Implantable access device and fluid circulation system

Abstract

The invention discloses an implantable access device and a fluid circulation system. The implantable access device comprises: a first access end comprising a self-sealing member allowing access of a needle to draw or inject fluid during a treatment phase; the first communication component and the second communication component are respectively communicated with the first access end and are used for providing a fluid flowing path flowing to or flowing out of the first access end; wherein, depending on the characteristic attributes of the first communication component and the second communication component, the flow resistance of the first communication component is greater than the flow resistance of the second communication component.

Description

Implantable access devices and fluid circulation systems Technical Field

[0001] The present application relates to the field of medical device technology, and in particular to an implantable access device and a fluid circulation system. Background Art

[0002] For kidney disease patients, when renal function declines to a certain extent, for example, to 10% of normal levels, they need hemodialysis to remove metabolic products from their blood. Hemodialysis is performed by filtering blood through a dialysis device, a time-consuming process.

[0003] To ensure that blood can flow back into the body at a higher rate, an arteriovenous graft (AVG) is usually surgically implanted in kidney patients before hemodialysis. The AVG connects the patient's artery and vein. During hemodialysis, external tubing is connected to the AVG through two dialysis needles to provide a blood flow path from and to the dialysis device.

[0004] However, this approach also brings some problems. One situation is that blood rushing into the veins at high pressure and speed for a long time will cause neointimal hyperplasia in the veins, thereby hindering venous flow and even blocking the veins to cause the blood flow path to disappear. Another situation is that during the treatment stage, because blood is drawn out of the body and returned to the body in an arteriovenous graft, reflux occurs, that is, the blood returned to the body is directly drawn out again without a path to the body's blood circulation, thus making hemodialysis inefficient. In addition, during the non-treatment stage, due to the presence of the arteriovenous graft, a part of the blood will also circulate through the arteriovenous graft, which causes the blood flow that should flow to the distal parts of the human body (such as the arms, hands, etc.) to be diverted, thereby leading to steal syndrome.

[0005] In view of the various problems caused by the above-mentioned arteriovenous grafts, one approach is to add an actuator to the arteriovenous graft, which actuates the flow path of the arteriovenous graft to open during the treatment phase or close during the non-treatment phase. However, this method still relies on the original arteriovenous graft structure and also requires a dialysis needle to be inserted into the arteriovenous graft. This requires the operator to be a professional with skilled medical treatment capabilities and is not suitable for home use. Moreover, the closure of the arteriovenous graft during the non-treatment phase will cause the blood inside to stop flowing, which can easily cause blood clotting.

[0006] Another approach is to implant ports in arteries and veins. These ports typically include a chamber plugged with a self-sealing material, from which a catheter extends and is surgically implanted into the corresponding artery and vein. One port can then be used to drain blood for dialysis, while the other port is used to return blood to the body. If two ports are implanted in an artery and vein independently, the surgery may require too many and complicated ports to connect, or the ports may cause blood clotting during non-treatment periods. If two ports are implanted in an artery and vein in a connected manner, while a needle-insertion port is provided for easy operation, the various problems associated with the aforementioned arteriovenous grafts also arise due to the connection between the two ports.

[0007] Summary of the Invention

[0008] In view of the shortcomings of the related technologies described above, the purpose of the present application is to provide an implantable access device and a fluid circulation system to reduce the complications and complex operations caused by traditional arteriovenous grafts.

[0009] To achieve the above-mentioned objectives and other related objectives, the first aspect of the present application discloses an implantable access device, which includes: a first access end, including a self-sealing component, which allows a needle to enter to extract or inject fluid during the treatment phase; a first connecting component and a second connecting component, which are respectively connected to the first access end and are used to provide a fluid flow path to or out of the first access end; wherein, depending on the characteristic properties of the first connecting component and the second connecting component, the flow resistance of the first connecting component is greater than the flow resistance of the second connecting component.

[0010] In a second aspect, the present application discloses an implantable access device, comprising: a second connecting section that allows a needle to enter to extract or inject fluid during a treatment phase; the portion of the second connecting section that allows the needle to enter being a first access end; a first connecting section that is connected to one end of the second connecting section to form a fluid flow path; wherein, depending on the characteristic properties of the first connecting section and the second connecting section, the flow resistance of the first connecting section is greater than the flow resistance of the second flow section.

[0011] A third aspect of the present application discloses a fluid circulation system, comprising an implantable access device as disclosed in any embodiment of the first and second aspects of the present application; an external pipeline device, comprising an outlet pipeline and a return pipeline, the outlet pipeline being used to connect to one access end of the implantable access device, and the return pipeline being used to connect to the other access end; a purification device, connected to the outlet pipeline and the return pipeline, for purifying the fluid output by the outlet pipeline for output to the return pipeline.

[0012] In summary, the implantable access device and fluid circulation system proposed in this application, by providing connecting components with different flow resistances on both sides of the access end, can effectively reduce the aforementioned complications such as arterial steal, venous hyperplasia, and thrombosis, and can also reduce reflux and improve blood purification efficiency. Furthermore, the different flow resistances of the connecting components in this application are determined based on the characteristic properties of the designed connecting components, and do not require additional operations on other objects. This makes the structure simple and easy to use, and can be applied to various modes of treatment, such as hospital treatment and home treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The specific features of the inventions of this application are set forth in the appended claims. The features and advantages of the inventions of this application can be better understood by referring to the exemplary embodiments described in detail below and the accompanying drawings. A brief description of the drawings is as follows:

[0014] FIG1 is a schematic diagram showing the structure of an implantable access device in one embodiment of the present application.

[0015] FIG. 2 is a schematic diagram showing an implantable access device according to one embodiment of the present application in which the flow resistance of the first connecting member is greater than the flow resistance of the second connecting member.

[0016] FIG3 is a schematic diagram showing a structure in which the flow resistance of the first connecting member is greater than the flow resistance of the second connecting member in an implantable access device according to one embodiment of the present application.

[0017] FIG. 4 is a schematic diagram showing a structure in which the flow resistance of the first connecting member is greater than the flow resistance of the second connecting member in an implantable access device according to one embodiment of the present application.

[0018] FIG5 is a schematic diagram showing the specific structure of an implantable device in one embodiment of the present application.

[0019] FIG6 is a schematic cross-sectional view of the implantable device in the embodiment shown in FIG5 of the present application.

[0020] FIG7 is a schematic diagram showing the disassembled structure of the implantable device in the embodiment shown in FIG5 of the present application.

[0021] FIG8 is a schematic diagram showing a specific structure of a first access terminal in one embodiment of the present application.

[0022] FIG9 and FIG10 are schematic diagrams showing the connection of an implantable access device to a blood vessel in different embodiments of the present application.

[0023] FIG11 is a schematic diagram showing the structure of an implantable access device in one embodiment of the present application.

[0024] FIG12 is a schematic diagram showing the specific structure of an implantable access device in one embodiment of the present application.

[0025] FIG13 is a schematic diagram showing the disassembled structure of the implantable device in the embodiment shown in FIG12 of the present application.

[0026] FIG14 is a schematic diagram showing the structure of an implantable access device in one embodiment of the present application.

[0027] FIG15 is a schematic diagram of the AA cross section of the embodiment shown in FIG14 .

[0028] FIG. 16 is a schematic diagram showing an implantable access device connected to a blood vessel in one embodiment of the present application.

[0029] FIG17 is a schematic diagram showing a third connecting member including two conduits connected to blood vessels in one embodiment of the present application.

[0030] FIG. 18 is a schematic diagram showing a connecting member of an implantable access device according to an embodiment of the present application being connected to a blood vessel by end-to-side anastomosis and end-to-end anastomosis.

[0031] FIG19 is a schematic diagram showing the structure of a fluid circulation system in one embodiment of the present application. DETAILED DESCRIPTION

[0032] The following describes the implementation of the present application through specific embodiments. People familiar with this technology can easily understand other advantages and effects of the present application from the contents disclosed in this specification.

[0033] In the following description, reference is made to the accompanying drawings, which describe several embodiments of the present application. It should be understood that other embodiments may also be used, and that mechanical, structural, electrical, and operational changes may be made without departing from the spirit and scope of the present disclosure. The following detailed description should not be considered restrictive, and the scope of the embodiments of the present application is limited only by the claims of the published patents. The terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present application. Spatially related terms, such as "upper", "lower", "left", "right", "below", "below", "lower", "above", "upper", etc., may be used in the text to illustrate the relationship of one element or feature shown in the figures to another element or feature.

[0034] Although in some instances the terms first, second, etc. are used in this document to describe various elements or parameters, these elements or parameters should not be limited by these terms. These terms are only used to distinguish one element or parameter from another element or parameter. For example, a first access terminal can be referred to as a second access terminal, and similarly, a second access terminal can be referred to as a first access terminal without departing from the scope of the various described embodiments. The first access terminal and the second access terminal are both describing an access terminal, but unless the context clearly indicates otherwise, they are not the same access terminal. Similar situations also include a first connecting member and a second connecting member, or a first connecting member and a second connecting member.

[0035] Furthermore, as used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context indicates otherwise. It should be further understood that the terms "comprises" and "includes" indicate the presence of the described features, steps, operations, elements, components, items, kinds, or / and groups, but do not exclude the presence, occurrence, or addition of one or more other features, steps, operations, elements, components, items, kinds, or / and groups. The terms "or" and "or / and" used herein are interpreted as inclusive, or mean any one or any combination. Thus, "A, B or C" or "A, B or / and C" means "any of the following: A; B; C; A and B; A and C; B and C; A, B and C". Exceptions to this definition occur only when the combination of elements, functions, steps or operations are inherently mutually exclusive in some way.

[0036] Before undergoing hemodialysis, a subcutaneous arteriovenous graft made of a biocompatible material is surgically implanted in a kidney patient. The biocompatible material can be a material such as a fluoropolymer polytetrafluoroethylene (PTFE) or polyether urethane (PEU). Typically, a hemodialysis access is formed by placing / burying an arteriovenous graft under the skin of the patient's leg, arm, or chest, with one end connected to a selected artery and the other end connected to a selected vein. In hemodialysis, in order to connect the patient to the dialysis machine, the needle portions of two large hypodermic needles / puncture needles need to be inserted through the skin into the arteriovenous graft. Blood is drawn from the patient's body through one needle, circulated through the dialysis machine, and returned to the patient's body through a second needle. Typically, patients undergo hemodialysis three days a week, for approximately three to four hours a day.

[0037] Long-term placement of an arteriovenous graft in the body can lead to complications, including arterial steal, venous hyperplasia, and graft thrombosis. Arterial steal occurs when excessive blood flow through the graft or the pathway connecting the arteries and veins "steals" blood from the distal artery; this prevents adequate blood supply from reaching the patient's limbs.

[0038] The venous hyperplasia is caused by the fact that the blood flowing through the arteriovenous graft usually reaches a turbulent flow rate. Then, this fast-flowing blood will enter the connected vein. The blood flow colliding with the vein will cause the development of myointimal hyperplasia, which will lead to the thickening of the vein wall and the narrowing of the blood vessel, thereby hindering the venous flow. In more serious cases, it will cause blood clotting, resulting in graft thrombosis.

[0039] Graft thrombosis is the formation of blood clots caused by stasis / cessation of blood flow through the graft, which is known as graft thrombosis. Graft thrombosis remains one of the recurring complications associated with the use of arteriovenous grafts.

[0040] Furthermore, during treatment with an arteriovenous graft, blood can be drawn in and returned to the body through the graft, leading to reflux. This occurs when blood that has returned to the body is directly withdrawn from the graft again without passing through the body's circulation, resulting in inefficient blood purification.

[0041] In view of the above-mentioned problems, the present application proposes an implantable access device and fluid circulation system. By providing connecting components with different flow resistances on both sides of the access end, it can effectively reduce the aforementioned complications such as arterial steal, venous hyperplasia, and thrombosis, and can also reduce reflux and improve blood purification efficiency. Furthermore, the different flow resistances of the connecting components of the present application are determined based on the characteristic properties of the designed connecting components, and do not require additional operation or intervention by other objects. As a result, the structure of the present application is simple and easy to use, and can be applied to various modes and medical scenarios such as hospital treatment and home treatment.

[0042] In some embodiments, the present application proposes an implantable access device. For example, the implantable access device can be used as an infusion port for the inflow and infusion of drugs or other liquids, or as a dialysis port for blood purification and hemodialysis. It can also be used in surgical scenarios of arteriovenous fistula (AVF), such as the therapeutic application / scenario of arteriovenous fistula commonly used for long-term hemodialysis vascular access. It should be understood that the arteriovenous fistula refers to an abnormal channel between the artery and venous system that diverts blood from the normal capillary bed; alternatively, an abnormal channel between the artery and vein is called an arteriovenous fistula. To facilitate the explanation of the implementation scheme of the present application, the following will temporarily illustrate the scenario in which the implantable access device of the present application is applicable to hemodialysis, which should not be understood as a limitation to the present application.

[0043] The implantable access device of the present application is suitable for use in hemodialysis scenarios, can increase the convenience of puncture, can reduce the learning cost of medical staff, especially home users, and can reduce the occurrence of reflux, especially in non-treatment conditions, can reduce arterial steal and vascular proliferation, reduce the risk of vascular stenosis, and thus increase service life.

[0044] Please refer to Figure 1, which shows a schematic diagram of the architecture of an implantable access device in one embodiment of the present application. As shown in the figure, the implantable access device 1 includes a first access end 10, a first connecting member 11, and a second connecting member 12. The first connecting member 11 and the second connecting member 12 are respectively connected to the first access end 10, and are used to provide a fluid flow path to or from the first access end 10. The first access end 10 includes a self-sealing member 100, which allows a needle to enter (for example, a needle pierces the self-sealing member). With the help of the inserted needle, fluid can be extracted or delivered during the treatment stage. For example, the inserted needle can extract fluid from the first access end 10 or deliver fluid to the first access end 10.

[0045] The connecting member in any of the foregoing and subsequent embodiments is a structure with a connecting function, which may, for example, include a tubular structure of at least one catheter. It should be understood that the "catheter" disclosed in this application refers to a component that can be fluidically connected to each other so as to provide a path for transferring fluid (i.e., saline, blood, or plasma, etc.) between these components. The "catheter" used in this manner broadly includes tubes, pipes, hoses, conduits, or other structures having one or more lumens adapted to transfer fluid between two ends. Typically, the tube is an elongated cylindrical structure with some flexibility, but the geometry and rigidity can be changed. In some embodiments, multiple components can also be connected by physical proximity, become a single structure as a whole, or be formed of the same material.

[0046] The connecting member in any of the foregoing and subsequent embodiments (which can also be understood as the conduit included therein) can be set as an artificial blood vessel, which can be, for example, an artificial blood vessel made of a polymer material, or can be, for example, a biological artificial blood vessel. The polymer material includes polyethylene (PE), polytetrafluoroethylene (PTFE), expanded polytetrafluoroethylene (ePTFE), polyester (also known as polyester fiber, PET), polyether urethane (PEU), and polyurethane (PU), etc. The biological artificial blood vessel can also be called a bioengineered tissue conduit, which refers to a blood vessel prepared using an extracellular matrix, such as a decellularized artificial blood vessel (Human Acellular Vessels, HAV) or a skeleton decellularized artificial blood vessel (Skeletal Acellular Vessels, SAV). In other embodiments, each connecting member can also be set as an animal or human blood vessel, etc. It should also be noted that each connecting component can also be set to a different type. For example, the connecting component used to connect to the blood vessel can be set to an artificial blood vessel, animal or human blood vessel, etc., and the connecting component used only to connect between the access ends can also use medical and implantable silicone rubber materials, elastomeric rubber materials (soft TPU), resin materials, or PTFE materials, etc. For example, in the subsequent embodiments shown in Figures 11 to 13, the second connecting component 12 and the third connecting component 13 can be set to an artificial blood vessel, animal or human blood vessel, etc., and the first connecting component 11 can use silicone rubber materials, elastomeric rubber materials (soft TPU), resin materials, or PTFE materials. In this way, the therapeutic effect of the implantable access device can be guaranteed while reducing costs.

[0047] Depending on the characteristic properties of the first connecting member 11 and the second connecting member 12, the flow resistance of the first connecting member 11 is greater than that of the second connecting member 12. Flow resistance refers to the ratio of the pressure difference across a flow path to the linear velocity of the fluid. In other words, flow resistance can characterize the resistance to movement / viscosity of the fluid within the flow path. For example, relatively speaking, if the fluid flowing through conduit A experiences low resistance to movement and the fluid flowing through conduit B experiences high resistance to movement, then the flow resistance of conduit A is lower than that of conduit B. In one embodiment of the present application, the flow resistance of the first connecting member 11 is greater than that of the second connecting member 12. For example, when the pipelines are in a "series" relationship, the flow resistance of the fluid flowing through the "series" pipeline is equal to the sum of the flow resistances of each segmented flow pipe. For another example, when the pipelines are in a "parallel" relationship, the reciprocal of the flow resistance is equal to the sum of the reciprocals of the flow resistances of each branched flow pipe.

[0048] The characteristic properties of the connecting components refer to the surface appearance and inherent properties or characteristics of the connecting components under natural conditions, such as the shape, structure, size, color, material, etc. In other words, the flow resistance of the first connecting component is greater than the flow resistance of the second connecting component. This is determined by the characteristic properties of the designed connecting components and does not require external control.

[0049] To be more precise, the "external control" mentioned in this application refers to the operation of other objects to cause the connecting component to change its characteristic properties. The other objects refer to objects other than the design of the connecting component itself, such as operators, actuators, etc. For example, in the prior art, patent documents with publication numbers US20060229548A1 and CN1374877A mention the use of active intervention measures to achieve changes in the flow resistance of the pipeline. These methods are all external control methods. For example, patent document US20060229548A1 discloses an arterial intervention valve device system. On the basis of the traditional AVG, a valve device is added to the arterial end of the artificial blood vessel. The valve device includes a magnetic piston. When a magnetic field is placed near the valve device, the piston moves to open the valve. When no treatment is being performed, the piston is always closed, which can prevent or minimize arterial stealing. Although it can intervene in the flow resistance in the pipeline through external control, the blood trapped inside the blood vessel in its solution stays and can easily cause coagulation. In addition, its solution also increases the difficulty of operation for medical staff, which is particularly unfavorable for home medical scenarios.

[0050] In one embodiment, the flow resistance of the first connecting member is greater than the flow resistance of the second connecting member by having a smaller pipe cross-sectional area than the pipe cross-sectional area of ​​the second connecting member. It should be noted that the shapes of the connecting members may not be uniform. Therefore, the pipe cross-sectional area of ​​the first connecting member is smaller than the pipe cross-sectional area of ​​the second connecting member only needs to have the minimum pipe cross-sectional area of ​​the first connecting member be smaller than the minimum pipe cross-sectional area of ​​the second connecting member to achieve designs with different flow resistances. Please refer to Figure 2, which is a schematic diagram of the structure of the implantable access device in one embodiment of the present application in which the flow resistance of the first connecting member is greater than the flow resistance of the second connecting member. As shown in the figure, the first connecting member 11 and the second connecting member 12 are uniform tubular structures and are arranged as circular tubular structures. The inner diameter of the pipe of the first connecting member 11 is smaller than the inner diameter of the pipe of the second connecting member 12, so that the pipe cross-sectional area of ​​the first connecting member 11 is smaller than the pipe cross-sectional area of ​​the second connecting member 12. For example, the ratio of the inner diameters of the pipes of the first connecting member 11 and the second connecting member 12 can be set to any ratio between 1 / 2 and 1 / 8, such as 1 / 2, 1 / 4, 1 / 6, and 1 / 8. In the example of setting it to 1 / 4, the inner diameter of the pipe of the first connecting member 11 is set to 2 mm, and the inner diameter of the pipe of the second connecting member 12 is set to 8 mm. For example, the inner diameter of the pipe of the first connecting member 11 can be set to any value between 1 and 3 mm, for example, 1 mm, 2 mm, and 3 mm, and the inner diameter of the pipe of the second connecting member 12 can be set to any value between 6 mm and 8 mm, for example, 6 mm, 7 mm, and 8 mm. Of course, other shapes and sizes can also be designed to achieve the pipe cross-sectional area requirements, and this application does not limit this.

[0051] In one embodiment, the flow resistance of the first connecting member is greater than that of the second connecting member by comprising a flow resistance structure disposed within its conduit. In one example, the flow resistance structure may be, for example, a protrusion disposed within the conduit, which increases the flow resistance within the conduit. The protrusion may be formed by an inward protrusion from the inner wall of the conduit, or may be a structural component fixed to the interior of the conduit. Referring to FIG3 , a schematic diagram of the structure of an implantable access device according to one embodiment of the present application in which the flow resistance of the first connecting member is greater than that of the second connecting member is shown. As shown, the inner diameters of the conduits of the first connecting member 11 and the second connecting member 12 are substantially equal, and a protrusion 110 is disposed within the conduit of the first connecting member 11. In another example, the flow resistance structure comprises a one-way valve structure, such as a one-way valve or a Tesla valve. In yet another example, the flow resistance structure comprises a two-way valve structure, which is not limited in this application.

[0052] In one embodiment, the flow resistance of the first connecting member is greater than that of the second connecting member by configuring the conduit of the first connecting member as a curved conduit to increase the flow resistance of the fluid within the conduit, for example, as an S-shaped or wavy conduit. Referring to FIG4 , a schematic diagram of the structure of an implantable access device according to one embodiment of the present application in which the flow resistance of the first connecting member is greater than that of the second connecting member is shown. As shown, the first connecting member 11 is designed as a wavy conduit, while the second connecting member 12 is non-kinking or anti-kinking.

[0053] As shown in Figure 1 , the first access end 10 is a portion for injecting or extracting fluid. Specific structures that may be used by the first access end 10 are exemplarily described below with reference to Figures 5 to 8 .

[0054] Please refer to Figures 5 to 7. Figure 5 shows a schematic diagram of the specific structure of an implantable device in one embodiment of the present application, Figure 6 shows a schematic diagram of the cross-sectional structure of the implantable device in the embodiment shown in Figure 5 of the present application, and Figure 7 shows a schematic diagram of the disassembled structure of the implantable device in the embodiment shown in Figure 5 of the present application. The first access end 10 of the implantable device 1 includes a self-sealing member 100 and an end body 101. The end body 101 is provided with an inner cavity 1010 (also referred to as a chamber), a first flow port 1011, a second flow port 1012, and an access port 1013. The first flow port 1011, the second flow port 1012, and the access port 1013 are interconnected through the inner cavity 1010. Among them, the first flow port 1011 is also connected to the first connecting member 11, the second flow port 1012 is also connected to the second connecting member 12, and the access port 1013 is used to set the self-sealing member 100.

[0055] In one embodiment, as shown in Figures 5 and 7 , the end body 101 is configured as a hexahedron, and further, adjacent faces are transitioned at radian angles. This results in curved edges and corners on the end body 101, making it smoother overall and less prone to irritation to human skin. Furthermore, it is easier to clean and disinfect, reducing the chance of bacterial growth.

[0056] In one embodiment, as shown in Figures 5 and 7, a limiting structure 1015 may be provided on the end body 101. The limiting structure 1015 is used to secure the end body 101 within the human body. For example, a doctor can secure the end body 101 to human tissue using the limiting structure 1015. In one example, the limiting structure 1015 is configured as ear holes formed at the corners of the bottom surface of the end body 101. In an example in which the end body 101 is configured as a hexahedral structure, the limiting structure 1015 can be configured as four ear holes corresponding to the four corners of the bottom surface. Those skilled in the art may also design the limiting structure 1015 into other structures or shapes based on the teachings of this application, and this application does not impose any restrictions thereto.

[0057] In one embodiment, as shown in FIG6 , a first flow opening 1011 and a second flow opening 1012 are disposed opposite each other, for example, formed on opposing surfaces of the end body 101. The inner cavity 1010 is configured as a smooth transition channel with increasing flow resistance from the second flow opening 1012 to the first flow opening 1011 within the end body 101. Increasing flow resistance refers to a gradual increase in flow resistance, rather than a sudden increase. Thus, providing a transition channel between the first connecting member 11 and the second connecting member 12, which have different flow resistances, can prevent blood stagnation and coagulation caused by uneven blood flow.

[0058] Furthermore, in the example where the inner diameter of the pipe through the first connecting member 11 is smaller than the inner diameter of the pipe through the second connecting member 12, so that the flow resistance of the first connecting member 11 is greater than the flow resistance of the second connecting member 12, the transition channel is configured as a channel with a conical inner wall. In this way, even if the flow rate of the fluid from the second connecting member 12 is too fast, it can flow through the transition channel along the conical surface spirally, avoiding coagulation caused by blood retention, etc. In addition, since the flow surface of the conical channel is circular, the pressure distribution of the end body 101 will be uniform, reducing the pressure and damage to the patient's local obstruction, and reducing the risk of infection and complications.

[0059] In one embodiment, as shown in FIG5 , the left and right side walls of the end body 101, which extend from the second flow opening 12 to the first flow opening 11, are configured as curved surfaces corresponding to the shape of the inner cavity 1010. This eliminates redundant portions of the end body 101 compared to a flat surface, maximizing the flow path of the inner cavity 1010 with minimal volume, thereby reducing the volume occupied inside and outside the patient's body.

[0060] In order to facilitate connection with the first and second connecting members, in one embodiment, the first access end further includes a first connecting mechanism and a second connecting mechanism. As shown in Figures 6 and 7, the first connecting mechanism 103 connects the first flow port 1011 and the first connecting member 11 so that the first connecting member 11 is connected to the first flow port 1011, and the second connecting mechanism 104 connects the second flow port 1012 and the second connecting member 12 so that the second connecting member 12 is connected to the second flow port 1012. The first connecting mechanism 103 and the second connecting mechanism 104 are respectively fixed to the end body 101 at positions corresponding to the first flow port 1011 and the second flow port 1012. For example, the first connecting member 11 and the second connecting member 12 can be respectively bonded to the first connecting mechanism 103 and the second connecting mechanism 104 by adhesion (for example, by medical glue or patch adhesion). The structural design of each connecting mechanism can also be used to mechanically fix the first connecting member 11 and the second connecting member 12. The structural design of the connecting mechanism can also be used to continue to mechanically fix the first connecting member 11 and the second connecting member 12 after bonding.

[0061] In one embodiment, as shown in FIG6 , the first connecting mechanism 103 has a first connecting channel 1030, and the second connecting mechanism 104 has a second connecting channel 1040. In order to prevent blood from being trapped or blood from flowing poorly at the connection points between the first connecting channel 1030 and the first circulation port 1010 and between the second connecting channel 1040 and the second circulation port 1012, a smooth transition connection is formed between the connecting channels (1030, 1040) and their corresponding circulation ports (1010, 1012). For example, as shown in FIG6 , a curved surface is provided at the connection point between the first connecting channel 1030 and the first circulation port 1010, and a curved surface is provided at the connection point between the second connecting channel 1040 and the second circulation port 1012.

[0062] As shown in FIG7 , in one embodiment, the first connecting mechanism 103 includes a first connecting member 1032 and a first fixing member 1031. The first connecting member 1032 is formed on the end body 101 and extends outwardly corresponding to the first flow port, and is used to fit the first connecting member 11. That is, the first connecting member 11 can fit its port onto the first connecting member 1032. The first fixing member 1031 cooperates with the first connecting member 1032 to fix the first connecting member 11 to the first connecting member 1032. For example, the cooperation between the first fixing member 1031 and the first connecting member 1032 may include clamping, snap-fitting, threaded cooperation, or a combination of any of the above, and this application is not limited thereto.

[0063] Please refer to Figure 8 and combine it with Figure 6. Figure 8 shows a schematic diagram of the specific structure of the first access end in one embodiment of the present application. The self-sealing component of the first access end is omitted in Figure 8. In the embodiment shown in Figures 6 and 8, the first connecting member 1032 includes a screwing portion 1032a and a connecting portion 1032b. An external thread is provided on the outer circumferential surface of the screwing portion 1032a for screwing with the first fixing member 1031. The connecting portion 1032b is formed by continuing to extend along the screwing portion 1032a. The connecting portion 1032b is used to sleeve the first connecting member 1011. As shown in Figure 6, the first connecting member 1011 is sleeved on the connecting portion 1032b. After the first fixing member 1031 is screwed on the screwing portion 1032a, the first connecting member 1011 will be clamped on the connecting portion 1032b. In order to prevent the first connecting component 1011 from falling off the connecting portion 1032b, a protruding structure 1032c may be further provided on the outer periphery of the connecting portion 1032b. When the first connecting component 1011 is sleeved on the connecting portion 1032b, it can be stuck by the protruding structure 1032c and cannot slide directly away from the connecting portion 1032b in the horizontal direction.

[0064] In one embodiment, as shown in Figures 6 and 7, the first fixing member 1031 is provided with a portion (not marked) that cooperates with the screwing portion 1032a and the connecting portion 1032b of the first connecting member 1032. When the first connecting member 1011 is sleeved on the connecting portion 1032b, the first fixing member 1031 passes through the first connecting member 1011 and is rotated and screwed into the screwing portion 1032a by means of an internal thread that cooperates with the screwing portion 1032a. Since the screwing portion does not contact the first connecting member 1011, it will not cause damage to the first connecting member 1011, thereby avoiding side bleeding or thrombosis. Furthermore, the first fixing member 1031 has an abutting portion 1031a on an end surface away from the end body 1010, as shown in FIG6 . When the first fixing member 1031 is engaged with the first connecting member 1032, the abutting portion 1031a presses the first connecting member 11 sleeved on the first connecting member 1032 against the end surface of the first connecting member 1032, so that the internal channel of the first connecting member 11 is flush with the connecting channel 1030 of the first connecting member 1032. In other words, the abutting portion 1031a can ensure a smooth connection between the internal channel of the first connecting member 11 and the connecting channel 1030 of the first connecting member 1032, without causing sudden changes in flow resistance or path, and further preventing blood stagnation and clotting between the channels.

[0065] In one embodiment, the second connecting mechanism 104 is configured to have a structure similar to the first connecting mechanism 103, differing only in size, shape, or position. The principles and mating methods are substantially the same as those of the first connecting mechanism 103. For example, in an embodiment where the inner diameter of the pipe passing through the first connecting member 11 is smaller than the inner diameter of the pipe passing through the second connecting member 12, such that the flow resistance of the first connecting member 11 is greater than the flow resistance of the second connecting member 12, the dimensions of the second connecting mechanism 104 need to be adapted to the second connecting member 12. As shown in FIG7 , the second connecting mechanism 104 may include a second connecting member 1042 and a first fixing member 1041. The second connecting member 1042 extends outward from the end body 101 corresponding to the second flow opening and is adapted to fit over the second connecting member 12. The second fixing member 1041 and the second connecting member 1042 cooperate to secure the second connecting member 12 to the second connecting member 1042. For example, the second fixing member 1041 and the second connecting member 1042 may cooperate by clamping, snapping, threading, or any combination thereof. In a specific example, the structure and coordination of the second fixing member 1041 and the second connecting member 1042 can be found in Figures 6 to 8 and their descriptions of the embodiments of the first fixing member 1031 and the first connecting member 1041, and will not be repeated here. Of course, in other embodiments, the second connecting mechanism 104 can also be configured to have a different structure from the first connecting mechanism 103, and this application is not limited to this.

[0066] In one embodiment, the end body 101 is configured as an integrally formed structure with the first connecting mechanism 103 and the second connecting mechanism 104. Furthermore, in an embodiment where the first connecting mechanism 103 includes a first fixing member and a first connecting member, and the second connecting mechanism 104 includes a second fixing member and a second connecting member, as shown in Figures 7 and 8 , the end body 101 is configured as an integrally formed structure with the first connecting member 1032 of the first connecting mechanism 103 and the second connecting member 1042 of the second connecting mechanism 104.

[0067] In one embodiment, the end body 101 is configured to be composed of a metal material, including stainless steel, copper, aluminum, titanium, and composites thereof. For example, composites of titanium include titanium alloys. Preferably, the end body 101 is made of titanium alloy or stainless steel. In another embodiment, the end body 101 is configured to be composed of a polymer material, including polycarbonate (PC), polypropylene (PP), polyethylene (PE), and polytetrafluoroethylene (PTFE), etc., wherein polycarbonate and polypropylene need to be medical grade. Of course, the end body 101 can also be composed of a composite of a metal material and a polymer material, or partially composed of a metal material and partially composed of a polymer material. This application does not impose any restrictions on this, such as other materials with a certain rigidity.

[0068] As mentioned above, in some embodiments, the end body 101 and the first connecting mechanism 103 and the second connecting mechanism 104 can be set to an integrally formed structure. In view of this, the parts of the first connecting mechanism 103 and the second connecting mechanism 104 that are integrally formed with the end body 101 can be set to be composed of the same material as the end body 101.

[0069] In one embodiment, an anticoagulant coating is further provided in the first access end to prevent blood coagulation. For example, the anticoagulant coating can be coated on the wall surface of the inner cavity 1010 as shown in Figure 5, and can be further coated on the connecting channel 1030 of the first connecting mechanism and the connecting channel 1040 of the second connecting mechanism. The anticoagulant coating can be an inert anticoagulant coating or an active anticoagulant coating. The inert anticoagulant coating is, for example, a phosphorylcholine coating, which inhibits the activation of the coagulation system by reducing the adsorption of plasma proteins and blood cell adhesion on the surface. The active anticoagulant coating is, for example, a heparin coating, which inhibits the activity of thrombin and coagulation factors by activating antithrombin in the blood, thereby blocking the coagulation reaction.

[0070] To further ensure the sealability of the implantable device, in one embodiment, a sealing coating is provided at the connection between each connecting member and the first access end. The sealing coating can be, for example, a silicone coating or a fluoropolymer coating. For example, the sealing coating can be applied to the outer surface of the connection after each connecting member is connected to the first access end. Alternatively, the sealing coating can be applied to the portion of the connecting member or structure connected to the first access end, and then applied again after the connection is complete.

[0071] Continuing with Figures 5 to 7, in one embodiment, the access port 1013 is located on the upper surface of the end body 101. It can be configured as a hole structure formed through the upper wall of the end body 101 (the upper wall is the side wall corresponding to the upper surface of the end body 101). The hole structure can be connected to the inner cavity 1010 by penetrating the upper wall of the end body 101. The self-sealing member 100 is disposed in the hole structure, so that a needle can penetrate the self-sealing member 100 and extend into the inner cavity 1010. In a specific example, the upper surface of the end body 101 is square, and the access port 1013 is an inscribed circle of the square on the upper surface. This design allows the largest circular surface on the access port to serve as the needle insertion area, making it easier for doctors or patients to puncture. Of course, in other examples, the upper surface of the end body 101 can also be configured as other shapes, such as a rectangle to maximize the puncture area. It should be understood that the terms "square" or "rectangular" refer to shapes that are approximately square or rectangular, and are not necessarily standard squares or rectangles.

[0072] Among them, the self-sealing component 100 is arranged in the access port 1013, and the self-sealing component 100 refers to a structure formed by a biocompatible, self-resealable / self-enclosed penetrable material. The self-sealing component 100 allows the needle to penetrate to communicate with the first access end 10 (for example, the inner cavity 1010 of the end body 101), so that fluid can be extracted from the first access end 10 or delivered to the first access end 10. The self-sealing component 100 reseals the hole formed by inserting the needle when the needle is pulled out, thereby preventing the fluid from being released or overflowing from the inside of the first access end 10 (for example, the inner cavity 1010). The material of the self-sealing component of the present application is made of a stretchable material suitable for repeated puncture. For example, the self-sealing component can be made of silicone material, rubber material, latex material, or polymer material. During treatment, the needle is inserted into the self-sealing component, and the treatment is completed. The self-sealing component can achieve self-sealing after the dialysis needle is removed. The needle can have a beveled end to create a perforation in the self-sealing component to facilitate its easier "healing" or sealing. In various embodiments, the self-sealing member 100 can have a thickness between about 1 mm and about 5 mm, or between about 1 mm and about 10 mm.

[0073] In one embodiment, the self-sealing component 100 is disposed in the access port 1013 by injection molding. For example, the material used for the self-sealing component 100 is directly injected into the access port 1013 for molding. In this way, the assembly can be completed during molding, the process is simple, and the sealing and stability of the access end can be ensured.

[0074] In one embodiment, the self-sealing member 100 is disposed in the access port 1013 in an assembled manner, for example, the self-sealing member 100 is produced independently and then inserted into the access port 1013. In this way, a more complex structure can be produced with flexibility.

[0075] In one embodiment, as shown in Figures 6 and 7 , the inner wall of the hole structure corresponding to the access port 1013 is conical. Furthermore, a groove 1014 is provided on the upper wall of the end body 101 surrounding the hole structure, and the self-sealing member 100 has a protrusion (not shown) adapted to the groove 1014 to prevent the self-sealing member 100 from being separated from the access port 1014.

[0076] In some embodiments, the needle used to pierce the self-sealing component 100 may also be referred to as a dialysis needle. In an embodiment, the needle may be a puncture needle, a straight needle, a curved needle, or a butterfly needle. Preferably, the needle may be a curved needle, so as to avoid the needle being accidentally dragged and separated from the self-sealing component during use. For example, the needle head of the needle may be a No. 16 needle or a No. 17 needle, with an inner hole diameter of 1.19 mm, and may also adapt to the required blood flow rate. For example, the needle head is No. 16 and the inner diameter is 1.19 mm, which is suitable for allowing a higher blood flow rate, such as 300cc / min. However, it is not limited to this. In actual applications, different types of needles can be selected according to the patient's condition.

[0077] In order to prevent the needle from piercing the self-sealing member 100 and entering the inner cavity 1010 and further piercing the end body 101, in one embodiment, the first access end 10 may also include a shell (not shown) to prevent needle puncture. The shell can be formed of a material with a certain rigidity, so that it has puncture resistance or puncture resistance relative to the needle during hemodialysis. It should be understood that the shell refers particularly to the bottom surface portion relative to the needle insertion surface. In other embodiments, a rigid structure can also be provided on the inner wall of the inner cavity 1010 of the first access end 10 (especially the bottom surface relative to the needle insertion surface) to prevent the needle from piercing the access end. Of course, in examples where the end body 101 already has a certain puncture resistance or puncture resistance due to its own material selection, a shell or rigid structure to prevent puncture may not be provided. For example, in examples where the end body 101 is made of metal, since the metal material has a certain rigidity and can prevent needle puncture, it is not necessary to provide a shell or rigid structure.

[0078] As previously mentioned, a needle can penetrate the self-sealing member to connect to the first access port, thereby injecting or withdrawing fluid from the first access port. However, in some embodiments, more than one access port may be implanted in the patient's body to form a fluid flow path. Each of the aforementioned and subsequent access ports may be used for either injecting or withdrawing fluid. To avoid operator error, such as inserting an access port for injecting fluid into a needle for withdrawing fluid, or inserting an access port for withdrawing fluid into a needle for delivering fluid, in some embodiments, each of the aforementioned and subsequent access ports is further provided with a needle entry indicator. The needle entry indicator is used to indicate the direction of fluid flow at the access port or to distinguish whether the access port is a venous access port or an arterial access port. The fluid flow direction refers to the direction in which fluid enters or leaves the body through the access port. When fluid enters the body through the access port, it can be referred to as injection or input, while the direction in which fluid leaves the body through the access port can be referred to as withdrawal or extraction. Alternatively, the needle entry indicator is used to indicate whether the access port is a venous access port or an arterial access port, thereby facilitating the operator's puncture operation and reducing the error rate of the operation.

[0079] In some examples, the needle entry mark is represented by the size, shape, position, or hardness of the access end. In this way, the operator can identify the direction of fluid flow by observing or touching the access end under the skin and sensing its size, shape, position, or hardness. For example, the access end for extraction is set to a circular structure, and the access end for injection is set to a triangular structure. If the operator touches the circular structure, the needle for extraction can be inserted into the access end. If the operator touches the triangular structure, the needle for injection can be inserted into the access end. Of course, the shape is not limited to the above examples, and those skilled in the art can make corresponding modified designs based on the inspiration of the above examples.

[0080] In other examples, the needle entry marker is configured as a concave-convex structure on the side of the access point closest to the skin after implantation. This allows an operator to sense or determine the direction of fluid flow through the access point by touching the concave-convex structure beneath the skin. For example, the access point for extraction may have a regular concave-convex structure, while the access point for injection may have a smooth structure. If an operator senses the concave-convex structure by touching an access point, they can then insert the needle for extraction into that access point and the needle for injection into the smooth access point.

[0081] In the treatment of patients, intelligent devices (such as surgical robots or surgical auxiliary intelligent devices) can replace manual treatment of patients. In view of this, in some embodiments, the access end is provided with a positioning structure, and the positioning structure is used to locate the position of the access end in the human body. In this way, the intelligent device can determine the position of the access end in the human body by identifying the positioning structure, so as to facilitate the insertion of the needle into the access end. In some examples, the positioning structure is a sensor receiving device provided at the access end, and the sensor receiving device is, for example, an ultrasonic sensor, an electromagnetic sensor, an infrared sensor, etc., so that the intelligent device can easily locate the access end. Of course, the above is only an example of a positioning structure, and this application does not limit this.

[0082] The implantable access device in any embodiment of the present application can be used to connect to a selected blood vessel to form a liquid flow path. In the application scenario of blood purification, such as hemodialysis, the implantable access device connects a selected artery and a selected vein. The implantable access device can also be used to connect to a cavity in the human body. For example, in the application scenario of peritoneal dialysis, the implantable access device connects to the peritoneal cavity to introduce peritoneal dialysis fluid into the peritoneal cavity. In other words, the present application does not limit the use of the implantable access device to only connecting blood vessels, but can be used to connect to any cavity in the body, such as a part that requires the formation of a liquid flow path.

[0083] Furthermore, the implantable access device provided in any embodiment of the present application may be placed on the patient using either a supracutaneous or subcutaneous implantation method. Subcutaneous implantation refers to the entire implantable device being buried beneath the patient's skin, which does not affect the patient's appearance. Supracutaneous implantation refers to the implantable device having the access end, or in particular the upper surface of the self-sealing member, located on the surface of the patient's skin, which facilitates puncture.

[0084] For different patients or conditions, the distance between two selected blood vessels used by an implantable access device varies. To address this, when connecting the two selected blood vessels, at least a portion of the connecting component of the implantable access device is configured to bend or stretch to meet the required distance between the blood vessels. For example, a portion of the connecting component may be configured as an elastic conduit. When the two selected blood vessels are relatively far apart, this portion of the connecting component can be stretched after implantation. When the two selected blood vessels are relatively close, this portion of the connecting component can be bent after implantation.

[0085] Please refer to Figures 9 and 10, which are schematic diagrams showing the connection of the implantable access device to the blood vessels in different embodiments of the present application. In the application scenario of blood purification such as hemodialysis, two implantable access devices (also referred to as access structures) mentioned in any of the embodiments of Figures 1 to 8 can be provided and connected to the blood vessels in the manner shown in Figures 9 and 10, respectively, to form a complete blood circulation loop. For ease of description and distinction, the implantable access devices shown in Figures 9 and 10 are referred to as the first implantable access device and the second implantable access device, respectively. It should be understood that in some application scenarios, only one implantable access device in Figures 9 and 10 can be provided to connect to the patient's blood vessels. Those skilled in the art can choose according to the actual situation of the patient. The present application does not limit the number of implantable access devices that need to be implanted.

[0086] As shown in FIG9 , a first implantable access device is used to connect a first blood vessel 20 and a second blood vessel 21. The first access end 10 of the first implantable access device is used to extract fluid (e.g., blood), the second connecting member 12 is used to connect to the second blood vessel 21, and the first connecting member 11 is used to connect to the first blood vessel 20. As shown in FIG10 , a second implantable access device is used to connect to a third blood vessel 22 and a fourth blood vessel 23. The first access end 10 of the second implantable access device is used to inject fluid (e.g., blood), the first connecting member 11 is used to connect to the third blood vessel 22, and the second connecting member 12 is used to connect to the fourth blood vessel 23. The structures of the implantable access devices shown in FIG9 and FIG10 can be found in the description of any of the embodiments described above with respect to FIG1 to FIG8 and their related descriptions, and will not be repeated here.

[0087] In the application scenario of blood purification such as hemodialysis, the first blood vessel 20 connected to the first implantable access device as shown in Figure 9 is a vein, the second blood vessel 21 is an artery, the third blood vessel 22 connected to the second implantable access device as shown in Figure 10 is an artery, and the fourth blood vessel 23 is a vein. The arteriovenous blood vessels connected to the first implantable access device and the arteriovenous blood vessels connected to the second implantable access device can be the same blood vessels or different blood vessels in the body. That is, the third blood vessel 22 and the second blood vessel 21 can be the same blood vessel or different blood vessels, and the fourth blood vessel 23 and the first blood vessel 20 can be the same blood vessel or different blood vessels. Whether they are the same blood vessel can be determined based on whether the parts accessed by the two implantable access devices do not have a branch or can also be determined based on whether they are in the same part of the body. Taking the determination based on whether they are in the same part of the body as an example, for example, the second blood vessel 21 and the first blood vessel 20 are an arterial blood vessel and a vein in the arm, respectively, while the third blood vessel 22 and the fourth blood vessel 23 can be an arterial blood vessel and a vein in the arm, respectively, or an arterial blood vessel and a vein in the chest. The present application does not impose any restrictions on the positions and relationship of the two implantable devices. It is only necessary that one of the access ends is used to extract fluid and the other access end is used to inject fluid.

[0088] In an embodiment in which two implantable access devices are simultaneously provided in a patient's body and connected to blood vessels in the manner shown in Figures 9 and 10 respectively to form an extracorporeal fluid circulation pathway during the treatment stage, the input end of the extracorporeal fluid circulation pathway (i.e., the needle for extracting fluid, such as the first needle 30 in Figure 9) is connected to the first access end 10 of the first implantable access device, and the output end of the extracorporeal fluid circulation pathway (i.e., the needle for injecting fluid, such as the second needle 31 in Figure 10) is connected to the first access end 10 of the second implantable access device. In a hemodialysis application scenario, the first and second implantable access devices are connected, for example, between the same arterial and venous vessels. To perform hemodialysis, a first needle 30 is inserted through the skin into the first access end 10 of the first implantable access device; a second needle 31 is inserted through the skin into the first access end 10 of the second implantable access device. As shown in FIG9 , blood flows through the arterial vessel (second vessel 21) via the second connecting member 12 into the first access end 10. The first needle 30 draws blood (as indicated by arrow S10 in FIG9 ) and then enters the dialysis machine. Through the operation of the dialysis machine, waste products are removed from the blood. After circulating through the dialysis machine, the blood then returns to the first access end 10 through the second needle 31, and then enters the venous vessel (fourth vessel 23) via the second connecting member 12, as indicated by arrow S11 in FIG10 . Because the second connecting members 12 in both FIG9 and FIG10 have low flow resistance, blood can be drawn and injected at a faster rate, significantly reducing the time of hemodialysis.

[0089] When hemodialysis is no longer performed, the needle used for hemodialysis is removed from the implantable access device (i.e., the non-treatment phase). During the non-treatment phase, as shown in FIG9 , when first needle 30 is removed, the first implantable access device can form a blood flow path between the second blood vessel 21, the second connecting member 12, the first access end 10, the first connecting member 11, and the first blood vessel 20, as indicated by the dashed arrow S20 in FIG9 . During the non-treatment period, as shown in FIG10 , when second needle 31 is removed, the second implantable access device can form a blood flow path between the third blood vessel 22, the first connecting member 11, the first access end 10, the second connecting member 12, and the fourth blood vessel 23, as indicated by the dashed arrow S21 in FIG10 . Because the implantable access device includes a first connecting member with a relatively large flow resistance, during the non-treatment phase, without external control, the fluid flow from the third blood vessel 22 or the second blood vessel 21 through the implantable access device to the fourth blood vessel 23 or the first blood vessel 20 can be reduced, thereby reducing complications such as the occurrence of venous hyperplasia. Furthermore, although the fluid flow is low, blood flowability can still be ensured within the implantable access device during the non-treatment phase, thereby preventing the formation of blood clots within the implantable access device.

[0090] In the access configuration shown in Figures 9 and 10 , during the treatment phase, since the two implantable access devices exist independently, backflow does not occur. Furthermore, the low flow resistance of the second connecting member ensures that fluid flows out and in at a relatively high rate, further improving fluid circulation efficiency. During the non-treatment phase, the high flow resistance of the first connecting member creates a relatively high resistance in the pathway between the first and second blood vessels, reducing the flow rate or velocity within the first implantable access device. This allows the majority of blood to flow through the second blood vessel to various parts of the body, thereby reducing various complications. Similarly, the high flow resistance of the first connecting member creates a relatively high resistance in the pathway between the third and fourth blood vessels, reducing the flow rate or velocity within the second implantable access device. This allows the majority of blood to flow through the third blood vessel to various parts of the body, thereby reducing various complications.

[0091] In one embodiment, please refer to FIG11 , which shows a schematic diagram of the architecture of an implantable access device in one embodiment of the present application. As shown in FIG11 , the implantable access device 1 may further include a second access port 14 and a third connecting member 13 based on the architecture shown in FIG1 . The first connecting member 11 and the third connecting member 13 are respectively connected to the second access port 14.

[0092] Given that the flow resistance of first connecting member 11 is greater than that of second connecting member 12, during the non-treatment phase, regardless of the relationship between the flow resistance of third connecting member 13 and first connecting member 11 or second connecting member 12, it does not affect the fact that, without external control, first connecting member 11 will reduce the flow rate of fluid through the implantable access device. Therefore, in some embodiments, depending on the characteristic properties of first connecting member 11 and third connecting member 13, the flow resistance of third connecting member 13 may be greater than, less than, or equal to the flow resistance of first connecting member 13.

[0093] To further increase the flow rate of fluid injection or withdrawal during the treatment phase, in some embodiments, the flow resistance of the first connecting member 11 is greater than the flow resistance of the third connecting member 13, depending on the characteristic properties of the first connecting member 11 and the third connecting member 13. That is, the flow resistance of the first connecting member 11 in the implantable access device is the largest. As a result, during the non-treatment phase, when there is no external control, the flow rate of fluid flowing through the implantable access device is relatively low. The second connecting member 12 and the third connecting member 13, used for connecting to the blood vessels, each have a lower flow resistance than the first connecting member 11. This allows for higher flow rates of fluid to be withdrawn and injected during the treatment phase, further improving treatment efficiency. It should be understood that the subsequent embodiments will use the example of the first connecting member 11 having a greater flow resistance than the third connecting member 13, which does not necessarily mean that the first connecting member 11 is necessarily greater than the third connecting member 13.

[0094] The functions, structures, materials, and shapes of the third connecting member 13 and the second access end 14 may be similar to those of the second connecting member 12 and the first access end 10 described in any of the embodiments in Figures 1 to 4 and the related descriptions thereof. The embodiment in which the flow resistance of the first connecting member 11 is greater than the flow resistance of the third connecting member 13 may refer to the embodiment in which the flow resistance of the first connecting member 11 is greater than the flow resistance of the second connecting member 12. It is sufficient to replace the second connecting member 12 with the third connecting member 13. This application does not elaborate on this embodiment.

[0095] Please refer to Figures 12 and 13. Figure 12 shows a schematic diagram of the specific structure of the implantable access device in one embodiment of the present application, and Figure 13 shows a schematic diagram of the disassembled structure of the implantable device in the embodiment shown in Figure 12 of the present application. The structure and connection method of the first connecting member 11, the first access end 10, and the second connecting member 12 can be referred to the aforementioned description of Figures 5 to 8. The second access end 14 may also include a self-sealing member 140 and an end body 141, and may further include a first connecting mechanism 143 and a second connecting mechanism 144. The third connecting member 13 is connected to the second access end 14 and can further be connected to the second connecting mechanism 144. The first connecting member 11 is connected to the first connecting mechanism 143. Among them, the functions, structures, materials, shapes, etc. specifically implemented or adopted by the self-sealing component 140, end body 141, first connecting mechanism 143, second connecting mechanism 144 of the second access end 14, and the third connecting component 13 can be similar to the self-sealing component, end body, first connecting mechanism, second connecting mechanism, and second connecting component of the first access end described in any embodiment in Figures 5 to 8 and their related descriptions. Please refer to the description of the aforementioned embodiments, and this application will not repeat them here.

[0096] In some embodiments, as shown in the implantable access device of Figures 11 to 13, the length of the first connecting member 11 can be relatively long, and the lengths of the second connecting member 12 and the third connecting member 13 can be relatively short. In this way, the flow resistance of the first connecting member 11 is greater and it is allowed to bend when implanted in the patient, thereby better achieving the effect of improving the treatment scenario, treatment efficiency, and reducing complications.

[0097] In some embodiments, the first connecting member 11 can be configured as an elastic conduit, and further, can be configured as a U-shaped conduit. In other words, the first connecting member 11 can be U-shaped when the implantable access device is not in use, allowing it to be stretched to increase the distance at which the implantable access device can connect to the blood vessels, thereby being suitable for different patients or different conditions. For example, when the two selected blood vessels are far apart, the first connecting member 11 can be stretched after the implantable access device is implanted, further increasing the connectable distance of the implantable access device. When the two selected blood vessels are very close, the first connecting member 11 can be maintained in the U-shaped state after the implantable access device is implanted, thereby maintaining a shorter connectable distance.

[0098] In one embodiment, in the architecture of an implantable access device having two access ends as shown in FIG11 , the first connecting member 11 may be configured as a through-hole structure connecting the first access end 10 and the second access end 14 . In this way, the two access ends may be connected or formed together so that they are adjacent to and close to each other, thereby meeting the needs or limitations of the patient's physical condition.

[0099] Please refer to Figures 14 and 15. Figure 14 is a schematic diagram of the architecture of the implantable access device in one embodiment of the present application, and Figure 15 is a schematic diagram of the AA section of the embodiment shown in Figure 14. The architecture and structure shown in Figures 14 and 15 are similar to those shown in Figures 11 to 13, with the only difference being that the first connecting member 11 can be set as a through-hole structure connecting the first access end 10 and the second access end 14. The flow resistance provided by the through-hole structure is greater than that of the second connecting member 12 and the third connecting member 13, respectively, and can also effectively reduce the aforementioned complications such as arterial steal, venous hyperplasia, and thrombosis, and can reduce reflux and improve blood purification efficiency.

[0100] In blood purification applications such as hemodialysis, a complete blood circulation circuit can be formed by simply connecting an implantable access device, such as shown in any of the embodiments of Figures 11 to 15, to a blood vessel. Referring to Figure 16, a schematic diagram of an implantable access device connected to a blood vessel in one embodiment of the present application is shown. The implantable access device shown in any of the embodiments of Figures 11 to 15 is used to connect a second blood vessel 21 and a first blood vessel 20. The third connecting member 13 connects to the first blood vessel 20, and the second connecting blood vessel 12 connects to the second blood vessel 21. The first connecting member 11 is located between the first access end 10 and the second access end 14. In this embodiment, the second blood vessel 21 can be, for example, an artery, and the first blood vessel 20 can be, for example, a vein. In this case, the second access end 14 is used for injecting fluid, and the first access end 10 is used for withdrawing fluid. In an embodiment where the second blood vessel 21 is an artery and the first blood vessel 20 is a vein, the third connecting member 13 can also be used to connect to the second blood vessel 21, and the second connecting member 12 can be used to connect to the first blood vessel 20. In this case, the first access end 10 is used for injecting fluid, and the second access end is used for withdrawing fluid. In other words, the second and third connecting members are connecting members for connecting blood vessels, thereby enabling an extracorporeal fluid circulation pathway during the treatment phase and a blood flow path from the second blood vessel 21 to the first blood vessel 20 during the non-treatment phase. Given that the flow resistance of the first connecting member is greater than that of the second connecting member in the present application, the flow rate of blood flowing from the second blood vessel through the implantable access device to the first blood vessel during the non-treatment phase, without external control, can be reduced. Furthermore, the implantable access device shown in Figures 11 to 15 can be connected to the first and second blood vessels in the manner shown in Figure 16 , or the arrangement shown in Figure 16 can be reversed to connect the first and second blood vessels (i.e., connecting the third connecting member 13 to the second blood vessel 21 and the second connecting blood vessel 12 to the first blood vessel 20 ). In this way, the two access ends can function alternately as injection or withdrawal points during the treatment phase, eliminating the need for doctors or patients to identify which blood vessels the different connecting members should connect to, thus avoiding connection errors and potentially medical accidents.

[0101] The following describes blood flow using the example of second blood vessel 21 being an artery and first blood vessel 20 being a vein, using the connection method shown in FIG16 . In FIG16 , a first needle 30 penetrates the self-sealing member 100 of the first access end 10, and a second needle 31 penetrates the self-sealing member 140 of the second access end 14, thereby forming an extracorporeal fluid circulation pathway during the treatment phase. In this application, the term "extracorporeal fluid circulation pathway" refers to a fluid flow path that draws fluid from the body outside the body for treatment and then returns it to the body.

[0102] As shown in Figure 16, the input end of the extracorporeal fluid circulation pathway (i.e., the needle for extracting fluid, such as the first needle 30 in Figure 16) is connected to the first access end 10, and the output end of the extracorporeal fluid circulation pathway (i.e., the needle for injecting fluid, such as the second needle 31 in Figure 16) is connected to the second access end 14, thereby connecting the implantable access device between the second blood vessel 21 and the first blood vessel 20. For example, in the application scenario of hemodialysis, the implantable access device is connected between the artery and the vein. In order to perform hemodialysis, the first needle 30 is inserted through the skin into the first access end 10; the second needle 31 is inserted through the skin into the second access end 14; blood passes through the artery (second blood vessel 21) through the second connecting member 12 to enter the first access end 10, and the first needle 30 extracts (as shown by the arrow S30 in Figure 16) and then enters the dialysis machine; through the operation of the dialysis machine, waste is removed from the blood, and after circulating through the dialysis equipment, the blood then returns to the second access end 14 through the second needle 31, and then enters the vein (first blood vessel 20) through the third connecting member 13, as shown by the arrow S31 in Figure 16. In this way, with the help of the second access end 14 and the first access end 10, it is convenient for the operator to insert the needle every time a treatment is performed, and even non-professionals can easily operate it.

[0103] When hemodialysis is no longer being performed, the needle used for hemodialysis is removed from the implantable access device. During the non-treatment phase, as shown in FIG16 , first needle 30 and second needle 31 are removed, and first connecting member 11 is connected to first access end 10 and second access end 14, forming a blood flow path from second blood vessel 21 through the implantable access device to the first blood vessel 20 (as indicated by the dashed arrow S32 in FIG16 ). This ensures that the implantable access device maintains blood flow during the non-treatment phase, preventing the formation of blood clots within the device.

[0104] To reduce other complications, such as venous hyperplasia and arterial steal, and to improve fluid circulation efficiency during the treatment phase, in the embodiment shown in FIG16 , the flow resistance of the first connecting member 11 is greater than that of the second connecting member 12, relying on the characteristic properties of the first through third connecting members. This allows, without external control, to reduce the flow of fluid from the second blood vessel 21 through the implantable access device to the first blood vessel 20. Furthermore, the flow resistance of the first connecting member 11 can also be greater than that of the third connecting member 13, meaning that the flow resistances of the second and third connecting members 12, 13 are relatively small. For example, during the treatment phase, due to the greater flow resistance of the first connecting member 11, fluid returning to the body through the second access port 14 is more likely to return to the first blood vessel 20 through the third connecting member 13, thereby reducing backflow (i.e., reducing the tendency of fluid returning through the second access port 14 to enter the first access port 10 directly through the first connecting member 11) and improving fluid circulation efficiency. During the non-treatment phase, the flow resistance of the first connecting member 11 is large, which reduces the flow rate in the implantable access device, while allowing most of the blood to flow into various parts of the body through the second blood vessel 21, thereby reducing complications.

[0105] In one embodiment, the connecting member for connecting blood vessels in any of the above embodiments can be connected to its corresponding blood vessel in an end-to-side anastomosis manner. In this application, the end-to-side anastomosis refers to a method of connecting the side wall of a tubular object with a port. For example, a small window can be opened on the side of a blood vessel wall, and one end of another tubular object can be connected to the window to form a "T"-shaped or "Y"-shaped anastomosis. The end-to-side anastomosis needs to maintain an angle of less than 90° and greater than 10°, and the opening direction of the angle conforms to the direction of blood flow to avoid the blood flow causing a greater impact on the end-to-side anastomosis.

[0106] Taking Figure 16 as an example, a small window is opened on the side of the wall of the second blood vessel 21 and the first blood vessel 20. One end of the second connecting member 12 is connected to the small window on the side of the wall of the second blood vessel 21. The connection can be maintained by surgical suturing or insertion. In this way, blood in the second blood vessel 21 can flow into the second connecting member 12 through the small window. One end of the third connecting member 13 is connected to the small window on the side of the wall of the first blood vessel 20. The connection can be maintained by surgical suturing or insertion. In this way, fluid in the third connecting member 13 can flow into the first blood vessel 20 through the small window.

[0107] In an embodiment in which the connecting member is connected to the blood vessel in an end-to-side anastomosis manner, the connecting member may include at least one catheter, and the two ends of the catheter are respectively connected to the blood vessel and the access end to which the connecting member is connected. Please refer to Figure 17, which shows a schematic diagram of an embodiment of the present application in which the third connecting member includes two catheters and is connected to a blood vessel. The figure uses the implantable access device shown in Figures 11 to 15 as an example to access the blood vessel in the manner shown in Figure 16, wherein the third connecting member 13 includes a first catheter 130 and a second catheter 131. One end of the first catheter 130 is connected to the first blood vessel 20, and the other end is connected to the second access end 140. One end of the second catheter 131 is connected to the first blood vessel 20, and the other end is connected to the second access end 140. It should be noted that in this example, the first blood vessel 20 is adapted to the number of catheters included in the third connecting member 13 and two small windows are provided on the side of the tube wall. Of course, the second connecting member 12 of the implantable access device shown in Figures 11 to 15 can also be set to include two or more catheters, and the first connecting member 11 and the second connecting member 12 in Figures 9 and 10 can be set to include one, two, three, or more catheters.

[0108] The above examples are merely illustrative of the number of tubes included in the connecting component. In other embodiments, depending on the actual condition and needs, the above connecting component may include any number of tubes, and the number of tubes included in different connecting components may be the same or different. This application does not impose any limitation on this.

[0109] In one embodiment, in any of the above embodiments, one connecting member for connecting a blood vessel is connected to the corresponding blood vessel by end-to-side anastomosis, and another connecting member for connecting a blood vessel is connected to the corresponding blood vessel by end-to-end anastomosis. In this application, end-to-end anastomosis refers to connecting a tubular object by directly coupling one end to another end. For example, a blood vessel may be partially resected to form two separated ends, and one end of another tubular object may be coupled to one of the ends, and the other end may be coupled to the other end to achieve connection.

[0110] Please refer to Figure 18, which is a schematic diagram of the connecting components of the implantable access device in one embodiment of the present application connected to blood vessels by end-to-side anastomosis and end-to-end anastomosis respectively. The figure takes the implantable access device shown in Figures 11 to 15 connected to the second blood vessel 21 and the first blood vessel 20 as an example for explanation. A small window is opened on the side of the wall of the first blood vessel 20, and one end of the third connecting component 13 is connected to the small window on the side of the wall of the first blood vessel 20. The connection can be maintained by surgical suturing or by insertion. In this way, the blood in the first blood vessel 20 can flow into the third connecting component 13 through the small window. The second blood vessel 21 is separated into two broken ends (210, 211). In order to adapt to the two broken ends (210, 211), in terms of structure, as shown in Figures 11 to 15, the second connecting member 12 that needs to be connected to the two broken ends (210, 211) also needs to be provided as two. For example, a new connecting member is added by adding a flow port and a connecting mechanism to the end body. In this way, the two ends of the two second connecting members 12 are respectively connected to the two broken ends (210, 211), thereby connecting the first access end 10 to the second blood vessel 21. It should be understood that Figure 18 is only an example. The third connecting member 13 in Figure 18 can also be provided to connect to the first blood vessel 20 in an end-to-end anastomosis manner, and the second connecting member 12 can be connected to the second blood vessel 21 in an end-to-side anastomosis manner. Of course, as described above in the embodiment of connecting blood vessels in an end-to-side anastomosis manner, in this embodiment, the connecting member used for end-to-side anastomosis can also include one or more catheters, which will not be described in detail here.

[0111] Some embodiments of the present application also provide an implantable access device comprising a first connecting segment and a second connecting segment. The second connecting segment allows for needle access for fluid extraction or injection during treatment. The first connecting segment is connected to one end of the second connecting segment to form a fluid flow path; depending on characteristic properties of the first and second connecting segments, the flow resistance of the first connecting segment is greater than the flow resistance of the second flow segment.

[0112] In one embodiment, the first and second connecting sections are integrally formed into an artificial blood vessel. In other words, the artificial blood vessel comprises a first and second connecting section, and the artificial blood vessel is distinguished into a first connecting section with a high flow resistance and a second connecting section with a low flow resistance by configuring different sections of the artificial blood vessel with different characteristic properties.

[0113] In one embodiment, the functions, structures, materials, shapes, etc. implemented by the first connecting section and the second connecting section may be similar to the second connecting member 12 and the first connecting member 11 described in any embodiment in Figures 1 to 4 and their related descriptions, respectively, wherein the first connecting section is equivalent to the first connecting member, and the second connecting section is equivalent to the second connecting member 12 and the first access end 10. The working principles of constructing the fluid pathway and in the treatment or non-treatment stage are the same as those described above. Please refer to the aforementioned Figures 1 to 4 and their related descriptions, and no further details will be given here.

[0114] The aforementioned implantable access device including the first connecting section and the second connecting section can be used to connect selected blood vessels for application in various medical scenarios. Taking the scenario of blood purification such as hemodialysis as an example, two implantable access devices can be provided to form a complete blood circulation pathway. In this embodiment, the manner in which each implantable access device connects to the blood vessels and the flow path formed during the treatment or non-treatment stage are similar to the aforementioned Figures 9 and 10 and their related descriptions. Those skilled in the art can equate the second connecting section with the second connecting component 12 and the first access end 10 in Figures 9 and 10, and the first connecting section with the first connecting component 11 in Figures 9 and 10. Please refer to the aforementioned description of Figures 9 and 10, which will not be repeated here.

[0115] Of course, the aforementioned implantable access device including the first and second connecting sections can also be configured to form a complete blood circulation pathway. In this embodiment, the manner in which the implantable access device connects to the blood vessels and the flow path formed during the non-treatment phase are similar to those in FIG. 9 and its related description. Those skilled in the art may equate the second connecting section with the second connecting member 12 and the first access end 10 in FIG. 9 , and the first connecting section with the first connecting member 11 in FIG. During the non-treatment phase, the first connecting section is equated with the first connecting member 11 and the second access end 14 in the aforementioned embodiments. The portion of the first connecting section that allows needle insertion serves as the second access end 14. Therefore, during the treatment phase, the second connecting section allows needle entry to extract fluid from the second blood vessel, and the first connecting section allows needle entry to inject fluid into the first blood vessel.

[0116] In one embodiment, the functions, structures, materials, shapes, etc. implemented by the first connecting section and the second connecting section may be similar to the second connecting member 12 and the first connecting member 11 described in any embodiment in Figures 1 to 4 and their related descriptions, respectively, wherein the first connecting section is equivalent to the first connecting member, and the second connecting section is equivalent to the second connecting member 12, the only difference being that the second connecting member 12 and the first connecting member 11 are respectively connected to the first access end 10 to use the first access end 10 as an interface for needle insertion, while the first connecting section and the second connecting section can be directly connected and the portion thereof allowing needle insertion can be used as an access port, and the construction of the fluid pathway and the working principle in the treatment or non-treatment stage are the same as those of the second connecting member 12 and the first connecting member 11, and reference may be made to Figures 1 to 4 and their related descriptions, which will not be repeated here.

[0117] In some embodiments, the implantable access device may further include a third communication segment in addition to the first and second communication segments, wherein the third communication segment is connected to the other end of the first communication segment and allows a needle to enter to inject or extract fluid during treatment.

[0118] In one embodiment, the first, second, and third connecting sections are integrally structured and configured as an artificial blood vessel. In other words, the artificial blood vessel comprises a first, second, and third connecting section, and by configuring different sections of the artificial blood vessel with different characteristic properties, the artificial blood vessel is distinguished into a first connecting section with relatively high flow resistance and a second and third connecting sections with relatively low flow resistance.

[0119] The artificial blood vessels in any of the above embodiments may be, for example, artificial blood vessels made of polymer materials, or may be, for example, biological artificial blood vessels. The polymer materials include polyethylene (PE), polytetrafluoroethylene (PTFE), expanded polytetrafluoroethylene (ePTFE), polyester (also known as polyester fiber, PET), polyether urethane (PEU), and polyurethane (PU). The biological artificial blood vessels may also be referred to as bioengineered tissue conduits, which refer to blood vessels prepared using extracellular matrix, such as human acellular vessels (HAV) or skeleton acellular artificial blood vessels (SAV).

[0120] In one embodiment, the functions, structures, materials, shapes, etc. implemented by the first connecting section, the second connecting section, and the third connecting section may be similar to the first connecting member 11, the second connecting member 12, and the third connecting member 13 described in any of the embodiments in Figures 11 to 18 and their related descriptions, respectively, wherein the first connecting section is equivalent to the first connecting member 11, the second connecting section is equivalent to the second connecting member 12 and the first access end, and the third connecting section is equivalent to the third connecting member 13 and the second access end 14. In other words, the portion of the second connecting section that allows needle insertion is the first access end, and the portion of the third connecting section that allows needle insertion is the second access end. The method of accessing the blood vessel, the fluid pathway constructed, and the working principle during the treatment or non-treatment stage in this embodiment can be found in the aforementioned Figures 11 to 18 and their related descriptions, and will not be repeated here.

[0121] In some embodiments of the present application, a fluid circulation system is also provided, which can be used for blood purification, such as hemodialysis. In one embodiment, the fluid circulation system is, for example, a hemodialysis system. Referring to FIG. 19 , a schematic diagram of the architecture of a fluid circulation system in one embodiment of the present application is shown, which includes at least one implantable access device 40, an external tubing device 41, and a purification device 42.

[0122] The implantable access device 40 can be implanted in subcutaneous tissue of the body, such as in the arm or chest, or can be implanted supracutaneously. The external conduit device 41 includes an outlet conduit 410, a return conduit 411, a first needle 412, and a second needle 413. The outlet conduit 410 is inserted into the access end 400 via the first needle 412 to connect to the access end 400 of the implantable access device 40. The return conduit 411 is inserted into the access end 401 via the second needle 413 to connect to the access end 401. The purification device 42 is connected to the outlet conduit 410 and the return conduit 411 and is used to purify the fluid output from the outlet conduit 410 before outputting it to the return conduit 411.

[0123] The implantable access device 40 may be configured as an implantable access device having a single access end, that is, access end 400 and access end 401 belong to different implantable access devices, such as the implantable access device described in any of the embodiments of Figures 1 to 10. Please refer to any of the aforementioned embodiments described in Figures 1 to 10 and their related descriptions, which will not be repeated here. The implantable access device may also be configured as an implantable access device having two access ends, that is, access end 400 and access end 401 belong to a single implantable access device, wherein access end 400 is used to extract fluid and access end 401 is used to inject fluid, such as the implantable access device described in any of the embodiments of Figures 11 to 18. Please refer to any of the aforementioned embodiments described in Figures 11 to 18 and their related descriptions, which will not be repeated here.

[0124] It should be understood that the implantable access device can also be configured as the aforementioned implantable access device including the first connecting section and the second connecting section, and can further include a third connecting section. Here, the portion of one connecting section that allows needle insertion serves as an access end to connect the lead-out line, and the portion of the other connecting section that allows needle insertion serves as another access end to connect the return line. This application does not limit the embodiment of the access end of the implantable access device.

[0125] Among them, the first needle 412 or the second needle 413 can also be called a dialysis needle. In an embodiment, the first needle 412 or the second needle 413 can be a puncture needle, a straight needle, a curved needle, or a butterfly needle. Preferably, the first needle 412 or the second needle 413 can be a curved needle, so as to avoid the needle being accidentally dragged and separated from the access end during use. For example, the needle head of the first needle 412 or the second needle 413 can be a 16-gauge needle head or a 17-gauge needle head with an inner hole diameter of 1.19 mm, and can also adapt to the required blood flow rate. For example, the needle head is 16-gauge and has an inner diameter of 1.19 mm, which is suitable for allowing a higher blood flow rate, such as 300cc / min. However, it is not limited to this. In actual applications, different types of needles can be selected according to the patient's condition.

[0126] The outlet line 410 is connected to the access end 400 to draw fluid from the body, and the return line 411 is connected to the access end 401 to output the purified fluid to the body. In an embodiment, the outlet line 410 is, for example, an arterial line, and the return line 411 is, for example, a venous line. The purification device 42 is, for example, a dialyzer, which is also connected to a dialysis line for introducing dialysate into the dialyzer. The dialyzer is used to purify blood flowing in the blood circuit and forms a blood flow path for the patient's blood and a dialysate flow path for the dialysate through a built-in purification membrane for blood purification. In an embodiment, the dialyzer includes a dialysate chamber, a blood chamber, and a semi-permeable membrane, etc. The membrane separates the dialysate chamber and the blood chamber from each other. In commonly used capillary dialyzers, the blood chamber is formed by the entire internal volume of the hollow fibers, and the dialysate chamber is formed by the inner cavity of the dialyzer shell surrounding the hollow fibers. In an embodiment, the top end of the dialyzer is connected to the arterial blood line, and the bottom end of the dialyzer is connected to the venous blood line. The types of dialyzers can include hemodialyzers, hemodiafilters, hemofilters, plasma separators, blood plasma component separators, and other instruments of various specifications or uses. As long as the instrument can separate toxins or molecular components in the blood, the present application can be used.

[0127] It should be understood that in an actual hemodialysis system, the arterial blood line is also provided with a hydrophobic filter, a dialysis pump with a built-in osmotic membrane and a hollow fiber membrane, a valve device, an arterial pressure sensor, an arterial pot and other components; the arterial blood line is also provided with a venous pot, a hydrophobic filter, a venous pressure sensor, a liquid level sensor, an air sensor, a valve device and the like.

[0128] In summary, the implantable access device and fluid circulation system proposed in this application, by providing connecting components with different flow resistances on both sides of the access end, can effectively reduce the aforementioned complications such as arterial steal, venous hyperplasia, and thrombosis, and can also reduce reflux and improve blood purification efficiency. Furthermore, the different flow resistances of the connecting components in this application are determined based on the characteristic properties of the designed connecting components, and do not require additional operations on other objects. This makes the structure simple and easy to use, and can be applied to various medical scenarios and treatment modes, such as hospital treatment and home treatment.

[0129] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical concepts disclosed in this application shall be covered by the claims of this application.

Claims

1. An implantable access device, characterized in that: include: a first access end comprising a self-sealing member that allows needle entry for withdrawing or injecting fluid during a treatment phase; A first connecting member and a second connecting member are respectively connected to the first access end, and are used to provide a fluid flow path to or from the first access end; Wherein, depending on characteristic properties of the first connecting member and the second connecting member, the flow resistance of the first connecting member is greater than the flow resistance of the second connecting member.

2. The implantable access device according to claim 1, wherein: The implantable access device is used to connect a first blood vessel and a second blood vessel, and further includes a second access end and a third connecting member, wherein the third connecting member is used to connect the first blood vessel and the second access end, wherein: The second connecting member is connected to the second blood vessel so that the second blood vessel is connected to the first access end; The second access end includes a self-sealing member, and a needle is inserted into the self-sealing members of the two access ends respectively to form an extracorporeal fluid circulation path during the treatment stage; The first connecting component is also connected to the second access end so that a flow path for fluid is formed from the second blood vessel to the first blood vessel in the non-treatment stage. The flow resistance of the first connecting component is greater than the flow resistance of the second connecting component, so that in the absence of external control, the fluid flow from the second blood vessel through the device to the first blood vessel is reduced.

3. The implantable access device according to claim 1, wherein: The implantable access device is used to connect a first blood vessel and a second blood vessel, and further includes a second access end and a third connecting member, wherein the third connecting member is used to connect to the second blood vessel, and the second access end, wherein: The second connecting member is connected to the first blood vessel so that the first blood vessel is connected to the first access end; The second access end includes a self-sealing member, and a needle is inserted into the self-sealing members of the two access ends respectively to form an extracorporeal fluid circulation path during the treatment stage; The first connecting component is also connected to the second access end so that a flow path for fluid is formed from the second blood vessel to the first blood vessel in the non-treatment stage. The flow resistance of the first connecting component is greater than the flow resistance of the second connecting component, so that in the absence of external control, the fluid flow from the second blood vessel through the device to the first blood vessel is reduced.

4. The implantable access device according to claim 2 or 3, characterized in that: The flow resistance of the first communicating member is also greater than the flow resistance of the third communicating member.

5. The implantable access device according to claim 2 or 3, characterized in that: The first connecting member is configured as a through-hole structure or a tubular structure connecting the first access end and the second access end.

6. The implantable access device according to claim 1, characterized in that The implantable access device is used to connect a first blood vessel and a second blood vessel, wherein the first access end is used to extract fluid, the first connecting member is used to connect the first blood vessel, and the second connecting member is used to connect the second blood vessel, so as to reduce the fluid flow from the second blood vessel toward the first blood vessel through the device without external control.

7. The implantable access device according to any one of claims 2 to 6, characterized in that: The first blood vessel is a vein, and the second blood vessel is an artery.

8. The implantable access device according to claim 1, wherein: The implantable access device is used to connect a third blood vessel and a fourth blood vessel, wherein the first access end is used to inject fluid, the first connecting member is used to connect the third blood vessel, and the second connecting member is used to connect the fourth blood vessel, so as to reduce the fluid flow from the third blood vessel to the fourth blood vessel through the device without external control.

9. The implantable access device according to claim 8, characterized in that: The third blood vessel is an arterial blood vessel, and the fourth blood vessel is a venous blood vessel.

10. The implantable access device according to claim 2, 3, 6, or 8, wherein: Each connecting member is connected to its corresponding blood vessel in an end-to-side anastomosis manner.

11. The implantable access device according to claim 10, characterized in that: Each connecting component comprises at least one catheter, and both ends of each catheter are respectively connected to the blood vessel and the access end corresponding to the connecting component.

12. The implantable access device according to claim 2, 3, 6, or 8, wherein: The connecting member for connecting the blood vessels is connected to the corresponding blood vessels in an end-to-side anastomosis manner, and the other connecting member for connecting the blood vessels is connected to the corresponding blood vessels in an end-to-end anastomosis manner.

13. The implantable access device according to any one of claims 1 to 12, characterized in that: The manner in which the flow resistance of one connecting component is greater than the flow resistance of another connecting component includes any one of the following: the pipe cross-sectional area of ​​one connecting component is smaller than the pipe cross-sectional area of ​​the other connecting component; or, one connecting component includes a flow resistance structure arranged in its pipe; or, the pipe of one connecting component is arranged as an S-shaped or wavy conduit.

14. The implantable access device according to claim 13, wherein: The flow resistance structure is a one-way valve or a Tesla valve.

15. The implantable access device according to any one of claims 1 to 3, characterized in that: Each access end includes an end body, which is provided with a first flow port, a second flow port, and an access port; the first flow port, the second flow port, and the access port are interconnected through the inner cavity of the end body, the first flow port is also connected to the first connecting component, the second flow port is also connected to the second connecting component, and the access port is used to set a self-sealing component.

16. The implantable access device according to claim 15, characterized in that The first flow opening and the second flow opening are arranged opposite to each other, and the inner cavity is arranged as a transition channel with increasing flow resistance and smooth surface formed from the second flow opening to the first flow opening in the end body.

17. The implantable access device according to claim 16, wherein: The transition channel is configured as a channel with a conical inner wall.

18. The implantable access device according to claim 15, wherein: The first access terminal further includes: a first connecting mechanism connecting the first flow port and the first communicating member so that the first communicating member is in communication with the first flow port; The second connecting mechanism connects the second flow port and the second communicating member so that the second communicating member communicates with the second flow port.

19. The implantable access device according to claim 18, wherein: Each connecting mechanism has a connecting channel, and the connecting channel is smoothly transitionally connected to its corresponding flow port.

20. The implantable access device according to claim 18, wherein: The first connecting mechanism includes: A first connecting member is formed on the end body and extends outwardly corresponding to the first flow opening, so as to be sleeved with the first connecting member; The first fixing member cooperates with the first connecting member to fix the first connecting member on the first connecting member.

21. The implantable access device according to claim 20, wherein: The end body and the first connecting member are configured as an integrally formed structure.

22. The implantable access device according to claim 20, wherein: The cooperation manner between the first fixing member and the first connecting member includes at least one of clamping, snapping, and threaded cooperation.

23. The implantable access device according to claim 20, wherein: The first connecting member includes: a screwing portion, the outer circumference of which is provided with an external thread for screwing with the first fixing member; The connecting portion is formed by continuing to extend along the screwing portion and is used for sleeve-mounting the first connecting member so that the first connecting member is clamped in the connecting portion after the first fixing piece is screwed.

24. The implantable access device according to claim 23, wherein: A protrusion structure is provided on the outer peripheral surface of the connecting portion to prevent the first connecting member from falling off.

25. The implantable access device according to claim 23, wherein: The first fixing member includes a supporting portion. When the first fixing member is engaged with the first connecting member, the supporting portion presses the first connecting member sleeved on the first connecting member against the end surface of the first connecting member so that the internal channel of the first connecting member is flush with the connecting channel of the first connecting member.

26. The implantable access device according to claim 15, wherein: The access port is configured as a hole structure formed through the upper wall of the end body, and the self-sealing component is configured in the hole structure by assembly or injection molding.

27. The implantable access device according to claim 26, wherein: The inner wall of the hole structure is a conical surface.

28. The implantable access device according to claim 26, wherein: A groove is provided on the upper wall of the end body around the hole structure, and the self-sealing member has a protrusion matched with the groove to prevent the self-sealing member from being separated from the hole structure.

29. The implantable access device according to claim 15, wherein: The upper surface of the end body is in the shape of a square, and the access port is an inscribed circle of the square on the upper surface.

30. The implantable access device according to claim 15, wherein: The left and right side walls of the end body in the direction from the first flow opening to the second flow opening are configured as arc-shaped surfaces having a corresponding inner cavity shape.

31. The implantable access device according to claim 15, wherein: The end body is configured to be made of metal material and / or polymer material.

32. The implantable access device according to claim 31, wherein: The metal materials include stainless steel, copper, aluminum, titanium, and composites thereof, and the polymer materials include polycarbonate, polypropylene, polyethylene, and polytetrafluoroethylene.

33. The implantable access device according to any one of claims 1 to 3, characterized in that: Each connecting member is respectively configured as an artificial blood vessel.

34. The implantable access device according to claim 33, wherein: The artificial blood vessels include artificial blood vessels made of PTFE material, ePTFE material, PEU material, PET material or PU material, and biological artificial blood vessels.

35. The implantable access device according to claim 34, wherein: The second connecting member and the third connecting member are made of a material that can be used as an artificial blood vessel, and the first connecting member includes a PTFE material.

36. The implantable access device according to claim 2 or 3, characterized in that The first communication member is configured as a U-shaped communication conduit.

37. The implantable access device according to claims 1 to 3, characterized in that Each access port is provided with a needle entry mark, which is used to indicate the fluid flow direction of the access port or to distinguish whether the access port is a venous access port or an arterial access port.

38. The implantable access device according to claim 37, wherein: The needle entry mark is represented by the size, shape, position, or hardness or softness of the access end.

39. The implantable access device according to claim 37, wherein: The needle entry mark is configured as a concave-convex structure on the side close to the human skin after the access end is implanted into the human body.

40. The implantable access device according to claim 1, wherein The self-sealing member is used to allow a needle to penetrate to communicate with the access port, and the needle is withdrawn to reseal the hole formed by inserting the needle and thereby prevent the release of fluid.

41. The implantable access device according to claim 40, wherein: The self-sealing component can be made of silicone material, rubber material, latex material, or polymer material.

42. The implantable access device according to any one of claims 1 to 3, characterized in that: Each access terminal is provided with a positioning structure, and the positioning structure is used to locate the position of the access terminal in the body.

43. The implantable access device according to any one of claims 1 to 3, characterized in that: The implantable access device is used for blood purification.

44. The implantable access device according to any one of claims 1 to 3, characterized in that: A rigid structure for preventing needle puncture is provided on the inner wall of the cavity of the first access end and / or the second access end.

45. The implantable access device according to any one of claims 1 to 3, characterized in that: The needle used is a puncture needle, straight needle, curved needle, or butterfly needle.

46. ​​The implantable access device according to claim 1, wherein An anti-coagulation coating is provided in the first access end.

47. The implantable access device according to any one of claims 1 to 3, characterized in that: The connection between each connecting component and each access end is provided with a sealing coating.

48. The implantable access device according to any one of claims 1 to 3, characterized in that: The inner diameter ratio of the first communicating member to the second communicating member or the third communicating member may be set to any ratio between 1 / 2 and 1 / 8.

49. The implantable access device according to any one of claims 1 to 3, characterized in that: The inner diameter of the pipe of the second connecting member or the third connecting member is set to any value from 6 mm to 8 mm, and the inner diameter of the pipe of the first connecting member is set to any value from 1 mm to 3 mm.

50. The implantable access device according to any one of claims 1 to 3, characterized in that: When the implantable access device connects the first blood vessel and the second blood vessel, at least a portion of the connecting member is allowed to bend or stretch to meet the distance requirement between the first blood vessel and the second blood vessel.

51. An implantable access device, characterized in that: include: a second communication section that allows needle access for withdrawing or injecting fluid during the treatment phase; The portion of the second communication section allowing the needle to enter is the first access end; A first communicating section is connected to one end of the second communicating section to form a fluid flow path; wherein, depending on characteristic properties of the first communicating section and the second communicating section, the flow resistance of the first communicating section is greater than the flow resistance of the second flow section.

52. The implantable access device according to claim 51, wherein: The implantable access device is used to connect a first blood vessel and a second blood vessel, and further includes a third connecting segment, wherein: The second communicating section is connected to the second blood vessel to allow a needle to enter and extract fluid from the second blood vessel during a treatment phase; The third connecting section is connected to the other end of the first connecting section and is also used to connect to the first blood vessel, allowing the needle to enter and inject fluid into the first blood vessel during the treatment phase; the portion of the third connecting section that allows the needle to enter is the second access end; The third communicating section also forms a fluid flow path together with the first communicating section and the second communicating section during a non-treatment phase, thereby reducing the fluid flow from the second blood vessel through the device toward the first blood vessel without external control.

53. The implantable access device according to claim 51, wherein: The implantable access device is used to connect a first blood vessel and a second blood vessel, and further includes a third connecting segment, wherein: The second communication section is connected to the first blood vessel to allow a needle to enter and extract fluid from the first blood vessel during a treatment phase; The third connecting section is connected to the other end of the first connecting section and is also used to connect to the second blood vessel, allowing the needle to enter and inject fluid into the second blood vessel during the treatment phase; the portion of the third connecting section that allows the needle to enter is the second access end; The third communicating section also forms a fluid flow path together with the first communicating section and the second communicating section during a non-treatment phase, thereby reducing the fluid flow from the second blood vessel through the device toward the first blood vessel without external control.

54. The implantable access device according to claim 52 or 53, wherein: The flow resistance of the first communication section is also greater than the flow resistance of the third flow section.

55. The implantable access device according to claim 51, wherein: The implantable access device is used to connect a first blood vessel and a second blood vessel; wherein the second connecting section is connected to the second blood vessel, allowing a needle to enter to extract fluid from the second blood vessel during a treatment phase; the first connecting section is connected to the first blood vessel, and in a non-treatment phase, without external control, reduces the fluid flow from the second blood vessel through the device toward the first blood vessel.

56. The implantable access device according to any one of claims 52 to 55, wherein: The first blood vessel is a vein, and the second blood vessel is an artery.

57. The implantable access device according to claim 55, wherein: The first communicating section further allows a needle to enter so as to inject fluid toward the first blood vessel during a treatment phase, and the portion of the first communicating section that allows the needle to enter is a second access end.

58. The implantable access device according to claim 51, wherein: The implantable access device is used to connect a third blood vessel and a fourth blood vessel, wherein the second connecting section is used to connect the fourth blood vessel to allow a needle to enter and inject fluid toward the first blood vessel during the treatment phase, and the first connecting section is used to connect the third blood vessel to reduce the fluid flow from the second blood vessel through the device toward the first blood vessel without external control.

59. The implantable access device according to claim 58, wherein: The third blood vessel is an arterial blood vessel, and the fourth blood vessel is a venous blood vessel.

60. The implantable access device according to any one of claims 51 to 53, wherein: Each communicating section is an integrated structure and is arranged as an artificial blood vessel.

61. The implantable access device according to claim 60, wherein: The artificial blood vessels include artificial blood vessels made of PTFE material, ePTFE material, PEU material, PET material or PU material, and biological artificial blood vessels.

62. A fluid circulation system, characterized in that: include: The implantable access device according to any one of claims 1 to 61; An external pipeline device, comprising an outlet pipeline and a return pipeline, wherein the outlet pipeline is used to connect to one access end of the implantable access device, and the return pipeline is used to connect to the other access end; The purification device is connected to the outlet pipeline and the return pipeline, and is used for purifying the fluid output from the outlet pipeline and outputting it to the return pipeline.

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