Intrusive ventricular assist system catheter inlet window
By optimizing the lumen design and window structure of the guidewire outlet at the catheter tip, the problems of blood stagnation and eddy currents were solved, achieving stable blood flow and reducing thrombus, adapting to domestic guidewire size requirements, and improving the effectiveness of catheter use.
Patent Information
- Application Number
- CN202411195995.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-29
- Publication Date
- 2026-03-17
AI Technical Summary
In existing technologies, the lumen space near the guidewire exit of the PVAD catheter tip is unsuitable, leading to blood stagnation and eddy currents, which can easily cause thrombosis. At the same time, the guidewire exit is too small or the depth is unsuitable, making it difficult to be compatible with guidewires of commonly used sizes in China. Furthermore, the window design is unreasonable, making it easy for myocardial blockage to occur, affecting blood flow.
The design incorporates a suitable angle between the lumen and the catheter tip axis in the area near the guidewire exit point, provides an appropriate number and depth of openings, employs precision machining techniques to ensure a smooth connection, is compatible with 0.035-inch guidewires, and avoids thrombosis and myocardial infarction.
It effectively avoids blood stagnation and eddies, ensures blood flow, reduces thrombus formation, and improves guidewire passage and blood flow efficiency.
Smart Images
Figure CN121668508A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of medical devices, and in particular to an inlet window and device for an interventional ventricular assist system catheter. Background Technology
[0002] Vascular disease (CVD) has become one of the leading causes of disease burden globally and in China. From 1990 to 2019, the number of people suffering from cardiovascular disease worldwide surged from 270 million to 523 million, a rapid increase. The number of deaths from cardiovascular disease has also continued to rise, from 12.1 million in 1990 to 18.6 million in 2019, posing a serious threat to public health. Studies show that among cardiovascular diseases, the number of patients with coronary heart disease and cardiogenic shock is also increasing year by year, and their mortality rates remain high.
[0003] Coronary artery disease and its complications are characterized by a sharp decline in the heart's pumping function, leading to insufficient perfusion of multiple organs and ultimately multiple organ failure. While traditional cardiovascular disease treatments can alleviate symptoms to some extent, they often fall short in the face of complex and critical cardiovascular conditions. This is especially true in emergencies such as high-risk coronary intervention (HR-PCI) and cardiogenic shock, where they may not be able to rapidly and effectively improve cardiac function. Therefore, there is an urgent clinical need for a treatment that can rapidly and effectively provide circulatory support for acute and critical cardiovascular conditions such as coronary artery disease and high-risk coronary intervention. pVAD (prophylactic vascular access device) emerged to address this need.
[0004] A percutaneous ventricular assist device (pVAD) is a device that provides short-term assistance to the heart or temporarily replaces its function when the heart is unable to function. It is typically inserted through the skin (percutaneously) and then connects to the heart to assist or take over the heart's pumping function. It is used in emergency situations, such as during and after high-risk coronary intervention procedures for short-term cardiac support. Therefore, pVADs are designed with a focus on miniaturization, convenience, and minimal invasiveness.
[0005] The problems with existing technology are as follows: the internal space near the guidewire exit point of the PVAD catheter is unsuitable, causing blood to stagnate and eddy near the exit point, easily leading to thrombosis. Simultaneously, the number of openings for blood outflow is too small, making them susceptible to blockage by the myocardium during cardiac contraction, thus reducing blood flow into the openings. Furthermore, the cavity at the guidewire exit point of existing technology can only accommodate 0.025-inch guidewires, incompatible with the commonly used 0.035-inch guidewires in China; the guidewire exits the oral cavity too deeply, easily leading to thrombus accumulation and making guidewire passage difficult. In terms of manufacturing, the proximal end of the catheter tip and the opening are separate designs in existing technology, necessitating welding to connect them. However, this design and manufacturing process result in an uneven interface, potentially obstructing blood flow and causing thrombus formation.
[0006] Objective of the invention: The present application provides an inner lumen at a suitable angle to the catheter tip axis near the guidewire outlet, which can prevent blood from stagnating near the guidewire outlet and the possibility of eddy currents, thus reducing the occurrence of thrombi. It also provides an appropriate number of openings to prevent blockage by the myocardium during cardiac contraction, ensuring sufficient blood flow into the openings. The guidewire outlet of this application is compatible with commonly used 0.035-inch guidewires in China. Simultaneously, the guidewire exit depth is moderate, reducing the likelihood of thrombus accumulation and facilitating guidewire passage. In terms of manufacturing, the proximal end of the catheter tip and the openings utilize precision machining technology, resulting in a smoother interface between the design and manufacturing process, thereby reducing the possibility of obstructing blood flow and thrombus formation. Summary of the Invention
[0007] This application discloses a catheter inlet window and device for interventional ventricular assist systems. It includes a proximal end, a mid-section of the catheter head, and a distal end. The proximal end has a cross-sectional area that provides a suitable internal space between the line segment and the axis of the catheter head, preventing thrombus formation. The mid-section of the catheter head has a specific ratio between its total opening area and its surface area, ensuring sufficient blood flow while preventing blockage by the myocardium during cardiac contraction. The distal end of the catheter head has a thickness slightly lower than the aforementioned portions, allowing for better integration with the catheter. This invention effectively prevents blood stagnation and eddies at the catheter tip, further preventing thrombus formation.
[0008] Embodiments of this application disclose a catheter inlet window and device for an interventional ventricular assist system, including: a proximal end (10), an outer surface (101), an inner surface (102), a guidewire passage (103), an inner lumen (104), a catheter head midsection (20), a support (201), an opening window (202), a catheter head distal end (30), a first catheter portion (40), a flow direction switching valve (50), a second catheter portion (60), a blood pumping device (70), and a drive device (80).
[0009] Furthermore, the proximal end (10) includes a dome-shaped or arc-shaped outer surface (101); a smooth inner surface (102), a longitudinal cross-sectional line segment of the inner surface (102), and the space enclosed by the inner surface (102) is an inner cavity (104); it also includes a guidewire passage (103) with a certain depth and a certain diameter.
[0010] Furthermore, the radial length of the inner cavity (104) is m, the horizontal distance between the guidewire passing through the edge point (k point) of the opening (103) and the distal end of the inner cavity (104) on its proximal side is n, a straight line with the k point as the endpoint is defined as l, and there is an angle α between l and n; the area where the line formed by the longitudinal section of the inner surface (102) falls is set as S, the range of S is the area enclosed by l, m and n, which can facilitate blood flow and reduce the formation of eddies;
[0011] Furthermore, the included angle α ranges from 45° to 70°.
[0012] Furthermore, the guidewire through the port (103) has a certain depth and diameter, wherein the depth ranges from 0.5 to 2 mm and the diameter ranges from 0.5 to 1.5 mm.
[0013] Furthermore, the preferred depth of the guidewire through the port (103) is 1 mm.
[0014] Furthermore, the preferred diameter of the guidewire through the port (103) is 1 mm.
[0015] Furthermore, the radial length of the proximal end (10) is in the range of 0.4D-1D, preferably 0.5D.
[0016] Furthermore, the middle section (20) of the catheter head is a hollow cylinder with an outer diameter of D, which ranges from 4 to 8 mm. The middle section (20) of the catheter head includes multiple support pillars (201), and the support pillars form an arc-shaped opening (202).
[0017] Furthermore, the number of open windows (202) ranges from 4 to 6.
[0018] Furthermore, the ratio of the total area of the opening window (202) to the surface area of the middle section (20) of the catheter head is constant, ranging from 0.5 to 0.9, with a preferred area ratio of 0.75. Since the area ratio remains constant, when the number of opening windows (202) changes, its unit area will also change accordingly.
[0019] Furthermore, the middle section (20) of the catheter head has a first thickness, specifically ranging from 0.02D to 0.1D.
[0020] Furthermore, the distal end (30) of the catheter tip mainly refers to the part that connects with the catheter.
[0021] Furthermore, the distal end (30) of the catheter tip has a second thickness, specifically ranging from 0.015D to 0.05D.
[0022] Furthermore, the overall diameter of the catheter tip ranges from 4 to 8 mm.
[0023] Furthermore, the material of the catheter tip includes, but is not limited to: SUS304, SUS316, NITI alloy, implantable polymer materials, etc.
[0024] This application also provides a ventricular assist device, including any of the blood inflow catheter heads described above, and further including: a first catheter portion (40), a flow direction switching valve (50), a second catheter portion (60), a blood pumping device (70), and a drive device (80). The first catheter portion (40) is in an angled bent state, and may further include shape memory coils such as elastic metal parts to facilitate catheter bending, and may be configured to include one or more bends or curves in a relaxed state.
[0025] The advantages of this application are as follows: The catheter tip near the guidewire exit area has an internal lumen at a suitable angle to the catheter tip axis, which avoids blood stagnation and the possibility of eddy currents near the guidewire exit, reducing the occurrence of thrombi. It also provides an appropriate number of openings to prevent myocardial blockage during cardiac contraction, ensuring sufficient blood flow into the openings. The guidewire exit is compatible with commonly used 0.035-inch guidewires in China. Simultaneously, the guidewire exit depth is moderate, reducing the likelihood of thrombus accumulation and facilitating guidewire passage. In terms of manufacturing, the proximal end of the catheter tip and the openings utilize precision machining technology, resulting in a smoother interface between the design and manufacturing process, thus reducing the possibility of blood flow obstruction and thrombus formation. Attached Figure Description
[0026] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals are used to identify the same parts throughout the drawings. In the drawings:
[0027] Figure 1 This is a diagram of the entire catheter tip.
[0028] Figure 2 This is a cross-sectional view of the catheter tip.
[0029] Figure 3 This is a magnified view of the lumen inside the catheter tip.
[0030] Figure 4 This is a three-dimensional illustration of the catheter tip.
[0031] Figure 5 This is a cross-sectional view of the catheter tip.
[0032] Figure 6 Components for ventricular assist devices
[0033] Explanation of the reference numerals in the attached figures.
[0034] 10: Proximal end tip, 101: Outer surface, 102: Inner surface, 103: Guidewire passage, 104: Lumen, 20: Middle section of catheter tip, 201: Support, 202: Opening window, 30: Distal end of catheter tip, 40: First catheter section, 50: Flow direction switching valve, 60: Second catheter section, 70: Blood pumping device, 80: Drive device. Detailed Implementation
[0035] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.
[0036] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also mean including the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a specific order as described or illustrated, unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.
[0037] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.
[0038] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "over," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, in addition to those depicted in the figure. For example, if the device in the figure is flipped, then an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented as "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.
[0039] In the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0040] In the field of interventional medical devices, the end of a medical device implanted in the human or animal body that is closer to the operator is generally called the "proximal end," and the end that is farther from the operator is called the "distal end." Based on this principle, the "proximal end" and "distal end" of any component of a medical device are defined.
[0041] A catheter inlet window and device for use in interventional ventricular assist systems, such as Figures 1 to 4As shown, it includes: a proximal end (10), an outer surface (101), an inner surface (102), a guidewire passage (103), an inner lumen (104), a catheter head mid-section (20), a support (201), an opening window (202), a catheter head distal end (30), a first catheter section (40), a flow direction switching valve (50), a second catheter section (60), a blood pumping device (70), and a drive device (80).
[0042] Figure 1 A three-dimensional diagram depicting blood flowing into the catheter tip is provided, wherein the proximal tip (10) includes: an outer surface (101), an inner surface (102), a guidewire passage (103), and an inner lumen (104). The outer surface (101) is generally dome-shaped or arc-shaped and may have any shape that facilitates the insertion of the catheter of the ventricular assist device into the lumen of the patient's blood vessel, such as a conical or curved conical shape, or a cylindrical profile with rounded edges. The inner surface (102) is a smooth surface, which appears as a straight line or a curve or a combination of both in the longitudinal section. It forms an inner cavity channel near the guidewire outlet, and the space enclosed by the inner surface (102) is the inner cavity (104). The radial length of the inner cavity (104) is m. The horizontal distance between the edge point (k point) of the guidewire through the orifice (103) and the distal end of the inner cavity (104) on its proximal side is n. A straight line with the k point as the endpoint is defined as l. There is an angle α between l and n. The area where the line formed by the longitudinal section of the inner surface (102) falls is set as S. The range of S is the area enclosed by l, m and n. The value of the angle α is between 45° and 70°. This can reduce the possibility of eddies when blood flows here, and further reduce the possibility of blood stagnation here, thereby generating thrombi. Furthermore, if the line formed by the longitudinal section of the inner surface (102) is a curve, the curve should be a quadratic function curve on a coordinate system with point k as the origin, its longitudinal tangent and the horizontal line as the horizontal and vertical axes, and the slope of the curve is negative.
[0043] The guidewire passage (103) is compatible with guidewires up to 0.035 inches, further assisting in the positioning of the ventricular assist device. Its diameter ranges from 0.5 to 1.5 mm, with a preferred diameter of 1 mm. To reduce the risk of blood stasis and thrombosis after guidewire withdrawal, the guidewire passage (103) needs to have a suitable depth, ranging from 0.5 to 2 mm, with a preferred depth of 1 mm. Furthermore, the radial length of the proximal end (10) should range from 0.4D to 1D, preferably 0.5D.
[0044] Secondly, the middle section (20) of the catheter tip is a hollow cylinder with an outer diameter D ranging from 4 to 8 mm. The middle section (20) includes multiple supports (201), which together form an arc-shaped opening (202). At the proximal end, the middle section (20) connects to the proximal end (10). The supports (201) extend parallel to each other within the middle section (20) and can extend to connect to the distal end (30) of the catheter tip where it connects to the middle section (20). Multiple arc-shaped openings (202) are defined between the supports, allowing blood to flow into the catheter tip through these openings. Although... Figure 2 The exemplary blood inflow catheter tip shows five struts (201), but any number, such as two or more struts (201), can be used. The inner and outer edges of the struts (201) are rounded, which reduces pressure and abrasion on the vascular system when the catheter assembly of the ventricular assist device is inserted into a blood vessel, and reduces damage to blood cells during blood flow, thus lowering the probability of hemolysis.
[0045] Furthermore, the ratio of the total area of all openings (202) to the total surface area of the middle section (20) of the catheter tip is constant, ranging from 0.5 to 0.9, with a preferred ratio of 0.75. A suitable area ratio provides openings that are more conducive to blood inflow, allowing for greater blood flow flux. Since the area ratio remains constant, when the number of openings (202) changes, their unit area will also change accordingly.
[0046] Furthermore, the distal end (30) of the catheter tip is the part that connects to the middle section (20) of the catheter tip. Its outer surface can be treated in various ways, including but not limited to etching, texturing, coating with another material, or laser engraving. This treatment can make the connection with the catheter more secure. Its inner surface is smooth, which facilitates blood flow. Further, the aforementioned middle section (20) of the catheter tip has a first thickness, specifically ranging from 0.02D to 0.1D; while the distal end (30) of the catheter tip has a second thickness, specifically ranging from 0.015D to 0.05D. This thickness difference can ensure that when the catheter and the blood flow into the overall component of the catheter tip are connected, the overall outer surface remains smooth, reducing the possibility of damage to the inside of the blood vessel.
[0047] Furthermore, the materials that can be used for the blood flow catheter tip of ventricular assist devices include, but are not limited to: SUS304, SUS316, NITI alloy, implantable polymer materials, etc.
[0048] See Figures 1 to 5Once the guidewire has positioned the ventricular assist device through the guidewire through-hole (103), it is withdrawn through the guidewire through-hole (103), and the ventricular assist device begins to operate. Blood flows into the catheter tip through the opening (202). Since the total area of the opening (202) is in a suitable ratio to the total external surface area of the middle section (20) of the catheter tip, the blood flow rate can be guaranteed, and the blood flow efficiency can be increased. At the same time, the inner surface (103) of the lumen (104) of the proximal end of the catheter tip (10) has a suitable curve, which can reduce the possibility of blood eddies in it, so that blood stays in it as little as possible and thrombus accumulation is less likely.
[0049] This application also provides a ventricular assist device, including a blood inflow catheter tip as described above. Figure 6 The diagram shows the assembly of a blood inflow catheter tip and a ventricular assist device, including: a first catheter section (40), a flow direction switching valve (50), a second catheter section (60), a blood pumping device (70), and a drive device (80). The first catheter section (40) is in an angled bent state, and may further include shape memory coils, such as elastic metal parts, to facilitate catheter bending. It can be formed such that it includes one or more bends or curves in a relaxed state. The elastic metal parts are made of materials such as nickel-titanium alloy, platinum, nickel, iridium, and tungsten, such as nickel-titanium wire springs; this application is not limited to these materials. The catheter tip uses the blood inflow catheter tip described in this application, which has a simple and stable structure, is more conducive to increasing the blood aspiration volume of the catheter, and reduces risks.
[0050] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.
Claims
1. An interventional ventricular assist system catheter access window, characterized by, It comprises: The proximal end tip (10) comprises a dome-shaped or circular-arc-shaped outer surface (101); a smooth inner surface (102); and a guide wire passing port (103) with a certain depth and diameter, the depth ranging from 0.5 to 2 mm, and the diameter ranging from 0.5 to 1.5 mm; the space surrounded by the inner surface (102) is an inner cavity (104), the radial length of the inner cavity (104) is m, the horizontal distance between the edge point (k point) of the guide wire passing port (103) and the distal end of the inner cavity (104) proximal to it is n, and a straight line with the k point as an endpoint is defined as l, the angle between l and n is α; the area in which the line formed by the longitudinal section of the inner surface (102) falls is S, and the range of S is the area surrounded by l, m and n; The catheter head middle section (20) is a hollow cylinder, the outer diameter D of which ranges from 4 to 8 mm, and the catheter head middle section (20) comprises a plurality of struts (201) which surround a plurality of circular-arc-shaped window openings (202) between the struts, and the number of the window openings (202) ranges from 4 to 6; The catheter head distal end (30) is mainly the part that is connected to the catheter.
2. The catheter tip of claim 1, wherein, The value of the angle α ranges from 45° to 70°.
3. The catheter tip of claim 1, wherein, The radial length of the proximal end tip (10) ranges from 0.4D to 1D, and is preferably 0.5D.
4. The catheter tip of claims 1-2, wherein, The preferred depth of the guide wire passing port (103) is 1 mm.
5. The catheter tip of claims 1-2, wherein, The preferred diameter of the guide wire passing port (103) is 1 mm.
6. The catheter tip of claim 1, wherein, The ratio of the total area of the window openings (202) to the surface area of the catheter head middle section (20) is constant, and ranges from 0.5 to 0.9, and the area ratio is preferably 0.75, so when the number of the window openings (202) changes, the unit area will also change accordingly.
7. The catheter tip of claim 1, wherein, The catheter head middle section (20) has a first thickness, and the thickness ranges from 0.02D to 0.1D.
8. The catheter tip of claim 1, wherein, The catheter head distal end (30) has a second thickness, and the thickness ranges from 0.015D to 0.05D.
9. The catheter tip of claim 1, wherein, The diameter of the catheter head as a whole ranges from 4 to 8 mm.
10. A ventricular assist device, characterized by The blood inflow catheter head for a ventricular assist device according to any one of claims 1 to 9 further comprises a first catheter portion (40), a flow direction conversion valve (50), a second catheter portion (60), a blood pumping device (70), and a driving device (80), wherein the first catheter portion (40) is in an angularly bent state, and the outside can further comprise a shape memory coil such as an elastic metal piece to facilitate the bending of the catheter, and can be formed such that it comprises one or more bending portions or curves in a relaxed state.