CN216908915U

CN216908915U - Ventricular assist device

Info

Publication number: CN216908915U
Application number: CN202123308928.0U
Authority: CN
Inventors: 张家良; 刘刚
Original assignee: Magassist Inc
Current assignee: Xinqing Medical Suzhou Co ltd
Priority date: 2021-12-27
Filing date: 2021-12-27
Publication date: 2022-07-08
Anticipated expiration: 2031-12-27

Abstract

The present application relates to a ventricular assist device comprising: the device comprises a motor, a conduit, a drive shaft penetrating through the conduit and a pump assembly. The pump assembly includes: the impeller is connected to the distal end of the drive shaft to be driven to rotate to draw blood into the pump housing from the inlet end and discharge the blood from the outlet end. A flexible support is connected to the distal end of the pump housing for spacing the inlet end from the interior wall of the ventricle when the pump assembly is in operation. The driving shaft and the flexible supporting piece are of hollow structures and communicated with each other to form a guide wire channel for the guide wire to pass through. A seal is disposed in the guide wire channel distal to the distal end of the drive shaft, and a guide wire hole is formed in the seal for the guide wire to pass through and is closed after the guide wire is withdrawn. The depth of the wire guide hole is 0.1-5 mm.

Description

Ventricular assist device

Technical Field

The utility model relates to a ventricular assist device, and belongs to the technical field of medical instruments.

Background

Heart failure is a health problem with a high mortality rate. In the case of cardiogenic shock, the ejection performance of the left ventricle of a patient is significantly diminished, and the diminished coronary blood supply may lead to irreversible cardiac deterioration. Thus, for this case, temporary intervention support (ventricular assist) will replace the left ventricular pumping function locally or largely and increase the coronary blood supply. In particular, in the face of acute heart failure, physicians desire the ability to rapidly and minimally invasively deploy such interventional regimens.

Clinically, an intervention scheme conforming to the operation habit of a doctor is to guide a ventricular assist device to the left ventricle by means of a guide path established by a guide wire. However, applicants have found in long-term practice that threading a guidewire through a working portion of a ventricular assist device is very difficult and obstructive, which greatly hinders the rapid clinical deployment of interventional treatment protocols.

The research shows that the reason for the phenomenon is as follows: a resealable seal is present in the guide wire channel of the working portion of the ventricular assist device to permit backflow of perfusate from the distal end of the drive shaft to flush the bearings supporting the distal end of the drive shaft. Therefore, the sealing element has the functions of both liquid blocking and thread guiding. Therefore, the seal is provided with a guide wire hole which is automatically closed after the guide wire is threaded through by the flexibility of the seal material itself. Therefore, during the guide wire threading process, due to the better resilience or flexibility of the sealing element, the sealing element tightly wraps the outer wall of the guide wire when the guide wire passes through the sealing element, and further the resistance of the guide wire passing through the sealing element is larger, so that the guide wire threading is difficult.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a ventricular assist device capable of reducing resistance between a guide wire and a sealing member during threading.

In order to achieve the purpose, the utility model provides the following technical scheme: a ventricular assist device comprising:

a motor;

a conduit;

a drive shaft passing through the catheter, the proximal end being connected to the motor;

a pump assembly, comprising: a pump housing connected to a distal end of the conduit and having an inlet end and an outlet end, an impeller received within the pump housing, the impeller being connected to a distal end of the drive shaft to be driven in rotation to draw blood into the pump housing from the inlet end and discharge it from the outlet end;

a flexible support connected to the distal end of the pump housing for spacing the inlet end from an interior wall of a heart chamber when the pump assembly is in operation;

the driving shaft and the flexible supporting piece are of hollow structures and are communicated to form a guide wire channel for a guide wire to pass through;

a seal disposed in the guidewire channel distal to the distal end of the drive shaft;

a guide wire hole for the guide wire to pass through is formed in the sealing element, and the guide wire hole is closed after the guide wire is withdrawn; wherein the depth of the wire guide hole is 0.1-5 mm.

Preferably, the depth of the wire guide hole is 0.2 to 2mm, and more preferably 0.3 to 1 mm.

Preferably, the far end of the pump shell is provided with a far end bearing chamber, a far end bearing is arranged in the far end bearing chamber, the far end of the driving shaft penetrates through the far end bearing, and the flexible supporting piece is connected to the far end of the far end bearing chamber; a seal member is disposed within the distal bearing chamber and is positioned between the distal end of the drive shaft and the proximal end of the flexible support member.

Preferably, there is no region of potential energy change at the side wall surface where the seal member contacts the inner wall of the distal bearing chamber.

Preferably, all of the side wall surfaces of the seal member are flush with the inner wall of the distal bearing chamber.

Preferably, the sealing element is pre-shaped at the distal end of the drive shaft under an external force to provide the sealing element with a pre-load; the pre-pressing amount is 0 to 40%, more preferably 2 to 25%, and still more preferably 5 to 20%.

Preferably, at least partial region of the distal end face of the sealing element is inwards recessed to form a thickness reduction region, and the wire guide hole is formed in the thickness reduction region.

Preferably, the diameter of the guidewire hole is gradually larger from the proximal end to the distal end at each position along the axial direction, or is equal or tends to be equal.

Preferably, the cross-sectional area of the distal end face of the sealing element is greater than the cross-sectional area of the proximal end face of the sealing element; preferably, the proximal end face of the seal is planar.

Preferably, the cross-sectional area of the distal end face of the sealing element is equal to the cross-sectional area of the proximal end face of the sealing element; preferably, the proximal and distal end faces of the seal are planar.

The utility model has the beneficial effects that: the depth of the wire guide hole of the sealing element is 0.1-5mm, the resistance between the outer wall of the guide wire and the inner wall of the wire guide hole is small in the range, the guide wire can be smoothly threaded and guided within expected time to realize rapid deployment of interventional operation, and the wire guide hole can be closed after the guide wire is withdrawn, so that the sealing element has good sealing function, and perfusion fluid entering from the wire guide channel flows back under the action of the sealing element.

Drawings

Fig. 1 is a schematic structural view of a ventricular assist device of the present invention.

Fig. 2 is another schematic structural diagram of the ventricular assist device of the present invention.

Fig. 3 is a schematic cross-sectional view of fig. 1.

Fig. 4 is a partial structural schematic diagram of fig. 3.

Fig. 5 is another partial structural schematic diagram of fig. 3.

Fig. 6 is another schematic cross-sectional view of fig. 1.

Fig. 7 is a partial structural schematic view of fig. 6.

FIG. 8 is a further cross-sectional view of FIG. 1

Fig. 9 is a partial structural schematic of fig. 8.

Fig. 10 is a further schematic cross-sectional view of fig. 1.

Fig. 11 is a partial structural schematic of fig. 10.

Detailed Description

The present invention will be described in detail below with reference to specific embodiments shown in the drawings. These embodiments are not intended to limit the present invention, and structural, methodological, or functional changes made by those skilled in the art according to these embodiments are included in the scope of the present invention.

The terms "proximal", "posterior" and "distal", "anterior" are used herein with respect to the clinician administering the ventricular assist device of this embodiment. The terms "proximal", "posterior" refer to the portion that is relatively close to the clinician, and the terms "distal", "anterior" refer to the portion that is relatively far from the clinician. For example, the motor is at the proximal and rear ends, the flexible support is at the distal and front ends; for another example, the proximal end of a component/assembly is shown as being relatively close to the end of the motor, and the distal end is shown as being relatively close to the end of the flexible support.

The ventricular assist device of the present invention defines an "axial" or "axial extension direction" with the extension direction of the drive shaft. As used herein, the term "inner" and "outer" are used with respect to an axially extending centerline, with the direction toward the centerline being "inner" and the direction away from the centerline being "outer".

It is to be understood that the terms "proximal," "distal," "rear," "front," "inner," "outer," and these terms are defined for convenience of description. However, ventricular assist devices may be used in many orientations and positions, and thus these terms of expressing relative positional relationships are not intended to be limiting and absolute. For example, the above definitions of the directions are only for convenience of illustrating the technical solution of the present invention, and do not limit the directions of the ventricular assist device of the present invention in other scenarios, including but not limited to product testing, transportation, and manufacturing, which may cause the device to be inverted or to change its position. In the present invention, the above definitions shall follow, if any, if they are otherwise explicitly defined and limited.

In the present invention, the terms "connected" and the like are to be understood broadly, unless otherwise explicitly specified or limited. For example, the connection can be fixed connection, detachable connection, movable connection or integration; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

Referring to fig. 1 to fig. 4, a ventricular assist device 100 according to an embodiment of the present invention may at least partially assist a blood pumping function of a heart, so as to at least partially reduce a burden on the heart.

In one scenario, the ventricular assist device 100 may be used as a left ventricular assist device, with the pump assembly 4 being insertable into the left ventricle, and the impeller 42 of the pump assembly 4 being operative to pump blood in the left ventricle into the ascending aorta.

Of course, the ventricular assist device 100 may also be used as a right ventricular assist device, with the pump assembly 4 being inserted into the right ventricle, the pump assembly 4 being operative to pump blood in the veins into the right and left ventricles.

Alternatively, the ventricular assist device 100 may also be adapted 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 renal vein into the vena cava, and may be configured for placement within the subclavian or jugular vein at the junction of the vein and the lymphatic catheter 2, and for increasing the flow of lymphatic fluid from the lymphatic vessel into the vein.

The following will be described primarily in the context of the ventricular assist device 100 being used as a left ventricular assist. It will nevertheless be understood that no limitation of the scope of the embodiments of the utility model is thereby intended, as illustrated in the accompanying drawings.

The ventricular assist device 100 includes a motor 1, a catheter 2, a drive shaft 3 inserted through the catheter 2 and connected proximally to the motor 1, and a pump assembly 4. Power is transmitted between the motor 1 and the impeller 42 of the pump assembly 4 through the drive shaft 3 to drive the pump assembly 4 to perform a blood pumping function.

The transmission of the motor 1 and the drive shaft 3 may be any suitable known technique, such as magnetic coupling, and will not be described in detail herein. When magnetic coupling is used, the ventricular assist device 100 further includes a hub connected to the motor 1 and a coupler 6 mated with the hub, the coupler 6 communicating with the proximal end of the catheter 2.

In use of the ventricular assist device 100, the pump assembly 4 and the forward end portion of the catheter 2 are delivered to and held within the subject, and it is desirable that the pump assembly 4 and the catheter 2 be as small in size as possible. The smaller size of the pump assembly 4 and catheter 2 allows access to the body via the smaller interventional size, reduces the pain to the subject from the interventional procedure, and may reduce complications due to the oversized interventional procedure.

Drive shaft 3 includes flexible axle 31 and is connected to the hard axle 32 of flexible axle 31 distal end, and flexible axle 31 wears to establish in pipe 2, and pipe 2 avoids drive shaft 3 and external contact, ensures drive shaft 3's normal work on the one hand, and on the other hand avoids 3 working processes of drive shaft in the direct contact examinee, causes the injury to the examinee. The hard shaft 32 is connected with the impeller 42, and one feasible way is that the hard shaft 32 is arranged in a hollow channel of a hub of the impeller 42 in a penetrating way, and the outer wall of the hard shaft 32 is fixed with the inner wall of the hollow channel through adhesion.

As described above, the pump assembly 4, which can be delivered to a desired location of a heart chamber, such as the left ventricle of a heart, through the catheter 2, includes a pump housing 41 connected to the distal end of the catheter 2 and having an inlet end and an outlet end, an impeller 42 housed within the pump housing 41.

In the present embodiment, the pump housing 41 includes a holder 411 made of nickel or titanium alloy and having a metal lattice structure, and an elastic coating 412 covering the holder 411. The metal lattice of the stent 411 has a mesh design, the cover 412 covers the middle and rear end portions of the stent 411, and the mesh of the portion of the stent 411 not covered by the cover 412 at the front end forms the inlet end. The rear end of the cover 412 covers the distal end of the catheter 2, and the outlet end is an opening formed at the rear end of the cover 412.

The impeller 42 includes a hub and blades supported on an outer wall of the hub. The blade has a blade root connected to the hub and a blade tip connected to the blade root. The impeller 42 can be driven to rotate to draw blood into the pump housing 41 from the inlet end and expel it from the outlet end.

Wherein the pump assembly 4 is a collapsible pump having a compressed state and an expanded state. In the pump assembly 4 corresponding to the interventional configuration, the pump housing 41 and impeller 42 are in a compressed state such that the pump assembly 4 is delivered in a first, smaller radial dimension within the vasculature of a subject. In the corresponding operating configuration of the pump assembly 4, the pump housing 41 and impeller 42 are in an expanded state such that the pump assembly 4 pumps blood at a desired location with a second radial dimension that is greater than the first radial dimension.

At the distal end of the pump assembly 4, a flexible support 5 is provided. In particular, the flexible support 5 is connected to the distal end of the pump housing 41. The flexible support 5 is made of a flexible material, which may be any material that macroscopically exhibits flexibility. Because of the nature of the material from which the flexible support 5 is made, it is configured to be soft so as not to damage the subject's tissue. Specifically, the flexible support member 5 is a flexible protrusion with 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-invasive manner to separate the suction inlet of the pump assembly 4 from the inner wall of the ventricle, so that the suction inlet of the pump assembly 4 is prevented from being attached to the inner wall of the ventricle due to the reaction force of the fluid (blood) in the working process of the pump assembly 4, and the effective pumping area is ensured.

A proximal bearing chamber 7 is connected between the distal end of the catheter 2 and the proximal end of the stent 411. That is, the holder 411 is connected to the catheter 2 through the proximal bearing chamber 7. In particular, the distal end of the catheter 2 may be adhesively bonded to the proximal bearing chamber 7, the proximal bearing chamber 7 being snap-fit connected to the holder 411. The socket joint relation of the three is as follows: the distal end of the catheter 2 is inserted into the proximal opening of the proximal bearing housing 7 and the distal end of the proximal bearing housing 7 is inserted into the proximal opening of the holder 411.

The drive shaft 3 is passed through a proximal bearing 71 located in the proximal bearing chamber 7. Wherein the proximal bearings 71 are provided in two and the proximal end of the hard shaft 32 is provided with a stop 72 between the two proximal bearing chambers 7 to limit the drive shaft 3 and/or the impeller 42.

Wherein, the impeller 42 has a tendency to move distally due to the action of the blood backpressure during the blood pumping process, the relative distal proximal bearing 71 can limit the distal movement of the drive shaft 3 and/or the impeller 42, so as to avoid the impeller 42 moving distally in the pump housing 41 during the blood pumping process, and maintain the position of the impeller 42 in the pump housing 41 stable.

The relatively proximal end bearing 71 serves to limit proximal movement of the stop 72 and to prevent undesired friction of the stop 72 against contact with the distal end of the catheter 2 during operation to avoid abrading of the distal end of the catheter 2 by undesired friction. It is known that the generation of these abrasive dust can enter the human body with the perfusate, which is extremely harmful.

From this point of view, therefore, the relatively proximal bearing 71 can be replaced by another structure, such as a collar, as long as it serves as a proximal stop for the stop 72.

The distal end of the pump housing 41 is provided with a distal bearing chamber 8. Specifically, a distal bearing chamber 8 is provided between the distal end of the holder 411 of the pump housing 41 and the flexible support 5, and the flexible support 5 is connected to the distal end of the distal bearing chamber 8. That is, the flexible support 5 is connected to the bracket 411 through the distal bearing chamber 8. In particular, at least part of the proximal end of the flexible support 5 protrudes into the distal bearing chamber 8 to be fixed, which may be adhesive.

A distal bearing 81 is provided in the distal bearing chamber 8, and the distal end of the drive shaft 3 is inserted into the distal bearing 81. The rotatable support of the impeller 42 by the proximal bearing 71 and the distal bearing 81, combined with the higher rigidity of the hard shaft 32, allows the impeller 42 to be preferably held in the pump casing 41, and the pump gap between the impeller 42 and the pump casing 41 to be stably maintained.

The outer wall of the distal end bearing chamber 8 is provided with a plurality of axial grooves arranged along the circumferential direction and a circumferential groove, and the circumferential groove is communicated with the distal side of the plurality of axial grooves. The distal end of the holder 411 is formed with a plurality of substantially T-shaped coupling legs, the axial portions of which are fitted into the axial grooves, and the circumferential portions coupled to the distal ends of the axial portions and disposed substantially perpendicularly thereto are fitted into the circumferential grooves. Thereby, fixation of the bracket 411 to the distal bearing compartment 8 is achieved.

Meanwhile, in order to prevent the connecting leg from popping up and causing the bracket 411 and the far-end bearing chamber 8 to be disconnected, the far-end bearing chamber 8 is also coated with a fixing piece 82, and the fixing piece 82 is formed by a heat shrinkage process through a heat shrinkage pipe. During assembly, after the plurality of connecting legs at the far end of the bracket 411 are buckled into the grooves on the outer wall of the far-end bearing chamber 8, the heat-shrinkable tube is sleeved outside the far-end bearing chamber 8, then a heating process is performed on the heat-shrinkable tube, and the heat-shrinkable tube is tightly wrapped outside the far-end bearing chamber 8 after being shrunk, so that the fixing piece 82 is formed.

In other embodiments, the fixing element 82 may be other elements, such as an elastic element forming a closed loop, and the like, which is not limited herein, and only needs to achieve the above-mentioned effect of fixing and limiting the distal bearing chamber 8.

The driving shaft 3 and the flexible support 5 are hollow structures, and the driving shaft and the flexible support are communicated to form a guide wire channel. It is worth noting that the guide wire channel, which is also used for the perfusion channel of the perfusion fluid (Purge) during operation, is proximally connected to the proximal end face of the coupler 6 and distally connected to the flexible support 5.

As shown in fig. 1 and fig. 2, the coupler 6 is provided with a perfusion fluid interface 61, the perfusion fluid is injected into the catheter 2 through the interface 61, and the flexible shaft 31 penetrating the catheter 2 is of a liquid permeable woven structure. Therefore, the perfusion fluid can enter the flexible shaft 31 in a penetration mode in the process of flowing forwards in the conduit 2.

Wherein the perfusate flowing in the catheter 2 washes and lubricates the two proximal bearings 71 after flowing to the distal end. The perfusion fluid flowing in the flexible shaft 31 continues to flow forward into the hard shaft 32 and out of the distal end of the hard shaft 32. The perfusate flows back, flushing and lubricating the distal bearing 81 under the sealing or damming action of the seal 9 (described below) distal to the distal end of the hard shaft 32.

It is noted that the perfusion fluid flowing out of the catheter 2 may also lubricate the drive shaft 3, in particular the flexible shaft 31.

Before use, the hub of the motor 1 is disconnected from the coupling 6. When in use, the guide wire with the guiding function is firstly inserted into the vascular system of a subject. Subsequently, the user (typically a medical professional) holds the distal end of the ventricular assist device 100 (distal end of the flexible support 5), and passes the proximal end of the guide wire into the distal end of the guide wire channel until the guide wire passes through the entire flexible support 5 and drive shaft 3 and out of the proximal end face of the coupler 6. Subsequently, the catheter 2 is advanced, causing the pump assembly 4 to be delivered to a desired location (e.g., the left ventricle) along a guide path established by the guidewire in the vasculature of the subject. Thereafter, after the pump assembly 4 is advanced to the desired location, the guidewire is withdrawn, completing the interventional operation of the pump assembly 4. Then, the connector of the motor 1 is connected with the coupler 6, and the motor 1 is activated to work.

The perfusion of the perfusion fluid is performed from the interface 61 of the coupler 6 and may be assisted by a syringe. The syringe contains a perfusion fluid, and the perfusion fluid is injected into the catheter 2 through the interface 61 by pushing the syringe. As mentioned above, the driving shaft 3 is disposed in the catheter 2, and the driving shaft 3 includes a flexible shaft 31 and a hard shaft 32 connected to a distal end of the flexible shaft 31. Wherein, the flexible shaft 31 can not form a closed state on the inner and outer walls of the flexible shaft 31 due to the particularity of the weaving structure thereof, thereby forming communication. Therefore, when the perfusion fluid enters the catheter 2 and flows from the proximal end to the distal end, even if the perfusion fluid is completely perfused inside the flexible shaft 31, the perfusion fluid exists inside and outside the flexible shaft 31. Therefore, at the beginning of perfusion, only the perfusion fluid needs to be injected into the catheter 2, and the perfusion fluid does not need to be injected at a specific position, so that the perfusion is more convenient and quicker.

At the hard shaft 32, insulation may be provided between the inner and outer walls of the hard shaft 32 due to the rigidity of the material of the hard shaft 32. That is, the perfusion fluid outside the hard shaft 32 cannot directly permeate from the hard shaft 32 into the hard shaft 32. However, due to the connectivity between the flexible shaft 31 and the hard shaft 32, the perfusion fluid in the flexible shaft 31 can flow forward and directly flow into the hard shaft 32. The specific flow direction of the perfusate can be seen in the arrows in fig. 5, 7, 9 and 11.

As mentioned above, in order to lubricate the distal bearing 81 by recirculating the perfusion fluid flowing out of the distal end of the hard shaft 31, a seal 9 is provided in the guide wire channel, the seal 9 being located distally of the distal end of the drive shaft 3. The seal 9 serves to intercept the path of the perfusate continuing forward out of the distal end of the flexible support 5 so that the perfusate can only back flush the distal bearing 81.

In an alternative embodiment, a seal 9 may be provided within the distal bearing chamber 8 between the distal end of the drive shaft 3 and the proximal end of the flexible support 5. Alternatively, in another possible embodiment, the sealing member 9 may be provided in the flexible support 5, in particular at the distal end of the flexible support 5.

In order to enable the perfusion fluid flowing from the guide wire channel to the distal end of the drive shaft 3 to flow from inside the guide wire channel to outside the guide wire channel for lubrication and/or cooling of the rotating part (the flow direction of the perfusion fluid at the seal can be seen in the arrows in fig. 5, 7, 9 and 11), there is also a spacing between the seal 9 and the distal end of the drive shaft 3. Therefore, the inner wall of the distal bearing chamber 8 forms an abutting surface 83, the abutting surface 83 abuts against the proximal end of the sealing member 9, and the distal end of the sealing member 9 abuts against the proximal end of the flexible supporting member 5, so as to fix the sealing member 9.

As is apparent from the above, the guide wire passage is used for the guide wire to pass through, and accordingly, the seal member 9 is formed with a guide wire hole 91 through which the guide wire passes, and the guide wire hole 91 is closed after the guide wire is withdrawn. Wherein the sealing member 9 is made of a flexible material, such as silicone, rubber, polyurethane, or other biocompatible material.

In the process of threading the guide wire, the inner wall of the guide wire hole 91 is contacted with the outer wall of the guide wire, so that friction force is generated, and the friction force forms resistance to threading of the guide wire. Should not take an undesirably long time during the guidewire threading procedure.

The magnitude of the frictional force is positively correlated with the contact area between the inner wall of the guide wire hole 91 and the outer wall of the guide wire. That is, the larger the depth of the guide wire hole 91 is, the longer the inner wall of the guide wire hole 91 is, and the larger the contact area between the inner wall of the guide wire hole 91 and the outer wall of the guide wire is. Wherein the measuring direction of the depth of the thread guide hole 91 is along the axial direction of the driving shaft 3.

However, after the seal 9 is withdrawn from the guide wire, the guide wire hole 91 needs to be closed to trap the perfusion fluid and allow the perfusion fluid to flow back to lubricate the distal bearing 81. Therefore, the sealing member 9 also needs a strong sealing property to prevent leakage of the priming liquid.

The friction force of the sealing element 9 to the guide wire and the sealing consideration of the perfusion fluid are combined, so that the guide wire threading can be completed in the shortest time possible, meanwhile, the sealing element 9 can also have good sealing performance, and in a preferred embodiment, the depth of the guide wire hole 91 is 0.1-5mm to meet the requirement.

It is noted that the above numerical values include all values of lower and upper values that are incremented by one unit from the lower limit value to the upper limit value, and that there may be an interval of at least two units between any lower value and any higher value. For example, the guide wire holes 91 are illustrated as having a depth of 0.1 to 5mm, preferably 0.2 to 2mm, and more preferably 0.3 to 1mm, for the purpose of illustrating the values such as 0.4mm, 0.6mm, 0.9mm, which are not explicitly enumerated above.

As described above, the example in which the minimum end points of the respective numerical ranges are spaced apart by 0.1 and the maximum end points are spaced apart by 1 does not exclude the increase in the spacing of other appropriate unit numerical values. For example, the minimum endpoints are separated by 0.2, 0.3, etc., and the maximum endpoints are separated by 0.5, 2, etc. These are only examples of what is intended to be explicitly recited, and all possible combinations of numerical values between the lowest value and the highest value that are enumerated are to be considered to be explicitly recited in this specification in a similar manner.

Unless otherwise indicated, all ranges include the endpoints and all numbers between the endpoints. The use of "about" or "approximately" with a range applies to both endpoints of the range. Thus, "about 20 to 30" is intended to cover "about 20 to about 30", including at least the endpoints specified.

For other definitions of numerical ranges appearing herein, reference is made to the above description and further description is omitted.

The sealing element 9 is pre-formed at the distal end of the drive shaft 3 under the influence of an external force, so that the sealing element 9 has a pre-load. In short, in the embodiment where the seal 9 is provided in the distal bearing chamber 8, the seal 9 has a diameter slightly larger than the inner diameter of the distal bearing chamber 8 before being fitted into the distal bearing chamber 8. Due to the flexible elasticity of the seal 9, it can be forced to compress and fit into the distal bearing chamber 8, thereby creating said preload.

The influence of the preload of the seal 9 on the smoothness of the guide wire insertion and the sealing performance of the seal 9 is important. The preload can reflect the variation of the radial dimension of the sealing element 9 before and after installation, and can be specifically expressed as:

ξ＝(d0-d)/d0

where d0 is the diameter of the seal 9 before installation and d is the diameter of the seal 9 after installation.

The amount of preload affects the rebound of the seal 9. If the seal 9 is pressed to a high degree, the diameter of the installed seal 9 is small, and the d0-d is large, so that the preload is high, which results in poor rebound resilience of the seal 9, and thus increases the friction between the inner wall of the guide wire hole 91 and the outer wall of the guide wire. Conversely, if the seal 9 is compressed to a low degree, the diameter of the installed seal 9 is large, and the value of d0-d is small, so that the pre-compression is low, which may cause poor or uncompressed closing of the guide wire hole 91 after the guide wire is withdrawn from the guide wire hole 91, thereby causing leakage.

In order to balance the friction between the inner wall of the guide wire hole 91 and the outer wall of the guide wire when the guide wire is passed through the guide wire hole 91 and the sealing performance of the sealing member 9 (the closing performance of the guide wire hole 91) after the guide wire is withdrawn from the guide wire hole 91, in a preferred embodiment, the pre-pressing amount of the sealing member 9 is 0-40% so that the guide wire can be passed through the guide wire hole 91 in a desired time, and the sealing member 9 can intercept the perfusion fluid after the guide wire is withdrawn and make the perfusion fluid flow back to the rotating part.

Similarly, the numerical values include all values from the lower value to the upper value which are incremented by one unit, and there may be an interval of at least two units between any lower value and any higher value.

For example, the seal 9 is described as having a preload of 0-40%, preferably 2-25%, and more preferably 5-20%, for the purpose of illustrating values such as 6%, 10%, 13%, 15%, 19% that are not expressly recited above.

It should be noted that the setting conditions of the preload amount and the depth of the guide wire hole 91 are all to ensure that the threading of the guide wire is completed in as short a time as possible, and the sealing member 9 has good sealing performance after the guide wire is withdrawn, so as to prevent leakage. Therefore, the pre-pressing amount and the depth of the wire guiding hole 91 may be set simultaneously in the same embodiment, or the pre-pressing amount and the depth of the wire guiding hole 91 may be set separately in different embodiments to achieve the above-mentioned purpose, which is not particularly limited herein and is determined according to actual circumstances.

Under the setting conditions of the above-described preload amount and/or the depth of the wire hole 91, the hole diameters at respective positions of the wire hole 91 in the axial direction thereof are equal or tend to be equal. Where the trend toward equality is expressed as: the value of the difference between the hole diameters at respective positions of the wire hole 91 in the axial direction thereof is small or almost 0. In order to further improve the smoothness of the guide wire threading so that the guide wire threading is completed in as short a time as possible, the hole diameters of the guide wire holes 91 at respective positions in the axial direction thereof become gradually larger from the side close to the distal end bearing 81 to the side away from the distal end bearing 81, and the smoothness of the guide wire threading can also be improved so that the guide wire threading can be completed in a desired time. That is, in the present embodiment, the cross section of the guide hole 91 in the axial direction is flared.

Referring to fig. 6, 7, 8 and 9, it can be seen from the above that the guide wire is threaded from the distal end to the proximal end of the ventricular assist device 100 during the threading process. Therefore, at least a partial region of the distal end face of the sealing member 9 is recessed inward to form a reduced thickness region, which can guide the threading direction of the guide wire and increase the speed of the guide wire passing through the guide wire hole 91.

The diameter of the wire guide hole 91 on the distal end face of the sealing element 9 is large, and when the proximal end of the wire guide reaches the distal end face of the sealing element 9, the aligning speed between the wire guide and the wire guide hole 91 is increased, so that the smoothness of wire guide threading can be improved, and the time of wire guide threading is shortened. The diameter of the guide wire hole 91 in the proximal end surface of the seal member 9 is small, and the seal member can be closed after the guide wire is withdrawn, thereby achieving good sealing performance.

The sealing element 9 forms the special function of "the distal end is easily deformed proximally and the proximal end is not easily deformed distally" in the area of the vicinity of the wire hole 91 by forming the wire hole 91 in the area of the reduced thickness corresponding to the above-described characteristics. Wherein the "distal end is easily deformed proximally", which allows the seal 9 to easily slightly flip over in the region of the proximal portion of the guidewire aperture 91 during guidewire passage, thereby allowing rapid guidewire passage.

Whereas "the proximal end is less prone to distal deformation", a better seal and liquid interception can be formed. In particular, when the perfusion fluid forms a hydraulic pressure at the proximal end of the sealing member 9, the sealing member 9 is deformed distally by the hydraulic pressure of the perfusion fluid in the region near the guidewire hole 91, and the deformation further seals the guidewire hole 91.

The diameter of the guidewire hole 91 of the distal end face of the sealing member 9 may be equal to the size of the hollow of the flexible support 5, so that when the proximal end of the guidewire reaches the distal end face of the sealing member 9, it can enter into the guidewire hole 91 without an alignment operation.

Alternatively, at least a part of the distal end surface of the sealing member 9 is recessed inward to form a reduced thickness region, and the wire hole 91 is provided in the reduced thickness region. The reduced thickness region may be formed by inwardly recessing all of the distal end surface of the sealing member 9, that is, the distal end surface of the sealing member 9 is disposed obliquely. The distal end surface is inclined from the distal end to the proximal end toward the guide wire hole 91. The end face formed after the end face of the far end is inwards concave can be an arc-shaped face, a plane face or a corrugated face and the like, and the end face is not particularly limited and is determined according to actual conditions. In this embodiment, the concave formed distal end face is preferably an arc-shaped face, and when the proximal end of the guide wire reaches the distal end face of the seal member 9, it can be quickly aligned with the guide wire hole 91 directly under the guiding action of the obliquely arranged distal end face.

Referring to fig. 10 and 11, alternatively, the cross-sectional area of the distal end surface of the sealing member 9 is larger than the cross-sectional area of the proximal end surface of the sealing member 9. Wherein the distal end face is obliquely arranged towards the proximal end to form an inclined surface so as to guide the threading reversal of the guide wire. Likewise, the obliquely arranged distal end surface can be an arc surface, a plane surface, a wavy surface or the like. Alternatively, if the distal end surface is partially recessed, the cross-sectional area of the distal end surface is the sum of the areas of the un-recessed region and the recessed region.

In order to enable the proximal end face of the sealing member 9 to better intercept and return the perfusion fluid, the proximal end face is plane. The proximal end face that the plane set up can with the better laminating of the inner wall of distal end bearing room 8, simultaneously, the laminating between the outer periphery of sealing member 9 and the inner wall of distal end bearing room 8 prevents when the face of proximal end face for evagination or indent, and the perfusate can enter into the clearance between proximal end face and the distal end bearing room 8, increases the possibility of perfusate seepage.

In short, all the side wall surfaces of the sealing member 9 and the inner wall of the distal bearing chamber 8 are fitted to reduce the possibility of the perfusate entering between the side wall surfaces of the sealing member 9 and the inner wall of the distal bearing chamber 8, thereby improving the sealing effect of the sealing member 9 so that the perfusate can flow back to the distal bearing 81 at the sealing member 9 to lubricate the distal bearing.

Alternatively, there is no region of potential energy change at the side wall surface where the seal 9 contacts the inner wall of the distal bearing chamber 8. That is, the side wall surface of the seal 9 in contact with the inner wall of the distal bearing chamber 8 is not deformed by the external force, so that a gap is prevented from being generated between the side wall surface of the seal 9 and the inner wall of the distal bearing chamber 8 when the side wall surface of the seal 9 is deformed, and the perfusion fluid flows into the gap, thereby increasing the possibility of leakage. Wherein the external acting force is the fluid power of the perfusate.

Referring to fig. 3 to 5, alternatively, the cross-sectional area of the distal end surface of the sealing member 9 is equal to the cross-sectional area of the proximal end surface of the sealing member 9. At this time, the proximal end surface and the distal end surface of the sealing member 9 are flat surfaces, so that the proximal end surface of the sealing member 9 is fitted to the inner wall of the distal bearing chamber 8, and the distal end surface of the sealing member 9 is fitted to the proximal end of the flexible support member 5.

In summary, the depth of the guide wire 91 of the sealing element 9 of the present invention is 0.1-5mm, and in this range, the resistance between the outer wall of the guide wire and the inner wall of the guide wire hole 91 is small, so that the guide wire can be smoothly threaded and guided within a desired time to achieve rapid deployment of the interventional operation, and the guide wire hole 91 can be closed after the guide wire is withdrawn to enable the sealing element 9 to have a good sealing function, so that the perfusion fluid entering from the guide wire channel flows back under the action of the sealing element 9.

The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above examples only show some embodiments of the present invention, and the description thereof is more specific and detailed, but not to be construed as limiting the scope of the utility model. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A ventricular assist device, comprising:

a motor;

a conduit;

a drive shaft extending through the catheter and having a proximal end connected to the motor;

a pump assembly including a pump housing connected to the distal end of the conduit and having an inlet end and an outlet end, and an impeller received within the pump housing, the impeller being connected to the distal end of the drive shaft to be driven in rotation to draw blood into the pump housing from the inlet end and discharge it from the outlet end;

a guide wire hole for the guide wire to pass through is formed in the sealing element, and the guide wire hole is closed after the guide wire is withdrawn;

wherein the depth of the wire guide hole is 0.1-5 mm.

2. A ventricular assist device as claimed in claim 1, wherein the depth of the guidewire hole is 0.2-2mm, more preferably 0.3-1 mm.

3. A ventricular assist device as claimed in claim 1, wherein a distal end of the pump housing is provided with a distal bearing chamber in which a distal bearing is provided, the distal end of the drive shaft passing through the distal bearing, the flexible support being connected to a distal end of the distal bearing chamber;

the seal member is disposed within the distal bearing chamber and between the distal end of the drive shaft and the proximal end of the flexible support member.

4. A ventricular assist device as claimed in claim 3, wherein the side wall surface of the seal in contact with the inner wall of the distal bearing chamber is free of regions of varying potential energy.

5. A ventricular assist device as claimed in claim 3, wherein all of the side wall surfaces of the seal member are flush with the inner wall of the distal bearing chamber.

6. A ventricular assist device as claimed in claim 1, wherein the sealing member is pre-shaped at the distal end of the drive shaft under an external force to provide the sealing member with a pre-load;

the preload amount of the seal member is 0 to 40%, more preferably 2 to 25%, and still more preferably 5 to 20%.

7. A ventricular assist device as claimed in any one of claims 1 to 6, wherein at least a region of the distal end face of the seal member is recessed inwardly to form a reduced thickness region, the guidewire port being provided in the reduced thickness region.

8. A ventricular assist device as claimed in any one of claims 1 to 6, wherein the guidewire hole has a progressively larger, equal or nearly equal, bore diameter at each location along its axial direction from the proximal end to the distal end.

9. A ventricular assist device as claimed in any one of claims 1 to 6, wherein the cross-sectional area of the distal end face of the seal is greater than the cross-sectional area of the proximal end face of the seal; preferably, the proximal end face of the seal is planar.

10. A ventricular assist device as claimed in any one of claims 1 to 6, wherein the cross-sectional area of the distal end face of the seal is equal to the cross-sectional area of the proximal end face of the seal; preferably, the proximal and distal end faces of the seal are planar.