Support structure for intravascular blood pump

Abstract

To provide a localization and positioning structure and method for an intravascular blood pump.SOLUTION: An improved system for supporting (e.g., localization and / or positioning of) intravascular devices provides, for example, a multi-element arrangement. A set of struts optionally projects from the intravascular device and contacts the vessel walls. The localization and positioning of a pump may be provided by the struts and / or by use of a tether opposing a propulsive force to ensure localization.SELECTED DRAWING: Figure 3A

Description

Technical Field

[0001] This field relates to positioning and alignment structures and methods for intravascular blood pumps.

Background Art

[0002] (Cross - reference to related applications) This application claims priority to U.S. Provisional Patent Application No. 62 / 947,940, filed Dec. 13, 2019, the entire content of which is incorporated herein by reference in its entirety for all purposes. This application also claims priority to International Application No. PCT / US2020 / 062928, filed Dec. 2, 2020, which claims priority to U.S. Provisional Patent Application No. 62 / 943,062, filed Dec. 3, 2019, the entire content of each of which is incorporated herein by reference in its entirety for all purposes. Any application in which foreign or domestic priority claims are identified in the application data sheet filed with this application is incorporated herein by reference under 37 C.F.R. 1.57.

[0003] In the field of heart assist devices and mechanical circulatory support, blood pumps are used to assist the heart in circulating blood through the body. Some of these blood pumps are intravascular blood pumps, designed or adapted for use within blood vessels.

[0004] Some intravascular blood pumps have been described as including hooks for securing the intravascular pump to the inner wall of the blood vessel. The hooks prevent translation of the device along the axis of the blood vessel and rotation of the device about the axis of the blood vessel through direct local contact.

Summary of the Invention

[0005] A support or positioning structure for a pump, or any combination thereof, that can limit or prevent translation, limit or prevent rotation, and help maintain the position of some parts of the pump relative to some anatomical structures is required. The positioning structure can be designed for acute, semi-acute, semi-chronic, or chronic use.

[0006] Blood is a harsh environment for the device, and thrombi, foreign bodies, or pathogens within blood vessels can have fatal consequences. There is a need for a new positioning structure that is biocompatible, non-thrombogenic, and non-hemolytic well beyond the expected service life. Furthermore, the function and removal of the new positioning means should preferably coincide with any endothelialization that may occur during the expected service life.

[0007] A new positioning structure for an intravascular device preferably provides biocompatibility of materials and surfaces, design for hemodynamic compatibility (reduction or minimization of flow-mediated thrombosis and hemolysis and disruption of natural flow), reduction or minimization of trauma to the interior of blood vessels or other anatomical structures, sufficient positioning and freedom of movement, and removability when the treatment provided by the positioning device is complete.

[0008] Positioning and positioning systems and methods for medical devices such as intravascular blood pumps or other intravascular devices are disclosed herein. Various embodiments comprise one or more of the following elements: struts extending from the device to be positioned, the struts providing constant or intermittent contact with the vessel wall; tethers (e.g., power leads) that limit translation and assist in positioning; and propulsion for maintaining positioning.

[0009] In some embodiments, the positioning and alignment system can be part of or include a support structure having struts that are projections extending distally and radially outwardly from the device for contacting the vessel wall or other anatomical features. The various illustrated embodiments show struts extending distally from the pump housing and impeller. However, it should be understood that instead, any of the struts may instead extend proximally to the pump head (e.g., proximally to the motor housing). In such embodiments, one or more struts can extend proximally from the drive unit or shroud. In still other embodiments, one or more, e.g., a first plurality of struts, can extend distally from the pump housing and impeller, and one or more, e.g., a second plurality of struts, can extend proximally to the pump head (e.g., proximally to the motor housing). The struts can be shaped, formed, and processed such that the radial force and / or the force moving from the expanded configuration to the folded configuration is reduced (e.g., minimized) for a given outward radial force in the expanded configuration.

[0010] The struts may be made of a biocompatible metal such as nitinol, a shape memory alloy, or an alloy, or may be formed by other methods and may be designed to have a particular shape and / or geometric form. Through constant or intermittent contact with the inner wall of a blood vessel or some other anatomical feature, the struts can provide localization or positioning or both. The device to be positioned can have multiple sets of struts, which can project from the device at one or more angles or at any angle. In some embodiments, the struts may have features such as hooks. In other embodiments, the struts may have pads that engage the surface of the blood vessel wall. For use with an intravascular device, the struts can have a folded configuration for fitting within a sheath and an expanded configuration for providing localization and / or positioning. In some embodiments, the struts may have knees (or twists or bends) to prevent hooks or other features from contacting the inner wall of the sheath in the folded configuration. The struts may be shaped, formed, and processed such that the radial force in the folded configuration and / or the force required to move from the expanded configuration to the folded configuration is reduced or minimized for a given outward radial force in the expanded configuration.

[0011] In some embodiments, the localization, stabilization, and positioning system (or support structure) can include one or more tethers that connect the device to be localized and / or positioned to one or more anchors or contact points. The tethers may be flexible and may preferentially limit translation or rotation in one direction. In some embodiments, the tethers may have additional functionality. As one non-limiting example, the tethers may also include power leads that transmit power to the device to be localized or positioned.

[0012] In some embodiments, the localization, stabilization, and positioning system can comprise a propulsion means (e.g., a pump in various embodiments). When the device to be localized and / or positioned is an intravascular blood pump, in some embodiments, pumping blood is an important function of the device. The propulsion force or reaction force generated by blood pumping can be used as part of the localization and positioning system.

[0013] In some embodiments, the localization and / or positioning system can comprise a combination of the above elements that together provide unique benefits or advantages.

[0014] The description herein provides a fairly broad overview of various features of the present disclosure so that the following detailed description can be better understood. Further features and advantages of the present disclosure are described below.

[0015] In one embodiment, a blood flow assistance system is disclosed. The blood flow assistance system can include, or consist essentially of, an impeller disposed within a pump housing of a pump, the pump having a longitudinal axis, the impeller generating a thrust force when operating intravascularly to pump blood, and a tether extending away from the pump housing, the tether being configured to oppose loads applied in opposite directions at both of its ends. In some embodiments, the longitudinal component of the thrust force generated by the impeller directed along the longitudinal axis of the pump is opposed by the tether, and the tether is configured to maintain the position of the pump within the blood vessel without requiring contact between the pump and the vessel wall of the blood vessel.

[0016] In some embodiments, the system includes a support structure coupled to or formed with the pump housing, the support structure configured to at least intermittently contact the blood vessel wall to maintain a spacing of the pump housing from the blood vessel wall in which the pump housing is disposed. In some embodiments, the support structure comprises a plurality of elongate struts having a first end coupled to the pump housing and a second end opposite the first end, each elongate strut of the plurality of struts having an elongate body extending between the first end and the second end. In some embodiments, the system includes convex contact pads disposed at distal portions of each of the plurality of struts, the convex contact pads configured to at least intermittently contact the blood vessel wall to maintain a spacing of the pump housing from the blood vessel wall in which the pump housing is disposed. In some embodiments, the plurality of struts includes a first plurality of struts and a second plurality of struts, and when the plurality of struts are in an expanded configuration, the first contact pads of the first plurality of struts are configured to engage the blood vessel wall at a first longitudinal position and the second contact pads of the second plurality of struts are configured to engage the blood vessel wall at a second longitudinal position spaced from the first longitudinal position. In some embodiments, the contact pads are disposed distally and radially outward of the pump housing and are configured to reversibly deflect to hold the pump housing within the blood vessel to hold the pump housing away from the blood vessel wall. In some embodiments, the contact pads comprise a convex peripheral portion surrounding a convex blood vessel engagement surface. In some embodiments, the contact pads comprise a convex profile within a cross-sectional plane disposed transverse to the longitudinal axis of the pump. In some embodiments, the tether comprises a conductor configured to transmit an electrical current from a source connectable to the proximal end of the tether to a motor operably coupled to the impeller. In some embodiments, the system further includes a motor housing coupled to a proximal portion of the pump housing, the motor disposed within the motor housing. In some embodiments, the tether comprises a rotatable drive shaft connected to a motor disposed outside the patient's body.In some embodiments, the kit comprises a blood flow assistance system and a sheath sized and shaped to receive a pump housing, a tether, and a support structure.

[0017] In another embodiment, a blood flow assistance system is disclosed. The blood flow assistance system can include or consist essentially of an impeller disposed within a pump housing of a pump, the pump including a longitudinal axis, the impeller generating a thrust force when operating within a blood vessel to pump blood, a tether extending away from the pump housing and configured to oppose loads applied in opposite directions at both of its ends, and a support structure.

[0018] In some embodiments, the support structure comprises convex contact pads configured to at least intermittently contact the blood vessel wall to maintain a spacing of the pump housing from the blood vessel wall in which the pump housing is disposed. In some embodiments, the system can include a motor operably coupled to the impeller. In some embodiments, the tether comprises a hollow elongate member surrounding a conductor disposed therein, the conductor configured to transmit an electric current from a source connectable to a proximal end of the tether to the motor, the tether configured to oppose loads applied in opposite directions at its opposing ends. In some embodiments, the system includes a plurality of elongate struts having a first end coupled to a second end of the pump and a second end opposite the first end, each elongate strut of the plurality of elongate struts comprising an elongate body extending between the first end and the second end, each strut of the plurality of elongate struts configured to accumulate strain energy when a lateral load is applied. In some embodiments, the blood flow assistance system includes contact pads disposed at the second ends of each elongate strut of the plurality of elongate struts, each contact pad having an enlarged width compared to the width of the spread immediately adjacent the corresponding elongate strut of the plurality of elongate struts. In some embodiments, in use, the longitudinal component of the thrust force generated by the impeller directed along the longitudinal axis of the pump is opposed by a tension member of the tether.

[0019] In some embodiments, the contact pad comprises a generally circular pad having a diameter larger than the width of the spread adjacent to the corresponding elongate strut. In some embodiments, the elongate strut comprises at least one bend along its elongate body to facilitate folding of the strut into the lumen of the sheath. In some embodiments, each of the contact pads comprises a smooth surface without sharp edges or hooks. In some embodiments, each of the contact pads comprises a convex cross-sectional profile on the side facing the blood vessel. In some embodiments, each of the contact pads comprises a spherical portion. In some embodiments, the elongate strut is configured to apply a load to the aortic wall when deployed to locally radially expand the vessel wall tissue where the contact pad is disposed. In some embodiments, the contact pad comprises a hole configured to allow the vessel wall tissue to be received therein. In some embodiments, each of the contact pads comprises one or more scalloped edges configured to allow the vessel wall tissue to be received therein. In some embodiments, each of the contact pads comprises a domed portion. In some embodiments, the hollow elongate member is configured to receive a reinforcing member to facilitate introduction of the pump housing. In some embodiments, the pump further comprises a motor housing coupled to the proximal portion of the pump housing, and the motor is disposed within the motor housing. In some embodiments, the lateral component of the thrust force directed in a direction transverse to the longitudinal axis of the pump is opposed by the strain energy accumulated in at least one of the plurality of elongate struts when one or more of the plurality of struts flex. In some embodiments, the kit comprises a blood flow assistance system and a sheath sized and shaped to receive a pump housing, a motor, a tether, and a plurality of elongate struts.

[0020] In some embodiments, the support structure comprises a plurality of elongated struts having a first end coupled to a second end of the pump and a second end opposite the first end, each of the plurality of struts having an elongated body extending between the first end and the second end, and the convex contact pads are disposed at the distal portion of each of the plurality of struts. In some embodiments, the plurality of struts includes a first plurality of struts and a second plurality of struts, and when the plurality of struts are in an expanded configuration, the first contact pads of the first plurality of struts are configured to engage the vessel wall at a first longitudinal position and the second contact pads of the second plurality of struts are configured to engage the vessel wall at a second longitudinal position spaced from the first longitudinal position. In some embodiments, in the collapsed configuration of the struts, at least a portion of the struts has a major transverse dimension that is less than or equal to the major transverse dimension of the pump housing. In some embodiments, the contact pads are disposed distally and radially outward of the pump housing and are configured to reversibly deflect to hold the pump housing within the vessel away from the vessel wall. In some embodiments, the contact pads comprise a convex peripheral portion surrounding a convex vessel engagement surface. In some embodiments, the contact pads comprise a convex profile within a cross-sectional plane disposed transverse to the longitudinal axis of the pump. In some embodiments, the tether comprises a conductor configured to transmit current from a source connectable to the proximal end of the tether to a motor operably coupled to the impeller. In some embodiments, the pump further comprises a motor housing coupled to the proximal portion of the pump housing, and the motor is disposed within the motor housing. In some embodiments, the tether comprises a rotatable drive shaft connected to a motor disposed outside the patient's body.

[0021] In another embodiment, a blood flow assistance system is disclosed. The blood flow assistance system includes an impeller disposed within a pump housing of a pump and a support structure comprising a plurality of struts coupled to the pump housing or formed with the pump housing, the plurality of struts having an extended configuration extending outwardly relative to the pump housing and a folded configuration in which the pump is disposed within a sheath, and in the folded configuration, at least a portion of the struts has a major transverse dimension that is less than or equal to a major transverse dimension of the pump housing. In some embodiments, the major transverse dimension of at least a portion of the struts is less than the major transverse dimension of the pump housing. In some embodiments, the blood flow assistance system includes a motor housing and a motor disposed within the motor housing, and the major transverse dimension of at least a portion of the struts is less than the major transverse dimension of the motor housing. In some embodiments, the blood flow assistance system includes a convex contact pad at a distal portion of the strut, the convex contact pad configured to contact a blood vessel wall to maintain a spacing of the pump housing from the blood vessel wall on which the pump housing is disposed.

[0022] In another embodiment, a blood flow assistance system is disclosed. The blood flow assistance system includes an impeller disposed within a pump housing of a pump, and a support structure comprising a plurality of struts coupled to the pump housing or formed with the pump housing, the plurality of struts having an extended configuration in which the plurality of struts extend outwardly relative to the pump housing, and a folded configuration in which the pump is disposed within a sheath, the plurality of struts including a first plurality of struts and a second plurality of struts, wherein when the plurality of struts are in the extended configuration, a first contact pad of the first plurality of struts is configured to engage a blood vessel wall at a first longitudinal position, and a second contact pad of the second plurality of struts is configured to engage the blood vessel wall at a second longitudinal position spaced from the first longitudinal position. In some embodiments, the blood flow assistance system includes convex contact pads at distal portions of the plurality of struts, the convex contact pads being configured to contact the blood vessel wall at least intermittently to maintain a spacing of the pump housing from the blood vessel wall in which the pump housing is disposed. In some embodiments, a major lateral dimension of at least a portion of the struts is smaller than a major lateral dimension of the pump housing. In some embodiments, the blood flow assistance system includes a tether extending away from the pump housing, the tether being configured to oppose loads applied in opposite directions at both ends thereof.

[0023] In another embodiment, a blood flow assistance system is disclosed. The blood flow assistance system includes an impeller disposed within a pump housing of a pump, the pump including a longitudinal axis, the impeller configured to generate a thrust force when operating within a blood vessel to pump blood, a tether coupled to a first end of the pump, and a support structure including a contact pad that is elastically deflectable toward and away from the longitudinal axis of the pump, the free state of the contact pad being spaced from the longitudinal axis of the pump by a distance greater than a half-width of a blood vessel in which the pump housing is deployed, the contact pad applying a force to the wall of the blood vessel sufficient to push a portion of the contact pad into the wall such that a circumferential portion of the blood vessel wall is radially inward of a contact surface of the contact pad, or can consist essentially of or consist of these. In some embodiments, the contact pad is configured to engage without snagging the wall of the blood vessel when applied. In some embodiments, the contact pad includes an elongate member and an enlarged blood vessel wall contact surface disposed at an end of the elongate member. In some embodiments, the tether includes a conductor configured to transmit an electrical current from a source connectable to a proximal end of the tether to a motor operably coupled to the impeller.

[0024] In another embodiment, a blood flow assistance system is disclosed. The blood flow assistance system includes an impeller disposed within a pump housing, and a strut having a first end disposed in or coupled to the pump housing, a second end opposite the first end, and a bending zone disposed between the first end and the second end, wherein the second end is elastically deflectable toward and away from the longitudinal axis of the pump, the free state of the strut spaces the second end away from the longitudinal axis of the pump, and the second end of the strut is configured to engage a wall of a blood vessel, and the pump including or consisting essentially of the strut. The system can include or consist essentially of a sheath disposed over the pump and having an inner wall configured to deflect the strut between its first and second ends, and the bending zone is configured such that when the strut is deflected by the inner wall of the sheath, the second end of the strut spaces away from the inner wall of the sheath. In some embodiments, the second end of the strut includes a hook. In some embodiments, the bending zone includes an S-shaped connection between a first span of the strut and a second span of the strut, and the first and second spans are disposed along parallel tracks. In some embodiments, the blood flow assistance system includes a tether coupled to a first end of the pump, and the tether includes an electrical conveyance including a conductor configured to carry current between a source connectable to a proximal end of the electrical conveyance.

[0025] In another embodiment, it is a method of operating a blood flow assistance system. The method includes providing a pump at a treatment location within a patient's blood vessel, the pump including a pump housing disposed within a sheath, an impeller disposed within the pump housing, and a plurality of elongated struts extending from the pump housing in a folded configuration, each of the plurality of struts including a convex contact pad at its distal end; providing relative movement between the sheath and the pump to remove the pump from the sheath, the plurality of elongated struts radially self-expanding to an expanded configuration in which at least one convex contact pad at least intermittently contacts the blood vessel wall of the blood vessel to maintain the spacing of the pump from the blood vessel wall; and rotating the impeller to pump blood, and may include or consist essentially of these. In some embodiments, the method includes conveying an electric current to a motor by a tether including a conductor, the motor being operably coupled to the impeller, the tether being coupled to the pump, and a thrust force being generated when the impeller is rotated, the tether opposing the thrust force. In some embodiments, the method includes percutaneously delivering the sheath to the treatment location and then delivering the pump to the treatment location. In some embodiments, the method includes pushing a portion of the contact pad into the blood vessel wall. In some embodiments, the method includes removing the pump from the patient.

[0026] In another embodiment, a method of operating a blood flow assistance system is disclosed. The method includes providing a pump at a treatment location within a patient's blood vessel, the pump including a pump housing disposed within a sheath, an impeller disposed within the pump housing, and a plurality of elongate struts extending distally from the pump housing in a folded configuration; providing relative movement between the sheath and the pump to remove the pump from the sheath, the plurality of elongate struts radially self-expanding to an expanded configuration in which at least one contact pad at an end of at least one of the plurality of elongate struts at least intermittently contacts the blood vessel wall of the blood vessel to maintain a spacing of the pump from the blood vessel wall, and the at least one contact pad applying to the blood vessel wall a force sufficient to push a portion of the contact pad into the blood vessel wall such that a circumferential portion of the blood vessel wall is radially inward of the contact pad; and rotating the impeller to pump blood, and may include or consist essentially of these. In some embodiments, the method includes percutaneously delivering the sheath to the treatment location and then delivering the pump to the treatment location. In some embodiments, the method includes removing the pump from the patient. In some embodiments, the method includes conveying an electric current to a motor by a tether including a conductor, the motor being operably coupled to the impeller and the tether being coupled to the pump.

[0027] In another embodiment, a method of manufacturing a blood flow assistance system is disclosed. The method includes providing an impeller within a pump housing of a pump, where the pump is disposed along a longitudinal axis and the impeller is configured to generate a thrust force when operating within a blood vessel to pump blood; coupling a tether to a first end of the pump; and coupling a support structure to a second end of the pump, the support structure including a convex contact pad configured to at least intermittently contact a blood vessel wall to maintain a spacing of the pump housing from the blood vessel wall in which the pump housing is disposed. In some embodiments, the method includes providing a motor within a motor housing of the pump, where the motor housing is disposed distal to the pump housing. In some embodiments, the support structure includes a plurality of elongate struts having a first end coupled to the second end of the pump and a second end opposite the first end, each elongate strut of the plurality of struts having an elongate body extending between the first end and the second end, and each strut of the plurality of elongate struts being configured to accumulate strain energy when a lateral load is applied to the second end of the struts of the plurality of elongate struts. In some embodiments, the method includes patterning the plurality of elongate struts. In some embodiments, patterning includes laser cutting the plurality of elongate struts from a sheet of material.

[0028] In another embodiment, a method of operating a blood flow assistance system is disclosed. The method includes providing a pump at a treatment location within a patient's blood vessel, the pump including a pump housing disposed within a sheath, an impeller disposed within the pump housing, and a tether extending proximally from the pump housing to outside the patient, the tether being configured to oppose loads applied in opposite directions at both of its ends; providing relative movement between the sheath and the pump to remove the pump from the sheath; and rotating the impeller to pump blood and generate a thrust force, wherein a longitudinal component of the thrust force generated by the impeller directed along the longitudinal axis of the pump is opposed by the tether, and the tether is configured to maintain the position of the pump within the blood vessel without requiring contact between the pump and the blood vessel wall. In some embodiments, the pump includes a plurality of elongated struts extending distally from the pump housing in a folded configuration, each elongated strut of the plurality of struts including a convex contact pad at its distal end, and providing relative movement includes radially self-expanding the plurality of elongated struts to an expanded configuration in which at least one convex contact pad contacts the blood vessel wall of the blood vessel at least intermittently to maintain the spacing of the pump from the blood vessel wall. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] These and other features, aspects, and advantages are described below with reference to the drawings, which are for illustrative purposes only and are not to be construed as limiting the scope of the embodiments in any way. Additionally, various features of the different disclosed embodiments can be combined to form additional embodiments that are part of this disclosure. In the drawings, like reference numerals consistently denote corresponding features throughout the like embodiments. A brief description of each drawing is provided below.

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DETAILED DESCRIPTION OF THE INVENTION

[0057] Referring now to the drawings, the elements shown are not necessarily drawn to scale, and like or similar elements are designated by the same reference numeral throughout several figures.

[0058] In general, referring to the drawings, it will be understood that the illustrations are for the purpose of describing particular embodiments of the present disclosure and are not intended to be limiting. Most of the terms used herein will be recognizable to those of ordinary skill in the art, but where terms are not explicitly defined, they should be construed to adopt the meaning currently accepted by those of ordinary skill in the art.

[0059] I. Overview of the Blood Flow Assistance System The various embodiments disclosed herein relate to a blood flow assistance system 1 configured to provide circulatory support to a patient, as shown in FIGS. 1A-1I. The system 1 can be sized for intravascular delivery to a treatment location within the patient's circulatory system, such as a location within the patient's descending aorta. As shown in FIG. 1A, the system 1 can have a proximal end 21 having a connector 23 configured to connect to an external control system, such as a console (not shown). The connector 23 can provide electrical communication between the control system and an electrical lead 20 that extends distally along the longitudinal axis L from the connector 23 and the proximal end 21. The electrical lead 20 can comprise an elongated body that electrically and mechanically connects to the pump 2 at or near the distal end 22 of the blood flow assistance system 1, and the distal end 22 is spaced apart from the proximal end 21 along the longitudinal axis L. As described herein, the electrical lead 20 can also function as a flexible tether configured to oppose loads applied in opposite directions at both ends of the electrical lead 20.

[0060] The pump 2 can include a pump head 50 that includes a pump housing 35 connected to a drive unit 9 that includes a motor housing 29. A recovery mechanism 48 can be provided at the proximal end portion of the pump 2. In some embodiments, the recovery mechanism can be coupled to the distal end of the power lead 20 between the power lead 20 and the motor housing 29. After the procedure, the clinician can remove the pump 2 from the patient by engaging a tool (e.g., a snare, clamp, hook, etc.) with the recovery mechanism 48 and pulling the pump 2 out of the patient. For example, the recovery mechanism 48 can include a neck portion 49 (e.g., a reduced diameter portion) at the proximal curved portion 51c of the motor housing 29 and an enlarged diameter portion disposed proximal to the neck portion 49. The enlarged diameter portion can include a first curved portion 51a and a second curved portion 51b as shown in FIGS. 1B, 1C, and 1I. The first and second curved portions 51a, 51b can include a convex surface, e.g., a convex ball portion. The first and second curved portions 51a, 51b can have different radii of curvature. For example, as shown in FIG. 1I, the first curved portion 51a can have a larger radius of curvature than the second curved portion 51b. In some embodiments, the first curved portion 51a can be disposed on both sides of the recovery mechanism 48. The second curved portion 51b can be disposed around the first curved portion 51a and can have a surface facing radially outward and a convex surface facing proximally that is coupled to the distal end of the power lead 20. The neck portion 49 can have a first depth at a first circumferential position of the recovery mechanism 48 and a second depth that is less than the first depth at a second circumferential position of the recovery mechanism 48 spaced from the first circumferential position.

[0061] Advantageously, as shown in FIG. 1I, one or more first planes P1 extending parallel to the longitudinal axis L and intersecting the first curved portion 51a can have a first angle or taper between the proximal curved portion 51c of the motor housing 29 and the first curved portion 51a. One or more second planes P2 extending parallel to the longitudinal axis L and intersecting the second curved portion 51b can have a second angle or taper (different from the first angle or taper) between the proximal curved portion 51c of the motor housing 29 and the second curved portion 51b. The first angle or taper can provide a smooth, continuous (substantially monotonically decreasing) geometric transition between the proximal curved portion 51c of the motor housing 29 and the power lead 20, thereby providing smooth blood flow and reducing the risk of thrombosis. The second curved portion 51b can function as a lobe extending radially outward, for example, radially outward of the first curved portion 51a. The second curved portion 51b can be used to engage a retrieval device or snare to remove the pump 2 from the anatomical structure. Some cross-sections through the longitudinal axis of the retrieval mechanism 48 can include a substantial neck portion (e.g., a minimum value of the radius of curvature measured along its central axis), while other cross-sections through the longitudinal axis of the retrieval mechanism 48 can include a non-substantial minimum value or no minimum value. In the illustrated embodiment, there are two first curved portions 51a that can function as a double-lobe retrieval mechanism. In other embodiments, more or fewer lobes can be provided to enable pump retrieval while ensuring a smooth flow transition between the motor housing 29 and the power lead 20.

[0062] As shown in FIGS. 1B - 1C, 1E, and 1I, the neck portion 49 can be disposed between the curved portions 51a, 51b and the proximal convex surface 51c of the motor housing 29. In the illustrated embodiment, the recovery mechanism 48 can be coupled to or integrally formed with the motor housing 29. In other arrangements, the recovery mechanism 48 can be disposed at other locations of the pump 2. As shown, the recovery mechanism 48 can be symmetrically and continuously disposed about the longitudinal axis L. In other configurations, the recovery mechanism 48 can include a plurality of discrete surfaces spaced circumferentially and / or longitudinally apart. In the illustrated embodiment, the motor housing 29 (and the motor) may be part of the pump 2 and may be disposed inside the vasculature of the patient during use. However, in other embodiments, the motor housing 29 (and the motor) can be disposed outside the patient, and the drive cable can be connected to the impeller 6.

[0063] As shown in FIGS. 1A - 1C, the drive unit 9 can be configured to impart rotation to an impeller assembly 4 disposed within a pump housing 35 of a pump head 50. As described herein, the drive unit 9 can include a drive magnet 17 (see FIG. 1D) and a motor 30 (see FIGS. 1D - 1E) disposed within a motor housing 29 covered by a distal drive unit cover 11. The motor 30 is schematically shown in FIG. 1D. The drive unit cover 11 can be formed by or coupled to a drive bearing 18. The drive magnet 17 can be magnetically coupled to a corresponding driven or rotor magnet (not shown) of the impeller assembly 4 disposed proximal to the impeller 6 within a shroud 16. The power lead 20 can extend outside the patient's body from a treatment position and can provide power (e.g., current) and / or control to the motor 30. Thus, in some embodiments, the rotational drive shaft does not extend outside the patient's body. As described herein, the power lead 20 can energize the motor 30, thereby rotating the drive magnet 17 about the longitudinal axis L, which can function as, be aligned with, or correspond to the axis of rotation. Rotation of the drive magnet 17 can impart rotation to the rotor magnet and the primary or first impeller 6 of the impeller assembly 4 about the longitudinal axis L. For example, as described herein, the rotor magnet (which can be mechanically fixed to the impeller shaft 5) can rotate the impeller shaft 5 (which can function as a flow tube) and the first impeller 6 to pump blood. In other embodiments, the drive unit 9 can include a stator or other stationary magnetic device. The stator or other magnetic device can be energized, for example, with an alternating current to impart rotation to the rotor magnet. In the illustrated embodiment, the impeller 6 can have one or more blades 40 extending radially outward along a radial axis R that transversely crosses the longitudinal axis L in the radial direction.For example, the first impeller 6 can have a plurality (e.g., two) of longitudinally aligned blades 40 that extend radially outward from a common hub and have a common length along the longitudinal axis L. The curvature and / or overall profile can be selected to improve flow rate and reduce shear stress. Those skilled in the art will understand that other designs of the first impeller 5 may be appropriate.

[0064] As shown in FIGS. 1A - 1C, the impeller assembly 4 can be disposed within the shroud 16. The impeller shaft 5 can be supported at its distal end by a sleeve bearing 15 connected to the distal portion of the shroud 16. A support structure such as a positioning system 100 (described further below) can include a base 36 coupled to the sleeve bearing 15 and / or the shroud 16. In some embodiments, the base 36, the sleeve bearing 15, and / or the shroud 16 can be welded to each other. In other embodiments, the sleeve bearing 15 and / or the shroud 16 can be formed as a single piece. As shown in FIGS. 1A and 1C, the base 36, the sleeve bearing 15, and the shroud 16 of the support structure or positioning system 100 (which can be part of or function as the support structure) can cooperate to at least partially define the pump housing 35. The positioning system 100 can include a plurality of self - expanding struts 19 having convex contact pads 24 configured to contact the wall of the blood vessel in which the pump housing 35 is disposed to maintain the spacing of the pump housing 35 from the wall of the blood vessel. In FIGS. 1A - 1C, the struts 19 of the positioning system 100 are shown in an expanded deployed configuration, and the contact pads 24 extend radially outward to a position where the contact pads 24 contact the wall of the blood vessel in which the pump 2 is disposed, and at least partially control the position and / or orientation of the pump head 50 relative to the blood vessel wall during operation of the system 1, for example, fixing the pump 2.

[0065] The first fluid port 27 can be provided distal to the impeller assembly 4 at the distal end of the pump housing 35. The shroud 16 can include a proximal ring 26 coupled to the motor housing 29 and a plurality of second fluid ports 25 formed in a proximal portion of the shroud 16 adjacent to (e.g., immediately distal to) the proximal ring 26. As shown in FIG. 1C, the second fluid ports 25 can include openings formed between axial extension members 60 (also referred to as pillars) that extend along a longitudinal axis L (which can also function as the longitudinal axis of the pump head 2 and / or the pump housing 35) between the proximal ring 26 and the cylindrical section 59 of the shroud 16. In some embodiments, the axially extending members 60 can be shaped or otherwise configured to function as vanes that can shape or direct the flow of blood through the second fluid ports 25. For example, in various embodiments, the axially extending members 60 can be angled, tapered, or curved (e.g., in a helical pattern) to match the profile of the impeller blades 40 and / or to accelerate the blood flow through the pump 2. In other embodiments, the axially extending members 60 may not be angled to match the blades 40. In some embodiments, the first fluid port 27 can include an inlet port through which blood flows. In such embodiments, the impeller assembly 4 can draw blood into the first fluid port 27 and discharge the blood from the pump 2 through the second fluid port 25, which can function as an outlet port. However, in other embodiments, the direction of blood flow may be reversed, in which case the second fluid port 25 may function as a fluid inlet and the first fluid port 27 may function as a fluid outlet.

[0066] As shown in FIGS. 1A - 1D, the system 1 comprises a drive unit 9 having a motor 30 that can be encapsulated within a motor housing 29. The drive magnet 17 can be rotated by the motor 30 via a motor shaft 51. The motor 30 can be electrically connected to a power lead 20. The power lead 20 can function as a flexible tether comprising an elongate tension member configured to oppose loads applied in opposite directions at both ends of the power lead 20. In one embodiment, the power lead 20 is hollow as further described below. As shown in FIGS. 1D and 1F, the power lead 20 can comprise an insulator having a central lumen 55 and a plurality (e.g., three) of outer lumens 56A - 56C extending along the length of the power lead 20. One or more conductors can be disposed within the hollow elongate power lead 20 and configured to transmit current from a source such as an external control system to the motor 30. For example, in some embodiments, the outer lumens 56A - 56C can be sized and shaped to receive corresponding electrodes or wires (not shown) for supplying power to the motor 30. For example, the lumens 56A - 56C can receive wires configured to supply ground voltage and drive voltage to corresponding windings on the motor. The electrodes can extend through corresponding openings 57A - 57C in a motor mounting support 54 configured to support the motor 30. The central lumen 55 can be sized and shaped to receive an elongate reinforcement member or guide wire (not shown). The reinforcement member or guide wire can be inserted into the central lumen 55 through an opening 65 at the proximal end 21 (see FIG. 1G) during delivery to guide the pump 2 to a treatment position or to help maintain the pump 2 in a given position. The reinforcement member or guide wire can be easily inserted and removed during finishing. As shown in FIG. 1G, a connector 23 near the proximal end 21 of the system 1 can have electrical contacts 58A - 58C electrically connected to wires or conductors within the corresponding outer lumens 56A - 56C.The contacts 58A - 58C can comprise rings separated by an insulating material and can be configured to electrically connect to corresponding electrical components within a control system or console (not shown).

[0067] Advantageously, the blood flow assistance system 1 can be delivered percutaneously to a treatment location of a patient. FIG. 1H shows the pump 2 disposed within the elongate sheath 28. As shown, the strut 19 is held in a configuration folded by the inner wall of the sheath 28. As further discussed below, the strut 19 can be configured to fold in a controlled manner, for example, such that at least a portion is deflected outwardly from the inner wall of the sheath 28 when disposed within the sheath. As shown, the strut 19 can include a knee 102 that can serve to space the distal end of the strut 19 (e.g., at or near the contact pad 24 or hook) from the inner wall of the sheath 28 such that a space 46 exists between the contact pad 24 or hook and the inner wall of the sheath 28 in the folded configuration within the sheath 28.

[0068] In one embodiment, the knees 102 can have the same configuration for each of the struts 19. In such an embodiment, the struts 19 can all be folded or folded back in the same way within the sheath 28. In another embodiment, the knees 102 of one or more of the struts 19 can be distinguished from the knees 102 of one or more other struts 19 such that the struts are folded or folded back in different ways. As described herein, in various embodiments, the struts may be longitudinally aligned, or longitudinally offset, or staggered. For example, a pair of opposing struts 19 (e.g., arranged radially opposite each other) can have knees 102 that cause the pair of opposing struts to fold before the other struts 19 of the pump 2 are folded. In one example, the pump 2 has four struts 19. Two opposing struts 19 are configured to bend at the knees 102 before bending the knees of the other struts 19. In this way, the two opposing struts 19 can be folded into the space between the other two struts to provide a compact arrangement. The knees 102 can be configured such that some of the struts undergo a greater degree of flexion or folding. Thus, the space 46 between the contact pad 26 and the inner wall of the sheath 28 can be provided to avoid entanglement of the struts, and can be made two to six times (in some cases three to four times) larger for one or more, e.g., a pair of struts, than for one or more, e.g., another pair of struts 19. Thus, in various embodiments, some of the struts may be structured to fold first when engaging the sheath 28, and the remaining struts can fold when the sheath 28 induces the folding of the initial struts.

[0069] In some embodiments, one or more struts include knees 102 that can control the order of strut folding. For example, one or more struts can have knees 102 positioned more proximally compared to the knees 102 of one or more other struts. In one example, two opposing struts 19 can have knees 102 positioned more proximally than the knees 102 of another strut 19. In one example, a first set of opposing struts 19 can have knees 102 positioned more proximally than a second set of struts 19 that are disposed approximately 90 degrees offset from the first set of struts 19. This can enable the first set of struts to be folded more completely by the distal advancement of the sheath 28 before the more complete folding of the second set of struts 19. In a further variation, the knees 102 can be longitudinally spaced on adjacent struts 19 such that adjacent struts are folded at different times or speeds. The illustrated embodiment includes knees 102, but in other embodiments, knees may not be provided. For example, the struts 19 can be retracted at different speeds by hinges and / or by changing the thickness or properties of the material within or along the length of one or more of the struts 19 to control the timing or speed of folding when advancing the sheath 28. A living hinge structure can be formed along the length of one or more of the struts 19 to control the timing, speed, and / or sequence of retraction of the struts 19. In one example, a region of reduced thickness across the length of the strut 19 folds or bends the strut when the sheath advances across the region of reduced thickness. By offsetting the longitudinal position of the region of thickness reduction within the strut 19, the order of retraction can be controlled.

[0070] In the folded configuration, the strut 19 can be compressed in diameter or major transverse dimension at one or more positions that are approximately the same as (or slightly smaller than) the diameter of the shroud 16. Thus, as shown in the folded configuration of FIG. 1H, at least a portion of the strut 19 is compressed to a diameter or major transverse dimension that is smaller than the major transverse dimension or diameter of the pump housing 35, the shroud 16, and / or the drive unit 9. In some embodiments, at least a portion of the strut has a major transverse dimension that is less than or equal to the major transverse dimension of the pump housing 35. In some embodiments, at least a portion of the strut has a major transverse dimension that is smaller than the major transverse dimension of the pump housing 35 and / or the motor housing 29. The patient can be prepared for the procedure in a standard manner in a catheterization laboratory, and the femoral artery can be accessed by percutaneous or surgical techniques. The sheath 28 (or the dilator structure within the sheath 28) can be passed over a guidewire and positioned, for example, at a treatment location within the descending aorta. After the sheath 28 is positioned (and the dilator removed), the pump 2 can be advanced into the sheath 28, and the pump 2 is positioned in the mid-thoracic aorta approximately 4 cm below the takeoff of the left subclavian artery. In other embodiments, the pump 2 and the sheath 28 can be advanced together to the treatment location. Positioning the pump 2 at this location can advantageously enable sufficient cardiac assistance and increased perfusion of other organs such as the kidneys. Once at the treatment location, relative movement can be provided between the sheath 28 and the pump 2 (e.g., the sheath 28 can be retracted relative to the pump 2, or the pump 2 can be advanced from the sheath 28). The strut 19 of the positioning system can self-expand radially outward along the radial axis R due to the stored strain energy to the deployed and expanded configurations shown in FIGS. 1A-1C. In some embodiments, such as those in which the vasculature is accessed by the femoral artery, the strut 19 can extend distally, for example, beyond the distal end of the shroud 16 and / or the impeller 6. In other embodiments, as described herein, the pump 2 can be delivered percutaneously through the subclavian artery.In such an embodiment, the strut 19 may extend proximally, for example, proximally to the pump housing 35 and / or the motor housing 29. In yet other embodiments, a plurality of struts may extend both proximally and distally with respect to the pump 2. The convex contact pad 24 can engage the blood vessel wall to stabilize (e.g., assist in anchoring) the pump 2 within the patient's vasculature. When in the treatment position, the clinician can engage the control system to activate the motor 30 and rotate the impeller assembly 4 to pump blood.

[0071] Accordingly, in some embodiments, the pump 2 can be inserted into the femoral artery and advanced to a desired treatment position within the descending aorta. In such a configuration, the pump 2 can be arranged such that the distal end 22 is upstream of the impeller 6, for example, such that the first fluid port 27 located distally is upstream of the second fluid port 25. For example, in embodiments accessing the treatment position surgically or percutaneously via the femoral artery, the first fluid port 27 can function as an inlet to the pump 2 and the second port 25 can function as an outlet of the pump 2. The strut 19 can extend distally beyond the distal end of the pump housing 35. However, in other embodiments, the pump 2 can be inserted percutaneously through the left subclavian artery and advanced to a desired treatment position within the descending aorta. In such a configuration, the pump 2 can be arranged such that the distal end 22 of the system 1 is downstream of the impeller 6, for example, such that the first fluid port 27 arranged distally is downstream of the second fluid port 25. In embodiments accessing the treatment position via the left subclavian artery, the second fluid port 25 can function as an inlet to the pump 2 and the first port 27 can function as an outlet of the pump 2.

[0072] When the treatment procedure is completed, the pump 2 can be removed from the patient. For example, in some embodiments, the pump can be withdrawn proximally (and / or the sheath 28 can be advanced distally) such that the distal edge of the sheath 28 engages the surface 43 facing radially outward of the strut 19. In some embodiments, the distal edge of the sheath 28 can engage the knee 102 of the strut (see, e.g., FIGS. 2A-3C). The distal edge of the sheath 28 can apply a radially inward force to the radially outer opposing surface 43 (e.g., at approximately the location of the knee 102) to fold the strut 19 and draw it inside the sheath 28. To fold the strut 19 into the sheath 28 in the folded configuration, a relative movement opposite to that used to deploy the pump 2 can be provided between the sheath 28 and the pump 2 (e.g., between the sheath 28 and the impeller assembly 4 and the pump housing 35). In some embodiments, the pump 2 can be withdrawn from the sheath 28 together with the sheath 28 within the patient's body, and the sheath 28 can then be used for another treatment or removed. In other embodiments, the sheath 28 and the pump 2 can be removed together from the patient's body.

[0073] The above description includes embodiments in which the proximal end of the drive shaft 51 is disposed within the drive unit 9. The proximal end of the drive shaft 51 and the motor 30 are disposed within the body during use. FIG. 1J shows another embodiment in which the motor 30A is disposed outside the body during use. The elongated flexible shaft 51' is coupled to the drive magnet 17 at its distal end. The shaft 51' extends through the elongated body 20' and is or can be coupled to the motor 30A at its proximal end. Since the motor 30A does not need to be disposed within the profile of the sheath 28, it can be made larger than the motor 30. The elongated body 20' can have one or more lumens. The shaft 51' may extend through the central lumen 55. One or more outer lumens 56a can be provided for flowing fluid within the system to lubricate and / or cool the shaft 51'. Rotation of the proximal end of the shaft 51' by the motor 30a results in rotation of the entire length of the shaft 51' through the elongated body 20', and also results in rotation of the drive magnet 17. Rotation of the drive magnet 17 causes rotation of one or more magnets within the impeller 6, creating a flow through the pump 2 by magnetic attraction of these magnets across the distal drive unit cover. In other embodiments, the shaft 51' can be directly mechanically coupled to the impeller 6 such that rotation does not rely on magnetic coupling. One or more shaft rotation supports 54A can be provided within the distal housing 29A to support the distal portion of the shaft 51'. The elongated body 20' and / or the shaft 51' can comprise a tether for controlling or assisting the position of the pump, for example, to oppose the thrust force of the impeller 6 to reduce or minimize movement of the pump 2 during operation.

[0074] Further details of the pump 2 and associated components shown in FIGS. 1A - 1H can be found throughout the specification of International Patent Application No. PCT / US2020 / 062928, filed Dec. 2, 2020, the entire content of which is hereby incorporated by reference in its entirety for all purposes.

[0075] II. Struts As described herein, the support structure or positioning system 100 can include a plurality of struts 19. The struts 19 can have a first fixed end 38 of a base 36 coupled to or formed on the shroud 16 and a second free end 39 opposite the first end 38. The struts 19 can extend from a housing of a device such as an intravascular device (e.g., pump housing 35), and can include protrusions that extend radially and distally outwardly to contact the vessel wall 37 (see FIGS. 4A-4B) of the patient's vasculature either continuously or intermittently. As described above, in other embodiments, the struts 19 can extend proximally with respect to the pump housing 35 and / or the motor housing 29. For example, as shown in FIGS. 1A-1C, the struts 19 can extend distally along the longitudinal axis L distal to the first fluid port 27 and the impeller 6. In embodiments where the vasculature is accessed through the femoral artery, the struts 19 can extend distally and upstream of the first fluid port 27 and the impeller 6. In embodiments where the vasculature is accessed through the subclavian artery, the struts 19 can extend downstream of the fluid port 27. The struts 19 can extend to the most distal end of the blood flow assistance system 1 and can at least partially define the most distal end of the blood flow assistance system 1. In some embodiments, no portion of the blood flow assistance system 1 is disposed distal to the distal end of the struts 19. In some embodiments, the struts 19 can be made of a flexible shape set metal or alloy such as nitinol. A support structure 100 including a plurality of struts 19 can be used to provide positioning of an intravascular device such as the pump 2. Using a plurality of struts 19 allows each of the struts 19 to transmit a radial force to the region of the strut 19 in contact with the vessel wall 37 by acting against each other. The plurality of struts 19 can also be effective to position an intravascular device (such as the pump 2) or a portion of an intravascular device with respect to the vessel wall 37. For example, a plurality of struts 19 surrounding the first fluid port 27 (e.g., an inlet port in some embodiments) of the intravascular pump 2 effectively positions the inlet port 27 of the pump 2 substantially centrally within the vessel 37.The strut 19 for positioning the intravascular device can have a folded configuration for movement through a sheath 28 (see FIG. 1H) for deployment or retrieval and an expanded configuration for providing positioning.

[0076] FIG. 2A is an image showing a front perspective view of a positioning system 100A according to one embodiment. FIG. 2B is a schematic side view of the positioning system 100A of FIG. 2A. FIG. 2C is a schematic plan view of a laser cutting pattern for the positioning system 100A. FIG. 2D is a schematic side view of a strut 19A having a dome-shaped or spherical contact pad 24A. Unless otherwise specified, the components of FIGS. 2A-2D may be the same as or substantially similar to the components of FIGS. 1A-1H, and some reference numerals are appended by the letter "A". For example, as shown in FIGS. 2A-2D, each strut 19A can include an elongated body extending between a first end 38 and a second end 39. Each strut 19A can include a material (e.g., a shape memory alloy) configured to accumulate strain energy when a lateral compressive load is applied compressively along, for example, a radial axis R. The accumulated strain energy can be used to effect positioning and / or maintain positioning relative to the vessel wall 37 as described herein. For example, the accumulated strain energy can result in a radially outward force being applied to the vessel wall 37. The radially outward force can at least in part serve to position, stabilize, and / or position the pump 2 relative to the vessel wall 37.

[0077] In some embodiments, a portion of the strut 19A that contacts the vessel wall 37 can have a desired shape that aids in identification and / or positioning. In some embodiments, a portion of the strut 19A, such as the second end 39 of the strut 19A, can include a contact element 104 configured to be shaped as a substantially flat contact pad 24A. In the illustrated embodiment, the contact pad 24A is shown as being generally circular or dome-shaped. Other shaped ends, such as oval ends, may be suitable. In some embodiments, a shape of the contact pad 24 that avoids sharp corners and / or edges may be preferred. When deployed, the contact pad 24A can be pressed against the wall 37 of the blood vessel by the radial force transmitted by the strut 19A. When the pad 24A presses against the vessel wall 37, the vessel wall 37 can "cushion" around the edge of the pad 24A or form a depression in which the pad seats. The elongate strut can be configured to apply a load to the vessel wall 37 (e.g., the aorta wall) when deployed to locally radially expand the vessel wall tissue against which the contact pads 24A are juxtaposed. For example, the contact pad 24 can be elastically deflectable toward and away from the longitudinal axis L of the pump housing 35. The contact pad 24 can have a free state spaced from the longitudinal axis L of the pump housing 35 by a distance greater than the half-width of the blood vessel 37 in which the pump housing 35 is deployed.

[0078] The contact pad 24 can apply sufficient force to the wall of the blood vessel 37 to push or lift a part of the contact pad 24 into the wall. The contact pad 24 can be configured to engage without snagging the wall of the blood vessel 37 during application. In some configurations, the strut 19A can bend with the movement of the blood vessel wall (e.g., involving expansion and contraction of the blood vessel wall) so that the strut 19A can maintain contact with the blood vessel 37 even when the blood vessel 37 expands or contracts. This butting can enhance the ability of the strut 19A and the pad 24A to locate the intravascular device (e.g., the pump 2) by resisting the sliding movement of the pad 24A. The amount by which the pad 24A is pushed into the blood vessel wall 37 (and thus the amount of butting) can be controlled by adjusting the radial force that the strut 19A transmits to the contact pad 24A. The pad 24A may have holes or irregular edges to enhance the butting effect.

[0079] As shown in FIGS. 2E-2G, the strut 19A' can include a contact pad 24B having a "slide runner" edge 66 that flares or slopes away from the blood vessel wall 37 so that a sharp edge is not pushed into the blood vessel wall 37. As shown in FIGS. 2E-2G, the contact pad 24B can include a contact surface 67 that engages and presses into the blood vessel wall 37 such that at least a portion of the contact pad 24B (e.g., the contact surface 67) where the peripheral portion of the wall 37 engages the wall 37 extends radially inward. The profile of the pad 24B in FIGS. 2E-2G, including the edge 66, the contact surface 67, and the elongate member of the strut 19A, can define a convex profile or shape. In the illustrated configuration, the contact surface 67 can include a generally planar or flat shape, and the edge 66 can extend at an obtuse angle with respect to the contact surface 67. In some embodiments, the contact surface 67 can include a curved surface such as a convex spherical or domed surface. Such a design can reduce or minimize the potential for traumatic injury to the blood vessel wall 37, assist in removal without non-endothelialization and damaging the blood vessel. With sufficient radial force and butting, such a design can provide stable location of the strut contact pad 24A.

[0080] As shown in FIGS. 2A-2B, the strut 19A can include a knee portion 102 that, as shown upwardly in FIG. 1H, can serve to keep the strut 19A away from the inner wall of the sheath 28 when a plurality of struts 19A are folded within the sheath 28. The sheath 28 can include a bending portion where the curvature of the surface facing the outer radial direction of the strut 19A changes. As shown in FIG. 2B, for example, the strut 19A can include a plurality of segments 103a-103d that are integrally formed and connected to each other. The first segment 103a can extend distally and radially outwardly from the base 36A by an angle A with respect to the longitudinal axis L. The second segment 103b can extend distally and radially inwardly from the distal end of the first segment 103a by an angle B with respect to the longitudinal axis L. The third segment 103c can extend distally and radially outwardly from the distal end of the second segment 103b by an angle C with respect to the longitudinal axis L. The fourth segment 103d can extend distally and radially inwardly from the distal end of the third segment 103c by an angle D with respect to the longitudinal axis L.

[0081] Therefore, as shown in FIG. 2B, the strut 19A can have a plurality of changes in curvature and / or angle along the length of the strut 19A. In various embodiments, the angle A can range from 30° to 70°, from 40° to 60°, or from 45° to 55° with respect to the longitudinal axis L. The angle B can range from 10° to 30°, from 15° to 25°, or from 18° to 24° with respect to the longitudinal axis L. The angle C can range from 20° to 60°, from 30° to 50°, or from 35° to 45° with respect to the longitudinal axis L. The angle D can range from 20° to 45°, or from 25° to 35° with respect to the longitudinal axis L. The base 36A can have a first height H1 in the range of 0.1 inch to 0.3 inch. In the extended configuration, the radial separation along the radial axis R between the ends of the strut 19A can have a second height H2 in the range of 1 inch to 2 inches, or from 1.2 inches to 1.6 inches.

[0082] Advantageously, using a plurality of angles and curvatures in the strut 19A can enable the strut 19A to provide sufficient positioning and support for the pump 2. Additionally or alternatively, using a plurality of angles and / or curvatures in the strut can appropriately space a portion of the strut, such as the free end of the strut 19A, from the inner wall of the sheath 28. Spacing the pad 24A from the inner wall of the sheath 28 can reduce friction and / or damage to the strut 19A and / or the sheath when the pump 2 moves within and / or in and out of the sheath 28. Further, as described above, the flat contact pad 24A can beneficially provide a non-invasive interface that provides sufficient positioning and / or alignment between the strut 19A and the blood vessel wall 37. The strut 19A can be manufactured, for example, by laser cutting a shape memory alloy as shown in the laser cut pattern in the material sheet of FIG. 2C. A shape memory alloy (e.g., nitinol) can be cut and shaped by a laser or other device to form the strut 19A. The patterned material can be folded and / or wound into a closed, generally cylindrical profile. In other embodiments, the pattern can be cut from a pre-formed tube.

[0083] In some embodiments, such as those shown in FIG. 2D, the distal portion of contact pad 24A or strut 19A can include a spherical or domed profile 42 that functions as a contact surface 67. As a non-limiting example, the spherical profile 42 may be formed as a ball of plastic or other material formed on a portion of strut 19A to contact the vessel wall 37. For example, as shown in FIGS. 2B-2D, the spherical profile 42 can be disposed on the radial outer surface 43 of strut 19A configured to face and engage the vessel wall 37. The radial inner wall 44 can be disposed on the radially opposite side of the radial outer surface 43. In FIG. 2C, the struts 19A can be circumferentially spaced such that there are respective gaps 45 between adjacent sides of adjacent struts 19A of the plurality of struts 19A. The spherical contact mechanism 24A can advantageously be non-traumatic and can provide good cushioning and resistance to translation. As shown, the contact pad 24A can comprise a pad that is generally circular (or oval) in profile view having a diameter larger than the width of the spread immediately adjacent the corresponding elongate strut 19A. The contact pad 24A can comprise an elongate member and an enlarged vessel wall contact surface (e.g., surface 67 of FIGS. 2D-2G) disposed at an end of the elongate member. In various embodiments, the contact pad 24A can comprise a convex cross-sectional profile along the radial outer surface 43 of the strut 19A facing the vessel wall 37. For example, the contact pad 24A can comprise a convex profile in a cross-sectional plane disposed transverse to the longitudinal axis L of the pump housing 35. In some embodiments, the contact pad 24A can include a smooth surface without sharp edges or hooks. In some embodiments, each of the contact pads 24A can comprise one or more scalloped edges to allow tissue of the vessel wall 37 to be received therein.

[0084] In some embodiments, the positioning system 100A can have the goal of resisting but not eliminating the translation or rotation of the device (such as the pump 2) relative to the vessel wall 37. As a non-limiting example, the design of some struts 19A and / or contact pads 24A can allow for some small rotation of the device within the blood vessel even when deployed. However, such a design can also utilize other features described herein to further increase the resistance to rotation during operation of the device, such as an increase in the resistance resulting from propulsion.

[0085] Alternatively, some embodiments of the contact pads may be designed to increase the resistance to translation and / or rotation relative to the vessel wall 37. FIG. 3A is an image of a front perspective view of a positioning system 100B according to another embodiment. FIG. 3B is an image of a side view of the positioning system 100B of FIG. 3A. FIG. 3C is a schematic side view of the positioning system 100B of FIGS. 3A-3B. FIG. 3D is a schematic enlarged view of the second end 39 of the strut 19B of FIGS. 3A-3C. FIGS. 3E and 3F are schematic plan views of the positioning system 100B in a laser cut pattern before assembly. Unless otherwise specified, the components of FIGS. 3A-3F may be the same as or substantially the same as the components of FIGS. 1A-2C with the same reference numerals, and some reference numerals are appended by the letter "B". In some embodiments, the contact element 104 (e.g., the portion of the strut 19B that contacts the vessel wall 37) may include a hook 105 designed to penetrate the vessel wall 37 and provide a stable anchor point with a high level or resistance to translation and / or rotation. A design having an edge or hook 105 that is always in contact with the vessel wall is typically intended to provide stable positioning and / or location, so there is little or no movement of the hook 105 or edge relative to the initial contact area of the vessel wall 37 upon deployment.

[0086] As shown in FIG. 3C, the strut 19B can comprise a plurality of segments 106a-106d that are integrally formed and connected to each other. The first segment 106a can extend distally and radially outwardly from the base 36B by an angle E with respect to the longitudinal axis L. The second segment 106b can extend distally and radially inwardly from the distal end of the first segment 106a so as to at least partially define the inflection point and / or knee 102 as described above. The third segment 106c can extend distally and radially outwardly from the distal end of the second segment 106b by an angle F with respect to the longitudinal axis L. The fourth segment 106d can extend proximally rearwardly from the distal end of the third segment 106c by an angle G with respect to the third segment 106c. The third and fourth segments 106c, 106d can function as a hook 105 and can secure the pump 2 to the blood vessel wall 37. As shown in FIG. 3G, which is a plan view of the fourth segment 106d of the strut 19B, the fourth segment 106d of the strut 19B can include a split 106e having tines that can be fixed to the blood vessel wall in some embodiments. As shown, in some embodiments, the tine width t w can be, for example, in the range from 0.01 inches to 0.1 inches, or in the range from 0.01 inches to 0.05 inches.

[0087] As shown in FIG. 3C, the strut 19B can have a plurality of curvatures and / or changes in angle along the length of the strut 19B. In various embodiments, the angle E can range from 30° to 70°, from 40° to 60°, or from 45° to 55° with respect to the longitudinal axis L. The angle F can range from 20° to 60°, from 30° to 50°, or from 35° to 45° with respect to the longitudinal axis L. The angle G can range from 40° to 80°, from 50° to 70°, or from 55° to 65° with respect to the segment 106c that is inclined proximally as shown. The base 36B can have a first height H1 in the range of 0.1 inch to 0.3 inch. In the extended configuration, the radial separation along the radial axis R between the ends of the strut 19B can have a second height H2 in the range of 1 inch to 2 inches, or in the range of 1 inch to 1.4 inches. Further, as shown in FIG. 3C, the knee 102 can have a bulge height h b indicating the amount of bulge or swelling defined by the knee 102. The bulge height h b can be measured between the outward apex of the knee 102 and the protrusion of the third segment 106c. In various embodiments, the bulge height h b can range from 0.03 inch to 0.09 inch, or from 0.05 inch to 0.07 inch (e.g., about 0.054 inch in one embodiment). Further, the fourth segment 106d can function as the tine of the hook 105 and can have a tine length l t extending proximally from the third segment 106c. The tine length l t can range from 0.03 inch to 0.09 inch, or from 0.05 inch to 0.07 inch (e.g., about 0.058 inch in one embodiment).

[0088] Figures 3E - 3F show the laser pattern of the system 100B of FIGS. 3A - 3D. As shown in FIGS. 3E - 3F, in some embodiments, the strut 19B can be tapered along its length from proximal to distal, i.e., from right to left in FIGS. 3E - 3F, across its width. The laser cutting can be non - perpendicular to the longitudinal axis and can form a helical or spiral pattern in various arrangements.

[0089] FIG. 5A is a schematic perspective view of a positioning system 100C according to another embodiment. FIG. 5B is a schematic plan view of the laser cutting design of the system 100C of FIG. 5A. Unless otherwise specified, the components of FIGS. 5A - 5B may be the same as or substantially similar to the components of FIGS. 1A - 4E with some reference numerals being appended by the letter "C". In some embodiments, as shown in FIGS. 5A - 5B, the plurality of struts 19C may have different lengths. For example, as shown in FIGS. 5A - 5B, the system 100C includes struts 19C arranged in a jaster hat design. As shown, adjacent struts 19C may have different lengths. In some embodiments, every other strut may be designed to have approximately the same length. For example, as shown in FIGS. 5A - 5B, the first strut 19C' of the plurality of struts 19C may have a first length, and the second strut 19C'' of the plurality of struts 19C may have a second length 19C'' that is shorter than the first length. The second struts 19C'' may be circumferentially arranged between the first struts 19C' respectively. Although not shown in FIGS. 5A - 5B, the strut 19C can include a contact pad 24 at its distal end. In other embodiments, the strut 19C can include a hook 105 at its distal end.

[0090] While not limited by theory, the different lengths enable the system 100C to be supported against the blood vessel 37 at a plurality of longitudinal positions along the length of the blood vessel 37, thereby enabling improved localization and positioning. For example, in the expanded configuration of the struts 19C', 19C'', the first strut 19C' can engage the blood vessel wall 37 at a position more distal than the position at which the second strut 19C'' engages the blood vessel wall 37 such that the first strut 19C' and the second strut 19C'' engage the blood vessel wall 37 at offset longitudinal positions. Engagement at offset longitudinal positions of the blood vessel wall 37 can beneficially improve the stabilization of the pump 2 along a plurality of planes and can also provide a resistance moment with the plurality of contact planes. Further, the different lengths of the struts 19C', 19C'' can improve the collapsibility of the struts by enabling the sheath 28 to engage the struts 19C' and 19C'' separately. For example, since the lengths (and / or curvatures) of the struts 19C', 19C'' are different, the sheath 28 may first engage a first set of struts (e.g., strut 19C'' in some embodiments) to initiate folding of the first set of struts. During or after folding of the first set of struts, the sheath 28 may subsequently engage a second set of struts (e.g., strut 19C' in some embodiments) to fold the second set of struts. Dividing the folding of the struts 19C', 19C'' into two or more stages can advantageously reduce the amount of force used to fold each of the struts 19C', 19C''.

[0091] It should be understood that any of the support structures disclosed herein can comprise struts having different lengths. For example, in some embodiments, a plurality of struts (e.g., strut 19 or 19A) includes a first plurality of struts and a second plurality of struts. When the plurality of struts is in an expanded configuration, a first contact element (e.g., contact pad 24 or hook 105) of the first plurality of struts can be configured to engage the vessel wall at a first longitudinal position, and a second contact element (e.g., contact pad 24 or hook 105) of the second plurality of struts can be configured to engage the vessel wall at a second longitudinal position spaced from the first longitudinal position. In some embodiments, the first plurality of struts can have a different length than the second plurality of struts. Additionally or alternatively, the first plurality of struts can have a different radius of curvature (or departure angle) than the second plurality of struts.

[0092] FIG. 6 is a schematic side view of a plurality of struts 19D according to various embodiments. In some embodiments, as shown in FIG. 6, the first set of struts 19D' can have an elongated portion with a first radius of curvature, and the second set of struts 19D'' can have an elongated portion with a second radius of curvature that is different from (e.g., less than) the first radius of curvature. In the arrangement of FIG. 6, the first strut 19D' has a steeper withdrawal angle with respect to the longitudinal axis L compared to the second strut 19D''. As shown in FIG. 6, the angle between the longitudinal axis of the pump 2 and the portion of the second strut 19D'' adjacent to the base to which the strut is connected can be made larger than the corresponding angle of the first strut 19D'. The steeper withdrawal angle of the first strut 19D' can engage the sheath 28 with the first strut 19D' before engaging the second strut 19D'', initiating the folding of the first strut 19D'. As described above, the staging, staggering, or sequencing of the folding of the struts 19D', 19D'' can advantageously reduce the force used to fold the struts to improve the operation of the pump 2. By staging, staggering, or sequencing the folding of the struts, the force profile can be adjusted over the length of the movement of the sheath 28 on the strut 19 such that it is felt from the initial movement before folding to the initial folding adjacent to the base 36 to the final and complete folding of the strut 19 by advancing the sheath adjacent to or beyond the distal end of the strut. The staging, staggering, or sequencing can reduce the maximum force required over the length of the movement of the sheath 28 on the strut 19. Further, the different curvatures of the struts 19D', 19D'' can also enable the distal ends of the struts 19D', 19D'' to engage the blood vessel wall 37 at longitudinally offset positions, which, as described above, can improve the stabilization of the pump 2, for example, due to multiple contact surfaces or rings with the blood vessel wall 37.

[0093] Accordingly, FIG. 6 shows an embodiment in which the struts 19D', 19D'' can have substantially the same length along the longitudinal direction from the proximal end to the distal end in the retracted state, but can be offset in the longitudinal position so as to contact the blood vessel wall in an expanded state, for example, by two spaced planes arranged transversely, for example perpendicularly, to the longitudinal axis of the pump 2. The struts 19D', 19D'' can contact the blood vessel wall at least intermittently over a range of positions along the blood vessel wall that is 2 times, 3 times, 4 times, 5 times, 6 times, up to 10 times, or up to 100 times the contact length of the contact pads of the struts or other blood vessel wall contact surfaces, either individually or in groups defining a contact surface. It will be appreciated that these types of distributed contact regions can also be provided by struts having different lengths in the retracted state, as shown in FIGS. 5A-5B. In some embodiments, the contact element 104 of the second free end 39 of the strut 19D can be curled or coiled such that the curled portion contacts the blood vessel wall 37. As a non-limiting example, the second free end 39 of the strut 39D can be curled or coiled (e.g., at an angle in the range of about 270° to 360°).

[0094] The contact regions of the contact elements 104 of the struts 19 - 19D can be designed such that endothelialization over a longer duration does not impede, or prevent, removal of the intravascular device (e.g., pump 2) when the device is removed, or does not increase the likelihood of trauma to the vessel wall 37. Generally, single - end contact shapes can be more readily withdrawn from under any endothelialization. In contrast, non - single - end contact shapes may increase the likelihood of trauma to the vessel wall 37 when the device is removed. In some embodiments having hooks 105, the struts 19B can be shaped such that the operation of advancing the sheath 28 to fold a plurality of struts 19B pulls the hooks 105 away from the vessel wall 37, or in a direction opposite to the direction in which it was inserted, like a dart from a dartboard. In some embodiments having contact pads 24, 24A, the pads 24, 24A may be tapered so that the intravascular device (e.g., pump 2) can be withdrawn from under the endothelialized tissue by translating the device. Lifting the edges of the contact pads 24, 24A (e.g., a "thread" type design) may also prevent restrictive endothelialization.

[0095] The amount of the radial force pressing the contact area at the second free ends 39 of the struts 19 to 19D against the blood vessel wall 37 can be changed by varying the number of the struts 19 to 19D, the material of the struts 19 to 19D, and / or the shape of the struts 19 to 19D and the contact pads 24 to 24A. The important geometric factors can include, but are not limited to, the length of the struts 19 to 19D, the cross-section of the struts 19 to 19D, the attachment angle of the struts 19 to 19D to the pump housing 35, and the curvature of the struts 19 to 19D. Generally, the struts 19 to 19D have a spring function such that the radial force of the struts 19 to 19D against the blood vessel wall 37 increases as the struts 19 to 19D are compressed by the blood vessel wall 37. The design and shaping of the struts may be selected to reduce this dependency such that the radial force provided by the struts 19 to 19D is relatively independent of the radius at which the struts are compressed. Equalizing such spring forces among the plurality of struts 19 to 19D can provide a centering positioning effect.

[0096] In some embodiments, the struts 19 to 19D are designed to intermittently contact and can have zero radial force unless in contact with the blood vessel wall 37. As a non-limiting example, the plurality of struts 19 to 19D may have different lengths and / or shapes (e.g., FIGS. 5A-5B). The different lengths and / or shapes can, in some embodiments as shown in FIGS. 5A-5B, allow the struts 19C to be arranged such that not all of the struts 19C contact the blood vessel wall 37 simultaneously. Further, in some examples, the struts 19 to 19D can be utilized with a device that applies a force to the struts 19 to 19D during operation (e.g., gyroscopic effect), such that the force applied to the struts 19 to 19D can change. Due to the spring-like nature of the struts 19 to 19D, folding or releasing in such situations can be facilitated. It should be noted that each of the struts 19 to 19D among the plurality of struts may have a different shape or contact area design.

[0097] In some embodiments, the struts 19-19D can have a knee 102 as described above. The knee 102 within the strut can function to keep a portion of the struts 19A-19D away from the inner wall of the sheath 28 when the plurality of struts 19A-19D are folded within the sheath 28. For example, the knee 102 can function to keep the hook 105 away from the inner wall of the sheath 28 such that the hook 105 does not contact the sheath 28 and generate particles due to wear, cutting, or gouging. The knee 102 can comprise a bending zone disposed between a first end 38 and a second end 39, and the second end 39 can be elastically deflectable toward and away from the longitudinal axis L of the pump housing 35. The free state of the strut can space the second end 39 thereof away from the longitudinal axis L of the pump housing 35. The second end 39 of the strut can be configured to engage the blood vessel wall 37 (e.g., to at least intermittently contact the blood vessel wall 37). The bending zone can include an S-shaped connection between a first span of the strut and a second span of the strut. The first span and the second span can be disposed along parallel trajectories.

[0098] It can be important to minimize the diameter of the sheath 28 used to implant or retrieve an intravascular device (such as the pump 2). An advantage of the embodiments disclosed herein is that the plurality of struts 19-19D can be folded to a diameter that is less than or equal to the diameter of the pump 2 itself, such that a large sheath is not required due to the presence of the plurality of struts 19-19D.

[0099] In some embodiments, the plurality of struts 19-19D may be designed to contact the vessel wall 37 in a plurality of cross-sections along the central axis of the vessel (e.g., at a plurality of longitudinal positions). In some embodiments, the plurality of struts 19-19D can be attached to the pump 2 in one cross-section, but the struts 19-19D can have different shapes and can contact the vessel wall 37 in a plurality of cross-sections along the central axis of the vessel. In some embodiments, the plurality of struts 19-19D may be attached to the pump 2 in two or more cross-sections along the central axis or longitudinal axis L of the pump 2. As a non-limiting example, a set of struts 19-19D may be present at each end of the pump 2 (e.g., at the proximal and distal ends of the pump 2).

[0100] In some embodiments, the plurality of struts 19-19D may be directly integrated with the pump 2 such that the shroud 16 and the struts 19-19D are formed monolithically as a single piece. In other embodiments, the plurality of struts 19-19D may instead be coupled or connected to the pump 2 and may include one or more separate components. As a non-limiting example, the struts 19-19D may be attached to a ring attached to the pump 2.

[0101] Tether In some embodiments, one or more tethers can be components of the localization and positioning systems 100-100C. Devices such as pump 2 that utilize a cable or lead for power or infusion can use that cable or lead as a tether. For example, as shown herein, power lead 20 can function as a tether in the illustrated embodiment. A tether (e.g., power lead 20) can have an anchor point outside of the blood vessel and / or the patient and can limit the translation of the intravascular device (e.g., away from its anchor point). As described herein, for example, the connector 23 at the proximal end 21 of system 1 can be connected to a console outside of the patient (which can function as an anchor point in some embodiments). In some embodiments, an arteriotomy and the path through the patient's skin can function as an anchor point for the tether. Sutures can be used to secure a tether (e.g., power lead 20) adjacent to the proximal end 21 in some procedures.

[0102] Propulsion One non-limiting example of an intravascular device that can be used with the disclosed embodiments is, for example, a blood pump 2A as shown in FIGS. 4A-4E. As shown in FIG. 4A and as described above, the sheath 28 can be percutaneously inserted into a treatment location within a blood vessel such as the descending aorta. In some embodiments, as shown in FIG. 4B, after the sheath 28 is positioned, the pump 2A can be pushed distally within the sheath 28 by a reinforcing member or guide wire (not shown) that can be positioned within the central lumen 55. In other embodiments, the pump 2A is pre-loaded into the sheath 28, and the sheath 28 and pump 2A can be advanced together to the treatment location. As shown in FIGS. 4C-4D, relative movement is provided between the sheath 28 and the pump 2A to bias the pump 2A out of the sheath 28. A support structure including struts 19-19D can self-expand to contact the inner wall of the blood vessel 37. The struts used in the support structure of the pump 2A shown in FIGS. 4A-4E can include any of the struts 19-19D described herein. For example, in some embodiments as shown in FIG. 4C, a mesh 47 can extend between or span adjacent struts at a location near the distal end of the shroud 16. The mesh 47 can extend partially along the length of the struts, for example, within a range of 10% to 70% of the length of the struts. The strut 19A in FIG. 4D is shown with a contact pad 24. The strut in FIG. 4E is shown with a hook 105.

[0103] When the struts are deployed, the impeller 6 can be actuated to pump blood. Some blood pumps 2A discharge blood with jets 34 or exert a large force during operation. These pumps 2A can generate a reaction (or propulsion) force 33 on the pump 2A in the direction opposite to the pump discharge, for example, when pumping the propulsion force 33 downward as shown in FIG. 4D. Some embodiments may be designed to utilize this propulsion force 33 as a component of the positioning systems 100-100C. As a non-limiting example, the struts 19-19D can provide a shape that causes an increase in the spring-like force as a result of the propulsion force 33. For example, the propulsion force 33 can further compress the struts 19-19D and increase the spring force. In various embodiments, the longitudinal component of the thrust force 33 along the longitudinal axis L can be opposed by the tension in the tether (e.g., the power lead 20). The lateral component of the thrust force 33 directed in a direction transverse to the longitudinal axis L (e.g., along the radial axis R) can be opposed by the strain energy accumulated in at least one of the elongated struts 19-19D when the struts 19-19D are deflected. As described herein, when the procedure is complete, the clinician can provide further relative movement between the sheath 28 and the pump 2A to fold the struts 19-19D into the sheath 28 (see FIG. 1H).

[0104] Advantageously, in various embodiments disclosed herein, the power lead 20 can function as a tether strong enough to oppose loads applied in opposite directions at its opposite ends. In some pumps, the thrust force from the pump 2 may be too strong, and if the proximal end of the tether is not sufficiently fixed and / or the power lead 20 is not strong enough, the pump 2 may move through the blood vessel. In such situations, the pump 2 may stretch the tether and / or the tether may not be sufficiently fixed. Advantageously, the embodiments disclosed herein can be made strong enough such that when fixed outside the blood vessel, the longitudinal component of the thrust force generated by the impeller directed along the longitudinal axis of the pump can be appropriately opposed by the tether. Thus, in various embodiments, the tether (e.g., the power lead 20) can be configured to maintain the position of the pump 2 within the blood vessel without requiring contact between the pump 2 and the blood vessel wall 37 of the blood vessel.

[0105] In some embodiments, the struts of the support structure need not contact the wall 37 during operation of the blood pump 2, and the tether can serve to properly position the pump 2. In some procedures, the struts may at least intermittently contact the vessel wall 37 (e.g., the struts may only intermittently contact the wall 37). In such a configuration, the struts can intermittently contact the wall 37 and move away from the vessel wall 37 over the course of the procedure. Thus, the embodiments disclosed herein do not require a constant contact between the support structure of the pump and the vessel wall 37. In fact, in such embodiments, the struts can be short and / or robust struts that can function as bumpers that non-invasively, e.g., elastically, intermittently engage the vessel wall 37 when the pump 2 moves towards the wall 37 and pushes the pump 2 back towards the central position of the blood vessel. In some embodiments, the struts can be omitted such that the tether and the thrust force establish the position of the operating pump. However, in other embodiments, the struts may be shaped or configured to maintain a substantially constant contact with the vessel wall 37 when in the deployed configuration during use of the pump 2. In yet other embodiments, the pump 2 may not include struts, such that the tether can perform the positioning and / or orientation function without struts.

[0106] Exemplary Designs The various design features described above can be mixed and combined in any desired way. The non-limiting examples described below herein show one possible embodiment that combines the design elements described above and does not show the boundaries of potential combinations.

[0107] The systems and methods described herein are used to provide localization and positioning of devices such as intravascular pumps 2, 2A. A plurality of struts 19-19D having contact elements 104 project from a ring attached to the inlet end of pump 2. The embodiments of FIGS. 1A-3G show four struts 19-19B, although any number of struts can be used. For example, as shown in FIGS. 5A-5B, in some embodiments, more than four struts (e.g., six struts 19C) can be used. The contact pads 24, 24A are shown as circular, although contact pads 24, 24A of any shape can be used. The shape of the struts is designed to provide a radial force within a set range in strut contact pads 24, 24A for blood vessels within a particular diameter range. The struts 19-19D can also be designed to reduce or minimize the force required for sheath 28 to fold the struts 19-19D.

[0108] The circular contact pads 24, 24A can be designed to slide along the inner arterial wall 37 without causing trauma. By adjusting this radial force, the plurality of expandable struts 19-19D provide consistent positioning of the inlet ports 27-27B of pumps 2, 2a at the center of the blood vessel lumen and do not strictly prevent translation and rotation of pumps 2, 2a. This feature allows for safe translation of pumps 2, 2a whether intentional (to move pumps 2, 2A to a preferred position) or unintentional (e.g., when a power lead is pulled).

[0109] In some embodiments, the propulsive force 33 of pumps 2, 2A tends to move it in a preferred direction and / or this movement can be restricted by the tethering effect of the power lead 20 of the pump, such that providing limited localization is sufficient. One advantage of this embodiment is that it provides stable long-term localization while allowing for momentary movement of pumps 2, 2A while minimizing or reducing the risk of trauma to the vessel wall 37. This embodiment is more adaptable to greater degrees of freedom of movement, for example, for patients who sit freely, bend at the waist, and / or make other similar movements.

[0110] In some embodiments, the shape of struts 19-19D can be modified such that struts 19-19D contact the vessel wall 37 only intermittently. In such embodiments, the propulsive force 33 acting on the tether (e.g., power lead 20) provides localization and struts 19-19D maintain the positioning of ports 27-27B of pumps 2, 2A at the center of the vessel lumen.

[0111] Advantages The systems and methods described herein, including but not limited to the embodiments described in detail and shown in the drawings, have several advantages. Many of these advantages have been described above. The following are merely additional non-limiting examples of advantages, some of which result from combinations of various design elements. a. Struts 19-19D (including struts 19C’, 19C’’, 19D’, 19D’’) are designed such that they do not increase the diameter of pump 2 when struts 19-19D are in a folded configuration. b. Struts 19-19D (including struts 19C’, 19C’’, 19D’, 19D’’) have knees 102 and hooks 105, whereby knees 102 prevent hooks 105 from contacting the inner surface of sheath 28 during implantation or retrieval of pump 2. c. Non-traumatic contact pads 24, 24A are designed to resist, but not preclude, translation or rotation of the intravascular device (e.g., pumps 2, 2A). i. A tether (e.g., power lead 20) that cooperates with and / or ii. Due to the desired endothelialization, it becomes more resistant to translation over time. d. Intermittent contact positioning (centering) with struts 19 - 19D (including struts 19C’, 19C’’, 19D’, 19D’’) with long - term positioning provided by the propulsive force 33 acting on the tether (e.g., power lead 20).

[0112] The embodiments described herein are included to demonstrate certain aspects of the present disclosure. It should be understood by those skilled in the art that the embodiments described herein merely represent exemplary embodiments of the present disclosure (e.g., non - limiting examples). Those skilled in the art can make many modifications to the specific embodiments described herein, including various combinations of different elements, components, steps, features, etc. in light of the present disclosure, and still obtain similar or analogous results without departing from the spirit and scope of the present disclosure. From the foregoing description, those skilled in the art should be able to readily identify the essential features of the present disclosure and make various modifications and changes to adapt the present disclosure to various applications and conditions without departing from its spirit and scope. The above - described embodiments are intended for illustration only and should not be construed as limiting the scope of the present disclosure.

[0113] Previous studies are detailed in U.S. Patent No. 8,012,079 and U.S. Patent Application Publication No. 2017 / 0087288, both of which are hereby incorporated by reference in their entirety.

[0114] Conditional language such as "can", "could", "might", or "may" generally intends to convey that a particular embodiment includes a particular feature, element, and / or step, but other embodiments do not, unless otherwise specified or understood in a different sense within the context in which it is used. Thus, such conditional language generally does not imply that a feature, element, and / or step is required in any form in one or more embodiments.

[0115] Terms such as "comprising", "including", "having", etc. are synonyms and are used in an inclusive, open-ended fashion, not excluding additional elements, features, acts, operations, etc. Also, the term "or" is used in an inclusive sense (not an exclusive sense), e.g., when used to connect a list of elements, the term "or" means one, some, or all of the elements in the list. Further, the articles "a", "an", and "the" used in this application and the appended claims should be construed to mean "one or more" or "at least one" unless otherwise specified.

[0116] The ranges disclosed herein also include any and all overlaps, subranges, and combinations thereof. Terms such as "up to", "at least", "greater than", "less than", "between" include the recited numbers. Numbers preceded by terms such as "about" or "approximately" include the recited numbers and should be interpreted based on the context (e.g., as accurate as reasonably possible in the circumstances, such as ±5%, ±10%, ±15%, etc.). For example, "about 1" includes "1". Terms such as "substantially", "generally" preceding a phrase include the recited phrase and should be interpreted based on the context (e.g., as reasonably possible in the circumstances). For example, "substantially spherical" includes "spherical". Unless otherwise specified, all measurements are made under standard conditions including temperature and pressure.

[0117] As used herein, the phrase referring to "at least one of" a list of items refers to any combination of those items, including a single member. As an example, "at least one of A, B, or C" is intended to include A, B, C, A and B, A and C, B and C, and A, B, and C. Connectives such as the phrase "at least one of X, Y, and Z" are generally understood in other meanings in the context in which they are generally used to convey that an item, term, etc. can be at least one of X, Y, or Z, unless otherwise specified. Thus, such connectives are generally not intended to mean that a particular embodiment requires at least one of X, at least one of Y, and at least one of Z for each to exist.

[0118] While specific embodiments and examples have been described herein, it should be emphasized that many variations and modifications can be made to the humeral head assembly shown and described in the present disclosure, and its elements can be combined and / or modified differently to form further alternative embodiments or acceptable examples. All such changes and modifications are intended to be included within the scope of the present disclosure. A wide variety of designs and techniques are possible. The features, structures, or steps disclosed herein are not essential or indispensable.

[0119] Some embodiments are described in relation to the accompanying drawings. However, it should be understood that the drawings are not drawn to scale. Distances, angles, etc. are merely illustrative and do not necessarily have an exact relationship to the actual dimensions and layout of the devices shown. Components can be added, removed, and / or rearranged. Further, the disclosure herein of any particular feature, aspect, method, property, quality, attribute, element, etc. related to various embodiments can be used in all other embodiments described herein. Additionally, it will be recognized that any method described herein can be implemented using any device suitable for performing the recited steps.

[0120] For the purposes of the present disclosure, certain aspects, advantages, and novel features are described herein. It should be understood that not all such advantages can necessarily be achieved in accordance with any particular embodiment. Thus, for example, one skilled in the art will recognize that the present disclosure can be embodied or implemented to achieve one advantage or group of advantages as taught herein without necessarily achieving other advantages that can be taught or suggested herein.

[0121] Furthermore, while exemplary embodiments are described herein, the scope of the present invention extends beyond the specifically disclosed embodiments to include equivalent elements, modifications, omissions, combinations, or sub-combinations of particular features and aspects of the embodiments (e.g., aspects across various embodiments), adaptations and / or alternatives, and any and all embodiments having the use of the present invention as would be understood by one of ordinary skill in the art based on the present disclosure. Limitations in the claims are to be fairly construed based on the language employed in the claims and are not to be limited during the examination of the application or by the examples set forth herein, which examples are to be construed as non-exclusive. Additionally, the acts of the disclosed processes and methods can be changed in any manner, including reordering the acts, and / or inserting additional acts, and / or deleting acts. Accordingly, the specification and examples are to be considered as illustrative only, and the true scope and spirit are intended to be indicated by the full scope of the claims and their equivalents.

Claims

1. 1. A blood flow assist system comprising: an impeller disposed within a pump housing of the pump, the pump including a longitudinal axis, the impeller generating a thrust force as it operates within a blood vessel to pump blood; a tether extending away from the pump housing, the tether configured to resist loads applied in opposite directions at opposite ends of the tether; a support structure including a convex contact pad configured to at least intermittently contact a vessel wall to maintain spacing of the pump housing from the vessel wall in which the pump housing is disposed; Equipped with Blood flow support system.

2. the support structure comprises a plurality of elongated struts having a first end coupled to a second end of the pump and a second end opposite the first end, each of the plurality of struts having an elongated body and extending between the first end and the second end, and the convex contact pad is disposed on a distal portion of each of the plurality of struts; The blood flow assist system of claim 1 .

3. the plurality of struts includes a first plurality of struts and a second plurality of struts, and when the plurality of struts is in an expanded configuration, first contact pads of the first plurality of struts are configured to engage the vessel wall at a first longitudinal position and second contact pads of the second plurality of struts are configured to engage the vessel wall at a second longitudinal position spaced from the first longitudinal position; The blood flow assist system of claim 2 .

4. when the strut is in a collapsed configuration, at least a portion of the strut has a major lateral dimension that is less than or equal to a major lateral dimension of the pump housing; A blood flow assist system according to any one of claims 1 to 3.

5. the contact pad is disposed distally and radially outwardly of the pump housing and configured to reversibly deflect to retain the pump housing within the blood vessel and to maintain the pump housing away from the vessel wall. A blood flow assist system according to any one of claims 1 to 3.

6. the contact pad includes a convex periphery surrounding a convex vessel-engaging surface; A blood flow assist system according to any one of claims 1 to 3.

7. the contact pad having a convex profile in a cross-sectional plane disposed across the longitudinal axis of the pump; A blood flow assist system according to any one of claims 1 to 3.

8. the tether comprising a conductor configured to transmit electrical current from a source connectable to a proximal end of the tether to a motor operably coupled to the impeller. A blood flow assist system according to any one of claims 1 to 3.

9. the pump further comprising a motor housing coupled to a proximal portion of the pump housing, the motor being disposed within the motor housing.

9. The blood flow assist system of claim 8.

10. the tether comprising a rotatable drive shaft connected to a motor located outside the patient's body; A blood flow assist system according to any one of claims 1 to 3.

11. At least one strut of the plurality of elongated struts has a first end disposed on or coupled to the pump housing, a second end opposite the first end, and a bending region disposed between the first end and the second end, the second end being elastically deflectable toward and away from a longitudinal axis of the pump, and in a free state of the strut, the second end is away from the longitudinal axis of the pump and the second end of the strut is configured to engage a wall of a blood vessel. The blood flow assist system of claim 2 .

12. a sheath disposed over the pump and including an inner wall configured to deflect the strut between the first end and the second end, the bending region configured such that the second end of the strut moves away from the inner wall of the sheath when the strut is deflected by the inner wall of the sheath.

12. The blood flow assist system of claim 11.

13. A kit comprising the blood flow assist system of any one of claims 1 to 3 and a sheath sized and shaped to accommodate the pump housing, the tether, and the support structure.

14. 1. A blood flow assist system comprising: an impeller disposed within a pump housing of the pump; a support structure coupled to or integrally formed with the pump housing, the support structure including a plurality of struts, the support structure having an expanded configuration in which the plurality of struts extend outwardly relative to the pump housing and a collapsed configuration in which the pump is disposed within a sheath, wherein in the collapsed configuration at least some of the plurality of struts have a major lateral dimension that is less than or equal to a major lateral dimension of the pump housing; Equipped with Blood flow support system.

15. the major lateral dimension of at least some of the struts is less than the major lateral dimension of the pump housing; 15. The blood flow assist system of claim 14.

16. a motor housing; and a motor disposed within the motor housing, wherein the major lateral dimension of at least some of the plurality of struts is smaller than a major lateral dimension of the motor housing.

16. A blood flow assist system according to claim 14 or 15.

17. further comprising a convex contact pad on a distal portion of the strut, the convex contact pad configured to contact a vessel wall to maintain spacing of the pump housing from the vessel wall in which the pump housing is disposed.

17. A blood flow assist system according to claim 15 or 16.

18. At least one strut of the plurality of elongated struts has a first end disposed on or coupled to the pump housing, a second end opposite the first end, and a bending region disposed between the first end and the second end, the second end being elastically deflectable toward and away from a longitudinal axis of the pump, and in a free state of the strut, the second end is away from the longitudinal axis of the pump and the second end of the strut is configured to engage a wall of a blood vessel.

18. A blood flow assist system according to any one of claims 15 to 17.

19. a sheath disposed over the pump and including an inner wall configured to deflect the strut between the first end and the second end, the bending region configured such that the second end of the strut moves away from the inner wall of the sheath when the strut is deflected by the inner wall of the sheath.

20. The blood flow assist system of claim 18.

20. 1. A blood flow assist system comprising: an impeller disposed within a pump housing of the pump; a support structure coupled to or integrally formed with the pump housing, the support structure including a plurality of struts, the support structure having an expanded configuration in which the struts extend outward relative to the pump housing and a collapsed configuration in which the pump is disposed within a sheath; Equipped with the plurality of struts includes a first plurality of struts and a second plurality of struts, and when the plurality of struts is in an expanded configuration, first contact pads of the first plurality of struts are configured to engage the vessel wall at a first longitudinal position and second contact pads of the second plurality of struts are configured to engage the vessel wall at a second longitudinal position spaced from the first longitudinal position; Blood flow support system.

21. further comprising convex contact pads on distal portions of the plurality of struts, the convex contact pads configured to at least intermittently contact a vessel wall to maintain a spacing of the pump housing from the vessel wall in which the pump housing is disposed.

21. The blood flow assist system of claim 20.

22. a major lateral dimension of at least some of the struts is less than a major lateral dimension of the pump housing; 22. A blood flow assist system according to claim 20 or 21.

23. a tether extending away from the pump housing, the tether configured to resist loads applied in opposite directions at opposite ends thereof.

22. A blood flow assist system according to claim 20 or 21.

24. 1. A blood flow assist system comprising: an impeller disposed within a pump housing of the pump, the pump including a longitudinal axis, the impeller generating a thrust force as it operates within a blood vessel to pump blood; a tether coupled to a first end of the pump; a support structure comprising a contact pad resiliently deflectable toward and away from a longitudinal axis of the pump, the contact pad in its free state being spaced from the longitudinal axis of the pump by a distance greater than half the width of a vessel in which the pump housing is deployed, the contact pad applying sufficient force to a wall of the vessel to compress a portion of the contact pad against the wall such that a peripheral portion of the vessel wall is radially inward from the contact surface of the contact pad; Equipped with Blood flow support system.

25. the contact pad is configured to engage the wall of the blood vessel without snagging upon application; 25. The blood flow assist system of claim 24.

26. the contact pad comprises an elongated member and an enlarged vessel wall contact surface disposed at an end of the elongated member; 26. A blood flow assist system according to claim 24 or 25.

27. the tether comprising a conductor configured to transmit electrical current from a source connectable to a proximal end of the tether to a motor operably coupled to the impeller.

26. A blood flow assist system according to claim 24 or 25.

28. 26. A kit comprising the blood flow assist system of claim 24 or 25 and a sheath sized and shaped to accommodate the pump housing, the tether, and the support structure.

29. 1. A blood flow assist system comprising: A pump, an impeller disposed within the pump housing; a strut having a first end disposed on or coupled to the pump housing, a second end opposite the first end, and a bending region disposed between the first end and the second end, the second end being elastically deflectable toward and away from a longitudinal axis of the pump, the second end of the strut being configured to engage a wall of the blood vessel in a free state such that the second end is away from the longitudinal axis of the pump; a pump including: a sheath disposed over the pump, the sheath including an inner wall configured to deflect the strut between the first end and the second end; Equipped with the bending region is configured such that the second end of the strut moves away from the inner wall of the sheath when the strut is deflected by the inner wall of the sheath. Blood flow support system.

30. the second end of the post includes a hook; 30. The blood flow assist system of claim 29.

31. the bending region includes an S-shaped connection between a first span of the column and a second span of the column, the first span and the second span being disposed along parallel trajectories.

31. A blood flow assist system according to claim 29 or 30.

32. further comprising a tether coupled to a first end of the pump, the tether comprising an electrical transmission line, the electrical transmission line including a conductor configured to transmit electrical current from and to an electrical power source connectable to a proximal end of the electrical transmission line.

31. A blood flow assist system according to claim 29 or 30.

33. further comprising a convex contact pad on the second end of the strut, the convex contact pad configured to at least intermittently contact the wall of the blood vessel to maintain spacing of the pump housing from the wall of the blood vessel in which the pump housing is disposed.

31. A blood flow assist system according to claim 29 or 30.

34. the support structure includes a plurality of struts including the strut, the support structure having an extended configuration in which the plurality of struts extend outwardly relative to the pump housing and a collapsed configuration in which the pump is disposed within a sheath, and in the collapsed configuration, at least some of the plurality of struts have a major lateral dimension that is less than or equal to a major lateral dimension of the pump housing; 31. A blood flow assist system according to claim 29 or 30.

35. 1. A method of manufacturing a blood flow assist system, comprising: providing an impeller within a pump housing of the pump, the pump disposed along a longitudinal axis, the impeller generating a thrust force as it operates within a blood vessel to pump blood; connecting a tether to a first end of the pump; coupling a support structure to a second end of the pump, the support structure comprising a convex contact pad configured to at least intermittently contact a vessel wall to maintain spacing of the pump housing from the vessel wall in which the pump housing is disposed; Including, method.

36. and providing a motor within a motor housing of the pump, the motor housing being disposed distally of the pump housing.

36. The method of claim 35.

37. the support structure comprises a plurality of elongated struts having a first end coupled to the second end of the pump and a second end opposite the first end, each elongated strut of the plurality of struts having an elongated body and extending between the first end and the second end, each strut of the plurality of elongated struts configured to store strain energy when a lateral load is applied to the second end of the strut of the plurality of elongated struts; 37. The method of claim 35 or 36.

38. further comprising patterning the plurality of elongated posts.

38. The method of claim 37.

39. said patterning comprising laser cutting a plurality of elongated posts from a sheet of material; 39. The method of claim 38.

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