direction of the connecting section is 4mm-7mm.

In one embodiment, the guiding structure is a balloon.

In one embodiment, the connecting section is further provided with a channel communicated with the air bag, and one end of the channel away from the air bag is used for being connected with the pressure charging and releasing device.

In one embodiment, the tip assembly further comprises an adjustment rod, one end of the adjustment rod is connected with the balloon, and the other end of the adjustment rod passes through the balloon and extends into the connecting section.

In one embodiment, the guide structure includes a plurality of elastic segments, each of which has one end connected to the second end of the connecting segment.

In one embodiment, each elastic section is arranged in an arc shape, the other ends of the plurality of elastic sections are connected together, and the dimension of the middle part of the guide structure in the radial direction of the connecting section is larger than the dimension of the end part of the guide structure in the radial direction of the connecting section; or,

the middle part of each elastic section is provided with a bending part far away from the connecting section, and the other end of each elastic section extends towards the first end of the connecting section.

In one embodiment, the guide structure includes a plurality of resilient bars, each of which has an end connected to a side wall of the connection section, the plurality of resilient bars being spaced around the connection section.

In one embodiment, the end of the guiding structure remote from the connecting section is rounded.

In one embodiment, the tip assembly further comprises a tapered section disposed at a central location on a side of the tip assembly facing away from the catheter or guidewire.

In one embodiment, the second end of the connection section is provided with a plug-in part connected to the catheter or the guide wire, and the side wall of the plug-in part is provided with threads for threaded connection to the catheter or the guide wire.

In another aspect, there is provided an interventional medical catheter comprising a catheter and the tip assembly provided in any of the embodiments described above.

In yet another aspect, an interventional medical guidewire is provided that includes a guidewire and a tip assembly as provided in any of the embodiments described above.

The tip assembly, the interventional medical catheter and the interventional medical guide wire provided by any of the embodiments of the application have the following beneficial effects: before interventional operation, the first end of the connecting section can be connected with the distal end of the catheter or the guide wire, and when the catheter or the guide wire is pushed, the maximum size of the guide structure in the radial direction of the connecting section is larger than the diameter of the branch blood vessel and the size of the intimal tearing part of the blood vessel, so that the catheter or the guide wire cannot be pushed into the unintended branch blood vessel or the blood vessel interlayer in the blood vessel, and the risk of interventional operation is reduced.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings that are required for the description of the embodiments or exemplary techniques will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person of ordinary skill in the art.

FIG. 1 is a schematic view of a tip assembly according to an embodiment of the present application;

FIG. 2 is a schematic view of another tip assembly according to an embodiment of the present application;

FIG. 3 is a schematic view of a tip assembly according to an embodiment of the present application;

FIG. 4 is a schematic structural view of yet another tip assembly provided in an embodiment of the present application;

FIG. 5 is a schematic structural view of yet another tip assembly provided in an embodiment of the present application;

FIG. 6 is a schematic structural view of yet another tip assembly provided in an embodiment of the present application;

FIG. 7 is a schematic structural view of yet another tip assembly provided in an embodiment of the present application;

FIG. 8 is a schematic structural view of yet another tip assembly provided in an embodiment of the present application;

FIG. 9 is a schematic structural view of yet another tip assembly provided in an embodiment of the present application;

FIG. 10 is a schematic structural view of yet another tip assembly provided in an embodiment of the present application;

FIG. 11 is a schematic structural view of yet another tip assembly provided in an embodiment of the present application;

FIG. 12 is a schematic structural view of yet another tip assembly provided in an embodiment of the present application;

FIG. 13 is a schematic structural view of yet another tip assembly provided in an embodiment of the present application;

FIG. 14 is a schematic view of a still further tip assembly provided in an embodiment of the present application;

FIG. 15 is a schematic structural view of yet another tip assembly provided in an embodiment of the present application;

FIG. 16 is a schematic structural view of yet another tip assembly provided in an embodiment of the present application;

FIG. 17 is a schematic view of a still further tip assembly according to an embodiment of the present application;

FIG. 18 is a schematic structural view of yet another tip assembly provided in an embodiment of the present application;

FIG. 19 is a schematic view of yet another tip assembly provided in an embodiment of the present application;

fig. 20 is a schematic structural view of yet another tip assembly according to an embodiment of the present application.

Wherein, each reference numeral in the figure mainly marks:

1. a connection section; 11. an insertion part; 12. a channel;

2. a guide structure; 21. an air bag; 22. an elastic section; 221. a bending portion; 23. an elastic rod; 24. a spring; 25. a support part;

3. an adjusting rod;

4. a conical section.

Detailed Description

In order to make the technical problems, technical schemes and beneficial effects to be solved by the present application more clear, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the present application.

It will be understood that when an element is referred to as being "mounted" 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, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present application, the meaning of "a plurality" is two or more, unless explicitly defined otherwise. The meaning of "a number" is one or more than one unless specifically defined otherwise.

In the description of the present application, it should be understood that the terms "center," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate orientations or positional relationships that are based on the orientation or positional relationships shown in the drawings, merely to facilitate description of the present application and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present application.

In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art as the case may be.

Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present application. Thus, the appearances of the phrase "in one embodiment" or "in some embodiments" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

As noted in the background, in the prior art, without the aid of imaging devices, catheters or guidewires are easily pushed into unintended branch vessels or vascular dissection in the blood vessel, with a significant surgical risk.

To solve the above-mentioned problems, the present embodiment provides a tip assembly, referring to fig. 1-3, which includes a connection section 1 and a guiding structure 2, wherein a first end of the connection section 1 is used for connecting a distal end of a catheter or a guide wire. The guide structure 2 is arranged at the second end of the connecting section 1, the guide structure 2 being made of an elastic material. Wherein the maximum dimension of the guide structure 2 in the radial direction of the connecting section 1 is 4mm-7mm.

In this embodiment of the present application, before performing an interventional operation, the first end of the connecting section 1 may be connected to the distal end of the catheter or the guide wire, and when the catheter or the guide wire is pushed, the maximum dimension of the guide structure 2 in the radial direction of the connecting section 1 is greater than the diameter of the branch vessel and the dimension of the intimal tear of the vessel, so as to ensure that the catheter or the guide wire cannot be pushed into the unintended branch vessel or the vessel interlayer in the vessel, and reduce the risk of the interventional operation.

Furthermore, the maximum dimension of the guide structure 2 in the radial direction of the connecting section 1 is smaller than the diameter of the blood vessel, so that the flow of blood flow in the blood vessel can be ensured. It is worth mentioning that when the tip assembly touches the branch vessel or the intimal tear of the vessel in the vessel, the medical staff can feel a blockage when operating the catheter or the guide wire, so that the catheter or the guide wire can be adjusted to reach the lesion along the vessel. When touching the branch vessel or the intima tearing part of the vessel, the tip assembly can elastically deform the guide structure 2, and the deformation of the guide structure 2 can play a role in buffering, so that the vessel is prevented from being damaged.

It should be noted that the distal end of the catheter or guidewire is the end of the catheter or guidewire distal from the medical personnel. The connection section 1 may be fixed to the distal end of the catheter or the guide wire by welding or bonding, etc. in a suitable manner, and is not limited herein. The guide structure 2 may be made of a suitable elastic material such as silicone, rubber or elastic polymer. Illustratively, when the connection section 1 is used to connect a conduit, the connection section 1 may be a cylindrical structure in communication with the conduit; when the connection section 1 is used for connecting a guide wire, the connection section 1 may have a columnar structure.

In one embodiment, as shown in fig. 1, the guiding structure 2 includes a plurality of guiding plates, and a plurality of guiding plates are annularly arranged on a side wall of the second end of the connecting section 1, and each guiding plate smoothly transitions away from the end of the connecting section 1. In another embodiment, as shown in fig. 2, the guiding structure 2 may be an arc plate disposed at the second end of the connecting section 1, and further, the outer edge of the arc plate is provided with a plurality of notches, and the notches provide deformation spaces for the arc plate. In other embodiments, as shown in fig. 3, the guiding structure 2 may be a spiral-like structure arranged at the second end of the connecting section 1.

Optionally, a lubricant layer may be applied to the surface of the guide structure 2 to facilitate pushing of the catheter or guidewire by medical personnel.

Illustratively, a visualization ring may be placed over the connection segment 1 and medical personnel may use imaging equipment to position the tip assembly within the vessel.

After the connection segment 1 is connected to a catheter or a guidewire, a blood vessel of the patient, such as the femoral artery, is punctured. Since the guide structure 2 is made of an elastic material, the guide structure 2 can be squeezed so that the tip assembly and the catheter or guidewire can be passed through the interventional sheath into the patient's vessel. The guiding structure 2 is restored after being passed out of the interventional sheath, avoiding that the catheter or guidewire is pushed into the non-purposeful branch vessel or vessel dissection.

In one embodiment, referring to fig. 4-8, as a specific implementation of the tip assembly provided in the embodiments of the present application, the guiding structure 2 is a balloon 21.

The shape of the air bag 21 may be set as needed, for example, as shown in fig. 4, and the air bag 21 may be set to an approximately gourd-shape.

In this structure, when the balloon 21 is used as a guiding structure, the balloon 21 can prevent the catheter or the guide wire from being pushed into the unintended branch vessel or the vessel interlayer when the medical staff pushes the catheter or the guide wire, and the tip assembly can play a role in buffering when touching the intima tearing part of the branch vessel or the vessel, so that the damage to the vessel is avoided. In addition, the balloon 21 may be squeezed so that the tip assembly and catheter or guidewire may be passed through the interventional sheath into the patient's vessel.

In a specific embodiment, referring to fig. 5-7, as a specific implementation of the tip assembly provided in the embodiment of the present application, the connection section 1 is further provided with a channel 12 communicating with the air bag 21, and an end of the channel 12 away from the air bag 21 is used for connecting with a pressure charging and discharging device.

The pressure pump, the air pump cylinder, or the like may be used as the pressure relief device, and is not limited only herein. Illustratively, the end of the passageway 12 remote from the bladder 21 may be connected to a pressure relief device via a conduit.

With this structure, the diameter of the balloon 21 can be adjusted by inflating and deflating the device, and the balloon 21 can be contracted and passed through the interventional sheath with the catheter or guidewire into the vessel of the patient during the interventional procedure. When the balloon 21 is penetrated out of the interventional sheath, the balloon 21 is inflated by the inflation and pressure relief device, so that the diameter of the balloon 21 is expanded to 4mm-7mm, and the catheter or the guide wire is prevented from being pushed into an unintended branch vessel or a vessel interlayer. After the catheter or guidewire has reached the lesion along the vessel, the balloon 21 may be depressurized by inflation and pressure relief means.

In a specific embodiment, referring to fig. 8, as a specific implementation of the tip assembly provided as an embodiment of the present application, the tip assembly further includes an adjusting rod 3, one end of the adjusting rod 3 is connected to the air bag 21, and the other end of the adjusting rod 3 passes through the air bag 21 and extends into the connecting section 1.

Illustratively, the adjusting rod 3 is coaxially arranged with the connecting section 1, and it should be noted that when the connecting section 1 is used for connecting a catheter, a passage for other instruments or medicines to be delivered may be provided on the adjusting rod 3.

With this structure, the diameter of the air bag 21 can be adjusted by providing the length of the adjusting lever 3 extending into the connecting section 1.

In one embodiment, referring to fig. 9-15, as a specific implementation of the tip assembly provided in the embodiments of the present application, the guiding structure 2 includes a plurality of elastic segments 22, and one end of each elastic segment 22 is connected to the second end of the connecting segment 1.

The number of elastic segments 22 is not limited and can be set by one skilled in the art as desired. Illustratively, a plurality of resilient segments 22 may be arranged in an annular array at the second end of the connecting segment 1. It will be appreciated that the elastic segments 22 may be elastically deformed, such that the plurality of elastic segments 22 may be folded toward the middle to form a strip-like structure when the guide structure 2 is compressed, and such that the elastic segments 22 return after the guide structure 2 is passed out of the insertion sheath.

In this structure, the plurality of elastic segments 22 of the guiding structure 2 can prevent the catheter or the guide wire from being pushed into the unintended branch vessel or the vessel interlayer after being opened, and the elastic deformation of each elastic segment 22 can play a role of buffering when the tip assembly touches the inner membrane tearing part of the branch vessel or the vessel.

In one embodiment, referring to fig. 9-13, as a specific implementation of the tip assembly provided in the embodiment of the present application, each elastic segment 22 is disposed in an arc shape, the other ends of the plurality of elastic segments 22 are connected together, and the dimension of the middle portion of the guiding structure 2 in the radial direction of the connecting segment 1 is greater than the dimension of the end portion of the guiding structure 2 in the radial direction of the connecting segment 1.

Illustratively, the guide structure 2 formed by the plurality of elastic segments 22 is a "shuttle-shaped" structure, which has a smaller diameter when pressed, and which recovers under the elastic force of each elastic segment 22 when the external force is removed.

In this configuration, the guide structure 2 is configured as a "shuttle" structure, and the guide structure 2 may act as a guide as the catheter or guidewire is advanced within the vessel.

Alternatively, as shown in fig. 12, a spring 24 may be provided between the plurality of elastic segments 22, the spring 24 may extend in the axial direction of the connecting segment 1, and by providing the spring 24 to support the guiding structure 2, the guiding structure 2 may absorb more kinetic energy when the tip assembly touches a branched blood vessel or an intimal tear of the blood vessel, further avoiding damaging the blood vessel.

Alternatively, as shown in fig. 13, a support portion 25 may be provided between the plurality of elastic segments 22, and the support portion 25 may include a plurality of arc-shaped support bars. By providing the support 25 to support the guiding structure 2, the plurality of elastic segments 22 are not easily gathered in the blood vessel, and the catheter and the guide wire are thus less likely to enter the branch blood vessel and the blood vessel interlayer.

In another possible implementation, as shown in fig. 14 and 15, the middle portion of each elastic segment 22 is disposed away from the bending portion 221 of the connection segment 1, and the other end of each elastic segment 22 extends toward the first end of the connection segment 1.

In this structure, the elastic section 22 can play a role of guiding when the catheter or the guide wire is advanced in the blood vessel, and at the same time, the bending portion 221 can play a role of protecting the blood vessel when the end of the guiding structure 2 away from the connecting portion touches the blood vessel, so as to prevent the blood vessel from being damaged.

In one embodiment, referring to fig. 16 and 17, as a specific implementation of the tip assembly provided in the embodiment of the present application, the guiding structure 2 includes a plurality of elastic rods 23, wherein ends of the elastic rods 23 are connected to the side wall of the connection section 1, and the plurality of elastic rods 23 are spaced around the connection section 1.

Optionally, the end of each elastic rod 23 far away from the connecting section 1 is smoothly transited, so as to avoid the guiding structure 2 from scratching the inner wall of the blood vessel. When the guiding structure 2 is pressed, the elastic rods 23 can be bent to extend into the interventional sheath, and when the guiding structure 2 is penetrated out of the interventional sheath, the elastic rods 23 are restored.

In one possible implementation, as shown in fig. 17, the plurality of elastic rods 23 may be arranged in multiple layers on the connection section 1, with the elastic rods 23 of adjacent two layers being staggered.

In one embodiment, referring to fig. 1-17, as a specific implementation of the tip assembly provided in the embodiments of the present application, the end of the guiding structure 2 away from the connecting section 1 is rounded. When the catheter or guidewire is advanced in the blood vessel, the end of the guiding structure 2 remote from the connection section 1 does not cause damage to the blood vessel when in contact with the blood vessel.

In one embodiment, referring to fig. 7, 11 and 15, as a specific implementation of the tip assembly provided in the embodiments of the present application, the tip assembly further includes a tapered section 4, where the tapered section 4 is disposed at a center position of a side of the tip assembly facing away from the catheter or guidewire. Wherein the conical section 4 extends beyond the guide structure 2.

Schematically, the large diameter end of the conical section 4 faces the connecting section 1, and the small diameter end of the conical section 4 is blunt, so that the damage to the inner wall of the blood vessel caused by the small diameter end of the conical section 4 touching the blood vessel is avoided.

This configuration, by providing the tapered section 4, increases the passability of the tip assembly in the blood vessel, so that the tip assembly more easily passes through a stenosed site in the blood vessel. The conical section 4 is arranged at the center of one side of the tip assembly, which is far away from the catheter or the guide wire, so that the contact between the conical section 4 and the inner wall of the blood vessel can be reduced, and the inner wall of the blood vessel is not easily damaged by the conical section 4.

In one embodiment, referring to fig. 5-15, 18 and 19, as a specific implementation of the tip assembly provided in the embodiment of the present application, the second end of the connection section 1 is provided with a plug-in portion 11 connected to a catheter or a guide wire, and a side wall of the plug-in portion 11 is provided with threads for threaded connection to the catheter or the guide wire.

In one possible implementation, as shown in fig. 5 to 15, when the connection section 1 is used for connecting a catheter, the insertion part 11 may be a through hole opened on the connection section 1; when the connection section 1 is used for connecting a guide wire, the insertion portion 11 may be a blind hole opened on the connection section 1. The side wall of the insertion part 11 may be internally threaded, and correspondingly, the outer circumferential surface of the distal end of the catheter or guide wire is provided with external threads, and the distal end of the catheter or guide wire extends into the insertion part 11 and is screwed with the insertion part 11.

In another possible implementation, as shown in fig. 18 and 19, the insertion part 11 may be a cylindrical structure disposed at an end of the connection section 1 remote from the guide structure 2, a sidewall of the cylindrical structure being provided with external threads, and an inner circumferential surface of a distal end of the catheter being provided with internal threads, respectively; the distal end of the guide wire is provided with a slot and the side wall of the slot is provided with an internal thread. The insertion portion 11 extends into the distal end of the catheter or guidewire and is threadably connected to the catheter or guidewire. In this embodiment, the stability of the connection between the connection section 1 and the catheter or guide wire can be ensured, and in addition, the replacement of the tip assembly by medical staff is facilitated.

In other embodiments, as shown in fig. 20, the side wall of the insertion portion 11 is not provided with threads, and after the insertion portion 11 is connected with the distal end of the catheter or the guide wire in an inserted manner, the connection section 1 may be fixed with the catheter or the guide wire by bonding or welding, which is not limited only herein.

Embodiments of the present application also provide an interventional medical catheter comprising a catheter and the tip assembly provided by any of the embodiments described above. Wherein the distal end of the catheter is connected to the first section of the connection section 1, the catheter may be any of a microcatheter, a guide catheter, a contrast catheter, a microcatheter, an infusion catheter, an aspiration catheter, or a balloon catheter, which is not limited only herein. With the structure, the distal end of the interventional medical catheter can not be pushed into an unintended branch vessel or vessel interlayer when the interventional medical catheter is pushed, so that the risk of interventional operation is reduced.

Embodiments of the present application also provide an interventional medical guidewire comprising a guidewire and a tip assembly as provided in any of the embodiments described above. The distal end of the guide wire is connected to the first section of the connecting section 1, and the guide wire may be any of a contrast guide wire, a guiding guide wire, a rotary cutting guide wire, a micro guide wire or a broken bolt guide wire, which is not limited only herein. According to the structure, when the interventional medical guide wire is pushed, the distal end of the interventional medical guide wire cannot be pushed into an unintended branch blood vessel or a blood vessel interlayer, so that the risk of interventional operation is reduced.

The foregoing is merely an alternative embodiment of the present application and is not intended to limit the present application, and any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the scope of the present application.

Claims

1. A tip assembly, comprising:

a connection section having a first end for connecting to a distal end of a catheter or guidewire;

2. The tip assembly of claim 1, wherein the guide structure is a balloon.

3. The tip assembly of claim 2, wherein the connecting section further defines a passageway in communication with the balloon, an end of the passageway remote from the balloon being adapted to connect with a pressure relief device.

4. The tip assembly of claim 2, further comprising an adjustment rod having one end connected to the balloon and the other end extending through the balloon and into the connecting section.

5. The tip assembly of claim 1, wherein the guide structure comprises a plurality of resilient segments, one end of each of the resilient segments being connected to the second end of the connecting segment.

6. The tip assembly of claim 5, wherein each of said resilient segments is arcuate, and wherein a plurality of said resilient segments are connected together at opposite ends, and wherein a central portion of said guide structure has a greater radial dimension in said connecting segment than an end portion of said guide structure; or,

7. The tip assembly of claim 1, wherein the guide structure comprises a plurality of resilient bars, an end of each of the resilient bars being connected to a side wall of the connecting section, the plurality of resilient bars being spaced around the connecting section.

8. The tip assembly of any one of claims 1-7, wherein an end of the guide structure distal from the connecting section transitions smoothly.

9. The tip assembly of any one of claims 1-7, further comprising a tapered section disposed at a central location on a side of the tip assembly facing away from the catheter or guidewire.

10. A tip assembly according to any one of claims 1-7, wherein the second end of the connection section is provided with a spigot for connection with the catheter or guidewire, and the sidewall of the spigot is provided with threads for threaded connection with the catheter or guidewire.

11. An interventional medical catheter comprising a catheter and a tip assembly as defined in any one of claims 1-10.

12. An interventional medical guidewire comprising a guidewire and a tip assembly as defined in any one of claims 1-10.