CN114452527B - Device for assisting heart in the event of failure - Google Patents

Abstract

Provided is a device for assisting the heart in the event of functional failure, comprising a motor, a coupler detachably engaged with the motor, a driving rotor, a driven rotor disposed in the coupler, a catheter proximally connected to the coupler , a drive shaft passing through the catheter and driven by the rotor shaft, and a pump driven by the drive shaft to pump blood. The driving rotor includes a first bracket connected to the output shaft of the motor, and a driving element arranged on the first bracket; the driven rotor includes a rotor shaft, a driven element arranged on the rotor shaft and coupled with the driving element. One of the driving member and the driven member is a magnetic force providing element, and the other is a conductor, forming a gap therebetween.

Description

A device used to assist the heart when it fails

【Technical field】

The invention relates to a device for assisting the heart when its function fails, and belongs to the technical field of medical devices.

【Background technique】

Heart failure is a health problem with a high mortality rate. Taking cardiogenic shock as an example, the ejection performance of the left ventricle of the patient is significantly weakened, and the weakened coronary blood supply may lead to irreversible heart failure. Therefore, for this case, temporary interventional support (ventricular assist) will partially or mostly replace the pumping function of the left ventricle and improve coronary blood supply.

In existing ventricular assist devices, due to the requirement of liquid sealing (preventing the perfusate from entering the motor), it is relatively common to use magnetic coupling to transmit the power of the motor to the drive shaft. Specifically: the active magnet provided on the output shaft of the motor is coupled with the passive magnet connected to the proximal end of the drive shaft. When the motor drives the active magnet to rotate, the drive shaft is driven to rotate under the action of the magnetic force coupling between the active and passive magnets, and then Drive the impeller to rotate to achieve blood pumping.

As described in CN103120810B, the magnetic coupling has the effect of a clutch. When the transmissible torque of the magnetic coupling exceeds the set torque, for example, the rotation of the impeller at the front end is blocked, and the two magnets are separated. At this time, even though the motor rotates normally, the drive shaft and the impeller are in or basically in a stalled state, and the pump fails and cannot continue to pump blood.

It is worth noting that the magnetic coupling has the property of blocking the rotation and disconnecting the power transmission, which is designed to protect the ventricular tissue from being damaged. But at the same time, this can lead to a series of undesirable consequences, including:

1. In the case that the pump loses its function of pumping blood, and the subject (for example, a person) who is involved in the ventricular assist device has insufficient heart pumping ability, it will inevitably lead to poor or even no flow of blood, and the intervention of the ventricular assist device Parts of the subject's body, including the catheter and pump components, are prone to thrombus formation. The hazards of thrombus are obvious, including but not limited to: thrombus enters the brain with the blood flow through the whole body and causes stroke, and thrombus does not flow but stays somewhere in the blood vessel, causing poor oxygen supply to nearby nerve tissue and nerve damage.

2. Based on the principle of magnetic coupling, after the rotation is blocked and the impeller slows down significantly, it is difficult or even impossible to achieve a complete rerotation after the resistance disappears. Practically speaking, in the high-speed scenario of ventricular assist, if the impeller wants to turn back after the speed is reduced, it can only be realized by stopping the impeller. This is obviously unfavorable for the clinical need to provide continuous ventricular assistance to the subjects.

Further, without using other automatic detection means to feedback the decrease in blood flow due to the large speed reduction of the impeller, generally it can only be judged manually through observation and experience. Moreover, even after the resistance disappears, human intervention is required to achieve recovery. This is also unrealistic for the tense medical resources and complex clinical environment usually faced by the high-risk application scenario of ventricular assistance.

【Content of invention】

The purpose of the present invention is to provide a device for assisting the heart in failure, which can solve at least one of the above problems.

The purpose of the present invention is to realize through the following technical solutions:

A device for assisting the heart in the event of functional failure, comprising: a motor, a coupler detachably engaged with the motor, a driving rotor, a driven rotor disposed in the coupler, a catheter proximally connected to the coupler , a drive shaft passed through the catheter and driven by the rotor shaft, and a pump driven by the drive shaft to pump blood. Wherein, the pump includes: a pump casing connected to the distal end of the conduit and having an inlet end and an outlet end, and an impeller accommodated in the pump casing. The impeller is driven in rotation by the drive shaft to draw blood into the pump casing from the inlet end and out through the outlet end. The driving rotor includes: a first bracket connected to the output shaft of the motor, and a driving member arranged on the first bracket. The driven rotor includes: a rotor shaft, a driven part arranged on the rotor shaft and coupled with the driving part. One of the driving member and the driven member is a magnetic force providing element, and the other is a conductor, forming a gap therebetween.

Compared with the prior art, the present invention has the following beneficial effects:

1. The magnetic force supply element is coupled with the conductor to form a power transmission structure similar to an eddy current coupling. Based on the working principle of the eddy current coupling, when this structure is used to transmit the rotating power, if the rotation of the impeller is blocked, compared with the power transmission method of magnetic coupling, the speed of the working side (drive shaft or impeller) will not drop significantly. Therefore, it has a certain clutch function, and in the case of protecting the ventricular tissue, it will not significantly reduce the pump blood flow, thereby greatly reducing the risk of thrombus formation due to the decrease of blood flow and the intervention of the device.

2. Based on the working principle of the eddy current coupling, the speed difference between the driving part and the driven part is also the reason why it can be coupled. Therefore, after the resistance to the rotation of the impeller disappears, as long as the motor is still working normally, the follower will automatically realize the re-rotation without restarting the motor after stopping the machine. Therefore, the continuity of providing ventricular assistance to the subject is better, and this continuity does not depend on complex monitoring and control means, and the clinical stability is higher.

【Description of drawings】

Fig. 1 and Fig. 2 are three-dimensional schematic diagrams of different angles of the device of the embodiment of the present invention;

Fig. 3 is a three-dimensional schematic diagram of the separation of the driving assembly and the working assembly in Fig. 1;

Fig. 4 is a structural schematic diagram of a part of the transmission mechanism provided by the first embodiment of the present invention;

5 is a schematic structural view of a part of the transmission mechanism provided by the second embodiment of the present invention;

Fig. 6 is a schematic structural diagram of a part of the transmission mechanism provided by the third embodiment of the present invention;

Fig. 7 is a schematic structural diagram of a part of the transmission mechanism provided by the fourth embodiment of the present invention;

Fig. 8 is a schematic structural diagram of a part of the transmission mechanism provided by the fifth embodiment of the present invention;

9a to 9e are structural schematic diagrams of different seals used in the fifth embodiment of the present invention;

Fig. 10 is a schematic structural view of a part of the transmission mechanism provided by the sixth embodiment of the present invention;

FIG. 11 is a schematic perspective view of the partial structure shown in FIG. 10 .

Fig. 12 is a schematic structural diagram of a part of the transmission mechanism provided by the seventh embodiment of the present invention;

Fig. 13 is a schematic structural diagram of a part of the transmission mechanism provided by the eighth embodiment of the present invention.

[Specific examples]

The present invention will be described in detail below in conjunction with the embodiments shown in the accompanying drawings. However, these embodiments do not limit the present invention, and any structural, method, or functional changes made by those skilled in the art according to these embodiments are included in the protection scope of the present invention.

The terms "proximal", "rear" and "distal", "anterior" as used herein are relative to the clinician manipulating the device. The terms "proximal" and "posterior" refer to the part relatively close to the clinician, and the terms "distal" and "anterior" refer to the part relatively far away from the clinician. For example, the driving component is at the proximal end and the rear end, and the working component is at the distal end and the front end; for another example, the proximal end of a certain part/component means the end relatively close to the driving component, and the far end means the end relatively close to the working component.

The device of the present invention defines "axial direction" or "axial extension direction" by the extension direction of the motor shaft, rotor shaft, and drive shaft. The terms "inner" and "outer" used in the present invention are relative to the axially extending centerline, the direction relatively close to the centerline is "inner", and the direction relatively far away from the centerline is "outer".

It should be understood that the orientations of "near", "far", "rear", "front", "inner", and "outer" are definitions for convenience of description. However, the device can be used in many orientations and positions, and thus these terms expressing relative positional relationships are not intended to be limiting and absolute.

For example, the above definition of each direction is only for the convenience of explaining the technical solution of the present invention, and does not limit the auxiliary device of the present invention when it includes but is not limited to product testing, transportation and manufacturing, etc., which may lead to its inversion or position The orientation in the scene where the transformation occurs. In the present invention, if the above definitions are otherwise clearly defined and limited, they shall follow the above clearly specified and limited.

In the present invention, terms such as "connected" and "connected" should be interpreted in a broad sense unless otherwise specified and limited. For example, it can be a fixed connection, a detachable connection, a movable connection, or an integral body; it can be directly connected or indirectly connected through an intermediary, and it can be the internal communication of two components or two components. interaction relationship. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

Please refer to FIG. 1 to FIG. 3 , the device 100 according to the embodiment of the present invention can at least partially assist the pumping function of the heart, and at least partially reduce the burden on the heart. In an exemplary scenario, the device 100 can be used as a left ventricular assist, and its working part (specifically referred to as the pump below) can be inserted into the left ventricle. When the pump is running, the blood in the left ventricle can be pumped to in the ascending aorta.

It should be noted that the above example of being used as left ventricular assistance is only a possible application scenario of the device 100 . In other feasible scenarios that cannot be explicitly excluded, the device 100 can also be used as a right ventricular assist, a pump can be inserted into the right ventricle, and the pump pumps blood in the vein to the right ventricle during operation.

Alternatively, device 100 may also be adapted to pump 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, and may also be configured to The junction of the vein and the lymphatic duct is placed within the subclavian or jugular vein and is used to increase the flow of lymphatic fluid from the lymphatic vessel to the vein.

In the following, the scenario where the device 100 is used as left ventricular assistance is mainly described. However, based on the above description, it can be seen that the protection scope of the embodiments of the present invention is not limited thereby.

Please combine FIG. 3 and FIG. 4 , the device 100 includes a driving assembly 10 and a working assembly 30 . The driving assembly 10 provides power for the working assembly 30 to drive the working assembly 30 to realize the function of pumping blood. The driving assembly 10 includes a motor housing 12 and a motor 14 accommodated in the motor housing 12 . The driving assembly further includes a driving rotor, and the driving rotor includes: a first bracket 511 connected to the output shaft of the motor 14 , and a driving member 994 arranged on the first bracket 511 . The output shaft of the motor 14 may be directly driven by the motor shaft 16, or indirectly driven by the motor shaft.

The device 100 also includes a control module electrically or communicatively connected with the motor 14 , which will be described in detail later.

The working assembly 30 includes a coupler 39 detachably engaged with the motor 14 , and the joining methods include plug-in, snap-fit connection, nut locking connection and the like. The working assembly also includes a driven rotor arranged in the coupler 39. The driven rotor includes: a rotor shaft 44, a follower 896 arranged on the rotor shaft 44, the follower 896 is coupled with a driving member 994 to be driven around The axis of rotation turns.

The working assembly 30 also includes a conduit 32 , a drive shaft (not shown) passing through the conduit 32 , and a pump 36 driven by the drive shaft. The proximal end of catheter 32 is connected to the distal end of coupler 39 . The drive shaft passes through the conduit 32 and is driven by the rotor shaft 44 .

The pump 36 can be delivered to the desired position of the heart (for example: the left ventricle) to pump blood through the catheter 32, and includes a pump housing 363 connected to the distal end of the catheter 32 and having an inlet end 361 and an outlet end 362, and a pump housing housed in the pump housing. An impeller (not shown), driven in rotation by the drive shaft to draw blood into pump housing 363 from inlet port 361 and out from outlet port 362 .

The pump casing 363 includes a bracket 3631 made of nickel or titanium alloy in a metal lattice structure and an elastic film 3632 covering the bracket 3631 . The metal lattice of the bracket 3631 has a mesh design, the coating 3632 covers the part of the bracket 3631 , and the mesh of the front end of the bracket 3631 not covered by the coating 3632 forms the inlet port 361 . The rear end of the membrane 3632 covers the outside of the distal end of the catheter 32 , and the outlet end 362 is an opening formed at the rear end of the membrane 3632 .

The impeller includes a hub connected to the far end of the drive shaft and blades supported on the outer wall of the hub. The blades are helical, and the number of the blades can be one or more, such as two.

A proximal bearing chamber (not shown) is connected between the distal end of the catheter 32 and the proximal end of the bracket 3631 . That is, the bracket 3631 is connected with the catheter 32 through the proximal bearing chamber. The drive shaft passes through the proximal bearing located in the proximal bearing chamber. A distal bearing chamber 37 is provided between the distal end of the bracket 3631 and the protective head 38 (described in detail later). That is, the protective head 38 is connected with the bracket 3631 through the distal bearing chamber. The distal end of the drive shaft passes through the distal bearing located in the distal bearing chamber 37 . The impeller is limited by the proximal and distal bearings, so that the impeller can be preferably held in the pump casing 363 , and the pump gap between the impeller and the pump casing 363 is stably maintained.

The pump 36 is a collapsible pump with a compressed state and an expanded state. In the corresponding interventional configuration of the pump 36, the pump casing 363 and the impeller are in a compressed state, and the pump 36 can be inserted into the vasculature of the human body or delivered in the vascular system of the subject with a small first outer diameter. In the corresponding working configuration of the pump 36 , the pump housing 363 and the impeller are in a deployed state, and the pump 36 can pump blood in the left ventricle with a second radial dimension greater than the first radial dimension.

In the art, the size and hydrodynamic performance of the pump 363 are two conflicting parameters. In short, it is desirable that the size of the pump 363 be small from the standpoint of relieving the subject's pain and ease of intervention. In order to provide a strong auxiliary function for the subject, it is desirable that the flow rate of the pump 363 be large, which generally requires a large size of the pump 363 .

By setting the collapsible pump 363, the pump 363 has a smaller collapsed size and a larger expanded size, so as to reduce the pain of the subject during the intervention/transportation process, facilitate the intervention, and provide a large flow rate demand.

Based on the above, the multi-mesh design of the pump casing 3631, especially the diamond-shaped mesh, can achieve better folding, and at the same time, it can be unfolded by virtue of the memory characteristics of nickel-titanium alloy.

When the pump 36 corresponds to the intervention configuration, the blades are wrapped on the outer wall of the hub and at least partly in contact with the inner wall of the pump casing. The vanes extend radially outward from the hub and are spaced from the inner wall of the pump 36 when the pump 36 corresponds to the operative configuration. The blades are made of soft and elastic materials, which store energy when they are folded, and release the energy storage of the blades to unfold them after the external constraints are removed. The pump 36 is folded by means of external constraints, and after the constraints are removed, the pump 36 realizes self-deployment.

In this embodiment, the "compressed state" refers to the state in which the pump 36 is radially constrained. That is, the pump 36 is radially compressed and folded into the smallest radial dimension under external pressure. "Deployed state" refers to the state in which the pump 36 is not radially constrained. That is, the bracket 3631 and the radially outer side of the impeller are expanded to a state of maximum radial size.

The aforementioned application of external constraints is accomplished by sliding a folded sheath (not shown) over the catheter 32 . When the foldable sheath moves forward outside the catheter 32, the pump 36 can be accommodated in it as a whole, so that the pump 36 can be forcibly folded. When the folded sheath is moved rearwardly, the radial constraint on the pump 36 is lost and the pump 36 self-deploys.

From the above, the pump 36 is collapsed by the radial constraint force exerted by the folded sheath, and the impeller contained in the pump 36 is accommodated in the pump casing 363 . Therefore, in essence, the folding process of the pump 36 is: the folded sheath exerts a radial constraint force on the pump casing 363 , and when the pump casing 363 radially compresses, it exerts a radial constraint force on the impeller.

That is, the pump casing 363 is retracted directly under the action of the folding sheath, while the impeller is directly retracted under the action of the pump casing 363 . And as mentioned above, the impeller has elasticity. Therefore, although the impeller is in the collapsed state, the energy storage of the impeller always has a tendency to expand radially, and then the impeller will contact the inner wall of the pump casing 363 and exert a reaction force on the pump casing 363 .

After the restraint of the folded sheath is removed, the pump housing 363 expands the supporting elastic membrane 3632 under the action of its own memory characteristics, and the impeller expands by itself under the action of released energy storage. In the deployed state, the outer diameter of the impeller is smaller than the inner diameter of the pump housing 363 . In this way, a gap is maintained between the radially outer end of the impeller (that is, the tip of the blade) and the inner wall of the pump casing 363 (specifically, the inner wall of the bracket 3631 ), and the gap is the pump gap. The existence of the pump gap enables the impeller to rotate without hindrance without hitting a wall.

In addition, for hydrodynamic considerations, it is desirable that the pump clearance size be kept at a small value. In this embodiment, the outer diameter of the impeller is slightly smaller than the inner diameter of the bracket 3631, so that the pump clearance is as small as possible under the condition that the impeller rotates without bumping against the wall.

The main means of maintaining the pump clearance is the supporting strength provided by the bracket 3631, which can resist the back pressure of the fluid (blood) without deformation, thereby keeping the shape of the pump casing 363 stable, and the pump clearance is also maintained. Hold steady.

Below the folding and unfolding process of the pump 36 are introduced as follows:

During insertion of the pump 36 into the left ventricle, the pump 36 is radially constrained (compressed) due to an externally applied radial constraining force. Alternatively, pump 36 is collapsed only during intervention in the subject's vasculature. After intervention into the left ventricle (delivered forward in the vasculature in a collapsed configuration), or after intervention into the vasculature of the subject (delivered forward in the vasculature in a deployed configuration), withdraw Radial restraint force, the bracket 3631 utilizes its own memory characteristics and the blades of the impeller expand autonomously with the release of energy storage, so the pump 36 automatically assumes its unconstrained shape (expanded state).

Conversely, when the device 100 completes its work and needs to be withdrawn from the subject, use the foldable sheath to fold the pump 36. After the pump 36 is completely withdrawn from the subject, remove the restraint of the foldable sheath on the pump 36, so that the pump 36 Return to the natural state of least stress, that is, the unfolded state.

The protective head 38 is soft and can be made of any macroscopically flexible material without harming the tissue of the subject. Specifically, the protective head 38 is a flexible protrusion with an arc-shaped or coiled end, and the flexible end is supported on the inner wall of the ventricle in a non-invasive or non-damaging manner, connecting the suction port 361 of the pump 36 with the ventricle. The inner wall is separated to prevent the suction port 361 of the pump 36 from adhering to the inner wall of the ventricle due to the reaction force of blood during the working process of the pump 36, so as to ensure the effective area of pumping.

The driving assembly 10 is detachably connected to the working assembly 30 through the coupler 39 and the motor housing 12 . Thus, when the pump 36 and the distal end portion of the catheter 32 are ready to be delivered into the body of the subject, the driving assembly 10 and the working assembly 30 can be disassembled to prevent the larger and heavier driving assembly 10 from affecting the movement of the pump 36 and the catheter 32. The operation in which the front end part is sent into the subject's body is easier to operate.

Please focus on FIGS. 3 and 4 , the driving assembly 10 includes a driving member 99 driven by the motor shaft 16 of the motor 14 . The working assembly 30 includes a follower 89 coupled to a drive 99 to be driven in rotation about an axis of rotation, the follower 89 driving the drive shaft. The rotor shaft 44 is arranged between the driven part 89 and the drive shaft, the driven part 89 drives the rotor shaft 44, and the drive shaft is connected to the rotor shaft 44, so that the driven part 89 drives the rotor shaft 44, the drive shaft and the pump 36 in sequence.

One of the driving member 99 and the driven member 89 is a magnetic force providing element, and the other is a conductor, forming a gap 79 therebetween. The magnetic force providing element is a magnet with its own magnetism, such as a permanent magnet or a hard magnet. Alternatively, the magnetic force providing element may also be an electromagnetic element capable of generating magnetism after electrification, such as a coil. The conductor can be made of metal, such as copper, aluminum or an alloy containing copper and aluminum with better electrical conductivity.

After the motor shaft 16 rotates to drive the driving member 99 to rotate, the conductor will cut the magnetic field lines in the magnetic field generated by the magnetic force providing element, and then generate eddy current in the conductor. The eddy current generates a reverse induced magnetic field on the conductor, and the induced magnetic field is magnetically coupled with the magnetic field generated by the magnetic force providing element, thereby realizing the coupling between the driven member 89 and the driving member 99 and being driven to rotate around the rotation axis. The rotation of the driven member 89 drives the rotor shaft 44 and the drive shaft to rotate, and finally drives the pump 36 .

It is particularly worth noting that the coupling between the magnetic force providing element and the conductor constitutes a power transmission structure similar to an eddy current coupling (EddyCurrent). Based on the working principle of the eddy current coupling, when using this structure to transmit the rotating power, if the rotation of the impeller is blocked, compared with the power transmission method of magnetic coupling, the speed of the working side (drive shaft or impeller) will not drop significantly. Therefore, it has a certain clutch function, and in the case of protecting the ventricular tissue, it will not significantly reduce the pump blood flow, thereby greatly reducing the risk of thrombus formation due to the decrease of blood flow and the intervention of the device.

Moreover, based on the working principle of the eddy current coupling, the speed difference between the driving part and the driven part is also the reason why it can be coupled. Therefore, after the resistance to the rotation of the impeller disappears, as long as the motor is still working normally, the follower will automatically realize the re-rotation without restarting the motor after stopping the machine. Therefore, the continuity of providing ventricular assistance to the subject is better, and this continuity does not depend on complex monitoring and control means, and the clinical stability is higher.

The gap 79 between the driving member 99 and the driven member 89 enables the magnetic coupling between the driving member 99 and the driven member 89 to realize non-contact power transmission, which is beneficial to realize the sealing of the fluid and prevent the liquid from entering the motor 14 .

The above-mentioned liquid is the Purge liquid that needs to be poured into the human body during the operation of the device 100. The Purge liquid is a physiological fluid that can partially maintain the functions of the human body, such as physiological saline, glucose solution, anticoagulant, or any combination of the above. In order to infuse the Purge liquid into the human body smoothly, the device 100 includes a perfusion system, which includes a housing, and a perfusion pump communicated with the coupler 39 through a pipeline. The control unit (the second control unit described below) set in the casing controls the operation of the perfusion pump. The perfusion pump injects Purge liquid into the coupler 39 through the pipeline, and injects the Purge liquid into the human body through the pipeline system in the working assembly 30 .

The proximal end of the catheter 32 is connected to the coupler 39 and is in liquid communication. The coupler 39 is provided with an interface suitable for connecting with the pipeline. flow forward. During this process, the drive shaft is lubricated and the proximal bearing is flushed to achieve lubrication.

The gap 79 is configured as the distance between the magnetized surface of the magnetic force providing element and the surface of the conductor facing the magnetized surface. There needs to be a clearance 79 between the driving member 99 and the driven member 89, but if the clearance 79 is too large, the transmission efficiency will be affected. Therefore, in this embodiment, the width of the gap 79 is less than or equal to 5mm. The width of the gap 79 is further smaller than 4 mm, further smaller than 3 mm, further smaller than 2 mm, especially further smaller than 1 mm.

It should be noted that the above values include all values from the lower value to the upper value in increments of one unit for the lower and upper values, with a separation of at least two units between any lower value and any higher value That's it.

For example, the width of the stated gap 79 is less than or equal to 5mm, preferably 0.5-4.5mm, more preferably 1-4mm, and further preferably 1.5-3.5mm, the purpose is to illustrate the above-mentioned not explicitly listed such as 2mm, 2.5mm , 3mm value.

As mentioned above, the exemplary ranges of integers do not preclude increments at intervals of numerical units such as 0.1, 0.2, 0.3, 0.5 etc. as appropriate. These are merely examples intended to be expressly stated, and it is considered that all possible combinations of numerical values recited between the lowest value and the highest value are expressly set forth in this specification in a similar manner.

Unless otherwise indicated, all ranges include the endpoints and all numbers between the endpoints. "About" or "approximately" used with a range applies to both endpoints of the range.

For other limitations on the numerical range presented herein, reference may be made to the above description, and details are not repeated here.

In order to constrain the magnetic force lines of the driving member 99 toward the driven member 89 , a first magnetic constraint member 71 is provided on the side of the driving member 99 away from the driven member 89 . The first magnetic constraint member 71 is made of a magnetically permeable material, such as a solid back iron, a parallel magnetic flux silicon steel sheet back iron, a perpendicular magnetic flux silicon steel sheet back iron, and the like. The first magnetic constraining member 71 moves synchronously with the driving member 99 .

Similarly, in order to constrain the magnetic force lines of the follower 89 toward the driving member 99 , the side of the follower 89 facing away from the driving member 99 is provided with a second magnetic constraint member 72 . The second magnetic constraining member 72 is made of magnetically permeable material, and reference may be made to the above description, and details are not repeated here. The second magnetic constraint 72 moves synchronously with the follower 89 .

The first and second magnetic constraint members 71 and 72 cooperate to constrain the magnetic force lines between the driving member 99 and the driven member 89, so that the magnetic force between the two is maximized, thereby improving the transmission efficiency.

The eddy current transmission principle between the driving member 99 and the driven member 89 in the embodiment of the present invention has been described above, and the specific transmission structure will be described below through different embodiments. The principles of these transmission structures are the same and will not be repeated here.

Please refer to FIG. 4 , which shows part of the transmission mechanism of the first embodiment of the present invention.

In this embodiment, the distal end surface of the driving member 99 is opposite to the proximal end surface of the driven member 89, and is configured as end surface coupling. The driving member 99 includes a main body 993 and a connecting portion 995 connected to a side of the main body 993 away from the driven member 89 . The main body 993 is disc-shaped, and the connecting portion 995 is tubular or hollow cylindrical. The motor shaft 16 is inserted into the connecting portion 995 to realize the drive of the motor shaft 16 to the driving member 99 .

The follower 89 is annular, and the rotor shaft 44 is inserted into the central hole of the annular follower 89 to be connected with the follower 89 , and the proximal end surface of the rotor shaft 44 is flush with the proximal end surface of the follower 89 . The gap 79 between the distal end surface of the driver 99 and the proximal end surface of the follower 89 is less than or equal to 5mm.

The first magnetic constraining member 71 constrains the magnetic field lines of the driving member 99 to the far side of the first magnetic constraining member 71 , preventing the magnetic flux lines of the driving member 99 from spreading away from the driven member 89 . The first magnetic constraining member 71 is ring-shaped and sheathed on the connecting portion 995 of the driving member 99 , and the first magnetic constraining member 71 abuts against the proximal end surface of the main body 993 of the driving member 99 , and has a compact structure.

The first magnetic constraining member 71 moves synchronously with the driving member 99 . One way is that the outer surface of the connecting portion 995 of the first magnetic constraining member 71 and the driving member 99 is tightly matched to realize synchronous movement of the first magnetic constraining member 71 and the driving member 99 . Another way is that the first magnetic constraining member 71 and the proximal end surface of the driving member 99 are connected in some way, such as adhesion, to realize the synchronous movement of the first magnetic constraining member 71 and the driving member 99 .

Of course, other ways to realize the synchronous movement of the first magnetic constraining component 71 and the driving component 99 are also possible, and any solution that is the same as or similar to this embodiment falls within the protection scope of the present invention.

Likewise, the second magnetic constraint 72 constrains the magnetic flux of the follower 89 near the second magnetic constraint 72 , preventing the flux of the follower 89 from spreading away from the driver 99 . The second magnetic constraining member 72 moves synchronously with the follower 89 , and the implementation method refers to the above description, which will not be repeated here.

The driven member 89 and the driving member 99 realize magnetic coupling through eddy current transmission and sequentially drive the rotor shaft 44, the drive shaft and the impeller of the pump 36, and the first and second magnetic constraint members 71, 72 cooperate to constrain the magnetic force lines between the two time, so that the transmission is efficient.

Please refer to FIG. 5 , which shows a part of the transmission mechanism of the second embodiment of the present invention.

The known embodiment represented by US7393181 B2 provides a solution that meets the above-mentioned needs, and basically opens the precedent of a collapsible ventricular assist device (abbreviated as a blood pump). The foldability of the blood pump is reflected in the fact that the pump head (including the pump casing and impeller) is folded during the intervention and unfolded after the intervention is in place. The advantage is that it can reduce the size of the intervention, thereby reducing infection and complications, and reducing patient pain, and can also obtain the best hydraulic performance when the pump head is working.

The pump head (specifically the impeller) of the collapsible blood pump is generally driven by a motor located outside the body by means of a very long flexible shaft. During the driving process, the rotating flexible shaft will inevitably rub against the inner wall of the catheter that accommodates it, thereby generating heat. This heating increases the wear of the flexible shaft and the catheter, resulting in a shortened life of these components. The same problem also exists in other rotating parts in the whole transmission chain, such as bearings.

Therefore, the known embodiment represented by US8591393B2 provides a solution for cooling and/or lubricating the above-mentioned very long transmission link when the collapsible blood pump is in operation. The general process is: the fluid supply source outside the body pours fluid into the catheter, and the fluid lubricates the rotating flexible shaft and bearings, reduces the heat generated by friction, and cools the heat generated in time.

However, the introduction of cooling/lubricating fluids, and the ensuing problem of sealing, has to be taken care of. Essentially, you don't want priming fluid to get into the motor, lest it get damaged.

Therefore, how to transmit the rotational power of the motor to the impeller of the pump head through the flexible shaft and prevent the perfusion liquid from entering the motor during the process has always been an urgent problem in this field.

The difference between this embodiment and the first embodiment shown in FIG. 4 is that a liquid separation wall 75 is provided in the gap 79 between the driving member 99 and the driven member 89, so as to facilitate the sealing of the fluid and prevent the liquid from entering the motor. 14.

During the operation of the device 100, the human body needs to be perfused with Purge solution. As mentioned above, if the purge liquid flows into the motor 14, it may damage the motor 14 and cause device failure. Therefore, disposing the liquid separation wall 75 in the gap 79 between the driving member 99 and the driven member 89 can effectively prevent liquid from being injected into the motor 14 .

In addition, heat will be generated during a series of transmissions of the working assembly 30, which will aggravate the wear of the components. Accordingly, thermal management of the working assembly 30 is required. The liquid separation wall 75 limits the flow direction of the liquid, so that the liquid can only flow towards the front end, that is, the working assembly 30 , so as to reduce the temperature of the working assembly 30 .

The liquid partition wall 75 surrounds at least part of the end surface and at least part of the side surface of the follower 89, so as to better prevent the liquid from flowing into the motor 14 and cause damage to the motor 14, and to perform thermal management on the working assembly 30 more uniformly and efficiently. .

The follower 89 is provided with a liquid isolation layer (not shown) for isolating the contact of the liquid with the follower 89 . This liquid is the Purge liquid mentioned above. The liquid separation wall isolates the contact between the liquid and the follower 89, which can prevent the liquid from corroding the follower 89, thereby maintaining the performance of the follower 89 to the greatest extent.

Specifically, in the embodiment where the follower 89 is used as the magnetic force providing element, the liquid isolation can prevent the magnet or coil from being corroded by the liquid and cause the magnetic force to weaken, and prolong the life of the follower 89 providing the magnetic force as much as possible. In the embodiment where the follower 89 is used as a conductor, the liquid isolation can prevent the conductor from being corroded and lead to a decrease in electrical conductivity, and ensure that the follower 89 can generate eddy currents and then generate an induced magnetic field with stable performance.

In one embodiment, the liquid barrier layer may be a waterproof coating, such as a titanium coating. The waterproof coating can be light and thin but effectively isolate the contact between the liquid and the follower 89 . The liquid isolation layer constructed by the waterproof coating has the advantages of thin thickness, light weight, easy forming and high bonding strength, and these advantages will provide beneficial promotion for coupling efficiency, assembly, production cost and service life.

In another embodiment, the liquid isolation layer can be a mechanical structure that wraps or wraps the follower 89 such as resin encapsulation to form a storage cavity for receiving the follower 89 therein. Similar to the above embodiment of the waterproof coating, the receiving cavity can reliably protect the follower 89 and reliably isolate the follower 89 from being eroded by liquid.

Please refer to FIG. 6 , which shows a part of the transmission mechanism of the third embodiment of the present invention.

Different from the first embodiment, in this embodiment, the inner and outer peripheral surfaces of the driving member 993 and the driven member 893 are opposite to realize eddy current transmission, and are configured as radial coupling.

Regardless of whether the end faces are facing each other or the inner and outer peripheral faces are facing each other to realize the transmission, the principle is the same and will not be repeated here. It should be noted that the "circumferential surface" may be a "circumferential surface" or a peripheral surface of other shapes.

Specifically, the driving member 993 and the driven member 893 at least partially overlap in the circumferential direction of the rotation axis, and are spaced apart in the radial direction of the rotation axis to have a gap 79 . In other words, the driving member 993 includes a channel 73 , and the driven member 893 is disposed in the channel 73 .

More specifically, the driving member 993 and the driven member 893 are annular continuously in the circumferential direction, or, the driving member 993 and the driven member 893 include a plurality of annular segments arranged at intervals along the circumferential direction. It should be noted that the driver 993 and the follower 893 overlap at least partially in the circumferential direction, and it is not strictly required that the driver 993 and the follower 893 be in the shape of a ring or a segment of a ring, and rings of other shapes are also acceptable.

In order to install the driving part 993, the motor shaft 16 is connected with the first bracket 51, the first bracket 51 includes the first hollow part 52, the driving part 993 is arranged on the outer wall of the first hollow part 52, and the first magnetic constraint part 713 is arranged on the driving part. Radially outside of 993.

The function of the first magnetic constraining member 713 is the same as that of the foregoing embodiments, and will not be repeated here.

The first bracket 51 includes a mounting portion 53 connected to the first hollow portion 52 . The mounting portion 53 has a mounting hole for mounting the motor shaft 16 . The first bracket 51 is driven to rotate by the motor shaft 16 to drive the driving member 993 to rotate. The first bracket 51 also includes a limiting portion 54 connected to the first hollow portion 52, the limiting portion 54 extends radially outward from the distal end of the first hollow portion 52, and the extending direction of the limiting portion 54 is the same as that of the first hollow portion. The extension direction of 52 is vertical. The driving member 993 abuts against the first hollow portion 52 and the limiting portion 54 at the same time. Preferably, the first hollow portion 52 , the mounting portion 53 and the limiting portion 54 of the first bracket 51 are integrally formed. The limiting part 54 is flush with the outer peripheral surface of the driving part 993, the first magnetic constraining part 713 and the driving part 993 are attached to the outer peripheral surface of the limiting part 54, and the magnetic force lines of the driving part 993 are constrained to the first magnetic constraining part 713 inside.

Of course, it can be understood that the first magnetic constraining member 713 can only be attached to the outer peripheral surface of the driving member 993 , and any solution that is the same as or similar to this embodiment falls within the protection scope of the present invention.

The follower 893 has a through hole, and the rotor shaft 44 is inserted into the through hole to connect with the follower 893 , so that the rotation of the follower 893 drives the rotor shaft 44 to rotate. The proximal end face of the rotor shaft 44 is flush with the proximal end face of the follower 893 .

The working assembly 30 further includes a second magnetic constraining member 723 disposed between the rotor shaft 44 and the driven member 893 , and the second magnetic constrained member 723 connects the driven member 893 and the rotor shaft 44 . The second magnetic constraint member 723 is sleeved on the outer peripheral surface of the rotor shaft 44 , and the follower 893 is sleeved on the outer peripheral surface of the second magnetic constraint member 723 . The second magnetic restraint 723 constrains the magnetic force lines of the follower 893 outside the second magnetic restraint 723 . The axial length of the second magnetic constraining member 723 is the same as that of the follower 893, and the second magnetic constraining member 723 and the follower 893 are aligned in the axial direction, that is, the proximal and distal surfaces of the two Even.

Thus, the rotation of the motor shaft 16 drives the first bracket 51 to rotate, the rotation of the first bracket 51 drives the rotation of the driving part 993, the rotation of the driving part 993 drives the rotation of the follower 893 through the eddy current transmission, and the rotation of the follower 893 drives the rotation of the rotor shaft 44, Thus, the pump 36 is driven to work through the drive shaft. The first magnetic force constraining member 713 and the second magnetic force constraining member 723 cooperate to constrain the magnetic force lines between them.

In an alternative embodiment, the second magnetic constraint 723 is integral with the rotor shaft 44 . In other words, the rotor shaft 44 itself is made of magnetically permeable material, and the rotor shaft 44 itself is configured as the second magnetic restraint 723 , so the independent second magnetic restraint 723 can be omitted, and the structure is simpler.

In this embodiment, the driving member 993 forms a channel, and the driven member 893 at least partially protrudes into the channel. In some other alternative embodiments, the follower 893 includes a channel, and the driver 993 is disposed in the channel.

In this embodiment, the motor shaft 16 is connected to the first bracket 51 , and the driving member 993 is connected to the first bracket 51 , or the first bracket 51 itself constitutes the driving member 993 . In some other alternative embodiments, the rotor shaft 44 is connected with a second bracket, the second bracket includes a second hollow part, the follower 893 is arranged on the outer wall of the second hollow part, and the second hollow part is configured as a second magnetic constraint or, the follower 893 is arranged on the inner wall of the second hollow part, and the second magnetic constraint is arranged on the radial inner side of the follower 893 .

Same as the second embodiment, in this embodiment, a liquid separation wall 75 is also provided in the gap 79 , which will not be repeated here.

When the device 100 is working, the motor shaft 16 drives the driving member 993 to rotate, the driven member 893 is coupled with the driving member 993, the driven member 893 is driven to rotate by the driving member 993, and the driven member 893 rotates to drive the rotor shaft 44 and the driving shaft to rotate in turn , the drive shaft rotates to drive the pump 36 to realize the function of pumping blood.

Please refer to FIG. 7 , which shows a part of the transmission mechanism of the fourth embodiment of the present invention.

As mentioned above, based on the transmission principle of the eddy current coupling, the rotational speeds of the driving member 993 and the driven member 893 are not synchronized. Moreover, it is precisely because of this asynchronous rotational speed that the coupling between the driving member 993 and the driven member 893 can be realized through the eddy current generated in the conductor and the reverse induced magnetic field. In short, there must be a rotational speed difference between the motor shaft 16 and the drive shaft or impeller.

If there is no speed difference between the motor shaft 16 and the drive shaft, the control module can indirectly control the speed of the drive shaft or the impeller by directly detecting and controlling the speed of the motor shaft 16, so that the speed of the impeller is within a reasonable range, so that the pump Meet the needs of the job.

However, in the present invention, the coupling mode of the driving member 993 and the driven member 893 determines that there must be a speed difference between the motor shaft 16 and the driving shaft (usually, the rotating speed of the driving shaft is lower than that of the motor shaft 16). Then, it is very necessary for the control module to know the speed of the drive shaft in time for the control of the drive shaft and the normal operation of the pump. To this end, the device 100 includes a rotational speed detection component communicated with the control module for detecting the rotational speed of the drive shaft.

When the control module judges that the speed of the drive shaft is lower than the target speed based on the signal provided by the speed detection component, it controls the motor 14 to increase the speed, thereby increasing the speed of the drive shaft, so that the speed of the drive shaft is adjusted to near the target speed. It should be noted that when the speed of the drive shaft fluctuates within 10%, preferably 5%, and more preferably within 1% of the target speed, the control module determines that the speed of the drive shaft is near the target speed.

When the control module determines that the rotational speed of the drive shaft is near the target rotational speed based on the signal provided by the rotational speed detection component, the motor 14 is controlled to maintain the current rotational speed, so that the rotational speed of the drive shaft is maintained near the target rotational speed.

Preferably, the device 100 further includes an alarm unit electrically or communicatively connected to the control module. The control module judges that the speed of the drive shaft is lower than the target speed based on the signal provided by the speed detection component, but the speed of the motor 14 is higher than the set speed. When the value is set, control the operation of the alarm unit. That is to say, when the rotational speed of the motor 14 is higher than the set value, theoretically, the rotational speed of the drive shaft will not be lower than the target rotational speed. In this case, if it is detected that the rotational speed of the drive shaft is lower than the target rotational speed, it means , There is a problem in the transmission link from the motor 14 to the drive shaft, for example, there is rotational resistance in the impeller or the drive shaft, resulting in a stall problem of the impeller or the drive shaft compared with the motor shaft 16 . At this time, the alarm unit sends out an alarm signal, so that the operator (such as a doctor) can be informed of the situation in time, so that corresponding measures can be taken in time, thereby improving safety. The alarm unit can be, for example, a sound alarm, a light flash alarm, or a combination of the two alarms.

The control module comprises a first control unit integrated in the motor 14, a second control unit arranged in the housing of the perfusion system. The first control unit can provide the converted level signal to the motor 14 and can also provide reverse electrical isolation to the motor 14 . The second control unit is electrically or communicatively connected with the rotational speed detection component, and controls the operation of the motor 14 and the perfusion pump.

The first control unit is the first PCB unit, and its functions include: first, supplying a suitable voltage to the motor 14 to realize voltage conversion, such as converting high level to low level, or converting low level to high voltage level, and then supplied to the motor 14. Second, electrical isolation makes electrical and electronic regulations based on safety requirements. For example, when there are other high-voltage scenarios on the intervention side, such as a defibrillator passing back to the motor 14 through a conductive flexible shaft, it may cause failure and damage to the device 100 , so electrical isolation is required.

The second control unit is a second PCB unit, and its functions include: controlling the operation of the motor 14 . For example, based on the received signal, the rotational speed of the motor 14 is controlled. Wherein, the above-mentioned signals at least include: an electric speed signal, and then the second PCB unit converts the electric speed signal (voltage) into speed information for judgment and further speed control. The role of the second PCB unit also includes controlling the motor (syringe pump motor) in the perfusion system, thereby controlling the perfusion of the Purge solution.

Since the control module includes a first PCB unit and a second PCB unit that are separately arranged, the first PCB unit and the second PCB unit can be respectively arranged in different positions and perform their own duties, instead of all being arranged in the motor 14, thereby The size of the motor 14 can be reduced.

The difference between this embodiment and the third embodiment will be mainly described below.

In order to detect the rotational speed of the drive shaft, the rotational speed detection component includes a synchronizer 202 that rotates synchronously with the drive shaft, and a sensor 204 that detects the rotational speed of the synchronizer 202, and the sensor 204 is electrically or communicatively connected with the control module.

The sensor 204 can detect the rotation speed of the drive shaft, and transmit the rotation speed information of the drive shaft to the control module, and the control module can judge whether the rotation speed of the drive shaft meets the requirements, and judge whether it is necessary to adjust the rotation speed of the driving member 994 by adjusting the rotation speed of the motor 14 , and finally control the rotational speed of the drive shaft within the required range, so as to meet the working needs of the pump driven by the drive shaft.

For example, in one scenario, if the control module judges that the speed of the drive shaft is lower than the minimum requirement, the speed of the drive shaft can be increased by increasing the speed of the motor 14, thereby increasing the speed of the drive shaft through the coupling of the driving member 994 and the driven member 894, thereby satisfying Pump work required. Certainly, the reverse control is also possible, so no more details are given here.

In one embodiment, the synchronizer 202 is a magnetic force providing element, and the sensor 204 is a coil. According to the principle of electromagnetic induction, when the magnetic force supply element rotates synchronously with the drive shaft, a current will be generated in the coil, and when the magnetic force supply element rotates at different speeds, the magnitude of the current in the coil will change, and the coil is electrically connected to the control module or Communication connection, the control module can determine the rotation speed of the magnetic force providing element through certain calculations through the change of the current magnitude of the coil, thereby determining the rotation speed of the drive shaft, and judging whether it is necessary to adjust the rotation speed of the motor 14, thereby adjusting the rotation speed of the drive shaft Rotating speed.

In other embodiments of the present invention, the rotational speed detection component can be realized by grating, light reflection, stroboscope and other principles, and any solution that is the same as or similar to this embodiment is covered within the protection scope of the present invention.

In another embodiment, the synchronizer 202 is a magnetic force providing element, and the sensor 204 is a Hall sensor. When the magnetic force supply element rotates at different speeds, the Hall sensor will send out different pulse signals. The control module can detect the change of the pulse signal sent by the Hall sensor and obtain the speed of the drive shaft through certain calculations, and judge according to the needs Is it necessary to adjust the speed of the motor and thus the speed of the drive shaft.

Since the Hall sensor is a sensor 204 with relatively mature technology, it is only necessary to select and purchase a suitable sensor, which makes the design and manufacture of the device simpler.

As mentioned above, the rotor shaft 44 is arranged between the driven part 894 and the driving shaft, the driven part 894 is installed on the rotor shaft 44 and drives the rotor shaft 44, and the driving shaft is connected with the rotor shaft 44, so that the driven part 894 sequentially Drives the rotor shaft 44, drive shaft and pump.

When the device is working, the distal part of the driving shaft is sent into the body of the subject along with the catheter, and the driving shaft includes a flexible flexible shaft, which can be deformed visible to the naked eye. The rotor shaft 44 is equipped with a follower 894, and the rotor shaft 44 is a hard shaft, which can make the installation of the follower 894 more stable and run more reliably.

The synchronizer 202 is provided on the rotor shaft 44 . That is to say, when the synchronizer 202 rotates with the rotor shaft 44 , the positions of the synchronizer 202 and the sensor 204 will not change, and the sensor 204 can detect the speed of the synchronizer 202 more accurately.

As previously mentioned, the synchronizer 202 is the magnetic force providing element, and the synchronizer 202 is disposed on the rotor shaft 44 . Preferably, the rotor shaft 44 is made of non-magnetic material. The non-magnetic material can be, for example, stainless steel, ceramics, polymer materials and combinations of these materials. Therefore, the rotor shaft 44 itself will not affect the magnetic field of the synchronizer 202 , which makes the sensor 204 detect the rotational speed of the synchronizer 202 more accurately.

The device 100 is in a liquid environment during use, and the liquid environment is not friendly to the operation of the synchronizer 202. For example, when the synchronizer 202 is a magnetic force providing element, if the magnetic force providing element contacts liquid, the liquid will corrode the magnetic force providing element. This leads to weakening of the magnetism. In order to prevent the liquid from corroding the synchronizer 202 , the synchronizer 202 is covered with a casing 206 , and the casing 206 is circumferentially fixed to the rotor shaft 44 .

The housing 206 isolates the synchronizer 202 from the liquid environment, keeping the synchronizer 202 in good working condition. The housing 206 covers the synchronizer 202 therein, that is, the housing 206 forms a receiving space, and the synchronizer 202 matches the shape of the receiving space, so that the synchronizer 202 and the housing 206 move synchronously. The casing 206 and the rotor shaft 44 are fixed in the circumferential direction, that is, the casing 206 and the rotor shaft 44 rotate synchronously to ensure that the synchronizer 202 and the rotor shaft 44 rotate synchronously, thereby accurately measuring the rotation speed of the rotor shaft 44 and the drive shaft, thereby determining whether the rotation speed of the motor 14 is adjusted Provide reliable support.

The manner in which the housing 206 and the rotor shaft 44 realize synchronous movement may be, for example, that the housing 206 is tightly fitted with the rotor shaft 44 , or that the housing 206 is flattened with the rotor shaft 44 . The housing 206 is flattened with the rotor shaft 44 , that is, the cross section of the rotor shaft 44 is non-circular. Specifically, the peripheral surface of the rotor shaft 44 includes a first surface and a second surface, and the first surface or the circumscribed surface of the first surface is set at an angle to the second surface or the circumscribed surface of the second surface. The housing 206 has a central passage for inserting the rotor shaft 44. The surface of the central passage matches the shape of the peripheral surface of the rotor shaft 44, so that the housing 206 is fitted flatly with the rotor shaft 44, and the housing 206 and the synchronizer 202 are aligned with the rotor shaft. 44 rotate synchronously.

The housing 206 is made of insulating material to prevent the synchronizer 202 from interacting with possible currents.

In one embodiment, the housing 206 includes a first part 208 and a second part 210 , the first part 208 and the second part 210 are manufactured independently and cooperate to form a space for receiving the synchronizer 202 . Thus, during installation, after the synchronizer 202 is installed on the first part 208 , the second part 210 is mated with the first part 208 , so that the synchronizer 202 can be packaged in the housing 206 .

In another embodiment, the synchronizer 202 can be integrally molded on the casing 206 , so that the casing 206 can better cover the synchronizer 202 .

The synchronizer 202 is arranged on the radial inner side of the liquid separation wall 75 , and the sensor 204 is arranged on the radial outer side of the liquid separation wall 75 . Therefore, the liquid separation wall 75 makes the synchronizer 202 and the sensor 204 spaced apart to ensure the normal operation of the synchronizer 202 and the sensor 204 . Moreover, rational use of the space on both sides of the liquid separation wall 75 is beneficial to the miniaturization of the device.

It can be seen from this that the synchronizer 202 is packaged in the housing 206, and the housing 206 and the rotor shaft 44 are circumferentially fixed, so that the synchronizer 202 and the rotor shaft 44 are circumferentially fixed, and there is basically no relative rotation between the two. When the rotor shaft 44 rotates at a certain speed, the synchronizer 202 rotates synchronously with the rotor shaft 44 . When the synchronizer 202 rotates at different speeds, a signal change will occur in the sensor 204, and the sensor 204 is electrically connected or communicated with the control module of the device. After the control module detects the signal change, it can determine the synchronization through certain calculations. 202, so as to determine the rotating speed of the rotor shaft 44 and the drive shaft (the drive shaft and the rotor shaft 44 rotate synchronously), and determine whether the speed of the drive shaft is within a reasonable range. If the rotation speed of the drive shaft is not within a reasonable range, the control module can adjust the rotation speed of the rotor shaft 44 and the drive shaft by adjusting the rotation speed of the motor, so as to ensure the normal operation of the pump.

During the working process of the device, the synchronizer 202, the sensor 204 and the control module are in the process of dynamic adjustment. That is, after the control module adjusts the rotational speed of the rotor shaft 44 as described above, the synchronizer 202 and the sensor 204 will feed back the rotational speed of the rotor shaft 44 to the control module again, and the control module determines whether further adjustment is required. So repeatedly, always ensure that the pump works in a relatively stable state.

Please refer to Fig. 8 and Fig. 9, which show part of the transmission mechanism of the fifth embodiment of the present invention.

In this embodiment, the follower 895 is a magnetic force providing element, specifically a magnetic ring, and a second magnetic constraint 725 is provided between the magnetic ring and the rotor shaft 44 . The second magnetic restraint 725 is an annular back iron, which is sheathed on the rotor shaft 44, and the follower 895 is sleeved on the second magnetic restraint 725, and the two magnetic restraints 725 and the follower 895 The ends are even.

In order to prevent the liquid from corroding the follower 895, the two ends of the rotor shaft 44 are respectively provided with first and second end covers 231, 232 located at the two end sides of the follower 895, the first and second end covers 231, 232, 232 provides sealing for follower 895 in the axial direction. The first and second end caps 231, 232 are disc-shaped and have a certain thickness. It tightly fits with the rotor shaft 44 to provide axial sealing protection for the follower 895 .

The outer diameters of the first and second end caps 231 , 232 are larger than the outer diameter of the follower 895 . Alternatively, the first and second end caps 231 , 232 extend radially beyond the follower 895 . The radial outer side of the follower 895 is provided with a protective layer 234, the protective layer 234 is connected with the first and second end caps 231, 232 to cover the follower 895 inside, and the protective layer 234 is the follower 895 in the radial direction. Provides a seal.

The protective layer 234 is in the shape of a hollow cylinder, and is connected with the parts of the first and second end caps 231, 232 that exceed the follower 895 in the radial direction, so that the protective layer 234 cooperates with the first and second end caps 231, 232 to form an accommodating The receiving cavity of the follower 895. Preferably, the first and second end caps 231, 232 are provided with stepped surfaces, the protective layer 234 cooperates with the stepped surfaces, and the outer surface of the protective layer 234 does not exceed the radially outer surface of the first and second end caps 231, 232 . More preferably, the outer surface of the protective layer 234 is flush with the radially outer surfaces of the first and second end caps 231 , 232 . Thus, the first and second end covers 231 , 232 , the protective layer 234 , and the rotor shaft 44 cooperate to fully cover the driven member 895 therein, thereby preventing the liquid from corroding the driven member 895 . It can be understood that the second magnetic restraint 725 is arranged between the driven member 895 and the rotor shaft 44, and the cooperation of the first and second end covers 231, 232, the protective layer 234, and the rotor shaft 44 also binds the second magnetic restraint 725 It is completely covered in it to prevent liquid from corroding the second magnetic constraint member 725 .

Due to inconsistencies in processing, assembly, material uniformity, etc., it is possible and highly probable that the center of mass of the rotor shaft 44 will deviate from the axis. During the high speed process of the rotor shaft 44, vibration will be caused, and the extra vibration will cause some problems. For example, it is not conducive to the stable maintenance of the gap 79 where the liquid partition wall 75 is provided.

To reduce vibration, the first end cap 231 and/or the second end cap 232 include a connected body and trim (not shown). The trim part can realize the balance of the first end cover 231 and/or the second end cover 232 on the rotor shaft 44, thereby reducing vibration.

In one embodiment, the trim portion is an opening extending from one end of the main body to the other end, and the extending length of the opening is less than the thickness of the end cover. That is to say, the trim part reduces the weight of the main body, thereby achieving trim and reducing vibration. In order to achieve better balance, the first end cover 231 and/or the second end cover 232 are preferably made of a metal material or a ceramic material with relatively high density, so that the effect of weight reduction and balance is more obvious. The thickness of the first end cap 231 and/or the second end cap 232 is greater than the minimum thickness of the metal material that can be processed, preferably greater than 10% of the minimum thickness of the material that can be processed, further greater than 30%, and further greater than 50%, but not more than 20 times the minimum thickness of the material that can be processed.

For example, the minimum thickness of the material that can be processed by the first end cover 231 and/or the second end cover 232 is 0.3mm, then the actual design thickness of the first end cover 231 and/or the second end cover 232 is greater than or equal to 0.3 mm. mm, less than or equal to 10mm. Preferably, the thickness of the main body is greater than 1mm and less than or equal to 8mm.

The main purpose of this design is to achieve the desired dynamic balance by means of metal or ceramic end cover weight reduction and balance, and at the same time reduce the thickness of the end cover as soon as possible to meet the needs of dynamic optimization and structural miniaturization.

In another embodiment, the main body and the trim portion are stacked, and the trim portion includes an aperture or a weight. That is to say, the trim part adds weight to the main body, and the trim part itself can be lightened or weighted, so that the first end cover 231 and/or the second end cover 232 can balance the rotor shaft 44 to a greater extent.

The second end cover 232 is arranged on the side of the rotor shaft 44 where the drive shaft is installed, and the second end cover 232 is close to the drive shaft relative to the first end cover 231. During the working process of the pump, in probability, the second end cover 232 is relatively close to the first end cover 231. One end cap 231 is more likely to vibrate. In order to reduce vibration to a greater extent, the thickness of the second end cover 232 is greater than that of the first end cover 231 . That is to say, there may be more space on the second end cover 232 to set the trim part on the second end cover 232, thereby performing a trim design on the second end cover 232 to a greater extent, thereby realizing the second end cover 232 to a greater extent. End cap 232 dampens the effect of rotor shaft 44 vibration.

The rotor shaft 44 is provided with a first bearing 235 on the side of the first end cover 231 away from the second end cover 232, and is provided with a second bearing 236 on the side of the second end cover 232 away from the first end cover 231. The first bearing 235 and the second bearing 236 can support the rotor shaft 44 . Consistent with the principle that the thickness of the second end cover 232 is greater than that of the first end cover 231 , the size of the second bearing 236 is greater than that of the first bearing 235 . Specifically, the thickness of the second bearing 236 is greater than that of the first bearing 235 , and the radial dimension of the second bearing 236 is greater than that of the first bearing 235 . In this way, the second bearing 236 cooperates with the first bearing 235 to more stably support the rotor shaft 44 and further reduce vibration.

For the convenience of description, the part that can be delivered into the body of the subject is called the access component.

In order to smoothly send the access component into the body of the subject, the device further includes a guide channel 237 passing through the working component. In use, a guiding wire (not shown) is first passed through the vasculature into the subject. Subsequently, the user (generally a medical staff) holds the entry assembly, and passes the proximal end of the guide wire into the distal end of the guide channel 237 until the guide wire passes through the entire working assembly, so that its proximal end passes through the proximal end of the operating assembly. . Subsequently, the pump is delivered to the left ventricle along the guiding path established by the guide wire in the subject's vasculature, and after the proximal end of the pump is sent into the left ventricle, the guide wire is pulled out, the working component is connected to the driving component, and the activation Motor 14, can work.

The guide channel 237 includes an end-side outlet 238 located at the proximal end side. As shown in FIG. The flanged portion of the end is compressed between the coupler 39 and the motor housing 12 when the coupler 39 is engaged with the motor 14 . This enables the liquid separation wall 75 to be compressed, thereby ensuring a liquid-tight effect.

The liquid separation wall 75 includes a proximal portion, and the end side outlet 238 is provided at the proximal end portion of the liquid separation wall 75 for the guide wire to pass through. The end side outlet 238 is provided at the proximal end portion of the liquid partition wall 75 . The end-side outlet 238 forms part of the perfusion channel. Therefore, the end-side outlet 238 needs to be designed to be re-openable or sealed.

Specifically, a resealable seal 240 is provided in the end-side outlet 238 . The seal 240 has two states: a sealed state and an open state. When the seal 240 is in the first state, the seal 240 closes the end-side outlet 238 to prevent the Purge liquid from flowing out from the end-side outlet 238 to corrode the motor. When the seal 240 is in the second state, the end-side outlet 238 is open to allow passage of a guide wire to deliver the access assembly into the subject.

When it is necessary to pass the guide wire, the sealing member 240 is opened to allow the guide wire to pass through the opening at the end side to ensure that the pump enters the body of the subject. After the intervention of the pump is completed, the guide wire is withdrawn, and the sealing member 240 is sealed to avoid leakage of the Purge fluid during the operation of the pump.

In one embodiment, the sealing member 240 includes a flexible sealing plug 241 that can move axially in the end-side outlet 238, and the outer wall of the flexible sealing plug 241 and/or the inner wall of the end-side outlet 238 are designed to be inclined, so that the flexible sealing plug 241 moves along the When the axis moves in the first direction, it is squeezed to switch to the first state, and when it moves in the second direction opposite to the first direction, it expands in the radial direction to switch to the second state.

The seal 240 also includes a rigid operating portion 242 connected to the flexible sealing plug 241 , the operating portion has a hardness greater than that of the flexible sealing plug 241 , and the operating portion is farther away from the end side outlet 238 relative to the flexible sealing plug 241 .

Figures 9a to 9e show perspective and front views of different specific exemplary seals 240.

It can be seen that: the operating part 242 and the flexible sealing plug 241 can be connected through the connecting part 243; the operating part 242 and the flexible sealing plug 241 can also be directly connected. The maximum outer diameter of the operating portion 242 may be larger than the maximum outer diameter of the flexible sealing plug 241 ; the maximum outer diameter of the operating portion 242 may also be equal to the maximum outer diameter of the flexible sealing plug 241 . The thickness of the operating part 242 can be greater than or smaller than that of the flexible sealing plug 241 , and the thickness of the operating part 242 can also be equal to the thickness of the flexible sealing plug 241 . The operating part 242 and the flexible sealing plug 241 form a gradual truncated cone shape; or, the operating part 242 is in the shape of a pull ring, and the size of the ring-shaped operating part 242 is obviously larger than that of the flexible sealing plug 241 to provide better reliability. operability. The operating part 242 and the flexible sealing plug 241 can be completely inserted into the end side outlet 238 when sealing the end side outlet 238; or, only the flexible sealing plug 241 or a part of the flexible sealing plug 241 is inserted into the end side outlet 238...etc. , which will not be described in detail here, any solutions that are the same as or similar to those in this embodiment are covered by the protection scope of the present invention.

In another embodiment, the sealing member 240 is a bladder structure, the first state corresponds to the state when the bladder structure is filled with fluid medium or elastic material, and the second state corresponds to the state after the fluid medium in the bladder structure is at least partially released. state.

Please refer to FIG. 10 and FIG. 11 , which show part of the transmission mechanism of the sixth embodiment of the present invention.

The difference between this embodiment and the third embodiment will be mainly described below.

In the third embodiment, the driving member 993 is disposed on the outer wall of the first hollow portion 52 of the first bracket 51 . In this embodiment, the driving member 996 is arranged on the inner wall of the first hollow portion 522 of the first bracket 511, and the first hollow portion 522 is made of a magnetically permeable material, and the first hollow portion 522 itself is configured as a first magnetic constraint , the structure is simpler. Moreover, the gap between the driving member 996 and the driven member 896 is relatively smaller, and the transmission efficiency is higher.

The front end of the housing of the motor 14 is connected to the cylindrical fixing bracket 250 , and the cylindrical first bracket 511 is fixedly connected to the output shaft of the motor 14 and located in the fixing bracket 250 . A bearing (not shown) is provided between the rear end of the outer wall of the first bracket 511 and the inner wall of the fixed bracket 250 , and another bearing is provided at the rear end of the inner wall of the first bracket 511 for insertion of the liquid partition wall 75 .

In this embodiment, the driving element 996 is a conductor, the conductor is formed in a ring shape, and the conductor forms a channel, and the magnetic force providing element as the follower 896 at least partially extends into the channel. Specifically, the conductor is a copper ring, and the copper ring is arranged in the first bracket 511 .

During the high-speed rotation of the conductor, the heat is serious. After the work of the device is completed, the drive assembly and the working assembly need to be disassembled, and the heating conductor may burn the operator. In order to avoid scalding, a heat-insulating cover 252 is arranged inside the conductor, and the heat-insulating cover 252 is made of a heat-insulating material, which can prevent the operator from being scalded by the conductor when the machine is disassembled.

The heat insulation sleeve 252 includes an end cap 254 , and the heat insulation sleeve 252 can be embedded in the fixing bracket 250 to prevent the copper ring from being burned due to manual misuse. More preferably, an air flow channel is formed between the heat insulation sleeve 252 and the conductor. Thus, the heat generated by the conductor during operation can be dissipated through the airflow channel, so that the heat will not pass through the heat insulation sleeve 252 to reach the magnetic force providing element, drive shaft and other components inside the heat insulation sleeve 252, thereby avoiding the heat generated by the conductor. The heat has an impact on the patient, such as avoiding the heat generated by the conductor to increase the temperature of the pruge fluid and cause adverse effects on the patient. Therefore, although the structure of the heat insulation sleeve 252 is simple, it is not only simple heat insulation, but also can guide heat to dissipate heat in a set direction.

Preferably, on the side facing the magnetic force providing element, the heat insulation sleeve 252 is as long as the conductor, or the heat insulation sleeve 252 is slightly longer than the conductor. Thereby ensuring heat insulation and heat dissipation guiding effect. The applicant has proved through practice that the heat generation of a conductor is inversely related to its length, that is to say, the longer the conductor is, the lower the heat generation will be. Therefore, from the perspective of heat dissipation, the longer the length of the conductor, the better. However, if the length of the conductor is too long, the volume and weight of the device will increase, and the portability of operation will be reduced. The applicant has repeatedly confirmed that the length of the conductor is greater than or equal to 15mm and less than or equal to 85mm. The length of the heat insulating sleeve 252 is greater than or equal to 20mm and less than or equal to 80mm.

In this embodiment, the follower 896 is a magnetic force providing element. In one embodiment, the magnetic force providing element is in a circumferential continuous ring shape, which is more convenient for installation and more stable in performance. In another embodiment, the magnetic force providing element includes at least two arc-shaped extending magnetic pieces, and the at least two magnetic pieces are arranged on the outer wall of the rotor shaft 44 along the circumferential direction. Adjacent magnetic sheets can be in contact with each other, or can be arranged at intervals. When the magnetic sheets are arranged at intervals, the distance between adjacent magnetic sheets is less than or equal to 2mm. This design can simplify the processing difficulty of the magnetic force providing element.

Please refer to FIG. 12 , which shows a part of the transmission mechanism of the seventh embodiment of the present invention.

The difference between this embodiment and the sixth embodiment will be mainly described below.

In this embodiment, the motor 14 is provided with a generally cylindrical cage 1 , the driving rotor is located in the cage 1 , and the bearing 2 is provided between the first bracket 511 and the cage 1 . The bearing 2 is provided between the inner wall of the cage 1 and the outer wall of the first hollow portion 522 of the first bracket 511 .

When the device 100 is working, the motor 14 runs at high speed, and the driving rotor needs more stable support and better dynamic balance. The bearing 22 provided between the first bracket 511 and the cage 1 can provide stable support and better dynamic balance for the driving rotor. The dynamic balance of the device makes the working output of the device more stable and improves the user experience.

In this embodiment, the number of bearings 2 is two, and the center of gravity of the driving rotor is located between the two bearings 2, so that the bearings 2 can better play their role. In other variants of this embodiment, the number of bearings 2 may be more than two, and the center of gravity of the driving rotor may be located between any two bearings 2 .

Please refer to FIG. 13 , which shows part of the transmission mechanism of the eighth embodiment of the present invention.

The difference between this embodiment and the seventh embodiment will be described below with emphasis.

In this embodiment, there is only one bearing 2, and the bearing 2 is located near the center of gravity of the driving rotor. That is, the distance between the center of gravity of the bearing 2 and the center of gravity of the driving rotor is less than or equal to 5mm. The number of the bearing 2 is only one, which can reduce the weight and cost of the device.

The series of detailed descriptions listed above are only specific descriptions for feasible embodiments of the present invention, and they are not intended to limit the protection scope of the present invention. Any equivalent embodiment or All changes should be included within the protection scope of the present invention.

Claims (48)

1. An apparatus for assisting a heart in the occurrence of functional failure, comprising:

a motor;

a drive rotor comprising: a first bracket connected to an output shaft of the motor, a driving member provided on the first bracket;

a coupler detachably engaged with the motor;

a driven rotor provided in the coupler, including: a rotor shaft, a follower disposed on the rotor shaft, the follower coupled with the driver to be driven to rotate about a rotational axis;

a catheter having a proximal end connected to a distal end of the coupler;

A drive shaft penetrating the guide tube and driven by the rotor shaft;

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

wherein one of the driving member and the driven member is a magnetic force providing element, and the other is a conductor; a gap is formed between the driving piece and the driven piece; the conductor cuts magnetic force lines in the magnetic field generated by the magnetic force providing element, so that eddy current is generated in the conductor, the eddy current generates a reverse induction magnetic field on the conductor, and the reverse induction magnetic field and the magnetic field generated by the magnetic force providing element are magnetically coupled;

the magnetic force providing element is mounted on a rotor shaft, the rotor shaft is provided with a first end cover and a second end cover which are positioned at two end sides of the magnetic force providing element, and the first end cover and the second end cover provide sealing for the magnetic force providing element in the axial direction.

2. The device of claim 1, a distal end face of the driver being opposite a proximal end face of the follower; alternatively, the driving member and the driven member are at least partially overlapped in the circumferential direction of the rotation axis, and are arranged at intervals in the radial direction of the rotation axis so as to have the gap; alternatively, one of the driving member and the driven member includes a channel, and the other of the driving member and the driven member is disposed in the channel.

3. The device of claim 1, wherein a side of the driving member facing away from the driven member is provided with a first magnetic restraint, the first magnetic restraint being made of magnetically permeable material.

4. The device of claim 1, wherein a side of the follower facing away from the driver is provided with a second magnetic restraint, the second magnetic restraint being made of magnetically permeable material.

5. The device of claim 3, the first bracket comprising a first hollow portion, the driving member being disposed on an outer wall of the first hollow portion, the first magnetic restraint being disposed radially outward of the driving member; alternatively, the driving member is disposed on an inner wall of the first hollow portion, and the first hollow portion is configured as the first magnetic force restraining member.

6. The apparatus of claim 4, the second magnetic restraint connecting the follower and rotor shaft.

7. The apparatus of claim 4, the second magnetic restraint being integrally provided with the rotor shaft; or, the rotor shaft is connected with a second bracket, the second bracket comprises a second hollow part, the driven piece is arranged on the outer wall of the second hollow part, and the second hollow part is configured as the second magnetic force restraint piece; or, the follower is disposed on an inner wall of the second hollow portion, and the second magnetic force restraint member is disposed radially inward of the follower.

8. The device of claim 1, the gap having a width of 5mm or less.

9. The device of claim 1, the gap having a width of less than 4mm.

10. The device of claim 1, the gap having a width of less than 3mm.

11. The device of claim 1, the gap having a width of less than 2mm.

12. The device of claim 1, the gap having a width of less than 1mm.

13. The apparatus of claim 1, the apparatus further comprising: the motor is electrically connected or in communication with the motor, and the rotating speed detection assembly is in communication connection with the control module and is used for detecting the rotating speed of the driving shaft.

14. The apparatus of claim 13, wherein the control module controls the motor to increase the rotational speed when the rotational speed of the drive shaft is determined to be less than a target rotational speed based on the signal provided by the rotational speed detection assembly.

15. The apparatus of claim 13, the control module controlling the motor to maintain a current rotational speed when determining that the rotational speed of the drive shaft is near a target rotational speed based on a signal provided by the rotational speed detection assembly.

16. The apparatus of claim 13, further comprising an alarm unit electrically or communicatively coupled to the control module, the control module controlling the alarm unit to operate when the rotational speed of the drive shaft is determined to be below a target rotational speed but the rotational speed of the motor is above a set point based on a signal provided by the rotational speed detection assembly.

17. The apparatus of claim 13, further comprising a perfusion system, the perfusion system comprising: the casing and the perfusion pump are communicated with the coupler through a pipeline;

the control module includes: a first control unit integrated in the motor, a second control unit provided in the housing; the first control unit is configured to provide the converted level signal to the motor, further providing reverse electrical isolation for the motor;

the second control unit is electrically or communicatively connected with the rotation speed detection assembly and controls the motor and the perfusion pump to operate.

18. The apparatus of claim 13, the rotational speed detection assembly comprising: the synchronous drive device comprises a drive shaft, a synchronizer rotating synchronously with the drive shaft, and a sensor for detecting the rotating speed of the synchronizer, wherein the sensor is electrically communicated or in communication connection with the control module.

19. The apparatus of claim 18, the synchronizer being a magnetic force providing element and the sensor being a coil or a hall sensor.

20. The apparatus of claim 18, wherein the driven member is coupled to the drive shaft by a rotor shaft, and wherein the synchronizer is disposed on the rotor shaft.

21. The apparatus of claim 18, the rotor shaft being made of a magnetically non-conductive material.

22. The apparatus of claim 18, further comprising a housing encasing the synchronizer, the housing being circumferentially fixed with the rotor shaft.

23. The device of claim 22, wherein the housing is a close fit to the rotor shaft or wherein the housing mates with a flat square rotor shaft.

24. The device of claim 22, the housing being made of an insulating material.

25. The apparatus of claim 22, the housing comprising a first portion and a second portion, the first portion and the second portion being independently manufactured and mated to form a space for receiving the synchronizer.

26. The apparatus of claim 18, the follower radially outward being provided with a liquid barrier configured at least for isolating liquid from contact with the follower.

27. The device of claim 26, the synchronizer being disposed radially inward of the liquid isolation layer and the sensor being disposed radially outward of the liquid isolation layer.

28. The device of claim 1, wherein the magnetic force providing element is provided radially outwardly with a protective layer, the protective layer being coupled to the first and second end caps to encase the magnetic force providing element therein, the protective layer providing a seal for the magnetic force providing element in a radial direction.

29. The device of claim 1, the first end cap and/or the second end cap comprising a body and a trim portion connected.

30. The device of claim 29, the trim portion being an aperture extending from one end face to the other end face of the body, the aperture extending a length less than the thickness of the end cap.

31. The device of claim 29, wherein the body has a thickness of 0.3mm or more and 10mm or less.

32. The apparatus of claim 29, the body and the trim portion overlapping, the trim portion comprising an aperture or a weight.

33. The device of claim 1, wherein the first and second end caps are preferably made of a metallic or ceramic material having a thickness greater than a minimum thickness at which the material can be processed.

34. The device of claim 1, wherein the first and second end caps have a thickness of between 0.3mm and 10mm.

35. The device of claim 1, further comprising a liquid barrier wall; the liquid partition wall includes a cylindrical portion that is located in the gap and encloses the driven rotor therein, and a burring portion that is located at an end of the cylindrical portion and is configured to be compressed between the coupler and a motor housing when the coupler is engaged with the motor.

36. The device of claim 35, the liquid barrier wall comprising a proximal portion provided with an end-side outlet; the device further comprises a seal, the end side outlet being closed by the seal when the seal is in the first state; the end outlet is open when the seal is in the second state.

37. An apparatus as defined in claim 36, the seal comprising a flexible sealing plug axially movable in the end outlet, the flexible sealing plug outer wall and/or the end outlet inner wall being of a ramped design such that the flexible sealing plug is compressed to switch to the first state when moved axially in a first direction and expands radially to switch to a second state when moved in a second direction opposite the first direction.

38. The device of claim 37, the seal further comprising a rigid handle portion connected to the flexible sealing plug, the handle portion having a hardness greater than a hardness of the flexible sealing plug, the handle portion being remote from the end side outlet relative to the flexible sealing plug.

39. The device of claim 36, wherein the seal is a bladder structure, the first state corresponds to a state when the bladder structure is filled with a fluid medium or an elastic material, and the second state corresponds to a state after the fluid medium in the bladder structure is at least partially released.

40. The device of claim 1, wherein the driving member is a conductor, the conductor is annular, and a heat insulation sleeve is arranged on the inner side of the conductor.

41. An apparatus according to claim 40, wherein an air flow channel is formed between said sleeve and said conductor.

42. An apparatus according to claim 40, wherein said sleeve is of equal length as said conductor on the side facing said magnetic force providing element or is slightly longer than said conductor.

43. An apparatus according to claim 40, wherein the length of the sleeve is greater than or equal to 15mm and less than or equal to 85mm.

44. The device of claim 1, wherein the driven member is a magnetic force providing element comprising a circumferentially continuous magnetic ring or at least two arcuately extending magnetic sheets circumferentially disposed on an outer wall of the rotor shaft; the distance between the circumferential end parts of the adjacent magnetic sheets is less than or equal to 2mm.

45. The assembly of claim 44, the circumferential ends of adjacent magnetic sheets are in contact.

46. The device of claim 1, wherein a substantially cylindrical cage is provided outside the motor, the drive rotor is positioned in the cage, and a bearing is provided between the first bracket and the cage.

47. The apparatus of claim 46, said number of bearings being at least two, said drive rotor having a center of gravity located between any two bearings.

48. The apparatus of claim 46, said number of bearings being one, one said bearing being located near the center of gravity of said drive rotor.

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