Disclosure of Invention
The embodiment of the application aims to at least solve one of the technical problems existing in the prior art. Therefore, the embodiment of the application provides a catheter pump housing structure and a catheter pump device, which are ingenious in structure, can ensure that the preset gap between the pump housing and the impeller is within a controllable range, ensure the structural stability of the pump housing and the impeller in the operation process of the pump housing and the impeller in a human body, avoid mechanical hemolysis and mechanical faults, and can discharge insoluble particles and heat generated in the operation process of the catheter pump device.
In a first aspect, embodiments of the present application provide a catheter pump housing structure comprising:
A support base;
the transmission assembly comprises a rotating shaft arranged on the supporting seat and an impeller suspended at the far end of the rotating shaft;
The pump shell comprises a pressure relief part and a pressure bearing part, wherein the pressure relief part is surrounded by a plurality of elastic bending strips, the pressure bearing part is in butt joint with the pressure relief part and is integrally formed, the proximal end of the pressure bearing part is connected with the supporting seat, the pressure bearing part is surrounded by an elastic net structure so as to surround the impeller, and the distal end of the pressure relief part and the proximal end of the pressure bearing part are respectively provided with a blood suction inlet and a blood outflow outlet;
An elastic covering layer covering the net mouth of the pressure-bearing part to form a first cavity communicated with the blood suction inlet and the blood outflow outlet in a sealing manner;
wherein the pump housing and the impeller are each configured as a self-expanding structure upon compression.
The catheter pump housing structure according to the embodiment of the first aspect of the application has at least the following beneficial effects:
According to the catheter pump housing structure provided by the embodiment of the application, the pump housing is provided with the pressure relief part and the pressure bearing part which are integrally formed, when the whole catheter pump housing structure is inserted into a corresponding ventricle or blood vessel of a human body through percutaneous operation, if the distal end of the pump housing collides with the blood vessel wall, the pressure relief part at the distal end of the pump housing is preferentially subjected to the action of external force of the blood vessel wall, and the pressure relief part is surrounded by a plurality of elastic bending strips, so that the elastic bending strips forming the pressure relief part are elastically deformed under the action of the external force, so that the whole pressure relief part can buffer and relieve the external force, the pressure bearing part is prevented from being greatly deformed due to the transmission of the external force, the gap between the impeller inside the pressure bearing part and the pressure bearing part is prevented from being reduced, and the probability that the impeller is blocked on the pressure bearing part due to the contact with the inner wall of the pressure bearing part is reduced. In addition, because the pressure-bearing part in butt joint with the pressure relief part is formed by enclosing an elastic net structure, the pressure-bearing part has certain hardness, can bear larger radial and axial bending torques, and when the whole catheter pump housing structure works and runs in a human ventricle or a blood vessel, if the outer wall of the pressure-bearing part collides with the wall of the human ventricle or the blood vessel, the acting force of the wall of the ventricle or the blood vessel basically does not deform the pressure-bearing part due to the stronger strength and the bending resistance of the pressure-bearing part, thereby ensuring that the gap between the pressure-bearing part and the impeller is maintained in a preset range, further reducing the probability of mechanical hemolysis, and simultaneously ensuring the stability of the rotation action of the impeller. According to the catheter pump housing structure, the pump housing is arranged to be the pressure relief part and the pressure bearing part which are integrally formed, and by means of the structural characteristics of the pressure relief part and the pressure bearing part, the function that the whole pump housing and the impeller can be automatically unfolded after compression is maintained, so that the catheter pump device can obtain larger flow, the preset gap between the pump housing and the impeller can be ensured to be within a controllable range, the housing supporting requirement of the impeller suspended at the far end of the rotating shaft is met, meanwhile, the structural stability of the pump housing and the impeller in the operation process of the pump housing and the impeller in a human body is ensured, and mechanical hemolysis and mechanical failure are avoided.
According to some embodiments of the application, the elastic bending strips are formed by connecting a plurality of sections of connecting sections in an S shape or a W shape in sequence, and two adjacent elastic bending strips do not cross.
According to some embodiments of the application, the portal is diamond-shaped.
According to some embodiments of the application, the bearing portion includes a radial bearing portion abutting the pressure relief portion and an axial bearing portion connected to the support base, the radial bearing portion being formed in a cage shape by a plurality of first elastic ribs enveloping the radial bearing portion, the axial bearing portion being formed in a cage shape by a plurality of second elastic ribs enveloping the radial bearing portion and abutting the radial bearing portion, the thickness of the second elastic ribs being greater than the thickness of the first elastic ribs.
According to some embodiments of the application, the impeller comprises a hub coaxially connected with the rotation shaft and a plurality of elastic blades circumferentially arranged on the hub.
According to some embodiments of the application, the device further comprises a tail tube connected to the distal end of the pressure relief portion and a guide wire for penetrating the tail tube, wherein the distal end of the guide wire can extend out of the distal end of the tail tube, and the proximal end of the guide wire can extend out of the blood suction port.
According to some embodiments of the application, the impeller further comprises a delivery tube for sheathing the support base and the pump housing and compressing the pump housing and the impeller into a contracted state.
In a second aspect, embodiments of the present application provide a catheter pump device comprising:
The above-mentioned catheter pump housing structure; the support seat is a support sleeve, and a perfusion cavity is arranged at the distal end of the support sleeve;
The transmission assembly further comprises a bearing sleeve and a transmission bearing which are arranged in the supporting sleeve, the rotating shaft is arranged in the bearing sleeve through the transmission bearing, an outer layer runner communicated with the pouring cavity is formed in the outer wall of the bearing sleeve, and an inner layer runner communicated with the pouring cavity is formed in a gap between an inner ring and an outer ring of the transmission bearing;
the distal end of the multi-cavity sheath tube is connected with the proximal end of the supporting sleeve, and an inflow channel communicated with the outer-layer runner and an outflow channel communicated with the inner-layer runner are formed.
The catheter pump device according to the embodiment of the second aspect of the application has at least the following advantageous effects:
According to the catheter pump device provided by the embodiment of the application, the bearing sleeve is arranged in the supporting sleeve, the outer-layer flow channel is arranged on the outer wall of the bearing sleeve, meanwhile, the multi-cavity sheath tube with the inflow channel and the outflow channel is arranged, so that an operator can pour liquid into the inflow channel when the whole catheter pump device is in operation, so that the liquid flows into the pouring cavity at the far end of the supporting sleeve after passing through the inflow channel and the outer-layer flow channel, the inner-layer flow channel formed by the gap between the inner ring and the outer ring of the transmission bearing is respectively communicated with the pouring cavity and the outflow channel in the multi-cavity sheath tube, the liquid in the pouring cavity can continuously flow through the inner-layer flow channel and the outflow channel, and finally flows out from the outlet of the outflow channel, and insoluble particles generated when the rotating shaft and the transmission bearing do synchronous high-speed rotation movement can be effectively discharged in the flowing mode, and the insoluble particles are prevented from entering human blood to cause danger to human body. Meanwhile, in the circulating flow process of the liquid along the flow path, heat exchange can be continuously carried out with the rotating shaft and the transmission bearing, so that heat generated by the rotating shaft and the transmission bearing in the high-speed rotation process is timely discharged, structural damage of the rotating shaft and the transmission bearing due to overheating is avoided, the rotating operation function of the impeller suspended at the far end of the rotating shaft is guaranteed, and the normal and stable blood pumping function of the whole catheter pump device is further guaranteed.
According to some embodiments of the application, the outer flow channel, the inflow channel and the outflow channel are all annular.
According to some embodiments of the application, the middle part of the multi-cavity sheath tube is further provided with an installation cavity, the proximal end of the rotating shaft is connected with the driving piece through a transmission twisted wire, and the transmission twisted wire is arranged in the installation cavity in a penetrating way.
According to some embodiments of the application, the blood outlet is covered by the flexible tube, the flexible tube is arranged on the outer wall of the pressure-bearing part, at least one outflow window is arranged on the outer wall of the flexible tube, the cavity of the flexible tube forms a circulation cavity communicated with the blood outlet and the outflow window, and the flexible tube is configured into an elastic hose structure with the outer wall capable of expanding and contracting.
According to some embodiments of the application, the flexible tube comprises a linear interface section, a round angle section, an arc transition section, a middle linear section and a guiding-out section which are sequentially and smoothly connected, wherein the arc transition section is tangent to the middle linear section, the outflow window is formed in the guiding-out section, the distal end of the flexible tube is connected with the outer wall of the pressure bearing part through the linear interface section so as to cover the blood outflow port, the proximal end of the flexible tube is connected with the outer wall of the multi-cavity sheath tube through the guiding-out section, the inner diameters of the round angle section and the arc transition section are gradually increased along the distance from the distal end to the proximal end, the inner diameter of the round angle section is larger than the inner diameter of the linear interface section, and the inner diameter of the arc transition section is larger than the inner diameter of the round angle section.
According to some embodiments of the application, the shape of the flexible tube is configured to satisfy the following condition:
the diameter of the straight line interface section is D1;
the diameter of the middle straight line segment is D2;
The axial length of the pump shell which allows radial expansion deformation is L1;
the sum of the axial lengths of the straight line interface section, the round angle section and the circular arc transition section is L2;
an included angle between a connecting line between the middle point of the main boundary of the straight line interface section and the middle point of the main boundary of the middle straight line section and the central axis of the pump shell is alpha;
The radius of the circle where the round angle section is positioned is R1, and the radius of the circle where the circular arc transition section is positioned is R2;
Wherein,
The value range of alpha is 0-10 degrees;
The value range of R1 is 0-L1/tan (alpha/2);
the value range of R2 is 0 to (D2-D1)/(2 tan (alpha/2) sin (alpha));
The value of L2 is in the range of 0 to (D2-D1)/(2 tan (alpha)).
According to some embodiments of the application, the shape of the flexible tube is configured to satisfy the following condition:
α=5°;
said r1=l1/tan (α/2);
the R2= (D2-D1)/(2 tan (α/2) sin (α));
The l2= (D2-D1)/(2 tan (α)).
Detailed Description
Features and exemplary embodiments of various aspects of the application are described in detail below. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the application. It will be apparent, however, to one skilled in the art that embodiments of the application may be practiced without some of these specific details. The following description of the embodiments is merely intended to provide a better understanding of the application by showing examples of the application.
In the description of the present application, it should be understood that references to orientation descriptions such as upper, lower, front, rear, left, right, etc. are based on the orientation or positional relationship shown in the drawings, are merely for convenience in describing embodiments of the present application and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the embodiments of the present application.
In the description of the embodiments of the present application, the meaning of several is one or more, the meaning of several is two or more, greater than, less than, exceeding, etc. are understood to not include the present number, and above, below, within, etc. are understood to include the present number. The description of the first and second is for the purpose of distinguishing between technical features only and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.
In the description of the embodiments of the present application, unless explicitly defined otherwise, terms such as arrangement, installation, connection, etc. should be construed broadly, and those skilled in the art may reasonably ascertain the specific meaning of the terms in the present application by combining the specific contents of the technical solutions.
It should be noted that, without conflict, the embodiments of the present application and features of the embodiments may be combined with each other. The embodiments will be described in detail below with reference to the accompanying drawings.
In addition, it should be noted that, in the description of the embodiments of the present application, "in vivo" means inside the tissue organ of the patient and "in vitro" means outside the tissue organ of the patient, unless explicitly defined otherwise. Meanwhile, in the embodiment of the present application, "distal" means a direction away from a physician, and "proximal" means a direction close to the physician.
It should be noted that, in a pulse cycle of the heart of a normal human body, when the heart contracts, an aortic valve located between a left ventricle and an aorta is opened, and blood in the left ventricle flows into the aorta under contraction pressure, so that the aorta transfuses into tissue organs of the human body; simultaneously, the pulmonary valve between the right ventricle and the pulmonary artery is opened, and the blood in the right ventricle flows into the pulmonary artery, so that the pulmonary artery transfuses blood into the pulmonary vein and the branch organs of the human body. When the heart is relaxed, the aortic valve is closed, and blood in the aorta is prevented from flowing back to the left ventricle; simultaneously, the pulmonary valve is closed, and blood in the pulmonary artery is prevented from flowing back to the right ventricle. The aorta of the human body is divided into an ascending aorta, an aortic arch and a descending aorta in turn along the blood flow direction, and the ascending aorta, the aortic arch and the descending aorta are communicated in turn.
The etiology of coronary heart disease or other cardiovascular diseases mainly shows that blood can not flow to cardiac muscle or brain in time, so that the organ tissue is necrotized by hypoxia. The catheter pump housing structure and the catheter pump device can provide stable blood circulation support for the heart of a patient, improve the perfusion quantity of coronary artery and remote organs, and simultaneously reduce the heart burden, thereby being beneficial to the stability of the physical sign of the patient in operation and the rehabilitation after operation.
Referring to fig. 1, 2,3 and 4, an embodiment of the present application discloses a catheter pump housing structure including a support base 100, a transmission assembly 200, a pump housing 300 and an elastic cover 400.
Wherein the pump casing 300 and the impeller 220 are each configured as a structure that is self-expandable after compression.
The transmission assembly 200 includes a rotation shaft 210 provided to the support 100 and an impeller 220 suspended from a distal end of the rotation shaft 210.
The pump case 300 includes a pressure relief portion 310 surrounded by a plurality of elastic bending strips 311 and a pressure bearing portion 320 butted with the pressure relief portion 310 and integrally formed, wherein a proximal end of the pressure bearing portion 320 is connected to the supporting base 100, the pressure bearing portion 320 is surrounded by an elastic net structure to surround the impeller 220, and a distal end of the pressure relief portion 310 and a proximal end of the pressure bearing portion 320 are respectively provided with a blood suction inlet 340 and a blood outflow outlet 350.
The elastic cover layer 400 covers the mesh 321 of the pressure-receiving portion 320 to seal the first chamber 330 communicating with the blood suction port 340 and the blood outflow port 350. That is, the first cavity 330 is enclosed by the pressure-bearing portion 320 covered with the elastic covering layer 400.
It should be noted that, the supporting seat 100 is preferably a tubular structure with two substantially sealed ends, and the supporting seat 100 is a rigid structure, which may be made of stainless steel, PEEK, POM, etc. with mechanical strength and high density, so as to ensure that the supporting seat 100 has no unacceptable deformation under a certain pressure and bending force, so as to perform a bearing and supporting function on the bearing portion 320 of the pump casing 300, thereby providing an installation carrier for the whole pump casing 300.
The proximal end of the rotation shaft 210 may be rotatably installed in the support 100 by a rotation member such as a bearing, and the distal end of the rotation shaft 210 protrudes out of the support 100 to facilitate the installation of the impeller 220, thereby facilitating the surrounding of the impeller 220 by the pressure-bearing portion 320 of the pump casing 300 to suspend the impeller 220 in the pump casing 300. It should be noted that, the proximal end of the rotation shaft 210 may also be directly connected to a rotation driving member mounted on the support 100; of course, the proximal end of the rotation shaft 210 may be indirectly connected to a rotation driving member located outside the body through a transmission twisted wire, and the rotation driving member may be a motor, etc. so that the rotation driving member directly or indirectly drives the rotation shaft 210 to rotate, thereby driving the impeller 220 suspended in the pump housing 300 to rotate, so as to realize the function of pumping blood.
Referring again to fig. 2 and 3, in the pump case 300 of the embodiment of the present application, the plurality of elastic bent strips 311 constituting the pressure relief portion 310 and the elastic net structure constituting the pressure receiving portion 320 are made of an elastic memory material. In addition, the impeller 220 and the elastic cover layer 400 are also made of elastic memory materials, preferably memory plastics with high strength, but also memory alloys, and the elastic memory materials are not limited in particular. With the above arrangement, the entire pump casing 300 and the impeller 220 within the pump casing 300 can be compressed into a compressed state, and at the same time, can be expanded into an initial state after compression.
In the description of the present application, the forced compression of the pump casing 300 and the impeller 220 disposed in the pump casing 300 means that a doctor compresses the outer wall of the pump casing 300 through a delivery tube or other compression device, and further causes the pump casing 300 and the impeller 220 disposed in the pump casing 300 to be disposed in the compression device, and at this time, the pump casing 300 and the impeller 220 disposed in the pump casing 300 are forced to be in a contracted state by external force, and when the corresponding compression device is withdrawn from the pump casing 300, the pump casing 300 and the impeller 220 disposed in the pump casing 300 are expanded and restored to an initial maximum volume state by their own elastic force.
The pump casing 300 is subjected to an optional external force, that is, the pressure relief portion 310 and the pressure bearing portion 320 of the pump casing 300 are subjected to the extrusion force of the vessel wall when the pressure relief portion and the pressure bearing portion are touched with the vessel wall in the patient during the operation of the whole catheter pump casing structure in the patient. It will be appreciated that the non-forced external force applied to the pump casing 300 is much smaller than the artificially applied forced force, and the magnitude of the non-forced external force is insufficient to compress the pump casing 300 and the impeller 220 disposed within the pump casing 300 into a contracted state, and the non-forced external force can only cause radial or axial bending deformation of the pump casing 300.
In addition, referring to fig. 2 and 3, in the pump casing 300 according to the embodiment of the present application, the pressure relief portion 310 and the pressure bearing portion 320 that is integrally formed and is in butt joint with the pressure relief portion 310 are substantially cage-shaped in the deployed state, and central axes of the pressure relief portion 310 and the pressure bearing portion 320 overlap, so that regularity of the pump casing 300 is ensured. Meanwhile, it should be noted that, in the embodiment of the present application, since the pressure relief portion 310 is formed by enclosing the plurality of elastic bending strips 311, a gap exists between two adjacent elastic bending strips 311, and the elastic covering layer 400 may also cover the gap formed between two adjacent elastic bending strips 311 on the outer periphery of the pressure relief portion 310, so that the gap between two adjacent elastic bending strips 311 on the pressure relief portion 310 is sealed.
Of course, referring back to fig. 1 to4, when the gap formed between the adjacent two elastic bending strips 311 on the pressure relief portion 310 is not covered by the elastic cover layer 400 or is only partially covered by the elastic cover layer 400, the blood suction port 340 may be formed by a gap between the adjacent two elastic bending strips 311 located at the distal end of the pressure relief portion 310; or the distal end of the pressure relief portion 310 may be provided with one or more blood suction ports 340 alone; similarly, the blood outflow port 350 may be formed by one or more mesh openings 321 at the proximal end of the pressure-bearing portion 320, in which case the one or more mesh openings 321 acting as the blood outflow port 350 are not sealed by the elastic covering layer 400, ensuring smooth outflow of blood therefrom; or the pressure-bearing portion 320 may be separately provided at its proximal end with one or more blood outflow openings 350.
It should be noted that, the whole pump housing 300 is substantially football-shaped in the deployed state, i.e., the distal end of the pressure relief portion 310 and the proximal end of the pressure bearing portion 320 are substantially tapered, and the blood inlet 340 and the blood outlet 350 are respectively located at the tapered positions at the two ends of the pump housing 300, so that blood can flow from the blood inlet 340 into the first cavity 330 and from the blood outlet 350 into the blood vessel.
Referring to fig. 6, it should be noted that the catheter pump housing structure of the present embodiment of the application may be entirely within a delivery device, which may be a smaller diameter delivery tube 900, prior to insertion into the patient, where both the pump housing 300 and the impeller 220 within the pump housing 300 are forcibly compressed by the delivery tube 900, being within the delivery tube 900 in a minimum volume compressed state; when the catheter pump housing structure is to be inserted into the patient, the physician can insert the whole catheter pump housing structure into the target position in the patient by percutaneous surgery and using the carrier action of the delivery tube 900, and then withdraw the delivery tube 900 out of the body to be integrally separated from the catheter pump housing structure, at this time, the pump housing 300 and the impeller 220 in the pump housing 300 are not acted by the delivery tube 900, i.e. are respectively unfolded radially at the target position, and return to the initial maximum volume state, and the first cavity 330 is in the maximum volume state at this time.
Specifically, the blood inlet 340 located at the distal end of the pressure relief portion 310 is located in a ventricle, the blood outlet 350 located at the proximal end of the pressure-receiving portion 320 is located in a blood vessel communicating with the ventricle, and the blood in the ventricle flows into the first chamber 330 from the blood inlet 340 and then flows into the blood vessel from the blood outlet 350 by the rotational attraction of the impeller 220. Obviously, the above-mentioned way not only can reduce the operation wound area generated in the whole catheter pump shell structure through the percutaneous operation intervention patient, but also can obtain larger pump blood flow.
Referring back to fig. 1,2 and 3, in the catheter pump housing structure of the embodiment of the present application, since only the proximal end of the pressure-bearing portion 320 is positioned in connection with the supporting seat 100, the impeller 220 is suspended at the distal end of the rotation shaft 210 and surrounded by the pressure-bearing portion 320, and the pressure relief portion 310 integrally abutting the distal end of the pressure-bearing portion 320 is not correspondingly supported and has a certain distance in the axial direction from the impeller 220, if the distal end or the outer wall of the pump housing 300 is subjected to an optional external force, i.e., the distal end and the outer wall of the pressure relief portion 310 and the outer wall of the pressure-bearing portion 320 are subjected to an optional external force, i.e., the distal end and the outer wall of the pressure relief portion 310 collide with the vessel wall, the pressure relief portion 310 at the distal end of the pump housing 300 is preferentially subjected to the external force of the vessel wall. In the present application, since the pressure relief portion 310 is surrounded by the plurality of elastic bending strips 311, the elastic bending strips 311 forming the pressure relief portion 310 are elastically deformed by the external force, so that the whole pressure relief portion 310 can buffer and relieve the external force, thereby effectively avoiding the large deformation of the pressure bearing portion 320 caused by the transmission of the external force to the pressure bearing portion 320, preventing the reduction of the gap between the impeller 220 and the pressure bearing portion 320 in the pressure bearing portion 320, and reducing the probability of mechanical hemolysis and the locking of the impeller 220 on the pressure bearing portion 320 due to the contact with the inner wall of the pressure bearing portion 320.
Meanwhile, in the present application, since the pressure-bearing portion 320 abutting against the pressure relief portion 310 is surrounded by the elastic mesh structure, the pressure-bearing portion 320 has a certain hardness, and can bear a relatively large radial and axial bending torque, when the outer wall of the pressure-bearing portion 320 collides with the vessel wall, the pressure-bearing portion 320 does not substantially deform radially and circumferentially due to its relatively strong strength and bending resistance, the force of the ventricular wall or the vessel wall does not substantially deform the pressure-bearing portion 320, so that the gap between the pressure-bearing portion 320 and the impeller 220 is maintained within a predetermined range, the probability of occurrence of mechanical hemolysis is further reduced, and meanwhile, the stability of the rotation motion of the impeller 220 is also ensured.
Through the above arrangement, compared with the pump case 300 with basically consistent strength of each part in the prior art, the pressure relief part 310 and the pressure bearing part 320 forming the pump case 300 are designed to have different bending strength, namely, the integral bending strength of the pressure relief part 310 is designed to be smaller than that of the pressure bearing part 320, so that the pressure bearing part 320 is ensured not to be deformed greatly under the action of non-forced external force at the distal end of the pump case 300 or the outer wall of the pump case 300, the gap between the inner wall of the pressure bearing part 320 and the impeller 220 is ensured to be maintained in a preset range, the probability of mechanical hemolysis is reduced, and the structural characteristics of the impeller 220 suspended in the pressure bearing part 320 can be well adapted.
Obviously, in the conduit pump housing structure of the embodiment of the present application, by arranging the pump housing 300 as the pressure relief portion 310 and the pressure bearing portion 320 which are integrally formed, by means of the structural characteristics of the pressure relief portion 310 and the pressure bearing portion 320, not only the function that the whole pump housing 300 and the impeller 220 can be automatically unfolded after compression is maintained, so that the conduit pump device can obtain a larger flow, but also the preset gap between the pump housing 300 and the impeller 220 can be ensured to be ensured within a controllable range, the housing supporting requirement of the impeller 220 suspended at the distal end of the rotating shaft 210 is met, and meanwhile, the structural stability of the pump housing 300 and the impeller 220 in the operation process of the human body is ensured, and the occurrence of mechanical hemolysis and mechanical failure is avoided.
Referring to fig. 1,2 and 3 again, in some embodiments of the present application, the elastic bending strips 311 are formed by connecting multiple segments of S-shaped or W-shaped connecting segments in sequence, and two adjacent elastic bending strips 311 are not crossed, by the design of the S-shaped or W-shaped connecting segments, the structure of the elastic bending strips 311 is relatively soft, and meanwhile, the two adjacent elastic bending strips 311 are not crossed, so that the overall structural strength of the pressure relief portion 310 is smaller than that of the pressure bearing portion 320 with a net structure, when the distal end of the pump casing 300 is subjected to an optional external force, the pressure relief portion 310 will preferentially deform greatly, so that most of the acting force is buffered and borne, so that only a small amount of or even no acting force is transmitted to the pressure bearing portion 320 through the pressure relief portion 310, and the larger deformation of the pressure bearing portion 320 is avoided to affect the preset gap between the pressure bearing portion 320 and the impeller 220.
Of course, in other embodiments, the connecting segments that form the elastic bending strip 311 may have other non-closed bending shapes, and is not limited in particular.
Referring to fig. 2 and fig. 3 again, in some embodiments of the present application, the mesh openings 321 are diamond-shaped, and the strength of the whole pressure-bearing portion 320 is improved by using better stability of the diamond shape, so as to further avoid the outer wall of the pressure-bearing portion 320 from being deformed greatly due to an optional external force. Of course, in other embodiments, the net opening 321 of the pressure-bearing portion 320 may be a triangle, a circle, a rectangle, or other closed patterns with good stability, so as to enhance the overall strength of the pressure-bearing portion 320.
Referring again to fig. 3, in some embodiments of the present application, the bearing portion 320 includes a radial bearing portion 322 abutting the pressure relief portion 310 and an axial bearing portion 323 connected to the support base 100, the radial bearing portion 322 is formed in a cage shape by a plurality of first elastic rib envelopes, the axial bearing portion 323 is formed in a cage shape by a plurality of second elastic rib envelopes and abuts the radial bearing portion 322, and the thickness of the second elastic rib is greater than the thickness of the first elastic rib.
The radial bearing portion 322 having a cage shape and the axial bearing portion 323 having a cage shape are butted and integrally formed to form the bearing portion 320 having a cage shape as a whole. It will be appreciated that the outer peripheral wall of the radial pressure-bearing portion 322 has a plurality of openings formed by a plurality of first elastic ribs in a two-to-two crossing arrangement, each opening is covered by a corresponding elastic covering layer 400, so as to ensure the tightness of the radial pressure-bearing portion 322, and each opening is preferably diamond-shaped and has substantially equal size, so as to ensure that the strength of each position of the radial pressure-bearing portion 322 is relatively uniform or even, the impeller 220 is integrally suspended inside the radial pressure-bearing portion 322, and when the outer wall of the radial pressure-bearing portion 322 is subjected to an optional external force, the stronger strength can ensure that the radial deformation of the radial pressure-bearing portion 322 is smaller, so that the gap between the inner wall of the radial pressure-bearing portion 322 and the outer wall of the impeller 220 is controlled within a predetermined range, and further avoid the probability of mechanical hemolysis of blood flowing through the inside of the radial pressure-bearing portion 322, and further avoid the occurrence of undesirable conditions that the impeller 220 collides with the inner wall of the radial pressure-bearing portion 322 and even is jammed on the inner wall of the radial pressure-bearing portion 322.
Similarly, the outer peripheral wall of the axial pressure-bearing portion 323 has a plurality of openings formed by a plurality of second elastic ribs in a two-to-two crossed arrangement mode, each opening is covered by a corresponding elastic covering layer 400, the shape of each opening is preferably diamond-shaped and the size of each opening is basically equal, the size of each opening of the axial pressure-bearing portion 323 is larger than that of each opening of the radial pressure-bearing portion 322, meanwhile, the thickness of the second elastic rib is designed to be larger than that of the first elastic rib, so that the whole axial pressure-bearing portion 323 can bear larger axial bending torque, the outer wall of the axial pressure-bearing portion 323 is subjected to non-forced external force, the radial deformation and the axial deformation of the outer wall of the axial pressure-bearing portion 323 are smaller, the bending deformation resistance of the whole pressure-bearing portion 320 is further enhanced, the gap between the inner wall of the pressure-bearing portion 320 and the outer wall of the impeller 220 is basically in a stable and unchanged state, and mechanical hemolysis of blood flowing through the inside of the pressure-bearing portion 320 is prevented.
Referring to fig. 6, in some embodiments of the present application, the impeller 220 includes a hub 221 coaxially coupled with the rotation shaft 210 and a plurality of elastic blades 222 circumferentially provided to the hub 221. Specifically, the elastic blade 222 may be a spiral blade to improve the blood flow of the pump of the whole catheter pump housing structure, the wheel axle 221 and the elastic blade 222 are integrally formed, and the wheel axle 221 may be sleeved at the distal end of the rotating shaft 210 to realize coaxial connection with the rotating shaft 210, so as to improve the convenience of the overall disassembly and assembly of the impeller 220.
Referring to fig. 1, 4 and 5, in some embodiments of the present application, the support base 100 has a tubular shape, a central axis of the support base 100 coincides with a central axis of the pump case 300, and a proximal end of the pressure-bearing portion 320 is sealingly connected to a peripheral wall of the support base 100.
Specifically, the support base 100 is a support tube with two substantially sealed ends, the rotation shaft 210 may be rotatably disposed at a central axis of the support tube through a transmission bearing, and a distal end of the rotation shaft 210 penetrates out of a distal end of the support tube and further extends into the bearing portion 320 of the pump casing 300, so as to provide a carrier for suspending the impeller 220, and also prevent blood in the first cavity from entering the support tube as much as possible. Meanwhile, by designing the central axis of the support base 100 to coincide with the central axis of the pump casing 300, irregular expansion of the pump casing 300 after forced compression can be avoided, the pump casing 300 is ensured to be expanded into a substantially cage shape or a rugby shape after forced compression, and overall stability of the whole pump casing 300 is improved.
Referring to fig. 1, 6 and 7, in some embodiments of the present application, the catheter pump housing structure of the present application further includes a tail tube 700 connected to the distal end of the pressure relief portion 310 and a guide wire 800 for threading the tail tube 700, the distal end of the guide wire 800 may extend out of the distal end of the tail tube 700, and the proximal end of the guide wire 800 may extend out of the blood suction port 340.
Specifically, in this embodiment, the distal end of the pressure relief portion 310 and the proximal end of the pressure bearing portion 320 have interfaces with smaller inner diameters, the proximal end of the tail tube 700 and the sleeve joint portion, the supporting seat 100 is tubular, the distal end of the supporting seat 100 is also the sleeve joint portion, and when the tail tube 700, the pump housing 300 and the supporting seat 100 are installed and connected, the interfaces of the distal end of the pressure relief portion 310 and the proximal end of the pressure bearing portion 320 can be respectively and hermetically sleeved on the sleeve joint portion of the tail tube 700 and the supporting seat 100, so as to complete the installation and connection of the tail tube 700, the pump housing 300 and the supporting seat 100, thereby enabling the tail tube 700 and the supporting seat 100 to respectively bear and support the distal end and the proximal end of the pump housing 300, ensuring stable and regular expansion after the pump housing 300 is forcedly compressed, and further reducing the probability of mechanical hemolysis occurring in blood flowing through the pump housing 300.
In addition, in the present embodiment, the distal end of the pigtail 700 has a curved section, which plays a role of drainage, so that the blood can quickly enter the first cavity from the blood suction inlet 340 under the power of the impeller 200, and then flows into the blood vessel from the blood outflow port 350.
In addition, referring to fig. 6 again, in the present embodiment, a delivery tube 900 is further included, and the delivery tube 900 is used to sleeve the support base 100 and the pump casing 300, and forcibly compress the pump casing 300 and the impeller 220 into a contracted state.
Referring again to fig. 6, it should be noted that the catheter pump housing structure of the present embodiment of the application may be entirely disposed within a smaller diameter delivery tube 900 prior to insertion into the patient, and the delivery device may be a smaller diameter delivery tube, at which time, the pump housing 300 and the impeller 220 disposed within the pump housing 300 are both forcibly compressed by the delivery tube 900 to be disposed within the delivery tube in a minimum volume compressed state. At this time, the plurality of elastic blades 222 provided along the circumferential direction of the axle 221 are wound around the outer wall of the axle 221 under the forced compression force, and maintain the compression state of the minimum volume. In addition, an opening is provided at the distal outer wall of the delivery tube 900 for the guidewire 800 to pass through.
When the catheter pump housing structure needs to be inserted into the patient, a physician can insert the distal end of the guide wire 800 into the target position in the patient according to a predetermined path, and make the guide wire 800 extend along the path of the blood vessel to extend the proximal end of the guide wire to extend out of the body, and then sleeve the tail tube 700 connected to the distal end of the pressure relief portion 310 on the proximal end of the guide wire 800 and enter the target position along the track of the guide wire 800, so that the tail tube 700 can drive the catheter pump housing structure as a whole to the target position under the guidance of the guide wire 800, and at this time, the proximal end of the guide wire 800 sequentially passes through the guide cavity in the guide hose 500 and the blood suction inlet 340 at the distal end of the pressure relief portion 310 and extends out of the opening of the outer wall of the distal end of the delivery tube 900, thereby completing the precise intervention of the whole catheter pump housing structure. Then, the physician sequentially withdraws the guide wire 800 and the delivery tube 900 from the body, so that the pump housing 300 and the impeller 220 positioned in the pump housing 300 are not forced by the delivery tube 900, i.e. are respectively radially expanded at the target position, the pump housing 300 and the plurality of elastic blades 222 of the wheel shaft 221 are radially expanded to restore to the initial maximum volume state, and the first cavity 330 is also in the maximum volume state at this time, so as to obtain the larger pump blood flow.
It is understood that the present application, through the arrangement of the pigtail 700, the guide wire 800 and the delivery tube 900, not only facilitates the physician to insert the whole catheter pump housing structure into the corresponding blood transfusion organ quickly, but also improves the accuracy of the whole catheter pump housing structure inserted into the corresponding blood transfusion organ, and simultaneously, can effectively reduce the surgical wound area generated in the patient body by the whole catheter pump housing structure through the percutaneous operation, and can obtain the larger pump blood flow. Simultaneously, can guarantee the smoothness of whole pipe pump housing structure introduction in the patient and furthest reduce the operation damage to the patient, can avoid the damage that whole pipe pump housing structure caused to the primary tissue in the position such as vascular stenosis, aortic arch and ventricular valve department betterly.
It can be understood that, when the tail pipe 700 enters the target position along the track of the guide wire 800 and the tail pipe 700 contacts or collides with the vessel wall, the pressure relief portion 310 connected with the tail pipe 700 is preferentially subjected to the acting force transmitted by the tail pipe 700, and the elastic bending strip 311 forming the pressure relief portion 310 is elastically deformed by the acting force, so that the whole pressure relief portion 310 can buffer and relieve the acting force, thereby effectively avoiding the large deformation of the pressure bearing portion 320 caused by the further transmission of the acting force to the pressure bearing portion 320, preventing the gap between the impeller 220 and the pressure bearing portion 320 in the pressure bearing portion 320 from being reduced, and further reducing the probability that the mechanical hemolysis of blood occurs and the impeller 220 is blocked on the pressure bearing portion 320 due to the contact with the inner wall of the pressure bearing portion 320.
Referring additionally to fig. 1, 4 and 5, an embodiment of the present application further provides a catheter pump device comprising a multi-lumen sheath 500 and the catheter pump housing structure described above.
Wherein, supporting seat 100 is the supporting sleeve, the distal end of supporting sleeve is equipped with fills chamber 110, drive assembly 200 is still including locating the interior bearing housing 240 of supporting sleeve and drive bearing 230, rotation axis 210 passes through drive bearing 230 and installs in bearing housing 240, the outer runner 241 with filling chamber 110 intercommunication is seted up to the outer wall of bearing housing 240, the clearance between the inner circle and the outer lane of drive bearing 230 forms the inlayer runner 231 with filling chamber 110 intercommunication, the distal end of multi-chamber sheath 500 is connected in the proximal end of supporting sleeve, inflow passageway 510 and the outflow passageway 520 with inlayer runner 231 intercommunication of outer runner 241 intercommunication have been seted up to multi-chamber sheath 500. It should be noted that the number of the transmission bearings 230 may be one or more, and the specific number is not limited.
According to the catheter pump device provided by the embodiment of the application, the bearing sleeve 240 is arranged in the supporting sleeve, the outer layer runner 241 is arranged on the outer wall of the bearing sleeve 240, meanwhile, the multi-cavity sheath tube 500 with the inflow channel 510 and the outflow channel 520 is arranged, so that when the whole catheter pump device is operated, an operator can pour liquid into the inflow channel 510, the liquid flows into the perfusion cavity 110 at the far end of the supporting sleeve after passing through the inflow channel 510 and the outer layer runner 241, the inner layer runner 231 formed by the gap between the inner ring and the outer ring of the transmission bearing 230 is communicated with the perfusion cavity 110 and the outflow channel 520 in the multi-cavity sheath tube 500 respectively, the liquid in the perfusion cavity 110 continuously flows through the inner layer runner 231 and the outflow channel 520 and finally flows out from the outlet of the outflow channel 520, and insoluble particles generated when the rotating shaft 210 and the transmission bearing 230 do synchronous high-speed rotation movement can be effectively discharged in the flowing mode, so that the insoluble particles are prevented from entering human blood and endangering human bodies.
Meanwhile, in the circulating flow process of the liquid along the flow path, heat exchange can be continuously performed with the rotating shaft 210 and the transmission bearing 230, so that heat generated in the high-speed rotation process of the rotating shaft 210 and the transmission bearing 230 is timely discharged, structural damage of the rotating shaft 210 and the transmission bearing 230 caused by overheating is avoided, the rotation operation function of the impeller 220 suspended at the far end of the rotating shaft 210 is ensured, and the normal and stable blood pumping function of the whole catheter pump device is further ensured.
In addition, referring again to fig. 5, in some embodiments of the present application, the outer layer flow channel 241, the inflow channel 510 and the outflow channel 520 are all ring-shaped, thereby adapting to the cylindrical shape of the driving bearing 230 and the ring-shaped inner layer flow channel 231 formed by the inner ring and the outer ring of the driving bearing 230, so that the perfusate can more comprehensively carry insoluble particles and heat generated when the rotation shaft 210 and the driving bearing 230 perform the synchronous high speed rotation motion out of the body.
In addition, referring again to fig. 5, in some embodiments of the present application, a mounting cavity is further formed in the middle of the multi-lumen sheath 500, and the proximal end of the rotation shaft 210 is connected to the driving member through a transmission wringing wire 250, and the transmission wringing wire 250 is disposed in the mounting cavity.
Specifically, the multi-cavity sheath 500 includes an inner sheath and an outer sheath that are nested, the distal ends of the inner sheath and the outer sheath are embedded on the inner wall of the proximal end of the supporting sleeve, so as to realize the butt-joint assembly of the whole multi-cavity sheath 500, the middle cavity of the inner sheath forms an installation cavity for the transmission twisted wire 250 to penetrate, the rotating shaft 210 can be connected with a driving piece located outside the body through the transmission twisted wire 250, and the driving piece can be a motor or a motor and other rotary driving piece, so as to provide rotary power for the rotating shaft 210 and the impeller 220.
In addition, the outflow channel 520 is annularly arranged on the inner wall or the outer wall of the inner sheath, and the inflow channel 510 is annularly arranged on the inner wall or the outer wall of the outer sheath, so as to ensure that the outflow channel 520 and the outflow channel 520 are respectively in annular butt joint with the outer layer runner 241 and the inner layer runner 231, and insoluble particles and heat generated when the rotating shaft 210 and the transmission bearing 230 do synchronous high-speed rotating motion can be quickly carried out by the poured liquid.
In addition, referring to fig. 7, in some embodiments of the present application, the catheter pump device further includes a flexible tube 600, the flexible tube 600 is disposed on the outer wall of the pressure-bearing portion 320 and covers the blood outflow port 350, at least one outflow window 610 is opened on the outer wall of the flexible tube 600, a cavity of the flexible tube 600 forms a circulation chamber 620 communicating with the blood outflow port 350 and the outflow window 610, and the flexible tube 600 is configured as an elastic hose structure with expandable and contractible outer wall. Of course, the flexible tube 600 may also be attached to the outer wall of the pressure relief portion 310. In addition, in this embodiment, the distal end of the flexible tube 600 is connected with the outer wall of the pressure-bearing portion 320 in a sealing manner, and the proximal end of the flexible tube 600 is connected with the outer wall of the multi-cavity sheath tube 500 in a sealing manner, so that the support sleeve and the multi-cavity sheath tube 500 are axially inserted into the cavity of the flexible tube 600, and the pressure-bearing portion 320 and the multi-cavity sheath tube 500 simultaneously support and bear the flexible tube 600, thereby ensuring that the flexible tube 600 is stably expanded or contracted.
Referring to fig. 7 and 8, in use, a physician may insert the entire catheter pump device into a patient by percutaneous surgery and by means of the carrier action of delivery tube 900, such that the entire catheter pump device is entirely across heart valve 30, and such that pump housing 300 and impeller 220 are both in the expanded state within patient's ventricle 20, such that blood intake 340 at the distal end of pressure relief portion 310 communicates with ventricle 20, while flexible tube 600 is positioned across heart valve 30 between ventricle 20 and vessel 10 communicating with ventricle 20, such that outflow window 610 on flexible tube 600 communicates with vessel 10, and such that heart valve 30 of the patient only contacts the outer wall of flexible tube 600.
When the whole catheter pump device is operated, the rotation shaft 210 drives the impeller 220 to rotate, blood in the ventricle 20 continuously enters the first cavity 330 of the pump housing 300 from the blood suction inlet 340 under the dynamic action of the impeller 220, flows into the circulation cavity 620 formed by the cavity of the flexible tube 600 through the blood outflow port 350, and finally flows into the blood vessel 10 from the outflow window 610, so that the blood delivery is completed.
In the above-mentioned blood conveying process, the flexible tube 600 is beneficial to the structural characteristic that the flexible tube 600 is an elastic tube, after the blood continuously enters the circulation cavity 620, the volume of the flexible tube 600 is continuously expanded and increased, when the volume of the flexible tube 600 is expanded to the maximum state, the flexible tube 600 is in the filling state, the caliber of the outflow window 610 opened on the flexible tube 600 is synchronously expanded to the maximum, at this time, the blood flow flowing through the circulation cavity 620 and the blood flow flowing into the blood vessel 10 from the outflow window 610 reach the maximum, and the blood flow conveyed into the blood vessel 10 by the whole catheter pump device is greatly increased under the condition that the rotation speed of the impeller 220 is not changed.
When the heart valve 30 is closed, the valve leaflets of the heart valve 30 are mutually coapted, so that the outer wall of the flexible tube 600 is extruded, the flexible tube 600 is contracted along the coaptation straight line of the valve leaflets, the caliber of the circulation cavity 620 is greatly reduced, and even the circulation cavity 620 is completely closed, so that blood cannot flow into the blood vessel 10; when the heart valve 30 is opened, the flexible tube 600 is then expanded to a maximum state under the pressure of the blood, and the blood flow again flows into the blood vessel 10 at a maximum flow rate. As the patient's heart valve 30 continues to open and close, the flexible tube 600 expands and contracts simultaneously, producing pulsatile or pulsatile flow output that is tailored to the diastolic and systolic characteristics of the patient's heart, improving coronary and distal organ perfusion while reducing cardiac burden, facilitating intraoperative patient physical stabilization and postoperative rehabilitation.
It should be noted that, in the above description, the ventricle 20 may correspond to a left ventricle or a right ventricle of the patient, the blood vessel 10 corresponds to an aorta communicating with the left ventricle or a pulmonary artery communicating with the right ventricle, and the corresponding heart valve 30 corresponds to an aortic valve between the left ventricle and the aorta or a pulmonary valve between the right ventricle and the pulmonary artery. Of course, the application of the catheter pump device is not limited to the left ventricle, the aorta, the right ventricle and the pulmonary artery, and the catheter pump device can be applied to other tissues and organs of a human body to play a role in assisting blood pumping.
According to the catheter pump device provided by the embodiment of the application, the flexible tube 600 is arranged on the pump shell 300, the flexible tube 600 is configured into the elastic hose structure with the expandable and contractible outer wall, meanwhile, the flexible tube 600 is skillfully arranged on the pump shell 300, the expandable and contractible structural characteristics of the flexible tube 600 are utilized, the pump shell 300 and the impeller 220 are positioned in the ventricle 20 in an unfolding state, the blood flow pumped into the blood vessel 10 is greatly increased on the premise of not changing the rotating speed of the impeller 200, and the flexible tube 600 is synchronously expanded and contracted under the opening and closing actions of the heart valve 30, so that the whole catheter pump device generates pulsating blood flow or pulsating blood flow output which is matched with the diastole and contractile characteristics of the heart of a patient, the heart burden is lightened while the perfusion of coronary artery and a distal organ is improved, and the stability of the patient in operation and postoperative rehabilitation are facilitated.
In addition, by utilizing the expandable and contractible structural characteristics of the flexible tube 600, the flexible tube 600 is in an initial contracted state before being inserted into the patient, at this time, the inner diameter and the volume of the flexible tube 600 are in a minimum state, and a doctor inserts the flexible tube 600 in this state into the heart valve 30 of the patient through percutaneous operation, so that the operation wound area can be reduced to the greatest extent, and simultaneously, the pump blood flow of the whole catheter pump device under the same operation wound area can be improved.
Referring to fig. 9, in some embodiments of the present application, the pump housing 300, the support sleeve, the multi-cavity sheath 500 connected to the proximal end of the support base 100, and the flexible tube 600 having both ends respectively connected to the outer wall of the pump housing 300 and the outer wall of the multi-cavity sheath 500 in a sealing manner are overlapped, and it should be noted that the multi-cavity sheath 500 is a flexible bendable structure, does not cause structural damage to the corresponding blood vessel or blood transfusion organ, and can well adapt to the bending or spiral shape of the corresponding blood line.
In this embodiment, the flexible tube 600 includes a straight line interface section, a rounded corner section, an arc transition section, a middle straight line section and a guiding section which are sequentially and smoothly connected, and the arc transition section is tangent to the middle straight line section, so that the outline of the outer wall of the whole flexible tube 600 is integrally and smoothly transited. The outflow windows 610 are provided in plurality and are circumferentially spaced apart on the outer wall of the lead-out section. It will be appreciated that the distal end of the flexible tube 600 is sealingly connected to the outer wall of the pressure-receiving portion 320, i.e. via the straight interface section, and thus will cover the blood outflow port 350, and the proximal end of the flexible tube 600 is sealingly connected to the outer wall of the multi-lumen sheath 500, i.e. via the lead-out section.
It will be appreciated that in this embodiment, the inner diameter of the rounded segment and the inner diameter of the arcuate transition segment both gradually increase along the distal end to the proximal end, the inner diameter of the rounded segment being greater than the inner diameter of the straight interface segment, the inner diameter of the arcuate transition segment being greater than the inner diameter of the rounded segment.
Referring again to fig. 9, in this embodiment, the diameter of the straight interface section is D1, D1 being determined by the maximum radial dimension of the pump casing 300 that allows radial deployment. The diameter of the middle straight line segment is D2, and D2 is determined by the diameter of the blood vessel of the patient. The pump case 300 allows radial extension deformation to have an axial length L1. The sum of the axial lengths of the straight line interface section, the round angle section and the circular arc transition section is L2. The angle between the line between the midpoint of the main boundary of the straight line interface section and the midpoint of the main boundary of the middle straight line section and the center axis of the pump casing 300 is alpha. The radius of the circle where the round angle section is positioned is R1, and the radius of the circle where the circular arc transition section is positioned is R2. In this embodiment, the value of R1 ranges from 0 to L1/tan (α/2), the value of R2 ranges from 0 to (D2-D1)/(2 tan (α/2) sin (α)), and the value of L2 ranges from (D2-D1)/(2 tan (α)).
It should be noted that, the R1 is too small, which indicates that the overall contour of the rounded section is curved, which easily causes the blood flowing through the rounded section to generate a vortex, which affects the stability of the blood flow and causes hemolysis injury; similarly, too small R2 value can easily cause the occurrence of flow-off vortex in the blood flowing through the arc transition section, so that the stability of the blood flow is affected and hemolysis injury is caused; meanwhile, the larger the value of α, the larger the difference between the diameter of the straight line interface section and the diameter of the middle straight line section, which means that the larger the overall radial dimension variation of the flow chamber 620 formed by the lumen of the flexible tube 600, the larger the overall radial dimension variation of the flow chamber 620, the more likely the blood flowing through the flow chamber 620 will be to have a vortex, which affects the stability of blood flow and causes hemolysis damage.
Referring to fig. 10 and 11, fig. 10 is a blood flow chart of the flow through the flow chamber 620 obtained by simulation software when the α value is 0; fig. 11 is a diagram of the blood flow through the flow chamber 620, as simulated by the simulation software, when the α value is 12 °. It is not difficult to find that when α has a value of 0, that is, the flexible tube 600 is similar to a long straight tube as a whole, the blood flow line in the flow chamber 620 is smooth, and no vortex phenomenon of current shedding occurs basically; when α is 12 °, the vortex phenomenon of the blood flowing through the flow chamber 620 is more obvious, which indicates that in this case, the blood flowing through the flow chamber 620 is unstable and is prone to hemolysis damage.
Therefore, in order to ensure that the flow lumen 620 formed by the entire flexible tube 600 can be normally expanded under the impact of blood, so as to increase the flow rate of the blood pumped by the entire catheter pump device, and at the same time, to reduce the probability of occurrence of a vortex shedding in the blood flowing through the flow lumen 620 as much as possible, in a preferred embodiment, the value of L2 is (D2-D1)/(2×tan (α)), where the value of R1 is L1/tan (α/2), and the value of R2 is (D2-D1)/(2×tan (α/2) ×sin (α)). According to the results of the simulation calculation and the experimental test, in the present preferred embodiment, when the shapes and dimensions of the straight line interface section, the rounded corner section, the circular arc transition section, and the middle straight line section of the flexible tube 600 satisfy the above conditions and parameters, not only the flexible tube 600 can be stably expanded to perform the function of increasing the pump blood flow of the catheter pump device, but also the blood flowing through the circulation cavity 620 formed by the cavity of the flexible tube 600 is least prone to occurrence of a stall vortex, and the occurrence of a hemolysis injury is avoided.
Although the present application is not limited to the embodiments, those skilled in the art will readily appreciate that various modifications and substitutions are possible, and these are within the scope of the embodiments disclosed herein. Therefore, the protection scope of the embodiments of the present application shall be subject to the protection scope of the claims.