Pump body of conduit pump and conduit pump

Abstract

The invention provides a pump body of a catheter pump and the catheter pump. The hemolysis risk can be reduced. The pump body of the catheter pump comprises a pump shell and an impeller located in the pump shell, and the pump shell is provided with a blood inlet area, a blood outlet area and a liquid-tight area located between the blood inlet area and the blood outlet area; the impeller comprises a blade, the blade is provided with a second near-end edge and a second far-end edge, the second far-end edge is located in the liquid-tight area, the blood outlet area comprises a near-end conical section, and the second near-end edge is located in the near-end conical section.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to a pump body and a catheter pump. Background Technology

[0002] A catheter pump is introduced into a patient via interventional procedures to assist in the transport of blood within the circulatory system. A catheter pump typically consists of a pump body located inside the patient and a motor located outside the patient's body. The motor is connected to the pump body via a slender drive shaft housed within the catheter, powering an impeller within the pump body. The rotation of the impeller drives the blood flow. For example, when the pump body is deployed in the left ventricle, the catheter pump can pump blood from the left ventricle into the aorta; when the pump body is deployed in the right ventricle, the catheter pump can pump blood from the inferior vena cava into the pulmonary artery. However, catheter pumps pose a relatively high risk of hemolysis during use. Summary of the Invention

[0003] The purpose of this application is to provide a pump body and a catheter pump that can reduce the risk of hemolysis.

[0004] The pump body of the duct pump provided in this application includes a pump housing and an impeller located within the pump housing. The pump housing has a blood inlet region, a blood outlet region, and a liquid-tight region located between the blood inlet region and the blood outlet region. The liquid-tight region has a first proximal edge and a first distal edge. The impeller includes blades, and the blades have a second proximal edge and a second distal edge. The second distal edge is located within the liquid-tight region. The blood outlet region is a proximal conical segment, and the second proximal edge is located within the proximal conical segment.

[0005] In one embodiment, the proximal tapered segment is tapered from the distal end to the proximal end.

[0006] In one embodiment, the second distal edge and the first distal edge have a first spacing D; the second proximal edge and the first proximal edge have a second spacing P, and the first spacing D is greater than the second spacing P.

[0007] In one embodiment, the ratio of the first spacing D to the length L of the liquid-tight region is 0.3 to 0.55.

[0008] In one embodiment, the ratio of the first spacing D to the length L of the liquid-tight region is 0.4 to 0.5.

[0009] In one embodiment, the ratio of the second spacing P to the length L of the liquid-tight region is 0.03 to 0.24.

[0010] In one embodiment, the ratio of the second spacing P to the length L of the liquid-tight region is 0.1 to 0.2.

[0011] In one embodiment, the pump housing includes a support and a diaphragm. The support has a mesh structure and includes a first support segment, a second support segment, and a third support segment connected sequentially from distal to proximal along its length. The diaphragm includes a cylindrical segment that wraps around the second support segment to form the liquid-tight region. At least a portion of the first support segment forms the blood inlet region, and at least a portion of the third support segment forms the blood outlet region.

[0012] In one embodiment, the membrane further includes an extension section located proximal to the cylindrical section, the extension section extending proximally beyond the blood outlet region, the proximal end of the extension section being connected to a conduit of the catheter pump; the proximal end of the extension section forms a liquid outlet, through which blood flowing from the blood outlet region continues to flow proximally along the extension section and exits from the liquid outlet.

[0013] In one embodiment, the first support segment is a distal conical segment, the second support segment is an intermediate pump segment, the axial lengths of the distal conical segment and the proximal conical segment are equal, and the axial length of the intermediate pump segment is greater than half the sum of the axial lengths of the distal conical segment, the intermediate pump segment, and the proximal conical segment.

[0014] This application positions the proximal end of the impeller blades within the conical blood outlet region of the support. When blood flows from the proximal end of the blades, it exits the support directly through the conical blood outlet region, reducing the blood flow path from the proximal end of the blades to the blood outlet region. This significantly reduces the exposure time of blood cells, thereby improving blood compatibility and reducing hemolysis. Furthermore, by shifting the blades from the distal end to the proximal end, there is no need to increase the cylindrical length of the support, ensuring its rigidity and preventing collapse of the cylindrical second support section due to excessive length after folding and unfolding, thus reducing the risk of blade-support collision. Simultaneously, it effectively maintains a stable blade tip clearance between the outer edge of the blades and the support, ensuring optimal pumping efficiency and also improving the support's bending performance. Excessive length results in poor bending performance, while shorter lengths provide relatively better bending performance.

[0015] Furthermore, with the same pump body length, extending the proximal end of the blades into the blood outlet area helps to lengthen the distance between the distal end of the blades and the blood inlet area. After blood enters the blood flow channel within the pump housing at an angle to the pump body's central axis from the blood inlet area, it does not immediately contact the blades. Instead, it flows a distance within the blood flow channel of the pump housing, allowing more blood to contact the blades and be further pumped in a direction parallel or nearly parallel to the pump body's central axis. This improves pumping efficiency and, correspondingly, reduces the velocity gradient of blood entering the blood flow channel within the pump housing, lowering the risk of hemolysis. Moreover, because the distance between the blades and the blood inlet area is lengthened, free chordae tendineae plates extending into the blood flow channel of the pump housing are less likely to contact the blades, thus reducing the problem of chordae tendineae becoming entangled in the impeller and causing stoppage.

[0016] This application also provides a pump body for a duct pump, including a pump housing and an impeller located within the pump housing. The pump housing has a blood inlet region, a blood outlet region, and a liquid-tight region located between the blood inlet region and the blood outlet region. The liquid-tight region has a first proximal edge and a first distal edge. The impeller includes blades, each blade having a second proximal edge and a second distal edge. The second distal edge is located within the liquid-tight region, and the ratio of a first distance D between the second distal edge and the first distal edge to the length L of the liquid-tight region is 0.3 to 0.55.

[0017] In one embodiment, the blood outlet region is a proximal conical segment, and the second proximal edge is located within the proximal conical segment.

[0018] In one embodiment, the ratio of the first spacing D to the length L of the liquid-tight region is 0.4 to 0.5.

[0019] In one embodiment, the pump housing includes a support and a diaphragm. The support has a mesh structure and includes a first support segment, a second support segment, and a third support segment connected sequentially from distal to proximal along its length. The diaphragm includes a cylindrical segment that wraps around the second support segment to form the liquid-tight region. At least a portion of the first support segment forms the blood inlet region, and at least a portion of the third support segment forms the blood outlet region.

[0020] In one embodiment, the membrane further includes an extension section located proximal to the cylindrical section, the extension section extending proximally beyond the blood outlet region, the proximal end of the extension section being connected to a conduit of the catheter pump; the proximal end of the extension section forms a liquid outlet, through which blood flowing from the blood outlet region continues to flow proximally along the extension section and exits from the liquid outlet.

[0021] In one embodiment, the first support segment is a distal conical segment, the second support segment is an intermediate pump segment, and the third support segment is a proximal conical segment. The axial lengths of the distal conical segment and the proximal conical segment are equal. The axial length of the intermediate pump segment is greater than half the sum of the axial lengths of the distal conical segment, the intermediate pump segment, and the proximal conical segment.

[0022] This application sets the ratio of the first distance D between the second distal edge and the first distal edge to the length L of the liquid-tight region to 0.3~0.55, thereby lengthening the distance between the distal end of the blade and the blood inlet region. In this way, after blood enters the blood flow channel within the pump housing at an angle to the pump body's central axis from the blood inlet region, it does not immediately contact the blades within the pump housing. Instead, it flows a distance within the blood flow channel of the pump housing, allowing more blood to contact the blades and be further pumped in a direction parallel or nearly parallel to the pump body's central axis. This improves pumping efficiency and, correspondingly, reduces the velocity gradient of blood after entering the blood flow channel within the pump housing, lowering the risk of hemolysis. Furthermore, because the distance between the distal end of the blade and the blood inlet region is lengthened, the free chordae tendineae plates extending into the blood flow channel of the pump housing are less likely to contact the blades, thus reducing the problem of chordae tendineae becoming entangled in the impeller and causing it to stop rotating.

[0023] This application also provides a catheter pump, including a drive assembly, a drive shaft, a catheter, and a pump body of any of the above-described catheter pumps, wherein the proximal end of the pump body is connected to the distal end of the catheter; the drive shaft passes through the catheter; the proximal end of the drive shaft is connected to the power output shaft of the drive assembly, and the distal end of the drive shaft is connected to an impeller in the pump body; the drive assembly drives the impeller to rotate via the drive shaft to draw blood from the blood inlet area into the pump housing, and then discharges it from the blood outlet area.

[0024] The duct pump includes the pump body described above and has the same technical effects as the pump body described above, so it will not be described in detail. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the conduit pump in an embodiment of this application; Figure 2 for Figure 1 Front view of the center-duct pump; Figure 3 for Figure 1 A schematic diagram showing the deployment of the catheter pump in the left ventricle. Figure 4 for Figure 1 A schematic diagram of the pump body location of a center-duct pump; Figure 5 for Figure 4 A magnified view of a portion of position A in the diagram; Figure 6 for Figure 4 A cross-sectional view of the pump body along its length, which is the direction from the proximal end to the distal end of the pump body; Figure 7 for Figure 6 A magnified view of a portion of position B in the diagram; Figure 8 The velocity vector diagrams of the overall flow field of the pump body with four different first spacings D in the embodiments of this application are shown. Figure 9 These are velocity cloud maps of blood in pump bodies for four different first spacings D in embodiments of this application; Figure 10 for Figure 9 A magnified view of the area near the blood inlet; Figure 11 These are velocity gradient cloud maps of blood in the pump body for four different first spacings D in the embodiments of this application; Figure 12 This is a vector diagram showing the velocity of four different first spacing D pumps in the blood inlet region according to embodiments of this application.

[0026] The annotations in the attached figures are explained as follows: 1000-duct pump; 100 - Drive assembly; 200 - Coupler; 300 - Conduit; 301 - Protective head; 200a - Perfusion fluid inlet section; 400-Pump body; 401-Support; 4011-First support section; 4012-Second support section; 4013-Third support section; 402-Membrane; 4021-Extension section; 4022-Cylindrical section; 400A-Liquid-tight zone; 400A1-First distal edge; 400A2-First proximal edge; 400B-Blood inlet zone; 400C-Blood outlet zone; 403-Impeller; 4031-Hub; 4032-Blade; 40321-Second distal edge; 40322-Second proximal edge; 500-Drive Shaft; 2000 - Left ventricle. Detailed Implementation

[0027] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] Please refer to Figures 1 to 3 , Figure 1 This is a schematic diagram of the structure of the conduit pump 1000 in the embodiments of this application; Figure 2 for Figure 1 Front view of the 1000 medium-duct pump; Figure 3 for Figure 1A schematic diagram showing the deployment of the catheter pump 1000 in the left ventricle 2000.

[0029] The catheter pump 1000 in this embodiment typically needs to be at least partially inserted into the patient's body, for example, it can be deployed at a predetermined location in the left or right ventricle to pump blood, at least partially replacing the heart's pumping function. As an example, when the pump body 400 is deployed in the left ventricle, the catheter pump 1000 can pump blood from the left ventricle of the heart into the aorta; when the pump body 400 is deployed in the right ventricle, the catheter pump 1000 can pump blood from the inferior vena cava into the pulmonary artery.

[0030] Figure 1 In the middle, the conduit pump 1000 includes a drive assembly 100 and a drive shaft 500 (the drive shaft 500 passes through the conduit 300, Figure 1 Not shown in the image, see [link / reference]. Figure 6 , Figure 7 The device comprises a catheter 300 and a pump body 400. In this embodiment, the drive assembly 100 is specifically a motor, configured as a power component to provide power. The drive assembly 100 can be connected to the proximal end of the catheter 300 via a coupler 200. The coupler 200 has an infusion fluid inlet 200a, through which the infusion fluid enters the catheter 300 to infuse the interior of the catheter 300, preventing air bubbles from entering the body and preventing blood backflow. The distal end of the catheter 300 is connected to the proximal end of the pump body 400. A drive shaft 500 passes through the catheter 300, and the proximal end of the drive shaft 500 is connected to the power output shaft of the drive assembly 100. It should be noted that in this embodiment, "proximal end" and "distal end" are defined from the operator's perspective; the end closer to the operator is the proximal end, and the end farther from the operator is the distal end. Proximal and distal ends are relative terms.

[0031] Can continue to combine Figure 4-7 understand, Figure 4 for Figure 1 A schematic diagram of the pump body at position 400 of the central guide pipe pump 1000; Figure 5 for Figure 4 A magnified view of a portion of position A in the diagram; Figure 6 for Figure 4 A cross-sectional view of the pump body 400 along its length, which is the direction from the proximal end to the distal end of the pump body 400. Figure 7 for Figure 6 A magnified view of a portion of position B in the diagram.

[0032] The pump body 400 includes a pump casing and an impeller 403 located inside the pump casing. The impeller 403 is connected to the distal end of the aforementioned drive shaft 500. Thus, the drive assembly 100 can drive the drive shaft 500 to rotate, and when the drive shaft 500 rotates, it can drive the impeller 403 inside the pump casing to rotate as well. Figure 7 As shown, the pump casing has a blood inlet region 400B, a blood outlet region 400C, and a liquid-tight region 400A located between the blood inlet region 400B and the blood outlet region 400C. The distal end of the liquid-tight region 400A is adjacent to the blood inlet region 400B, and the proximal end of the liquid-tight region 400A is adjacent to the blood outlet region 400C. When the impeller 403 rotates, it can draw blood from the blood inlet region 400B into the pump casing and then discharge it from the blood outlet region 400C.

[0033] For example, the pump housing may include a bracket 401, which has a mesh structure, such as... Figure 5 , 6 As shown, the bracket 401 can be made of alloys such as nickel or titanium. The pump housing also includes a diaphragm 402, which is mounted on the pump housing. Figure 7 In this stent 401, a first stent segment 4011, a second stent segment 4012, and a third stent segment 4013 are sequentially connected from distal to proximal along its length. A covering 402 includes a cylindrical segment 4022, which covers the surface of the second stent segment 4012, forming a liquid-tight region 400A. A flow channel exists between the covering 402 and the third stent segment 4013, forming a blood flow channel. The first stent segment 4011 may be a tapered inlet segment at the distal end of the stent, the second stent segment 4012 may be a cylindrical segment in the middle of the stent, and the third stent segment 4013 may be a tapered outlet segment at the proximal end of the stent. The diameter of the tapered inlet segment increases from distal to proximal, and the diameter of the tapered outlet segment decreases from distal to proximal. The mesh of the first stent segment 4011 and the third stent segment 4013 serves as a through hole, allowing fluid to enter and exit. At least a portion of the first stent segment 4011 can form the aforementioned blood inlet region 400B, and at least a portion of the third stent segment 4013 can form the aforementioned blood outlet region 400C.

[0034] In some embodiments, the pump body 400 may be foldable, which facilitates the insertion of the catheter pump 1000 into the human body. The pump body 400 and the tip portion of the catheter 300 are inserted into and held within the patient's body; therefore, the peripheral dimensions of the pump body 400 and the catheter 300 should be designed to be as small as possible. Smaller pump body 400 and catheter 300 mean that they can be inserted into the patient's body through a smaller puncture site, reducing patient discomfort during the interventional procedure and minimizing complications caused by excessively large puncture sites.

[0035] The pump body 400 can have a folded configuration and an unfolded configuration. In the folded configuration, the pump body 400 is folded, thus occupying the smallest possible peripheral dimensions. This folded configuration corresponds to the intervention process of the catheter pump 1000. In the unfolded configuration, the pump body 400 returns to its unfolded state from the folded state. This unfolded state is the natural unfolded state of the blades; although the blades are inserted into the body, they do not rotate. In the unfolded state, the catheter pump 1000 can be started, the blades begin to rotate, and it enters the working state. In this state, the blood pumping channel of the pump body 400 is in its normally unfolded state, enabling it to pump blood normally.

[0036] In some embodiments, the pump casing of the pump body 400 may be made of an alloy material such as nickel-titanium, and the pump body 400 is configured with a mesh structure, while simultaneously utilizing the shape memory properties of the nickel-titanium alloy to achieve deployment. The blades 4032 of the impeller 403 may be made of a flexible material or a shape memory material, and can be folded relative to the hub 4031 of the impeller 403. When the pump body 400 includes a folded configuration, the blades 4032 of the impeller 403 are close to the hub 4031 to reduce the size they occupy. After the external force constraining the blades 4032 of the impeller 403 is released, the energy stored in the blades 4032 is released, causing the blades 4032 to unfold and return to the unfolded state.

[0037] The catheter pump 1000 also includes a protective head 301 connected to the distal end of the pump body 400, which guides the intervention of the catheter pump 1000 during insertion into a predetermined location in the body. After the catheter pump 1000 is inserted into the predetermined location (i.e., after the catheter pump 1000 is deployed), during operation of the catheter pump 1000, the protective head 301 maintains the posture of the pump body 400 within the heart, preventing the pump body 400 from adhering to the endocardial wall or from drawing cardiac chordae tendineae into the pump body 400, thus preventing potential danger. The protective head 301 may be made of a soft material to avoid damaging the patient's tissues. In some embodiments, the flexible end of the protective head 301 is supported on the ventricular wall in a non-invasive or non-damaging manner, separating the blood inlet region 400B of the pump body 400 from the ventricular wall. Figure 1 In the illustration, the protective head 301 is circular. It should be understood that the shape shown is merely exemplary, and the protective head 301 can be any other suitable shape.

[0038] It is noteworthy that, in this embodiment, the liquid-tight region 400A of the pump body 400 is defined as a liquid-tight region formed by the membrane-coated cylindrical section 4022 covering the outer surface of the second support section 4012 (also a cylindrical section) of the support. Blood can flow proximally within the liquid-tight region, but cannot flow radially out of the through-hole of the support section. The liquid-tight region 400A has a first proximal edge 400A2 and a first distal edge 400A1. The impeller 403 includes blades 4032, which have a second proximal edge 40322 and a second distal edge 40321. The second distal edge 40321 is located within the liquid-tight region 400A. Furthermore, the second proximal edge 40322 is located within the blood outlet region 400C.

[0039] The pump body 400 mentioned above can also be foldable. The second proximal edge 40322, as referred to in this application, is located within the blood outlet region 400C, specifically in the unfolded state. Alternatively, if the blood outlet region 400C is a conical segment and is proximal, it can also be defined as a proximal conical segment with the second proximal edge 40322 located within it. Specifically, in this embodiment, the first support segment 4011 is a distal conical segment, the second support segment 4012 is an intermediate pump segment, and the third support segment 4013 is a proximal conical segment.

[0040] After the blood is pumped by the rotating impeller 403, its velocity can be decomposed into axial velocity from distal to proximal end and circumferential velocity around the drive shaft 500. That is, while the blood flows proximally, it also rotates around the drive shaft 500, performing circumferential motion. In addition, excessive velocity gradients near the stent wall can lead to excessively high shear stress. Figure 6 From this perspective, if the blade is set entirely within the cylindrical support section (second support section 4012), and the blood outlet area extends into the cylindrical support section, that is, assuming the blood outlet area includes a conical part and a cylindrical part, then when the blood moves circumferentially in the cylindrical part of the blood outlet area, the blood cells need to pass through the cylindrical part and the conical part, passing through more high shear force areas, and the circumferential movement itself has a longer path. This results in the blood cells being exposed for too long, and the probability of shear rupture increases dramatically.

[0041] In this embodiment, the proximal end of the blade 4032 is positioned in the conical blood outlet area 400C of the stent 401. When blood flows out from the proximal end of the blade 4032, it flows directly out of the stent 401 through the conical blood outlet area 400C, which greatly reduces the exposure time of blood cells, thereby improving blood compatibility and reducing hemolysis.

[0042] Furthermore, by shifting the distal end of blade 4032 towards the proximal end, there is no need to increase the cylindrical length of support 401. This ensures the support rigidity of support 401 and prevents the collapse of the cylindrical second support section 4012 due to excessive length after folding and unfolding, thus reducing the risk of collision between blade 4032 and support 401. Simultaneously, it effectively ensures a stable tip clearance between the outer edge of blade 4032 and support 401, guaranteeing better pumping efficiency. It also helps ensure the bending performance of support 401; excessive length results in poor bending performance, while shorter length leads to relatively better bending performance.

[0043] In this embodiment, the proximal conical segment is tapered from the distal end to the proximal end, resulting in a pump body 400 that is smaller at both ends and larger in the middle. This tapering design facilitates the rapid flow of blood from the blood outlet area 400C, reducing the exposure time of blood cells and further lowering the probability of shear damage.

[0044] Furthermore, let's look at... Figure 7 In this embodiment of the application, the first proximal edge 400A2 and the second proximal edge 40322 of the liquid-tight region 400A have a second distance P (i.e., the axial length of the blade 4032 extending into the blood outlet region 400C), the second distal edge 40321 and the first distal edge 400A1 have a first distance D, and the first distance D is greater than the second distance P.

[0045] The inventors further investigated the problems of low blood pumping efficiency and relatively high hemolysis risk in the catheter pump 1000 mentioned in the background art. They discovered that the distance between the second distal edge 40321 of the blade 4032 and the first distal edge 400A1 of the liquid-tight region 400A is relatively short. This causes blood entering from the blood inlet region 400B to continuously contact the blade 4032 at an angle to the central axis of the pump body 400 and be further pumped. This pumping method is one of the reasons for the low blood pumping efficiency. Simultaneously, this design results in a large velocity gradient in the inlet section after blood enters the pump body 400 from the blood inlet region 400B. A large velocity gradient will generate a large shear force on the blood, increasing the risk of hemolysis. Moreover, there are many free chordae tendineae in the ventricles of the heart. When the distance between the second distal edge 40321 of the blade 4032 and the first distal edge 400A1 of the liquid-tight zone 400A is close, under the suction force of the pump body 400, one end of the chordae tendineae will extend into the blood flow channel of the pump body 400 and be continuously agitated by the high-speed rotating blade 4032. In severe cases, the chordae tendineae will become entangled on the impeller 403, causing it to stop rotating.

[0046] Accordingly, in this embodiment of the application, the second proximal edge 40322 of the blade 4032 extends into the blood outlet region 400C and has a second distance P with the first proximal edge 400A2. At the same time, the first distance D is greater than the second distance P. That is, after the second proximal edge 40322 extends into the blood outlet region 400C, the second distal edge 40321 is also kept as far away as possible from the blood inlet region 400B, so as to improve the above-mentioned problems and produce the following technical effects: After blood enters the blood flow channel inside the pump housing from the blood inlet area 400B at an angle to the central axis of the pump body 400, it does not immediately come into contact with the blades 4032 inside the pump housing. Instead, it flows a certain distance in the blood flow channel of the pump housing, allowing more blood to come into contact with the blades 4032 in a direction parallel or nearly parallel to the central axis of the pump body 400 and be further pumped. This improves pumping efficiency and, correspondingly, reduces the velocity gradient of blood after entering the blood flow channel inside the pump housing, thus reducing the risk of hemolysis. Moreover, because the first distance D between the second distal edge 40321 of the blades 4032 and the first distal edge 400A1 of the liquid-tight region 400A is lengthened, the free chordae tendineae plates in the ventricle extending into the blood flow channel of the pump housing are less likely to come into contact with the blades 4032, thereby reducing the problem of chordae tendineae getting entangled on the impeller 403 and causing it to stop rotating.

[0047] In addition, as mentioned above, the second proximal edge 40322 extending into the blood outlet region 400C greatly reduces the exposure time of blood cells, thereby improving blood compatibility, reducing hemolysis, and also helps to improve the flow field within the blood outlet region 400C.

[0048] like Figure 8 As shown, Figure 8 This is a velocity vector diagram of the overall flow field of the pump body 400 with four different first spacings D in the embodiments of this application. The first spacings D of the four pump bodies 400 are D1, D2, D3, and D4, respectively. The changes of these four first spacings D are based on spacing D1. The increase of spacings D2, D3, and D4 is achieved by moving the impeller 403 from the far end to the near end. On the one hand, this satisfies the requirement that the second proximal edge 40322 extends into the blood outlet area 400C, and on the other hand, it can lengthen the first spacing D.

[0049] Figure 8The distal edge of the blood outlet region 400C is indicated by a green line. When the first spacing D is D1, the second proximal edge 40322 of the blade 4032 is located on the distal side of the distal edge of the blood outlet region 400C. When the first spacing D is D2, the second proximal edge 40322 of the blade 4032 is approximately flush with the distal edge of the blood outlet region 400C. When the first spacing D is D3, the second proximal edge 40322 of the blade 4032 is located on the proximal side of the distal edge of the blood outlet region 400C. When the first spacing D is D4, the second proximal edge 40322 of the blade 4032 is located at or near the proximal edge of the blood outlet region 400C. Figure 12 It can be seen that as the first gap D increases, the vortex region upstream of the distal end of impeller 403 becomes smaller and smaller. When the first gap D is D4, almost no obvious vortex is visible downstream of impeller 403. The smaller the vortex, the less energy loss of the fluid, which can improve pumping efficiency and pump more blood under the same rotational speed and head conditions.

[0050] Therefore, the first spacing D should be as large as possible to ensure that the distal end of the blade 4032 is sufficiently far from the blood inlet region 400B, while the proximal end of the blade 4032 should not extend too far into the blood outlet region 400C. This means the second spacing P also has certain limitations. It needs to ensure that the blade 4032 is entirely within the liquid-tight region 400A, improving the efficiency of blood pumping within the liquid-tight region 400A. Furthermore, it also prevents the proximal end of the blade 4032 from getting too close to the proximal end of the pump housing, which could interfere with the rotation of the blade 4032. Accordingly, in some embodiments, the ratio of the second spacing P to the length L of the liquid-tight region 400A can be 0.03 to 0.24.

[0051] Furthermore, such as Figure 7 As shown, the ratio of the first distance D between the second distal edge 40321 and the first distal edge 400A1 to the length L of the liquid-tight region 400A is 0.3 to 0.55, and this range includes the endpoint values. Specifically, this embodiment further limits the ratio of the first distance D between the second distal edge 40321 and the first distal edge 400A1 of the blade 4032 to the length L of the liquid-tight region 400A, specifically limiting the ratio to 0.3 to 0.55.

[0052] That is, the first spacing D occupies a relatively large proportion of the length of the liquid-tight region 400A, and the first spacing D between the second distal edge 40321 of the blade 4032 and the first distal edge 400A1 of the liquid-tight region 400A is relatively long, so as to further ensure the above-mentioned technical effects.

[0053] You can refer to Figure 9 , 10 understand, Figure 9These are velocity cloud maps of blood in pump bodies 400 with four different first spacings D in embodiments of this application. Figure 9 From top to bottom, the first spacing D is D1, D2, D3, and D4, where D1 / L=0.1, D2 / L=0.3, D3 / L1=0.45, and D4 / L1=0.55; Figure 10 for Figure 9 A magnified view of the area around 400B in the blood inlet region. Figure 9 , 10 In the diagram, the blue area has the lowest speed, representing a low-speed region; the red area has the highest speed, representing a high-speed region; the orange area is close to red and also represents a high-speed region; and the green and yellow areas are between low-speed and high-speed and can be defined as medium-low speed regions.

[0054] As can be seen, with the increase of the first spacing D, the area of ​​the low-velocity region (corresponding to the area within the red box) in the blood inlet region near 400B increases significantly. For example, from D1 to D2, although the low-velocity region in D3 and D4 does not increase, the medium-low velocity region remains in a large range, while the area of ​​the high-velocity region (red and orange) decreases significantly. Figure 10 In the velocity contour maps of pump bodies 400 with spacing D1, a large red high-speed region exists. In pump bodies 400 with spacing D2, a small amount of orange region remains at the edge of the contour map. However, in the velocity contour maps of pump bodies 400 with spacings D3 and D4, both the orange and red high-speed regions are eliminated. This indicates that as the first spacing D increases, the blood flow field becomes significantly smoother, and the abrupt velocity changes are significantly improved.

[0055] Let's look again. Figure 11 , Figure 11 These are velocity gradient cloud maps of blood in pump bodies 400 with four different first spacings D in embodiments of this application. Figure 11 From top to bottom, the first spacing D is D1, D2, D3, and D4 respectively. Similarly, red indicates the maximum velocity gradient, orange is close to red, and both red and orange can represent high gradient regions. Blue indicates the minimum velocity gradient, representing low gradient regions. Green and yellow are between high and low gradient regions and can represent medium to low gradient regions.

[0056] In the velocity gradient cloud map of pump body 400 with spacing D1, the velocity gradient of the blood inlet region (the region corresponding to the red box) is relatively large, and it contains red, yellow, green and blue regions. Moreover, the blue region accounts for a small proportion. In contrast, in the velocity gradient cloud maps of pump body 400 with spacings of D2, D3 and D4, the blue region with lower values ​​occupies most of the inlet area. This indicates that after the first spacing D is increased, the velocity change slows down significantly, which can reduce the shear force on the blood and reduce the risk of hemolysis.

[0057] You can continue to refer to this. Figure 12 , Figure 12 This is a velocity vector diagram of the pump body 400 with four different first spacings D in the blood inlet region in the embodiments of this application, i.e., a local velocity vector diagram.

[0058] like Figure 12 In the area highlighted by the red box, when the first spacing D is D1, the blood contacts the hub 4031 of the impeller 403 at an angle to the central axis of the pump body 400, resulting in a relatively turbulent flow field and significant energy loss. When the first spacing D is D2 and D3, it is evident that as the blood contacts the hub 4031, more and more fluid can flow along the central axis of the pump body 400. When the spacing is D4, most of the fluid is already flowing along the central axis of the pump body 400, indicating that increasing the first spacing D has a significant effect on creating a smooth flow field and can reduce the energy loss of the pump body 400.

[0059] like Figure 7 As shown, the pump housing in this embodiment includes a support 401 and a membrane 402. The support 401 includes a first support segment 4011, a second support segment 4012, and a third support segment 4013 connected sequentially from distal to proximal along its length. The membrane 402 includes a cylindrical segment 4022, which encloses the second support segment 4012 to form the aforementioned liquid-tight region 400A. At least a portion of the first support segment 4011 forms the aforementioned blood inlet region 400B, and at least a portion of the third support segment 4013 forms the aforementioned blood outlet region 400C. In this embodiment, the cylindrical segment 4022 completely covers the entire cylindrical second support segment 4012 and is substantially parallel to the outer surface of the second support segment 4012, which is beneficial for improving pumping efficiency.

[0060] It can be seen that the structure of the pump casing is not limited to this. For example, the pump casing can be an integral structure, with the pump casing directly forming the liquid-tight zone 400A.

[0061] like Figure 6 As shown, the membrane 402 in this embodiment also includes an extension section 4021 located proximal to the cylindrical section 4022. The extension section 4021 extends proximally beyond the blood outlet region 400C. The proximal end of the extension section 4021 is connected to the conduit 300 of the catheter pump 1000. A liquid outlet is formed at the proximal end of the extension section 4021. Blood flowing out from the blood outlet region 400C continues to flow proximally along the extension section 4021 and flows out from the liquid outlet.

[0062] In some embodiments, the axial lengths of the distal and proximal tapered sections of the stent 401 are equal. The length of the distal tapered section is the length of the blood inlet region 400B, the length of the proximal tapered section is the length of the blood outlet region 400C, and the length of the intermediate pump section is the length of the liquid-tight region 400A. The axial length of the intermediate pump section is greater than half the sum of the axial lengths of the distal tapered section, the intermediate pump section, and the proximal tapered section. This ensures the length of the stent 401 accommodating the impeller 403 and the length of blood flow within the liquid-tight region 400A.

[0063] In the above embodiment, the second proximal edge 40322 of the blade 4032 can be located within the blood outlet region 400C, that is, the second proximal end of the blade 4032 extends into the blood outlet region 400C. Since the pump body 400 needs to be inserted into the human body, the length of the pump body 400 is limited. For example, if the pump body 400 is completely placed in the left ventricle of the human body, the pump body 400 needs to pass through the aortic arch during the process of insertion into the left ventricle. This determines that the overall length of the pump body 400 is limited to a certain extent. Under the condition of this overall length limitation, in order to maximize pumping efficiency and reduce the risk of hemolysis, the second distal edge 40321 of the blade 4032 should be as far away from the first distal edge 400A1 as possible. Therefore, without increasing or not excessively increasing the length of the pump body 400, the blade 4032 can be moved towards the proximal end, so that the second proximal edge 40322 of the blade 4032 is located within the blood outlet region 400C. In this way, the first spacing D can be increased or decreased without increasing or not excessively increasing the length of the pump body 400. However, it is understood that, for the purpose of lengthening the first distance D, the second proximal edge 40322 is not limited to being located within the blood outlet region 400C. If the size of the pump body 400 allows, the second proximal edge 40322 can also be located within the liquid-tight region 400A. In this case, the ratio of the first distance D between the second distal edge 40321 and the first distal edge 400A1 to the length L of the liquid-tight region 400A is still limited to 0.3~0.55. The technical effect can be referenced... Figure 9-11 I understand, so I won't elaborate further.

[0064] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this application. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A pump body for a duct pump, characterized in that, The device includes a pump housing and an impeller located within the pump housing. The pump housing has a blood inlet region, a blood outlet region, and a liquid-tight region located between the blood inlet region and the blood outlet region. The impeller includes blades having a second proximal edge and a second distal edge, the second distal edge being located within the liquid-tight region. The blood outlet region is a proximal conical segment, and the second proximal edge is located within the proximal conical segment.

2. The pump body of the duct pump according to claim 1, characterized in that, The proximal tapered segment is gradually tapered from the distal end to the proximal end.

3. The pump body of the duct pump according to claim 1, characterized in that, The second distal edge and the first distal edge have a first spacing D; the second proximal edge and the first proximal edge have a second spacing P, and the first spacing D is greater than the second spacing P.

4. The pump body of the duct pump according to claim 3, characterized in that, The ratio of the first spacing D to the length L of the liquid-tight region is 0.3 to 0.

55.

5. The pump body of the duct pump according to claim 4, characterized in that, The ratio of the first spacing D to the length L of the liquid-tight region is 0.4 to 0.

5.

6. The pump body of the duct pump according to any one of claims 3-5, characterized in that, The ratio of the second spacing P to the length L of the liquid-tight region is 0.03 to 0.

24.

7. The pump body of the duct pump according to claim 6, characterized in that, The ratio of the second spacing P to the length L of the liquid-tight region is 0.1 to 0.

2.

8. The pump body of the duct pump according to any one of claims 1-5, characterized in that, The pump housing includes a support and a diaphragm. The support has a mesh structure and includes a first support segment, a second support segment, and a third support segment connected sequentially from distal to proximal along its length. The diaphragm includes a cylindrical segment that wraps around the second support segment to form the liquid-tight region. The liquid-tight region has a first proximal edge and a first distal edge. At least a portion of the first support segment forms the blood inlet region, and at least a portion of the third support segment forms the blood outlet region.

9. The pump body of the duct pump according to claim 8, characterized in that, The membrane also includes an extension section located proximal to the cylindrical section, the extension section extending proximally beyond the blood outlet area, the proximal end of the extension section being connected to the conduit of the catheter pump; the proximal end of the extension section forms a liquid outlet, and the blood flowing out from the blood outlet area continues to flow proximally along the extension section and flows out from the liquid outlet.

10. The pump body of the duct pump according to claim 8, characterized in that, The first support segment is a distal conical segment, and the second support segment is an intermediate pump segment. The axial lengths of the distal conical segment and the proximal conical segment are equal. The axial length of the intermediate pump segment is greater than half the sum of the axial lengths of the distal conical segment, the intermediate pump segment, and the proximal conical segment.

11. A pump body for a duct pump, characterized in that, The device includes a pump housing and an impeller located within the pump housing. The pump housing has a blood inlet region, a blood outlet region, and a liquid-tight region located between the blood inlet region and the blood outlet region. The liquid-tight region has a first proximal edge and a first distal edge. The impeller includes blades, each blade having a second proximal edge and a second distal edge. The second distal edge is located within the liquid-tight region, and the ratio of a first distance D between the second distal edge and the first distal edge to the length L of the liquid-tight region is 0.3 to 0.

55.

12. The pump body of the duct pump according to claim 11, characterized in that, The blood outlet area is a proximal conical segment, and the second proximal edge is located within the proximal conical segment.

13. The pump body of the duct pump according to claim 11, characterized in that, The ratio of the first spacing D to the length L of the liquid-tight region is 0.4 to 0.

5.

14. The pump body of the duct pump according to any one of claims 11-13, characterized in that, The pump housing includes a support and a diaphragm. The support has a mesh structure and includes a first support segment, a second support segment, and a third support segment connected sequentially from the distal end to the proximal end along its length. The diaphragm includes a cylindrical segment that wraps around the second support segment to form the liquid-tight region. At least a portion of the first support segment forms the blood inlet region, and at least a portion of the third support segment forms the blood outlet region.

15. The pump body of the duct pump according to claim 14, characterized in that, The membrane also includes an extension section located proximal to the cylindrical section, the extension section extending proximally beyond the blood outlet area, the proximal end of the extension section being connected to the conduit of the catheter pump; the proximal end of the extension section forms a liquid outlet, and the blood flowing out from the blood outlet area continues to flow proximally along the extension section and flows out from the liquid outlet.

16. The pump body of the duct pump according to claim 15, characterized in that, The first support segment is a distal conical segment, the second support segment is an intermediate pump segment, and the third support segment is a proximal conical segment. The axial lengths of the distal conical segment and the proximal conical segment are equal. The axial length of the intermediate pump segment is greater than half the sum of the axial lengths of the distal conical segment, the intermediate pump segment, and the proximal conical segment.

17. A duct pump, characterized in that, The pump includes a drive assembly, a drive shaft, a conduit, and a pump body as described in any one of claims 1-16, wherein the proximal end of the pump body is connected to the distal end of the conduit; the drive shaft passes through the conduit; the proximal end of the drive shaft is connected to the power output shaft of the drive assembly, and the distal end of the drive shaft is connected to an impeller in the pump body; the drive assembly drives the impeller to rotate via the drive shaft to draw blood from the blood inlet area into the pump housing and then discharge it from the blood outlet area.

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