Dilation catheter
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- LIFETECH SCI (SHENZHEN) CO LTD
- Filing Date
- 2021-12-30
- Publication Date
- 2026-07-10
Smart Images
Figure CN116407737B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of medical device technology, and in particular relates to a dilation catheter. Background Technology
[0002] In the treatment of cardiovascular stenosis, aneurysms, and aortic dissections, interventional procedures are increasingly used to implant stents or valves into the lesion site to address cardiovascular diseases. After implantation, balloon dilation is often used to circumferentially dilate the device to ensure accurate positioning and prevent dislodgement later. Depending on the specific circumstances, pre-dilation of the narrowed vessel may also be necessary before implantation, often using a balloon catheter in clinical practice.
[0003] like Figure 1 As shown, most existing balloon dilation devices use balloon catheters, which consist of a balloon 1' made of a polymer membrane and a sheath 2' that inserts the balloon 1' into the body and provides a channel for its expansion and contraction. Externally, saline or other solutions, or gas, are injected through the sheath 2' to inflate the balloon 1', increasing its outer diameter and expanding the implanted device. This type of balloon dilation completely blocks the blood vessel 3', preventing blood flow, thus requiring precise timing and skill during the procedure.
[0004] If blood flow is impaired for an extended period, the corresponding organs will not receive sufficient blood supply, potentially leading to organ necrosis. Therefore, when using balloon catheters for clinical treatment, if the narrowed blood vessel does not dilate smoothly, it is necessary to remove the fluid or gas from the balloon for repeated dilation, or even remove the balloon catheter, replace it, and reinsert it. This prolongs the procedure time, increases the complexity of the clinical operation, and raises the difficulty of the surgery.
[0005] Therefore, a new technical solution is needed to address the problem that existing dilation catheters can easily block blood vessels during surgery, leading to poor blood flow. Summary of the Invention
[0006] The purpose of this invention is to provide a dilation catheter that solves the problem that existing dilation catheters can easily block blood vessels during surgery, leading to poor blood flow.
[0007] This invention is implemented as follows:
[0008] An expansion catheter includes a sheath and a sheath core axially inserted into the lumen of the sheath, with a gap formed between the sheath core and the sheath. The catheter further includes an expansion assembly comprising an expansion member and a sliding member. The sliding member is disposed within the sheath and is movably connected to the sheath core via the sliding member. The sheath core axially passes through the expansion member. The expansion member is helically arranged, with its proximal end connected to the sheath core and its distal end connected to the sliding member.
[0009] The dilation catheter of this invention controls the sliding of the sliding element or the sheath core, thereby causing the dilator to contract or expand. The spiral dilator contracts or expands to dilate blood vessels or implants, thereby forming a non-closed expansion space with variable radial dimensions. This not only maintains blood flow during dilation surgery but also allows for dynamic adjustment of the radial dimensions of the expansion, thereby improving the operability of the surgery and avoiding the valuable time wasted and surgical risks associated with replacing the dilation catheter due to an unsuitable size during the operation.
[0010] In some embodiments of the present invention, the expansion member includes a spiral coiled wire formed from a metal wire with memory function, the proximal end of the coiled wire being fixedly connected to the proximal end of the sheath core, and the distal end of the coiled wire being fixedly connected to the sliding member.
[0011] In some embodiments of the present invention, the expansion member further includes a flexible membrane tube sleeved on the outside of the coiled wire, a closed expansion cavity is formed between the coiled wire and the inner wall of the membrane tube, the expansion cavity can expand after being filled with gas or liquid; the membrane tube is fixedly disposed on the coiled wire, or the proximal end of the membrane tube is fixedly disposed on the sheath core, and the distal end of the membrane tube is fixedly disposed on the sliding member.
[0012] In some embodiments of the present invention, an injection catheter is inserted into the sheath, and the inner lumen of the injection catheter is connected to the dilation cavity.
[0013] In some embodiments of the present invention, a fixing portion is provided at the proximal end of the sheath core, and the proximal end of the expansion member is fixedly disposed on the fixing portion, and a developing structure is provided on the fixing portion.
[0014] In some embodiments of the present invention, the sliding member is axially slidably connected to the sheath tube, the sliding member is sleeved on the sheath core, the sliding member is threadedly connected to the outer wall of the sheath core, or the sliding member is axially slidably connected to the sheath core, the sliding member is threadedly connected to the inner wall of the sheath tube; the sheath core is rotated to cause the sliding member to move axially relative to the sheath core.
[0015] In some embodiments of the present invention, the distal end of the sheath core is provided with a handle for driving the sheath core to rotate.
[0016] In some embodiments of the present invention, the sliding member is fixedly connected to the sheath tube, and the sheath core is slidably connected to the sliding member.
[0017] In some embodiments of the present invention, the radial dimension of the expansion member is set to gradually change along the axial direction, and the radial dimension of the middle part of the expansion member is greater than the radial dimension of the two ends of the expansion member.
[0018] In some embodiments of the present invention, the expansion member is provided with a developing filament, which is wound around the expansion member; the outer surface of the expansion member is provided with a drug coating. Attached Figure Description
[0019] Figure 1 This is a schematic diagram of a prior art balloon catheter provided by the present invention;
[0020] Figure 2 This is a schematic diagram of the dilation catheter provided in Embodiment 1 of the present invention;
[0021] Figure 3 This is a partial cross-sectional schematic diagram of the dilation catheter provided in Embodiment 1 of the present invention;
[0022] Figure 4 This is Embodiment 1 of the present invention. Figure 3 Enlarged view of point A in the middle;
[0023] Figure 5 This is Embodiment 1 of the present invention. Figure 3 A cross-sectional view of the sheath core at point A in the middle;
[0024] Figure 6 This is a schematic diagram of the connection between the proximal end of the coiled wire and the proximal end of the sheath core provided in Embodiment 1 of the present invention;
[0025] Figure 7 This is a schematic diagram of an embodiment of the connection between the sliding member and the distal end of the coiled wire provided in Embodiment 1 of the present invention;
[0026] Figure 8 yes Figure 7 A top-view diagram of the slider;
[0027] Figure 9 This is a schematic diagram of another embodiment of the connection between the sliding member and the distal end of the coiled wire provided in Embodiment 1 of the present invention;
[0028] Figure 10 This is Embodiment 1 of the present invention. Figure 9 A cross-sectional view of the sliding component;
[0029] Figure 11 This is a schematic diagram of the prismatic mold for manufacturing coiled wire provided in Embodiment 1 of the present invention;
[0030] Figure 12 This is a schematic diagram of the expansion catheter provided in Embodiment 1 of the present invention, which is threadedly connected to the sliding member and the sheath tube.
[0031] Figure 13 This is Embodiment 1 of the present invention. Figure 12 A schematic diagram of the radial cross-section of the dilation catheter;
[0032] Figure 14 Embodiment 1 of the present invention Figure 12 Enlarged view of the structure at point B;
[0033] Figure 15 This is a schematic diagram of the dilation catheter provided in Embodiment 2 of the present invention;
[0034] Figure 16 This is a cross-sectional schematic diagram of the expansion member provided in Embodiment 2 of the present invention;
[0035] Figure 17 This is in Embodiment 2 of the present invention Figure 15 A partial cross-sectional schematic diagram of the dilation catheter;
[0036] Figure 18 This is a schematic diagram of an embodiment of the connection between the sliding member, membrane tube, and injection catheter provided in Embodiment 2 of the present invention;
[0037] Figure 19 This is a schematic diagram of another embodiment of the connection between the sliding member, membrane tube, and injection catheter provided in Embodiment 2 of the present invention;
[0038] Figure 20 This is a schematic diagram of yet another embodiment of the connection between the sliding member, membrane tube, and injection catheter provided in Embodiment 2 of the present invention;
[0039] Figure 21 This is Embodiment 2 of the present invention. Figure 20 A schematic diagram of the radial section of the sliding component;
[0040] Figure 22 This is a schematic diagram of the dilation catheter provided in Embodiment 3 of the present invention;
[0041] Figure 23 This is in Embodiment 3 of the present invention Figure 22 A schematic diagram of a partial cross-section of the dilation catheter. Detailed Implementation
[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0043] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly on the other component or may have an intervening component present. When a component is referred to as "connected to" another component, it can be directly connected to the other component or may have an intervening component present.
[0044] It should also be noted that the directional terms such as left, right, up, and down in this embodiment are only relative concepts or are based on the normal use of the product, and should not be considered as restrictive.
[0045] Example 1
[0046] like Figure 2 and Figure 3 The diagram shown is a schematic representation of the dilation catheter 100 provided in Embodiment 1 of the present invention. The dilation catheter 100 includes a sheath 1, a sheath core 2, and a dilation assembly 3. The sheath 1 has an inner lumen, and the sheath core 2 is axially inserted into the inner lumen of the sheath 1, with the proximal end of the sheath core 2 protruding outside the sheath 1. A receiving gap is formed between the outer wall of the sheath core 2 and the inner wall of the sheath 1 to form a receiving space.
[0047] The expansion assembly 3 includes an expansion member 31a and a sliding member 32. The proximal end of the expansion member 31a is connected to the sheath core 2 and fixed to the proximal end of the sheath core 2. The distal end of the expansion member 31a is connected to and fixed to the sliding member 32. The sliding member 32 is disposed inside the sheath tube 1 and sleeved on the sheath core 2. The expansion member 31a has a memory function and is spiral-shaped. The sheath core 2 is axially inserted into the expansion member 31a.
[0048] The radial dimension of the expander 31a along the axial direction gradually changes, with the radial dimension at the middle of the expander 31a being larger than that at both ends. This gradual change in the radial dimension of the expander 31a means that its radial dimension D increases or decreases slowly from the middle to both ends, with a relatively gentle trend rather than a sudden increase or decrease. This allows the expander 31a to gradually contract or expand, preventing sudden increases or decreases in the expanded space that could cause harm to the patient.
[0049] In this embodiment, the expansion member 31a includes a spiral coiled wire 311a formed by shaping a metal wire with memory function into a spiral shape. Specifically, a nickel-titanium alloy metal wire can be heat-treated to form a spiral coiled wire 311a. The proximal end of the coiled wire 311a is fixedly connected to the proximal end of the sheath core 2, and the distal end of the coiled wire 311a is fixedly connected to the sliding member 32. It can be fixed by welding, pressing or bonding.
[0050] The sliding member 32 is sleeved on the sheath core 2 and can move relative to the sheath core 2 along the axial direction of the sheath tube 1. After moving, the sliding member 32 can drive the expansion member 31a to be gradually released from the sheath tube 1 or to be retracted into the sheath tube 1 after release. Before being released, the expansion member 31a is housed in the receiving gap between the outer wall of the sheath core 2 and the inner wall of the sheath tube 1. After being released, the sliding member 32 slides relative to the sheath core 2 along the axial direction, driving the expansion member 31a to contract or expand.
[0051] Because the coiled wire 311a is made of a metal wire with memory function and is shaped into a spiral, and the radial dimension of the expander 31a gradually changes, the expander 31a can achieve the functions of stretching and relaxing in the axial direction. While it stretches and relaxes in the axial direction, the radial dimension of the expansion space it encloses in the circumferential direction also changes accordingly. In this way, through the axial and radial changes of the expander 31a, the blood vessel can be dynamically expanded. Even during the operation, the radial dimension of the expansion can be controlled, thereby reducing the chance of replacing the dilation catheter during the operation, saving valuable operation time, and reducing the risk of the operation.
[0052] On the other hand, since the dilator 31a is spiral-shaped, the expansion space it encloses is not a sealed space. Therefore, even when the dilator 31a expands within the blood vessel, blood can still flow inside and outside the expansion space it encloses, thus preventing complete blockage of the blood vessel and improving the maneuverability of the surgery. It should be noted that since the coiling diameter of the spiral coiled wire 311a gradually changes, the radial force during blood vessel dilation can be ensured by setting the number of coils of the coiled wire 311a. For example, when a larger radial force is required, the number of coils of the coiled wire 311a can be increased. To ensure that the radial dimension of the coiled wire 311a changes regularly during contraction and relaxation, allowing for regular expansion of the blood vessel and improving the maneuverability of the surgery, such as... Figure 1 As shown, the radial dimension of the coiled wire 311a along the axial direction shows a trend of first gradually increasing and then gradually decreasing.
[0053] The most frequently used non-compliant balloons in clinical practice have a fixed maximum outer diameter, requiring the appropriate size to be prepared before surgery. If the balloon size selected during surgery is not suitable, it must be removed from the body, replaced, and then reinserted, which poses a significant risk to clinical procedures.
[0054] In this embodiment, by setting a spiral-shaped expansion member 31a and adopting a variable diameter design, the radial dimension of the coiled wire 311a along the axial direction gradually increases and then gradually decreases. Therefore, the operator can control the radial dimension by controlling the length of the coiled wire 311a, without having to remove the expansion catheter from the body for replacement and re-intervention, thus reducing the risks associated with clinical operations.
[0055] like Figure 4 As shown, the sliding member 32 is axially slidably connected to the sheath tube 1, and the sliding member 32 is threadedly connected to the outer wall of the sheath core 2. Specifically, the sliding member 32 is axially slidably connected to the sheath tube 1, and a tube wall groove 10 is provided on the inner wall of the sheath tube 1. The tube wall groove 10 is arranged along the axial direction of the sheath tube 1, and the sliding member 32 is slidably connected within the tube wall groove 10, so that the sliding member 32 can slide axially within the sheath tube 1. The sliding member 32 is threadedly connected to the sheath core 2, so that the sliding member 32 can rotate along the thread of the sheath core 2. The sheath core 2 can be made into a rod shape, with threaded teeth machined on its outer wall. Correspondingly, a through groove 321 adapted to the shape of the sheath core 2 is provided on the sliding member 32, and a corresponding threaded groove that is threadedly connected to the sheath core 2 is machined on the inner wall of the through groove 321, so that a screw drive transmission form is formed between the sliding member 32 and the sheath core 2; of course, it can also be as follows. Figure 5 As shown, a threaded groove is machined on the sheath core 2, and a threaded tooth is machined on the sliding part 32 to connect with it, so that the same transmission form of screw drive can be realized, thereby driving the coiled wire 311a to contract or expand.
[0056] like Figure 1 As shown, a handle 4 is provided at the distal end of the sheath core 2 for manual adjustment. By rotating the handle 4, the sliding member 32 can be controlled to slide relative to the sheath tube 1 and move axially relative to the sheath core 2. This creates a relative displacement between the sliding member 32 and the sheath core 2. The sliding member 32 can drive the connected spiral coiled wire 311a to expand or contract in both the axial and radial directions, thereby continuously adjusting the radial dimension and radial force of the coiled wire 311a to appropriately expand blood vessels and implants.
[0057] In this embodiment, when it is necessary to move the sheath core 2 quickly, the sheath core 2 is pushed directly along the axial direction of the sheath tube 1. At this time, the sheath core 2 drives the sliding member 32 to move rapidly axially along the tube wall groove 10 in the sheath tube 1. When it is necessary to precisely adjust the position between the sheath core 2 and the sliding member 32, the sliding member 32 is slowly moved by rotating the handle 4 through the lead screw drive, thereby achieving fine adjustment of the position between the sheath core 2 and the sliding member 32.
[0058] like Figure 6As shown, a fixing part 5 can also be provided at the position where the proximal end of the coiled wire 311a is fixedly connected to the proximal end of the sheath core 2, and the proximal end of the coiled wire 311a is connected through the fixing part 5. In addition, a developing structure can also be provided on the fixing part 5. The developing structure is a developing point fixedly provided on the fixing part 5, so that the operator can easily observe the transport of the coiled wire 311a and the proximal end of the sheath core 2 in the body through the developing point.
[0059] In other embodiments, a radiopaque fiber can also be wound around the coiled fiber 311a, so that when the coiled fiber 311a expands in the body, the working status of the coiled fiber 311a can be observed in real time according to the radiopaque fiber development, so as to grasp the surgical situation in a timely manner and make adjustments as needed, thereby improving the safety of the surgery and saving surgical operation time.
[0060] See Figure 7 and Figure 8 The coiled wire 311a can be fixed to the outer wall of the sliding member 32 by welding, pressing or other methods. At this time, a cutting wall 322 can be provided on the side wall of the sliding member 32 to fix the coiled wire 311a to the cutting wall 322, which facilitates processing and manufacturing.
[0061] See Figure 9 and Figure 10 In some other embodiments, the coiled wire 311a may also be threaded through the slider 32 and fixed by welding or other means. This method can make the coiled wire 311a more securely connected to the slider 32 and can avoid the coiled wire 311a interfering with the slider 32 when it slides.
[0062] See Figure 11 For the processing of coiled wire 311a, the following method can be used: Prepare an approximately shuttle-shaped prismatic mold 9, on which a spiral groove 91 is provided. Then, wind the nickel-titanium metal wire into the spiral groove 91. The free ends of the metal wire can be fixed together with the prismatic mold 9 using bolts or the like. Finally, heat treatment is used to shape the wire, thus producing a shape like... Figure 1 The spiral-shaped coiled wire 311a is shown.
[0063] See also Figure 12 , Figure 13 and Figure 14 In some other embodiments, the sliding member 32 is axially slidably connected to the sheath core 2, and the sliding member 32 is threadedly connected to the inner wall of the sheath tube 1. The sliding member 32 can be threadedly connected to the inner wall of the sheath tube 1, with threads machined on the inner wall of the sheath tube 1, and threads adapted to the threads on the outer wall of the sliding member 32 are machined to the inner wall of the sheath tube 1, thus forming a screw drive relationship between the sliding member 32 and the sheath tube 1.
[0064] A core wall groove 20 is provided on the outer wall of the sheath core 2, and the core wall groove 20 is arranged along the axial direction of the sheath core 2. A sliding member 32 is slidably connected within the core wall groove 20. Thus, the sliding member 32 can slide axially relative to the sheath tube 1 on the sheath core 2. When the sheath core 2 is rotated, since a screw drive is formed between the sliding member 32 and the sheath tube 1, the rotation of the sheath core 2 will drive the sliding member 32 to slide, which can similarly drive the dilator 31a to contract or expand, thereby achieving the function of dilating blood vessels or implants. (See also...) Figure 12 A handle 4 can be provided at the distal end of the sheath 1, which can be used to control the sliding of the slider 32.
[0065] See Figure 6 The sheath core 2 has a guide head 6 at its proximal end. The guide head 6 is tapered and has a lower hardness than the sheath core 2. The guide head 6 not only effectively reduces contamination but also makes the sheath core 2 easier to push.
[0066] Example 2
[0067] like Figures 15 to 21 The diagram shown is a schematic representation of the dilation catheter 100 provided in Embodiment 2 of the present invention. (See also...) Figure 15 The expansion catheter 100 includes a sheath 1, a sheath core 2, and an expansion assembly 3. The main difference between this embodiment and the first embodiment described above is that the structure of the expansion member 31b is different; the structures of other parts can be referred to in the first embodiment described above.
[0068] The expansion assembly 3 includes an expansion member 31b and a sliding member 32. The proximal end of the expansion member 31b is connected to and fixed to the proximal end of the sheath core 2. The distal end of the expansion member 31b is connected to and fixed to the sliding member 32. The sliding member 32 is disposed inside the sheath tube 1 and sleeved on the sheath core 2. The expansion member 31b has a memory function and is spiral-shaped. The sheath core 2 is axially inserted into the expansion member 31b. The radial dimension of the expansion member 31b gradually changes along the axial direction. In this embodiment, the radial dimension of the expansion member 31b first gradually increases and then gradually decreases, allowing the expansion member 31b to gradually contract or expand, preventing sudden increases or decreases in the expanded space that could cause harm to the patient.
[0069] See also Figure 16The dilator 31b includes a coiled wire 311b and a flexible membrane tube 312b sleeved on the coiled wire 311b. The coiled wire 311b can be made of a metal wire with memory function shaped into a spiral. The membrane tube 312b can be made of a polymer film material. A closed expansion cavity 313 is formed between the inner walls of the coiled wire 311b and the membrane tube 312b. After gas or liquid is filled into the expansion cavity 313, the expansion cavity 313 can expand. When the liquid or gas is released, the expansion cavity 313 can shrink. This method allows the dilator 31b to directly contact the blood vessel with the flexible membrane tube 312b when dilating blood vessels in the body, while avoiding direct contact between the coiled wire 311b and the inner wall of the blood vessel. Thus, the contact method is a flexible contact, which reduces the stimulation and damage to the blood vessel and reduces the patient's discomfort.
[0070] The membrane tube 312b is fixedly mounted on the coiled wire 311b, or the proximal end of the membrane tube 312b is fixedly mounted on the sheath core 2, and the distal end of the membrane tube 312b is fixedly mounted on the sliding member 32. The specific configuration is determined according to actual needs.
[0071] See also Figure 15 and Figure 17 An injection catheter 7 is inserted inside the sheath 1. The inner lumen of the injection catheter 7 is connected to the expansion cavity 313. The injection catheter 7 can extend all the way outside the body. The expansion cavity 313 is filled by external injection. The injection catheter 7 is connected and communicates with the membrane tube 312b in the sliding member 32.
[0072] In other embodiments, a drug coating can be added to the outer surface of the membrane tube 312b, so that the dilator catheter 100 also has a therapeutic function. Another beneficial effect of the dilator 31b provided in this embodiment is that the dilator 31b can be recovered under special circumstances. Since the volume of the dilation cavity 313 can change with the amount of injected material, when an appropriate amount of liquid or gas is injected into the dilation cavity 313, the membrane tube 312b expands and is squeezed together. If necessary, it can even temporarily block the blood flow in the blood vessels to facilitate later observation or treatment.
[0073] like Figure 18 and Figure 19 As shown, the membrane tube 312b and the injection catheter 7 can be located on the same side of the sliding member 32. This allows the liquid or gas in the injection catheter 7 to quickly reach the membrane tube 312b, enabling the membrane tube 312b to be quickly filled. The transition connection between the membrane tube 312b and the injection catheter 7 can be... Figure 18 As shown, it is in a straight state, or it can be as follows: Figure 19 It is shown to be in a bent state.
[0074] See Figure 20 and Figure 21The membrane tube 312b and the injection catheter 7 can be located on opposite sides of the sliding member 32. In this case, it is only necessary to set an intermediate connecting tube in the sliding member 32 to connect the injection catheter 7 and the membrane tube 312b; or the injection catheter 7 can be connected to the membrane tube 312b after wrapping around half of the sliding member 32, which can also achieve the purpose of connecting the injection catheter 7 and the membrane tube 312b. This situation can be adapted to situations where rapid expansion of the expansion cavity 313 is not required.
[0075] In this embodiment, the portion of the dilator 31b that directly contacts the inner wall of the blood vessel is a flexible membrane tube 312b. After the dilator 31b is released, the instantaneous irritation to the inner wall of the blood vessel is minimal. Furthermore, the membrane tube 312b gradually increases in strength as it is filled with gas or liquid. Therefore, by placing the membrane tube 312b outside the coiled wire 311b, this embodiment reduces the irritation and damage of the dilator 31b to the inner wall of the blood vessel, thus reducing patient discomfort.
[0076] Example 3
[0077] like Figure 22 and Figure 23 The diagram shown is a schematic representation of the dilation catheter 100 provided in Embodiment 3 of the present invention. The dilation catheter 100 includes a sheath 1, a sheath core 2, and a dilation assembly 3. The main difference between this embodiment and the previous embodiments lies in the connection and engagement method between the dilation assembly 3, the sheath 1, and the sheath core 2.
[0078] The expansion assembly 3 includes an expansion member 31c and a sliding member 32c. The sliding member 32c is fixedly connected to the sheath tube 1, and the sheath core 2 is slidably connected to the sliding member 32c.
[0079] Specifically, the sliding element 32 and the sheath core 2 are in a clearance fit, allowing the sheath core 2 to slide relative to the sliding element 32. At this time, the sliding element 32 is stationary relative to the sheath tube 1. After the dilator 31c is released, the dilator 31c can be contracted or expanded by controlling the sheath core 2 to move back and forth along the axial direction. When the sheath core 2 moves backward, that is, when the proximal end of the sheath core 2 moves towards the proximal end of the sheath tube 1, the dilator 31c is contracted, the axial length of the dilator 31c decreases, and the radial force increases, which facilitates the dilation of blood vessels or implants. When the sheath core 2 moves forward, that is, when the proximal end of the sheath core 2 moves away from the proximal end of the sheath tube 1, the axial length of the dilator 31c increases, and the radial force decreases, which facilitates the retraction of the dilator 31c.
[0080] The dilation catheter 100 provided in this embodiment does not require threading on the sliding member 32c, sheath 1, and sheath core 2, and its structure is relatively simpler. It can also control the contraction and expansion of the dilation member 31c, thereby controlling its dilation of blood vessels or implants, achieving the effect of dilation without blocking blood vessels.
[0081] In other embodiments, a handle (not shown in the figure) may be provided at the distal end of the sheath core 2, and the movement of the sheath core 2 may be controlled by manually operating the handle, or the movement of the sheath core 2 may be controlled by other means.
[0082] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.
Claims
1. A dilating catheter, comprising a sheath and a sheath core axially inserted into the lumen of the sheath, wherein a gap is formed between the sheath core and the sheath, characterized in that, Also includes: An expansion assembly includes an expansion member and a sliding member. The sliding member is disposed inside the sheath tube, and the sheath tube and the sheath core are movably connected through the sliding member. The sheath core passes axially through the expansion member. The expansion member is spirally arranged, with its proximal end connected to the sheath core and its distal end connected to the sliding member. The expansion member includes a spiral coiled wire made of a metal wire with memory function, the proximal end of which is fixedly connected to the proximal end of the sheath core, and the distal end of which is fixedly connected to the sliding member. The expander also includes a flexible membrane tube sleeved on the outside of the coiled wire, and a closed expansion cavity is formed between the coiled wire and the inner wall of the membrane tube. The expansion cavity can expand after being filled with gas or liquid. The membrane tube is fixedly disposed on the coiled wire, or the proximal end of the membrane tube is fixedly disposed on the sheath core, and the distal end of the membrane tube is fixedly disposed on the sliding member. After the expander is released, the sheath core is rotated, and the sliding member slides axially relative to the sheath core, causing the expander to contract or expand. The radial dimension of the expander can be controlled by controlling the length of the coiled wire. When an appropriate amount of liquid or gas is injected into the expansion cavity, the membrane tube can expand and squeeze together to temporarily block blood flow in the blood vessels.
2. The dilation catheter as described in claim 1, characterized in that, An injection catheter is inserted into the sheath, and the inner lumen of the injection catheter is connected to the dilation cavity.
3. The dilation catheter as described in claim 1, characterized in that, The proximal end of the sheath core is provided with a fixing part, the proximal end of the expansion member is fixedly disposed on the fixing part, and the fixing part is provided with a developing structure.
4. The dilation catheter as described in claim 1, characterized in that, The sliding member is axially slidably connected to the sheath tube, the sliding member is sleeved on the sheath core, and the sliding member is threadedly connected to the outer wall of the sheath core, or the sliding member is axially slidably connected to the sheath core and threadedly connected to the inner wall of the sheath tube; the sheath core is rotated to cause the sliding member to move axially relative to the sheath core.
5. The dilation catheter as described in claim 4, characterized in that, The distal end of the sheath core is provided with a handle for driving the sheath core to rotate.
6. The dilation catheter as described in claim 1, characterized in that, The sliding member is fixedly connected to the sheath tube, and the sheath core is slidably connected to the sliding member.
7. The dilation catheter as described in claim 1, characterized in that, The radial dimension of the expansion member is set to gradually change along the axial direction, and the radial dimension of the middle part of the expansion member is larger than the radial dimensions of the two ends of the expansion member.
8. The dilation catheter as described in claim 1, characterized in that, The expander is provided with a developing wire, which is wound around the expander; the outer surface of the expander is provided with a drug coating.