Intravascular blood pump and pump with expandable scaffold

Abstract

A catheter blood pump with an expandable pump portion. The pump portion includes a collapsible blood conduit defining a blood lumen. The collapsible blood conduit includes a collapsible scaffold adapted to provide radial support to the blood conduit. The pump portion also includes one or more impellers. The collapsible scaffold may include portions with different radial stiffness based on the position of the one or more impellers therein.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 157,360, entitled "CATHETER BLOOD PUMPS AND COLLAPSIBLE BLOOD CONDUITS," filed on March 5, 2021, and U.S. Provisional Patent Application No. 63 / 193,544, entitled "INTRAVASCULAR BLOOD PUMPS AND PUMPS WITH EXPANDABLE SCAFFOLDS," filed on May 26, 2021, each of which is incorporated by reference in its entirety. Incorporation by Reference

[0002] All publications and patent applications mentioned in this specification are herein incorporated by reference in their entirety as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference. [Background technology]

[0002]

[0003] Cardiac patients may have a severely impaired ability to facilitate blood flow through their heart and vascular system, placing them at significant risk during corrective procedures such as balloon angioplasty and stent delivery. Methods are needed to improve the volume and stability of cardiac outflow in these patients, especially during corrective procedures.

[0003]

[0004] Intra-aortic balloon pumps (IABPs) are commonly used to support circulatory function, including in the treatment of patients with heart failure. The use of IABPs is common in the treatment of patients with heart failure, including supporting patients during high-risk percutaneous coronary intervention (HRPCI), stabilizing blood flow in patients after cardiogenic shock, treating patients with acute myocardial infarction (AMI), and treating decompensated heart failure. Such circulatory support can be used alone or in combination with medical therapy.

[0004]

[0005] An IABP is typically placed within the aorta and functions by expanding and contracting in a counterpulsating manner with the contractions of the heart, one of its functions being to provide additional support to the circulatory system. Summary of the Invention [Problem to be solved by the invention]

[0005]

[0006] Recently, minimally invasive rotary blood pumps have been developed that can be inserted into the body in relation to the cardiovascular system, such as pumping arterial blood from the left ventricle into the aorta to increase the natural blood pumping capacity of the left side of the patient's heart. Another known method is to pump venous blood from the right ventricle into the pulmonary artery to increase the natural blood pumping capacity of the right side of the patient's heart. The overall goal is to reduce the load on the patient's myocardium to stabilize the patient prior to a heart transplant or to provide ongoing support to the patient, such as during a medical procedure that may place additional stress on the heart.

[0006]

[0007] The smallest rotary blood pumps currently available can be inserted percutaneously into the patient's vasculature through an access sheath, eliminating the need for surgical intervention or vascular access grafts. An overview of this type of device is the percutaneously inserted ventricular support device.

[0007]

[0008] There is a need to provide further improvements in the field of ventricular assist devices and similar blood pumps for treating blood flow disorders in the heart. [Means for solving the problem]

[0008]

[0009] The present disclosure relates to intravascular blood pumps and methods and manufacture thereof.

[0009]

[0010] One aspect of the disclosure is an intravascular blood pump comprising a collapsible blood conduit defining an internal lumen for moving blood, the collapsible blood conduit including a proximal portion defined by at least two annular rows of connector elements arranged about a central axis of the collapsible blood conduit, a distal portion defined by at least one annular row of connector elements arranged about the central axis of the collapsible blood conduit, a central portion axially disposed between the distal portion and the proximal portion, the central portion including a plurality of axially extending elongated elements arranged in a helical pattern, and a proximal impeller disposed within at least a portion of the proximal portion.

[0010]

[0011] In some embodiments, the proximal scaffold portion, the central scaffold portion, and the distal scaffold portion are coupled (optionally integrally) to one another.

[0011]

[0012] In other embodiments, the central portion has a relative flexibility compared to the distal and proximal portions such that in response to a lateral force applied to the blood conduit of the distal impeller portion, the blood conduit deforms and assumes a more highly curved shape at the central portion than the proximal and distal portions.

[0012]

[0013] In some examples, the central portion includes at least one of a material or structure such that the central portion is more prone to collapse than the proximal and distal portions when a rotational force is applied to the distal end of the blood conduit.

[0013]

[0014] In one embodiment, at least a portion of the proximal and distal portions do not include a helical scaffold pattern.

[0014]

[0015] In some examples, an axially extending elongate element extends between at least two annular rows of connector elements in the proximal portion.

[0015]

[0016] In some embodiments, the distal portion is defined by at least two annular rows of connector elements disposed about a central axis of the collapsible blood conduit.

[0016]

[0017] In some embodiments, an axially extending elongate element extends between at least two annular rows of connector elements in the distal portion.

[0017]

[0018] In one example, the proximal portion is defined by at least four annular rows of connector elements disposed about a central axis of the collapsible blood conduit.

[0018]

[0019] In another example, the connector elements in each annular row are in a zigzag pattern.

[0019]

[0020] In some embodiments, the angle between the connector element and the axially extending elongate element is between about 10 degrees and 50 degrees.

[0020]

[0021] In some examples, the angle between the connector element and the axially extending elongate element is between about 10 degrees and 30 degrees.

[0021]

[0022] In another example, the angle between the connector element and the axially extending elongate element is between about 30 degrees and 50 degrees.

[0022]

[0023] In some embodiments, the scaffold has an axial length of about 50 mm to about 80 mm.

[0023]

[0024] In other embodiments, the proximal portion has a greater lateral bending stiffness than the distal portion.

[0024]

[0025] In some embodiments, the collapsible blood conduit comprises a scaffold configured to transition between a collapsed state and an expanded state, the scaffold having a diameter of 5.0 mm to 10 mm in the expanded state and a diameter of 2.5 mm to 4.5 mm in the collapsed state.

[0025]

[0026] In one embodiment, the pump further comprises a plurality of proximal struts extending proximally from the proximal portion.

[0026]

[0027] In some examples, the pump further comprises a plurality of distal struts extending distally from the distal portion.

[0027]

[0028] In other embodiments, the number of proximal struts is twice the number of distal struts.

[0028]

[0029] In one example, an intravascular blood pump includes 10 proximal struts and 5 distal struts.

[0029]

[0030] In another embodiment, the width of the distal struts is greater than the width of the proximal struts.

[0030]

[0031] In some instances, the axially extending elongate element increases in width near the distal portion.

[0031]

[0032] One aspect of the disclosure is an intravascular blood pump comprising: a collapsible blood conduit having an internal lumen for passing blood therethrough, the blood conduit including a scaffold arranged and configured to provide radial support to the blood conduit, the scaffold including a proximal portion having greater radial stiffness than a distal portion of the scaffold; a proximal impeller disposed within at least a portion of the proximal portion of the scaffold; and a distal impeller disposed within at least a portion of the distal portion of the scaffold.

[0032]

[0033] In this aspect, the proximal portion may have a longer axial length than the distal portion.

[0033]

[0034] In this aspect, the proximal portion can include a first pattern of structural elements defining a first set of openings and the distal portion can include a second pattern of structural elements defining a second set of openings, the first set of openings being smaller than the second set of openings.

[0034]

[0035] In this aspect, the scaffold can include a central portion between the proximal and distal portions.

[0035]

[0036] In this aspect, the proximal portion may have a greater radial stiffness than the central portion.

[0036]

[0037] In this manner, the distal portion may have a greater radial stiffness than the central portion.

[0037]

[0038] In this manner, the central portion can be configured to flex laterally when a lateral force is applied to the distal portion.

[0038]

[0039] In this aspect, the scaffold can include elongate elements extending axially within the proximal, central, and distal portions.

[0039]

[0040] In this aspect, the portion of the elongate element in the proximal portion may be wider than the portion of the elongate element in the central portion.

[0040]

[0041] In this aspect, the portion of the elongate element in the distal portion may be wider than the portion of the elongate element in the central portion.

[0041]

[0042] In this aspect, circumferentially adjacent elongate elements may be circumferentially connected by connector elements in the proximal and distal portions.

[0042]

[0043] In this aspect, the proximal portion may include more connector elements than the distal portion.

[0043]

[0044] In this aspect, the connector elements can be configured to bend to bring circumferentially adjacent elongate elements closer together as the scaffold transitions from the expanded state to the collapsed state.

[0044]

[0045] In this embodiment, the elongate elements are not connected to one another within the central portion.

[0045]

[0046] In this aspect, some of the elongate elements within the central portion may be arranged in a helical pattern about the central axis of the scaffold.

[0046]

[0047] In this aspect, the scaffold can be configured to transition between a collapsed state and an expanded state.

[0047]

[0048] In this aspect, the intravascular blood pump may further include a drive shaft operably coupled to the proximal impeller and the distal impeller, with the scaffold surrounding at least a portion of the drive shaft.

[0048]

[0049] In this aspect, the proximal impeller and the distal impeller may be configured to collapse together with the collapsible blood conduit.

[0049]

[0050] In this aspect, the scaffold may include elongate elements extending axially along the length of the scaffold, the axially extending elongate elements being connected by one or more annular rows of connector elements in the proximal portion.

[0050]

[0051] In this embodiment, the elongate elements may be connected by three annular rows of connector elements in the proximal portion.

[0051]

[0052] In this embodiment, the elongate elements may be connected by four annular rows of connector elements in the proximal portion.

[0052]

[0053] In this embodiment, the elongate elements may be connected by five annular rows of connector elements in the proximal portion.

[0053]

[0054] In this embodiment, the connector elements in each annular row may be in a zigzag pattern.

[0054]

[0055] In this aspect, the scaffold may include elongate elements extending axially along the length of the scaffold, the axially extending elongate elements being connected by a first set of annular rows of connector elements in the proximal portion and a second set of annular rows of connector elements in the distal portion, the first set having a greater number of annular rows of connector elements than the second set.

[0055]

[0056] In this aspect, the scaffold may include elongate elements extending axially along the length of the scaffold and connector elements connecting the elongate elements, the angle between the connector elements and the elongate elements being between about 10 degrees and 50 degrees.

[0056]

[0057] In this embodiment, the angle between the connector element and the elongate element may be between about 10 degrees and 30 degrees.

[0057]

[0058] In this embodiment, the angle between the connector element and the elongate element may be between about 30 degrees and 50 degrees.

[0058]

[0059] In this embodiment, the axial length of the scaffold may be from about 50 mm to about 80 mm.

[0059]

[0060] In this aspect, the proximal portion may have a greater lateral bending stiffness than the distal portion.

[0060]

[0061] In this embodiment, the blood conduit may be configured to transition between a collapsed state and an expanded state, with the scaffold having a diameter of 5.0 mm to 10 mm in the expanded state and a diameter of 2.5 mm to 4.5 mm in the collapsed state.

[0061]

[0062] One aspect of the disclosure is a method of using an intravascular blood pump, the method including: delivering the intravascular blood pump in a collapsed state towards a heart; expanding a scaffold of the intravascular blood pump in at least a portion of the heart, wherein the expanded scaffold provides radial support to a blood conduit defining a lumen, a proximal portion of the scaffold having a greater radial stiffness than a distal portion of the scaffold; and rotating a proximal impeller disposed within at least a portion of the proximal portion of the scaffold and a distal impeller disposed within at least a portion of the distal portion of the scaffold to pump blood through the lumen of the blood conduit.

[0062]

[0063] In this aspect, the method may further include expanding the proximal and distal impellers within the scaffold.

[0063]

[0064] In this aspect, the proximal portion may have a longer axial length than the distal portion.

[0064]

[0065] In this aspect, the method may further include disposing an intravascular blood pump within at least a portion of the heart, wherein when the scaffold is expanded, a proximal portion of the scaffold provides more radial support to the blood conduit than a distal portion of the scaffold (in some cases, a central portion of the scaffold provides less radial support to the blood conduit than a distal portion of the blood conduit).

[0065]

[0066] In this aspect, the scaffold may include a central portion between the proximal and distal portions, and the method further includes positioning the intravascular blood pump within at least a portion of the heart such that a lateral force applied to the scaffold (optionally to the central portion) (optionally from the native aortic valve leaflets) causes the central portion to bend laterally to a greater extent than the proximal portion and than the distal portion.

[0066]

[0067] In this aspect, the scaffold may include elongate elements extending axially within the proximal and distal portions, and expanding the scaffold may include moving the elongate elements radially away from one another.

[0067]

[0068] In this aspect, the method may further include folding the scaffold such that the elongate elements move radially inward toward one another.

[0068]

[0069] In this aspect, the expanding step may include placing a central scaffold portion at the aortic valve leaflets, placing at least a portion of a distal portion in the left ventricle, and placing at least a portion of a proximal portion in the ascending aorta, the central scaffold having flexibility such that when placed at the aortic valve leaflets, the central portion assumes a more curved shape than the proximal and distal portions.

[0069]

[0070] In this aspect, the proximal portion may have a greater lateral bending stiffness than the distal portion.

[0070]

[0071] In this embodiment, the scaffold may have a diameter of 5.0 mm to 10 mm when expanded.

[0071]

[0072] In this aspect, the method may further include folding the scaffold for placement within the sheath, wherein the diameter of the scaffold when folded is between 2.5 mm and 4.5 mm.

[0072]

[0073] One aspect of the present disclosure is an intravascular blood pump comprising a collapsible blood conduit defining an internal lumen for moving blood, the collapsible blood conduit including a distal impeller portion, a proximal impeller portion, and an axial central portion between the distal impeller portion and the proximal impeller portion, a proximal impeller disposed within at least a portion of the proximal impeller portion, and a distal impeller disposed within at least a portion of the distal impeller portion.

[0073]

[0074] In this aspect, the collapsible blood conduit may comprise a collapsible scaffold arranged and configured to provide radial support to the blood conduit, the proximal impeller portion comprising a proximal scaffold portion, the distal impeller portion comprising a distal scaffold portion, and the central portion comprising a central scaffold portion.

[0074]

[0075] In this embodiment, the proximal scaffold portion, the central scaffold portion, and the distal scaffold portion may be joined together (optionally integrally).

[0075]

[0076] In this aspect, the central portion may have a relative flexibility compared to the distal and proximal portions such that in response to a lateral force applied to the blood conduit by the distal impeller portion, the blood conduit deforms and assumes a more highly curved shape at the central portion than the proximal and distal portions.

[0076]

[0077] In this embodiment, the central portion may include at least one of a material or structure such that the central portion is more prone to collapsing than the proximal and distal portions when a rotational force is applied to the distal end of the blood conduit.

[0077]

[0078] In this aspect, the central portion may include a helical scaffold pattern that is absent from at least a portion of the proximal and distal portions.

[0078]

[0079] In this aspect, the scaffold may be elongated elements extending axially along the length of the scaffold, the axially extending elongated elements being connected by one or more annular rows of connector elements in the proximal portion.

[0079]

[0080] In this embodiment, the elongate elements may be connected by three annular rows of connector elements in the proximal portion.

[0080]

[0081] In this embodiment, the elongate elements may be connected by four annular rows of connector elements in the proximal portion.

[0081]

[0082] In this embodiment, the elongate elements may be connected by five annular rows of connector elements in the proximal portion.

[0082]

[0083] In this embodiment, the connector elements in each annular row may be in a zigzag pattern.

[0083]

[0084] In this aspect, the scaffold may include elongate elements extending axially along a length of the scaffold, the axially extending elongate elements being connected by a first set of annular rows of connector elements in the proximal portion and a second set of annular rows of connector elements in the distal portion, the first set having a greater number of annular rows of connector elements than the second set.

[0084]

[0085] In this aspect, the scaffold may include elongate elements extending axially along the length of the scaffold and connector elements connecting the elongate elements, the angle between the connector elements and the elongate elements being between about 10 degrees and 50 degrees.

[0085]

[0086] In this embodiment, the angle between the connector element and the elongate element may be between about 10 degrees and 30 degrees.

[0086]

[0087] In this embodiment, the angle between the connector element and the elongate element may be between about 30 degrees and 50 degrees.

[0087]

[0088] In this embodiment, the axial length of the scaffold is about 50 mm to about 80 mm.

[0088]

[0089] In this aspect, the proximal impeller portion may have a greater lateral bending stiffness than the distal impeller portion.

[0089]

[0090] In this aspect, the collapsible blood conduit may comprise a scaffold configured to transition between a collapsed state and an expanded state, the scaffold having a diameter of between 5.0 mm and 10 mm in the expanded state and a diameter of between 2.5 mm and 4.5 mm in the collapsed state.

[0090]

[0091] One aspect of the present disclosure is an intravascular blood pump including a collapsible blood conduit defining an internal lumen for moving blood, the collapsible blood conduit including a collapsible scaffold, a plurality of struts (e.g., 2951, 2952) extending from the blood conduit, the plurality of struts being disposed at either the pump inflow or the pump outflow, and one or more impellers (optionally distal and proximal impellers) disposed at least partially within the blood conduit.

[0091]

[0092] In this aspect, the plurality of struts can include a plurality of outflow struts, a first of the plurality of outflow struts having a different configuration than at least one other outflow strut.

[0092]

[0093] In this aspect, the first strut may have a proximal region that has a different configuration than a proximal region of at least one other outflow strut.

[0093]

[0094] In this embodiment, the proximal region may be a region of the strut that cannot expand and collapse (optionally coupled to a central hub), and a first region of the strut distal to the proximal region is coupled to the blood conduit (optionally integral) and is expandable and collapsible.

[0094]

[0095] In this aspect, the proximal region may have a width that is narrower than a width of at least one other outflow strut at the same axial location.

[0095]

[0096] In this aspect, the second outflow strut may have a width at an axial position that is smaller than a width of at least one other outflow strut at that axial position (optionally the same width as the first strut).

[0096]

[0097] In this aspect, first and second circumferentially adjacent outflow struts may have a width at an axial location that is less than a width of at least one other outflow strut at that axial location.

[0097]

[0098] In this embodiment, the first and second circumferentially adjacent outflow struts each have a sensor housing recess formed at an axial location, with the recesses facing each other in the circumferential direction.

[0098]

[0099] In this aspect, the plurality of struts may include a plurality of inflow struts, at least one inflow strut having a different configuration than at least one other inflow strut.

[0099]

[0100] In this aspect, the different configuration may be any of the differences described or claimed herein (e.g., narrower width in the distal non-expandable region, circumferential recess, etc.).

[0100]

[0101] In this aspect, the first outflow strut has a different configuration than at least one other outflow strut, and the first inflow strut has a different configuration than at least one other inflow strut.

[0101]

[0102] In this aspect, the first outflow and first inflow struts may be circumferentially offset.

[0102]

[0103] In this embodiment, the first outflow and first inflow struts may be circumferentially aligned (eg, as shown by the "center" strut in FIG. 29A).

[0103]

[0104] In this aspect, the first and second outflow struts may each have a different configuration than at least the other outflow struts (optionally to accommodate an outflow pressure sensor housing) and may optionally have a proximal non-expandable region thereof.

[0104]

[0105] In this aspect, the first and second inflow struts may each have a different configuration than at least the other inflow struts (optionally to accommodate an inflow pressure sensor housing) and may optionally have a distal non-expandable region thereof.

[0105]

[0106] In this aspect, at least one of the first and second inflow struts may be circumferentially offset from at least one of the outflow struts.

[0106]

[0107] In this aspect, at least one of the plurality of struts may include a pressure sensor recess formed therein that is sized and positioned relative to the pressure sensor and / or pressure sensor housing to accommodate the presence of the pressure sensor and / or pressure sensor housing.

[0107]

[0108] In this aspect, the pressure sensor recess may include a region that is relatively narrow in width.

[0108]

[0109] In this aspect, the plurality of struts may have an axially extending configuration.

[0109]

[0110] In this aspect, the scaffold may include elongate elements extending axially along the length of the scaffold, the axially extending elongate elements being connected by one or more annular rows of connector elements in the proximal portion.

[0110]

[0111] In this embodiment, the elongate elements may be connected by three annular rows of connector elements in the proximal portion.

[0111]

[0112] In this embodiment, the elongate elements may be connected by four annular rows of connector elements in the proximal portion.

[0112]

[0113] In this embodiment, the elongate elements may be connected by five annular rows of connector elements in the proximal portion.

[0113]

[0114] In this embodiment, the connector elements in each annular row may be arranged in a zigzag pattern.

[0114]

[0115] In this aspect, the scaffold may include elongate elements extending axially along a length of the scaffold, the axially extending elongate elements being connected by a first set of annular rows of connector elements in the proximal portion and a second set of annular rows of connector elements in the distal portion, the first set having a greater number of annular rows of connector elements than the second set.

[0115]

[0116] In this aspect, the scaffold may include elongate elements extending axially along the length of the scaffold and connector elements connecting the elongate elements, the angle between the connector elements and the elongate elements being between about 10 degrees and 50 degrees.

[0116]

[0117] In this embodiment, the angle between the connector element and the elongate element may be between about 10 degrees and 30 degrees.

[0117]

[0118] In this embodiment, the angle between the connector element and the elongate element may be between about 30 degrees and 50 degrees.

[0118]

[0119] In this embodiment, the axial length of the scaffold may be from about 50 mm to about 80 mm.

[0119]

[0120] In this aspect, the collapsible scaffold may include a proximal portion having a greater lateral bending stiffness than a distal portion of the collapsible scaffold.

[0120]

[0121] In this aspect, the scaffold may be configured to transition between a collapsed state and an expanded state, the scaffold having a diameter of 5.0 mm to 10 mm in the expanded state and a diameter of 2.5 mm to 4.5 mm in the collapsed state.

[0121]

[0122] One aspect of the disclosure is an intravascular blood pump comprising: a collapsible blood conduit having an internal lumen for passing blood therethrough, the collapsible blood conduit including a scaffold arranged and configured to provide radial support to the blood conduit, the scaffold including a proximal portion, a central portion, and a distal portion, the central portion being disposed between the proximal portion and the distal portion and being more flexible than the distal portion and the proximal portion; a proximal impeller disposed within at least a portion of the proximal portion of the scaffold; and a distal impeller disposed within at least a portion of the distal portion of the scaffold, wherein when the blood conduit is positioned across an aortic valve with the central portion positioned at the aortic valve leaflets, the flexibility of the central portion causes the central portion to assume a curved shape, and the curved configuration causes an axis of rotation of the proximal impeller to be misaligned with an axis of rotation of the distal impeller.

[0122]

[0123] In this aspect, the central portion may include multiple helical portions, optionally not circumferentially connected to one another by a scaffold.

[0123]

[0124] In this aspect, the proximal, central, and distal portions may have different radial stiffnesses.

[0124]

[0125] In this aspect, the proximal portion may have a greater radial and lateral bending stiffness than the distal portion.

[0125]

[0126] In this aspect, the scaffold may be configured to transition between a collapsed state and an expanded state, the scaffold having a diameter of 5.0 mm to 10 mm in the expanded state and a diameter of 2.5 mm to 4.5 mm in the collapsed state.

[0126]

[0127] One aspect of the disclosure is a tubular scaffold for an intravascular blood pump, comprising: a first impeller portion configured to accommodate a first impeller; a second impeller portion configured to accommodate a second impeller; and a central portion between the first impeller portion and the second impeller portion, the central portion having a plurality of elongated elements extending axially in a helical manner and unconnected to one another within the central portion, the helical arrangement of the elongated elements being configured to bend the central portion laterally when a lateral force is applied to the tubular scaffold.

[0127]

[0128] In this embodiment, the first and second impeller portions may include a connector element connecting the elongated elements in the first and second impeller portions.

[0128]

[0129] In this embodiment, the elongate elements may be parallel to a central axis of the tubular scaffold within the first impeller portion.

[0129]

[0130] In this embodiment, the elongate elements may be parallel to a central axis of the tubular scaffold within the second impeller portion.

[0130]

[0131] In this embodiment, the central portion may have greater lateral flexibility than the first impeller portion or the second impeller portion.

[0131]

[0132] In this aspect, the first and second impeller portions may each have a greater radial stiffness than the central portion.

[0132]

[0133] In this embodiment, the first and second impeller portions may include a connector element connecting the elongated elements in the first and second impeller portions.

[0133]

[0134] In this aspect, the tubular scaffold may include a plurality of struts curved radially inward and configured to connect to a central hub of the intravascular blood pump.

[0134]

[0135] In this aspect, the tubular scaffold may be configured to transition between a radially expanded state and a radially collapsed state.

[0135]

[0136] In this embodiment, the central portion may have a longer axial length than each of the first and second impeller portions.

[0136]

[0137] In this embodiment, the elongated elements may be connected by one or more annular rows of connector elements in the first impeller portion.

[0137]

[0138] In this embodiment, the elongated elements may be connected by three annular rows of connector elements within the first impeller portion.

[0138]

[0139] In this embodiment, the elongated elements may be connected by four annular rows of connector elements within the first impeller portion.

[0139]

[0140] In this embodiment, the elongated elements may be connected by five annular rows of connector elements within the first impeller portion.

[0140]

[0141] In this embodiment, the connector elements in each annular row may be arranged in a zigzag pattern.

[0141]

[0142] In this embodiment, the tubular scaffold may further comprise a membrane covering at least a portion of the inner and / or outer surface of the tubular scaffold.

[0142]

[0143] In this embodiment, the elongate element may extend axially through the first impeller portion, the central portion, and the second impeller portion.

[0143]

[0144] In this embodiment, lateral bending of the central portion may cause the first impeller portion to become axially misaligned relative to the second impeller portion.

[0144]

[0145] In this aspect, the first impeller portion may have a greater radial and lateral bending stiffness than the second impeller portion.

[0145]

[0146] In this aspect, the tubular scaffold may be configured to transition between a collapsed state and an expanded state, the tubular scaffold having a diameter of between 5.0 mm and 10 mm in the expanded state and a diameter of between 2.5 mm and 4.5 mm in the collapsed state.

[0146]

[0147] One aspect of the disclosure is an intravascular blood pump comprising a tubular scaffold including a proximal portion at least partially surrounding a proximal impeller, a distal portion at least partially surrounding a distal impeller, and a central portion between the proximal and distal portions having a plurality of helically arranged, axially extending elongated elements that are not connected to one another within the central portion.

[0147]

[0148] In this aspect, the helical arrangement may provide sufficient lateral flexibility to allow the central portion to flex when a lateral force is applied to the tubular scaffold.

[0148]

[0149] In this manner, deflection of the central portion may cause the proximal portion to shift axially relative to the distal portion.

[0149]

[0150] In this manner, deflection of the central portion may cause the proximal portion to shift axially relative to the distal portion.

[0150]

[0151] In this aspect, the central portion may be configured to return to its original shape after the lateral force is released from the tubular scaffold.

[0151]

[0152] In this aspect, when the scaffold returns to its original shape, the proximal portion may be axially aligned with the distal portion.

[0152]

[0153] In this aspect, the proximal and distal portions may each include a number of struts coupled to a central hub of the intravascular blood pump.

[0153]

[0154] In this aspect, the tubular scaffold may surround at least a portion of the central drive shaft.

[0154]

[0155] In this aspect, the drive shaft may be configured to bend laterally when the tubular scaffold bends laterally.

[0155]

[0156] In this aspect, the proximal portion may have a greater radial and lateral bending stiffness than the distal portion.

[0156]

[0157] In this aspect, the tubular scaffold may be configured to transition between a collapsed state and an expanded state, the tubular scaffold having a diameter of between 5.0 mm and 10 mm in the expanded state and a diameter of between 2.5 mm and 4.5 mm in the collapsed state.

[0157]

[0158] One aspect of the present disclosure is a tubular scaffold for an intravascular blood pump comprising: a first impeller portion configured to at least partially house a first impeller, the first impeller portion having a first scaffold pattern; and a second impeller portion configured to at least partially house a second impeller, the second impeller portion having a second scaffold pattern, wherein the first scaffold pattern is more densely packed than the second scaffold pattern.

[0158]

[0159] In this aspect, the first scaffold pattern is associated with a first stiffness and the second scaffold pattern is associated with a second stiffness, the first stiffness being greater than the second stiffness.

[0159]

[0160] In this aspect, the first and second stiffnesses may include one or more of a radial stiffness and a bending stiffness.

[0160]

[0161] In this aspect, the tubular scaffold may further include a central portion between the first impeller portion and the second impeller portion, the central portion having a more loosely packed scaffold pattern than each of the first impeller portion and the second impeller portion.

[0161]

[0162] In this aspect, the central portion may include a plurality of helically arranged, axially extending, unconnected elongate elements within the central portion, the helical arrangement of the elongate elements configured to cause the central portion to bend laterally upon application of a lateral force to the tubular scaffold.

[0162]

[0163] In this embodiment, the first impeller portion may be the proximal portion and the second impeller portion may be the distal portion.

[0163]

[0164] In this aspect, the tubular scaffold may be configured to transition between a collapsed state and an expanded state, the tubular scaffold having a diameter of between 5.0 mm and 10 mm in the expanded state and a diameter of between 2.5 mm and 4.5 mm in the collapsed state.

[0164]

[0165] These and other aspects are described herein. [Brief description of the drawings]

[0165] [Figure 1]

[0166] FIG. 13 is a side view of an exemplary expandable pump portion including an expandable impeller housing and multiple impellers including a scaffold and a blood conduit. [Diagram 2]

[0167] FIG. 1 is a side view of an exemplary expandable pump portion including an expandable impeller housing, a blood conduit, multiple impellers, and multiple expandable scaffold portions or support members. [Figure 3A]

[0168] FIG. 1 illustrates an exemplary expandable pump portion including a blood conduit, multiple impellers, and multiple expandable scaffold portions or support members. [Figure 3B] FIG. 1 illustrates an exemplary expandable pump portion including a blood conduit, multiple impellers, and multiple expandable scaffold portions or support members. [Figure 3C] FIG. 1 illustrates an exemplary expandable pump portion including a blood conduit, multiple impellers, and multiple expandable scaffold portions or support members. [Figure 3D] FIG. 1 illustrates an exemplary expandable pump portion including a blood conduit, multiple impellers, and multiple expandable scaffold portions or support members. [Figure 4]

[0169] FIG. 1 illustrates an exemplary target location for an expandable pump portion, the pump portion including a blood conduit, multiple expandable scaffold portions or support members, and multiple impellers. [Diagram 5]

[0170] FIG. 1 illustrates an exemplary pump portion including an expandable impeller housing, a blood conduit, and multiple impellers. [Figure 6A]

[0171] FIG. 1 illustrates at least a portion of an exemplary catheter blood pump that includes a pump portion having at least two different impellers capable of rotating at different speeds. [Figure 6B]

[0172] FIG. 1 illustrates at least a portion of an exemplary catheter blood pump that includes a pump portion having at least two different impellers capable of rotating at different speeds. [Figure 6C]

[0173] FIG. 1 illustrates at least a portion of an exemplary catheter blood pump including a pump portion with at least two impellers having different pitches. [Figure 7]

[0174] FIG. 1 illustrates a portion of an exemplary catheter blood pump including a pump portion. [Figure 8]

[0175] FIG. 1 illustrates an exemplary expandable pump portion including multiple expandable impellers, including one or more bends formed between adjacent impellers. [Figure 9]

[0176] FIG. 1 illustrates an exemplary expandable pump portion with multiple impellers and blood conduits. [Figure 10]

[0177] FIG. 1 illustrates an exemplary scaffold design and exemplary struts. [Figure 11]

[0178] FIG. 1 illustrates an exemplary scaffold design and exemplary struts. [Figure 12A]

[0179] 1A-1C illustrate an exemplary sequence of steps that may be performed to deploy an exemplary pump portion of a catheter blood pump. [Figure 12B] 1A-1C illustrate an exemplary sequence of steps that may be performed to deploy an exemplary pump portion of a catheter blood pump. [Figure 12C]1A-1C illustrate an exemplary sequence of steps that may be performed to deploy an exemplary pump portion of a catheter blood pump. [Figure 12D] 1A-1C illustrate an exemplary sequence of steps that may be performed to deploy an exemplary pump portion of a catheter blood pump. [Figure 12E] 1A-1C illustrate an exemplary sequence of steps that may be performed to deploy an exemplary pump portion of a catheter blood pump. [Figure 12F] 1A-1C illustrate an exemplary sequence of steps that may be performed to deploy an exemplary pump portion of a catheter blood pump. [Figure 13A]

[0180] 1A-1C show exemplary portions of an expandable pump portion. [Figure 13B] 1A-1C show exemplary portions of an expandable pump portion. [Figure 13C]

[0181] FIG. 13C shows the scaffold of FIGS. 13A and 13B in a flattened, unexpanded configuration, further showing optional distal and proximal struts extending axially therefrom. [Figure 14A]

[0182] FIG. 1 illustrates an exemplary expanded scaffold that may be part of an expandable pump portion of the present disclosure. [Figure 14B]

[0183] FIG. 14B illustrates the scaffold and struts of FIG. 14A in a flattened, unexpanded configuration. [Figure 15A]

[0184] FIG. 1 illustrates an exemplary expanded scaffold that may be part of an expandable pump portion of the present disclosure. [Figure 15B]

[0185] FIG. 15B illustrates the scaffold and struts of FIG. 15A in a flattened, unexpanded configuration. [Figure 16]

[0186] FIG. 1 illustrates an exemplary scaffold and optionally joined struts in a flattened, unexpanded configuration. [Figure 17]

[0187] FIG. 1 illustrates an exemplary scaffold and optionally joined struts in a flattened, unexpanded configuration. [Figure 18A]

[0188] FIG. 1 illustrates an exemplary scaffold in a flattened, unexpanded configuration. [Figure 18B]

[0189] FIG. 18B illustrates the scaffold of FIG. 18A in an expanded configuration. [Figure 19A]

[0190] FIG. 1 illustrates an exemplary scaffold in a flattened, unexpanded configuration. [Figure 19B]

[0191] FIG. 19B illustrates the scaffold of FIG. 19A in an expanded configuration. [Figure 20A]

[0192] FIG. 1 illustrates an exemplary scaffold in a flattened, unexpanded configuration. [Figure 20B]

[0193] FIG. 20B illustrates the scaffold of FIG. 20A in an expanded configuration. [Figure 21A]

[0194] FIG. 1 illustrates an exemplary scaffold in a flattened, unexpanded configuration. [Figure 21B]

[0195] FIG. 21B illustrates the scaffold of FIG. 21A in an expanded configuration. [Figure 22A]

[0196] FIG. 1 illustrates an exemplary scaffold in a flattened, unexpanded configuration. [Figure 22B]

[0197] FIG. 22B illustrates the scaffold of FIG. 22A in an expanded configuration. [Figure 23A]

[0198] FIG. 1 illustrates an exemplary scaffold in a flattened, unexpanded configuration. [Figure 23B]

[0199] FIG. 23B illustrates the scaffold of FIG. 23A in an expanded configuration. [Figure 24A]

[0200] FIG. 1 illustrates an exemplary scaffold in a flattened, unexpanded configuration. [Figure 24B]

[0201] FIG. 24B illustrates the scaffold of FIG. 24A in an expanded configuration. [Figure 25A]

[0202] FIG. 1 illustrates an exemplary scaffold in a flattened, unexpanded configuration. [Figure 25B]

[0203] FIG. 25B illustrates the scaffold of FIG. 25A in a flat expanded configuration. [Figure 26A]

[0204] FIG. 1 illustrates an exemplary scaffold in a flattened, unexpanded configuration. [Figure 26B]

[0205] FIG. 26B highlights an exemplary cross section of the scaffold shown in FIG. 26A. [Figure 27A]

[0206] FIG. 1 illustrates an exemplary scaffold in a flattened, unfolded configuration. [Figure 27B]

[0207] FIG. 27B illustrates the scaffold of FIG. 27A in an unfolded configuration. [Figure 28A]

[0208] FIG. 13 illustrates an exemplary foldable pump portion that includes a central scaffold portion that is not unitary but is unconnected to one or more axially adjacent scaffold portions. [Figure 28B] FIG. 13 illustrates an exemplary foldable pump portion that includes a central scaffold portion that is not unitary but is unconnected to one or more axially adjacent scaffold portions. [Figure 29A]

[0209] FIG. 1 illustrates an exemplary scaffold having sections of different stiffness. A flattened view of the scaffold is shown. [Figure 29B] FIG. 1 illustrates an exemplary scaffold having portions of different stiffness. FIG. 2 illustrates a blood conduit with a scaffold with a membrane in an expanded configuration. [Figure 29C] FIG. 13 illustrates an exemplary scaffold having portions of different stiffness, showing the proximal impeller region of a blood conduit (including the scaffold and membrane) in a collapsed configuration within a sheath. [Figure 29D]FIG. 1 illustrates an exemplary scaffold having portions of different stiffness. A close-up of a proximal portion of the scaffold. [Figure 29E] FIG. 1 illustrates an exemplary scaffold having portions of different stiffness, with an enlarged view of a distal portion of the scaffold. [Diagram 30]

[0210] FIG. 13 is a flattened view of another exemplary scaffold having a different scaffold pattern. [Diagram 31]

[0211] FIG. 13 is a flattened view of another exemplary scaffold having a different scaffold pattern. [Figure 32A]

[0212] FIG. 13 illustrates another exemplary scaffold having a different scaffold pattern, showing a flattened view of the scaffold. [Figure 32B] FIG. 13 illustrates another exemplary scaffold having a different scaffold pattern, showing the scaffold in an expanded state. [Figure 33A]

[0213] FIG. 1 illustrates another exemplary scaffold in a flattened view. [Figure 33B] FIG. 1 illustrates another exemplary scaffold in an expanded state. [Diagram 34]

[0214] FIG. 1 illustrates another exemplary scaffold in a flattened view. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0166]

[0215] The present disclosure relates to medical devices, systems, and methods of use and manufacture. The medical devices herein can include a distal pump portion (also referred to herein as an actuating portion) adapted to be placed within a physiological blood vessel, the distal pump portion including one or more components that act on a fluid. For example, the pump portion herein can include one or more rotating members that can rotate to facilitate the movement of a fluid, such as blood.

[0167]

[0216] Any disclosure herein relating to one aspect of a system, device, or method of use may be incorporated into other appropriate disclosures herein. For example, a diagram illustrating only one aspect of an apparatus or method may be included in other embodiments even if not specifically described in the description of one or both parts of the disclosure. Thus, it is understood that combinations of different parts of the disclosure are included herein.

[0168]

[0217] FIG. 1 is a side view showing a distal portion of an exemplary catheter blood pump including a pump portion 1600, which includes a proximal impeller 1606 and a distal impeller 1616, both of which are in operative communication with a drive cable 1612 (also referred to as a drive shaft). The pump portion 1600 is in an expanded configuration in FIG. 1, but is adapted to be folded into a delivery configuration so that it can be delivered with a lower profile. The impellers can be attached to a drive mechanism 1612 (e.g., a drive cable). The drive mechanism 1612 is in operative communication with an external motor, not shown, which extends through an elongated shaft 1610. The phrases "pump portion" and "actuating portion" (or derivatives thereof) may be used interchangeably herein unless otherwise noted. For example, but not by way of limitation, the "pump portion" 1600 may also be referred to herein as the "actuating portion." It should be understood that although the embodiment of FIG. 1 shows two impellers (i.e., a distal impeller and a proximal impeller), the embodiment of FIG. 1, or other embodiments of the present disclosure, may include only a single impeller, such as only a proximal impeller or only a distal impeller.

[0169]

[0218] The pump portion 1600 also includes an expandable member or expandable scaffold 1602, which in this embodiment has a proximal end 1620 that extends proximally further than the proximal end of the proximal impeller 1606, and a distal end 1608 that extends distally further than the distal end 1614 of the distal impeller 1616. The expandable member may also be referred to herein as an expandable scaffold or scaffold portion. The expandable scaffold 1602 is disposed radially outward of the impeller along the axial length of the impeller. The expandable scaffold 1602 may be constructed in a manner and made from materials similar to many types of expandable structures known in the medical arts that can be folded and expanded, examples of which are provided herein. Examples of suitable materials include, but are not limited to, polyurethane, polyurethane elastomers, metal alloys, and the like.

[0170]

[0219] The pump portion 1600 also includes a blood conduit 1604 coupled to and supported by the expandable member 1602, having a length L, and extending axially between the impellers. The conduit 1604 forms and provides a fluid lumen between the two impellers. In use, fluid travels through the lumen defined by the conduit 1604. The conduits herein may be non-permeable, semi-permeable, or even porous so long as they define a lumen. The conduits herein are also flexible unless otherwise noted. The conduits herein extend completely (i.e., 360 degrees) around at least a portion of the pump portion. In the pump portion 1600, the conduit extends completely around the expandable member 1602, but does not extend to the proximal end 1602 or the distal end 1608 of the expandable member 1602. The structure of the expandable member forms at least one inlet opening to allow inflow "I" and at least one outlet opening to allow outflow "O". The conduit 1604 improves the pumping dynamics of the impeller compared to pump portions without conduits. As described herein, the expandable member or scaffold may generally be considered to be part of a blood conduit, together defining a blood lumen. In these cases, the scaffold and the material supported by the scaffold may be referred to herein as an expandable impeller housing or housing.

[0171]

[0220] The expandable member 1602 may have a variety of configurations and be made from a variety of materials. For example, the expandable member 1602 may be formed similar to an expandable stent or stent-like device, or other examples provided herein. For example, but not limited to, the expandable member 1602 may have an open braided configuration, such as a 24-end braid, although more or less braided wires may be used. Exemplary materials for the expandable members and struts herein include Nitinol, cobalt alloys, and polymers, although other materials may be used. The expandable member 1602 has an expanded configuration, as shown, in which the outer dimensions of the expandable member (measured perpendicular to the longitudinal axis of the working portion) are greater at least in the region disposed radially outward of the impellers than in a central region 1622 of the expandable member that extends axially between the impellers. In this embodiment, the drive mechanism 1612 is coaxial with the longitudinal axis. In use, the central region may be positioned across a valve, such as the aortic valve. In some embodiments, the expandable member 1602 is adapted and constructed to expand to an outermost dimension of 12-24F (4.0-8.0 mm) when the impellers are axially within the expandable member, and an outermost dimension of the central region 1622 between the impellers that is 10-20F (3.3-6.7 mm). The smaller outer dimension of the central region reduces the forces acting on the valve and can reduce or minimize damage to the valve. The larger dimension of the expandable member in the region of the impellers can help axially stabilize the working portion during use. The expandable member 1602 has a general dumbbell shape. The expandable member 1602 has an outer shape that tapers as it transitions from the impeller region to the central region 1622, then tapers again at the distal and proximal ends of the expandable member 1602.

[0172]

[0221] The expandable member 1602 has a proximal end 1620 coupled to a shaft 1610 and a distal end 1608 coupled to a distal tip 1624. An impeller and drive mechanism 1612 rotates within the expandable member and conduit assembly. The drive mechanism 1612 is axially stable relative to the distal tip 1624 but is free to rotate relative to the tip 1624.

[0173]

[0222] In some embodiments, the expandable member 1602 can be collapsed by pulling tension from one end of the expandable member to the other. This can include linear motion (e.g., but not limited to, 5-20 mm of movement) to axially expand the expandable member 1602 into a collapsed configuration having a collapsed outer dimension. The expandable member 1602 can also be collapsed by pushing an outer shaft, such as a sheath, over the expandable member / conduit assembly to collapse the expandable member and conduit toward their collapsed delivery configuration.

[0174]

[0223] Impellers 1606 and 1616 are also adapted and constructed such that one or more blades are stretched or radially compressed to a reduced outermost dimension (measured perpendicular to the longitudinal axis of the working portion). For example, but not limited to, any of the impellers herein may include one or more blades made from a plastic compound having spring properties, such as any of the impellers described in U.S. Pat. No. 7,393,181, the disclosure of which is incorporated herein by reference for all purposes and may be incorporated into embodiments herein unless the present disclosure indicates to the contrary. Alternatively, for example, one or more foldable impellers may be constructed of a superelastic wire frame with a polymer or other material acting as a webbing across the wire frame, such as that described in U.S. Pat. No. 6,533,716, the disclosure of which is incorporated herein by reference for all purposes.

[0175]

[0224] The inflow and / or outflow configuration of the working portion 1600 may be mostly axial in nature.

[0176]

[0225] Exemplary covering and uncovering techniques and concepts for collapsing and expanding medical devices are known, such as those described and shown in U.S. Pat. No. 7,841,976 or U.S. Pat. No. 8,052,749, the disclosures of which are incorporated herein by reference.

[0177]

[0226] 2 is a side view showing a deployed configuration (shown outside the body) of a distal portion of an exemplary embodiment of a catheter blood pump. The exemplary blood pump 1100 includes an actuating portion 1104 (also referred to herein as a pump portion, as described herein) and an elongated portion 1106 extending from the actuating portion 1104. The elongated portion 1106 may extend to a more proximal region of the system (not shown for clarity) and may include, for example, a motor. The actuating portion 1104 includes a first expandable scaffold or member 1108 and a second expandable scaffold or member 1110 axially spaced apart along a longitudinal axis LA of the actuating portion 1104. The first scaffold 1108 and the second scaffold 1110 (and other separate scaffolds herein) may also be referred to as part of a common scaffold and may be referred to herein as scaffold portions. In this context, axially spaced refers to the entire first expandable member being axially spaced from the entire second expandable member along the longitudinal axis LA of the actuation portion 1104. The first end 1122 of the first expandable member 1108 is axially spaced from the first end 1124 of the second expandable member 1110.

[0178]

[0227] The first and second expandable members 1108 and 1110 generally include a plurality of elongated segments disposed relative to one another to define a plurality of openings 1130, only one of which is labeled in the second expandable member 1110. The expandable members can have a variety of configurations and can be constructed in a variety of ways, such as, for example, but not limited to, any of the configurations or structures of U.S. Pat. No. 7,841,976 or the tubes of U.S. Pat. No. 6,533,716 described as self-expanding metallic endoprosthetic materials. For example, but not limited to, one or both of the expandable members can have a braided structure or can be formed at least in part by laser cutting a tubular element.

[0179]

[0228] The working portion 1104 also includes a blood conduit 1112 coupled to the first and second expandable members 1108 and 1110 and extending axially between the first and second expandable members 1108 and 1110 in the deployed configuration. A central region 1113 of the conduit 1112 spans an axial distance 1132 that is free of the first and second expandable members 1108 and 1110 in the working portion. The central region 1113 can be considered to be axially midway between the expandable members. The distal end 1126 of the conduit 1112 does not extend as distally as the distal end 1125 of the second expandable member 1110, and the proximal end 1128 of the conduit does not extend as proximally as the proximal end 1121 of the first expandable member 1108.

[0180]

[0229] When the disclosure herein refers to a blood conduit coupled to an expandable scaffold or member, the term coupled in this context does not require that the conduit be directly attached to the expandable member such that the conduit physically contacts the expandable member. However, even if not directly attached, the term coupled in this context refers to the conduit and expandable member being coupled together such that as the expandable member expands or collapses, the conduit also begins to transition to a different configuration and / or size. Thus, coupled in this context refers to the conduit moving as the expandable member to which it is coupled transitions between the expanded and collapsed configurations.

[0181]

[0230] Any of the blood conduits herein are deformable to some degree. For example, the conduit 1112 includes an elongated member 1120 that can be made of one or more materials that allow the central region 1113 of the conduit to deform radially inward (towards the LA) to some degree, for example, in use when the working portion 1104 is deployed toward the configuration shown in FIG. 2 in response to forces from the valve tissue (e.g., leaflets) or replacement valve. In some embodiments, the conduit may be stretched tightly between the expandable members. The conduit may also be designed with slack that induces greater compliance. This may be desirable when the working portion is positioned across a fragile structure, such as the aortic valve, allowing the valve to compress the conduit in a manner that minimizes point stresses within the valve. In some embodiments, the conduit may include a membrane attached to the proximal and distal expandable members. Exemplary materials that may be used for any of the conduits herein include, but are not limited to, polyurethane rubber, silicone rubber, acrylic rubber, expanded polytetrafluoroethylene, polyethylene, polyethylene terephthalate, and any combination thereof.

[0182]

[0231] Any of the conduits herein may have a thickness in thousandths of an inch (thou) from 12.7 μm to 508 μm (0.5 to 20 thou), for example, from 25.4 to 381 μm (1 to 15 thou), or from 38.1 to 381 μm (1.5 to 15 thou), from 38.1 to 254 μm (1.5 to 10 thou), or from 50.8 to 254 μm (2 to 10 thou).

[0183]

[0232] Any of the blood conduits herein, or at least a portion of the conduit, may be impermeable to blood. In FIG. 2, the working portion 1104 includes a lumen that extends from the distal end 1126 of the conduit 1112 and extends to the proximal end 1128 of the conduit 1112. The lumen is defined by the conduit 1112 in the central region 1113, but can be considered to be defined by both the portions of the expandable member and the conduit in the region axially adjacent to the central region 1113. However, in this embodiment, it is the conduit material that causes the lumen to exist and prevents blood from passing through the conduit.

[0184]

[0233] The conduits herein secured to one or more expandable members, unless otherwise specified, may be secured such that the conduit is disposed radially outward of the one or more expandable members, radially inward of the one or more expandable members, or both, allowing the expandable members to be impregnated with the conduit material.

[0185]

[0234] The proximal and distal expandable scaffolds or members serve to maintain the blood conduit in an open configuration to form a lumen, and each also forms the operating environment for an impeller, described below. When in a deployed configuration, each of the expandable scaffolds is maintained in a spaced apart relationship to the respective impeller, allowing the impeller to rotate within the expandable member without contacting the expandable member. The actuating portion 1104 includes a first impeller 1116 and a second impeller 1118, the first impeller 1116 being radially disposed within the first expandable member 1108, and the second impeller 1118 being radially disposed within the second expandable member 1110. In this embodiment, the two impellers, despite being separate impellers, are in operative communication with a common drive mechanism (e.g., drive cable 1117), such that when the drive mechanism is actuated, the two impellers rotate together. In this deployed configuration, the impellers 1116 and 1118 are axially spaced apart along the longitudinal axis LA, similar to the axial spaced apart arrangement of the expandable members 1108 and 1110. Although the embodiment of Figure 2 shows two impellers (i.e., a distal impeller and a proximal impeller), it should be understood that the embodiment of Figure 2, or other embodiments of the present disclosure, may include only a single impeller, such as only a proximal impeller or only a distal impeller.

[0186]

[0235] The impellers 1116 and 1118 are also axially within the ends of the expandable members 1108 and 1110, respectively (in addition to being radially within the expandable members 1108 and 1110). The impellers herein can be considered to be axially within the expandable members even if the expandable members include struts (e.g., struts that are tapered in side view) that extend from a central region of the expandable member toward the longitudinal axis of the working portion. In FIG. 2, the second expandable member 1110 extends from a first end 1124 (proximal end) to a second end 1125 (distal end).

[0187]

[0236] 2, a distal portion of impeller 1118 extends distally beyond distal end 1126 of conduit 1112, and a proximal portion of impeller 1116 extends proximally beyond proximal end 1128 of conduit 1112. In this illustration, a portion of each impeller is axially within the conduit in this deployed configuration.

[0188]

[0237] In the exemplary embodiment shown in FIG. 2, the impellers 1116 and 1118 are in operative communication with a common drive mechanism 1117, in which the impellers are each coupled to the drive mechanism 1117 that extends through the shaft 1119 and the actuating portion 1104. The drive mechanism 1117 can be, for example, an elongated drive cable that rotates the impellers when rotated. In this example, as shown, the drive mechanism 1117 extends to the distal tip 1114 and is axially fixed relative to the distal tip 1114, but is adapted to rotate relative to the distal tip 1114 upon actuation. Thus, in this embodiment, as the drive mechanism rotates, the impellers and the drive mechanism 1117 rotate together. Any number of known mechanisms can be used to rotate the drive mechanism, such as a motor (e.g., an external motor).

[0189]

[0238] The expandable member and the conduit are not in rotational communication with the impeller and the drive mechanism. In this embodiment, the proximal end 1121 of the proximal expandable member 1108 is coupled to a shaft 1119, which may be the shaft of the elongated portion 1106 (e.g., an outer catheter shaft). The distal end 1122 of the proximal expandable member 1108 is coupled to a central tubular member 1133 through which the drive mechanism 1117 extends. The central tubular member 1133 extends distally from the proximal expandable member 1108 within the conduit 1112 and is also coupled to the proximal end 1124 of the distal expandable member 1110. Thus, the drive mechanism 1117 rotates within and relative to the central tubular member 1133. The central tubular member 1133 extends axially from the proximal expandable member 1108 to the distal expandable member 1110. As shown, the distal end 1125 of the distal expandable member 1110 is coupled to a distal tip 1114. A drive mechanism 1117 is adapted to rotate relative to the tip 1114, but is axially fixed relative to the tip 1114.

[0190]

[0239] The actuating portion 1104 is adapted and configured to be folded into a smaller profile than the deployed configuration (shown in FIG. 2). This allows for delivery using a lower profile delivery device (smaller French size) than would be required if none of the actuating portions 1104 were collapsible. Although not specifically described herein, both the expandable member and the impeller may be adapted and configured to be collapsible to some degree into a smaller delivery configuration.

[0191]

[0240] The working portions herein can be folded into a folded delivery configuration (e.g., by axially moving one or both of the sheath and working portion) using conventional techniques, such as an outer sheath that is movable relative to the working portion. For example, folding of the working portions herein can be facilitated using any of the systems, devices, or methods shown in the following references, which are incorporated by reference herein for all purposes, without limitation: U.S. Pat. No. 7,841,976 or U.S. Pat. No. 8,052,749.

[0192]

[0241] Figures 3A-3D show an exemplary pump portion similar in some respects to the pump portion shown in Figure 2. Pump portion 340 is similar to pump portion 1104 in that it includes two expandable members that are axially spaced apart from one another when the pump portion is expanded, and a conduit extending between the two expandable members. Figure 3A is a perspective view, Figure 3B is a side cross-sectional view, and Figures 3C and 3D are enlarged side cross-sectional views of a portion of Figure 3B.

[0193]

[0242] The pump portion 340 includes a proximal impeller 341 and a distal impeller 342, which are coupled to and in operative communication with a drive cable that defines a lumen therein. The lumen can be sized to accommodate a guidewire, which can be used to deliver the working portion to a desired location. In this embodiment, the drive cable includes a first portion 362 (e.g., a wound material), a second portion 348 (e.g., a tubular member) to which the proximal impeller 341 is coupled, a third portion 360 (e.g., a wound material), and a fourth portion 365 (e.g., a tubular material) to which the distal impeller 342 is coupled. The drive cable portions all have the same inner diameter, so that the inner diameter of the lumen is constant. The drive cable portions can be secured to one another using known attachment techniques. A distal end of the fourth portion 365 extends to a distal region of the working portion, allowing the working portion to be advanced over a guidewire, for example, to position the working portion. In this embodiment, the second and fourth portions can be stiffer than the first and third portions, for example the second and fourth portions can be tubular and the first and third portions can be rolled material to provide less stiffness.

[0194]

[0243] The pump portion 340 includes a proximal expandable scaffold 343 and a distal expandable scaffold 344, each extending radially outward of one of the impellers. The expandable scaffolds have distal and proximal ends that also extend axially beyond the distal and proximal ends of the impellers, as seen in FIGS. 3B-3D. A blood conduit 356 having a proximal end 353 and a distal end 352 is coupled to the two expandable scaffolds. Each of the two expandable scaffolds includes a plurality of proximal struts and a plurality of distal struts. The proximal struts of the proximal expandable scaffold 343 extend to and are secured to a shaft portion 345, which is coupled to a bearing 361 and configured and sized to rotate with a drive cable extending therethrough. The distal struts of the proximal expandable scaffold 343 extend to and are secured to a proximal region (in this case the proximal end) of a central tubular member 346 that is axially disposed between the expandable members. The proximal end of the central tubular member 346 is coupled to a bearing 349 through which a drive cable extends and rotates, as shown in FIG. 3C. The proximal struts extend axially from the distal expandable scaffold 344 and are secured to a distal region (in this case the distal end) of the central tubular member 346. A bearing 350 is also coupled to a distal region of the central tubular member 346, as shown in FIG. 3D. The drive cable extends through and rotates relative to the bearing 350. The distal struts extend from the distal expandable scaffold and are secured to a shaft portion 347 (see FIG. 3A), which can be considered part of the distal tip. Shaft portion 347 is coupled to bearing 351 (see FIG. 3D) through which the drive cable extends and rotates relative to shaft portion 347. The distal tip also includes bearing 366 (see FIG. 3D), which is a thrust bearing. Actuating portion 340 may be similar or identical in some aspects to actuating portion 1104, even if not explicitly included in the description. In this embodiment, unlike actuating portion 1104, conduit 356 extends at least to the end of the impeller. Either embodiment can be modified such that the conduit extends to the positions described in other embodiments.In some embodiments, portion 360 may be a tubular portion rather than a rolled portion.

[0195]

[0244] In alternative embodiments, at least a portion of any of the impellers herein may extend outside the fluid lumen. For example, only a portion of the impeller may extend proximally or distally beyond the end of the fluid lumen. In some embodiments, the portion of the impeller that extends outside the fluid lumen is the proximal portion of the impeller, including the proximal end (see, e.g., the proximal impeller in FIG. 2). In some embodiments, the portion of the impeller that extends outside the fluid lumen is the distal portion of the impeller, including the distal end (see, e.g., the distal impeller in FIG. 2). When the disclosure herein refers to an impeller extending outside (or beyond) the end of a fluid lumen, this is meant to refer to the relative axial location of the components, which is most easily seen in a side or top view, such as FIG. 2.

[0196]

[0245] However, a second impeller at the other end of the fluid lumen may not extend beyond the fluid lumen. For example, an exemplary alternative design may include a proximal impeller that extends proximally beyond the proximal end of the fluid lumen (as in the proximal impeller of FIG. 2), and the fluid lumen does not extend distally beyond the distal end of the distal impeller (as in FIG. 3B). Alternatively, the distal end of the distal impeller may extend distally beyond the distal end of the fluid lumen, but the proximal end of the proximal impeller does not extend proximally beyond the proximal end of the fluid lumen. In any of the pump portions herein, the impellers may not extend beyond the end of the fluid lumen. While the embodiment of FIGS. 3A-3D shows two impellers (i.e., a distal impeller and a proximal impeller), it should be understood that this or other embodiments of this disclosure may include only a single impeller, such as only a proximal impeller or only a distal impeller.

[0197]

[0246] Although certain exemplary locations are shown here, the fluid pump could be used in a variety of locations within the body. Some exemplary placement locations include placement near the aortic or pulmonary valve, for example, straddling the valve on one or both sides of the valve, and in the case of the aortic valve, optionally including a portion located in the ascending aorta. In some other embodiments, for example, the pump may be placed further downstream, such as in the descending aorta during use.

[0198]

[0247] FIG. 4 illustrates an exemplary placement of the pump portion 1104 of the catheter blood pump 1000 of FIG. 2. One difference illustrated in FIG. 4 is that the conduit extends at least to the end of the impeller, similar to FIGS. 3A-3D. FIG. 4 illustrates the pump portion 1104 in a deployed configuration with the pump portion 1104 positioned in place across the aortic valve. The pump portion 1104 can be delivered, as illustrated, for example and without limitation, via femoral artery access (a known access procedure). Although not shown for clarity, the system 1000 can also include an outer sheath or shaft within which the working portion 1104 is positioned during delivery to a location near the aortic valve. The sheath or shaft can be moved proximally (toward the ascending aorta "AA" and away from the left ventricle "LV") to allow for deployment and expansion of the working portion 1104. For example, the sheath can be retracted to allow expansion of the second expandable scaffold 1110 and the first expandable scaffold 1108 can be expanded by continued proximal movement.

[0199]

[0248] In this embodiment, the second expandable scaffold 1110 is expanded and positioned in a deployed configuration such that the distal end 1125 is in the left ventricle "LV", distal to the aortic valve leaflets "VL" and further distal to the valve annulus. The proximal end 1124 is also positioned distal to the leaflets VL, although in some methods the proximal end 1124 may extend axially slightly within the leaflets VL. This embodiment is an example of how at least half of the second expandable member 1110 is in the left ventricle as measured along its length (as measured along the longitudinal axis). And, as shown, this is also an example of how the entire second expandable member 1110 is in the left ventricle. This is also an example of how at least half of the second impeller 1118 is positioned in the left ventricle, as well as an embodiment in which the entire second impeller 1118 is positioned in the left ventricle.

[0200]

[0249] Continued retraction of the outer shaft or sheath (and / or distal movement of the working end 1104 relative to the outer sheath or shaft) continues to release the conduit 1112 until the central region 1113 is released and deployed. Expansion of the expandable scaffolds 1108 and 1110 causes the blood conduit 1112 to assume a more open configuration, as shown in FIG. 4. Thus, in this embodiment, the conduit 1112 does not have the same self-expanding properties as an expandable scaffold, but the conduit will assume a deployed, more open configuration when the working end is deployed. At least a portion of the central region 1113 of the conduit 1112 is disposed in the aortic valve coaptation region and engages the leaflets. In FIGS. 3A-3D, there is a short length of the central region 1113 that extends distally beyond the leaflets VL, but at least a portion of the central region 1113 is axially within the leaflets.

[0201]

[0250] Continued retraction of the outer shaft or sheath (and / or distal movement of the working end 1104 relative to the outer sheath or shaft) deploys the first expandable member 1108. In this embodiment, the first expandable scaffold 1108 is expanded and positioned in a deployed configuration (as shown) such that the proximal end 1121 is within the ascending aorta AA and proximal to the valve leaflet "VL". The distal end 1122 is also positioned proximal to the valve leaflet VL, although in some methods the distal end 1122 may extend axially slightly within the valve leaflet VL. This embodiment is an example of how at least half of the first expandable member 1110 is within the ascending aorta as measured along its length (as measured along the longitudinal axis). And, as shown, this is also an example of how the entire first expandable member 1110 is within the AA. This is also an example of how at least half of the first impeller 1116 is disposed within the AA, as well as an embodiment in which the entire first impeller 1116 is disposed within the AA.

[0202]

[0251] At any time during or after deployment of the pump portion 1104, the position of the pump portion can be assessed in any manner, such as under fluoroscopy. The position of the pump portion can be adjusted at any time during or after deployment. For example, the pump portion 1104 can be moved axially (distally or proximally) to change the position of the pump portion after the second expandable scaffold 1110 is released and before the first expandable member 1108 is released. Additionally, the pump portion can be repositioned, for example, after the entire working portion is released from the sheath to a desired final position.

[0203]

[0252] It will be understood that the positions of the components (relative to the anatomical structures) shown in FIG. 4 are to be considered as exemplary final positions of the different components of the working portion 1104, even if repositioning is performed after the initial deployment.

[0204]

[0253] The expandable member or members herein can be configured to be expandable in a variety of ways, such as by self-expansion, by mechanical actuation (e.g., one or more axial forces on the expandable member, expanded by a separate balloon disposed radially within the expandable member and inflated to push the expandable member radially outward), or a combination thereof.

[0205]

[0254] As used herein, expansion generally refers to a reconfiguration to a larger profile having a larger radially outermost dimension (relative to the longitudinal axis), regardless of the particular manner in which one or more components are expanded. For example, a stent that self-expands and / or is subjected to a radially outward force can be "expanded" as the term is used herein. A device that deploys or deploys can also assume a larger profile and can be considered to expand as the term is used herein.

[0206]

[0255] The impellers can be similarly adapted and configured to expand in a variety of ways depending on their construction. For example, when released from the sheath, one or more impellers can automatically return to or toward a different, larger profile configuration depending on the materials and / or construction of the impeller design (see, e.g., U.S. Pat. No. 6,533,716 or U.S. Pat. No. 7,393,181, both of which are incorporated by reference herein for all purposes). Thus, in some embodiments, retraction of the outer restraint can cause both the expandable member and the impeller to naturally return to their larger profile deployed configurations without further actuation.

[0207]

[0256] As shown in the example of FIG. 4, the actuating portion includes first and second impellers spaced apart on either side of the aortic valve, each disposed within a separate expandable member. This contrasts with some designs in which the actuating portion includes a single elongated expandable member. Rather than a single, generally tubular, expandable member that extends across the valve, the actuating end 1104 includes a conduit 1112 that extends between the expandable members 1108 and 1110. The conduit is more flexible and deformable than an expandable basket, which may allow for more deformation of the actuating portion at the leaflets than would occur if the expandable member were to span the aortic valve leaflets. This reduces damage to the leaflets after the actuating portion is deployed in a subject.

[0208]

[0257] Furthermore, forces exerted by the leaflets on the central region of a single expandable member may be transferred axially to other regions of the expandable member, possibly causing undesired deformation of the expandable member at the location of one or more impellers. This may cause the outer expandable member to contact the impeller and prevent the impeller from rotating. A design including separate expandable members around each impeller provides a high level of precision in the positioning of the impeller relative to the expandable member, especially when each expandable member and each impeller is supported at both ends (i.e., distal and proximal). Two separate expandable members may be able to more reliably hold the deployed configuration compared to a single expandable member.

[0209]

[0258] As described herein above, it may be desirable to be able to reconfigure the working portion to be able to be delivered into a 9F sheath and still have sufficient flow rate when in use, but this is not possible with some products currently under development and / or testing. For example, some products may be too large to be reconfigured to a small enough delivery profile, while some compact designs may not be able to achieve the required high flow rate. An exemplary advantage of the examples of Figures 1, 2, 3A-3D, and 4 is that, for example, the first and second impellers can work together to achieve the desired flow rate, and by having two axially spaced impellers, the entire working portion can be reconfigured to a smaller delivery profile than a design that uses a single impeller to achieve the desired flow rate. Thus, these embodiments use multiple smaller axially spaced reconfigurable impellers to achieve both the desired smaller delivery profile and the desired high flow rate. However, it should be understood that these or other embodiments in the present disclosure may include only a single impeller, such as only a proximal impeller or only a distal impeller.

[0210]

[0259] FIG. 5 shows an actuating portion similar to that shown in FIG. 1. Actuating portion 265 includes a proximal impeller 266, a distal impeller 267, both of which are coupled to a drive shaft 278 that extends into a distal bearing housing 272. There is a similar proximal bearing housing at the proximal end of the actuating portion. The actuating portion also includes an expandable scaffold or member, generally designated 270, and a blood conduit 268 secured to the expandable member and extending substantially the entire length of the expandable member. Expandable member 270 includes distal struts 271 secured to and extending to strut supports 273 secured to distal tips 273. Expandable member 270 also includes proximal struts secured to proximal strut supports. All features similar to those shown in FIG. 1 are incorporated by reference into this embodiment for all purposes, even if not expressly stated. The expandable member 265 also includes a helical tensile member 269 disposed along a periphery of the expandable member and having a helical configuration when the expandable member is in the illustrated expanded configuration. The helical tensile member 269 is positioned and adapted to induce a rotational wrap upon folding. Upon folding from the illustrated expanded configuration, the actuating portion 265 can rotate one or both impellers at a relatively slow speed to promote a curled fold of the impellers due to interaction with the expandable member. The helical tension member 269 (or helical arrangement of expandable member cells) is configured to act as a collective tension member such that when the expandable basket is pulled in tension along its length (by stretching to a much longer length, such as approximately doubling in length) and collapses, the tension member 269 is pulled into a straighter alignment, which causes a rotation / twist of the desired segment of the expandable member during collapse, which causes the impeller blades to wrap radially inward as the expandable member and blades collapse. An exemplary configuration of such a tension member, when in a helical configuration, would have a curved shape approximately equal to the maximum length of the expandable member when folded. In an alternative embodiment, only the portion of the expandable member that surrounds the collapsible impeller is rotated when folded.

[0211]

[0260] There are also other ways to construct the actuating portion to cause rotation of the expandable member (and thus cause the impeller blades to wrap and fold) upon collapse due to stretching. Any expandable member, even dual impeller designs, can be constructed with this feature. For example, in an expandable member (e.g., a laser cut elongated member) that includes a plurality of "cells," a commonly known term, the expandable member may have a plurality of specific cells that together define a particular configuration, such as a helical configuration, where the cells that define the configuration have different physical properties than other cells in the expandable member. In some embodiments, the expandable member can have a braided structure, where the twisted region can comprise an entire group of wires, or a significant portion (e.g., more than half) of the braided wires. Such a twisted braided structure can be achieved, for example, by twisting the mandrel on which the wires are braided during the braiding process, especially along the length of the largest diameter portion of the braided structure, as the mandrel is pulled. This structure can also be achieved during a second operation of the construction process, such as mechanically twisting the braided structure prior to heat setting the wound profile on the shaped mandrel.

[0212]

[0261] Any of the blood conduits herein are operative, configured and made of a material to form a fluid lumen between a first end (e.g., distal end) and a second end (e.g., proximal end). Fluid enters the inflow region and exits the outflow region through the fluid lumen. Inflow into the inflow region may be labeled as "I" and outflow from the outflow region may be labeled as "O". Any of the conduits herein may be impermeable. Alternatively, any of the conduits herein may be semi-permeable. Any of the conduits herein may be porous but still define a fluid lumen therethrough. In some embodiments, the conduits are membranes, or other relatively thin layered members. Any of the conduits herein may be secured to the expandable member such that, unless otherwise noted, the conduit, when secured, may be radially inward and / or outward of the expandable member. For example, the conduit can extend radially within the expandable member such that an inner surface of the conduit is positioned radially within the expandable member where the conduit is secured to the expandable member.

[0213]

[0262] Any of the expandable scaffolds or members herein may be constructed of a variety of materials and in a variety of ways. For example, the expandable members may have a braided structure or may be formed by laser machining. Materials may be modified such as Nitinol. The expandable members may be self-expandable or adapted to be at least partially actively expanded.

[0214]

[0263] In some embodiments, the expandable scaffold or member is adapted to self-expand upon release from within a containing tubular member, such as a delivery catheter, guide catheter, or access sheath. In some alternative embodiments, the expandable member is adapted to expand by active expansion, such as the action of a pull rod that moves at least one of the distal and proximal ends of the expandable member toward one another. In alternative embodiments, the deployed configuration may be influenced by the configuration of one or more expandable structures. In some embodiments, one or more expandable members may be deployed at least in part by the influence of blood flowing through the conduit. Any combination of the above expansion mechanisms may be used.

[0215]

[0264] The blood pumps and fluid movers, systems and methods herein can be used and located in a variety of locations within the body, and although specific examples are provided herein, it will be understood that the working portions can be located in areas of the body different than those specifically described herein.

[0216]

[0265] In any of the embodiments herein in which the catheter blood pump includes multiple impellers, the device may be adapted to rotate the impellers at different speeds. FIG. 6A shows a medical device including a gear set 1340 coupled to both an inner drive member 1338 and an outer drive member 1336 in operative communication with a distal impeller 1334 and a proximal impeller 1332, respectively. The device also includes a motor 1342 that drives the rotation of the inner drive member 1338. The inner drive member 1338 extends through the outer drive member 1336. When the motor 1332 is actuated, the two impellers rotate at different speeds due to an underdrive or overdrive ratio. The gear set 1340 may be adapted to drive either the proximal or distal impeller faster than the other. The device herein may include any of the gear sets for driving the impellers at different speeds.

[0217]

[0266] Figure 6B shows a portion of an alternative embodiment of a dual impeller device (1350) in which the different impellers are also adapted to rotate at different speeds. A gear set 1356 is coupled to both an inner drive member 1351 and an outer drive member 1353, which are coupled to a distal impeller 1352 and a proximal impeller 1354, respectively. The device also includes a motor as in Figure 6A. Figures 6A and 6B show how the gear set can be adapted to drive the proximal impeller slower or faster than the distal impeller.

[0218]

[0267] 7 shows an exemplary alternative embodiment of a fluid pump 1370 that can rotate the first and second impellers at different speeds. A first motor 1382 drives a cable 1376 coupled to the distal impeller 1372, and a second motor 1384 drives (via a gear set 1380) an outer drive member 1378 coupled to the proximal impeller 1374. The drive cable 1376 extends through the outer drive member 1378. The motors can be controlled and operated independently, allowing the speeds of the two impellers to be controlled independently. This system setup can be used with any system herein that includes multiple impellers.

[0219]

[0268] In some embodiments, a common drive mechanism (e.g., cable and / or shaft) can drive the rotation of two (or more) impellers, but the blade pitch (angle of rotational curvature) of the two impellers can be different, with the distal or proximal impeller at a steeper or less steeper angle than the other impeller. This can achieve a similar effect to using a gear set. FIG. 6C shows a portion of a medical device (1360) including a proximal impeller 1364 and a distal impeller 1362, as well as a common drive cable 1366 coupled to a motor, not shown. The proximal impeller herein can have a larger or smaller pitch than the distal impeller herein. Any of the working portions (or distal portions) herein with multiple impellers can be modified to include first and second impellers with different pitches.

[0220]

[0269] In any of the embodiments herein, the pump portion may have a compliant or semi-compliant (collectively referred to as "compliant") exterior structure. In various embodiments, the compliant portion is flexible. In various embodiments, the compliant portion only partially deforms under pressure. For example, a central portion of the pump may be formed with a flexible exterior structure such that it deforms in response to valve forces. In this manner, the external pump forces on the valve leaflets are reduced. This may prevent damage to the valve at the valve spanning location.

[0221]

[0270] FIG. 8 illustrates an exemplary embodiment of a pump portion including first, second, and third impellers 152 spaced apart axially, each impeller disposed within an expandable member 154. A conduit 155 may extend along the length of the pump portion, as described in various embodiments herein, and may help to form and define a fluid lumen. However, in alternative embodiments, the first, second, and third impellers may be disposed within a single expandable member similar to that shown in FIG. 1. In FIG. 8, the fluid lumen extends from the distal end to the proximal end, the features of which are described elsewhere herein. The embodiment of FIG. 8 may include other suitable features, including the methods of use described herein.

[0222]

[0271] The embodiment of Figure 8 is also an example of an outer housing having at least one bend formed between the proximal impeller distal end and the distal impeller proximal end such that the distal region of the housing distal to the bend is not axially aligned along the axis with the proximal region of the housing proximal to the bend. In this embodiment, two bends 150 and 151 are formed in the housing, each between two adjacent impellers.

[0223]

[0272] In a method of use, the bends formed in the housing can be positioned to span a valve, such as the aortic valve shown in Figure 8. In this positioning, the central and distal most impellers are positioned in the left ventricle and the proximal most impeller is positioned in the ascending aorta. The bend 151 is located immediately downstream of the aortic valve.

[0224]

[0273] Bends, such as bends 150 or 151, may be incorporated into any embodiment or design herein. The bends may be at a pre-formed angle or may be adjusted in situ.

[0225]

[0274] In any of the embodiments herein, unless otherwise specified, the outer housing can have a substantially uniform diameter along its length.

[0226]

[0275] In Figure 8, the pump is placed via the axillary artery, which is an exemplary method of accessing the aortic valve and allowing the patient to be ambulate and active with less interruption. Any of the devices described herein can be placed via the axillary artery. However, it will be understood from the description herein that the pump can be introduced and tracked into place in a variety of ways, including a femoral approach to the aortic arch.

[0227]

[0276] One aspect of the present disclosure is a catheter blood pump including a distal impeller axially spaced from a proximal impeller. The distal impeller and the proximal impeller can be axially spaced from each other. For example, the distal impeller and the proximal impeller can be connected only by separate attachment to a common drive mechanism. This is different from a single impeller with multiple blade rows or sections. The distal impeller as used herein does not necessarily mean the most distal impeller of the pump, but can generally refer to an impeller located further distal than the proximal impeller, even if there is an additional impeller located further distal than the distal impeller. Similarly, the proximal impeller as used herein does not necessarily mean the most proximal impeller of the pump, but can generally refer to an impeller located further proximally than the proximal impeller, even if there is an additional impeller located further proximally than the proximal impeller. Axial spacing (or some derivative thereof) refers to the spacing along the length of the pump segment, such as along the longitudinal axis of the pump segment, even if there is flexure in the pump segment. In various embodiments, each of the proximal and distal impellers is disposed within a respective housing and configured to maintain a precise and consistent tip gap, with the span between the impellers having a relatively more flexible (or fully flexible) fluid lumen. For example, each impeller may be disposed within a respective housing having a relatively rigid outer wall that resists radial collapse. The section between the impellers may be relatively rigid, and in some embodiments, this section is held open primarily by internal fluid pressure.

[0228]

[0277] Although not required for the embodiments therein, there may be advantages to minimizing the axial spacing between the proximal and distal impellers. For example, the pump portion may be delivered to the target location through a portion of the anatomy that has a relatively tight bend, such as the aorta, and delivered to the aortic valve. For example, the pump portion may be delivered to the aortic valve through a femoral artery access. It may be advantageous to make the system more flexible to facilitate delivery through bends in the anatomy. In some designs where multiple impellers are in close proximity to each other, the system may be relatively stiff along the entire length that spans the multiple impellers. Axial spacing of the impellers, and optionally providing a relatively flexible region between the impellers, allows portions of the system to be more flexible and easier to bend, making it easier and safer to advance through bends. An additional exemplary advantage is that the axial spacing allows for a relatively more compliant region between the impellers, which may be located, for example, at the location of a valve (e.g., the aortic valve). Additionally, there are other potential advantages and functional differences between the various embodiments herein and a typical multi-stage pump. A typical multi-stage pump includes blade rows (sometimes called impellers) at closely spaced functional intervals, where the blade rows act as synchronized stages. It will be appreciated that the flow may separate as it passes through the distal impeller. In various embodiments described herein, the distal and proximal impellers may be spaced apart sufficiently such that flow separation from the distal impeller is substantially reduced (i.e., flow reattachment is increased) and localized turbulence dissipates before the flow enters the proximal impeller.

[0229]

[0278] In any of the embodiments including a distal impeller and a proximal impeller, or in any portion of the description herein, the axial spacing between the distal end of the proximal impeller and the proximal end of the distal impeller can be 1.5 cm to 25 cm inclusive along the longitudinal axis of the pump portion or along the longitudinal axis of the housing portion including the fluid lumen. The distance can be measured when the pump portion including the impeller is in an expanded configuration. This exemplary range can provide the exemplary flexibility advantages described herein when the pump portion is delivered through curved portions of the anatomy, such as, for example, the aorta through the aortic valve. FIG. 9 (shown outside the patient's body in an expanded configuration) shows a length Lc indicating the axial spacing between the impellers, which in some embodiments can be 1.5 cm to 25 cm as described herein. In embodiments where there can be more than two impellers, any two adjacent impellers (i.e., impellers that do not have other rotating impellers between them) can be axially spaced by any of the axial spacing distances described herein.

[0230]

[0279] Some embodiments include a proximal impeller distal end that is axially spaced 1.5 cm to 25 cm from the distal impeller proximal end along the axis, however, the disclosure herein also includes any axial spacing that is a subrange within the general range of 1.5 cm to 25 cm. That is, the disclosure includes all ranges within that range with any lower limit equal to or greater than 1.5 and all subranges with any upper limit equal to or less than 25 cm. The following examples provide exemplary subranges. In some embodiments, the distal end of the proximal impeller is axially spaced 1.5 cm to 20 cm, 1.5 cm to 15 cm, 1.5 cm to 10 cm, 1.5 cm to 7.5 cm, 1.5 cm to 6 cm, 1.5 cm to 4.5 cm, 1.5 cm to 3 cm from the proximal end of the distal impeller along the axis. In some embodiments, the axial spacing is 2 cm to 20 cm, 2 cm to 15 cm, 2 cm to 12 cm, 2 cm to 10 cm, 2 cm to 7.5 cm, 2 cm to 6 cm, 2 cm to 4.5 cm, 2 cm to 3 cm. In some embodiments, the axial spacing is 2.5 cm to 15 cm, 2.5 cm to 12.5 cm, 2.5 cm to 10 cm, 2.5 cm to 7.5 cm, or 2.5 cm to 5 cm (e.g., 3 cm). In some embodiments, the axial spacing is 3 cm to 20 cm, 3 cm to 15 cm, 3 cm to 10 cm, 3 cm to 7.5 cm, 3 cm to 6 cm, or 3 cm to 4.5 cm. In some embodiments, the axial spacing is 4 cm to 20 cm, 4 cm to 15 cm, 4 cm to 10 cm, 4 cm to 7.5 cm, 4 cm to 6 cm, or 4 cm to 4.5 cm. In some embodiments, the axial spacing is 5 cm to 20 cm, 5 cm to 15 cm, 5 cm to 10 cm, 5 cm to 7.5 cm, or 5 cm to 6 cm. In some embodiments, the axial spacing is 6 cm to 20 cm, 6 cm to 15 cm, 6 cm to 10 cm, or 6 cm to 7.5 cm. In some embodiments, the axial spacing is 7 cm to 20 cm, 7 cm to 15 cm, or 7 cm to 10 cm. In some embodiments, the axial spacing is 8 cm to 20 cm, 8 cm to 15 cm, or 8 cm to 10 cm. In some embodiments, the axial spacing is 9 cm to 20 cm, 9 cm to 15 cm, or 9 cm to 10 cm.In various embodiments, the fluid lumen between the impellers is relatively unsupported.

[0231]

[0280] In any of the embodiments herein, the one or more impellers may have a length measured axially between the impeller distal end and the impeller proximal end (referred to as "L" and "L" in FIG. 9, respectively). SD " and "L SP "), may have a range of 0.5 cm to 10 cm or subranges thereof. The following examples show exemplary subranges. In some embodiments, the axial length of the impeller is 0.5 cm to 7.5 cm, 0.5 cm to 5 cm, 0.5 cm to 4 cm, 0.5 cm to 3 cm, 0.5 cm to 2 cm, or 0.5 cm to 1.5 cm. In some embodiments, the axial length of the impeller is 0.8 cm to 7.5 cm, 0.8 cm to 5 cm, 0.8 cm to 4 cm, 0.8 cm to 3 cm, 0.8 cm to 2 cm, or 0.8 cm to 1.5 cm. In some embodiments, the axial length of the impeller is 1 cm to 7.5 cm, 1 cm to 5 cm, 1 cm to 4 cm, 1 cm to 3 cm, 1 cm to 2 cm, or 1 cm to 1.5 cm. In some embodiments, the axial length of the impeller is 1.2 cm to 7.5 cm, 1.2 cm to 5 cm, 1.2 cm to 4 cm, 1.2 cm to 3 cm, 1.2 cm to 2 cm, or 1.2 cm to 1.5 cm. In some embodiments, the axial length of the impeller is 1.5 cm to 7.5 cm, 1.5 cm to 5 cm, 1.5 cm to 4 cm, 1.5 cm to 3 cm, or 1.5 cm to 2 cm. In some embodiments, the axial length of the impeller is 2 cm to 7.5 cm, 2 cm to 5 cm, 2 cm to 4 cm, or 2 cm to 3 cm. In some embodiments, the axial length of the impeller is 3 cm to 7.5 cm, 3 cm to 5 cm, or 3 cm to 4 cm. In some embodiments, the axial length of the impeller is 4 cm to 7.5 cm, or 4 cm to 5 cm.

[0232]

[0281] In any of the embodiments herein, the fluid lumen can have a length from the distal end to the proximal end, shown as length Lp in Figure 9. In some embodiments, the fluid lumen length Lp is 4 cm to 40 cm, or any subrange therein. For example, in some embodiments, the length Lp can be 4 cm to 30 cm, 4 cm to 20 cm, 4 cm to 18 cm, 4 cm to 16 cm, 4 cm to 14 cm, 4 cm to 12 cm, 4 cm to 10 cm, 4 cm to 8 cm, 4 cm to 6 cm.

[0233]

[0282] In any of the embodiments herein, the scaffold (also referred to as the housing) may have a deployed (expanded) diameter (e.g., outer diameter) at least at the location of the impellers (and optionally between the impellers), shown as dimension Dp in FIG. 9. In some embodiments, Dp may be 0.3 cm to 1.5 cm (3.0 mm to 15.0 mm), or any subrange therein. For example, Dp may be 0.4 cm to 1.4 cm, 0.4 cm to 1.2 cm, 0.4 cm to 1.0 cm, 0.4 cm to 0.8 cm, or 0.4 cm to 0.6 cm. In some embodiments, Dp may be 0.5 cm to 1.4 cm, 0.5 cm to 1.2 cm, 0.5 cm to 1.0 cm, 0.5 cm to 0.8 cm, or 0.5 cm to 0.6 cm, 0.5 cm to 0.8 cm, or 0.5 cm to 1.0 cm. In some embodiments, Dp may be 0.6 cm to 1.4 cm, 0.6 cm to 1.2 cm, 0.6 cm to 1.0 cm, or 0.6 cm to 0.8 cm. In some embodiments, Dp may be 0.7 cm to 1.4 cm, 0.7 cm to 1.2 cm, 0.7 cm to 1.0 cm, or 0.7 cm to 0.8 cm.

[0234]

[0283] In any of the embodiments herein, the impeller may be dimensioned as shown in FIG. I In some embodiments, the deployed diameter may be represented as D I can be from 1 mm to 30 mm, or any subrange therein. For example, in some embodiments, D Imay be 1 mm to 15 mm, 2 mm to 12 mm, 2.5 mm to 10 mm, or 3 mm to 8 mm.

[0235]

[0284] In any of the embodiments herein, a tip gap exists between the outer diameter of the impeller and the inner diameter of the fluid lumen. In some embodiments, the tip gap can be between 0.01 mm and 1 mm, such as between 0.05 mm and 0.8 mm, or such as between 0.1 mm and 0.5 mm.

[0236]

[0285] In any of the embodiments herein that include multiple impellers, the axial spacing between the impellers (along the length of the pump portion, even if there is a bend in the pump portion) can be from 2 mm to 100 mm, or any combination of upper and lower limits inclusive of 5 mm and 100 mm (e.g., 10 mm to 80 mm, 15 mm to 70 mm, 20 mm to 50 mm, 2 mm to 45 mm, etc.).

[0237]

[0286] Any pump portion herein that includes multiple impellers may also include more than two impellers, such as (for example) three, four, or five impellers.

[0238]

[0287] In any of the embodiments herein, the diameter (e.g., inner diameter) of the scaffold (also called the housing) in the collapsed state (e.g., for covering) can be 2.0 mm to 7.0 mm, or any subrange therein. For example, the diameter (e.g., inner diameter) of the scaffold in the collapsed state can be 2.0 mm to 2.5 mm, 2.0 mm to 3.0 mm, 2.0 mm to 4.0 mm, 2.0 mm to 5.0 mm, 2.0 mm to 6.0 mm, 2.5 mm to 4.5 mm, 2.5 mm to 6.0 mm, 3.0 mm to 6.0 mm, or 3.0 mm to 4.5 mm.

[0239]

[0288] FIG. 10 shows an expandable scaffold 250 that can be one of at least two expandable scaffolds of a pump portion, such as the expandable scaffolds of FIGS. 3A-3D, each of which at least partially surrounds an impeller. The scaffold design of FIG. 10 has a proximal strut 251 (only one is labeled) extending axially therefrom. Having a separate expandable scaffold 250 for each impeller allows for different geometries for any of the individual impellers. Additionally, this design reduces the amount of scaffold material (such as Nitinol) over the length of the expandable blood conduit, which may improve compliance when sheathed. Potential challenges with these designs may include creating a continuous membrane between the expandable scaffolds in the absence of axially extending scaffold material (see FIG. 3A). Other aspects of expandable scaffolds or members herein, such as those described in Figures 3A-3D, may be incorporated by reference into this exemplary design. Strut 251 may be located at the inflow or outflow of the pump. Strut 251 may be a proximal or distal strut.

[0240]

[0289] FIG. 11 illustrates an exemplary scaffold along the length of a blood conduit. A central region "CR" may be axially between the proximal and distal impellers. The flexibility of the central region "CR" is increased relative to the scaffold impeller regions "IR" due to breaks or discontinuities in the scaffold pattern in the central region. The scaffold has a relatively stiffer impeller portion "IR" adjacent to the central region where the impeller may be located (not shown). The relatively increased stiffness of the impeller region IR may help maintain tip gap and impeller concentricity. This pump scaffold pattern provides a flexibility distribution along its length with a relatively less flexible proximal portion ("IR") than the central region, a relatively more flexible central region "CR", and a relatively less flexible distal portion "IR". The relatively less flexible portions (i.e., the two IR regions) are where the proximal and distal impellers may be located (not shown, but other embodiments are fully incorporated herein in this regard), with the relatively more flexible regions in between. Examples of the benefits of relative flexibility in each of these portions are described elsewhere herein. FIG. 11 is an example of a scaffold that is continuous from the first end region to the second end region, despite breaks or discontinuities in some locations of the scaffold. There is at least one line that can be traced along a continuous structural path from the first end region to the second end region.

[0241]

[0290] The following disclosure provides exemplary method steps that may be performed when using any of the blood pumps or portions thereof described herein. It is understood that not all steps need to be performed, and that these steps are intended to illustrate the procedure. It is also contemplated that, where appropriate, one or more steps may be ordered differently in some cases. Prior to use, the blood pump may be prepared for use by priming the lumen (including the annular space) and pump assembly with a sterile solution (such as heparinized saline) and removing air bubbles from the fluid lines. A catheter including any number of purge lines may be connected to the console. Alternatively, the catheter may be connected to a console and / or a separate pump that is used to prime the catheter to remove air bubbles.

[0242]

[0291] After priming the catheter, an appropriately sized introducer sheath can be used to access the patient's vasculature (e.g., but not limited to, via femoral access). Using standard valve crossing techniques, the diagnostic pigtail catheter can be advanced over, for example, a 0.035 inch guidewire until the pigtail catheter is firmly positioned at the target location (such as the left ventricle). The guidewire can then be removed and a second wire 320 (e.g., a 0.018 inch wire) can be inserted through the pigtail catheter. The pigtail catheter can then be removed (see FIG. 12A) and the blood pump 321 (including the catheter, catheter sheath, and pump portion within the sheath; see FIG. 12B) can be advanced over the second wire toward the target location, such as past the aortic valve (AV) to reach the target location (e.g., the left ventricle (LV)) by using, for example, one or more radiopaque markers to position the blood pump.

[0243]

[0292] Once proper placement is confirmed, the catheter sheath 322 (see FIG. 12C) can be retracted to initially expose the distal region of the pump portion. In FIG. 12C, the distal region of the expandable housing has been released from the sheath 322 and expanded as has the distal impeller 324. The proximal end of the housing 323 and the proximal impeller have not yet been released from the sheath 322. Continued retraction of the sheath 322 past the proximal end of the housing 323 allows the housing 323 and the proximal impeller 325 to expand (see FIG. 12D). The inflow region (indicated by arrows, although the impeller is not yet rotating) and the distal impeller are in the left ventricle. The outflow (indicated by arrows, although the impeller is not yet rotating) and the proximal impeller are in the ascending aorta AA. The region of the outer housing between the two impellers may be more flexible than the housing region surrounding the impellers, as described in more detail herein, and spans the aortic valve AV. In the exemplary operating position shown, the inlet portion of the pump portion is distal to the aortic valve in the left ventricle and the outlet portion of the pump portion is proximal to the aortic valve in the ascending aorta ("AA").

[0244]

[0293] A second wire (e.g., a 0.018 inch guidewire) can then be moved (see FIG. 12E) prior to operation of the pump assembly. If desired or necessary, the pump portion can be deflected (actively or passively) in one or more positions as described herein, as shown in FIG. 12F. For example, the area between the two impellers can be deflected by applying tension to a tension member that extends to a position between the two impellers. Deflection may be desirable or necessary to accommodate a particular anatomical structure. If necessary, the pump portion can be repositioned to achieve the intended arrangement, for example, having a first impeller on one side of the heart valve and a second impeller on another side of the heart valve. It is understood that in FIG. 12F, the pump portion does not interfere or interact in any way with the mitral valve, although it may appear so from the illustration.

[0245]

[0294] As discussed above, the present disclosure includes a catheter blood pump including an expandable pump portion extending distally relative to the catheter. The pump portion includes an impeller housing including an expandable blood conduit defining a blood lumen. The blood conduit may include one or more scaffold portions, also collectively referred to herein as a single scaffold. In some exemplary embodiments, the expandable blood conduit may include one or more of a proximal impeller scaffold, a distal impeller scaffold, and a central scaffold disposed between the proximal and distal impeller scaffolds, any combination of which may also be referred to herein as a scaffold. Any individual proximal or distal impeller scaffold may also be referred to herein as an expandable member, as shown in FIGS. 3A-3D. In some embodiments, the expandable blood conduit may include a proximal impeller scaffold and an additional scaffold extending distally therefrom, such as when the pump portion includes a proximal impeller but not a distal impeller. In any of the embodiments herein, reference to a distal impeller is merely an example, and the pump portion herein need not include a distal impeller. The central scaffold herein is generally less stiff in response to radially inward forces than the proximal scaffold, and optionally less stiff than the distal scaffold, such as the distal impeller scaffold. Exemplary advantages of a less stiff central scaffold portion are described elsewhere herein. The blood conduit may also include a membrane coupled to one or more scaffolds, the membrane at least partially defining the blood lumen. The membrane in this context may be incorporated herein by reference in the disclosure of the conduit, including any features or methods of manufacture described above. The catheter blood pump may include an impeller disposed in a proximal region of the impeller housing, which may be the proximal impeller. The catheter blood pump may also include a distal impeller in a distal region of the impeller housing. Exemplary impellers, including exemplary proximal and distal impellers, are described herein by way of example.An impeller at least partially within a portion of a scaffold can be described in terms of a relative location of the scaffold, such as a proximal impeller within at least a portion of a proximal scaffold, or a distal impeller within at least a portion of a distal scaffold.

[0246]

[0295] When a proximal impeller is described as being within a proximal scaffold, it is understood that the proximal scaffold need not extend axially the entire length of the impeller, so long as there is some axial overlap. For example, some proximal impellers herein extend proximally from a blood conduit, and the proximal region of the proximal impeller is not surrounded by the blood conduit scaffold, but the distal region of the impeller is surrounded by the scaffold. Similarly, when a distal impeller (if the pump includes a distal impeller) herein is described as being within a distal scaffold, it is understood that the distal scaffold need not extend axially the entire length of the impeller, so long as there is some axial overlap between them.

[0247]

[0296] 13A-17 show exemplary designs of expandable scaffolds herein that can at least partially surround an impeller that is at least partially disposed within a conduit forming a fluid lumen. The scaffold patterns in FIG. 13A-17 may be scaffold patterns that extend only over a particular impeller (e.g., a proximal basket or a distal basket) or may be scaffold patterns that extend over the entire blood conduit scaffold.

[0248]

[0297] 13A-17 each show an expandable support member or scaffold having an expanded configuration, where the support member is an expandable support member (e.g., L s) extending axially in succession over at least 50% of the length of the expandable support member, and the expandable support member includes a plurality of sets of connectors (e.g., 412 / 414, 409, 422 / 424, 432 / 434, 442 / 444), each set of connectors extending between first and second circumferentially adjacent continuous axially extending elements. In some embodiments, the axially extending elements are straight or substantially straight.

[0249]

[0298] 13A-13C show an exemplary pump portion 400, or a portion thereof comprising an expandable impeller housing 402 having a blood conduit 404 defining a blood lumen between a housing inflow "I" and a housing outflow "O". The expandable impeller housing also includes an expandable scaffold or support member 406 at least partially surrounding an impeller (not shown in FIGS. 13A-13C) at least partially disposed within the conduit. FIGS. 14A-17 show an expandable scaffold of the pump portion. It is understood that any of the expandable scaffolds of FIGS. 13A-17 may be used in place of any of the expandable scaffolds herein. The impeller housing 402 may represent the entire impeller housing or only a portion thereof including only a single scaffold portion, such as any of the multi-impeller designs herein. It will therefore be understood that the structure shown in Figures 13A-13C is only a portion of the expandable housing of the pump portion, For example, the pump portion may include two expandable scaffold portions shown in Figures 13A-13C that are axially spaced apart and connected, for example, by a flexible membrane.

[0250]

[0299] 13A-13C show an expandable impeller housing including multiple axially extending elements 408 spaced circumferentially from adjacent axially extending elements around the housing 402 as shown. FIGS. 13A and 13B show an expanded configuration of the housing, and FIG. 13C shows a model of a flattened, unexpanded configuration having a single strut 401 axially extending therefrom as shown. It is understood that the multiple axially extending elements may be referred to as "elements" in the context of the scaffold for simplicity, but are not considered other types of "elements" herein unless specifically indicated as such. The elements in this embodiment may be axial and straight in the expanded configuration of the housing. The expandable scaffold 406 also includes circumferential connectors 409 that connect adjacent axial elements circumferentially and extend from one axial element to an adjacent axial element. In this exemplary embodiment, all connectors have the same general configuration and include first and second segments that meet at a rounded apex oriented axially (proximally or distally depending on the frame of reference) and are otherwise referred to as pointing axially. The scaffold length Ls and element length Le are shown in FIG. 13C. An optional strut 401 is shown (which may be integral with the scaffold). The axial element 408 in this embodiment extends from a first axial element end 405 to a second axial element end 405', and extends nearly the entire length of the scaffold Ls. As shown, the element ends 405' (only one is labeled) extend to the distal end region 407' of the scaffold 406. The ends 405 extend to the proximal end region 407. The pump portion also includes a transition region 411, which includes a circumferential extension of adjacent axial elements before they merge to form the strut 401 as shown.

[0251]

[0300] 14A (expanded state) and 14B (unexpanded state) show an exemplary expandable scaffold 406' including multiple axially extending elements 410. A first set of connectors 412 have an "S" shape and a second circumferentially adjacent set of connectors 414 have an inverted (opposite) "S" shape. In the expanded configuration of FIG. 14A, the axial elements 410 may be straight or may have a slightly curved configuration as shown. The scaffold 406' includes a transition region 411' that may have similar features as the transition region 411 herein. Relevant descriptions from other embodiments can be incorporated into the scaffold of FIGS. 14A-B (e.g., length of the scaffold or support member and axial element, transition region, etc.). A portion of the optional struts 413 are shown, as are the ends 405 / 405' of the axial elements. The scaffold 406' may be a proximal or distal scaffold and may extend along the length of the impeller housing.

[0252]

[0301] 15A and 15B show an exemplary expandable scaffold 406″ similar to that of FIGS. 13A-13C, 14A-14B, 16, and 17. Axially extending elements 420 are shown with adjacent elements connected by circumferential connectors 422 and 424, the ends of which are axially offset. A first set of connectors 422 has a general S-shape, and a second set of connectors 424 is an inverted S-shape. In this embodiment, the axially extending elements 420 are curved as shown. As with the scaffold of FIGS. 14A and 14B, the S-shape and inverted S-shape patterns alternate around the expandable member. The scaffold 406″ also includes a transition region 421, examples of which are described elsewhere herein. The scaffold 406″ may be a proximal or distal scaffold, or may extend along the length of the impeller housing.

[0253]

[0302] FIG. 16 illustrates an exemplary scaffold 406″ in a collapsed (unexpanded) configuration, which may have other suitable features of other support members or scaffolds herein. Axially extending elements 430 are shown connected by a first set of S-shaped connectors 434 and a second set of inverted S-shaped connectors 432. As shown, the S-shaped and inverted S-shaped patterns alternate circumferentially around the scaffold 406″. The scaffold 406″ may be a proximal or distal scaffold, or may extend along the length of the impeller housing.

[0254]

[0303] FIG. 17 illustrates a collapsed (unexpanded) configuration of the exemplary scaffold 406'''', which may have other suitable features of other support members or scaffolds herein. Axially extending elements 440 are shown and are connected by inverted S-shaped connectors. All sets of connectors in this embodiment (e.g., set 442 and set 444) have the same configuration and are all inverted S-shaped in this embodiment. The exemplary struts are shown axially disposed relative to the scaffold 406'''', which may include transition sections as described elsewhere herein. The scaffold 406'''' may be a proximal or distal scaffold or may extend along the length of the impeller housing.

[0255]

[0304] The scaffold and blood conduit embodiments of Figures 13A-17 are exemplary and may be modified to include aspects of other embodiments herein. The following description may provide modifications to the scaffolds of Figures 13A-17, any of which may be incorporated into any of the scaffolds of Figures 13A-17.

[0256]

[0305] In any of the scaffolds shown in FIGS. 13A-17, at least a first end of each of the multiple axially extending elements can extend to one or more proximal end regions (e.g., 417', 407') and distal end regions (e.g., 417) of the expandable scaffold.

[0257]

[0306] In any of the scaffolds shown in Figures 13A-17, at least one, and optionally all, of the multiple axially extending elements may be straight. In any of the scaffolds shown in Figures 13A-17, at least one, and optionally all, of the multiple axially extending elements may be curvilinear.

[0258]

[0307] In any of the scaffolds shown in Figures 13A-17, each of the multiple axially extending elements can have a proximal end and a distal end, where the proximal and distal ends are substantially circumferentially aligned.

[0259]

[0308] In any of the scaffolds shown in FIGS. 13A-17, each of the multiple axially extending elements may have a circumferential span (shown in FIG. 15A as "CS") of 10 degrees or less in the circumferential direction around the expandable scaffold, optionally 5 degrees or less of the expandable scaffold.

[0260]

[0309] In any of the scaffolds shown in Figures 13A-17, each of the multiple axially extending elements can follow a path substantially parallel to the longitudinal axis of the expandable scaffold.

[0261]

[0310] In any of the embodiments of Figures 13A-17, each of the multiple axially extending elements is continuous and can extend axially over at least 55%, optionally over at least 60%, optionally over at least 65%, optionally over at least 70%, optionally over at least 75%, optionally over at least 80%, optionally over at least 85%, optionally over at least 90%, and optionally over at least 95% of the length of the expandable scaffold.

[0262]

[0311] In any of the scaffolds shown in Figs. 13A-17, all connectors in every set of the multiple sets of connectors may have the same configuration. In any of the scaffolds shown in Figs. 13A-17, all connectors in every set of the multiple sets of connectors may not have the same configuration. In any of the scaffolds shown in Figs. 13A-17, each set of connectors may have multiple connectors with the same configuration. In any of the embodiments of Figs. 13A-17, all connectors in every set of the multiple sets of connectors may have an S-shape. In any of the embodiments of Figs. 13A-17, all connectors in every set of the multiple sets of connectors may have an inverted (or reversed) S-shape. In any of the scaffolds shown in Figs. 13A-17, all connectors in a first set of connectors may have an S-shape. In any of the scaffolds shown in Figs. 13A-17, all connectors in a second set of connectors circumferentially adjacent to the first set of connectors may have an inverted S-shape. In any of the scaffolds shown in Figures 13A-17, the S-shaped / reverse S-shaped connectors may be arranged in alternating fashion around the circumference of the expandable scaffold.

[0263]

[0312] In any of the embodiments of Figures 13A-17, a first set of connectors extending in a first circumferential direction from a first axially extending element may extend from the first axially extending element at an axial position that is different from the axial position at which a second set of connectors extend in a second circumferential direction from the first axially extending element (i.e., the connectors have axially offset ends).

[0264]

[0313] In any of the embodiments of Figures 13A-17, the expandable scaffold may include a transition region connecting the first axially extending elements with the struts, and optionally the transition region is considered part of the expandable scaffold. The transition region may also connect the struts with a second axially extending element, the second axially extending element circumferentially adjacent the first axially extending element around the blood conduit. In any of the scaffolds shown in Figures 13A-17, the expandable scaffold may extend along substantially the entire length of the conduit. In any of the scaffolds shown in Figures 13A-17, the expandable scaffold may extend along less than 50% of the length of the expandable impeller housing. In any of the embodiments of Figures 13A-17, the expandable scaffold may extend only into the region of the expandable housing where the impeller is located.

[0265]

[0314] In any of the embodiments of Figures 13A-17, the expandable impeller housing may include a second expandable scaffold axially spaced from the first expandable scaffold. The second expandable scaffold may have an expanded configuration with a second plurality of axially extending elements extending axially over at least 50% of the length of the second expandable scaffold, and the second expandable scaffold may also include a plurality of sets of connectors, each set of connectors extending circumferentially between circumferentially adjacent first and second axially extending elements. The second expandable scaffold may include any feature described in any of the claims or elsewhere herein. In any of the scaffolds shown in Figures 13A-17, the expandable scaffold may be monolithic, i.e., fabricated from a single starting material.

[0266]

[0315] 18A and 18B show an exemplary scaffold 450 with multiple axially extending elements 452 (8 in this example). The scaffold 450 includes a proximal scaffold 460, a central scaffold 462, and a distal scaffold 464. In this example, the axially extending elements 452 are straight. In this example, the central scaffold 462 is connected to the proximal scaffold 460 and the distal scaffold 464, and is particularly integral therewith in this example. FIG. 18B shows an expanded configuration, and FIG. 18A shows an as cut flat view of the scaffold. The axially extending elements 452 labeled in FIG. 18B are circumferentially adjacent axial elements. The adjacent axially extending elements are connected by multiple circumferential connectors 451, which in this example have a generally S-shaped or inverted S-shaped configuration with at least one bend formed therein. As shown, each circumferential connector is circumferentially adjacent to another circumferential connector and together extend around the blood conduit. In this example, the circumferentially adjacent circumferential connectors are axially displaced relative to one another as shown. For example, circumferential connector 451' is axially displaced (or axially offset) relative to circumferential connector 451". Axially displaced or axially offset in this context refers to a proximal end of a connector being axially offset, a distal end of a connector being axially offset, or both. In this example, each portion of an axially extending element connects adjacent axially displaced circumferential connectors. For example, one portion 453 of axially extending element 452 connects circumferential connectors 451' and 451'', which results in the axially displaced nature of the circumferentially adjacent circumferential connectors. In this example, the distal end of connector 451'' is further distal than the distal end of circumferentially adjacent connector 451'', as shown. 18A and 18B also show a first group of a plurality of circumferential connectors having a first axial position and a second group of a plurality of circumferential connectors having a second axial position, the first and second axial positions alternating circumferentially around the blood conduit as shown.

[0267]

[0316] 19A and 19B show an exemplary scaffold 470. The scaffold 470 includes multiple axially extending elements 472 that are partially straight, but not straight along the entire length of the scaffold 470. The scaffold 470 also includes connectors 471 that circumferentially connect circumferentially adjacent axial elements 472. The connectors 471 include axially oriented or axially oriented pointed apices, which in this example may be oriented in the distal or proximal direction. The scaffold 470 includes connected proximal, central, and distal scaffolds that are unitary in this example, similar to the scaffold of FIGS. 18A and 18B. The proximal, central, and distal scaffolds each comprise a plurality of linear, axially extending elements spaced apart about the blood conduit, with first and second adjacent linear, axially extending elements each connected by a circumferential connector having at least one bend formed therein. The circumferential connectors define a plurality of circumferential connectors about the blood conduit, with circumferentially adjacent connectors of the plurality of circumferential connectors being axially displaced relative to one another. Similar to FIG. 18A and FIG. 19B, each portion 473 of the axially extending elements (linear in this example) connects circumferentially adjacent connectors that are axially displaced as shown. FIG. 19A and FIG. 19B show a first group of the plurality of circumferential connectors having a first axial position, and a second group of the plurality of circumferential connectors having a second axial position, with the first and second axial positions alternating circumferentially about the blood conduit. In this embodiment, the proximal, central, and distal scaffolds are generally of the same construction (except for the ends of the distal and proximal scaffolds).

[0268]

[0317] The scaffold 470 also includes a second region 477 axially adjacent to the first region 476, the second region 477 comprising a plurality of vertices 478 shown oriented perpendicular to the long axis of the blood conduit (membranes not shown for clarity). In this example, each of the plurality of vertices 478 is an extension of one of the axially extending elements 472 in the first region 476, as shown. The scaffold 470 also includes a third region 479 axially adjacent to the second region 477, the third region 470 comprising a second plurality of linear axially extending elements as shown spaced around the blood conduit, and a second plurality of circumferential connectors 471, the second region 477 joining the first region 476 and the third region 479. In this example, this pattern continues along the length of the scaffold.

[0269]

[0318] 20A and 20B show an exemplary scaffold 500, with FIG. 20B showing an expanded configuration and FIG. 20A showing a flat unexpanded configuration. Features shown in FIGS. 20A and 20B that are the same as features shown in other scaffolds herein may be expressly included in this embodiment even if not described herein. Scaffold 500 includes a proximal scaffold 510, a central scaffold 520, and a distal scaffold 530, which are unitary in this embodiment. In this embodiment, central scaffold 520 has a pattern and configuration such that it is less stiff in response to radially inward forces than proximal scaffold 510 and distal scaffold 530. Proximal scaffold 510 may be a proximal impeller scaffold and distal scaffold 530 may be a distal impeller scaffold, at least a portion of which may have proximal and distal impellers disposed therein, respectively. 18A and 18B , all of which are incorporated by reference herein, along with the circumferential connectors 451 of scaffold 450.

[0041] In this example, scaffold portions 510 and 530 have substantially the same pattern. As shown, scaffold 500 includes circumferential connectors at proximal scaffold 510, central scaffold 520, and distal scaffold 530. For example, proximal scaffold 510 includes circumferential connector 512 and distal scaffold 530 includes circumferential connector 532. The circumferential connectors of scaffold 500 have the same configuration as circumferential connector 451 of scaffold 450 of FIGS. 18A and 18B, all of which are incorporated by reference herein, along with the circumferential connectors of all scaffold portions of scaffold 500. By way of example only, circumferentially adjacent circumferential connectors are axially displaced (i.e., axially offset) relative to one another, as described in more detail elsewhere herein. Circumferential connectors also have S-shaped and inverted S-shaped configurations, as described with respect to other scaffolds herein. Central scaffold 520 of scaffold 500 also includes apexes 521 and 521', similar to apex 478 of the scaffold of Figures 19A and 19B.The first plurality of apexes 521 have a first axial location and the second plurality of apexes 521' have a second axial location, which is clearly shown in FIG. 20A. As shown, the axial locations alternate circumferentially around the scaffold. The apexes 521 and 521' extend from axially extending elements 522, as in the scaffold of FIGS. 19A and 19B. In this embodiment, the proximal and distal scaffolds do not include apexes. The axially extending elements 522 of the central scaffold portion have a width that is greater than the width of the scaffold in the apex 521 region, as shown. This difference in width increases the flexibility of the apex region, and the wider width of the axially extending elements provides sufficient radial support to the central scaffold. Any of the scaffold portions having apexes can be considered a first region, and the axially adjacent portions having circumferential connectors and axially extending elements can be considered a second region, examples of which are described elsewhere herein. In this embodiment, the axially extending elements are straight as shown, but in other embodiments may be curved.

[0270]

[0319] 21A and 21B show an exemplary scaffold 550, with FIG. 21B showing an expanded configuration and FIG. 21A showing a flat, unexpanded configuration. Features shown in FIGS. 21A and 21B that are the same as features shown in other scaffolds herein may be explicitly included in this embodiment even if not described herein. Scaffold 550 includes a proximal scaffold 560, a central scaffold 570, and a distal scaffold 580, which are unitary in this embodiment. Proximal scaffold 560 may be a proximal impeller scaffold and distal scaffold 580 may be a distal impeller scaffold, at least a portion of which may have a proximal impeller and a distal impeller, respectively, disposed therein. Central scaffold 570 of scaffold 550 has a pattern that is different from the patterns of scaffold portions 560 and 580. In this example, scaffold portions 560 and 580 have substantially the same pattern. As shown, scaffold 550 includes circumferential connectors at proximal scaffold 560, central scaffold 570, and distal scaffold 580. For example, proximal scaffold 560 includes circumferential connector 562 and distal scaffold 580 includes circumferential connector 582. The circumferential connectors of scaffold 550 have the same configuration as circumferential connector 451 of scaffold 450 of FIGS. 18A and 18B, the full description of which is incorporated by reference with all scaffold portions of scaffold 550 along with the circumferential connectors. By way of example only, circumferentially adjacent circumferential connectors are axially displaced (i.e., axially offset) relative to one another, as described in more detail elsewhere herein. The circumferential connectors also have S-shaped and inverse S-shaped configurations, as described with respect to other scaffolds herein. Elements 571 in the central scaffold extend into the proximal and distal scaffold portions as shown, forming straight axially extending elements in the proximal and distal scaffolds. Axially extending elements 561 of proximal scaffold 560 do not extend into the central scaffold as shown.Similarly, as shown, the axially extending elements 581 of the distal scaffold 580 do not extend into the central scaffold. The elements 571 of the central scaffold 570 have a helical configuration as shown. As shown, adjacent elements 571 are connected with connectors 572. The connectors 572 may have any of the features of any circumferential connector herein, such as alternating S-shaped and inverted S-shaped configurations. FIG. 21A shows a flattened, unexpanded configuration, and the scaffold 550 can be formed into the configuration shown in FIG. 21B, such as by twisting the ends relative to each other to set the scaffold into the configuration shown in FIG. 21B.

[0271]

[0320] 22A and 22B show an exemplary scaffold 600, with FIG. 22B showing an expanded configuration and FIG. 22A showing a flat, unexpanded configuration. Features shown in FIG. 22A and 22B that are the same as features shown in other scaffolds herein may be expressly included in this embodiment even if not described herein. Scaffold 600 includes a proximal scaffold 610, a central scaffold 620, and a distal scaffold 630, which are unitary in this embodiment. Proximal scaffold 610 may be a proximal impeller scaffold and distal scaffold 630 may be a distal impeller scaffold, at least a portion of which may have a proximal impeller and a distal impeller, respectively, disposed therein. Central scaffold 620 of scaffold 600 has a pattern that is different from the patterns of scaffold portions 610 and 630. In this example, scaffold portions 610 and 630 have substantially the same pattern. As shown, scaffold 600 includes circumferential connectors at proximal scaffold 610, central scaffold 620, and distal scaffold 630. For example, proximal scaffold 610 includes circumferential connector 612 and distal scaffold 630 includes circumferential connector 632. The circumferential connectors at the proximal and distal portions of scaffold 600 have the same configuration as circumferential connector 451 of scaffold 450 of FIGS. 18A and 18B, the full description of which is incorporated by reference with respect to all scaffold portions of scaffold 600 along with the circumferential connectors. By way of example only, circumferentially adjacent circumferential connectors are axially displaced (i.e., axially offset) from one another, as described in more detail elsewhere herein, and connect axially extending elements 611 and 631, respectively. The circumferential connectors also come in S-shaped and inverted S-shaped configurations, which are described with respect to other scaffolds herein. Axially extending elements 621 in the central scaffold extend into the proximal and distal scaffold portions as shown, and elements 621 are straight axially extending elements in the proximal and distal scaffolds as well as the central scaffold.The axially extending elements 611 of the proximal scaffold 610 do not extend into the central scaffold, as shown. Similarly, the axially extending elements 631 of the distal scaffold 630 do not extend into the central scaffold, as shown. The elements 621 of the central scaffold 620 have an axially extending straight configuration, as shown. The central scaffold 620 includes axially extending elements 621 connected by circumferential connectors. The circumferential connectors include multiple axially extending elements 624, each connecting circumferentially adjacent circumferential connectors 622, as shown. When the scaffold 600 is expanded to the configuration shown in FIG. 22B, the circumferential connectors assume the configuration shown, but the elements 624 no longer extend purely axially, but form an angle with the long axis of the scaffold, as shown.

[0272]

[0321] 23A and 23B show an exemplary scaffold 650, with FIG. 23B showing an expanded configuration and FIG. 23A showing a flat unexpanded configuration. Features shown in FIGS. 23A and 23B that are the same as features shown in other scaffolds herein may be explicitly included in this embodiment even if not described herein. Scaffold 650 includes a proximal scaffold 660, a central scaffold 670, and a distal scaffold 650, which are unitary in this embodiment. Proximal scaffold 660 may be a proximal impeller scaffold and distal scaffold 650 may be a distal impeller scaffold, at least a portion of which may have a proximal impeller and a distal impeller, respectively, disposed therein. Central scaffold 670 of scaffold 650 has a pattern that is different from the patterns of scaffold portions 660 and 680. In this example, scaffold portions 660 and 680 have substantially the same pattern. As shown, scaffold 650 includes circumferential connectors at proximal scaffold 660, central scaffold 670, and distal scaffold 680. For example, proximal scaffold 660 includes circumferential connector 662 and distal scaffold 650 includes circumferential connector 682. The circumferential connectors at the proximal and distal portions of scaffold 650 have the same configuration as circumferential connector 451 of scaffold 450 of FIGS. 18A and 18B, the full description of which is incorporated by reference with respect to all scaffold portions of scaffold 650 along with the circumferential connectors. By way of example only, circumferentially adjacent circumferential connectors are axially displaced (i.e., axially offset) from one another, as described in more detail elsewhere herein, and connect axially extending elements 661 and 681, respectively. The circumferential connectors also come in S-shaped and inverted S-shaped configurations, which are described with respect to other scaffolds herein. Axially extending elements 671 in the central scaffold extend into the proximal and distal scaffold portions as shown, and elements 671 are straight axially extending elements in the proximal and distal scaffolds as well as the central scaffold.The axially extending elements 661 of the proximal scaffold 660 do not extend into the central scaffold, as shown. Similarly, the axially extending elements 681 of the distal scaffold 650 do not extend into the central scaffold, as shown. The elements 671 of the central scaffold 670 have an axially extending straight configuration, as shown. The central scaffold 670 includes axially extending elements 671 connected by circumferential connectors. The circumferential connectors include multiple axially extending elements 674, each connecting circumferentially adjacent circumferential connectors 672, as shown. When the scaffold 650 is expanded to the configuration shown in FIG. 23B, the circumferential connectors 672 assume the configuration shown, but the elements 674 no longer extend purely axially, but form an angle with the long axis of the scaffold, as shown. The elements 674 in FIG. 23A are formed by removing material axially disposed between axially adjacent elements 674.

[0273]

[0322] 24A and 24B show an exemplary scaffold 700, with FIG. 24B showing an expanded configuration and FIG. 24A showing a flat, unexpanded configuration. Features shown in FIG. 24A and 24B that are the same as features shown in other scaffolds herein may be explicitly included in this embodiment even if not described herein. For example, scaffold 700 is the same in some respects as the scaffolds shown in FIG. 19A, FIG. 19B, FIG. 20A and FIG. 20B. Scaffold 700 includes a proximal scaffold 710, a central scaffold 720, and a distal scaffold 730, which are unitary in this embodiment. Proximal scaffold 710 may be a proximal impeller scaffold and distal scaffold 730 may be a distal impeller scaffold, at least a portion of which may include a proximal impeller and a distal impeller, respectively, disposed therein. 18A and 18B , all of which are incorporated by reference herein, along with the circumferential connectors 451 of scaffold 450.

[0041] In this example, scaffold portions 710 and 730 have substantially the same pattern. Scaffold 700 includes circumferential connectors at proximal scaffold 710, central scaffold 720, and distal scaffold 730, as shown. For example, proximal scaffold 710 includes circumferential connector 712, and distal scaffold 730 includes circumferential connector 732. The circumferential connectors at the proximal and distal portions of scaffold 700 have the same configuration as circumferential connector 451 of scaffold 450 of FIGS. 18A and 18B, all of which are incorporated by reference herein, along with the circumferential connectors, for all scaffold portions of scaffold 700. By way of example only, circumferentially adjacent circumferential connectors are axially displaced (i.e., axially offset) from one another, as described in more detail elsewhere herein, and connect axially extending elements 711 and 731, respectively. The circumferential connectors also have S-shaped and inverted S-shaped configurations that alternate circumferentially around the scaffold, as described herein with respect to other scaffolds.The scaffold 700 includes a plurality of axially extending elements 711 that are straight in cross section but do not extend along the entire length of the scaffold 700. The scaffold 700 also includes circumferential connectors 712 that circumferentially connect circumferentially adjacent axial elements 711. The proximal, central, and distal scaffolds each include a plurality of straight, axially extending elements 711, 721, and 731 that are circumferentially spaced about the respective scaffold portions, with first and second adjacent straight, axially extending elements each being connected by a circumferential connector 712, 722, and 732, respectively, that has at least one bend formed therein. The circumferential connectors define a plurality of circumferential connectors about the scaffold, with circumferentially adjacent connectors of the plurality of circumferential connectors being axially displaced relative to one another, as shown and described elsewhere herein. As in Figures 18A and 19B, each portion of an axially extending element (in this example a straight element) connects axially displaced circumferentially adjacent circumferential connectors as shown. Figures 24A and 24B show a first group of multiple circumferential connectors having a first axial location and a second group of multiple circumferential connectors having a second axial location, with the first and second axial locations alternating circumferentially around the scaffold.

[0274]

[0323] The scaffold 700 also includes a second region axially adjacent to the first region, the second region comprising a plurality of vertices 724 shown oriented perpendicular to the long axis of the scaffold 700. In this example, each of the plurality of vertices 724 is an extension of one of the axially extending elements 721, as shown. The scaffold 700 also includes a third region axially adjacent to the second region, the third region comprising a second plurality of linear axially extending elements spaced around the scaffold and a second plurality of circumferential connectors 722, as shown, the second region joining the first and third regions. In this embodiment, the second region includes a first protrusion 725 and a second protrusion 727 connected at location 729.

[0275]

[0324] 25A and 25B show an exemplary scaffold 750, in this example including a unitary proximal scaffold 760, a central scaffold 770 and a distal scaffold 780. Scaffold 750 is similar in several respects to scaffold 700 of FIGS. 24A and 24B, the disclosure of which is fully incorporated by reference into the description of FIGS. 25A and 25B, any features of which may be included in scaffold 750. One difference is that central scaffold 770 of scaffold 750 includes a first region including apex 774, the first region including portions 775 and 777 connected at location 779, portions 775 and 777 forming a smoother curved region than portions 725 and 727 of scaffold 700. A further difference is that scaffold 750 includes proximal and distal scaffolds that both include mirrored portions, such as portions 763 and 765 as shown in FIG. 25B. The mirrored aspect refers to the axially adjacent connector 762 of portion 763 mirrored with respect to connector 762 of portion 765. The same mirrored aspect is shown in distal scaffold 780. As shown, the mirrored portion of proximal scaffold 760 is closer to central scaffold 770 than the mirrored portion of distal scaffold 780. In alternative embodiments, the mirrored portion of the distal scaffold may be closer to the central scaffold than the mirrored portion of the proximal scaffold. The description of all other aspects of the scaffold herein, including axially extending elements and circumferential connectors, are incorporated by reference herein for scaffold 750. FIG. 25B shows a flattened expanded configuration, and FIG. 25A shows a flattened unexpanded configuration.

[0276]

[0325] 26A and 26B show scaffold 800 including many of the same features as scaffold 750 shown in FIGS. 25A and 25B, as illustrated. FIG. 26A shows a flattened, unexpanded configuration, and FIG. 26B shows the transition region 801 of scaffold 800 mentioned in FIG. 26A. The difference between the scaffolds is that in FIGS. 26A and 26B, the proximal scaffold 810 includes a mirrored portion that is further from the central scaffold 820 than the mirrored portion of the distal scaffold, as illustrated. FIG. 26B shows the transition region between the proximal scaffold 810 and the central scaffold 820. Scaffold 800 includes orthogonally oriented vertices 824, as described elsewhere herein. The first region of the scaffold includes portions 825 and 827, which may be the same as portions 775 and 777 of scaffold 750. 26B shows that the width of axially extending element 811 is greater than the width of element 821 in the central scaffold, as shown. Thickness measurements are into the page of the figure (the "z" direction) and width measurements are in the plane of the page of the figure. The thickness "t" of one of the elements 811 is labeled for reference. As shown, the thickness "t" of element 811 is greater than the thickness of element 821 in the central scaffold portion.

[0277]

[0326] 27A and 27B show an exemplary scaffold 850 that is similar in some respects to scaffold 550 shown in FIGS. 21A and 21B. Scaffold 850 includes a proximal scaffold 860, a central scaffold 870, and a distal scaffold 880, which in this embodiment may be unitary. Central scaffold 870 of scaffold 850 includes helical elements 871 in an unfolded configuration (FIG. 27A) and a wrapped configuration (FIG. 27B). In this embodiment and other embodiments herein, the scaffold can be manufactured (e.g., including laser cutting of a tubular member) such that the expanded shape is the shape in which the scaffold is laser cut from a tubular member. This is in contrast to any examples herein where the scaffold is laser cut from a smaller diameter tubular member and then expanded and set in the expanded configuration. In any of the embodiments herein, the laser cut diameter may be equal to the unfolded diameter, for example and without limitation, to provide better concentricity, which may allow the membrane coating to adhere to the struts and also result in a smoother inner diameter.

[0278]

[0327] Proximal scaffold 860 and distal scaffold 880 have substantially the same configuration, but they are circumferentially displaced by circumferential interval "CS" (labeled in FIG. 27A). Adjacent helical elements 871 are connected by connectors 872. All other similar aspects of other scaffolds herein can be incorporated herein, including, by way of example only, the axially offset nature of circumferentially adjacent circumferential connectors in proximal scaffold 860 and distal scaffold 880.

[0279]

[0328] 27A shows exemplary distal and proximal struts extending axially from a scaffold, only one of which is labeled 865. In this example, there are four proximal and four distal struts. As shown, the struts are tapered and wider at the ends distal to the scaffold, which may provide improved stability on the impeller compared to struts that have a constant width along their entire length. Any of the pump portions herein can include any number of struts having the same configuration as strut 865.

[0280]

[0329] In any of the embodiments herein, the scaffold may be cut from a tubular member having an expanded scaffold diameter. In these embodiments, the tubular member has the same or substantially the same diameter as the desired scaffold deployed configuration (uncoated). Alternatively, in any of the embodiments herein, the scaffold may be cut from a tubular member having an unexpanded scaffold diameter. In this embodiment, the tubular member has a diameter smaller than the expanded diameter of the scaffold, and once cut, the scaffold can be expanded and set to the expanded deployed configuration.

[0281]

[0330] In any of the embodiments herein, the distal scaffold may have a length greater than the length of the proximal scaffold. In any of the embodiments herein, the distal scaffold may have a length less than the length of the proximal scaffold. In any of the embodiments herein, the distal scaffold may have a length the same as the length of the proximal scaffold.

[0282]

[0331] In any embodiment herein, the central scaffold may have a length greater than the length of one or both of the proximal and distal scaffolds.

[0283]

[0332] Any of the different scaffold portions herein may be connected by one or more welds or may not be integral to one another.

[0284]

[0333] In any of the embodiments herein, any portion of the scaffold may have a thickness (measured radially between the scaffold inner diameter and the scaffold outer diameter) that may be the same or different than the thickness of any other portion of the scaffold. For example, the thickness of a scaffold portion may be reduced by electropolishing one or more portions more than other portions (or may not include electropolishing). Varying thickness may be in addition to or instead of varying width, which may allow for more design options, if desired.

[0285]

[0334] In any of the embodiments herein, the axial distance between the proximal and distal scaffold portions may be between 30 mm and 50 mm, such as between 35 mm and 45 mm.

[0286]

[0335] In any of the embodiments herein the pump section may be from 40mm to 80mm, such as from 50mm to 70mm, for example from 55mm to 65cm.

[0287]

[0336] In any of the embodiments herein including first and second impellers, the axial distance between the impellers may be from 40mm to 60mm, for example from 45mm to 55mm.

[0288]

[0337] In any of the embodiments herein, the diameter of the expanded (or uncollapsed) blood conduit may be between 6 mm and 8.5 mm, such as between 6 mm and 8 mm, for example between 6.5 mm and 7.5 mm.

[0289]

[0338] In any of the embodiments herein, the impeller diameter when expanded may be between 5mm and 7mm, for example between 5.5mm and 6.5mm.

[0290]

[0339] Some of the pump portions herein include a collapsible and expandable blood conduit and one or more impellers that are at least partially disposed within the blood conduit when the pump portion is in an operating state. In some embodiments herein, the collapsible blood conduit includes a scaffold that can extend along at least a portion of the length of the blood conduit and provide radial support to the blood conduit. In some embodiments herein, the scaffold can be integral along the blood conduit. In some embodiments, different scaffold portions may not be integral (formed from the same starting material), but may be directly attached or connected to one another (e.g., directly welded together).

[0291]

[0340] In some embodiments, axially adjacent scaffold portions may not be integral and connected to each other. They may still be bound together by independent attachment to one or more membranes herein. In these examples, the central scaffold portion may not be connected to one or both of the distal or proximal scaffold portions. In some embodiments of the pump portion herein that includes only a single impeller, the central scaffold portion may not be connected to one or both scaffold portions that may be axially adjacent to the central scaffold portion.

[0292]

[0341] 28A and 28B show an exemplary collapsible blood conduit 900 of the pump portion in an expanded (not collapsed) state. The blood conduit 900 includes a collapsible scaffold including a central scaffold portion 902, a proximal scaffold portion 904, and a distal scaffold portion 906. Proximal and distal in this context do not necessarily mean that they are the most distal or most proximal scaffold portions. Proximal and distal in this context generally refer to relative position with respect to the central axial scaffold portion. In this example, the central axial scaffold portion 902 is not connected to or integral with either the proximal scaffold portion 904 or the distal scaffold portion 906. The proximal, central, and distal scaffold portions are each individually connected to one or more membrane layers, which are described in more detail elsewhere herein.

[0293]

[0342] 28A and 28B can be considered similar to other pump portions herein, such as the pumps shown in FIGS. 2, 3A-4, 9, in that the pump portion can be considered to include proximal and distal expandable impeller baskets, examples of which are described herein. For example, pump portion 340 of FIGS. 3A-3D includes an exemplary proximal scaffold or basket 343 and a distal scaffold or basket 344. Proximal scaffold portion 904 can be considered similar to proximal scaffold portion 343, and distal scaffold portion 906 can be considered similar to distal scaffold portion 344. Thus, pump portion 900 can be considered otherwise similar to pump portion 340 described herein, but further includes a central scaffold portion 902 that is not directly attached to the proximal and distal scaffold portions. The pump membrane, which forms the blood conduit, may be composed of one or more layers of membrane material, as described in more detail herein.

[0294]

[0343] As an alternative to the pump portion shown in FIGS. 28A and 28B, the pump portion may not include a basket, as that term is used herein, but the central scaffold may still be non-integral and not connected to one or both of the proximal and distal scaffold portions. For example, the pump 900 may alternatively omit a basket with distal and proximal struts, similar to the scaffold shown in FIG. 11. Additionally, the scaffold of FIG. 11 may include a discontinuity between the central scaffold portion and one or both of the proximal and distal scaffolds, such that the central scaffold is not integral and not connected to the proximal and / or distal scaffold portions. Thus, any of the scaffolds herein may be modified to include a discontinuity between the central scaffold portion and one or both of the proximal and distal scaffolds, such that the central scaffold is not integral and not connected to the proximal and / or distal scaffold portions.

[0295]

[0344] Although Figures 28A and 28B show a pump portion with multiple impellers, the pump portion may include a single impeller, such as a proximal or distal impeller. If the pump portion includes a single impeller, the axial location of the impeller may differ from that shown in Figures 28A and 28B. For example, the proximal impeller may be located entirely within the blood conduit. The impellers in Figures 28A and 28B are exemplary and may be replaced with any suitable impeller herein or generally known in the art.

[0296]

[0345] Any central scaffold portion herein may be connected or integral to one of the distal or proximal scaffold portions, but may be unintegral or unconnected to the other of the distal and proximal scaffold portions.

[0297]

[0346] Any of the central scaffold portions herein may have a different scaffold configuration than one or both of the proximal and distal scaffold portions. For example, in the example of Figures 28A and 28B, the central scaffold portion 902 has a different overall configuration than both the proximal portion 904 and the distal portion 906. In Figures 28A and 28B, the proximal and distal scaffold portions may have the same or similar configuration as any of the proximal and distal scaffold portions as shown in, for example, Figures 13A-13C, 14A and 14B, 15A and 15B, 16, 17, 18A and 18B, 19A and 19B, 20A and 20B, 21A and 21B, 22A and 22B, 23A and 23B, 24A and 24B, 25A and 25B, 26A and 26B, or 27A and 27B, the descriptions of which are incorporated by reference into the examples of Figures 28A and 28B. The proximal and distal scaffold portions may have the same configuration, similar configurations, or different overall configurations. In this regard, configurations are compared overall, including repeating portions and the entire structure from proximal to distal ends. The example in Figures 28A and 28B shows proximal and distal scaffold portions that are the same.

[0298]

[0347] In alternatives of any of the embodiments herein, the central scaffold portion may be connected or integral to one of the proximal and distal scaffolds but not connected to the other. For example, with reference to FIG. 28A, an alternative scaffold portion 902 may be integral or connected to scaffold portion 906 or scaffold portion 904 but not integral to the other scaffold portion 904 or scaffold portion 906.

[0299]

[0348] Any scaffold or scaffold portion herein may be understood to have a proximal end and a distal end. For example, the proximal end 901 and distal end 903 of a central scaffold 902 are shown in FIGS. 28A and 28B, respectively. P in FIG. 28A points proximally and D points distally. Inflow I and outflow O are also labeled. Other aspects of any pump portion herein may be incorporated into pump portion 900, including any of its alternatives. An exemplary proximal impeller 920 and a distal impeller 930 are also shown in FIGS. 28A and 28B, as is an exemplary drive assembly 940 in rotational communication with a motor (not shown) that drives rotation of one or more impellers.

[0300]

[0349] The pump portion herein generally has a central region that is generally more flexible than one or both of the proximal and distal impeller regions, the advantages of which are described elsewhere herein. Generally, the central scaffold portion herein is more flexible than the proximal and distal impeller portions. For example, the central scaffold 902 shown in FIGS. 28A and 28B can be considered to have a similar configuration to the central scaffold portion shown in FIGS. 25A-26B (the description of which is fully incorporated by reference), which may provide greater flexibility to the central scaffold than the flexibility of the proximal and distal scaffold portions. Additionally, at least one of the proximal and distal ends 901 and 903 of the central scaffold portion is not connected to an adjacent scaffold portion, which may provide additional flexibility to the blood conduit in the vicinity of the central scaffold portion.

[0301]

[0350] 28A and 28B, pump portion 900 includes a proximal impeller basket, the scaffold portion of which defines a proximal scaffold portion 904. Pump portion 900 also includes a distal impeller basket, the scaffold portion of which defines a distal scaffold portion 906. The proximal basket also includes a proximal basket proximal strut 908 and a proximal basket distal strut 910, additional exemplary details of which are described elsewhere herein. The distal basket includes a distal basket proximal strut 912 and a distal basket distal strut 914, additional exemplary details of which are described elsewhere herein. Pump portion 900 may incorporate any suitable features or aspects of the expandable baskets described herein.

[0302]

[0351] During pump collapse, one or more of the basket ends, such as the bearing housing, may move axially relative to the drive assembly 940 or other radially inner components to facilitate collapse, additional exemplary details of which are described elsewhere herein. Additionally, any of the struts herein may have free ends that are coupled, connected, or integral to a central hub, central assembly, or bearing assembly, examples of which are shown and described herein.

[0303]

[0352] 29A-29E show an exemplary scaffold 2950 similar to scaffold 850 shown in Figures 27A and 27B, but with a different scaffold pattern. In this embodiment and other embodiments herein, the scaffold 2950 can be manufactured (e.g., including laser cutting a tubular member) such that the expanded configuration is a configuration in which the scaffold is laser cut from a tubular member. In this example, the proximal and distal ends of the scaffold include free ends, and the free ends include a number of free strut ends.

[0304]

[0353] 29A shows a flat view of the scaffold. The scaffold 2950 includes a proximal scaffold portion 2960, a central scaffold portion 2970, and a distal scaffold portion 2980. The proximal portion 2960 can be configured to surround a proximal impeller and the distal portion 2980 can be configured to surround a distal impeller. In other embodiments, the scaffold is configured to surround only a single impeller, such as surrounding only the proximal impeller in the proximal portion 2960 and not including the distal impeller in the distal portion 2980. In some cases, the diameter and axial length of the proximal and / or distal impellers may be the same. In some cases, the diameter and / or axial length of the proximal and / or distal impellers may differ. The scaffold 2950 may be unitary and made of a single material (e.g., metal). For example, scaffold 2950 includes a series of axially extending elongate elements 2911 extending from a proximal portion 2960, through a central portion 2970, to a distal portion 2980. A first set of elongate elements 2911 form proximal struts 2952 at a proximal end of scaffold 2950. Similarly, a second set of elongate elements 2911 form distal struts 2951 at a distal end of scaffold 2950. The axially extending elongate elements 2911 can be connected by connector elements 2912 at the proximal portion 2960 and by connector elements 2922 at the distal portion 2980.

[0305]

[0354] In this example, the proximal and distal portions 2960, 2980 each include ten axially extending elongate elements 2911. This configuration can provide the scaffold 2950 with a higher radial stiffness as compared to the proximal and distal portions 860, 880 of FIGS. 27A and 27B, which each include eight axially extending elongate elements. Modifications that increase radial stiffness can also increase bending stiffness. Thus, the proximal and distal portions 2960, 2980 of the scaffold 2950 of FIGS. 29A-E can have a greater lateral bending stiffness as compared to the proximal and distal portions 860, 880 of the scaffold 850 of FIGS. 27A and 27B. Bending stiffness can refer to the ability of the scaffold 2950, ​​or a portion of the scaffold 2950, ​​to withstand deformation when a lateral force is applied to the side of the scaffold or to a portion of the scaffold 2950.

[0306]

[0355] Note that in this case, the greater number of extending elongate elements 2911 in scaffold 2950 results in a greater number of proximal struts 2952 and distal struts 2951 as compared to scaffold 850 of Figures 27A and 27B. Specifically, scaffold 2950 includes five proximal struts 2952 and five distal struts 2951, while scaffold 850 includes four proximal struts and four distal struts. This arrangement may provide scaffold 2950 with a higher radial stiffness in this region than scaffold 850. In some cases, one or more of the proximal struts 2952 and one or more of the distal struts 2951 may include a notch or recess 2918 (optionally a region of reduced relative circumferential width) that provides space for or accommodates the presence of one or more sensing elements (e.g., one or more pressure sensors and / or pressure sensor housings) on the central hub of the blood pump assembly.

[0307]

[0356] In the central portion 2970 of the scaffold 2950, ​​the elongate elements 2911 can be axially angled to have a helical or spiral shape that wraps around a central or long axis of the scaffold 2950. This helical or spiral arrangement of the elongate elements in the central portion can allow the central portion 2970 to be more laterally flexible and bendable as compared to the proximal portion 2960 and the distal portion 2980. This embodiment can allow the central portion 2970 to flex when a lateral force is applied to the side of the blood conduit as it passes through a blood vessel and / or heart chamber of a patient. For example, the central portion 2970 can be configured to bend laterally due to a lateral force applied to the distal portion 2980 and / or the proximal portion 2960. In some cases, it may be desirable for the central portion 2970 to bend laterally as the blood conduit traverses the ascending aorta and to assume a temporarily bent configuration as the blood conduit is positioned across the aortic valve, as described herein. The spiral or helical pattern of the central portion may allow it to bend laterally without collapsing the lumen of the central portion 2970, thereby allowing blood to flow through the central portion 2970. When the lateral bending force is released, the central portion 2970 may assume its original straight shape with the proximal portion 2960 and distal portion 2980 axially aligned. In some examples, the scaffold 2950 may be made of a shape memory material (e.g., Nitinol), and the scaffold 2950 is shape set in an expanded configuration and the proximal portion 2960, central portion 2970, and distal portion 2980 are axially aligned (e.g., the central portion 2970 is unbent). Thus, when the lateral bending force on the scaffold 2950 is released, the scaffold 2950 can return to its original shape-set state.

[0308]

[0357] In the example scaffold 2950, ​​the spirals or helical portions 2971 of the elongated elements 2911 in the central portion 2970 are not connected to each other by an intervening connector (e.g., connector 872 in FIGS. 27A and 27B ). Thus, the spirals or helical portions 2971 in the central portion 2970 can be circumferentially decoupled from each other by the scaffold 2950. This embodiment can increase the lateral flexibility of the central portion 2970. Additionally, the width of the helical portions 2971 of the elongated elements can be less than the width of the elongated elements 2911 in the proximal and distal portions 2960 and 2980. This arrangement can provide more flexibility to the central portion 2970 compared to the proximal and distal portions 2960 and 2980, which can also contribute to the lateral flexibility of the central portion 2970. The central portion 2970 can be adapted to bend more or have a greater degree of bending than both the proximal portion 2960 and the distal portion 2980 in response to a lateral force applied to the distal portion 2980. The central portion 2970 can be positioned across the aortic valve in use, and the flexibility of the central portion 2970 can help the central portion 2970 deform or bend when positioned across the valve.

[0309]

[0358] In some cases, the central portion 2970 is sufficiently flexible to allow the central portion 2970 to assume a curved configuration when a blood conduit is placed across a valve (e.g., an aortic valve) and the central portion 2970 is placed at a valve leaflet location. The curved configuration may cause the axis of rotation of the proximal impeller to be misaligned (e.g., non-parallel) with the axis of rotation of the distal impeller (e.g., similar to that shown in FIG. 4).

[0310]

[0359] The proximal portion 2960, the central portion 2970, and / or the distal portion 2980 may have different patterns of structural elements, thereby providing different stiffness to the proximal portion 2960, the central portion 2970, and / or the distal portion 2980. For example, the connector elements 2912 of the proximal portion 2960 and the connector elements 2922 of the distal portion 2980 are arranged in annular rows about the central axis of the tubular scaffold, providing radial and / or bending stiffness to the respective portions. In this case, the proximal portion 2960 includes more connector elements 2912 (four annular rows) than the distal portion 2980 (three annular rows), thereby providing greater radial and / or bending stiffness to the proximal portion 2960 as compared to the distal portion 2980.

[0311]

[0360] Spacing between scaffold elements (e.g., connector elements 2912 / 2922 and elongate elements 2911) can also be associated with radial and / or bending stiffness of the scaffold portion. For example, axially adjacent connector elements 2912 may be axially closer to each other in the proximal portion 2960 than in the distal portion 1980, which can help impart a greater relative stiffness (e.g., radial and / or bending stiffness) in the proximal portion 2960. In this example, the proximal portion 2960 has a denser scaffold pattern than the distal portion 2980, resulting in the proximal portion 2960 having a greater radial and / or bending stiffness than the distal portion 2980. For example, connector elements 2912 circumferentially connecting axially extending elongate elements 2911 in the proximal portion 2960 can be a first distance 2934 apart, and connector elements 2922 connecting axially extending elongate elements 2911 in the distal portion 2980 can be a second distance 2936 apart, where the first distance 2934 is less than the second distance 2936. This can result in openings 2966 between scaffold elements in the proximal portion 2960 being smaller than openings 2968 between scaffold elements in the distal portion 2980.

[0312]

[0361] For any of the scaffolds described herein, a scaffold portion having a pattern with a greater cumulative area of ​​spacings (e.g., spacings between scaffold elements) may be referred to as "loosely packed" and a scaffold portion having a pattern with a smaller cumulative area of ​​spacings may be referred to as "tightly packed." For example, the proximal portion 2960 may be characterized as having a more tightly packed scaffold pattern than the distal portion 2980. The portions having a more tightly packed scaffold pattern may be associated with having a greater radial and / or bending stiffness compared to portions having a more loosely packed scaffold pattern.

[0313]

[0362] In some examples, the vertical spacing 2933 between the elongate elements 2911 may be within a range bounded by any two of the following values: 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3.0 mm, 3.5 mm, 4 mm, 4.5 mm, and 5 mm.

[0314]

[0363] In some examples, the first distance 2934 between the connector elements 2912 of the proximal portion 2960 may be within a range bounded by any two of the following values: 3.0 mm, 3.5 mm, and 4.0 mm.

[0315]

[0364] In some examples, the second distance 2936 between the connector elements 2922 of the distal portion 2980 may be within a range bounded by any two of the following values: 4.0 mm, 4.5 mm, and 5.0 mm.

[0316]

[0365] The proximal portion 2960 and the distal portion 2980 may have different axial lengths. In this example, the proximal portion 2960 may have an axial length 2975 that is longer than the axial length 2977 of the distal portion 2980. In some cases, the axial length 2975 of the proximal portion 2960 may be about 5% to 20% longer than the axial length 2977 of the distal portion 2980. The axial length 2979 of the central portion 2970 may be greater than the axial length 2975 of the proximal portion 2960 and / or the axial length 2977 of the distal portion 2980. The axial length 2975 of the proximal portion 2960 may be within a range bounded by any two of the following values: 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, 25 mm. The axial length 2977 of the distal portion 2980 may be within a range bounded by any two of the following values: 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, and 16 mm. The axial length 2979 of the central portion 2970 may be within a range bounded by any two of the following values: 22 mm, 23 mm, 24 mm, 25 mm, 26 mm, 27 mm, 28 mm, 29 mm, and 30 mm. The axial length 2961 of the proximal strut 2952 and / or the axial length 2981 of the distal strut 2951 may be within a range bounded by any two of the following values: 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm.

[0317]

[0366] In some cases, the axial length 2975 of the proximal portion 2960 can be longer than the axial length 2977 of the distal portion 2980 based on the different forces that these portions are expected to experience during surgery in a patient. For example, the distal region 2967 of the proximal portion can experience a higher level of radially inward force compared to, for example, the proximal region 2969 of the distal portion 2980. Having a longer proximal portion 2960 can compensate for this expected greater radially inward force at the distal region 2967 of the proximal portion 2960 to prevent collapse of this region of the scaffold 2950.

[0318]

[0367] In some examples, the overall axial length of the scaffold 2950, ​​and any scaffold described herein, may be within a range bounded by any two of the following values: 50 mm, 55 mm, 60 mm, 65 mm, 70 mm, 75 mm, 80 mm.

[0319]

[0368] In some cases, it may be beneficial for the proximal portion 2960 to be radially stiffer and longer than the distal portion 2980. For example, a particular placement of the scaffold 2950 within a patient may cause the proximal portion 2960 to experience a greater radially inward force (e.g., bending force) than the distal portion 2980. For example, the proximal portion 2960 may experience more bending forces within the ascending aorta compared to the distal portion 2980 within the left ventricle. A stiffer and longer proximal portion 2960 may reduce or prevent deformation of the proximal portion 2960, thereby preventing the proximal impeller from contacting the walls of the blood conduit and / or maintaining the integrity of the blood conduit lumen for blood flow through the proximal portion of the scaffold 2950.

[0320]

[0369] In some cases, the axial length 2979 of the central portion 2970 is greater than or less than the axial length 2975 of the proximal portion 2960 and / or the axial length 2977 of the distal portion 2980. In the illustrated example, the central portion 2970 is longer than the axial length 2975 of the proximal portion 2960 and the axial length 2977 of the distal portion 2980.

[0321]

[0370] The axially extending elongate elements 2911 in the central portion 2970 may be angled relative to a longitudinal axis of the scaffold 2950. The angle Θ of the axially extending elongate elements 2911 in the central portion 2970 may be non-parallel and non-orthogonal to the longitudinal axis of the scaffold 2950 while forming a helix / spiral arrangement of the axially extending elongate elements 2911 about a central axis of the scaffold 2950.

[0322]

[0371] The angle Θ may be determined based on a number of factors. For example, the angle Θ may be determined based on a desired degree of lateral bendability of the central portion 2970. In some examples, the central portion 2970 may be more flexible in the lateral direction at a larger angle Θ and less flexible in the lateral direction at a smaller angle Θ.

[0323]

[0372] The angle Θ may be determined based on expected axial forces on the blood conduit when the blood pump traverses the patient's blood vessel / heart and / or when the blood conduit is covered and / or uncovered. For example, it may be desirable for the central portion 2970 to have sufficient axial stiffness to at least partially deform axially when such axial forces are applied to the blood conduit. In some examples, the central portion 2970 may have a higher axial stiffness at smaller angles Θ and a lower axial stiffness at larger angles Θ.

[0324]

[0373] Another factor determining the angle Θ may include the degree of elongation of the blood conduit as it collapses during covering. The blood conduit may be longer in the collapsed state (e.g., when covered) compared to the expanded state (e.g., uncovered). In some cases, the proximal and / or distal central hubs of the scaffold 2950 may be configured to accommodate changes in length as the blood conduit transitions between the expanded and collapsed states. However, in some cases, it may be desirable to minimize such changes in length or keep the degree of change in length within a threshold value. The degree to which the blood conduit stretches may be based at least in part on the angle Θ. In some examples, a larger angle Θ may be associated with a greater degree of elongation as the blood conduit transitions to the collapsed state compared to a smaller angle Θ.

[0325]

[0374] In some examples, the angle Θ of the axially extending elongate elements 2911 in the central portion 2970 may be within a range bounded by any two of the following values: 10 degrees, 15 degrees, 20 degrees, 25 degrees, 30 degrees, 35 degrees, 40 degrees, 45 degrees, 50 degrees, 55 degrees, 60 degrees. In some examples, the angle Θ may be within a range bounded by any two of the following values: 20 degrees, 25 degrees, 30 degrees, 35 degrees, 40 degrees, and 45 degrees.

[0326]

[0375] In some cases, the width of the axially extending elongate elements 2911 may vary along the length of the scaffold 2950. In some instances, the width 2927 of the axially extending elongate elements 2911 in the central portion 2970 is less than the width 2928 of the axially extending elongate elements 2911 in the proximal portion 2960 and / or the width 2929 of the axially extending elongate elements 2911 in the distal portion 2980. The axially extending elongate elements 2911 in the proximal portion 2960 and / or the distal portion 2980 may have a greater relative width to provide adequate support for the scaffold 2950 around the respective impellers. The axially extending elongate elements 2911 in the central portion 2970 may have a narrower relative width to provide lateral flexibility of the central portion 2970 to lateral bending of the pump, for example, when placed in a curved portion of the patient's anatomy. The smaller relative width of the axially extending elongate elements 2911 of the central portion 2970 may alternatively or additionally facilitate folding of the scaffold, thereby reducing strain on the covering.

[0327]

[0376] 29B illustrates an exemplary blood conduit 2901 with a scaffold 2950 in an assembled and expanded configuration. A proximal portion 2960 of the scaffold 2950 surrounds or encircles at least a portion of the proximal impeller 2920, and a distal portion 2980 of the scaffold 2950 surrounds at least a portion of the distal impeller 2930. The scaffold 2950 also surrounds at least a portion of a drive shaft 2959 to which the proximal impeller 2920 and the distal impeller 2930 are operatively coupled, including a central region of the drive shaft that extends between the impellers. The proximal struts 2952 can bend radially inward to couple to a proximal central hub 2986, and the distal struts 2951 can bend radially inward to couple to a distal central hub 2988. In some cases, each of the proximal central hub 2986 and the distal central hub 2988 at least partially houses or abuts a bearing assembly operably coupled to a drive shaft 2959. The drive shaft 2959 can be configured to flex laterally when the scaffold flexes laterally and to maintain a motion function (e.g., to rotate the impellers 2920 and 2930) as the drive shaft 2959 flexes.

[0328]

[0377] In the illustrated example, a membrane 2949 covers the opening of the scaffold 2950 to form a blood conduit. In some cases, the membrane 2949 may cover at least a portion or all of the interior and / or exterior surfaces of the scaffold 2950. For example, in some cases, the entire scaffold 2950 (including the inner and outer diameters) may be covered by the membrane 2949. In some cases, the membrane 2949 may not cover the struts 2951 / 2952. In some cases, the membrane 2949 may cover at least a portion of the struts 2951 / 2952. The blood conduit may optionally include an inner membrane extending over at least a portion of the interior surface of any of the scaffolds herein. The membrane 2949 may be made of a material that is flexible enough to allow expansion and collapse of the blood conduit. The membrane 2949 may be made of any of the membrane materials (e.g., biocompatible polymeric materials) described herein.

[0329]

[0378] The membrane 2949 may be formed on the scaffold 2950 using any of a number of techniques. In some cases, the membrane 2949 may be applied using a spray-on technique. In some instances, the membrane 2949 may be formed in one or more layers. In some cases, the membrane 2949 is formed by applying heat, pressure, and / or vacuum to a membrane material.

[0330]

[0379] 29C shows the proximal impeller region of the blood pump in a collapsed state and encased within an outer sheath 2955. The scaffold 2950 can be configured to be in a higher energy state when in the collapsed state such that a radially inward force is required, for example, from an inner wall of the outer sheath 2955, to maintain the scaffold in the collapsed state. When the outer sheath 2955 is removed (e.g., by pulling the outer sheath 2955 proximally and / or pushing the blood pump distally), the scaffold 2950 can relax and transition to a lower energy expanded state. 29C illustrates how the connector elements 2912 bend to move the axially extending elongate elements 2911 radially inward and toward one another, thereby folding the scaffold 2950 (optionally, the ends of the connector elements 2912 may be relatively more curved than the central straight portion of the connector elements 2912, which may facilitate bending at the ends of the connectors 2912). Similarly, when the scaffold 2950 is expanded, the connector elements 2912 can relax to their low energy state such that the connector elements 2912 move radially outward and away from one another. Additionally, the struts 2952 can transition from a curved shape when the scaffold 2950 is in an expanded configuration to a straighter shape when the scaffold 2950 is in a folded configuration.

[0331]

[0380] 29D and 29E show close-up views of the proximal and distal portions, respectively, of scaffold 2950. As noted above, width 2928 of axially extending elements 2911 in proximal portion 2960 and / or width 2929 of axially extending elements 2911 in distal portion 2980 may be greater than width 2927 of axially extending elements 2911 in central portion 2970. This may contribute to greater radial and / or bending stiffness of proximal portion 2960 and / or distal portion 2980 compared to central portion 2970. In some embodiments, width 2928 of axially extending element 2911 in proximal portion 2960 and / or width 2929 of axially extending element 2911 in distal portion 2980 may be within a range bounded by any two of the following values: 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4, and 0.45 mm. In some embodiments, width 2927 of axially extending element 2911 in central portion 2970 may be within a range bounded by any two of the following values: 0.15 mm, 0.2 mm, 0.25 mm, and 0.3 mm. In some embodiments, width 2928 and / or 2929 may be greater than width 2927 by a percentage ranging between about 2% and 100%.

[0332]

[0381] The transition between width 2928 and / or 2929 and width 2927 can occur in a transition region 2947 between central portion 2970 and proximal portion 2960 or distal portion 2980. The axially extending elements 2911 in the transition region 2947 can have a curved shape such that the axially extending elements 2911 can transition from a parallel state (with respect to the central axis of the blood conduit) in proximal portion 2960 or distal portion 2980 to a helical configuration in central portion 2970. In some embodiments, the radius of curvature 2944 of each axially extending element 2911 in the transition region 2947 may be within a range bounded by any two of the following values: 0.1 inch, 0.2 inch, 0.3 inch, 0.4 inch, and 0.5 inch. In some embodiments, the length of the transition region 2947 along the axially extending element 2911 may be within a range bounded by any two of the following values: 0.10 inch, 0.15 inch, 0.20 inch, and 0.25 inch.

[0333]

[0382] The shape and size of connector elements 2912 (in proximal portion 2960) and / or 2922 (in distal portion 2980) can vary depending on, for example, the desired bending and / or outward expansion force. As discussed above, connector elements 2912 and / or 2922 can bend as scaffold 2950 transitions from an expanded state to a collapsed state. In the illustrated example, connector elements 2912 and 2922 can each have a straight portion 2991 and a curved portion 2992 where they connect to axially extending elongate element 2911. Note that in this example, the radius of curvature of curved portions 2992 of connector elements 2912 and 2922 is smaller than the radius of curvature of the connector elements in exemplary scaffold 850 of FIGS. 27A and 27B. In some cases, connector elements 2912 / 2922 are circumferentially arranged in a zigzag pattern around scaffold 2950.

[0334]

[0383] The angle α between the connector elements 2912 of the proximal portion 2960 (or the connector elements 2922 of the distal portion 2980) and the axially extending elements 2911 may be about 30 degrees to 50 degrees. As shown, the row of connector elements 2912 may generally resemble a zigzag or chevron pattern as they extend radially or circumferentially around the proximal and / or distal portions. In some embodiments, adjacent connector elements may be approximately orthogonal or perpendicular to other connector elements, such as when the angle α between the connector elements and the axially extending elements is about 45 degrees.

[0335]

[0384] In general, scaffold patterns can be customized to achieve specific performance characteristics. As explained above, the angle Θ can be selected to achieve a desired amount of lateral bendability and axial stiffness in the central portion (e.g., 2970). Additionally, the scaffold patterns in and around the proximal portion (e.g., 2960) and distal portion (e.g., 2980) can at least partially determine the radial and / or bending stiffness of the proximal and distal portions. On the one hand, it may be desirable for the proximal portion (e.g., 2960) and distal portion (e.g., 2980) to have a radial stiffness high enough to withstand radially inward pressures experienced during operation of the blood pump within the patient's body when in an expanded state. Additionally, it may be desirable for the proximal portion (e.g., 2960) and distal portion (e.g., 2980) to have a bending stiffness high enough to withstand deformation when lateral forces are applied to the sides of the scaffold as the blood conduit crosses the walls of the patient's blood vessels and / or ventricles. Such radial and / or bending stiffness can maintain the blood conduit in an expanded state to prevent the impeller from contacting the inner wall of the blood conduit during pumping. On the other hand, it may be desirable for the proximal portion (e.g., 2960) and the distal portion (e.g., 2980) to be able to assume a collapsed state having a diameter small enough to be re-sheathed without applying an excessive amount of covering force. The collapsibility of the scaffold may be related, at least in part, to the degree of elastic strain of the scaffold. In some instances, the greater the amount of elastic strain (relative to plastic strain), the greater the ability to compress the scaffold into a collapsed state without permanently deforming it. The pattern of the scaffold may be designed to mitigate such covering strain. If the scaffold is made of a shape memory material, the scaffold may be heat set to have a desired shape and material properties at a particular temperature (e.g., body temperature).In some cases, one or more computer modeling techniques (e.g., finite element analysis or other modeling analyses) are used to estimate the degree of strain a scaffold will undergo during use based on the scaffold pattern, materials, and / or other variables.

[0336]

[0385] 30 shows a flattened view of another exemplary scaffold 3050, which is similar to scaffold 2950 shown in FIGS. 29A-29E, but with a different scaffold pattern variation. Like scaffold 2950, ​​scaffold 3050 includes a proximal scaffold portion 3060, a central scaffold portion 3070, and a distal scaffold portion 3080, where proximal portion 3060 can be configured to at least partially surround a proximal impeller, and distal portion 3080 can be configured to at least partially surround a distal impeller. Scaffold 3050 includes a series of axially extending elongate elements 3011 that extend from proximal portion 3060, through central portion 3070, to distal portion 3080. Similar to scaffold 2950, ​​scaffold 3050 includes ten axially extending elongate elements 3011.

[0337]

[0386] Various characteristic dimensions of scaffold 3050 may be similar to those of scaffold 2950 of FIGS. 29A-29E. For example, the angle Θ of axially extending elongate elements 3011 in central portion 3070 may be the same as scaffold 2950. As with scaffold 2950, ​​width 3027 of axially extending elongate elements 3011 in central portion 3070 may be less than width 3028 of axially extending elongate elements 3011 in proximal portion 3060 and / or width 3029 of axially extending elongate elements 3011 in distal portion 3080. Axial length 3061 of proximal strut 3052 may be the same as axial length 2961 of proximal strut 2952, and axial length 3081 of distal strut 3051 may be the same as axial length 2981 of distal strut 2951. Widths 3027, 3028, and 3029 may be the same as widths 2927, 2928, and 2929, respectively, of scaffold 2950. The radius of curvature of each axially extending element 3011 in transition region 3047 may be the same as the radius of curvature of axially extending elements 2911 in transition region 2947 of scaffold 2950. Proximal portion 3060 may have a greater radial and / or bending stiffness as compared to distal portion 3080.

[0338]

[0387] The scaffold 3050 of FIG. 30 has a different connector element pattern compared to the scaffold 2950 of FIGS. 29A-29E, which may allow the scaffold 3050 to have reduced sheathing strains compared to the scaffold 2950. The angle α between the connector element 3012 of the proximal portion 3060 (or the connector element 3022 of the distal portion 3080) and the axially extending element 3011 is less than the angle α of the scaffold 2905 of FIGS. 29A-29E. In some examples, the angle α may be about 10 degrees to 30 degrees. The axial length 3075 of the proximal portion 3060 may be substantially the same as the axial length 2975 of the proximal portion 2960 of the scaffold 2905 of FIGS. 29A-29E. However, because the angle α is smaller, the proximal portion 3060 includes three annular rows of connector elements 3012 (compared to five annular rows of connector elements 2912 of scaffold 2950) and the distal portion 3080 includes two annular rows of connector elements 3022 (compared to three annular rows of connector elements 2922 of scaffold 2950). Fewer annular rows of connector elements 3012 / 3022 may allow the scaffold to be easily folded from an expanded configuration to a folded configuration. Additionally, the length of connector elements 3012 is greater than the length of connector elements 2912 and the length of connector elements 3022 is greater than the length of connector elements 2922. Similarly, a first distance 3034 between connector elements 3012 is greater than a first distance 2934 between connector elements 2912 and a second distance 3036 between connector elements 3022 is greater than a second distance 2936 between connector elements 2922.

[0339]

[0388] In some examples, the first distance 3034 between the connector elements 3012 of the proximal portion 3060 may be within a range bounded by any two of the following values: 5.0 mm, 5.5 mm, 6.0 mm, 6.5 mm, and 7.0 mm.

[0340]

[0389] In some examples, the second distance 3036 between the connector elements 3022 of the distal portion 3080 may be within a range bounded by any two of the following values: 6.0 mm, 6.5 mm, 7.0 mm, 7.5 mm, and 8.0 mm.

[0341]

[0390] FIG. 31 shows a flattened view of a further exemplary scaffold 3150 similar to scaffold 3050 (FIG. 30) but with a different scaffold pattern. Like scaffold 3050, scaffold 3150 includes a proximal scaffold portion 3160, a central scaffold portion 3170, and a distal scaffold portion 3180, where proximal portion 3160 may be configured to at least partially surround a proximal impeller and distal portion 3180 may be configured to at least partially surround an (optional) distal impeller. Scaffold 3150 includes a series of axially extending elongate elements 3111 that extend from proximal portion 3160 through central portion 3170 to distal portion 3180. Like scaffold 3050, scaffold 3150 includes ten axially extending elongate elements 3111.

[0342]

[0391] Various characteristic dimensions of scaffold 3150 may be similar to those of scaffold 3050. For example, the angle Θ of axially extending elongate elements 3111 in central portion 3170 may be the same as scaffold 3050. As with scaffold 3050, width 3127 of axially extending elongate elements 3111 in central portion 3170 may be less than width 3128 of axially extending elongate elements 3111 in proximal portion 3160 and / or width 3129 of axially extending elongate elements 3111 in distal portion 3180. Widths 3127, 3128, and 3129 may be the same as scaffold 3050. The radius of curvature of each axially extending element 3111 in transition region 3147 may be the same as the radius of curvature of scaffold 3050. The proximal portion 3160 may have greater radial and / or bending stiffness as compared to the distal portion 3180.

[0343]

[0392] The proximal portion 3160 of the scaffold 3150 has a slightly longer axial length 3175 compared to the axial length 3075 of the proximal portion 3060 of the scaffold 3050 of FIG. 30. The longer axial length 3175 may provide greater radial and / or bending stiffness to the proximal portion 3160 of the scaffold 3150 compared to the proximal portion 3060 of the scaffold 3050. The axial lengths 3161 / 3181 of the proximal / distal struts 3152 / 3151 may be shorter than the axial lengths 3061 / 3081 of the proximal / distal struts 3052 / 3051 such that the overall axial length of the scaffold 3150 is substantially the same as the scaffold 3050. Additionally, the proximal portion 3160 of scaffold 3150 has a different connector element pattern as compared to the proximal portion 3060 of scaffold 3050. For example, the proximal portion 3160 has four annular rows of connector elements 3112 as compared to three annular rows of connector elements 3012 of scaffold 3050. This increased number of connector elements can allow for more structural support around the proximal impeller.

[0344]

[0393] 32A and 32B show another exemplary scaffold 3250. FIG. 32A shows a flattened view of the scaffold 3250. The scaffold 3250 is similar to the scaffold 3150 shown in FIG. 31. The angle Θ of the axially extending elongate elements 3211 in the central portion 3270 may be the same as the scaffold 3150. The angle α between the connector element 3212 of the proximal portion 3260 (or the connector element 3222 of the distal portion 3280) and the axially extending elements 3211 may be the same as the scaffold 3150. Similar to the scaffold 3150, the axial length 3279 of the central portion 3270 may be longer than the axial length 3275 of the proximal portion 3260 and / or the axial length 3277 of the distal portion 3280. Similar to scaffold 3150, axial length 3275 of proximal portion 3260 may be greater than axial length 3277 of distal portion 3280. Similar to scaffold 3150, width 3227 of axially extending elongate elements 3211 in central portion 3270 may be less than width 3228 of axially extending elongate elements 3211 in proximal portion 3260 and / or width 3229 of axially extending elongate elements 3211 in distal portion 3280. Width 3228 of axially extending elongate elements 3211 in proximal portion 3160 and width 3229 of axially extending elongate elements 3211 in distal portion 3280 may be the same as in scaffold 3150. The radius of curvature of each axially extending element 3211 in transition region 3247 may be the same as the radius of curvature of scaffold 3050. The proximal portion 3260 may have greater radial and / or bending stiffness as compared to the distal portion 3280.

[0345]

[0394] One difference between scaffold 3250 and scaffold 3150 (FIG. 31) is the number of struts. Scaffold 3250 includes eight proximal struts 3252 and eight distal struts 3251, compared to five proximal struts 3150 and five distal struts 3152 of scaffold 3150. Additionally, the proximal struts 3252 and distal struts 3251 have a width 3299 that is smaller than the width of scaffold 3150. The smaller the width of the struts, the greater the number of struts 3252 / 3251 that can be accommodated within scaffold 3250. In some examples, the width of the proximal and distal struts 3252 / 3251 of scaffold 3250 is about 10-90% smaller than the width of the struts 3152 / 3151 of scaffold 3150. As the strut width decreases, the radial and / or bending stiffness and / or coverage strain properties of the scaffold 3250 may also change.

[0346]

[0395] Another difference between scaffold 3250 and scaffold 3150 (FIG. 31) is the scaffold pattern of the proximal portion 3260 and the distal portion 3280. In addition to the axially extending elongate elements 3211, the proximal portion 3260 of scaffold 3250 includes secondary axially extending elements 3298 that are shorter than the axially extending elongate elements 3211 and do not extend into the central portion 3270. Additionally, the proximal portion 3260 and distal portion 3280 of scaffold 3250 have a greater number of connector elements 3221 / 3222 compared to scaffold 3150. Additionally, the distal portion 3280 includes three annular rows of connecting elements 3222 compared to two annular rows of connecting elements 3122 in the distal portion 3180 of scaffold 3150. The width 3228 of the axially extending elongate elements 3211 in the proximal and distal portions 3260, 3280 may be smaller (e.g., 10-90% smaller) than the width of the scaffold 3150 to accommodate more elements. This difference in the number and width of the axially extending elongate elements 3211 and the number of connecting elements 3222 may result in different radial and / or bending stiffness and / or coverage strain properties of the scaffold 3250.

[0347]

[0396] Another difference between scaffold 3250 and scaffold 3150 (FIG. 31) is the characterization of the axially extending elongate elements 3211 in the central portion 3270. Scaffold 3250 includes eight axially extending elongate elements 3211 in the central portion 3270, while scaffold 3150 includes ten axially extending elongate elements 3111 in the central portion 3170. Additionally, the width 3227 of the axially extending elongate elements 3211 of scaffold 3250 is smaller than the width 3127 of the axially extending elongate elements 3111 of scaffold 3150. The fewer and smaller widths of the axially extending elongate elements 3211 in the central portion 3270 may be associated with a greater lateral bendability of the central portion 3270 compared to the lateral bendability of scaffold 3150.

[0348]

[0397] The axial length of the proximal portion 3260, the central portion 3270 and / or the distal portion 3280 may be slightly different than the axial length of the scaffold 3150 (FIG. 31) to accommodate different numbers and arrangements of struts, axially extending elongate elements and connector elements. In some cases, the length 3275 of the proximal portion 3260 of the scaffold 3250 is shorter than the length 3175 of the proximal portion 3160 of the scaffold 3150. In some cases, the length 3279 of the central portion 3270 of the scaffold 3250 is greater than the length 3179 of the central portion 3170 of the scaffold 3150. In some cases, the length 3277 of the distal portion 3280 of the scaffold 3250 is the same as the length 3177 of the central portion 3180 of the scaffold 3150.

[0349]

[0398] Figure 32B shows scaffold 3250 in a radially expanded state. In Figure 32B, struts 3252 and 3251 are shown in a straight state (e.g., prior to shape setting and coupling to the central hub). When coupled to the central hub (which may include a bearing assembly), as shown in Figure 29B, struts 3252 and 3251 can bend radially inward to connect to the central hub.

[0350]

[0399] 33A-33B show another exemplary scaffold 3350. FIG. 33A shows a flattened view of the scaffold 3350 and FIG. 33B shows a three-dimensional view of the scaffold in an expanded state. The scaffold 3350 is similar to the previously described scaffolds and can include many of the same elements, including a proximal portion 3360, a central portion 3370, and a distal portion 3380. One difference between the scaffold 3350 and the previously described scaffolds is the number of struts. The scaffold 3350 includes ten proximal struts 3352 and five distal struts 3351. It should be understood that in other embodiments, the number of distal and proximal struts may be different. Generally, in this embodiment, the scaffold can have twice as many proximal struts as distal struts (i.e., 8 proximal and 4 distal struts, 10 proximal and 5 distal struts, 12 proximal and 6 distal struts, etc.). Additionally, the proximal struts 3352 can have a width greater than the width of the distal struts 3351. In one embodiment, as shown, the width of the distal struts 3351 is approximately the same as the width of the axially extending elongate elements 3311.

[0351]

[0400] Because the scaffold 3350 has a different number of proximal struts than the distal struts, there are more connector elements 3312 in the proximal portion 3360 than there are connector elements 3322 in the distal portion 3380. As shown in FIG. 33A , the proximal portion 3360 can have 20 connector elements 3312 in each annular row of connector elements compared to only 10 connector elements 3322 in each annular row of connector elements in the distal portion 3380. Generally, the number of connector elements 3312 in the proximal portion 3360 is twice the number of proximal struts 3352. Similarly, the number of connector elements 3322 in the distal portion 3380 is twice the number of distal struts 3351.

[0352]

[0401] 33A , the central portion can include ten axially extending elongate elements 3311. In general, the scaffold 3350 can include as many axially extending elongate elements 3311 as there are proximal struts 3352. Thus, the illustrated example includes ten proximal struts 3352 and ten axially extending elongate elements 3311. In the proximal portion 3360, an axially extending elongate element 3311 can extend distally from each distally facing apex 3382 of the distal-most annular row of connector elements 3312. In contrast, in the distal portion 3380, an axially extending elongate element 3311 can extend proximally from each proximally facing apex 3384 and each distally facing apex 3386 of the annular row of connector elements 3322.

[0353]

[0402] The proximal portion 3360 of the scaffold 3350 can also include secondary axially extending elements 3398 that are shorter than the axially extending elongate elements 3211 and do not extend into the central portion 3270. The distal portion 3380, however, does not include secondary axially extending elongate elements because it includes only a single annular row of connector elements 3322. Generally, when multiple annular rows of connector elements are used, secondary axially extending elongate elements are included only in the distal or proximal portions.

[0354]

[0403] Another difference between scaffold 3350 and previously described scaffolds is the number of annular rows of connector elements in the proximal and distal portions. With reference to FIGS. 33A-B, proximal portion 3360 can include two annular rows of connector elements 3312. The proximal portion 3360 of scaffold 3350 surrounds or encircles at least a portion of a proximal impeller (not shown). In contrast, distal portion 3380 can include a single annular row of connector elements 3322. In the embodiment of FIGS. 33A-B, there is no distal impeller disposed in the distal portion, so the pump is designed and configured to operate as a single (proximal) impeller device. However, it should be understood that a distal impeller can also be included if desired.

[0355]

[0404] FIG. 34 illustrates another exemplary scaffold 3450 with some modifications compared to the scaffold 3350 of FIGS. 33A-33B. One difference is that the distal portion 3480 of the scaffold 3450 includes two annular rows of connector elements 3422 compared to only one annular row of connector elements in the embodiment of FIGS. 33A-33B. The additional annular row of connector elements provides additional stiffness to the distal portion 3480 compared to the distal portion 3380 of the scaffold 3350. Because the distal portion includes two annular rows, both the distal and proximal portions can include secondary axially extending elements 3498 extending between the annular rows of connector elements. Even though the scaffold 3450 includes two annular rows of connector elements in both the proximal portion 3460 and the distal portion 3480, in the exemplary embodiment, only a single proximal impeller is housed in the proximal portion and no distal impeller is housed in the distal portion. However, it should be understood that the scaffold can be used to accommodate both distal and proximal impellers if desired.

[0356]

[0405] Because the scaffold 3450 has two annular rows of connector elements in both the proximal and distal portions, the pattern of structural elements in the proximal portion can define a set of openings 3466 and the pattern of structural elements in the distal portion can define a set of openings 3468. The pattern of structural elements defining the set of openings can include connector elements and axially extending auxiliary elements in each portion. The openings 3468 in the distal portion can be smaller than those in the proximal portion because the distal portion has fewer distal struts and therefore fewer connector elements.

[0357]

[0406] Another difference between scaffold 3450 and scaffold 3350 is that distal struts 3451 can have at least a portion having a wider width than proximal struts 3452. As a result, the width of axially extending elongate elements 3411 can gradually taper from a first width to a second (thinner) width in tapered region 3488. In some embodiments, as shown in FIG. 34, distal struts 3451 can further include a taper 3490 from the first width to the second (thinner) width. The portion of the distal strut distal to the taper 3490 can be configured and designed to cover or fit over a distal hub (not shown).

Claims

1. 1. An intravascular blood pump comprising: a collapsible blood conduit defining an internal lumen for transporting blood, said collapsible blood conduit comprising: a proximal portion defined by at least two annular rows of connector elements disposed about a central axis of the collapsible blood conduit; a distal portion defined by at least one annular row of connector elements disposed about the central axis of the collapsible blood conduit; a central portion axially disposed between the distal portion and the proximal portion, the central portion including a plurality of axially extending elongated elements arranged in a helical pattern; a proximal impeller disposed within at least a portion of the proximal portion; An intravascular blood pump comprising:

2. 10. The intravascular blood pump of claim 1, wherein the proximal, central, and distal scaffold portions are coupled to one another (optionally integrally).

3. 3. The intravascular blood pump of claim 1, wherein the central portion has a relative flexibility compared to the distal and proximal portions such that in response to a lateral force applied to the blood conduit by the distal impeller portion, the blood conduit deforms and assumes a more highly curved shape at the central portion than the proximal and distal portions.

4. 4. The intravascular blood pump of claim 1, wherein the central portion includes at least one of a material or structure such that the central portion is more likely to collapse than the proximal and distal portions when a rotational force is applied to the distal end of the blood conduit.

5. 5. The intravascular blood pump of claim 1, wherein at least a portion of the proximal and distal portions do not include a helical scaffold pattern.

6. The intravascular blood pump of claim 1 , wherein the axially extending elongated element extends between at least two annular rows of connector elements in the proximal portion.

7. The intravascular blood pump of claim 1 , wherein the distal portion is defined by at least two annular rows of connector elements disposed about the central axis of the collapsible blood conduit.

8. The intravascular blood pump of claim 7 , wherein the axially extending elongate element extends between at least two annular rows of connector elements in the distal portion.

9. The intravascular blood pump of claim 1 , wherein the proximal portion is defined by at least four annular rows of connector elements disposed about the central axis of the collapsible blood conduit.

10. 2. The intravascular blood pump of claim 1, wherein said connector elements in each annular row are in a zigzag pattern.

11. 11. An intravascular blood pump according to any one of claims 1 to 10, wherein an angle between the connector element and the axially extending elongate element is between about 10 degrees and 50 degrees.

12. 11. The intravascular blood pump of claim 1, wherein the angle between the connector element and the axially extending elongate element is between about 10 degrees and 30 degrees.

13. 11. The intravascular blood pump of claim 1, wherein an angle between the connector element and the axially extending elongate element is between about 30 degrees and 50 degrees.

14. 14. The intravascular blood pump of any one of claims 1 to 13, wherein the scaffold has an axial length of about 50 mm to about 80 mm.

15. 15. An intravascular blood pump as claimed in any one of claims 1 to 14, wherein the proximal portion has a greater lateral bending stiffness than the distal portion.

16. 16. The intravascular blood pump of any one of claims 1 to 15, wherein the collapsible blood conduit comprises a scaffold configured to transition between a collapsed state and an expanded state, the scaffold having a diameter of 5.0 mm to 10 mm in the expanded state and a diameter of 2.5 mm to 4.5 mm in the collapsed state.

17. 17. The intravascular blood pump of claim 1, further comprising a plurality of proximal struts extending proximally from the proximal portion.

18. 20. The intravascular blood pump of claim 17, further comprising a plurality of distal struts extending distally from the distal portion.

19. 20. The intravascular blood pump of claim 18, wherein the number of proximal struts is twice the number of distal struts.

20. 20. The intravascular blood pump of claim 18, wherein the intravascular blood pump includes ten proximal struts and five distal struts.

21. 20. The intravascular blood pump of claim 18, wherein the width of the distal struts is greater than the width of the proximal struts.

22. 22. The intravascular blood pump of claim 21, wherein the axially extending elongate element increases in width near the distal portion.

23. a collapsible blood conduit defining an internal lumen for transporting blood, the collapsible blood conduit including a collapsible scaffold; a plurality of proximal struts extending proximally from the blood conduit; a plurality of distal struts extending distally from the blood conduit, the plurality of proximal struts being twice as numerous as the plurality of distal struts; a proximal impeller disposed at least partially within the blood conduit; An intravascular blood pump comprising:

24. 24. The intravascular blood pump of claim 23, wherein the plurality of proximal struts extend proximally from a proximal portion of the intravascular blood pump.

25. 25. The intravascular blood pump of claim 24, wherein the proximal impeller is disposed at least partially within the proximal portion.

26. 24. The intravascular blood pump of claim 23, wherein the plurality of distal struts extend distally from a distal portion of the intravascular blood pump.

27. 24. The intravascular blood pump of claim 23, wherein the plurality of proximal struts comprises ten proximal struts and the plurality of distal struts comprises five distal struts.

28. 28. The intravascular blood pump of claim 23, wherein a width of the plurality of proximal struts is less than a width of the plurality of distal struts.

29. 25. The intravascular blood pump of claim 24, wherein the proximal portion is defined by at least two annular rows of connector elements disposed about a central axis of the collapsible blood conduit.

30. 27. The intravascular blood pump of claim 26, wherein the distal portion is defined by at least one annular row of connector elements disposed about a central axis of the collapsible blood conduit.

31. 31. The intravascular blood pump of any one of claims 23 to 30, wherein the scaffold includes a central portion disposed between a proximal portion and a distal portion, the central portion including axially extending elongated elements arranged in a helical pattern.

32. 31. The intravascular blood pump of claim 29 or 30, wherein the connector elements in each annular row are arranged in a zigzag pattern.

33. 33. The intravascular blood pump of any one of claims 23 to 32, wherein the scaffold has an axial length of about 50 mm to about 80 mm.

34. 25. The intravascular blood pump of claim 24, wherein the proximal portion has a greater lateral bending stiffness than the distal and central portions of the collapsible scaffold.

35. 35. The intravascular blood pump of any one of claims 23 to 34, wherein the scaffold is configured to transition between a collapsed state and an expanded state, the scaffold having a diameter of 5.0 mm to 10 mm in the expanded state and a diameter of 2.5 mm to 4.5 mm in the collapsed state.

36. 1. A tubular scaffold for an intravascular blood pump, comprising: a proximal portion configured to accommodate a proximal impeller; A distal portion; and a central portion between the proximal portion and the distal portion, the central portion having a plurality of elongated elements arranged in a helical manner and extending axially, the elongated elements not connected to one another within the central portion; A tubular scaffold comprising:

37. 37. The tubular scaffold of claim 36, wherein the proximal and distal portions include connector elements connecting the elongate elements within the proximal and distal portions.

38. 38. The tubular scaffold of claims 36 or 37, wherein the elongate elements are parallel to a central axis of the tubular scaffold in the proximal portion.

39. 39. The tubular scaffold of any one of claims 36-38, wherein the elongate elements are parallel to a central axis of the tubular scaffold within the distal portion.

40. 40. The tubular scaffold of any one of claims 36-39, wherein the central portion has greater lateral flexibility than the proximal and distal portions.

41. 41. The tubular scaffold of any one of claims 36-40, wherein the proximal and distal portions each have a greater radial stiffness than the central portion.

42. 42. The tubular scaffold of any one of claims 36-41, wherein the tubular scaffold comprises a plurality of struts curved radially inward and configured to connect to a central hub of the intravascular blood pump.

43. 43. The tubular scaffold of any one of claims 36-42, wherein the tubular scaffold is configured to transition between a radially expanded state and a radially collapsed state.

44. 44. The tubular scaffold of any one of claims 36-43, wherein the central portion has a longer axial length than each of the first and second impeller portions.

45. 45. The tubular scaffold of any one of claims 36-44, wherein the elongate elements are connected by one or more annular rows of connector elements in the proximal portion.

46. 46. ​​The tubular scaffold of any one of claims 36-45, wherein the elongate elements are connected by at least two annular rows of connector elements in the proximal portion.

47. 47. The tubular scaffold of claim 45 or 46, wherein the connector elements in each annular row are arranged in a zigzag pattern.

48. 48. The tubular scaffold of any one of claims 36-47, further comprising a membrane covering at least a portion of an interior and / or exterior surface of the tubular scaffold.

49. 49. The tubular scaffold of any one of claims 36-48, wherein the elongate element extends axially through the proximal portion, the central portion, and the distal portion.

50. 50. The tubular scaffold of any one of claims 36-49, wherein bending the central portion laterally causes the proximal portion to be axially offset relative to the distal portion.

51. 51. The tubular scaffold of any one of claims 36-50, wherein the proximal portion has a greater radial and lateral bending stiffness than the distal portion.

52. 52. The tubular scaffold of any one of claims 36-51, wherein the tubular scaffold is configured to transition between a collapsed state and an expanded state, wherein the tubular scaffold has a diameter of 5.0 mm to 10 mm in the expanded state and a diameter of 2.5 mm to 4.5 mm in the collapsed state.

53. 37. The intravascular blood pump of claim 36, wherein the helical arrangement of the elongated elements is configured to cause the central portion to bend laterally when a lateral force is applied to the tubular scaffold.

54. 1. A tubular scaffold for an intravascular blood pump, comprising: a proximal portion configured to at least partially house a proximal impeller, the proximal portion having a first scaffold pattern; a distal portion having a second scaffold pattern, the first scaffold pattern being more densely packed than the second scaffold pattern; A tubular scaffold comprising:

55. 55. The tubular scaffold of claim 54, wherein the first scaffold pattern is associated with a first stiffness and the second scaffold pattern is associated with a second stiffness, the first stiffness being greater than the second stiffness.

56. 56. The tubular scaffold of claim 55, wherein the first and second stiffnesses comprise one or more of a radial stiffness and a bending stiffness.

57. 57. The tubular scaffold of any one of claims 54-56, further comprising a central portion between said proximal and distal portions, said central portion having a more loosely packed scaffold pattern than each of said proximal and distal portions.

58. 58. The tubular scaffold of claim 57, wherein the central portion comprises a plurality of helically arranged, axially extending, unconnected elongate elements within the central portion, the helical arrangement of the elongate elements configured to laterally bend the central portion upon application of a lateral force to the tubular scaffold.

59. 59. The tubular scaffold of any one of claims 54-58, wherein the tubular scaffold is configured to transition between a collapsed state and an expanded state, wherein the tubular scaffold has a diameter of 5.0 mm to 10 mm in the expanded state and a diameter of 2.5 mm to 4.5 mm in the collapsed state.

60. 1. An intravascular blood pump comprising: a collapsible blood conduit having an internal lumen for passing blood therethrough, the collapsible blood conduit comprising a scaffold arranged and configured to provide radial support to the blood conduit, the scaffold including a proximal portion including a first pattern of structural elements defining a first set of openings and a distal portion including a second pattern of structural elements defining a second set of openings, the first set of openings being smaller than the second set of openings; The intravascular blood pump further comprises: a proximal impeller disposed within at least a portion of the proximal portion of the scaffold; An intravascular blood pump comprising:

61. 61. The intravascular blood pump of claim 60, wherein the proximal portion has a longer axial length than the distal portion.

62. 62. The intravascular blood pump of claim 60 or 61, wherein a first pattern of structural elements defining the first set of openings includes a plurality of axially extending elongate elements and a plurality of connector elements extending radially between the plurality of axially extending elongate elements.

63. 62. The intravascular blood pump of claim 60 or 61, wherein the second pattern of structural elements defining the second set of openings includes a plurality of axially extending elongate elements and a plurality of connector elements extending radially between the plurality of axially extending elongate elements.

64. 63. The intravascular blood pump of claim 62, wherein the plurality of connector elements of the proximal portion form a plurality of annular rows of connector elements.

65. 64. The intravascular blood pump of claim 63, wherein the plurality of connector elements of the distal portion form a plurality of annular rows of connector elements.

66. 66. An intravascular blood pump as claimed in claim 64 or 65, wherein each annular row of connector elements is formed in a zigzag pattern.

67. 67. The intravascular blood pump of any one of claims 60 to 66, wherein the scaffold includes a central portion between the proximal portion and the distal portion.

68. 68. The intravascular blood pump of claim 67, wherein the proximal portion has a greater radial stiffness than the central portion.

69. 68. The intravascular blood pump of claim 67, wherein the distal portion has a greater radial stiffness than the central portion.

70. 68. The intravascular blood pump of claim 67, wherein the central portion is configured to bend laterally upon application of a lateral force to the distal portion.

71. 68. The intravascular blood pump of claim 67, wherein the scaffold includes elongate elements extending axially within the proximal portion, the central portion, and the distal portion.

72. 72. The intravascular blood pump of claim 71, wherein the portion of the elongated element in the proximal portion is wider than the portion of the elongated element in the central portion.

73. 72. The intravascular blood pump of claim 71, wherein the portion of the elongated element in the distal portion is wider than the portion of the elongated element in the central portion.

74. 72. The intravascular blood pump of claim 71, wherein circumferentially adjacent elongate elements are circumferentially connected by connector elements in the proximal and distal portions.

75. 75. The intravascular blood pump of claim 74, wherein the proximal portion includes more connector elements than the distal portion.

76. 75. The intravascular blood pump of claim 74, wherein the connector elements are configured to flex to bring circumferentially adjacent elongate elements closer together when the scaffold transitions from the expanded state to the collapsed state.

77. 72. The intravascular blood pump of claim 71, wherein the elongated elements are not connected to one another within the central portion.

78. 72. The intravascular blood pump of claim 71, wherein a portion of the elongated elements within the central portion are arranged in a helical pattern about a central axis of the scaffold.

79. 79. The intravascular blood pump of any one of claims 60 to 78, wherein the scaffold is configured to transition between a collapsed state and an expanded state.

80. 80. The intravascular blood pump of any one of claims 60 to 79, further comprising a drive shaft operably coupled to the proximal impeller, the scaffold surrounding at least a portion of the drive shaft.

81. 81. The intravascular blood pump of any one of claims 60 to 80, wherein the proximal impeller is configured to collapse with the collapsible blood conduit.

82. 82. The intravascular blood pump of any one of claims 60 to 81, wherein the scaffold includes elongated elements extending axially along a length of the scaffold, the axially extending elongated elements being connected by one or more annular rows of connector elements in the proximal portion.

83. 83. The intravascular blood pump of claim 82, wherein the elongate elements are connected by three annular rows of connector elements within the proximal portion (e.g., FIG. 30).

84. 83. The intravascular blood pump of claim 82, wherein the elongated elements are connected by four annular rows of connector elements within the proximal portion (e.g., FIG. 31).

85. 83. The intravascular blood pump of claim 82, wherein the elongate elements are connected by five annular rows of connector elements within the proximal portion (e.g., Figures 29A-29E).

86. 83. The intravascular blood pump of claim 82, wherein the connector elements in each annular row are in a zigzag pattern.

87. 87. The intravascular blood pump of any one of claims 60 to 86, wherein the scaffold includes elongated elements extending axially along a length of the scaffold, the axially extending elongated elements being connected by a first set of annular rows of connector elements in the proximal portion and a second set of annular rows of connector elements in the distal portion, the first set having a greater number of annular rows of connector elements than the second set.

88. 88. The intravascular blood pump of any one of claims 60-87, wherein the scaffold includes elongated elements extending axially along a length of the scaffold and connector elements connecting the elongated elements, the angle between the connector elements and the elongated elements being between about 10 degrees and 50 degrees.

89. 89. The intravascular blood pump of claim 88, wherein the angle between the connector element and the elongate element is between about 10 degrees and 30 degrees (eg, Figures 30 and 31).

90. 89. The intravascular blood pump of claim 88, wherein the angle between the connector element and the elongate element is about 30 degrees to 50 degrees (eg, Figures 29A-29E).

91. 91. The intravascular blood pump of any one of claims 60 to 90, wherein the scaffold has an axial length of about 50 mm to about 80 mm.

92. 92. An intravascular blood pump as claimed in any one of claims 60 to 91, wherein the proximal portion has a greater lateral bending stiffness than the distal portion.

93. 93. The intravascular blood pump of any one of claims 60 to 92, wherein the blood conduit is configured to transition between a collapsed state and an expanded state, and the scaffold has a diameter of 5.0 mm to 10 mm in the expanded state and a diameter of 2.5 mm to 4.5 mm in the collapsed state.

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