Intravascular blood pumps and methods of use

Abstract

This provides further improvements in the field of ventricular support devices and similar blood pumps for treating cardiac blood flow disorders. [Solution] The blood pump 10 includes a pump section 20 which includes a foldable blood conduit that defines the blood flow lumen between the inlet and outlet. The pump section 20 includes a distal foldable impeller 50 which is axially spaced apart from a proximal foldable impeller 40, and at least a portion of each of the distal and proximal foldable impellers 50 and 40 is disposed between the inlet and the outlet.

Description

Technical Field

[0001] Cross - Reference to Related Applications

[0001] This application claims priority to the following U.S. provisional applications: Application No. 62 / 741,970, filed on October 5, 2018; Application No. 62 / 778,804, filed on December 12, 2018; and Application No. 62 / 905,818, filed on September 25, 2019, each of which is hereby incorporated by reference in its entirety for all purposes. Incorporation by Reference

[0002] All publications and patent applications cited herein are hereby incorporated by reference into this specification to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference.

Background Art

[0002]

[0003] Patients with heart disease may have severely impaired ability to pump blood into the heart and vascular system, and show significant risks during corrective procedures such as balloon angioplasty and stent delivery. In particular, during corrective procedures, there is a need for methods to improve the cardiac output or stability of these patients.

[0003]

[0004] An intra - aortic balloon pump (IABP) is generally used to assist circulatory function, such as treating patients with heart failure. The use of IABP is common in the treatment of patients with heart failure, such as assisting patients during high - risk percutaneous coronary intervention (HRPCI), stabilizing patient blood flow after cardiogenic shock, treating patients associated with acute myocardial infarction (AMI), or treating decompensated heart failure. Such circulatory support can be used alone or together with drug therapy.

[0004]

[0005] IABPs are typically placed inside the aorta and operate by inflating and deflating in a counterpulse manner with cardiac contractions. One of their functions is to provide additional support to the circulatory system.

[0005]

[0006] Furthermore, in recent years, minimally invasive rotary blood pumps have been developed that can be inserted into the body and connected to the cardiovascular system, such as pumping arterial blood from the left ventricle into the aorta to supplement the patient's natural blood pumping capacity on the left side of the heart. Another known method is pumping venous blood from the right ventricle into the pulmonary artery to supplement the patient's natural blood pumping capacity on the right side of the heart. The overall goal is to reduce the workload on the patient's myocardium to stabilize the patient during medical procedures that may place additional stress on the heart, to stabilize the patient before a heart transplant, or for ongoing patient support.

[0006]

[0007] The smallest rotary blood pumps currently available can be inserted percutaneously into the patient's vascular system through an access sheath, thus eliminating the need for surgical intervention, or they can be inserted through a vascular access graft. One type of this device is a percutaneously inserted ventricular assist device. [Overview of the project] [Problems that the invention aims to solve]

[0007]

[0008] Further improvements are needed in the field of ventricular support devices and similar blood pumps for treating cardiac blood flow disorders. [Means for solving the problem]

[0008]

[0009] This disclosure relates to fluid motion devices such as intravascular blood pumps and methods of using them.

[0010] One aspect of the present disclosure is an intravascular blood pump comprising a pump portion including a foldable blood conduit defining a blood flow lumen between an inlet and an outlet, and a distal foldable impeller axially spaced apart from a proximal foldable impeller, wherein at least a portion of each of the distal and proximal foldable impellers is disposed between the inlet and the outlet. The blood pump may include one or more stators positioned in the blood flow lumen when the pump is expanded, the stators being axially positioned between the distal and proximal impellers. Any of the one or more stators may include one or more flow modifiers or flow modifier elements (e.g., blades) axially disposed between the distal and foldable impellers, the flow modifiers having at least one surface configured to modify or influence the flow of blood between the impellers.

[0009]

[0011] In this embodiment, any of the flow modifiers may be considered as stators configured to increase the pressure between the first impeller and the second impeller, either individually or collectively. There may be multiple stators spaced apart in the axial direction, each of which may be considered to have multiple flow modifier elements (which may also be called flow modifiers or their derivatives).

[0010]

[0012] In this embodiment, any flow modifier of any stator may be disposed between the shroud and the longitudinal axis of the pump portion (even if the pump portion includes a bend formed therein). Any flow modifier may be disposed between the shroud and a central tubular element (e.g., a hub), such as a tubular shaft not adapted to rotate with the impeller, and / or a tubular element adapted to rotate with the impeller.

[0011]

[0013] In this embodiment, one or more blood flow modifiers can be fixed to the surface of a foldable blood conduit.

[0014] In this embodiment, one or more blood flow modifiers may extend radially inward from the surface of the foldable blood conduit, and each of the one or more blood flow modifiers has at least one axially extending surface configured to alter the blood flow between the distal impeller and the proximal impeller.

[0012]

[0015] In this embodiment, one or more blood flow modifiers may extend radially outward from the central hub and may or may not be in contact with the blood conduits.

[0016] In this embodiment, one or more blood flow modifiers may extend radially outward from the central hub and may or may not be fixed to the blood conduit.

[0013]

[0017] In this embodiment, one or more blood flow modifiers may extend radially inward from the surface of the foldable blood conduit, and may or may not extend to the central hub.

[0018] In this embodiment, one or more blood flow modifiers do not need to extend radially to the central hub.

[0014]

[0019] In this embodiment, the radially innermost region of each of one or more blood flow modifiers may be a free region.

[0020] In this embodiment, one or more flow deflectors may be formed integrally with at least a portion of the foldable blood conduit. One or more flow deflectors may be integrated with the scaffold of the foldable blood conduit. One or more flow deflectors may be biased into an unfolded configuration in which they extend radially inward relative to the outer area of ​​the scaffold.

[0015]

[0021] In this embodiment, one or more blood flow modifiers may extend radially to the central hub.

[0022] In this embodiment, one or more blood flow modifiers are fixed to an outer annular member that does not extend axially all the way from the inlet to the outlet, and may extend radially inward from there. The outer annular member may provide radial support to the foldable blood conduit.

[0016]

[0023] In this embodiment, one or more blood flow modifiers may be formed from a polymer material.

[0024] In this embodiment, one or more blood flow modifiers may have radially outer ends having at least one surface with a configuration that is molded to stably align with a corresponding portion of a foldable blood conduit. The blood pump may further include a scaffold having one or more blood flow modifier apertures passing through it, each of which has a configuration that is molded to stably align with one of the blood flow modifier apertures. The pump may further include a membrane layer extending across the scaffold that helps to secure one or more blood flow modifiers to the apertures. The apertures may extend axially and may be parallel to the long axis of the scaffold. The pump may further include a self-expanding scaffold, in which one or more blood flow modifiers have radially outer ends with a configuration that is molded to stably align with the self-expanding scaffold. One or more blood flow modifiers may be made of a different material (e.g., a polymer material) than the scaffold material and may be more flexible than the scaffold material.

[0017]

[0025] In this embodiment, one or more blood flow modifiers may comprise at least four blood flow modifiers.

[0026] In this aspect, one or more blood flow modifiers may each be fixed to one of the one or more struts, which define a part of an expandable basket in which the proximal impeller or the distal impeller is disposed. The pump portion may further include a membrane layer (either directly or indirectly) fixed to the expandable basket, and the membrane layer at least partially defines a blood conduit. The one or more struts may be proximal struts of the expandable basket, which may be the distal basket or the proximal basket. The struts may be at a non-orthogonal angle to the long axis of the pump portion at the location of the struts.

[0018]

[0027] In this aspect, one or more blood flow modifiers may have an inner free end disposed parallel to the longitudinal axis of the pump portion in which the flow modifier is disposed. The foldable blood conduit may include one or more bends formed along its length, and the one or more bends are axially spaced from the one or more blood flow modifiers.

[0019]

[0028] In this aspect, one or more blood flow modifiers may be integrally formed with at least one other component of the foldable blood conduit.

[0029] In this aspect, one or more blood flow modifiers are fixed to the foldable blood conduit and have a radially outer region extending therefrom along a length of at least 1 mm and up to 15 cm, optionally at least 1 mm and up to 10 cm, optionally up to 9 cm, 8 cm, 7 cm, 6 cm, or 5 cm.

[0020]

[0030] In this aspect, one or more blood flow modifiers are fixed to a blood conduit longer than the radially inner edge of the blood flow modifier and have a radially outer region extending therefrom.

[0021]

[0031] In this aspect, one or more blood flow modifiers have a distal end surface and a proximal end surface, and at least one of the ends is tapered.

[0032] In this embodiment, the pump portion fixes one or more blood flow modifiers to the blood conduit. It may be equipped with a membrane that helps to do so.

[0022]

[0033] In this embodiment, one or more blood flow modifiers may be self-deploying.

[0034] In this embodiment, at least one axially extending surface may be configured to transition the blood flow to a laminar flow.

[0023]

[0035] In this embodiment, one or more blood flow modifiers may be foldable between an extended configuration and a folded configuration.

[0036] In this embodiment, one or more blood flow modifiers may be movable or reconfigurable between a first position and an deployed position.

[0024]

[0037] In this embodiment, one or more blood flow modifiers are positioned in close proximity to at least one of the proximal and distal impellers when the proximal and distal impellers are in an extended configuration.

[0025]

[0038] In this embodiment, one or more blood flow modifiers may be located closer to the proximal impeller than to the distal impeller.

[0039] In this embodiment, one or more blood flow modifiers may be located closer to the distal impeller than to the proximal impeller.

[0026]

[0040] In this embodiment, the first end of one or more blood flow modifiers may be 0.01 mm to 20 mm from at least one of the distal impeller and the proximal impeller.

[0041] In this embodiment, one or more blood flow modifiers may be fixed to (optionally integrated with) an annular member that provides radial support for one or more of the impeller basket or the scaffold of the blood conduit.

[0027]

[0042] In this embodiment, one or more blood flow modifiers may be parts of a foldable intermediate member that are positioned and fitted to provide radial support to a blood conduit.

[0043] In this embodiment, one or more blood flow modifiers may be parts of a foldable intermediate member positioned to maintain a tip gap between at least one of the impellers and the blood conduit.

[0028]

[0044] In this embodiment, the distal regions of one or more stators may be configured to act as diffusers for the fluid in the fluid conduit to restore pressure from the distal impeller, and the proximal regions of one or more fluid modulators may be configured to act as stators to direct the flow toward the proximal impeller.

[0029]

[0045] One aspect of the present disclosure is an intravascular blood pump comprising a pump portion including a collapsible blood conduit defining a blood flow lumen between an inlet and an outlet; a distal collapsible impeller axially spaced apart from a proximal collapsible impeller, with at least a portion of each of the distal and proximal collapsible impellers disposed between the inlet and the outlet; and one or more stators, each including one or more flow modifiers axially disposed between the distal and collapsible impellers, wherein each of the one or more flow modifiers has at least one axially extending surface configured to increase the fluid pressure between the distal and proximal impellers.

[0030]

[0046] In this embodiment, at least one axially extending surface may be configured to transition the flow to a laminar flow.

[0047] In this embodiment, one or more blood flow modifiers are located on the surface of the foldable blood conduit. It can be fixed and may also extend radially inward from there.

[0031]

[0048] In this embodiment, one or more flow modifiers include any feature of any of the flow modifier elements in this specification.

[0049] One aspect of the present disclosure is an intravascular blood pump comprising: a foldable blood conduit defining a blood flow lumen between an inlet and an outlet; a proximal foldable impeller axially spaced apart from a distal foldable impeller, wherein at least a portion of each of the distal and proximal foldable impellers is disposed between the inlet and the outlet; and a proximal foldable basket on which the proximal impeller is disposed, wherein the proximal foldable basket provides radial support to the blood conduit at the location of the proximal impeller. An intravascular blood pump comprising a pump section including a foldable basket, a distal foldable basket on which a distal impeller is disposed, the distal foldable basket providing radial support to a blood conduit at the location of the distal impeller, and a foldable radial support member supporting one or more of the distal region of the proximal foldable basket, the proximal region of the distal foldable basket, or the central region of a blood conduit axially disposed between the proximal and distal baskets.

[0032]

[0050] In this embodiment, the radial support member may include an annular peripheral member and a plurality of support elements extending radially inward from the annular peripheral member. The plurality of support elements may or may not extend to the central hub. The plurality of support elements may have radially inward free ends.

[0033]

[0051] In this embodiment, the radial support member can support the distal region of the proximal basket.

[0052] This embodiment may further include a second radial support member spaced axially apart from the radial support member, the second radial support member being positioned to radially support the proximal region of the distal basket. The second radial support member may include a second annular peripheral member and a plurality of second support elements extending radially inward from the second annular peripheral member.

[0034]

[0053] In this embodiment, the radial support member can support the proximal region of the distal basket.

[0054] In this embodiment, the foldable radial support member may comprise a stator including one or more blood-changing elements, such as any of the blood-changing elements described herein.

[0035]

[0055] One aspect of the present disclosure is an intravascular blood pump comprising: a foldable blood conduit defining a blood flow lumen between an inlet and an outlet; a proximal foldable impeller axially spaced apart from a distal foldable impeller, wherein at least a portion of each of the distal and proximal foldable impellers is disposed between the inlet and the outlet; a proximal foldable basket on which the proximal impeller is disposed, wherein the proximal foldable basket provides radial support to the blood conduit at the location of the proximal impeller; and a distal foldable bus on which the distal impeller is disposed. An intravascular blood pump comprising a distal foldable basket, the distal foldable basket providing radial support to a blood conduit at the location of the distal impeller, and a foldable radial support member including an annular peripheral member and a plurality of support elements extending radially inward from the annular peripheral member, wherein the foldable radial support radially supports one or more of the distal region of the proximal foldable basket, the proximal region of the distal foldable basket, or the central region of a blood conduit axially disposed between the proximal and distal baskets.

[0036]

[0056] In this embodiment, the multiple support elements may or may not extend to the central hub.

[0057] In this embodiment, multiple support elements may have free ends that are radially inward.

[0037]

[0058] In this embodiment, the foldable radial support may be radially arranged within at least one of the distal region of the proximal foldable basket and the proximal region of the distal foldable basket.

[0038]

[0059] In this embodiment, the foldable radial support may be radially arranged within the distal region of the proximal basket, and the proximal basket includes a plurality of proximal supports but does not include a plurality of distal supports.

[0039]

[0060] In this embodiment, the foldable radial support may include a stator, the stator comprising a plurality of support elements. The plurality of support elements may be configured to increase the fluid pressure between the distal impeller and the proximal impeller.

[0040]

[0061] One aspect of the present disclosure is a repositionable blood pump comprising an elongated member including a pump portion, the elongated member being sized for intravascular positioning in a target, and a proximal portion extending radially from the elongated member, the proximal portion being sized to remain outside the target, and the proximal portion including a motor assembly coupling region configured to be tightly aligned with a motor assembly, the proximal portion including a proximal guidewire port, the guidewire port being positioned relative to the motor assembly coupling region such that the motor assembly is tightly aligned with the motor coupling region, and the guidewire port is accessible so that a guidewire can advance into the port.

[0041]

[0062] In this embodiment, the proximal region may include a rotatable member that is in rotational communication with the impeller in the blood pump, and the motor assembly coupling region and motor assembly are configured such that the motor assembly is in rotational communication with the rotatable member when the motor assembly is tightly aligned with the motor coupling region. The rotatable member may have a portion of a guidewire path formed therein, and when the rotatable member is in a rotationally aligned position, the guidewire path extends from the portion of the guidewire path within the rotatable member to the guidewire port, and when the rotatable member is in a rotationally unaligned position, the guidewire path does not extend from the portion of the guidewire path within the rotatable member to the guidewire port. The portion of the guidewire path formed in the rotatable member may be at least partially curved and optionally have a proximal port within the rotatable member on the radial side of the rotatable member.

[0042]

[0063] In this embodiment, the guidewire port may be located on the side of the proximal portion.

[0064] In this embodiment, the guide wire port may be configured to fit snugly with the fluid line coupler.

[0043]

[0065] This embodiment may further comprise any preferred features or elements described herein.

[0066] One aspect of the present disclosure is a method of using an intravascular blood pump, comprising the step of starting a motor to cause rotation of an impeller while the guidewire port is outside the patient and not covered by the motor assembly. This aspect may further comprise any preferred method step within this specification.

[0044]

[0067] One aspect of the present disclosure is a method of using an intravascular blood pump, the method comprising the step of inserting a guidewire into a guidewire port located in the proximal portion of the intravascular blood pump, where the proximal portion is located outward relative to the object, while the motor assembly is fixed to the proximal portion of the intravascular blood pump device.

[0045]

[0068] In this embodiment, the guidewire port may be on the radial side of the proximal portion, The step of inserting the guidewire may include inserting the guidewire into a guidewire port located on the radial side.

[0046]

[0069] This embodiment may further include the step of repositioning the pump portion of the intravascular blood pump while the motor assembly is fixed to the proximal portion.

[0070] This embodiment may further include the step of removing the guidewire from the guidewire port while the motor assembly is secured to the proximal portion of the intravascular blood pump device after the insertion step.

[0047]

[0071] This embodiment may also include any other preferred method steps as provided herein.

[0072] One aspect of the present disclosure is a method of using an intravascular blood pump, the method comprising the step of removing a guidewire through a guidewire port provided in the proximal portion of the intravascular blood pump, when the proximal portion is positioned outward relative to the object, while the motor assembly is fixed to the proximal portion of the intravascular blood pump device.

[0048]

[0073] In this embodiment, the guidewire port may be on the radial side of the proximal portion, and the step of removing the guidewire may include removing the guidewire from the guidewire port on the radial side.

[0049]

[0074] This embodiment may further include either receiving the outflow fluid from the proximal guidewire port into a fluid line that is in fluid communication with the guidewire lumen, or advancing the inflow fluid from the fluid line into the guidewire port.

[0050]

[0075] One aspect of the present disclosure is an intravascular blood pump comprising an elongated member including a blood pump, the elongated member being sized for intravascular positioning in a target, and a proximal portion extending distally from the elongated member, the proximal portion being sized to remain outside the target, and including a guidewire port extending through the radial side of the proximal portion. This aspect may further include any preferred features or elements described herein.

[0051]

[0076] One aspect of the present disclosure is an intravascular blood pump comprising an elongated member including a blood pump, the elongated member being sized for intravascular positioning in a target, and a proximal portion extending distally from the elongated member, the proximal portion being sized to remain outside the target, and the proximal portion including a portion of a guidewire passage having a bend formed therein.

[0052]

[0077] In this embodiment, the proximal portion may include a rotatable component that is in rotational communication with the impeller in the pump portion of the elongated member, and the rotatable component may have a portion of a guide wire passage in which a bent portion is formed.

[0053]

[0078] In this embodiment, the proximal portion may further include a guidewire port formed on the radial side surface of the proximal portion.

[0079] In this embodiment, the guidewire path may include a guidewire port and a portion of the guidewire path having a bend when the rotatable component is in a rotationally aligned position.

[0054]

[0080] This embodiment may further include any other preferred features or elements described herein.

[0081] One aspect of the present disclosure is an intravascular blood pump comprising an elongated member including a blood pump, the elongated member being sized for intravascular positioning in a target, and a proximal portion extending distally to the elongated member, the proximal portion being sized to remain outside the target. An intravascular blood pump is determined in which the proximal portion includes a rotatable component that is in rotational operation with an impeller within the pump portion of an elongated member, the rotatable component includes a portion of a guidewire passage, and the rotation of the component causes misalignment or alignment between the portion of the guidewire passage and the second portion of the guidewire passage formed within a second component of the proximal portion that is not in rotational operation with the impeller. This embodiment may further include any other preferred features or elements described herein.

[0055]

[0082] One aspect of the present disclosure is an intravascular blood pump comprising an elongated member including a blood pump, the elongated member being sized for intravascular positioning in a target, and a proximal portion extending distally to the elongated member, the proximal portion being sized to remain outside the target, and the proximal portion including a guidewire access port, the guidewire access port being configured to connect to a connector of a fluid line when a guidewire is not in the access port, so that fluid can be delivered from a fluid line into the guidewire port or received from the guidewire port into the fluid line.

[0056]

[0083] In this embodiment, the guidewire port may be located on the radial side of the proximal portion. The connector may include a luer connector.

[0084] In this embodiment, the guidewire port may be the portion of the guidewire passage that extends distally beyond the distal end of the impeller within the pump portion of the blood pump.

[0057]

[0085] In this embodiment, the guidewire path may further include a guidewire port, and the guidewire path further includes a portion having a curved configuration, the curved configuration being a proximal portion.

[0086] This embodiment may further comprise any other preferred features or elements described herein.

[0058]

[0087] One aspect of the present disclosure is an intravascular blood pump comprising an expandable blood flow conduit having a distal end and a proximal end, and at least one impeller radially disposed within the conduit, wherein the conduit has a central region, a proximal region proximal to the central region, and a distal region distal to the central region, the central region having greater flexibility than both the proximal and distal regions, and the distal and proximal regions being located between the proximal and distal ends of the conduit.

[0059]

[0088] In this embodiment, the impeller may be a proximal impeller, located radially within the proximal region, and the blood pump further comprises a distal impeller distal to the proximal impeller, the distal impeller located radially within the distal region, and neither the distal nor the proximal impeller extends axially into the central region.

[0060]

[0089] In this embodiment, the conduit may optionally include a support structure that extends over the entire length of the fluid lumen.

[0090] This embodiment may further comprise any other preferred features or elements described herein.

[0061]

[0091] This embodiment includes a method for positioning the pump in this embodiment, the method including the step of positioning the distal region distal to the aortic valve and the proximal region proximal to the valve.

[0062]

[0092] One aspect of the present disclosure is an intravascular blood pump comprising an outer conduit having a distal end and a proximal end, the pump comprising a support structure comprising a plurality of elongated elements disposed in the proximal region of the support structure, each of the elongated elements having a transition portion where each arm transitions from a larger diameter region to a smaller diameter region, and in the transition portion, each of the arms has a region perpendicular to the longitudinal axis of the outer housing. The intravascular blood pump includes a support structure and an impeller at least partially disposed within a conduit.

[0063]

[0093] In this embodiment, multiple elongated elements have a bent region adjacent to a vertical region, and the bent region transitions the vertical region to one of a larger diameter region and a smaller diameter region. Multiple elongated elements may have a second bent region adjacent to a vertical region, and the second bent region transitions the vertical region to the other of a larger diameter region and a smaller diameter region.

[0064]

[0094] In this embodiment, the multiple slender elements are configured such that they do not affect or alter the fluid flow in any meaningful way, as will be understood by those skilled in the art. This embodiment may further comprise any other preferred features or elements described herein.

[0065]

[0095] One aspect of the present disclosure is an intravascular blood pump comprising an external blood flow conduit defining a fluid lumen having a distal end and a proximal end, the pump also comprising a support structure having a proximal region having a plurality of vertices pointing in a proximal direction, wherein a first set of the plurality of vertices extends to a first axial position and a second set of the plurality of vertices extends further proximal to the first axial position, and an impeller radially disposed within the fluid lumen.

[0066]

[0096] In this embodiment, a second set of multiple apex sections may be integrally formed with multiple proximal struts, each of which has a vertical section that transitions the strut from a larger diameter section to a smaller diameter section. This embodiment may include any other preferred features or elements described herein.

[0067]

[0097] One aspect of the present disclosure is an intravascular blood pump comprising an outer expandable blood flow conduit defining a fluid lumen having a distal end and a proximal end, wherein at least one of the distal and proximal ends of the fluid lumen is configured to flared radially outward, the pump further comprising a support structure, the pump portion also comprising an impeller radially disposed within the outer expandable blood flow conduit.

[0068]

[0098] In this embodiment, the support structure may include a plurality of columns, the proximal end of the fluid lumen is flared and distally positioned in the transition region in each of the plurality of columns.

[0099] In this embodiment, the proximal end of the fluid lumen may be flared, and the proximal end of the impeller extends even further proximal than the proximal end of the lumen.

[0069]

[0100] In this embodiment, at least one extended configuration may be supported by a support structure.

[0101] This embodiment may further include any other preferred features or elements described herein.

[0070]

[0102] One aspect of the present disclosure is an intravascular blood pump comprising an outer expandable conduit defining a fluid lumen having a distal end and a proximal end, the pump also comprising a support structure having a first portion having a proximal end and a distal end, wherein the first portion comprises a plurality of elongated elements, each of which has a helical configuration, and an impeller radially disposed within the fluid lumen.

[0071]

[0103] In this embodiment, the first portion may overlap axially with at least a portion of the impeller.

[0104] In this embodiment, the first part may completely overlap with the impeller in the axial direction.

[0072]

[0105] In this embodiment, when viewed from the side, each of the multiple elongated elements may follow the helical configuration of at least one impeller blade, and in this respect, the following does not require the helical configuration to have the same pitch as at least one impeller blade.

[0073]

[0106] In this embodiment, when viewed from the side, the multiple elongated elements may form a larger angle with respect to the longitudinal axis of the fluid lumen in the regions immediately proximal and immediately distal to the first portion (a larger curvature in the first portion with respect to the longitudinal axis).

[0074]

[0107] In this embodiment, when viewed from the side, each of the elongated elements may have a tangent that forms an angle of 45 degrees or less, optionally 35 degrees or less, optionally 20 degrees or less, optionally 15 degrees or less, and optionally 10 degrees or less with respect to the tangent of the helical impeller blade (see Figure 23).

[0075]

[0108] In this embodiment, when viewed from the side, each of the elongated elements may have a tangent line that forms an angle of 45 degrees or less, optionally 35 degrees or less, optionally 20 degrees or less, optionally 15 degrees or less, and optionally 10 degrees or less with respect to the camber line of the helical blade where the elongated element and the helical blade overlap in the axial direction (see, for example, Figure 23).

[0076]

[0109] In this embodiment, at least one of the multiple elongated elements having a helical configuration does not rotate completely (i.e., 360 degrees in the end view) around the support structure.

[0110] In this embodiment, at least one of the multiple elongated elements having a helical configuration can rotate completely (i.e., 360 degrees in the end view) around the support structure.

[0077]

[0111] In this embodiment, the support structure may further comprise a second part having a second plurality of elongated elements, each of which may have a helical configuration. The second part may be spaced axially apart from the first part. The second part may at least partially overlap the impeller in the axial direction. The second part may at least partially overlap a second impeller spaced axially apart from the impeller. The second part may have the same configuration as the first part.

[0078]

[0112] In this embodiment, each slender element may be a connecting element to an adjacent area of ​​the support structure.

[0113] In this embodiment, each elongated element may have a first end connected to a first adjacent area of ​​the support structure and a second end connected to a second adjacent area of ​​the support structure.

[0079]

[0114] In this embodiment, the first portion may have an axial length of 1 to 20 mm.

[0115] In this embodiment, the first portion may have an axial length of 1-100%, optionally 1-80%, optionally 1-70%, optionally 1-60%, optionally 1-50%, optionally 1-40%, or optionally 1-30% of the impeller length.

[0080]

[0116] In this embodiment, the first portion may overlap the impeller axially along at least 100% of the impeller length, optionally 90% or less, optionally 80% or less, optionally 70% or less, optionally 60% or less, optionally 50% or less, optionally 40% or less, and optionally 30% or less.

[0081]

[0117] One aspect of the present disclosure is a method for folding the pump portion of a blood pump, the method comprising the step of rotating an elongated member to which the foldable pump portion is fixed when the elongated member is placed in a patient.

[0082]

[0118] In this embodiment, rotation can facilitate the folding of one or more blades of the impeller in the pump section, optionally helical blades.

[0119] In this embodiment, this rotation may cause the support structure of the pump section to apply a force to one or more blades (optionally helical blades) of the impeller within the pump section.

[0083]

[0120] In this embodiment, the method may further include the step of applying a tensile force to the elongated member, which occurs either simultaneously with the rotation or at a separate time.

[0121] One aspect of the present disclosure is a method for folding an impeller of a pump portion of a blood pump, comprising the step of folding a support structure on which the impeller is disposed, the folding step of applying a radially inward folding force to the helical blades of the impeller by an elongated member of the support structure having a helical configuration (optionally formed integrally with the rest of the scaffold pattern, i.e., not another component coupled to the scaffold pattern), wherein the radially inward folding force from the elongated member having a helical configuration ensures that the helical blades fold in a particular direction relative to a central support structure, optionally a hub.

[0084]

[0122] In this embodiment, the folding step may involve applying a radially inward folding force to the helical blades of the impeller by a plurality of elongated members of a support structure, each having a helical configuration.

[0085]

[0123] In this embodiment, the folding step may include applying at least one of a tensioning force and a rotational force to the elongated member to which the support structure is connected.

[0124] In this embodiment, the method may further include any other preferred method steps within this specification.

[0086]

[0125] One aspect of the present disclosure is an intravascular blood pump comprising: an outer expandable blood flow conduit defining a fluid lumen having a distal end and a proximal end; an impeller radially disposed within the fluid lumen, the impeller being coupled to a rotatable shaft; a rotatable drive member (e.g., a drive cable) in operational communication with the rotatable shaft, the rotatable drive member being rotatable in response to an energy source (e.g., a motor); and a speed increaser operably interacting with the drive member and the rotatable shaft, the speed increaser causing the rotatable shaft to rotate faster than the rotatable drive member.

[0087]

[0126] In this embodiment, the speed increaser may comprise a first gear coupled to a drive member and a second gear coupled to a rotatable shaft, wherein the first and second gears interact with each other and the second gear has a smaller diameter than the first gear.

[0088]

[0127] In this embodiment, the rotatable drive member may be coaxial with the rotatable shaft.

[0128] In this embodiment, the rotatable drive member does not have to be coaxial with the rotatable shaft.

[0089]

[0129] In this embodiment, the speed increaser may include a planetary gearbox.

[0130] In this embodiment, the speed increaser may include a shaft separate from the drive member and the rotatable shaft. [Brief explanation of the drawing]

[0090] [Figure 1]

[0131] This is a side view of an exemplary pump section, including conduits, multiple impellers, and expandable components. [Figure 2]

[0132] This is a side view of an exemplary pump section including conduits, multiple impellers, and multiple expandable members. [Figure 3A]

[0133] This diagram illustrates an exemplary pump section including a conduit, multiple impellers, and multiple expandable members. [Figure 3B] This diagram illustrates an exemplary pump section including a conduit, multiple impellers, and multiple expandable members. [Figure 3C] This diagram illustrates an exemplary pump section including a conduit, multiple impellers, and multiple expandable members. [Figure 3D] This diagram illustrates an exemplary pump section including a conduit, multiple impellers, and multiple expandable members. [Figure 4]

[0134] This diagram illustrates an exemplary arrangement of a pump section, including a conduit, multiple expandable members, and multiple impellers. [Figure 5]

[0135] This is a diagram illustrating an exemplary pump section. [Figure 6A]

[0136] This figure illustrates at least a portion of an exemplary medical device having a pump section in which at least two different impellers can rotate at different speeds. [Figure 6B]

[0137] This figure illustrates at least a portion of an exemplary medical device having a pump section in which at least two different impellers can rotate at different speeds. [Figure 6C]

[0138] This figure illustrates at least a portion of an exemplary medical device having a pump section with at least two impellers of different pitches. [Figure 7]

[0139] This figure illustrates at least a portion of an exemplary medical device having a pump section. [Figure 8]

[0140] This diagram illustrates a pump section having multiple impellers, wherein a bent section is formed between adjacent impellers. [Figure 9]

[0141] This diagram illustrates a pump section having multiple impellers. [Figure 10]

[0142] This is a side view of a portion of a fluid motion device, including a pump section, which includes a central or intermediate member spaced axially between a first impeller and a second impeller. [Figure 11A]

[0143] Figure 11A illustrates an exemplary central or intermediate member. [Figure 11B] Figure 11B illustrates an exemplary central or intermediate member. [Figure 11C] Figure 11C illustrates an exemplary central or intermediate member. [Figure 12A]

[0144] This is a diagram illustrating an exemplary medical device including a pump section or a portion of a pump section, including a first central (intermediate) member and a second central (intermediate) member. [Figure 12B]This is a diagram illustrating an exemplary medical device including a pump section or a portion of a pump section, including a first central (intermediate) member and a second central (intermediate) member. [Figure 12C] This is a diagram illustrating an exemplary medical device including a pump section or a portion of a pump section, including a first central (intermediate) member and a second central (intermediate) member. [Figure 12D] This is a diagram illustrating an exemplary medical device including a pump section or a portion of a pump section, including a first central (intermediate) member and a second central (intermediate) member. [Figure 13A]

[0145] Figure 13A is a diagram of an exemplary central or intermediate member. [Figure 13B] Figure 13B shows an exemplary central or intermediate member. [Figure 13C] Figure 13C shows an exemplary central or intermediate member. [Figure 14A]

[0146] Figure 14A illustrates an exemplary blood pump in which at least the components shown are non-foldable and not folded for delivery. [Figure 14B] Figure 14B illustrates an exemplary blood pump in which at least the components shown are non-foldable and not folded for delivery. [Figure 15A]

[0147] This figure illustrates an exemplary blood pump that includes a guidewire passage and at least one fluid purge passage. [Figure 15B] This figure illustrates an exemplary blood pump that includes a guidewire passage and at least one fluid purge passage. [Figure 15C] This figure illustrates an exemplary blood pump that includes a guidewire passage and at least one fluid purge passage. [Figure 15D] This figure illustrates an exemplary blood pump that includes a guidewire passage and at least one fluid purge passage. [Figure 16A]

[0148] This figure illustrates an exemplary blood pump that includes a guidewire passage and at least two fluid purge passages that are not in fluid communication. [Figure 16B] This figure illustrates an exemplary blood pump that includes a guidewire passage and at least two fluid purge passages that are not in fluid communication. [Figure 17A]

[0149] This figure illustrates an exemplary pump section, including an expandable housing and an exemplary scaffold design. [Figure 17B] This figure illustrates an exemplary pump section, including an expandable housing and an exemplary scaffold design. [Figure 17C] This figure illustrates an exemplary pump section, including an expandable housing and an exemplary scaffold design. [Figure 17D] This figure illustrates an exemplary pump section, including an expandable housing and an exemplary scaffold design. [Figure 17E] This figure illustrates an exemplary pump section, including an expandable housing and an exemplary scaffold design. [Figure 17F] This figure illustrates an exemplary pump section, including an expandable housing and an exemplary scaffold design. [Figure 18A]

[0150] Figure 18A illustrates an exemplary scaffold design. [Figure 18B] Figure 18B illustrates an exemplary scaffold design. [Figure 19A]

[0151] Figure 19A illustrates an exemplary scaffold design. [Figure 19B] Figure 19B illustrates an exemplary scaffold design. [Figure 20]

[0152] This is a diagram illustrating an exemplary scaffold design. [Figure 21A]

[0153] This is a diagram illustrating an exemplary scaffold design. [Figure 21B]This is a diagram illustrating an exemplary scaffold design. [Figure 21C] This is a diagram illustrating an exemplary scaffold design. [Figure 22A]

[0154] Figure 22A illustrates an exemplary scaffold design. [Figure 22B] Figure 22B illustrates an exemplary scaffold design. [Figure 23]

[0155] This figure illustrates a portion of an expandable housing with a fluid lumen having a configuration that widens outward at at least one end of the fluid lumen. [Figure 24]

[0156] This figure illustrates an outer housing that includes one or more blades extending radially inward. [Figure 25]

[0157] This figure illustrates the proximal portion of an exemplary pump section, which includes one or more blades, sized and configured to align with a portion of the scaffold. [Figure 26A]

[0158] Figure 26A illustrates an exemplary blood pump component with an exemplary speed booster assembly and mechanism that may be incorporated into a blood pump. [Figure 26B] Figure 26B illustrates an exemplary blood pump component with an exemplary speed booster assembly and mechanism that may be incorporated into a blood pump. [Figure 27]

[0159] This figure illustrates an exemplary pump portion adapted by at least one optionally adjustable extension member, such that the pump portion can be deflected at at least one location along the length of the pump portion. [Figure 28A]

[0160] This figure illustrates an exemplary series of steps that can be performed based on an exemplary method using an exemplary blood pump. [Figure 28B] This figure illustrates an exemplary series of steps that can be performed based on an exemplary method using an exemplary blood pump. [Figure 28C] This figure illustrates an exemplary series of steps that can be performed based on an exemplary method using an exemplary blood pump. [Figure 28D] This figure illustrates an exemplary series of steps that can be performed based on an exemplary method using an exemplary blood pump. [Figure 28E] This figure illustrates an exemplary series of steps that can be performed based on an exemplary method using an exemplary blood pump. [Figure 28F] This figure illustrates an exemplary series of steps that can be performed based on an exemplary method using an exemplary blood pump. [Figure 29A]

[0161] Figure 29A illustrates an exemplary foldable flow-changing element, which may be part of a pump section, optionally positioned between two foldable impellers. [Figure 29B] Figure 29B illustrates an exemplary foldable flow-changing element, which may be part of a pump section, optionally positioned between two foldable impellers. [Figure 30A]

[0162] This figure illustrates an exemplary blood flow conduit support member that includes multiple apertures within it, sized and configured to receive and align with one or more flow-changing elements. [Figure 30B]

[0163] This is an example end view of a support member in which multiple flow-changing elements are each arranged in one of multiple support member apertures. [Figure 31A]

[0164] Figure 31A illustrates an exemplary flow-changing element that may be sized and configured to advance through a conduit support member aperture, such as those shown in Figures 30A and 30B. [Figure 31B] Figure 31B illustrates an exemplary flow-changing element that may be sized and configured to advance through a conduit support member aperture, such as those shown in Figures 30A and 30B. [Figure 32A]

[0165] Figure 32A illustrates an exemplary conduit support member, which includes a plurality of flow-changing elements that are integrally formed with the support member and can self-deploy into an active flow-changing configuration extending radially inward. [Figure 32B] Figure 32B illustrates an exemplary conduit support member, which includes a plurality of flow-changing elements that are integrally formed with the support member and can self-deploy into an active flow-changing configuration extending radially inward. [Figure 32C] Figure 32C illustrates an exemplary conduit support member, which includes a plurality of flow-changing elements formed integrally with the support member and capable of self-deploying into an active flow-changing configuration extending radially inward. [Figure 33A]

[0166] Figure 33A illustrates an exemplary pump section, which includes a plurality of flow-changing elements 445 that are optionally fixed to the support column of the pump section. [Figure 33B] Figure 33B illustrates an exemplary pump section, which includes a plurality of flow-changing elements 445 that are optionally fixed to the support column of the pump section. [Figure 34]

[0167] This is a side view of an exemplary flow-changing element positioned between a first impeller and a second impeller. [Figure 35A]

[0168] Figure 35A is a side view of an exemplary flow-changing element (for example, a diffuser in the figure). [Figure 35B] Figure 35B is a top view of an exemplary flow-changing element (for example, a diffuser in the figure), illustrating the configuration of the diffuser as seen from above, as well as the fluid direction relative to the diffuser. [Modes for carrying out the invention]

[0091]

[0169] This disclosure relates to medical devices, systems, and methods of use and manufacture. Medical devices as defined herein may include a pump portion adapted and configured to be placed within a physiological blood vessel, the pump comprising one or more components that act on a fluid. For example, a pump portion as defined herein may include one or more impellers, the one or more impellers configured to, when rotated, facilitate the movement of a fluid such as blood.

[0092]

[0170] Figure 1 is a side view illustrating the distal portion of an exemplary intravascular fluid pump, including the pump section 1600, which includes a proximal impeller 1606 and a distal impeller 1616, both of which are coupled to a drive cable 1612. 0, which is in an extended configuration in Figure 1, is adapted to fold into a delivery configuration so that it can be delivered with a lower profile. The impeller may be in direct or indirect rotational communication with the drive cable 1612. The drive cable 1612 is in conjunction with an external motor (not shown) and extends through the elongated shaft 1610. The terms “pump section” and “working section” (or their derivatives) may be used synonymously within this specification unless otherwise indicated. For example, “pump section” 1600 may also be referred to as “working section” within this specification, though not limited to this.

[0093]

[0171] Figure 2 is a side view illustrating the deployed configuration (shown outside the body) of the distal portion of an exemplary embodiment of a fluid motion system. The exemplary system 1100 includes a pump portion 1104 (which may be referred to herein as the pump portion, as specified herein) and an elongated portion 1106 extending from the pump portion 1104. The elongated portion 1106 may extend to a more proximal region of the system, which is not shown for clarity and may include, for example, a motor. The pump portion 1104 includes a first expandable member 1108 and a second expandable member 1110 that are axially spaced apart along the longitudinal axis LA of the pump portion 1104. In this context, axial space means that the entire first expandable member is axially spaced apart from the entire second expandable member along the longitudinal axis LA of the pump portion 1104. The first end 1122 of the first expandable member 1108 is axially spaced apart from the first end 1124 of the second expandable member 1110. Some of the “expandable members” in this specification may also be referred to as baskets.

[0094]

[0172] The first and second expandable members 1108 and 1110 each generally include a plurality of elongated sections arranged relative to each other to define a plurality of apertures 1130, with only one of the plurality of apertures being 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, for example, any of the configurations or structures in U.S. Patent No. 7,841,976, or a tube in U.S. Patent No. 6,533,716, described as a self-expanding metallic internal prosthesis material. For example, one or both of the expandable members may have a braided structure or may be formed at least partially by laser cutting a tubular element.

[0095]

[0173] The pump portion 1104 also includes a blood flow conduit 1112 supported by a first expandable member 1108 and a second expandable member 1110 in this embodiment. The conduit 1112 also extends axially between the first expandable member 1108 and the second expandable member 1110 in the deployed configuration. The central region 1113 of the conduit 1112 extends over an axial distance 1132 where the first and second expandable members 1108 and 1110 are not present in the pump portion. The central region 1113 can be considered axially located 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 of the conduit 1128 does not extend as proximal as the proximal end 1121 of the first expandable member 1108.

[0096]

[0174] When the disclosure herein refers to a conduit coupled to an expandable member, the term "coupled" in this context does not require that the conduit be directly attached to the expandable member so that the conduit is in physical contact with the expandable member. However, even if not directly attached, the term "coupled" in this context means that the conduit and the expandable member are joined together so that the expandable member can expand or fold, and the conduit also begins to transition to different configurations and / or sizes. Thus, "coupled" in this context refers to a conduit that moves as the expandable member to which the conduit is coupled transitions between an expanded configuration and a folded configuration. Within this specification, a conduit is considered to create a passage through which fluid is moved and may be defined by one or more components of a pump portion.

[0097]

[0175] Any of the conduits described herein may be deformable to some extent. For example, conduit 1112 includes an elongated member 1120 which may be made of one or more materials that allows the central region 1113 of the conduit to deform to some extent radially inward (towards LA) in response to forces from valve tissue (e.g., valve leaflets) or a replacement valve, for example, when the pump portion 1104 is deployed towards the configuration shown in Figure 2 during use. In some embodiments, the conduit may be stretched taut between the expandable members. Alternatively, the conduit may be designed with slack to cause greater compliance. This may be desirable when the pump portion is arranged across a fragile structure such as an aortic valve, which may allow the valve to compress the conduit in a way that minimizes point stress within the valve. In some embodiments, the conduit may include membranes fitted to the proximal and distal expandable members. Exemplary materials that may be used in any conduit as specified herein include, but are not limited to, urethane rubber, silicone rubber, acrylic rubber, stretched polytetrafluoroethylene, polyethylene, polyethylene terephthalate, and any combination thereof.

[0098]

[0176] Any of the conduits described herein may have thicknesses such as, for example, 12.7 to 508 micrometers (0.5 to 20 1 / 1000 inches (sau)), 25.4 to 381 micrometers (1 to 15 sau), or 38.1 to 381 micrometers (1.5 to 15 sau), 38.1 to 254 micrometers (1.5 to 10 sau), or 50.8 to 254 micrometers (2 to 10 sau).

[0099]

[0177] Any or at least a portion of the conduits described herein may be blood impermeable. In Figure 2, the pump portion 1104 includes a lumen extending from the distal end 1126 of conduit 1112 to the proximal end 1128 of conduit 1112. The lumen is defined by conduit 1112 within the central region 1113, but can be considered to be defined by both the conduit and portions of the expandable member in regions axially adjacent to the central region 1113. However, in this embodiment, it is the conduit material that provides the lumen and prevents blood from passing through the conduit.

[0100]

[0178] Any of the conduits described herein, fixed to one or more expandable members, may be fixed such that, unless otherwise indicated, the conduit is located radially outward of one or more expandable members, radially inward of one or more expandable members, or both, and the expandable members may be impregnated with conduit material.

[0101]

[0179] The proximal and distal expandable members help maintain the conduit in an open configuration by providing radial support to the conduit and simultaneously creating an operating environment for the impellers described below. When in the deployed configuration, each expandable member is maintained at a distance from its respective impeller, thereby allowing the impellers to rotate within the expandable members without contact with them. The pump section 1104 includes a first impeller 1116 and a second impeller 1118, the first impeller 1116 being radially positioned within the first expandable member 1108, and the second impeller 1118 being radially positioned within the second expandable member 1110. In this embodiment, the two impellers, even though they are different impellers, are coupled to a common drive mechanism (e.g., drive cable 1117), and as a result, when the drive mechanism is activated, the two impellers rotate together. In this deployment configuration, the impellers 1116 and 1118 are spaced axially along the longitudinal axis LA, just as the expandable members 1108 and 1110 are spaced axially apart.

[0102]

[0180] Impellers 1116 and 1118 are also axially located within the ends of expandable members 1108 and 1110, respectively (radially located within expandable members 1108 and 1110). In addition, the impellers described herein may be considered axially oriented within the expandable member, even if the expandable member includes a support (for example, a tapered support when viewed from the side) that extends from the central region of the expandable member toward the longitudinal axis of the pump portion. In Figure 2, the second expandable member 1110 extends from the first end 1124 (proximal end) to the second end 1125 (distal end).

[0103]

[0181] In Figure 2, the distal portion of impeller 1118 extends distally beyond the distal end 1126 of conduit 1112, and the proximal portion of impeller 1116 extends proximal beyond the proximal end 1128 of conduit 1112. In this figure, each portion of the impeller is axially located within the conduit in this deployed configuration.

[0104]

[0182] In the exemplary embodiment shown in Figure 2, impellers 1116 and 1118 are coupled to a common drive mechanism 1117, in which case each impeller is coupled to the drive mechanism 1117 extending through the shaft 1119 and the pump section 1104. The drive mechanism 1117 may be, for example, an elongated drive cable that rotates the impeller when rotated. In this example, as shown, the drive mechanism 1117 extends to and is fixed axially to the distal tip 1114, but is adapted to rotate relative to the distal tip 1114 when operated. Thus, in this embodiment, the impeller and the drive mechanism 1117 rotate together when the drive mechanism is rotated. Any number of known mechanisms may be used to rotate the drive mechanism, for example, by using a motor (e.g., an external motor).

[0105]

[0183] The expandable member and conduit are not rotationally coupled to the impeller and 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., the 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. The drive mechanism 1117 therefore 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. The distal end 1125 of the distal expandable member 1110 is coupled to the distal tip 1114, as shown. The drive mechanism 1117 is adapted to rotate relative to the tip 1114 but is fixed axially relative to the tip 1114.

[0106]

[0184] The pump section 1104 is adapted and configured to fold into a smaller profile than its deployed configuration (shown in Figure 2). This allows the pump section 1104 to be delivered using a delivery device with a lower profile (smaller French size) than would be required if the pump section 1104 were not foldable. Not specifically described herein, either the expandable member or the impeller may be adapted and configured to fold to some extent into a smaller delivery configuration.

[0107]

[0185] The pump portion described herein may be folded into a folded delivery configuration using prior art, such as by using an outer sheath that is movable relative to the pump portion (for example, by moving one or both of the sheath and the pump portion axially). For example, but not limited to, any of the systems, devices, or methods shown in U.S. Patent No. 7,841,976 or U.S. Patent No. 8,052,749 may be used to facilitate the folding of the pump portion described herein, and these disclosures are incorporated herein by reference for any purpose.

[0108]

[0186] Figures 3A to 3E show exemplary pump sections that are similar in several respects to the pump section shown in Figure 2. Pump section 340 is similar to pump section 1104 in that it includes two expandable members that are axially separated from each other when the pump section is expanded, and a conduit extending between the two expandable members. Figure 3A is a perspective view, Figure 3B is a side section view, and Figures 3C and 3D are enlarged side sections of the area shown in Figure 3B.

[0109]

[0187] The pump section 340 includes a proximal impeller 341 and a distal impeller 342, which are coupled to and in conjunction with a drive cable defining a lumen. The lumen may be sized to accommodate a guidewire, which may be used for delivering the pump section to a desired location. In this embodiment, the drive cable includes a first section 362 (e.g., a coiled material), a second section 348 (e.g., a tubular member) to which the proximal impeller 341 is coupled, a third section 360 (e.g., a coiled material), and a fourth section 365 (e.g., a tubular material) to which the distal impeller 342 is coupled. All drive cable sections have the same inner diameter, and as a result, the lumen has a constant inner diameter. The drive cable sections may be fixed to each other using known mounting techniques. The distal end of the fourth section 365 extends to the distal region of the pump section, allowing the pump section to be advanced, for example, via a guidewire for positioning the pump section. In this embodiment, the second and fourth regions may be stiffer than the first and third regions. For example, the second and fourth regions may be tubular, while the first and third regions may be made of a coiled material to impart less rigidity.

[0110]

[0188] The pump section 340 includes a blood flow conduit, a proximal expandable member 343, and a distal expandable member 344, each of which extends radially outside one of the impellers. The expandable members have distal and proximal ends that also extend axially beyond the distal and proximal ends of the impeller, which can be seen in Figures 3B to 3D. The pump also includes a conduit 356 having a proximal end 353 and a distal end 352. Each of the two expandable members includes a plurality of proximal struts and a plurality of distal struts. The proximal struts in the proximal expandable member 343 extend to and are fixed to a shaft section 345, the shaft section 345 is coupled to a bearing 361, and the drive cable is configured and sized to extend through this bearing 361 and rotate. The distal support of the proximal expandable member 343 extends to and is fixed to the proximal region (in this case, the proximal end) of the central tubular member 346, which is axially positioned between the expandable members. The proximal end of the central tubular member 346 is coupled to a bearing 349, as shown in Figure 3C, and the drive cable extends and rotates through this bearing 349. The proximal support of the distal expandable member 344 extends to and is fixed to the distal region (in this case, the distal end) of the central tubular member 346. The bearing 350 is also coupled to the distal region of the central tubular member 346, as shown in Figure 3D. The drive cable extends through and rotates with respect to the bearing 350. The distal support of the distal expandable member extends to and is fixed to a shaft region 347 (see Figure 3A), which can be considered the distal tip portion. The shaft section 347 is coupled to a bearing 351 (see Figure 3D), through which the drive cable extends and rotates relative to this bearing 351. The distal end also includes a bearing 366 (see Figure 3D), which may be a thrust bearing. The working section 340 may be similar to or identical to the working section 1104 in several embodiments, even if not explicitly included in the description. In this embodiment, the conduit 356 extends at least to the end of the impeller, unlike the working section 1104. Any embodiment may be modified so that the conduit extends to a position as specified in other embodiments. In some embodiments, the section 360 may be a tubular section instead of a coiled section.

[0111]

[0189] In alternative embodiments, at least a portion of any of the impellers described herein may extend outside the fluid lumen. For example, only a portion of the impeller may extend proximal or The impeller may extend beyond the end of the fluid lumen in either the distal direction. In some embodiments, the portion of the impeller extending outside the fluid lumen is the proximal portion of the impeller, including the proximal end (see, for example, the proximal impeller in Figure 2). In some embodiments, the portion of the impeller extending outside the fluid lumen is the distal portion of the impeller, including the distal end (see, for example, the distal impeller in Figure 2). When the disclosure herein refers to an impeller extending outside (or beyond the end of) the fluid lumen, it means referring to the relative axial position of the components, which is most readily visible in a side view or top view such as Figure 2.

[0112]

[0190] However, a second impeller at another end of the fluid lumen may not extend beyond the fluid lumen. For example, an illustrative alternative design may include a proximal impeller that extends proximal to the proximal end of the fluid lumen (as the proximal impeller in Figure 2), and the fluid lumen does not extend distally beyond the distal end of the distal impeller (as in Figure 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 proximal to the proximal end of the fluid lumen. In any of the pump components described herein, neither impeller may extend beyond the end of the fluid lumen.

[0113]

[0191] While specific exemplary locations may be shown herein, the fluid pump may be used in a variety of locations within the body. Some exemplary locations for placement include placement near the aortic valve or pulmonary valve, such as extending to a valve and being positioned on one or both sides of the valve, and in the case of the aortic valve, optionally including a portion positioned within the ascending aorta. In some other embodiments, for example, the pump may be positioned further downstream, such as being located within the descending aorta during use.

[0114]

[0192] Figure 4 illustrates an exemplary arrangement of the pump portion 1104 from system 1000 from Figure 2, and also illustrates exemplary arrangement locations for any of the pump portions described herein. One difference shown in Figure 4 is that the conduit extends at least to the end of the impeller, as in Figures 3A–3D. Figure 4 shows the pump portion 1104 in a deployable configuration, positioned in place across (in other words, straddling) the aortic valve. The pump portion 1104 may be delivered, for example, by femoral artery access (a known access procedure), as shown. Not shown for clarity, system 1000 may also include an outer sheath or shaft to which the pump portion 1104 is positioned during delivery to a location near the aortic valve. The sheath or shaft may be moved proximal (towards the ascending aorta "AA" and away from the left ventricle "LV") to allow deployment and expansion of the pump portion 1104. For example, the sheath may be retracted to allow the expansion of the second expandable member 1110, along with a continuous proximal movement that allows the first expandable member 1108 to expand.

[0115]

[0193] In this embodiment, the second expandable member 1110 is expanded and positioned in an unfolded configuration such that its distal end 1125 is located within the left ventricle "LV," distal to the aortic valve leaflet "VL," and distal to the valve annulus. The proximal end 1124 is also positioned distal to the valve leaflet VL, although in some ways the proximal end 1124 may extend slightly axially within the valve leaflet VL. This embodiment is an example of how at least half of the second expandable member 1110 is located within the left ventricle when measured along its length (measured along its longitudinal axis). As also shown, this is also an example of how the entire second expandable member 1110 is located within the left ventricle. This is also an example of how at least half of the second impeller 1118 is located within the left ventricle, and also an embodiment in which the entire second impeller 1118 is located within the left ventricle.

[0116]

[0194] The continuous retraction of the outer shaft or sheath (and / or distal movement of the working end 1104 relative to the outer sheath or shaft) causes the central region 1113 to release and expand. The conduit 1112 is kept open until it is opened. The expansion of the expandable members 1108 and 1110 causes the conduit 1112 to take on an open configuration, as shown in Figure 4. Thus, in this embodiment, the conduit 1112 does not have the same self-expanding properties as the expandable members, but the conduit takes on an expanded, more open configuration when its working end is expanded. At least a portion of the central region 1113 of the conduit 1112 is located in the aortic valve coaptation region. In Figure 3, there is a short length of central region 1113 that extends distally beyond the valve leaflet VL, but at least some portion of the central region 1113 is axially oriented within the valve leaflet.

[0117]

[0195] 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 member 1108 is expanded and positioned in a deployed configuration (as shown) such that its 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 ways the distal end 1122 may extend slightly axially within the valve leaflet VL. This embodiment is an example of how at least half of the first expandable member 1110 is located within the ascending aorta when measured along its length (measured along the longitudinal axis). As also shown, this is also an example of how the entire first expandable member 1110 is located within the AA. This also provides an example of a method in which at least half of the first impeller 1116 is positioned within AA, and also an embodiment in which the entire first impeller 1116 is positioned within AA.

[0118]

[0196] At any time during or after the deployment of the pump section 1104, the position of the pump section can be accessed by some means, such as under fluorescence imaging. The position of the pump section can be adjusted at any time during or after deployment. For example, after the second expandable member 1110 has been released but before the first expandable member 1108 has been released, the pump section 1104 can be moved axially (distal or proximal) to reposition the pump section. In addition, for example, the pump section can be repositioned after the entire working part has been released from the sheath to the desired final position.

[0119]

[0197] It should be understood that the positions of the components (relative to the biological structure) shown in Figure 4 are considered exemplary final positions for different components of the working portion 1104, even if any repositioning occurred after the initial deployment.

[0120]

[0198] One or more expandable members described herein may be configured to expand, or may be expandable, in a variety of ways, such as self-expansion, mechanical action (e.g., one or more axially directed forces on the expandable member, which are expanded by a separate balloon positioned axially within the expandable member and inflated to push radially outward relative to the expandable member), or a combination thereof.

[0121]

[0199] As used herein, expansion generally refers to the reconfiguration of one or more components into a larger profile having a larger radially outer dimension (relative to the longitudinal axis), regardless of the specific manner in which they are expanded. For example, a stent that expands itself and / or is under the influence of radially outward forces can be “expanded” when the term is used herein. A spreading or opening device can also take on a larger profile and may be considered expanded when the term is used herein.

[0122]

[0200] Impellers can also be adapted and configured to expand in various ways, depending on their structure, and may be expanded in such ways. For example, one or more impellers, when released from the sheath, may expand to different larger sizes due to the materials and / or structure of the impeller design. The configuration can automatically return to or toward a larger profile (see, for example, U.S. Patent No. 6,533,716 or U.S. Patent No. 7,393,181, both of which are incorporated herein by reference for all purposes). Thus, the pull-back of the external restraint may, in some embodiments, allow both the expandable member and the impeller to return naturally to a larger profile, deployed configuration without any further action.

[0123]

[0201] As shown in the example in Figure 4, the pump portion includes first and second impellers spaced apart on either side of the aortic valve, each housed within a separate expandable member. This is in contrast to some designs in which the working portion includes a single elongated expandable member. Instead of a single substantially tubular expandable member extending across the valve, the working end 1104 includes a conduit 1112 extending between expandable members 1108 and 1110. The conduit is more flexible and deformable than the pump at the location of the impellers, which may allow for further deformation of the pump portion at the location of the valve leaflets than would occur if the expandable members were to extend across the aortic valve leaflets. Having a more flexible central region may also reduce damage to the valve leaflets after the pump portion has deployed within the target.

[0124]

[0202] In addition, forces from the valve leaflets to the central region of a single expandable member may be axially transferred to other regions of the expandable member, potentially causing undesirable deformation of the expandable member at the location of one or more impellers. This can cause the outer expandable member to come into contact with the impeller, unnecessarily hindering the rotation of the impeller. Designs that include separate expandable members around each impeller result in a higher level of precision in positioning the impellers relative to the expandable members, 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 their deployed configuration compared to a single expandable member.

[0125]

[0203] As described herein above, the working part may be delivered within a 9F sheath, and it may still be desirable that the working part be reconfigurable during use to obtain a sufficiently high flow rate, which is not possible in some products currently under development and / or testing. For example, some products are too large to be reconfigured into a sufficiently small delivery profile, while some smaller designs may not be able to achieve the desired high flow rate. The exemplary advantages of the examples in Figures 1, 2, 3A–3D, and 4 are, for example, that the first and second impellers can work together to achieve the desired flow rate, and that by having two axially spaced impellers, the entire working part can be reconfigured into a smaller delivery profile than a design in which a single impeller is used to achieve the desired flow rate. Thus, these embodiments use multiple axially spaced smaller reconfigurable impellers for both achieving the desired smaller delivery profile and achieving the desired high flow rate.

[0126]

[0204] Therefore, embodiments herein can achieve a smaller delivery profile while maintaining a sufficiently high flow rate, while creating a more deformable and flexible central region of the working part, and these exemplary benefits are described above (e.g., delicate valves). (Aligning with the point).

[0127]

[0205] Figure 5 illustrates an operating portion similar to the operating portion shown in Figure 1. The operating portion 265 includes a proximal impeller 266 and a distal impeller 267, both of which are coupled to a drive shaft 278 extending into a distal bearing housing 272. A similar proximal bearing housing is present at the proximal end of the operating portion. The operating portion also includes an expandable member generally referred to as 270, and a conduit 268 fixed to the expandable member and extending substantially along the entire length of the expandable member. The expandable member 270 extends to a support 273 fixed to its distal tip 273. The expandable member 270 also includes a distal support 271 located thereto and fixed thereto. The expandable member 270 also includes a proximal support fixed to a proximal support. All features similar to those shown in Figure 1 are incorporated by reference for any purpose, even if not explicitly stated. The expandable member 265 also includes a helical extension member 269 disposed along the outer edge of the expandable member, having a helical configuration when the expandable member is in the expanded configuration as shown. The helical extension member 269 is disposed and adapted to induce rotational winding when folded. The working portion 265 can be folded from the shown expanded configuration, simultaneously rotating one or both impellers at a relatively slow speed to facilitate the rounded folding of the impellers due to their interaction with the expandable member.

[0128]

[0206] Alternative methods exist for constructing the pump section such that extension causes rotation of the expandable member when folded (and thus causes winding and folding of the impeller blades). Any expandable member can be constructed with this feature, even in a double-impeller design. For example, in an expandable member containing multiple “cells,” where the term is commonly known (e.g., a laser-cut elongated member), the expandable member may have multiple specific cells that together define a particular configuration, such as a helical configuration, and the cells defining the configuration have different physical properties from the other cells in the expandable member. In some embodiments, the expandable member may have a braided structure, where the twisted region may constitute the entire group of wires, or a significant portion (e.g., more than half) of the braided wire. Such a twisted braided structure can be achieved during the braiding process, for example, by twisting the core over which the wires are braided, as the core is pulled, particularly along the length of the widest diameter portion of the braided structure. This structure can also be achieved during a second construction process, such as mechanically twisting the braided structure before heat-setting the winding profile on the molded core.

[0129]

[0207] Any of the conduits described herein are made of a material that acts, is configured, and makes such a fluid lumen between a first end (e.g., a distal end) and a second end (e.g., a proximal end). The fluid flows into the inlet region, through the fluid lumen, and then out of the outlet region. The flow into the inlet region may be labeled "I" herein, and the flow out of the outlet region may be labeled "O". Any of the conduits described herein may be impermeable. Alternatively, any of the conduits described herein may be semipermeable. Any of the conduits described herein may also be porous, but still define a fluid lumen through which the fluid passes. In some embodiments, the conduit is a membrane or other relatively thin layered member. Any of the conduits described herein may be fixed to an expandable member unless otherwise indicated, and as a result, the conduit may be radially inward and / or outward of the expandable member, where it is fixed. For example, a conduit may extend radially within an expandable member, and as a result, the inner surface of the conduit is located within the expandable member in the radial direction, if it is fixed to the expandable member.

[0130]

[0208] Any of the expandable members described herein may be made of a variety of materials and constructed in a variety of ways. For example, an expandable member may have a braided structure, or it may be formed by laser processing. The material may be deformable, such as nitinol. The expandable member may be self-expanding or may be adapted to expand at least partially actively.

[0131]

[0209] In some embodiments, the expandable member is adapted to self-expand when released from a tubular member containing it, 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 by the action of a pull rod that moves at least one of the distal and proximal ends of the expandable member toward each other. In alternative embodiments, the deployment configuration may be influenced by the configuration of one or more expandable structures. In the embodiment, one or more expandable members may be deployed at least partially by the influence of blood flowing through the conduit. Any combination of the above mechanisms of deployment may be used.

[0132]

[0210] The blood pump and fluid motion devices, systems, and methods described herein may be used and positioned in various locations within the body. While specific examples may be provided herein, it should be understood that the working portion may be located in body regions different from those specifically described herein.

[0133]

[0211] In any embodiment of this specification in which a medical device includes multiple impellers, the device may be adapted to allow the impellers to rotate at different speeds. Figure 6A illustrates a medical device including a gear set 1340 coupled to both an inner drive member 1338 and an outer drive member 1336, which are coupled to 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. Starting the motor 1332 causes the two impellers to 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. Any of the devices of this specification may include any of the gear sets of this specification to drive the impellers at different speeds.

[0134]

[0212] Figure 6B illustrates a portion of an alternative embodiment of a dual impeller device (1350) similarly adapted so that different impellers rotate at different speeds. The gearset 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 shown in Figure 6A. Figures 6A and 6B illustrate how the gearset may be adapted to drive the proximal impeller slower or faster than the distal impeller.

[0135]

[0213] Figure 7 shows an exemplary alternative embodiment of the fluid pump 1370 in which the first and second impellers can be rotated at different speeds. A first motor 1382 drives a cable 1376 coupled to the distal impeller 1372, while a second motor 1384 drives an outer drive member 1378 coupled to the proximal impeller 1374 (via a gear set 1380). The drive cable 1376 extends through the outer drive member 1378. The motors can be controlled and operated individually, and therefore the speeds of the two impellers can be controlled separately. This system setup can be used with any system in this specification that includes multiple impellers.

[0136]

[0214] In some embodiments, a common drive cable or shaft can drive the rotation of two (or more) impellers, but the blade pitches (angles of rotational bending) of the two impellers may differ, with the distal or proximal impeller having a steeper or gentler angle than the other impeller. This can produce an effect similar to having a gear set. Figure 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 impellers described herein may have a larger or smaller pitch than the distal impellers described herein. Any of the working portions (or distal portions) described herein having multiple impellers may be modified to include first and second impellers having different pitches.

[0137]

[0215] In any of the embodiments described herein, the pump portion is compliant (in other words, flexible) or semi-compliant (generally collectively referred to as "comp") It may have an external structure (referred to as a "compliant"). In various embodiments, the compliant portion is flexible. In various embodiments, the compliant portion deforms only partially under pressure. For example, the central portion of the pump may be formed with a compliant external structure so that it deforms in response to the force of the valve. In this configuration, the external force of the pump on the valve leaflet is reduced. This can help prevent damage to the valve where the pump spreads to the valve.

[0138]

[0216] Figure 8 illustrates an exemplary embodiment of a pump section, including first, second, and third axially spaced impellers 152, each disposed within an expandable member 154. A conduit 155 may extend along the length of the pump section, as described in various embodiments herein, thereby helping to create 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 Figure 1. In Figure 8, the fluid lumen extends from the distal end to the proximal end, a feature described elsewhere herein. The embodiment in Figure 8 may include any other preferred features, including methods of use, as described herein.

[0139]

[0217] The embodiment in Figure 8 is also an example of an outer housing having at least one bend formed between the distal end of a proximal impeller and the proximal end of a distal impeller, such that the distal region of the housing distal to the bend is not axially aligned with the proximal region of the housing proximal to the bend along the axis. In this embodiment, there are two bends 150 and 151 formed within the housing, each located between two adjacent impellers.

[0140]

[0218] In its use, the bent portion formed within the housing can be positioned to extend towards a valve, such as the aortic valve shown in Figure 8. In this configuration, the central impeller and the most distal impeller are located within the left ventricle, and the most proximal impeller is located within the ascending aorta. The bent portion 151 is located just downstream of the aortic valve.

[0141]

[0219] A bend, such as the bend 150 or 151, may be incorporated into any of the embodiments or designs described herein. The bend may be at a pre-formed angle or may be adjusted in situ.

[0142]

[0220] In any of the embodiments herein, unless otherwise indicated, the outer housing may have a substantially uniform diameter along its length.

[0221] In Figure 8, the pump is positioned via the axillary artery, which is an exemplary method of accessing the aortic valve, allowing the patient to walk and become active with minimal interruption. Any of the devices described herein may be positioned via the axillary artery. However, it will be understood from the description herein that the pump may be introduced and tracked to position in a variety of ways, including a femoral approach via the aortic arch.

[0143]

[0222] One aspect of the present disclosure is an intravascular blood pump including a distal impeller axially spaced apart from a proximal impeller. In one embodiment, the distal and proximal impellers are separated from each other. For example, the distal and proximal impellers may be connected only by their individual mounting on a common drive shaft. This is different from an impeller having multiple rows of blades. The distal impeller, as used herein, does not necessarily mean the most distal impeller of the pump, but generally refers to an impeller located further distal to the proximal impeller, even if there are additional impellers located further distal to the proximal impeller. Similarly, the proximal impeller, as used herein, does not necessarily mean the most nearest impeller of the pump, but generally refers to an additional impeller located further proximal to the proximal impeller. Even if impellers exist, this may refer to impellers positioned even more proximal than the proximal impeller. Axial spacing (or any derivative thereof) refers to spacing along the length of the pump section, for example, along the longitudinal axis of the pump section, even if bends exist in the pump section. In various embodiments, each of the proximal and distal impellers is positioned within its respective housing and configured to maintain a precise and constant tip clearance, and the span between the impellers has a relatively more flexible (or fully flexible) fluid lumen. For example, each of the impellers may be positioned within its respective housing, which has a relatively rigid outer wall to resist radial folding. The area between the impellers may be relatively rigid, and in some embodiments, this area is kept open primarily by the fluid pressure within it.

[0144]

[0223] Although not required in the embodiments herein, it may be advantageous to have a minimum axial separation between the proximal and distal impellers. For example, the pump portion may be delivered to a target site by passing through a portion of a biostructure with a relatively narrow bend, such as the aorta, and descending into the aortic valve. For example, the pump portion may be delivered to the aortic valve via femoral artery access. It may be advantageous to have a system that is more easily bent, so that it is easier to deliver the system through bends in biostructures. Some designs in which the impellers are fairly close to each other may make the system along the length extending across the impellers relatively rigid along the entire length extending across the impellers. Separating the impellers axially and optionally providing a relatively flexible region between the impellers can create a portion of the system that is more flexible, more easily bent, and can advance more easily and safely through bends. An additional exemplary advantage is that the axial separation may allow a relatively more compliant region between the impellers, which may be located at the site of a valve (e.g., the aortic valve). Furthermore, there are other potential advantages and functional differences between the various embodiments described herein and a typical multistage pump. A typical multistage pump includes rows of blades (sometimes referred to as impellers) that are closely spaced functionally, so that the rows of blades act together as synchronized stages. It should be understood that the flow may separate as it passes through the distal impeller. In the various embodiments described herein, the distal and proximal impellers may be spaced far enough apart so that flow separation from the distal impeller is substantially reduced (i.e., increased flow reattachment) and local turbulence dissipates before the flow enters the proximal impeller.

[0145]

[0224] In any of the embodiments, or in any part of the description herein, including distal and proximal impellers, the axial distance between the distal end of the proximal impeller and the proximal end of the distal impeller may 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. This distance may be measured when the pump portion including any impeller is in an extended configuration. This exemplary range can provide the exemplary flexibility benefits described herein when the pump portion is delivered through a curved portion of a biological structure, such as through the aorta and the aortic valve. Figure 9 (shown outside the patient in an extended configuration) illustrates the axial distance between impellers and also illustrates a length Lc, which may be 1.5 cm to 25 cm as specified herein in some embodiments. In embodiments where three or more impellers may be present, any two adjacent impellers (i.e., impellers that do not have any other rotating impellers between them) may be spaced axially apart by any of the axial spacing distances described herein.

[0146]

[0225] Some embodiments include a proximal impeller distal end spaced axially 1.5 cm to 25 cm from the distal impeller proximal end along the axis, and the disclosure herein also includes any axial spacing that is a partial range within its entire range of 1.5 cm to 25 cm. That is, the disclosure includes all ranges having any lower limit from 1.5 cm or more, and all partial ranges having any upper limit from 25 cm or less. The following examples provide exemplary partial ranges. In some embodiments, the distal end of the proximal impeller is spaced axially from the proximal end of the distal impeller along the axis by 1.5cm to 20cm, 1.5cm to 15cm, 1.5cm to 10cm, 1.5cm to 7.5cm, 1.5cm to 6cm, 1.5cm to 4.5cm, and 1.5cm to 3cm. In some embodiments, the axial spacing is 2cm to 20cm, 2cm to 15cm, 2cm to 12cm, 2cm to 10cm, 2cm to 7.5cm, 2cm to 6cm, 2cm to 4.5cm, and 2cm to 3cm. In some embodiments, the axial spacing is 2.5cm to 15cm, 2.5cm to 12.5cm, 2.5cm to 10cm, 2.5cm to 7.5cm, or 2.5cm to 5cm (e.g., 3cm). In some embodiments, the axial spacing is 3cm to 20cm, 3cm to 15cm, 3cm to 10cm, 3cm to 7.5cm, 3cm to 6cm, or 3cm to 4.5cm. In some embodiments, the axial spacing is 4cm to 20cm, 4cm to 15cm, 4cm to 10cm, 4cm to 7.5cm, 4cm to 6cm, or 4cm to 4.5cm. In some embodiments, the axial spacing is 5cm to 20cm, 5cm to 15cm, 5cm to 10cm, 5cm to 7.5cm, or 5cm to 6cm. In some embodiments, the axial spacing is 6cm to 20cm, 6cm to 15cm, 6cm to 10cm, or 6cm to 7.5cm. In some embodiments, the axial spacing is 7cm to 20cm, 7cm to 15cm, or 7cm to 10cm. In some embodiments, the axial spacing is 8cm to 20cm, 8cm to 15cm, or 8cm to 10cm. In some embodiments, the axial spacing is 9cm to 20cm, 9cm to 15cm, or 9cm to 10cm. In various embodiments, the fluid duct between the impellers is not relatively supported.

[0147]

[0226] In any of the embodiments described herein, one or more impellers have a length measured axially between the distal end and proximal end of the impeller, ranging from 5 cm to 10 cm, or any partial range therefrom (in Figure 9, these are referred to as "L"). SD " and "L SPIt may have (as indicated by ). The following examples provide exemplary subranges. In some embodiments, the impeller axial length is 0.5cm to 7.5cm, 0.5cm to 5cm, 0.5cm to 4cm, 0.5cm to 3cm, 0.5cm to 2cm, or 0.5cm to 1.5cm. In some embodiments, the impeller axial length is 0.8cm to 7.5cm, 0.8cm to 5cm, 0.8cm to 4cm, 0.8cm to 3cm, 0.8cm to 2cm, or 0.8cm to 1.5cm. In some embodiments, the impeller axial length is 1cm to 7.5cm, 1cm to 5cm, 1cm to 4cm, 1cm to 3cm, 1cm to 2cm, or 1cm to 1.5cm. In some embodiments, the axial length of the impeller is 1.2cm to 7.5cm, 1.2cm to 5cm, 1.2cm to 4cm, 1.2cm to 3cm, 1.2cm to 2cm, or 1.2cm to 1.5cm. In some embodiments, the axial length of the impeller is 1.5cm to 7.5cm, 1.5cm to 5cm, 1.5cm to 4cm, 1.5cm to 3cm, or 1.5cm to 2cm. In some embodiments, the axial length of the impeller is 2cm to 7.5cm, 2cm to 5cm, 2cm to 4cm, or 2cm to 3cm. In some embodiments, the axial length of the impeller is 3cm to 7.5cm, 3cm to 5cm, or 3cm to 4cm. In some embodiments, the axial length of the impeller is 4cm to 7.5cm, or 4cm to 5cm.

[0148]

[0227] In any of the embodiments described herein, the fluid lumen may have a length from the distal end to the proximal end, which is shown as length Lp in Figure 9. In some embodiments, the fluid lumen length Lp is 4 cm to 40 cm or any partial range thereof. For example, in some embodiments, the length Lp may 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, or 4 cm to 6 cm.

[0149]

[0228] In any of the embodiments described herein, the housing is dimensional in Figure 9. The expanded diameter may be at least at the location of the impeller (optionally at the location between the impellers), indicated as Dp. In some embodiments, Dp may be 0.3 cm to 1.5 cm or any sub-range thereof. 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. 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 0.7cm to 1.4cm, 0.7cm to 1.2cm, 0.7cm to 1.0cm, or 0.7cm to 0.8cm.

[0150]

[0229] In any of the embodiments described herein, the impeller may have an unfolded diameter, which is shown as dimension Di in Figure 9. In some embodiments, Di may be 1 mm to 30 mm or any partial range thereof. For example, in some embodiments, Di may be 1 mm to 15 mm, 2 mm to 12 mm, 2.5 mm to 10 mm, or 3 mm to 8 mm.

[0151]

[0230] In any of the embodiments described herein, the tip clearance extends between the outer diameter of the impeller and the inner diameter of the fluid tube lumen. In some embodiments, the tip clearance may be 0.01 mm to 1 mm, such as 0.05 mm to 0.8 mm or 0.1 mm to 0.5 mm.

[0152]

[0231] In any of the embodiments herein, at least one of at least one of flow diffusers and stators is located between two or more impellers along the catheter shaft, any one of which can increase the fluid pressure between the impellers, reduce fluid vortices, and / or increase the combined efficiency of the multiple impellers.

[0153]

[0232] In any of the embodiments herein, features at the fluid outlet of the expandable shroud basket or expandable member may be shaped to act as a flow diffuser, such as a stent-like support at the attachment point between the outer dimensions of the catheter shaft and the outer dimensions of the expandable member, which may be a twisted blade shape directed to alter the direction of blood flow. In any of the embodiments herein, one or more portions of the catheter shaft downstream of the impeller may widen to a larger diameter to alter the angle of blood flow and cause a deceleration of blood flow to a velocity closer to that of the original aortic blood flow. Exemplary locations for a larger diameter downstream of the impeller may be at or near the region where the expandable shroud basket attaches to the catheter shaft, and / or at the bearing housing adjacent to the impeller, or on or adjacent to the internal motor.

[0154]

[0233] In some embodiments, the pump section may include one or more central members disposed axially between the proximal and distal impellers. The one or more central members may or may not be directly coupled to one another. The one or more central members may provide one or more of the following exemplary functions: structural support, flow diversion, and maintenance of impeller alignment. If the one or more central members provide structural support, they may provide structural support to the outer conduit (which may be referred to herein as the “housing”) and / or to one or more impellers. For example, they may help maintain the tip clearance in one or more impellers. In the following description, unless otherwise indicated, the one or more central members are coupled to the impellers and to the rotational operating state. No. As used herein, the term “central member” or its derivatives does not imply that the member is located at least midpoint between the two impellers, but merely implies that the central member is located somewhere axially between the two impellers. “Central member” may therefore be used synonymously with the term “intermediate member” within this specification.

[0155]

[0234] Figure 10 is a side view illustrating an exemplary pump section 20 of a fluid pumping device 10. The distal direction is indicated by "D" and the proximal direction by "P". The pump section 20 (and other pump sections in this specification) may also be referred to herein as the distal section. The pump section 20 includes a fluid flow conduit as described herein, as well as an expandable member 30. The pump section 20 also includes a support structure 33 (which may be referred to herein as a scaffold), which is a stent-like member, in this embodiment, but may be constructed using any of the examples provided herein. The conduit includes a membrane 34 having a distal end 31 and a proximal end 32. The membrane 34 is coupled to the support structure 33. The membrane 34 at least partially creates and defines an internal lumen through which fluid flows when the impellers 40 and 50 are started. The membrane 34 may have any of the properties of any of the conduits described herein. When the support structure 33 extends to the deployment and extension configuration shown in Figure 10, the conduit also takes on the open configuration shown in Figure 10. The fluid flow is generally indicated in the direction of the arrow "F" when the impellers 40 and 50 are started. The impellers 40 and 50 may be any of the impellers described herein and may have any of the characteristics described herein.

[0156]

[0235] In this embodiment, the pump section 20 includes a central member 60 disposed axially between the distal impeller 40 and the proximal impeller 50. In this embodiment, the central member 60 functions as at least a flow control member to alter or control the flow of blood in the fluid lumen. Figures 11A, 11B, and 11C show perspective, side, and distal end views of the central member 60 with the other pumps in the distal section removed for clarity. The central member 60 includes a hub 67 and a plurality of blades extending therefrom, in this embodiment three (i.e., blades 63, 64, and 65), although more or fewer blades may be used. The central member 60 has a distal or anterior region 61 and a posterior or proximal region 62. The blades in the distal region 61 are configured to recover pressure from the distal impeller 40, and the blades in the proximal region 62 are configured to direct the flow towards the proximal impeller 50. The blades in the distal region 61 have a greater degree of curvature relative to the hub than the blades in the proximal region 62. The degree of curvature generally decreases from the distal end to the proximal end. This results in a transition from the distal region, which acts more like a diffuser, to the proximal end, which acts more like a stator or guide vane. In this embodiment, the proximal region 62 provides the functionality of a stator.

[0157]

[0236] In addition to controlling the flow and creating a specific type of flow along its length, the central member 60 also provides structural support to the conduit. Member 60 provides stability in the axial region between the impellers 40 and 50. The central region between the impellers can receive various forces, and member 60 can reinforce the central region in response to those forces. For example, the distal region 20 may be located within the heart, and in particular, the central region between the impellers may be located across a heart valve (e.g., the aortic valve) where a lot of movement occurs when the valve opens and closes. Forces from the valve joint can impart radially inward forces to the expandable member 30, and member 60 reinforces at least some portion (including substantially the entire portion) of the central span (in other words, the central distance) of the expandable member 30. This strengthens the gap and keeps the lumen open. In addition, for example, member 60 can also reduce vibrations between the impellers that occur when the impellers rotate. The structural support provided in the central region can help maintain the gap between the impeller tips and the expandable member 30. The central member 60 is fitted and configured to fold into a delivery configuration. When expanded (like an impeller) to the state shown in Figure 10, the central member 60 engages with the expandable member 30 and provides structural support from within the lumen. In an alternative embodiment, the central member 60 may be permanently attached to the expandable member, as a result they fold and expand as a single unit. In this embodiment, the central member 60 is thus adapted and configured for both controlling and creating a specific flow along its length between the impellers, and for providing structural support to the expandable member.

[0158]

[0237] Any central member (e.g., control member 60) may extend axially over substantially the entire central span ("CS") between the impellers. The length of the central span "CS" is shown in Figure 10. As discussed above, there are structural supports that are advantageous to have a structural support member (e.g., member 60) disposed directly adjacent to the impeller, as in the case of both impellers in the embodiment in Figure 10. If it is desirable to have a single central member extending from the distal end to the proximal end (as in the embodiment in Figure 10), the central member may extend for at least 75%, or at least 80%, or at least 85%, or at least 90%, or at least 95% of the central span distance between the impellers. It is desirable to have a gap between the impeller and the control member, which prevents friction from contact between the rotating impeller and the control member.

[0159]

[0238] In other embodiments of this specification, the intermediate member may not extend along a substantial portion of the length between the impellers (see, for example, intermediate members 92 and 102 in Figure 12A). In any embodiment of this specification, the central member may extend for 5% or less, 10% or less, 15% or less, 20% or less, 25% or less, 30% or less, 35% or less, 40% or less, 45% or less, 50% or less, 55% or less, 60% or less, 65% or less, 70% or less, 75% or less, 80% or less, 85% or less, 90% or less, 95% or less, or 99% or less of the central span between the first impeller and the second impeller.

[0160]

[0239] In any of the embodiments herein that include multiple impellers, the axial spacing between impellers (along the length of the pump portion, even if there are bends in the pump portion) may be 2 mm to 100 mm, or any combination of upper and lower limits including 5 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.).

[0161]

[0240] The length of one or more central members can be any desired length between the first impeller and the second impeller.

[0241] In some embodiments, at least 50% of the length of the central member provides functionality that is considered more like a stator than a diffuser. For example, in the embodiment in Figure 10, the proximal half of the central member 60 functions more like a stator than a diffuser. The diffuser region may be long enough to recover at least 5–50% of the pressure from the kinetic energy created by the previous stage (e.g., the distal impeller). The stator region may be long enough to direct the flow to the next stage (e.g., the proximal impeller) without causing excessive frictional losses.

[0162]

[0242] The embodiments in Figures 10–11C illustrate a single central member 60 between the impellers, but in some alternative embodiments, the distal or working portion may include two or more separate, axially spaced central members arranged between the impellers. Figures 12A–13C illustrate such exemplary designs.

[0163]

[0243] Figure 12A is a perspective view of an exemplary distal portion 80 of the pumping device 70. The embodiments in Figures 12A to 13C are similar in several respects to the double impeller design shown herein with multiple expandable members (e.g., Figure 3A). One difference between the two is that the distal portion 80 includes a distal central member 92 and a proximal central member 102, each of which is disposed in close proximity to one of the impellers. At least a portion of the central member 92 is axially disposed within the end of a structural support 91 (e.g., a stent-like device) which is part of the distal expandable member 90. The central member 92 is also radially located within the structural support 91. At least a portion of the central member 102 is axially disposed within the end of a structural support 101 (e.g., a stent-like device) which is part of the proximal expandable member 100. The central member 102 is also radially located within the structural support 101. The conduit 95 (which may have any of the conduit characteristics described herein) extends from the distal end to the proximal end, including extending axially between the central member 92 and the central member 102.

[0164]

[0244] Figures 13A, 13B, and 13C show end face perspective views, perspective views, and side views of the central members 92 and 102 (other components are not shown for clarity). The central member includes an outer annular member 110 and an inner annular member 113, with a plurality of blades 112 extending between them.

[0165]

[0245] Similar to the central member 60 in Figure 10, the central members 92 and 102 are fitted and configured to provide fluid control and structural support. The central members 92 and 102 are disposed radially within the expandable members 90 and 100, and at least partially axially within the expandable members 90 and 100, respectively. The annular member 110 and the radially extending blade 112 provide radial reinforcement and support, and thus can help keep the lumen open, maintain tip clearance, and reduce vibration between impellers. In this embodiment, the blades are also configured so that the central members 92 and 102 act as stators. For example, the proximal central member 102 can direct the flow before it reaches the proximal impeller. The distal central member 92 can also help restore pressure. "Directing the flow" and its derivatives, as used herein, may include altering the ratio of axial to radial flow components. For example, any stator functionality (and any component that enables the stator to function) described herein can increase the axial flow component and decrease the radial flow component.

[0166]

[0246] In this embodiment, a portion of the central span between the impellers does not include an expandable member or support member, but includes a conduit 95 (e.g., a flexible membrane). This is similar to the embodiment in Figure 3A. The deformable conduit 95 may allow the central region to deform to some extent up to where the valve leaflets are joined. However, the support members 92 and 102 help reinforce the ends of the expandable members 90 and 100, even though the conduit 95 can deform over a larger central region.

[0167]

[0247] A further difference between the embodiment in Figure 3A and Figures 12A to 13C is that in Figures 12A to 13C, the expandable member does not have supports in the inner portion of the expandable member (closer to the center along the longitudinal axis). The central members 92 and 102 replace those supports.

[0168]

[0248] The central members 92 and 102 are foldable and expandable, just like the impellers described herein. The central members 92 and 102 are fixed to components passing through the lumen 114 (see Figure 13B) and are fixed so as not to rotate when the impeller rotates. The rotatable shaft passes through the central members 92 and 102. The central members 92 and 102 are directly adjacent to the impeller but are spaced far enough apart to prevent any friction between the parts.

[0169]

[0249] In other embodiments, there are three or more central members spaced apart in the axial direction between the impellers. For example, one or more separate central members may be disposed between the central members 92 and 102, and may also be fixed to the same elongated shaft to which the central members 92 and 102 are fixed.

[0170]

[0250] The central members 92 and 102 can be permanently attached to the expandable members 90 and 100, respectively, so that they can expand and fold together. For example, the radially outer surface of the annular area 110 can be fixed to the expandable member. Alternatively, the central members 92 and 102 may not be attached to the expandable member, but the central members may be sized to contact / engage with the expandable member when both the central members and the expandable member are in their deployed configuration.

[0171]

[0251] The shaft operably connected to the impeller may extend through the shaft to which the central members 92 and 102 are fixed, and as a result, the shaft can rotate within a non-rotating elongated shaft to drive the rotation of the impeller without causing rotation of the central members.

[0172]

[0252] In several alternative embodiments not shown, the configurations of central members 92 and 102 may be incorporated into a single central member design. For example, the annular outer region 110 on which the blades 112 extend may also be incorporated into all or some portion of the length of a single central member. For example, in several alternative embodiments to Figure 10, the central member 60 may include one or more annular outer regions somewhere along the length of the central member 60. For example, the central member 60 may include a single outer annular region extending along its length, and the blades 63, 64, and 65 may extend from the single outer annular region. Alternatively, for example, the central member 60 may include multiple annular outer regions disposed at any location along its length. For example, the distal and proximal end regions of the central member 60 may each include separate annular outer regions on which the blades 63, 64, and 65 extend. The separate annular outer regions may be of any desired length and may occupy any desired proportion of the axis extending between the impellers. Alternatively, for example, the central member may also include a third separate annular outer region at the center of the central member 60. The additional separate outer annular regions may be spaced axially along the length of the central member 60 (or any other single central member).

[0173]

[0253] In several alternative embodiments not shown, the configuration of the central member 60 may be incorporated into a design comprising multiple central members (e.g., central members 92 and 102). For example, the blades 112 within the central members 92 and 102 (shown in Figures 13A and 13B) do not need to have a straight configuration, but may be curved to some extent, as shown in the portions of blades 63, 64, and 65 in Figure 10. Alternatively, some portions of blade 112 may be straight, while others may be curved, as shown in the portions of blades 63-65 in Figure 10. For example, the distal central member 92 may have blades with curved portions, while the proximal central member 102 may have straight blades. In these designs, the central member 92 may act more to restore pressure, while the proximal central member 102 may function more like a stator that directs flow.

[0174]

[0254] In addition, the distal central member 92 does not need to have the same configuration as the proximal central member 102.

[0255] In addition, in other embodiments, the embodiments of the distal regions 20 and 80 in Figures 10 and 12A can be incorporated together with other distal regions. For example, in Figure 10, the support structure 33 extends across the entire central span between the impellers. In the distal region 80 shown in Figure 12A, the support structure may similarly extend across the span between the central members 92 and 102. For example, the distal support structure 91 may extend proximal to the central span, forming a proximal support structure 101 as well.

[0175]

[0256] The fluid pumps described with respect to Figures 10–13C can be positioned in any anatomical location described herein. In exemplary uses, the fluid pump may be used in a manner that positions the device as shown in Figure 4 during use. The entire description herein relating to Figure 4 is incorporated by reference for all purposes relating to the embodiments in Figures 10–13C. For example, the fluid pump 10 may be positioned straddling the aortic valve, with the distal impeller positioned in the left ventricle and the proximal impeller positioned in the ascending aorta. In this position, the central region of the distal portion, including a portion of the control member 60, is positioned at the location of the aortic valve.

[0176]

[0257] Any of the pump sections in this specification that include multiple impellers may also include three or more impellers, such as three, four, or five impellers (for example).

[0258] Some of the embodiments described above describe pump sections or components that are foldable and expandable (or at least movable between a foldable configuration and an expanded configuration), and in any of those embodiments, the components and the expandable outer housing may also be non-expandable and non-foldable. That is, any of the components in those embodiments may exist, but this component may be a non-expandable variant of those components. For example, the impeller shown above may not be expandable and may be non-expandable.

[0177]

[0259] Figures 14A and 14B show a side view of the distal portion of an exemplary embodiment of a blood pump in which the components are not expandable and foldable. All components in this embodiment may be rigid, fixed parts.

[0178]

[0260] Figure 14B illustrates internal components not visible in Figure 14A. The descriptions in Figures 14A and 14B are illustrative and not limiting. The pump section shown in Figures 14A and 14B includes Stage 1 and Stage 2 sections spaced axially apart along the length of the pump section. In this embodiment, a central section between the two stages (generally labeled the “flexible section”) has a bend formed therein, which may extend along any portion of the central section between the stages, such as at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, or at least 95%. The flexed portion may be manufactured within the central region so that it is located outside the body, but the central region may be sufficiently flexible so that it can be reconfigured into a straight delivery configuration within a delivery device such as a delivery sheath or introducer.

[0179]

[0261] The pump section includes multiple axially aligned inlet apertures distal to the Stage 1 component. While Figures 14A and 14B show two inlet apertures, there may be three or more inlet apertures. There are also two outlet apertures axially aligned with a portion of the Stage 2 rotor. The inlet and outlet apertures extend through the radially outer wall of the pump section. The distal apertures are on the right side in the figure, and the proximal apertures are on the left side. In various embodiments, the pump section includes a set of distal inlet apertures relative to the Stage 1 component and a set of proximal outlet apertures relative to the Stage 2 component. In various embodiments, the pump section includes a set of distal inlet apertures relative to the distal pump and a set of proximal outlet apertures relative to the proximal pump. In various embodiments, there are no apertures (for inlet or outlet) between the Stage 1 and Stage 2 components. In various embodiments, there are no apertures (for inlet or outlet) between the distal pump impeller and the proximal pump impeller.

[0180]

[0262] Stage 1 in this embodiment includes a distal impeller (labeled rotor), an inlet guide vane distal to the rotor, and an outlet guide vane proximal to the distal rotor. A vane (and any vane as used herein) is generally considered a flow-changing element or derivative, where the term is used herein. Either the vane or the rotor may include a hub and extending blades as shown, or other known impeller and stator / vane designs. The vane (and any flow-changing element as used herein) is positioned close to the distal impeller, less than 10 mm away (along the length of the device), or less than 9 mm, or less than 8 mm, or less than 7 mm, or less than 6 mm, or less than 5 mm, or less than 4 mm, or less than 3 mm, or less than 2 mm, or less than 1 mm, etc. “Close to” where used herein may include any of these axial distances. "In close proximity" may also, as used herein, refer to a distance of less than twice the diameter of the central lumen.

[0181]

[0263] In this embodiment, Stage 2 includes a proximal impeller (rotor) and an inlet guide vane distal to the proximal impeller. All of the above disclosures relating to the vane in Stage 1 are incorporated into, and may be incorporated into, the Stage 2 vane.

[0182]

[0264] In this example, the Stage 1 (distal) rotor is configured as an axial flow impeller, and the proximal impeller (Stage 2) is configured as a mixed (diagonal) flow impeller; however, these are illustrative examples, and other impeller designs may be used for either impeller.

[0183]

[0265] The pump portion in this embodiment includes a flexible outer housing between the stages. The flexible outer housing may be, for example, a flexible polymer material formed with a slight degree of curvature, which may be straightened for delivery and coupled to the distal and proximal stage regions. In some embodiments, the flexible central region may be a rigid material with an ultrathin wall that imparts some flexibility. In other embodiments, for example, the flexible region may include a plurality of elongated support members (e.g., nitinol wires) on which the flexible membrane is mounted. The elongated support members may be formed therein with bends and spaced apart around the outer edge of the flexible region, so as a result the flexible membrane forms a lumen through which it passes. In some embodiments, the flexible region may include a laser-cut tube (e.g., a laser-cut polymer or metallic material, e.g., nitinol) from which one or more slots have been cut out in at least one region to impart flexibility (e.g., creating a vertebra along one side with ribs extending around at least a portion of the outer edge, the ribs being formed by cutting the material), and a membrane-like material may be attached to the slotted tubular member to cover the removed material. The flexible material may also include a stent-like device configured with a bend, and a membrane-like material covering the stent aperture.

[0184]

[0266] As used herein, “axially spaced” includes embodiments in which the bend is located on the outer profile (e.g., Figures 14A and 14B), and the bend may be included in any of the embodiments herein. Where the expression is used herein, “axially spaced” is intended to mean spaced along the device, even if the bend is located on the outer profile of the pump portion (e.g., Figures 14A and 14B). It may, for example, mean spaced along the longitudinal axis of the pump portion.

[0185]

[0267] In alternative embodiments to those shown in Figures 14A and 14B, it is not necessary to include all the components shown. For example, one of the wings may be absent depending on the required flow.

[0186]

[0268] Any other disclosures herein relating to any aspect or method of use of the pump device (e.g., external motor, arrangement when used) are incorporated by reference into the embodiments in Figures 14A and 14B.

[0187]

[0269] The explanation shown in Figure 14A illustrates an exemplary placement of the device by showing the surrounding / surrounding biostructure. The distal impeller may be located within the left ventricle, while the proximal impeller may be located within the ascending aorta, and the impellers may be spaced apart accordingly.

[0188]

[0270] A blood pump, such as any of the intravascular pumps described herein, may benefit from having one or more fluid passages through which a fluid can flow. For example, but not limited to, a blood pump may benefit from having one or more fluid passages through which a fluid can flow in order to perform any of these exemplary functions: cooling rotating components (e.g., drive cables) to prevent them from overheating; flushing away small particles that could disrupt rotating components (e.g., drive cables) to prevent damage to rotating components by small particles; lubricating rotating components (e.g., one or more bearings); and preventing blood from entering the pump (e.g., near the distal end of the pump or the distal end of the pump). Fluid delivery through one or more passages may provide any number of these functions.

[0189]

[0271] Figures 15A–15D illustrate exemplary embodiments of a fluid delivery system incorporated into an exemplary fluid pump (e.g., a blood pump) having fluid inlet and outlet ports. Figure 15A illustrates a portion of a device proximal to one or more impellers, which in this embodiment includes the proximal end of a catheter, a drive cable and motor assembly causing rotation of the impellers, fluid inlet and outlet ports, and a guidewire port enabling access to a guidewire passage or lumen.

[0190]

[0272] Figure 15B shows the region of the device distal to the region shown in Figure 15A, but includes some of the catheter components shown in Figure 15A. Figure 15C shows the region of the device distal to the region in Figure 15B, and Figure 15D shows the region of the device distal to what is visible in Figure 15C.

[0191]

[0273] Figures 15A to 15D illustrate different areas of an exemplary blood pumping device, but it should be understood that in alternative embodiments, the configuration of the system can vary. For example, in alternative embodiments, the part of the device having an impeller can vary, and may include only a single impeller, or the expandable housing around the impeller may have various configurations. It should be understood that the individual parts of the device themselves can be incorporated into various different types of blood pumps.

[0192]

[0274] One aspect of this exemplary embodiment includes a guidewire access port that also functions as a fluid port, in this embodiment, a fluid outlet port. The motor sealing cap 138 includes a guidewire channel 137 formed within it, which includes a guidewire port on its radial side providing access to the channel 137 from outside the device. The motor sealing cap may be an optional component, and the guidewire channel 137 may alternatively be formed in a different part of the device (for example, it may not function as a motor sealing cap). The device also includes a drive cable coupler 135 that includes a guidewire channel 136 formed within it, which is part of the guidewire passage. The drive cable coupler 135 is rotated by the motor, causing the drive cable 143 to rotate, which in turn causes one or more impellers in the pump section to rotate. These components are therefore considered to be in rotational communication. The channel 137, which includes the guidewire port, is formed within the device, and the motor rotates It is not adapted to rotate when doing so. The channel 136 formed within the drive cable coupler 135 rotates when the drive cable coupler rotates. When the drive cable coupler 135 is in the position shown in FIG. 15A, the channel 137 is in alignment with the channel 136, which enables the guide wire to be advanced through or removed from the channel 137 and to be advanced through the channel 136. When the guide wire is inserted, the guide wire can be further advanced distally through the entire device and exit from the distal end as will be described in more detail below. Also, as will be described in more detail below, the guide wire access port acts as a fluid outlet port that enables return fluid to flow from the return region 139 out of the outlet port.

[0193]

[0275] One advantage of having the guide wire access port (portion of channel 137) where it is present in this embodiment is that after the pump portion has already been advanced to a location within the patient, if necessary, the guide wire can be reinserted into the port, inserted all the way to the distal end and exit therefrom. Importantly, the guide wire can be reinserted without the need to remove most of the device from the patient as in some rapid exchange designs and without the need to remove the motor assembly. Thus, this exemplary embodiment enables easy reentry of the guide wire without the need to remove the motor assembly and without the need to remove the device from the subject.

[0194]

[0276] The ability to reinsert the guide wire during use can be advantageous in that it can enable, for example but not limited to, repositioning of the pump portion if desired or necessary. For example, if the pump portion has moved out of place relative to an anatomical landmark (e.g., the aortic valve), the guide wire may need to be inserted to safely reposition it relative to the anatomical landmark.

[0195]

[0277] Since the guide wire path extends through a rotating component (e.g., drive cable coupler 135), it is important that the guide wire not be present within the guide wire path when the rotating component is active. The devices herein may also include an automatic detection mechanism for detecting the presence of a guide wire within the guide wire passageway and / or a prevention mechanism for preventing the motor from starting if the guide wire is within the lumen. For example, without limitation, there may be a sensor that selectively detects the presence of a guide wire within the guide wire passageway and communicates that fact to a controller that prevents the motor from starting.

[0196]

[0278] In this embodiment, there is a single fluid inlet channel or lumen 131 through which fluid can be delivered into the device. FIG. 15B illustrates a region of the device and also illustrates the different paths that the fluid can take after being delivered into the device. After the fluid has advanced into the fluid inlet port channel 131 (including the inlet port), the fluid travels through the space 147 between the clean purge tube 141 and the drive cable tube 142. This is considered clean input fluid. This path terminates at the distal catheter cap 149. The fluid passes through one or more apertures 146 formed within the distal region of the drive cable tube 142 as shown in FIG. 15B and enters into the annular space between the drive cable tube 142 and the drive cable 143. A portion (optionally a majority) of this fluid returns proximally through this annular space to lubricate and cool the drive cable 143 and wash away potential particulates along its path. This return fluid continues to flow proximally and into the region 139 shown in FIG. 15A and also continues to flow out through the channel 137 and out of the fluid port (which is also the guide wire access port). Thus, the fluid outlet port also functions as the guide wire access port in this embodiment.

[0197]

[0279] Most of the fluid returns proximally to region 139, but some of the fluid continues distally beyond the distal end of the drive cable 143 after passing through aperture 146. Some of the fluid follows the proximal bearing path 160 through the aligned bearing 162 to prevent blood intrusion. The fluid flow toward the bearing 162 along path 160 can be controlled, for example, by controlling the input flow pressure and throttling of the return fluid in the proximal region of the device.

[0198]

[0280] A portion of the fluid, after passing through the aperture 146, will flow along the path 161 through the drive cable 143, and also through the device (e.g., through the hypotube 144) and distally out of the hole, to lubricate any rotating surfaces and prevent blood intrusion, as will be described in more detail below. Thus, the guidewire lumen 145 is positioned to also function as a distal bearing fluid passage.

[0199]

[0281] Some fluid flows distally along path 161, as shown in Figure 15C, and passes through a hole along path 163 to lubricate one or more of the bearings 162, thrust bearing 177, and alignment bearing 178. Some fluid continues distally through impeller 165 (which is the proximal impeller in this embodiment) in the direction of arrow 164 shown in Figure 15C. Some fluid passes through an aperture along path 167 to lubricate an optional alignment bearing 172 supporting a central member 171, which may be one of the foldable support members, including either the central or intermediate member as specified herein. Some fluid continues distally through a guidewire lumen in the direction of arrow 168 and through an optional distal impeller 173. Some fluid passes through a hole along path 169 to lubricate a bearing 174 which is distal to the distal impeller. Some of the fluid can also flow through valve 175 and out of the distal end of the device, helping to prevent blood from entering.

[0200]

[0282] In this exemplary embodiment, a single flow path through the tubular member (a path 161 extending distally through the guidewire lumen shown in Figure 15B) connects to (and is in fluid communication with) at least three distally located bearing lubrication fluid paths 163, 167, and 169 that lubricate three axially spaced bearing regions. In some alternative embodiments, depending on the number of bearings and structures disposed within the expandable housing that require lubrication, there may be a single bearing region, two bearing regions, or four or more bearing regions that are lubricated.

[0201]

[0283] An exemplary method using the devices shown in Figures 15A–D includes inserting a guidewire near the target site (e.g., into the left ventricle via femoral artery access), then supplying a distal guidewire port through the guidewire, and advancing the device through the guidewire toward the target site (e.g., the aortic valve). The method may also include removing the guidewire from the guidewire path and coupling the proximal portion shown in Figure 15A to fluid inlet and fluid outlet couplers located at the inlet and outlet fluid positions, respectively. The motor may be started to start one or more impellers. If the guidewire needs to be reinserted, the fluid output connector may be removed and the guidewire may be reinserted (e.g., for repositioning). The guidewire may then be removed, and the fluid outlet coupler may be restored to fluid communication with the guidewire path. These methods, or any of them, may be incorporated into the use of any of the preferred devices described herein, such as the devices shown in Figures 16A and 16B. In addition, any of the steps in any of the exemplary uses described herein, such as those listed below, may be incorporated into the use of the blood pump in this embodiment.

[0202]

[0284] Figures 16A and 16B show an example of a fluid pump (e.g., a blood pump) having a first flow path with a first fluid inlet port and a first fluid outlet port. An exemplary embodiment of a fluid delivery system is illustrated. However, in this embodiment, there is also a second fluid channel that is not in fluid communication with the first channel. The device 180 in Figures 16A and 16B is similar to that shown in the embodiments in Figures 15A–D, except that in this embodiment, the fluid channel 161 from Figure 15B does not result in fluid flowing through the drive cable. In this embodiment, the fluid channel containing the guidewire lumen (see fluid channel 196 in Figure 16B) is in fluid communication with a separate second fluid inlet port 189, similarly positioned to function as a guidewire access port, as shown in Figure 16A. The drive cable 183 has a drive cable liner 187 on its inner surface to seal the distal bearing channel 196 (through the guidewire lumen). In this embodiment, the guidewire access port does not function as a fluid outlet as in Figures 15A–D, but functions as a fluid inlet port and therefore still functions as a fluid port or fluid access.

[0203]

[0285] The blood pump also includes a first fluid pathway, which includes an inlet port 181 and an outlet port 182 as shown in Figure 16A. This pathway is very similar to the pathways in Figures 15A–D, except that it does not include the pathway through the drive cable and hypotube (i.e., does not include the guidewire lumen). The fluid advances through the port inlet port 181 and flows distally along the pathway 197 in Figure 16B, which is between the clean purge tube 185 and the drive cable tube 184. This pathway, as in the embodiments in Figures 15A–D, is terminated at the distal catheter cap. The fluid flows through a hole in the drive cable tube 184 and returns proximal through the annular space between the drive cable tube 184 and the drive cable 183. In this part of the pathway, the fluid lubricates and cools the drive cable and washes away potential particles along its pathway, carrying them proximal to the fluid exit port 182 shown in Figure 16A. The seal 200 prevents the fluid from passing proximal to seal the device.

[0204]

[0286] The fluid flowing through the first fluid path then lubricates and cools the drive cable, as well as washes away potential particulate matter, and returns to the exit port 182. The fluid flowing through the second fluid path travels further distally through the system and lubricates one or more distal bearings, as in the embodiments in Figures 15A-D. For example, path 199 shown in Figure 16B is the same as path 163 in Figure 15C, which lubricates the bearings within its bearing region. Although not shown, a fluid path distal to the figure shown in Figure 16B may be exactly the same as that in Figure 15D, and thus lubricates further bearings and optionally exits through a valve at the distal end of the device. Thus, this second path can also prevent the intrusion of blood, which is described in more detail in Figures 15A-D.

[0205]

[0287] In any of the devices described herein, the pump portion may include a distal end valve distal to the impeller to seal the distal guidewire port after the guidewire has been removed, but allowing the guidewire to be reinserted through it.

[0206]

[0288] Figures 17A–17F illustrate an exemplary pump portion 201 of an exemplary blood pump. Pump portion 201 may be used interchangeably with any other embodiment of any of the blood pumps herein. Pump portion 201 is also shown in embodiments in Figures 15A–16B, and any features or methods of use described therein are incorporated into this embodiment by reference. In addition, not all aspects of this embodiment must be included, and instead, any preferred features in pump portion 201 may be replaced with different features or methods of use from different preferred embodiments or parts of this disclosure. For example, any impeller in pump portion 201 may be replaced with any preferred impeller from any other part of this disclosure. Figure 17A is a side view, and Figure 17B is a cross-sectional side view.

[0207]

[0289] The pump section 201 is the drive to which the distal impeller 203 and the proximal impeller 202 are fixed. The pump includes a drive cable tubular member 204. The rotation of the drive cable tubular member 204, via the rotation of a drive cable (not shown), causes the impeller to rotate. More than two or fewer impellers may be included in the pump section.

[0208]

[0290] The pump section 201 also includes a foldable housing 205 which includes a foldable support structure 206 (which may also be referred to herein as a scaffold) having a proximal end 210 and a distal end 211, and a conduit 212 (see Figure 17E) which forms a fluid lumen between the distal and proximal ends of the fluid lumen.

[0209]

[0291] The pump section 201 includes an optional intermediate (which may be referred to herein as central, or located between the impellers) member 209 between two impellers, which may be any central member(s) as herein.

[0210]

[0292] In any of the embodiments described herein, the distal impeller may have a shorter length than the proximal impeller, such as the device shown in Figure 17A.

[0293] Figure 17C is a side view of the proximal portion of the support structure 206 in the extended configuration (other portions are not shown for clarity). Figure 17D is a proximal end view of the support structure. The region shown generally surrounds the impeller 202 in Figures 17A and B. The support structure 206 may be formed using various techniques, such as laser cutting of tubular initiation material. The support structure 206 includes a plurality (four in this embodiment) of arms that transition from a larger diameter to a smaller diameter within region 218 in the proximal region. Each of the arms has a bend within region 219, and the areas between the bends are vertical, as shown. The vertical areas may help stabilize the transition area between the larger diameter region and the smaller diameter region, reducing, and preferably eliminating, the impact on the fluid at the outflow.

[0211]

[0294] In the larger diameter region of the support structure, the support structure 206 includes staggered tops 221 (only two are labeled) with alternating tops. In this context, staggered refers to the axial location of the top ends. Each of the four arms forms a top that extends more proximal to the adjacent top. The staggered tops can facilitate sheath covering and offset the filling volume during the folding of the pump section. Tops may also be considered valleys depending on their orientation, as convex and concave are relative terms as used herein.

[0212]

[0295] The support structure 206 also includes a plurality of hub features 220, each configured to stably adhere to a component 222 (four in this embodiment) located in the distal region of the scaffold landing zone 179 (see Figure 17E). The hub features 220 can be subjected to axial motion along the bearing hub.

[0213]

[0296] The support structure 206 also includes axially spaced helical regions 213 (only a portion of which are labeled in Figures 17A and 17B) which include a plurality of arms (or portions of arms) having a helical configuration. In Figure 17C, the helical region 213 includes helical arms 214 (only four are labeled). In this embodiment, the helical arms extend between adjacent non-helical regions of the support structure. The regions between the helical regions may have any number of configurations, and exemplary configurations are shown. In this exemplary embodiment, the proximal impeller 202 axially overlaps with at least a portion of two adjacent helical regions 213, and the distal impeller axially overlaps with at least a portion of two adjacent helical regions 213. Any impeller may axially overlap with one or more helical regions 213. The pitch of the helical arms may vary.

[0214]

[0297] Figure 17F further illustrates the scaffold pattern, as shown in Figures 17A-E. Illustrated in a plan view that flattens the scaffold design of the [persons]. Only a part of the scaffold portion is labeled for clarity.

[0215]

[0298] The axial length of one or more helical regions 213 may be shorter than the axial length of the impeller that axially overlaps it. For example, in FIG. 17E, each helical region 213 is shorter than the entire length of the impeller. The axial length of the helical region 213 is also shorter than the length of the distal impeller 203, even if a single helical region does not completely axially overlap the impeller.

[0216]

[0299] The configuration or shape of the plurality of helical arms can generally follow the helical shape of the outermost region of the impeller (e.g., the outermost region of the helical blade), and is configured to promote sheath covering and radial compression with respect to the blade to promote sheath covering. Stated another way, the scaffold and any given blade can each, when sheathed and when the sheath is removed, twist each component in a complementary manner to perform one or more of reducing sheath covering force, increasing packing efficiency, and reducing component strain. It may have a strut pattern (and in particular, a helical arm configuration) and a camber line (one area of which is labeled "CL" in FIG. 23). The camber line of the blade can generally follow the helical configuration of at least one of the helical arms within the helical region, which can be seen in FIG. 17E, and one area of the camber line CL of one blade is shown in FIG. 23. In a side view of the pump portion (e.g., FIG. 17E or FIG. 23), and in some embodiments, the helical element and the blade may overlap at one or more locations, and the tangent "T" (see FIG. 23) of the helical element and the blade camber line at the overlap location may form an angle of 45 degrees or less, 35 degrees or less, 20 degrees or less, 15 degrees or less, or 10 degrees or less.

[0217]

[0300] There can be any number of helical regions 213 spaced axially along the support structure. Adjacent helical regions do not need to be equally spaced along the entire length of the scaffold.

[0218]

[0301] In some exemplary methods of sheathing, the method may optionally include a folding process that involves the rotational movement of the components to which the support structure is coupled, and this rotational movement may be controlled by an actuator (e.g., a handle) located outside the patient.

[0219]

[0302] In some embodiments, the four proximal arms (collectively labeled 218) can be inverted such that the bends in the larger diameter sections are located further proximal than the bends in the smaller diameter sections.

[0220]

[0303] The scaffold design in the embodiments shown in Figures 17A to 17F offers several advantages compared to other scaffold designs. For example, the staggered proximal valley 221 (which may also be present at the distal end of the scaffold) reduces the scaffold's filling volume at the location of the staggered apex. In addition, during bending, the scaffold resists twisting and maintains a smooth curve within the bending region. This can be advantageous when placed in target sites where the scaffold needs to take on a bent configuration, such as when the scaffold is placed in the ascending aorta and extends from there to the left ventricle. Furthermore, the design is a closed-cell design (no free ends exist within the design, and all ends are connected to other regions), yet it retains sufficient flexibility along the length of the scaffold. This design also includes struts that terminate individually at hubs (the proximal end of the scaffold) rather than being coupled to other struts. The unconnected struts at the hubs improve the manufacturing processes for heat treatment, membrane coating, and impeller loading. The advantages of helical connectors are described elsewhere in this specification.

[0221]

[0304] The scaffold designs in Figures 17A–17F offer at least the exemplary advantages described herein, but other scaffold designs are conceived, and some potential drawbacks of these alternative designs are discussed below, although they (or embodiments thereof) may still be used in the pump parts described herein. For example, depending on the particular application, one or more features may be less important than others.

[0222]

[0305] Figures 18A–B illustrate an expandable member 250 which is one of at least two expandable members (which may also be referred to herein as a foldable housing), such as the expandable members in Figures 3A–3D, with each expandable member surrounding an impeller. The scaffold designs in Figures 18A and B have more proximal struts 251 (only one is labeled) than the designs in Figures 17A–17E (there are nine in this exemplary embodiment, compared to four). Having a separate expandable member 250 for each impeller provides the ability to have very different geometry for any of the individual impellers. In addition, this design reduces the amount of scaffold material (e.g., nitinol) over the length of the scaffold (compared to the full-length scaffold herein), which may provide increased tracking when sheathed. A potential challenge with this design is creating a continuous membrane between expandable members when there is no axially extending scaffold material (see Figure 3A). In addition, a relatively large number of proximal supports 251 in the outflow path may obstruct the outflow more than designs with fewer supports, such as the four supports in the embodiments shown in Figures 17A–F. Any other embodiments of the expandable members described herein, such as those described in Figures 3A–3D, may be incorporated by reference into this exemplary design. Figure 18B shows a plan view of the scaffold in a non-expandable configuration to further illustrate the design.

[0223]

[0306] Figures 19A and 19B illustrate scaffold designs having the same overall pattern as Figures 18A and B, except that the scaffold pattern is not divided into two separate regions, but rather the scaffold is a single elongated member as shown. Figure 19A is a plan view of an unextended scaffold, while Figure 19B is an extended configuration. The scaffold designs in Figures 19A and B have a proximal end 256 and distal end 257 (i.e., hub-connecting region) that are a continuous, integrated structure, rather than separate proximal hub ends as in the designs in Figures 17A–F. In this design and the designs in Figures 17A–F, it may be easier to apply (e.g., cover) a membrane to a single scaffold (compared to, for example, separate axially spaced expandable members such as in Figures 18A–B). An exemplary drawback may be a relatively large number of proximal struts (nine in this embodiment) that can obstruct the outflow when blood leaves the fluid lumen, as in the designs in Figures 18A–B. This particular pattern may also be too rigid for some applications or access routes where greater bending and folding are desired. This design is relatively rigid along the axial length and does not bend or fold easily. In this design, each apex 258 and valley 260 within adjacent regions 261 are joined by connectors 259 that are radially aligned and parallel to the longitudinal axis of the fluid lumen.

[0224]

[0307] Figure 20 illustrates an exemplary scaffold 280 extending along the entire axial length from the proximal hub end 281 to the distal hub end 282, with the hub region having the same design as in Figures 19A and B. The cells 383 in this design (only one is labeled and has a diamond pattern in the extended configuration) are smaller in size compared to the designs in Figures 18 and 19. The number of struts 284 in this design is also fewer than in Figures 18 and 19 (e.g., four at each end in this design compared to nine), which in this embodiment means that, rather than all struts, every other strut 285 at the scaffold ends (only two are labeled) are coupled to the proximal strut 284 (e.g., integral to it). This means that the length of the struts in this embodiment is greater than that in Figures 18 and 19, which allows the proximal end 286 (terminal location) of the membrane to be axially spaced a short distance from the end of the terminal apex 285, as shown in the figures. This additional strut length therefore allows the membrane (or conduit) to be introduced into the sheath before the terminal apex, thereby reducing the possibility of the proximal apex getting caught in the sheath during the sheath coating process. This design makes it easier to apply the membrane to the scaffold along its length, as with other full-length scaffolds. The apex and valleys in adjacent areas are each coupled with short linear connectors. This design is relatively rigid along its length, as in Figures 19A and B, and does not have particularly strong bending or folding characteristics, which may be required in some applications. Additional potential drawbacks to this design include insufficient compressive resistance during sheath removal, difficult sheath application due to the scaffold geometry / pattern, and the possibility that the expandable hub areas at the proximal and distal ends may be sensitive to fatigue and plastic deformation.

[0225]

[0308] Figures 21A–C show a scaffold design similar to Figure 20A, but with the differences described below. In the central region “CR”, where the proximal and distal impellers are located, the design aims for improved flexibility compared to Figures 20A and B. The benefits of such increased flexibility in this region are described herein. In the central region, alternating cell connections are eliminated as shown in order to improve flexibility in this region. In each axial region, alternating (radial) apex connections and alternating valley connections are joined. These eliminated alternating cell connections create a helical region 291 around the scaffold without connecting elements (see Figure 21C) and a helical region 292 around the scaffold with connecting elements (see enlarged view in Figure 21C). The helical regions alternate between unconnected regions 291 and connected regions 292.

[0226]

[0309] The flexibility of the central region "CR" is increased in this design compared to the design in Figure 20-B due to the non-connected region 291, and the scaffold has a relatively stiffer impeller region "IR" adjacent to the central region (not shown) where the impeller is located. The relatively increased stiffness in the impeller region IR helps maintain the tip clearance and impeller concentricity. This scaffold pattern therefore results in a flexibility distribution along its length of a relatively small flexible proximal region ("IR"), a relatively more flexible central region "CR", and a relatively small flexible distal region "IR". The relatively small flexible region (i.e., the two IR regions) is where the proximal and distal impellers may be located (not shown, but other embodiments are fully incorporated herein in this respect), with a relatively more flexible region in between. The benefits of relative flexibility in each of these regions are described elsewhere herein.

[0227]

[0310] However, in this design, the lack of alternating connectors in the central CR region can make the shaping and membrane application process more difficult. Unconnected (i.e., unbonded) areas of the scaffold within the central region also rub against and cut into the membrane, increasing the possibility of membrane breakage at those locations. In addition, the flexibility of the scaffold along its length may still be inadequate once the membrane is applied, depending on the application, target placement site in the patient, and access route. Further potential drawbacks based on similar characteristics are noted above with reference to Figure 20 (e.g., sheath coating difficulties due to the scaffold's geometry).

[0228]

[0311] Figures 22A and 22B illustrate a scaffold design 300 that is similar to Figures 21A and B, but has the differences described below. Any feature from the scaffolds in this specification may be incorporated into this scaffold design. This design includes the apex 301 and valley 302 of axially adjacent areas 303 (only one set is labeled for clarity). These apex 301 and valley 302 (which are omitted) are connected by a spring connector 304 (only one is labeled for clarity), which connects the radially aligned apex 301 and valley 302 of adjacent areas. The spring-like connector 304 in this design provides better flexibility along the length of the scaffold compared to Figures 21A-B. This is partly because the spring connector 304 provides individual cell joints.

[0229]

[0312] The proximal and distal hub ends 305 and 306 each have four independent, free-end (i.e., not coupled to one another) members 307 (only one is labeled at the proximal end for clarity) coupled to their respective hubs (not shown). Thus, the struts 308 (only one is labeled) have greater flexibility relative to one another. More or fewer members 307 may be present at each end (e.g., two members at each end), and the ends may have different numbers of members (e.g., four at the proximal end and eight at the distal end). The individual (i.e., uncoupled) members 307 at the hub ends improved the manufacturing processes for heat treatment, membrane coating, and impeller loading. Some potential drawbacks of this design are that, depending on the application, strut buckling may occur during sheath coating removal due to insufficient compressive strength. In addition, the sheath coating force may be undesirably high, which may be at least partially attributable to the membrane. In addition, flexibility may be considered insufficient once the film is applied to a scaffold.

[0230]

[0313] In certain exemplary applications where the pump portion is navigated for placement across the aortic valve (aspects of which are described herein), the scaffold designs in Figures 17A–F may yield the benefits specified herein, while the scaffolds in Figures 18–22 may be suboptimal in one or more respects for this particular application (e.g., not sufficiently flexible, suboptimal process of membrane application to the scaffold). However, in some applications, one or more features of the scaffolds in Figures 18–22 may be desirable. For example, the blood pump may be placed in a location where flexibility is not critical, or where relatively high rigidity over the length of the scaffold is desired or acceptable. Thus, any of the features in the scaffold designs in Figures 18–22 may be combined in any suitable combination to yield a scaffold structure that provides the desired functionality. For example, the designs in Figures 17A–F may instead have a hub region that is not a separate component (as in Figures 22A–B) but is instead continuous, as in the designs in Figures 19–21.

[0231]

[0314] Figure 23 illustrates the proximal region of an exemplary pump section, and its features may be incorporated into any of the pump sections described herein. Not all features in the embodiments in Figure 23 are necessarily included in the pump sections shown. The proximal end 310 of the fluid lumen has a smooth curve and a widened radially outward configuration as shown (the end of the lumen is most radially outward), which may facilitate radial flow of the impellers in the outlet (optionally the proximal impeller and optionally one of several impellers). The distal end of the fluid lumen may also have the same or similar type of widened configuration (not shown), with or without the widened proximal end. The widened distal end configuration can limit the amount of contact between the rigid portion of the pump portion and the left ventricular wall (where it is located), reducing the likelihood of tissue coming into contact with the rotating impeller, which can prevent or minimize obstruction of the pump portion inlet, and can also prevent movement of the pump portion by acting as an enlarged interface area that can conform with natural tissue, and can help prevent further movement (e.g., engagement with natural valve tissue such as valve leaflets, preventing the pump portion from passing through the valve opening). Any other preferred embodiments of the present disclosure are incorporated into this embodiment by reference.

[0232]

[0315] Some aspects of the disclosure herein describe pump components that include one or more central members (which may also be referred to herein as “intermediate members”) that are optionally stationary and optionally located between two first and second impellers (see, for example, Figures 10–13C). Figure 24 is a perspective view illustrating a portion of an exemplary conduit (optionally foldable) having a central member incorporated herein. In this context, incorporated herein includes a central member formed integrally with the conduit, as well as a central member that is attached to a foldable conduit and as a result considered to be a portion of the foldable blood conduit. For example, a central member may have an outer surface 313 that is attached (e.g., bonded) (e.g., attached to a flexible membrane portion of the conduit) to the inner surface of any of the foldable conduits herein and as a result considered to be a portion of the foldable conduit. The central member shown in Figure 24 may have one or more flow-changing elements (e.g., blades) 314 that extend radially inward from the peripheral portion 315 toward the central region 316 (but not from the central region), but are not coupled to one another in the central hub. The flow-changing elements 314 (e.g., blades) in Figure 24 (or any other embodiment or claim herein) that are parts of the impeller and an object not in rotational motion may be referred herein to as stator parts or diffuser blades. Each flow-changing element may have a variety of cross-sectional geometries. The flow-changing elements may be configured to increase the fluid pressure between the impellers (by reducing velocity) and / or, optionally, to reduce the vortex velocity between the distal and proximal impellers.

[0233]

[0316] In some embodiments, the central member may have multiple blade-like extensions that are cords of a peripheral curved portion (which may have a circular cross-section), and as a result, the cords do not have free ends, as the flow-changing element 314 in Figure 24 has. One or more cords may extend from one different region of the peripheral curved portion to another. If multiple cords are present, and in the end-face cross-sectional view, the cords may have different lengths between the two endpoints where they connect (integrally or are attached) to the outer peripheral region.

[0234]

[0317] Figure 25 is a perspective view of the proximal portion of a pump section, including an expandable scaffold and at least one impeller (not labeled, but easily identifiable based on other figures herein). The pump section also includes an intermediate member 316, which is similar in some respects to other intermediate or central members herein. The intermediate member 316 includes flow-changing elements 317 (e.g., blades), each having an outermost engaging feature 318 (e.g., flange), which is configured to stably align (in other words, contact or couple) with the corresponding mating feature (e.g., apex or valley) in the scaffold. The blade / scaffold engagement can cause the blade to fold during radial compression and sheath covering of the scaffold. In addition, the blades and scaffold can be aligned or coupled using a variety of techniques. For example, the flow-changing elements and scaffold can be coupled by spot welding. In some embodiments, the ends of the flow-changing elements 317 may have features that connect to features on the central hub 319 by positioning features on the central span bearing, rather than by drive cables (e.g., dovetail joints). This may simplify manufacturing. The outer housing in this embodiment may be any of the outer housings described herein.

[0235]

[0318] One or more impellers, which are part of a blood pump system (such as any of the specifications herein), may be rotated at relatively high speeds, such as 10,000 to 50,000 RPM. The impellers may be rotated by rotational communication with a drive member (e.g., a drive cable) or other component, which is rotationally connected to the impeller and may be rotated by an energy source (e.g., a motor). Rotating the drive member at the same RPM as the impeller may cause wear, vibration, and possibly require lubrication of the drive member (exemplary forms of lubrication systems are described elsewhere in this specification). It may be advantageous to rotate the drive member at a lower speed than the impeller while still allowing the impeller to rotate at a desired higher RPM. One aspect of the present disclosure is a blood pump comprising one or more drive members that can be rotated at a lower RPM than one or more impellers. This may reduce drive member wear, reduce the required lubrication, and reduce vibration. This may be particularly advantageous in applications where the blood pump is used for relatively long periods (e.g., 24 hours or more). For example, this may be particularly advantageous in cardiogenic shock symptoms.

[0236]

[0319] A rotary drive member (e.g., a drive cable, a magnetic stator) can rotate slower than one or more impellers. In some exemplary embodiments, the rotary drive member may rotate between 0 and 1 times (1×) the impeller RPM. For example, if any impeller rotates at 20,000 RPM, the drive member may rotate at 0 to 20,000 RPM. In some embodiments, the drive member may rotate at 0.25 to 1×, or 0.3 to 1×, or 0.4 to 1×, or 0.5 to 1×, or 0.6 to 1×, or 0.7 to 1×, or 0.8 to 1×, or 0.9 to 1× of the impeller RPM.

[0237]

[0320] Figure 26A illustrates only a portion of an exemplary blood pump to illustrate an exemplary embodiment of how the impeller rotates faster than the drive member. The exemplary acceleration mechanism in Figure 26A utilizes gearing to achieve acceleration, with an output gear having a smaller diameter than the input gear, causing the output shaft to rotate at a higher speed on the output gear axis. Thus, the output shaft (and the impeller to which it is coupled) rotates faster than the input shaft (e.g., the drive member). Figure 26B illustrates how multiplicative gearing is used to obtain a larger speed difference (compared to Figure 26A) between the input shaft (e.g., the drive member) and the output shaft 2 (to which the impeller is coupled). The input gear 2 has a larger diameter than the output gear 2.

[0238]

[0321] In addition, gearing systems such as planetary gearboxes and magnetic gearboxes can also be used to increase the speed of one or more impellers relative to the rotation of the input drive member.

[0239]

[0322] Figure 27 illustrates an exemplary design of a pump section 140, comprising at least one stretching member 143 (e.g., a pull wire) which, when stretched, induces bending of at least one portion of the pump section. The stretching member may extend as distally as possible (or even further distally or even further proximal) between the distal and proximal impellers, causing the pump section to form a bend between the two impellers after it has been deployed from the delivery system. For example, a handle may include an actuator (e.g., a lever, a button) which, when actuated, stretches one or more stretching members to cause deflection in a region. All known stretching member (e.g., a pull wire) designs and uses may be incorporated into this embodiment to implement one or more deflectable regions. For example, a catheter may include one or more pull wire lumens extending along any portion thereof, the pull wires being attached to one or more portions of the catheter at their distal ends, depending on the location of the desired deflection region.

[0240]

[0323] The following disclosures provide exemplary method steps that may be performed when using any of the blood pumps or parts thereof described herein. It should be understood that not all steps must be performed, and rather the steps are intended to be illustrative procedures. It is also intended that, where preferred, the order of one or more steps may sometimes differ.

[0241]

[0324] Before use, the blood pump lumen (including any annular spaces) and pump assembly should be sterilized with a sterile solution (e.g., heparinized) to remove any air bubbles from any fluid lines. The catheter can be prepared for use by priming it with physiological saline. The catheter, containing any number of purge lines, can then be connected to a console. Alternatively, the catheter can be connected to a console and / or a separate pump used to prime the catheter and remove air bubbles.

[0242]

[0325] After priming the catheter, access to the patient's vascular system may be obtained using a appropriately sized introducer sheath (e.g., via femoral access, but not limited to this). Using standard valve transverse techniques, the diagnostic pigtail catheter may then be advanced through a guidewire, e.g., 0.0889 cm (0.035 inch) until the pigtail catheter is safely positioned within the target site (e.g., the left ventricle). The guidewire may then be removed, and a second wire 320 (e.g., a 0.04572 cm (0.018 inch) wire) may be inserted through the pigtail catheter. The pigtail catheter may then be removed (see Figure 28A), and the blood pump 321 (including the catheter, catheter sheath, and pump portion within the sheath, see Figure 28B) may be advanced toward and into a target site (e.g., the left ventricle, LV), for example, by spreading to the aortic valve "AV" through a second wire, using one or more radiopaque markers to position the blood pump.

[0243]

[0326] Once proper positioning is confirmed, the catheter sheath 322 (see Figure 28C) can be retracted, first exposing the distal region of the pump section. In Figure 28C, the distal region of the expandable housing, as well as the distal impeller 324, is released from the sheath 322 and expands. The proximal end of the housing 323 and the proximal impeller are not yet released from the sheath 322. Continued retraction of the sheath 322 beyond the proximal end of the housing 323 allows the housing 323 and the proximal impeller 325 to expand (see Figure 28D). The inflow region (indicated by the arrow, although the impeller has not yet rotated) and the distal impeller are located in the left ventricle. The outflow region (indicated by the arrow, although the impeller has not yet rotated) and the proximal impeller are located in the ascending aorta AA. As described in detail herein, the region of the outer housing between the two impellers, which may be more flexible than the housing region surrounding the impellers, extends to 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]

[0327] Next, a second wire (e.g., a 0.04572 cm (0.018 inch) guidewire) may be moved before the pump assembly operates (see Figure 28E). Where desired or required, the pump portion may be deflected (actively or passively) at one or more locations as described herein, as illustrated in Figure 28F. For example, the region between the two impellers may be deflected by extending a stretch member that extends to the location between the two impellers. The deflection may be desired or required to conform to a particular biostructure. Where necessary, the pump portion may be repositioned to achieve an intended arrangement, for example, having the first impeller on one side of the heart valve and the second impeller on the second side of the heart valve. An exemplary pump portion with an exemplary stretch member is shown in Figure 27. In Figure 28F, it should be understood that the pump portion does not obstruct or interact with the mitral valve in any way, even though it may appear from the figure to do so.

[0245]

[0328] Next, any number of purge lines may be attached to the proximal portion of the blood pump located outside the patient. For example, fluid inlet and fluid outlet lines may be attached to one or more fluid ports in the proximal portion of the blood pump. Then, the purging process may be initiated to move fluid into the blood pump through at least one fluid passage. One or more verification steps may be taken to ensure that the purging is working as intended before turning on the pump. This may be performed for verification. The pump assembly may then be operated, causing one or more impellers to rotate. The flow rate, pressure, and motor operation may be monitored at all times.

[0246]

[0329] Figures 29–35B illustrate additional exemplary intermediate members, which may function at least partially as stators (and may also provide radial support), and which may be disposed between the distal and proximal impellers and adapted to affect blood flow between the impellers, and other examples thereof are provided herein. Any embodiment of Figures 29–35B may be incorporated with any other embodiment of the blood pump herein. For example, impellers may not be shown in Figures 29–35B for clarity, but it should be understood that one or more impellers may be incorporated into these embodiments.

[0247]

[0330] Figures 29A and 29B illustrate an exemplary blood conduit 402 having flow deflectors 402 extending radially inward from the inner surface of the conduit. The flow deflectors (e.g., blades) do not extend to the central hub, but rather have radially inward free ends, which can be seen more clearly in the end view of Figure 29B. The flow deflectors 402 (e.g., stator elements) may be individually molded and then fixed to the inner surface of the conduit (e.g., membrane). The conduit 402 may also include any other support members as specified herein, such as any of the Nitinol scaffolds as specified herein, but not limited to these. The flow deflectors may have a slight curvature relative to them, which can be seen in Figure 29B. The flow deflectors 402 may be considered as part of a single stator.

[0248]

[0331] Figures 30A, 30B, 31A, and 31B illustrate an exemplary support member having multiple apertures, each aperture configured to receive and align with a flow modifier 408 through it, the flow modifier 408 having an enlarged region 409 that aligns with a portion of the support member to help stabilize the position of the flow modifier relative to the support member. The location of the elongated aperture 407 establishes the position and orientation of the flow modifier (e.g., stator element). After the flow modifier is inserted into the aperture, conduit material (e.g., membrane) may be sprayed onto the subassembly to further secure the modifier 408 in place. Alternatively, the material may be sprayed first, and then the aperture 407 into which the modifier can be inserted is cut. An additional layer of material may be sprayed to create a seal. The flow modifier 408 may be considered as a part of a single stator.

[0249]

[0332] Figures 32A to 32C illustrate exemplary support members 420 (e.g., scaffold, e.g., nitinol), where one or more flow modifiers 421 are integrated (are integrated) into an expandable scaffold structure that can be oriented radially inward during the shaping process, thus creating a flow modifier (e.g., stator). A material (e.g., polymer) may be applied to member 420 to create a blood conduit. The scaffold and flow modifiers may also be manufactured separately and designed to be joined after a membrane material (e.g., polymer) is applied to the scaffold. The scaffold may have any pattern described herein. A flow modifier 421 may be considered part of a single stator.

[0250]

[0333] Figures 33A and 33B illustrate an exemplary foldable pump section 440 including a conduit 441, a distal impeller 442, and a proximal impeller 443. The pump also includes a plurality of flow deflectors 445 fixed to a strut 444 within the pump. The strut may be a section of the distal impeller basket, an example of which is described herein. In this embodiment, the flow deflectors are fixed to the proximal strut of the distal impeller basket, but may be fixed to the distal or proximal strut of the proximal impeller basket. The flow deflectors in this embodiment may be a flexible membrane or other relatively flexible and thin material. The flow deflectors are positioned to manage the flow on the strut and to direct the flow longitudinally through the blood conduit. To support this, it is fixed to a longitudinal vertebral element 449 extending from the scaffold (this element is covered by a flow-diverting material 445, hence the line shown in transparency). The flow-diverting material (e.g., stator) may be a flexible polymer with or without fabric reinforcement to support collapse and sheath covering. The flow-diverting material 445 may be considered as part of a single stator.

[0251]

[0334] The subsequent disclosures, including Figures 34, 35A, and 35B, may be referred to as embracing foldable diffusers for increasing outflow pressure. Figure 34 illustrates the concept with embracing vanes for the diffuser / stator. Figures 35A and 35B illustrate (A) a side view and (B) a top view of the profile of the embracing vane. Diffusers are generally designed as stationary components to convert the rotational velocity / energy of the flow into a desired additional pressure by eliminating flow vortices (i.e., removing the rotational velocity components of the fluid). The shape of the diffuser (stator) plays a crucial role in the efficiency of this process. The pump portion here is foldable as a whole for delivery (e.g., to an aortic valve) and later expanded for use.

[0252]

[0335] Figures 34–35B illustrate exemplary concepts in which the diffuser blades have a special geometry / configuration that embraces / overlaps with each other to allow the pump to crimp to a desired delivery profile size. Concepts related to flow modifiers found elsewhere in this specification can be incorporated into these embodiments as well (e.g., scaffolds that are compatible with flow modifiers).

[0253]

[0336] With respect to Figure 34, the diffuser is designed to be a conforming shroud / blood conduit portion and may be adapted to further increase the pressure. In some embodiments, an elastic material such as nitinol may be used for the inner portion of the diffuser, which may be coated with a material (e.g., a polymer, which may be the same as the blood conduit material) to create the outer surface of the diffuser.

[0254]

[0337] Any of the stators described herein, including any of the flow-changing elements (also known as flow-changing bodies), may be incorporated in conjunction with any preferred embodiment of any shroud, housing, blood flow conduit, impeller basket, etc., as described herein, including any method for manufacturing such an embodiment.

[0255]

[0338] In some embodiments, the diffuser may be made of the same or similar material as the blood conduit membrane. Injection molding may be used to fabricate the diffuser.

[0339] An exemplary clinical benefit might be maintaining the RPM of the drive cable / pump within reasonable limits to avoid hemolysis while still increasing the pressure to the desired range using a pump with a diffuser. The present invention includes the following embodiments. 1. The pump section, A foldable blood conduit that defines the blood flow lumen between the inlet and outlet, A distal foldable impeller is axially separated from a proximal foldable impeller, wherein at least a portion of each of the distal and proximal foldable impellers is disposed between an inlet and an outlet, A pump section comprising one or more stators in the blood flow lumen, which are axially positioned between a distal impeller and a proximal impeller. An intravascular blood pump equipped with this system. 2. The blood pump according to paragraph 1, wherein one or more stators are each fixed to the surface of a foldable blood conduit and extend radially inward therefrom. 3. Each of one or more stators comprises a plurality of blood flow modifiers, each of which is a distant The blood pump according to claim 1, having at least one axially extending surface configured to increase the pressure between the positional impeller and the proximal impeller. 4. The blood pump as described in item 1 above, wherein the stator does not include a central hub from which multiple flow-changing elements extend. 5. The blood pump according to item 1 above, wherein the stator includes a central hub from which multiple flow-changing elements extend. 6. The blood pump according to paragraph 1, wherein one or more stators each include a plurality of blood flow modifiers integrally formed with at least a portion of a foldable blood conduit. 7. The blood pump according to 6 above, wherein one or more flow modifiers are integrated with a scaffold of a foldable blood conduit. 8. The blood pump according to 7, wherein one or more flow modifiers are biased into an unfolded configuration in which they extend radially inward relative to the outer area of ​​the scaffold. 9. The blood pump according to claim 1 above, wherein the stator is fixed to an outer annular member that does not extend axially from the inlet to the outlet, and further comprises a plurality of blood flow modifiers extending radially inward from thereto. 10. The blood pump according to 9 above, wherein the outer annular member provides radial support to the foldable blood conduit. 11. The blood pump according to item 1 above, wherein the stator comprises a plurality of blood flow modifiers (e.g., blades) formed of a polymer material. 12. The blood pump according to claim 1, wherein one or more stators each comprises a plurality of blood flow modifiers having radially outward ends having a configuration that is shaped to stably fit with a portion of a foldable blood conduit. 13. The blood pump according to 12, further comprising a scaffold, the scaffold having one or more flow-modifying apertures through which it passes, and each of its radially outer ends being shaped to stably align with one of the flow-modifying apertures. 14. The blood pump according to 13, further comprising a membrane layer extending over a scaffold and further securing one or more blood flow modifiers to an aperture. 15. The blood pump as described in 14 above, wherein the aperture extends axially and is parallel to the long axis of the scaffold. 16. The blood pump according to 12, further comprising a self-expanding scaffold, wherein one or more blood flow modifiers have radially outward ends having a configuration that is shaped to stably align with the self-expanding scaffold. 17. The blood pump according to 13 above, wherein one or more blood flow modifiers are made of a material different from the scaffold material, and the material is more flexible than the scaffold material. 18. The blood pump described in 17 above, wherein one or more blood flow modifiers are made of polymer material. 19. The blood pump according to item 1 above, wherein one or more stators each comprise a plurality of blood flow modifiers made of polymer material. 20. The blood pump according to paragraph 1 above, wherein each stator comprises at least two blood flow modifiers, optionally four blood flow modifiers. 21. The blood pump according to paragraph 1, wherein one or more stators each comprises a plurality of flow modifiers, each of which is fixed to one or more struts, the struts defining a portion of an expandable basket in which a proximal impeller or a distal impeller is disposed. 22. The blood pump according to 21, wherein the pump portion further comprises a membrane layer that is fixed (directly or indirectly) to an expandable basket, the membrane layer defining at least partially a blood conduit. 23. The blood pump according to 22 above, wherein one or more struts are proximal struts of an expandable basket. 24. The blood pump according to 23 above, wherein the expandable basket is a distal basket on which a distal impeller is disposed, and the pump portion further comprises a proximal expandable basket on which a proximal impeller is disposed. 25. The blood pump according to 23 above, wherein the expandable basket is a proximal basket on which a proximal impeller is disposed, and the pump portion further comprises a distal expandable basket on which a distal impeller is disposed. 26. The blood pump as described in 21 above, wherein the support column is at a non-perpendicular angle to the long axis of the pump portion at the location of the support column. 27. The blood pump according to claim 1, wherein one or more stators each comprises a plurality of blood flow modifiers, and each of the one or more blood flow modifiers has an inner free end disposed parallel to the longitudinal axis of the pump portion on which the flow modifiers are arranged. 28. The blood pump according to 27, wherein the foldable blood conduit includes one or more bends formed therein along its length, and one or more bends are axially spaced apart from one or more blood flow modifiers. 29. The blood pump according to paragraph 1, wherein one or more stators include one or more blood flow modifiers formed integrally with at least one other component of a foldable blood conduit. 30. The blood pump according to paragraph 1, wherein one or more stators are fixed to a foldable blood conduit and include one or more blood flow modifiers having radially outward regions extending therefrom along a length of at least 1 mm and no more than 15 cm. 31. The blood pump according to 30, wherein one or more blood flow modifiers are fixed to a foldable blood conduit and have radially outermost areas extending from therein along lengths of at least 1 mm and 10 cm or less, optionally 9 cm or less, 8 cm or less, 7 cm or less, 6 cm or less, or 5 cm or less. 32. The blood pump according to paragraph 1, wherein one or more stators are fixed to a blood conduit that is longer than the radially inner edge of the blood flow modifier, and the blood flow modifier comprises one or more blood flow modifiers having radially outer regions extending therefrom. 33. The blood pump according to paragraph 1, wherein one or more stators include one or more blood flow modifiers having a distal end surface and a proximal end surface, and at least one of the ends is tapered. 34. The blood pump according to item 1 above, wherein the pump portion comprises a membrane that helps to fix one or more blood flow modifiers to a blood conduit. 35. The blood pump according to paragraph 1 above, wherein one or more stators include one or more blood flow modifiers adapted to be self-deploying. 36. The blood pump according to paragraph 1, wherein one or more stators include a plurality of blood flow modifiers, each of which includes a plurality of blood flow modifiers having an axially extending surface configured to transition the blood flow to laminar flow. 37. The blood pump according to item 1 above, wherein one or more blood flow modifiers are foldable between an extended configuration and a folded configuration. 38. The blood pump according to paragraph 1, wherein one or more stators include one or more blood flow modifiers that are movable or reconfigurable between a first position and an deployed position. 39. The blood pump according to paragraph 1, wherein one or more stators include one or more blood flow modifiers positioned in close proximity to at least one of the proximal and distal impellers when the proximal and distal impellers are in an extended configuration. 40. The blood pump according to 39 above, wherein one or more blood flow modifiers are positioned in close proximity to the proximal and distal impellers. 41. The blood pump according to 39 above, wherein one or more blood flow modifiers are positioned in close proximity to the proximal impeller but not in close proximity to the distal impeller. 42. One or more blood flow modifiers are positioned close to the distal impeller, but proximal A blood pump as described in 39 above, which is not positioned in close proximity to the impeller. 43. The blood pump according to item 1 above, wherein one or more stators include one or more blood flow modifiers that are closer to the proximal impeller than to the distal impeller. 44. The blood pump according to item 1 above, wherein one or more stators include one or more blood flow modifiers that are closer to the distal impeller than to the proximal impeller. 45. The blood pump according to paragraph 1, wherein one or more stators include one or more blood flow modifiers, and the first end of one or more blood flow modifiers is 0.01 mm to 20 mm from at least one of the distal and proximal impellers. 46. ​​The blood pump according to claim 1 above, wherein one or more stators include one or more blood flow modifiers, and the first end of one or more blood flow modifiers is within 10x of the lumen diameter from at least one of the distal and proximal impellers. 47. The blood pump according to paragraph 1, wherein one or more stators include one or more blood flow modifiers (optionally integral therewith) fixed to an annular member that provides radial support for one or more of the impeller basket or blood conduit scaffolds. 48. The annular member is attached to the blood conduit, and is the blood pump described in 47 above. 49. The blood pump according to paragraph 1, wherein one or more stators are positioned to provide radial support to a blood conduit and include one or more blood flow modifiers which are parts of a foldable intermediate member to which are fitted. 50. The blood pump according to paragraph 1, wherein one or more stators include one or more blood flow modifiers which are parts of a foldable intermediate member positioned to maintain a tip clearance between at least one of the impellers and a blood conduit. 51. The blood pump according to paragraph 1, wherein one or more stators include one or more blood flow modifiers, the distal regions of one or more fluid modifiers are configured to act as diffusers for the fluid in the fluid conduit to restore pressure from the distal impeller, and the proximal regions of one or more fluid modifiers are configured to act as stators to direct the flow toward the proximal impeller. 52. The pump section, A foldable blood conduit that defines the blood flow lumen between the inlet and outlet, A distal foldable impeller is axially separated from a proximal foldable impeller, wherein at least a portion of each of the distal and proximal foldable impellers is disposed between an inlet and an outlet, One or more stators, each comprising one or more blood flow modifiers disposed axially between distal and foldable impellers, and It includes a pump section, An intravascular blood pump, wherein each of one or more blood flow modifiers has at least one axially extending surface configured to increase the fluid pressure between a distal impeller and a proximal impeller. 53. The blood pump according to 52, wherein at least one axially extending surface is configured to transition the flow to a laminar flow. 54. The blood pump according to 52, wherein one or more blood flow modifiers are fixed to the surface of a foldable blood conduit and extend radially inward therefrom. 55. The blood pump according to 52 above, wherein one or more flow changing bodies include any feature of any of the flow changing elements described herein. 56. The pump section, A foldable blood conduit that defines the blood flow lumen between the inlet and outlet, A proximal foldable impeller is axially separated from a distal foldable impeller, wherein at least a portion of each of the distal and proximal foldable impellers is disposed between an inlet and an outlet, A proximal foldable basket equipped with a proximal impeller, The sket provides radial support to the blood conduit at the location of the proximal impeller, and the proximal foldable basket provides radial support to the blood conduit. A distal foldable basket on which a distal impeller is provided, wherein the distal foldable basket provides radial support to a blood conduit at the location of the distal impeller, A foldable radial support member that supports one or more of the following: the distal region of a proximal foldable basket, the proximal region of a distal foldable basket, or the central region of a blood conduit axially positioned between the proximal and distal baskets; An intravascular blood pump comprising a pump section, including the pump section. 57. The blood pump according to 56, wherein the radial support member includes an annular peripheral member and a plurality of support elements extending radially inward from the annular peripheral member. 58. The blood pump described in 57 above, wherein the multiple support elements do not extend to the central hub. 59. The blood pump as described in 57 above, wherein multiple support elements extend to a central hub. 60. The blood pump according to 57 above, wherein the multiple support elements have radially inward free ends. 61. The radial support member supports the distal region of the proximal basket, as described in 57 above, in the blood pump. 62. The blood pump according to 57, further comprising a second radial support member spaced axially apart from the radial support member, wherein the second radial support member is positioned to radially support the proximal region of the distal basket. 63. The blood pump according to 62, wherein the second radial support member includes a second annular peripheral member and a plurality of second support elements extending radially inward from the second annular peripheral member. 64. The blood pump according to 56 above, wherein the radial support member supports the proximal region of the distal basket. 65. The blood pump according to 56, wherein the foldable radial support member comprises a stator including one or more blood-changing elements, such as any of the blood-changing elements described herein. 66. The pump section, A foldable blood conduit that defines the blood flow lumen between the inlet and outlet, A proximal foldable impeller is axially separated from a distal foldable impeller, wherein at least a portion of each of the distal and proximal foldable impellers is disposed between an inlet and an outlet, A proximal foldable basket on which a proximal impeller is disposed, wherein the proximal foldable basket provides radial support to a blood conduit at the location of the proximal impeller, A distal foldable basket on which a distal impeller is provided, wherein the distal foldable basket provides radial support to a blood conduit at the location of the distal impeller, A foldable radial support member comprising an annular peripheral member and a plurality of support elements extending radially inward from the annular peripheral member, It includes a pump section, An intravascular blood pump comprising a foldable radial support that radially supports one or more of the following: the distal region of a proximal foldable basket, the proximal region of a distal foldable basket, or the central region of a blood conduit axially positioned between the proximal and distal baskets. 67. The blood pump according to 66 above, wherein the multiple support elements do not extend to the central hub. 68. The blood pump as described in 66 above, wherein multiple support elements extend to a central hub. 69. The blood pump according to 68, wherein the multiple support elements have radially inward free ends. 70. The blood pump according to 68, wherein the foldable radial support is radially disposed within at least one of the distal region of the proximal foldable basket and the proximal region of the distal foldable basket. 71. The blood pump according to 66 above, wherein a foldable radial support is radially arranged within the distal region of the proximal basket, and the proximal basket includes a plurality of proximal supports but does not include a plurality of distal supports. 72. The blood pump according to 66 above, wherein the foldable radial support comprises a stator, the stator comprising a plurality of support elements. 73. The blood pump according to 72, wherein multiple support elements are configured to increase the fluid pressure between the distal impeller and the proximal impeller. 74. A method for deploying an intravascular blood pump across the aortic valve, A step of advancing an intravascular blood pump into the region of a heart valve, wherein the intravascular blood pump comprises a distal basket, a distal impeller, a proximal basket, a proximal impeller, and a blood flow conduit. The distal basket and distal impeller are each unfolded from a folded delivery configuration to an unfolded configuration. The steps include positioning at least a portion of the distal basket within the left ventricle such that the distal end of the distal basket is distal to the aortic valve leaflets, The proximal basket and proximal impeller are each unfolded from a folded delivery configuration to an unfolded configuration, The steps include positioning at least a portion of the proximal basket within the ascending aorta such that the proximal end of the proximal basket is proximal to the aortic valve leaflet, A step of positioning the central region of the axial conduit between the deployed distal basket and the deployed proximal basket adjacent to the aortic valve leaflet, The steps include starting the distal impeller to push the blood toward the proximal impeller, A step of changing the blood flow by at least one flow changing member at at least one flow changing location that is proximal to the distal impeller and distal to the proximal impeller, The steps include starting the proximal impeller to push the blood toward the outflow end of the conduit, and Methods that include... 75. The method according to 74, wherein the step of altering the blood flow by at least one flow-changing member includes increasing the fluid pressure between the distal impeller and the proximal impeller. 76. A method for deploying an intravascular blood pump across the aortic valve, A step of advancing an intravascular blood pump into the region of a heart valve, wherein the intravascular blood pump comprises a distal basket, a distal impeller, a proximal basket, a proximal impeller, and a blood flow conduit. The distal basket and distal impeller are each unfolded from a folded delivery configuration to an unfolded configuration. The steps include positioning at least a portion of the distal basket within the left ventricle such that the distal end of the distal basket is distal to the aortic valve leaflets, The proximal basket and proximal impeller are each unfolded from a folded delivery configuration to an unfolded configuration, The steps include positioning at least a portion of the proximal basket within the ascending aorta such that the proximal end of the proximal basket is proximal to the aortic valve leaflet, A step of positioning the central region of the axial conduit between the deployed distal basket and the deployed proximal basket adjacent to the aortic valve leaflet, The steps include starting the distal impeller to push the blood toward the proximal impeller, The steps include starting the proximal impeller to push the blood toward the outflow end of the conduit, The distal region of the proximal foldable basket, the proximal region of the distal foldable basket, or the central region of a blood conduit axially positioned between the proximal and distal baskets. The steps include deploying a foldable radial support to radially support at least one of them, and Methods that include... 77. The method according to 76, wherein the step of deploying a foldable radial support comprises deploying an annular peripheral member and a plurality of support elements extending radially inward from the annular peripheral member. 78. The method according to 77, wherein the step of deploying a foldable radial support includes deploying an annular peripheral member radially within the proximal region of the distal basket. 79. The method according to 77, wherein the step of deploying a foldable radial support includes deploying an annular peripheral member radially within the distal region of the proximal basket. 80. The method according to 79, further comprising the step of deploying a second foldable radial support within the proximal region of a distal basket in order to radially support the proximal region of the distal basket.

Claims

1. The pump part, A foldable blood conduit that defines the blood flow lumen between the inlet and outlet, A distal foldable impeller and a proximal foldable impeller, wherein the distal foldable impeller is axially separated from the proximal foldable impeller, and at least a portion of each of the distal and proximal foldable impellers is disposed between the inlet and the outlet. A pump portion comprising one or more stators in the blood flow lumen, which are axially positioned between the distal foldable impeller and the proximal foldable impeller and configured to increase the ratio of axial to radial flow of blood flowing through the blood flow lumen. Equipped with, An intravascular blood pump, wherein each of the one or more stators comprises a plurality of flow modifiers, each of which is fixed to one or more struts, the struts defining a portion of an expandable basket on which the proximal foldable impeller or the distal foldable impeller is disposed.

2. The intravascular blood pump according to claim 1, wherein one or more stators extend radially inward from the surface of the support column.

3. The intravascular blood pump according to claim 1, wherein each of the plurality of blood flow modifiers has at least one axially extending surface configured to increase the pressure between the distal foldable impeller and the proximal foldable impeller.

4. The intravascular blood pump according to claim 1, wherein the stator does not include a central hub from which the plurality of blood flow modulators extend.

5. The intravascular blood pump according to claim 1, wherein the stator includes a central hub from which the plurality of blood flow modulators extend.

6. The intravascular blood pump according to claim 1, wherein the plurality of blood flow modifiers are integrally formed with at least a portion of the support column.

7. The intravascular blood pump according to claim 6, wherein the plurality of blood flow modifiers are biased into an unfolded configuration that extends radially inward relative to the outer portion of the foldable blood conduit.

8. The intravascular blood pump according to claim 1, wherein the plurality of blood flow modifiers are formed of a polymer material.

9. The intravascular blood pump according to claim 1, wherein each of the plurality of blood flow modifiers has a radially outer end having a configuration that is shaped to stably fit with a portion of the foldable blood conduit.

10. The intravascular blood pump according to claim 9, wherein the collapsible blood conduit comprises a scaffold, the scaffold having one or more flow-modifying apertures through which it passes, and each of the radially outer ends is shaped to stably align with one of the flow-modifying apertures.

11. The intravascular blood pump according to claim 10, further comprising a membrane layer extending over the scaffold and further fixing the plurality of blood flow modifiers to the blood flow modifier aperture.

12. The intravascular blood pump according to claim 11, wherein the blood flow alternator aperture extends axially and is parallel to the long axis of the scaffold.

13. The intravascular blood pump according to claim 9, wherein the foldable blood conduit comprises a self-expanding scaffold, and the plurality of blood flow modifiers have radially outward ends having a configuration that is shaped to stably align with the self-expanding scaffold.

14. The intravascular blood pump according to claim 10, wherein the plurality of blood flow modifiers are made of a material different from the scaffold material, and the material is more flexible than the scaffold material.

15. The intravascular blood pump according to claim 1, wherein each of the one or more stators comprises at least two blood flow modifiers, optionally four blood flow modifiers.

16. The intravascular blood pump according to claim 1, wherein the pump portion further comprises a membrane layer fixed to the expandable basket, the membrane layer at least partially defining the foldable blood conduit.

17. The intravascular blood pump according to claim 16, wherein the one or more support columns are proximal support columns of the expandable basket.

18. The intravascular blood pump according to claim 17, wherein the expandable basket is a distal basket on which the distal foldable impeller is disposed, and the pump portion further comprises a proximal expandable basket on which the proximal foldable impeller is disposed.

19. The intravascular blood pump according to claim 17, wherein the expandable basket is a proximal basket on which the proximal foldable impeller is disposed, and the pump portion further comprises a distal expandable basket on which the distal foldable impeller is disposed.

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