Artery flow restrictor

Abstract

The invention provides an arterial flow limiter. The arterial flow limiter comprises a fixing support used for anchoring the flow limiter to an artery; the flow adjusting support is used for adjusting blood flow; the connecting part is used for connecting the fixed bracket and the flow adjusting bracket; the fixing support allows blood to pass through holes of the fixing support, and the mesh density of the fixing support is smaller than that of the flow adjusting support, so that after the blood flows through the fixing support, most of the blood flows through a gap between the flow adjusting support and an artery wall; the expansion degree of the flow adjusting support can be adjusted, the outer surface of the flow adjusting support is of a streamline structure, the curvature radius Rc of the outer contour is matched with the diameter D of the artery, and Rc / D = 0.25 is met, so that the wall surface shearing force of blood flow to the artery is stabilized within a certain range, and turbulent flow is prevented from being formed.

Description

Technical Field

[0001] The present application belongs to the technical field of medical devices, and specifically relates to an arterial flow restrictor. Background Art

[0002] Precise control of arterial blood flow is crucial in the treatment of arterial diseases. For example, during surgery, it is necessary to temporarily block or regulate arterial blood flow while ensuring blood supply to vital organs, allowing for repair or replacement of diseased areas. However, existing methods such as vascular occlusion clamps and balloon occlusion have drawbacks such as complex operation, significant damage to blood vessels, and difficulty in achieving precise regulation, making them unable to meet the diverse clinical needs for arterial blood flow control. Currently, there is a lack of a device that can safely, effectively, and precisely control arterial blood flow in clinical practice. Summary of the Invention

[0003] The present application provides an arterial flow restrictor to solve the technical problem of inaccurate blood flow control in the prior art.

[0004] In order to solve the above technical problems, a technical solution adopted in the present application is: an arterial flow restrictor, comprising: a fixed bracket, the fixed bracket is used to anchor the flow restrictor to the artery; a flow regulating bracket, the flow regulating bracket is used to regulate blood flow; a connecting part, the connecting part is used to connect the fixed bracket and the flow regulating bracket; the fixed bracket allows blood to pass through the pores of the fixed bracket, and the mesh density of the fixed bracket is smaller than the mesh density of the flow regulating bracket, so as to ensure that after the blood flows through the fixed bracket, the blood flows through the gap between the flow regulating bracket and the arterial wall; the expansion degree of the flow regulating bracket is adjustable, the outer surface of the flow regulating bracket is a streamlined structure, and the outer contour curvature radius Rc matches the artery diameter D, satisfying Rc / D=0.25.

[0005] According to one embodiment of the present application, there are multiple flow regulating stents, and along the blood flow direction, the mesh density of the upstream flow regulating stent is smaller than the mesh density of the downstream flow regulating stent.

[0006] According to one embodiment of the present application, both ends of the flow limiter are provided with developing marking rings, and the flow limiter is made of nickel-titanium alloy, which has a shape memory function.

[0007] In one embodiment, an arterial flow restrictor is also provided, comprising: a fixed bracket for anchoring the flow restrictor to the artery and regulating blood flow; a flow regulating bracket for regulating blood flow; a connecting portion; the fixed bracket and the flow regulating bracket are connected by the connecting portion, and the connecting portion adopts a smooth curve transition; blood flows into the opening of the fixed bracket, flows into the flow regulating bracket through the connecting portion, and then flows out from the outlet of the flow regulating bracket; along the blood flow direction, the blood flow inlet diameter of the upstream bracket is smaller than the blood flow inlet diameter of the downstream bracket, and the blood flow outlet diameter of the upstream bracket is larger than the outlet diameter of the downstream adjacent bracket; the diameter of the connecting portion is 1 / 3 to 1 / 2 of the maximum diameter of the downstream flow regulating bracket.

[0008] According to one embodiment of the present application, the fixed stent adopts a spindle-shaped or spherical gradual expansion-sudden contraction geometric configuration, and its cross-sectional diameter first slowly expands to a maximum value along the direction of blood flow and then narrows to the outlet; the inlet of the flow regulating stent slowly expands to a maximum diameter at an expansion angle of 10°-12° along the direction of blood flow, and then suddenly contracts to the outlet diameter at a contraction angle of 60°-85° at the maximum diameter.

[0009] According to one embodiment of the present application, the flow regulating stent adopts a spindle-shaped or spherical sudden expansion-gradual contraction geometric configuration, and its cross-sectional diameter first expands to a maximum value along the direction of blood flow, and then gradually narrows to the outlet; the inlet of the flow regulating stent is connected to the outlet of the fixed stent and suddenly expands to the maximum diameter at an expansion angle of 65°-85°, and then slowly narrows to the outlet diameter at a contraction angle of 20°-25°.

[0010] According to one embodiment of the present application, the fixed stent or the flow regulating stent adopts a spindle-shaped or spherical gradually expanding-contracting geometric configuration, and its cross-sectional diameter first slowly expands to a maximum value along the direction of blood flow and then gradually narrows to the outlet; the stent inlet begins to slowly expand at an expansion angle of less than 15° to reach the maximum diameter, and then gradually narrows to the outlet diameter at a contraction angle of 15°-20°.

[0011] According to one embodiment of the present application, both ends of the flow restrictor are provided with a developing marker ring, and the flow restrictor is made of nickel-titanium alloy, which has a shape memory function.

[0012] According to one embodiment of the present application, the surface of the flow restrictor is coated with a hydrophilic coating.

[0013] An arterial blood flow restriction device is also provided, comprising a loading assembly and the above-mentioned flow limiter. The loading assembly comprises a coil, a Luer connector, a guide wire, a loading sheath, a loader body, and a clamp. The coil is used to pre-install the guide wire, which is threadedly connected to the flow limiter. The Luer connector is integrated at the end of the loader body and is used to quickly and sealedly connect the loading sheath to the loader body. Before use, the flow limiter is encapsulated in the loading sheath.

[0014] The beneficial effects of the present application are as follows: by configuring the flow restrictor to include a fixing portion and a flow regulating bracket, the fixing portion is used to anchor the flow restrictor to the artery, the flow regulating bracket is used to regulate blood flow, and the blood flow is changed by changing the expansion degree of the flow regulating bracket; at the same time, the outer surface of the flow regulating bracket has a streamlined structure, and the outer contour curvature radius Rc matches the artery diameter D, satisfying Rc / D=0.25, so that the shear force of the blood flow on the arterial wall is stabilized within a certain range, avoiding the formation of turbulence;

[0015] In addition, by adjusting the mesh density combination of multiple flow-regulating stents, doctors can achieve more precise flow control based on the patient's vascular conditions. In addition, progressive adjustment can reduce the area of blood flow retention, and the dense mesh further evenly disperses the blood flow shear force, reducing the possibility of platelet aggregation and thrombosis. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present application. Those skilled in the art can also derive other drawings based on these drawings without inventive work, among which:

[0017] Figure 1 This is a schematic structural diagram of an arterial blood flow restriction device according to an embodiment of the present application;

[0018] Figure 2 1 is a schematic structural diagram of a current limiter according to an embodiment of the present application;

[0019] Figure 3 is a schematic structural diagram of a current limiter according to another embodiment of the present application;

[0020] Figure 4 1 is a schematic structural diagram of a current limiter according to another embodiment of the present application;

[0021] Figure 5 This is a schematic diagram of the structure of a current limiter according to another embodiment of the present application. DETAILED DESCRIPTION

[0022] The following will be combined with the accompanying drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0023] The proximal end in this application refers to the end close to the user, and the distal end refers to the end away from the user.

[0024] Please refer to Figure 1 The present application provides an arterial blood flow restriction device including a flow restrictor 1 and a loading assembly 2.

[0025] Please refer to Figure 2 The flow restrictor 1 includes a fixed bracket 1-1, a flow regulating bracket 1-2 and a connecting portion 1-3, and the fixed bracket 1-1 and the flow regulating bracket 1-2 are connected through the connecting portion 1-3.

[0026] In one embodiment, the fixed stent 1-1 is used to anchor the flow restrictor 1 to the artery, and adopts a low mesh density design to allow part of the blood flow to pass through the stent pores, reducing the risk of local blood flow stagnation; the fixed stent 1-1 is anchored to the arterial wall by barbs (not shown in the figure), and forms multi-point anchoring through the elastic deformation of the arterial wall to prevent displacement.

[0027] In one embodiment, the flow regulating stent 1-2 is used to regulate blood flow, and the mesh density is significantly higher than that of the fixed stent 1-1, which limits blood penetration and allows most of the blood flow to flow through the gap between the flow regulating stent 1-2 and the arterial wall to facilitate blood flow regulation.

[0028] Among them, the expansion degree of the flow regulating stent 1-2 can be controlled by a guide wire, so that the blood flow varies within the range of 20%-90% of the baseline value. The end 1-4 of the flow regulating stent 1-2 is fixedly connected to the guide wire, and the expansion degree of the flow regulating stent 1-2 is adjusted by the guide wire to regulate the blood flow; the guide wire operation and the deformation of the flow regulating stent 1-2 are directly coupled through mechanical transmission, and the adjustment response time is <10 seconds, and the blood flow effect can be verified immediately during the operation.

[0029] In one embodiment, the outer surface of the flow regulating stent 1-2 is a streamlined structure to reduce the damage of shear force to the blood vessel wall and avoid the formation of turbulence.

[0030] Specifically, CFD simulation verified that the outer contour curvature radius Rc matched the artery diameter D, satisfying Rc / D = 0.25, reducing the blood flow velocity gradient dv / dr by 45% and stabilizing the wall shear force at 0.3-0.5 Pa (physiological safety range).

[0031] In one embodiment, the connection parts 1-3 are flexible connections to reduce the generation of local vortexes. The connection parts 1-3 only play a connecting role and do not participate in the regulation of blood flow.

[0032] In one embodiment, both ends of the current limiter 1 are provided with development marking rings made of platinum-iridium alloy or other high-density metals; the development marks 1-4 adopt a double-layer structure design, with the outer layer being platinum-iridium alloy and the inner layer being high-density metal to improve the development effect; the diameter of the development marking ring is 2 mm and the thickness is 0.1 mm to enhance its visualization effect in the body.

[0033] In one embodiment, the flow regulating bracket 1-2 can be provided in plurality, and the plurality of flow regulating brackets 1-2 form a progressive regulation. Figure 3 For example, the flow regulating stent 1-2 includes a flow regulating stent 1-21 and a flow regulating stent 2 1-22. Along the direction of blood flow, the mesh density of the flow regulating stent 1-21 is smaller than that of the flow regulating stent 2 1-22. The sparse mesh upstream allows a larger flow to pass through, initially reducing the blood flow velocity. In addition, the sparse mesh converts laminar flow into a more uniform flow state, while the dense mesh further suppresses turbulence, making the blood flow smoother. This staged resistance design can reduce energy loss and endothelial damage caused by turbulence, and improve blood flow stability. The dense mesh downstream further restricts the flow, forming a progressive resistance, which can avoid the impact of a sudden drop in blood pressure on the blood vessel wall and reduce the risk of blood vessel damage. At the same time, the overall pressure gradient is dispersed to the two stent areas, avoiding the formation of a local high-pressure area at a single narrow point, reducing the risk of blood vessel wall rupture due to pressure concentration.

[0034] Among them, the expansion degree of the flow regulating stent 1-21 and the flow regulating stent 2 1-22 can also be adjusted by moving the guide wire.

[0035] Figure 4 This is a structural schematic diagram of another embodiment of the flow limiter of the present application; the difference between this embodiment and the above embodiment is that the mesh density of the fixed bracket 1-1' is greater than that of the above-mentioned fixed bracket 1-1, and the fixed bracket 1-1' not only has a fixing function but also has a blood flow regulating function, so that most of the blood flows in through the opening of the fixed bracket 1-1', and then flows into the flow regulating bracket 1-2' from the connecting part, and finally flows out from the outlet of the flow regulating bracket 1-2'. Similarly, the mesh density of the flow regulating bracket 1-2' is higher than that of the fixed bracket 1-1'.

[0036] For details, please refer to Figure 4 The flow limiter 1 includes a fixed bracket 1-1', a connecting part 1-3' and a flow regulating bracket 1-2'. The fixed bracket 1-1' and the flow regulating bracket 1-2' are connected by the connecting part 1-3'. The connection between the fixed bracket 1-1' and the connecting part 1-3' and the connection between the flow regulating bracket 1-2' and the connecting part 1-3' both adopt a smooth curve transition; one end of the fixed bracket 1-1' is the blood inlet end, and the blood flows into the flow regulating bracket 1-2' through the connecting part 1-3' and flows out from one end of the flow regulating bracket 1-2'. The cross-sectional area of the connecting part 1-3' is smaller than the maximum diameter of the fixed bracket 1-1', which can narrow the diameter of blood circulation and achieve the purpose of accurately regulating blood flow.

[0037] In one embodiment, the maximum expansion diameter of the fixed stent 1-1' is greater than the maximum expansion diameter of the flow regulating stent 1-2'. The cavity structure with a larger diameter is used to slow down the blood flow velocity, reduce shear stress, and may promote the formation of local vortexes. The blood flow resistance is increased by the smaller diameter connecting section (connecting portion 1-3') to form a pressure gradient; the blood flow inlet diameter of the fixed stent 1-1' is smaller than the blood flow inlet diameter of the flow regulating stent 1-2', forming a "gradual expansion" structure to reduce blood flow impact; the blood flow outlet diameter of the fixed stent 1-1' is larger than the blood flow outlet diameter of the flow regulating stent 1-2', forming a "gradual contraction" structure to increase the outlet resistance and avoid the risk of turbulence or thrombosis caused by a sudden drop in blood flow velocity.

[0038] In one embodiment, the connecting portion 1-3' serves as a bridge between the fixed stent 1-1' and the flow regulating stent 1-2'. Its diameter is typically 1 / 3 to 1 / 2 of the maximum diameter of the flow regulating stent 1-2', and its length is adjusted according to the required fluid resistance. The connection between the connecting portion and the fixed stent and the flow regulating stent adopts a smooth transition curve (such as a parabola or arc) to avoid blood flow separation or vortexes caused by sharp angles. The multi-stage structure disperses pressure differences to avoid the risk of tube wall rupture caused by single-point high pressure. The controllable vortex formed within the fixed stent and the flow regulating stent can promote drug mixing (such as for local drug delivery) while reducing platelet aggregation.

[0039] Please continue to refer to Figure 4 The fixed bracket 1-1' adopts a spindle-shaped or spherical gradual expansion-sudden contraction geometric configuration, and its cross-sectional diameter slowly expands to a maximum value along the direction of blood flow and then narrows to the outlet; at the inlet, it slowly expands to the maximum diameter at a low expansion angle of 10°-12° along the direction of blood flow, forming a gentle flow rate attenuation zone; at the maximum diameter, it suddenly contracts to the outlet diameter at an acute angle of 60°-85° to accelerate blood flow and prevent blood retention.

[0040] The flow regulating stent 1-2' adopts a spindle-shaped or spherical sudden expansion-gradual contraction geometric configuration. Its cross-sectional diameter first expands to a maximum value along the direction of blood flow, and then gradually narrows to the outlet. The inlet of the flow regulating stent 1-2' is connected to the outlet of the fixed stent 1-1' and suddenly expands to the maximum diameter in a very short length at a high expansion angle of 65°-85°, forming a sudden expansion step to induce controllable vortex; then it slowly narrows to the outlet diameter at a contraction angle of 20°-25° to restore laminar flow stability.

[0041] The fixed stent 1-1' reduces the flow velocity through the proximal gradually expanding section, reducing the shear stress of the proximal blood vessel wall; the sudden contraction section generates local high pressure through a sudden drop in cross-sectional area, driving the blood flow into the distal expanded part at high speed, which can suppress the risk of proximal thrombosis.

[0042] The proximal end of the flow regulating stent 1-2' forms a low-pressure vortex zone through a sudden expansion step to absorb tiny emboli in the blood flow; the tapered section suppresses turbulence through gradual contraction to avoid the risk of distal embolism.

[0043] In one embodiment, the inner walls of the fixing bracket 1-1' and the flow regulating bracket 1-2' adopt smooth curved surface transitions, and spiral guide grooves or microstructures are provided on the inner wall surfaces to guide the stratified flow of blood.

[0044] In one embodiment, the cross-sectional diameter of the fixed stent 1-1' or the flow regulating stent 1-2' may also be slowly expanded to a maximum value along the direction of blood flow and then gradually narrowed to the outlet. Starting from the inlet, it slowly expands at an expansion angle of less than 15°, passes through a transition section of 8 to 10 mm in length, reaches the maximum diameter of the fixed stent 1-1' or the flow regulating stent 1-2', and then gradually narrows at a contraction angle of 15-20°, and transitions to the inlet of the downstream narrowing portion after a length of 5-6 mm; the fixed stent or flow regulating stent of the present application reduces the energy loss caused by flow inertia by low-angle expansion (less than 15°), and with the slightly steep contraction angle of the outlet section (15-20°), a local low-pressure area is generated at the outlet of the fixed stent or the flow regulating stent, attracting blood flow to smoothly enter the downstream narrowing portion to avoid turbulence.

[0045] In one embodiment, the flow restrictor 1 is made of a superelastic nickel-titanium alloy (Nitinol), which exhibits shape memory properties and can self-expand to a preset configuration at body temperature. The flow restrictor 1 is designed to be 120 cm long, 5 mm in diameter, and 0.2 mm thick, ensuring stability and adaptability within the blood vessel.

[0046] In one embodiment, the surface of the flow restrictor 1 is treated with a hydrophilic coating to further reduce blood adhesion and reduce the risk of thrombosis.

[0047] In one embodiment, to reduce the risk of thrombosis, the flow restrictor 1 is coated or woven. The coating material is polyurethane, and the woven structure is polyester fiber material, both with a thickness of 0.05 mm. This not only improves the biocompatibility of the flow restrictor 1, but also further reduces the risk of thrombosis.

[0048] In other embodiments, the flow restrictor of the present application may also include more than two flow regulating brackets. Figure 5 For example, there are two flow regulating stents, and the fixed stent and the flow regulating stent, as well as the flow regulating stents themselves, are connected by connecting parts; along the direction of blood flow, the maximum expansion diameters of the fixed stent and the flow regulating stent decrease successively, and progressive blood flow restriction is achieved through the step-by-step decreasing outlet diameter.

[0049] Please continue reading Figure 1The loading assembly 2 includes a coil 2-1, a Luer connector 2-2, a guide wire, a loading sheath 2-3, a loader body 2-4, and a clamp 2-5.

[0050] The coil 2-1 is used to store and transport the guidewire. The material of the coil 2-1 is polyamide, and the surface is covered with a hydrophilic coating to reduce friction. The clamp 2-5 is used to mechanically clamp the proximal end of the guidewire, and trigger the threaded interface through rotational force to separate the flow limiter 1 from the guidewire. The loading sheath 2-3 is a transparent polymer tube with a tapered gradient design, which is used to compress the flow limiter 1 to the delivery state. The inner diameter of the loading sheath 2-3 is 5 mm, the outer diameter is 8 mm, and the length is 10 cm. It is made of polycarbonate, which ensures the stable compression and release of the flow limiter G during the delivery process. The loader body 2-4 is a carrier for the pre-installed diverter G and the delivery guidewire. It is compatible with the coil 2-1 and can be directly connected to the delivery system.

[0051] The Luer connector 2-2 is integrated at the end of the loader body 2-4 to achieve a quick and sealed connection with the loading sheath 2-3, supporting one-handed operation.

[0052] During assembly, the guide wire is loaded into the coil 2-1, and then the loading sheath 2-3 is inserted into the flow restrictor 1. The loading sheath 2-3 and the flow restrictor 1 are connected through the loader body 2-4, and the whole is encapsulated in a disposable sterile loader.

[0053] During use, the flow restrictor 1 is separated from the delivery guide wire by rotating the clamps 2-5. After separation, the flow restrictor 1 is released into the artery to precisely regulate blood flow through the dilated and constricted parts.

[0054] The above description is only an implementation method of the present application and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the description and drawings of this application, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. An arterial flow restrictor, characterized in that: include: a fixing stent, the fixing stent being used to anchor the flow restrictor to the artery; A flow regulating stent, wherein the flow regulating stent is used to regulate blood flow; a connecting portion, the connecting portion being used to connect the fixing bracket and the flow regulating bracket; The fixing stent allows blood to pass through the pores of the fixing stent, and the mesh density of the fixing stent is smaller than the mesh density of the flow regulating stent, so that after the blood flows through the fixing stent, the blood flows through the gap between the flow regulating stent and the arterial wall; The expansion degree of the flow regulating stent is adjustable. The outer surface of the flow regulating stent is a streamlined structure, and the outer contour curvature radius Rc matches the artery diameter D, satisfying Rc / D=0.

25.

2. The current limiter according to claim 1, characterized in that There are multiple flow regulating stents, and along the blood flow direction, the mesh density of the upstream flow regulating stent is smaller than the mesh density of the downstream flow regulating stent.

3. The current limiter according to claim 1, characterized in that Both ends of the flow limiter are provided with developing marking rings. The flow limiter is made of nickel-titanium alloy, and the nickel-titanium alloy has a shape memory function.

4. An arterial flow restrictor, characterized in that: include: a fixing bracket for anchoring the flow restrictor to the artery and regulating blood flow; Flow regulating stents, used to regulate blood flow; Connecting part; The fixing bracket and the flow regulating bracket are connected through the connecting portion, and the connecting portion adopts a smooth curve transition; Blood flows in from the opening of the fixed bracket, flows into the flow regulating bracket through the connecting portion, and then flows out from the outlet of the flow regulating bracket; along the blood flow direction, the blood flow inlet diameter of the upstream bracket is smaller than the blood flow inlet diameter of the downstream bracket, and the blood flow outlet diameter of the upstream bracket is larger than the outlet diameter of the downstream adjacent bracket; the diameter of the connecting portion is 1 / 3 to 1 / 2 of the maximum diameter of the downstream flow regulating bracket.

5. The current limiter according to claim 4, characterized in that The fixed bracket adopts a spindle-shaped or spherical gradually expanding-suddenly contracting geometric configuration, and its cross-sectional diameter first slowly expands to a maximum value along the direction of blood flow and then narrows to the outlet; the inlet of the flow regulating bracket slowly expands to a maximum diameter at an expansion angle of 10°-12° along the direction of blood flow, and then suddenly contracts to the outlet diameter at a contraction angle of 60°-85° at the maximum diameter.

6. The current limiter according to claim 5, characterized in that The flow regulating stent adopts a spindle-shaped or spherical sudden expansion-gradual contraction geometric configuration, and its cross-sectional diameter first expands to a maximum value along the blood flow direction, and then gradually narrows to the outlet; the inlet of the flow regulating stent is connected to the outlet of the fixed stent and suddenly expands to a maximum diameter at an expansion angle of 65°-85°, and then slowly narrows to the outlet diameter at a contraction angle of 20°-25°.

7. The current limiter according to claim 4, characterized in that The fixed stent or flow regulating stent adopts a spindle-shaped or spherical gradually expanding and contracting geometric configuration, and its cross-sectional diameter first slowly expands to a maximum value along the direction of blood flow and then gradually narrows to the outlet; the inlet of the stent starts to slowly expand at an expansion angle of less than 15° to reach the maximum diameter, and then gradually narrows to the outlet diameter at a contraction angle of 15°-20°.

8. The current limiter according to claim 4, characterized in that Both ends of the flow restrictor are provided with development marking rings. The flow restrictor is made of nickel-titanium alloy, and the nickel-titanium alloy has a shape memory function.

9. The current limiter according to claim 4, characterized in that The surface of the flow restrictor is coated with a hydrophilic coating.

10. An arterial blood flow restriction device, characterized in that: The invention comprises a loading assembly and a flow limiter according to any one of claims 1 to 9, wherein the loading assembly comprises a coil, a Luer connector, a guide wire, a loading sheath, a loader body, and a clamp, wherein the coil is used for pre-installing the guide wire, the guide wire is threadedly connected to the flow limiter, and the Luer connector is integrated at the end of the loader body and is used for quickly and sealingly connecting the loading sheath to the loader body; before use, the flow limiter is encapsulated in the loading sheath.

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