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 comprising medical-grade polyurethane and configured to have a contracted state and an actuated state. The medical-grade polyurethane may be configured for casting or injection molding, and upon curing, the medical-grade material advantageously has a Shore A hardness of 90-100 or a Shore B hardness of 35-55 and a Young's modulus of 60 MPa-250 MPa. During contraction, the rotor blade is compressed in a dry environment at a temperature of 20-25°C and subjected to a strain of up to approximately 160%. During actuation, the rotor blade is expanded in a humid environment at a temperature of 36-38°C and subjected to a strain of up to 10%.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 63 / 429,649, filed December 2, 2022, and U.S. Provisional Patent Application No. 63 / 470,663, filed June 2, 2023, the contents of each of which are incorporated herein by reference in their entirety.

[0002] FIELD OF THE DISCLOSURE The present disclosure relates to rotors for moving bodily fluids, and in particular to compressible rotors for moving blood. [Background technology]

[0003] Medical pumps, particularly blood pumps, are required to meet very specific design and performance characteristics. To provide the necessary fluid flow at manageable rotational speeds, pump rotors require blades with a specific minimum outer diameter that exceeds the inner diameter of many blood vessels. To facilitate easier surgical insertion and ensure minimal rotor impact during surgical insertion into small blood vessels, the rotor blades must be compressible. However, achieving such characteristics requires medical-grade polymers with very precise mechanical properties. Currently, the manufacture of such rotors has not been able to achieve both the desired combination of (1) medical-grade materials and (2) precise mechanical properties. The use of non-medical polymers can present challenges during long-term use within a patient, such as in blood pumps used to alleviate certain cardiac-related conditions. Therefore, compressible rotors that can be manufactured from medical-grade polymers using conventional manufacturing techniques are useful and desirable. Summary of the Invention [Means for solving the problem]

[0004] Various deficiencies in the prior art are addressed by the disclosed systems and methods as follows:

[0005] A rotor may be provided. Advantageously, the rotor may have a hub configured to rotate about a central axis. The rotor may have at least one rotor blade coupled to the hub and extending away from an outer surface of the hub. The rotor blade includes a medical-grade material. The rotor blade may be configured to have a retracted state and an activated state.

[0006] The medical material, such as medical thermoplastic polyurethane (TPU) or other thermoplastic elastomers (TPEs) such as polyvinyl acetate, or blends / combinations thereof, may be configured for casting or injection molding and, upon curing, advantageously have a Shore A hardness of 90-100 or a Shore B hardness of 35-55 as determined using DIN ISO 7619-1, and a Young's modulus of 60 MPa to 250 MPa as determined using ISO 527. In the contracted state, the rotor blades may be compressed in a dry environment at a temperature of 20-25°C and subjected to strains of up to approximately 160%. In the operating state, the rotor blades may be expanded in a wet environment (e.g., exposed to blood) at a temperature of 36-42°C, such as 36-38°C, and subjected to strains of up to 10%.

[0007] In some embodiments, the medical material may have a tensile strength of 15 MPa to 25 MPa and an elongation at break of 500% to 600%, as determined using DIN 53504. In some embodiments, the medical material may be selected so that the stress of the medical material at 5%, 10%, 20%, and 50% strain, as determined using DIN 53504, is in the range of 0.5 MPa or less. In some embodiments, the medical material may have a storage modulus such that it exhibits a rubbery plateau at temperatures below 0°C to above 150°C. In some embodiments, the medical material may have a storage modulus of 50 to 100 MPa at 0°C.

[0008] In some embodiments, the medical material can be a biocompatible material. In some embodiments, the medical material can be a thermoplastic polyurethane, polyvinyl acetate, or a blend. In some embodiments, the medical material can be a single-component resin. In some embodiments, the medical material can be a resin having a first component and a second component. The first component can be a prepolymer of (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 6,000 g / mol, and (iii) optionally, a polyester such as poly(caprolactone), polyethylene adipate, or polybutylene adipate. Here, the first component can have an average molecular weight of 10,000 g / mol to 14,000 g / mol. The second component may be diethyltoluenediamine (DETDA) or 1,4 butanediol. In some embodiments, the first component and the second component may be present in a stoichiometric ratio. In some embodiments, the first component and the second component may be present in a non-stoichiometric ratio. In some embodiments, the medical material may include a catalyst and / or an inhibitor.

[0009] In some embodiments, the medical material may be a resin having one or more soft segments and one or more hard segments. The one or more soft segments may include a difunctional or trifunctional terminal telechelic soft segment oligomer. The one or more hard segments may also include a diisocyanate. The medical material may also include one or more chain extenders.

[0010] In some embodiments, the medical material can be a silicone-polycarbonate-urethane, which can include polydimethylsiloxane (PDMS) and / or one or more chain extenders.

[0011] In some embodiments, the medical material may include one or more additional components that may be added, for example, depending on the material variation or to achieve a desired reactivity, cure rate, molding viscosity, surface tension, etc.

[0012] In some embodiments, the rotor may be formed by die casting or injection molding. In some embodiments, the rotor may be formed by vacuum casting or vacuum socketing.

[0013] In some embodiments, the medical material may be selected so that the force-elongation profile of the medical material exhibits a region with a first slope below the deformation threshold and a plateau region above the deformation threshold. In some embodiments, the force value in the plateau region may be 9-11 N.

[0014] In some embodiments, the medical material may be configured to withstand greater than 100% elongation without fracture. In some embodiments, the medical material may be configured such that when exposed to 100% elongation for at least 15 minutes, the material exhibits less than 5% irrecoverable plastic deformation. In some embodiments, the medical material may be sterilizable. In some embodiments, the medical material may be ethylene oxide sterilizable. In some embodiments, the medical material may be selected to have less than 1% dimensional mold shrinkage upon cooling to room temperature after forming the rotor.

[0015] In some embodiments, at least one blade may have a substantially smooth outer surface. In some embodiments, at least one blade may have an outer surface that is substantially free of an orange peel effect. In some embodiments, at least one blade may have an axial length of 7-8 mm. In some embodiments, at least one blade may have an outer diameter of 5-6 mm in an operating state. In some embodiments, at least one rotor blade may be spirally wound around the hub. In some embodiments, at least one rotor blade may have a constant helical pitch. In some embodiments, the helical pitch of at least one rotor blade may vary along the length of the hub. In some embodiments, at least one rotor blade may include a concave surface and a convex surface. In some embodiments, the concave surface may be disposed against the outer surface of the hub in the retracted state.

[0016] In some embodiments, the hub can have an axial length of 9-11 mm. In some embodiments, the hub does not have a lumen extending from its distal end to its proximal end. In some embodiments, the hub can have a lumen extending from its distal end to its proximal end. In some embodiments, the hub and at least one rotor blade can be cast or molded, particularly injection molded, from a medical grade material.

[0017] In some embodiments, a rotor may 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, the rotor blade may include a medical grade polyurethane or other thermoplastic elastomer, and the rotor blade may have a contracted state and an actuated state.

[0018] In some embodiments, the medical polyurethane can be a resin having a first component and a second component. The first component can be a prepolymer containing (i) hexamethyl diisocyanate (HDI), methylene dicyclohexyl diisocyanate (H12MDI), and / or methylene diphenyl diisocyanate (MDI), (ii) polytetramethylene ether glycol (PTMEG, also known as polytetrahydrofuran) or polypropylene glycol (PPG) having a molecular weight of 500 g / mol to 6,000 g / mol, and (iii) optionally, a polyester such as poly(caprolactone), polyethylene adipate, or polybutylene adipate. 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 and second components may be present in a stoichiometric ratio. In some embodiments, the first and second components may be present in a non-stoichiometric ratio. In some embodiments, the medical polyurethane may include a catalyst and / or an inhibitor.

[0019] In some embodiments, the first component comprises HDI, PPG, and poly(caprolactone), and the second component is DETDA. In some embodiments, the first component comprises H12MDI, PPO, and poly(caprolactone), and the second component is DETDA. In some embodiments, the first component comprises H12MDI, and / or MDI, PPO, and PTMEG, and the second component is 1,4 butanediol.

[0020] In some embodiments, medical polyurethanes or other thermoplastic elastomers can be resins having one or more soft segments and one or more hard segments, where the one or more soft segments can comprise di- or tri-functionally terminated telechelic soft segment oligomers, and the one or more hard segments can comprise diisocyanates.

[0021] Medical polyurethanes or other thermoplastic elastomers may include one or more chain extenders.

[0022] In some embodiments, the medical polyurethane or other thermoplastic elastomer can be a silicone-polycarbonate-urethane, which can include polydimethylsiloxane (PDMS) and / or one or more chain extenders.

[0023] In some embodiments, at least one blade may have a substantially smooth outer surface. In some embodiments, at least one blade may have an outer surface that is substantially free of an orange peel effect. In some embodiments, at least one blade may have an axial length of 7-8 mm. In some embodiments, at least one blade may have an outer diameter of 5-6 mm in an operating state. In some embodiments, at least one rotor blade may be spirally wound around the hub. In some embodiments, at least one rotor blade may have a constant helical pitch. In some embodiments, the helical pitch of at least one rotor blade may vary along the length of the hub. In some embodiments, at least one rotor blade may have a concave surface and a convex surface. In some embodiments, the concave surface may be disposed against the outer surface of the hub in the retracted state.

[0024] 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 its distal end to its proximal end. In some embodiments, the hub can have a lumen extending from its distal end to its proximal end. In some embodiments, the hub and at least one rotor blade can be cast or molded, particularly injection molded, from a medical grade material.

[0025] 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 disposed within the pump housing.

[0026] In some embodiments, the pump may include a drive shaft operably coupled to the rotor. In some embodiments, the drive shaft may be a metallic drive shaft. In some embodiments, the rotor may be fixedly attached to the metallic drive shaft. In some embodiments, the metallic drive shaft may include 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. In some embodiments, the metallic drive shaft may not include a structure extending radially outward from the drive shaft that interacts with the rotor. In some embodiments, the metallic drive shaft may be surface treated.

[0027] In some embodiments, the pump may include a motor operably coupled to a proximal end of a drive shaft. In some embodiments, the pump may include a catheter having a proximal end and a distal end operably coupled to the proximal end of a 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 blood vessel of a patient. In some embodiments, the pump housing may be configured to be inserted into a ventricle of a patient's heart.

[0028] 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.

[0029] In some embodiments, a kit may be provided that may include a pump as disclosed herein and a controller that may be configured to be operably coupled to the pump.

[0030] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present invention and, together with the summary of the invention given above and the detailed description of the embodiments given below, serve to explain the principles of the invention. [Brief explanation of the drawings]

[0031] [Figure 1] 1 is a schematic diagram of a system including a pump with a rotor inserted into a patient's blood vessel. [Figure 2A] FIG. 2 is a side view of the rotor in an operating state. [Figure 2B] FIG. 2 is an axial view of the rotor excluding the lumen. [Figure 2C] FIG. 1 is an axial view of a rotor including a lumen. [Figure 2D] FIG. 2B is a cross-sectional view of FIG. 2A. [Figure 3] FIG. 1 is a cross-sectional view of a collapsed rotor. [Figure 4A] 1 is a graph showing stress at various strains for a medical polymer. [Figure 4B] 1 is a graph showing the storage modulus (G') of a medical polymer during a temperature sweep. [Figure 4C] 1 is a graph showing an example of a force-elongation profile. [Figure 4D] 1 is a graph showing engineering stress-strain curves of medical polymers. [Figure 5A] FIG. 2 is a simplified cross-sectional view showing structural elements for connecting the rotor and the drive shaft. [Figure 5B] FIG. 2 is a simplified cross-sectional view showing structural elements for connecting the rotor and the drive shaft. [Figure 6] FIG. 1 is a diagram of a seat in a plan view according to one embodiment. [Figure 7] FIG. 1 is a diagram of a polymer synthesis reaction. DETAILED DESCRIPTION OF THE INVENTION

[0032] It should be understood that the accompanying drawings are not necessarily to scale and that various features are depicted in somewhat simplified form to illustrate the underlying principles of the present invention. Specific design features of the sequences of operations disclosed herein, including, for example, the specific dimensions, orientations, positions, and shapes of the various components shown, will be determined in part by the particular application and environment of use. Certain features of the illustrated embodiments have been enlarged or distorted relative to other features for ease of viewing and understanding. In particular, for example, thin features may be thickened for clarity of illustration.

[0033] The following description and drawings merely illustrate the principles of the present invention. Thus, those skilled in the art will understand that various configurations, not explicitly described or shown herein, can be devised that embody the principles of the present invention and are within the scope of the present invention. Furthermore, all examples referred to herein are expressly intended to be merely illustrative, primarily to help the reader understand the principles of the present invention and the concepts that the inventors have contributed to improving the art, and should not be construed as being limited to such specifically mentioned examples and conditions. Furthermore, the term "or" as used herein refers to a non-exclusive meaning (e.g., "or otherwise" or "or alternatively") unless otherwise indicated. Furthermore, the various embodiments described herein are not necessarily mutually exclusive, as some embodiments can be combined with one or more other embodiments to form new embodiments.

[0034] Many of the innovative teachings of the present application are described with particular reference to presently preferred exemplary embodiments. However, it should be understood that this class of embodiments provides only a few of the many advantageous uses of the innovative teachings herein. Generally, statements in the specification of the present application do not necessarily limit any of the various claimed inventions. Moreover, some statements may apply to some inventive features but not to others. Those skilled in the art and familiar with the teachings herein will understand that the present invention may also be applied to various other technical fields or embodiments, such as geology and data fusion.

[0035] Various embodiments relate to pumps, particularly blood pumps with compressible rotors made from medical grade polymers.

[0036] The term "medical grade" as used herein refers to materials intended for use in finished medical devices, such as products compliant with the European Parliament's Medical Device Regulation EU 2017 / 745, as well as the Medical Device Council (MDR) and the Committee for Medicinal Products for Human Use (CHMP). Such medical materials must comply with a number of minimum requirements, including the need for strict change control procedures for possible planned changes to material specifications or composition, manufacturing sites, manufacturing techniques, or regulatory status; specific quality control 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 testing according to DIN EN ISO 10933 standards and / or United States Pharmacopeia (USP) Class VI, tolerance limits for various chemical components, including metal ions, and testing related to product sterilization (e.g., resistance to radiation, ethylene oxide, or, if necessary, steam sterilization). Medical materials often have a Drug Master File (DMF) prepared and submitted to and maintained by regulatory authorities, such as the US Food and Drug Administration (FDA).

[0037] FIG. 1 shows a schematic diagram of a rotor used in a pump. Pump 1 may include a pump housing 2 and a catheter 3 having a lumen therein. Pump housing 2 may have a proximal end 11 and a distal end 13. In some embodiments, distal end 13 may have one or more openings 15 that form an inlet for drawing blood into pump housing 2. In one aspect, openings 15 may form an inflow cage. The direction of blood inflow is indicated by arrow 12. Proximal end 11 may have one or more openings 14 that form an outlet for conveying blood drawn by the inlet into a patient's blood vessel.

[0038] A drive shaft 4 may be disposed within the lumen of the catheter 3. A proximal end of the drive shaft 4 may be attached to a motor 6, and a distal portion of the drive shaft may extend within the pump housing 2. A rotor 100 may be attached to a distal end of the drive shaft 4 and disposed within the pump housing 2. The motor 6 may rotate the drive shaft 4, which may in turn rotate the rotor 100. It should be appreciated that the drive shaft 4 may be flexible to allow the drive shaft 4 and catheter 3 to be deployed within the patient.

[0039] As shown in FIG. 1, pump 1 can be introduced into a patient's blood vessels via port 7. For example, pump 1 can be introduced through an arteriotomy in femoral artery 8 and inserted through aortic arch 9 into the patient's ventricle 10 so that pump housing 2 is located in the region of the aortic valve (not shown). It should be understood that distal end 13 of pump housing 2 can extend into the patient's left ventricle, while proximal end 11 is positioned in the patient's aorta. Rotor 100 can be rotated by drive shaft 4 and motor 6 at a speed of, for example, between 3,000 and 50,000 revolutions per minute (rpm) to transport blood from ventricle 10 to inlet opening 15 (indicated by arrow 12) at distal end 13 of pump housing 2 and out outlet opening 14 at proximal end 11 into the aorta.

[0040] In one embodiment, the pump 1 may include a controller 31 operatively coupled to the pump 1 and configured to control and drive the motor 6 to control the operation of the pump 1. The controller may be integrated into the motor 6 or may be located separately from the motor 6.

[0041] In one embodiment, the pump housing 2 and rotor 100 may be configured to be radially compressible to a compressed (or "contracted") state to allow efficient deployment of the pump 1 through the patient's blood vessels. Additionally, after placement of the pump housing 2 and rotor 100 in and / or near the patient's ventricle 10, the pump housing 2 and rotor 100 may be configured to be radially expandable to an expanded (or "actuated") state for normal operation.

[0042] 2A, rotor 100 may advantageously include a hub 116 configured to rotate about a central axis 130. The rotor may have at least one rotor blade 117, 118 coupled to the hub and extending radially away from an outer surface 115 of the hub. The hub may have a distal end 119 and a proximal end 120, and rotation of the hub may generate blood flow, for example, from the distal end to the proximal end.

[0043] To reduce shear stress on the blood from the rotor, the rotor, particularly the blades, should have good quality surfaces. In some embodiments, at least one blade 117, 118 can have a substantially smooth outer surface, such as first surface 121, 123 and second surface 122, 124. In some embodiments, at least one blade can have an outer surface that is substantially free of the orange peel effect.

[0044] As used herein, "orange peel" or "orange peel effect" refers to a particular type of finish that can appear on a surface. This rough texture resembles the surface of an orange peel. Without being bound by any particular theory, it is believed that such an orange peel effect is caused by shrinkage during curing. Furthermore, such an effect may be related to differences in the linear expansion coefficients of the materials that comprise the rotor or uneven temperature control during processing of the part.

[0045] In some embodiments, at least one blade 117, 118 may have an axial length 129 of 7-8 mm.

[0046] In some embodiments, at least one rotor blade may be spirally wound around the hub. As shown in FIG. 2B, in some embodiments, at least one blade may be configured such that the rotor can have a maximum outer diameter 127 of 5-6 mm when in an operating state. In some embodiments, portions 125 and 126 are portions of blades 117 and 118, respectively, and may be configured to be positioned directly adjacent to and extend away from hub 116. As shown, portions 125 and 126 extend along a radial axis 140 that is perpendicular to the axis of rotation of rotor 100 (e.g., central axis 130) and extends through the center of hub 116. It should be understood that, as seen in the cross-sectional view of rotor 5 (FIG. 2A), portions 125 and 126 (FIG. 2B) extend from the hub (i.e., along radial axis 140) along at least a portion of the length of the hub (i.e., from distal end 119 to proximal end 120 of hub 116, partially or entirely), as shown in FIG. 4C.

[0047] In some embodiments, at least one rotor blade may have a constant helical pitch.

[0048] 2D , in some embodiments, at least one rotor blade 117, 118 may have a concave surface 122, 124 and a convex surface 121, 123, respectively. 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 blades 117, 118 varies depending on the position along the length of hub 116 across which blade 117, 118 extends. In some embodiments, the inner curvature of the concave surfaces (here, proximal-facing surfaces 122, 124) of blades 117, 118 is stronger (i.e., has a smaller angle) than the curvature (which forms a larger angle) of the convex surfaces (here, distal-facing surfaces 121, 123) of the blades. Thus, in some embodiments, the pitch of each outer portion of blades 117, 118 may vary along the length of hub 116.

[0049] In some embodiments, the hub can have an axial length 128 of 9-11 mm. In some embodiments, the hub can have no lumen extending from its distal end to its proximal end, as shown in FIG. 2B. In some embodiments, the hub can have an inner surface 135 that defines a lumen extending from its distal end to its proximal end, as shown in FIG. 2C.

[0050] The rotor blades may be configured to have a retracted state and an actuated state.

[0051] In some embodiments, the concave surface may be positioned against the outer surface of the hub in the contracted state. FIG. 3 shows an embodiment of a rotor in a compressed state. In the compressed state, the rotor blades 117, 118 fold onto the hub 116, preferably without any sharp creases that could cause twisting and permanent deformation. As shown in FIG. 3, in the compressed / contracted state, the 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 to conform to the curvature of the hub. This eliminates the sharp twist that occurs in some conventional rotors in the compressed state. Because the blades 117, 118 are relatively evenly positioned relative to the hub 116, the force acting on the blades 117, 118 during compression is transferred to a torque acting on the outer diameter of the hub 116, thereby reducing or eliminating twisting of the blades 117, 118 during compression. Reducing the stress on the blades 117, 118 in the compressed state reduces the likelihood of permanent deformation of the blades 117, 118 due to blade stress in the compressed state, thereby allowing the blades 117, 118 to be more likely to deploy to their natural position in the uncompressed / expanded ("actuated") state.

[0052] The 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 mixtures / combinations thereof. In some embodiments, the medical grade material may be a 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.

[0053] In some embodiments, the medical 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 (i) hexamethyl diisocyanate (HDI), methylene dicyclohexyl diisocyanate (H12MDI), and / or methylene diphenyl diisocyanate (MDI), (ii) polytetramethylene ether glycol (PTMEG) or polypropylene glycol (PPG) (also referred to herein as poly(propylene oxide) (PPO)) having a molecular weight of 500 g / mol to 6,000 g / mol, and (iii) optionally, a polyester such as poly(caprolactone), polyethylene adipate, or polybutylene adipate. 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.

[0054] In some embodiments, the first component comprises HDI, PPG, and poly(caprolactone), and the second component is DETDA. In some embodiments, the first component comprises H12MDI, PPO, and poly(caprolactone), and the second component is DETDA. In some embodiments, the first component comprises H12MDI, and / or MDI, PPO, and PTMEG, and the second component is 1,4 butanediol.

[0055] In some embodiments, the first and second components may be present in a stoichiometric ratio. In some embodiments, advantageously, the first and second components may be present in a non-stoichiometric ratio. In some embodiments, the second component is used in an amount less than the amount required for the stoichiometric ratio. In some embodiments, the second component may be present in an amount 60-90% of the amount required for the stoichiometric ratio. As a simple example of this, in some embodiments, the stoichiometric ratio of the components may range from 1:0.65 to 1:1.35. Preferably, the range may be 1:0.75 to 1:1.25. In some preferred embodiments, the range may be 1:0.90 to 1:1.10. In some preferred embodiments, the range may be 1:1 to 1:1.20. In some preferred embodiments, the non-stoichiometric ratio used may be 1:0.95 to 1:1.05.

[0056] In some embodiments, polyurethanes are composed of one or more soft segments and one or more hard segments, which may alternate (e.g., soft segment, hard segment, soft segment, hard segment, ...), which may include segmented polyurethanes, polyurethaneureas, and polyureas.

[0057] The soft segments can be di- or tri-functionally terminated telechelic soft segment oligomers. The soft segments can 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. All combinations and subranges thereof are included. Non-limiting examples of soft segments include polyethers, such as poly(ethylene oxide) (PEO), poly(propylene oxide) (PPO), poly(tetramethylene oxide) (PTMO), or any mixture thereof, including block copolymers of PEO and PPO.

[0058] The soft segments can include one or more halogen atoms, such as fluorine. For example, in some embodiments, the soft segments can include fluorinated polyether oligomers.

[0059] The hard segments may be composed of diisocyanates as 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.

[0060] Such segmented polyurethanes are known in the art, as are techniques for their manufacture. An example of such a material can be found, for example, in U.S. Pat. No. 3,658,746 A, the entire contents of which are incorporated herein by reference.

[0061] [Table 1]

[0062] It should be understood that polyurethanes can include one or more chain extenders. As understood in the art, chain extenders are used in polyurethane synthesis, particularly 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).

[0063] The polymers can be synthesized by either a one-shot polymerization method or a "prepolymer method." The latter consists of two steps: 1) the formation of an isocyanate-terminated "prepolymer," followed by 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 polyurethane-urea. An example of this is shown in Figure 7.

[0064] In some embodiments, the medical material can be a silicone-polycarbonate-urethane. Such materials are based on a soft polycarbonate urethane surrounded by long silicone chains (e.g., polydimethylsiloxane chains). The polycarbonate urethane can contain one or more polycarbonate diols (e.g., molecular weights of 500-6000 g / mol) and / or one or more aromatic or aliphatic isocyanates (see Table 1). Such urethanes can be polymerized with linear or branched diol chain extenders, such as 1,4-butanediol (BDO). It should be understood that different aromatic and aliphatic diamine chain extenders can be used. One example of a silicone-polycarbonate-urethane can be a polycarbonate (PC)-polydimethylsiloxane (PDMS)-MDI-BDO block copolymer. The relative ratios of different components can be adjusted to achieve desired mechanical properties.

[0065] The siloxane can be a dihydroxyalkyl-terminated polydialkylsiloxane, such as dihydroxypropyl-terminated polydimethylsiloxane.

[0066] The polysiloxane may have a variety of reactive end groups. In some embodiments, the polysiloxane may include a hydroxy group. In some embodiments, the polysiloxane may include an amino group. In some embodiments, the polysiloxane may include an isocyanate group. In some embodiments, the polysiloxane may include a hydroxy group, an amino group, an isocyanate group, or any combination thereof.

[0067] The polysiloxane may 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 about 8000 Da or less. In some embodiments, the molecular weight is about 7000 Da or less. In some embodiments, the molecular weight is about 6000 Da or less. In some embodiments, the molecular weight is about 5000 Da or less. In some embodiments, such urethanes may contain about 5 to about 30% by weight of polysiloxane. In some embodiments, such urethanes may contain at least about 5% by weight of polysiloxane. In some embodiments, such urethanes may contain at least about 10% by weight of polysiloxane. In some embodiments, such urethanes may contain at least about 15% by weight of polysiloxane. In some embodiments, such urethanes may contain at least about 20% by weight of polysiloxane. In some embodiments, such urethanes may contain at least about 25% by weight of polysiloxane. In some embodiments, such urethanes may contain no more than about 50% by weight of polysiloxane. In some embodiments, such urethanes may contain no more than about 40% by weight of polysiloxane. In some embodiments, such urethanes may contain no more than about 30% by weight of polysiloxane.

[0068] Silicone-urethane polymers are known in the art, along with techniques for their manufacture. An example of such a material can be found, for example, in U.S. Patent No. 8,242,189 B2, the entire contents of which are incorporated herein by reference.

[0069] In some embodiments, the medical material may include a catalyst and / or an inhibitor. Any suitable amount of catalyst and / or inhibitor may be used depending on the chemical properties involved. In some embodiments, the catalyst may be present in an amount of 0.1% or less by weight of the medical material (including the catalyst and / or inhibitor). In some embodiments, the inhibitor may be present in an amount of 5% or less by weight of the medical material (including the catalyst and / or inhibitor).

[0070] Traditionally, polymer materials are often identified by CAS numbers or groups (e.g., polypropylene, polystyrene, etc.). However, those skilled in the art will understand that this alone is insufficient. For example, because chain length, degree of branching, stereoregularity, etc. are not taken into account when assigning CAS numbers, a clear classification of polymers based solely on CAS numbers is insufficient. While polymers belonging to a group (e.g., polypropylene) are broadly defined by the assigned CAS number, specific properties vary depending on the polymer's macromolecular structure (such as the aforementioned characteristics), manufacturing process, raw material supplier, etc. Therefore, it may be meaningful to expand the features that the medical materials disclosed herein preferably incorporate.

[0071] The medical grade material may be configured for casting or injection molding. For example, in some embodiments, the rotor may be formed by die casting. In some embodiments, the rotor may be formed by injection molding. In some embodiments, the rotor may be formed by vacuum casting or vacuum socketing. It is preferable to use a material with low shrinkage. In some embodiments, the medical grade material may be selected to have a dimensional molding shrinkage of less than 1% upon cooling to room temperature after rotor formation.

[0072] In some embodiments, when cured, the medical material advantageously has a Shore A hardness value, determined using DIN ISO 7619-1, of 90 to 100. In some embodiments, when cured, the medical material advantageously has a Shore B hardness value, determined using DIN ISO 7619-1, of 33 to 55. In some embodiments, when cured, the medical material advantageously has a Young's modulus, determined using ISO 527, of 60 MPa to 250 MPa.

[0073] In some embodiments, the rotor blades may be configured to be exposed to two different use conditions for extended periods of time (30 minutes or more) without substantial permanent deformation (e.g., irrecoverable deformation of 5% or less). Specifically, in some embodiments, the rotor blades may be configured to be exposed to strains of up to approximately 160% in a dry environment at a temperature of 20-25°C in the contracted state. In some embodiments, the rotor blades may be configured to be exposed to strains of up to 10% in a humid environment (e.g., exposed to blood) at a temperature of 36-42°C during the actuation (extended) state. In some embodiments, the rotor blades may be configured to be exposed to strains of up to 10% in a humid environment (e.g., exposed to blood) at a temperature of 36-40°C during the actuation (extended) state. In some embodiments, the rotor blades may be configured to be exposed to strains of up to 10% in a humid environment (e.g., exposed to blood) at a temperature of 36-38°C during the actuation (extended) state.

[0074] In some embodiments, the medical material may preferably have a tensile strength of 15 MPa to 25 MPa and an elongation at break of 500% to 600%, as determined using DIN 53504. For example, one thermoplastic polyurethane disclosed herein was measured to have a tensile strength of 20 MPa and an elongation at break of 540%. In some embodiments, the material may have an elongation at break of 150% to 600%, as determined using DIN 53504.

[0075] In some embodiments, the medical material may be preferably selected to have a relatively constant stress measured over a range of strains. For example, as shown in Figure 4A, in some embodiments, the stress at 5%, 10%, 20%, and 50% strain of the medical material, as determined using DIN 53504, may range 0.5 MPa or less across the four stresses.

[0076] In some embodiments, the medical material may have a storage modulus that exhibits a rubbery plateau at temperatures below 0° C. and above 150° C. In some embodiments, the medical material may have a storage modulus of 50 to 100 MPa at 0° C. An example of this may be shown in FIG. 4B.

[0077] Preferably, the transition from the actuated state to the contracted state (e.g., when a clinician wishes to remove the pump from a patient) does not require excessive force. To achieve this, in some embodiments, the medical material can be selected so that the force-extension profile of the medical material exhibits a region with a first slope below the deformation threshold and a plateau region above the deformation threshold. FIG. 4C is an example of a force-extension test, showing a first region 402 with a first slope, i.e., below the deformation threshold 401, and a plateau region 403 above the deformation threshold. These same basic characteristics can also be observed when the force-extension curve is converted to an engineering stress-strain curve. This can be seen, for example, in FIG. 4D, where a similar first region and plateau region can be observed. In some implementations, the force value in the plateau region can be 9-11 N.

[0078] Depending on various factors such as the geometry of the rotor and blades, the amount of contraction required, etc., the amount of elongation required during use may exceed 100%, 150%, 200%, or 300%. In some embodiments, the medical material may be configured to withstand elongation of greater than 100% without breaking. In some embodiments, the medical material may be configured to withstand elongation of greater than 150% without breaking. In some embodiments, the medical material may be configured to withstand elongation of greater than 200% without breaking. In some embodiments, the medical material may be configured to withstand elongation of greater than 300% without breaking.

[0079] Furthermore, to avoid performance degradation over time, the rotor must be able to be subjected to a certain elongation without significant irrecoverable plastic deformation. In some embodiments, the medical material may be configured such that when subjected to 100% elongation for at least 15 minutes, the material exhibits less than 5% irrecoverable plastic deformation.

[0080] For rotors intended for use as part of a medical device, the rotor is required to be sterilizable. Thus, in some embodiments, the medical material may be a sterilizable material. In some embodiments, the medical material may be ethylene oxide (ETO) sterilizable. In preferred embodiments, the medical material may be ETO sterilizable, but may not be autoclave sterilizable and / or gamma radiation sterilizable. For example, in some embodiments, autoclaves may be unusable because the heat and pressure used in autoclaving can adversely affect the medical material. Preferably, the medical material does not absorb any detectable amounts of ETO.

[0081] In some embodiments, a pump may be provided. Referring to FIG. 1 , in some embodiments, the pump may have an inflatable and deflatable pump housing 2. In some embodiments, the pump housing may have a structural layer that may include, for example, a plurality of struts forming a cage or mesh. The struts may include, for example, Nitinol. The pump housing may have additional layers, such as inner and / or outer layers, disposed on the inner or outer surfaces of each of the struts or other structural layers. This may include filling the spaces between the struts to form sealed regions such that fluid cannot move between the interior and exterior of the housing through the sealed regions. The pump may have a rotor 100, as disclosed herein, disposed within the pump housing.

[0082] In some embodiments, the pump may have 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 metallic drive shaft. In some embodiments, the drive shaft may be comprised of a single filament. In some embodiments, the drive shaft may be comprised of multiple filaments, which may be combined in 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 glued to the metallic drive shaft.

[0083] In some embodiments, the metallic drive shaft may include at least one structure 501 extending radially (e.g., radially inward ( FIG. 5A ) and / or radially outward ( FIG. 5B )) from the outer surface 502 relative to the central axis 130 of the drive shaft, where the at least one structure is configured to interact with the rotor and prevent slippage (e.g., axial and / or circumferential movement relative to the drive shaft). In some embodiments, the metallic drive shaft may not include a structure extending radially outward from the drive shaft that interacts with the rotor. In some embodiments, at least a portion of the metallic drive shaft may be surface treated. Examples of such surface treatments may include laser blasting (e.g., laser bead blasting), sandblasting, transfer blasting, and plasma treatment. Surface treatments may include the creation of side holes (i.e., in combination with a hollow drive shaft). For example, in some embodiments, a portion of the drive shaft may be UV / ozone treated to improve adhesion of medical materials to the drive shaft.

[0084] 1, in some embodiments, the pump may include a motor 6 operably coupled to a proximal end of a drive shaft. In some embodiments, the pump includes a catheter 3 having a proximal end and a distal end, the distal end of which may be operably coupled to the proximal end of the pump housing.

[0085] In some embodiments, a drive shaft may be disposed within a lumen extending 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 helical bearing may be used. Referring to FIG. 6, a helical bearing 300 may have an outer surface 301 (facing radially outward from the central axis of rotation) and an inner surface 302 (facing radially inward from the central axis of rotation). The helical bearing may be a so-called helical groove bearing, preferably formed on the moving surface of the bearing gap, i.e., the bearing surface 303. In this case, multiple grooves 304 are spirally arranged on the surface 303. The grooves are shown only diagrammatically in FIG. 6. As the bearing rotates in the direction 305 indicated by the arrow, a lubricant film may be transported radially inward along the grooves 304, where pressure builds up. This ensures that the surfaces forming the bearing gap (e.g., the axial gap between surface 303 and another surface facing it) are spaced apart.

[0086] In some embodiments, the pump housing can be configured to be inserted into a blood vessel of a patient. In some embodiments, the pump housing can be configured to be inserted into a ventricle of a patient's heart.

[0087] In some embodiments, a system may be provided. The system may include the pump 1 disclosed herein. A controller 31 may be operably coupled to the pump.

[0088] In some embodiments, a kit may be provided that may include a pump 1 as disclosed herein and a controller 31 that may be configured to be operably coupled to the pump.

[0089] Embodiments of the present disclosure will now be described in detail with reference to the figures, in which like reference numerals identify similar or identical elements. It should be understood that the disclosed embodiments are merely examples of the disclosure and may be embodied in various forms. Well-known functions or structures will not be described in detail to avoid obscuring the present disclosure with unnecessary detail. Therefore, the specific structural and functional details disclosed herein should not be construed as limiting, but merely as a basis for the claims and as a representative basis for teaching those skilled in the art how to variously use the present disclosure in virtually any suitable detailed structure.

[0090] Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein which equivalents are intended to be encompassed by the following claims.

Claims

1. 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 rotor blade including a medical grade material and configured to have a contracted state and an activated state; A rotor comprising: the medical material is configured for casting or injection molding and, when cured, has a Shore A hardness value of 90 to 100, or a Shore B hardness value of 35 to 55, as determined using DIN ISO 7619-1, and a Young's modulus of 60 MPa to 250 MPa, as determined using ISO 527; In the contracted state, the at least one rotor blade is compressed in a dry environment at a temperature of 20-25°C and subjected to a strain of up to about 160%; In the operating condition, the at least one rotor blade expands in a humid environment at a temperature of 36-42°C and is subjected to a strain of up to 10%. Rotor.

2. 2. The rotor of claim 1, wherein the medical 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. 3. The rotor of claim 1, wherein the medical material has stresses at 5%, 10%, 20% and 50% strain in the ranges of 0.5 MPa or less, as determined using DIN 53504.

4. 4. The rotor according to claim 1, wherein the medical material has a storage modulus that exhibits a rubber-like plateau at temperatures from 0° C. or lower to 150° C. or higher.

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

6. the medical material is a resin having a first component and a second component, The first component comprises: hexamethyl 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 6,000 g / mol; Optionally, a polyester; and is a prepolymer comprising the first component has an average molecular weight of 10,000 g / mol to 14,000 g / mol; The second component is diethyltoluenediamine (DETDA) or 1,4 butanediol. A rotor according to any one of claims 1 to 5.

7. The rotor of claim 6 , wherein the polyester is poly(caprolactone), polyethylene adipate, or polybutylene adipate.

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

9. 8. A 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 material is a resin having one or more soft segments and one or more hard segments.

11. The rotor of claim 10 , wherein the one or more soft segments comprise di- or tri-functional terminated telechelic soft segment oligomers and the one or more hard segments comprise diisocyanates.

12. The rotor of claim 10 or 11, wherein the medical material further comprises one or more chain extenders.

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

14. The rotor of 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 material is a single-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. A rotor according to any preceding claim, wherein the rotor is formed by vacuum casting or vacuum socketing.

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

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

20. The rotor of claim 19, wherein the force value of the plateau region is between 9 and 11 N.

21. A rotor according to any preceding claim, wherein the medical grade material is configured to withstand elongation of more than 100% without fracture.

22. A rotor according to any preceding claim, wherein the medical material is configured such that when subjected to 100% elongation for at least 15 minutes, the material exhibits less than 5% irrecoverable plastic deformation.

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

24. A rotor according to any preceding claim, wherein the at least one rotor blade has a substantially smooth outer surface.

25. A rotor according to any preceding claim, wherein the at least one rotor blade has an outer surface that is substantially free of orange peel effect.

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

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

28. A rotor according to any preceding claim, wherein the medical grade material is selected to have a dimensional moulding shrinkage of less than 1% when cooled to room temperature after forming the rotor.

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

30. A rotor according to any preceding claim, wherein the at least one rotor blade has an axial length of 7 to 8 mm.

31. A rotor according to any preceding claim, wherein the rotor has an outer diameter of 5 to 6 mm in the operating state.

32. A rotor according to any preceding claim, wherein the hub has an axial length of 9 to 11 mm.

33. A rotor according to any preceding claim, wherein the hub does not have a lumen extending from the distal end to the proximal end.

34. A rotor according to any preceding claim, wherein the hub has a lumen extending from the distal end to the proximal end.

35. A rotor according to any one of the preceding claims, wherein the hub and the at least one rotor blade are cast or moulded, in particular injection moulded, from the medical grade material.

36. A rotor according to any preceding claim, wherein the at least one rotor blade is spirally wound around the hub.

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

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

39. A rotor according to any preceding claim, wherein the at least one rotor blade has a concave surface and a convex surface.

40. 40. The rotor of claim 39, wherein the concave surface is disposed against an outer surface of the hub in the contracted state.

41. 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 rotor blade comprising medical grade polyurethane and configured to have a contracted state and an actuated state; A rotor comprising:

42. The medical polyurethane is a resin having a first component and a second component, The first component comprises: hexamethyl 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 6,000 g / mol; Optionally, a polyester; and is a prepolymer comprising the first component has an average molecular weight of 10,000 g / mol to 14,000 g / mol; The second component is diethyltoluenediamine (DETDA) or 1,4 butanediol.

42. A rotor according to claim 41.

43. 43. The rotor of claim 42, wherein the polyester is poly(caprolactone), polyethylene adipate, or polybutylene adipate.

44. 44. The rotor of claim 42 or 43, wherein the first component comprises HDI, PPG, and poly(caprolactone), and the second component is DETDA.

45. 44. The rotor of claim 42 or 43, wherein the first component comprises H12MDI, PPO, and poly(caprolactone), and the second component is DETDA.

46. 44. A 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. A rotor according to any one of claims 41 to 46, wherein the medical polyurethane comprises a catalyst and / or an inhibitor.

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

49. 49. The rotor of claim 48, wherein the one or more soft segments comprise di- or tri-functional terminated telechelic soft segment oligomers and the one or more hard segments comprise diisocyanates.

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

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

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

54. A rotor according to any one of claims 41 to 53, wherein the rotor has an outer diameter of 5 to 6 mm in the operating condition.

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

56. A 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. A 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. A rotor according to any one of claims 41 to 57, wherein the hub and the at least one rotor blade are cast or moulded from the medical grade polyurethane.

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

60. 60. The rotor of claim 59, wherein the at least one rotor blade has a constant helical pitch.

61. 60. The rotor of claim 59, wherein the helical pitch of the at least one rotor blade varies along the length of the hub.

62. A rotor according to any one of claims 41 to 61, wherein the at least one rotor blade has a concave surface and a convex surface.

63. 63. The rotor of claim 62, wherein the concave surface is disposed against an outer surface of the hub in the contracted state.

64. an expandable and compressible pump housing; a rotor according to any one of claims 1 to 63, arranged within the pump housing; A pump comprising:

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

66. 66. The pump of claim 65, wherein the drive shaft is a metallic drive shaft.

67. 67. The pump of claim 66, wherein the rotor is fixedly attached to the metal drive shaft.

68. 68. The pump of claim 66 or 67, wherein the metallic 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. A pump according to any one of claims 66 to 68, wherein the metallic drive shaft does not include structure extending radially outwardly from the drive shaft that interacts with the rotor.

70. A pump as claimed in any one of claims 66 to 69, wherein the metal drive shaft is surface treated.

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

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

73. 73. A pump according to any one of claims 64 to 72, wherein the pump housing is configured for insertion into a blood vessel of a patient.

74. 73. A pump according to any one of claims 64 to 72, wherein the pump housing is configured for insertion into a ventricle of a patient's heart.

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

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

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