Fluid pump rotor, method for producing same, and mold

Abstract

To stabilize the form of a rotor of a compressible fluid pump in an expanded state.SOLUTION: The present invention relates to a rotor for a compressible fluid pump, which comprises one or more impeller elements 15, and is compressible and expandable between a first compressed state and a second radially expanded state, the impeller elements 15 each being composed of a plastic which is reinforced with reinforcing elements 10, 11, 13, 18, 19, 55, 56, 62, 63 embedded therein, the rotor being structured to rotate about an axis of rotation 14. The rotor is preloaded in a first compressed state and free from external stresses in a second expanded state. A third state exists, in which a rotor 42 occupies in an operating state under load. The reinforcing elements exist in a form of extending to a degree of prolonging by less than 5%, in particular less than 1%, in transition from the second state to the third state.SELECTED DRAWING: Figure 2c

Description

[Technical Field]

[0001] This patent application is in the field of mechanics and specifically relates to rotors for fluid pumps, and can be used to advantage in the field of medical engineering, especially for catheter pumps. [Background technology]

[0002] In the field of fluid pumps, rotor pumps are already known in various embodiments in the form of axial or radial pumps, in both cases the rotation of a rotor and an impeller element fixed to said rotor causes the fluid to be conveyed to be accelerated in the axial or radial direction.

[0003] Furthermore, such pumps can be compressed in accordance with the prior art to allow for space-saving placement or transport. This is particularly true for medical catheter pumps, which can be radially compressed and deployed, and are often delivered to an application site through a catheter or a cavity in a patient's body prior to surgical placement, and then deployed at the application site. Such pumps are used, for example, to assist a patient's heart in circulating blood, and for this purpose are delivered through blood vessels to or within a cardiac chamber.

[0004] In this case, the rotor's compactness and compressibility are particularly important. In the deployed state, the rotor must assume a reproducible operating configuration that remains as constant as possible, even when operating at maximum rotational transport speed, despite its compressibility, to prevent a loss of efficiency and damage to the blood components being transported.

[0005] For this reason, the use of a wide range of materials and material combinations has already been considered and investigated for this purpose, as an example from WO 2010 / 063494 the use of a wide range of elastomers in conjunction with fiber reinforcement is already known.

[0006] WO 2012 / 007141 discloses a reinforcement for a pump rotor by fibers that can be arranged in the rotor in a radially oriented manner, for example.

[0007] Finally, WO 2012 / 007140 discloses a pump rotor with strengthening elements that may be provided substantially on the exterior (eg, surface) of the impeller element. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] International Publication No. 2010 / 063494 [Patent Document 2] International Publication No. 2012 / 007141 [Patent Document 3] International Publication No. 2012 / 007140 Summary of the Invention [Problem to be solved by the invention]

[0009] Therefore, against the background of the prior art, it is an object of the present invention to create a plastic rotor of the type described above which exhibits minimal slack after deformation between the compressed and deployed states, and which is believed to have the most accurate reproducibility of its shape, at least in the deployed state. [Means for solving the problem]

[0010] The above objects are achieved by a rotor, a method for making the rotor, and a corresponding rotor mold.

[0011] The above provides, inter alia, a rotor for a compressible fluid pump, in particular a blood pump, which can be introduced into a patient's body through a blood vessel, the rotor having one or more impeller elements and being radially compressible and expandable between a first state, compressed, and a second state, radially expanded, the rotor being made at least in part of strand-like reinforcing elements, in particular plastic reinforced with fibers, and intended to rotate about an axis of rotation, characterized in that in the first state, compressed, a preload is applied, in the second state, expanded, no external stress is applied, and in the third state, the rotor is in an operating state under load, the fibers of the rotor being at least partially elongated.

[0012] This type of fluid pump is typically introduced into a blood vessel (e.g., an artery) in a compressed state through a port and advanced until it approaches or partially enters the patient's heart, where it is deployed. However, the present invention is not limited to this type of blood pump, but also includes other types of blood pumps with compressible and deployable rotors, or other fluid pumps that can be introduced into a cavity system for medical or non-medical purposes. In the compressed state, the rotor of such pumps is typically subjected to a radial compressive stress, for example, by being constricted by an outer sleeve. By way of example, the outer sleeve can be a catheter, from which the pump slides and deploys. However, the pump rotor can also be constricted by any other type of outer sleeve in the compressed state.

[0013] When the compression force is removed, the pump, or at least the pump rotor, expands and transitions to a second state, the expanded-extended state, which significantly increases the radial extent of the rotor compared to the first state, the compressed state.

[0014] Thereafter, when the rotor is driven to rotate and the pump is operated to deliver fluid, the rotor transitions to an operating state corresponding to a load state under the load of the delivered liquid. In particular, this operating state occurs according to the rotor's defined geometric design, but is independent of the magnitude of the load up to the maximum conceivable limit. Furthermore, the rotor undergoes minimal change in shape during the transition between the second and third states, except that in the third state under the load of the delivered liquid, the rotor is deformable such that its diameter increases compared to the second, deployed state.

[0015] The strand-like reinforcing elements / fibers reinforcing the plastic material of the rotor are arranged in the matrix of the plastic material in such a way that, in the third state, they are at least partially elongated and stretched, thereby stabilizing the rotor's shape against loads. Here, the fibers are intended to be subjected to a longitudinal tensile load. Since the fibers cannot actually be elongated in the longitudinal direction, the corresponding load in the longitudinal direction does not actually significantly change the shape of the matrix. Thus, the rotor or individual elements of the rotor (e.g., impeller elements) can easily change shape from a compressed state to an expanded state until the fibers are at least partially elongated. At this point, the fixation of the fibers in the plastic material of the rotor practically prevents longitudinal movement of the fibers, even under load, at least in the areas where the fibers are elongated.

[0016] As an example, in one particular embodiment of the solution, the reinforcing elements / fibers in the third state (operating state) of the rotor are at least partially elongated in the area of the rotor where tensile stress occurs and extend substantially in the direction of the tensile stress.

[0017] The reinforcing elements / fibers shall be at least partially arranged in the direction in which tensile stresses occur in the rotor, so that the absorption of longitudinal forces into the fibers prevents the tensile stresses and the rotor geometry remains practically unchanged or does not change further.

[0018] By way of example, this requires that in the impeller elements of the rotor, at least some of the reinforcing elements / fibers extend outside the so-called neutral fibers. In the region of the so-called neutral fibers and / or neutral plane in the field of bending mechanics, high-tensile fibers do not further stabilize the rotor. In the rotors described here, the neutral fibers in bending technology are generally planes, so that in the following, for the sake of clarity, the terms bending neutral plane or neutral plane are used.

[0019] It is therefore possible to provide that the majority of the reinforcing elements / fibers are arranged in areas of the rotor and / or impeller element where tensile stresses occur in operation, where it is particularly advantageous to arrange a large number of fibers in areas of the rotor or impeller element where tensile stresses occur under load.

[0020] It is also possible for the rotor to be configured such that there is no substantial difference between the second state, the deployed state, and the third state, the operational state, as far as the external configuration is concerned.

[0021] It is also possible, for example, for the reinforcing elements / fibers to extend radially beyond the axis of rotation, so that the rotor as a whole has particularly good stability, and the individual impeller elements are therefore stable not only against bending, but also against pivoting about a part of the rotor near the axis of rotation (e.g., the hub).

[0022] It is also possible and advantageous to configure at least a portion of the fibers, in particular the majority of the reinforcing elements / fibers, so that they extend partly straight in the operating state, although other straight and even curved sections of the fibers may be provided between the straight regions of the reinforcing elements / fibers.

[0023] It is also possible to configure at least some of the fibers, in particular the majority of the reinforcing elements / fibers, in the operating state to extend along the longitudinal direction of the impeller element with a curvature that is smaller in the material strength sense than the neutral plane of the impeller. As a result of this configuration of the reinforcing elements / fibers, on the one hand, they are highly elongated in the operating state, and on the other hand they extend outside the neutral plane of the impeller element and thus in a region where tensile stresses may occur under load.

[0024] It is also possible to configure the rotor plastic so that its Shore hardness is less than 100D, in particular less than 80D. Due to the low Shore hardness, which can be selected, for example, less than 80D, any large curvature or bending of the material can force the embedded reinforcing elements / fibers into the elastic substrate, limiting the radius of curvature downwards, thereby reducing the risk of breaking the elements / fibers.

[0025] It is also possible for this type of rotor to be configured such that more than 30%, in particular more than 50%, of the first group of reinforcing elements / fibers in the deployed state of the rotor extend substantially elongated from the part located closest to the axis of rotation to the second part located further from the axis of rotation, as a result of this positioning, orientation and formation of the reinforcing elements / fibers, effectively avoiding overstretching of the rotor beyond the deployed state.

[0026] The rotor can also be designed so that the first group of reinforcing elements / fibers, more than 30%, in particular more than 50%, of the reinforcing elements / fibers, have a length, measured in the radial direction of the rotor in the deployed state, that corresponds to at least 30%, in particular at least 50%, of the maximum height of the impeller element, thereby providing a stabilizing force over a larger portion of the rotor for overall stabilization.

[0027] It is also possible to configure the first group of reinforcing elements / fibers in the operating state so that they extend substantially perpendicular to the axis of rotation, as a result of which the tensile stresses in the rotor caused by the load of the fluid to be conveyed can be optimally absorbed.

[0028] Furthermore, the rotor can be designed so that the diameter of the reinforcing elements / fibers, particularly the first group of reinforcing elements / fibers, is less than 40 micrometers. Such small diameter reinforcing elements / fibers allows for small bending radii, further reducing the risk of breaking the reinforcing elements / fibers.

[0029] It is also possible to provide the reinforcing elements / fibers with an adhesion promoter on their surface, which allows for a better anchoring of the reinforcing elements / fibers in the matrix plastic material and further improves the absorption of tensile stresses by the reinforcing elements / fibers.

[0030] The invention also relates to a method for producing a rotor according to claim 1 and any of the following claims by a molding method, in particular an injection molding method, characterized in that the material of the impeller elements is introduced into the volumes of the impeller elements radially with respect to the axis of rotation, such that the molding material flows radially into the volumes of the individual impeller elements.

[0031] In this type of method, the molding material can be injected, for example, axially in a central region of the rotor (for example, in the volume of the rotor hub) and dispersed radially from there to the individual impeller elements, which are then completely filled from the radially inner to the outer side of the material flow, although it is also possible to fill the individual impeller elements radially inwards towards the rotation axis from their radially outer ends.

[0032] The reinforcing elements / fibers or membranes provided in the molding compound, which may be made of, for example, glass, but also carbon, polycarbonate or metal, are entrained in the flow of the matrix material and are primarily oriented in the direction of the material flow.

[0033] Also presented is a mold optimized for the production of said rotor and said method, characterized in that the mold is provided with overflow channels at the radially extending edges of the volume of the impeller element to allow an unhindered radial flow of the molding material.

[0034] The overflow channels at the edges of the impeller elements prevent the formation of swirls due to local backflows in the edge area and allow for a highly laminar flow. The reinforcing elements / fibers are thus embedded in the matrix at their primary elongation points, which is particularly advantageous since the rotor can be molded in the mold in the second deployed state, i.e., without external stress.

[0035] In addition to the overflow channels at the side edges of the impeller element, the mold can also form overflow channels at the radially outer ends of the volumes, which allow the molding material to flow out at the radially outer ends of the impeller element, and excess molding material can be removed once at least a portion of the rotor has solidified in the mold.

[0036] Regarding the arrangement of the reinforcing elements / fibers in the volume of the impeller element, the spacing from the bending neutral plane is considered desirable for the purpose of achieving a certain stability in a certain direction by elongating the reinforcing elements / fibers when the impeller element bends outward in the case of loading due to the resistance pressure of the fluid in the operating state. In any case, the reinforcing elements / fibers shall advantageously extend within the impeller element, maintaining a certain minimum distance from the outer boundary surface of the impeller element.

[0037] The rotor may also be provided with a plurality of groups of reinforcing elements / fibers of different lengths, with at least one group having a particular minimum length, while the reinforcing elements / fibers of one or more groups have a length distribution such that there is a negligible number of reinforcing elements / fibers that are shorter than this or that exceed a fiber length below the normal length of the first group of reinforcing elements / fibers, the average length of the shorter reinforcing elements / fibers typically being less than one third of the length of the first group of reinforcing elements / fibers.

[0038] Advantageously, the rotor can be designed so that each reinforcing element / fiber of the first group of reinforcing elements / fibers has an axial and / or azimuthal extension angle of up to 45° from the radial alignment with the rotor axis (14). The reinforcing elements / fibers then extend in a plane along the entire axis of rotation of the rotor, so that they can initially extend directly perpendicularly radially outward from the axis of rotation. However, orientation of the reinforcing elements / fibers from the axis of rotation in the radial direction at an angle between 45° and 90° to the axis of rotation is also possible. In one embodiment, the range of reinforcing elements / fibers has no azimuthal orientation (extending in the circumferential direction) or only a slight orientation of this kind.

[0039] The rotor can also be designed so that the impeller elements are made of a foam material. Closed-pore foam materials are particularly considered here, which can be effectively stabilized by reinforcing fibers while still being easily compressible to a sufficient extent. In particular, foam materials allow particularly easy deflection of the reinforcing elements / fibers during the compression movement to avoid falling below the critical curvature radius. This type of foam material typically has corresponding pores within the volume of the impeller elements, but is actually completely closed at the outer boundary surface.

[0040] The rotor can also be configured so that in the deployed state of the rotor, one group of reinforcing elements / fibers extends transversely to another group of reinforcing elements / fibers, in particular at an average angle of at least 30°. In this way, a specific group of fibers can almost completely prevent bending of the rotor or impeller element of the rotor in the longitudinal direction of the fibers, provided that the bending occurs in the direction in which tensile stress is applied to the fibers. If the two directions are distinguished as described above by the different arrangement of the two groups of fibers, the three-dimensional form of the rotor or part of the rotor can be very efficiently stabilized and strengthened against bending in various directions.

[0041] It is also possible for at least some of the reinforcing elements / fibers to be present in the form of a woven section in which the fibers extend in both the longitudinal and transverse directions. By way of example, the woven section can be stretched in the longitudinal direction at least 2, 3, 5 or 10 times as far as the transverse direction perpendicular thereto, in order to form elongated strips in each case. In this woven section, first fibers are easily laid in the longitudinal direction, and then second fibers extending in the transverse direction are easily laid at right angles or at an obtuse angle.

[0042] By way of example, the reinforcing elements can also be in the form of membrane strips whose length is at least three times, in particular at least five times, and more particularly at least ten times, their width. These membrane strips can consist, for example, of an anisotropic polymer whose tensile strength in the longitudinal direction is much greater than in the transverse direction. However, they can also consist, for example, of a high-tensile plastic material or of a metallic isotropic membrane, such as aluminum, silver, nitinol, titanium, or gold.

[0043] It is also advantageous to configure the reinforcing elements so that they are surrounded by the plastic of which the rotor is made, covering at least 90%, particularly 99%, of its surface, and more particularly the entire rotor. In individual cases, the reinforcing elements in the injection mold may contact the mold wall so that they appear on the outer surface of the rotor in the final product. However, in most cases, only the ends of the reinforcing elements are exposed to the outside of the rotor, but even this is relatively unlikely due to the introduction of the reinforcing elements and the proper flow guidance of the injection molding material during the injection molding process.

[0044] It is also possible in the case of rotors that the plastic material in which the reinforcing elements are embedded has different properties at least in the area of the non-flow-resistance-pressure-applied side of the impeller element during operation compared to the flow-resistance-pressure-applied side of the impeller element, in particular being more bridged or shrunk on the non-flow-resistance-pressure-applied side or having supports on its surface in the form of one or more membranes, coatings or fibers that are shrunk on the impeller element. In this context, the two sides of the impeller element are intended to mean the volumetric areas on either side of the surface or surfaces that constitute the bending neutral surface or surface under bending load in the volume of a particular impeller element.

[0045] One of the objects of the present invention is that the second state of the rotor assumed by the rotor in the absence of external forces is minimally different from the third state assumed by the rotor during operation, as the rotor rotates in the fluid under the action of fluid resistance pressure. Therefore, it is desirable that the reinforcing fibers already in the second state of the rotor are elongated to the greatest extent possible, at least in the direction that defines the curvature of the rotor.

[0046] This can be achieved by providing a plastic matrix formed by the injection molding material that differs in shape from the shape assumed by the rotor in the injection mold. By appropriately designing the plastic matrix formed by the injection molding material, the elastic force of the injection molding material can cause a deformation in the direction of the third state, preloading the fibers, even in the absence of external forces. This effect can be achieved, for example, by providing a material different from the reinforcing elements in or on the rotor, which causes the rotor, particularly the impeller elements, to assume a shape in which the reinforcing elements are preloaded. Since the actual molding of the reinforcing elements in the matrix effectively applies no force to these elements, this is achieved by modifying the plastic matrix or the rotor body as a whole after the injection molding process is completed. For example, the plastic matrix can be specifically treated after removal from the injection mold so that the material of the impeller elements expands on the side where the fluid resistance pressure is applied during operation, or contracts or anisotropically shortens on the opposite side. For example, this can be achieved by irregularly bridging different plastic matrices on two sides of the neutral fibers of the impeller elements. However, this can also be achieved by coating the impeller element on the side opposite to the side exposed to the fluid resistance pressure during operation with a film that shrinks after coating or is shrinkable, for example by electron beam crosslinking or UV crosslinking or heat treatment.

[0047] It is also possible to provide a rotor for a compressible fluid pump that is radially expandable and compressible between a first state, a compressed state, and a second state, an expanded state, in which one or more impeller elements of the rotor are made by injection molding with the simultaneous addition of reinforcing elements that provide reinforcement in the expanded state, the reinforcing elements being surrounded on all sides by the injection-molded material and at least partially elongated in the expanded state, in particular by at least 90%, more particularly 95%, even more particularly 99%, or by using a fabric to achieve the maximum possible elongation.

[0048] Also, by way of example, the rotor can be designed so that the reinforcing elements in a deployed state, which is a second state of the rotor in which there is no fluid resistance pressure, elongate by less than 5%, particularly less than 1%, upon transition to a third state, which constitutes an operating state in which there is fluid resistance pressure, the elongation being measured, in particular, based on the distance between the ends of the reinforcing elements before and during tensile loading.

[0049] Also, by way of example, in the case of a rotor, in the second state of the rotor, which is the deployed state, and / or in the third state, which is the operating state with fluid resistance pressure, at least a group of the reinforcing elements, in particular at least 10%, more particularly at least 30%, can be configured to extend straight in at least one curved region of the impeller element.

[0050] It is also possible to configure at least two groups of reinforcing elements in the curved region of the impeller element so that they extend in a straight line, the directions of extension of the reinforcing elements being parallel within the same group but different between the two different groups. The fibers in the various groups can be introduced into the injection mold connected to one another in the form of a fabric or separated from one another, in particular continuous.

[0051] In another embodiment of the rotor, the length of at least 30%, particularly at least 50%, of the reinforcing elements can be greater than the average thickness of the impeller element, particularly at least twice as long, more particularly at least five or ten times as long. Reinforcing elements of such length can be supplemented by other filling elements (e.g., very short fibers and / or particles) during filling with the molding material, which may also be present in an elongated form. However, since these fibers are typically very short, they have little effect on the limits of the rotor curvature. In this regard, the thickness of the impeller element at any point on the impeller element refers to the dimension in the direction in which the dimension of the impeller element is smallest.

[0052] In another embodiment of the rotor, the reinforcing elements, in particular the fibers, can be introduced into the embedded plastic during injection molding and configured so that when the rotor is placed in the injection mold, they have a direction of extension that is partially curved along the flow of the plastic into the injection mold.

[0053] The invention also relates to an injection mould for a rotor of the above kind, in which overflow channels are provided at the radially extending edges of the volumes of the impeller elements so that the moulding material can flow radially unhindered.

[0054] In the method for producing the rotor, the material for the impeller elements can also be configured to be introduced into the volumes of the impeller elements radially relative to the rotor axis, such that the molding material flows radially into the volumes of the individual impeller elements.

[0055] The flow direction of the incoming molding material and thus the orientation of the fibers along the flow can be controlled by the placement and size of the overflow channels in the mold.

[0056] Another way of producing the rotor is to produce it by molding, in particular by injection molding, and it is also possible to configure this injection molding process to be carried out in two successive stages with different injection directions and / or from two different injection points, so that reinforcing elements / fibers extending in groups in different directions can be introduced into the injection molding material in a targeted manner.

[0057] The method for producing a rotor can also be configured such that, after injection molding, the rotor undergoes a treatment that causes the molding material on the side of the impeller element that is subjected to the drag pressure during operation to shrink and / or crosslink differently from the opposite side. Thus, the rotor can be preloaded by creating internal stresses so that, when exposed to drag pressure, the rotor assumes a stable third state, or operating state, without the influence of external forces. This is achieved in that the internal stresses are directed and created so that tensile forces that exist in the order of the forces to which the reinforcing fibers are exposed during rotor operation are preloaded on the reinforcing elements.

[0058] Also, by way of example, a contractible or shrinkable layer may be applied to at least one of the impeller elements opposite the side exposed to the fluid resistance pressure during operation.

[0059] Alternatively or additionally, for example, the injection mold for the injection molding material can be configured to have at least two different injection openings. Thus, the flow of the injection molding material in the mold can be targeted during the molding process by adding reinforcing elements at various stages, so that the reinforcing elements can be positioned in different directions relative to the main flow direction of the injection molding material, in each case according to the various stages of the injection molding process. For this purpose, for example, first and second amounts of injection molding material can be injected through the first and second injection openings, respectively, sequentially, simultaneously, or at variable ratios to each other.

[0060] The innovation is presented and explained below on the basis of exemplary embodiments in the drawings. [Brief explanation of the drawings]

[0061] [Figure 1] FIG. 1 is a schematic cross-sectional view of a catheter pump introduced into a patient's ventricle. [Figure 2a] FIG. 1 is a diagram showing details of a rotor of a catheter pump that transports blood. [Figure 2b]FIG. 1 is a cross-sectional view of a spreading rotor with fibers shown as an example. [Figure 2c] FIG. 4 is a cross-sectional view of the rotor in a third or operating state. [Figure 2d] FIG. 2 is a cross-sectional view of the rotor in a compressed state. [Figure 2e] FIG. 10 is a cross-sectional view of an impeller element showing, by way of example, bending neutral plane markings and reinforcing fibers. [Figure 3] FIG. 2 is a schematic diagram of a plane including the rotation axis of the rotor. [Figure 4] FIG. 10 shows a detail of a planar impeller element with reinforcing fibers. [Figure 5a] FIG. 1 illustrates the orientation of fibers during the molding process. [Figure 5b] FIG. 5 is a side view of a portion of FIG. [Figure 6] FIG. 6 shows the portion of the impeller element shown in FIGS. 4 and 5 after the bending process. [Figure 7] 1 is a schematic diagram of a forming tool for a rotor, with flow arrows indicating the forming process. [Figure 8] FIG. 8 is a diagram showing a mold for a rotor in which the injection direction is opposite to that in FIG. 7. [Figure 9] FIG. 10 shows a mold in which measures are taken to prevent swirling of the injection molding material in the volume of the impeller element. [Figure 10] FIG. 10 is a diagram showing another mold. [Figure 11] FIG. 1 shows a membrane strip-shaped reinforcing element. [Figure 12] FIG. 1 shows a woven reinforcing element. [Figure 13] FIG. 2 is a cross-sectional view of an impeller element. [Figure 14a] FIG. 1 shows a woven fabric made of fibers in an unstressed state. [Figure 14b] FIG. 14b shows the fabric of FIG. 14a at maximum stretch under load. [Figure 15a] FIG. 2 is a perspective view of the impeller element in an unfolded state without the action of an external force. [Figure 15b]15b is a cross-sectional view of the impeller element taken along the line AA in FIG. 15a. [Figure 16a] FIG. 2 is a perspective view of the impeller element in an unfolded state without the action of an external force. [Figure 16b] FIG. 16b is a cross-sectional view of the impeller element taken along the line BB in FIG. 16a. [Figure 17a] FIG. 1 is a side view of the impeller element in an unfolded state without the action of an external force. [Figure 17b] 17b is a cross-sectional view of the impeller element taken along the line CC in FIG. 17a. DETAILED DESCRIPTION OF THE INVENTION

[0062] 1 shows a cross-sectional view of a patient's heart 1 having multiple chambers, with ventricles 2 connected to an aorta 12. A catheter 4 is advanced through the aorta 12 to ventricle 2, with a pump head 3 equipped with a rotary pump located at the end of catheter 4. The rotary pump is drivable by a rotatable shaft 6 extending through catheter 4, which is connected to a pump rotor 42 within pump head 3. The pump rotor rotates in a housing (not shown in detail) of pump head 3.

[0063] The flexible shaft 6 is connected to a motor 7, which is arranged, for example, outside the patient's body. Torque can be transmitted from the motor 7 to the shaft 6 in both directions of rotation 8, 9, for example by magnetic coupling.

[0064] The catheter 4 is typically advanced from outside the body through a port, through the skin and tissue, as well as the blood vessel wall, into the aorta 12 and its interior.

[0065] The pump draws blood from the ventricle 2 and delivers it to the aorta 12. In this way, the heart pump is able to assist or at least temporarily replace the function of the heart 1.

[0066] In addition to the illustrated mechanically driven catheter pump, other pumps, particularly for internal use, such as hydraulically or electrically driven pumps, including pumps driven inside the human body, also form the subject of this patent.

[0067] The pump, together with the pump head, pump housing and rotor, is radially compressed for displacement through the artery, for example within the catheter 4. The pump can then be axially slid out of the catheter 4 and radially expanded or deployed. This process places high demands on the material of the pump housing, and in particular the pump rotor. The impeller element of the pump rotor must have a very thin wall thickness, yet be dimensionally stable, to transport blood reproducibly, even at high rotational speeds.

[0068] For this purpose, reinforcing fibers (fibers) are embedded in the plastic matrix of which the rotor is made, and may be provided, for example, as glass or polycarbonate fibers. Such reinforcing elements / fibers are illustrated in three specific examples in Figure 2a. Three reinforcing elements / fibers 10, 11, 13 are shown, each having a first end or first portion 10a, 11a, 13a that is closer to the axis of rotation 14 than a second end / second portion 10b, 11b, 13b of the reinforcing element / fiber 10, 11, 13.

[0069] The reinforcing elements / fibers 10, 11, 13 extend substantially radially outward from a point at or near the rotor's axis of rotation 14. Here, the rotor 42 need not have a hub 43 as in the illustrated example. Also, the helical impeller element 15 may have inherent stability such that a rotor hub is not required.

[0070] In principle, the plastic matrix of one or more impeller elements 15 can be reinforced with reinforcing elements / fibers randomly distributed and arranged with respect to length, thickness, and / or orientation. In one embodiment, a certain minimum group of reinforcing elements / fibers in the deployed state of the rotor shown in FIG. 2b is substantially elongated and extends away from the rotation axis. In the operating state corresponding to the third state and shown in FIG. 2c, these reinforcing elements / fibers are elongated and further subjected to tensile stress caused by the load of the transport liquid. However, due to the longitudinal strength of the reinforcing elements / fibers, this tensile stress does not result in significant elongation, and the rotor geometry is hardly changed compared to the unstressed deployed state, i.e., no further deformation beyond a certain operating point. Of the total reinforcing elements / fibers embedded in the plastic of the rotor, the group of reinforcing elements / fibers that meets the above conditions should be at least 30%, preferably 50%, and even more preferably, 70%, based on a percentage measurement by volume or mass of the reinforcing elements / fibers or on the number of reinforcing elements / fibers. Advantageously, a certain minimum length of the reinforcing elements / fibers is provided here, such as at least about 20%, at least 40%, or 50% of the rotor radius. The reinforcing elements / fibers can easily change from their axial orientation, corresponding to the axial filling of the hub 43, to the radial position of the impeller element 15 during filling of the mold without bending, because they extend relatively flat, with an angle between the impeller element 15 and the hub 43 of less than 30°, preferably less than 20°. In this way, the reinforcing elements / fibers are easily taken up by the surrounding matrix during the radial filling of the impeller element 15, and are radially oriented by the material flow in the impeller element according to FIG. 2a.

[0071] Another advantageous property of the reinforcing elements / fibers is their maximum specific thickness; a diameter of up to 40 μm can be advantageous so that they do not break even in the case of severe bending of the reinforcing elements / fibers. At a size of approximately 40 μm, the reinforcing elements / fibers are sufficiently flexurally rigid to return the surrounding matrix to its initial state after deformation and to prevent long-term creep of the matrix under permanent bending loads. Furthermore, reinforcing elements / fibers with a diameter of 40 μm exhibit resistance to compressive and tensile stresses, and, when positioned outside the neutral bending region, generate restoring moments and resist other deformations.

[0072] The reinforcing elements / fibers can be coated with an adhesion promoter to improve their connection to the matrix.

[0073] Figure 2b shows a cross section of the rotor 42' with the impeller elements 15', 15'' in the extended, deployed state. In this state, the reinforcing elements / fibers 55, 56 are in their maximally elongated configuration and therefore resist further deformation of the rotor due to their longitudinal stiffness.

[0074] Arrow 57 indicates the direction of rotation of the rotor in operation. Arrows 58, 59 indicate the loads acting on the impeller elements 15', 15'' as a result of the conveying movement, i.e. the fluid resistance pressure acting on the impeller elements. Figure 2b shows a chord 60 representing the height of the impeller element 15' measured radially from the axis of rotation.

[0075] FIG. 2c shows the rotor 42' in a third state, i.e., in operation, also showing the chord 60. The reinforcing fibers 55, 56 are subjected to tensile stress due to the loads 58, 59 and absorb the strains that occur in the impeller elements 15', 15''. The length of the chord 60, i.e., the height of the impeller elements, remains constant in the operation state compared to the second state, or even increases slightly, but does not decrease.

[0076] Figure 2d shows rotor 42' in a compressed configuration, with the impeller elements folded against the rotor hub. In this position, the pump can be delivered through a narrow channel to the surgical site.

[0077] FIG. 2e is a detailed cross-sectional view of the impeller element 15' in an operating state. The "bending neutral fiber" or "bending neutral plane" is indicated by dashed line 61, i.e., the line or plane where no tension or compression occurs when the impeller element 15' is bent under load. A number of reinforcing fibers, shown by way of example at 62 and 63, are present on the side of line / plane 61 where tensile stress occurs in the operating state. The reinforcing elements / fibers are now partially elongated and run straight and substantially parallel to line / plane 61. As a result, the reinforcing elements / fibers can effectively absorb tensile stresses.

[0078] A possible orientation of the reinforcing elements / fibers will be explained in more detail with reference to Figure 3. In Figure 3, the rotor hub is designated 16 and the axis of rotation is designated 14. A plane 17 based on a cut rectangle is shown, which plane 17 includes the axis of rotation 14, i.e., the axis of rotation 14 extends completely within the plane 17. It should be noted that this figure is schematic, since the impeller elements are typically helical, and therefore the plane 17 is curved rather than flat.

[0079] By way of example, two reinforcing elements / fibers 18, 19 are shown, both of which extend substantially radially in plane 17 relative to axis of rotation 14. Fibers 18 extend at an angle α to axis of rotation 14, with an axial component, which angle α is conveniently between 45° and 90°. Fibers 19 are oriented so as to be disposed perpendicular to axis of rotation 14. Actual braids are often limited in the extent of the reinforcing elements / fibers in the azimuthal direction, due to their three-dimensional helical curvature.

[0080] The individual reinforcing elements / fibers do not have to be positioned so that their initial start / end points are within the region of the rotational axis 14 or rotor hub 16. Also, the individual reinforcing elements / fibers can be positioned to extend between two end points radially spaced apart from the rotor axis 14 and / or rotor hub 16. However, in any case beyond the axis, the individual reinforcing elements / fibers can extend from a first radially outer blade edge up to a second radially opposite blade edge.

[0081] A detail 20 of an impeller element is shown diagrammatically in Figure 4, this detail 20 being cubic in shape. The fibres 19 are shown in the part 20.

[0082] Figure 5a clearly shows how a central orientation of the fibres 19 can be achieved. The preferably laminar flow profile during filling of the mould between the boundary walls 53 and 54 has the highest flow velocity in the centre and the lowest flow velocity near the walls. The initially tilted fibres 19 are shown in three angular positions successively reached from left to right, and are drawn towards the centre of the flow profile by the material flow indicated by arrows 50, 51 as a result of the velocity distribution in the mould. The velocity distribution of the flow is shown in the graph 52 in the figure with axes x (velocity) and y (position coordinate in the mould).

[0083] FIG. 5b is a side view showing the material of section 20 in a see-through manner so as to reveal the direction of extension of fibers 19 approximately midway between the boundaries of the impeller elements.

[0084] The behavior of fibers under large curvature or bending of the impeller element will now be described based on FIG.

[0085] Figure 6 shows a section 20 of the impeller element after bending. The fibres 19 are also deformed. However, due to their specific intrinsic stiffness, in the event of bending, the elasticity of the material of the impeller element allows them to protrude outwards in the direction of the arrows 21, thus realising the maximum possible radius of curvature of the fibres and preventing them from breaking. In the region of the bending point, the fibres 19 therefore deviate from the centre between the boundary walls of the impeller element during bending. For clarity, in Figure 6 at least part of the central surface of the impeller element is shown by a dotted line 22. To achieve this effect, the flexibility of the plastic matrix of the rotor is advantageous, corresponding to a Shore hardness of less than 100D, in particular less than 80D.

[0086] In the following, the inventive design of a forming tool / mold for a rotor according to the invention will be discussed based on FIG.

[0087] FIG. 7 is a longitudinal cross-section of an injection mold, showing the area containing the rotor hub volume at 23 and the individual impeller element volumes at 24, 25, 26, and 27. Also in FIG. 7, the injection direction is indicated by arrow 28. Other arrows 29, 30, 31, 32, and 33 indicate that the injection molding material flows axially along the final rotor's rotational axis 14 and then radially outward into the impeller element volumes. By way of example, the longitudinal axis of one of the impeller elements is indicated by dashed-dotted line 44. When a sufficient number of reinforcing elements / fibers of appropriate length are introduced into the injection molding material, these reinforcing elements / fibers will orient themselves according to the main flow direction of the material and maintain that orientation as the material solidifies.

[0088] The displaced air and excess molding material can exit through openings 45 at the radially outer ends of the impeller elements.

[0089] 8 shows the opposite injection direction, where the injection molding material is injected radially inward from the radially outer ends 34, 35 of the impeller elements into the volume of the rotor 23. Again, long reinforcing elements / fibers can be introduced, oriented and positioned as intended in accordance with the present invention.

[0090] Based on Figure 9, it can be shown that in the case of narrow impeller elements 36, 37, the molding material flowing out radially from the inside does not flow laminarly when it enters, because friction causes the molding material to swirl at the edges 38, 39 of the volume of the particular impeller element.

[0091] The left side of FIG. 9 shows a mold variant with overflow openings or overflow slots in the area of the edges 40, 41, through which part of the injection molding material can escape in the axial direction of the rotor, thus eliminating the swirling shown on the right side of FIG. 9. Due to this pseudo-laminar flow in the central area of the impeller element 37, the introduced reinforcing elements / fibers can assume an elongated form in the area around the "neutral fibers" or neutral plane (under bending loads occurring during pump operation) without being deformed by the flow of the injection molding material. Once the injection molding material solidifies, the part that can escape through the openings at the edges 40, 41 of the volume of the impeller element in the injection molding mold is removed, for example by cutting. The same situation can also occur at the outer edge of the impeller element, as shown in FIG. 7. Here, an overflow channel 45 is provided through which the plastic without reinforcing elements / fibers can escape.

[0092] Due to the asymmetric distribution of the outflow openings (e.g., a larger outflow cross section near the area of the impeller element that is exposed to the fluid resistance pressure of the liquid during operation), the flow of the molding material is stronger there, so that more reinforcing elements / fibers are embedded there than on the other side of the "neutral plane", and as a result tensile stresses can be absorbed by a larger number of reinforcing elements / fibers.

[0093] FIG. 10 shows a schematic of an injection mold 70 with a first injection opening 71 and a second injection opening 72, located at opposite ends of a central cavity 73 where the rotor hub is formed during the molding process. The cavities where the impeller elements are formed are shown highly schematic and are designated 74 and 75. Arrows 76 and 77 indicate the flow direction of the plastic entering the mold. If plastic is injected into the mold through the first injection opening 71 and the second injection opening 72 sequentially or at alternating rates, different flow directions of the liquid molding material are created. If reinforcing elements are added, the resulting rotor will have different orientations of the reinforcing elements. Thus, different orientation patterns can be achieved by controlling the injection speed through the injection openings and varying the injection speed or the ratio of injection speeds through the various injection openings during the molding process.

[0094] A perspective view of a reinforcing element in the form of a metal foil or plastic film 78 is shown in Figure 11, which foil / film may be, by way of example, only a few micrometers thick, a few tenths of a millimeter wide and a few millimeters long.

[0095] 12 shows elongated fabric strips as reinforcing elements, which schematically have only two longitudinally extending fibres 79, 80 and a number of transversely extending short fibres 81. This type of fabric is able to fully absorb tensile forces in both longitudinal directions of the fibres present.

[0096] 13 is a schematic cross-sectional view showing the area of the impeller element 82, where 83 indicates the cover surface that is on the pressure side during operation and is exposed to the fluid resistance pressure indicated by arrows 84.

[0097] The opposite side or cover surface of cover surface 83 is designated 85. In the example shown, this side of impeller element 82 is provided with a coating 86, which may be provided by an adhesive film or a liquid coating (e.g., varnishing).

[0098] Also shown is dotted line 87, which is known in the mechanical sense as the neutral "fiber" or plane for the bending of impeller element 82 during pump operation.

[0099] If the impeller element shown in Figure 13 is considered to be in a no-force state, i.e., a state in which no external force is acting on the impeller element, then in this state, it is also possible to configure the reinforcing element, as shown by way of example at 88, to exist in an extended form with no force being applied thereto.

[0100] When the rotor rotates in the fluid, a bending force in the direction of arrow 84 acts on the impeller element due to the action of fluid resistance pressure 84. As a result of the bending of the impeller element, the neutral fibers 87 located on the left side of the figure become longer, and the reinforcing elements 88 are subjected to a tensile load. Since the reinforcing elements 88 actually resist elongation, they limit the bending.

[0101] To further reduce the difference in rotor geometry between the second, unloaded state and the third, or loaded, state, it is also possible to configure the reinforcing elements 88 to be pre-stressed internally in the unloaded state, i.e., when no external forces are acting on the rotor, in that the impeller elements are stretched on the cover surface 83 side or contracted on the cover surface 85 side after the rotor is fabricated, more particularly after the injection molding process is completed.

[0102] This is achieved, for example, in that a coating 86 is applied to the cover surface 85 after or during the injection molding process, for example by impregnation of the injection mold, but the coating can be shrunk during drying or crosslinking or by subsequent treatment, in particular by electron beam crosslinking, UV crosslinking or heat treatment. Also, electron beam crosslinking can be introduced, for example, by one or more laser beams, and can therefore be applied locally in a very focused manner.

[0103] However, in addition to or as an alternative to the cover layer 86, it is also conceivable that the material of the impeller element 82 on the neutral plane side of the fibers 87 facing the cover layer 85 may be shrunk, for example, by heat treatment or crosslinking / polymerization, which does not occur or occurs only to a small extent on the other side of the impeller element.

[0104] 14a and 14b show an example of a woven fabric made of fibers. Here, fibers 90 are part of a fiber bundle, extending at an angle relative to other fiber bundles 91, but the fiber bundles 91 are arranged perpendicular to the plane of the drawing, with fibers 90 passing through the fiber bundles 91 alternately from side to side. In FIG. 14a, which shows the rotor in its extended state, the fiber bundles 91 are spaced a distance a from each other, and the fibers 90 have a curved extension direction, back and forth. In FIG. 14b, which shows the rotor in operation, the fiber bundles 91 are spaced a greater distance a' from each other, and the fibers 90 have a curved extension direction, back and forth. From FIGS. 14a and 14b, it is clear that this type of system reaches a substantially stable state before the fibers 90 are fully extended. Beyond the state shown in FIG. 14b, the fiber bundles 91 would need to move perpendicular to the fibers 90 in the substrate, but this is essentially prevented by the fiber bundles 91 and the fibers 90.

[0105] FIG. 15a is a perspective view of the rotor in its unloaded, deployed state, showing cross section AA. FIG. 15b is a cross-sectional view of the same rotor along the cross section. Dotted lines 101 and 102 represent the neutral fibers or surfaces of each blade. Fibers 103 and 104 indicate, by way of example, the orientation of two fibers in the illustrated planar cross section. The fibers are curved in this state. Under load, the fluid exerts pressure on the blades in the direction of the arrows shown, causing the blades to further deploy. Under full operating load, fibers 103 and 104, at least in the regions indicated by 105 and 106, elongate, preventing further deployment of the blades. This is because the fibers, already under very high tension, must be further elongated in the axial direction. An advantage of this design is that the blade configuration remains virtually constant above a minimum rotational speed.

[0106] FIG. 16a shows a perspective view of the rotor in its unloaded state, also showing cross section BB. FIG. 16b shows a cross section of the same rotor along that cross section. Dotted lines 111 and 112 represent the neutral fibers or surfaces of each blade. Fibers 113 and 114 show, by way of example, the extension directions of two fibers in the cross section shown. As can be seen, the fibers in this example are already at their maximum elongation. Because the fibers are under very high tension, there is little chance of them becoming any longer. Even with the forces acting on the blades during operation, as indicated by the arrows in FIG. 16b due to flow pressure, such blades do not deform significantly, which has the advantage of keeping the blade configuration virtually constant throughout the entire range of rotational speeds.

[0107] Figure 17a shows a side view of the rotor in its unloaded, unstretched state, also showing cross section CC. Figure 17b shows a cross section of the same rotor along the cross section. Dotted lines 121 and 122 represent the neutral fibers or surfaces of each blade. Fibers 123 and 124 show, by way of example, the extension directions of two fibers in the cross section shown. As can be seen, the fibers in this example are already elongated over a large area. Because the fibers are under very high tension, there is little opportunity for them to lengthen further. Such blades do not deform significantly further under the forces, indicated by the arrows in Figure 17b, that occur during operation and act on the blades due to flow pressure.

[0108] As a result of the above-mentioned features, in particular as a result of the rotor design and the introduction of suitable reinforcing elements / fibers, a stable design of the rotor is achieved, with a sufficiently accurate shape even after partial overstretching, frequent load changes, or constant application of bending loads. As a result of the described manufacturing method and the proposed injection mold, a convenient and advantageous possibility for manufacturing the proposed rotor has been demonstrated.

[0109] The present invention also encompasses the following aspects, each of which may be protected individually and independently:

[0110] First aspect: A rotor for a compressible fluid pump, in particular a blood pump, that can be introduced into a patient's body through a blood vessel, comprising one or more impeller elements (15) and that can be radially compressed and expanded between a first state, compressed, and a second state, radially expanded, and that is at least partly made of strand-like reinforcing elements, in particular fiber-reinforced plastic, and that is intended to rotate about an axis of rotation, characterized in that in the first state, i.e. compressed, a preload is applied, in the second state, i.e. expanded, no external stress is applied, and there is a third state that the rotor (42) assumes when operating under load, the various materials of the rotor and their distribution are adapted to one another in such a way that in the second state of the rotor, material stresses are selectively generated that cause tension and / or elongation of the reinforcing elements.

[0111] Second aspect: A rotor according to the first aspect, characterized in that the reinforcing elements are further configured to be surrounded by plastic that constitutes a large part of the rotor's surface, at least 90%, in particular 99%, and more particularly the entire rotor.

[0112] Third aspect: A rotor according to the first or second aspect, characterized in that the plastic material in which the reinforcing elements are embedded has different properties compared to at least the fluid resistance pressure side of the impeller element during operation, in particular in the region of the corresponding side of the impeller element relative to the fibers or surfaces that form a curved neutral fiber or plane during pump operation under bending load, in particular being more bridged or shrunk on the fluid resistance pressure side or further configured to have supports on the surface of the impeller element in the form of one or more films, coatings or fibers.

[0113] Fourth aspect: A rotor according to the first, second or third aspect, characterized in that one or more impeller elements of the rotor are made by injection molding with simultaneous addition of reinforcing elements in the deployed state, the reinforcing elements being surrounded on all sides by the injection molding material and being present in an at least partially elongated form in the deployed state, in particular being present in an elongated form to an extent of at least 90%, more particularly 95%, even more particularly 99%.

[0114] Fifth aspect: A rotor according to the first, second, third or fourth aspect, further characterized in that the reinforcing elements in a deployed state, which is a second state of the rotor in which there is no fluid resistance pressure, are present in an elongated form to an extent that they become longer by less than 5%, in particular by less than 1%, upon transition to a third state, which constitutes an operating state in which there is fluid resistance pressure, and the elongation is measured in particular based on the distance between the two ends of the reinforcing elements.

[0115] Sixth aspect: A rotor according to the first, second, third, fourth or fifth aspect, further characterized in that in the second state of the rotor, that is, in a deployed state, and / or in a third state, that is, in an operating state with a fluid resistance pressure, at least a group of the reinforcing elements, in particular at least 10%, more particularly at least 30%, are configured to extend straight in at least one curved region of the impeller element.

[0116] Seventh aspect: A method of making a rotor for a fluid pump, in particular as described in the first aspect, characterized in that after injection molding the rotor is configured to undergo a treatment that causes the molding material on the fluid resistance pressure acting side of the impeller element during operation to shrink and / or crosslink differently from the opposite side.

[0117] Eighth aspect: A method for making a rotor for a fluid pump, in particular as described in the first aspect, by injection molding, characterized in that a shrinkable layer is applied to at least one of the impeller elements opposite the side exposed to the fluid resistance pressure of the impeller element during operation.

[0118] Ninth aspect: A mold for a rotor for a fluid pump having the impeller element according to the first aspect, characterized in that the mold is provided with at least two different injection openings.

[0119] Tenth aspect: A rotor according to any one of the above aspects, characterized in that the reinforcing elements have a two-dimensional extent and are configured, for example, as membrane pieces or fabrics in which groups of fibers cross each other (see Figures 14a and 14b).

[0120] <Additional Notes> [1] 1. A rotor for a compressible fluid pump, in particular a blood pump, that can be introduced into a patient's body through a blood vessel, the rotor having one or more impeller elements (15) and being radially compressible and expandable between a first compressed state and a second radially expanded state, the rotor being made of plastic reinforced at least in part by strand-like reinforcing elements, in particular fibers (10, 11, 13, 18, 19, 55, 56, 62, 63), the rotor being intended to rotate about an axis of rotation (14), the rotor being in tension in the first compressed state, and in the second expanded state without any external stress, and a third state that the rotor (42) assumes when operating under load, the fibers of the rotor in the third state being at least partially elongated. [2] 1. The rotor according to claim 1, wherein the reinforcing elements, in particular the fibers (10, 11, 13, 18, 19, 55, 56, 62, 63), in the third state (operating state) of the rotor are at least partially elongated in areas of the rotor (42) where tensile stresses occur and extend substantially in the direction of the tensile stresses. [3] 1. A rotor according to claim 1 or 2, characterized in that the reinforcing elements, in particular the fibres (10, 11, 13, 18, 19, 55, 56, 62, 63), are predominantly arranged in areas of the rotor and / or impeller element where tensile stresses occur in the operating state. [4] The rotor according to any one of the above [1] to [3], characterized in that in the case of the rotor (42), there is no substantial difference between the second state, which is an expanded state, and the third state, which is an operating state, as far as the external shape is concerned. [5] The rotor according to any one of the above [1] to [4], characterized in that the reinforcing elements, in particular the fibers (10, 11, 13, 18, 19, 55, 56, 62, 63), are arranged to extend radially beyond the rotation axis (14). [6] A rotor according to any one of the above [1] to [5], characterized in that in the operating state, the reinforcing elements, in particular at least some of the fibers, in particular the majority of the reinforcing elements / fibers (10, 11, 13, 18, 19, 55, 56, 62, 63) extend partially straight. [7] A rotor according to any one of the above [1] to [5], characterized in that in an operating state, at least some of the reinforcing elements, in particular the fibres (10, 11, 13, 18, 19, 55, 56, 62, 63), in particular the majority of the reinforcing elements / fibres, extend along the longitudinal direction of the impeller element (15) with a curvature that is smaller in the sense of material strength than the neutral fibres (neutral axis) and / or neutral plane of the impeller element (15). [8] The rotor according to any one of the above [1] to [7], characterized in that the Shore hardness of the plastic of the rotor (42) is less than 100D, particularly less than 80D. [9] The rotor according to any one of the above [1] to [8], characterized in that more than 30%, in particular more than 50%, of the first group of reinforcing elements / fibers (10, 11, 13, 18, 19, 55, 56, 62, 63) in the deployed state of the rotor (42) extend substantially elongated from the portion (10a, 11a, 13a) arranged closest to the axis of rotation (14) to the second portion (10b, 11b, 13b) arranged further from the axis of rotation (14).

[10] A rotor according to any one of the above [1] to [9], characterized in that a first group of reinforcing elements / fibers, which is more than 30% of the reinforcing elements / fibers (10, 11, 13, 18, 19, 55, 56, 62, 63), in particular more than 50% of the reinforcing elements / fibers, have a length, measured in the radial direction of the rotor (42) in the deployed state, which corresponds to at least 30%, in particular at least 50%, of the maximum height of the impeller element (15).

[11] A rotor according to [9] or

[10] above, characterized in that the first group of reinforcing elements / fibers (10, 11, 13, 18, 19, 55, 56, 62, 63) extend substantially perpendicular to the axis of rotation (14).

[12] A rotor according to any one of the above [1] to

[11] , characterized in that the diameter of the reinforcing elements / fibers (10, 11, 13, 18, 19, 55, 56, 62, 63), in particular the first group of reinforcing elements / fibers (10, 11, 13, 18, 19, 55, 56, 62, 63), is less than 40 micrometers.

[13] The rotor according to any one of the above [1] to

[12] , characterized in that an adhesion promoter is provided on the surface of the reinforcing elements / fibers (10, 11, 13, 18, 19, 55, 56, 62, 63).

[14] A rotor according to any one of the above [1] to

[13] , characterized in that a group of reinforcing elements / fibers in the deployed state of the rotor extend transversely to the reinforcing elements / fibers of the first portion, in particular encompassing an angle of at least 30° on average.

[15] A rotor according to any one of the above [1] to

[14] , characterized in that at least a portion of the reinforcing elements / fibers are present in the form of a woven portion in which the fibers extend in the longitudinal and lateral directions.

[16] A rotor according to any one of the above items [1] to

[15] , characterized in that the reinforcing elements are present in the form of membrane strips whose length is at least three times, in particular at least five times, more particularly at least ten times, their width.

[17] A rotor according to any one of the above [1] to

[16] , characterized in that the reinforcing elements are surrounded by plastic that constitutes a large part of the rotor, at least 90%, particularly 99%, of the surface, and more particularly the entire rotor.

[18] A rotor according to any one of the above [1] to

[17] , characterized in that the plastic material in which the reinforcing elements are embedded has different properties at least in the region of the non-fluid resistance pressure side of the impeller element during operation compared to the fluid resistance pressure side of the impeller element, in particular it is more bridged or shrunk on the non-fluid resistance pressure side, or it has a support portion (86) on the surface of the impeller element (82) that is shrunk, the support portion (86) being provided in the form of one or more films, coatings or fibers.

[19] 1. A rotor for a compressible fluid pump, radially expandable and compressible between a first state, a compressed state, and a second state, an expanded state, characterized in that one or more impeller elements of the rotor are made by injection molding with the simultaneous addition of reinforcing elements that reinforce the rotor in the expanded state, the reinforcing elements being surrounded on all sides by injection molding material and being at least partially in an extended form in the expanded state, in particular being at least 90%, more particularly 95%, and even more particularly 99% extended.

[20] A rotor according to any one of the above [1] to

[19] , characterized in that the reinforcing elements in the deployed state, which is the second state of the rotor in which there is no fluid resistance pressure, are in a form that elongates by less than 5%, particularly less than 1%, when transitioning to a third state that constitutes an operating state in which there is fluid resistance pressure, and the elongation is measured particularly based on the distance between both ends of the reinforcing elements. [twenty one] The rotor according to any one of the above [1] to

[20] , characterized in that in the second state of the rotor, which is a deployed state, and / or in the third state, which is an operating state with a fluid resistance pressure, at least a group of the reinforcing elements, in particular at least 10%, more particularly at least 30%, are elongated and extend straight in at least one curved region of the impeller element. [twenty two] The rotor according to

[21] above, characterized in that in the curved region of the impeller element, at least two groups of the reinforcing elements extend elongated and straight, and the extension directions of the reinforcing elements of the groups are parallel within the same group but different between the two different groups. [twenty three] A rotor according to any one of the above items [1] to

[22] , characterized in that the length of the reinforcing elements is greater than the average thickness of the impeller element in at least 30%, in particular in at least 50% of cases, in particular at least twice as long, more particularly at least 5 or 10 times as long. [twenty four] A rotor according to any one of the above items [1] to

[23] , characterized in that the reinforcing elements, in particular the fibers, are introduced into the plastic to be embedded during injection molding, and when the rotor is placed in the injection molding mold, have an extension direction that is partially curved along the flow of the plastic into the injection molding mold. [twenty five] A method for producing a rotor (42) according to any one of the above items [1] to

[24] by a molding method, in particular an injection molding method, characterized in that the material of the impeller elements (15) is introduced into the volumes of the individual impeller elements in a radial direction relative to the rotation axis (14) so that the molding material flows into the volumes of the individual impeller elements in a radial direction (30, 31, 32, 33).

[26] A method for producing a rotor according to any one of the above items [1] to

[24] , characterized in that the rotor is produced by a molding method, in particular an injection molding method, and the injection molding method is carried out in two successive stages from different injection directions and / or two different injection points.

[27] 2. The method according to claim 1, wherein after the injection molding, the rotor is subjected to a treatment in which the molding material on the fluid resistance pressure side of the impeller element during operation shrinks and / or crosslinks differently from the opposite side.

[28] The method according to any one of

[25] to

[27] above, characterized in that a shrinkable layer is applied to at least one of the impeller elements on a side opposite to the side exposed to the fluid resistance pressure of the impeller element during operation.

[29] A mold for the rotor (42) according to any one of the above [1] to

[24] , characterized in that overflow channels are provided at the radial edges (40, 41) of the volume of the impeller element (15) so that the molding material can flow radially unhindered.

[30] A mold for the rotor according to any one of the above items [1] to

[24] , characterized by at least two different injection openings.

Claims

1. A rotor for a compressible fluid pump, the rotor having one or more impeller elements (15) and being radially compressible and expandable between a first state, a compressed state, and a second state, a radially expanded state, the rotor being made of plastic reinforced at least in part by strand-like reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63), the rotor intended to rotate about an axis of rotation (14), the first state, compressed, being preloaded, the second state, expanded, being free of external stress, and a third state, the rotor's third state, being in operation under load, the reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) being at least partially elongated; the reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) in the deployed state, which is the second state of the rotor without fluid resistance pressure, are present in a form in which the distance between both ends of the reinforcing elements increases by 0% to 5%, in particular by 0% to 1%, when the rotor transitions to the third state, which constitutes an operating state with fluid resistance pressure; the impeller element (15) is made of plastic reinforced with the reinforcement elements (10, 11, 13, 18, 19, 55, 56, 62, 63) embedded therein; A rotor, characterized in that a majority of said reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) are arranged in areas of said rotor and / or said impeller element where tensile stresses occur in said operating state.

2. 2. A rotor according to claim 1, characterized in that in the third state (operating state) of the rotor, the reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) extend at least partially elongated in areas of the rotor (42) where tensile stresses occur and extend substantially in the direction of the tensile stresses.

3. 3. A rotor according to claim 1 or 2, characterized in that in the case of said rotor (42), there is substantially no difference as far as the external shape is concerned between said second state, the deployed state, and said third state, the operational state.

4. A rotor according to any one of claims 1 to 3, characterized in that in said operating state at least some of said reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) extend partly straight.

5. A rotor for a compressible fluid pump, comprising one or more impeller elements (15) and radially compressible and expandable between a first state, compressed, and a second state, radially expanded, made of plastic at least partially reinforced by strand-like reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63), intended to rotate about an axis of rotation (14), wherein in said first state, compressed, a preload is applied and in said second state, expanded, no external stress is applied, and wherein there is a third state in which the rotor (42) is assumed to be in operation under load, wherein in said third state, said reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) of the rotor are at least partially elongated and extended, the reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) in the deployed state, which is the second state of the rotor without fluid resistance pressure, are present in a form in which the distance between both ends of the reinforcing elements increases by 0% to 5%, in particular by 0% to 1%, when the rotor transitions to the third state, which constitutes an operating state with fluid resistance pressure; the impeller element (15) is made of plastic reinforced with the reinforcement elements (10, 11, 13, 18, 19, 55, 56, 62, 63) embedded therein; 1. A rotor according to claim 1 , characterized in that in said operating state at least a part of said reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63), in particular a majority of said reinforcing elements, extend along the longitudinal direction of said impeller element (15) with a curvature that is smaller in the sense of material strength than the neutral reinforcing element (neutral axis) and / or neutral plane of said impeller element (15).

6. A rotor for a compressible fluid pump, comprising one or more impeller elements (15) and radially compressible and expandable between a first state, compressed, and a second state, radially expanded, made of plastic at least partially reinforced by strand-like reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63), intended to rotate about an axis of rotation (14), wherein in said first state, compressed, a preload is applied and in said second state, expanded, no external stress is applied, and wherein there is a third state in which the rotor (42) is assumed to be in operation under load, wherein in said third state, said reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) of the rotor are at least partially elongated and extended, the reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) in the deployed state, which is the second state of the rotor without fluid resistance pressure, are present in a form in which the distance between both ends of the reinforcing elements increases by 0% to 5%, in particular by 0% to 1%, when the rotor transitions to the third state, which constitutes an operating state with fluid resistance pressure; the impeller element (15) is made of plastic reinforced with the reinforcement elements (10, 11, 13, 18, 19, 55, 56, 62, 63) embedded therein; A rotor (42) characterized in that the plastic of said rotor (42) has a Shore hardness of less than 100D, in particular less than 80D.

7. A rotor for a compressible fluid pump, comprising one or more impeller elements (15) and radially compressible and expandable between a first state, compressed, and a second state, radially expanded, made of plastic at least partially reinforced by strand-like reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63), intended to rotate about an axis of rotation (14), wherein in said first state, compressed, a preload is applied and in said second state, expanded, no external stress is applied, and wherein there is a third state in which the rotor (42) is assumed to be in operation under load, wherein in said third state, said reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) of the rotor are at least partially elongated and extended, the reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) in the deployed state, which is the second state of the rotor without fluid resistance pressure, are present in a form in which the distance between both ends of the reinforcing elements increases by 0% to 5%, in particular by 0% to 1%, when the rotor transitions to the third state, which constitutes an operating state with fluid resistance pressure; the impeller element (15) is made of plastic reinforced with the reinforcement elements (10, 11, 13, 18, 19, 55, 56, 62, 63) embedded therein; a rotor (42) characterized in that a first group of more than 30%, in particular more than 50%, of the reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) in the deployed state of the rotor (42) extend substantially elongated from a portion (10a, 11a, 13a) arranged closest to the rotation axis (14) to a second portion (10b, 11b, 13b) arranged further from the rotation axis (14).

8. A rotor for a compressible fluid pump, comprising one or more impeller elements (15) and radially compressible and expandable between a first state, compressed, and a second state, radially expanded, made of plastic at least partially reinforced by strand-like reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63), intended to rotate about an axis of rotation (14), said first state, compressed, being preloaded and said second state, expanded, being free from external stresses, and a third state in which said rotor (42) may be in operation under load, said reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) of said rotor being at least partially elongated and stretched, the reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) in the deployed state, which is the second state of the rotor without fluid resistance pressure, are present in a form in which the distance between both ends of the reinforcing elements increases by 0% to 5%, in particular by 0% to 1%, when the rotor transitions to the third state, which constitutes an operating state with fluid resistance pressure; the impeller element (15) is made of plastic reinforced with the reinforcement elements (10, 11, 13, 18, 19, 55, 56, 62, 63) embedded therein; 1. A rotor, characterized in that a first group of reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63), which is more than 30% of the reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63), in particular more than 50% of the reinforcing elements, have a length, measured in the radial direction of the rotor (42) in the deployed state, which corresponds to at least 30%, in particular at least 50%, of the maximum height of the impeller element (15).

9. A rotor according to claim 7 or 8, characterized in that the first group of reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) extend substantially perpendicular to the axis of rotation (14).

10. A rotor according to claim 7 or 8, characterized in that the diameter of the reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) is less than 40 micrometers.

11. A rotor according to claim 7 or 8, characterized in that the diameter of the first group of reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) is less than 40 micrometers.

12. A rotor for a compressible fluid pump, comprising one or more impeller elements (15) and radially compressible and expandable between a first state, compressed, and a second state, radially expanded, made of plastic reinforced at least in part by strand-like reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63), intended to rotate about an axis of rotation (14), wherein in said first state, compressed, a preload is applied and in said second state, expanded, no external stress is applied, and wherein there is a third state in which the rotor (42) is assumed to be in operation under load, wherein in said third state, said reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) of the rotor are at least partially elongated and stretched, the reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) in the deployed state, which is the second state of the rotor without fluid resistance pressure, are present in a form in which the distance between both ends of the reinforcing elements increases by 0% to 5%, in particular by 0% to 1%, when the rotor transitions to the third state, which constitutes an operating state with fluid resistance pressure; the impeller element (15) is made of plastic reinforced with the reinforcement elements (10, 11, 13, 18, 19, 55, 56, 62, 63) embedded therein; A rotor, characterized in that the surface of said reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) is provided with an adhesion promoter.

13. A rotor for a compressible fluid pump, comprising one or more impeller elements (15) and radially compressible and expandable between a first state, compressed, and a second state, radially expanded, made of plastic reinforced at least in part by strand-like reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63), intended to rotate about an axis of rotation (14), wherein in said first state, compressed, a preload is applied and in said second state, expanded, no external stress is applied, and wherein there is a third state in which the rotor (42) is assumed to be in operation under load, wherein in said third state, said reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) of the rotor are at least partially elongated and stretched, the reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) in the deployed state, which is the second state of the rotor without fluid resistance pressure, are present in a form in which the distance between both ends of the reinforcing elements increases by 0% to 5%, in particular by 0% to 1%, when the rotor transitions to the third state, which constitutes an operating state with fluid resistance pressure; the impeller element (15) is made of plastic reinforced with the reinforcement elements (10, 11, 13, 18, 19, 55, 56, 62, 63) embedded therein; A rotor, characterized in that in the deployed state of the rotor, a group of said reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) extends transversely to another group of said reinforcing elements.

14. A rotor for a compressible fluid pump, comprising one or more impeller elements (15) and radially compressible and expandable between a first state, compressed, and a second state, radially expanded, made of plastic at least partially reinforced by strand-like reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63), intended to rotate about an axis of rotation (14), wherein the first state, compressed, is preloaded and the second state, expanded, is free from external stresses, and wherein there is a third state in which the rotor (42) is assumed to be in operation under load, wherein the reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) of the rotor in the third state are at least partially elongated and extended, the reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) in the deployed state, which is the second state of the rotor without fluid resistance pressure, are present in a form in which the distance between both ends of the reinforcing elements increases by 0% to 5%, in particular by 0% to 1%, when the rotor transitions to the third state, which constitutes an operating state with fluid resistance pressure; the impeller element (15) is made of plastic reinforced with the reinforcement elements (10, 11, 13, 18, 19, 55, 56, 62, 63) embedded therein; 10. A rotor comprising: a rotor body having a plurality of reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) in a deployed state of the rotor, the plurality of reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) extending transversely to the plurality of reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) in a deployed state of the rotor; 15. A rotor for a compressible fluid pump, comprising one or more impeller elements (15) and radially compressible and expandable between a first state, compressed, and a second state, radially expanded, made of plastic reinforced at least in part by strand-like reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63), intended to rotate about an axis of rotation (14), wherein in said first state, compressed, a preload is applied and in said second state, expanded, no external stress is applied, and wherein there is a third state in which the rotor (42) is assumed to be in operation under load, wherein in said third state, said reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) of the rotor are at least partially elongated and stretched, the reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) in the deployed state, which is the second state of the rotor without fluid resistance pressure, are present in a form in which the distance between both ends of the reinforcing elements increases by 0% to 5%, in particular by 0% to 1%, when the rotor transitions to the third state, which constitutes an operating state with fluid resistance pressure; the impeller element (15) is made of plastic reinforced with the reinforcement elements (10, 11, 13, 18, 19, 55, 56, 62, 63) embedded therein; A rotor characterized in that at least some of said reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) are present in the form of woven sections with fibres extending longitudinally and transversely.

16. A rotor for a compressible fluid pump, comprising one or more impeller elements (15) and radially compressible and expandable between a first state, compressed, and a second state, radially expanded, made of plastic reinforced at least in part by strand-like reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63), intended to rotate about an axis of rotation (14), wherein the first state, compressed, is preloaded and the second state, expanded, is free from external stresses, and wherein there exists a third state in which the rotor (42) is assumed to be in operation under load, wherein the reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) of the rotor in the third state are at least partially elongated and extended, the reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) in the deployed state, which is the second state of the rotor without fluid resistance pressure, are present in a form in which the distance between both ends of the reinforcing elements increases by 0% to 5%, in particular by 0% to 1%, when the rotor transitions to the third state, which constitutes an operating state with fluid resistance pressure; the impeller element (15) is made of plastic reinforced with the reinforcement elements (10, 11, 13, 18, 19, 55, 56, 62, 63) embedded therein; A rotor characterized in that said reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) are present in the form of membrane strips whose length is at least three times, in particular at least five times, more particularly at least ten times, their width.

17. A rotor for a compressible fluid pump, comprising one or more impeller elements (15) and radially compressible and expandable between a first state, compressed, and a second state, radially expanded, made of plastic reinforced at least in part by strand-like reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63), intended to rotate about an axis of rotation (14), wherein in said first state, compressed, a preload is applied and in said second state, expanded, no external stress is applied, and wherein there is a third state in which the rotor (42) is assumed to be in operation under load, wherein in said third state, said reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) of the rotor are at least partially elongated and stretched, the reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) in the deployed state, which is the second state of the rotor without fluid resistance pressure, are present in a form in which the distance between both ends of the reinforcing elements increases by 0% to 5%, in particular by 0% to 1%, when the rotor transitions to the third state, which constitutes an operating state with fluid resistance pressure; the impeller element (15) is made of plastic reinforced with the reinforcement elements (10, 11, 13, 18, 19, 55, 56, 62, 63) embedded therein; 1. A rotor characterized in that the plastic material in which the reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) are embedded has different properties at least in the area of the non-flow-resistance-pressure-applied side of the impeller element during operation compared to the flow-resistance-pressure-applied side of the impeller element.

18. A rotor for a compressible fluid pump, comprising one or more impeller elements (15) and radially compressible and expandable between a first state, compressed, and a second state, radially expanded, made of plastic reinforced at least in part by strand-like reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63), intended to rotate about an axis of rotation (14), wherein in said first state, compressed, a preload is applied and in said second state, expanded, no external stress is applied, and wherein there is a third state in which the rotor (42) is assumed to be in operation under load, wherein in said third state, said reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) of the rotor are at least partially elongated and stretched, the reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) in the deployed state, which is the second state of the rotor without fluid resistance pressure, are present in a form in which the distance between both ends of the reinforcing elements increases by 0% to 5%, in particular by 0% to 1%, when the rotor transitions to the third state, which constitutes an operating state with fluid resistance pressure; the impeller element (15) is made of plastic reinforced with the reinforcement elements (10, 11, 13, 18, 19, 55, 56, 62, 63) embedded therein; 1. A rotor characterized in that the plastic material in which the reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) are embedded is more bridged or shrunk on the side not subject to the fluid resistance pressure, or has support portions (86) on the surface of the impeller element (82) that are shrunk, the support portions (86) being in the form of one or more films, coatings or fibers.

19. A rotor for a compressible fluid pump, comprising one or more impeller elements (15) and radially compressible and expandable between a first state, compressed, and a second state, radially expanded, made of plastic reinforced at least in part by strand-like reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63), intended to rotate about an axis of rotation (14), wherein in said first state, compressed, a preload is applied and in said second state, expanded, no external stress is applied, and wherein there is a third state in which the rotor (42) is assumed to be in operation under load, wherein in said third state, said reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) of the rotor are at least partially elongated and stretched, the reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) in the deployed state, which is the second state of the rotor without fluid resistance pressure, are present in a form in which the distance between both ends of the reinforcing elements increases by 0% to 5%, in particular by 0% to 1%, when the rotor transitions to the third state, which constitutes an operating state with fluid resistance pressure; the impeller element (15) is made of plastic reinforced with the reinforcement elements (10, 11, 13, 18, 19, 55, 56, 62, 63) embedded therein; A rotor characterized in that an internal material stress is pre-applied to the reinforcing element (10, 11, 13, 18, 19, 55, 56, 62, 63) arranged on the fluid resistance pressure side of the impeller element in a state where no fluid resistance pressure is applied.

20. A rotor for a compressible fluid pump, comprising one or more impeller elements (15) and radially compressible and expandable between a first state, compressed, and a second state, radially expanded, made of plastic reinforced at least in part by strand-like reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63), intended to rotate about an axis of rotation (14), wherein in said first state, compressed, a preload is applied and in said second state, expanded, no external stress is applied, and wherein there is a third state in which the rotor (42) is assumed to be in operation under load, wherein in said third state, said reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) of the rotor are at least partially elongated and stretched, the reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) in the deployed state, which is the second state of the rotor without fluid resistance pressure, are present in a form in which the distance between both ends of the reinforcing elements increases by 0% to 5%, in particular by 0% to 1%, when the rotor transitions to the third state, which constitutes an operating state with fluid resistance pressure; the impeller element (15) is made of plastic reinforced with the reinforcement elements (10, 11, 13, 18, 19, 55, 56, 62, 63) embedded therein; 1. A rotor characterized in that the length of at least 30%, in particular at least 50%, of said reinforcing elements (10, 11, 13, 18, 19, 55, 56, 62, 63) is greater than the average thickness of said impeller element, in particular at least twice as long, more particularly at least 5 or 10 times as long.

21. A rotor according to any one of the preceding claims, characterized in that the compressible fluid pump is a blood pump that can be introduced into a patient's body through a blood vessel.

22. 22. A method for making a rotor according to any one of claims 1 to 21, characterized in that the rotor is made by a molding method, in particular an injection molding method, which is carried out in two successive stages with different injection directions and / or from two different injection points.

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