CN113457006B

CN113457006B - Foldable impeller and blood pump

Info

Publication number: CN113457006B
Application number: CN202110734123.8A
Authority: CN
Inventors: 徐博翎; 张家良; 颜翊凡; 徐嘉颢
Original assignee: Magassist Inc
Current assignee: Xinqing Medical Suzhou Co ltd
Priority date: 2021-06-30
Filing date: 2021-06-30
Publication date: 2023-03-17
Anticipated expiration: 2041-06-30
Also published as: WO2023273506A1; CN113457006A

Abstract

A foldable impeller and blood pump are provided, the foldable impeller comprising: a hub (12); at least one blade (10), each blade includes at least two frames (11), frame (11) is long-strip, in order to encircle in the heliciform around the periphery of wheel hub (12), at least one end of frame (11) can be followed the axial of wheel hub (12) is slided. Therefore, the foldable impeller and the blood pump with the foldable impeller are high in reliability, high in impeller folding efficiency and small in size after being folded.

Description

Foldable impeller and blood pump

Technical Field

The invention relates to the field of medical instruments, in particular to a foldable impeller for an interventional blood pump and a blood pump with the foldable impeller.

Background

At present, ventricular assist devices (hereinafter, referred to as blood pumps) are widely used for assisting patients suffering from heart failure in circulating blood of the heart. Most commonly, left ventricular assist devices are adapted to the defective heart in order to assist left ventricular function. In addition, pumps for pumping blood from the vena cava and/or right atrium into the right ventricle, from the vena cava and/or right atrium into the pulmonary artery, and/or from the renal vein into the vena cava may also be adapted and configured for placement within the subclavian or jugular vein at the junction of the vein and lymphatic catheter, and for increasing the flow of lymphatic fluid from the lymphatic vessel to the vein.

The blood pump comprises a pump head and a driving component connected with the pump head, the impeller is an important component of the pump head, has a folding state and an unfolding state, is folded in the process of intervention or taking out, and is unfolded after the intervention is in place, so that the intervention size is reduced, and the injury to blood vessels or corresponding organs is prevented.

The overall external dimensions of the pump head and the dimensions of the impeller and the corresponding structures directly affect the overall dimensions of the pump head and the dimensions after folding, and therefore, how to reduce the dimensions of the impeller, especially the dimensions after folding, has been the subject of constant research by those skilled in the art.

Disclosure of Invention

The invention provides a foldable impeller with high reliability and small folding size and a blood pump with the same.

The foldable impeller according to the invention comprises: a hub; the blade comprises at least two frames, the frames are long-strip-shaped and spirally surround the periphery of the hub, and at least one end of each frame can slide along the axial direction of the hub.

According to the foldable impeller of the present invention, the blades are configured to switch from the folded state to the unfolded state when the two ends of the frame are moved axially towards each other, and to switch from the unfolded state to the folded state when the two ends of the frame are moved axially away from each other.

According to the foldable impeller of the present invention, the at least two frames are arranged in sequence substantially in a radial direction of the hub.

According to the foldable impeller, at least one end of the frame is fixedly connected with a sliding sleeve, and the sliding sleeve is slidably sleeved on the hub.

According to the foldable impeller, one end of the frame is fixed, and the other end of the frame can slide; alternatively, both ends of the frame may be slidable. According to the foldable impeller, the number of the sliding sleeves is one, the first end of the frame is fixedly connected to the hub, and the second end of the frame is fixedly connected to the sliding sleeves; or the number of the sliding sleeves is two, and the first end and the second end of the frame are respectively fixedly connected to the two sliding sleeves.

According to the foldable impeller of the present invention, the sliding sleeve has a degree of freedom that is slidable in the axial direction of the hub and rotatable in the circumferential direction of the hub, and the rotation of the sliding sleeve in the circumferential direction of the hub is restricted in the unfolded state of the blade.

According to the foldable impeller of the present invention, when the number of the sliding sleeves is one, the first ends of the at least two frames are adjacently or spacedly arranged around the circumference of the hub, and the second ends are adjacently or spacedly arranged around the circumference of the sliding sleeves, or, when the number of the sliding sleeves is two, the first ends and the second ends of the at least two frames are adjacently or spacedly arranged around the circumference of the sliding sleeves, respectively, and the portions of the at least two frames between the first ends and the second ends extend from the first ends to the second ends along substantially the same direction, and can form a helicoid surface which is substantially perpendicular or inclined with respect to the outer surface of the hub.

According to the foldable impeller, the hub is provided with a first hub section and a second hub section with the diameter larger than that of the first hub section, a limiting step is formed at the joint of the first hub section and the second hub section, and the sliding sleeve is sleeved on at least one first hub section.

According to the foldable impeller of the present invention, when the number of the sliding sleeves is one, the second end of the frame is sleeved on the first hub section through the sliding sleeve, and the first end of the frame is fixedly connected to the second hub section, or when the number of the sliding sleeves is two, the hub has two first hub sections, the two first hub sections axially clamp the second hub section, the second end of the frame is sleeved on one of the first hub sections through the sliding sleeve, and the first end of the frame is sleeved on the other of the first hub sections through the other of the sliding sleeves.

According to the foldable impeller of the present invention, the sliding sleeve can move in a manner of rotating around the first hub section while moving in the axial direction of the first hub section, so as to have a first limit position close to the second hub section where the sliding sleeve can abut against the limit step and a second limit position away from the second hub section where the frame can be attached to the outer circumferential surface of the hub.

According to the foldable impeller of the invention, the outer surface of the sliding sleeve is provided with a groove extending along the axial direction of the hub, when the number of the sliding sleeves is one, the second end of the frame is embedded in the groove, the radial outer surface of the frame is flush with the outer surface of the sliding sleeve, or when the number of the sliding sleeves is two, the first end and the second end of the frame are respectively embedded in the grooves of the two sliding sleeves, and the radial outer surface of the frame is flush with the outer surface of the sliding sleeve.

According to the foldable impeller, the sliding sleeve is cylindrical, the radial outer surface of the sliding sleeve is flush with the radial outer surface of the second hub section, or the sliding sleeve is in a frustum shape, the radial size of the sliding sleeve is gradually reduced from one end facing the limiting step to the end away from the limiting step, and the radial outer surface of one end of the sliding sleeve facing the limiting step is flush with the radial outer surface of the second hub section.

According to the foldable impeller, the foldable impeller further comprises a bearing arranged opposite to the sliding sleeve, the bearing is a far-end bearing or a near-end bearing, the far-end bearing is sleeved on the hub and is close to the second end of the frame, the near-end bearing is sleeved on the hub and is close to the first end of the frame, the foldable impeller further comprises an actuating piece, the actuating piece is located between the sliding sleeve and the bearing opposite to the sliding sleeve, and the actuating piece can apply force to the sliding sleeve, so that the sliding sleeve can press the frame.

According to the foldable impeller of the present invention, the actuating member is a spring, and the spring is provided between the sliding sleeve and the bearing so as to rotate with or without the hub.

According to the foldable impeller, one end of the spring is fixedly connected to the bearing inner ring of the bearing, and the other end of the spring is fixedly connected to the sliding sleeve; or one end of the spring is fixedly connected with the bearing outer ring of the bearing, and the other end of the spring abuts against the end face, facing the bearing, of the sliding sleeve.

According to the foldable impeller of the present invention, the sliding sleeve is a sliding bearing including a sliding bearing inner ring and a sliding bearing outer ring disposed outside the sliding bearing inner ring, an end portion of the frame is connected to one of the sliding bearing inner ring and the sliding bearing outer ring, one end of the spring is connected to the other of the sliding bearing inner ring and the sliding bearing outer ring, and the other end of the spring is connected to a bearing outer ring of the bearing; or an end of the frame is connected to one of the slide bearing inner ring and the slide bearing outer ring, one end of the spring is connected to the other of the slide bearing inner ring and the slide bearing outer ring, and the other end of the spring is connected to the bearing inner ring of the bearing.

According to the foldable impeller of the invention, the actuating member is a pair of magnets facing with opposite magnetic poles, one of the magnets is fixedly arranged on the sliding sleeve, and the other magnet is fixedly arranged on the bearing.

According to the foldable impeller, the actuating element is at least two elastic wires, one end of each elastic wire is fixedly connected to the proximal end bearing, and the other end of each elastic wire is fixedly connected to the sliding sleeve.

According to the foldable impeller of the invention, one of the outer wall of the first hub section and the inner side wall of the sliding sleeve is provided with a spiral guide protrusion, and the other of the outer wall of the first hub section and the inner side wall of the sliding sleeve is provided with a guide groove matched with the spiral guide protrusion.

According to the foldable impeller, one of the end surface of the sliding sleeve facing the limiting step and the limiting step is provided with the limiting pin, the other one of the end surface of the sliding sleeve facing the limiting step and the limiting step is provided with the limiting groove matched with the limiting pin, and when the sliding sleeve abuts against the limiting step, the limiting pin is inserted into the limiting groove.

According to the foldable impeller of the invention, the foldable impeller further comprises a pump sheath, the pump sheath comprises an outer support and a film laid on the outer support, the at least one blade and the sliding sleeve are both arranged in the outer support, a first magnetic element is arranged on the radially outermost side of the at least one blade, a second magnetic element is arranged on the inner surface of the outer support at the corresponding position, and the polarity of the first magnetic element is opposite to that of the second magnetic element.

According to the foldable impeller of the present invention, the frame is configured to provide the blades with sufficient strength against a fluid back pressure applied thereto by blood in an operating state of the impeller, so that the blades are not deformed against a rotational direction.

According to the foldable impeller of the present invention, the frame comprises: a front edge portion capable of forming a slope with gradually increasing potential energy away from the hub from the second end; a rear edge portion capable of forming a slope with gradually increasing potential energy away from the hub from the first end; and a main body portion that is connected between the leading edge portion and the trailing edge portion so as to be spirally wound around an outer periphery of the hub, wherein the main body portion has a length that is greater than a length of the leading edge portion or the trailing edge portion, and an angle a formed by an extending direction of the leading edge portion and a radial direction of the hub is greater than an angle B formed by an extending direction of the trailing edge portion and the radial direction of the hub.

According to the foldable impeller of the invention, the frame has a weakened portion formed on a partial region, the weakened portion deforming ahead of other regions during folding of the frame.

According to the foldable impeller of the invention, the weakening comprises a hole, a groove, a flexible material connecting two adjacent areas, a cut breaking the frame and being sewn.

The blood pump according to the invention comprises: a motor; one end of the flexible shaft is connected with an output shaft of the motor; the guide pipe is sleeved on the periphery of the flexible shaft and is connected to the motor through a coupling part; and the hub of the foldable impeller is connected to the other end of the flexible shaft.

Technical effects

According to the present application of the above configuration, since the blade of the present application includes at least two spiral frames, the blade can be formed by supporting the film only by the spiral frames without requiring radial frames. With this configuration, the blade can be folded into a more compact form and further attached to the hub. Meanwhile, because the radial frame is not arranged and only the spiral frame is arranged, the blades are smoother, blood drainage is facilitated, and better fluid performance is realized.

The helical frame comprises a front edge part which can gradually depart from the hub from the second end to form a slope with gradually increasing potential energy and a rear edge part which can gradually depart from the hub from the first end to form a slope with gradually increasing potential energy, so that the folding compliance of the impeller is very good.

Due to the adoption of the reducing shaft-shaped hub 12, the hub does not generate axial material deformation in the process of unfolding and folding the impeller, the conditions of stress fatigue and stress limit of the material caused by repeated stretching are avoided, the unfolding of the impeller is realized only by the memory characteristic of the frame memory alloy and is not realized by means of external force, and the reliability of the product is high. Meanwhile, the shaft-shaped hub has a relatively regular shape, so that the diameter of the shaft-shaped hub can be small.

Since the free end of the frame of the impeller of the blood pump is connected to the hub via the sliding sleeve, and can rotate around the hub and move along the hub, during the folding process, the frame of the spiral structure is forced to be compressed and stored, axial torque exists, the sliding sleeve can be easily driven by the frame of the spiral structure, and the frame moves along the hub and rotates around the hub to be attached to the outer surface of the hub. Therefore, the folding stroke is shorter, and the folding of the impeller can be completed quickly.

Because the external diameter of the sliding sleeve at least close to one side of the second hub section is equal to the external diameter of the second hub section 20, the sliding sleeve and the proximal section of the hub are in smooth transition, and the hydraulic effect is improved.

Preferably, the sliding sleeve is cylindrical, and the outer diameter of the sliding sleeve is the same as that of the second hub section, so that the outer diameter of the hub is kept unchanged, a protruding or groove structure is prevented from being formed on the outer wall of the hub, and hemolysis or thrombus is reduced or even avoided.

Because the surface of sliding sleeve is provided with the edge the axially extended recess of wheel hub, the second end embedding of frame in the recess, the radial surface of frame with the surface parallel and level of sliding sleeve, so the design is inlayed with sliding sleeve 13 to the free end of frame 11, avoids both junctions to form the arch, avoids the destruction to blood cell.

Because the impeller is also provided with an actuating piece, the actuating piece applies force to the direction of enabling the sliding sleeve to abut against the step, the sliding sleeve can reach the proximal end limit position more quickly, and the impeller can be unfolded more quickly.

One of the end surface of the sliding sleeve facing the limiting step and the limiting step is provided with a limiting pin, the other one of the end surface of the sliding sleeve facing the limiting step and the limiting step is provided with a limiting groove matched with the limiting pin, and when the sliding sleeve is located at the first limit position, the limiting pin is inserted into the limiting groove, so that when the impeller is in a spreading state to pump blood, the sliding sleeve cannot leave the near-end limit position due to the rotation of the blade during working, and the reliability of the blade during working is improved.

Because the first hub section is provided with the spiral guide protrusion, and the inner side wall of the sliding sleeve is provided with the guide groove matched with the spiral guide protrusion, the sliding sleeve can more reliably rotate and move to reach the expected position.

The impeller effectively pumps blood from the left ventricle of the patient into the aorta of the patient due to the clearance formed between the outer stent and the leaflets formed by the frame.

Optionally, the radially outermost surfaces of the blades of the impeller are coated with magnetic elements and the inner surfaces of the corresponding locations of the outer stent are coated with magnetically repulsive thin films, thereby maintaining a gap between the blades of the impeller and the outer stent for the impeller to more effectively pump blood from the left ventricle of the patient into the aorta of the patient.

Drawings

The above and/or other objects and advantages of the present invention will become more apparent from the following description of the embodiments taken in conjunction with the accompanying drawings, in which:

fig. 1 is a schematic perspective view illustrating a blood pump according to an embodiment of the present invention.

Fig. 2 is a schematic perspective view illustrating a blood pump according to an embodiment of the present invention in a state in which a pump sheath is removed.

Fig. 3 is an enlarged partial perspective view of a blood pump according to an embodiment of the present invention.

Fig. 4 is a partial side schematic view illustrating a blood pump according to an embodiment of the present invention.

Fig. 5 is a perspective view illustrating an impeller according to an embodiment of the present invention.

Fig. 6 is a side view illustrating an impeller according to an embodiment of the present invention.

Fig. 7 is a perspective view illustrating a hub according to an embodiment of the present invention.

Fig. 8 is a perspective view illustrating an impeller according to an embodiment of the present invention in a deployed state.

Fig. 9A and 9B are side views showing an embodiment in which the actuating member in the impeller according to the embodiment of the present invention is a spring.

Fig. 10A and 10B are side views showing an embodiment in which the actuating member in the impeller according to the embodiment of the present invention is a magnet.

Description of the reference numerals

100 blood pumps; 1, a motor; 2 a coupling member; 4, a conduit; 5 pump sheath; 6 protecting the head; 7 a blood inlet; 8, a blood outlet; 9, an impeller; 10 blades; 11 a frame; 12, a hub; 13, a sliding sleeve; 14 fixed ends; 15 a front edge portion; 16 a main body portion; 17 rear edge portion; 18 a free end; 19 a first hub section; 20. a second hub section; 21, steps; 22 an outer bracket; 23 rigid struts; 24 a distal end face; 25 a proximal end face; 26 grooves; 27 limiting grooves; 28, a limiting pin; 29 an actuator; 291 a spring; 292 magnets; 30 a guide projection; 31 a distal bearing; 32 proximal end bearing

Detailed Description

Reference will now be made in detail to the exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like parts. The embodiments are described below in order to explain the present invention by referring to the figures. The invention provides a foldable impeller suitable for an in vivo interventional blood pump and a blood pump with the foldable impeller. In the following description of the embodiments, the foldable impeller and the blood pump of the present invention are described by way of example of applying the blood pump between the left ventricle and the aorta, but the solution of the present invention is not limited thereto.

< construction of blood pump 100 >

As shown in fig. 1 and 2, the blood pump 100 includes a motor 1, a drive shaft, a pump head connected to the drive shaft, and a protective head 6 connected to a front end of the pump head. The drive shaft may be connected to the output shaft of the motor 1 by means of a coupling member 2. In some alternative embodiments, the way in which the coupling part 2 transfers power may be magnetic coupling. Specifically, the coupling member 2 includes an active magnet connected to the output shaft of the motor 1 and a passive magnet connected to the proximal end of the drive shaft, which are housed in an active housing and a passive housing, respectively. The driving and driven housings are engaged together by means of a locking element (e.g. a screw thread) so that the driving and driven magnets are magnetically coupled to transmit the rotation of the motor 1 to the drive shaft, which in turn rotates the impeller 9 of the pump.

As shown in fig. 3 and 4, the pump head may include a pump sheath 5 and a foldable impeller 9 (hereinafter, simply referred to as the impeller 9) provided in the pump sheath 5. The motor 1 performs a blood pumping function by driving the impeller 9 in the pump head to rotate via the drive shaft. The drive shaft may be a flexible shaft, which may be built into the catheter 4 in order to avoid damage to the blood vessels or blood caused by rotation of the drive shaft. One end of the conduit 4 may be connected to the motor 1 via a coupling member 2, the conduit 4 remaining stationary during rotation of the flexible shaft driven by the motor 1.

The protective head 6 is configured to be soft so as not to injure the organ tissue of the patient, and the protective head 6 may be made of any material that macroscopically exhibits flexibility. Specifically, the protective head 6 is a flexible protrusion (Pigtail or Tip member) having an arc-shaped or winding end, and the flexible end is supported on the inner wall of the ventricle in a non-invasive or non-destructive manner to separate the suction port of the pump sheath 5 from the inner wall of the ventricle, so that the suction port of the pump sheath 5 is prevented from being attached to the inner wall of the ventricle due to the reaction force of the fluid (blood) during the operation of the blood pump 100, and the effective pumping area is ensured.

In the following description, the side closer to the protection head 6 is referred to as a distal end side (distal side), and the side closer to the motor 1 is referred to as a proximal end side (proximal side).

A pump sheath 5 is provided at the end of the catheter 4 adjacent the guard head 6 and an impeller 9 is provided in a receiving cavity formed by the pump sheath 5. In the present embodiment, the impeller 9 is provided on the distal end side of the pump sheath 5. The specific structure of the impeller 9 will be described in detail later. A plurality of blood inlets 7 are provided on the distal end side of the pump sheath 5, and a plurality of blood outlets 8 are provided on the proximal end side. During operation of the impeller, blood enters the pump sheath 5 from the left ventricle via the plurality of blood inlets 7, through rotation of the impeller 9, and into the aorta via the plurality of blood outlets 8.

In an alternative embodiment, the pump sheath 5 is configured to be collapsible, comprising a stent substantially in a metal lattice design and a flexible covering the stent. The stent has a mesh, and a proximal end of the flexible covering is fixed to the catheter 4, and a distal end is fixed to an outer stent 22 described later, but a distal end of the outer stent 22 is exposed. In this way, the mesh of the area of the distal end of the external support 22 not covered by the coating constitutes the actual blood inlet 7, while the opening provided on the proximal end of the coating forms said blood outlet 8.

In this embodiment, the pump sheath 5 of the blood pump 100 is passed through the aortic valve of the patient such that the distal end of the pump sheath 5 is disposed in the left ventricle of the patient and the proximal end of the pump sheath 5 is disposed in the aorta of the patient. During operation of the blood pump 100, a pressure inside the pump is established which is greater than the pressure inside the aorta, so that blood can be pumped out of the blood outlet 8 of the blood pump 100 into the aorta.

< construction of impeller 9 >

The impeller 9 according to the embodiment of the present invention is explained in detail based on fig. 2 to 10.

As shown in fig. 2, the impeller 9 is built into the distal end of the pump sheath 5. The impeller 9 may comprise: hub 12, slidable cover establish the sliding sleeve 13 on hub 12 to and set up at least one blade 10 on hub 12 periphery, every blade 10 includes two piece at least frames 11, the first end 14 (near-end) fixed connection of frame 11 is in on hub 12, the second end 18 (distal end) fixed connection of frame 11 is in on the sliding sleeve 13, frame 11 is rectangular form to around with the heliciform the periphery of hub 12. The sliding sleeve 13 can slide on the hub 12 so that the impeller 9 has a collapsed state and an expanded state.

The pump sheath 5 may be formed of an outer support 22 surrounding the outer periphery of the vane 10 and a coating film laid on the outer support 22. Each of the components is described below.

In the present specification, "substantially" or "substantially" may be understood as being close to, approximate to, or within a predetermined range from a target value. By way of example, the outer support 22 assumes a substantially circular, elliptical or polygonal cross-sectional shape in the absence of any force applied to the pump sheath 5, it being understood that the outer support 22 assumes a cross-sectional shape that approximates (approximates) a circle, ellipse or polygon in the absence of any force applied to the pump sheath 5. Similarly, the blade 10 can form a helicoid that is substantially perpendicular to the outer surface of the hub 12. It is understood that the angle between the helicoid and the outer surface of the hub 12 is between 85 ° and 95 °. Meanwhile, the plurality of spiral frames 11 extend from the fixed end to the free end along substantially the same direction, and it is understood that the plurality of spiral frames 11 extend from the fixed end to the free end with an approximate tendency. The above examples of the difference are merely illustrative and are not limited thereto in practice.

In the present specification, the distal end refers to a side close to a human organ in an interventional medical device, and the proximal end refers to a side far from the human organ. "axial" refers to the direction of extension of the shaft, and "radial" refers to the direction perpendicular to the direction of extension of the shaft, i.e., the radial direction of the shaft.

It should be noted that the definitions of the directions in the present specification are only for convenience of describing the technical solution of the present invention, and do not limit the directions of the foldable impeller 9 of the embodiment of the present invention in other scenarios, including but not limited to use, product testing, transportation, manufacturing, etc., which may cause the foldable impeller 9 to be inverted or to change its position.

In the present specification, the "collapsed state" refers to a state in which the impeller 9 is radially constrained, that is, a state in which the impeller 9 is compressed and collapsed to a minimum radial dimension toward the hub 12 by an external pressure. The "developed state" refers to a state in which the impeller 9 is not radially constrained, that is, a state in which the impeller 9 is developed to the maximum radial dimension radially outward of the hub 12.

In addition, in the present specification, "attached" means that the two are in close or very close to each other or even in contact with each other in positional relationship. For example, the frame 11 is adhered to the outer surface of the hub 12 and in a radially constrained state, which is understood to mean that the frame 11 is in a very close or even partial contact with the outer surface of the hub 12.

It should be noted that the above embodiment, in which one end of the frame 11 is axially slidable and the other end is fixed by the single sliding sleeve 13, is only schematic. As can be understood from the above description of the embodiments, the technical spirit of the present application lies in that the extending state of the frame 11 in the axial direction is changed by the opposite or opposite axial movements of the two ends of the frame 11, so as to fold or unfold the blade 10. Specifically, when the two ends of the frame 11 move toward each other in the axial direction (the distance between the two ends of the frame 11 decreases), the blade 10 is switched from the folded state to the unfolded state. When the two ends of the frame 11 move back and forth in the axial direction (the distance between the two ends of the frame 11 increases), the blade 10 is switched from the unfolded state to the folded state.

It can be seen that, for this purpose, at least one end of the frame 11 is required to be slidable along the axial direction of the hub 12, and the sliding of one end of the frame 11, the fixing of the other end (the above-mentioned embodiment), and the sliding of both ends are all included.

The implementation manner of sliding one end and fixing the other end of the frame 11 is as described above, and is not described in detail.

And the embodiment in which both ends of the frame 11 are slidable may be described with reference to the above embodiment. Namely, the number of the sliding sleeves 13 is two, and both ends of the frame 11 are respectively fixedly connected to the two sliding sleeves 13.

It is noted that other descriptions presented herein for only one sliding sleeve 13, such as hub distal taper, stop step, helical guide protrusion and groove, actuator, etc., are also applicable to embodiments that include two sliding sleeves 13.

In both embodiments, the sliding sleeve 13 has a degree of freedom to be slidable in the axial direction of the hub 12 to enable the opposite or reverse movement of the two ends of the frame 11. Also, the sliding sleeves 13 each have a degree of freedom that is rotatable in the circumferential direction of the hub 12 and slidable in the axial direction of the hub 12, so as to be rotatable about the hub 12 together with the frame 11 while sliding along the hub 12. Bearing in mind the above, in order to maintain the vane shape, and to avoid the collapse of the vane 10 due to the external force, the rotation of the sliding sleeve 13 in the circumferential direction is restricted in the state where the vane 10 is deployed. Specific limitations may be found in reference to the spiral guide projections and guide slots, and the limit pins and limit slots described herein.

It should be noted that most of the text is directed to the description of only one sliding sleeve 13. In order to briefly explain the technical solution of the present application, a detailed description of the embodiment comprising two sliding sleeves 13 will not be provided herein, and the drawings in the specification are simplified accordingly. It should be understood that the embodiments of the application are not so limited in scope.

[ Structure of blade 10 ]

As shown in fig. 3, 4, 5, and 6, the impeller 9 has at least one blade 10, and in the present embodiment, as shown, an example in which there are two blades is shown. However, the number of the blades 10 is not limited, and may be one or more than three.

Each blade 10 comprises at least two frames 11 that can helically surround a hub 12. In some embodiments, the frame 11 may be made of a memory alloy, which may be a shape memory alloy, such as nitinol, or the like. In some alternative embodiments, the frame 11 may be made of a material with non-memory characteristics (e.g., any material with certain strength and toughness, including metal and polymer materials). Between each frame 11 is covered an elastic film (for convenience of explanation, the elastic film is not shown in the drawings), which may be thermoplastic polyurethane elastomer rubber (TPU). The blade 10 is formed by supporting an elastic film by a frame 11.

Alternatively, the membrane is formed from a thermoplastic polyurethane elastomer rubber (TPU), which is preferably biocompatible and therefore not easily rejected by the patient.

Conventionally, during operation of an impeller, fluid exerts a back pressure on the blades in the opposite direction. In the known embodiment in which the impeller is made of elastic material and can be folded and unfolded, the fluid back pressure of the blood during the operation of the impeller after the unfolding causes the blades to deform in the reverse rotation direction. It is clear that such deformation is undesirable and can have a negative effect on fluid mechanics and pump efficiency.

In this embodiment, the at least two spirally wound frames 11 are disposed on the blades 10, so that the blades 10 obtain a better blade shape when unfolded, and provide better strength and toughness support for the blades 10, so as to provide the blades 10 with enough strength to resist the fluid back pressure applied by blood to the blades 10 when the impeller 9 is in an operating state, and avoid the deformation of the impeller 9 in the reverse rotation direction.

That is, in this embodiment, the frame 11 provides strength to the blade 10 greater than the fluid backpressure exerted by blood on the blade 10. In this manner, the shape of the blade 10 can be preferably maintained without the above-described undesirable deformation.

In some embodiments, the blade 10 may self-expand by virtue of the memory properties of the helically configured frame 11. Of course, in alternative embodiments, the blades 10 may be forcibly deployed by means of mechanical guiding structures, specifically the structural design of the helical projections and guiding slots as described below.

During insertion of the blood pump 100 into the ventricle of a patient, the frame 11 is affixed to the outer surface of the hub 12 in a radially constrained state (collapsed state). After insertion into the left ventricle, the frame 11 automatically assumes its unconstrained shape (expanded state) as the frame 11 self-expands using its memory characteristics.

The frame 11 of the blade 10 has a fixed end (first end) 14, a leading edge portion 15, a main body portion 16, a trailing edge portion 17, and a free end (second end) 18 in this order from the proximal side to the distal side. The fixed end 14 is fixedly connected to the hub 12 and the free end 18 is fixedly connected to the sliding sleeve 13. The main body portion 16 is located between the front edge portion 15 and the rear edge portion 17, and has a length greater than the lengths of the front edge portion 15 and the rear edge portion 17, and the lengths of the front edge portion 15 and the rear edge portion 17 are substantially equal. The length of the frame 11 gradually increases from the inside to the outside in the radial direction.

The plurality of frames 11 are arranged in sequence in the radial direction of the hub 12. In particular, a plurality of frames 11 are arranged in sequence, substantially one inside the other substantially radially, to form substantially a helical support frame for supporting the elastic membrane to form the blade structure.

In other words, the plurality of helical frames 11 extend along substantially the same course from the fixed end to the free end, the blades 10 being able to form a helical surface that is substantially perpendicular or inclined with respect to the outer surface of the hub 12 when the impeller 9 is deployed. In some embodiments, the plurality of frames 11 included in each blade 10 are substantially parallel and helically wound around the hub 12.

As shown in the drawing, regarding the portion of the frame 11 between the first end and the second end, the distance between the point of each frame 11 on any plane taken in the direction perpendicular to the axial direction of the hub 12 from the center axis of the hub 12 is referred to as a frame radial distance, which increases in order from the frame closest to the outer surface side of the hub 12 described later.

As shown in fig. 5 and 6, the fixed ends 14 of the frames 11 of the blades 10 are arranged adjacently (may be equally spaced, may also be unequally spaced) or at intervals around the circumference of the hub 12, and the free ends 18 are arranged adjacently (may be equally spaced, may also be unequally spaced) or at intervals around the circumference of the sliding sleeve 13. When the impeller 9 is deployed, the leading edge portion 15 can gradually separate from the hub 12 from the free end 18 to form a slope with gradually increasing potential energy, and the trailing edge portion 17 can also gradually separate from the hub 12 from the fixed end 14 to form a slope with gradually increasing potential energy. This provides excellent compliance in folding of the impeller 9.

The frame 11 of the impeller may be divided into a plurality of groups, thereby forming a plurality of blades. Each set of frames 11 may comprise at least two frames 11 and in the example shown in the drawings, two sets of frames 11, each set comprising four frames 11, the first ends 14 of the first set of frames 11 being arranged on the hub 12 approximately 180 degrees apart from the first ends 14 of the second set of frames 11 and the second ends 18 of the first set of frames 11 being arranged on the hub 12 approximately 180 degrees apart from the second ends 18 of the second set of frames 11. However, the structure of the impeller of the present invention is not limited thereto, and the number of blades and the number of frames 11 included in each blade may be changed according to design requirements.

Optionally, the entrance angle a of the leading edge portion 15 is greater than the exit angle B of the trailing edge portion 17. The entrance angle a is an angle formed by the extending direction of the leading edge portion 15 and the radial direction of the hub 12, and the exit angle B is an angle formed by the extending direction of the trailing edge portion 17 and the radial direction of the hub 12.

By making the entrance angle a of the front edge portion 15 larger than the exit angle B of the rear edge portion 17, better hydraulics and better folding compliance can be ensured.

In some embodiments, to expand the frame 11 in a predetermined configuration, the frame 11 has a weakened portion (not shown) formed in a localized area that deforms before other areas during folding of the frame 11. In this way, the weakened portion may form a portion bridging adjacent areas such that the blade 10 eventually unfolds into a predetermined shape.

The weakened portions may be configured in any configuration, including structure and material, that is distinguishable from the material of the other regions. For example, the weakening portion may include a hole, a groove, a slit that cuts the frame 11 and is sewn, or a material modification using a flexible material that connects the adjacent two regions. Wherein, the softness of the flexible material is greater than the material of the two adjacent areas.

Since the weakened portion conforming to the above-described structure or material design has a low strength, it is easy for this region to develop stress concentration during the change of the frame 11 toward the deployment of the blade 10, leading to deformation. Thereby, the deployment of the blade 10 is accelerated, and the deployment of the blade 10 in accordance with a predetermined shape becomes controllable.

As an example, a plurality of weakened portions may be formed on any one or more of the front edge portion 15, the rear edge portion 17, and the main body portion 16, and the weakened portions are easily deformed by stress concentration, thereby causing the main body portion 16 to expand rapidly. The weakened portion may be formed at 1/2 or 1/3 of the length of the frame 11. Alternatively, a weakened portion may be formed to avoid the main body portion 16 to ensure strength against blood impact during operation of the impeller and ensure operational stability.

As another example, the weakened portion may be formed in the frame 11 on one side of the sliding sleeve 13. By providing the weakened portion near the active movement side of the blade 10, the unfolding operation of the impeller 9 can be further accelerated.

Structure of wheel hub 12

As shown in fig. 5 to 7, the hub 12 has a proximal end inserted in the proximal bearing 32 and a distal end inserted in the distal bearing 31, and the bearings 31 and 32 define a limit for the impeller 9. Wherein the proximal bearing 32 is received within a proximal bearing chamber connected between the proximal end of the outer carrier 22 and the distal end of the catheter 4. That is, the outer support 22 of the pump sheath 5 is connected to the catheter 4 via the proximal bearing chamber. Similarly, distal bearing 31 is received within a distal bearing chamber connected between the distal end of outer support 22 and protective head 6. That is, the protection head 6 is connected to the outer bracket 22 through the distal bearing chamber.

The hub 12 has a variable diameter structure and includes a first hub segment 19 and a second hub segment 20. Wherein the first hub section 19 is the portion near the distal side and the second hub section 20 is the portion near the proximal side. The diameter of the first hub section 19 is smaller than that of the second hub section 20, so that a limit step 21 is formed between the first hub section 19 and the second hub section 20 by the height difference between the first hub section 19 and the second hub section 20, and the limit step 21 can limit the proximal limit position of the sliding sleeve 13 moving along the axial direction.

As described above, the distal end of the hub 12 is connected to the protection head 6 through the distal bearing chamber, the proximal end is fixedly connected to the flexible shaft, the proximal bearing is located between the flexible shaft and the catheter 4, and the motor 1 drives the hub 12 to rotate through the flexible shaft to drive the blades 10 to rotate, thereby achieving the function of pumping blood.

Alternatively, as shown in fig. 7 and 8, a spiral guide protrusion 30 is formed on the first hub section 19 of the hub 12, and is engaged with a guide groove formed on an inner surface of the sliding sleeve 13, which will be described later, so that the sliding sleeve 13 can be rotated while being slid in the axial direction of the hub 12, and the blade 10 can be gradually extended from the spirally wound state. On one hand, the sliding sleeve 13 can be more reliably rotated and moved to reach the expected position, and on the other hand, the frame 11 is gradually unfolded along the axial length of the hub 12 from the state of being spirally wound on the hub 12, so that the diameter of the folded state is as small as possible, and the technical effect of reducing the folding size of the impeller 9 is achieved.

It is noted that the arrangement of the spiral guide projection 30 and the guide groove may be reversed from that described above.

In addition, since the guiding protrusions 30 and the guiding grooves are helical, the sliding sleeve 13 will be forced to twist circumferentially by the cooperation of the guiding protrusions 30 and the guiding grooves during the axial movement of the sliding sleeve 13. Thus, by virtue of this structural design, even if in some embodiments the frame of the impeller 9 is made of a material with non-memory properties (for example, any material with certain strength and toughness, including metals, polymeric materials), the deployment of the impeller 9 also allows the blades to obtain a helical configuration.

It should be noted that, the above description is directed to the case of only one sliding sleeve 13, and in the case of two sliding sleeves 13, the hub 12 has two first hub segments 19 and one second hub segment 20, wherein the two first hub segments 19 are respectively connected to two ends of the second hub segment 20, and a limit step 21 is respectively formed between the two first hub segments 19 and the second hub segment 20. The spiral guide projection and the guide groove can be combined and used as appropriate. It should be understood that the embodiments of the present application are not so limited in scope.

[ Structure of sliding bush 13 ]

As shown in fig. 5 and 6, the sliding sleeve 13 is sleeved on the first hub section 19 of the hub 12 and can move on the first hub section 19 of the hub 12 along the axial direction. The movement of the sliding sleeve 13 over the first hub section 19 has a proximal limit position (first limit position) and a distal limit position (second limit position). When the sliding sleeve 13 moves to the far end limit position, the impeller 9 is in a folding state, and when the sliding sleeve 13 moves to the near end limit position, the impeller 9 is in an unfolding state.

The limit position of the near end can be limited by the limit step 21 of the hub 12, when the sliding sleeve 13 moves to the limit step 21, the impeller 9 is unfolded in place and is in a completely unfolded state, and the blood pumping function can be executed through the driving of the driving shaft. The distal limit position is a position where the impeller is in a collapsed state in which the frame 11 is almost completely attached to the outer surface of the hub 12 to a state where the outer diameter dimension is minimum.

More specifically, when the impeller 9 is forced to switch from the expanded state to the collapsed state by an external force, the frame 11 rotates around the hub 12 and moves radially in the direction of being attached to the hub 12, and the sliding sleeve 13 is driven by the frame 11 to rotate around the hub 12 and move along the hub 12 to the distal end limit position, so that the impeller 9 is switched from the expanded state to the collapsed state.

When the impeller 9 is switched from the folded state to the unfolded state after the external force disappears, the frame 11 winds around the outer periphery of the hub 12 while rotating around the hub 12 as a center by utilizing the memory characteristics of the frame and moving in a radial direction away from the outer surface of the hub 12, and the sliding sleeve 13 moves to a proximal end limit position along the hub 12 while rotating around the hub 12 as a center by being driven by the frame 11, so that the impeller 9 is switched from the folded state to the unfolded state.

In order to maintain the unfolded state of the impeller 9 stably during operation, a limit structure is provided between the sliding sleeve 13 and the limit step 21, preventing the sliding sleeve 13 from rotating at a proximal limit position due to centrifugal force. As an example, one of the end surface of the sliding sleeve 13 facing the limit step 21 and the limit step 21 is provided with a limit pin 28, the other of the end surface of the sliding sleeve 13 facing the limit step 21 and the limit step 21 is provided with a limit groove 27 engaged with the limit pin 28, and when the sliding sleeve 13 is located at the proximal limit position, the limit pin 28 is inserted into the limit groove 27.

In the example shown in fig. 7 and 8, a stopper groove 27 recessed radially inward and opened to an axial distal end is formed in the stopper step 21, and a stopper pin 28 is formed on an end of the sliding sleeve 13 facing the stopper step 21. Preferably, the stopper pin 28 and the stopper groove 27 extend in the axial direction of the hub 12. As an alternative example, the limit pin 28 and the limit groove 27 may also be inclined at an angle with respect to the extension direction of the hub 12, but the inclination direction is kept in line with the direction of rotation of the impeller.

When the sliding sleeve 13 moves to the proximal end limit position, the impeller 9 is in the fully expanded state, and at this time, the limit pin 28 is inserted into the limit groove 27 to limit the sliding sleeve 13 to rotate around the circumferential direction. Therefore, the axial movement of the sliding sleeve 13 is limited by abutting against the step 21, and the circumferential rotation of the sliding sleeve 13 is limited by the cooperation of the limit pin 28 and the limit groove 27, so that when the impeller 9 is in the unfolded state to perform blood pumping operation, the sliding sleeve 13 does not leave the proximal end limit position due to the rotational centrifugal force generated when the vane 10 operates, and the reliability of the vane 10 during operation is improved.

As an embodiment, the sliding sleeve 13 may be cylindrical, the wall thickness is constant, and the outer diameter of the sliding sleeve 13 is equal to the height of the limiting step 21. By maintaining the outer diameter of the hub 12 constant, formation of a protrusion or groove structure on the outer wall of the hub 12 is avoided, thereby reducing or even avoiding hemolysis or thrombosis.

As another example, the sliding sleeve 13 may be in the shape of a frustum tube, and has a distal end surface 24 facing away from the limiting step 21 and a proximal end surface 25 facing the limiting step 21. Wherein the outer diameter of the distal end surface 24 is slightly larger than the outer diameter of the first hub section 19 and can approach the inner diameter of the central passage of the sliding sleeve 13. The outer diameter of the proximal end face 25 is equal to the diameter of the second hub section 20 such that the outer peripheral surface at the proximal end is flush with the outer peripheral surface of the second hub section 20 of the hub 12. The hydrodynamic effect can be improved by the smooth transition of the sliding sleeve 13 to the second hub section of the hub 12.

The outer wall of the sliding sleeve 13 may be provided with a groove 26, the free end 18 of the frame 11 being embedded in the groove 26, the thickness of the free end 18 being equal to the depth of the groove 26, so that the radially outer surface of the free end 18 is flush with the outer surface of the sliding sleeve 13. The free end 18 of the frame 11 and the sliding sleeve 13 are designed in an embedded mode, so that the joint of the two is prevented from forming a bulge, and damage to blood cells is avoided.

Of course, the free end 18 of the frame 11 can also be inserted into the proximal end face of the sliding sleeve 13, and by virtue of the design of the smooth outer surface of the sliding sleeve 13, the technical effect equivalent to that described above can also be achieved.

It should be noted that the above description is directed to only one sliding sleeve 13. In the case of two sliding sleeves 13, a similar structure is also provided. In order to briefly explain the technical solution of the present application, a detailed description of the embodiment comprising two sliding sleeves 13 will not be provided herein, and the drawings in the specification are simplified accordingly. It should be understood that the embodiments of the application are not so limited in scope.

[ STRUCTURE OF ACTUATING ELEMENT 29 ]

As shown in fig. 9A to 10B, the impeller 9 may further include an actuating member 29, and the actuating member 29 can apply a force to the sliding sleeve 13 to move the sliding sleeve 13 toward the limit step 21. Specifically, an actuator 29 can be positioned between the distal bearing 31 and the sliding sleeve 13 or between the proximal bearing 32 and the sliding sleeve 13 to apply a force to the sliding sleeve 13 that moves the sliding sleeve 13 toward the first end of the frame 11. The provision of the actuator 29 can contribute to the rapid return of the impeller 9 from the folded state to the unfolded state, thereby improving the unfolding efficiency.

As an example, as shown in fig. 9A and 9B, the actuating member 29 is a spring 291, and the spring 291 may be disposed between the sliding sleeve 13 and the distal end bearing 31 so as to rotate with or without the hub 12.

There are various ways of connecting the spring 291 to the sleeve 13 and the distal bearing 31. By way of example, when one end (distal end) of the spring 291 is fixedly connected to the bearing outer race of the distal bearing 31, the spring 219 does not rotate with the hub 12, and therefore, the other end (proximal end) of the spring 291 can be rotationally rubbed against the distal end face of the sliding sleeve 13. When the impeller 9 is transitioned from the folded state to the unfolded state, the spring applies force to the sliding sleeve 13 in the axial direction towards the proximal direction, so as to push the sliding sleeve 13 to slide towards the step 21 along the first hub section 19. At this time, the spring 291 is fixedly attached to the bearing outer race of the distal bearing so the spring does not rotate with the hub 12. When the impeller 9 is transitioned from the unfolded state to the folded state, the frame 11 is pressed by an external force and is switched to a posture of being attached to the hub 12, so that the sliding sleeve 13 is pushed to the distal end limit position against the elastic force of the spring 291.

As another example, one end (proximal end) of the spring 291 is fixedly connected to the distal end surface of the sliding sleeve 13, and the other end (distal end) is fixedly connected to the inner race of the distal bearing. When the impeller 9 is transitioned from the folded state to the unfolded state, the spring 291 applies a force to the sliding sleeve 13 in the axial direction toward the proximal direction, so as to push the sliding sleeve 13 to slide toward the limit step 21 along the first hub section 19. At this time, the spring 291 is fixedly connected to the sliding sleeve 13 and the bearing inner race of the distal end bearing, so the spring rotates together with the hub 12. When the impeller 9 is transitioned from the unfolded state to the folded state, the frame 11 is pressed by an external force and is switched to a posture attached to the hub 12, so that the sliding sleeve 13 is pushed to a distal end limit position against the elastic force of the spring.

It should be noted that the above description exemplifies the case where the spring 291 is provided between the sliding sleeve 13 and the distal end bearing 31, but the present invention is not limited thereto. As described above in the present specification, in the case where there are two sliding sleeves 13, a spring 291 may be provided between the sliding sleeve 13 and the proximal end bearing 32 in addition to the spring 291 provided between the sliding sleeve 13 and the distal end bearing 31, or of course, the spring 291 may be provided between the sliding sleeve 13 and the proximal end bearing 32 without providing the spring 291 between the sliding sleeve 13 and the distal end bearing 31 (that is, two springs 291 may be provided, or the spring 291 may be provided on either the distal end or the proximal end). The description of these embodiments is omitted herein for the sake of brevity in describing the subject technology.

In this embodiment, the sliding sleeve 13 may include any configuration conforming to the characteristics described above as "cylindrical" or "frustoconical", and this embodiment is not limited thereto.

As an example, in a further alternative embodiment, the sliding sleeve 13 may be a sliding bearing comprising a sliding bearing inner ring and a sliding bearing outer ring arranged outside the sliding bearing inner ring, the distal end of the frame 11 may be connected to one of the sliding bearing inner ring and the sliding bearing outer ring, the proximal end of the spring 291 is connected to the other of the sliding bearing inner ring and the sliding bearing outer ring, and the distal end of the spring 291 is connected to the bearing outer ring of the distal bearing, such that the spring remains circumferentially fixed during rotation of the hub.

The distal end of the frame 11 is connected to one of the inner and outer slide bearing rings, the proximal end of the spring 291 is connected to the other of the inner and outer slide bearing rings, and the distal end of the spring 291 is connected to the inner bearing ring of the distal bearing so that the spring can rotate with the hub 12 during rotation of the hub 12.

As a modification, as shown in fig. 10A and 10B, the actuator 29 is a pair of magnets 292 having a magnetic repulsive force, wherein the magnets 292 include a first magnet disposed on the slide sleeve 13 and a second magnet disposed in the distal bearing chamber. When the impeller 9 is transited from the folded state to the unfolded state, the first magnet and the second magnet push the sliding sleeve 13 to slide along the first hub section 19 to the limit step 21 due to the repulsive force between the first magnet and the second magnet. When the impeller 9 is transited from the unfolded state to the folded state, the frame 11 is pressed by external force and is switched to a posture attached to the hub 12, so that the sliding sleeve 13 is pushed to a far-end limit position against the repulsive force of the magnet.

It should be noted that the above description exemplifies a case where a pair of magnets having repulsive force is provided between the sliding sleeve 13 and the distal end bearing 31, but the present invention is not limited thereto. As described above in the present specification, in the case where there are two sliding sleeves 13, a pair of magnets may be provided between the sliding sleeve 13 and the proximal bearing 32 in addition to a pair of magnets provided between the sliding sleeve 13 and the distal bearing 31, but of course, a pair of magnets may be provided between the sliding sleeve 13 and the proximal bearing 32 instead of a pair of magnets provided between the sliding sleeve 13 and the distal bearing 31 (that is, two pairs of magnets may be provided, or a pair of magnets may be provided on either the distal end or the proximal end). The description of these embodiments is omitted herein for the sake of brevity in describing the subject technology.

As another modification, the actuating member 29 may be at least two elastic wires, one end (proximal end) of which is fixedly connected to the inner ring of the proximal bearing 32 and the other end (distal end) of which is fixedly connected to the sliding sleeve 13. When the impeller 9 is in the folded state, the elastic wire is in the stretched state and is charged with energy. When the impeller 9 is transited from the folding state to the unfolding state, the elastic wire is stored and released, the sliding sleeve 13 is pulled to move to the near-end limit position by utilizing the restoring contraction force of the elastic wire, and when the impeller 9 is transited from the unfolding state to the folding state, the frame 11 is extruded by external force and is changed to the posture attached to the hub 12, so that the sliding sleeve 13 is pushed to the far-end limit position by resisting the pulling force of the elastic wire.

Note that since the elastic wire is fixed to the inner race of the proximal bearing 32, it rotates together with the hub 12 and the sliding sleeve 13. I.e. the elastic wire is stationary relative to the impeller 9. To accommodate the elastic strands, an axial cavity may be provided in the hub 12 in which the elastic strands are received. The number of the elastic wires can be a plurality, and correspondingly, the number of the cavities is also a plurality.

As an example, the elastic wire may also be fixedly connected with the outer ring of the proximal bearing 32, and the other end is fixedly connected with the sliding sleeve 13. The elastic wire may be made of any material that is biocompatible and provides elasticity, and this embodiment is not limited thereto.

Further, the modification of the elastic thread is not limited to the above-described arrangement. For example, in the case of two sliding sleeves 13, both ends of the elastic thread may be provided on the two sliding sleeves 13, respectively.

The actuator 29 is not limited to the spring, the magnet, or the elastic wire, and may be any force that can move the impeller from the retracted state to the extended state with respect to the slide sleeve 13. By providing such an actuating member 29, the sliding sleeve 13 can be brought more quickly to the proximal limit position, and the impeller can be deployed more quickly.

[ STRUCTURE OF EXTERNAL FRAME 22 ]

As described above, the proximal and distal ends of the external bolster 22 are fixed to the distal end of the catheter 4 and the distal bearing chamber, respectively, as shown in fig. 3, 4. The outer stent 22 is formed of a shape memory alloy, such as nitinol, such that the outer stent 22 assumes a generally circular, elliptical, or polygonal cross-sectional shape in the absence of any force applied to the pump sheath 5. By assuming such a cross-sectional shape, the outer holder 22 is configured to hold the distal end side of the pump sheath 5 in an open state.

In detail, the outer carrier 22 is constituted by a plurality of rigid struts 23, the plurality of rigid struts 23 being configured such that at least a portion of the outer carrier 22 remains substantially parallel to the hub 12, thereby forming a space between the outer carrier 22 and the hub 12 for the blades 10 to rotate. In addition, the rigid struts 23 are configured such that the overall length of the outer stent 22 changes even if the outer stent 22 changes from a radially constrained state (collapsed state) to a non-radially constrained state (expanded state). Specifically, the length in the radially constrained state (collapsed state) is greater than the non-radially constrained state (expanded state). The length refers to the length in the axial direction.

Typically, during insertion of the blood pump 100 into a patient's ventricle, the outer stent 22 is in a radially constrained state (collapsed state) due to an externally applied radially constraining force. After insertion into the left ventricle and removal of the radially constraining force, the external stent 22 automatically assumes its unconstrained shape (expanded state) as the external stent 22 self-expands using its own memory properties.

During operation of the blood pump, the distal end of the pump sheath 5 is configured to be placed within the body of the patient (within the left ventricle). Thus, during operation of the blood pump, the distal side of the pump sheath 5 is arranged to cross the aortic valve into the left ventricle, and the outer stent 22 is configured to retain its externally-covered membrane by assuming its substantially circular, elliptical or polygonal cross-sectional shape, the membrane crossing the aortic valve and being clamped radially inwards by the aortic valve. In this way, during operation of the blood pump, blood pumped from the membrane outlet into the aorta is blocked by the aortic valve from regurgitating.

Optionally, the pump sheath 5 is sized to prevent the shape memory alloy of the outer stent 22 from fully assuming the shape memory alloy is shaped. Thereby, the radial dimension of the pump sheath 5 is preferably maintained against the influence of the fluid back pressure (blood pressure) on the pump sheath 5 due to the operation of the impeller 9, particularly the influence of the radial dimension. Furthermore, during operation of the blood pump, the clearance (pump clearance) between the radially outer end of the impeller 9 and the inner wall of the pump sheath 5 can be maintained at a constant value, and the pump efficiency and hydraulic performance are excellent.

Furthermore, a gap is left between the outer stent 22 and the blades constituted by the frame 11 and the cover, optionally a gap between the blades 10 of the impeller 9 and the outer stent 22 is relatively small, so that the impeller 9 effectively pumps blood from the left ventricle of the patient into the aorta of the patient.

In this embodiment, the magnetic elements are provided on the radially outermost surfaces of the vanes 10 of the impeller 9 and the magnetically repulsive thin film is provided on the inner surface of the corresponding portion of the outer support 22, so that a gap is maintained between the vanes 10 of the impeller 9 and the outer support 22, so that the impeller 9 effectively pumps blood from the left ventricle of the patient into the aorta of the patient.

The magnetic elements may be in the form of a coating film formed on the corresponding surface in a coating manner. Of course, the configuration and arrangement of the magnetic element are not limited to the above.

< operation of impeller 9 >

When the blood pump 100 is inserted into the ventricle of a patient, the impeller 9 is switched to the collapsed state by applying a radial pressing force to the impeller 9. That is, the blades (frame 11) and the outer holder 22 are switched to the collapsed state. In the process of folding the impeller 9, since the frame 11 having the spiral structure is forcibly pressed and there is an axial torque when it is stored, the slide sleeve 13 moves to the distal end limit position along the hub 12 while rotating around the hub 12. In the folding process, the frame 11 is also radially moved in the direction of being attached to the hub 12 while rotating around the hub 12, and is more and more attached to the outer surface of the hub 12. When the sliding sleeve 13 reaches the distal end limit position, the frame 11 is almost attached to the outer surface of the hub 12 and is in the collapsed state, and the outer support 22 is also in the collapsed state, so that the external dimension of the impeller 9 in the collapsed state is reduced as much as possible.

After the blood pump 100 is inserted into the left ventricle and the external radial force is removed, the frame 11 is rotated about the hub 12 by its memory property and radially moves away from the hub 12, and the sliding sleeve 13 automatically expands, and also moves to the proximal end limit position along the hub 12 by rotating about the hub 12. At the same time, the outer stent 22 also self-expands using its memory characteristics. When the sliding sleeve 13 reaches the proximal limit position, the sliding sleeve 13 abuts against the limit step 21 to limit further circumferential movement, the limit pin 28 is inserted into the limit groove 27 to limit the sliding sleeve 13 from rotating in the circumferential direction, and at this time, the frame 11 and the outer support 22 are both in the fully deployed state, so that the impeller 9 automatically assumes its unconstrained shape (deployed state).

When the impeller 9 is developed, the blades 10 form a spiral surface substantially perpendicular to the outer surface of the hub 12 by the development of the frame 11, thereby enabling blood pumping.

The following advantageous technical effects can be obtained by the structure and operation of the impeller 9 as described above.

(1) The blade 10 of the present application includes at least two helical frames 11, and the blade is formed by supporting a film only by the helical frames 11 without a radial frame. With this configuration, the blade 10 can be folded into a more compact form and further attached to the hub.

Meanwhile, because the radial frame is not arranged and only the spiral frame 11 is arranged, the blades of the blades 10 are smoother, the blood drainage is facilitated, and the better fluid performance is realized.

(2) In the prior art, only axial movement is present during the collapsing of the impeller. For example, in prior art solutions where the collapsing is achieved by means of springs, there is only an axial movement of the impeller during collapsing, because the frame of the blade is connected with the spring and the spring is elastically deformed in the axial direction. The frame of the blade to which the spring is attached will naturally not rotate, since the spring will not substantially twist when extended or compressed. And although the frame has a torque that tends to twist during axial elongation, the torque is insufficient to drive the spring to twist.

In contrast, the free end 18 of the frame 11 of the impeller 9 of the blood pump according to the present embodiment is connected to the hub 12 via the sliding bush 13, and can move along the hub 12 while rotating around the hub 12. Therefore, during the folding process, since the frame 11 having the spiral structure is forcibly pressed and the sliding sleeve 13 is easily driven by the frame 11 having the spiral structure, the frame 11 rotates around the hub 12 while moving along the hub 12, and adheres to the outer surface of the hub 12. Thus, the folding stroke is shorter, and the folding of the impeller 9 can be completed quickly.

(3) In addition, if an auxiliary member such as an actuator 29 (for example, a spring, a magnet, or an elastic wire) is further provided, the deployment of the impeller 9 can be further accelerated, and the use efficiency can be improved.

In contrast, in the present embodiment, the diameter-variable axial hub 12 is adopted, and the hub 12 does not undergo axial material deformation during the unfolding and folding processes of the impeller 9, so that the situations of stress fatigue and stress limit of the material due to repeated stretching are avoided, and the product reliability is high. Meanwhile, the shaft-shaped hub 12 can be made to be small in diameter due to the relatively regular shape.

< example of application of blood Pump 100 >

The blood pump 100 of the above-described embodiment may be applied to a left ventricular assist device suitable for a defective heart in order to assist left ventricular function. In addition, pumps for pumping blood from the vena cava and/or right atrium into the right ventricle, from the vena cava and/or right atrium into the pulmonary artery, and/or from the renal vein into the vena cava may also be suitably adapted and configured for placement within the subclavian or jugular vein at the junction of the vein and lymphatic catheter, and for increasing the flow of lymphatic fluid from the lymphatic vessel into the vein

Hereinafter, the operation of the blood pump 100 will be briefly described by taking the blood pump as an example of the left ventricular assist device.

The distal end of the blood pump 100 of the above-described embodiment is disposed in the left ventricle of the patient, the pump sheath 5 is passed through the aortic valve of the patient such that the proximal end of the pump sheath 5 (specifically, the proximal end of the covering membrane) is disposed in the aorta of the patient, and the distal end of the pump sheath 5 is disposed within the left ventricle.

Typically, the distal end (protection head 6 side) of the blood pump 100 is guided to the left ventricle with a guide wire (guide wire). During the guiding process, the impeller 9 of the blood pump 100 is in a collapsed state.

Specifically, in the process of guiding the distal end (protective head 6 side) of the blood pump 100 to the left ventricle, the outer stent 22 is in the collapsed state, the frame 11 of the spiral structure is attached to the outer surface of the hub 12 and the sliding sleeve 13 is in the distal limit position so that the blades are also in the collapsed state. I.e. the impeller 9 is in a collapsed state.

During the process of inserting the distal end of the pump sheath 5 into the left ventricle, the collapsible sheath exerts radial constraint on the pump sheath 5, collapsing the pump sheath 5, and the whole blood pump is transported forward in a collapsed state under the action of the guide path established in advance by the guide wire. Once the distal end of the blood pump 100 is delivered into the left ventricle, the collapsed sheath is withdrawn rearwardly, the constraint is removed, the pump sheath 5 is released, and the self-expandable member assumes the non-radially constrained configuration. The guide wire is then withdrawn from the blood pump, and the motor is then activated, which may initiate a blood pumping operation.

Specifically, if the sheath tube is retracted, the outer holder 22 of the pump sheath 5 is self-expanded and switched to the expanded state, and the frame 11 (blade) of the impeller 9 is radially moved in a direction away from the hub 12 while rotating about the hub 12 by utilizing the memory characteristics thereof, and the slide sleeve 13 is moved to the proximal end limit position of the hub 12 while rotating about the hub 12. When the sliding sleeve 13 reaches the proximal end limit position, the frame 11 and the outer support 22 are in the fully unfolded state, so that the impeller 9 self-expands to switch from the folded state to the unfolded state.

Thus, the blood pump 100 is inserted into the body of a patient to provide acute treatment to the patient.

During treatment, the proximal portion of the pump sheath 5 remains open during left ventricular contraction, pumping blood out of the blood outlet 8. During left ventricular diastole, the proximal side portion of the pump sheath 5 is closed and does not pump blood out of the blood outlet 8. Thus, blood is pumped from the left ventricle to the aorta in a pulsatile manner.

At the end of the treatment when it is desired to withdraw the blood pump 100 from the patient's body, the collapsed sheath is advanced to the distal end of the blood pump, causing the impeller 9 of the blood pump 100 to switch from the deployed state to the collapsed state. Specifically, the frame 11 rotates about the hub 12 and moves radially in the direction of attaching the hub 12, so that the frame is attached to the outer surface of the hub 12 more and more, and the sliding sleeve 13 moves to the distal end limit position along the hub 12 while rotating about the hub 12. When the sliding sleeve 13 reaches the distal end limit position, the frame 11 and the outer support 22 are both in the collapsed state, i.e. the impeller 9 is switched to the collapsed state.

The above-described application is to apply the blood pump of the present embodiment to pumping blood from the left ventricle of the subject to the aorta of the subject, or to pump blood from the right ventricle of the subject to the pulmonary artery of the subject, or to pump blood from the right atrium of the subject to the right ventricle of the subject, or to pump blood from the vena cava of the subject to the right ventricle of the subject, or to pump blood from the right atrium of the subject to the pulmonary artery of the subject, or to pump blood from the vena cava of the subject to the pulmonary artery of the subject, or the like.

The above embodiments of the present invention are merely exemplary, and the present invention is not limited thereto. Those skilled in the art will understand that: changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.

Claims

1. A foldable impeller (9), characterized in that it comprises:

a hub (12);

at least one blade (10), each blade comprising at least two frames (11) and a film, the frames (11) being elongated, the frames (11) of each blade being arranged in sequence at a position radially inward of the hubs (12) of the other blade, parallel and spirally surrounding the outer periphery of the hubs (12), at least one end of the frames (11) being capable of sliding in the axial direction of the hubs (12) and rotating around the hubs (12), the film of each blade being supported only by the frames (11),

at least one end of the frame (11) is fixedly connected with a sliding sleeve (13), the sliding sleeve (13) is slidably sleeved on the hub (12),

the sliding sleeve (13) has a degree of freedom that is slidable in the axial direction of the hub (12) and rotatable in the circumferential direction of the hub (12),

the hub (12) having a first hub section (19) and a second hub section (20) with a diameter greater than the first hub section (19), a limit step (21) being formed at the connection of the first hub section (19) and the second hub section (20),

the sliding sleeve (13) is sleeved on the first hub section (19),

when the blade (10) is in the deployed state, the sliding sleeve (13) is restricted from rotating in the circumferential direction of the hub (12), and the sliding sleeve (13) is also restricted from sliding axially in the direction in which the blade (10) is further deployed.

2. The foldable impeller (9) according to claim 1,

the blade (10) is configured to switch from a collapsed state to an expanded state when the two ends of the frame (11) are moved axially relative to each other, and to switch from an expanded state to a collapsed state when the two ends of the frame (11) are moved axially away from each other.

3. The foldable impeller (9) according to claim 1,

one end of the frame (11) is fixed, and the other end of the frame can slide; or,

both ends of the frame (11) can slide.

4. The foldable impeller (9) according to claim 1,

the number of the sliding sleeves (13) is one, the first end (14) of the frame (11) is fixedly connected to the hub (12), and the second end (18) of the frame (11) is fixedly connected to the sliding sleeves (13); or,

the number of the sliding sleeves (13) is two, and the first end (14) and the second end (18) of the frame (11) are fixedly connected to the two sliding sleeves (13) respectively.

5. The foldable impeller (9) according to claim 4,

the number of sliding sleeves (13) is one, the first ends (14) of the at least two frames (11) are arranged adjacently or at intervals around the circumference of the hub (12) and the second ends (18) are arranged adjacently or at intervals around the circumference of the sliding sleeves (13), or,

the number of the sliding sleeves (13) is two, the first ends (14) and the second ends (18) of the at least two frames (11) are respectively arranged adjacently or at intervals around the circumference of the sliding sleeves (13),

the portions of the at least two frames (11) between the first end (14) and the second end (18) extend along substantially the same course from the first end (14) to the second end (18) and can form a helicoid that is substantially perpendicular or inclined with respect to the outer surface of the hub (12).

6. The foldable impeller (9) according to claim 1,

the number of the sliding sleeves (13) is one, the second end (18) of the frame (11) is sleeved on the first hub section (19) through one sliding sleeve (13), the first end (14) of the frame (11) is fixedly connected on the second hub section (20), or,

the quantity of sliding sleeve (13) is two, wheel hub (12) have two first wheel hub sections (19), two first wheel hub sections (19) are connected respectively along the axial the both ends of second wheel hub section (20), frame (11) second end (18) via one sliding sleeve (13) cover is established one on first wheel hub section (19), frame (11) first end (14) via another sliding sleeve (13) cover is established another on first wheel hub section (19).

7. The foldable impeller (9) according to claim 1,

the sliding sleeve (13) can move around the first hub section (19) in a rotating mode while moving along the axial direction of the first hub section (19), so that a first limit position close to the second hub section (20) and a second limit position far away from the second hub section (20) are provided, the sliding sleeve (13) can abut against the limit step (21) at the first limit position, and the frame (11) can be attached to the outer peripheral surface of the hub (12) at the second limit position.

8. The foldable impeller (9) according to claim 1,

the outer surface of sliding sleeve (13) is provided with along axial extension's of wheel hub (12) recess (26), the frame (11) with the tip that sliding sleeve (13) are connected imbeds in recess (26), the radial surface of frame (11) with the surface parallel and level of sliding sleeve (13).

9. The foldable impeller (9) according to claim 1,

the sliding sleeve (13) is cylindrical, and the radial outer surface of the sliding sleeve (13) is flush with the radial outer surface of the second hub section (20), or

Sliding sleeve (13) are the frustum form, the radial dimension of sliding sleeve (13) from facing the one end of spacing step (21) is towards deviating from the one end of spacing step (21) diminishes gradually, the sliding sleeve (13) towards the radial surface of the one end of spacing step (21) with the radial surface parallel and level of second wheel hub section (20).

10. The foldable impeller (9) according to any one of claims 4 to 9,

the foldable impeller (9) further comprises a bearing which is arranged opposite to the sliding sleeve (13), the bearing is a far-end bearing (31) or a near-end bearing (32), the far-end bearing (31) is sleeved on the hub (12) and is close to the second end (18) of the frame (11), the near-end bearing (32) is sleeved on the hub (12) and is close to the first end (14) of the frame (11),

the foldable impeller (9) further comprises an actuating member (29), the actuating member (29) being located between the sliding sleeve (13) and the bearing opposite thereto, and being capable of applying a force to the sliding sleeve (13) that causes the sliding sleeve (13) to press the frame (11).

11. Foldable impeller (9) according to claim 10,

the actuator (29) is a spring (291), and the spring (291) is provided between the slide sleeve (13) and the bearing facing the slide sleeve (13) so as to rotate with or without rotating with the hub (12).

12. The foldable impeller (9) according to claim 11, characterized in that,

one end of the spring (291) is fixedly connected with a bearing inner ring of the bearing, and the other end of the spring (291) is fixedly connected with the sliding sleeve (13); or alternatively

One end of the spring (291) is fixedly connected with a bearing outer ring of the bearing, and the other end of the spring (291) abuts against the end face, facing the bearing, of the sliding sleeve (13).

13. The foldable impeller of claim 11,

the sliding sleeve (13) is a sliding bearing and comprises a sliding bearing inner ring and a sliding bearing outer ring arranged on the outer side of the sliding bearing inner ring,

an end of the frame (11) is connected to one of the inner and outer bearing rings, one end of the spring (291) is connected to the other of the inner and outer bearing rings, and the other end of the spring (291) is connected to the outer bearing ring of the bearing; or

An end of the frame (11) is connected to one of the slide bearing inner ring and the slide bearing outer ring, one end of the spring (291) is connected to the other of the slide bearing inner ring and the slide bearing outer ring, and the other end of the spring (291) is connected to the bearing inner ring of the bearing.

14. The foldable impeller of claim 10,

the actuating member (29) is a pair of magnets (292) facing with opposite magnetic poles, one of the magnets is fixedly arranged on the sliding sleeve (13), and the other magnet is fixedly arranged on the bearing.

15. The foldable impeller of claim 10,

the actuating piece (29) is at least two elastic wires, one end of each elastic wire is fixedly connected with the bearing, and the other end of each elastic wire is fixedly connected with the sliding sleeve (13).

16. The foldable impeller (9) according to claim 1,

one of the outer wall of the first hub section (19) and the inner side wall of the sliding sleeve (13) is provided with a spiral guide protrusion, and the other of the outer wall of the first hub section and the inner side wall of the sliding sleeve is provided with a guide groove matched with the spiral guide protrusion.

17. The foldable impeller (9) according to claim 1,

the utility model discloses a spacing step (21) of sliding sleeve (13) is including sliding sleeve (13) and limiting pin (28), sliding sleeve (13) towards the terminal surface of spacing step (21) with one in spacing step (21) is provided with spacer pin (28), sliding sleeve (13) towards the terminal surface of spacing step (21) with another in spacing step (21) be provided with spacer pin (28) complex spacing groove (27) sliding sleeve (13) support lean on in during spacing step (21), spacer pin (28) are inserted in spacer groove (27).

18. The foldable impeller (9) according to any one of claims 1 to 9,

the foldable impeller (9) further comprises a pump sheath comprising an outer support (22) and a membrane laid over the outer support (22),

the at least one blade (10) and the sliding sleeve (13) are both arranged in the outer bracket (22),

a first magnetic element is arranged on the radially outermost side of the at least one blade (10), a second magnetic element is arranged on the inner surface of the outer support (22) at the corresponding position, and the polarity of the first magnetic element is opposite to that of the second magnetic element.

19. Foldable impeller (9) according to any of the claims 1-8,

the frame (11) is configured to provide the blades (10) with sufficient strength against a fluid back pressure exerted thereon by blood when the impeller (9) is in an operating state, so that the blades (10) are not deformed against the rotational direction.

20. The foldable impeller (9) according to claim 4,

the frame (11) comprises:

a front edge portion (15) capable of forming a slope with gradually increasing potential energy from the second end away from the hub (12);

a rear edge portion (17) which is capable of forming a slope with gradually increasing potential energy from the first end to gradually depart from the hub (12); and

a main body part (16) that can be connected between the front edge part (15) and the rear edge part (17) so as to be spirally wound around the outer periphery of the hub (12),

the length of the main body part (16) is greater than the length of the front edge part (15) or the rear edge part (17), and the angle A formed by the extending direction of the front edge part (15) and the radial direction of the hub (12) is greater than the angle B formed by the extending direction of the rear edge part (17) and the radial direction of the hub (12).

21. The foldable impeller (9) according to claim 1,

the frame (11) has a weakening formed in a partial region, which is deformed before the other regions during folding of the frame (11).

22. The foldable impeller (9) according to claim 21, characterized in that,

the weakening comprises a hole, a groove, a flexible material connecting two adjacent areas, a cut that breaks the frame (11) and is sewn.

23. A blood pump (100) comprising:

a motor (1);

one end of the flexible shaft is connected with an output shaft of the motor (1);

a guide tube (4) which is sleeved on the periphery of the flexible shaft and is connected to the motor (1) through a coupling part (3); and

a foldable impeller (9) according to any of claims 1 to 22, the hub (12) of the foldable impeller (9) being connected to the other end of the flexible shaft.