Compressible rotor

Abstract

A rotor for a pump, such as a blood pump, may include a hub configured to rotate about a central axis, and at least one rotor blade coupled to the hub and extending away from an outer surface of the hub, the rotor blade including a medical grade polyurethane, the rotor blade configured to have a crimped state and an operating state. The medical grade polyurethane may be configured for casting or injection molding, and when cured, the medical grade material advantageously has a Shore A hardness of from 90 to 100, or a Shore B hardness of from 35 to 55, and a Young's modulus of from 60 MPa to 250 MPa. When curled, the rotor blade is compressed and exposed to a strain of up to about 160% in a dry environment at a temperature of 20-25 DEG C. When in operation, the rotor blade expands and is exposed to a strain of up to 10% in a humid environment at a temperature of 36-38 DEG C.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 429,649, filed Dec. 2, 2022, and U.S. Provisional Patent Application No. 63 / 470,663, filed Jun. 2, 2023, the contents of each of which are hereby incorporated by reference in their entirety. TECHNICAL FIELD

[0003] The present invention relates to rotors for moving body fluids, and more particularly to compressible rotors for moving blood. BACKGROUND OF THE INVENTION

[0004] Medical pumps, and more particularly blood pumps, need to meet very specific design and performance characteristics. In order to provide the necessary fluid flow at a controllable rotational speed, the pump rotor must have blades with a certain minimum outer diameter that is greater than the inner diameter of most blood vessels. To improve the ease of surgical insertion and to ensure minimal impact when the rotor is surgically inserted and passed through small blood vessels, the rotor blades must be compressible. However, to achieve these performance characteristics, a medical-grade polymer with a very specific set of mechanical properties is required. To date, it has not been possible to simultaneously meet the required specifications (e.g., (1) medical-grade material and (2) defined mechanical properties) for the manufacture of such rotors. The use of non-medical-grade polymers can be potentially problematic when used in a patient's body for an extended period of time, such as in a blood pump used to alleviate certain heart-related conditions. Accordingly, a compressible rotor that can be manufactured from a medical-grade polymer via conventional manufacturing techniques is desirable and useful. SUMMARY OF THE INVENTION

[0005] The various deficiencies in the prior art are addressed by the systems and methods disclosed herein.

[0006] A rotor may be provided. Advantageously, the rotor may include a hub configured to rotate about a central axis. The rotor may include at least one rotor blade coupled to the hub and extending away from an outer surface of the hub. The (one or more) rotor blades comprise a medical-grade material. The (one or more) rotor blades may be configured to have a crimped state and an operating state.

[0007] Medical-grade materials, such as medical-grade thermoplastic polyurethane (TPU), or other thermoplastic elastomers (TPE), such as polyvinylacetate, or blends / combinations thereof, can be configured for casting or injection molding, and when cured, the medical-grade materials advantageously have a Shore A hardness value of 90 to 100 or a Shore B hardness value of 35 to 55 as determined by DIN ISO 7619-1, and a Young's modulus of 60 MPa to 250 MPa as determined by ISO 527. In the curled state, the (one or more) rotor blades can be compressed and exposed to a strain of up to about 160% at a temperature of 20 - 25 °C in a dry environment. In the operating state, the rotor blades can expand and be exposed to a strain of up to 10% at a temperature of 36 - 42 °C (such as 36 - 38 °C) in a humid environment (e.g., exposed to blood).

[0008] In some embodiments, the medical-grade material can have a tensile strength of 15 MPa to 25 MPa and an elongation at break of 500% to 600% as determined by DIN 53504. In some embodiments, the medical-grade material can be selected such that the stress at 5% strain, the stress at 10% strain, the stress at 20% strain, and the stress at 50% strain of the medical-grade material have a range not exceeding 0.5 MPa as determined by DIN 53504. In some embodiments, the medical-grade material can have a storage modulus exhibiting a rubbery plateau at temperatures not exceeding 0 °C to not less than 150 °C. In some embodiments, the medical-grade material can have a storage modulus of 50 - 100 MPa at 0 °C.

[0009] In some embodiments, the medical-grade material can be a biocompatible material. In some embodiments, the medical-grade material can be thermoplastic polyurethane, polyvinyl acetate, or a blend. In some embodiments, the medical-grade material can be a one-component resin. In some embodiments, the medical-grade material can be a resin having a first component and a second component. The first component can be a prepolymer of the following substances: (i) hexamethyl diisocyanate (HDI), methylene dicyclohexyl diisocyanate (H12MDI), and / or methylene diphenyl diisocyanate (MDI); (ii) polytetramethylene ether glycol (PTMEG) or polypropylene glycol (PPG) having a molecular weight of 500 g / mol to 6000 g / mol; and (iii) an optional polyester, such as poly(caprolactone), polyethylene adipate, or polybutylene adipate, wherein the first component can have an average molecular weight of 10,000 g / mol to 14,000 g / mol. The second component can be diethyltoluenediamine (DETDA) or 1,4-butanediol. In some embodiments, the first component and the second component can be present in a stoichiometric ratio. In some embodiments, the first component and the second component can be present in a non-stoichiometric ratio. In some embodiments, the medical-grade material can include a catalyst and / or an inhibitor.

[0010] In some embodiments, the medical-grade material can be a resin having one or more soft segments and one or more hard segments. One or more soft segments can include difunctional or trifunctional end-capped telechelic soft segment oligomers, and one or more hard segments can include diisocyanates. The medical-grade material can also include one or more chain extenders.

[0011] In some embodiments, the medical-grade material can be silicone-polycarbonate-urethane. The silicone-polycarbonate-urethane can include polydimethylsiloxane (PDMS) and / or can include one or more chain extenders.

[0012] In some embodiments, the medical-grade material can include one or more additional components that can be added to accommodate, for example, material variations or to achieve a desired reactivity, cure rate, mold viscosity, surface tension, etc.

[0013] In some embodiments, the rotor can be formed by die casting or injection molding. In some embodiments, the rotor can be formed by vacuum casting or vacuum socketing.

[0014] In some embodiments, the medical-grade material can be selected such that the force-elongation profile of the medical-grade material exhibits a region with a first slope below a deformation threshold and a plateau region above the deformation threshold. In some embodiments, the value of the force in the plateau region can be 9 - 11 N.

[0015] In some embodiments, the medical-grade material can be configured to withstand an elongation rate greater than 100% without breaking. In some embodiments, the medical-grade material can be configured such that when exposed to an elongation rate of 100% for at least 15 minutes, the material exhibits less than 5% non-recoverable plastic deformation. In some embodiments, the medical-grade material can be sterilizable. In some embodiments, the medical-grade material can be ethylene oxide sterilizable. In some embodiments, the medical-grade material can be selected such that the dimensional molding shrinkage rate is less than 1% when cooled to room temperature after forming the rotor.

[0016] In some embodiments, at least one blade can have a substantially smooth outer surface. In some embodiments, at least one blade can have an outer surface that is substantially free of orange peel effect. In some embodiments, at least one blade can have an axial length of 7 - 8 mm. In some embodiments, at least one blade can have an outer diameter of 5 - 6 mm in the operating state. In some embodiments, at least one rotor blade can be helically wound around the hub. In some embodiments, at least one rotor blade can have a constant helical pitch. In some embodiments, the helical pitch of at least one rotor blade can vary along the length of the hub. In some embodiments, at least one rotor blade can include a concave side and a convex side. In some embodiments, when in the curled state, the concave side can abut against the outer surface of the hub.

[0017] In some embodiments, the hub can have an axial length of 9 - 11 mm. In some embodiments, the hub can have no lumen extending from the distal end to the proximal end. In some embodiments, the hub can have a lumen extending from the distal end to the proximal end. In some embodiments, the hub and at least one rotor blade are cast or molded from a medical-grade material, particularly by injection molding.

[0018] In some embodiments, a rotor can be provided that includes a hub configured to rotate about a central axis and at least one rotor blade coupled to the hub and extending away from an outer surface of the hub, where the rotor blade can include a medical grade polyurethane or other thermoplastic elastomer, and where the rotor blade can have a curled state and an operating state.

[0019] In some embodiments, the medical grade polyurethane can be a resin having a first component and a second component. The first component can be a prepolymer that includes: (i) hexamethylene diisocyanate (HDI), methylene dicyclohexyl diisocyanate (H12MDI), and / or methylene diphenyl diisocyanate (MDI); (ii) polytetramethylene ether glycol (PTMEG, sometimes referred to as polytetrahydrofuran) or polypropylene glycol (PPG) having a molecular weight of 500 g / mol to 6000 g / mol; and (iii) an optional polyester, such as polycaprolactone, polyethylene adipate, or polybutylene adipate, where the first component can have an average molecular weight of 10000 g / mol to 14000 g / mol. The second component can be diethyltoluenediamine (DETDA) or 1,4-butanediol. In some embodiments, the first component and the second component can be present in a stoichiometric ratio. In some embodiments, the first component and the second component can be present in a non-stoichiometric ratio. In some embodiments, the medical grade polyurethane can include a catalyst and / or an inhibitor.

[0020] In some embodiments, the first component includes HDI, PPG, and polycaprolactone, and the second component is DETDA. In some embodiments, the first component includes H12MDI, PPO, and polycaprolactone, and the second component is DETDA. In some embodiments, the first component includes H12MDI and / or MDI, PPO, and PTMEG, and the second component is 1,4-butanediol.

[0021] In some embodiments, the medical grade polyurethane or other thermoplastic elastomer can be a resin having one or more soft segments and one or more hard segments. The one or more soft segments can include a difunctional or trifunctional end-capped telechelic soft segment oligomer, and the one or more hard segments can include a diisocyanate.

[0022] The medical grade polyurethane or other thermoplastic elastomer can also include one or more chain extenders.

[0023] In some embodiments, the medical grade polyurethane or other thermoplastic elastomer can be a silicone polycarbonate urethane. The silicone polycarbonate urethane can include polydimethylsiloxane (PDMS) and / or can include one or more chain extenders.

[0024] In some embodiments, at least one vane may have a substantially smooth outer surface. In some embodiments, at least one vane may have an outer surface substantially free of orange peel effect. In some embodiments, at least one vane may have an axial length of 7 - 8 mm. In some embodiments, at least one vane may have an outer diameter of 5 - 6 mm in an operating state. In some embodiments, at least one rotor vane may be helically wound around a hub. In some embodiments, at least one rotor vane may have a constant helical pitch. In some embodiments, the helical pitch of at least one rotor vane may vary along the length of the hub. In some embodiments, at least one rotor vane may include a concave side and a convex side. In some embodiments, when in a curled state, the concave side may abut the outer surface of the hub.

[0025] In some embodiments, the hub may have an axial length of 9 - 11 mm. In some embodiments, the hub may not have a lumen extending from a distal end to a proximal end. In some embodiments, the hub may have a lumen extending from a distal end to a proximal end. In some embodiments, the hub and at least one rotor vane are cast or molded from a medical - grade material, and in particular, may be injection - molded.

[0026] In some embodiments, a pump may be provided. The pump may include an expandable and compressible pump housing. The pump may include a rotor as disclosed herein, and the rotor is disposed within the pump housing.

[0027] In some embodiments, the pump may include a drive shaft operably coupled to the rotor. In some embodiments, the drive shaft may be a metal drive shaft. In some embodiments, the rotor may be adhered to the metal drive shaft. In some embodiments, the metal drive shaft may include at least one structure extending radially outward from the central axis of the drive shaft, and the at least one structure is configured to interact with the rotor. In some embodiments, the metal drive shaft may not have a structure extending radially outward from the drive shaft that interacts with the rotor. In some embodiments, the metal drive shaft may have been surface - treated.

[0028] In some embodiments, the pump may include a motor operably coupled to the proximal end of the drive shaft. In some embodiments, the pump may include a catheter having a proximal end and a distal end, and the distal end is operably coupled to the proximal end of the pump housing. In some embodiments, the drive shaft may be disposed within a lumen extending from the proximal end to the distal end of the catheter. In some embodiments, the pump housing may be configured to be inserted into a patient's blood vessel. In some embodiments, the pump housing may be configured to be inserted into a ventricle of a patient's heart.

[0029] In some embodiments, a system may be provided. The system may include a pump as disclosed herein. A controller may be operably coupled to the pump.

[0030] In some embodiments, a kit may be provided. The kit may include a pump as disclosed herein and a controller that may be configured to be operably connected to the pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The drawings incorporated in and forming a part of this specification illustrate embodiments of the invention and, together with the general description of the invention given above and the detailed description of the embodiments given below, serve to explain the principles of the invention.

[0032] Figure 1 is a schematic view of a system including a pump having a rotor inserted into a patient's blood vessel.

[0033] Figure 2A is a side view of the rotor in an operating state.

[0034] Figure 2B is an axial view of the rotor without a lumen.

[0035] Figure 2C is an axial view of the rotor having a lumen.

[0036] Figure 2D is Figure 2A a view of section A as shown in

[0037] Figure 3 is a cross-sectional view of the coiled rotor.

[0038] Figure 4A is a graph showing the stress of a medical grade polymer at different strains.

[0039] Figure 4B is a graph showing the storage modulus (G’) of a medical grade polymer during a temperature scan.

[0040] Figure 4C is a graph showing an exemplary force-elongation distribution.

[0041] Figure 4D is a graph showing the engineering stress-strain curve of a medical grade polymer.

[0042] Figure 5A and Figure 5B are simplified cross-sectional views showing structural elements for coupling the rotor to a drive shaft.

[0043] Figure 6 is a plan view of a bearing surface according to one embodiment.

[0044] Figure 7 is an illustration of a polymer synthesis reaction.

[0045] It should be understood that the drawings are not necessarily drawn to scale and present a somewhat simplified representation of various features illustrating the basic principles of the invention. Specific design features of the operational sequences disclosed herein, including, for example, the specific dimensions, orientations, positions, and shapes of the various illustrated components, will be determined in part by the particular intended application and the environment of use. Certain features of the illustrated embodiments are enlarged or distorted relative to other features for purposes of visualization and clear understanding. In particular, thin features may be thickened, for example, for clarity or illustration. Detailed Description

[0046] The following description and drawings illustrate only the principles of the invention. Thus, it should be understood that those skilled in the art will be able to devise various arrangements which, although not explicitly described or shown herein, embody the principles of the invention and are included within its scope. In addition, all examples described herein are primarily intended expressly for illustrative purposes only to assist the reader in understanding the principles of the invention and the concepts contributed by the inventor to further the art and are to be construed as not being limited to these specifically described examples and conditions. Further, the term "or" as used herein refers to a non-exclusive or, unless otherwise specified (e.g., "or other" or "or in the alternative"). Moreover, the various embodiments described herein are not necessarily mutually exclusive, since some embodiments may be combined with one or more other embodiments to form new embodiments.

[0047] Numerous innovative teachings of the present application will be described with particular reference to presently preferred exemplary embodiments. However, it should be understood that such embodiments merely provide several examples of the many useful applications of the innovative teachings herein. In general, statements in the specification of the present application do not necessarily limit any claimed invention. In addition, some statements may apply to some inventive features but not to others. Those skilled in the art will recognize through the teachings herein that the present invention is also applicable to various other technical fields or embodiments, such as seismology and data fusion.

[0048] Various embodiments relate to pumps having a collapsible rotor made of a medical-grade polymer, particularly blood pumps.

[0049] The term "medically - grade" material as used herein refers to a material intended for use in a finished medical device product, such as a product that complies with the Medical Device Regulation EU 2017 / 745 of the European Parliament and of the Council (MDR) and the Committee for Medicinal Products for Human Use (CHMP). Such medically - grade materials shall meet a number of minimum requirements, including a strict change - management procedure for potential planned changes to the material specifications or composition, manufacturing location, manufacturing technology, or regulatory status, specific quality management for the development and handling of such materials, assurance of safety or supply and availability, and support for meeting regulatory testing requirements. Such regulatory testing requirements include tests related to biological requirements, such as biocompatibility tests conducted in accordance with the DIN EN ISO 10993 standard and / or United States Pharmacopeia (USP) Class VI, allowable limits for various chemical components including metal ions, and tests related to product sterilization (such as tolerance to radiation, ethylene oxide, or steam sterilization, as appropriate). In many cases, the medically - grade material may be a material for which a Drug Master File (DMF) has been created, archived, and is being maintained with a regulatory agency such as the United States Food and Drug Administration (FDA).

[0050] Figure 1 A schematic overview of a rotor used in a pump is shown. The pump 1 may include a pump housing 2 and a conduit 3 having a lumen therethrough. The pump housing 2 may include a proximal end 11 and a distal end 13. In some embodiments, the distal end 13 may include one or more openings 15 that form an inlet for drawing blood into the pump housing 2. In one aspect, the openings 15 may form an inflow cage. The direction of the inflowing blood is indicated by arrow 12. The proximal end 11 may include one or more openings 14 that form an outlet for delivering the blood drawn in through the inlet to a patient's blood vessel.

[0051] A drive shaft 4 may be disposed within the lumen of the conduit 3. The proximal end of the drive shaft 4 may be attached to a motor 6, and the distal portion of the drive shaft may extend into the interior of the pump housing 2. A rotor 100 may be mounted to the distal portion of the drive shaft 4 and disposed within the pump housing 2. The motor 6 may cause the drive shaft 4 to rotate, and the drive shaft 4 may cause the rotor 100 to rotate. It should be understood that the drive shaft 4 may be flexible to enable deployment of the drive shaft 4 and the conduit 3 into a patient's body.

[0052] As Figure 1As shown, the pump 1 can be introduced into a patient's blood vessel via port 7. For example, the pump 1 can be introduced and positioned through an arteriotomy in the femoral artery 8, and passed through the aortic arch 9 and into the patient's ventricle 10 such that the pump housing 2 is located in the aortic valve region (not shown). It should be understood that the distal end 13 of the pump housing 2 can extend into the patient's left ventricle, and the proximal end 11 can be positioned in the patient's aorta. The rotor 100 can be rotated by the drive shaft 4 and the motor 6 at a speed, for example, between 3000 and 50000 revolutions per minute (rpm) to pump blood from the ventricle 10 into the opening 15 of the inlet at the distal end 13 of the pump housing (as shown by arrow 12), and output it into the aorta from the opening 14 of the outlet at the proximal end 11.

[0053] In one aspect, the pump 1 can include a controller 31, which is operably coupled to the pump 1 and configured to control and drive the motor 6 to control the operation of the pump 1. The controller can be integrated in the motor 6 or placed separately from the motor 6.

[0054] In one aspect, the pump housing 2 and the rotor 100 can be configured to be radially compressible to a compressed (or "crimped") state to enable the pump 1 to be effectively deployed through the patient's blood vessel. Additionally, after the pump housing 2 and the rotor 100 are placed in and / or near the patient's ventricle 10, the pump housing 2 and the rotor 100 can be configured to be radially expandable to an expanded (or "operating") state for normal operation.

[0055] A rotor can be provided. Referring to Figure 2A , advantageously, the rotor 100 can include a hub 116 configured to rotate about a central axis 130. The rotor can include at least one rotor blade 117, 118, which is coupled to the hub and extends (radially) away from the outer surface 115 of the hub. The hub can have a distal end 119 and a proximal end 120, wherein rotation of the hub generates blood flow from, for example, the distal end to the proximal end.

[0056] To reduce the blood shear stress caused by the rotor, the rotor, particularly the (one or more) blades, should have a high-quality surface. In some embodiments, at least one of the blades 117, 118 can have a substantially smooth outer surface, such as the first surface 121, 123 and the second surface 122, 124. In some embodiments, at least one of the blades can have an outer surface that is substantially free of orange peel effect.

[0057] As used herein, "orange peel" or "orange peel effect" refers to a certain finish that may appear on the surface. The non-smooth texture is similar to the surface of an orange peel. Without being limited to a particular theory, this orange peel effect may be caused by shrinkage during curing. Additionally, this effect may be related to differences in the linear expansion coefficients between the materials that make up the rotor or uneven temperature control during component processing.

[0058] In some embodiments, at least one of the blades 117, 118 may have an axial length 129 of 7 - 8 mm.

[0059] In some embodiments, at least one rotor blade may be helically wound around the hub. As Figure 2B shown, in some embodiments, at least one blade may be configured such that the rotor may have a maximum outer diameter 127 of 5 - 6 mm in an operating state. In some embodiments, portions 125 and 126 are portions of blades 117 and 118, respectively, that are disposed directly adjacent to the hub 116 and may be configured to extend outwardly. As shown, portions 125 and 126 extend along a radial axis 140 that orthogonally traverses the rotational axis (e.g., central axis 130) of the rotor 100 and extends through the center of the hub 116. It should be understood that, as seen in a cross-sectional view of the rotor 5 ( Figure 2A ), portions 125 and 126 ( Figure 2B ) as Figure 4C shown (i.e., along the radial axis 140) extend from the hub along at least a portion of the hub length (i.e., from the distal end 119 to the proximal end 120 of the hub 116, either in part or in whole).

[0060] In some embodiments, at least one rotor blade may have a constant helical pitch.

[0061] Referring to Figure 2D , in some embodiments, at least one of the rotor blades 117, 118 may each include concave sides 122, 124 and convex sides 121, 123. In some embodiments, the helical pitch of at least one rotor blade may vary along the length of the hub. In some embodiments, the curvature of the outer portions of the blades 117, 118 varies according to the position along the length of the hub 116 from which they extend. In some embodiments, the inner curvature of the concave sides (here, the sides 122, 124 facing proximal) of the blades 117, 118 is tighter (i.e., at a smaller angle) than the curvature of the convex sides of the blades (here, the sides 121, 123 facing distal) (forming a greater angle). Thus, in some embodiments, the pitch of each of the outer portions of the blades 117, 118 may vary along the length of the hub 116.

[0062] In some embodiments, the hub may have an axial length 128 of 9-11 mm. In some embodiments, as Figure 2B shown, the hub may not have a lumen extending from the distal end to the proximal end. In some embodiments, as Figure 2C shown, the hub may have an inner surface 135 that defines a lumen extending from the distal end to the proximal end.

[0063] (One or more) rotor blades may be configured to have a curled state and an operating state.

[0064] In some embodiments, when in the curled state, the concave side may abut the outer surface portion of the hub. Figure 3 An embodiment of the rotor in the compressed state is shown. In the compressed state, the rotor blades 117, 118 are folded onto the hub 116, preferably without any folds having acute angles, which may cause kinking and possible permanent deformation. As Figure 3 shown, in the compressed / curled state, portions 125, 126 of the rotor blades 117, 118 relative to the radial axis 140 allow the blades 117, 118 to at least partially wrap around the hub 116, conforming to the hub curvature. Thus, the sharp kinking experienced by some conventional rotors in the compressed state is absent. Since the blades 117, 118 abut the hub 116 relatively uniformly, the forces acting on the blades 117, 118 when compressed are converted into torque on the outer diameter of the hub 116, thereby reducing or eliminating kinking in the blades 117, 118 during compression. The reduced stress on the blades 117, 118 in the compressed state further allows the blades 117, 118 to deploy to their natural position in the uncompressed / expanded ("operating") state due to the reduced likelihood of permanent deformation of the blades 117, 118 due to blade stress in the compressed state.

[0065] (One or more) rotor blades are made of a medical-grade material. The medical-grade material should be a biocompatible material. In some embodiments, the medical-grade material may include thermoplastic polyurethane, or other thermoplastic elastomers (such as polyvinyl acetate), or blends / combinations thereof. In some embodiments, the medical-grade material may be medical-grade polyurethane. In some embodiments, the medical-grade material may be polyvinyl acetate. In some embodiments, the medical-grade material may be a one-component resin.

[0066] In some embodiments, the medical-grade material can be a resin having a first component and a second component, such as a polyurethane resin. The first component can be a prepolymer of the following substances: (i) hexamethylene diisocyanate (HDI), methylene dicyclohexyl diisocyanate (H12MDI), and / or methylene diphenyl diisocyanate (MDI); (ii) polytetramethylene ether glycol (PTMEG) or polypropylene glycol (PPG) (sometimes referred to herein as propylene oxide (PPO)) having a molecular weight of 500 g / mol to 6000 g / mol; and (iii) an optional polyester, such as polycaprolactone, polyethylene adipate, or polybutylene adipate, wherein the first component can have an average molecular weight of 10000 g / mol to 14000 g / mol. The second component can be diethyltoluenediamine (DETDA) or 1,4-butanediol.

[0067] In some embodiments, the first component includes HDI, PPG, and polycaprolactone, and the second component is DETDA. In some embodiments, the first component includes H12MDI, PPO, and polycaprolactone, and the second component is DETDA. In some embodiments, the first component includes H12MDI and / or MDI, PPO, and PTMEG, and the second component is 1,4-butanediol.

[0068] In some embodiments, the first component and the second component can be present in a stoichiometric ratio. Advantageously, in some embodiments, the first component and the second component can be present in a non-stoichiometric ratio. In some embodiments, the amount of the second component is less than the amount specified by the stoichiometric ratio. In some embodiments, the second component can be present in an amount of 60-90% of the amount required to satisfy the stoichiometric ratio. As a simple example of this, in some embodiments, the stoichiometric ratio of the components can be in the range of 1:0.65 to 1:1.35. Preferably, the range can be 1:0.75 to 1:1.25. In some preferred embodiments, the range can be 1:0.90 to 1:1.10. In some preferred embodiments, the range can be 1:1 to 1:1.20. In some preferred embodiments, the non-stoichiometric ratio used can be 1:0.95 to 1:1.05.

[0069] In some embodiments, the polyurethane can be composed of one or more soft segments and one or more hard segments, which can be alternating (e.g., soft segment, hard segment, soft segment, hard segment,...). This can include segmented polyurethanes, polyurethaneureas, and polyureas.

[0070] (One or more) soft segments may be difunctional or trifunctional end-capped telechelic soft segment oligomers. The soft segments may have a molecular weight of at least 500 g / mol, 1000 g / mol or 1500 g / mol, up to 5000 g / mol, 5500 g / mol or 6000 g / mol, including all combinations and subranges thereof. Non-limiting examples of soft segments include polyethers (such as poly(ethylene oxide) (PEO), poly(propylene oxide) (PPO), poly(tetramethylene oxide) (PTMO) or any blend thereof, including block copolymers of PEO and PPO).

[0071] The soft segments may include one or more halogen atoms, such as fluorine. For example, in some embodiments, the soft segments may include a fluorinated polyether oligomer.

[0072] The hard segments may be composed of diisocyanates, such as those shown in Table 1 below. In some embodiments, one or more hard segments may be glassy. In some embodiments, one or more hard segments may be semi-crystalline. In some embodiments, one or more hard segments may be crystalline.

[0073] Such segmented polyurethanes and their manufacturing techniques are well known in the art. An example of such a material can be found, for example, in US3658746A, the entire content of which is incorporated herein by reference.

[0074] Table 1 (List of Diisocyanate Examples)

[0075]

[0076]

[0077] As will be appreciated, the polyurethane may include one or more chain extenders. As is known in the art, chain extenders are used in polyurethane synthesis, among other things, to increase the length of the hard segments and adjust the molecular weight of the polyurethane. Non-limiting examples of chain extenders include aromatic and aliphatic diamine chain extenders, such as 1,4-butanediol (BDO).

[0078] The polymer can be synthesized by a one-shot polymerization method or via the "prepolymer method", which includes two steps: 1) forming an isocyanate-terminated "prepolymer", and then 2) a "chain extension" step, in which the prepolymer reacts with a short organic diol or diamine to form a high molecular weight segmented polyurethane or segmented polyurethanurea. An example is in Figure 7Visible in

[0079] In some embodiments, the medical grade material can be a silicone polycarbonate urethane. Such materials are based on a soft polycarbonate urethane surrounded by long silicone chains (such as polydimethylsiloxane chains). The polycarbonate urethane can include one or more polycarbonate diols (which can have a molecular weight of, for example, 500 - 6000 g / mol), and / or one or more aromatic or aliphatic isocyanates (see Table 1). This urethane can be polymerized with a straight-chain or branched-chain diol chain extender (such as 1,4-butanediol (BDO)). It will be appreciated that different aromatic and aliphatic diamine chain extenders can be used. An example of a silicone polycarbonate urethane can be a polycarbonate (PC)-polydimethylsiloxane (PDMS)-MDI-BDO block copolymer. The relative ratios of the different components are adjusted to achieve the desired mechanical properties.

[0080] The silicone can be a dihydroxyalkyl-terminated polydialkylsiloxane, such as a dihydroxypropyl-terminated polydimethylsiloxane.

[0081] The polysiloxane can have various reactive end groups. In some embodiments, the polysiloxane can include hydroxyl groups. In some embodiments, the polysiloxane can include amino groups. In some embodiments, the polysiloxane can include isocyanate groups. In some embodiments, the polysiloxane can include hydroxyl groups, amino groups, isocyanate groups, or any combination thereof.

[0082] The polysiloxane can have a molecular weight between about 500 Da and about 8000 Da. In some embodiments, the molecular weight is at least about 500 Da. In some embodiments, the molecular weight is at least about 1000 Da. In some embodiments, the molecular weight is at least about 2000 Da. In some embodiments, the molecular weight is at least about 3000 Da. In some embodiments, the molecular weight is not greater than about 8000 Da. In some embodiments, the molecular weight is not greater than about 7000 Da. In some embodiments, the molecular weight is not greater than about 6000 Da. In some embodiments, the molecular weight is not greater than about 5000 Da. In some embodiments, the molecular weight is at least about 1000 Da. In some embodiments, such a carbamate can include from about 5% to about 30% by weight of the polysiloxane. In some embodiments, such a carbamate can include at least about 5% by weight of the polysiloxane. In some embodiments, such a carbamate can include at least about 10% by weight of the polysiloxane. In some embodiments, such a carbamate can include at least about 15% by weight of the polysiloxane. In some embodiments, such a carbamate can include at least about 20% by weight of the polysiloxane. In some embodiments, such a carbamate can include at least about 25% by weight of the polysiloxane. In some embodiments, such a carbamate can include not more than about 50% by weight of the polysiloxane. In some embodiments, such a carbamate can include not more than about 40% by weight of the polysiloxane. In some embodiments, such a carbamate can include not more than about 30% by weight of the polysiloxane.

[0083] Silicone carbamate polymers and their manufacturing techniques are well known in the art. An example of such a material can be found, for example, in US8242189B2, the entire contents of which are incorporated herein by reference.

[0084] In some embodiments, the medical grade material can include a catalyst and / or an inhibitor. Any suitable amount of catalyst and / or inhibitor can be used depending on the chemical composition involved. In some embodiments, the catalyst can be present in an amount not exceeding 0.1% by weight of the medical grade material (including the catalyst and / or inhibitor). In some embodiments, the inhibitor can be present in an amount not exceeding 5% by weight of the medical grade material (including the inhibitor and / or catalyst).

[0085] Conventionally, polymeric materials are typically specified by CAS numbers or groups (such as polypropylene, polystyrene, etc.). However, those skilled in the art will understand that these methods alone are insufficient. For example, it is not sufficient to clearly classify polymers based solely on CAS numbers because when assigning CAS numbers, chain length, degree of branching, stereoregularity, etc. are not considered. Although polymers belonging to a group (such as polypropylene) are broadly defined by their assigned CAS numbers, the specific properties will vary based on the macromolecular structure of the polymer (such as those characteristics listed earlier), manufacturing processes, raw material suppliers, etc. Therefore, it may be worthwhile to expand the characteristics that the medical-grade materials disclosed herein preferably include.

[0086] Medical-grade materials can be configured for casting or injection molding. For example, in some embodiments, the rotor can be formed by die casting. In some embodiments, the rotor can be formed by injection molding. In some embodiments, the rotor can be formed by vacuum casting or vacuum socketing. It is preferred to use materials with a low shrinkage rate. In some embodiments, the medical-grade material can be selected such that the dimensional molding shrinkage rate is less than 1% when cooled to room temperature after forming the rotor.

[0087] In some embodiments, when cured, the medical-grade material advantageously has a Shore A hardness value of 90 to 100 as determined by DIN ISO 7619-1. In some embodiments, when cured, the medical-grade material advantageously has a Shore B hardness value of 35 to 55 as determined by DIN ISO 7619-1. In some embodiments, when cured, the medical-grade material advantageously has a Young's modulus of 60 MPa to 250 MPa as determined by ISO 527.

[0088] In some embodiments, the (one or more) rotor blades can be configured to be able to be exposed to two different usage conditions for a long time (30 minutes or longer) without substantial permanent deformation (e.g., non-recoverable deformation of 5% or less). Specifically, in some embodiments, the (one or more) rotor blades can be configured to be exposed to strains up to about 160% at a temperature of 20 - 25°C in a dry environment in a curled state. In some embodiments, the (one or more) rotor blades can be configured to be exposed to strains up to 10% at a temperature of 36 - 42°C in a wet environment (e.g., exposed to blood) in an operating (expanded) state. In some embodiments, the (one or more) rotor blades can be configured to be exposed to strains up to 10% at a temperature of 36 - 40°C in a wet environment (e.g., exposed to blood) in an operating (expanded) state. In some embodiments, the (one or more) rotor blades can be configured to be exposed to strains up to 10% at a temperature of 36 - 38°C in a wet environment (e.g., exposed to blood) in an operating (expanded) state.

[0089] In some embodiments, the medical-grade material preferably has a tensile strength of 15 MPa to 25 MPa and an elongation at break of 500% to 600% determined using DIN 53504. For example, the measured tensile strength of a thermoplastic polyurethane disclosed herein is 20 MPa and the elongation at break is 540%. In some embodiments, the material may have an elongation at break of 150% - 600% determined using DIN 53504.

[0090] In some embodiments, the medical-grade material may be preferably selected such that the stress measured within a certain strain range is relatively constant. For example, as Figure 4A shown, in some embodiments, the stress at 5% strain, the stress at 10% strain, the stress at 20% strain, and the stress at 50% strain of the medical-grade material, among these four stresses, may have a range not exceeding 0.5 MPa determined using DIN 53504.

[0091] In some embodiments, the medical-grade material may have a storage modulus exhibiting a rubbery plateau at temperatures not exceeding 0 °C to not less than 150 °C. In some embodiments, the medical-grade material may have a storage modulus of 50 - 100 MPa at 0 °C. For example, this example can be seen in Figure 4B which.

[0092] Preferably, the force required to transition from the operating state to the coiled state (e.g., when a clinician wishes to remove the pump from a patient's body) is not excessive. To achieve this, in some embodiments, the medical-grade material may be selected such that the force-elongation distribution of the medical-grade material exhibits a region with a first slope below a deformation threshold and a plateau region above the deformation threshold. Figure 4C is an example of a force-elongation test, showing a first region 402 with a first slope below a deformation threshold 401 and a plateau region 403 above the deformation threshold. These same basic features can also be seen when the force-elongation curve is converted to an engineering stress-strain curve. This can be seen, for example, in Figure 4D where a similar first region and plateau region can be seen. In some embodiments, the value of the force in the plateau region may be 9 - 11 N.

[0093] Depending on various factors such as the shape of the rotor and the blades and the degree of curling desired, the elongation required in use may exceed 100%, 150%, 200%, or 300%. In some embodiments, the medical grade material can be constructed to withstand an elongation greater than 100% without breaking. In some embodiments, the medical grade material can be constructed to withstand an elongation greater than 150% without breaking. In some embodiments, the medical grade material can be constructed to withstand an elongation greater than 200% without breaking. In some embodiments, the medical grade material can be constructed to withstand an elongation greater than 300% without breaking.

[0094] In addition, to avoid a reduction in performance over time, the rotor should be able to be exposed to a certain elongation without significant irrecoverable plastic deformation. In some embodiments, the medical grade material can be constructed such that when exposed to an elongation of 100% for at least 15 minutes, the material exhibits less than 5% irrecoverable plastic deformation.

[0095] For a rotor intended to be used as part of a medical device, the rotor should be able to be sterilized. Thus, in some embodiments, the medical grade material can be a sterilizable material. In some embodiments, the medical grade material can be sterilizable ethylene oxide (ETO). In a preferred embodiment, the medical grade material can be sterilizable ETO but not autoclave sterilizable and / or gamma radiation sterilizable. For example, in some embodiments, the heat and pressure of an autoclave may have a negative impact on the medical grade material, and thus, an autoclave may not be used. Preferably, the medical grade material does not absorb any detectable amount of ETO.

[0096] In some embodiments, a pump can be provided. Referring Figure 1 , in some embodiments, the pump can include an expandable and compressible pump housing 2. In some embodiments, the pump housing can include a structural layer, and the structural layer can include, for example, a plurality of struts forming a cage or a network structure. The struts can include, for example, nitinol. The pump housing can include additional layers, such as an inner layer and / or an outer layer disposed on the inner surface or the outer surface of the struts or other structural layers, respectively. This may include filling the space between the struts to form a sealed area where fluid cannot flow between the inside and the outside of the housing through the sealed area. The pump can include a rotor 100 as disclosed herein, and the rotor is disposed within the pump housing.

[0097] In some embodiments, the pump may include a drive shaft 4 operably coupled to the rotor. In some embodiments, the drive shaft may be a flexible drive shaft. In some embodiments, the drive shaft may be a metal drive shaft. In some embodiments, the drive shaft may be composed of a single filament. In some embodiments, the drive shaft may be composed of multiple filaments, which may be combined into a single layer or multiple layers. In some embodiments, the drive shaft may be hollow (e.g., a lumen may extend from the distal end to the proximal end of the drive shaft). In some embodiments, the rotor may be adhered to the metal drive shaft.

[0098] In some embodiments, the metal drive shaft may include at least one structure 501 that extends radially (such as radially inward ( Figure 5A )) and / or radially outward ( Figure 5B )) from the outer surface 502 relative to the central axis 130 of the drive shaft, and the at least one structure is configured to interact with the rotor to prevent slipping (such as axial movement and / or circumferential movement relative to the drive shaft). In some embodiments, the metal drive shaft may have no structure that extends radially outward from the drive shaft and interacts with the rotor. In some embodiments, at least a portion of the metal drive shaft may have been surface treated. Such surface treatment may include, for example, laser blasting (such as laser bead blasting), sandblasting, transfer sandblasting, plasma treatment. The surface treatment may include creating side holes (i.e., in combination with the hollow drive shaft). For example, in some embodiments, a portion of the drive shaft may be exposed to UV / ozone treatment to improve the adhesion of the medical-grade material to the drive shaft.

[0099] Reference Figure 1 , in some embodiments, the pump may include a motor 6 operably coupled to the proximal end of the drive shaft. In some embodiments, the pump may include a catheter 3 having a proximal end and a distal end, and the distal end is operably coupled to the proximal end of the pump housing.

[0100] In some embodiments, the drive shaft may be disposed in a lumen that extends from the proximal end to the distal end of the catheter. The lumen may include a bearing (not shown). Various bearings may be used. In some embodiments, a spiral bearing may be used. Reference Figure 6 , the spiral bearing 300 may have an outer surface 301 (facing radially outward from the center of rotation axis) and an inner surface 302 (facing radially inward toward the center of rotation axis). The spiral bearing may be a so-called spiral groove bearing, which is preferably formed on the moving surface of the bearing clearance, i.e., correspondingly formed on the surface 303 of the bearing. In this case, a plurality of grooves 304 are spirally disposed in the surface 303. Figure 6Only the grooves are schematically shown. When the bearing rotates in the direction 305 as indicated by the arrow, the lubricating film can be radially inwardly conveyed along the groove 304 and a pressure is built up there, which in turn ensures that the surfaces forming the bearing clearance (e.g., the axial clearance, such as between the surface 303 and another surface opposite thereto) are kept at a certain distance.

[0101] In some embodiments, the pump housing can be configured to be inserted into a patient's blood vessel. In some embodiments, the pump housing can be configured to be inserted into a ventricle of a patient's heart.

[0102] In some embodiments, a system can be provided. The system can include the pump 1 as disclosed herein. The controller 31 can be operably coupled to the pump.

[0103] In some embodiments, a kit can be provided. The kit can include the pump 1 and the controller 31 as disclosed herein, and the controller 31 can be configured to be operably connected to the pump.

[0104] Embodiments of the present disclosure are described in detail with reference to the accompanying drawings, in which like reference numerals represent like or identical elements. It should be understood that the disclosed embodiments are merely examples of the present disclosure, which can be embodied in various forms. To avoid obscuring the present disclosure with unnecessary details, well-known functions or configurations are not described in detail. Therefore, the specific structural and functional details disclosed herein should not be construed as limiting, but only as a basis for the claims and as a representative basis for teaching those skilled in the art to use the present disclosure in various ways in almost any appropriate detailed structure.

[0105] Those skilled in the art will recognize or be able to use, without more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. These equivalents are intended to be covered by the following claims.

Claims

1. A rotor, comprising: a hub configured to rotate about a central axis; at least one rotor blade coupled to the hub and extending away from an outer surface of the hub, the at least one rotor blade comprising a medical-grade material, the at least one rotor blade configured to have a curled state and an operating state; wherein the medical-grade material is configured for casting or injection molding, and when cured, the medical-grade material has a Shore A hardness value of 90 to 100 or a Shore B hardness value of 35 to 55 determined using DIN ISO 7619-1, and a Young's modulus of 60 Mpa to 250 Mpa determined using ISO 527; wherein in the curled state, the at least one rotor blade is compressed and exposed to a strain of up to about 160% at a temperature of 20 - 25 °C in a dry environment; and wherein in the operating state, the at least one rotor blade expands and is exposed to a strain of up to 10% at a temperature of 36 - 42 °C in a humid environment.

2. The rotor according to claim 1, wherein the medical-grade material has a tensile strength of 15 Mpa to 25 MPa and an elongation at break of 500% to 600% determined using DIN 53504.

3. The rotor according to claim 1 or 2, wherein the stress of the medical-grade material at 5% strain, at 10% strain, at 20% strain, and at 50% strain has a range not exceeding 0.5 MPa determined using DIN 53504.

4. The rotor according to any one of claims 1 to 3, wherein the medical-grade material has a storage modulus exhibiting a rubbery plateau at a temperature not exceeding 0 °C to not less than 150 °C.

5. The rotor according to any one of claims 1 to 4, wherein the medical-grade material has a storage modulus of 50 - 100 MPa at 0 °C.

6. The rotor according to any one of claims 1 to 5, wherein the medical-grade material is a resin having a first component and a second component; wherein the first component is a prepolymer, and the prepolymer comprises: hexamethylene diisocyanate (HDI), methylene dicyclohexyl diisocyanate (H12MDI), and / or methylene diphenyl diisocyanate (MDI); polytetramethylene ether glycol (PTMEG) or polypropylene glycol (PPG) having a molecular weight of 500 g / mol to 6000 g / mol; and optionally, a polyester, the first component having an average molecular weight of 10000 g / mol to 14000 g / mol; and and wherein the second component is diethyl toluene diamine (DETDA) or 1,4-butanediol.

7. The rotor according to claim 6, wherein the polyester is polycaprolactone, polyethylene adipate, or polybutylene adipate.

8. The rotor according to claim 6 or 7, wherein the first component and the second component are present in a stoichiometric ratio.

9. The rotor according to claim 6 or 7, wherein the first component and the second component are present in a non-stoichiometric ratio.

10. The rotor according to any one of claims 1 to 9, wherein the medical-grade material is a resin having one or more soft segments and one or more hard segments.

11. The rotor according to claim 10, wherein the one or more soft segments comprise a difunctional or trifunctional end-capped telechelic soft segment oligomer, and the one or more hard segments comprise a diisocyanate.

12. The rotor according to claim 10 or 11, wherein the medical-grade material further comprises one or more chain extenders.

13. The rotor according to any one of claims 1 to 12, wherein the medical-grade material is a silicone polycarbonate urethane.

14. The rotor according to claim 13, wherein the silicone polycarbonate urethane comprises polydimethylsiloxane (PDMS) and one or more chain extenders.

15. The rotor according to any one of claims 1 to 14, wherein the medical-grade material is a one-component resin.

16. The rotor according to any one of claims 1 to 15, wherein the rotor is formed by die casting or injection molding.

17. The rotor according to any one of claims 1 to 15, wherein the rotor is formed by vacuum casting or vacuum socketing.

18. The rotor according to any one of claims 1 to 17, wherein the medical-grade material is thermoplastic polyurethane, polyvinyl acetate or a blend.

19. The rotor according to any one of claims 1 to 18, wherein the medical-grade material is selected such that the force-elongation distribution of the medical-grade material exhibits a region with a first slope below a deformation threshold and a plateau region above the deformation threshold.

20. The rotor according to claim 19, wherein the value of the force in the plateau region is 9 - 11 N.

21. The rotor according to any one of claims 1 to 20, wherein the medical-grade material is configured to withstand an elongation rate greater than 100% without rupture.

22. The rotor according to any one of claims 1 to 21, wherein the medical-grade material is configured such that when exposed to an elongation rate of 100% for at least 15 minutes, it exhibits less than 5% non-recoverable plastic deformation.

23. The rotor according to any one of claims 1 to 22, wherein the medical-grade material is a biocompatible material.

24. The rotor according to any one of claims 1 to 23, wherein the at least one rotor blade has a substantially smooth outer surface.

25. The rotor according to any one of claims 1 to 24, wherein the at least one rotor blade has an outer surface substantially free of orange peel effect.

26. The rotor according to any one of claims 1 to 25, wherein the medical-grade material is sterilizable.

27. The rotor according to claim 26, wherein the medical-grade material is ethylene oxide sterilizable.

28. The rotor according to any one of claims 1 to 27, wherein the medical-grade material is selected such that the dimensional molding shrinkage rate is less than 1% when cooled to room temperature after forming the rotor.

29. The rotor according to any one of claims 1 to 28, wherein the medical-grade material comprises a catalyst and / or an inhibitor.

30. The rotor according to any one of claims 1 to 29, wherein the at least one rotor blade has an axial length of 7 - 8 mm.

31. The rotor according to any one of claims 1 to 30, wherein, In the operating state, the rotor has an outer diameter of 5 - 6 mm.

32. The rotor according to any one of claims 1 to 31, wherein the hub has an axial length of 9 - 11 mm.

33. The rotor according to any one of claims 1 to 32, wherein the hub has no lumen extending from the distal end to the proximal end.

34. The rotor according to any one of claims 1 to 32, wherein the hub has a lumen extending from the distal end to the proximal end.

35. The rotor according to any one of claims 1 to 34, wherein the hub and the at least one rotor blade are cast or molded from the medical-grade material, in particular by injection molding.

36. The rotor according to any one of claims 1 to 35, wherein the at least one rotor blade is helically wound around the hub.

37. The rotor according to claim 36, wherein the at least one rotor blade has a constant helical pitch.

38. The rotor according to claim 36, wherein the helical pitch of the at least one rotor blade varies along the length of the hub.

39. The rotor according to any one of claims 1 to 38, wherein the at least one rotor blade comprises a concave side and a convex side.

40. The rotor according to claim 39, wherein, In the curled state, the concave side abuts against the outer surface of the hub.

41. A rotor, comprising: a hub configured to rotate about a central axis; and at least one rotor blade coupled to the hub and extending away from the outer surface of the hub, the at least one rotor blade comprising medical-grade polyurethane, the at least one rotor blade being configured to have a curled state and an operating state.

42. The rotor according to claim 41, wherein, the medical-grade polyurethane is a resin having a first component and a second component; wherein the first component is a prepolymer, and the prepolymer comprises: hexamethylene diisocyanate (HDI), methylene dicyclohexyl diisocyanate (H12MDI) and / or methylene diphenyl diisocyanate (MDI); polytetramethylene ether glycol (PTMEG) or polypropylene glycol (PPG) having a molecular weight of 500 g / mol to 6000 g / mol; and optionally, a polyester, the first component having an average molecular weight of 10000 g / mol to 14000 g / mol; and and wherein the second component is diethyl toluene diamine (DETDA) or 1,4-butanediol.

43. The rotor according to claim 42, wherein the polyester is polycaprolactone, polyethylene adipate or polybutylene adipate.

44. The rotor according to claim 42 or 43, wherein the first component comprises HDI, PPG and polycaprolactone, and the second component is DETDA.

45. The rotor according to claim 42 or 43, wherein the first component comprises H12MDI, PPO, and polycaprolactone, and the second component is DETDA.

46. The rotor according to claim 42 or 43, wherein the first component comprises H12MDI and / or MDI, PPO, and PTMEG, and the second component is 1,4 - butanediol.

47. The rotor according to any one of claims 41 to 46, wherein the medical - grade polyurethane comprises a catalyst and / or an inhibitor.

48. The rotor according to any one of claims 41 to 47, wherein the medical - grade polyurethane or other thermoplastic elastomer is a resin having one or more soft segments and one or more hard segments.

49. The rotor according to claim 48, wherein the one or more soft segments comprise difunctional or trifunctional capped telechelic soft - segment oligomers, and the one or more hard segments comprise diisocyanates.

50. The rotor according to claim 48 or 49, wherein the medical - grade polyurethane or other thermoplastic elastomer further comprises one or more chain extenders.

51. The rotor according to any one of claims 41 to 50, wherein the medical - grade polyurethane or other thermoplastic elastomer is a silicone polycarbonate urethane.

52. The rotor according to claim 51, wherein the silicone polycarbonate urethane comprises polydimethylsiloxane (PDMS) and one or more chain extenders.

53. The rotor according to any one of claims 41 to 52, wherein the at least one rotor blade has an axial length of 7 - 8 mm.

54. The rotor according to any one of claims 41 to 53, wherein, In the operating state, the rotor has an outer diameter of 5 - 6 mm.

55. The rotor according to any one of claims 41 to 54, wherein the hub has an axial length of 9 to 11 mm.

56. The rotor according to any one of claims 41 to 55, wherein the hub does not have a lumen extending from the distal end to the proximal end.

57. The rotor according to any one of claims 41 to 55, wherein the hub has a lumen extending from the distal end to the proximal end.

58. The rotor according to any one of claims 41 to 57, wherein the hub and the at least one rotor blade are cast or molded from the medical - grade polyurethane.

59. The rotor according to any one of claims 41 to 58, wherein the at least one rotor blade is helically wound around the hub.

60. The rotor according to claim 59, wherein the at least one rotor blade has a constant helix pitch.

61. The rotor according to claim 59, wherein the helix pitch of the at least one rotor blade varies along the length of the hub.

62. The rotor according to any one of claims 41 to 61, wherein the at least one rotor blade comprises a concave side and a convex side.

63. The rotor according to claim 62, wherein, In the curled state, the concave side abuts against the outer surface of the hub.

64. A pump, comprising: A pump housing, the pump housing being expandable and compressible; and A rotor according to any one of claims 1 to 63, the rotor being disposed in the pump housing.

65. The pump according to claim 64, further comprising a drive shaft operatively coupled to the rotor.

66. The pump according to claim 65, wherein the drive shaft is a metal drive shaft.

67. The pump according to claim 66, wherein the rotor is adhered to the metal drive shaft.

68. The pump according to claim 66 or 67, wherein the metal drive shaft includes at least one structure extending radially outward from a central axis of the drive shaft, the at least one structure configured to interact with the rotor.

69. The pump according to any one of claims 66 to 68, wherein the metal drive shaft has no structure extending radially outward from the drive shaft that interacts with the rotor.

70. The pump according to any one of claims 66 to 69, wherein the metal drive shaft has been surface treated.

71. The pump according to any one of claims 65 to 70, further comprising a motor operatively coupled to a proximal end of the drive shaft.

72. The pump according to any one of claims 65 to 71, further comprising a catheter having a proximal end and a distal end, the distal end being operatively coupled to a proximal end of the pump housing, the drive shaft being disposed in a lumen extending from the proximal end to the distal end of the catheter.

73. The pump according to any one of claims 64 to 72, wherein the pump housing is configured to be inserted into a blood vessel of a patient.

74. The pump according to any one of claims 64 to 72, wherein the pump housing is configured to be inserted into a ventricle of a patient's heart.

75. A system, comprising: a pump according to any one of claims 64 to 74; and a controller operatively coupled to the pump.

76. A kit, comprising: a pump according to any one of claims 64 to 74; and a controller configured to be operatively coupled to the pump.

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