Balloon dilatation catheter

Abstract

The application discloses a balloon dilatation catheter, which comprises an inner tube, an outer tube, a balloon, an outer tube seat and an inner tube seat; the inner tube passes through the inner cavity of the outer tube, the distal end of the balloon is connected to the inner tube, and the proximal end of the balloon is connected to the outer tube; an axially extending balloon inflation channel is formed between the outer tube and the inner tube, and the inner cavity of the balloon communicates with the balloon inflation channel; the catheter seat assembly comprises the outer tube seat and the inner tube seat which is arranged in relative axial movement with the outer tube seat, the proximal end of the outer tube is fixedly connected to the outer tube seat, the proximal end of the inner tube is fixedly connected to the inner tube seat, and the inner tube seat and the outer tube seat are arranged in relative axial movement; in the balloon pressure relief process, the inner tube seat can be controlled to move in the distal end direction or the outer tube seat can be controlled to move in the proximal end direction, the balloon is axially stretched, so that the overall outer diameter of the balloon after pressure relief is smaller, the balloon dilatation catheter is beneficial to be withdrawn from the blood vessel, and the risk that the balloon causes damage to the inner wall of the blood vessel in the withdrawal process is reduced.

Description

Technical Field

[0001] This invention relates to the field of interventional medical device technology, specifically to a balloon dilation catheter. Background Technology

[0002] Balloon dilation catheters typically consist of a long catheter and a balloon positioned at the distal end of the catheter. Once the balloon reaches the target location in the blood vessel, it inflates with pressure, dilating any narrowing of the vessel. After dilation is complete, the balloon is depressurized and withdrawn from the body.

[0003] In the prior art, the shape of the balloon after depressurization is irregular. After depressurization, the balloon usually has two attached structures that adhere to the surface of the catheter. This structure makes the overall outer diameter of the balloon relatively large after depressurization, which can easily lead to damage to the blood vessel wall and is not conducive to the withdrawal of the balloon from the body.

[0004] Therefore, how to make the overall outer diameter of the balloon deflation and contraction smaller is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] In view of this, the present invention provides a balloon dilation catheter to solve the defect that the balloon of the existing balloon dilation catheter has a large overall outer diameter after decompression and contraction, which is not conducive to the withdrawal of the balloon from the body.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows: A balloon dilation catheter includes an inner tube, an outer tube, a balloon, and a catheter seat assembly; The inner tube passes through the inner cavity of the outer tube, and the distal end of the inner tube extends outward from the distal opening of the outer tube. The distal end of the balloon is sealed to the inner tube, and the proximal end of the balloon is sealed to the outer tube. An axially extending balloon inflation channel is formed between the outer tube and the inner tube. The inner cavity of the balloon communicates with the balloon inflation channel, and fluid medium can flow in through the balloon inflation port to inflate the balloon or flow out to depressurize the balloon. The catheter hub assembly includes an outer tube hub and an inner tube hub that is axially movable relative to the outer tube hub. The proximal end of the outer tube is fixedly connected to the outer tube hub, and the proximal end of the inner tube is fixedly connected to the inner tube hub. The outer tube hub is provided with a balloon inflation port that communicates with the balloon inflation channel. During balloon decompression, the inner tube seat can be operably moved distally relative to the outer tube seat to stretch the balloon distally; or, the outer tube seat can be operably moved proximally relative to the inner tube seat to stretch the balloon proximally.

[0007] Furthermore, both the inner tube and the outer tube are rigid tubes capable of transmitting axial force.

[0008] Furthermore, the conduit seat assembly also includes a seal, which is sealed and fitted around the outer periphery of the inner tube and fixedly connected to the outer tube seat.

[0009] Furthermore, the sealing element includes a sealing seat fixedly connected to the outer tube seat, the sealing seat being sleeved on the outer periphery of the inner tube, the sealing seat having a cavity inside, the cavity containing sealant, and the sealant sealingly covering the outer periphery of the inner tube.

[0010] Furthermore, the sealing seat is bonded and fixed to the outer tube seat with adhesive.

[0011] Furthermore, the balloon dilation catheter also includes a tip tube, which is sealed to the outer periphery of the distal end of the inner tube, and the distal end of the balloon is sealed to the tip tube.

[0012] Furthermore, a circumferential anti-rotation and axial sliding fit structure is provided between the inner tube seat and the outer tube seat, which makes the inner tube seat and the outer tube seat relatively circumferentially fixed and relatively axially sliding. The catheter seat assembly also includes a knob, which is fixed in the axial direction relative to the inner tube seat and rotates in the circumferential direction relative to it, and the knob is threadedly connected to the outer tube seat; During balloon decompression, the outer tube seat remains stationary, while the knob is rotated. The knob causes the inner tube seat and the inner tube to move distally, stretching the balloon distally to reduce its outer diameter after decompression; or... During balloon decompression, the knob remains stationary while the outer tube seat is rotated. The outer tube seat drives the outer tube to move proximally, stretching the balloon and reducing its outer diameter after decompression.

[0013] Furthermore, the knob is threadedly connected to the proximal end of the outer tube seat.

[0014] Furthermore, the circumferential anti-rotation axial sliding fit structure includes a limiting rib disposed on the outer periphery of the inner tube seat and extending axially, and a limiting groove disposed on the inner wall of the outer tube seat and extending axially, wherein the limiting rib and the limiting groove slide in fit along the axial direction.

[0015] Furthermore, the outer periphery of the inner tube seat is provided with an axial limiting circumferential rotation structure, and the knob is kept in a relatively axially fixed position and can rotate relatively circumferentially with the inner tube seat through the axial limiting circumferential rotation structure.

[0016] Furthermore, the axial limiting circumferential rotation structure is an axial limiting groove with a pair of limiting walls at both ends of the axial direction. The knob is rotatably engaged with the axial limiting groove, and the pair of limiting walls of the axial limiting groove respectively block the near end and far end of the knob to achieve axial limiting of the knob.

[0017] Furthermore, the outer tube seat has an external thread structure on its outer periphery, and the inner tube seat includes an inner tube fixing part and a threaded sleeve part integrally connected to the inner tube fixing part. The inner tube fixing part is fixedly connected to the proximal end of the inner tube, and the threaded sleeve part is sleeved on the outer periphery of the outer tube seat. The inner wall of the threaded sleeve part is provided with an internal thread, and the internal thread of the inner wall of the threaded sleeve part is threaded to the external thread structure on the outer wall of the outer tube seat. During balloon decompression, the outer tube seat remains stationary, while the inner tube seat is rotated. The inner tube seat causes the inner tube to rotate circumferentially relative to the outer tube and move axially distally. The inner tube stretches and twists the balloon distally to reduce the outer diameter of the balloon after decompression; or... During balloon decompression, the inner tube seat remains stationary while the outer tube seat is rotated. The outer tube seat causes the outer tube to rotate circumferentially relative to the inner tube and move axially towards the proximal end. The outer tube stretches and twists the balloon towards the proximal end to reduce the outer diameter of the balloon after decompression.

[0018] Furthermore, the inner tube seat includes an inner tube seat threaded section with external threads on its outer periphery, and the guide seat assembly also includes a fixed seat and a threaded guide block. The threaded guide block is axially fixed relative to the fixed seat, and the threaded guide block is movably mounted on the fixed seat along the radial direction of the fixed seat. The fixing seat has a cavity inside. The fixing seat is fixedly connected to the proximal end of the outer tube seat and sleeved on the outer periphery of the inner tube seat. The inner tube seat passes through the cavity of the fixing seat. The threaded guide block has an inner hole that extends through both ends in the axial direction. The inner tube seat passes through the inner hole of the threaded guide block. The inner hole wall of the threaded guide block has a threaded guide structure that can be threadedly engaged with the threaded section of the inner tube seat. During balloon decompression, the fixed seat remains stationary. When the threaded guide block moves to a position where its inner wall's threaded guide structure engages with the threaded section of the inner tube seat, the inner tube seat is rotated. The inner tube seat causes the inner tube to rotate circumferentially relative to the outer tube and move axially toward the distal end. The inner tube stretches and twists the balloon toward the distal end to reduce the balloon's outer diameter after decompression. When the threaded guide block moves to a position where its inner wall's threaded guide structure disengages from the threaded section of the inner tube seat, the inner tube seat is operated to move axially toward the distal end in a single direction. The inner tube seat causes the inner tube to move axially toward the distal end only, and the inner tube stretches the balloon toward the distal end to reduce the balloon's outer diameter after decompression.

[0019] Furthermore, the threaded guide block is located in the cavity within the fixed seat, and a pressing member is fixedly connected to the threaded guide block. The pressing member is movably installed on the fixed seat along the radial direction of the fixed seat, and at least a portion of the pressing member is exposed outside the fixed seat. The outer wall of the threaded guide block is provided with a positioning groove, and the inner wall of the fixed seat is provided with a guide post that extends into the positioning groove. An elastic element is sleeved on the outer periphery of the guide post. The elastic element is elastically disposed between the threaded guide block and the fixed seat. The elastic force of the elastic element drives the threaded guide block to move to a position where it is threadedly engaged with the threaded section of the inner tube seat. When the pressing member is pressed, the threaded guide block moves to a position where it is disengaged from the threaded section of the inner tube seat, overcoming the elastic force of the elastic element; when the pressing member is released, the threaded guide block moves to a position where it is threadedly engaged with the threaded section of the inner tube seat under the elastic restoring force of the elastic element.

[0020] The balloon dilation catheter provided by this invention has the following advantages: Since the proximal end of the outer tube is fixedly connected to the outer tube seat, and the proximal end of the inner tube is fixedly connected to the inner tube seat, and the inner and outer tube seats maintain relative axial movement; during balloon decompression, the inner tube seat can be manipulated to move distally or the outer tube seat can be manipulated to move proximally. During balloon decompression, the balloon is subjected to an axially stretched force, and after decompression, the balloon is axially elongated. The shape of the balloon after decompression tends to adhere to the outer periphery of the inner tube, rather than forming a sheet-like shape. The overall outer diameter of the balloon after decompression and stretching will further decrease, which is beneficial for withdrawing the balloon dilation catheter from the blood vessel, reducing the risk of damage to the blood vessel wall during withdrawal, and improving safety. Attached Figure Description

[0021] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the overall structure of the balloon dilation catheter in Embodiment 1 of the present invention, wherein the balloon is in an inflated state before depressurization; Figure 2 for Figure 1 A sectional view; Figure 3 This is a schematic diagram of the overall structure of the balloon dilation catheter in Embodiment 1 of the present invention, wherein the balloon is axially stretched during the decompression process; Figure 4 for Figure 3 A sectional view; Figure 5 This is a schematic diagram of the overall structure of the balloon dilation catheter in Embodiment 2 of the present invention, wherein the balloon is in an inflated state before depressurization; Figure 6 for Figure 5 A sectional view; Figure 7 This is a schematic diagram of the overall structure of the balloon dilation catheter in Embodiment 2 of the present invention, wherein the balloon is axially stretched and twisted during the decompression process; Figure 8 for Figure 7 A sectional view; Figure 9 This is a schematic diagram of the overall structure of the balloon dilation catheter in Embodiment 3 of the present invention, wherein the balloon is in an inflated state before depressurization, and the threaded guide block is in a mating position with the threaded section of the inner tube seat. Figure 10 for Figure 9 A sectional view; Figure 11 for Figure 10 A schematic diagram of the connection structure of the threaded section of the inner tube seat, the fixed seat, the threaded guide block, the elastic element, and the pressing element; Figure 12 This is a schematic diagram of the overall structure of the balloon dilation catheter in Embodiment 3 of the present invention, wherein the pressing element is pressed down, the threaded guide block is in the released position where it is released from the threaded section of the inner tube seat, and the balloon is axially stretched during the decompression process; Figure 13 for Figure 12 A sectional view; Figure 14This is a schematic diagram of the overall structure of the balloon dilation catheter in Embodiment 3 of the present invention. When the pressing element is released, the threaded guide block is in a mating position with the threaded section of the inner tube seat. During the decompression of the balloon, it is axially stretched and twisted. Figure 15 for Figure 14 A sectional view.

[0023] Explanation of reference numerals in the attached drawings: 100, inner tube; 200, outer tube; 300, balloon; 400, head end tube; 500, outer tube seat; 510, balloon inflation interface; 520, external thread structure; 530, limiting groove; 600, inner tube seat; 610, limiting rib; 620, axial limiting circumferential rotation structure; 630, inner tube fixing part; 640, threaded sleeve part; 650, inner tube seat threaded section; 660, inner tube seat axial limiting section; 710, sealing seat; 720, sealant; 800, knob; 910, fixing seat; 911, guide post; 920, threaded guide block; 921, threaded guide structure; 930, elastic element; 940, pressing element. Detailed Implementation

[0024] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] In the description of this invention, it should be understood that the terms "proximal" and "distal" throughout the text refer to near and far relative to the operator. In use, the end closer to the doctor or operator is the "proximal" end, i.e., the end where the operator is located, and the end farther from the doctor or operator is the "distal" end. The above descriptions of orientation are merely for the convenience of describing this application and for simplification, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on this application.

[0027] In current interventional vascular treatments for arterial occlusion, an inflatable balloon, placed distal to a catheter, is typically used to dilate the blocked artery, widening the narrowed area to restore arterial patency and improve blood flow. After dilation, the balloon is depressurized to inflate and then withdrawn from the body.

[0028] However, the shape of the balloon after decompression is irregular. It typically presents as two pieces attached to the catheter surface, resulting in a relatively large overall outer diameter. This can easily damage the blood vessel wall and hinder balloon withdrawal. Furthermore, balloon withdrawal requires skilled operator intervention and carries certain safety risks. To address these issues, this invention provides a balloon dilation catheter with a small overall outer diameter after decompression, which is easy to withdraw and less likely to damage the blood vessel wall during withdrawal.

[0029] Example 1 like Figures 1 to 4 The illustrated balloon dilation catheter includes an inner tube 100, an outer tube 200, a balloon 300, a tip tube 400, and a catheter seat assembly. The inner tube 100 passes through the lumen of the outer tube 200, and the inner tube 100 and outer tube 200 are axially movable relative to each other. Both the inner tube 100 and outer tube 200 can be made of rigid polymer tubing or stainless steel tubing. The rigidity of the inner tube 100 allows it to reliably transmit axial forces and torques received proximally to its distal end, as does the rigidity of the outer tube 200. The distal end of the inner tube 100 extends outward from the distal opening of the outer tube 200, and the tip tube 400 is located at the distal end of the outer tube 200 and is sealed to the outer periphery of the distal end of the inner tube 100.

[0030] like Figures 1 to 4 As shown, the balloon 300 is made of a flexible material. The proximal end of the balloon 300 is sealed to the outer tube 200, and the distal end of the balloon 300 is sealed to the tip tube 400. An axially extending balloon inflation channel is formed between the outer tube 200 and the inner tube 100, and the inner lumen of the balloon 300 communicates with the balloon inflation channel. The catheter seat assembly includes an outer tube seat 500 and an inner tube seat 600. The outer tube seat 500 is provided with a balloon inflation port 510 that communicates with the balloon inflation channel. Fluid media can flow in through the balloon inflation port 510 to inflate the balloon 300 or flow out to depressurize the balloon 300.

[0031] like Figures 1 to 4As shown, the outer tube seat 500 and the inner tube seat 600 are axially movable relative to each other. The proximal end of the outer tube 200 is fixedly connected to the outer tube seat 500, and the axial tensile force or rotational torque on the outer tube seat 500 can be transmitted to the proximal end of the balloon 300 through the rigid outer tube 200. The proximal end of the inner tube 100 is fixedly connected to the inner tube seat 600, and the axial thrust or rotational torque on the inner tube seat 600 can be transmitted to the distal end of the balloon 300 through the rigid inner tube 100.

[0032] like Figures 1 to 4 As shown, the conduit seat assembly also includes a sealing element fixedly connected inside the outer tube seat 500, and the sealing element is fitted over the outer periphery of the inner tube 100. In some embodiments, the sealing element includes a sealing seat 710 and a sealant 720. The sealing seat 710 has a cylindrical shape with an internal cavity and the cavity opening facing the distal end, and the sealing seat 710 is fitted over the outer periphery of the inner tube 100. The distal end of the sealing seat 710 is bonded and fixed to the outer tube seat 500 with adhesive. The sealant 720 is elastically compressed within the cavity of the sealing seat 710, and the sealant 720 is tightly fitted over the outer periphery of the inner tube 100. The sealant 720 is used to reliably seal the gap between the sealing seat 710 and the inner tube 100. The material of the sealant 720 can be silicone with good elasticity and good adhesion to metals and plastics; due to the high resilience of the sealant 720, the sealant 720 in the cavity can elastically compress the outer wall of the inner tube 100, so that a reliable seal is maintained between the inner tube 100 and the sealant 720. Due to the good adhesion of the sealant 720, the inner tube 100 and the sealant 720 can still maintain a good contact and sealing state when the inner tube 100 moves or rotates relative to the sealing seat 710. Since the outer tube 200 and inner tube 100 are relatively movable in this invention, and the outer tube seat 500 is fixedly connected to the outer tube 200, the outer tube seat 500 and inner tube 100 are axially movable relative to each other. Compared with the traditional balloon dilation catheter where the outer tube seat and inner tube are bonded and fixed and cannot move axially, the sealing performance of the mating position between the outer tube seat 500 and inner tube 100 in this invention is relatively poor. However, the setting of the sealing seat 710 and sealant 720 between the outer tube seat 500 and inner tube 100 compensates for the poor sealing performance of the axially movable mating between the outer tube seat 500 and inner tube 100, thereby ensuring the sealing performance of the balloon inflation channel and enabling the balloon 300 to be stably inflated by the fluid medium.

[0033] During the withdrawal of this balloon dilation catheter from the body, the balloon 300 is depressurized through the negative pressure suction device connected to the balloon inflation port 510. During the depressurization of the balloon 300, the inner tube seat 600 is moved distally or the outer tube seat 500 is moved proximally. The balloon 300 is subjected to an axially stretched force during the depressurization process, and the axial length of the balloon 300 after depressurization is elongated. The overall outer diameter of the balloon 300 after depressurization and stretching is smaller than the overall outer diameter of the balloon 300 after direct depressurization, which is beneficial for withdrawing the balloon dilation catheter from the blood vessel.

[0034] like Figure 2 and Figure 4 As shown, a circumferential anti-rotation and axial sliding fit structure is provided between the inner tube seat 600 and the outer tube seat 500. This structure ensures that the inner tube seat 600 and the outer tube seat 500 are circumferentially fixed and axially sliding. In some embodiments, the circumferential anti-rotation and axial sliding fit structure includes a limiting rib 610 extending axially from the outer periphery of the inner tube seat 600 and a limiting groove 530 extending axially from the inner wall of the outer tube seat 500. The limiting rib 610 and the limiting groove 530 slide in the axial direction. It is understood that the number of limiting ribs 610 and limiting grooves 530 can be one or more, and their positions can be interchanged.

[0035] like Figure 2 and Figure 4 As shown, the outer wall of the proximal end of the outer tube seat 500 is provided with an external thread structure 520. The conduit seat assembly also includes a knob 800, the inner wall of which has an internal thread structure, and the knob 800 is threaded to the external thread structure 520 on the outer wall of the outer tube seat 500 through the internal thread structure of the inner wall.

[0036] like Figure 2 and Figure 4 As shown, the inner tube seat 600 has an axially limiting circumferential rotation structure 620 on its outer periphery. A knob 800 is rotatably connected to the axially limiting circumferential rotation structure 620 of the inner tube seat 600. The knob 800 is axially fixed and circumferentially rotated relative to the inner tube seat 600 through the axially limiting circumferential rotation structure 620. In some embodiments, the axially limiting circumferential rotation structure 620 is an axially limiting groove with a pair of limiting walls at both ends. The knob 800 rotates with the axially limiting groove, and the pair of limiting walls of the axially limiting groove respectively block the proximal and distal ends of the knob 800, thereby achieving axial limiting of the knob 800.

[0037] During the decompression of the balloon 300, the balloon 300 can be axially stretched by rotating the knob 800 or rotating the outer tube seat 500. Axial stretching of the balloon 300 during decompression causes it to conform to the outer periphery of the inner tube 100, preventing it from forming a two-piece sheet-like shape. The smaller overall outer diameter of the balloon 300 after axial stretching facilitates its retraction from the blood vessel, reducing the risk of damage to the vessel wall during retraction and improving safety. It also reduces the difficulty of the balloon 300 retraction process.

[0038] When the knob 800 is rotated, the outer tube seat 500 remains stationary. The knob 800 is rotated further to the distal end. Due to the limiting and guiding effect of the axial limiting circumferential rotation structure 620 between the knob 800 and the inner tube seat 600, and the circumferential anti-rotation axial sliding fit structure between the inner tube seat 600 and the outer tube seat 500, the knob 800 drives the inner tube seat 600 and the inner tube 100 to make a single axial movement relative to the outer tube seat 500 in the distal direction. The distal end of the balloon 300 is driven to move distally by the inner tube 100, while the proximal end of the balloon 300 remains stationary. The balloon 300 is axially stretched.

[0039] When the outer tube seat 500 is rotated, the knob 800 remains stationary. The outer tube seat 500 is rotated back towards the proximal end, and the inner tube seat 600 rotates synchronously with the outer tube seat 500 but remains stationary in the axial position. The outer tube seat 500 drives the outer tube 200 to move towards the proximal end. The proximal end of the balloon 300 is stretched towards the proximal end by the outer tube 200, while the distal end of the balloon 300 remains stationary. The balloon 300 is stretched axially.

[0040] Example 2 like Figures 5 to 8 The balloon dilation catheter shown differs from Embodiment 1 in that the knob 800 of the catheter seat assembly is omitted, and the connection structure between the outer tube seat 500 and the inner tube seat 600 is changed. In this embodiment, the outer wall of the proximal end of the outer tube seat 500 is provided with an external thread structure 520; the inner tube seat 600 includes an inner tube fixing part 630 and a threaded sleeve part 640 integrally formed with the inner tube fixing part 630. The threaded sleeve part 640 is sleeved on the outer periphery of the proximal end of the outer tube seat 500, and the inner wall of the threaded sleeve part 640 is provided with an internal thread. The internal thread of the inner wall of the threaded sleeve part 640 is threadedly connected to the external thread structure 520 on the outer wall of the outer tube seat 500.

[0041] In this balloon dilation catheter, during the decompression process of balloon 300, the balloon 300 can be axially stretched and twisted by rotating either the inner tube seat 600 or the outer tube seat 500. The simultaneous axial stretching and twisting of balloon 300 during decompression results in an elongated axial length after decompression, causing it to adhere to the outer circumference of the inner tube 100 in a twisted shape. The overall outer diameter of balloon 300 after decompression, stretching, and twisting is smaller than its overall outer diameter after direct decompression, facilitating the retraction of the balloon dilation catheter from the blood vessel. Compared to embodiment one, embodiment two eliminates the knob 800, and the structures of the outer tube seat 500 and inner tube seat 600 are simpler, resulting in lower manufacturing costs. The balloon 300 is axially stretched while tending to rotate, forming a circumferentially twisted shape.

[0042] When the inner tube seat 600 is rotated, the outer tube seat 500 remains stationary, and the inner tube seat 600 is rotated distally. The inner tube seat 600 drives the inner tube 100 to rotate circumferentially relative to the outer tube 200 and to move axially distally. The distal end of the balloon 300 is stretched and rotated distally by the inner tube 100, while the proximal end of the balloon 300 remains stationary. Therefore, the balloon 300 is stretched and twisted axially.

[0043] When the outer tube seat 500 is rotated, the inner tube seat 600 remains stationary, and the outer tube seat 500 rotates back towards the proximal end. The outer tube seat 500 drives the outer tube 200 to rotate circumferentially relative to the inner tube 100 and to move axially towards the proximal end. The proximal end of the balloon 300 is stretched and rotated towards the proximal end by the outer tube 200, while the distal end of the balloon 300 remains stationary. Therefore, the balloon 300 is stretched and twisted axially.

[0044] Example 3 like Figures 9 to 15 The balloon dilation catheter shown differs from Embodiment 1 in that the catheter seat assembly further includes a fixing seat 910, a threaded guide block 920, an elastic element 930, and a pressing element 940. The inner tube seat 600 includes an inner tube seat threaded section 650 with external threads on its outer periphery and an inner tube seat axial limiting section 660 with a locally enlarged outer diameter.

[0045] like Figures 9 to 15As shown, the fixed seat 910 has an internal cavity. The fixed seat 910 is fixedly connected to the proximal end of the outer tube seat 500 and sleeved on the outer periphery of the inner tube seat 600. The inner tube seat 600 passes through the cavity of the fixed seat 910, and the threaded section 650 of the inner tube seat is located within the cavity of the fixed seat 910. The threaded guide block 920 is located within the cavity of the fixed seat 910. The threaded guide block 920 is axially fixed relative to the fixed seat 910, and is movably mounted on the fixed seat 910 along the radial direction. The threaded guide block 920 has an inner hole extending through both ends axially. The inner tube seat 600 passes through the inner hole of the threaded guide block 920, and the inner wall of the threaded guide block 920 has a threaded guide structure 921 that can thread-mate with the threaded section 650 of the inner tube seat.

[0046] like Figures 9 to 15 As shown, the outer wall of the threaded guide block 920 is provided with a pair of positioning grooves, and the inner wall of the fixed seat 910 is provided with a pair of guide posts 911. The guide posts 911 extend into one of the positioning grooves corresponding to their positions. An elastic element 930 is sleeved on the outer periphery of the guide post 911. The elastic element 930 is elastically disposed between the threaded guide block 920 and the fixed seat 910. The elastic force of the elastic element 930 drives the threaded guide block 920 to move to the position where it is threadedly engaged with the threaded section 650 of the inner tube seat. The elastic element 930 is specifically a spring. The pressing member 940 and the threaded guide block 920 are fixedly connected or are an integral structure. The pressing member 940 is movably installed on the fixed seat 910 along the radial direction of the fixed seat 910, and at least a portion of the pressing member 940 is exposed outside the fixed seat 910.

[0047] When the pressing member 940 is pressed, the threaded guide block 920 overcomes the elastic force of the elastic member 930 and moves to a position where it is disengaged from the threaded section 650 of the inner tube seat. At this time, the inner tube seat 600 can be axially pushed to drive the inner tube 100 to make a single axial movement towards the distal end. When the pressing member 940 is released, the threaded guide block 920 moves to a position where it is threadedly engaged with the threaded section 650 of the inner tube seat under the elastic restoring force of the elastic member 930. At this time, the inner tube seat 600 can be controlled to rotate to drive the inner tube 100 to make circumferential rotation and axial movement towards the distal end.

[0048] In this balloon dilation catheter, during the decompression of the balloon 300, the fixed seat 910 remains stationary. When the pressing element 940 is released, the threaded guide block 920, under the action of the elastic element 930, is in a mating position with the threaded section 650 of the inner tube seat. At this time, rotating the inner tube seat 600 causes the inner tube 100 to rotate circumferentially relative to the outer tube 200 and move axially towards the distal end. The distal end of the balloon 300 is stretched and rotated distally by the inner tube 100, while the proximal end of the balloon 300 remains stationary. Therefore, the balloon 300 is axially stretched and twisted. The axial stretching of the balloon 300 during decompression causes the shape of the balloon 300 after decompression to tend to adhere to the outer circumference of the inner tube 100, rather than forming a two-piece sheet-like shape on the outer circumference of the inner tube 100. The overall outer diameter of the balloon 300 after axial stretching after decompression is smaller. When the pressing element 940 is pressed, the threaded guide block 920 moves to a position where the threaded guide structure 921 on its inner wall is disengaged from the threaded section 650 of the inner tube seat. At this time, the inner tube seat 600 is pushed to make a single axial movement towards the distal end. The inner tube seat 600 drives the inner tube 100 to move axially towards the distal end. The distal end of the balloon 300 is stretched distally by the inner tube 100, while the proximal end of the balloon 300 remains stationary. Therefore, the balloon 300 is axially stretched. During the decompression process, the balloon 300 is axially stretched and twisted, which causes the axial length of the balloon 300 after decompression to be elongated and attached to the outer periphery of the inner tube 100 in a twisted shape. The overall outer diameter of the balloon 300 after decompression stretching and twisting is smaller than the overall outer diameter of the balloon 300 after direct decompression, which is beneficial for withdrawing the balloon dilation catheter from the blood vessel.

[0049] Compared with Embodiment 1 or Embodiment 2, Embodiment 3 allows the inner tube seat 600 to stretch the balloon 300 in two ways: single axial movement and spiral propulsion movement, depending on whether the pressing member 940 is pressed down. The appropriate method can be selected according to the actual changes in the shape of the balloon 300 during the decompression process. For example, the inner tube seat 600 can be manipulated to perform single axial movement or spiral propulsion movement at different stages of balloon 300 decompression. The two methods work together to minimize the overall outer diameter of the balloon 300 after decompression.

[0050] In summary, the balloon dilation catheter provided by this invention has the following advantages: the proximal end of the outer tube 200 is fixedly connected to the outer tube seat 500, and the proximal end of the inner tube 100 is fixedly connected to the inner tube seat 600, with the inner tube seat 600 and the outer tube seat 500 maintaining relative axial movement. During the decompression of the balloon 300, the inner tube seat 600 can be manipulated to move distally, or the outer tube seat 500 can be manipulated to move proximally. During the decompression of the balloon 300, it is subjected to an axially stretched force, and after decompression, the balloon 300 is axially elongated. The shape of the balloon 300 after decompression tends to adhere to the outer periphery of the inner tube 100, rather than forming a sheet-like shape. The overall outer diameter of the balloon 300 after decompression and stretching is further reduced compared to the overall outer diameter of the balloon 300 after direct decompression, which is beneficial for withdrawing the balloon dilation catheter from the blood vessel and reduces the risk of damage to the inner wall of the blood vessel during the withdrawal process, resulting in better safety.

[0051] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A balloon dilation catheter, characterized in that, Includes an inner tube (100), an outer tube (200), a balloon (300), and a catheter hub assembly; The inner tube (100) passes through the inner cavity of the outer tube (200), and the distal end of the inner tube (100) extends outward from the distal opening of the outer tube (200). The distal end of the balloon (300) is sealed to the inner tube (100), and the proximal end of the balloon (300) is sealed to the outer tube (200). An axially extending balloon inflation channel is formed between the outer tube (200) and the inner tube (100), and the inner cavity of the balloon (300) communicates with the balloon inflation channel. The catheter seat assembly includes an outer tube seat (500) and an inner tube seat (600) that is axially movable relative to the outer tube seat (500). The proximal end of the outer tube (200) is fixedly connected to the outer tube seat (500), and the proximal end of the inner tube (100) is fixedly connected to the inner tube seat (600). The outer tube seat (500) is provided with a balloon inflation port (510) communicating with the balloon inflation channel. During balloon (300) decompression, the inner tube seat (600) can be operably moved distally relative to the outer tube seat (500) to stretch the balloon (300) distally by the inner tube (100); or, the outer tube seat (500) can be operably moved proximally relative to the inner tube seat (600) to stretch the balloon (300) proximally by the outer tube (200).

2. The balloon dilation catheter according to claim 1, characterized in that, Both the inner tube (100) and the outer tube (200) are rigid tubes capable of transmitting axial force.

3. The balloon dilation catheter according to claim 1, characterized in that, The conduit seat assembly also includes a seal, which is fitted around the outer periphery of the inner tube (100) and fixedly connected to the outer tube seat (500).

4. The balloon dilation catheter according to claim 1, characterized in that, It also includes a head tube (400) that is sealed to the outer periphery of the distal end of the inner tube (100), and the distal end of the balloon (300) is sealed to the head tube (400).

5. The balloon dilation catheter according to any one of claims 1-4, characterized in that, The inner tube seat (600) and the outer tube seat (500) are provided with a circumferential anti-rotation and axial sliding fit structure, which makes the inner tube seat (600) and the outer tube seat (500) relatively circumferentially fixed and relatively axially sliding. The catheter seat assembly also includes a knob (800), which is fixed in the axial direction and rotates in the circumferential direction relative to the inner tube seat (600), and the knob (800) is threaded to the outer tube seat (500). During the decompression of the balloon (300), the outer tube seat (500) remains stationary, and the knob (800) is rotated. The knob (800) drives the inner tube seat (600) and the inner tube (100) to move distally. The inner tube (100) stretches the balloon (300) distally to reduce the outer diameter of the balloon (300) after decompression. Alternatively, the knob (800) remains stationary, and the outer tube seat (500) is rotated. The outer tube seat (500) drives the outer tube (200) to move proximally. The outer tube (200) stretches the balloon (300) proximally to reduce the outer diameter of the balloon (300) after decompression.

6. The balloon dilation catheter according to claim 5, characterized in that, The circumferential anti-rotation axial sliding fit structure includes a limiting rib (610) provided on the outer periphery of the inner tube seat (600) and extending axially, and a limiting groove (530) provided on the inner wall of the outer tube seat (500) and extending axially. The limiting rib (610) and the limiting groove (530) slide fit together in the axial direction.

7. The balloon dilation catheter according to claim 5, characterized in that, The outer periphery of the inner tube seat (600) is provided with an axial limiting circumferential rotation structure (620). The knob (800) is fixed in a relatively axial direction and rotates relatively in a relatively circumferential direction with the inner tube seat (600) through the axial limiting circumferential rotation structure (620).

8. The balloon dilation catheter according to any one of claims 1-4, characterized in that, The outer tube seat (500) is provided with an external thread structure (520) on its outer periphery. The inner tube seat (600) includes an inner tube fixing part (630) and a threaded sleeve part (640) integrally connected to the inner tube fixing part (630). The inner tube fixing part (630) is fixedly connected to the proximal end of the inner tube (100). The threaded sleeve part (640) is sleeved on the outer periphery of the outer tube seat (500), and the inner wall of the threaded sleeve part (640) is provided with a sleeve internal thread. The sleeve internal thread of the inner wall of the threaded sleeve part (640) is threaded to the external thread structure (520) on the outer wall of the outer tube seat (500). During the decompression of the balloon (300), the outer tube seat (500) remains stationary, while the inner tube seat (600) is rotated. The inner tube seat (600) causes the inner tube (100) to rotate circumferentially relative to the outer tube (200) and move axially toward the distal end. The inner tube (100) stretches and twists the balloon (300) distally to reduce the outer diameter of the balloon (300) after decompression. Alternatively, the inner tube seat (600) remains stationary, while the outer tube seat (500) is rotated. The outer tube seat (500) causes the outer tube (200) to rotate circumferentially relative to the inner tube (100) and move axially toward the proximal end. The outer tube (200) stretches and twists the balloon (300) proximally to reduce the outer diameter of the balloon (300) after decompression.

9. The balloon dilation catheter according to any one of claims 1-4, characterized in that, The inner tube seat (600) includes an inner tube seat threaded section (650) with external threads on its outer periphery. The guide seat assembly also includes a fixed seat (910) and a threaded guide block (920). The threaded guide block (920) is axially fixed relative to the fixed seat (910), and the threaded guide block (920) is movably mounted on the fixed seat (910) along the radial direction of the fixed seat (910). The fixing seat (910) has a cavity inside. The fixing seat (910) is fixedly connected to the proximal end of the outer tube seat (500) and sleeved on the outer periphery of the inner tube seat (600). The inner tube seat (600) passes through the cavity of the fixing seat (910). The threaded guide block (920) has an inner hole that extends through both ends in the axial direction. The inner tube seat (600) passes through the inner hole of the threaded guide block (920). The inner wall of the threaded guide block (920) has a threaded guide structure (921) that can be threadedly engaged with the threaded section (650) of the inner tube seat. During the decompression of the balloon (300), the fixing seat (910) remains in place; When the threaded guide block moves to the position where the threaded guide structure (921) on its inner wall engages with the threaded section (650) of the inner tube seat, the inner tube seat (600) is rotated. The inner tube seat (600) drives the inner tube (100) to rotate circumferentially relative to the outer tube (200) and move axially toward the distal end. The inner tube (100) stretches and twists the balloon (300) toward the distal end to reduce the outer diameter of the balloon (300) after depressurization. When the threaded guide block moves to the position where the threaded guide structure (921) on its inner wall is disengaged from the threaded section (650) of the inner tube seat, the inner tube seat (600) is operated to make a single axial movement toward the distal end. The inner tube seat (600) drives the inner tube (100) to make an axial movement toward the distal end only. The inner tube (100) stretches the balloon (300) toward the distal end to reduce the outer diameter of the balloon (300) after depressurization.

10. The balloon dilation catheter according to claim 9, characterized in that, The threaded guide block (920) is located in the cavity of the fixed seat (910). The threaded guide block (920) is fixedly connected to a pressing member (940). The pressing member (940) is movably installed on the fixed seat (910) along the radial direction of the fixed seat (910), and at least a portion of the pressing member (940) is exposed outside the fixed seat (910). The outer wall of the threaded guide block (920) is provided with a positioning groove, and the inner wall of the fixed seat (910) is provided with a guide post (911) extending into the positioning groove. An elastic element (930) is sleeved on the outer periphery of the guide post (911). The elastic element (930) is elastically disposed between the threaded guide block (920) and the fixed seat (910). The elastic force of the elastic element (930) drives the threaded guide block (920) to move to the position where it is threadedly engaged with the threaded section (650) of the inner tube seat. When the pressing member (940) is pressed, the threaded guide block (920) moves against the elastic force of the elastic member (930) to a position where it is released from the threaded section (650) of the inner tube seat; when the pressing member (940) is released, the threaded guide block (920) moves under the elastic restoring force of the elastic member (930) to a position where it is threadedly engaged with the threaded section (650) of the inner tube seat.

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