Fluid pumping conduit

Abstract

The invention provides a fluid pumping guide pipe. The fluid pumping guide pipe comprises a first expansion body and a main body, the far end of the main body is provided with a fluid inflow channel, and the near end of the main body is provided with a fluid outflow channel; and the first expansion body is arranged at the far end of the main body. The contact force between the first expansion body and the inner wall of the tissue is buffered through the flexibility characteristic of the first expansion body, the first expansion body deforms after making contact with the inner wall of the tissue, the contact area is increased, intracardiac tissue cannot be damaged, and structures such as valves and chordae tendineae cannot be hooked. The impact force on the inner wall of the tissue is effectively reduced, and the problem that the intracardiac tissue is damaged is avoided; the safety of the instrument is effectively improved, and the occurrence probability of clinical adverse events is remarkably reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a fluid pumping catheter. Background Art

[0002] The blood pumping catheter is a type of blood auxiliary circulation device. The device is introduced into the heart through PCI surgery to provide patients with stable blood flow circulation support, improve coronary artery and distal organ perfusion, and reduce the burden on the left ventricle. It is beneficial to the stabilization of physical signs and postoperative rehabilitation of patients with heart failure, cardiogenic shock and other critically ill patients, and promotes the recovery of patients' heart function. In the related art, the distal end of the blood pumping catheter is a J-shaped head or a ring head (pigtail) to increase the contact area between the catheter head and the ventricular wall and reduce the damage of the blood pumping catheter head to the ventricular wall. Because there are valve chordae and myocardial fiber mesh in the ventricle, the head end of the J-shaped head and the ring head (pigtail) will hook the chordae or fiber mesh, causing the device to damage the intracardiac tissue, and even the device is difficult to withdraw from the heart. Furthermore, since the outer diameter of the J-shaped head and the ring head (pigtail) is usually smaller than the blood pumping catheter, the blood pumping catheter will be close to the ventricular wall, and then the ventricular wall tissue will be sucked into the blood pumping catheter, resulting in a decrease in blood pumping flow and even damage to the ventricular wall. Therefore, there is an urgent need for a safe and effective pumping catheter to reduce or eliminate the above-mentioned clinical adverse events. Summary of the invention

[0003] In order to overcome at least one of the problems in the related art, the present invention provides a fluid pumping catheter.

[0004] Wherein, the fluid pumping conduit comprises a first expansion body and a main body;

[0005] The distal end of the main body is provided with a fluid inflow channel, and the proximal end is provided with a fluid outflow channel;

[0006] The first expansion body is arranged at the distal end of the main body, and the volume of the first expansion body is adjustable.

[0007] In an optional embodiment, a fluid flow gap is provided on the outer surface of the first expansion body.

[0008] In an optional embodiment, the first expansion body includes a plurality of sub-regions;

[0009] Some of the sub-regions are fluidically connected, or none of the sub-regions are fluidically connected.

[0010] In an optional embodiment, the connection between the outer surfaces of adjacent sub-areas forms the fluid flow gap.

[0011] In an optional embodiment, the distal end of the main body is provided with a shaft extending along the axial direction of the main body;

[0012] The first expansion body covers the shaft rod and is respectively connected to both ends of the shaft rod.

[0013] In an optional embodiment, the catheter further comprises a second expansion body, the second expansion body is arranged at the distal end of the main body, and the second expansion body is arranged inside the first expansion body;

[0014] A first space is formed between the inner surface of the first expansion body and the outer surface of the second expansion body.

[0015] In an optional embodiment, the first space is filled with a developing substance.

[0016] In an optional embodiment, the catheter further includes a third expansion body, the third expansion body is disposed outside the body, and the interior of the first expansion body and the interior of the third expansion body are fluidically connected.

[0017] In an optional embodiment, the third expansion body includes at least a primary expansion state and a secondary expansion state, and when the internal pressure of the third expansion body is greater than or equal to a set pressure threshold, the third expansion body switches from the primary expansion state to the secondary expansion state.

[0018] In an optional embodiment, a pressure measuring unit is provided at the distal end of the main body and on the surface of the first expansion body.

[0019] In an optional embodiment, a pacing unit is disposed at the distal end of the main body and on the surface of the first expansion body.

[0020] The technical solution of the present invention has the following advantages or beneficial effects:

[0021] (1) The head end of the fluid pumping catheter of the present invention adopts a first expansion body to replace the J-shaped head or the ring head in the prior art. Before the fluid pumping catheter enters the ventricle, the first expansion body is filled and completely covers the catheter head end. The flexibility of the first expansion body buffers the contact force between it and the inner wall of the tissue, and the first expansion body deforms after contacting the inner wall of the tissue to increase the contact area, which will not damage the intracardiac tissue, and will not hook the valve and chordae tendineae and other structures. It effectively solves the problems of hooking chordae tendineae or fiber mesh existing in the J-shaped head or the ring head used in the prior art. In addition, the contact area between the first expansion body and the intracardiac tissue is significantly larger than the end structure in the prior art, which effectively reduces the impact force on the inner wall of the tissue and avoids the occurrence of problems such as damage to the intracardiac tissue; it effectively improves the safety of the device and significantly reduces the probability of clinical adverse events.

[0022] (2) The volume of the first expansion body of the present invention is adjustable; when in use, the operator can flexibly adjust the volume of the expansion body as needed, so that the volume of the expansion body is large enough to separate the fluid inflow channel on the main body from the ventricular wall, effectively solving the problem of ventricular wall tissue being sucked into the inflow channel in the prior art. Moreover, when the pumping catheter is close to the ventricular wall, the operator can adjust the pumping flow of the catheter by adjusting the volume of the first expansion body. In addition, a fluid flow gap is set on the outer surface of the expansion body, and the flow gap can guide the flow direction of the fluid, reduce or delay the phenomenon of the boundary layer separating from the surface of the expansion body, and reduce the resistance of the fluid flowing through the surface of the expansion body, thereby increasing the pumping flow.

[0023] (3) The first expansion body includes a plurality of sub-regions; some of the sub-regions are fluidically connected, or none of the sub-regions are connected. In the case where the sub-regions are connected, the operator only needs to control the gas supply of the gas source at the proximal end to synchronously control the expansion or contraction of multiple connected sub-regions; in the case where there are independent sub-regions, when the user needs a sub-region in a certain direction to expand, the sub-region in the corresponding direction can be filled, and other sub-regions may not be filled. The sub-region that is not inflated is in a contracted state, which reduces the resistance of the fluid to flow on the surface of the first expansion body, thereby increasing the fluid flow rate inside the pumping catheter.

[0024] (4) The distal end of the present invention is provided with two nested expansion bodies, and the developing substance is filled in the interlayer of the double-layer nested expansion bodies, and the interlayer constrains the distribution of the developing substance. Compared with the scheme of directly filling the developing substance inside the single-layer balloon, the developing substance in this scheme is more evenly distributed in space, which is conducive to observing the state of the expansion body in the body through the display device. The pumping catheter can effectively be compatible with existing development equipment, reducing the learning cost of operators, so that they can get started with the catheter device of the present invention more quickly. In addition, the first space between the first expansion body and the second expansion body is filled with developer and / or a small amount of gas, so that the pressure inside the first expansion body is smaller than the pressure of the second expansion body; and then when the second expansion body accidentally ruptures, the gas inside it can enter the first expansion body, avoiding the risk of gas directly entering the blood or organs and forming gas embolism, thereby improving the safety of the catheter.

[0025] (5) By setting up two expansion bodies connected by fluids inside and outside the body, the operator does not need to use developing materials or additional display devices to observe the state of the expansion body inside the body. The operator can understand the state of the first expansion body inside the body by observing the state of the third expansion body outside the body. This achieves the purpose of simply observing the state of the pumping catheter. At the same time, it also solves various problems caused by the operator's misoperation of the expansion body inside the body in the prior art. In addition, the device disclosed in the present invention enables the operator to deal with emergencies in a timely manner when observing that the third expansion body outside the body is abnormal, avoiding problems such as leakage and embolism of blood vessels in the expansion body inside the body, effectively improving the safety of the use of the pumping catheter and improving the efficiency of clinical medical treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings are used to better understand the present invention and do not constitute an improper limitation of the present invention.

[0027] Figure 1 is a schematic diagram of a fluid pumping conduit according to an embodiment of the present invention;

[0028] Figure 2 is a schematic diagram of a fluid pumping catheter in a working state in a ventricle according to an embodiment of the present invention;

[0029] Figure 3 is a schematic cross-sectional view of a first expansion body structure according to an embodiment of the present invention;

[0030] Figure 4 is a schematic cross-sectional view of another first expansion body structure according to an embodiment of the present invention;

[0031] Figure 5 is a schematic cross-sectional view of another first expansion body structure according to an embodiment of the present invention;

[0032] Figure 6 is a schematic diagram of an expanded state of a double-layer expansion body according to an embodiment of the present invention;

[0033] Figure 7 is a schematic diagram of a device having an extracorporeal expansion body according to an embodiment of the present invention;

[0034] Figure 8 is a schematic diagram of a folding portion in a folded state according to an embodiment of the present invention;

[0035] Fig. 9 is a schematic diagram of an expansion body in a second expansion state according to an embodiment of the present invention;

[0036] Fig.10 is a schematic diagram of an expansion body in a third expansion state according to an embodiment of the present invention;

[0037] Fig.11is a schematic diagram of an apparatus having a pressure measuring unit according to an embodiment of the present invention;

[0038] Fig.12 is a schematic diagram of an apparatus having a pacing unit according to an embodiment of the present invention;

[0039] Fig.13 It is a schematic diagram of the working state of the blood pumping catheter in the ventricle in the prior art;

[0040] Fig.14 It is a schematic diagram of the structure of a blood pump catheter in the prior art;

[0041] Fig.15 is a schematic diagram of a fluid pumping catheter having a shaft according to an embodiment of the present invention. DETAILED DESCRIPTION

[0042] The following is a description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, including various details of the embodiments of the present invention to facilitate understanding, which should be considered as merely exemplary. Therefore, it should be recognized by those of ordinary skill in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present invention. Similarly, for clarity and conciseness, the description of well-known functions and structures is omitted in the following description.

[0043] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0044] It should be understood that although the terms first, second, third, etc. may be used in the present application to describe various information, these information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0045] The blood pumping catheter is a type of blood auxiliary circulation device. When used, the device can be introduced into the heart through PCI surgery. The blood pumping catheter can pump blood from the left ventricle into the aorta, provide patients with stable blood flow circulation support, improve coronary and distal organ perfusion, and reduce the burden on the left ventricle, which is beneficial to the stability of vital signs and postoperative rehabilitation of patients with heart failure, cardiogenic shock and other critically ill patients, and promote the recovery of cardiac function in patients. The distal end of the common blood pumping catheter in the prior art is a J-shaped head or a ring head (pigtail) to increase the contact area between the catheter and the ventricular wall and reduce the damage of the head end of the blood pumping catheter to the ventricular wall. Because there are valve chordae tendineae and myocardial fiber mesh in the ventricle, it is found in some clinical studies that the head end of the J-shaped head or the ring head (pigtail) will hook the chordae tendineae or fiber mesh, causing the device to damage the intracardiac tissue, and even the problem of difficulty in withdrawing the device. The J-shaped head or the ring head (pigtail) can be made of polymer materials such as PEBAX, PVC, PU, ​​PE, PP, etc., and is made by extrusion process, heat setting process, tip molding process, etc. Then it is connected and fixed by bonding, hot melting, heat shrinking, laser welding, etc. And its inner cavity can be used as a channel for the guide wire. In addition, if Fig.14 As shown in the figure, since the outer diameter of the J-shaped head and the pigtail is usually smaller than that of the blood pumping catheter, some clinical studies have found that the blood pumping catheter will stick to the ventricular wall (such as Fig.13 When the blood pumping catheter is working, it will suck the ventricular wall tissue into the blood pumping catheter, resulting in a decrease in blood pumping flow and even damage to the ventricular wall.

[0046] In order to solve at least one of the above problems, a first aspect of the present invention provides a fluid pumping catheter.

[0047] The fluid pumping catheter comprises a first expansion body and a main body; a fluid inflow channel is arranged at the distal end of the main body, and a fluid outflow channel is arranged at the proximal end; the first expansion body is arranged at the distal end of the main body.

[0048] like Figure 1 and Fig.14 As shown, Figure 1 A partial structural schematic diagram of a fluid pumping conduit of the present invention is disclosed; Fig.14A schematic diagram of the structure of a blood pumping catheter is shown. The fluid pumping catheter mainly includes a main body and a first expansion body 101. In one embodiment, the first expansion body can be made into a liquid-filled balloon or an inflatable balloon. From the perspective of use, the fluid pumping catheter includes a distal end and a proximal end, wherein the distal end is the end away from the operator, and the proximal end is the end close to the operator. During actual use, the operator controls the fluid pumping catheter at the proximal end, such as controlling the inflation and deflation of the expansion body. The first expansion body is arranged at the distal end, which is located in the human body during use, and its volume expands when inflated. It should be noted that in this embodiment, the head end of the fluid pumping catheter uses a first expansion body to replace the J-shaped head or the pigtail in the prior art. Before the fluid pumping catheter enters the ventricle, the first expansion body is filled and completely covers the catheter head end. The flexibility of the first expansion body buffers the contact force between it and the inner wall of the tissue, and the first expansion body deforms after contacting the inner wall of the tissue to increase the contact area, which will not damage the intracardiac tissue, and will not hook the valve and chordae tendineae and other structures. The problem of hooking chordae tendineae or fiber mesh existing in the J-shaped head or the pigtail used in the prior art is effectively solved. In addition, the contact area between the first expansion body and the intracardiac tissue is significantly larger than the end structure in the prior art, which effectively reduces the impact force on the inner wall of the tissue and avoids the occurrence of the problem of damaging the intracardiac tissue; the safety of the device is effectively improved, and the probability of clinical adverse events is significantly reduced.

[0049] The distal end of the main body is provided with a fluid inflow channel 1404, and the proximal end is provided with a fluid outflow channel 1402. When in use, when the fluid pumping catheter reaches the target position, the fluid to be pumped is driven by the driving device 1401 to flow and enter the fluid inflow channel, and the fluid flows along the axial direction of the main body, and finally flows out of the pumping catheter from the fluid outflow channel. The driving device includes but is not limited to a rotor. The rotor can be made of metal, polymer or a composite material of multiple materials. The rotor is usually designed in the shape of a spiral blade, and is mechanically or electromagnetically connected to the rotating shaft. The rotating shaft drives the rotor to rotate through the rotation of the motor, thereby driving the fluid to flow inside the pumping catheter. Exemplarily, the fluid inflow channel and the fluid outflow channel can be made of metal materials such as stainless steel, nickel titanium, etc., for example, by machining, laser cutting, MIT, welding and other processes. In one embodiment, a transvalve catheter 1403 is also provided between the fluid inflow channel and the fluid outflow channel. The transvalve catheter can be a metal tube, a polymer tube or a composite tube of multiple materials. Preferably, the transvalvular catheter has a certain bending angle, and the bending angle can be any angle between 0° and 150°. It should be noted that the bending angle refers to the initial angle of the transvalvular catheter when it is not subjected to external force. The bending angle enables the fluid pumping catheter to have good pushing properties, twist control, support and bending flexibility, ensuring that the fluid pumping catheter passes through the aortic arch smoothly and is inserted into the valve opening and closing, so that the fluid inflow channel and the fluid outflow channel are respectively located below and above the valve, thereby achieving the purpose of crossing the valve. The inner cavity of the transvalvular catheter is a circulation channel for the fluid. In an optional embodiment, a driving device 1401 is provided inside the fluid outflow channel, and one end of the fluid outflow channel is connected to the transvalvular catheter, and the other end is connected to the main catheter.

[0050] In an optional embodiment, the volume of the first expansion body is adjustable. The end of the blood pumping catheter in the prior art adopts a J-shaped head or a ring-shaped head, which has the problem that the fluid inflow channel is sucked into the ventricular wall tissue. It is understandable that once the ventricular wall tissue is sucked in, it will block the fluid inflow channel, which will not only affect the pumping efficiency of the fluid, but also may cause the inflow channel to over-squeeze the sucked ventricular wall tissue and damage the tissue. Fig.13As shown, the J-shaped head cannot effectively support the main structure of the blood pumping catheter, causing the fluid inflow channel to rest against the inner wall of the ventricle, and there is a risk of tissue being sucked into the inflow channel. To this end, in one embodiment of the present invention, the volume of the first expansion body can be adjusted. When in use, the operator can flexibly adjust the volume of the expansion body as needed, so that the volume of the expansion body is large enough to separate the fluid inflow channel on the main body from the ventricular wall, effectively solving the problem of ventricular wall tissue being sucked into the inflow channel in the prior art. In addition, the operator can also adjust the volume of the first expansion body by observing the blood pumping flow of the catheter with the aid of an instrument or observing the distance between the catheter and the ventricular wall. It can be understood that when the distance is large, the fluid can enter the fluid inflow channel with low resistance, so that there is a large fluid flow in the pumping catheter. Therefore, when the pumping catheter is close to the ventricular wall, the operator can adjust the pumping flow of the catheter by adjusting the volume of the first expansion body. Preferably, the outer diameter of the first expansion body is larger than the outer diameter of the pumping catheter, thereby reducing the probability of the pumping catheter fitting the ventricular wall. Furthermore, the size of the actual ventricle should also be considered when adjusting the first expansion body. If the outer diameter of the first expansion body is too large, it will occupy too much space in the ventricle and affect the blood flow in the ventricle, and also weaken the pumping function of the heart itself. The first expansion body can be made of natural latex, synthetic latex, silicone, rubber, TPE, TPX, TPU, WPU, Pebax and other materials; and connected and fixed to the end of the pumping catheter by bonding, hot melting, heat shrinking, laser welding and other methods.

[0051] In an optional embodiment, the outer surface of the first expansion body is provided with a fluid flow gap. Generally, the first expansion body can be made into a spherical structure to reduce production costs. In this structure, the fluid needs to pass over the surface of the sphere before entering the fluid inflow channel of the catheter. It can be understood that the surface area of ​​the sphere is relatively large, resulting in greater resistance to the fluid. In addition, after the fluid flows over the surface of the sphere, the boundary layer will detach and produce a larger turbulent flow. When the laminar flow changes to turbulent flow, it will further affect the fluid from entering the inflow channel and reduce the pumping flow. To this end, in one embodiment of the present invention, a fluid flow gap is provided on the outer surface of the expansion body. The flow gap can guide the flow direction of the fluid, reduce or delay the boundary layer detaching from the surface of the expansion body, reduce the resistance of the fluid flowing through the surface of the expansion body, and thus increase the pumping flow. For example, Figures 3 to 5In the illustrated embodiment, the first expansion body includes a petal-like structure, such as 3 petals or 4 petals, etc., and the number does not constitute a limitation on the scope of protection of the present invention. The connection between the petals constitutes the flow gap 305. Preferably, the flow gap extends along the axial direction of the pumping conduit. When the fluid flows, the reverse fluid can flow along the flow gap, and the adjacent petal-like structure provides a semi-open guide channel for the fluid, so that the fluid can stably and low-resistance pass through the surface of the first expansion body and then enter the fluid inflow channel.

[0052] In an optional embodiment, the first expansion body includes a plurality of sub-regions; some of the sub-regions are fluidically connected, or none of the sub-regions are connected. In practice, in order to facilitate the control of inflation and deflation of the first expansion body, in one embodiment of the present invention, the interior of the first expansion body is divided into a plurality of sub-regions. When the plurality of sub-regions are partially or fully connected, ventilation can be synchronously provided to the connected sub-regions through the same air source to control volume changes. When some or all of the sub-regions are not connected, the operator can independently control the air supply to the non-connected regions to control their volumes. Specifically, as Figure 3 In the illustrated embodiment, it shows the state of the first expansion body being located in a blood vessel or intracardiac tissue 302. The first expansion body includes three petal structures 301, i.e., has three sub-regions, and the three sub-regions are interconnected. An inner tube 304 is provided inside the first expansion body, and an air injection opening 303 connected to the interior of the first expansion body is provided on the inner tube. When it is necessary to control the volume of the first expansion body, the operator only needs to control the air supply of the air source at the proximal end to synchronously control the expansion or contraction of the three sub-regions. Furthermore, Figure 4 A schematic diagram with four petal structures is shown. When the number of the petal structures increases, the flow gap also increases accordingly. Properly increasing the flow gap can effectively increase the flow rate of the fluid flowing through the surface of the first expansion body. Figure 5 In the illustrated embodiment, the sub-regions are not connected to each other, so it is necessary to set a plurality of gas injection openings on the inner tube, and each of the sub-regions is connected to at least one gas injection opening. When the user needs a sub-region in a certain direction to expand, the sub-region in the corresponding direction can be filled, and other sub-regions may not be filled. The uninflated sub-region is in a contracted state, which reduces the resistance of the fluid to flow on the surface of the first expansion body, thereby increasing the fluid flow rate. In some embodiments, only one inner tube may be provided, and the gas injection openings are all provided on the inner tube. In other embodiments, the number of inner tubes may be greater than one, and the distribution of the gas injection openings on the inner tube may be adjusted according to the distribution of the sub-regions.

[0053] In an optional embodiment, Fig.15As shown, the distal end of the main body is provided with a shaft 1501 extending along the axial direction of the main body; the first expansion body covers the shaft and is respectively connected to the two ends of the shaft to reduce the eccentricity of the first expansion body. It can be understood that if only one end of the first expansion body is connected to the distal end of the main body, the distal end of the first expansion body will be in a free state, and then eccentric movement will occur when subjected to external force, for example, it will swing along the connection point between the first expansion body and the main body. This eccentric movement will increase the probability of the fluid pumping catheter fitting the ventricular wall. To this end, in this embodiment, a shaft extending along the axial direction of the main body is provided at the distal end of the main body, and the two ends of the shaft are respectively connected to the first expansion body, and the first expansion body can cover the shaft when it expands; thereby, the two ends of the first expansion body are constrained by the shaft to prevent its eccentric movement. Preferably, the distal end and the proximal end of the first expansion body are respectively connected to the two ends of the shaft. For example, when the first expansion body is spherical, the distal end and the proximal end of the first expansion body are located at two endpoints of the same diameter, and the tendency of the first expansion body to undergo eccentric movement due to external force can be effectively restrained by connecting the two endpoints to the shaft rod respectively. When the first expansion body is a rotating body structure, the distal end and the proximal end of the first expansion body are two endpoints located on the axis of rotation. In an optional embodiment, the shaft rod is provided with air holes, and the air holes are connected to the interior of the first expansion body, and the air holes are used to inject or discharge gas into or out of the expansion body. In some embodiments, the shaft rod is arranged in parallel with the inner tube 304 described above, for example, the shaft rod and the inner tube are coaxially sleeved, or the shaft rod and the inner tube are non-coaxially arranged side by side and in parallel. In some embodiments, the shaft rod can be the inner tube described above, and this arrangement can reduce the complexity of the structure and save manufacturing costs.

[0054] In an optional embodiment, the catheter further includes a second expansion body, which is disposed at the distal end of the main body and inside the first expansion body; a first space is formed between the inner surface of the first expansion body and the outer surface of the second expansion body. Preferably, the first space is filled with a developing substance. At this time, the fluid pumping catheter can be effectively compatible with the digital subtraction angiography device (DAS) commonly used in the prior art, and the operator can observe the working state of the fluid pumping catheter in the human body through the digital subtraction angiography device.

[0055] See also Figure 6, which shows a partial enlarged view of the distal end of a fluid pumping catheter with a second expansion body. The first expansion body 101 and the second expansion body 602 can be made into a balloon shape. The second expansion body is nested inside the first expansion body; a first space 603 is formed between the inner surface of the first expansion body and the outer surface of the second expansion body. The two nested expansion bodies ensure that when the inner second expansion body ruptures and leaks due to excessive gas filling, the outer first expansion body can contain the gas to prevent it from entering the blood vessels or organs.

[0056] Preferably, the first space is filled with a developing substance. The developing substance may be a contrast agent, or other substances with equivalent functions. Since the developing substance is filled in the interlayer of the double-layer nested expansion body, the first space constrains the distribution of the developing substance. Compared with the solution of directly filling the developing substance inside a single-layer balloon, the distribution of the developing agent in the space in this embodiment is more uniform, which is more conducive to observing the state of the expansion body in the body through a display device. The first space between the first expansion body and the second expansion body is filled with a developing agent and / or a small amount of gas, so that the pressure inside the first expansion body is smaller than the pressure of the second expansion body. Therefore, when the second expansion body accidentally ruptures, the gas inside it can enter the first expansion body, and the smaller pressure condition of the first expansion body can effectively accommodate the gas leaked from the second expansion body, thereby avoiding the risk of gas directly entering the blood and forming an air embolism, and ultimately improving the safety of the catheter.

[0057] In an optional embodiment, the second expansion body is made of an elastic material, and / or the first expansion body is made of a semi-compliant material. The elastic material includes highly elastic materials such as synthetic latex, silicone, rubber, TPE, TPX, TPU, WPU, etc. In practice, the first expansion body preferably uses highly elastic materials such as synthetic latex, thermoplastic elastomer (TPE), thermoplastic polyurethane elastomer (TPU), etc. Compared with the solution of making balloons with natural latex used in the prior art, it is compatible with people who are intolerant to latex, and improves the safety of the pumping catheter and the range of applicable people. In addition, the semi-compliant material may be PEBAX, etc. Among them, the material with an expansion ratio of 110-130% is a semi-compliant material.

[0058] In an optional embodiment, the distal end of the main body is provided with a first air hole 606 and a second air hole 605; wherein the first air hole is connected to the interior of the second expansion body; and the second air hole is connected to the first space. Figure 6 As shown, in order to facilitate the filling of gas into the first space and the internal space 604 of the second expansion body respectively and control the amount of gas filled respectively, it is necessary to set corresponding inflation channels for the first space and the internal space of the second expansion body respectively.

[0059] In an optional embodiment, the catheter further comprises a third expansion body, the third expansion body is disposed outside the body, and the interior of the first expansion body is fluidically connected to the interior of the third expansion body. Figure 7 As shown, the pumping catheter includes a first expansion body 101 located at the distal end and a third expansion body 702 located near the proximal handle. And the internal fluid of the first expansion body and the internal fluid of the third expansion body are connected. It should be noted that in this embodiment, the first expansion body arranged at the distal end is not filled with a developing substance, and no developer is added to its manufacturing material, so the operator cannot observe the state of the first expansion body located in the body through the commonly used developing equipment. Correspondingly, in order to facilitate the operator to understand the state of the first expansion body located in the body in real time, a double expansion body design scheme is adopted in one embodiment of the present disclosure, and the third expansion body is arranged at the proximal end. When in use, the first expansion body is inserted into the human body along the blood vessel, and the third expansion body is placed outside the body. Due to the communication of the internal space fluid of the first expansion body and the third expansion body, the internal pressure of the two expansion bodies is equal in real time. When the state parameters such as pressure and volume of any expansion body change, the state parameters of the other expansion body will change accordingly. That is, through the structural design of this embodiment of the present disclosure, when the first expansion body is located in the body and the third expansion body is located outside the body, the volume change of the third expansion body can reflect the working state of the first expansion body. Therefore, the operator can understand the state of the first expansion body in real time by observing the state of the third expansion body outside the body. Specifically, when the operator performs inflation or deflation operations, the volumes of the first expansion body and the third expansion body will expand or contract synchronously. By connecting the internal spaces of the two expansion bodies in series, the operator does not need to use developing materials, nor does he need to use additional display devices to observe the state of the internal expansion body. He can understand the state of the first expansion body inside the body by observing the state of the third expansion body outside the body; the purpose of simply observing the state of the pumping catheter is achieved; at the same time, it also solves various problems caused by the operator's misoperation of the internal expansion body in the prior art, such as repeated inflation and deflation confirmation will prolong the operation time, increase the risk of balloon rupture, and balloon leakage will cause the injection gas to directly enter the blood and blood vessels, which are all adverse events in clinical practice. In addition, the device disclosed in the present invention enables the operator to deal with emergencies in a timely manner when observing abnormalities in the third expansion body outside the body, avoiding problems such as leakage and embolism of blood vessels in the internal expansion body, effectively improving the safety of the use of the pumping catheter and improving the efficiency of clinical medical treatment. It can be understood that the above-mentioned third expansion body in vitro is also applicable to the scheme with nested expansion bodies in vivo. For the scheme with nested expansion bodies in vivo, preferably, the third expansion body in vitro is configured to be fluidically connected to the innermost expansion body in vivo.

[0060] In an optional embodiment, when the first expansion body is in a non-compressed state, the outer diameters of the first expansion body and the third expansion body are equal. Since the internal space of the blood vessels or organs of the human body is small, the outer diameters of the first expansion body and the third expansion body are also small. Under such conditions, when the volume difference of the two expansion bodies in the normal inflation expansion state is large, especially the outer diameter difference is large, and the volume or pressure of the internal expansion body changes slowly, it will be difficult for the operator to timely discover the volume change of the external expansion body. In particular, when the volume of the external expansion is significantly larger than the volume of the internal expansion body, the small diameter change of the external expansion body is less obvious visually. In addition, when the outer diameters of the two expansion bodies are different, it is also difficult for the operator to understand the real-time volume change of the internal expansion body during the inflation process. For this reason, in one embodiment of the present disclosure, the outer dimensions of the two expansion bodies are set to be the same, so that the two expansion bodies have the same size in the non-inflated state and the normal inflation state, especially the outer diameter is the same. When the first expansion body works normally in the body, that is, when the first expansion body is in a non-compressed state, the outer diameter of the first expansion body is equal to the outer diameter of the third expansion body. The above-mentioned design enables the operator to understand the outer diameter of the first expansion body inside the body by observing the outer diameter of the third expansion body outside the body when inflating or deflating the expansion body, and stop inflation when the outer diameter of the third expansion body reaches the target value, thereby safely and efficiently controlling the outer diameter of the first expansion body inside the body.

[0061] In an optional embodiment, the first expansion body and the third expansion body are made of materials with the same expansion ratio. In order to enable the volume, outer diameter and other parameters of one expansion body to change synchronously and stably with the changes of the other expansion body, especially to ensure that the outer diameters of the two are the same during inflation or deflation, an embodiment of the present disclosure uses materials with the same expansion ratio to make two expansion bodies to solve this problem. Preferably, the two expansion bodies are made of the same material. Exemplarily, the expansion body can be made of highly elastic materials such as synthetic latex, silicone, rubber, TPE, TPX, TPU, WPU, etc. Advantageously, compared to natural latex, the expansion bodies made of the above materials are compatible with people who are intolerant to latex, thereby improving the safety of the pumping catheter and the range of applicable people.

[0062] In an optional embodiment, the third expansion body includes at least a primary expansion state and a secondary expansion state, and when the internal pressure of the first expansion body is greater than or equal to a set pressure threshold, the third expansion body switches from the primary expansion state to the secondary expansion state. Figures 8 to 10 In the embodiment shown, the third expansion body includes three expansion states, namely Figure 8 The first expansion state shown, Fig. 9 The secondary expansion state shown and Fig.10In each of the three expansion states, the outer diameter of the expansion body is distributed discontinuously and discretely; that is, Figure 8 The diameter OD1 shown will only step to Fig. 9 OD2 shown; similarly, Fig. 9 The diameter OD2 shown will only step to Fig.10 OD3 shown. It should be noted that the number of the above-mentioned expansion states is only an example and can be reasonably set according to the needs of use in practice. In practice, different expansion states are set to reflect the working state of the first expansion body in the body. For example, taking the safety pressure threshold as the set pressure threshold, since the first expansion body is located in a blood vessel or organ, the expansion of its volume is constrained by the blood vessel or organ. When the first expansion body is continuously inflated, the blood vessel or organ will compress the first expansion body and its volume cannot increase. At this time, the external pressure on the first expansion body increases, and the internal pressure also gradually increases. When the internal pressure of the first expansion body is greater than or equal to the safety pressure threshold, the third expansion body will be expanded. Figure 8 The first expansion state shown jumps to Fig. 9 The secondary expansion state shown. The outer diameter of the secondary expansion state is significantly larger than that of the primary expansion state. The operator can clearly find the change in the outer diameter of the third expansion body outside the body, and confirm that the internal pressure of the first expansion body inside the body has reached the safety threshold. More advantageously, when the third expansion body jumps to the second expansion state, its large volume change will reduce the internal pressure, thereby reducing the internal pressure of the first expansion body to a safe range, and the outer diameter will be reduced accordingly, avoiding problems such as bursting, giving the operator sufficient time to deal with the internal pressure of the expansion body, further improving the safety of the use of the device. Of course, when the pressure of the expansion body is within the safety threshold, the maximum outer diameter of the expansion body is Figure 8 OD1 shown.

[0063] In an optional embodiment, the third expansion body includes an unexpanded portion, wherein when the internal pressure of the first expansion body is greater than or equal to the set pressure threshold, the unexpanded portion opens to switch from the primary expansion state to the secondary expansion state. In an optional embodiment, the unexpanded portion includes a folded portion. In order to achieve the step change of the outer diameter of the expansion body between different expansion states described above, an embodiment of the present disclosure adopts an unexpanded portion to be provided on the expansion body to solve this problem. The unexpanded portion can be provided at multiple positions of the expansion body, and the number can also be multiple. By reasonably controlling the connection strength of the unexpanded portion, it can be matched with the corresponding pressure threshold to achieve expansion under different pressure thresholds. Preferably, the unexpanded portion is provided in the radial direction of the third expansion body, and can cause a significant change in the outer diameter when it is expanded. Figures 8 to 10The third expansion body is folded in the diameter direction with a first folding portion 401 and a second folding portion 402, and the unfolding pressures of the two folding portions are different. When the internal pressure of the first expansion body reaches a first pressure threshold, the first folding portion 401 unfolds, while the second folding portion 402 does not unfold, and the outer diameter of the third expansion body jumps from OD1 to OD2; when the internal pressure of the first expansion body further increases and reaches a second pressure threshold, the second folding portion 402 unfolds, and the outer diameter of the third expansion body jumps from OD2 to OD3. The folding portion can be used as follows Figure 8 The single-sided folding method described above can of course also be a double-sided folding method (not shown in the figure). The above folding methods are all examples and are not enough to limit the scope of protection of the present disclosure. It is understandable that the folded portion or the unfolded portion can be in other forms than the form described in the embodiment of the present disclosure, and only needs to meet the requirements of unfolding under a predetermined pressure.

[0064] In an optional embodiment, the unfolded portion is kept in an unfolded state by at least one of bonding, heat melting, heat shrinking or welding. Figure 8 Taking the folded state shown as an example, in practice, the connection strength of the folded portion needs to be designed according to the predetermined unfolding pressure. The folded position can be bonded, hot-melted, heat-shrunk or welded to obtain sufficient connection strength. Among them, the welding method can be laser welding. The specific connection position and connection area of ​​the folded portion can be flexibly adjusted as needed.

[0065] In an optional embodiment, a pressure measuring unit 1101 is provided on the surface of the first expansion body disposed at the distal end of the main body. In practice, the pumping catheter will collide with human tissue during intervention in the human body. How to accurately measure the impact load of the front end of the catheter on the human tissue is an important prerequisite for ensuring the safety of the intervention process. To this end, in one embodiment of the present invention, a pressure measuring unit is provided on the surface of the expansion body to solve this problem. For a solution in which only one expansion body is provided in the body, the pressure measuring unit is provided on the surface of the expansion body; and for a solution with multiple expansion bodies in the body, the pressure measuring unit is provided on the surface of the outermost expansion body. Preferably, the pressure measuring unit is provided on the outer surface of the expansion body. The pressure measuring unit is capable of measuring the received pressure load. When the expansion body collides with human tissue, the measured value of the pressure measuring unit will jump significantly. The measured value can be transmitted to the display unit through the sensor connector 1102 provided at the proximal end, so that the operator can understand the pressure state of the expansion body in real time.

[0066] In an optional embodiment, a pacing unit 1201 is provided on the surface of a first expansion body disposed at the distal end of the main body. Preferably, the pacing unit is a pacing electrode, and a pacing electrode connector 1202 electrically connected to the pacing electrode is also provided at the handle of the instrument. When a patient conduction block is encountered during surgery, the operator can quickly pace the ventricle through the pacing electrode. For a solution in which only one expansion body is provided in the body, the pacing unit is provided on the surface of the expansion body; and for a solution with multiple expansion bodies in the body, the pacing unit is provided on the surface of the outermost expansion body. Preferably, the pacing unit is provided on the outer surface of the expansion body.

[0067] The above specific implementation methods do not constitute a limitation on the scope of protection of the present invention. After considering the specification and practicing the technical solutions disclosed in this application, those skilled in the art will easily think of other implementation methods of the present disclosure. This application is intended to cover any modification, use or adaptive changes of the present disclosure, which follow the general principles of the present disclosure and include common knowledge or customary technical means in the technical field that are not disclosed in the present disclosure. The description and examples are regarded as exemplary only, and the true scope and spirit of the present disclosure are indicated by the following claims.

[0068] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A fluid pumping catheter, Features: The catheter comprises a first expansion body and a main body; The distal end of the main body is provided with a fluid inflow channel, and the proximal end is provided with a fluid outflow channel; The first expansion body is arranged at the distal end of the main body, and the volume of the first expansion body is adjustable.

2. The fluid pumping catheter according to claim 1, characterized in that: The outer surface of the first expansion body is provided with a fluid flow gap.

3. The fluid pumping catheter according to claim 2, characterized in that: The first expansion body includes a plurality of sub-regions; Some of the sub-regions are fluidically connected, or none of the sub-regions are fluidically connected.

4. The fluid pumping catheter according to claim 3, characterized in that: The connection between the outer surfaces of the adjacent sub-areas forms the fluid flow gap.

5. The fluid pumping catheter according to claim 1, characterized in that: The distal end of the main body is provided with a shaft extending along the axial direction of the main body; The first expansion body covers the shaft rod and is respectively connected to both ends of the shaft rod.

6. The fluid pumping catheter according to any one of claims 1 to 5, characterized in that: The catheter further comprises a second expansion body, which is arranged at the distal end of the main body and inside the first expansion body; A first space is formed between the inner surface of the first expansion body and the outer surface of the second expansion body.

7. The fluid pumping catheter according to claim 6, characterized in that: The first space is filled with developing material.

8. The fluid pumping catheter according to claim 1, characterized in that: The catheter further comprises a third expansion body, which is arranged outside the body, and the interior of the first expansion body and the interior of the third expansion body are fluidically connected.

9. The fluid pumping catheter according to claim 8, characterized in that: The third expansion body includes at least a primary expansion state and a secondary expansion state. When the internal pressure of the third expansion body is greater than or equal to a set pressure threshold, the third expansion body switches from the primary expansion state to the secondary expansion state.

10. The fluid pumping catheter according to any one of claims 1 to 5, characterized in that: A pressure measuring unit is arranged at the distal end of the main body and located on the surface of the first expansion body.

11. The fluid pumping catheter according to any one of claims 1 to 5, characterized in that: A pacing unit is arranged at the distal end of the main body and located on the surface of the first expansion body.

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