Magnetic Coupler for Hemostatic Rotary Seal

Abstract

To provide an alternative medical device, and an alternative method for manufacturing and using the medical device.SOLUTION: A medical device comprises: a housing 120 including at least one inlet for receiving blood stream; a fluid barrier 135 disposed in the housing; an impeller 160 disposed in a first section 121 of the housing; at least one first magnet 140 connected with an impeller shaft 150; a drive shaft 190 disposed in a second section 122 of the housing; and at least one second magnet 142 disposed on the drive shaft in the second section of the housing. Rotation of the second magnet rotates the first magnet. The second magnet, while allowing axial movement of the second magnet along the drive shaft in order to allow the second magnet to be attracted toward the fluid barrier, is rotatably connected with the drive shaft.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to medical devices, and more particularly to blood flow assist devices including implantable rotary blood pumps for assisting the heart to drive blood flow, and methods of using such medical devices. [Background technology]

[0002] A wide variety of medical devices have been developed for medical use, including, for example, medical devices utilized to assist the heart in pumping blood throughout the circulatory system. These medical devices may be temporarily or permanently implanted and are manufactured and used according to any of a variety of different methods. Of the known medical devices and methods, each has certain advantages and disadvantages. There continues to be a need to provide alternative medical devices and alternative methods for manufacturing and using medical devices. Summary of the Invention

[0003] The present invention provides designs, materials, manufacturing methods, and uses for alternative medical devices. An exemplary medical device includes a housing, the housing including at least one inlet for receiving blood flow and at least one outlet for delivering blood flow, the housing having a longitudinal axis, a fluid barrier disposed within the housing and separating the housing into a first section and a second section including the at least one inlet and the at least one outlet, the fluid barrier being impermeable to fluids, an impeller disposed within the first section of the housing, the longitudinal axis of the impeller and the longitudinal axis of the housing being the same, the impeller extending radially from the body, and a fluid barrier disposed within the first section of the housing, the fluid barrier being impermeable to fluids, the impeller extending radially from the body, and a fluid barrier disposed within the first section of the housing, the fluid barrier being impermeable to fluids, the fluid barrier being impermeable to fluids, and the fluid barrier being impermeable to fluids, ... The rotor has at least one blade extending outwardly, and includes at least one first magnet coupled to an impeller shaft, the impeller shaft coupled to the impeller, the first magnet disposed in a first section of the housing and rotatably coupled to the impeller shaft, a drive shaft disposed within a second section of the housing, and at least one second magnet disposed on the drive shaft within the second section of the housing, the first magnet and second magnet constructed and arranged such that rotation of the second magnet rotates the first magnet.

[0004] Alternatively or additionally to any of the above described embodiments, the medical device further includes a power source coupled to the drive shaft. Alternatively or additionally to any of the above described embodiments, the power source is disposed within the catheter shaft attached to the second section of the housing.

[0005] Alternatively or additionally to any of the above described embodiments, the power source is a motor. Alternatively or additionally to any of the above described embodiments, the power source is a second impeller connected to the drive shaft, the catheter shaft defining a fluid flow path, and the drive shaft and second impeller are positioned in the fluid flow path such that fluid impacting the second impeller drives the impeller, thereby rotating the second magnet which rotates the first magnet and causes the impeller shaft and impeller to rotate.

[0006] Alternatively or additionally to any of the above described embodiments, the at least one outlet includes a plurality of side openings spaced apart around the circumference of the housing, and the impeller is disposed within the housing such that at least one blade is disposed adjacent to the plurality of side openings.

[0007] Alternatively or additionally to any of the above described embodiments, the first magnet has a first opening extending therethrough configured to receive an impeller shaft to couple to the first magnet, the second magnet has a second opening extending therethrough configured to receive a drive shaft to couple to the second magnet, the first and second openings each have a first cross-sectional shape that is perpendicular to a longitudinal axis of the drive shaft, the drive shaft and at least a portion of the impeller shaft each have a second cross-sectional shape that is perpendicular to the longitudinal axis of the shaft, and the first and second cross-sectional shapes are non-circular such that rotation of the impeller shaft and drive shaft causes rotation of the first magnet and second magnet, respectively.

[0008] Alternatively or additionally to any of the embodiments described above, the first and second cross-sectional shapes are racetrack-shaped with straight sides and semicircular ends. Alternatively or additionally to any of the above described embodiments, the distal region of the impeller shaft is cylindrical.

[0009] Alternatively or additionally to any of the above-described embodiments, a proximal end of the impeller shaft extends proximal to the first magnet, the proximal end having a first protrusion configured to be received by a first recess in the fluid barrier.

[0010] Alternatively or additionally to any of the embodiments described above, the impeller shaft includes a disk adjacent the first projection, the disk extending perpendicularly from a longitudinal axis of the impeller shaft.

[0011] Alternatively or additionally to any of the above described embodiments, the disc has two opposing lobes. Alternatively or additionally to any of the embodiments described above, the medical device further includes a pivot member disposed between the second magnet and the fluid barrier.

[0012] Alternatively or additionally to any of the embodiments described above, the pivot member has a projection extending distally therefrom, the projection configured to be received by a second recess in the fluid barrier.

[0013] Alternatively or additionally to any of the above-described embodiments, the medical device further includes a bearing assembly configured to support and center a distal end of the impeller shaft, the bearing assembly including a bearing housing secured to the housing, a spacer slidably disposed within the bearing housing, and a distal bearing secured within the spacer.

[0014] Alternatively or additionally to any of the above described embodiments, the bearing assembly further includes a spring member disposed about the spacer. Another exemplary medical device includes a housing including an inlet for receiving blood flow and a plurality of side openings for delivering blood flow, the housing having a longitudinal axis, a fluid barrier disposed within the housing separating the housing into a first section including the inlet and the plurality of side openings and a second section, the fluid barrier being impermeable to fluids, an impeller disposed within the first section of the housing, the longitudinal axis of the impeller and the longitudinal axis of the housing being the same, the impeller having a body and at least one blade extending radially outward from the body, The catheter includes at least one first magnet disposed in a first section of the housing and coupled to the impeller such that rotation of the magnet rotates the impeller; a drive shaft disposed within a second section of the housing; and at least one second magnet coupled to the drive shaft and disposed within the second section of the housing, the first magnet and second magnet being constructed and arranged such that rotation of the second magnet rotates the first magnet; a catheter shaft coupled to the housing; and a power source coupled to the drive shaft, the power source being disposed within the catheter shaft.

[0015] Alternatively or additionally to any of the above described embodiments, the power source is a second impeller connected to the drive shaft, the catheter shaft defining a fluid flow path, and the drive shaft and second impeller are positioned in the fluid flow path such that fluid impacting the second impeller drives the impeller, thereby rotating the second magnet, which rotates the first magnet, which rotates the impeller.

[0016] Alternatively or additionally to any of the above-described embodiments, the medical device further includes an impeller shaft disposed on and coupled to the impeller and the first magnet, and a bearing assembly configured to support and center a distal end of the impeller shaft, the bearing assembly including a bearing housing secured to the housing, a spacer slidably disposed within the bearing housing, and a distal bearing secured within the spacer.

[0017] A method of assisting blood flow from a patient's heart to the patient's circulatory system includes inserting a device into the ascending aorta, the device including a housing including at least one inlet for receiving blood flow from a left ventricle of the heart and at least one outlet for delivering blood flow to the ascending aorta, the housing having a longitudinal axis and including a fluid barrier disposed within the housing separating the housing into a first section including the at least one inlet and the at least one outlet and a second section, the fluid barrier being impermeable to blood, and including an impeller disposed within the first section of the housing, the longitudinal axis of the impeller and the longitudinal axis of the housing being the same. the impeller having a body and at least one blade extending radially outward from the body, including an impeller shaft disposed within and coupled to the impeller, including at least one first magnet having a first opening for receiving the impeller shaft, the first magnet disposed in a first section of the housing and rotatably coupled to the impeller shaft, including a drive shaft disposed within a second section of the housing, including at least one second magnet disposed on the drive shaft within the second section of the housing, the first magnet and second magnet configured and arranged such that rotation of the second magnet rotates the first magnet. The method further includes rotating the drive shaft, thereby rotating the second magnet, thereby rotating the first magnet, thereby rotating the impeller shaft and the impeller to generate suction, thereby drawing blood from the left ventricle into the housing through the at least one inlet and delivering blood through the at least one outlet to the ascending aorta.

[0018] The above summary of some embodiments, aspects, and / or examples is not intended to describe each embodiment or every implementation of the present invention. The following figures and detailed description more particularly exemplify these embodiments.

[0019] The present invention may be more fully understood upon consideration of the following detailed description of various embodiments in conjunction with the accompanying drawings. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is a diagram of an exemplary mechanism for transmitting force across an impermeable barrier. [Diagram 2] FIG. 13 is a diagram of another exemplary mechanism for transmitting force across an impermeable barrier. [Diagram 3] FIG. 13 is a diagram of another exemplary mechanism for transmitting force across an impermeable barrier. [Figure 4] 1 illustrates an exemplary device positioned within the heart for assisting blood flow. [Diagram 5] 1 is a cross-sectional view of an exemplary device for assisting blood flow. [Figure 6] 1 is a cross-sectional view of another exemplary device for assisting blood flow. [Figure 7A] 2 is a cross-sectional view of an exemplary housing. [Figure 7B] 1A-1C are cross-sectional views of different exemplary housings. [Figure 8] FIG. 2 is a partial perspective view of an exemplary catheter shaft, drive shaft, and second magnet. [Figure 9A] 1A-1C are perspective views of two different exemplary magnets. [Figure 9B] 1A-1C are perspective views of two different exemplary magnets. [Figure 9C] FIG. 9C is a cross-sectional view of the magnet shown in FIG. 9B. [Figure 10] 1 is a partial perspective exploded view of an exemplary device for assisting blood flow. [Figure 11] 1 is a partial perspective view of an exemplary device for assisting blood flow. [Figure 12] FIG. 2 is a proximal end view of an exemplary impeller shaft. [Figure 13] FIG. 2 is a perspective cross-sectional view of an exemplary impeller. [Figure 14] FIG. 2 is a partial cutaway view of an exemplary distal bearing assembly. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] While aspects of the invention are susceptible to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit aspects of the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

[0022] For the following defined terms, these definitions shall be applied, unless a different definition is given in the claims or elsewhere in this specification. In this specification, all numerical values, whether explicitly stated or not, are assumed to be modified by the term "about". The term "about", in the context of numerical values, generally refers to a range of numerical values ​​that one of ordinary skill in the art would consider equivalent to the recited value (e.g., having the same function or result). In many cases, the term "about" may include numerical values ​​that are rounded to the nearest significant figure. Other uses of the term "about" (e.g., in non-numerical contexts) are understood from the context of the specification and are deemed to have the ordinary and customary definition consistent therewith, unless otherwise specified.

[0023] The recitation of numerical ranges by endpoints includes all numbers within that range, inclusive of the endpoints (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5.) Although several suitable dimensions, ranges, and / or values ​​for various components, features, and / or specifications have been disclosed, one of ordinary skill in the art stimulated by this specification will recognize that the desired dimensions, ranges, and / or values ​​may deviate from those expressly disclosed.

[0024] As used herein and in the appended claims, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. As used herein and in the appended claims, the term "or" is generally used in its sense, including "and / or," unless the content clearly dictates otherwise. For ease of understanding, it should be noted that certain features of the disclosure may be described in the singular even though they may be plural or repeated within a disclosed embodiment. Unless otherwise noted, each instance of a feature may be included and / or encompassed by a single disclosure. For purposes of simplicity and clarity, not all elements of the disclosure are necessarily shown in each figure or described in detail below. However, it will be understood that the following description may be equally applicable to any and / or all of the multiple components unless clearly stated to the contrary. In addition, for clarity, not all instances of some components or features are shown in each figure.

[0025] Relative terms such as "proximal," "distal," "advance," "retract," and variations thereof, are generally considered to relate to the placement, orientation, and / or operation of various components relative to a user, operator, or operator of the device, with "proximal" and "retract" representing or meaning closer to or toward a user, and "distal" and "advance" meaning away from or away from a user. In some cases, the terms "proximal" and "distal" may be arbitrarily assigned to facilitate understanding of the disclosure, and such instances will be readily apparent to one of ordinary skill in the art. Other relative terms such as "upstream," "downstream," "inflow," and "outflow" refer to the direction of fluid flow within a lumen, such as a body lumen, within a vessel, or within a device.

[0026] The term "extent" should be understood to mean the maximum dimension of a stated or identified dimension, unless the extent or size in question is modified or identified by "minimum," which may be understood to mean the smallest dimension of the stated or identified size. For example, an "outer extent" may be understood to mean the largest outer dimension, a "radial extent" may be understood to mean the largest radial dimension, a "longitudinal extent" may be understood to mean the largest longitudinal dimension, etc. Each instance of "extent" may be different (e.g., axially, longitudinally, laterally, radially, circumferentially, etc.) and will be clear to one of skill in the art from the context of the particular usage. In general, an "extent" may be considered to be the largest possible dimension measured according to the intended usage, while a "minimum extent" is the smallest possible dimension measured according to the intended usage. In some cases, an "extent" may generally be measured orthogonally in a plane and / or cross section, but in special contexts may be measured differently, such as, but not limited to, angularly, radially, circumferentially (e.g., along an arc), etc.

[0027] The terms "monolithic" and "unitary" shall generally refer to a component or components made from or consisting of a single structure or base unit / element. Monolithic and / or unitary elements shall exclude structures and / or mechanisms that are assembled or otherwise comprised of multiple separate and independent elements joined together.

[0028] References herein to "one embodiment," "some embodiments," "other embodiments," and the like indicate that the described embodiment may include a particular feature, structure, or characteristic, but not all embodiments include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. Moreover, where a particular feature, structure, or characteristic is described in relation to an embodiment, it is within the knowledge of one of ordinary skill in the art to affect the particular feature, structure, or characteristic in relation to other embodiments, whether or not expressly described, unless expressly stated to the contrary. In other words, it is contemplated that various individual elements described below, even if not explicitly shown in a particular combination, can nevertheless be combined or arranged with one another to form other additional embodiments or to complement and / or enhance the described embodiments, as understood by one of ordinary skill in the art.

[0029] For purposes of clarity, certain distinguishing numerical designations (e.g., first, second, third, fourth, etc.) may be used throughout the specification and / or claims to name and / or distinguish the various described and / or claimed features. It should be understood that the numerical designations are not intended to be limiting, but are merely exemplary. In some embodiments, substitutions and departures from previously used numerical nomenclature may be made for brevity and clarity. That is, a feature identified as a "first" element may later be referred to as a "second" element, a "third" element, etc., or may be omitted entirely, and / or a different feature may be referred to as the "first" element. The meaning and / or indication in each instance will be apparent to the skilled practitioner.

[0030] The following description should be read with reference to the drawings, which are not necessarily to scale, and similar elements in different drawings are numbered the same. The detailed description and drawings are intended to illustrate the disclosure, and not to limit it. Those skilled in the art will recognize that the various elements described and / or shown can be arranged in various combinations and configurations without departing from the scope of the invention. The detailed description and drawings show exemplary embodiments of the invention. However, for clarity and ease of understanding, not all features or elements may be shown in each drawing, but it can be understood that the features or elements are present unless otherwise specified.

[0031] As will be described in more detail below, FIG. 1 illustrates a partial cross-sectional view of an exemplary power transmission mechanism that may be utilized within a blood flow assist device. Specifically, FIG. 1 illustrates how magnetic force transmitted through a blood impermeable barrier is used to drive an impeller to assist blood flow through the vessel. In this view, device 10 is positioned within blood vessel 5. Device 10 may include a housing 20 separated into a distal first section 21 and a proximal second section 22 by a fluid barrier 35 that is impermeable to blood. In some examples, fluid barrier 35 may be made of ultra-high molecular weight polyethylene (UHMWPE), polyoxymethylene such as Delrin® acetal homopolymer resin, polyetheretherketone (PEEK), nylon, high density polyethylene (HDPE), other polymers commonly used in medical devices, sapphire, ruby, nickel-cobalt based alloys such as MP35N®, cobalt chromium alloys, titanium, titanium alloys, and the like. In other examples, fluid barrier 35 may be fiber filled or oil impregnated. The fluid barrier 35 may extend across the interior of the housing 20 to provide a complete seal against blood leakage into the second section 22 when the first section 21 is filled with blood. The device 10 may further include a first magnet 40 disposed in the first section 21 of the housing 20 and coupled to the impeller shaft 50 and the impeller 60. The first magnet 40 may be coupled to the impeller shaft 50 by a physical structure such as an opening in the first magnet 40 that receives the impeller shaft 50. Alternatively, the first magnet 40 may have a protrusion that is received within a recess in the impeller shaft 50. The opening / recess may be keyed to the shaft / protrusion to couple the magnet and shaft. For example, the opening / recess may have a shape that matches the shape of the shaft / protrusion. In other examples, the first magnet 40 may be coupled to the impeller shaft 50 by welding, sintering, adhesive bonding, etc. The device may include one or more bearings 70 that surround or support the impeller shaft.

[0032] In the second section 22 of the housing 20, the second magnet 42 may be coupled to a drive shaft 90, which may be coupled to a power source 95. The second magnet 42 may be coupled to the drive shaft 90 as described above with respect to the first magnet 40 and the impeller shaft 50. One or more bearings 70 may surround the drive shaft 90. In some examples, the power source 95 may be an electric motor with a power cord 97 that extends proximally through the housing 20, outside the body, through a catheter (not shown) connected to the housing.

[0033] In the example shown in FIG. 1, the first and second magnets 40, 42 are bipolar magnets, with the north pole N of the first magnet 40 positioned across the fluid barrier 35 from the south pole S of the second magnet 42, and the south pole S of the first magnet 40 positioned across the fluid barrier 35 from the north pole N of the second magnet 42. This orientation of the first and second magnets 40, 42 ensures that the attractive force between the magnets, indicated by arrow 99, couples the rotational motion of the second magnet 42 to the rotational motion of the first magnet 40. The magnetic force is transferred through the fluid barrier 35. It will be understood that magnets with more than two poles may be used. In use, the power source 95 rotates the drive shaft 90, thereby rotating the second magnet 42, thereby causing the first magnet 40 to rotate at the same speed as the second magnet 42. Rotation of the first magnet 40 rotates the attached impeller shaft 50, which in turn rotates the attached impeller 60. Because the impeller 60 is in fluid contact with the blood in the blood vessel 5, rotation of the impeller 60 assists in blood flow through the blood vessel 5. The fluid barrier 35 prevents blood from leaking into the second section 22 of the housing 20, and thus prevents blood from contacting the drive shaft 90 and power source 95.

[0034] Additionally, multiple magnets may be used on either side of the fluid barrier 35. Regardless of the number and / or type of magnets used, the one or more magnets are constructed and arranged such that rotation of the one or more magnets connected to the drive shaft 90 and power source 95 rotates the one or more magnets connected to the impeller 60.

[0035] FIG. 2 illustrates another exemplary power transmission mechanism that may be utilized within a blood flow assist device. Specifically, FIG. 2 illustrates a method of assisting blood flow through a blood vessel using magnetic force transmitted through a blood impermeable barrier. The device shown in FIG. 2 is similar to the device shown in FIG. 1, but with a fluid as a power source. It will be understood that the fluid source may be provided under pressure or under vacuum, and the fluid may flow at high or low pressure. One end of the drive shaft 90 may be connected to the second magnet 42, and a second end of the drive shaft 90 may be connected to the second impeller 65. The second section 22 of the housing 20 and a catheter (not shown) connected to the housing 20 may both include an inner lumen 24 and an outer lumen 26. As indicated by arrow 25, a high or low pressure fluid, such as saline or other suitable fluid, may be injected through the inner lumen 24 toward the second impeller 65. The high or low pressure fluid rotates the second impeller 65, which rotates the drive shaft 90 and the attached second magnet 42. As shown in the first example diagram in FIG. 1, the rotation of the second magnet rotates the first magnet 40, which in turn rotates the impeller shaft 50 and the impeller 60. The impeller 60 is in contact with the blood in the blood vessel 5, and thus the rotation of the impeller 60 assists blood flow through the blood vessel 5. After rotating the second impeller 65, the high or low pressure fluid then returns through the outer lumen 26, as indicated by the arrow 27. The fluid barrier 35 prevents the fluid from entering the blood vessel 5. Similarly, the fluid barrier 35 prevents blood from entering the second section 22 and mixing with the fluid. The high or low pressure fluid may be provided from a pressurized or vacuum source outside the body, and the return fluid may be collected and reused outside the body.

[0036] FIG. 3 illustrates another exemplary power transmission mechanism that may be utilized within the blood flow assist device. The device shown in FIG. 3 is similar to that shown in FIG. 2, but with the fluid direction reversed. Specifically, FIG. 3 illustrates how high or low pressure fluid may be injected through the outer lumen 26 toward the second impeller 65, as indicated by arrow 28. The high or low pressure fluid rotates the second impeller 65, which in turn rotates the drive shaft 90 and the attached second magnet 42. As in the first example illustration in FIG. 1, the rotation of the second magnet rotates the first magnet 40, which in turn rotates the impeller shaft 50 and the impeller 60. The impeller 60 is in contact with the blood in the blood vessel 5, and thus the rotation of the impeller 60 assists blood flow through the blood vessel 5. After rotating the second impeller 65, the high or low pressure fluid then returns through the inner lumen 24, as shown by arrow 29. The fluid barrier 35 prevents the fluid from entering the blood vessel 5. Similarly, the fluid barrier 35 prevents blood from entering the second section 22 and mixing with the fluid. The high or low pressure fluid may be provided from a source outside the body, and the return fluid may be collected and reused outside the body. The fluid source may be under pressure or under vacuum.

[0037] FIG. 4 illustrates an exemplary device 110 including a power transmission mechanism positioned within a patient's heart 1. As shown in FIG. 4, the device 110 is connected to a catheter shaft 115 and may be positioned in the ascending aorta 4 with a distal end 128 of the device 110 adjacent the aortic valve 3. This position may be beneficial because blood exiting the left ventricle 2 (indicated by arrow 8) enters the distal end 128 of the device 110, which causes the device 110 to pump the blood so that it exits a side opening 130 of the device 110 with additional force provided only by the left ventricle 2 (blood exiting the device 110 is indicated by arrow 9). It may be appreciated that the additional pumping action of the device 110 may assist the heart 1 in circulating blood throughout the body. Alternatively, the device 110 may be positioned past the aortic valve 3 such that the distal end 128 of the device 110 is in the left ventricle 2 and the side opening 130 is in the ascending aorta 4. In a further example, the device 110 may be positioned such that the side opening 130 is in the descending aorta. It is also understood that the size of the device 110 relative to the size of the heart chamber and aorta is not intended to be limiting, and the size of the device 110 may be altered to provide the desired blood flow assistance. A catheter shaft 115 connected to the device 110 may extend through the vascular system to the outside of the body. The catheter shaft 115 may include a power cord connected to an external power source. The device 110 may include a power source, or a power source may be provided internal to the patient, but is also contemplated to be remote from the device 110, such as an internal pacemaker.

[0038] While the above description describes the advantages of using the device 110 in the ascending aorta of the heart, it is contemplated that the device 110 may be used in other parts of the heart or in other parts of the body (e.g., other body lumens). In some examples, the device 110 may be inserted into a patient with the housing positioned in the descending aorta upstream of the renal arteries. This location may increase blood flow to the kidneys. Alternatively, the device 110 may be positioned in the renal arteries. Yet another alternative is to position the device 110 downstream of the renal arteries just before the iliac bifurcation. In a further example, the device 110 may be positioned in the right ventricle to pump blood through the pulmonary valve.

[0039] Figure 5 shows a blood assist device 110 similar in form and function to the device shown in Figure 4. In other words, Figure 5 illustrates a blood assist device 110 that may be placed in a patient's blood vessel. In addition, as discussed in more detail below, the blood assist device shown in Figure 5 may include a power transmission mechanism as described and shown in any of Figures 1-3.

[0040] The device 110 may include a catheter shaft 115 coupled to a proximal end 129 of a housing 120. The housing 120 may be separated into a distal first section 121 and a proximal second section 122 by a fluid barrier 135 that is impermeable to fluids including blood. The first section 121 of the housing 120 may have at least one side opening 130 that penetrates a wall of the housing 120. The fluid barrier 135 may extend across the interior of the housing 120 and completely seal blood leakage into the second section 122 when the first section 121 is filled with blood. The fluid barrier 135 further prevents any fluid in the second section 122 from entering the first section 121 that may attempt to enter the bloodstream. The device 110 may further include a first magnet 140 disposed within the first section 121 of the housing 120 and coupled to the impeller shaft 150 and the impeller 160. The first magnet 140 and the impeller 160 may both be coupled to the impeller shaft 150 such that rotation of the first magnet 140 rotates the impeller shaft 150 which rotates the impeller 160. The impeller 160 may be a separate structure from the impeller shaft 150 and may be coupled to the impeller shaft 150. In some examples, the impeller shaft 150 may be disposed within the impeller 160. In other examples, the impeller 160 may be attached to the impeller shaft 150 by gluing, welding, molding, etc. Alternatively, the impeller 160 and the impeller shaft 150 may be formed as a single monolithic structure. The impeller 160 may be disposed within the first section 121 of the housing 120 adjacent the side opening 130. The impeller shaft distal end 151 may be mounted to a distal bearing assembly 170 disposed at the housing distal end 128. The distal bearing assembly 170 may be coupled to the housing 120 at separate locations circumferentially spaced about the housing 120 such that the distal end 128 serves as an inlet about the distal bearing assembly 170 and can accommodate blood flow into the housing 120. The side openings 130 may serve as an outlet through which blood flow can exit the housing. The housing 120 may have a single side opening 130 or multiple side openings 130.When multiple side openings 130 are present, they may be circumferentially spaced about a portion or the entire circumference of the housing 120. The distal bearing assembly 170 may include a distal bearing 171, a spacer 175, and a bearing housing 180.

[0041] In the second section 122 of the housing 120, the second magnet 142 may be coupled to a drive shaft 190 that may be coupled to a power source 195. The device 110 may lack fluid between the second magnet 142 and the drive shaft 190. In the example shown in FIG. 5, the power source 195 may be an electric motor with a power cord 197 that extends proximally through the catheter shaft 115 to the outside of the body. Alternatively, the power source may be located outside the body or may be located within the body remote from the device 110. The pivot member 136 may provide an interface between the fluid barrier 135 and the second magnet 142. In addition to preventing fluid from passing between the first section 121 and the second section 122 of the housing 120, the fluid barrier 135 may function as a thrust bearing about which the pivot member 136 and the impeller shaft 150 rotate. In some examples, the fluid barrier 135 may be made from ultra-high molecular weight polyethylene (UHMWPE), polyoxymethylene such as Delrin® acetal homopolymer resin, polyetheretherketone (PEEK), nylon, high density polyethylene (HDPE), or other polymers traditionally used in medical devices, sapphire, ruby, nickel-cobalt based alloys such as MP35N®, cobalt chrome alloys, titanium, titanium alloys, etc. In other examples, the fluid barrier 135 may be fiber filled or oil impregnated.

[0042] The first magnet 140 and the second magnet 142 can be any shape that provides a balanced mass during rotation. In some examples, the first magnet 140 and the second magnet 142 can be bipolar magnets that are cylindrical in shape with north and south poles disposed adjacent to opposing flat sides. The north pole of the first magnet 140 can be disposed across the fluid barrier 135 from the south pole of the second magnet 142, or the south pole of the first magnet 140 can be disposed across the fluid barrier 135 from the north pole of the second magnet 142. This orientation of the first and second magnets 140, 142 ensures that the attractive force between the magnets couples the rotational movement of the second magnet 142 with the rotational movement of the first magnet 140. The magnetic force is transferred through the fluid barrier 135. In use, the power source 195 rotates the drive shaft 190, which rotates the second magnet 142, which causes the first magnet 140 to rotate at the same speed as the second magnet 142. The rotation of the first magnet 140 rotates the attached impeller shaft 150, which in turn rotates the attached impeller 160. The impeller 160 can be in fluid contact with blood within the vessel, and thus the rotation of the impeller 160 can create suction to draw blood into the distal end 128 of the housing 120 and push blood out through the side opening 130, thereby increasing blood flow from the left ventricle to the ascending aorta when the device 110 is positioned as shown in FIG. 4. The fluid barrier 135 prevents blood from leaking into the second section 122 of the housing 120, and thus preventing blood contact with the drive shaft 190 and the power source 195.

[0043] In other examples, first magnet 140 and second magnet 142 may have more than two poles. Additionally, two or more dipole or multi-pole magnets may be disposed on either side of fluid barrier 135. Regardless of the number and / or type of magnets used, the one or more magnets are constructed and arranged such that rotation of the one or more magnets connected to drive shaft 190 and power source 195 rotates the one or more magnets connected to impeller 160.

[0044] FIG. 6 illustrates another embodiment of a device 210 for assisting blood flow. The device 210 is similar to that illustrated in FIG. 5, but with a different power source. In the device 110 illustrated in FIG. 5, the power source 195 is illustrated as an electric motor, whereas in the device 210, the power source is a high or low pressure fluid, similar to the exemplary mechanisms illustrated in FIGS. 2 and 3. The device 210 illustrated in FIG. 6 may include a catheter shaft 215 coupled to the proximal end 129 of the housing 120. The distal end of the drive shaft 290 may be connected to the second magnet 142, and the proximal end of the drive shaft 290 may be connected to the second impeller 265. The catheter shaft 215 may include an inner lumen 224 and an outer lumen 226. A high or low pressure fluid, such as saline or other suitable fluid, may be injected through the inner lumen 224 toward the second impeller 265, as indicated by arrow 225. The high or low pressure fluid rotates the second impeller 265, which rotates the drive shaft 290 and the attached second magnet 242. As in the device 110, the rotation of the second magnet 142 rotates the first magnet 140, which in turn rotates the impeller shaft 150 and the impeller 160. The impeller 160 is in contact with the blood in the blood vessel, and thus the rotation of the impeller 160 assists in blood flow through the blood vessel. After rotating the second impeller 265, the high or low pressure fluid then returns through the outer lumen 226, as indicated by the arrow 222. The fluid is prevented from entering the blood vessel by the fluid barrier 135. Similarly, the fluid barrier 135 prevents blood from entering the catheter shaft 215 and mixing with the high or low pressure fluid. High or low pressure fluid may be provided from a pressurized source outside the body, and return fluid may be collected and reused outside the body.

[0045] Alternatively, the direction of fluid flow may be reversed, similar to that shown in Figure 3. High or low pressure fluid may be injected through the outer lumen 226 toward the second impeller 265. The high or low pressure fluid rotates the second impeller 265, which rotates the drive shaft 290 and the attached second magnet 242, which rotates the first magnet 140, thereby rotating the impeller shaft 150 and the impeller 160. After rotating the second impeller 265, the high or low pressure fluid returns through the inner lumen 224.

[0046] 7A and 7B show two examples of housings. A single piece housing 120 is shown in FIG. 7A. The housing 120 can include a proximal end 129 configured to be coupled to a catheter shaft. In the embodiment shown in FIG. 7A, the proximal end 129 has an internal thread. Alternatively, the proximal end 129 can be connected to the catheter shaft with a snap fit, a welded joint, an adhesive joint, or the like. The housing 120 can have at least one side opening 130 that extends completely through the wall of the housing. If the housing 120 includes multiple side openings 130, the multiple side openings 130 can be spaced around the circumference of the housing 120, as shown in FIG. 7A. The distal end 128 of the housing 120 can include at least one opening or slot 127 configured to connect to a bearing housing 180, as shown in FIGS. 5 and 6.

[0047] A two-piece housing 220 is shown in Figure 7B. The only difference between the two housing embodiments is the number of parts. The two-piece housing 220 has a proximal portion 223 and a distal portion 221. Similar to the single-piece housing 120, the two-piece housing 220 has an internally threaded proximal end 229, a number of side openings 230, and one or more slots 227 at the distal end 228 of the housing 220.

[0048] FIG. 8 illustrates the distal end region of an exemplary catheter shaft 115 and the second magnet 142, as well as the structure providing their connection. The catheter shaft 115 may have threads 116 at its distal end for mating with the threaded proximal end 129, 229 of the housing 120, 220 shown in FIGS. 7A and 7B. Alternatively, the distal end of the catheter shaft 115 may connect to the proximal end of the housing with a snap fit or welded connection. The drive shaft 190 may be connected to a power source within the catheter shaft 115 and may have a non-circular shape configured to mate with the non-circular opening 143 through the second magnet 142. In some examples, the drive shaft 190 may have at least one flat surface 191 configured to engage with at least one flat surface within the opening 143 through the second magnet 142. In the exemplary device shown in FIG. 7, the drive shaft 190 has a cross-sectional racetrack shape with two opposing flat surfaces 191 that engage with two opposing flat surfaces 144 of the opening 143 through the second magnet 142. The engagement of the flat surfaces 191 of the drive shaft 190 with the flat surfaces 144 of the opening 143 through the second magnet 142 allows the second magnet 142 to rotate with the drive shaft 190 while allowing some relative axial movement of the second magnet 142 with respect to the drive shaft 190. The allowed axial movement of the second magnet allows the second magnet to be attracted towards the fluid barrier 135 while allowing the attractive force of the magnet to act on the fluid barrier 135 and reducing the axial force acting on the drive shaft 190 and the power source. 8 is of a shaft 190 with a flat surface 191, the shaft 190 and the opening 143 that opens into the second magnet 142 may have any cross-sectional shape that allows axial movement and rotational coupling between the drive shaft 190 and the second magnet 142. Examples of suitable shapes include a "D" shape, a racetrack shape, a polygon, a star, an oval, an ellipse, a crescent, a teardrop, etc.

[0049] The first magnet 140 and the second magnet 142 may be a single piece structure, as shown in FIG. 9A. Alternatively, as shown in FIG. 9B and FIG. 9C, the first magnet 240 and / or the second magnet 242 may have an insert 245 that defines an opening 243. The insert 245 may be made of a non-magnetic or magnetic material. The insert 245 may include a locking mechanism, such as a tab 246, as shown in FIG. 9B and FIG. 9C. For both the first and second magnets 140, 142, 240, 242, the cross-sectional shape of the opening 143, 243 taken perpendicular to the longitudinal axis of the drive shaft may be any non-circular shape that matches the cross-sectional shape of the shaft in which the magnet rests. A non-circular shape helps balance the shaft when rotating at very high RPM. In the example shown in FIG. 8-10, the cross-sectional shape of the opening 143, 243 is a rectangular racetrack shape with semicircles on each end. The racing field shape of the opening 143 , 243 , particularly the opposing flat faces 144 , 244 , mates with the flat sided impeller shaft 150 or drive shaft 190 .

[0050] The internal components of the device 110 shown in FIG. 5 are shown in an exploded perspective view in FIG. 10. The pivot member 136 acts as a spacer between the rotating second magnet 142 and the stationary fluid barrier 135, directing the magnetic attraction toward the fluid barrier 135 to prevent wear on the second magnet 142 and reduce axial loading on the drive shaft and power source. The pivot member 136 may have a proximal protrusion 137 shaped to be received within an opening 143 in the second magnet 142. The shape of the proximal protrusion 137 and the shape of the opening 143 in the second magnet 142 are non-circular to ensure rotation of the proximal protrusion 137 with rotation of the second magnet 142. In some examples, the proximal protrusion 137 may be racetrack shaped and configured to be received within the racetrack shaped opening 143 in the second magnet 142. The engagement of the proximal protrusion 137 within the opening 143 causes the pivot member 136 to rotate with the second magnet 142. The pivot member 136 can have a distal protrusion 138 extending from the bearing surface and shaped to be received in a proximal recess 133 of the fluid barrier 135. The distal protrusion 138 and the proximal recess 133 are shaped such that when the distal protrusion 138 seats in the proximal recess 133, the pivot member 136 rotates relative to the stationary fluid barrier 135. The distal protrusion 138 and the proximal recess 133 can be cone-shaped, as shown in FIG. 10. Alternatively, the distal protrusion 138 and the proximal recess 133 can be spherical. In another example, the pivot member 136 can have a recess in its distal surface shaped to mate with a proximal protrusion on the fluid barrier 135. The pivot member 136 may be made of a material that slides with minimal friction against the fluid barrier 135. For example, the pivot member 136 may be made of materials such as ceramic, zirconia, alumina, cobalt chromium alloys, titanium alloys such as Nitinol, hardened steel, metals coated with diamond-like carbon (DLC) or titanium nitride, ceramics, or polymers. In some examples, a lubricant may be added to the proximal or bearing surface of the pivot member 136.

[0051] The impeller shaft 150 may have a proximal protrusion 152 shaped to mate with a distal recess 131 of the fluid barrier 135. As with the distal protrusion 138 and proximal recess 133 of the pivot member, the proximal protrusion 152 and distal recess 131 are shaped such that when the proximal protrusion 152 seats in the distal recess 131, the impeller shaft 150 rotates relative to the stationary fluid barrier 135. The proximal protrusion 152 and distal recess 131 may be conical as shown in FIG. 10, or they may be spherical. The proximal protrusion 152 protrudes from a disk 153 that extends perpendicularly from the longitudinal axis of the impeller shaft 150. Alternatively, the impeller shaft 150 may have a recess in the proximal surface of the disk 153 shaped to mate with the distal protrusion of the fluid barrier 135.

[0052] The disk 153 acts as a spacer between the rotating first magnet 140 and the stationary fluid barrier 135 to prevent wear on the first magnet 140. The disk 153 positions the first magnet 140 at a desired distance from the second magnet 142. In some examples, this distance is between 0.01 mm and 3.00 mm. Like the pivot member 136, the proximal protrusion 152 and disk 153 of the impeller shaft 150 can be made of a material that slides against the fluid barrier 135 with minimal friction. The impeller shaft 150 can have a proximal region 155 shaped to be received within the opening 143 of the first magnet 140. The proximal region 155 passes through the first magnet 140 and into the impeller 160. Similar to the drive shaft 190 described above, the proximal region 155 of the impeller shaft 150 may have any non-circular cross-sectional shape that matches the non-circular cross-sectional shape of the opening 143 of the first magnet 140. In the example shown in FIG. 10, the proximal region 155 of the impeller shaft 150 has a cross-sectional racetrack shape with opposing flat surfaces 158 that mate with the flat surfaces 144 of the opening 143 of the first magnet 140, thereby mechanically fixing the first magnet 140 to the impeller shaft 150 for torque transmission. The flat surfaces 158 may balance the impeller shaft 150 for smooth, vibration-free rotation. The flat surfaces 158 of the impeller shaft 150 extend into the impeller 160, thereby locking the impeller 160 to the first magnet 140. The distal region 157 of the impeller shaft 150 may be cylindrical.

[0053] The impeller 160 may have a base 161, a body 162, and at least one blade 163. In the example shown in FIG. 10, the impeller 160 has two opposing blades 163. In other examples, there may be three, four, or more blades. It will be understood that the shape of the blade 163 is exemplary and other shapes of the blade 163 may be provided. The impeller 160 may be disposed within the housing 120 such that the blade 163 is adjacent the side opening 130. The blade 163 may be shaped such that rotation of the impeller 160 creates suction, drawing blood into the housing 120 through the distal end 128 of the housing 120 and pushing blood out through the side opening 130. Alternatively, the blade 163 may be shaped and configured such that rotation of the impeller 160 draws blood into the housing 120 through the side opening 130 and pushes blood out through the distal end 128 of the housing. In some examples, the shape of the blades 163 may be opposite to that shown in Figure 10. The impeller 160 may have a distal opening 168 through which the distal end 151 of the impeller shaft 150 extends. As shown in Figure 5, the distal end 151 of the impeller shaft 150 may be shaped to mate with a distal bearing assembly 170 secured to the distal end 128 of the housing 120.

[0054] 10, the impeller 160 is a separate structure from and coupled to the impeller shaft 150. In other examples, the impeller 160 may be fixedly attached to the impeller shaft 150 by bonding, welding, molding, etc. Alternatively, the impeller 160 and the impeller shaft 150 may be formed as a single monolithic structure. In a further example, the impeller may be formed from blades 163 that are directly coupled to the impeller shaft 150 by bonding, welding, molding, etc. Alternatively, the blades 163 and the impeller shaft 150 may be formed as a single monolithic structure.

[0055] The distal bearing assembly 170 may include a distal bearing 171, a spacer 175, and a bearing housing 180. The distal end 151 of the impeller shaft 150 may be received in a recess 172 in the distal bearing 171. In the example shown in FIG. 10, the distal end 151 of the impeller shaft 150 and the recess 172 are conical in shape. Alternatively, the distal end 151 of the impeller shaft 150 and the recess 172 may be spherical in shape. The distal bearing 171 may be made of a material that allows the impeller shaft 150 to rotate relative to the distal bearing 171 with minimal friction. The distal bearing 171 may be secured to a spacer 175 that may slide axially within the bearing housing 180. The bearing housing 180 may be secured to the housing 120. Bearing housing 180 may have at least one fin 182 extending radially outward and configured to mate with slot 127 of housing 120 shown in FIG. 7A. Distal bearing assembly 170 centers impeller shaft 150 in housing 120 with the longitudinal axis of impeller shaft 150 aligned with the longitudinal axis of housing 120. Distal bearing assembly 170 may allow limited axial movement of impeller shaft 150 within housing 120.

[0056] Figure 11 shows the device of Figure 10 assembled. As shown in Figure 11, the fins 182 of the bearing housing 180 are configured such that when the fins 182 are installed in the slots 127 of the housing 120, blood can flow between the fins 182 and into the distal end 128 of the housing 120. Blood flow is indicated by arrows 184. Blood flows into spaces 183 between adjacent fins 182 and through the interior of the housing 120. The rotating impeller blades 163 force blood out of the side openings 130, as indicated by arrows 185.

[0057] 12 is a proximal end view of an exemplary impeller shaft 150, showing the structure of the disk 153. The disk 153 can have two opposing angled grooves or lobes 154, 156 that create outward turbulence to remove any blood that would otherwise tend to pool between the first magnet 140 and the fluid barrier 135.

[0058] Details of the internal structure of the impeller 160 are shown in FIG. 13. The impeller 160 may have a central channel 169 that extends along the longitudinal axis of the impeller 160. A first region 164 of the channel 169 may extend through the base 161 and a second region 167 of the channel 169 may extend through the body 162. The first region 164 may be shaped to receive the proximal region 155 of the impeller shaft 150. In the example shown in FIG. 13, the first region 164 is racetrack shaped with opposing flat sides 166 that mate with the flat faces 158 of the impeller shaft 150. The second region 167 may be rounded to mate with the rounded distal region 157 of the impeller shaft 150. The central channel 169 terminates in a distal opening 168.

[0059] FIG. 14 illustrates an alternative distal bearing assembly 270 disposed within the distal end of the housing 120. The distal bearing assembly 270 may include a distal bearing 271, a spacer 275, and a bearing housing 280. The distal end 151 of the impeller shaft 150 may be received in a recess 272 in the distal bearing 271. In the example illustrated in FIG. 14, the distal end 151 of the impeller shaft 150 and the recess 272 are conical in shape, with the recess 272 being significantly larger than the distal end 151 of the impeller shaft 150. Alternatively, the distal end 151 of the impeller shaft 150 and the recess 272 may be spherical in shape. The distal bearing 271 may be made of a material that allows the impeller shaft 150 to rotate relative to the distal bearing 271 with minimal friction. The distal bearing 271 may be embedded within a spacer 275. The spacer 275 may slide axially within the bearing housing 280. The spacer 275 may have a proximal ridge 276. The spring member 278 may be disposed circumferentially around an outer surface of the spacer 275 between the proximal ridge 276 and the bearing housing 280. The spring member 278 provides a light but constant pressure on the impeller shaft 150 to keep the impeller shaft 150 centered within the housing 120 and allow the impeller shaft 150 to rotate smoothly. In some examples, the spring member 278 may be metal. In other examples, the spring member 278 may be made of a resilient material. The bearing housing 280 may be fixed to the housing 120. The bearing housing 280 may have at least one fin 282 configured to mate with the slot 127 of the housing 120.

[0060] Materials that can be used for the various components of the device 110, 210 for assisting blood flow (and / or other systems or components disclosed herein) and the various elements thereof disclosed herein may include those generally associated with medical devices. For simplicity, the following description refers to the device 110, 210 (and variations, systems, or components disclosed herein). However, this is not intended to limit the devices and methods described herein, as the description may apply to other elements, members, components, or devices disclosed herein.

[0061] In some embodiments, the devices 110, 210 (and variations, systems or components thereof disclosed herein) may be made from metals, metal alloys, ceramics, zirconia, polymers (some examples of which are disclosed below), metal-polymer composites, combinations thereof, and the like, or other suitable materials. Some examples of suitable metals and metal alloys include stainless steels, such as 444V, 444L, 314LV stainless steel; mild steel; nickel-titanium alloys, such as linear elastic Nitinol and / or superelastic Nitinol; cobalt-chromium alloys, titanium and its alloys, alumina, metals with diamond-like coatings (DLC) or titanium nitride coatings, other nickel alloys, such as nickel-chromium-molybdenum alloys (e.g., UNS:N06625, such as INCONEL® 625, HASTELLOY® C-22®, etc.). nickel-copper alloys (e.g., UNS: N04400 such as MONEL® 400, NICKELVAC® 400, NICORROS® 400, etc.); nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R44035 such as MP35-N®); nickel-molybdenum alloys (e.g., HASTELLOY® ALLOY®, UNS: N10276, etc.); B2®), other nickel-chromium alloys, other nickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-iron alloys, other nickel-copper alloys, other nickel-tungsten or tungsten alloys, and the like; cobalt-chromium alloys; cobalt-chromium-molybdenum alloys (e.g., UNS: R44003, such as ELGILOY®, PHYNOX®, etc.); platinum strengthened stainless steels; titanium; platinum; palladium; gold; combinations thereof; others; or other suitable materials.

[0062] As noted herein, within the family of commercially available nickel titanium or nitinol alloys, there are categories designated as "linear elastic" or "non-superelastic" that may be chemically similar to conventional shape memory or superelastic varieties, but may exhibit distinctly different and useful mechanical properties. Linear elastic and / or non-superelastic nitinol may be distinguished from superelastic nitinol in that the linear elastic and / or non-superelastic nitinol does not exhibit the substantial "superelastic plateau" or "flag region" seen in superelastic nitinol in its stress / strain curve. Instead, in linear elastic and / or non-superelastic nitinol, as recoverable strain increases, stress continues to increase in a generally linear manner, i.e., somewhat linear, but not necessarily linear relationship all the way to the onset of plastic deformation, or at least in a more linear relationship than the superelastic plateau and / or flag region seen in superelastic nitinol. Thus, for purposes of the present invention, linear elastic and / or non-superelastic nitinol may also be referred to as "approximately" linear elastic and / or non-superelastic nitinol.

[0063] In some cases, linear elastic and / or non-superelastic Nitinol may also be distinguished from superelastic Nitinol in that the linear elastic and / or non-superelastic Nitinol may accommodate a maximum of about 2%-5% strain while remaining generally elastic (e.g., before plastic deformation begins), while superelastic Nitinol may accommodate a maximum of about 8% strain before plastically deforming. Both of these materials are distinguishable from other linear elastic materials (which may also be distinguished based on their composition), such as stainless steel, which may accommodate only about 0.2%-0.44% strain before plastically deforming.

[0064] In some embodiments, linear elastic and / or non-superelastic nickel-titanium alloys are alloys that do not exhibit martensite / austenite phase changes detectable by differential scanning calorimetry (DSC) and dynamic metal thermal analysis (DMTA) analyses over a wide temperature range. For example, in some embodiments, linear elastic and / or non-superelastic nickel-titanium alloys may not have martensite / austenite phase changes detectable by DSC and DMTA analyses in the range of about -60 degrees Celsius (°C) to about 120°C. Thus, the mechanical bending properties of such materials may be generally inert to temperature effects over this very wide temperature range. In some embodiments, the mechanical bending properties of linear elastic and / or non-superelastic nickel-titanium alloys at ambient or room temperature are generally the same as the mechanical properties at body temperature, e.g., in that they do not exhibit a superelastic plateau and / or flag region. For example, over a wide temperature range, linear elastic and / or non-superelastic nickel-titanium alloys maintain their linear elastic and / or non-superelastic properties and / or characteristics.

[0065] In some embodiments, the linear elastic and / or non-superelastic nickel-titanium alloy may range from about 50 to about 60 weight percent nickel, with the remainder generally being titanium. In some embodiments, the composition ranges from about 54 to about 57 weight percent nickel. One example of a suitable nickel-titanium alloy is FHP-NT alloy, available from Furukawa Techno Materials, Inc., Kanagawa, Japan. Other suitable materials may include ULTANIUM™ (available from Neo-Metrics) and GUM METAL™ (available from Toyota). In some other embodiments, a superelastic alloy, such as superelastic Nitinol, may be used to achieve the desired properties.

[0066] In at least some embodiments, some or all of the devices 110, 210 (and variations, systems or components thereof disclosed herein) may also be doped, manufactured or otherwise comprise radiopaque materials. A radiopaque material is understood to be a material capable of producing a relatively bright image on a fluoroscopy screen or other imaging technique during a medical procedure. This relatively bright image aids the user in determining the location of the device 110, 210 (and variations, systems or components thereof disclosed herein). Some examples of radiopaque materials may include, but are not limited to, gold, platinum, palladium, tantalum, tungsten alloys, polymeric materials filled with radiopaque fillers, and the like. Additionally, other radiopaque marker bands and / or coils may also be incorporated into the design of the device 110, 210 (and variations, systems or components thereof disclosed herein) to achieve the same results.

[0067] In some embodiments, the devices 110, 210 (and variations, systems or components thereof disclosed herein) and / or portions thereof may be made of or include a polymer or other suitable material. Some examples of suitable polymers include polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), polyoxymethylene (POM, e.g., DELRIN® available from DuPont), polyether block esters, polyurethanes (e.g., Polyurethane 85A), polypropylene (PP), polyvinyl chloride (PVC), polyether-esters (e.g., ARNITEL® available from DSM Engineering Plastics), ether or ester based copolymers (e.g., butylene / poly(alkylene ether) phthalates and / or other polyester elastomers, such as HYTREL® available from DuPont), polyamides (e.g., DURETHAN® available from Bayer, or CRISTAMID® available from Elf Atochem), elastomeric polyamides, block polyamide / ethers, polyether block amides (PEBA, e.g., PEBA ... Examples of suitable polymers include those available under the trade name PEBAX®, ethylene vinyl acetate copolymer (EVA), silicone, polyethylene (PE), Marlex high density polyethylene, Marlex low density polyethylene, linear low density polyethylene (e.g., REXELL®), polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polytrimethylene terephthalate, polyethylene naphthalate (PEN), polyether ether ketone (PEEK), polyimide (PI), polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene oxide (PPO), polyparaphenylene terephthalamide (e.g., KEVLAR®), polysulfone, nylon, nylon-12 (such as GRILAMID® available from EMS American Grillon), perfluoro(propyl vinyl ether) (PFA), ethylene vinyl alcohol, polyolefin, polystyrene, epoxy, polyvinylidene chloride (PVdC),The sheath may include poly(styrene-b-isobutylene-b-styrene) (e.g., SIBS and / or SIBS50A), polycarbonate, ionomer, polyurethane silicone copolymer (e.g., ElastEon® from Aortech Biomaterials or ChronoSil® from AdvanSource Biomaterials), biocompatible polymers, other suitable materials, or mixtures, combinations, copolymers, polymer / metal composites, and the like. In some embodiments, the sheath may be blended with a liquid crystal polymer (LCP). For example, the mixture may include up to about 6 percent LCP.

[0068] In some embodiments, the devices 110, 210 (and variations, systems or components thereof disclosed herein) may include and / or be treated with a suitable therapeutic agent. Some examples of suitable therapeutic agents include antithrombotic agents (such as heparin, heparin derivatives, urokinase, and PPack (dextrophenylalanine proline arginine chloromethyl ketone)); antiproliferative agents (such as enoxaparin, angiopeptin, monoclonal antibodies capable of inhibiting smooth muscle cell proliferation, hirudin, acetylsalicylic acid, etc.); anti-inflammatory agents (such as dexamethasone, prednisolone, corticosterone, budesonide, estrogen, sulfasalazine, mesalamine, etc.); antitumor / antiproliferative / antimitotic agents (such as paclitaxel, 5-fluorouracil, cisplatin, vinblastine, vincristine, epothilones, endostatin, angiostatin, and thymidine kinase inhibitors); anesthetic agents (such as lidocaine, bupivacaine, ropivacaine, etc.). insulin, etc.); anticoagulants (D-Phe-Pro-Arg chloromethyl ketone, RGD peptide-containing compounds, heparin, antithrombin compounds, platelet receptor antagonists, antithrombin antibodies, antiplatelet receptor antibodies, aspirin, prostaglandin inhibitors, platelet inhibitors, and mite antiplatelet peptides); vascular cell growth promoters (growth factor inhibitors, growth factor receptor antagonists, transcription activators, translation promoters, etc.); vascular cell growth inhibitors (growth factor inhibitors, growth factor receptor antagonists, transcription repressors, translation repressors, replication inhibitors, inhibitory antibodies, antibodies against growth factors, bifunctional molecules consisting of a growth factor and a cytotoxin, bifunctional molecules consisting of an antibody and a cytotoxin); cholesterol-lowering drugs; vasodilators; and agents that interfere with endogenous vasoactive mechanisms.

[0069] It will be understood that this disclosure is, in many respects, merely illustrative. Changes may be made in details, particularly in matters of shape, size, and arrangement of steps, without exceeding the scope of the invention. This may include, to the extent appropriate, the use of any of the features of one illustrative embodiment used in other embodiments. The scope of the invention is, of course, defined in the language in which the appended claims are expressed.

Claims

1. 1. A medical device, comprising: a housing having a longitudinal axis, the housing including at least one inlet for receiving blood flow and at least one outlet for delivering blood flow; a fluid barrier disposed within the housing and separating the housing into a first section including at least one inlet and at least one outlet, and a second section; an impeller disposed within the first section of the housing, the impeller having a longitudinal axis that is the same as a longitudinal axis of the housing, the impeller having a body and at least one blade extending radially outward from the body; at least one first magnet coupled to an impeller shaft coupled to the impeller, the first magnet being disposed within the first section of the housing and coupled to the impeller shaft such that rotation of the first magnet rotates the impeller; and a drive shaft disposed within the second section of the housing; at least one second magnet disposed on the drive shaft within the second section of the housing, the second magnet configured and arranged with the first magnet such that rotation of the second magnet rotates the first magnet and the second magnet is rotatably coupled to the drive shaft while allowing axial movement of the second magnet along the drive shaft to allow the second magnet to be attracted towards the fluid barrier, thereby allowing an attractive magnetic force to act on the fluid barrier and reduce axial load on the drive shaft; and a pivot member longitudinally disposed between the second magnet and the fluid barrier, the pivot member having a non-circular proximal protrusion configured to engage a non-circular opening in the second magnet such that rotation of the second magnet rotates the pivot member, and further having a circular distal protrusion configured to engage a circular opening in the fluid barrier such that the pivot member is rotatable against the fluid barrier; A medical device comprising:

2. The medical device of claim 1 , further comprising a power source coupled to the drive shaft, the power source being adapted to permit axial movement of the second magnet thereby reducing load on the power source.

3. The medical device of claim 2 , wherein the power source is disposed within a catheter shaft attached to the second section of the housing.

4. The medical device of claim 3 , wherein the power source is a motor.

5. 4. The medical device of claim 3, wherein the power source is a second impeller connected to the drive shaft, the catheter shaft defining a fluid flow path, and the drive shaft and the second impeller are disposed within the fluid flow path such that fluid impinging against the second impeller drives the second impeller, which rotates the second magnet, which in turn rotates the first magnet, thereby rotating the impeller shaft and the impeller.

6. 2. The medical device of claim 1, wherein the at least one outlet includes a plurality of side openings spaced circumferentially about the housing, and the impeller is positioned within the housing such that at least one blade is positioned adjacent to the plurality of side openings.

7. 2. The medical device of claim 1, wherein a proximal end of the impeller shaft extends proximal to the first magnet, the proximal end having a first protrusion configured to be received by a first recess of the fluid barrier.

8. The medical device of claim 7 , wherein the impeller shaft includes a disk adjacent the first protrusion, the disk extending perpendicularly from a longitudinal axis of the impeller shaft.

9. The medical device of claim 8 , wherein the disk has two opposing lobes.

10. 10. The medical device of claim 1, further comprising a bearing assembly configured to support and center a distal end of an impeller shaft, the bearing assembly including a bearing housing secured to the housing, a spacer slidably disposed within the bearing housing, and a distal bearing secured within the spacer.

11. The medical device of claim 10 , wherein the bearing assembly further includes a spring member disposed about the spacer.

12. 1. A medical device for implantation within a patient's body, comprising: a housing having a longitudinal axis and dimensioned for placement within the heart, the housing including an inlet for receiving blood flow and a plurality of side openings for delivering blood flow; a fluid barrier disposed within the housing and separating the housing into a first section including the inlet and the plurality of side openings and a second section, the first section being impermeable to the fluid; an impeller disposed within the first section of the housing, the impeller having a longitudinal axis that is the same as a longitudinal axis of the housing, the impeller having a body and at least one blade extending radially outward from the body; at least one first magnet disposed within a first section of the housing and coupled to the impeller such that rotation of the first magnet causes rotation of the impeller; a drive shaft disposed within the second section of the housing, the drive shaft having a stop surface and at least one flat surface extending from the stop surface; at least one second magnet coupled to the drive shaft and disposed within the second section of the housing, the second magnet configured and arranged with the first magnet such that rotation of the second magnet rotates the first magnet and allows axial movement of the second magnet along the drive shaft between a stop surface of the drive shaft and a spacer disposed between the second magnet and the fluid barrier to allow the second magnet to be attracted towards the fluid barrier, thereby allowing an attractive magnetic force between the magnets to act on the fluid barrier and reduce axial load on the drive shaft and drive source; and Equipped with the first magnet has a first opening configured to receive an impeller shaft through the first magnet and couple to the first magnet, the second magnet has a second opening configured to receive the drive shaft through the second magnet and couple to the second magnet, the first opening and the second opening each having a first cross-sectional shape perpendicular to a longitudinal axis of the drive shaft; the drive shaft has a second cross-sectional shape intersecting the at least one planar surface and perpendicular to a longitudinal axis of the drive shaft, and at least a portion of the impeller shaft has a second cross-sectional shape perpendicular to the longitudinal axis of the impeller shaft, the first cross-sectional shape and the second cross-sectional shape being non-circular such that rotation of the impeller shaft and the drive shaft rotates the first magnet and the second magnet, respectively. Medical equipment.

13. 13. The medical device of claim 12, further comprising a catheter shaft, the drive source being a second impeller connected to the drive shaft, the catheter shaft defining a fluid flow path, and the drive shaft and the second impeller disposed within the fluid flow path such that fluid impinging against the second impeller drives the second impeller, which rotates the second magnet, which rotates the first magnet, thereby rotating the impeller.

14. 13. The medical device of claim 12, further comprising an impeller shaft disposed on and coupled to the impeller and first magnet, and a bearing assembly configured to support and center a distal end of the impeller shaft, the bearing assembly including a bearing housing secured to the housing, a spacer slidably disposed within the bearing housing, and a distal bearing secured within the spacer.

15. 2. The medical device of claim 1, wherein the drive shaft is configured to rotate within the second section of the housing, thereby rotating the second magnet which rotates the first magnet, such that when the medical device is positioned within the ascending aorta, the impeller shaft and impeller are configured to rotate such that the medical device creates suction that enables the medical device to draw blood from the left ventricle into the housing through at least one inlet in the housing and deliver the blood into the ascending aorta through at least one outlet.

16. 1. A medical device for implantation within a patient's heart, comprising: a housing having a longitudinal axis and sized for placement within the heart, the housing including at least one inlet for receiving blood flow and at least one outlet for delivering blood flow; a fluid barrier disposed within the housing, the fluid barrier separating the housing into a first section including at least one inlet and at least one outlet and a second section, the fluid barrier being impermeable to fluids and having a first side and a second side opposite the first side; an impeller disposed within the first section of the housing, the impeller having a longitudinal axis that is the same as a longitudinal axis of the housing; a drive shaft disposed within the second section of the housing; and a first magnet coupled to an impeller shaft coupled to the impeller, the first magnet being disposed in the first section of the housing and coupled to the impeller shaft such that rotation of the first magnet rotates the impeller; and a second magnet disposed on the drive shaft within the second section of the housing, the second magnet constructed and arranged with the first magnet such that rotation of the second magnet rotates the first magnet; and a disk coupled to the impeller shaft, the disk having a projection extending therefrom; a pivot member disposed between the fluid barrier and the second magnet, the pivot member having at least one protrusion extending therefrom; and Equipped with wherein the at least one protrusion of the pivot member is configured to engage the second side of the fluid barrier and the at least one protrusion of the disk is configured to engage the first side of the fluid barrier such that the fluid barrier functions as a thrust bearing about which the pivot member and the disk, and thus the impeller shaft, rotate. Medical equipment.

17. 17. The medical device of claim 16, further comprising a distal bearing assembly disposed at a distal end of the housing, the distal bearing assembly including a distal bearing configured to receive a portion of the impeller shaft, a spacer secured to the distal bearing, and a bearing housing secured to the housing of the medical device, the spacer configured to be axially slidable within the bearing housing.

18. 18. The medical device of claim 17, wherein the distal bearing assembly has a recess that receives a distal end of the impeller shaft, the distal end of the impeller shaft and the recess in the distal bearing being conical in shape.

19. 20. The medical device of claim 18, wherein the bearing housing has at least one fin extending radially outward, the housing having at least one slot, and the at least one fin of the bearing housing is received within the at least one slot of the housing.

20. 20. The medical device of claim 18, wherein the distal bearing assembly further comprises a spring member circumferentially disposed about an outer surface of the spacer and configured to maintain the impeller shaft centered within the housing.

21. The medical device of claim 1 , wherein the fluid barrier functions as a thrust bearing allowing the pivot member to rotate.

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