Balloon dilatation catheter

Abstract

The utility model provides a balloon dilatation catheter which comprises a catheter body and an expandable and contractible balloon, and the catheter body comprises a first section which is located at the far end of the catheter body and penetrates through the interior of the balloon in the axial direction; the pipe body further comprises a first fluid channel and a second fluid channel which are used for conveying filling liquid. The first fluid channel is communicated with an inner cavity of the balloon through a first liquid passing opening, and the first liquid passing opening is formed in the near-side section of the first section; the catheter body further comprises a one-way conduction structure, and the one-way conduction structure is arranged on the far side section of the first section and used for conducting the inner cavity of the balloon and the second fluid channel in a one-way mode so as to allow the filling liquid to flow into the inner cavity of the balloon from the second fluid channel and limit the filling liquid from flowing out of the inner cavity of the balloon to the second fluid channel. The one-way conduction structure can greatly reduce the possibility of air retention when the balloon exhausts, and further improves the reliability and safety of the balloon dilatation catheter.

Description

Technical Field

[0001] This application belongs to the technical field of medical devices, and particularly relates to a balloon dilatation catheter. Background Art

[0002] Balloon aortic valvuloplasty (BAV) and transcatheter aortic valve replacement (TAVR) have become important surgeries for the treatment of aortic valve stenosis (AS). Among them, the balloon dilatation catheter plays an important role in the above surgeries. For example, in transcatheter aortic valve replacement, the balloon dilatation catheter is used to reach the aortic valve through the femoral artery to pre-dilate the aortic valve, so that the artificial valve can smoothly reach the lesion position of the aortic valve and be fully released. Another example is in balloon aortic valvuloplasty. First, the balloon dilatation catheter is advanced through the femoral artery to the middle of the stenotic aortic valve, and then the stenotic valve is dilated by balloon inflation, thereby reducing stenosis.

[0003] The existing balloon dilatation catheter includes an inner tube, an outer tube, and an inflatable balloon. The distal part of the inner tube passes through the inside of the balloon, and the other parts of the inner tube extend proximally after passing through the proximal end of the balloon. The outer tube is sleeved outside the inner tube and has a gap for transmitting the filling liquid between the outer tube and the inner tube to drive the state conversion of the balloon.

[0004] Clinically, the balloon dilatation catheter needs to be exhaust-operated before use. Specifically, the balloon is pre-filled with a certain amount of liquid and then repeatedly aspirated. The purpose is to evacuate the air in the balloon to prevent the air from interfering with the balloon filling effect during the balloon filling process. If the balloon accidentally ruptures during the filling process in the body, the air in the balloon will form an air embolism in the blood circulation system, bringing serious consequences.

[0005] Since the filling liquid enters the balloon through the gap between the inner tube and the outer tube at the proximal end of the balloon, during the pre-filling process, the proximal end of the balloon is preferentially filled, thereby squeezing the air to the distal end of the balloon, making the air concentrated at the distal end of the balloon. Also, since the filling liquid is withdrawn from the balloon through the gap between the inner tube and the outer tube at the proximal end of the balloon, the air concentrated at the distal end of the balloon is difficult to be completely exhausted, thus affecting the reliability and safety of the surgery. Summary of the Utility Model

[0006] Aiming at the problems existing in the prior art, the utility model provides a balloon dilatation catheter, which can greatly reduce the possibility of air retention during balloon exhaust and improve the reliability and safety of the balloon dilatation catheter.

[0007] The balloon dilation catheter includes a catheter body and an expandable and contractible balloon. The catheter body includes a first section located at its distal end and axially passing through the interior of the balloon. The catheter body further includes a first fluid passage and a second fluid passage for transmitting a filling fluid.

[0008] The first fluid passage communicates with the inner cavity of the balloon through a first fluid injection port, and the first fluid injection port is opened on the proximal section of the first section.

[0009] The catheter body further includes a one-way conduction structure, which is arranged on the distal section of the first section and is used to conduct the inner cavity of the balloon and the second fluid passage in one direction, so as to allow the filling fluid to flow from the second fluid passage into the inner cavity of the balloon and restrict the filling fluid from flowing out of the inner cavity of the balloon into the second fluid passage.

[0010] When performing the exhaust operation on the balloon dilation catheter provided by the present utility model, by setting the second fluid passage and the one-way conduction structure at the distal section of the first section, when the filling fluid is injected into the second fluid passage, the one-way conduction structure connects the first fluid passage with the inner cavity of the balloon, so that the filling fluid can enter the inner cavity of the balloon through the one-way conduction structure, thereby realizing the pre-filling of the balloon. Since the one-way conduction structure is arranged at the distal side of the first section (i.e., the distal side of the balloon), the distal part of the balloon can be preferentially filled, so that the air in the balloon is pushed to the proximal side of the balloon, and then the air converges at the proximal side of the balloon. Also, since the one-way conduction structure restricts the filling fluid from flowing out of the inner cavity of the balloon into the second fluid passage, it is ensured that the air converging at the proximal side of the balloon is discharged into the first fluid passage through the first fluid injection port arranged at the proximal side of the first section (i.e., the proximal side inside the balloon), thereby greatly reducing the air retention rate in the balloon and avoiding the situation that air accumulates at the distal end of the balloon and stays in the balloon, increasing the reliability and safety of the balloon dilation catheter during the operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings described below are only some embodiments provided by the embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0012] Figure 1 is a schematic diagram of the overall structure of a balloon dilation catheter provided by an embodiment of the present utility model;

[0013] Figure 2 is Figure 1 a schematic diagram of the structure when the one-way conduction structure in

[0014] Figure 3 is Figure 2 A schematic cross-sectional view of a structural form at line A-A in

[0015] Figure 4 is Figure 2 A schematic cross-sectional view of another structural form at line A-A in

[0016] Figure 5 is Figure 1 A schematic cross-sectional view at line B-B in

[0017] Figure 6 is Figure 1 A schematic diagram of the structure when the one-way conduction structure in

[0018] Figure 7 is a schematic diagram of the flow direction after the filling liquid enters the balloon through the one-way conduction structure;

[0019] Figure 8 is a schematic diagram of the structure when the one-way conduction structure provided by another embodiment of the present invention is in an expanded state;

[0020] Figure 9 is Figure 8 A schematic diagram of the structure when the one-way conduction structure in

[0021] Figure 10 is a schematic diagram of the structure when the one-way conduction structure provided by still another embodiment of the present invention is in a contracted state;

[0022] Figure 11 is Figure 10 A schematic diagram of the structure when the one-way conduction structure in Detailed implementation manners

[0023] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described implementation manners are only a part of the implementation manners of the present invention, rather than all of the implementation manners. Based on the implementation manners in the present invention, all other implementation manners obtained by those of ordinary skill in the art without making creative efforts fall within the protection scope of the present invention.

[0024] The following descriptions of the embodiments refer to the attached drawings, which are used to illustrate specific embodiments in which the present utility model can be implemented. The directional terms mentioned in the description of the present utility model, such as "upper", "lower", "front", "rear", "left", "right", "inner", "outer", "side", "side wall", etc., only refer to the directions shown in the attached drawings. Therefore, the directional terms used are for better and clearer description and understanding of the present utility model, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation on the present utility model.

[0025] In the description of the present utility model, for example, "first", "second", etc. are only used to distinguish the described objects and do not have any sequential or technical meanings.

[0026] In the description of the present utility model, the "connection" and "coupling" involved, unless otherwise specified, both include direct connection (coupling) and indirect connection (coupling).

[0027] In the field of interventional medical devices, the proximal end refers to the end closer to the operator, while the distal end refers to the end farther from the operator; the direction of the rotation central axis of an object such as a cylinder or a tube is defined as the axial direction; the circumferential direction is the direction around the axis of an object such as a cylinder or a tube (perpendicular to the axis and at the same time perpendicular to the cross-sectional radius); the radial direction refers to the direction along the diameter or radius. It should be noted that regardless of the "end" in words such as "proximal end", "distal end", "one end", "the other end", "first end", "second end", "initial end", "terminal end", "both ends", "free end", "upper end", "lower end", etc., it is not limited to the end head, end point or end face, but also includes the part that extends an axial distance and / or a radial distance on the element to which the end head, end point or end face belongs from the end head, end point or end face. The above definitions are only for the convenience of expression and cannot be construed as a limitation on the present utility model.

[0028] The embodiments of the present utility model provide a balloon dilation catheter, which can be widely used in cardiovascular interventional surgeries, especially suitable for treatment surgeries for aortic stenosis such as aortic balloon valvuloplasty and transcatheter aortic valve replacement. Of course, the balloon dilation catheter is not limited to being applied to the aortic valve and can also be applied to other tissues, such as the mitral valve, tricuspid valve, and pulmonary valve.

[0029] Please refer to Figures 1 - 3 , the balloon dilation catheter 100 includes a tube body 2 and an inflatable and deflatable balloon 1. The tube body 2 includes a first section a located at its distal end and axially fixedly passing through the inside of the balloon 1; the tube body 2 further includes a first fluid channel b1 and a second fluid channel b2 for transmitting liquid.

[0030] Among them, the first fluid passage b1 communicates with the inner cavity of the balloon 1 through the first liquid passage port c, and the first liquid passage port c is opened at the proximal section of the first section a.

[0031] The tube body 2 further includes a one-way conduction structure 23, and the one-way conduction structure 23 is arranged at the distal section of the first section a and is used for one-way conduction between the inner cavity of the balloon 1 and the second fluid passage b2, so as to allow the liquid to flow from the second fluid passage b2 into the inner cavity of the balloon 1 and restrict the liquid from flowing out of the inner cavity of the balloon 1 into the second fluid passage b2.

[0032] Among them, the above-mentioned liquid can be, for example, a filling liquid, and the filling liquid is, for example, normal saline, heparinized normal saline, normal saline containing a contrast agent, etc.

[0033] It can be understood that when the balloon dilation catheter 100 provided in this application performs an exhaust operation, through the one-way conduction structure 23 arranged at the distal section of the first section a, when the filling liquid is injected into the second fluid passage b1, the one-way conduction structure 23 connects the second fluid passage b with the inner cavity of the balloon 1, so as to realize the pre-filling of the balloon 1. Since the one-way conduction structure 23 is arranged at the distal side of the first section a (that is, the distal side of the balloon 1), the distal part of the balloon 1 can be preferentially filled, so as to push the air in the balloon 1 to the proximal side of the balloon 1 (as Figure 7 shown, Figure 7 shows the flow direction of the filling liquid into the balloon through the one-way conduction structure 23 during exhaust), and then the air converges on the proximal side of the balloon 1. Moreover, since the one-way conduction structure 23 restricts the filling liquid from flowing out of the inner cavity of the balloon 1 into the second fluid passage b2, it is ensured that the air converging on the proximal side of the balloon 1 is discharged into the first fluid passage b1 through the first liquid passage port c arranged at the proximal side of the first section a (that is, the proximal side inside the balloon 1), thereby greatly reducing the air retention rate in the balloon 1 and avoiding the situation that air accumulates at the distal end of the balloon 1 and stays in the balloon 1, and increasing the reliability and safety of the balloon dilation catheter 100 during the operation.

[0034] Optionally, as Figure 1As shown, the balloon 1 includes a proximal tapered section 11, a distal tapered section 12, and an intermediate working section 13 located between the proximal tapered section 11 and the distal tapered section 12. In some embodiments, the proximal tapered section 11 and the distal tapered section 12 of the balloon 1 after inflation are generally conical in shape, and the intermediate working section 13 of the balloon 1 after inflation is generally cylindrical. The outer diameter of the intermediate working section 13 is between 11.8 mm and 28.6 mm, and the axial length of the intermediate working section 13 is between 36 mm and 44 mm. Taking aortic balloon valvuloplasty as an example, the intermediate working section 13 of the balloon 1 is used to be positioned in the middle of the aortic valve during the operation to expand and support the aortic valve. The parameter specifications such as the diameter and length of each part of the balloon 1 should be selected according to the degree of stenosis of the aortic valve to be treated to adapt to the anatomical structure size of the valve. In other embodiments, the overall shape of the balloon 1 can also be gourd-shaped, peanut-shaped, etc., and the present utility model does not limit this.

[0035] Further, as Figure 2 shown, the one-way conduction structure 23 includes a second liquid passage opening 231 and a valve film 232. Among them, the second liquid passage opening 231 is opened at the distal section of the first section a and directly communicates with the inner cavity of the balloon 1 and the second fluid passage b2. The valve film 232 is arranged outside the second liquid passage opening 231, and the valve film 232 can expand (radially outward) or contract (radially inward) after being stressed to open or block the second liquid passage opening 231.

[0036] As some examples, the valve film 232 is made of a material with high elasticity and strong flexibility, so that the valve film 232 can flexibly expand or contract inside the balloon 1 under the fluid pressure of the second fluid passage b2. Optionally, the material of the valve film 232 is selected from one or a combination of materials such as silica gel, rubber, nylon elastomer, block polyether amide elastomer, polyurethane elastomer, etc. In order to ensure that the valve film 232 has good deformation ability under the action of fluid to increase the reliability of the one-way conduction structure 23, preferably, the tensile strength of the valve film 232 is greater than 50 Mpa, the elastic modulus is less than 18 Gpa, and the elongation at break is greater than 300%.

[0037] As some examples, both the second liquid passage opening 231 and the valve film 232 are located in the distal tapered section 13 of the balloon 1 to ensure that the second liquid passage opening 231 and the valve film 232 are located on the distal side of the inner cavity of the balloon 1, so as to ensure that the distal part of the balloon 1 can be preferentially filled to expel the air in the balloon 1 to the proximal side of the balloon 1.

[0038] As some examples, the first liquid passage opening c (as Figure 1 shown) is located in the proximal tapered section 11 of the balloon 1 and is specifically opened at the proximal end of the balloon 1 to facilitate the effective discharge of the air expelled to the proximal side of the balloon 1.

[0039] Understandably, the present utility model realizes the one-way conduction function of the one-way conduction structure 23 through the combination of the second liquid passage port c and the elastic valve film 232, and in cooperation with the fluid action of the filling liquid, with simple structure, high safety, low cost and strong reliability. In other embodiments, existing one-way valve structures such as piston-type one-way valves and ball-type one-way valves can also be used to realize the one-way conduction function of the one-way conduction structure 23, which will not be elaborated here.

[0040] Further, as Figure 2 shown, when the valve film 232 expands (radially outward), an interval cavity 233 is formed between the valve film 232 and the outer surface of the first section a, and the interval cavity 233 communicates the second liquid passage port 231 with the inner cavity of the balloon 1. As Figure 6 shown, when the valve film 232 contracts (radially inward), the valve film 232 fits against the outer surface of the first section a to block the second liquid passage port 231.

[0041] Optionally, the initial state of the valve film 232 (i.e., the state when the valve film 232 is installed in the balloon 1 and is not affected by the filling liquid and other external forces) can be an expanded state or a contracted state.

[0042] Please refer to Figures 1 - 3 again. In some embodiments, the initial state of the valve film 232 is an expanded state. When the valve film 232 is in the initial state, an interval cavity 233 is formed between the valve film 232 and the outer surface of the first section a, and the second liquid passage port 231 communicates the second fluid passage b2 with the inner cavity of the balloon 1. When filling liquid is injected into the second fluid passage b2, the pressure on the side of the valve film 232 close to the second liquid passage port 231 is greater than the pressure on the side of the valve film 232 away from the second liquid passage port 231, and the valve film 232 continues to maintain the state of expanding radially outward along the first section a. The second fluid passage b2, the second liquid passage port 231, the interval cavity 233 and the inner cavity of the balloon 1 are sequentially communicated, and the filling liquid can flow from the second fluid passage b2 into the inner cavity of the balloon 1 to realize pre-filling of the balloon 1. After the pre-filling is completed, the valve film 232 radially contracts under the pressure of the filling liquid in the balloon 1 (as Figure 6 shown), so that the inner wall of the valve film 232 closely adheres to the outer surface of the first section a and the second liquid passage port 231, blocking the second liquid passage port 231, thereby restricting the filling liquid from flowing out of the inner cavity of the balloon 1 into the second fluid passage b2, and the filling liquid in the balloon 1 can be discharged through the first liquid passage port c and the first fluid passage b1 in sequence.

[0043] Preferably, the valve film 232 is disposed outside the second liquid passage port 231 and the first section a, and the second liquid passage port 231 is located within the projection of the valve film 232 in the axial direction of the first section a. The above arrangement can avoid or reduce the possibility that the valve film 232 cannot contract well under fluid pressure and thus cannot block the second liquid passage port 231, so as to increase the reliability of the one-way conduction structure 23.

[0044] It should be noted that the distal segment of the first section a includes both the part of the first section a close to the distal end and the distal end face of the first section a, and the proximal segment of the first section a includes both the part of the first section a close to the proximal end and the proximal end face of the first section a.

[0045] Preferably, when the valve film 232 is in the expanded state, the proximal end of the spacer cavity 233 is closed and the distal end is open, and the distal end of the spacer cavity 233 is spaced from the distal end of the inner wall of the balloon 1. It can be understood that by setting the proximal end of the spacer cavity 233 to be closed, the distal end to be open and the distal end of the spacer cavity 233 to be spaced from the distal end of the balloon 1, the fluid outlet of the one-way conduction structure 23 faces the distal end of the balloon 1 and the distal end of the balloon 1 does not block the fluid outlet of the one-way conduction structure 23, further ensuring that the distal end of the balloon 1 can be preferentially filled, ensuring that the air in the balloon 1 can be effectively emptied, and increasing the reliability of the one-way conduction structure 23.

[0046] Exemplarily, the axial distance between the distal end of the spacer cavity 233 and the distal end of the inner wall of the balloon 1 is between 3 mm and 8 mm.

[0047] Optionally, the proximal end of the valve film 232 is fixedly connected to the first section a to close the proximal end of the spacer cavity 233 and at the same time fix the relative position between the proximal end of the valve film 232 and the first section a.

[0048] Please refer to again Figure 2 and Figure 3 , as some examples, the valve film 232 is arranged as a frustum-shaped structure that is hollow and has a smaller inner diameter at the proximal end than at the distal end. The valve film 232 is sleeved on the distal segment of the first section a, and the proximal end of the valve film 232 is fixedly and tightly connected to the outer surface of the part of the first section a on the proximal side of the second liquid passage port 231 in the circumferential direction to achieve the seal between the proximal end of the valve film 232 and the first section a. The valve film 232 surrounds the second liquid passage port 231 in the circumferential direction so that it can block the second liquid passage port 231 well when in the contracted state.

[0049] Figure 2The valve membrane 232 with a frustum-shaped structure as shown is in an expanded state in the initial state. There is a spacer cavity 233 formed between the valve membrane 232 and the outer surface of the first section a. When the balloon 1 needs to be exhausted, a filling liquid is injected into the second fluid passage b2 through an external fluid pump. The filling liquid can flow from the second fluid passage b2 into the inner cavity of the balloon 1 through the above-mentioned spacer cavity 233, thereby realizing pre-filling of the balloon 1 to squeeze the air in the balloon 1 to the proximal end of the balloon 1, or even directly squeeze the air out of the proximal end of the balloon 1 into the first passage. After the pre-filling is completed, the filling liquid in the balloon 1 presses the valve membrane 232 in the reverse direction, and the second liquid passage port 231 is blocked. After that, the balloon 1 can be filled and depressurized through the first fluid passage b1 and the first liquid passage port c.

[0050] More specifically, the proximal end of the valve membrane 232 can be connected to the first section a by glue bonding, welding, heat fusion connection or suture fixation.

[0051] More specifically, as Figure 3 shown, the number of the second liquid passage ports 231 and the second fluid passages b2 can both be 1. In other embodiments, as Figure 4 shown, the number of the second liquid passage ports 231' and the second fluid passages b2' can be greater than 1 and are in one-to-one correspondence and communication. Preferably, when the number of the second liquid passage ports 231' and the second fluid passages b2' are both greater than 1, the multiple second liquid passage ports 231' and their corresponding second fluid passages b2' are uniformly arranged along the circumferential direction of the first section a.

[0052] More specifically, the axial distance between the distal end of the valve membrane 232 and the second liquid passage port 231 is between 1.0 mm and 4.5 mm, the overall axial length of the valve membrane 232 is between 5 mm and 10 mm, and the thickness of the valve membrane 232 is between 0.0013 inch and 0.003 inch.

[0053] Further, in order to limit the degree of opening of the distal end of the spacer cavity 233 and prevent the distal end of the valve membrane 232 from being reversely turned over, resulting in the situation that the valve membrane 232 cannot block the second liquid passage port 231, the one-way conduction structure 23 in the embodiment of the present invention further includes at least one restraint wire 234. Each restraint wire 234 is connected between the distal end of the valve membrane 232 and the distal end of the first section a to limit the degree of opening of the distal end of the spacer cavity 233.

[0054] Among them, the material of the restraint wire 234 can be selected from materials with high strength and good toughness such as polymer fibers and nylon. Preferably, there are multiple restraint wires 234, and they are connected between the proximal edge of the valve membrane 232 and the distal end of the first section a in a circumferential arrangement. The connection method can be selected from glue bonding, heat fusion connection or suture fixation, etc.

[0055] It should be noted that the cone angle, size and length of the above valve film 232, the opening size and quantity of the second liquid passage port 231, and the quantity and length of the constraint line 234 can all be set according to the actual balloon specifications, and the present utility model does not make special restrictions on this.

[0056] Please refer to Figure 1 , Figure 2 and Figure 5 , the tube body 2 is used to realize the pushing, filling and pressure relief of the balloon 1. Among them, the first fluid passage b1 and the second fluid passage b2 both extend along the axial direction of the tube body 2.

[0057] Optionally, the tube body 2 includes an inner tube 21 and an outer tube 22, and both the inner tube 21 and the outer tube 22 are slender members. Among them, the inner tube 21 is disposed inside the outer tube 22, and the proximal ends of the inner tube 21 and the outer tube 22 are fixedly connected. Moreover, the distal end of the inner tube 21 extends out of the distal end of the outer tube 22 and penetrates through the balloon 1. The balloon 1 is fixedly sleeved axially outside the first section a of the part of the inner tube 21 extending out of the outer tube 22. That is to say, the part of the distal end of the inner tube 21 extending out of the outer tube 22 at least includes the first section a, and the first section a is the part of the part of the distal end of the inner tube 21 extending out of the outer tube 22 that penetrates through the balloon 1. The distal end of the balloon 1 is hermetically connected to the distal end of the first section a, and the proximal end of the balloon 1 is hermetically connected to the distal end of the outer tube 22.

[0058] More specifically, the relative positions of the inner tube 21 and the outer tube 22 are fixed and the central axes are collinear. The inner diameter of the outer tube 22 is larger than the outer diameter of the inner tube 21, so that there is a gap between the inner wall of the outer tube 22 and the outer wall of the inner tube 21, thereby forming the first fluid passage b1 that penetrates through the outer tube 22. The first fluid passage b1 communicates with the inner cavity of the balloon 1 through its distal opening (i.e., the first liquid passage port c), so that the filling liquid from the proximal end of the tube body 2 can enter the inner cavity of the balloon 1 through the first fluid passage b1, and then the balloon 1 expands. Of course, the filling liquid can also flow out of the balloon 1 from the inner cavity of the balloon 1 through the first fluid passage b1, so that the balloon 1 shrinks after pressure relief. It should be noted that the filling through the first fluid passage b1 is to expand the balloon 1 to the required degree of the native valve or the artificial valve. During the filling process through the first fluid passage b1, the valve film 232 blocks the second liquid passage port 231 to prevent the leakage of the inner cavity of the balloon 1 from the second fluid passage b, ensuring that the balloon 1 can effectively expand when expanding the native valve or the artificial valve and improving the success rate of the operation.

[0059] Please refer to Figures 3 - 5, optionally, the inner tube 21 in the embodiment of the present utility model is a multi-chamber tube, including at least one second fluid channel b2 and a guide wire cavity d. Among them, the guide wire cavity d axially penetrates the inner tube 21, so that the inner tube 21 can be sleeved with a guide wire (not shown in the figure), and then reach the target position under the guidance of the guide wire. The second fluid channel b2 extends axially from the proximal end of the inner tube 21 to at least the distal end to the second liquid outlet 231 to ensure the communication between the second fluid channel b2 and the second liquid outlet 231; and the distal end of the second fluid channel b2 is closed, and the second fluid channel b2 and the guide wire cavity d are isolated from each other to prevent the filling liquid from leaking from the distal end of the inner tube 21.

[0060] Please refer to again Figure 1 , further, the balloon dilation catheter 100 further includes a catheter seat 24 provided at the proximal end of the tube body 2. The catheter seat 24 is fixedly connected to the proximal ends of the inner tube 21 and the outer tube 22 to realize the relative fixation between the inner tube 21 and the outer tube 22. The catheter seat 24 is provided with a guide wire port 241, a first filling port 242 and a second filling port 243. The guide wire port 241 is communicated with the guide wire cavity d of the inner tube 21. Thus, the guide wire port 241 and the guide wire cavity d of the inner tube 21 are used for sleeving the guide wire. Preferably, in order to improve the mobility between the guide wire and the inner tube 21, the guide wire port 241 faces the proximal opening of the guide wire cavity d of the inner tube 21. The first filling port 242 is communicated with the first fluid channel b1, and the second filling port 243 is communicated with the second fluid channel b2. Thus, the first filling port 242 and the first fluid channel b1 form a channel for filling and deflating the balloon 1, and the second filling port 243 and the second fluid channel b2 form a channel for pre-filling the balloon 1 to realize the exhaust of the balloon 1. Among them, the first filling port 242 realizes the filling and deflating of the balloon 1 by connecting an external fluid pump or a suction device, and the second filling port 243 realizes the pre-filling of the balloon 1 by connecting an external fluid pump (not shown in the figure).

[0061] Exemplarily, the outer diameter of the inner tube 21 is between 2.5 mm and 2.8 mm, the inner diameter of the outer tube 22 is between 3.2 mm and 3.5 mm, the outer diameter of the outer tube 22 is between 3.8 mm and 4.1 mm, the axial length of the inner tube 21 is between 1225 mm and 1275 mm, and the axial length of the outer tube 22 is between 1200 mm and 1250 mm; the inner diameter of the guide wire cavity d of the inner tube 21 is between 1.5 mm and 1.8 mm, and the inner diameter of the second fluid channel b2 of the inner tube 21 is between 0.4 mm and 0.6 mm.

[0062] In other embodiments, the tube body 2 may also include only the inner tube 21. Alternatively, the first liquid passage port c and the first fluid passage b1 may also be provided on the inner tube 21 (not shown in the figure). For example, the first liquid passage port c is provided on the proximal segment of the first section a of the inner tube 21, and the first fluid passage b1 extends axially from the proximal end of the inner tube 21 to at least the first liquid passage port c in the distal direction to ensure that the first fluid passage b1 communicates with the first liquid passage port c; and the distal end of the first fluid passage b1 is closed, and the first fluid passage b1 and the guide wire cavity d are isolated from each other to prevent the filling liquid from leaking from the distal end of the inner tube 21.

[0063] Please refer to again Figure 1 , optionally, a tip e is further provided at the distal end of the inner tube 21, and the tip e is configured as a tapered structure with a smooth transition at the distal end. The tip e can be made of a relatively soft metal material, and the outer diameter of the tip e gradually decreases from its proximal end to the distal end, so as to reduce the scratching of the inner wall of the lumen tissue by the tip e.

[0064] Please refer to Figure 8 , in other embodiments, Figure 2 and Figure 3 the valve membrane 232 shown in Figure 8 can also be replaced with the valve membrane 232a shown in

[0065] . The valve membrane 232a is arranged as an arc-shaped sheet structure. The valve membrane 232a is integrally attached to the outer surface of the distal segment of the first section a along the axial direction on the side where the second liquid passage port 231 is located, and the connection method of bulging along the direction away from the first section a can be glue bonding, welding, heat melting connection or stitching and fixing, etc. Figure 9 shown), and the valve membrane 232a presents a (radial) expanded form. There is an interval cavity 233 formed between the valve membrane 232 and the outer surface of the first section a. The proximal end of the interval cavity 233 is closed and the distal end is open, so that the fluid outlet of the one-way conduction structure 23 faces the distal end of the balloon 1. The filling liquid can flow into the inner cavity of the balloon 1 from the second fluid passage b2 to realize the pre-filling of the balloon 1. After the pre-filling is completed, the valve membrane 232 radially contracts inward under the pressure of the filling liquid in the balloon 1 (as shown in

[0066] shown), so that the valve membrane 232 is tightly attached to the outer surface of the first section a and the second liquid passage port 231, and the second liquid passage port 231 is blocked by the valve membrane 232, thereby restricting the filling liquid from flowing out of the inner cavity of the balloon 1 to the second fluid passage b2.

[0067] Among them, the material of the valve film 232a, the relative positional relationship with the second liquid passage port 231, the overall axial length, the thickness, etc. can all refer to Figure 2 the relevant description of the valve film 232 shown, which will not be elaborated here.

[0068] It can be understood that the valve film 232a is arranged in an arc-shaped sheet structure, so that the valve film 232a has better abutting performance with the first section a, and there is no need to set the constraint line 234, which simplifies the structure of the one-way conduction structure 23 and reduces the production cost of the product.

[0069] Please refer to Figure 10 and Figure 11 , in other embodiments, Figure 2 and Figure 3 the valve film 232 shown in can also be replaced by Figure 10 the valve film 232b shown. The valve film 232b is arranged as a hollow cylindrical structure. The valve film 232b is sleeved on the distal section of the first section a and surrounds the second liquid passage port 231. Preferably, the proximal end of the valve film 232b is hermetically connected to the proximal end of the first section a in the circumferential direction. When the valve film 232 (radially) expands, the proximal end of the spacer cavity 233 formed between the valve film 232 and the first section a is blocked, so that the fluid outlet of the one-way conduction structure 23 faces the distal end of the balloon 1, ensuring that the distal part of the balloon 1 can be preferentially filled.

[0070] In the initial state, the valve film 232b presents a contracted form and is closely attached to the first section a. When the filling liquid is injected into the second fluid passage b2, the pressure on the side of the valve film 232b close to the second liquid passage port 231 is greater than the pressure on the side of the valve film 232b away from the second liquid passage port 231. The valve film 232b expands radially outward along the first section a under the impact of the fluid (as shown in Figure 11 ), so as to radially move away from the first section a and the second liquid passage port 231, forming a spacer cavity 233 between the valve film 232b and the outer surface of the first section a, so that the second fluid passage b2, the second liquid passage port 231 and the inner cavity of the balloon 1 are communicated, and the filling liquid can flow from the second fluid passage b2 into the inner cavity of the balloon 1, and then the balloon 1 can be pre-filled through the second fluid passage b2 and the one-way conduction structure 23. When the pre-filling is completed, the filling liquid in the balloon 1 presses the valve film 232b reversely, so that the valve film 232b radially contracts and tightly adheres to the outer surface of the first section a and the second liquid passage port 231, and the second liquid passage port 231 is blocked, thereby restricting the filling liquid from flowing out of the inner cavity of the balloon 1 into the second fluid passage b2.

[0071] Among them, the material of the valve film 232b, the relative positional relationship with the second liquid passage port 231, the overall axial length, the thickness, the number and arrangement mode of the second liquid passage port 231 and the second fluid passage b2, etc. can all refer to Figure 2The related description of the valve film 232 shown is not elaborated here.

[0072] The above are some implementation manners of the present utility model. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present utility model, several improvements and refinements can be made, and these improvements and refinements are also regarded as the protection scope of the present utility model.

Claims

1. A balloon dilation catheter, characterized in that, Comprising a tube body and an expandable and contractible balloon disposed on the tube body, the tube body includes a first section located at its distal end and axially passing through the interior of the balloon; the tube body further includes a first fluid passage and a second fluid passage; The first fluid passage communicates with the inner cavity of the balloon through a first liquid passage opening, and the first liquid passage opening is provided on the proximal section of the first section; The tube body further includes a one-way conduction structure, and the one-way conduction structure is disposed on the distal section of the first section for one-way conduction between the inner cavity of the balloon and the second fluid passage, allowing liquid to flow from the second fluid passage into the inner cavity of the balloon and restricting liquid from flowing out of the inner cavity of the balloon into the second fluid passage.

2. The balloon dilation catheter according to claim 1, wherein The one-way conduction structure includes: A second liquid passage opening, provided on the distal section of the first section and communicating the inner cavity of the balloon with the second fluid passage; and A valve film, disposed outside the second liquid passage opening, and the valve film can expand or contract to open or block the second liquid passage opening.

3. The balloon dilation catheter according to claim 2, wherein When the valve film expands, a spacer cavity is formed between the valve film and the outer surface of the first section, and the spacer cavity communicates the second liquid passage opening with the inner cavity of the balloon; when the valve film contracts, the valve film fits against the outer surface of the first section to block the second liquid passage opening.

4. The balloon dilation catheter according to claim 3, wherein In the expanded state, the proximal end of the spacer cavity is closed and the distal end is open, and the distal end of the spacer cavity is spaced from the distal end of the inner wall of the balloon.

5. The balloon dilation catheter according to claim 4, wherein The proximal end of the valve film is fixedly connected to the first section to close the proximal end of the spacer cavity.

6. The balloon dilation catheter according to claim 4, wherein In the initial state, the valve film presents an expanded state; The valve film is a frustum-shaped structure that is hollow and has a smaller inner diameter at the proximal end than at the distal end, and the valve film is sleeved on the distal section of the first section; or, The valve film is an arc-shaped sheet structure, and the valve film is axially attached to the outer surface of the distal section of the first section and bulges in a direction away from the first section.

7. The balloon dilation catheter according to claim 6, wherein The one-way conduction structure further includes at least one restraining wire, and each restraining wire is connected between the distal end of the valve film and the distal end of the first section to limit the degree of opening of the distal end of the spacer cavity.

8. The balloon dilation catheter according to claim 4, characterized in that, In the initial state, the valve film presents a contracted state; the valve film is a hollow cylindrical structure, and the valve film is sleeved on the distal section of the first section.

9. The balloon dilation catheter according to any one of claims 2-8, characterized in that, The material of the valve film is selected from one or more combinations of silicone, rubber, nylon elastomer, block polyether amide elastomer, and polyurethane elastomer.

10. The balloon dilation catheter according to any one of claims 1-8, characterized in that, The tube body includes an inner tube and an outer tube, the outer tube is sleeved outside the inner tube and has a gap with the inner tube to form the first fluid passage axially penetrating the outer tube, and the first liquid passage opening is the distal opening of the first fluid passage; The distal end of the inner tube extends out of the distal end of the outer tube, the second fluid passage axially penetrates the inner tube, and the part of the inner tube extending out of the distal end of the outer tube includes the first section.

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