WO2017173995A1

WO2017173995A1 - Catheter

Info

Publication number: WO2017173995A1
Application number: PCT/CN2017/079527
Authority: WO
Inventors: 贾罗琦; 贾宗毅
Original assignee: 上海庆之医疗科技有限公司
Priority date: 2016-04-08
Filing date: 2017-04-06
Publication date: 2017-10-12
Also published as: CN105903117A; CN105903117B

Abstract

Disclosed is a catheter with a bendable head and a variable bending radius, comprising a main body (2), and the head (1) being located at a distal end of and connected to the main body (2). The head (1) comprises a central tube (20) having at least one bendable section (11, 12); at least one group of traction ropes (24, 25) respectively fixed to the corresponding one of the at least one bendable section (11, 12); and a guide wire (30) threaded into the central tube (20). The guide wire (30) comprises a distal portion (31) and a proximal portion (32) connected with one other, with the stiffness of the distal portion (31) being less than that of the proximal portion (32). The guide wire (30) is movable relative to the central tube (20), so that when the position where the distal portion (31) is connected to the proximal portion (32) of the guide wire (30) is located at different positions of one (11 or 12) of the at least one bendable section (11, 12), the bending section (11 or 12) can bend at a different radius by controlling the corresponding group (24 or 25) of the at least one group of traction ropes (24, 25). The catheter is adaptable to being threaded into blood vessel bifurcations of various shapes, angles and bending lengths.

Description

catheter

Technical field

The present invention relates to medical devices, and more particularly to a catheter for minimally invasive interventional procedures for blood vessels.

Background technique

Minimally invasive surgery began in the 1980s, and interventional surgery was an important branch. Interventional surgery can be divided into vascular intervention and non-vascular intervention. In recent years, Minimally invasive vascular surgery (MIVS) has been widely used at home and abroad. Vascular minimally invasive interventional surgery refers to the insertion of a catheter into a blood vessel and the direction of movement of the catheter's front end in vitro, guided by a medical image X-ray image during surgery, and the catheter is delivered from the patient's puncture site to the target vessel for corresponding surgery. treatment. The operation has the advantages of small wound, less bleeding, less pain, quick recovery and safety, and has been applied in various clinical disciplines such as cardiovascular surgery, neurosurgery, obstetrics and gynecology, oncology, vascular surgery, ear and nose. Throat surgery, etc.

The method of operation for endovascular interventions has been combined with the conventional method of selecting a guidewire in the head of the catheter tip to select a vessel bifurcation by rotating the catheter and guidewire from the day of birth. The rotation of the catheter and the guide wire and the damage to the vessel wall are the scratches on the intima of the blood vessel. The human body will naturally repair these injuries. The natural repair of these organisms will cause the proliferation and thickening of the intimal tissue. A new round of stenosis and blockage of the inner diameter of the blood vessel. This is one of the main drawbacks of traditional intubation methods.

The traditional intubation method uses a rotating catheter to select the test to enter the vascular bifurcation. The experienced doctor also has to undergo multiple rotational trials to penetrate. The ordinary novice doctors are struggling to penetrate the catheter after a large number of rotations. Therefore, the scratch damage to the blood vessel wall can be imagined.

In addition, for a patient who is a little older, the inner wall of the blood vessel is more or less formed due to the accumulation of harmful impurities in the blood for a long time. The traditional intubation method uses the rotating catheter and the guide wire to select the test to enter the blood vessel. The fork increases the chance that it will scratch the plaque, which may cause plaque The detachment of the genus rushes into the small blood vessels to form an embolism, sometimes even directly endangering life. This dangerously extreme case occurs during intravascular clinical procedures and is a major risk for endovascular interventions.

In order to reduce the scratch damage of the catheter to the vessel wall, the conventional intravascular interventional operation method must be insufficient to rotate the catheter and the guide wire. In the prior art, a catheter whose head can be bent under control has been developed. For example, a catheter having a controllable curved joint at the front end is disclosed in the Chinese Patent Publication No. CN 103372260 A and the US Patent Publication No. US 2008/0139999 A1, by providing joints having different hardnesses at the front end of the catheter and controlling the pulling of the joints to the respective joints. The rope can control the bending angle of each joint so that the catheter can bend according to the direction of the blood vessel. However, once the above-mentioned existing catheter is completed, the achievable bending parameters, especially the range of the bending radius at a certain bending angle, are substantially fixed, and the blood vessels in the human body are diverse, and the blood vessels are different between There can be significant differences in shape, angle and radius of curvature, which allows existing catheters of this type to enter certain blood vessels, especially those with bending angles and/or bend radii that exceed the achievable range of the catheter. To the difficulty, even forced to stop the operation. Therefore, it is necessary to develop a more versatile head flexible catheter.

Summary of the invention

In view of the above, it is an object of the present invention to provide a catheter having a bendable head and a variable radius of curvature.

To achieve the above object, the present invention provides a catheter comprising a body and a head at a distal end of the body and coupled thereto, wherein the head comprises: a central tube having at least one bendable section; a set of pull cords secured to respective ones of said at least one bendable segment; a guidewire threaded into said central tube, said guidewire comprising an associated distal portion and a proximal portion, said distal end The hardness of the portion is less than the hardness of the proximal portion; wherein the guide wire is movable relative to the central tube such that when the junction of the distal end portion and the proximal end portion of the guide wire is located at the at least one bendable The one bendable section can be bent at a different radius by controlling a corresponding one of the at least one set of drawstrings when different positions of one of the segments are bendable.

Optionally, the hardness of the at least one bendable segment is sequentially increased from the distal end to the proximal end. plus.

Optionally, the stiffness of the proximal portion of the guidewire is greater than the stiffness of at least one of the at least one bendable segment.

Optionally, the at least one bendable segment comprises a first bendable segment at a distal end of the central tube and a second bendable portion at a proximal end of the first bendable segment and connected to the first bendable segment The at least one set of drawstrings includes a first set of drawstrings secured to the first bendable section and a second set of drawstrings secured to the second bendable section.

Optionally, the hardness of the first bendable section is less than the hardness of the second bendable section.

Optionally, when the connection between the distal end portion and the proximal end portion of the guide wire is at different positions of the first bendable segment, the first can be made by controlling the first set of pull cords The bendable segments are bent at different radii.

Optionally, when the connection between the distal end portion and the proximal end portion of the guide wire is at different positions of the second bendable segment, the second can be made by controlling the second set of pull cords The bendable segments are bent at different radii.

Optionally, by further controlling the first set of pull cords, the first bendable section can also be bent independently of the second bendable section.

Optionally, further comprising a first fixing member fixed at a distal end of the first bendable segment, and a second fixing member fixed at a distal end of the second bendable segment, the first group a pulling cord is secured to the distal end of the first bendable section by the first securing member, the second set of pulling cords being secured to the distal end of the second bendable section by the second securing member At the end.

Optionally, further comprising at least one first guiding element fixed on the first bendable section, each of the at least one first guiding element having a central large hole and a plurality of peripheral small holes, a first bendable section passes through a central large aperture of the first guiding element, the number of the plurality of peripheral apertures of the first guiding element being greater than or equal to the number of pulling cords in the first set of pulling cords Each of the first set of drawstrings passes through a respective peripheral aperture of the first guide element.

Optionally, further comprising at least one second guiding element fixed on the second bendable segment, Each of the at least one second guiding element has a central large aperture and a plurality of peripheral apertures, the second bendable section passing through a central large aperture of the second guiding element, the second The number of the plurality of peripheral apertures of the guiding element is greater than or equal to the sum of the number of pulling cords in the first set of pulling cords and the number of pulling cords in the second set of pulling cords, the first set of Each of the drawstrings in the drawstring and each of the drawstrings of the second set of drawstrings pass through respective peripheral apertures of the second guide member.

Optionally, a radiopaque marker on the head is further included for indicating a direction of movement of the head.

Optionally, the radiopaque marker comprises a first marking portion and a second marking portion having different extending directions, and at least one of a length, a width and a shape of the first marking portion and the second marking portion different.

Optionally, the catheter body has a central chamber and a plurality of peripheral chambers, the central tube is in communication with the central chamber, and the at least one set of drawstrings is from the plurality of peripheral chambers Pass through one or more of them.

The present invention provides a guide wire which is harder in the distal end portion of the distal end portion by providing a softer guide wire in the central tube. In addition to various bending angles of the existing catheter, the position of the guide wire in the central tube can be changed to change the position of the catheter. The bending radius allows the catheter head to be combined with a variety of catheter head postures under the control of at least one set of pulling ropes to accommodate the penetration of blood vessel bifurcations of various shapes, angles and bending radii. Enriched the changes in the bending of the catheter head. Thereby, the catheter head can be directly inserted into the blood vessel of the target by precise micro-swing, minimizing the scratch damage of the catheter to the blood vessel wall.

DRAWINGS

Figure 1 is a schematic illustration of a catheter of the present invention;

Figure 2 is a schematic view showing the internal structure of the head of the catheter shown in Figure 1;

3A is a schematic view showing a bending range of a conventional bendable joint;

3B to 3D are schematic views showing the bending range of the bendable section of the present invention;

Figures 4A through 4C show guidewires made in different ways.

detailed description

The catheter of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Advantages and features of the present invention will be apparent from the description and appended claims. It should be noted that the drawings are in a very simplified form and all use non-precise proportions, and are only for convenience and clarity to assist the purpose of the embodiments of the present invention.

The invention provides a catheter suitable for interventional surgery, in particular for minimally invasive vascular surgery, which is performed by delivering a catheter from a patient's puncture site to a target blood vessel (ie, a blood vessel in which the lesion is located).

As shown in Figure 1, the catheter comprises an associated body 2 and a head 1 which, during delivery of the catheter, serves as a guiding member, along with the body 2 behind it, under the control of an operator (e.g., a doctor). A predetermined or real-time determined vascular path passes until the target vessel is reached. The body 2 is typically a multi-lumen tube and has a very long length to ensure that when the head 1 of the catheter reaches the target vessel, at least a portion of the body 2 is located outside the patient, as shown schematically in FIG. The actual length of a small part of the body 2 connected to the part 1 should not be limited thereto. When the head 1 of the catheter reaches the lesion site, a surgical device, a drug, or the like can be delivered to the lesion through the chamber (usually the central main chamber) in the body 2 to treat the lesion. The body 2 (ie, the multi-lumen tube) may further include a plurality of auxiliary chambers located outside the central main chamber for the passage of the pulling rope described below, and/or as a backup chamber, such as an endoscope Working hole.

For convenience of description, the end where the head 1 is located is defined as the distal end, that is, the end away from the operator, and the end where the main body 2 is located is defined as the proximal end, that is, the end closer to the operator. Therefore, the head 1 is located at the farthest end of the entire catheter.

It will be readily understood by those skilled in the art that whether the catheter can smoothly travel along a predetermined path within the blood vessel and whether it causes unnecessary scratch damage to the blood vessel wall depends mainly on the maneuverability of the catheter head 1, and thus the following will focus on Introduce the structure of the catheter head 1 and its handling to better the body The beneficial effects of the present invention are now available.

Referring again to FIG. 1, the catheter head 1 of the present embodiment includes a probe 10, a first bending joint 11 and a second bending joint 12, which are sequentially connected from the distal end to the proximal end, and the second bending joint 12 The proximal end is connected to the distal end of the catheter body 2. The probe 10 can be, for example, an intravascular interventional tactile probe having a contact force and orientation information feedback disclosed by the inventors in Chinese Patent Publication No. CN103877664A, the entire contents of which are incorporated herein by reference. The structure is not described.

See Figure 2 for the detailed structure of the first curved joint 11 and the second curved joint 12. The catheter head 1 includes a central tube 20 that extends through the first curved joint 11 and the second curved joint 12. The center tube 20 may be a hollow tube made of an elastic material so as to be bendable under an external force. The distal end of the central tube 20 is mounted with the probe 10, and the proximal end of the central tube 20 can be inserted and fixed to the central main chamber of the main body 2 (ie, the multi-lumen tube), and communicates with the central main chamber, thereby performing surgery. Instruments, drugs, and the like can enter the central tube 20 through the central main chamber.

In order for the catheter head 1 to enter a different vessel bifurcation, the head 1, in particular the central tube 20, needs to be bent into different shapes, such as a "C" shape, a "U" shape, an "S" shape or the like. In the case of the "C" shape and the "U" shape, it is only necessary to apply a force in one direction to the center tube 20, or to apply a resultant force in two or more directions toward the same side, that is, to bend into a corresponding shape; In the case of the S" shape, it is necessary to apply at least a force directed in the opposite direction to different portions of the center tube 20. To this end, the central tube 20 preferably has two or more bending sections to enable control of the bending direction of each of the bendable sections, respectively. Further, in order to improve the maneuverability, each of the bendable segments may be set to have different hardnesses, and preferably, the hardness of each bendable segment is sequentially increased from the distal end to the proximal end so that each bendable segment can be substantially Bending independently of other bendable segments.

In the embodiment shown in Figure 2, the central tube 20 has two bendable sections, a first bendable section 21 and a second bendable section 22 from the distal end to the proximal end, respectively, wherein the first bendable section 21 The hardness is less than the hardness of the second bendable section 22. Specifically, the first bendable section 21 is formed by a portion 20a of the center tube, and the second bendable section is formed by another portion 20b of the center tube plus a sleeve 23. When it is desired to form more bendable sections, variations in hardness can be achieved by placing different thicknesses or different numbers of sleeves on different central tube sections.

In addition, a plurality of bendable segments in which the hardness is sequentially increased may be produced by, for example, by integrally molding a polymer material to form a center tube corresponding to different bendable segments, and the outer diameters of the corresponding portions thereof are sequentially increased. 20; different areas are punched in the center tube 20 and/or the sleeve 23 by different punching densities, where the punching is less than the punching or the punching; the center tube 20 corresponds to The sleeves 23 of the different bendable sections are respectively sleeved from the distal end to the proximal end, and the sleeves 23 can be made of a polymer elastic material of different hardness; the central tube 20 is divided into two from the distal end to the proximal end. A segment or two or more segments of the central tube unit that are hardened in sequence, and the adjacent central tube units are connected by splicing or plugging. The above-described and more specific embodiments of achieving a bendable section of increasing hardness can be found in the inventor's application, the disclosure of which is incorporated herein by reference.

With continued reference to Figure 2, the catheter further includes a first set of pull cords 24 secured to the distal end of the first bendable section 21 by a first fastener and secured to the second bendable section by a second fastener A second set of pulling cords 25 at the distal end of 22. Specifically, the first fixing member is a first flange 26 having a central large hole (not shown) for the first bendable section 21 (that is, the central tube portion 20a) to pass through, and A plurality of peripheral apertures (not shown) are provided for the ends of the first set of pull cords 24 to pass therethrough and knotted. The second fixing member is a second flange 27 having a central large hole 27a for the second bendable portion 22 (that is, the central tube portion 20b and the sleeve 23) to pass therethrough, and has a plurality of peripheral small holes. 27b and 27c, wherein the peripheral aperture 27b is for the first set of pull cords 24 to pass through, and the peripheral apertures 27c are for the ends of the second set of pull cords 25 to pass therethrough and knotted. Although the drawstring is described herein as being fixed by knotting, the invention is not limited thereto, and the drawstring can also be secured by any means well known in the art, such as riveting, bonding, by an auxiliary joint, and the like. To the fixture. Correspondingly, the attachment member may also be provided with a peripheral aperture for the end of the pull cord to pass through to knot, or the peripheral aperture may be replaced with a connector that mates with the connector of the end of the pull cord.

In order to avoid mutual interference between the pulling ropes and affect the handling precision, it is preferable to make the first group Each of the pulling cords in the drawstring 24 is offset from the respective drawstrings of the second set of drawstrings 25, for example, arranged in an alternating arrangement and evenly distributed on the outer circumference of the center tube 20. Optionally, one or more guiding elements can also be attached to the first and/or second bendable section for guiding the direction of extension of the pulling rope, further avoiding mutual interference of adjacent pulling ropes. As shown in Fig. 2, since the length of the first bendable section 21 is short, it is not necessary to provide a guiding member, and the length of the second bendable section 22 is relatively long, and therefore, it is preferable to provide one or more guiding members. In the embodiment shown in Figure 2, a third flange 28 is provided as a guiding element at a substantially central position of the second bendable section 22. The third flange 28 has a central large hole 28a for the second bendable section 22 to pass through, and also has a plurality of peripheral

small holes

28b and 28c, wherein the peripheral small hole 28b is for the first set of pull ropes 24 passes through, and peripheral apertures 28c are used for the second set of pulling cords 25 to pass through. Thus, each of the first and second sets of pulling

ropes

24, 25 does not affect each other.

The first and second sets of

drawstrings

24 and 25 shown in Figure 2 each have four drawstrings, and the four drawstrings in each set of drawstrings are evenly distributed around the central tube 20. Taking the first bendable section 21 as an example, when pulling any one of the first set of pull cords 24, the distal end of the first bendable section 21 will be from the side where the pull cord is located The proximal direction is curved. When any two adjacent ones of the first set of drawstrings 24 are pulled, the distal end of the first bendable section 21 can be from the side between the two pullstrings to the proximal end as needed The direction is curved. Similarly, the distal end of the second bendable section 22 can also be bent in any direction by controlling the second set of pull cords 25. When the direction of curvature of the distal end of the first bendable section 21 is substantially opposite to the direction of curvature of the distal end of the second bendable section 22, the "S" shape can be bent.

Those skilled in the art will readily appreciate that when a set of drawstrings contains three or more drawstrings, regardless of whether the drawstrings are evenly distributed, bending of the bendable section in any direction can be achieved. However, in order to reduce the difficulty of handling and improve the handling efficiency, it is preferable to use an even number of pulling ropes of four or more and evenly distribute the pulling ropes, so that it is easy to determine the need according to the direction and angle at which the catheter head needs to be bent. Which or which of the pulling ropes are pulled and the pulling force of each pulling rope.

Although the present embodiment is described as having four pulling ropes for each set of pulling ropes, and it is recommended to use even-numbered pulling ropes of four or more, the present invention is not limited thereto. In fact, using less than four pulling ropes The invention can be implemented. For example, a pulling rope is fixed at the distal end of the first bendable section 21, and the distal end of the first bendable section 21 can be bent in the direction in which the pull cord is tightened by pulling; two pulls are employed The cord is fixed at the distal end of the first bendable section 21, and by pulling the two pull cords respectively, the distal end of the first bendable section 21 can be bent in two corresponding directions; One of the ropes is fixed at the distal end of the first bendable section 21, and the other is fixed at the distal end of the second bendable section 22, and the pulling of the two pull cords can bend the opposite two The bending curvature of the direction can be bent out of an "S" shape; the three pulling ropes are fixed at the distal end of the first bendable section 21, and the first bendable can be made by sequentially pulling and relaxing the pulling rope. After the segment 21 is bent, the central tube 20 is used as a shaft for 360 degree circumferential movement; six pulling ropes are used, and three sets are respectively fixed at the distal ends of the first and second

bendable segments

21, 22, and each is pulled. The ropes are sequentially combined to pull and relax, and the catheter head 1 can be bent into an "S" shape and then subjected to a 360 degree circumferential movement with the center tube 20 as an axis. Bent out by the various forms of upper and lower halves having a deflection angle of the "S" shaped.

As described above, the catheter head 1 of the present invention can be bent into various shapes in any direction at an arbitrary angle under the control of the pulling rope. How to change the bending radius or bending arc length of the bendable section by the guide wire will be explained in detail below.

As described in the background, the catheters disclosed in CN 103372260A and US 2008/0139999 A1 can also be bent at different angles in various directions under the control of the pulling rope, but as shown in Fig. 3A, the bending of each controllable bending joint The movement is based on the proximal end A of the joint as a fulcrum. Once the catheter is completed, the bending arc length of each controllable bending joint is fixed, which is basically equal to the length of the controllable bending joint, and correspondingly, each The bending radius of a controllable bending joint at a certain bending angle is also substantially fixed. The solid line in Fig. 3A shows the radius R1 when the controllable bending joint is bent by 90 degrees.

In contrast to prior art catheters, the catheter of the present invention also includes a guidewire 30 (see Figures 4A through 4C) that penetrates into the central tube 20 and is movable relative to the central tube 20, the guidewire 30 including the associated distal portion A distal portion 31 and a proximal portion 32 having a hardness that is less than the stiffness of the proximal portion 32. By changing the distal portion 31 and the proximal portion 32 The position of the junction 33 within the bendable section can change the position of the "fulcrum" such that the same bendable section can bend any desired radius or arc length. 3B to 3D respectively show a bending range of the bendable section at different positions of the joint 33 of the distal end portion and the proximal end portion of the guide wire at different positions within the bendable section (ie, corresponding to the fulcrums B, C, D), The solid lines in Figs. 3B to 3D respectively show the radii R2, R3, R4 when the bendable section is bent by 90 degrees. By comparing FIG. 3A with FIGS. 3B to 3D, it can be found that, when the guide wire of the present invention is used, not only the position of the fulcrum can be arbitrarily changed, but correspondingly, the bending arc length of the bendable section and the bending angle at a certain bending angle are The bending radius can also be arbitrarily changed. It is thus clear that the catheter head of the present invention has significant advantages in maneuverability.

Regarding the specific structure and manufacturing manner of the guide wire 30, an example is shown in FIG. 4A, the distal end portion 31 of the guide wire can be made of a first material having a lower hardness, and the proximal end portion can be made of a second material having a higher hardness. 32. The guide wires 30 are formed by inserting, splicing, bonding or welding the two parts together. Preferably, the distal end portion 31 and the proximal end portion 32 have substantially the same outer diameter at the junction 33 such that the guidewire 30 formed after the two portions are joined has a smooth outer surface, connected between the two

portions

31 and 32. There are no corners or protrusions at the location 33 to avoid unnecessary damage to the vessel wall. In addition, the distal end 34 of the distal end portion 31 of the guide wire 30 can also be rounded, as well as avoiding unnecessary damage to the vessel wall. Since the hardness of the distal end portion 31 and the proximal end portion 32 are different, a portion where the hardness is changed is formed at the joint 33 of the both. When the guidewire 30 is inserted into the bendable section of the central tube 20 and the corresponding puller is pulled, the distal end portion 31 (softer) of the guidewire is pulled together with the bendable section, while the proximal portion 32 (harder) acts as a support and does not substantially bend with the bendable section. To ensure that the proximal portion 32 of the guidewire has sufficient support force, the proximal portion 32 preferably has a higher stiffness than any of the bendable segments. The hardness of the distal end portion 31 is not excessively limited and may be higher or lower than the hardness of any of the bendable segments as long as the distal end portion 31 can be bent together with the bendable segment.

Another example of a guidewire can be made using the same material as shown in Figure 4B, such that the outer diameter of the distal portion 31 is smaller than the proximal portion 32, thereby achieving a lower stiffness of the distal portion 31 than the proximal portion. 32. Similarly, in order to avoid unnecessary damage to the vessel wall by the guide wire, the guide wire 30 can be far The end 34 and the junction 33 of the distal portion 31 and the proximal portion 32 are made as smooth as possible to avoid the creation of corners or protrusions. In this case, the junction 33 of the distal portion 31 and the proximal portion 32 forms a short transition region that has little effect on the bending radius or arc length of the guidewire to change the bendable segment. When there is a transition zone, the guidewire can have a natural transitional curvature when bent. In addition, a sleeve 35 of soft material may be placed over the distal portion 31 to streamline the distal end of the guidewire.

As another example of a guide wire, as shown in Fig. 4C, a flexible filament 37 is inserted in the middle of a hollow capillary 36, and a portion of the flexible filament 37 extending beyond the capillary 36 constitutes a distal end portion of the guide wire. 31, the capillary 36 and its surrounding portion of flexible filament 37 collectively form the proximal portion 32 of the guidewire. Similarly, to avoid unnecessary damage to the vessel wall by the guide wire, the distal end of the capillary 36 can be formed in a ramp shape, and the distal end of the flexible filament 37 can be formed in a circular arc shape. Here, the capillary 36 and the flexible filament 37 may be fixedly coupled to each other such that the length of the portion of the flexible filament 37 extending beyond the capillary 36 is fixed, or the capillary 36 and the flexible filament 37 may not be connected in a fixed manner, thereby changing the capillary The relative position between the 36 and the flexible filaments 37 adjusts the length of the portion of the flexible filament 37 that extends beyond the capillary 36. The advantages of this length adjustable design are described below.

In addition to the various guide wires 30 shown in FIGS. 4A to 4C, a combination of any one or more of a plurality of ways of fabricating a plurality of bendable segments having different hardnesses as described above may be employed to produce portions having different hardness portions. The guide wire 30, or may be implemented in any other well-known manner in the art, will not be described herein.

In addition to changing the bend radius or arc length of the bendable section, the guidewire 30 also has an important function of the liner in the center tube 20 so that the center tube 20 is not pulled up and wrinkled. Since the central tube 20 itself is a hollow tube body, it is easy to be pulled up and wrinkled without an internal filling, and after the liner of the distal end portion 31 of the guide wire, the problem can be effectively solved. The center tube 20 serves to support and protect. To this end, the distal end portion 31 of the guidewire 30 should be of sufficient length such that the distal end portion 31 can be cushioned regardless of which bendable portion the distal portion 31 and the proximal portion 32 are located in. In the bendable section and the remaining bendable section of the distal end. For example, for the graph The catheter head 1 having two bendable segments as shown in Fig. 2, when the junction 33 of the distal end portion 31 of the guide wire and the proximal portion 32 is located in the second bendable section 22, the distal end portion 31 can at least The liner is in the entire first bendable section 21 and may also slightly extend beyond the distal end of the first bendable section 21. For a catheter head having three bendable segments (first, second, third bendable segments from distal to proximal end), the junction 33 of the distal end portion 31 and the proximal portion 32 is located In the third bendable section, the distal end portion 31 can be at least padded throughout the second and first bendable segments, and can also extend slightly beyond the distal end of the first bendable segment.

In order to ensure the cushioning effect of the distal end portion 31 of the guidewire, for a guidewire of non-adjustable length, it is possible that when the junction of the distal end portion 31 and the proximal end portion 32 is located in the first bendable section 21, The end portion 31 extends a long distance from the first bendable section 21 and extends into the portion of the probe 10, which requires a consideration of the size of each bendable section, the size of the distal end portion of the guidewire, and The probe is sized to ensure that the distal length of the probe 10 does not travel an excessive length during movement of the guidewire 30 relative to the central tube 20, thereby affecting the bending or damage of the catheter head to the vessel wall.

In this case, it would be more advantageous to use a length-adjustable guidewire as shown in Figure 4C, which can adjust the length of the distal end portion 31 of the guidewire in real time during operation, thereby not ensuring the effect of the cushion. The probe 10 will be worn over an extended distance, making the design of the dimensions of the various sections of the catheter more flexible.

Referring again to FIG. 2, the catheter can also include a radiopaque marker 40 near the distal end of the head for indicating the current phase of the catheter head 1. The radiopaque marker 40 is made of a radiopaque material such as a metal, a metal mixture, a metal compound, or the like. In order to be able to indicate the current phase of the catheter head 1, but not just the position, the radiopaque markers 40 include a first marking portion 41 and a second marking portion 42 having different extending directions, and the first marking portion 41 At least one of the length, the width and the shape is different from the second marking portion 42. Preferably, the first marking portion 41 is disposed along the axial direction of the center tube 20 and has a first feature, which may be one of the length, width and shape of the first marking portion 41 or A plurality of decisions, such as the first indicia portion 41 being one or more lines; the second indicia portion 42 may be disposed along the circumferential or radial direction of the central tube 20 and having a second feature, the second feature also The length, width and length of the second marking portion 42 are One or more of the shapes are determined, for example, the second indicia portion 42 is a rectangular indicium. The first marking portion 41 and the second marking portion 42 may be connected or disposed separately. The position of the radiopaque marker 40 can be clearly recognized by X-ray imaging, and since the first and second marker portions 41, 42 have different characteristics, it can be easily discerned which is the axial marker and which is the circumferential direction. Or radial marking to determine the current phase of the catheter head 1.

A specific method of making the radiopaque marker 40, for example, referring to FIG. 2, a third flange 43 is disposed at the distal end of the first bendable section 21, and the third flange 43 is also worn outside the center tube 20 and It is fixed to the center tube 20. The wire is vertically inserted into one or a plurality of small holes of the third flange 43 to form an axial first mark portion 41, and then the skin made of a material containing barium sulfate is cut into a horizontal strip. The outer circumference of the third flange 43 constitutes a second marking portion 42 in the circumferential direction, and the skin may cover a half circumference or even a quarter circumference of the third flange 43. Thus, the "L" shaped radiopaque marker 40 is formed to visually indicate the phase of the catheter head and then determine in which direction the catheter head is bent and which or which traction cords are pulled.

Although the present embodiment describes the use of two differently oriented, differently characterized marking portions to form the radiopaque marker 40, the invention is not limited thereto, and other numbers, other orientations or shapes of marking designs may be employed, as long as Help the operator to determine which direction the catheter head is going to bend and prompt the operator to pull which pull rope to handle.

In summary, the present invention provides a guide wire which is harder in the distal end portion of the distal end portion of the central tube, in addition to various bending angles of the existing catheter, and adjustment of the guide wire in the central tube. Position to change the bending radius or arc length of the catheter, so that under the control of at least one set of pulling ropes, the catheter head can be combined to change a variety of catheter head postures, adapting to different diameters of the blood vessel bifurcation to the interventional catheter Different requirements for bending direction, bending angle and bending radius.

The above description is only for the description of the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Any changes and modifications made by those skilled in the art in light of the above disclosure are all within the scope of the appended claims.

Claims

A catheter comprising a body and a head at a distal end of the body and coupled thereto, wherein the head comprises:

a central tube having at least one bendable section;

At least one set of pulling ropes respectively secured to respective ones of said at least one bendable section;

a guide wire penetrating into the central tube, the guide wire comprising an associated distal portion and a proximal portion, the distal portion having a hardness that is less than a hardness of the proximal portion;

Wherein the guide wire is movable relative to the central tube such that when the junction of the distal end portion and the proximal end portion of the guide wire is at a different position of one of the at least one bendable segment, The one bendable section can be bent at a different radius by controlling a corresponding one of the at least one set of drawstrings.
The catheter of claim 1 wherein the stiffness of said at least one bendable segment increases sequentially from the distal end to the proximal end.
A catheter according to claim 1 or 2, wherein the proximal portion of the guidewire has a hardness greater than the stiffness of at least one of the at least one bendable segment.
The catheter of claim 1 wherein said at least one bendable section comprises a first bendable section at a distal end of the central tube and a proximal end of said first bendable section and said first a second bendable section joined by the bendable segments; the at least one set of drawstrings comprising a first set of pull cords secured to the first bendable section and a second set secured to the second bendable section Pull the rope.
The catheter of claim 4 wherein said first bendable section has a hardness that is less than said second bendable section.
A catheter according to claim 4 or 5, wherein when said junction of the distal end portion and the proximal end portion of said guide wire is located at a different position of said first bendable section, said first The group pulls the cord so that the first bendable section can be bent at different radii.
A catheter according to claim 4 or 5, wherein the distal end portion of the guide wire The second bendable section can be bent at a different radius by controlling the second set of pull cords when the junction with the proximal end portion is at a different position of the second bendable section.
The catheter of claim 7 wherein said first bendable section is further bendable independently of said second bendable section by further controlling said first set of pull cords.
The catheter of claim 4, further comprising a first fixture secured to the distal end of the first bendable section and a first end secured to the distal end of the second bendable section a second fixing member, the first group of pulling ropes being fixed to the distal end of the first bendable section by the first fixing member, and the second group of pulling ropes being fixed to the second fixing member by the second fixing member At the distal end of the second bendable section.
The catheter of claim 9 further comprising at least one first guiding element secured to said first bendable section, each of said at least one first guiding element having a central large aperture And a plurality of peripheral apertures, the first bendable section passing through the central large aperture of the first guiding element, the number of the plurality of peripheral apertures of the first guiding element being greater than or equal to the first group The number of pulling cords in the pulling cord, each of the first set of pulling cords passing through a respective peripheral aperture of the first guiding element.
A catheter according to claim 9 or 10, further comprising at least one second guiding element secured to said second bendable section, each of said at least one second guiding element having a central a large aperture and a plurality of peripheral apertures, the second bendable section passing through the central aperture of the second guiding element, the number of the plurality of peripheral apertures of the second guiding element being greater than or equal to the number a sum of the number of pulling ropes in a set of pulling ropes and the number of pulling ropes in the second set of pulling ropes, each of the first set of pulling ropes and the second set of pulling ropes Each of the pulling cords in the drawstring passes through a respective peripheral aperture of the second guiding element.
The catheter of claim 1 further comprising a radiopaque marker on said head for indicating the direction of movement of said head.
The catheter of claim 12, wherein said radiopaque marker comprises a first marker portion and a second marker portion having different extension directions, and wherein said first marker portion is long At least one of a degree, a width, and a shape is different from the second mark portion.
The catheter of claim 1 wherein said catheter body has a central chamber and a plurality of peripheral chambers, said central tube being in communication with said central chamber, said at least one set of drawstrings Passing through one or more of the plurality of peripheral chambers.