CN116158805A

CN116158805A - Medical catheter and medical device

Info

Publication number: CN116158805A
Application number: CN202111407178.4A
Authority: CN
Inventors: 刘庆龙; 刘云云; 罗雪莉
Original assignee: Microport Neurotech Shanghai Co Ltd
Current assignee: Microport Neurotech Shanghai Co Ltd
Priority date: 2021-11-24
Filing date: 2021-11-24
Publication date: 2023-05-26

Abstract

The invention provides a medical catheter and a medical device, wherein the medical catheter comprises a catheter body and an electric heating element; the tube body comprises a main body part and an expansion part, and the expansion part is connected to the distal end of the main body part; the pipe wall of the pipe body comprises a metal layer and a sheath layer coated on the outer side of the metal layer, and the metal layer and the sheath layer extend to the distal end of the expansion part along the proximal end of the main body part; the electric heating element is used for heating the metal layer; the portion of the metal layer located at the expansion portion expands in the radial direction when heated to a predetermined temperature or higher, so that the expansion portion expands in the radial direction. When the medical catheter is used for sucking thrombus, the thrombus catching efficiency can be improved, and the thrombus escape can be reduced.

Description

Medical catheter and medical device

Technical Field

The invention relates to the technical field of medical instruments, in particular to a medical catheter and a medical device.

Background

Thrombus can cause blockage of blood vessels of a human body, cause partial blood supply deficiency, cause tissue dysfunction and necrosis, and harm the health and life of the human body. To solve this problem, there are currently aspiration techniques, mechanical thrombolysis and aspiration techniques in combination with mechanical thrombolysis for the interventional treatment of thrombi. The suction technique is based on the principle that after a medical catheter is delivered to the thrombus site, the thrombus is sucked and removed by using negative pressure. The mechanical thrombus taking principle is to utilize a conveying device to convey a thrombus taking mechanism to a thrombus position, and to take the thrombus through the jogged action of the thrombus taking mechanism and the thrombus. Aspiration technique in combination with mechanical thrombolysis refers to the removal of thrombus by a combination of aspiration technique and mechanical thrombolysis.

When using the suction technique, the improvement of the suction efficiency is the key to the improvement of the thrombus taking effect. The cross-sectional area of the inner cavity of the medical catheter used for sucking the thrombus is smaller than that of thrombus and blood vessel, so that the suction efficiency is low, thrombus can be possibly caused to escape, and the thrombus can not be smoothly and effectively sucked.

Disclosure of Invention

The invention aims to provide a medical catheter and a medical device, wherein the distal end of the medical catheter can be expanded to increase the cross-sectional area and improve the thrombus suction efficiency.

In order to achieve the above object, the present invention provides a medical catheter, comprising a catheter body and an electric heating element; the tube body comprises a main body part and an expansion part, and the expansion part is connected to the distal end of the main body part; the pipe wall of the pipe body comprises a metal layer and a sheath layer coated on the outer side of the metal layer, and the metal layer and the sheath layer extend to the distal end of the expansion part along the proximal end of the main body part; the electric heating element is used for heating the metal layer;

the portion of the metal layer located at the expansion portion expands in the radial direction when heated to a predetermined temperature or higher, so that the expansion portion expands in the radial direction.

Optionally, the metal layer includes first and second axially connected segments, the first segment being located in the main body portion, the second segment being located in the expansion portion, and the first segment being at least partially integrally formed with the second segment.

Optionally, the metal layer comprises a tubular mesh structure woven from wires; or the metal layer comprises a pipe network structure engraved by the pipe; alternatively, the metal layer comprises a spiral structure formed by spirally winding a wire material around the axis of the medical catheter.

Optionally, the wall of the pipe body further comprises a first lubrication layer disposed on an inner surface of the second section of the metal layer.

Optionally, the electric heating element comprises a first wire and a thermal resistor, and the first wire is arranged in the pipe wall of the pipe body and is connected with the thermal resistor; the first lead is used for transmitting electric energy provided by a power supply to the thermal resistor, and the thermal resistor is used for converting the electric energy into heat energy and transmitting the heat energy to the metal layer so that the metal layer is heated.

Optionally, the thermal resistor is disposed between the metal layer and the sheath layer, the sheath layer includes an outer sheath layer and a heat insulation layer, and the heat insulation layer is disposed on an inner surface of the outer sheath layer and at least covers the thermal resistor.

Optionally, a portion of the outer sheath located at the expansion portion is configured to have elasticity.

Optionally, the electric heating element includes a first wire, the first wire is disposed in a wall of the pipe body, and the first wire is used for transmitting electric energy provided by a power supply to the metal layer, and the metal layer converts the electric energy into heat energy and is heated.

Optionally, the first lead extends from the proximal end of the main body portion to the proximal end of the expansion portion, or the first lead extends from the proximal end of the main body portion to the interior of the expansion portion.

Optionally, the tube body has a press-holding state; when the pipe body is in the press-holding state, the outer diameter of the expansion part is smaller than or equal to the outer diameter of the main body part. Optionally, the wall of the pipe body further comprises a lining, and the lining is arranged on the inner surface of the metal layer and at least positioned on the main body part; and/or the number of the groups of groups,

the pipe wall of the pipe body further comprises a second lubricating layer, and the second lubricating layer is arranged on at least part of the outer surface of the sheath layer.

Optionally, the hardness of the body portion decreases gradually in a proximal-to-distal direction.

Optionally, the expansion portion is configured to be developable.

To achieve the above object, the present invention also provides a medical device comprising the medical catheter as set forth in any one of the preceding claims and a handle, the handle comprising a power supply portion for connection with the proximal end of the tube body, and the power supply portion for connection with the electric heating element.

Compared with the prior art, the medical catheter and the medical device have the following advantages:

the medical catheter comprises a catheter body and an electric heating element, wherein the catheter body comprises a main body part and an expansion part, and the expansion part is connected to the distal end of the main body part; the pipe wall of the pipe body comprises a metal layer and a sheath layer coated on the outer side of the metal layer, and the metal layer and the sheath layer extend to the distal end of the expansion part along the proximal end of the main body part; the electric heating element is used for heating the metal layer; the part of the metal layer positioned at the expansion part expands in the radial direction when being heated to a preset temperature, so that the expansion part expands in the radial direction, thereby increasing the cross section area of the expansion part, and effectively improving the suction efficiency of thrombus and reducing the escape of thrombus when the medical catheter is used for sucking thrombus.

Further, the metal layer comprises a first segment and a second segment which are axially connected, the first segment is located on the main body part, the second segment is located on the expansion part, and the first segment is at least partially integrally formed with the second segment, so that the pushing property and the bending property of the tube body are improved, and the expansion part of the medical catheter can more easily pass through a tortuous blood vessel and reach the position where a thrombus is located.

Drawings

The drawings are included to provide a better understanding of the invention and are not to be construed as unduly limiting the invention. Wherein:

FIG. 1 is a schematic view of a medical catheter according to an embodiment of the present invention, illustrating the medical catheter in a non-expanded state;

FIG. 2 is a partial cross-sectional view of a medical catheter provided in accordance with an embodiment of the present invention;

FIG. 3 is a schematic view of a medical catheter according to an embodiment of the present invention, illustrating the medical catheter in an expanded state;

FIG. 4 is a schematic view of a medical catheter according to an embodiment of the present invention, in which the shape of the expanded portion is different from that shown in FIG. 3;

fig. 5 is a schematic view of the structure of a handle of a medical device according to an embodiment of the present invention.

Reference numerals are described as follows:

100-of a pipe body, 101-of a main body part, 102-of an expansion part, 110-of a metal layer, 111-of a first section, 112-of a second section, 120-of a sheath layer, 121-of an outer sheath layer, 122-of a heat insulation layer, 130-of an inner liner, 140-of a second lubrication layer;

200-an electric heating element, 210-a first lead and 220-a thermal resistor;

300-a handle body;

400-power supply part, 410-power supply body, 420-second wire, 430-control switch.

Detailed Description

Other advantages and effects of the present invention will become apparent to those skilled in the art from the following disclosure, which describes the embodiments of the present invention with reference to specific examples. The invention may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present invention. It should be noted that, the illustrations provided in the present embodiment merely illustrate the basic concept of the present invention by way of illustration, and only the components related to the present invention are shown in the drawings and are not drawn according to the number, shape and size of the components in actual implementation, and the form, number and proportion of the components in actual implementation may be arbitrarily changed, and the layout of the components may be more complex.

In addition, each embodiment of the following description has one or more features, respectively, which does not mean that the inventor must implement all features of any embodiment at the same time, or that only some or all of the features of different embodiments can be implemented separately. In other words, those skilled in the art can implement some or all of the features of any one embodiment or a combination of some or all of the features of multiple embodiments selectively, depending on the design specifications or implementation requirements, thereby increasing the flexibility of the implementation of the invention where implemented as possible.

As used in this specification, the singular forms "a", "an" and "the" include plural referents, unless the content clearly dictates otherwise. As used in this specification, the term "or" is generally employed in its sense including "and/or" unless the content clearly dictates otherwise, and the terms "mounted," "connected," and "connected" are to be construed broadly, as for example, they may be fixed, they may be removable, or they may be integrally connected. Either mechanically or electrically. 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 above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

As used herein, the terms "proximal" and "distal" refer to the relative orientation, relative position, orientation of elements or actions relative to one another from the perspective of the physician using the medical device, although "proximal" and "distal" are not intended to be limiting, and "proximal" generally refers to the end of the medical device that is adjacent to the physician during normal operation, and "distal" generally refers to the end that first enters the patient.

The invention will be further described in detail with reference to the accompanying drawings, in order to make the objects, advantages and features of the invention more apparent. It should be noted that the drawings are in a very simplified form and are all to a non-precise scale, merely for convenience and clarity in aiding in the description of embodiments of the invention. The same or similar reference numbers in the drawings refer to the same or similar parts.

Fig. 1 and 3 are schematic structural views of a medical catheter according to an embodiment of the present invention, and fig. 2 is a partial sectional view of the medical catheter.

As shown in fig. 1 to 3, the medical catheter includes a tube body 100 and an electric heating element 200. The tube body 100 includes a main body portion 101 and an expansion portion 102, as viewed in the axial direction, the expansion portion 102 being connected to the distal end of the main body portion 101. The pipe wall of the pipe body 100 includes a metal layer 110 and a sheath layer 120 covering the metal layer 110, and the metal layer 110 and the sheath layer 120 extend from the proximal end of the main body 101 to the distal end of the expansion portion 102. The heating element 200 is used to heat the metal layer 110. The portion of the metal layer 110 located in the main body portion 101 is referred to herein as a first segment 111, and the portion of the metal layer 110 located in the expansion portion 102 is referred to herein as a second segment 112. When the second segment 112 is heated to a predetermined temperature, the second segment 112 expands radially to radially expand the expansion 102.

The medical catheter may be used to introduce into a blood vessel and aspirate thrombus in the blood vessel. In operation, the heating element 200 may be configured to receive electrical energy from the outside, the electrical energy being configured to heat the metal layer 110. When the temperature of the second section 112 of the metal layer 110 rises above the predetermined temperature, the second section 112 expands radially to an expanded configuration, so that the expanded portion 102 expands, and the cross section of the expanded portion 102 expands, and at this time, suction of the thrombus starts, which can improve the thrombus extraction efficiency and reduce thrombus escape.

In other words, the medical catheter has a non-expanded state and an expanded state. When the temperature of the second section 112 of the metal layer 110 is below the predetermined temperature, the medical catheter is in the unexpanded state, and the outer diameter of the expanded portion 102 is less than or equal to the outer diameter of the main body portion 101. When the second segment 112 is heated above the predetermined temperature, the second segment 112 switches to the expanded configuration and causes the outer diameter of the expanded portion 102 to be greater than the outer diameter of the main body portion 101 to switch the medical catheter to the expanded state. The shape of the second segment 112 may be tapered (as shown in fig. 3) with a cross-section that increases distally along the proximal end, hemispherical, or a distal portion of the second segment 112 may be cylindrical (as shown in fig. 4), or other shape, as the second segment 112 is in the expanded configuration, as embodiments of the invention are not limited in this respect. When the expansion portion 102 is expanded, the outer diameter thereof may be 0.5mm to 50mm.

The metal layer 110 is fabricated from a shape memory alloy and the second segment 112 may be heat set to an expanded configuration using any suitable means, such as an atmospheric heat treatment furnace, salt bath heat treatment, or flame spray gun. Thus, when the second segment 112 is heated above the predetermined temperature, the second segment 112 is in the expanded configuration, and when the second segment 112 is cooled below the predetermined temperature, the second segment 112 radially contracts to return the medical catheter to the unexpanded state. The shape memory alloys include, but are not limited to, nickel titanium alloys. The predetermined temperature is typically higher than the temperature of the body fluid (e.g., higher than 37 ℃), alternatively the predetermined temperature may be 60-70 ℃.

Optionally, in the embodiment of the present invention, the non-expanded state includes two situations, one of which is a natural state and the other of which is a press-holding state. The natural state refers to a state in which all areas of the pipe body 100 are not subjected to a radial pressing force. The press-and-hold state refers to a state in which the expansion portion 102 is subjected to a radial pressing force during processing, so that the expansion portion 102 is compressed to have a smaller outer diameter. It will be appreciated that the expansion 102 may remain in the press-and-hold condition when the radial compressive force is unloaded. In practice, the medical catheter can be delivered into the blood vessel by a delivery mechanism, and the medical catheter is in the press-holding state during the delivery process. And the ratio of the outer diameter of the expansion part 102 to the outer diameter of the main body part 101 is 0.1 to 1.0. In fact, the smaller the outer diameter of the flared portion 102 in the crimped state, the more advantageous the delivery of the medical catheter. Alternatively, the outer diameter of the main body portion 101 may be 0.5mm to 50mm and the outer diameter of the expanding portion 102 may be 0.1mm to 50mm when the medical catheter is in the press-held state. In addition, when the medical catheter is in the natural state, the outer diameter of the expansion portion 102 may be smaller than or equal to the outer diameter of the main body portion 101, and the length of the expansion portion 102 may be 2mm to 1000mm.

In use, the delivery mechanism is used to first deliver the dilating portion 102 of the medical catheter to the thrombus, and then the sheath (for example, the delivery mechanism includes a sheath and the medical catheter is delivered into the body through the lumen of the sheath) is retracted and at least the dilating portion 102 is released. In some embodiments, the medical catheter is completely released (i.e., the sheath is withdrawn from the body). The second segment 112 is then heated using the electrical heating element 200 to expand the expansion 102. The thrombus may then be aspirated, and after the thrombus removal procedure is completed, heating of the second section 112 is stopped and the second section 112 is allowed to cool, and the medical catheter is withdrawn after the expansion portion 102 has radially contracted to the unexpanded state. Alternatively, in other embodiments, only the expansion portion 102 may be released while the sheath is withdrawn, and the main body portion 101 remains inside the sheath (i.e., the sheath is not completely withdrawn from the body), after the removal of the thrombus is completed, the sheath may be pushed forward (i.e., the sheath is moved in a proximal-to-distal direction), and the expansion portion 102 may be recovered back inside the sheath, and then the sheath and the medical catheter are withdrawn from the body together.

In this embodiment of the present invention, the metal layer 110 may include a tubular mesh structure woven from wires, or the metal layer 110 includes a tubular mesh structure engraved from a metal tube, or the metal layer 110 includes a spiral structure formed by spirally winding wires around an axis of the medical catheter. When the metal layer 110 is a pipe network structure, the shape of the mesh on the metal layer 110 may be at least one of prismatic, hexagonal, parallelogram, circular, elliptical, square, and irregular. In some embodiments, the first section 111 and the second section 112 of the metal layer 110 may have different structures, for example, the first section 111 is a tubular mesh structure woven by wires, and the second section 112 is a spiral structure spirally wound by wires around the axis of the medical catheter.

Preferably, the first section 111 is partially integrally formed with the second section 112, or the first section 111 is entirely integrally formed with the second section 112. In so doing, the push performance and the over-bending performance of the medical catheter can be improved, which is advantageous for the expanded portion 102 to pass through a tortuous blood vessel and reach the location of a thrombus. Here, the first segment 111 is partially integrally formed with the second segment 112, and it means that the first segment 111 includes at least two sub-segments (shown in the drawing), wherein one of the sub-segments located at the most distal end is integrally formed with the second segment 112, that is, one of the sub-segments located at the most distal end is integrally woven with the second segment 112, or is engraved from the same metal tube, or is coiled from the same strand of wire, and the other sub-segments are formed separately, and then all sub-segments are connected by any suitable means to form the complete metal layer 110. And, the first section 111 and the second section 112 are all integrally formed, which means that the first section 111 and the second section 112 are integrally woven and formed, or are engraved and formed by the same metal tube, or are coiled by the same strand of wire.

Referring back to fig. 2, the electric heating element 200 is disposed inside the pipe wall of the pipe body 100, and includes a first conductive wire 210 and a thermal resistor 220. The first conductive wire 210 extends along the axial direction of the pipe body 100, the thermal resistor 220 may be disposed at the second section 112, for example, disposed at the second section 112 near the first section 111, and the thermal resistor 220 is connected to the distal end of the first conductive wire 210. The proximal end of the first wire 210 is used for being connected to an external power source, receiving the electric energy provided by the external power source, and transmitting the electric energy to the thermal resistor 220, and the thermal resistor 220 converts the electric energy into heat energy and transmits the heat energy to the metal layer 110, so that the second segment 112 is heated above the predetermined temperature. It is understood that the thermal resistor 220 may or may not be directly connected to the metal layer 110, so long as the thermal energy is capable of being transferred to the second segment 112.

With continued reference to fig. 2, the sheath 120 includes at least an outer sheath 121, and the outer sheath 121 may be made of the same or different materials throughout the length of the tube 100. It will be appreciated that the outer sheath 121 may include axially connected third and fourth segments, the third segment being located at the main body portion 101 and the fourth segment being located at the expansion portion 102. Wherein the material of the fourth section is soft and elastic, and can be any one of polyurethane, high-elasticity polytetrafluoroethylene, polyethylene and silica gel. It will also be appreciated that the third and fourth segments may be integrally or separately formed, with the proximal end of the fourth segment extending a predetermined length toward the third segment when the third and fourth segments are separately formed so that the third and fourth segments partially overlap and then fixedly attached to the fourth segment by heat shrinking, gluing, welding or any other suitable means.

The thermal resistor 220 may be disposed between the sheath layer 120 and the metal layer 110, and the sheath layer 120 preferably further includes a heat insulation layer 122, and the heat insulation layer 122 is disposed on an inner surface of the outer sheath 121 and covers at least the thermal resistor 220. This is because the temperature at the thermal resistor 220 is relatively high, which if in direct contact with the outer jacket 121 will cause the outer jacket 121 to soften by excessive heating, affecting the overall performance of the pipe body 100. Of course, the insulating layer 122 may also cover at least a portion of the outer surface of the metal layer 110. In other implementations, the wall of the pipe body 100 further includes an inner liner 130, and the inner liner 130 is disposed on the inner surface of the metal layer 110 and at least at the main body 101. The material of the liner 130 may be PTFE, polyurethane, low density polyethylene, or the like. In these implementations, the thermal resistor 220 may also be disposed between the metal layer 110 and the first lubrication layer 130. The thermal resistor 220 may be in direct contact with the first lubricant layer 130 due to the higher melting point of PTFE. In addition, according to the arrangement position of the thermal resistor 220, the first conductive line 210 may be partially disposed between the metal layer 110 and the sheath layer 120, or partially disposed between the metal layer 110 and the first lubricant layer 130, or by being interposed at the mesh (or aperture) of the metal layer 110 such that a portion of the first conductive line 210 is located between the metal layer 110 and the sheath layer 120 and another portion is located between the metal layer 110 and the first lubricant layer 130. In addition, the first conductive wire 210 may be disposed in a straight line in the wall of the pipe body 100, or may be spirally wound around the axis of the pipe body 100 in a spiral structure. And, the wall of the first pipe body 100 further includes a first lubrication layer (not shown in the drawing) disposed on the inner surface of the second section 112 of the metal layer 110, and the first lubrication layer may be a PTFE coating.

It should be noted that the number of the first wires 210 may be two, the distal ends of the two first wires 210 are both connected to the thermal resistor 220, the proximal end of one first wire 210 is used for being connected to the positive electrode of the power supply, and the proximal end of the other first wire 210 is used for being connected to the negative electrode of the power supply.

It should be noted that the thermal resistor 220 is not a necessary component. In other words, in an alternative embodiment, the electric heating element 200 may include only the first conductive wire 210, where the distal end of the first conductive wire 210 is directly connected to the metal layer 110, preferably, the distal end of the first conductive wire 210 is connected to the second section 112 near the first section 111, and when the first conductive wire 210 is electrically connected to an external power source, the first conductive wire 210 conducts the electric energy provided by the power source to the metal layer 110, and the metal layer 110 converts the electric energy into heat energy under the effect of its own resistance, so that the metal layer 110 is heated. In addition, in the embodiment of the present invention, the hardness of the main body 101 gradually decreases in the direction from the proximal end to the distal end, so as to further improve the pushability and bending performance of the main body 101. To achieve this, in an alternative implementation, the portion of the outer sheath 121 located on the main body 101 may be composed of a plurality of materials, and the plurality of materials may be arranged in a proximal-to-distal direction in order of hardness from greater to lesser. The specific materials can be high molecular polymers of the same type but with different brands. It will be appreciated that the various portions of the outer sheath 121 formed of different materials may be connected by heat fusion or any other suitable means, and further, each portion of the outer sheath 121 may be a dense mesh structure formed by electrospinning, which may be connected to the metal layer 110 by heat fusion welding or sewing, or the outer sheath 121 may be a coating structure dip-coated or sprayed on the metal layer 110. The outer sheath 121 should be smooth and wrinkle-free, regardless of how the outer sheath 121 is shaped.

Alternatively, the hardness of the main body 101 may be changed as required by appropriately configuring the parameters of the first segment 111 of the metal layer 110. For example, when the metal layer 110 is formed by braiding or spirally winding a wire, the cross section of the wire may gradually decrease in a proximal-to-distal direction, the cross section of the wire may be any suitable shape such as circular, square, semicircular, trapezoid, etc., and the outer diameter (when the cross section of the wire is circular or semicircular) or side length (when the cross section of the wire is square or other polygonal) may be 0.0005 "to 0.008". When the metal layer 110 is engraved from a metal tube, the thickness of the metal tube may decrease in a proximal-to-distal direction, the thickness of the metal tube may be 0.0005 "to 0.008", and the inner diameter of the metal tube may be 0.2mm to 50mm.

Preferably, the wall of the pipe body 100 further includes a second lubrication layer 140, and the second lubrication layer 140 is disposed on the outer surface of the sheath layer 120 and at least located on the expansion portion 102. The second lubricious layer 140 includes, but is not limited to, a hydrophilic coating to reduce friction of the medical catheter during pushing.

Preferably, the expansion portion 102 is further configured to be developable to facilitate determining the position of the expansion portion 102 within a blood vessel. There are various options for realizing the developability of the expansion portion 102, for example, a radiopaque metal may be provided on at least a part of the area of the second section 112, the thickness of the radiopaque metal may be 5um to 500um, and the length of the radiopaque metal in the axial direction of the tube body 100 may be 0.5mm to 50mm. The radiopaque metal may be disposed on the second section 112 by electroless plating, electroplating, vacuum spraying, ion implantation, or the like. The radiopaque metals include, but are not limited to, tungsten and its alloys, platinum and its alloys, tantalum and its alloys, palladium and its alloys, gold and its alloys, silver and its alloys, and the like. For another example, a developing mark tape having a thickness of 0.0005 "to 0.01" and a length of 0.5mm to 10mm in the axial direction of the tube body 100 is coated on at least a part of the area of the second segment 112. For another example, a developing compound including, but not limited to, a barium salt or bismuth salt is mixed into the material of the outer sheath 121 at the expansion portion 102.

The medical catheter is further described herein with reference to specific examples.

Example 1

Referring to fig. 3, in the present embodiment, the second section 112 in the expanded configuration is tapered with a cross section gradually increasing radially and distally, and the first section 111 and the second section 112 are formed by carving the same nitinol tube with laser, and the mesh has a polygonal shape.

When the medical catheter is in a natural state, the outer diameters of the expansion part 102 and the main body part 101 are 4.0mm, and the length of the expansion part 102 is 20mm. The maximum outer diameter of the expansion 102 is 6.0mm when the medical catheter is in an expanded state. When the expansion part 102 is subjected to a radial pressing force and the medical catheter is in a press-grip state (i.e., the expansion part 102 is press-gripped and the main body part 101 is not press-gripped), the outer diameter of the expansion part 102 is 2.0mm (at this time, the outer diameter of the main body part 101 is still 4.0 mm).

Further, the first conductive wire 210 is disposed in a linear shape in the wall of the pipe body 100, and the material of the portion of the outer sheath 121 located at the expansion portion 102 is a polyurethane film having elasticity, and bismuth titanate is mixed therein to enable the expansion portion 102 to be developed. The first lubrication layer (not shown in fig. 3) extends along the proximal end of the main body portion 101 to the distal end of the expansion portion 102. In addition, when the third section and the fourth section of the outer sheath 121 are formed separately, the predetermined length of the proximal end of the fourth section extending toward the third section may be 40mm.

< example two >

Referring to fig. 4, in this embodiment, when the second segment 112 is in the expanded configuration, the second segment 112 includes a proximal portion and a distal portion, the proximal portion being a tapered transition region with a cross-section that increases gradually from proximal to distal, and the distal portion being cylindrical.

In this embodiment, the first section 111 and the second section 112 are integrally woven from nickel-titanium alloy wires with a diameter of 0.003", and the mesh is diamond-shaped. When the medical catheter is in the natural state, the length of the expansion part 102 is 50mm, and the outer diameters of the expansion part 102 and the main body part 101 are 3.6mm. When the expansion 102 is in the expanded state, the maximum outer diameter of the expansion 102 (i.e., the outer diameter of the distal portion of the expansion 102) is 5.0mm. When the expansion part 102 is subjected to the radial pressing force and the medical catheter is in the press-holding state (i.e., the expansion part 102 is pressed and the main body part 101 is not pressed), the outer diameter of the expansion part 102 is 3.0mm (the outer diameter of the main body part 101 is still 3.6 mm)

Further, the material of the portion of the outer sheath 121 located at the expansion portion 102 is elastic polytetrafluoroethylene, and when the third section and the fourth section of the outer sheath 121 are molded separately, the predetermined length of the proximal end of the fourth section extending toward the third section may be 70mm. A gold plating is provided on a portion of the outer surface of the second segment 112 to render the expansion 102 developable.

Further, the embodiment of the invention also provides a medical device which comprises a handle and the medical catheter. The structure of the handle is shown in fig. 5, and specifically includes a handle body 300 and a power supply unit 400 provided on the handle body 300. The handle is used to connect with the proximal end of the tube 100, and the power supply part 400 is used to connect with the electric heating element 200 (specifically, the proximal end of the first wire 210) to supply electric power to the electric heating element 200. The power supply part 400 may specifically include a power supply body 410, a second wire 420, and a control switch 430, where the power supply body 410, the second wire 420, the first wire 210, the thermal resistor 220 (when the thermal resistor 220 is present), and the control switch 430 are sequentially connected in series.

Although the present invention is disclosed above, it is not limited thereto. Various modifications and alterations of this invention may be made by those skilled in the art without departing from the spirit and scope of this invention. Thus, it is intended that the present invention also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

Claims

1. A medical catheter, which is characterized by comprising a catheter body and an electric heating element; the tube body comprises a main body part and an expansion part, and the expansion part is connected to the distal end of the main body part; the pipe wall of the pipe body comprises a metal layer and a sheath layer coated on the outer side of the metal layer, and the metal layer and the sheath layer extend to the distal end of the expansion part along the proximal end of the main body part; the electric heating element is used for heating the metal layer;

2. The medical catheter of claim 1, wherein the metal layer comprises first and second axially connected segments, the first segment being located in the main body portion, the second segment being located in the flared portion, and the first segment being at least partially integrally formed with the second segment.

3. The medical catheter according to claim 1 or 2, wherein the metal layer comprises a mesh-like structure woven from wire; or the metal layer comprises a pipe network structure engraved by the pipe; alternatively, the metal layer comprises a spiral structure formed by spirally winding a wire material around the axis of the medical catheter.

4. The medical catheter of claim 2, wherein a wall of the tube further comprises a first lubricious layer disposed on an inner surface of the second section of the metal layer.

5. The medical catheter of claim 1, wherein the electrical heating element comprises a first lead and a thermal resistor, the first lead being disposed in a wall of the tube body and connected to the thermal resistor; the first lead is used for transmitting electric energy provided by a power supply to the thermal resistor, and the thermal resistor is used for converting the electric energy into heat energy and transmitting the heat energy to the metal layer so that the metal layer is heated.

6. The medical catheter of claim 5, wherein the thermal resistor is disposed between the metal layer and the sheath layer, the sheath layer comprising an outer sheath and a thermally insulating layer disposed on an inner surface of the outer sheath and covering at least the thermal resistor.

7. The medical catheter of claim 6, wherein a portion of the outer sheath located at the flared portion is configured to be resilient.

8. The medical catheter of claim 1, wherein the electrical heating element comprises a first wire disposed in a wall of the tube body, and wherein the first wire is configured to transfer electrical energy provided by a power source to the metal layer, and wherein the metal layer converts the electrical energy into thermal energy and is heated.

9. The medical catheter of claim 5 or 8, wherein the first guide wire extends from the proximal end of the main body portion to the proximal end of the dilating portion, or wherein the first guide wire extends from the proximal end of the main body portion to the interior of the dilating portion.

10. The medical catheter of claim 1, wherein the tube has a crimped state; when the pipe body is in the press-holding state, the outer diameter of the expansion part is smaller than or equal to the outer diameter of the main body part.

11. The medical catheter of claim 1, wherein the tube wall of the tube further comprises a liner disposed on the inner surface of the metal layer and at least on the main body portion; and/or the number of the groups of groups,

12. The medical catheter of claim 1, wherein the hardness of the body portion decreases progressively in a proximal-to-distal direction.

13. The medical catheter of claim 1, wherein the dilating portion is configured to be developable.

14. A medical device comprising a medical catheter according to any one of claims 1 to 13 and a handle, the handle comprising a power supply portion, the handle being adapted to be connected to the proximal end of the tube and the power supply portion being adapted to be connected to the electrical heating element.