A flow rate control structure for a balloon catheter

Abstract

This application discloses a flow control structure for a balloon catheter. The balloon catheter has a distal end and a proximal end, wherein the distal end has a balloon body that can be inflated and deformed by fluid. A fluid channel communicating with the balloon body is provided inside the balloon catheter. At least a portion of the fluid channel is a control zone with an annular cross-sectional shape. The flow control structure includes a flow-controlling baffle, which is annular in shape and located within the control zone. The flow-controlling baffle is a deformable structure and has a first state and a second state depending on different fluid directions. In the first state, fluid is pushed from the proximal end to the distal end of the balloon catheter; in the second state, fluid is discharged from the distal end to the proximal end of the balloon catheter. Compared to the first state, the flow-controlling baffle reduces the degree of obstruction to the fluid channel in the second state. This control structure enables slow inflation and rapid depressurization of the balloon body.

Description

Technical Field

[0001] This application relates to the field of medical device technology, specifically to a flow control structure for a balloon catheter. Background Technology

[0002] Balloon angioplasty is a common minimally invasive surgery used to treat cardiovascular diseases. It involves making a small incision in the upper or lower limb to reach the diseased artery, inserting a small, expandable balloon through the incision, and using the physical expansion of the balloon to remove obstructions in the narrowed or blocked artery, thus acting as a plaque removal device.

[0003] Balloon catheters are commonly used consumables in balloon angioplasty. A balloon catheter has a distal end and a proximal end, with the distal end containing a balloon body that can be inflated and deformed by fluid. The balloon catheter has a fluid channel communicating with the balloon body. During the operation, the balloon body is inserted into the lesion site within the blood vessel along with the balloon catheter. Under pressure, fluid is delivered into the balloon body through the fluid channel within the balloon catheter. The balloon body inflates and repairs the lesion on the inner wall of the blood vessel. After the repair is completed, under pressure, the fluid in the balloon body is discharged from the fluid channel, and the balloon body is depressurized and withdrawn along with the balloon catheter.

[0004] Due to the unique characteristics of intracranial blood vessels, which have smaller diameters and thicker walls, a faster inflation rate during the use of an intracranial balloon dilation catheter can cause the blood vessels to be stretched due to sudden changes, increasing the risk of rupture. On the other hand, a slower inflation rate can lead to an excessively slow decompression of the balloon, or even prevent the balloon from being decompressed properly. Summary of the Invention

[0005] This invention provides a flow rate control structure for balloon catheters. The flow rate control structure of this application is disposed in the fluid channel, and the balloon body can be slowly pressurized and quickly depressurized through the control structure, thus solving the problems existing in the prior art.

[0006] A flow control structure for a balloon catheter, the balloon catheter having opposing distal and proximal ends, wherein the distal end has a balloon body that can be inflated and deformed by fluid, and the balloon catheter has a fluid channel communicating with the balloon body.

[0007] At least a portion of the fluid channel is a control zone, which has an annular cross-sectional shape. The flow rate control structure includes a flow control baffle, which is annular in shape and located in the control zone. The flow control baffle is a deformable structure and has a relative first state and a second state depending on different fluid directions.

[0008] In the first state, fluid is pushed from the proximal end to the distal end of the balloon catheter; in the second state, fluid is discharged from the distal end to the proximal end of the balloon catheter. Compared with the first state, the flow control baffle reduces the degree of obstruction to the fluid channel in the second state.

[0009] Several alternative methods are provided below, but they are not intended as additional limitations on the overall solution above. They are merely further additions or optimizations. Provided there are no technical or logical contradictions, each alternative method can be combined individually with respect to the overall solution above, or multiple alternative methods can be combined with each other.

[0010] Optionally, for the location of the flow control baffle, the flow rate Q1 in the first state of the fluid channel under the same pressure is 10% to 50% of the flow rate Q2 in the second state.

[0011] The same pressure here can be understood as follows: under test conditions, assuming no other factors are considered and the upstream pressure of the flow control baffle is consistent, the fluid flow rate Q1 flowing through the flow control baffle in the first state (pressurization) is 10% to 50% of the fluid flow rate Q2 flowing through the flow control baffle in the second state (depressurization). The upstream location of the flow control baffle changes according to the fluid flow direction. In the first state, the upstream is the proximal side of the flow control baffle, and in the second state, the upstream is the distal side of the flow control baffle.

[0012] In other words, it can be understood that under the test conditions, assuming no other influencing factors are considered, when the upstream pressure of the flow control baffle is consistent, the fluid velocity flowing through the flow control baffle is consistent. At this time, under the action of the flow control baffle, the flow area S1 of the flow control baffle in the first state (pressurization) is 10% to 50% of the flow area S2 of the flow control baffle in the second state (depressurization). Consequently, the fluid flow rate Q1 flowing through the flow control baffle in the first state (pressurization) is also 10% to 50% of the fluid flow rate Q2 flowing through the flow control baffle in the second state (depressurization).

[0013] In practical applications, during balloon inflation, fluid is pushed from the proximal end to the distal end of the balloon catheter within the fluid channel. Due to the obstruction of the flow control device, the flow area S1 at the location of the flow control device is small, and the inflation pressure can also be controlled. Fluid can slowly enter the balloon body, allowing the balloon to slowly reach its diameter, reducing damage to intracranial blood vessels. Simultaneously, the depressurization pressure can be controlled, allowing fluid (e.g., contrast fluid) to drain from the distal end to the proximal end of the balloon catheter within the fluid channel. The flow control device deforms under the depressurization pressure, weakening its obstructive effect. The flow area S2 at the location of the flow control device increases, allowing fluid to flow out rapidly, reducing depressurization time and surgical time.

[0014] Optionally, the control area has opposing inner and outer sidewalls, the flow control baffle has opposing inner and outer edges and a sidewall connecting the inner and outer edges, and the sidewall of the flow control baffle has a through-hole.

[0015] Optionally, the inner edge of the flow control baffle is fixed to the inner sidewall of the control area, and the outer edge of the flow control baffle is tightly fitted to the outer sidewall of the control area in the first state and detached from the outer sidewall of the control area and retracted to the inner sidewall of the control area in the second state.

[0016] Optionally, S2 is more than 30% of the annular cross-sectional area of ​​the control area.

[0017] Optionally, the sidewall of the flow control baffle is a cylindrical structure, the cylindrical structure having a distal end and a proximal end, the distal end of the cylindrical structure being fixed to the inner sidewall of the control area, and the proximal end of the cylindrical structure being a flared opening.

[0018] Optionally, the fluid through-holes are distributed in a region near the inner edge of the flow control baffle. The fluid through-holes converge towards the fixed end of the flow control baffle, which is more conducive to maintaining the shape of the flow control baffle when fluid is introduced.

[0019] Optionally, the fluid through-holes are distributed in the two-thirds sidewall region near the inner edge of the flow control baffle.

[0020] Optionally, the maximum outer diameter at the distal end of the cylindrical structure is larger than the inner diameter of the outer tube. This ensures a perfect fit between the control baffle and the outer tube, and the flow control baffle expands to form a barrier within the outer tube, controlling the flow rate during balloon inflation.

[0021] Preferably, the maximum outer diameter of the distal end of the cylindrical structure is slightly larger than the inner diameter of the outer tube by 5% to 10%.

[0022] Optionally, the outer edge of the flow control baffle is fixed to the outer wall of the control area, and the inner edge of the flow control baffle is tightly fitted to the inner wall of the control area in the first state and detached from the inner wall of the control area and abutting against the outer wall of the control area in the second state.

[0023] Optionally, the sidewall of the flow control baffle is a cylindrical structure, the cylindrical structure having a distal end and a proximal end, the distal end of the cylindrical structure being a flared opening and the edge of the flared opening being fixed to the outer wall of the control area.

[0024] Optionally, the fluid through-holes are distributed in the region near the outer edge of the flow control baffle. Alternatively, the fluid through-holes are distributed in the two-thirds of the sidewall region near the outer edge of the flow control baffle.

[0025] Optionally, multiple reinforcing ribs are spaced apart circumferentially on the inner wall of the cylindrical structure, and each reinforcing rib extends along the generatrix of the cylindrical structure.

[0026] Optionally, the fluid passage can be a circular hole, a strip-shaped hole, or an irregularly shaped hole.

[0027] Optionally, the flow control baffle includes:

[0028] The reinforcing ribs are made of elastic material and are arranged in multiple intervals along the circumference of the cylindrical structure, with each reinforcing rib extending along the generatrix of the cylindrical structure.

[0029] A deformable membrane provides the sidewalls of the cylindrical structure and connects all the reinforcing ribs circumferentially.

[0030] Optionally, the reinforcing ribs have opposite proximal and distal ends, and along the length direction of the reinforcing ribs, the deformable membrane extends beyond the proximal ends of each reinforcing rib and forms an annular boneless skirt.

[0031] Optionally, the flow control baffle is a thin sheet structure made of PTFE, FEP, PA, or PEBAX polymer materials. It possesses the supporting force to maintain its shape without external force and the ability to deform under external force.

[0032] Optionally, the sidewall of the flow control component is a cylindrical structure integrally formed from an elastic or flexible membrane, or a cylindrical structure spliced ​​together from multiple elastic or flexible membranes.

[0033] Optionally, when multiple membrane blocks are spliced ​​together, adjacent membrane blocks are overlapped and bonded to each other at the splicing point.

[0034] Optionally, the balloon catheter includes an inner tube and an outer tube nested together, the radial gap between the inner tube and the outer tube forming the fluid channel, the outer wall of the inner tube forming the inner sidewall of the control area, and the inner wall of the outer tube forming the outer sidewall of the control area.

[0035] Optionally, the flow rate control structure can be used in a laser balloon dilation catheter. Therefore, this application also provides a laser balloon dilation catheter, including the balloon catheter, the balloon body, and the flow rate control structure disposed within the fluid channel of the balloon catheter.

[0036] Optionally, the laser balloon dilation catheter further includes:

[0037] The flexible tip is located at the distal end of the balloon catheter.

[0038] Optionally, the elastic element is a helical structure made of wound metal wire.

[0039] Optionally, the diameter of the metal wire is 0.03-0.1 mm, and the winding spacing is 0.01-0.05 mm.

[0040] Optionally, the metal wire can be made of stainless steel, nickel-titanium, gold, platinum-iridium alloy, platinum-tungsten alloy, etc.

[0041] A flow rate control device for a balloon catheter, the balloon catheter having opposing distal and proximal ends, wherein the distal end has a balloon body that can be inflated and deformed by fluid, and the balloon catheter having a fluid channel communicating with the balloon body; at least a portion of the fluid channel is a control zone having opposing inner and outer sidewalls and having an annular cross-sectional shape, the flow rate control device including a flow control baffle, the flow control baffle comprising:

[0042] The annular sidewall has opposing inner and outer edges, which are fixedly connected to the inner and outer sidewalls of the control area, respectively. A drainage window is provided on the annular sidewall.

[0043] A movable piece is correspondingly disposed at the drain window. The movable piece has an inlet hole that is connected to the corresponding drain window, and the effective flow area S1 of the inlet hole is smaller than the effective flow area S2 of the corresponding drain window.

[0044] The movable flap is a deformable structure and has a first state and a second state depending on different fluid directions; in the first state, fluid is pushed from the proximal end to the distal end of the balloon catheter, the movable flap is attached to the corresponding drainage window to close the drainage window, and the fluid passes through the inlet hole; in the second state, fluid is discharged from the distal end to the proximal end of the balloon catheter, the movable flap flips to open the drainage window, and the fluid passes through the drainage window.

[0045] During balloon inflation, the movable flap adheres to the drainage window under inlet pressure to close the drainage window (first state). Fluid passes through the inlet hole. Since the effective area S1 formed by the inlet hole is small, the balloon can slowly reach its diameter, reducing damage to intracranial blood vessels. During balloon depressurization, the movable flap deforms under drainage pressure and flips in the direction of fluid flow to open the drainage window (second state). Fluid passes through the drainage window. The effective area S2 formed by the drainage window is large, allowing fluid (such as contrast fluid) to flow out quickly, reducing depressurization time and surgical time.

[0046] Optionally, S1 is 10% to 50% of S2.

[0047] Optionally, the liquid inlet and the liquid outlet window may partially overlap, or the liquid outlet window may completely cover the liquid inlet.

[0048] Optionally, the total opening area of ​​all drainage windows is 20% to 50% of the area of ​​the annular sidewall.

[0049] Optionally, the drainage windows are evenly distributed circumferentially and located in the central region of the annular sidewall.

[0050] Optionally, the annular sidewall has opposing proximal and distal sides, the proximal side facing the proximal end of the balloon catheter, and the movable flap is located on the proximal side.

[0051] Optionally, a portion of the movable piece is fixed to the annular sidewall, and a portion extends toward the corresponding drainage window and covers the entire drainage window.

[0052] Optionally, the fixed portion of the movable piece is located near the outer edge of the annular sidewall.

[0053] Optionally, the fixed portion of the movable piece is bonded and fixed to the annular sidewall.

[0054] Optionally, the inner edge of the annular sidewall is bonded and fixed to the inner sidewall of the control area, and the outer edge of the annular sidewall is bonded and fixed to the outer sidewall of the control area.

[0055] Optionally, the annular sidewall and movable sheet are made of PTFE, FEP, PA or PEBAX polymer materials in the form of a sheet structure. Attached Figure Description

[0056] Figure 1 This is a schematic diagram of the overall structure of the flow rate control structure in one application scenario of this application.

[0057] Figure 2 This is a schematic diagram of the cross-section of the control area;

[0058] Figure 3 A schematic diagram of one implementation of a flow rate control structure;

[0059] Figure 4 for Figure 1 Enlarged view of a partial embodiment of the first implementation method in Part A;

[0060] Figure 5 for Figure 4 A schematic diagram of the central flow control device in its first state (balloon inflation);

[0061] Figure 6 for Figure 4 A schematic diagram of the central flow control device in its second state (balloon depressurization);

[0062] Figures 7-9 A schematic diagram of one embodiment of the cylindrical structure;

[0063] Figure 10 and Figure 11 A schematic diagram of another embodiment of the cylindrical structure;

[0064] Figure 12 and Figure 13 Schematic diagrams of the elastic tip from different perspectives;

[0065] Figure 14 for Figure 1 Enlarged view of a partial embodiment of the second implementation method in Part A;

[0066] Figure 15 for Figure 14 A schematic diagram of the central flow control device in its first state (balloon inflation);

[0067] Figure 16 for Figure 14 A schematic diagram of the central flow control device in its second state (balloon depressurization);

[0068] Figure 17 for Figure 1 Enlarged view of the third implementation method in Part A;

[0069] Figure 18 for Figure 17 A schematic diagram of the central flow control device in its first state (balloon inflation);

[0070] Figure 19 for Figure 17 A schematic diagram of the central flow control device in its second state (balloon depressurization);

[0071] Figure 20 for Figure 17 Plan view of the central flow control baffle.

[0072] The reference numerals in the figure are as follows:

[0073] 1. Balloon body; 2. Balloon catheter; 21. Annular cross-sectional area; 22. Inner wall; 23. Outer wall; 24. Inner tube; 25. Outer tube; 26. Fluid channel; 3. Stress relief tube; 4. Catheter seat; 41. Fluid interface; 42. Fiber optic interface; 5. Elastic tip; 6. Fiber optic connector; 7. Flow control baffle; 71. Inner edge; 72. Side wall; 73. Outer edge; 74. Fluid passage; 75. Reinforcing rib; 76. Annular side wall; 77. Drain window; 78. Movable plate; 79. Inlet port. Detailed Implementation

[0074] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0075] To better describe and illustrate the embodiments of this application, reference may be made to one or more accompanying drawings, but the additional details or examples used to describe the drawings should not be considered as limiting the scope of any of the inventive creations of this application, the embodiments or preferred methods described herein.

[0076] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0077] In this application, "distal" and "proximal" refer to the balloon catheter itself. The direction in which the distal or proximal end points may change as the spatial configuration of the balloon catheter changes. During surgery, the proximal end refers to the end of the balloon catheter facing the surgeon, and the distal end refers to the end of the balloon catheter facing the patient.

[0078] A flow control structure for balloon catheters, see [link / reference]. Figures 1-3 The balloon catheter 2 has a distal end and a proximal end, wherein the distal end has a balloon body 1 that can be inflated and deformed by fluid, and a fluid channel communicating with the balloon body is provided within the balloon catheter. At least a portion of the fluid channel is a control region, which has an annular cross-sectional area 21 (see...). Figure 2 The flow rate control structure includes a flow control baffle 7, which is generally annular and located in the control area (see schematic diagram). Figure 3 The flow control baffle is a deformable structure and has a first state and a second state depending on the different fluid directions. In the first state, the fluid is pushed from the proximal end to the distal end of the balloon catheter, and in the second state, the fluid is discharged from the distal end to the proximal end of the balloon catheter. Compared with the first state, the flow control baffle reduces the degree of obstruction to the fluid channel in the second state.

[0079] Regarding the flow control baffle reducing its obstruction of the fluid channel in the second state, further, for the location of the flow control baffle, the flow rate Q1 in the fluid channel under the same pressure in the first state is 10% to 50% of the flow rate Q2 in the second state. This can also be understood as the flow area S1 of the location of the flow control baffle in the first state being 10% to 50% of the flow area S2 of the location of the flow control baffle in the second state.

[0080] The control region, having an annular cross-sectional shape, has opposing inner walls 22 and outer walls 23 (see...). Figure 2 The flow control baffle 7 has opposing inner edges 71 and outer edges 73, and a sidewall 72 connecting the inner and outer edges. The sidewall 72 of the flow control baffle has a fluid passage 74 for fluid to pass through (see...). Figure 3 ).

[0081] As the first implementation of the flow control baffle, see Figures 4-6 The inner edge of the flow control baffle 7 is fixed to the inner sidewall of the control zone, and the outer edge of the flow control baffle 7 mates with the outer sidewall of the control zone. In the first state, it is tightly fitted to the outer sidewall of the control zone; in the second state, it disengages from the outer sidewall of the control zone and retracts towards the inner sidewall of the control zone, thereby forming a radial gap between the sidewall of the flow control baffle and the outer sidewall of the control zone. This radial gap is significantly larger than the opening area of ​​the fluid through-hole, and the flow area S2 of the location of the flow control baffle in the second state is significantly larger than the flow area S1 in the first state. In this embodiment, after the flow control baffle retracts, the flow area S2 of this location can reach at least 50% of the annular cross-sectional area of ​​the control zone.

[0082] In the first state, fluid is propelled from the proximal end to the distal end of the balloon catheter within the fluid channel (see...). Figure 5 In the first state, fluid passes through a fluid passage on the side wall of the flow control baffle, and the balloon slowly inflates; in the second state, fluid is discharged from the distal end to the proximal end of the balloon catheter within the fluid channel (see...). Figure 6 After the flow control baffle retracts towards the inner wall of the control zone, a radial gap is formed between it and the outer wall of the control zone. The fluid passes through the radial gap and quickly relieves pressure.

[0083] In some embodiments, such as Figures 4-6 As shown, the sidewall of the flow control baffle 7 is a cylindrical structure with opposing distal and proximal ends. The distal end of the cylindrical structure is fixed to the inner sidewall of the control zone, and the proximal end of the cylindrical structure is a funnel shape. The distal edge of the cylindrical structure is the inner edge of the flow control baffle, and the proximal edge of the cylindrical structure is the outer edge of the flow control baffle. The sidewall of the cylindrical structure is the sidewall of the flow control baffle. The overall flow control baffle of the cylindrical structure is funnel-shaped, with the small end (distal end) facing the distal end of the balloon catheter and the flared end (proximal end) facing the proximal end of the balloon catheter. The small end (distal end) is fixed to the inner sidewall of the control zone. In the first state, the edge of the funnel is tightly fitted to the outer sidewall of the control zone and maintains its first-state shape even under the impact of the inlet pressure. Fluid can only pass through the fluid passage on the sidewall of the cylindrical structure.

[0084] In a design where the flow control baffle is fixed at its distal end to the inner wall of the control area and has a flared end, the fluid through-holes 74 are distributed in the area near the inner edge of the flow control baffle, for example, in the area of ​​the two-thirds of the side wall near the inner edge of the flow control baffle. The fluid through-holes converge toward the fixed end of the flow control baffle, which is more conducive to maintaining the shape of the flow control baffle when fluid is introduced.

[0085] In a design where the flow control baffle is fixed at its distal end to the inner wall of the control area and has a flared end, optionally, the maximum outer diameter at the proximal end of the cylindrical structure is larger than the inner diameter of the outer tube. This ensures a perfect fit between the control baffle and the outer tube, and the flow control baffle self-expands to form a barrier within the outer tube. Because the maximum outer diameter at the proximal end of the cylindrical structure is larger than the inner diameter of the outer tube, under the impact of the inlet pressure, the flared end of the flow control baffle is squeezed against the inner wall of the outer tube. On the one hand, this allows for a tighter fit between the flow control baffle and the inner wall of the outer tube, preventing fluid from passing through the gap between them. On the other hand, this squeezed state also strengthens the support force of the flow control baffle to better maintain its initial state. Preferably, the maximum outer diameter at the distal end of the cylindrical structure is slightly larger than the inner diameter of the outer tube by 5% to 10%.

[0086] As a second implementation of the flow control baffle, see Figures 14-16 The flared opening of the flow control baffle faces exactly the opposite direction to that in the first embodiment; the outer edge of the flow control baffle 7 is fixed to the outer wall of the control area, and the inner edge of the flow control baffle 7 mates with the inner wall of the control area. In the first state, its inner edge is tightly fitted to the inner wall of the control area; in the second state, its inner edge detaches from the inner wall of the control area and abuts against the outer wall of the control area. In the first state, fluid is pushed from the proximal end to the distal end of the balloon catheter within the fluid channel, and the fluid passes through the fluid passage on the side wall of the flow control baffle (see...). Figure 15 In the second state, fluid is discharged from the distal end to the proximal end of the balloon catheter within the fluid channel. The flow control baffle abuts against the outer wall of the control zone, forming a radial gap with the inner wall of the control zone. Fluid passes through this radial gap (see...). Figure 16 ).

[0087] In some embodiments of this scheme, the sidewall of the flow control baffle is a cylindrical structure with opposing distal and proximal ends. The distal end of the cylindrical structure is a flared opening, and the edge of the flared opening is fixed to the outer wall of the control area. The distal edge of the cylindrical structure is the outer edge of the flow control baffle, and the proximal edge of the cylindrical structure is the inner edge of the flow control baffle. The sidewall of the cylindrical structure is the sidewall of the flow control baffle. The overall flow control baffle of the cylindrical structure is flared, with the flared end (the distal end of the cylindrical structure) facing the distal end of the balloon catheter and the small-bore end (the proximal end of the cylindrical structure) facing the proximal end of the balloon catheter. The flared end (the distal end of the cylindrical structure) is fixed to the inner wall of the control area. In the first state, the edge of the small-bore end (the proximal end of the cylindrical structure) is tightly fitted to the inner wall of the control area and maintains its shape even under the impact of inlet pressure. Fluid can only pass through the fluid passage on the sidewall of the cylindrical structure.

[0088] In a design where the flow control baffle is fixed at its distal end to the outer wall of the control area and has a flared shape at the distal end, the fluid through-holes are distributed in the area near the outer edge of the flow control baffle, for example, in the area of ​​the side wall near the outer edge. The fluid through-holes converge towards the fixed end of the flow control baffle, which is more conducive to maintaining the shape of the flow control baffle when fluid is introduced.

[0089] In the scheme where the flow control baffle is fixed at its distal end to the outer wall of the control area and the distal end is a flared mouth, the diameter of the small end of the flow control baffle is larger than the outer diameter of the inner tube. In the first state, the small end is squeezed and stacked on the outer wall of the inner tube. In the second state, under the pressure impact of the balloon depressurization, the small end is blown open by the fluid into a larger gap, and the fluid flows out from the gap. The flow area S2 of the part where the flow control baffle is located in the second state is significantly larger than the flow area S1 in the first state.

[0090] In the two embodiments described above, the flow control baffle is further described in [reference needed]. Figure 9 and Figure 11 Multiple reinforcing ribs 75 are spaced circumferentially on the inner wall of the cylindrical structure, with each rib extending along the generatrix of the cylindrical structure. The reinforcing ribs help maintain the shape of the flow control baffle better during fluid inflow.

[0091] In both of the aforementioned embodiments, the fluid passage of the flow control baffle can be a circular hole that penetrates the sidewall (see...). Figures 7-9 ), slotted holes (see) Figure 10 and Figure 11 Or irregularly shaped holes; more preferably, the diameter of the fluid through hole is 0.05~0.15mm.

[0092] In the two embodiments described above, the flow control baffle is preferably made of a deformable elastic material, requiring the support force to maintain its shape without external force and the ability to deform under external force. Preferably, the flow control baffle is a sheet structure made of PTFE, FEP, PA, or PEBAX polymer materials.

[0093] In the two embodiments described above, the sidewall of the flow control component can be a cylindrical structure integrally formed from an elastic or flexible membrane (see...). Figure 7 , Figure 9 and Figure 11 It can also be a cylindrical structure composed of multiple elastic or flexible membranes (see...). Figure 8 and Figure 10 In the first embodiment, the integrally molded flow control baffle can be directly bonded after being sleeved on the inner tube. When multiple pieces are spliced ​​together, the multiple spliced ​​flow control baffles can be wound around the outer wall of the inner tube to form a shape like... Figure 7As shown in the diagram, adjacent membrane blocks overlap and bond at the joints. A similar approach can be used in the second embodiment. The fluid vias 74 on the polymer film can be fabricated using methods such as laser drilling, physical drilling, or cutting.

[0094] In a more specific embodiment of the flow control baffle, see [link to relevant documentation]. Figure 1 , Figure 9 and Figure 11 The flow control baffle includes reinforcing ribs 75 and a deformable membrane: the reinforcing ribs are made of elastic material and are arranged in multiple circumferentially along the cylindrical structure, each rib extending along the generatrix of the cylindrical structure; the deformable membrane provides the sidewall 72 of the cylindrical structure and connects all the reinforcing ribs 75 circumferentially. The reinforcing ribs 75 have opposing proximal and distal ends, and along the length of the reinforcing ribs, the deformable membrane extends beyond the proximal ends of each reinforcing rib, forming an annular, boneless skirt (see...). Figure 9 and Figure 11 ).

[0095] As a third implementation of the flow control baffle, see [link to relevant documentation]. Figure 1 , Figure 2 and Figures 17-20 A flow control device for a balloon catheter 2 has a distal end and a proximal end, wherein the distal end has a balloon body 1 that can be inflated and deformed by fluid, and a fluid channel communicating with the balloon body is provided within the balloon catheter. At least a portion of the fluid channel is a control zone, which has an annular cross-sectional area 21 (see...). Figure 2 The flow rate control structure includes a flow control baffle 7, which is generally annular and located in the control area (see schematic diagram). Figure 20 ).

[0096] See Figures 17-20 The flow control baffle includes an annular sidewall 76 and a movable plate 78.

[0097] The annular sidewall 76 has opposing inner and outer edges, which are fixedly connected to the inner and outer sidewalls of the control area, respectively. A drainage window 77 is provided on the annular sidewall.

[0098] The movable piece 78 is correspondingly disposed at the drain window 77. The movable piece has an inlet hole 79 that is connected to the corresponding drain window, and the effective flow area S1 of the inlet hole 79 is smaller than the effective flow area S2 of the corresponding drain window.

[0099] In this embodiment, the movable piece 78 is a deformable structure and has a first state and a second state depending on different fluid directions; in the first state, fluid is pushed from the proximal end to the distal end of the balloon catheter (balloon inflating), the movable piece is attached to the corresponding drainage window, and the fluid passes through the inlet hole; in the second state, fluid is discharged from the distal end to the proximal end of the balloon catheter (balloon depressurization), the movable piece flips under fluid pressure to open the drainage window, and the fluid passes through the drainage window.

[0100] During balloon inflation, the movable flap 78 adheres to the drain window 77 under fluid pressure to close the drain window 77 (first state, see below). Figure 18 Fluid flows through the inlet. Due to the small effective area S1 formed by the inlet, the balloon can slowly reach its diameter, reducing damage to intracranial blood vessels. When the balloon is depressurized, the movable flap deforms under fluid pressure and flips in the direction of fluid flow to open the drainage window (second state, see [link]). Figure 19 The fluid passes through the drainage window, and the effective area S2 formed by the drainage window is large, so the fluid (such as contrast fluid) can flow out quickly, reducing the depressurization time and operation time.

[0101] The inlet and outlet windows partially overlap, or the outlet window completely covers the inlet window. The effective area S1 formed by the inlet window can be understood as the area of ​​the overlapping part between the inlet and outlet windows. Normally, when the inlet window is completely covered by the outlet window, the effective area S1 formed by the inlet window can be understood as the opening area of ​​the inlet window, and the effective area S2 formed by the outlet window can be understood as the opening area of ​​the outlet window. During drainage, the entire outlet window is fully opened. Optionally, S1 can be 10% to 50% of S2.

[0102] In some embodiments of this scheme, the total opening area of ​​the drainage window is 20% to 50% of the area of ​​the annular sidewall.

[0103] One or more inlet holes can be provided on each movable piece corresponding to the drain window. When there is only one inlet hole, the opening area of ​​a single inlet hole is smaller than the opening area of ​​the drain window. In this scheme, the opening area of ​​the drain window can be 2 to 10 times the opening area of ​​the inlet hole. When there are multiple inlet holes, the sum of the opening areas of the multiple inlet holes is smaller than the opening area of ​​the drain window. In this scheme, the opening area of ​​the drain window can be 2 to 10 times the sum of the opening areas of the inlet holes on the corresponding movable piece.

[0104] In some embodiments of this scheme, the opening diameter of the liquid inlet is 0.05~0.1mm.

[0105] In some embodiments of this scheme, the drainage windows are evenly distributed circumferentially and located in the central region of the annular sidewall.

[0106] In some embodiments of this design, the annular sidewall 76 has opposing proximal and distal sides, wherein the proximal side is the face facing the proximal end of the balloon catheter, and the movable flap 78 is located on this face. A portion of the movable flap 78 is fixed to the annular sidewall 76, and a portion extends toward and covers the entire drainage window 77. In some embodiments, the fixed portion of the movable flap 78 is close to the outer edge of the annular sidewall 76 (see...). Figure 20 The fixed part of the movable piece can be fixed to the annular sidewall by bonding.

[0107] In some embodiments of this scheme, the inner edge of the annular sidewall is bonded and fixed to the inner sidewall of the control area, and the outer edge of the annular sidewall is bonded and fixed to the outer sidewall of the control area. The annular sidewall and the movable piece are sheet structures made of PTFE, FEP, PA, or PEBAX polymer materials.

[0108] In this solution, the material, manufacturing method, and other common components such as the balloon catheter structure of the flow control baffle can all be the same as those of the fluid passageway, and will not be described in detail here.

[0109] like Figure 1 As shown, this flow control structure can be used in intracranial laser balloon catheters. Components associated with the flow control structure include a stress relief tube 3 and a catheter seat 4. The stress relief tube 3 connects between the balloon catheter 2 and the catheter seat 4. The catheter seat 4 is connected to the proximal end of the balloon catheter 2. The catheter seat 4 has a fluid interface 41 communicating with a fluid channel and an optical fiber interface 42 communicating with an optical fiber channel. The optical fiber extends from the proximal end into the optical fiber channel and connects to the laser generating module via an optical fiber connector 6. The optical fiber can be made of plastic or quartz fiber. The portion located within the balloon is the light-emitting segment. The optical fiber connects to the laser generating module at the proximal end, emitting a low-intensity red laser at 638nm in the balloon segment to repair vascular tissue, reduce the probability of restenosis, and improve elastic recoil.

[0110] Balloon catheter 2 includes an inner tube 24 and an outer tube 25 nested together, as shown in [reference]. Figure 4 The radial gap between the inner tube and the outer tube forms the fluid channel 26. The outer wall of the inner tube 24 constitutes the inner sidewall of the control area, and the inner wall of the outer tube constitutes the outer sidewall of the control area. In some embodiments, the inner cavity of the inner tube serves as an optical fiber channel. In some embodiments, the inner cavity of the inner tube can also serve as an optical fiber channel and a guide wire channel. In embodiments that serve as both an optical fiber channel and a guide wire channel, the optical fiber channel and the guide wire channel are not interconnected.

[0111] The balloon body 1 is located at the distal end of the balloon catheter 2. The proximal end of the balloon body 1 is fixed to the distal end of the outer tube 25. The fluid channel 26 formed by the radial gap between the inner and outer tubes communicates with the interior of the balloon body 1. The interior of the balloon body 1 can be inflated and deformed by fluid.

[0112] At the distal end of the balloon, the inner tube 24 intersects with the distal end of the balloon body 1. An elastic tip 5 is welded to the distal end of the inner tube. The elastic tip may also be welded to the distal end of the balloon body. The elastic tip is located at the distal end of the inner tube as a whole. The elastic tip includes a welded section and an exposed section. The welded section overlaps with the distal end of the inner tube and can be fixedly connected by welding. The exposed section is directly exposed to the outside and is neither inside the inner tube wall nor overlapped or fixed with other components.

[0113] The elastic tip 5 has a certain degree of elasticity. As the first part of the balloon catheter to be inserted into the blood vessel, the elastic tip has the characteristic of being deformable when it encounters a blood vessel obstruction, which can avoid puncturing the blood vessel. At the same time, based on the elasticity of the elastic tip, it can restore its own shape after the external force is removed.

[0114] One implementation method, see Figure 12 and Figure 13 The elastic tip 5 is a helical structure made of wound metal wire with a diameter of 0.03-0.1 mm and a winding spacing of 0.01-0.05 mm. The metal wire can be made of stainless steel, nickel-titanium, gold, platinum-iridium alloy, platinum-tungsten alloy, etc. The metal wire has imaging capabilities, and the elastic tip can also serve as an imaging component, indicating the position of the balloon within the body. The spring tip has better flexibility, conforms more closely to the guidewire, and eliminates the "fishmouth phenomenon." The visualized spring tip facilitates the identification of blood vessel locations and prevents vascular perforation.

[0115] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0116] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A flow control structure for a balloon catheter, the balloon catheter having opposing distal and proximal ends, wherein the distal end has a balloon body that can be inflated and deformed by fluid, and the balloon catheter has a fluid channel communicating with the balloon body; characterized in that, At least a portion of the fluid channel is a control zone, which has an annular cross-sectional shape. The flow rate control structure includes a flow control baffle, which is annular in shape and located in the control zone. The flow control baffle is a deformable structure and has a relative first state and a second state depending on different fluid directions. In the first state, fluid is pushed from the proximal end to the distal end of the balloon catheter; in the second state, fluid is discharged from the distal end to the proximal end of the balloon catheter. Compared with the first state, the flow control baffle reduces the degree of obstruction to the fluid channel in the second state. For the location of the flow control baffle, under the same pressure, the flow rate Q1 in the first state of the fluid channel is 10% to 50% of the flow rate Q2 in the second state; The control area has opposing inner and outer sidewalls, the flow control baffle has opposing inner and outer edges and a sidewall connecting the inner and outer edges, and the sidewall of the flow control baffle has a through-hole.

2. The flow rate control structure according to claim 1, characterized in that, The inner edge of the flow control baffle is fixed to the inner wall of the control area. The outer edge of the flow control baffle is tightly attached to the outer wall of the control area in the first state and detached from the outer wall of the control area in the second state and retracted to the inner wall of the control area.

3. The flow rate control structure according to claim 2, characterized in that, The sidewall of the flow control baffle is a cylindrical structure with a distal end and a proximal end. The distal end of the cylindrical structure is fixed to the inner sidewall of the control area, and the proximal end of the cylindrical structure is a flared opening.

4. The flow rate control structure according to claim 2, characterized in that, The fluid through-holes are distributed in the area near the inner edge of the flow control baffle.

5. The flow rate control structure according to claim 1, characterized in that, The outer edge of the flow control baffle is fixed to the outer wall of the control area. The inner edge of the flow control baffle is tightly fitted to the inner wall of the control area in the first state and detached from the inner wall of the control area in the second state and abuts against the outer wall of the control area.

6. The flow rate control structure according to claim 5, characterized in that, The sidewall of the flow control baffle is a cylindrical structure with opposite distal and proximal ends. The distal end of the cylindrical structure is a flared opening, and the edge of the flared opening is fixed to the outer wall of the control area.

7. The flow rate control structure according to claim 5, characterized in that, The fluid through-holes are distributed in the area near the outer edge of the flow control baffle.

8. The flow rate control structure according to claim 3 or 6, characterized in that, Multiple reinforcing ribs are spaced circumferentially on the inner wall of the cylindrical structure, and each reinforcing rib extends along the generatrix of the cylindrical structure.

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