Pumping device and ventricular assist system

Abstract

The utility model discloses a blood pumping device and a ventricular assist system.The blood pumping device comprises a motor and a perfusion tube, the motor comprises a machine shell, a rotor assembly and a far-end sealing cover, the machine shell defines a containing cavity, a first circulation pipeline is arranged in the machine shell, the far-end sealing cover is connected with the far end of the machine shell, and a first shaft hole penetrating in the axial direction is formed in the far-end sealing cover; the rotor assembly comprises a rotating shaft, at least part of the rotating shaft penetrates through the first shaft hole and extends out of the containing cavity, a gap between the rotating shaft and the contour surface of the first shaft hole forms a second circulation pipeline, and the second circulation pipeline communicates with the first circulation pipeline; the infusion tube is connected with the near end of the motor, and a third circulation pipeline communicated with the first circulation pipeline is arranged in the infusion tube; the flow Q1 of the first circulation pipeline, the flow Q2 of the second circulation pipeline and the flow Q3 of the third circulation pipeline meet the formula, wherein k1 belongs to (0, 2), k2 belongs to (0, 2), k3 belongs to (0, 2), and Qx belongs to [10, 50].

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of medical devices, and particularly relates to a blood pumping device and a ventricular assist system. BACKGROUND

[0002] In a heart surgery, due to the patient's own disease or the need of the surgery, the patient's heart function is weakened, and the blood pumping capacity is insufficient. At this time, an active intervention type medical device such as a ventricular assist device needs to be inserted into the heart to assist the heart in pumping blood. The ventricular assist device uses the principle of heart blood pumping to pump blood in the heart out through a pumping mechanism and guide the blood to the aorta outside the heart to flow to the whole body.

[0003] In the normal working of the ventricular assist device, in order to avoid the blood flowing into the ventricular assist device, a certain hydraulic pressure needs to be provided for the ventricular assist device by relying on a perfusion pipeline filled with perfusion liquid during use. In order to achieve the blood blocking function, there is a certain requirement for the total flow of the perfusion liquid of the perfusion pipeline, and the total flow of the perfusion pipeline is related to the flow at each branch. Due to the differences in the sizes of the ventricular assist device at different places, the sizes of the perfusion branches that can be carried are also different, and in addition, the demand for blood blocking at each perfusion branch is also different, so the flow of each perfusion branch is not necessarily the same. Therefore, in some scenarios, even if the total flow of the perfusion is large enough, the blood blocking effect of the perfusion pipeline is not ideal. CONTENT OF THE UTILITY MODEL

[0004] Embodiments of the present application provide a blood pumping device and a ventricular assist system, aiming to improve the perfusion effect of the perfusion pipeline in the blood pumping device.

[0005] Embodiments of the first aspect of the present application provide a blood pumping device, comprising a motor and a perfusion pipeline, the motor comprising a motor shell, a rotor assembly and a distal end cover, the motor shell being enclosed to form an accommodation cavity, a first flow pipeline being arranged in the motor shell, the distal end cover being connected to the distal end of the motor shell, the distal end cover being provided with a first shaft hole penetrating in the axial direction, the rotor assembly comprising a rotating shaft, at least part of the rotating shaft extending out of the accommodation cavity through the first shaft hole, a gap between the rotating shaft and the profile surface of the first shaft hole forming a second flow pipeline, the second flow pipeline being in communication with the first flow pipeline; the perfusion pipeline being connected to the proximal end of the motor, the perfusion pipeline being provided with a third flow pipeline in communication with the first flow pipeline; the flow Q1 of the first flow pipeline, the flow Q2 of the second flow pipeline and the flow Q3 of the third flow pipeline satisfying the formula wherein k1∈(0, 2], k2∈(0, 2], k3∈(0, 2], Q x ∈[10, 50].

[0006] According to an embodiment of the first aspect of the application, the distal end cover is further provided with a sixth flow passage communicating with the first flow passage and the first shaft hole; the motor further comprises a proximal end cover connected to the proximal end of the casing, the proximal end cover being provided with a fourth flow passage and a fifth flow passage, the fifth flow passage communicating with the first flow passage and the fourth flow passage, and the perfusion liquid flowing from the perfusion pipe to the motor sequentially flows through the third flow passage, the fourth flow passage, the fifth flow passage, the first flow passage, the sixth flow passage and the second flow passage.

[0007] According to an embodiment of the first aspect of the application, the motor further comprises a bearing sleeved on the rotating shaft; the proximal end cover is provided with a proximal end bearing chamber for accommodating the bearing, and the distal end cover is provided with a distal end bearing chamber for accommodating the bearing.

[0008] According to an embodiment of the first aspect of the application, the flow area S4 of the fourth flow passage and the flow area S5 of the fifth flow passage satisfy the formula and / or, the flow area S1 of the first flow passage and the flow area S5 of the fifth flow passage satisfy the formula

[0009] According to an embodiment of the first aspect of the application, the flow area S6 of the sixth flow passage and the flow area S2 of the second flow passage satisfy the formula and / or, the flow area S1 of the first flow passage and the flow area S6 of the sixth flow passage satisfy the formula

[0010] According to an embodiment of the first aspect of the application, the angle between the extension direction of the sixth flow passage and the extension direction of the first shaft hole is greater than 90° and less than 180°; in the direction from the proximal end to the distal end, the sixth flow passage is inclined to the direction of the axis of the first shaft hole.

[0011] According to an embodiment of the first aspect of the application, the angle between the extension direction of the fifth flow passage and the extension direction of the fourth flow passage is greater than 90° and less than 180°; in the direction from the distal end to the proximal end, the fifth flow passage is inclined to the direction of the axis of the fourth flow passage.

[0012] According to an embodiment of the first aspect of the application, the proximal end cover is provided with a backflow hole penetrating in the axial direction; the pump device further comprises a backflow pipe connected to the proximal end of the motor, the backflow hole communicating with the backflow pipe and the accommodation cavity, and at least part of the perfusion liquid located at the first shaft hole sequentially flows through the accommodation cavity and the backflow hole into the backflow pipe.

[0013] According to an embodiment of the first aspect of the present application, the plurality of first flow channels are arranged in the casing, the number of the fifth flow channels and the sixth flow channels are the same as the number of the first flow channels, one fifth flow channel corresponds to one first flow channel, and one sixth flow channel corresponds to one first flow channel.

[0014] According to an embodiment of the first aspect of the present application, the first flow channels extend in a straight line direction or a spiral direction.

[0015] An embodiment of the second aspect of the present application provides a ventricular assist system, which comprises an outflow channel, a sheath tube and the blood pumping device according to any one of the above embodiments, the outflow channel is connected to the distal end of the motor, and the sheath tube is connected to the proximal end of the motor.

[0016] The blood pumping device according to the embodiments of the present application analogizes the relationship between the flow rate Q1 of the first flow channel, the flow rate Q2 of the second flow channel, the flow rate Q3 of the third flow channel and the total flow rate of the perfusion channel to the relationship between the branch resistances and the total resistance in a parallel circuit, so that the flow rate Q1 of the first flow channel, the flow rate Q2 of the second flow channel and the flow rate Q3 of the third flow channel are mutually limited while satisfying the total flow rate of the perfusion channel, the extreme values of the first flow channel, the second flow channel and the third flow channel are reduced, and the overall perfusion effect is ensured to be good. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be used in the embodiments of the present application will be briefly introduced below. Those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0018] Figure 1 FIG. 1 is a structural schematic diagram of a ventricular assist device according to some embodiments of the present application;

[0019] Figure 2 FIG. 2 is a longitudinal sectional structural schematic diagram of the ventricular assist device in FIG. 1; Figure 1

[0020] FIG. 3 is a partially expanded structural schematic diagram of the casing in FIG. 2; Figure 3

[0021] FIG. 4 is a perspective structural schematic diagram of the distal end cover in FIG. 3; Figure 4

[0022] FIG. 5 is a longitudinal sectional structural schematic diagram of the ventricular assist device in FIG. 1 from another angle; Figure 5 Figure 1 FIG. 6 is a longitudinal sectional structural schematic diagram of the ventricular assist device in FIG. 5 from another angle; and

[0023] Figure 6 ​A side view structural schematic diagram of an example proximal end cover is shown.

[0024] Figure 7 A side view structural schematic diagram of an example proximal end cover is shown. Figure 6 A sectional view structural schematic diagram of the proximal end cover in the A-A position is shown.

[0025] Figure 8 A sectional view structural schematic diagram of the proximal end cover in the B-B position is shown. Figure 6 A sectional view structural schematic diagram of the proximal end cover in the B-B position is shown.

[0026] Reference signs:

[0027] 10, motor; 11, first flow passage; 12, second flow passage; 13, third flow passage; 14, fourth flow passage; 15, fifth flow passage; 16, sixth flow passage; 20, sheath tube; 21, perfusion tube; 22, return tube; 30, outflow channel; 31, outflow window; 32, impeller;

[0028] 100, casing; 110, accommodating cavity;

[0029] 200, rotor assembly; 210, rotating shaft; 220, magnetic steel;

[0030] 300, distal end cover; 310, first shaft hole; 320, distal end bearing chamber;

[0031] 400, proximal end cover; 410, proximal end bearing chamber; 420, return hole;

[0032] 500, bearing;

[0033] 600, stator assembly; 610, winding;

[0034] x, first direction. DETAILED DESCRIPTION

[0035] The features and exemplary embodiments of various aspects of the present application will be described below in detail, in order to make the purposes, technical solutions and advantages of the present application more clear and apparent, the present application will be further described in detail below in combination with the drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, but not to limit the present application. The present application can be implemented without some of these specific details by those skilled in the art. The following description of the embodiments is only to provide a better understanding of the present application by showing examples of the present application.

[0036] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0037] To address the technical problems mentioned in the background art, the applicant proposes a blood pumping device, including a motor and an infusion tube. The motor includes a housing, a rotor assembly, and a distal end cap. The housing encloses a receiving cavity, and a first flow channel is provided within the housing. The distal end cap is connected to the distal end of the housing, and a first shaft hole penetrating the distal end cap is provided on the distal end cap. The rotor assembly includes a rotating shaft, at least a portion of which extends out of the receiving cavity through the first shaft hole. The gap between the rotating shaft and the contour surface of the first shaft hole forms a second flow channel, which communicates with the first flow channel. The infusion tube is connected to the proximal end of the motor, and a third flow channel communicating with the first flow channel is provided within the infusion tube. The flow rates Q1 of the first flow channel, Q2 of the second flow channel, and Q3 of the third flow channel satisfy the formula... Where k1∈(0,2], k2∈(0,2], k3∈(0,2], Q x ∈[10, 50].

[0038] The blood pumping device of this application compares the relationship between the flow rate Q1 of the first flow line, the flow rate Q2 of the second flow line, and the flow rate Q3 of the third flow line and the total flow rate of the perfusion line to the relationship between the resistance of each branch and the total resistance in a parallel circuit. This allows the device to satisfy the total flow rate of the perfusion line while also limiting the flow rates Q1, Q2, and Q3 of the first, second, and third flow lines, reducing the occurrence of extreme values ​​in the first, second, and third flow lines, and thus ensuring a better overall perfusion effect.

[0039] Before describing the blood pumping device, a brief description of the ventricular assist device including the blood pumping device is provided with reference to the accompanying drawings to help understand the working environment of the blood pumping device. It should be noted that in the accompanying drawings, the direction extending from the distal end to the proximal end of the motor, pointing towards the proximal end, is the first direction, denoted as x. For ease of drawing, the dimensions in the accompanying drawings are not necessarily proportional to actual dimensions.

[0040] Figure 1 A structural schematic diagram of a ventricular assist device containing a blood pumping device according to some embodiments of the present application. Figure 2 A longitudinal sectional structural schematic diagram of a ventricular assist device is shown. Figure 1 A longitudinal sectional structural schematic diagram of a ventricular assist device is shown.

[0041] Figure 3 A partially expanded structural schematic diagram of a housing is shown. In conjunction with Figures 1 to 3 It can be seen that the present application provides a ventricular assist device containing a blood pumping device, which comprises a blood pumping device, a sheath 20 and an outflow channel 30. The blood pumping device comprises a motor 10 and a perfusion tube 21. The outflow channel 30 is connected to the distal end of the motor 10, and the sheath 20 is connected to the proximal end of the motor 10. The perfusion tube 21 is located in the sheath 20. The outflow channel 30 is provided with an intake window (not shown) and an outflow window 31. In use, the motor 10 and the outflow channel 30 are pushed by the sheath 20 to intervene in the blood vessels of a patient until the motor 10 and the outflow channel 30 are located at a designated position in the blood circulation system of the patient. At this time, the outflow window 31 and the intake window are located at different positions in the blood circulation system. When the motor 10 in the blood pumping device is started, the motor 10 drives blood to flow from the intake window into the outflow channel 30 and out of the outflow window 31, thereby realizing the blood pumping function of the ventricular assist device.

[0042] When the blood pumping device, the sheath 20 and the outflow channel 30 intervene in the patient's body, the end of the sheath 20 away from the motor 10 protrudes out of the patient's body and is connected to a liquid storage tank (not shown), a power supply device (not shown), a control switch (not shown) and the like. The motor is provided with a flow channel for circulating perfusion liquid. The perfusion liquid is transported into the motor 10 through the perfusion tube 21 and the flow channel, carries away the heat generated by the operation of the motor 10 and provides a certain perfusion liquid pressure for the motor 10. The perfusion liquid can be at least one of physiological saline, glucose and an anticoagulant, and the anticoagulant can be heparin. The anticoagulant in the perfusion liquid reduces the probability of blood clotting, thereby reducing the probability of blood pumping function failure of the motor 10 caused by blood clotting.

[0043] After describing the structure of the ventricular assist device, the blood pumping device provided by the embodiments of the present application will be further described in conjunction with the drawings.

[0044] Please continue to refer to Figures 1 to 3The application provides a blood pumping device, which comprises a motor 10 and a perfusion tube 21. The motor 10 comprises a casing 100, a rotor assembly 200 and a distal end cover 300. The casing 100 is enclosed to form a containing cavity 110. The casing 100 is provided with a first flow passage 11. The distal end cover 300 is connected to the distal end of the casing 100. The distal end cover 300 is provided with a first shaft hole 310 penetrating the distal end cover 300. The rotor assembly 200 comprises a rotating shaft 210. At least part of the rotating shaft 210 extends out of the containing cavity 110 through the first shaft hole 310 and is connected to an impeller 32 in an outflow channel 30. The gap between the rotating shaft 210 and the profile surface of the first shaft hole 310 forms a second flow passage 12. The second flow passage 12 is in communication with the first flow passage 11. The perfusion tube 21 is connected to the proximal end of the motor 10. The perfusion tube 21 is provided with a third flow passage 13 in communication with the first flow passage 11. The flow rate Q1 of the first flow passage 11, the flow rate Q2 of the second flow passage 12 and the flow rate Q3 of the third flow passage 13 satisfy the formula wherein k1∈(0, 2], k2∈(0, 2], k3∈(0, 2], Q x ∈[10, 50].

[0045] It can be understood that, in the application, the proximal end refers to the end towards the operator or the physician, and the distal end refers to the end away from the operator or the physician. The proximal end of the motor 10 is towards the sheath 20, and the distal end of the motor 10 is towards the outflow channel 30.

[0046] It should be noted that, since the entire flow passage in the blood pumping device is composed of multiple branches, and the equivalent diameters of the multiple branches are not necessarily the same, the flow rates at the branches can also be different. In the embodiment, the relationship between the total flow rate of the entire flow passage and the local fluid leakage of each branch is analogous to the relationship between the resistance of each branch and the total resistance in a parallel circuit. The coefficients k1, k2 and k3 are respectively affected by the lengths and equivalent diameters of the first flow passage 11, the second flow passage 12 and the third flow passage 13. It can also be understood that the size of the coefficient k represents the importance of the required flow leakage of the branch to the required fluid leakage Q x of the entire flow passage. For example, the total flow rate of the entire flow passage in the blood pumping device is 10m 3 / s-50m 3 / s.

[0047] The flow rates of the first flow line 11, the second flow line 12, and the third flow line 13 all contribute to the blood clotting (balancing external blood pressure at the blood pumping device) of the pumping device. The first flow line 11 extends from the proximal end to the distal end of the housing 100. Besides delivering perfusion fluid to the second flow line 12 to balance blood pressure, the perfusion fluid in the first flow line 11 also helps balance the polarization generated during the rotation of the rotor assembly 200, thereby reducing the impact on the patient during the operation of the motor 10. The second flow line 12 comes into direct contact with blood during use, and its flow rate Q2 directly affects the blood clotting effect of the motor 10. The third flow line 13 extends from the proximal end to the distal end of the sheath 20, is relatively long, and is the supply line for perfusion fluid to the motor 10. Its flow rate Q3 directly affects the maximum flow rate of each branch within the motor 10. (In the formula...) In this scenario, with the flow rates Q1, Q2, and Q3 of the first, second, and third circulation pipelines remaining constant, the larger the value of k, the greater the total flow rate Q. x The smaller the value. If the total flow Q... x With the value of k remaining constant, the larger the value, the greater the flow rate of the corresponding branch flow path. For example, Q x When k1 is a constant, the smaller the value of k1, the greater the difference between the flow rate Q1 in the first flow path and the total flow rate Q in the entire flow path. x The smaller the impact, the better. When the value of k1 approaches 0, it represents the influence of the flow rate Q1 in the first flow path on the total flow rate Q of the entire flow path. x The effect is negligible. When k1 is 2, it represents the influence of the flow rate Q1 in the first flow path on the total flow rate Q of the entire flow path. x The impact is significant. The values ​​of K2 and k3 are similar and will not be elaborated further here.

[0048] In one specific application implementation, the total flow rate Q of the entire circulation pipeline of the blood pumping device... x 30m 3 / s, k1=1, k2=0.1, k3=0.9. That is, in this implementation, the relationship between the flow rates Q1 of the first flow path, Q2 of the second flow path, and Q3 of the third flow path is as follows: The flow rates Q1 and Q3 of the first and third flow channels, respectively, affect the total flow rate Q of the entire flow channel. x Both are relatively large; the flow rate Q2 in the second circulation pipe is relatively large compared to the total flow rate Q in the entire circulation pipe. x Smaller.

[0049] In some implementations, the first flow channel 11 extends in a straight line or a spiral direction. In this application, the first flow channel 11 extending in a spiral direction is exemplified. Compared with the scheme of extending in a straight line, the first flow channel 11 extending in a spiral direction can make the physical thickness of the casing 100 in the first direction x more uniform, thereby improving the field distribution uniformity of the motor 10. Secondly, the first flow channel 11 extending in a spiral direction can also make the perfusion liquid in the first flow channel 11 balance the polarization generated when the rotor assembly 200 rotates, thereby reducing the impact on the patient when the motor 10 operates.

[0050] In some implementations, the casing 100 can be a two-layer casing with an inner layer and an outer layer. The inner layer and the outer layer are attached to each other. The inner layer is provided with a groove recessed to one side of the accommodation cavity 110. The groove and the outer layer form the first flow channel 11. In order to better show the structure of the casing 100, Figure 3 the casing 100 part of the casing 100 is partially unfolded, and the outer layer is not shown.

[0051] In other embodiments, the first flow channel 11 can also be directly punched on the casing 100, or integrally formed with the casing 100 by casting, 3D printing, etc.

[0052] In some implementations, the casing 100 can be a cylinder, or a polygonal cylindrical structure such as a square cylinder. In this embodiment, the casing 100 is exemplified as a cylinder.

[0053] The blood pumping device of this application analogizes the relationship between the flow rate Q1 of the first flow channel 11, the flow rate Q2 of the second flow channel 12, the flow rate Q3 of the third flow channel 13, and the total flow rate of the perfusion channel to the relationship between each branch resistance and the total resistance in a parallel circuit. While meeting the total flow rate of the perfusion channel, the flow rate Q1 of the first flow channel 11, the flow rate Q2 of the second flow channel 12, and the flow rate Q3 of the third flow channel 13 are also limited by the formula , which reduces the occurrence of extreme values of the first flow channel 11, the second flow channel 12, and the third flow channel 13, thereby ensuring that the overall perfusion effect of the perfusion channel in the blood pumping device is good.

[0054] In some embodiments, the distal cover 300 further comprises a sixth flow passage 16 connecting the first flow passage 11 and the first shaft hole 310. The motor 10 further comprises a proximal cover 400 connected to the proximal end of the casing 100, and the proximal cover 400 comprises a fourth flow passage 14 and a fifth flow passage 15. The fifth flow passage 15 connects the first flow passage 11 and the fourth flow passage 14. The perfusion liquid flowing from the perfusion pipe 21 to the motor 10 sequentially flows through the third flow passage 13, the fourth flow passage 14, the fifth flow passage 15, the first flow passage 11, the sixth flow passage 16, and the second flow passage 12.

[0055] In some embodiments, the sixth flow passage 16 extends along the radial direction of the distal cover 300, and the extension direction of the sixth flow passage 16 forms an obtuse angle with the radial direction of the distal cover 300. The fourth flow passage 14 extends along the axial direction of the proximal cover 400, and the fifth flow passage 15 extends along the radial direction of the proximal cover 400, and the extension direction of the fifth flow passage 15 forms an obtuse angle with the radial direction of the proximal cover 400.

[0056] It should be noted that although the flow passages in the blood pumping device further comprise the fourth flow passage 14, the fifth flow passage 15, and the sixth flow passage 16, the influence of the fourth flow passage 14, the fifth flow passage 15, and the sixth flow passage 16 on the total flow of the entire flow passage is omitted in this embodiment because the lengths of the three branches are relatively short compared to the lengths of the other branches connected thereto. Only the relationship between the local flow of the first flow passage 11, the second flow passage 12, and the third flow passage 13 and the total flow of the entire flow passage is discussed.

[0057] In some embodiments, the casing 100 comprises a plurality of first flow passages 11, and the number of the fifth flow passages 15 and the sixth flow passages 16 is the same as the number of the first flow passages 11. Each fifth flow passage 15 corresponds to a first flow passage 11, and each sixth flow passage 16 corresponds to a first flow passage 11.

[0058] In some embodiments, the motor 10 further comprises a bearing 500 sleeved on the rotating shaft 210 of the rotor assembly 200. The proximal cover 400 comprises a proximal bearing chamber 410 for accommodating the bearing 500, and the distal cover 300 comprises a distal bearing chamber 320 for accommodating the bearing 500. The rotating shaft 210 extends along the first direction (x direction in the figure), and the bearing 500 in the proximal bearing chamber 410 and the bearing in the distal bearing chamber 320 are both sleeved on the rotating shaft 210.

[0059] In some embodiments, the motor 10 further comprises a stator assembly 600, which comprises windings 610 located in the accommodating cavity 110 and connected to the inner circumferential surface of the housing 100. The housing 100 can also serve as a core in the stator assembly 600 to provide a magnetic field. The rotor assembly 200 further comprises a magnetic steel 220 located in the accommodating cavity 110, which is sleeved on and connected to the rotating shaft 210, and has a gap with the windings for circulating the perfusion liquid.

[0060] The blood pumping device provided by the application reduces the manufacturing cost and simplifies the assembly steps by integrating the two bearings 500 at the proximal end and the distal end of the motor 10 on the proximal end cover 400 and the distal end cover 300 respectively, and the integrated molding improves the coaxiality of the first shaft hole 310 and the bearing chamber, avoids the problem of different coaxialities of the motor 10 after assembly due to the fitting tolerance of the parts, and affects the efficiency and service life of the motor 10.

[0061] Figure 4 A perspective structural schematic diagram of an example distal end cover is shown.

[0062] In combination Figures 1 to 4 It can be seen that in some embodiments, the plurality of sixth flow channels 16 are in direct communication with the plurality of first flow channels 11 respectively, and converge the perfusion liquid at the plurality of first flow channels 11 into the second flow channel 12.

[0063] In some embodiments, the angle between the extension direction of the sixth flow channel 16 and the extension direction of the first shaft hole 310 is greater than 90° and less than 180°. In the direction from the proximal end to the distal end, the sixth flow channel 16 is inclined to the direction of the axis of the first shaft hole 310.

[0064] It should be noted that the sixth flow channel 16 can be a straight or curved extension channel, or a composite channel composed of multiple straight lines. In this embodiment, the direction of the line connecting the outlets at both ends of the sixth flow channel 16 is considered as the overall extension direction of the sixth flow channel 16.

[0065] The blood pumping device provided by the application reduces the manufacturing cost and simplifies the assembly steps by integrating the two bearings 500 at the proximal end and the distal end of the motor 10 on the proximal end cover 400 and the distal end cover 300 respectively, and the integrated molding improves the coaxiality of the first shaft hole 310 and the bearing chamber, avoids the problem of different coaxialities of the motor 10 after assembly due to the fitting tolerance of the parts, and affects the efficiency and service life of the motor 10.

[0066] In some embodiments, the flow area S6 of the sixth flow channel 16 and the flow area S2 of the second flow channel 12 satisfy the formula and / or, the flow area S1 of the first flow passage 11 and the flow area S6 of the sixth flow passage 16 satisfy the formula

[0067] wherein the flow area of a flow passage is equal to four times the equivalent diameter multiplied by the wetted perimeter length according to the formula of equivalent diameter. The first flow passage 11 is usually a rectangular passage, and for a rectangular passage with width a and height b, the flow area S1 is a*b. The second flow passage 12 is usually a circular ring passage, and for a ring passage with outer diameter D and inner diameter d, the flow area S2 is equal to π(D 2 -d 2 ) / 4. The third flow passage 13 is usually a circular passage, and the flow area S3 is πD 2 / 4.

[0068] The blood pumping device of the present application reduces the difference between the flow areas of the sixth flow passage 16 and the second flow passage 12 by limiting the ratio of the flow areas between the sixth flow passage 16 and the second flow passage 12, thereby reducing the residual air bubbles caused by the sudden change in diameter when the perfusion fluid flows through the sixth flow passage 16 and the second flow passage 12. The blood pumping device of the present application reduces the difference between the flow areas of the sixth flow passage 16 and the first flow passage 11 by limiting the ratio of the flow areas between the sixth flow passage 16 and the first flow passage 11, thereby reducing the residual air bubbles caused by the sudden change in diameter when the perfusion fluid flows through the sixth flow passage 16 and the first flow passage 11, ensuring better perfusion effect. In addition, limiting the ratio of the flow areas between the sixth flow passage 16 and the first flow passage 11 and the ratio of the flow areas between the sixth flow passage 16 and the second flow passage 12 can also indirectly reduce the extreme values of the flow areas S1 and S2 of the first flow passage 11 and the second flow passage 12 in the design process, avoiding perfusion failure.

[0069] Figure 5 Fig. 1 shows a longitudinal sectional view of a ventricular assist device in accordance with an example of the present application; Figure 1 Fig. 2 shows a longitudinal sectional view of the ventricular assist device in Fig. 1 from another angle; Figure 6 Fig. 3 shows a side view of a proximal cover in accordance with an example of the present application; Figure 7 Fig. 4 shows a longitudinal sectional view of the proximal cover in Fig. 3 at position A-A; Figure 6 Fig. 5 shows a longitudinal sectional view of the proximal cover in Fig. 3 at position B-B. Wherein, Figure 8 Fig. 6 shows a perspective view of the ventricular assist device in Fig. 1; Figure 6 Fig. 7 shows a perspective view of the ventricular assist device in Fig. 6 rotated 90° around its axis. Figure 5 Fig. 8 shows a perspective view of the ventricular assist device in Fig. 6 from another angle. Figure 2 Fig. 9 shows a perspective view of the ventricular assist device in Fig. 6 rotated 90° around its axis.

[0070] Fig. 10 shows a perspective view of the ventricular assist device in Fig. 6 from another angle.Figures 1 to 3 , Figures 5 to 8 It can be seen that in some embodiments, the angle between the extension direction of the fifth flow channel 15 and the extension direction of the fourth flow channel 14 is greater than 90° and less than 180°. In the direction from the distal end to the proximal end, the fifth flow channel 15 is inclined to the direction of the axis of the fourth flow channel 14.

[0071] It should be noted that the fifth flow channel 15 can be a straight or curved extension channel, or a composite channel composed of multiple straight lines. In this embodiment, the direction of the line connecting the outlets at both ends of the fifth flow channel 15 is considered as the overall extension direction of the fifth flow channel 15.

[0072] The blood pumping device provided by the present application reduces the resistance and impact on the channel wall surface of the perfusion liquid when flowing through the fifth flow channel 15 and the fourth flow channel 14 by making the angle between the extension direction of the fifth flow channel 15 and the extension direction of the fourth flow channel 14 obtuse, and in the direction from the distal end to the proximal end, the fifth flow channel 15 is inclined to the direction of the axis of the fourth flow channel 14, thereby improving the flowability of the perfusion liquid.

[0073] In some embodiments, the flow area S4 of the fourth flow channel 14 and the flow area S5 of the fifth flow channel 15 satisfy the formula And / or, the flow area S1 of the first flow channel 11 and the flow area S5 of the fifth flow channel 15 satisfy the formula

[0074] It should be noted that the fourth flow channel 14 corresponds to the perfusion main path on the proximal end cover 400 and is directly connected to the perfusion tube 21 in the sheath 20. The plurality of fifth flow channels 15 correspond to the perfusion branch paths on the proximal end cover 400, and the plurality of fifth flow channels 15 connect the fourth flow channel 14 and the plurality of first flow channels 11 on the casing 100. The fourth flow channel 14 and the fifth flow channel 15 are usually circular channels. The perfusion liquid flows through the third flow channel 13 in the perfusion tube 21, the fourth flow channel 14 on the proximal end cover 400, and the fifth flow channel 15 in sequence, and then flows to the plurality of first flow channels 11 on the casing 100.

[0075] The blood pumping device of the present application reduces the difference of flow area between the fourth flow passage 14 and the fifth flow passage 15 by limiting the ratio of the flow area between the directly connected fourth flow passage 14 and fifth flow passage 15, thereby reducing the bubble residue caused by the sudden change of pipe diameter when the perfusion fluid flows through the fourth flow passage 14 and the fifth flow passage 15. By limiting the ratio of the flow area between the directly connected fifth flow passage 15 and first flow passage 11, the difference of flow area between the fifth flow passage 15 and the first flow passage 11 is reduced, thereby reducing the bubble residue caused by the sudden change of pipe diameter when the perfusion fluid flows through the fifth flow passage 15 and the first flow passage 11. In addition, limiting the ratio of the flow area between the directly connected fifth flow passage 15 and first flow passage 11 can also indirectly reduce the extreme value of the flow area S1 of the first flow passage 11 in the design process.

[0076] In some embodiments, the proximal cover 400 is further provided with a backflow hole 420 axially penetrating. The blood pumping device further comprises a backflow tube 22 located in the sheath tube 20, and the backflow tube 22 is connected to the proximal end of the motor 10. The backflow hole 420 communicates the backflow tube 22 and the accommodation cavity 110, and at least part of the perfusion fluid located at the first shaft hole 310 flows into the backflow tube 22 through the accommodation cavity 110 and the backflow hole 420 in sequence.

[0077] In some embodiments, the perfusion fluid flows from the perfusion tube 21, then flows through the fourth flow passage 14, and then is divided in the fifth flow passage 15 and flows into the plurality of first flow passages 11, respectively, and then converges to the first shaft hole 310 (second flow passage 12) through the plurality of sixth flow passages 16. Then, part of the perfusion fluid at the second flow passage 12 flows to the outflow channel 30 for balancing the blood at the outflow channel 30, and the other part flows to the accommodation cavity 110, passes through the gap between the magnetic steel 220 and the winding 610, and enters the backflow tube 22 from the backflow hole 420 and finally flows out of the body. The part of the perfusion fluid flowing out of the body will flush the bearings 500 at the distal bearing chamber 320 and the proximal bearing chamber 410 when passing through the accommodation cavity 110, which can not only carry away the heat generated by the rotation of the bearings 500, but also carry away the particles generated by the friction between the balls of the bearings 500, thereby improving the safety of the blood pumping device.

[0078] In addition, the present application also provides a ventricular assist system, which comprises an outflow channel 30, a sheath tube 20, and a blood pumping device provided in any of the above embodiments. The outflow channel 30 is connected to the distal end of the motor 10, the sheath tube 20 is connected to the proximal end of the motor 10, and the perfusion tube 21 is located in the sheath tube 20.

[0079] Since the ventricular assist system provided in the second aspect of the present application comprises the blood pumping device of any of the above embodiments, the ventricular assist system provided in the second aspect of the present application has the beneficial effects of the blood pumping device of any of the above embodiments, which will not be described herein.

[0080] The above describes only specific embodiments of the present application. Those skilled in the art can clearly understand the specific working processes of the system, module and unit described above for the convenience and brevity of description, which can refer to the corresponding processes in the foregoing embodiments, which will not be described herein. It should be understood that the protection scope of the present application is not limited in this way. Any person skilled in the art can easily think of various equivalent modifications or replacements within the technical range disclosed in the present application, and these modifications or replacements should be covered within the protection scope of the present application.

Claims

1. A blood pumping device, characterized by The pump blood device comprises: a motor, comprising a casing, a rotor assembly and a distal end cover, the casing is enclosed to form a containing cavity, the casing is provided with a first flow passage, the distal end cover is connected with the distal end of the casing, the distal end cover is provided with a first shaft hole penetrating in the axial direction, the rotor assembly comprises a rotating shaft, at least part of the rotating shaft extends out of the containing cavity through the first shaft hole, the gap between the rotating shaft and the profile surface of the first shaft hole forms a second flow passage, the second flow passage is communicated with the first flow passage; a perfusion tube connected with the proximal end of the motor, the perfusion tube is provided with a third flow passage communicated with the first flow passage; The flow rate Q1 of the first flow passage, the flow rate Q2 of the second flow passage, and the flow rate Q3 of the third flow passage satisfy the formula wherein k1 ∈ (0, 2], k2 ∈ (0, 2], k3 ∈ (0, 2], Q x ∈ [10, 50].

2. The blood pumping device of claim 1, wherein the distal end cover is further provided with a sixth flow passage communicated with the first flow passage and the first shaft hole; the motor further comprises a proximal end cover, the proximal end cover is connected with the proximal end of the casing, the proximal end cover is provided with a fourth flow passage and a fifth flow passage, the fifth flow passage is communicated with the first flow passage and the fourth flow passage, the perfusion liquid flowing from the perfusion tube to the motor sequentially flows through the third flow passage, the fourth flow passage, the fifth flow passage, the first flow passage, the sixth flow passage and the second flow passage.

3. The blood pumping device of claim 2, wherein, the motor further comprises a bearing sleeved on the rotating shaft; the proximal end cover is provided with a proximal end bearing chamber for accommodating the bearing, and the distal end cover is provided with a distal end bearing chamber for accommodating the bearing.

4. The blood pumping device of claim 2, wherein, The flow area S4 of the fourth flow passage and the flow area S5 of the fifth flow passage satisfy the formula And / or, the flow area S1 of the first flow passage and the flow area S5 of the fifth flow passage satisfy the formula 5. The blood pumping device of claim 2, wherein, The flow area S6 of the sixth flow passage and the flow area S2 of the second flow passage satisfy the formula And / or, the flow area S1 of the first flow passage and the flow area S6 of the sixth flow passage satisfy the formula 6. The blood pumping device of claim 2, wherein, the included angle between the extension direction of the sixth flow passage and the extension direction of the first shaft hole is greater than 90° and less than 180°; in the direction from the proximal end to the distal end, the sixth flow passage is inclined to the direction of the axis of the first shaft hole.

7. The blood pumping device of claim 2, wherein, the included angle between the extension direction of the fifth flow passage and the extension direction of the fourth flow passage is greater than 90° and less than 180°; in the direction from the distal end to the proximal end, the fifth flow passage is inclined to the direction of the axis of the fourth flow passage.

8. The blood pumping device of claim 2, wherein, the proximal end cover is provided with a reflux hole penetrating in the axial direction; the pump blood device further comprises a reflux tube connected with the proximal end of the motor, the reflux hole is communicated with the reflux tube and the containing cavity, and at least part of the perfusion liquid located at the first shaft hole sequentially flows through the containing cavity and the reflux hole and flows into the reflux tube.

9. The blood pumping device of claim 2, wherein, the casing is provided with a plurality of first flow passages, the number of the fifth flow passages and the sixth flow passages is the same as the number of the first flow passages, one fifth flow passage is correspondingly arranged with one first flow passage, and one sixth flow passage is correspondingly arranged with one first flow passage.

10. The blood pumping device of claim 9, wherein, the first flow passage extends in a straight line direction or a spiral direction.

11. A ventricular assist system, characterized by the pump blood device comprises an outflow channel, a sheath and the pump blood device as claimed in any one of claims 1 to 10, the outflow channel is connected with the distal end of the motor, and the sheath is connected with the proximal end of the motor.

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