CN218075978U - Medical catheter - Google Patents

Abstract

The utility model relates to the technical field of medical instruments, in particular to a medical catheter, which comprises an outer tube, an inner tube and a reinforcing structure, wherein the outer tube is provided with a near-end opening and a far-end opening which are opposite, the outer tube is provided with a reducing section with the outer diameter reducing towards the far-end opening, and the reducing section is reduced to the far-end opening; the inner tube is arranged in the outer tube in a penetrating way, the inner tube extends outwards from the distal opening of the outer tube to form the distal end of the medical catheter, and the outer surface of the tapered section and the outer surface of the inner tube are in smooth transition; a reinforcing structure is disposed through the outer tube and connected to the inner tube, the reinforcing structure being longitudinally confined within the distal opening. The medical catheter of the utility model can not interfere with the human body in the insertion process while achieving the mechanical performance strength, on one hand, the medical catheter can be accurately controlled, and the damage to the human body in the insertion process can be avoided; on the other hand, the medical catheter can not be bent due to interference, the operation difficulty is reduced, and the operation success rate and efficiency are improved.

Description

Medical catheter

Technical Field

The utility model relates to the technical field of medical equipment, in particular to a medical catheter.

Background

In the medical field, doctors often diagnose and treat blood vessels (peripheral blood vessels, coronary blood vessels, and the like) through medical catheters, and can also be used for supporting guide wires to work and the like, such as common balloon catheters, ultrasonic catheters, pressure microcatheters, and the like. For some medical catheters, the outer diameters of the proximal end and the distal end of the catheter are often different, and the material may also be changed, and the outer diameter of the distal end of the catheter is usually smaller than the outer diameter of the proximal end of the catheter, so that the distal end of the catheter can pass through small blood vessels more smoothly, and the passability of the catheter is improved.

In the prior art, a medical catheter generally comprises a lumen, an inner layer, a braided layer, a spring layer, an outer layer and the like from inside to outside. In some medical catheters, the positions of the braid and spring layers may also be interchanged. However, few medical catheters can ensure the conditions of small size, good pushing performance and flexibility, and good bending resistance. This is because, when a conventional medical catheter is subjected to a diameter-changing treatment, two catheters having different outer diameters are usually joined together by axial butt-joining. This has two disadvantages, one is that the stability of the adhesive is poor, and the catheter is easy to bend due to stress concentration when passing through a tortuous blood vessel; secondly, if the connecting part of the catheter is not smooth, the blood vessel is easy to scratch, and the connecting part of the inner cavity is not smooth and is easy to be blocked when passing through a guide wire or other equipment.

SUMMERY OF THE UTILITY MODEL

Based on this, the utility model provides a medical catheter, this medical catheter have level and smooth convergent section, effectively avoid medical catheter to take place stress concentration and buckle or scratch vascular problem easily.

The utility model discloses a medical catheter, which comprises an outer tube, an inner tube and a reinforcing structure, wherein the outer tube is provided with a near-end opening and a far-end opening which are opposite, the outer tube is provided with a reducing section with the outer diameter reducing towards the far-end opening, and the reducing section reduces to the far-end opening; the inner tube is arranged in the outer tube in a penetrating way, the inner tube extends outwards from the distal opening of the outer tube to form the distal end of the medical catheter, and the outer surface of the tapered section is smoothly transited with the outer surface of the inner tube; the reinforcing structure is arranged in the outer pipe in a penetrating mode and connected with the inner pipe, and the reinforcing structure is limited in the far-end opening in the length direction.

In some embodiments, a tangent to a radially projected contour of the tapered section forms an angle of 0 ° to 5 ° with the longitudinal axis.

In some embodiments, a tangent line of a contour line of the tapered section projected in the radial direction of the medical catheter forms an angle of 2-3 degrees with the longitudinal axis of the medical catheter.

In some embodiments, the axial length of the tapered section is greater than 20mm and less than 100mm.

In some embodiments, the length of the tapered section in the axial direction is greater than 50mm and less than 60mm.

In some of the embodiments, the reinforcing structure is located between the inner pipe and the outer pipe and is connected to both the outer pipe and the inner pipe.

In some of the embodiments, the outer tube, the reinforcing structure and the inner tube are connected by hot melting.

In some embodiments, the stiffness of the reinforcing structure decreases towards the distal end of the medical catheter.

In some of these embodiments, the reinforcing structure is a tubular woven mesh and/or a tubular coil spring.

In some of these embodiments, the distal end of the inner tube is provided with a visualization structure.

Advantageous effects

Compare conventional art, the utility model discloses a medical catheter makes the inner tube wear out from the distal end opening of outer tube to make the outer tube have the convergent section, and the surface of this convergent section and the surface smooth transition of inner tube, this is just so feasible the utility model discloses a shoulder among the conventional art can not appear in medical catheter. Thus, the medical catheter of the utility model can not interfere with the human body in the insertion process while achieving the mechanical performance strength of the medical catheter in the traditional technology, on one hand, the medical catheter can be accurately controlled by an operator easily, and the injury to the human body in the insertion process caused by the far end of the catheter due to excessive force application caused by interference in the traditional technology is avoided; on the other hand, the medical catheter can not be bent due to interference, the operation difficulty is reduced, and the operation success rate and efficiency are improved.

Moreover, since the inner tube extends outwardly from the distal opening of the outer tube to form the distal end of the medical catheter, and the reinforcement structure is limited in the distal opening in the length direction, this means that the reinforcement structure will not form the distal end of the medical catheter, in other words, the performance of the distal end of the medical catheter will only be determined by the inner tube, in addition to the structural strength for reinforcing the overlapping portion of the outer tube and the inner tube. So, through selecting the inner tube of suitable size, suitable bending property, the utility model discloses a medical catheter can the propelling movement to farther, in the thinner blood vessel, improves the success rate of operation.

Drawings

FIG. 1 is a schematic view of a medical catheter in accordance with the prior art prior to assembly;

FIG. 2 is a prior art schematic view of a medical catheter after assembly;

FIG. 3 is a perspective view of a medical catheter of the present invention in some embodiments;

FIG. 4 is an axial cross-sectional view of a medical catheter of the present invention in some embodiments;

wherein, 1 is an inner tube, 2 is an outer tube, 3 is a reinforcing structure, 20 is a far end opening, and 21 is a tapered section.

Detailed Description

In order to make the above objects, features and advantages of the present invention more comprehensible, embodiments of the present invention are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, as those skilled in the art will be able to make similar modifications without departing from the spirit and scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the present application, unless expressly stated or limited otherwise, a first feature "on" or "under" a second feature may be directly contacting the second feature or the first and second features may be indirectly contacting the second feature through intervening media. Also, a first feature "on," "above," and "over" a second feature may be directly on or obliquely above the second feature, or simply mean that the first feature is at a higher level than the second feature. A first feature "under," "beneath," and "under" a second feature may be directly under or obliquely under the second feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. As used herein, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like are for purposes of illustration only and do not denote a single embodiment.

Referring to fig. 1, fig. 1 is a schematic view showing a conventional medical catheter, and it can be seen from fig. 1 that the conventional medical catheter generally includes at least two segments having different outer diameters, wherein one segment has the same inner diameter as the other segment, so that the two segments can be butted together and then bonded together. To ensure the strength of the bond, the bond 100 of the two sections of tubing is significantly larger in size than the other sections, i.e., the bond forms a large shoulder 200, as shown in fig. 2. During the insertion of the catheter into the human body, the shoulder 200 may generate a large resistance with the human body, the operation is not very good, and the distal end of the catheter may cause damage to the human body during the insertion process. The other two sections of catheters are fixed by bonding, the bonding stability is poor, and the catheters are easy to generate stress concentration and bend when passing through tortuous blood vessels; and the catheter is connected by two sections of butt joints, the blood vessel is easily scratched when the connecting part of the catheter is not smooth, and the connecting part of the inner cavity is easily blocked when the connecting part of the inner cavity passes through a guide wire or other equipment in a non-smooth way.

In order to solve the problem, the utility model provides a medical catheter. Fig. 3 is a perspective view of a medical catheter according to some embodiments of the present invention, and fig. 4 is a cross-sectional view of the medical catheter according to the present invention. As can be seen from fig. 3 and 4, the medical catheter of the present invention comprises an outer tube 2, an inner tube 1 and a reinforcing structure 3, wherein the outer tube 2 has a proximal opening and a distal opening 20 opposite to each other, the outer tube 2 has a tapered section 21 with an outer diameter tapered toward the distal opening 20, and the tapered section 21 is tapered to the distal opening 20; the inner tube 1 is arranged in the outer tube 2 in a penetrating way, the inner tube 1 extends outwards from the distal end opening 20 to form the distal end of the medical catheter, and the outer surface of the tapered section 21 is in smooth transition with the outer surface of the inner tube 1; a reinforcing structure 3 is provided through the outer tube 2 and is connected to the inner tube 1, the reinforcing structure 3 being longitudinally confined within the distal opening 20 of the outer tube 2.

Compare conventional art, the utility model discloses a medical catheter makes inner tube 1 wear out from the distal end opening 20 of outer tube 2 to make outer tube 21 have the convergent section, and the surface of this convergent section 21 and the surface smooth transition of inner tube 1, this is just so make the utility model discloses a shoulder among the conventional art can not appear in medical catheter. Thus, the medical catheter of the utility model can not interfere with the human body in the insertion process while achieving the mechanical performance strength of the medical catheter in the traditional technology, on one hand, the medical catheter can be accurately controlled by an operator easily, and the injury to the human body in the insertion process caused by the far end of the catheter due to excessive force application caused by interference in the traditional technology is avoided; inner tube 1, additional strengthening 3 and 2 three integrated into one piece stability of outer tube are higher, and medical catheter can not take place to buckle because of interfering, and the operation degree of difficulty reduces and operation success rate and efficiency improve, and medical catheter's inner chamber does not have the linkage segment for medical catheter's inner chamber is smooth to be favorable to the seal wire to pass through.

Furthermore, since the distal end of the catheter of the present invention is constituted by the inner tube 1 only, the performance of the distal end of the catheter will be determined by the inner tube only. So, through selecting suitable size, the inner tube 1 of suitable bending property, the utility model discloses a medical catheter can the propelling movement to farther, in the thinner blood vessel, improves the success rate of operation.

On this basis, the distal end of the reinforcing structure 3 extends to the tapered section 21 of the outer tube 2, which is beneficial to enhancing the strength of the tapered section 21 and avoiding the phenomenon that the tapered section 21 is broken. Meanwhile, the reinforcing structure 3 is also limited in the distal opening 20 of the outer tube 2 in the length direction, in other words, the reinforcing structure 3 does not extend out of the distal opening 20, so that the risk that the reinforcing structure 3 is exposed out of the catheter can be avoided in the using process, and the reinforcing structure 3 is effectively prevented from damaging the blood vessel.

In some embodiments, it is preferable that a tangent line of a contour line of a projection of the tapered section 21 in the radial direction of the medical catheter is arranged at an angle of more than 0 ° and less than 5 ° with respect to the longitudinal axis. The tangent line through the control contour line is 0 to 5 with the contained angle of longitudinal axis, can make convergent section 21 have comparatively mild outline, helps medical personnel will the utility model discloses a medical catheter is to the propelling movement of deeper department. It is further preferred that the tangent of the contour line of the tapered section 21 projected in the radial direction of the medical catheter forms an angle of 2 ° to 3 ° with the longitudinal axis of the medical catheter.

It will be appreciated that the tapered section 21 of the medical catheter of the present invention has a variety of implementations. In some embodiments, the contour line of the projection of the tapered section 21 in the radial direction of the medical catheter may be an inclined straight line as shown in fig. 4, and then the included angle between the tangent of the contour line and the longitudinal axis in this embodiment is the included angle between the inclined straight line and the longitudinal axis. In other embodiments, the projected contour line of the tapered section 21 in the radial direction of the medical catheter may also be a curve, and since the included angles between the tangent line of the curve and the longitudinal axis are all 0 ° to 5 °, the overall undulation of the tapered section 21 is still small, so that the tapered section 21 in the form of the curve can be pushed into human tissue more easily.

In some embodiments, the medical catheter of the present invention preferably controls the length of the tapered section 21 in the axial direction to be 20mm to 100mm. Through the length of control convergent section 21 at least for 20mm, can be so that the convergent section 21 of outer tube 2 can present for comparatively mild result in the course of working to make the surface of convergent section 21 and the surface of inner tube 1 realize smooth transition, guarantee the utility model discloses a medical catheter can easily impel to the human tissue in. In some preferred embodiments, the length of the tapered section 21 is controlled to be 50mm to 60mm. Through extension convergent section 21 length in the axial, can further reduce the processing degree of difficulty of convergent section 21 to can be so that the thickness of the distal end opening 20 department of outer tube 2 is close to for zero, there is not any shoulder between outer tube 2 and the inner tube 1 almost, medical catheter when passing human tissue, inner tube 1, outer tube 2 can pass through human tissue successively without hindrance, have improved greatly the utility model discloses a medical catheter's maneuverability, the operation precision is very high.

It is understood that the medical catheter of the present invention is not limited to the specific form and the specific installation position of the reinforcing structure 3. In some embodiments, the reinforcing structure 3 is a tubular mesh grid, the inner tube 1 is sleeved on the tubular mesh grid after being heat-shrunk, and the outer tube 2 is fixed on the inner tube 1 after being heat-formed. In other embodiments, the reinforcing structure 3 is a cylindrical coil spring wound around the inner tube 1, and the outer tube 2 covers the outside of the coil spring and is thermoformed integrally with the coil spring and the inner tube 1. In this embodiment, since the reinforcing structure 3 is disposed outside the inner tube 1, the guide wire can smoothly pass through the inner tube 1 without any concern of interference with the reinforcing structure 3, and since the outer surface of the reinforcing structure 3 can be treated as a frosted surface, and the reinforcing structure 3 itself has many gaps, the outer tube 2 can be firmly connected with the reinforcing structure 3 and the inner tube 1 as a whole, thereby improving the fixing effect of the three.

Obviously, the reinforcing structure 3 may also have a tubular woven mesh and a tubular coil spring, for example, in some embodiments, the tubular woven mesh and the tubular coil spring are coaxially and continuously arranged, that is, one of the sections is the woven mesh, and the other section is the coil spring, while in other embodiments, the tubular woven mesh and the tubular coil spring may also be coaxially sleeved, and these reinforcing structures 3 may both play a role of reinforcing the strength of the inner pipe 1 and the outer pipe 2.

As a partially concrete practical example, the reinforcing structure 3 is constituted by a tubular woven mesh and a tubular coil spring, and the front end of the reinforcing structure is the tubular coil spring and the rear end of the reinforcing structure is the tubular woven mesh. The front end part of the reinforcing structure is formed by a cylindrical spiral spring, so that the supporting performance of the front end of the medical catheter can be improved, and the rear end of the reinforcing structure is formed by a cylindrical woven net, so that the bending resistance of the rear end of the medical catheter can be improved.

In some preferred embodiments, the stiffness of the reinforcing structure 3 decreases towards the distal end of the medical catheter. Through constantly reducing the rigidity that is close to the additional strengthening 3 of distal end, can make the utility model discloses a medical catheter is close to the position of distal end more, and its rigidity is lower and bending property is better, and then increases the utility model discloses the trafficability characteristic of medical catheter makes the utility model discloses a medical catheter can be applied to in the changeable blood vessel of crooked condition, accomplishes comparatively complicated operation.

Specifically, in order to make the rigidity of the reinforcing structure 3 variable, for the reinforcing structure 3 in the form of a woven mesh, the density of mesh openings of a portion closer to the distal end in the woven mesh may be made smaller, and thus, the bending property of a portion closer to the distal end of the woven mesh is better. For the reinforcing structure 3 in the form of a coil spring, the pitch of the portion closer to the distal end is larger, which also makes it possible to obtain better bending performance for the portion closer to the distal end.

In some embodiments, the material of the reinforcing structure 3 is selected from stainless steel, fiber or nickel-titanium alloy, the coil spring can be formed by winding round wire, flat wire or elliptical wire, and the mesh grid can be formed by weaving round wire, flat wire or elliptical wire.

As a specific example, the medical catheter of the present invention is manufactured by thermally melting the outer tube 2, the reinforcing structure 3 and the inner tube 1. In particular, the medical catheter of the utility model has the following steps when being manufactured,

(1) Sleeving the inner tube 1 on a fixed mandrel, wherein the surface of the fixed mandrel can be provided with lubricating coatings such as Polytetrafluoroethylene (PTFE) coatings and the like, so that the catheter can be conveniently pulled out after being formed; the material of the inner tube 1 can be Polyethylene (PE), high Density Polyethylene (HDPE), nylon material (PA) and other high polymer materials, and it should be noted that, when the medical catheter is an ultrasonic catheter, the PE, HDPE and PA materials can better transmit the ultrasonic wave emitted by the ultrasonic probe in the catheter to the outside of the catheter;

(2) Sleeving a reinforcing structure 3 outside the inner tube 1, wherein the length of the reinforcing structure 3 is smaller than that of the inner tube 1, two ends of the reinforcing structure 3 are fixed on the inner tube 1 by using heat shrinkable tubes, the fixed heat shrinkable tube material is a polyester resin (PET) heat shrinkable tube,

(3) Sleeving an outer pipe 2 on the surface of a reinforcing structure 3, wherein the length of the outer pipe 2 is smaller than that of an inner pipe 1, the outer pipe 2 is made of a material with a heating flow characteristic, and the initial outer diameter of the outer pipe 2 is larger than that of the inner pipe 1; the material of the outer tube 2 can be Pebax (Pebax 3533\ Pebax4033\ Pebax5033\ Pebax7233, etc.) with different hardness, or nylon material (PA 12), etc.;

(4) A layer of heat-shrinkable protective layer, typically a fluorinated ethylene propylene copolymer (FEP) heat-shrinkable material, is applied over the outer tube 2, and extends outwardly to cover part of the inner tube 1 as well as the outer tube 2,

(5) Heating and molding the heat-shrinkable protective layer;

during the heating, the pyrocondensation protective layer can shrink, and consequently, the pyrocondensation protective layer can wrap up outer tube 2 and inner tube 1 firmly, because the initial external diameter of outer tube 2 is greater than the external diameter of inner tube 1, the pyrocondensation protective layer can form domaticly in outer tube 2 and 1 juncture of inner tube. Because the outer tube 2 has the characteristic of heating flow, after the outer tube 2 is melted, the outer tube 2 can flow to the inner tube 1 through a gap in the middle of the heating structure 3 to be integrated with the inner tube 1, and on the other hand, under the constraint of the heat-shrinkable protective layer, the outer tube 2 can flow along the axial direction of the inner tube 1, the gap between the heat-shrinkable protective layer and the inner tube 1 is filled to form a tapered transition section, and the tapered transition section becomes the tapered section 21 of the outer tube 2 after cooling. After cooling, the thermal shrinkage protective layer is removed, and the medical catheter of the utility model can be obtained.

In some embodiments, the distal end of the inner tube 1 is further provided with a visualization structure. Through setting up the development structure at the distal end of inner tube 1, medical personnel can clearly judge the position of inner tube 1 in the human body through the development structure to medical personnel will more accurately the utility model discloses medical catheter propelling movement to target location improves operation efficiency and success rate.

It will be appreciated that the form of the development structure may be various, in some embodiments, the development structure may be a development ring made of development material, and in other embodiments, the end of the distal end of the inner tube 1 may be entirely doped with development material, so that the entire distal end of the inner tube 1 may be used for development, thereby improving the developability of the distal end of the inner tube 1. Specifically, the developing material may include, but is not limited to, tungsten powder, and may be powder made of radiopaque metal or metal compound such as gold, platinum, iridium, platinum-iridium alloy, barium sulfate, bismuth-based compound (bismuth oxide, bismuth trioxide, bismuth oxycarbonate, bismuth subcarbonate, bismuth tungstate), zirconium oxide, tantalum, cobalt-chromium alloy, tungsten-based compound (tungsten oxide, tungsten dioxide, tungsten trioxide), stainless steel, titanium, or the like.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only represent some embodiments of the present invention, and the description thereof is specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the concept of the present invention, several variations and modifications can be made, which all fall within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims (10)

1. A medical catheter, comprising an outer tube, an inner tube, and a reinforcing structure, wherein,

the outer tube has opposite proximal and distal openings, the outer tube having a tapered section that tapers in outer diameter toward the distal opening, the tapered section tapering to the distal opening;

the inner tube is arranged in the outer tube in a penetrating way, the inner tube extends outwards from the distal opening of the outer tube to form the distal end of the medical catheter, and the outer surface of the tapered section is smoothly transited with the outer surface of the inner tube;

the reinforcing structure is arranged in the outer pipe in a penetrating mode and connected with the inner pipe, and the reinforcing structure is limited in the far-end opening in the length direction.

2. The medical catheter of claim 1, wherein a tangent to a radially projected contour of the tapered section includes an angle of 0 ° to 5 ° with respect to the longitudinal axis.

3. The medical catheter of claim 2, wherein a tangent to a contour line of the tapered section projected in a radial direction of the medical catheter makes an angle of 2 ° to 3 ° with a longitudinal axis of the medical catheter.

4. The medical catheter of claim 1, wherein the axial length of the tapered section is greater than 20mm and less than 100mm.

5. The medical catheter of claim 4, wherein the axial length of the tapered section is greater than 50mm and less than 60mm.

6. The medical catheter of claim 1, wherein the reinforcing structure is located between and connected to both the inner and outer tubes.

7. The medical catheter of claim 6, wherein the outer tube, the reinforcing structure, and the inner tube are thermally fused.

8. The medical catheter of claim 1, wherein the stiffening structure decreases in stiffness toward the distal end of the medical catheter.

9. The medical catheter of claim 1, wherein the reinforcing structure is a tubular woven mesh and/or a tubular coil spring.

10. The medical catheter of claim 1, wherein the distal end of the inner tube is provided with a visualization structure.

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