Conveying micro-catheter

Abstract

The invention provides a conveying micro catheter, and belongs to the technical field of interventional medical instruments. The conveying micro-catheter comprises a catheter body, the catheter body is provided with an axially-extending conveying catheter cavity, and the far end of the catheter body is provided with a radial expansion component so that the far end of the catheter body can keep a set distance from the blood vessel wall in the advancing process in the blood vessel; the radial expansion component comprises a plurality of supporting strips arranged in the circumferential direction of the catheter body at intervals, each supporting strip is sequentially provided with an expansion section and a supporting section which are integrally arranged from the far end to the near end, the far end of each expansion section is fixedly connected with the catheter body, and each supporting section extends into the side wall of the catheter body and is in sliding fit with the side wall of the catheter body. The supporting section slides towards the far end, so that the expansion section protrudes in the direction away from the catheter body and is used for supporting a blood vessel, and it is guaranteed that the catheter body smoothly passes through the special position of the blood vessel. The conveying microcatheter is mainly used for solving the technical problem that in the conveying process of an existing conveying microcatheter, the windowsill effect is prone to occurring.

Description

Technical Field

[0001] This invention belongs to the field of interventional medical device technology, specifically relating to a delivery microcatheter. Background Technology

[0002] Acute ischemic stroke (AIS) is a leading cause of death and disability worldwide. Its core pathogenic mechanism is primarily cerebral ischemia-hypoxia damage caused by acute occlusion of large intracranial vessels. Timely restoration of blood flow to the ischemic area is a key treatment principle. In endovascular interventional therapy, thrombus aspiration catheters, with their ability to rapidly remove thrombi, have become one of the cornerstone devices for treating large vessel occlusion-type AIS, providing crucial support for saving patients' lives and reducing the risk of disability.

[0003] This type of device is essentially a transvascular interventional tubular device based on the principle of negative pressure suction. By locating and establishing a negative pressure environment inside the blood vessel, it directly extracts the thrombus blocking the blood vessel from the body, thereby quickly restoring vascular patency.

[0004] However, in the clinical application of thrombus aspiration catheters, especially in the crucial step of delivering them to the target thrombus location in the brain via a microcatheter, the "windowsill effect" can easily occur. Specifically, the "windowsill effect" refers to the phenomenon where, when the microcatheter is advanced to a narrow or angled branch (daughter vessel) location in the intracranial blood vessel, the tip of the microcatheter can easily interact unexpectedly with the vessel wall in that area due to the special anatomical morphology of the vessel or the characteristics of the microcatheter itself (the branch opening forming a "windowsill"-like structure with the main vessel wall, or the step structure easily forming at the distal end of the microcatheter due to the large difference in diameter between the guidewire and the microcatheter). This can lead to physical phenomena such as jamming, obstruction, or the tip deviating from the target vessel. This common clinical problem is defined as the "windowsill effect."

[0005] The adverse consequences of the "windowsill effect" have significant clinical hazards: On the one hand, if the surgeon forcibly pushes the delivery catheter to overcome the obstruction, the hard contact between its tip and the blood vessel wall can easily scratch or even tear the vascular intima, leading to serious complications such as vascular dissection. When the pushing force is too great, it may even directly puncture the blood vessel wall, causing fatal bleeding events such as subarachnoid hemorrhage, significantly increasing the patient's surgical and prognostic risks. On the other hand, to avoid the above risks, the surgeon often needs to repeatedly withdraw the delivery catheter, adjust its angle and path of advancement, and repeatedly attempt to pass through. This back-and-forth adjustment process significantly prolongs the surgical operation time. The extended surgical time not only means delayed perfusion recovery of the patient's ischemic brain tissue but may also aggravate neurological damage, leading to a significant increase in the time spent on core medical resources such as the operating room, anesthesia team, and medical staff.

[0006] Therefore, there is a need to provide an improved technical solution that addresses the shortcomings of the existing technology. Summary of the Invention

[0007] The purpose of this invention is to provide a delivery microcatheter to solve the technical problem that the existing delivery microcatheter is prone to the "windowsill effect" during delivery.

[0008] To achieve the above objectives, the delivery microcatheter of the present invention provides the following technical solution: A delivery microcatheter includes a catheter body having an axially extending delivery lumen and a radially expanding member at the distal end of the catheter body to maintain a predetermined distance between the distal end of the catheter body and the vessel wall during its travel within the blood vessel. The radial expansion component includes multiple support strips arranged circumferentially along the catheter body. Each support strip has an integrally formed expansion section and a support section from the distal end to the proximal end. The distal end of the expansion section is fixedly connected to the catheter body. The support section extends into the side wall of the catheter body and slides in cooperation with the side wall of the catheter body. The support section slides distally, causing the expansion section to bulge away from the catheter body to support the blood vessel, thereby ensuring that the catheter body can smoothly reach the target position.

[0009] As a further optimized technical solution, the support section is covered with an elastic protective layer structure to reduce the damage of the support strip to the blood vessels.

[0010] As a further optimized technical solution, the elastic protective layer structure is collectively sleeved on the outside of each of the support bars, so that the expansion state of the radial expansion component is a bladder-like structure.

[0011] As a further optimized technical solution, the elastic protective layer structure is respectively sleeved on the outside of each of the support bars, so that the expansion state of the radial expansion component is a cage-like structure.

[0012] As a further optimized technical solution, the catheter body is provided with a driving component to drive the radial expansion and contraction of the support strip.

[0013] As a further optimized technical solution, the driving component includes multiple sets of magnetic blocks and electromagnets, the same number as the support bars. In each set of the driving component, the magnetic blocks are arranged on the side of the support bar facing the conduit body, and the electromagnets are arranged on the conduit body opposite to the magnetic blocks.

[0014] As a further optimized technical solution, a multi-way valve is provided at the proximal end of the catheter body. The multi-way valve has a main channel and a branch channel. The main channel is used to connect the delivery lumen, and the electrical wire of the electromagnet is used to extend out from the branch channel to connect to external control equipment.

[0015] As a further optimized technical solution, the catheter body is provided with a support layer and a protective layer from the inside out. The distal end of the support layer has an extension section that extends a predetermined distance beyond the protective layer, and the expansion section of the support strip is provided on the extension section.

[0016] As a further optimized technical solution, the protective layer has an axially arranged sliding channel, and the support bar is slidably disposed within the sliding channel.

[0017] As a further optimized technical solution, the proximal end of the sliding channel is connected to an annular receiving cavity, and an elastic reset member is arranged inside the annular receiving cavity. The proximal end of the support bar is fixedly connected to the elastic reset member.

[0018] Beneficial effects: By setting a radial expansion component at the distal end of the catheter body, this invention can actively "suspend" the catheter tip within the blood vessel during passage through special locations, maintaining a safe distance from the vessel wall. This fundamentally avoids hard contact and jamming between the catheter tip and the vessel wall (especially at the opening of branch vessels), thus ensuring smooth delivery. This invention eliminates the need for the surgeon to forcibly push the catheter through complex anatomical structures, greatly reducing the risk of scratching the vascular intima, causing vascular dissection or perforation. It also effectively avoids repeated attempts to pass through complex blood vessels, significantly shortening the operation time, facilitating early blood flow recanalization, improving patient prognosis, and saving valuable medical resources.

[0019] Furthermore, the elastic protective layer structure further buffers the contact force between the support strip and the blood vessel wall, improves the biocompatibility and safety of the radial expansion component, and can effectively reduce the risk of damage to the vascular intima by the support strip, thereby reducing the probability of complications such as vascular dissection and bleeding.

[0020] Furthermore, through electromagnetic drive, the radial expansion component can be precisely and rapidly expanded and contracted. The operator can adjust the support status in real time according to the vascular anatomy, making the operation intuitive and responsive. Attached Figure Description

[0021] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. Wherein: Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of the microcatheter delivery method of the present invention. At this time, the radial expansion component is in a contracted state. Figure 2 This is another overall structural schematic diagram of embodiment 1 of the microcatheter delivery of the present invention. In this case, the radial expansion component is in an expanded state. Figure 3 for Figure 2 A cross-sectional view along the AA direction; Figure 4 for Figure 2 A cross-sectional view along the BB direction; Figure 5 This is a schematic diagram of the overall structure of Embodiment 2 of the microcatheter delivery method of the present invention; Figure 6 for Figure 5 A cross-sectional view along the CC direction; Figure 7 This is a schematic diagram of the overall structure of Embodiment 3 of the microcatheter delivery method of the present invention.

[0022] In the diagram: 100, catheter body; 110, delivery lumen; 120, support layer; 130, protective layer; 131, sliding channel; 140, annular receiving cavity; 200, radial expansion component; 210, support bar; 300, elastic protective layer structure; 400, driving component; 410, magnet; 420, electromagnet; 500, multi-way valve; 510, main channel; 520, branch channel; 600, elastic reset component; 700, imaging ring. Detailed Implementation

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0024] In the description of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and do not require the invention to be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention. The terms "connected" and "linked" used in this invention should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; they can refer to a direct connection or an indirect connection through intermediate components. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances. Furthermore, the term "proximal end" uniformly refers to the end closer to the operator, while "distal end" refers to the end farther from the operator.

[0025] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0026] The shapes and sizes of the components in the accompanying drawings do not reflect the actual proportions of the product; they are only intended to illustrate the content of the invention.

[0027] This invention provides a delivery microcatheter, primarily addressing the technical problem of the "windowsill effect" that easily occurs in special locations within blood vessels with existing delivery microcatheters. The delivery microcatheter includes a catheter body 100 with an axially extending delivery lumen 110. A radial expansion component 200 is located at the distal end of the catheter body 100. The radial expansion component 200 is composed of multiple circumferentially spaced support strips 210. Each support strip 210 has a distally fixed expansion section and a slidable support section extending into the catheter sidewall. By driving the support section to slide distally, the expansion section protrudes outward, forming a support structure. This ensures that the distal end of the catheter body 100 maintains a predetermined distance from the vessel wall as it travels within the blood vessel, thus facilitating smooth passage through narrow, angular, and other special locations within the vessel and effectively preventing jamming and vascular damage. This invention, through the radial expansion component, maintains a predetermined distance between the distal end of the catheter and the vessel wall, effectively preventing jamming, reducing the risk of vascular damage, adapting to different vascular scenarios, and ensuring the smooth delivery of thrombus aspiration catheters.

[0028] Example 1 like Figure 1As shown, the delivery microcatheter includes a catheter body 100 with an axially extending delivery lumen 110. This lumen 110 is used to accommodate and deliver therapeutic instruments such as thrombus aspiration catheters, providing a channel for the instruments to travel within the blood vessel. A radial expansion member 200 is provided at the distal end of the catheter body 100. This radial expansion member 200 can protrude away from the axis of the catheter body 100 when needed, thereby maintaining a predetermined safe distance between the distal end of the catheter body 100 and the vessel wall, preventing the tip of the catheter body 100 from directly contacting the vessel wall and causing jamming. It should be noted that there is no fixed standard for the "predetermined distance" between the distal end of the catheter body 100 and the vessel wall; it must be flexibly selected based on the specific conditions of the blood vessel during surgery. The core principle is: in special locations such as vascular stenosis or angular branch openings, the surgeon, through fluoroscopic observation, ensures that the tip of the catheter body 100 does not directly adhere to the vessel wall and can safely pass through the area without jamming or hard friction. In addition, the specific range of the "set distance" can be dynamically adjusted by the expansion amplitude of the radial expansion component 200: if the blood vessel diameter is large or the vessel wall has good elasticity, the expansion amplitude can be appropriately increased to maintain stable support; if the blood vessel diameter is small or the vessel wall is fragile, the protrusion amplitude of the support strip 210 can be controlled to avoid excessive compression of the blood vessel wall while meeting the requirement of "not sticking to the wall".

[0029] Specifically, the radial expansion component 200 includes multiple (e.g., 4-8) support bars 210 arranged circumferentially along the catheter body 100. The support bars 210 are made of shape memory materials such as nickel-titanium alloy, and their cross-section is an arc centered on the axis of the catheter body 100, possessing both good elasticity and support strength, and can stably maintain the set shape after deformation. The support bars 210 are divided into an integrally formed expansion section and a support section from the distal end to the proximal end. The distal end of the expansion section is fixedly connected to the distal end of the catheter body 100, while the support section extends into the side wall of the catheter body 100 and forms a sliding fit structure with the side wall. When the support section slides distally along the axial direction of the catheter body 100, the exposed expansion section at the distal end protrudes away from the catheter body 100 due to the thrust at both ends, forming a support structure. It achieves support and positioning through flexible contact with the blood vessel wall, ensuring that the catheter body 100 can pass smoothly through special positions such as narrowing and angulation of blood vessels. When the support section slides proximally, the expansion section returns to the contracted state that fits the catheter body 100, which facilitates the retraction of the catheter body 100 or its travel in straight sections.

[0030] To achieve drive control of the protrusion and contraction states of the support bar 210, a drive component 400 is provided on the catheter body 100. The drive component 400 includes multiple sets of magnetic blocks 410 and electromagnets 420, the same number as the support bar 210. In each set, the magnetic blocks 410 are fixed on the side of the support bar 210 facing the catheter body 100, specifically in the middle of the expansion section along its length. The electromagnets 420 are correspondingly disposed in the side wall of the catheter body 100, opposite to the magnetic blocks 410. By adjusting the current direction of the electromagnets 420 through an external control device, the magnetic poles of the electromagnets 420 can be changed, thereby achieving attraction or repulsion with the magnetic blocks 410: when the electromagnets 420 and the magnetic blocks 410 generate a repulsive force, they push the support section of the support bar 210 to slide distally, causing the expansion section to expand; when an attractive force is generated, it pulls the support section to slide proximally, cooperating with the elastic reset component 600 to achieve rapid contraction of the expansion section. Furthermore, this driving method ensures that when the support bar 210 expands, the expansion force is mainly concentrated at the position opposite the magnet 410 and the electromagnet 410. The biggest difference between this and commonly used fluid-inflated balloons is that the deformation location is specific. While the fluid pressure drives the balloon to expand radially, it also generates a component force along the axial direction of the catheter body 100, causing axial tensile deformation of the balloon. This redundant axial deformation is extremely dangerous in the "windowsill effect" scenario. For example, when the balloon expands at the branch opening, axial tension will cause the catheter tip to shift distally towards the main vessel, further deviating from the target branch opening. If the catheter body 100 is advanced to correct this shift, the axial compression of the balloon may trigger radial contraction, resulting in a loss of support. In contrast, the support section of the support bar 210 is slidably positioned within the catheter body 100, and the channel forms a strict axial constraint on the support bar 210, ensuring that the driving force transmitted by the electromagnet 420 and the magnet 410 is completely converted into radial expansion force, with no axial force loss. Meanwhile, the expansion section of the support bar 210 is fixed to the distal end of the catheter body 100. When the support section slides to the distal end, it only causes the expansion section to "bend and bulge". The axial length of the entire radial expansion component 200 remains constant, ensuring that the positional accuracy of the catheter body 100 tip is not affected during the expansion support process. After the support is stable, the operator can directly advance the catheter body 100 and smoothly pass through the branch opening, completely solving the problem of advancement interference caused by traditional balloon-driven methods.

[0031] Furthermore, an elastic protective layer structure 300 is provided on the outside of the support section to reduce damage to blood vessels caused by the support strip 210. In this embodiment, the elastic protective layer structure 300 is collectively applied to the outside of all support strips 210 so that when the radial expansion member 200 expands, it forms a smooth sac-like structure to provide gentle support and protection for blood vessels.

[0032] Furthermore, the catheter body 100 adopts a multi-layer composite structure design, with a support layer 120 and a protective layer 130 arranged sequentially from the inside out. The support layer 120 is made of braided steel wire or polyimide material, providing sufficient radial support and torsional strength for the catheter body 100, preventing the catheter body 100 from bending or collapsing during advancement; the protective layer 130 is made of medical-grade polytetrafluoroethylene material, which has good lubricity and can reduce the frictional resistance between the catheter body 100 and the blood vessel wall. The distal end of the support layer 120 has an extension section that extends a predetermined distance beyond the protective layer 130, and the expansion section of the support bar 210 is fixed on this extension section. This design allows the distal end of the catheter body 100 to form a radially gradually decreasing stepped structure, and the expansion section of the support bar 210 is set on the stepped structure, which can avoid excessive radial dimension increase at the distal end of the catheter body 100 due to the arrangement of the radial expansion component 200, thereby ensuring the flexibility of the distal end of the catheter body 100 during advancement. An axially arranged sliding channel 131 is provided inside the protective layer 130, and the support section of the support bar 210 is slidably disposed in the channel to provide guidance for the movement of the support bar 210.

[0033] Furthermore, the proximal ends of all sliding channels 131 are connected to an annular receiving cavity 140, within which an elastic reset member 600 is arranged. This reset member employs a helical spring structure, with its proximal end fixedly connected to the annular receiving cavity 140 and its distal end fixedly connected to the proximal ends of all support bars 210. When the support bars 210 slide to their distal ends, the elastic reset member 600 is stretched, accumulating elastic potential energy. When the attractive force or external force of the driving component 400 is removed, the elastic reset member 600 releases its potential energy, pulling the support bars 210 to quickly return to their contracted state, thereby improving operational efficiency. Furthermore, by incorporating the elastic reset element 600, once the electromagnet 420 is de-energized and de-stressed, the elastic reset element 600 immediately provides a uniform and consistent radial retraction force, synchronously and stably pulling all the support bars 210 back to their initial contracted positions. This ensures the expansion structure can fully retract, avoiding potential vascular scraping or retraction difficulties caused by individual support bars 210 becoming stuck or not fully retracted. Simultaneously, compared to relying entirely on reverse drive signals or manual operation for reset, the elastic reset element 600 provides a faster reset speed, facilitating rapid restoration of the catheter's original shape after passing the lesion site for subsequent procedures, thus improving surgical efficiency. Finally, this design constitutes a mechanical failure protection mechanism. Even in extreme cases where the drive system fails, the elastic reset element 600 acts as a safety barrier, striving to pull the support bars 210 back to a safe state, reducing the risk of instrument retention or continuous pressure on blood vessels, and significantly improving system safety.

[0034] Furthermore, a contrast ring 700 is provided at the distal end of the catheter body 100. The contrast ring 700 is made of tungsten alloy or platinum-iridium alloy and can be clearly visualized under X-ray fluoroscopy, which facilitates the operator to observe the position of the microcatheter body 100 and the expansion state of the radial expansion component 200 in real time, providing a basis for precise operation.

[0035] Furthermore, a multi-port valve 500 is integrated and installed at the proximal end of the catheter body 100. The multi-port valve 500 has a main channel 510 and multiple branch channels 520. The main channel 510 communicates with the delivery lumen 110 and can be used for aspirating thrombi or injecting contrast agents. The electrical leads (not shown) of the electromagnet 420 are led out from the branch channels 520 and connected to an external control device, realizing functional integration and operational convenience.

[0036] Working principle: When the catheter body 100 travels along the blood vessel, the designated electromagnet 420 is energized by the external control system. The electromagnet 420 generates a magnetism opposite to that of the magnetic block 410. At this time, the electromagnet 420 and the magnetic block 410 are tightly attracted, so that the radial expansion component 200 is in a stable contracted state, ensuring that the catheter body 100 travels smoothly forward. When the distal end approaches a special position where the "windowsill effect" is likely to occur, such as an angle or branch of the blood vessel, the designated electromagnet 420 is energized by the external control system, causing it to generate the same magnetism as the magnetic block 410, thereby repelling the magnetic block 410 and causing the support strip 210 to slide distally. Since the distal end of the support strip 210 is fixed, its middle part protrudes outward from the catheter body 100 under the action of sliding thrust, forming an expanded support structure. In this state, the distal end of the catheter body 100 is supported in the center of the blood vessel, maintaining an installation distance from the blood vessel wall, thus allowing it to pass smoothly through the special position. After the catheter body 100 passes through, the current of the electromagnet 420 is cut off, the magnetic force disappears, and under the action of the elastic reset member 600, the support bar 210 is pulled back to the proximal end, the expansion structure contracts, and the original shape of the catheter is restored, making it easier to continue its journey to reach the target position.

[0037] Example 2 like Figure 5 and Figure 6As shown, the main difference between this embodiment and Embodiment 1 lies in the shape of the radial expansion component 200. In this embodiment, the elastic protective layer structure 300 is an independent silicone tube respectively sleeved on the outside of each support strip 210. When the support strip 210 slides distally and bulges under magnetic drive, it forms an open cage-like structure. This structure provides effective central support while having less impact on blood flow, allowing forward blood flow (anterograde perfusion) to be preserved to the greatest extent when the instrument passes through and is supported on the target vascular segment. This is crucial for acute ischemic stroke surgery because it can prevent "iatrogenic occlusion" of branch vessels along the path before opening the main occluded vessel, continuously providing a weak but potentially life-saving blood supply to the distal endangered brain tissue, and buying valuable time for the final recanalization of the main vessel.

[0038] Example 3 like Figure 7 As shown, the main difference between this embodiment and Embodiment 2 lies in the reset method of the radial expansion component 200. In this embodiment, the elastic reset component 600 is not provided. Instead, the radial expansion component 200 contracts after radial expansion by changing the magnetic poles of the electromagnet 420, causing the magnetic block 410 and the electromagnet 420 to attract each other, thereby achieving rapid contraction of the expansion section. The purpose of this design is that, without the driving force of the elastic reset component 600, each support bar 210 corresponds to an independent driving component. By adjusting the current intensity of different electromagnets 420, differentiated expansion of a single or partial support bar 210 can be achieved. For example, when the catheter body 100 travels through a curved blood vessel, traditional uniform expansion will cause the distal end of the catheter body 100 to deviate towards the convex side of the curve, still posing a risk of contact with the blood vessel wall. However, the differentiated expansion of this embodiment can individually increase the expansion force and amplitude of the support bar 210 on the convex side of the curve, generating a directional thrust on the distal end of the catheter body 100, thereby dynamically and precisely adjusting and stabilizing the distal end of the catheter body 100 within the blood vessel, thus facilitating contactless delivery to the blood vessel wall. For example, when dealing with eccentric plaques or irregularly stenotic vessels, the support strip 210 on the side away from the plaque can be precisely controlled to provide the main support, while the support strip 210 on the side closer to the plaque can be selectively kept at a small expansion or not moved at all. This minimizes direct contact and compression of the fragile plaque and greatly reduces the risk of plaque detachment and distal embolism during the procedure.

[0039] In summary, the present invention, by incorporating a controllable radial expansion component at the distal end of the catheter body, coupled with a precise electromagnetic drive system and a safe protective structure, effectively solves the "windowsill effect" problem of existing microcatheters, enabling safe and rapid passage through special locations in blood vessels. Its rational structural design and strong adaptability allow for the selection of appropriate expansion structure forms according to different clinical scenarios, providing more reliable instrument support for interventional treatment of acute ischemic stroke.

[0040] It is understood that the above description is merely exemplary and the embodiments of this application do not limit the scope of the application.

[0041] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are within the protection scope of the present invention.

Claims

1. A delivery microcatheter, comprising a catheter body (100) having an axially extending delivery lumen (110), characterized in that, The distal end of the catheter body (100) has a radial expansion member (200) to maintain a set distance between the distal end of the catheter body (100) and the vessel wall during its travel within the blood vessel; The radial expansion component (200) includes multiple support strips (210) arranged circumferentially along the catheter body (100). Each support strip (210) has an integrally formed expansion section and a support section from the distal end to the proximal end. The distal end of the expansion section is fixedly connected to the catheter body (100). The support section extends into the side wall of the catheter body (100) and slides in cooperation with the side wall of the catheter body (100). The support section slides distally, causing the expansion section to bulge away from the catheter body (100) to support the blood vessel, so as to ensure that the catheter body (100) can smoothly reach the target position.

2. The delivery microcatheter according to claim 1, characterized in that, The support section is covered with an elastic protective layer structure (300) to reduce the damage to blood vessels caused by the support strip (210).

3. The delivery microcatheter according to claim 2, characterized in that, The elastic protective layer structure (300) is collectively sleeved on the outside of each of the support bars (210) so that the radial expansion member (200) expands into a bladder-like structure.

4. The delivery microcatheter according to claim 2, characterized in that, The elastic protective layer structure (300) is respectively sleeved on the outside of each of the support bars (210) so that the radial expansion member (200) is in a cage-like state when expanded.

5. The delivery microcatheter according to claim 1, characterized in that, The catheter body (100) is provided with a driving component (400) to drive the radial expansion and contraction of the support bar (210).

6. The delivery microcatheter according to claim 5, characterized in that, The driving component (400) includes multiple sets of magnetic blocks (410) and electromagnets (420) in the same number as the support bar (210). In each set of the driving component (400), the magnetic block (410) is disposed on the side of the support bar (210) facing the conduit body (100), and the electromagnet (420) is disposed on the conduit body (100) opposite to the magnetic block (410).

7. The delivery microcatheter according to claim 6, characterized in that, The catheter body (100) is provided with a multi-way valve (500) at its proximal end. The multi-way valve (500) has a main channel (510) and a branch channel (520). The main channel (510) is used to connect to the delivery lumen (110). The electrical wire of the electromagnet (420) is used to extend out from the branch channel (520) to connect to an external control device.

8. The delivery microcatheter according to any one of claims 1-7, characterized in that, The catheter body (100) is provided with a support layer (120) and a protective layer (130) from the inside to the outside. The support layer (120) has an extension section at the distal end that extends a set distance beyond the protective layer (130). The expansion section of the support bar (210) is provided on the extension section.

9. The delivery microcatheter according to claim 8, characterized in that, The protective layer (130) has an axially arranged sliding channel (131), and the support bar (210) is slidably disposed in the sliding channel (131).

10. The delivery microcatheter according to claim 9, characterized in that, The sliding channel (131) is connected to an annular cavity (140) at its proximal end. An elastic reset member (600) is arranged in the annular cavity (140). The proximal end of the support bar (210) is fixedly connected to the elastic reset member (600).

Images