Cardiac catheter pump

Abstract

The invention relates to a cardiac catheter pump comprising: a preferably flexible cannula (1) having an inlet region (2) at the distal end thereof and a pump housing (3) at the proximal end thereof, which pump housing has an impeller (4) and an outlet region (5), to which blood can be conveyed, in particular by rotation of the impeller (4), from the inlet region (2); and a drive (6) which is connected to the pump housing (3) and by means of which the impeller (4) in the pump housing (3) can be rotated, the drive (6) comprising a series arrangement of a plurality of drive units (6a, 6b, 6c, 6d) which are flexibly connected to one another.

Description

Technical Field

[0001] The invention relates to a cardiac catheter pump comprising a cannula, preferably a flexible cannula, which has an inlet region at its distal end and a pump housing with an impeller and an outlet region at its proximal end. In particular, blood can be conveyed from the inlet region to the outlet region by rotation of the impeller. The cardiac catheter pump further comprises a drive connected to the pump housing, by means of which the impeller can be rotated within the pump housing. Background Art

[0002] In this case, position or direction specifications, such as “distal” (entrance) or “proximal” (exit), are given from the perspective of the attending physician.

[0003] Such cardiac catheter pumps are already known in the prior art, for example from the publication DE 103 36 902 B3.

[0004] These pumps are used to draw blood from the heart and deliver it to the aorta, thereby supporting the heart. To position the cardiac catheter pump, it must be flexible enough to pass through the aortic arch. This required flexibility limits the maximum possible rigid length of the pump housing and driver. Furthermore, the driver's length also affects its driving power. The rigid length here is understood to be the length to which the cardiac catheter pump cannot bend.

[0005] Therefore, the parameters "driving power" and "rigid length" limit each other. Summary of the Invention

[0006] Against this background, an object of the present invention is to provide an improved cardiac catheter pump having increased flexibility and a more powerful driver. Preferably, another object of the present invention is to provide a cardiac catheter pump that can be propelled to the heart via alternative pathways due to the increased flexibility.

[0007] According to the invention, this object is achieved in that the drive comprises a series arrangement of a plurality of drive units which are flexibly connected to one another.

[0008] Here, the present invention utilizes the characteristic that the driving torques of the various driving units are added together to form the total torque, so that all the driving units drive the impeller together.

[0009] This allows for high drive power without increasing the rigid length of the cardiac catheter pump, as the flexible connection of the drive units allows the cardiac catheter pump to bend even in the driver region. This allows the cardiac catheter pump to follow the natural curvature of blood vessels, such as the aortic arch, without damaging the vessel during implantation. The rigid length of the cardiac catheter pump is limited solely by the length of the rigid / hard region of the respective drive unit or by the length of the longest of all drive units. Preferably, all drive units have the same rigid length.

[0010] Furthermore, it may also be provided that at least some of the plurality of drive units have different rigid lengths. For example, a drive unit having a shorter rigid length than the other drive units may be arranged in the series arrangement at a location where, when the pump is in use, a greater degree of curvature is required than in other areas of the series arrangement.

[0011] The flexible connections between the individual drive units of the actuator are designed so that the series arrangement of the drive units can be bent / curved from a strictly straight orientation. Thus, not only can the flexible cannula be bent, but the series arrangement of the drive units can also assume a curved orientation. This allows the series arrangement to follow the curvature of a body vessel, such as the aortic arch.

[0012] Preferably, the respective flexible connections between the drive units are designed such that regions of the serial arrangement located in front of and behind the respective flexible connections, in particular two adjacent drive units, can move about a point or region within their flexible connection regions.

[0013] In one possible embodiment of the present invention, provision can be made for the remote drive unit in the series arrangement of all drive units to comprise the pump housing or to be rigidly connected to the pump housing.

[0014] This can result in the rigid length of the cardiac catheter pump being greater than the length of each individual drive unit, particularly the distal drive unit, thereby increasing the rigid length of the pump housing. However, this embodiment may be preferred due to the simplified connection structure between the drive unit and the pump housing.

[0015] The present invention may also preferably provide that the remote drive unit of the serial arrangement of all drive units is flexibly connected to the pump housing.

[0016] In the present invention, it can be provided that the drive comprises at least two, preferably at least three, more preferably at least four drive units arranged in series and flexibly connected. Preferably, all drive units have the same power and / or the same torque and / or the same rigid length.

[0017] It may also be provided that the drive units of the cardiac catheter pump according to the present invention are releasably connected or connectable to one another. To this end, the flexible connections and electrical connections between the drive units may be designed to be releasable. This allows for combining more or fewer drive units to form the drive of the cardiac catheter pump according to the present invention, depending on the required power.

[0018] Furthermore, at least two assemblies of cardiac catheter pumps of the type according to the present invention may be provided, wherein each cardiac catheter pump has a different number of drive units, so that the user can select a suitable cardiac catheter pump from the assemblies according to needs.

[0019] It is preferably provided that each drive unit comprises a housing having a stator arranged non-rotatably in the housing and a rotor rotatably supported in the housing, the housings of all drive units being non-rotatably and flexibly connected to one another, and the rotors of all drive units being non-rotatably and flexibly connected to one another, in particular at least outside the housing.

[0020] It is preferably provided that the stator and the rotor interact electromagnetically to drive the rotor. Thus, each drive unit preferably forms an electric motor.

[0021] The present invention may provide that each drive unit is controlled by at least one identical electrical control signal (e.g., from a control unit) so that all drive units operate synchronously. For example, the power of the drive units can be controlled via the control signal, for example, in a discrete manner (in the simplest case, on or off) or in a stepless manner. To this end, at least one common control signal line can be routed from the control unit to each drive unit in sequence, preferably with all drive units electrically connected in parallel to the at least one control signal line. Preferably, the at least one control signal line is connected from the control unit to the proximal drive unit and is transmitted sequentially from the proximal drive unit to the next drive unit, all the way to the distal drive unit.

[0022] The individual drive units can also be operated synchronously by driving them with a rotating magnetic field of the same frequency and by mechanically coupling the rotor elements to set the same slip in all drive units.

[0023] Synchronization can also be achieved by a controller that inputs independent control signals to the individual drive units. Each drive unit thus preferably receives its own control signal. It can preferably be provided that any mechanical slip is compensated for by individual phase shifts between the individual control signals. In particular, the input variables for controlling the control signals can be, for example, the voltage of the back electromotive force in sensorless motor operation or the measured speed.

[0024] One possible preferred embodiment of the present invention can provide that the rotors of adjacent drive units each have their own rigid rotor shaft, and that the rotor shafts of adjacent drive units are flexibly connected to one another, in particular via a flexible shaft section or via a joint (in particular, a universal joint) as a flexible connecting element. The respective rigid rotor shaft, as well as the rotor shafts in the embodiments described below, are preferably rotatably mounted in the housing of the drive unit, in particular at opposite end walls of the respective housing.

[0025] The fixation between the rigid rotor shaft and a section of the flexible shaft can preferably be designed as a positive fit and / or a non-positive fit and / or a material fit, for example by gluing or welding.

[0026] In particular in the case of a positive-locking and / or non-positive connection, it can be provided that the drive units are detachably coupled to one another.

[0027] Another possible preferred embodiment of the present invention can provide that the rotors of adjacent drive units each have a common rotor shaft, preferably an integral rotor shaft, wherein the common rotor shaft is designed to be rigid in the corresponding sections within each drive unit and to be flexible in the corresponding sections between adjacent drive units.

[0028] The common rotor shaft preferably consists of a tube, in particular at least one tube, which is made flexible in corresponding sections between adjacent drive units by material processing, in particular configured as a flexible connecting element. The rotor shaft can also consist of two or more such nested tubes, which preferably touch in the radial direction.

[0029] By means of this material processing, at least one cutout or preferably a plurality of cutouts, particularly preferably a helical or spirally extending cutout or at least one helical or spirally extending cutout, is preferably provided in the tube, which makes the tube flexible in the region of the cutout or the at least one cutout.

[0030] In such a notched rotor shaft, regions of the rotor shaft on either side of the at least one notch can be connected to one another in a form-fitting manner, particularly by meshing with one another, for example, by a projection on the rotor shaft with an undercut on one side of the notch, which sits in a correspondingly (particularly complementary) shaped groove on the other side of the notch. The connection between the projection and the groove can be configured as a dovetail connection. Preferably, multiple such connection regions are arranged equidistantly along the notch. This allows for axial and / or rotational stability of the rotor shaft. Alternatively, at least two groups of multiple axially spaced notches can be arranged in the rotor shaft, wherein the respective notches extend at least partially circumferentially around the rotor shaft axis, particularly with an axial inclination. Due to the axial offset between the groups, the ends of the notches of one group lie between the ends of the notches of the other group. Each group of notches can preferably widen from both ends toward the center of the respective notch.

[0031] The advantage of such a corresponding embodiment with at least one cutout is that, due to the common rotor shaft extending through all drive units, connection points between the drive units and the attendant mechanical fragility, in particular at the component interfaces, are avoided.

[0032] Another possible preferred embodiment of the present invention can provide that the rotors of adjacent drive units all have a common rotor shaft, in particular an integral rotor shaft, wherein the common rotor shaft is constructed as a whole to be flexible, in particular as a flexible connecting element, and is accommodated in the corresponding rotor in a form-locked and / or material-locked manner, preferably in the hollow rotor shaft of the rotor.

[0033] By accommodating the flexible rotor shaft in a form-fitting and / or materially bonded manner in the respective rotor, a rigidification of the flexible rotor shaft is achieved, ie, the flexible rotor shaft loses its flexibility within the rotor.

[0034] This also avoids connection points and / or component interfaces between the drive units and the mechanical fragility that comes with them. Furthermore, commercially available flexible shafts can be used directly.

[0035] It can also be preferably provided that the common flexible rotor shaft is filled in the region thereof that is received in a form-fitting manner in the rotor (e.g., its hollow rotor shaft). For example, a pin can be inserted into the common rotor shaft in a form-fitting and / or material-locking manner for this purpose. The hollow region of the common flexible rotor shaft within the rotor can also be filled / potted with a potting agent.

[0036] A preferred refinement provides that the housings of adjacent drive units are each connected in a rotationally fixed manner via a flexible, liquid-tight hollow element. This element can preferably be a flexible, tubular or hose-shaped liquid-tight element. The cross-section of the element is preferably smaller than the cross-section of the drive unit housing. The liquid-tight element can, for example, be made of plastic, in particular an elastomer. The liquid-tight element can be connected to the housing, in particular to the corresponding end wall of the housing, for example, by a material-locked connection.

[0037] Another preferred refinement provides that the housings of adjacent drive units are connected in a rotationally fixed manner via a common, integrally flexible, fluid-tight hollow element, in particular a tubular or hose-shaped hollow element, which surrounds the housing radially on the outside. The material of this element can again be a plastic, such as an elastomer. All drive units are preferably located within this element. Due to the radially external connection of this element to the respective housing, the element preferably loses its flexibility locally in this connection area.

[0038] Another preferred improvement provides that the housings of adjacent drive units are non-rotatably connected via a common hollow element, in particular a tubular element, which is segmentally rigid in the region of the drive units, in particular in the region of their housings, and is segmentally flexible in the region between the drive units, in particular in the region between their housings, and which surrounds the housing radially on the outside or constitutes a part of the housing in the rigid region.

[0039] The common hollow element preferably consists of a tube with a liquid-tight coating on the radial outside, which is made flexible in corresponding sections between adjacent drive units by material processing, for example at least one cut, preferably a spiral / helical cut or multiple cuts, in particular in the manner of processing the rotor shaft as described above.

[0040] Accordingly, it is preferably provided that the liquid-tight coating liquid-tightly covers the region of the tube rendered flexible by material processing, in particular the region provided with at least one cutout, in particular a plurality of cutouts.

[0041] In the above-described embodiment, it is preferably provided that the flexible connecting element connecting the respectively adjacent rotors is guided through the hollow element.

[0042] Furthermore, it is preferably provided that the electrical connection lines between the stators of adjacent drive units are guided through the hollow element, in particular through the interior of its walls. These electrical connection lines are preferably used as control signal lines in order to electrically control the stators and rotate the drive. The wiring between the individual drive units can also be carried out in such a way that the lines extend within a common outer flexible tubular element and leave the preceding drive unit at the front end and enter the following drive unit at the front end. In particular, in this case, Figure 9 As shown, the bearing point is to pass through the radially outer portion of the stationary outer ring.

[0043] In an embodiment of the present invention, in which at least some, preferably all, drive units of the drive are arranged in a hollow element, it is preferably provided that a non-rotatable connection is formed between the common hollow element and the respective housings by means of a material lock and / or form lock and / or force lock between the radial outer walls of the respective housings and the inner wall of the common element.

[0044] The material connection is preferably produced by bonding between the radially outer wall of the housing and the inner wall of the common hollow element.

[0045] The force-locking connection is preferably produced by shrink-fitting the common hollow element onto the housing.

[0046] The form fit is preferably formed by projections or recesses / grooves on the radially outer wall of the housing, which extend at least partially into the common hollow element, in particular its inner wall, or by recesses in the radially outer wall of the housing, into which the common liquid-tight element extends at least partially.

[0047] In the present description, rigid or stiff is preferably understood to mean that the element referred to as rigid cannot bend or deform under normal conditions of use, ie retains its geometric shape.

[0048] Flexible is preferably understood to mean that the element designated as flexible, for example a flexible connecting element, is deformable, in particular bendable, preferably reversibly deformable multiple times under normal conditions of use.

[0049] A so-called flexible element can preferably extend in a straight line in a relaxed state, ie when no force acts on it. Due to its flexibility, the element can bend from this state under the action of a force and preferably automatically return to the relaxed state when the force disappears.

[0050] However, the flexible element may also be self-stable or unpreferential in any possible shape state, and in particular may have any indefinite shape.

[0051] In particular, it can be provided that at least some, and in particular all, of the so-called flexible elements are shaped in a relaxed state (i.e., when no forces are acting on them) such that the entire cardiac catheter pump, in the relaxed state, assumes a shape corresponding to its later configuration during use (e.g., in the aortic arch), in particular a curved shape. This can reduce / eliminate forces acting on the vessel wall during use. It can be provided that, in order to insert and advance the cardiac catheter pump in a blood vessel, it must be deformed from its relaxed shape into a shape that is at least substantially straight or that follows the curvature of the vessel.

[0052] In order to obtain a suitable bending curve for the entire cardiac catheter pump according to the invention, which allows movement of the cardiac catheter pump through the aortic arch, a specific ratio between the rigid and flexible parts of the rotor shaft or the shaft connecting them can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The prior art and embodiments of the present invention will be described in more detail with reference to the following drawings. DETAILED DESCRIPTION

[0054] The prior art is shown in Figure 1. A portion of the human heart is shown, into which a cardiac catheter pump known hitherto is inserted via the aortic arch.

[0055] The cardiac catheter pump comprises a flexible cannula 1 having an inlet region 2 at its distal end, through which blood can enter the cannula 1 from the ventricle. A pump housing 3 is provided at the proximal end of the cannula 1, within which an impeller 4 is rotatably mounted. The pump housing 3 also has an outlet region 5. When the impeller is rotated by a drive 6 adjacent to the pump housing, the impeller can convey blood from the cannula 1 through the outlet region into the aortic arch.

[0056] As can be seen from the slight bend in FIG1 , cannula 1 is designed to be flexible and thus bendable. However, the combination of pump housing 3 and driver 6 is inflexible and its length constitutes the so-called rigid length of the cardiac catheter pump, i.e., the length that cannot be bent. This rigid length must not exceed a certain maximum length in order for the cardiac catheter pump to be guided through the aortic arch with its rigid portion.

[0057] It follows directly from this that the drive 6 must also not exceed a certain length, which means that the maximum possible electrical power of the drive is also limited.

[0058] The cardiac catheter pump of the present invention also has the elements described herein with reference to FIG. 1 , but the improvement of the present invention lies in the specific structure of the driver 6 .

[0059] Figure 2 The structure of a cardiac catheter pump according to the present invention is shown. As can be seen from the enlarged detail view, in this embodiment of the present invention, the driver 6 is composed of a plurality of drive units 6a-6d, which are arranged in series, with adjacent drive units 6a / 6b, 6b / 6c, or 6c / 6d flexibly connected to each other. Due to this flexible interconnection, adjacent drive units 6a-6d can move relative to each other, particularly while at least substantially maintaining the distance between the drive units.

[0060] Therefore, the serial arrangement of the drive units 6a-6d can not only adopt a straight configuration as in the prior art drive, but also a curved configuration. Therefore, the serial arrangement of the drive units 6a-6d can adapt to the curvature of the aortic arch or other blood vessel lumens.

[0061] By dividing the entire driver into a plurality of flexibly connected driver units, the length of the driver can be made longer than in the prior art because the rigid length of the cardiac catheter pump is not increased.

[0062] Thus, since the rigid length (which is now determined only by the length of the individual drive unit housings or the length of the longest of all drive units) no longer limits the overall length of the drive, a longer drive can provide greater electrical power or greater torque. The sum of the electrical power and / or torque of all individual drive units 6a-6d constitutes the total power and / or total torque.

[0063] In particular, the structure starting from the pump housing towards the distal end of the sleeve 1 can essentially correspond to the structures known from the prior art.

[0064] Figure 2 Here, an embodiment of the present invention is shown in which the distal drive unit 6a of all drive units 6a-6d forms a single unit with the pump housing 3, in particular a rigid unit, i.e., the pump housing and the distal drive unit 6a are rigidly connected to one another. The drive unit 6a and the pump housing 3 can be accommodated in a common housing or, alternatively, at least rigidly connected. In this configuration, the unit formed by the drive unit 6a and the pump housing 3 can define the maximum rigid length of the cardiac catheter pump.

[0065] In contrast, Figure 3 Another embodiment of the invention is shown, in which the distal drive unit 6a of all drive units 6a - 6d does not form a unit with the pump housing 3, in particular is not flexibly connected.

[0066] Therefore, with Figure 2 Compared with the embodiment of the present invention, the rigid length of this embodiment can be reduced. In all possible embodiments, the lengths of the drive units are preferably equal, but can also be different.

[0067] For all possible embodiments, both shown and not shown, each drive unit 6a-6d preferably includes a housing 7 having a stator 8 arranged in a rotationally fixed manner within the housing 7 and a rotor 9 rotatably supported within the housing. In particular, the stator 8 and rotor 9 drive the rotor 9 via electromagnetic interaction. The housings 7 of all drive units 6a, 6b, 6c, and 6d are connected to one another in a rotationally fixed and axially flexible manner, and the rotors 9 of all drive units 6a, 6b, 6c, and 6d are connected to one another in a rotationally fixed and axially flexible manner, and in particular, are connected to one another in a rotationally fixed and axially flexible manner, at least outside the housing 7. Thus, the stator and rotor preferably form an electric motor, wherein the stator may have coil windings that can be energized. However, other drive principles between the stator and rotor are also possible in principle. The mode of operation of the drive is not critical to the present invention.

[0068] Figure 4 A first possible implementation for realizing flexible connection of adjacent drive units 6a-6d is shown.

[0069] In this embodiment, each drive unit 6a-6d has its own rigid rotor shaft 10. This rigid rotor shaft 10 can be made of solid material or a rigid tube. In particular, as in all possible embodiments, the rotor shaft 10 is rotatably mounted at the rotor ends on both sides.

[0070] exist Figure 4In the embodiment, the rigid rotor shafts 10 of adjacent drive units 6a-6d are flexibly connected by arranging a flexible shaft (particularly a bendable shaft) segment between the mutually facing ends of the rigid rotor shafts 10. Such a bendable shaft can employ a well-known structure, for example, a helically wound metal wire. The segments of the bendable shaft 11 can be fixed to the respective free ends of the rigid rotor shafts 10, so that the rotor shafts are non-rotatable relative to each other but flexibly connected. This fixation can be implemented as a form-locking, non-positive, and / or material-locking connection.

[0071] Figure 5 An embodiment is shown in which the flexible connection between the rigid rotor shafts 10 of adjacent drive units is realized by means of a joint 12, in particular a universal joint 12, as a flexible connection element. Figure 5 The implementation method and Figure 4 The joint forms a flexible connecting element which has no preferred shape, in particular no relaxed state.

[0072] Figure 6 An embodiment is shown, according to which the rotors 9 of adjacent drive units 6a-6d each have a common rotor shaft 13, preferably a one-piece rotor shaft 13, wherein the common rotor shaft 13 is constructed to be rigid in a corresponding section 13a within a drive unit 6a-6d and to be flexible in a corresponding section 13b between adjacent drive units 6a-6d.

[0073] In the embodiment shown, the common rotor shaft 13 is preferably formed by a tube which is made flexible in the respective sections 13b between adjacent drive units 6a, 6b, 6c, 6d by material processing (here by cuts, particularly preferably helically extending cuts 13c), so that the flexible sections can act as flexible connecting elements.

[0074] Figure 7 An embodiment is shown in which the rotors 9 of adjacent drive units 6a-6d each have a common rotor shaft 13, in particular a one-piece rotor shaft 13, which is designed as a whole to be flexible (in particular as a flexible connecting element) and is accommodated in the corresponding rotor 9 in a form-fitting and / or material-fitting manner, preferably in a hollow rotor shaft 14.

[0075] In the area where the common rotor shaft 13 is received in the rotor 9 in a form-fitting manner, the common rotor shaft 13 is preferably filled, for example by means of a pin 13d inserted therein in a form-fitting and / or materially sealing manner. Alternatively, the common rotor shaft can be filled with a potting compound. Thus, the flexibility of the otherwise generally flexible common rotor shaft is locally eliminated within the rotor.

[0076] Preferably, in addition to the different structure of the flexible connection or the different structure of the rotor shaft, Figures 4 to 7 The embodiments of the present invention have the same features in other respects.

[0077] for Figures 4 to 7 In all embodiments, the housings 7 of adjacent drive units 6a-6d are each connected in a rotationally fixed manner via a flexible, fluid-tight hollow element 15, in particular a flexible tubular or hose-like fluid-tight element 15. Figures 4 to 7 In the embodiment shown, the cross section of the flexible, fluid-tight hollow element 15 is smaller than the cross section of the housing 7. The cross section is here viewed perpendicularly to the connection direction of the adjacent drive units.

[0078] The individual flexible connecting elements 11 , 12 , 13 , 13 b connecting the respective adjacent rotors 9 pass through the hollow element 15 , and the same applies to the subsequent embodiments shown in the other figures.

[0079] Figures 8 to 11 Furthermore, an embodiment is shown in which the housings 7 of adjacent drive units 6a-6d are each connected in a rotationally fixed manner via a common, integrally flexible, fluid-tight hollow element 15 (in particular a tubular or hose-like hollow element 15), which surrounds the housing 7 radially on the outside. In this case, all housings 7 of all drive units 6a-6d or all drive units 6a-6d are preferably arranged in the same common element 15.

[0080] according to Figure 8 The common hollow element can be, for example, a flexible hose, which is connected to the housing 7 by force-locking, for example by shrink fit. By means of the shrink fit, a slight cross-sectional constriction is formed between adjacent housings 7.

[0081] Figure 9 An embodiment is shown in which the housings 7 of adjacent drive units 6a-6d are connected in a rotationally fixed manner via a common hollow element 15 (in particular, a tubular element 15), which is rigid in sections in the region of the drive units 6a-6d (in particular, in the region of their housings 7) and flexible in sections in the region between the drive units 6a-6d (in particular, between their housings 7), and which surrounds the housing 7 radially on the outside. In this embodiment, in the rigid region, the element 15 even forms part of the housing 7, in particular, the part directly adjacent to the respective stator.

[0082] The common hollow element 15 is formed here by a tube with a liquid-tight coating on the radial outside. This tube can preferably be formed by an originally rigid tube that is made flexible in the corresponding sections between adjacent drive units 6a-6d by material processing (in particular, cutouts 15a, preferably spiral cutouts 15a). The originally continuous cutouts 15a are sealed by the coating.

[0083] The coating is arranged at least above the cutout 15 a or approximately above the material processing area in order to seal this area, but can also be applied over the entire length of the element 15 .

[0084] Figure 10 An embodiment is shown in which a positive fit is formed between the hollow element 15 and the outer wall of each drive unit housing 7 by projections 17 on the radially outer wall of the housing 7, which at least partially extend into the common element (particularly its inner wall). To this end, the material hardness of the hollow element 15 is preferably lower than the material hardness of the housing outer wall having the projections. For example, the material of the hollow element 15 can be made of plastic, while the housing 7 can be made of metal. It can preferably be provided that such projections extend at least partially in the circumferential direction on the wall of the housing 7, and particularly preferably, these projections have an axial inclination in their extension.

[0085] Figure 11 Another variant is shown, in which the hollow element 15 is connected to the outer wall of the housing 7 in a materially bonded manner by means of adhesive bonding 18 .

[0086] Figures 8 to 11 The flexible connection between the rotors 9 of adjacent drive units is shown in FIG. Figure 4 It should be noted that, unlike the one shown, Figures 8 to 11 The implementation method can be based on Figures 5 to 7 The shaft and rotor structure.

[0087] therefore, Figures 4 to 7 All flexible rotor connection embodiments shown can be used with Figures 8 to 11 All the different embodiments of the flexible hollow elements 15 shown, which completely surround the housing 7 from the outside, can be combined as desired.

[0088] All embodiments also have the following features in common: Figures 4 to 7 As shown, the electrical connection lines 16 between the stators 8 of adjacent drive units 6a-6d are led through the hollow element 15, in particular in its wall. Figures 8 to 11 Not shown or not fully shown in , but still exists.

[0089] In general, all embodiments achieve internal flexibility in the driver, which, according to the present invention, is composed of a plurality of drive units arranged axially in series. "In series" here means arranged sequentially in the connection direction, particularly in the direction from the proximal end to the distal end.

Claims

1. Cardiac catheter pump, including a. A preferably flexible cannula (1) having an inlet region (2) at its distal end and a pump housing (3) at its proximal end, the pump housing having an impeller (4) and an outlet region (5), wherein blood can be conveyed from the inlet region (2) to the outlet region (4) in particular by rotation of the impeller (4), and b. a drive (6) connected to the pump housing (3), by means of which the impeller (4) in the pump housing (3) is rotated, It is characterized in that c. The drive (6) comprises a serially arranged structure of a plurality of drive units (6a, 6b, 6c, 6d), which are flexibly connected to each other.

2. The cardiac catheter pump according to claim 1, wherein The remote drive unit (6a) of the serially arranged structure includes a pump housing (3) or is rigidly connected to the pump housing (3).

3. The cardiac catheter pump according to claim 1, wherein The remote drive unit (6a) of the serially arranged structure is flexibly connected to the pump housing (3).

4. The cardiac catheter pump according to any one of the preceding claims, characterized in that Each drive unit (6a, 6b, 6c, 6d) comprises a housing (7), wherein the housing has a stator (8) arranged in a non-rotatable manner in the housing (7) and a rotor (9) supported rotatably in the housing, in particular, the stator (8) and the rotor (9) interact with each other in an electromagnetic manner to drive the rotor (9), the housings (7) of all the drive units (6a, 6b, 6c, 6d) are non-rotatably and flexibly connected to each other, and the rotors (9) of all the drive units (6a, 6b, 6c, 6d) are non-rotatably and flexibly connected to each other, in particular, at least outside the housing (7).

5. The cardiac catheter pump according to claim 4, wherein rotors (9) of adjacent drive units (6a, 6b, 6c, 6d) a. Each has its own rigid rotor shaft (10), and the rotor shafts (10) of adjacent drive units (6a, 6b, 6c, 6d) are flexibly connected, in particular by means of a section of a flexible shaft (11) or by means of a joint (12), in particular a universal joint (12), as a flexible connecting element, or b. each having a common rotor shaft (13), preferably a one-piece rotor shaft (13), wherein the common rotor shaft is rigid in a corresponding section (13a) inside the drive unit (6a, 6b, 6c, 6d) and flexible in a corresponding section (13b) between adjacent drive units (6a, 6b, 6c, 6d), in particular the common rotor shaft is formed by a tube which is flexible in a corresponding section (13b) between adjacent drive units (6a, 6b, 6c, 6d) by material processing, preferably by at least one cutout, in particular a plurality of cutouts, particularly preferably at least one helical or spirally extending cutout (13c) or a plurality of cutouts (13c), in particular as a flexible connecting element, or c. Each has a common rotor shaft (13), in particular a one-piece rotor shaft (13), wherein the common rotor shaft (13) is designed as a whole to be flexible, in particular to be designed as a flexible connecting element, and is accommodated in the corresponding rotor (9), in particular in a hollow rotor shaft (14) in a form-locking and / or material-locking manner, preferably in the area of ​​the common rotor shaft (13) in which it is accommodated in the rotor (9) in a form-locking manner, the common rotor shaft (13) is filled, preferably a pin (13d) is inserted in the common rotor shaft in a form-locking and / or material-locking manner or the common rotor shaft is filled with a potting agent.

6. The cardiac catheter pump according to claim 4 or 5, characterized in that Housings (7) of adjacent drive units (6a, 6b, 6c, 6d) a. respectively connected in a rotationally fixed manner by a flexible, liquid-tight hollow element (15), in particular a flexible tubular or hose-shaped liquid-tight element (15), the cross section of which is preferably smaller than the cross section of the housing (7), or b. connected in a rotationally fixed manner via a common, integrally flexible, fluid-tight hollow element (15), in particular a tubular or hose-shaped hollow element (15), which surrounds the housing (7) radially on the outside, or c. being connected in a rotationally fixed manner via a common hollow element (15), in particular a tubular element (15), which is rigid in sections in the region of the drive units (6a, 6b, 6c, 6d), in particular in the region of their housings (7), and flexible in sections in the region between the drive units (6a, 6b, 6c, 6d), in particular in the region between their housings (7), which hollow element radially surrounds the housing (7) or forms part of the housing (7) in the rigid region, preferably the common hollow element (15) being formed by a tube having a liquid-tight coating radially on the outside, which tube is made flexible in the corresponding sections between adjacent drive units (6a, 6b, 6c, 6d) by material processing, preferably at least one cutout, in particular a helical or spiral cutout (15a), In particular, the flexible connecting elements (11, 12, 13b) connecting the respective adjacent rotors (9) pass through the hollow element (15).

7. The cardiac catheter pump according to claim 6, wherein Electrical connecting lines (16) between the stators (8) of adjacent drive units (6a, 6b, 6c, 6d) are guided through the hollow element (15), in particular within the wall of the hollow element.

8. The cardiac catheter pump according to claim 6a or 6b, characterized in that A rotationally fixed connection between the common hollow element (15) and the housing (7) is formed by a material connection and / or a form fit and / or a force fit between the radial outer wall of the housing (7) and the inner wall of the common element (15).

9. The cardiac catheter pump according to claim 8, wherein a. forming a material connection by bonding (18) between the radially outer wall of the housing (7) and the inner wall of the common element (15), and / or b. forming a force-locking connection by shrink-fitting the common element (15) onto the housing (7), and / or c. A form-fitting connection is formed by projections (17) on the radially outer wall of the housing (7), which projections at least partially extend into the common element, or a form-fitting connection is formed by recesses in the radially outer wall of the housing (7), into which recesses the common element (15) at least partially extends.

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