Intravascular fluid movement devices, systems, and methods of use

Abstract

To provide medical devices that are adapted to, when in use, move fluid such as blood.SOLUTION: An intravascular fluid movement device includes: an expandable member having a collapsed, delivery configuration and an expanded, deployed configuration, the expandable member having a proximal end and a distal end; a rotatable member disposed radially and axially within the expandable member; and a conduit coupled to the expandable member, the conduit at least partially defining a blood flow lumen between a distal end of the conduit and a proximal end of the conduit, the conduit disposed solely radially inside of the expandable member in a distal section of the expandable member.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to the following U.S. Provisional Patent Applications: U.S. Provisional Patent Application No. 62 / 516,296, filed June 7, 2017, and U.S. Provisional Patent Application No. 62 / 542,488, filed August 8, 2017, which are incorporated herein by reference. Incorporation by Reference

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

[0002]

[0003] Patients with cardiac disease may have a significantly reduced ability to carry blood through their heart and vasculature, which may pose significant risks during corrective procedures such as balloon angioplasty and stent delivery. There is a need for techniques to improve the volume or stability of the cardiac outflow tract in these patients, particularly during corrective procedures.

[0003]

[0004] Intra-aortic balloon pumps (IABPs) are commonly used to support circulatory function, such as in treating patients with heart failure. The use of IABPs is common in treating patients with heart failure, such as supporting patients during high-risk percutaneous coronary intervention (HRPCI), stabilizing a patient's blood flow after cardiogenic shock, treating patients suffering from acute myocardial infarction (AMI), or treating decompensated heart failure. Such circulatory support can be utilized alone or in conjunction with pharmacological therapy.

[0004]

[0005] An IABP typically functions by being placed within the aorta and inflated and deflated in a counter-pulsatile manner relative to cardiac contraction, thereby providing additional support to the circulatory system.

[0005]

[0006] More recently, minimally invasive rotary blood pumps have been developed that can be inserted into the body and connected to the cardiac system, such as to pump arterial blood from the left ventricle into the aorta to enhance the natural pumping capacity of the left side of a patient's heart. Another known method is to pump venous blood from the right ventricle to the pulmonary artery to enhance the natural pumping capacity of the right side of a patient's heart. The overall goal is to reduce the workload of a patient's cardiac muscle and stabilize the patient, such as during a medical procedure that may place additional stress on the heart, to stabilize the patient before a heart transplant, or to provide continuous support to the patient.

[0006]

[0007] The smallest rotary blood pumps currently available can be inserted percutaneously into a patient's vasculature through an access sheath or through a vascular access graft to avoid the need for surgical intervention. The name for this type of device is a percutaneously inserted ventricular assist device (pVAD).

[0007]

[0008] Additional improvements need to be achieved in the field of pVADs and similar blood pumps for treating reduced cardiac blood flow. Current pVADs, which are designed to enhance or replace cardiac output, may be undesirably too large to be inserted into a patient's vasculature (e.g., requiring a large femoral artery access sheath or requiring venous dissection, which increases the chance of post-procedure complications), may provide insufficient blood flow, or may cause significant hemolytic damage to blood cells, which can lead to adverse outcomes and, in some cases, death.

[0008]

[0009] There is a need for improvements to pVADs or similar devices to minimize the insertion profile and thereby minimize procedural complications associated with vascular access, maximize the blood flow created or assisted by the device, minimize hemolysis and thrombosis of the blood, and facilitate the procedural steps that a physician or their staff must complete during use of the product.

[0009]

[0010] In one aspect, there is a need for a device with a smaller delivery profile that can be inserted through an access sheath, such as an 8FR or 9FR, optionally 12FR or smaller, and that can pump blood flow in the range of 3.5 L / min to 6.0 L / min, such as 4.0 L / min to 5.0 L / min, at a head pressure of about 8.0 kPa (60 mmHg). Because increasing the impeller speed of a rotary pump is known to increase the risk of hemolysis, in one aspect, there is a need for a pump that can provide sufficient flow rates at rotational speeds significantly below the 50,000 rpm employed by some pVAD pumps. This need, as well as other problems with existing approaches, are addressed by the disclosure herein. Summary of the Invention [Means for solving the problem]

[0010]

[0011] FIELD OF THE DISCLOSURE The present disclosure relates to medical devices that are adapted to move fluids, such as blood, in use.

[0012] One aspect of the present disclosure is an intravascular blood pump comprising: an expandable member having a collapsed delivery configuration and an expanded deployment configuration, the expandable member having a proximal end and a distal end; an impeller radially and axially disposed within the expandable member; and a conduit coupled to the expandable member, the conduit at least partially defining a blood flow lumen between the distal end of the conduit and the proximal end of the conduit, the conduit being disposed radially inward of the expandable member only in a distal section of the expandable member.

[0011]

[0013] The proximal and distal sections of the expansible member can each have an outermost dimension that is greater than an outermost dimension of a central region of the expansible member that is axially disposed between the proximal and distal sections.

[0012]

[0014] The distal end of the conduit may have a flared configuration, and the proximal end of the conduit may not have a flared configuration.

[0015] The blood pump may further include a drive cable operably connected to the impeller.

[0013]

[0016] The blood pump may further have a plurality of distal centering struts coupled to the expandable member and extending around the drive cable distal to the impeller, and a plurality of proximal centering struts coupled to the expandable member and extending around the drive cable proximal to the impeller.

[0014]

[0017] In some instances, the conduit may be impermeable, semi-permeable, or even porous.

[0018] The expansible member may comprise a plurality of elongate elements defining a plurality of apertures.

[0015]

[0019] The conduit may be radially disposed within the expandable member from the proximal end of the conduit to the distal end of the conduit.

[0020] If the conduit is disposed only radially inward of the expandable member, the conduit may be radially spaced from the expandable member with a gap between the conduit and the expandable member.

[0016]

[0021] Additionally, a conduit may be disposed radially outward of the expansible member at a proximal region of the expansible member.

[0022] One aspect of the present disclosure is an intravascular fluid pump including a working portion having a deployment configuration, the working portion including: a distal expandable member having a collapsed delivery configuration and a deployment configuration, the distal expandable member having a proximal end and a distal end; a distal impeller radially disposed within the distal expandable member; a proximal expandable member having a collapsed delivery configuration and a deployment configuration, the proximal expandable member having a proximal end and a distal end, the distal end of the proximal expandable member being axially spaced from the proximal end of the distal expandable member; and a proximal impeller radially disposed within the proximal expandable member, the proximal impeller being spaced from the distal impeller. the proximal expandable member includes a proximal impeller spaced apart from the distal end; a conduit extending axially between the proximal end of the distal expandable member and the distal end of the proximal expandable member, the conduit at least partially defining a blood flow lumen between the distal end of the conduit and the proximal end of the conduit, a central region of the conduit extending a fixed axial distance, the distal and proximal expandable members not extending axially into the central region, the distal end of the distal expandable member extending further distally than the distal end of the conduit, and the proximal end of the proximal expandable member extending further proximally than the proximal end of the conduit; and an elongated portion extending proximally from the working portion.

[0017]

[0023] A conduit may be coupled to the distal and proximal expandable members.

[0024] The working portion can further include a central tubular element coupled to the expandable member, the central tubular element being disposed within the lumen and disposed between the proximal and distal expandable members. The distal end of the proximal expandable member can be coupled to the proximal end of the central tubular element, and the proximal end of the distal expandable member can be coupled to the distal end of the central tubular element, the central tubular element extending between the proximal and distal expandable members. The central tubular element can have the same outermost dimension in both the collapsed and deployed configurations.

[0018]

[0025] The proximal and distal impellers may optionally be driven by a common drive mechanism, such as a common drive cable that may be coupled to the proximal and distal impellers. The common drive mechanism may define a lumen that may optionally be used as a guidewire lumen.

[0019]

[0026] The common drive cable can have a first section coupled to a second section with the second section adjacent to the first section, the first and second sections having a common longitudinal axis and common outer dimensions measured perpendicularly relative to the common longitudinal axis, the first section having a higher stiffness than the second section, and either the distal or proximal impeller coupled to the first section. The first section can have a first tubular member and the second section can have a winding member. The drive cable can further have a third section adjacent to the second section, the third section coupled to the other of the distal and proximal impellers. are combined.

[0020]

[0027] The proximal and distal impellers may be operably connected to a common motor.

[0028] A distal expansible member may be coupled to the distal bearing and the proximal bearing, with a drive mechanism extending through the distal bearing and the proximal bearing.

[0021]

[0029] A proximal expansible member may be coupled to the distal and proximal bearings, with a drive mechanism extending through the distal and proximal bearings.

[0030] The distal expandable member can include a plurality of elongate segments arranged relative to one another to define a plurality of apertures, a portion of at least one of the plurality of apertures being distal to the distal end of the conduit, thereby defining at least one blood inlet aperture for allowing blood to enter the lumen, and the proximal expandable member can include a plurality of elongate segments arranged relative to one another to define a second plurality of apertures, a portion of at least one of the second plurality of apertures being proximal to the proximal end of the conduit, thereby defining at least one outlet aperture for allowing blood to exit the lumen.

[0022]

[0031] At least one of the distal and proximal expandable members has a plurality of elongated segments that are braided.

[0032] The conduit may optionally be impermeable, optionally be semi-permeable, or optionally be porous.

[0023]

[0033] The conduit may be made of a material in a central region axially between the distal and proximal expandable members such that the material is adapted to deform radially inward more easily than the expandable members in response to a radially inward force applied to the working portion.

[0024]

[0034] The conduit may be coupled to the proximal expandable member at a location along the proximal expandable member such that its maximum diametric dimension is measured perpendicular to the longitudinal axis of the proximal expandable member, and the conduit may be coupled to the distal expandable member at a location along the distal expandable member such that its maximum diametric dimension is measured perpendicular to the longitudinal axis of the distal expandable member.

[0025]

[0035] The conduit may be radially disposed within the proximal expandable member at a location where it is coupled to the proximal expandable member, and the conduit may be radially disposed within the distal expandable member at a location where it is coupled to the distal expandable member. The conduit may be radially disposed outside the proximal expandable member at a location where it is coupled to the proximal expandable member, and the conduit may be radially disposed outside the distal expandable member at a location where it is coupled to the distal expandable member. The proximal expandable member may have a distal section tapering radially inward and distally, the distal expandable member may have a proximal section tapering radially inward and proximally, the conduit may be positioned only radially outward of the proximal expandable member at a first location within the distal section and not directly coupled to the proximal expandable member at the first location, and the conduit may be positioned only radially outward of the distal expandable member at a second location within the proximal section and not directly coupled to the distal expandable member at the second location.

[0026]

[0036] The distal end of the distal impeller may not extend further distally than the distal end of the conduit in the expanded configuration.

[0037] The proximal end of the proximal impeller may not extend further proximally than the proximal end of the conduit in the expanded configuration.

[0027]

[0038] The conduit may be flexible and optionally conformable.

[0039] The proximal impeller may extend further proximally than the proximal end of the conduit in the deployed configuration.

[0028]

[0040] The distal impeller may extend further distally than the distal end of the conduit in the deployed configuration.

[0041] A first portion of the conduit can be disposed only radially outward from the proximal expandable member, and a second portion of the conduit proximal to the first portion of the conduit can be disposed radially inward from the proximal expandable member. The first portion of the conduit can be distal to the distal end of the proximal impeller.

[0029]

[0042] A first portion of the conduit can be disposed only radially outward of the distal expandable member, and a second portion of the conduit distal to the first portion of the conduit can be disposed radially inward of the distal expandable member. The first portion of the conduit can be proximal to the proximal end of the distal impeller.

[0030]

[0043] One aspect of the present disclosure relates to a method of deploying an intravascular blood pump to span a valve, such as the aortic valve. [Brief explanation of the drawings]

[0031] [Figure 1]

[0044] Figure 1A is a diagram showing a merely exemplary external profile for a working portion of a medical device herein; Figure 1B is a diagram showing a merely exemplary external profile for a working portion of a medical device herein; Figure 1C is a diagram showing a merely exemplary external profile for a working portion of a medical device herein; Figure 1D is a diagram showing a merely exemplary external profile for a working portion of a medical device herein; and Figure 1E is a diagram showing a merely exemplary external profile for a working portion of a medical device herein. [Figure 2]

[0045] FIG. 2A is a side view of an exemplary working portion having an expandable member and impeller, and a conduit.

[0046] FIG. 2B is an enlarged view of a portion of the view of FIG. 2A. [Figure 3]

[0047] FIG. 3A is a side view showing an exemplary working portion in which a portion of the conduit is radially only within the expandable member.

[0048] FIG. 3B is a side view of an exemplary working portion having an impeller. [Figure 4]

[0049] Figure 4A shows an example arrangement of the device of Figure 3B. Figure 4B shows an example arrangement of the device of Figure 3B. [Figure 5]

[0050] FIG. 10 is a side view showing an example working portion. [Figure 6]

[0051] Figures 6A, 6B, and 6C are diagrams illustrating at least a portion of an exemplary working portion. [Figure 7]

[0052] Figure 7A illustrates at least a portion of an exemplary working portion; Figure 7B illustrates at least a portion of an exemplary working portion; Figure 7C illustrates at least a portion of an exemplary working portion; Figure 7D illustrates at least a portion of an exemplary working portion; and Figure 7E illustrates at least a portion of an exemplary working portion. [Figure 8]

[0053] Figure 8A is a diagram illustrating at least a portion of an exemplary working portion; Figure 8B is a diagram illustrating at least a portion of an exemplary working portion; Figure 8C is a diagram illustrating at least a portion of an exemplary working portion; Figure 8D is a diagram illustrating at least a portion of an exemplary working portion; Figure 8E is a diagram illustrating at least a portion of an exemplary working portion; and Figure 8F is a diagram illustrating at least a portion of an exemplary working portion. [Figure 9]

[0054] 1A-1C illustrate at least a portion of an exemplary medical device having a working portion. [Figure 10]

[0055] 1A-1C illustrate at least a portion of an exemplary medical device having a working portion. [Figure 11]

[0056] 1A-1C illustrate at least a portion of an exemplary medical device having a working portion. [Figure 12]

[0057] 1A-1C illustrate at least a portion of an exemplary medical device having a working portion. [Figure 13]

[0058] FIG. 13A illustrates at least a portion of an exemplary medical device having a working portion in which at least two different impellers can be rotated at different speeds.

[0059] FIG. 13B illustrates at least a portion of an exemplary medical device having a working portion in which at least two different impellers can be rotated at different speeds.

[0060] FIG. 13C illustrates at least a portion of an exemplary medical device having a working portion comprising at least two impellers having different pitches. [Figure 14]

[0061] 1A-1C illustrate at least a portion of an exemplary medical device having a working portion. [Figure 15]

[0062] Figures 15A, 15B, 15C, and 15D are cross-sectional views illustrating an exemplary outer profile of an exemplary working portion during use. [Figure 16]

[0063] FIG. 1 is a side view of an exemplary working portion having a conduit, multiple impellers, and an expandable member. [Figure 17]

[0064] FIG. 10 is a side view of an exemplary working portion having a conduit, multiple impellers, and multiple expandable members. [Figure 18A]

[0065] 1A-1C illustrate an exemplary working portion having a conduit, multiple impellers, and multiple expandable members. [Figure 18B] 1A-1C illustrate an exemplary working portion having a conduit, multiple impellers, and multiple expandable members. [Figure 18C] 1A-1C illustrate an exemplary working portion having a conduit, multiple impellers, and multiple expandable members. [Figure 18D] 1A-1C illustrate an exemplary working portion having a conduit, multiple impellers, and multiple expandable members. [Figure 19]

[0066] 10A-10C show an example arrangement of a working portion having a conduit, multiple expansible members, and multiple impellers. [Figure 20]

[0067] Figures 20A, 20B, and 20C show exemplary distal end configurations and configurations for working portions. [Figure 21]

[0068] FIG. 21A shows an exemplary position of the deployed working portion.

[0069] Figures 21B and 21C show exemplary distal regions of the working portion. [Figure 22]

[0070] Figures 22A and 22B show end views of an exemplary impeller with the blades in a folded configuration and an expanded configuration, respectively. [Figure 23]

[0071] Figures 23A, 23B, and 23C show an example impeller. [Figure 24]

[0072] 24A and 24B show an example impeller. [Figure 25]

[0073] Figures 25A and 25B show an exemplary multi-lumen working portion in a collapsed delivery configuration and an expanded configuration, respectively. [Figure 26]

[0074] Figures 26A and 26B illustrate an exemplary multi-lumen design for the working portion, showing a deployed configuration and an expanded configuration, respectively. [Figure 27]

[0075] Figures 27A, 27B, and 27C show exemplary embodiments of a working portion with at least one additional lumen. [Figure 28]

[0076] FIG. 1 illustrates an exemplary working part. [Figure 29]

[0077] 1A-1C illustrate an exemplary fluid transfer medical device having a working portion. [Figure 30]

[0078] 1 illustrates an exemplary magnetic coupling for a motor and drive cable. [Figure 31]

[0079] FIG. 1 illustrates an embodiment of a 90 degree gear set. [Figure 32]

[0080] FIG. 32A illustrates an exemplary working portion having a lumen region and a distal tip in a generally straight configuration.

[0081] 32B shows an elongate inner member, such as a guidewire, advanced through the working section to the distal tip, with the upper straight tip permanently adopting various configurations. [Figure 33]

[0082] Figures 33A, 33B, 33C, 33D, and 33E show an example distal end of an example working portion. [Figure 34]

[0083] FIG. 1 illustrates an exemplary working part. [Figure 35]

[0084] 1 illustrates an exemplary embodiment of an impeller. [Figure 36]

[0085] FIG. 1 illustrates an exemplary pump console with a display. DETAILED DESCRIPTION OF THE INVENTION

[0032]

[0086] The present disclosure relates to medical devices, systems, and methods of use and manufacture. The medical devices herein can have a distal working portion adapted for placement within a physiological vessel, the distal working portion having one or more components that act on a fluid. For example, the distal working portion herein can have one or more rotating members that can promote the movement of a fluid, such as blood, when rotated.

[0033]

[0087] Any disclosure of the present specification relating to the aspects of a system, a device, or a method of use can be incorporated into any other appropriate disclosure of the present specification.For example, a diagram illustrating only one aspect of a device or a method can be included in other embodiments even if it is not specifically described in the description of one or any part of the present disclosure.Therefore, it should be understood that the combination of different parts of the present disclosure is included in the present specification unless otherwise specified.

[0034]

[0088] 1A-1E illustrate exemplary exterior profiles (i.e., exterior configurations) for a medical device working portion (described in more detail below) that spans or extends across a valve, such as the aortic valve. Only a portion of the elongated proximal portion extending proximally from the working portion is shown. The relative positions of the aortic valve, ascending aorta, and left ventricle are shown. FIG. 1A illustrates an exemplary embodiment in which the medical device has a working portion 100 having an enlarged configuration that is generally cylindrical (i.e., not truly cylindrical, but closely resembling a cylinder to the extent that one skilled in the art would consider it cylindrical), with a central region having an outermost dimension (measured perpendicularly relative to the longitudinal axis LA and shown only in FIG. 1A for simplicity) that extends to span the valve, with the outermost dimension decreasing in the proximal and distal directions. The working portion is sized so that when the proximal end is positioned within the ascending aorta, the distal end will be positioned within the left ventricle.

[0035]

[0089] When the working portion is expanded at the valve location, it may come into contact with the valve leaflets (whether the valve leaflets are native leaflets or part of a replacement heart valve). Regardless of the type of working portion, damage to the valve leaflets can occur during heart pumping and when the leaflets are pressed against the working portion to facilitate closing an effective valve seal against the working portion. Therefore, to minimize damage to the valve leaflets, it can be advantageous to minimize or reduce the profile of the working portion at locations where the working portion extends across or across the valve (e.g., the aorta). Figures 1B-1E show exemplary working portion configurations that may be positioned at valve locations having a central region with reduced profile dimensions to reduce the likelihood of valve damage.

[0036]

[0090] 1B shows an example working portion having a generally cylindrical expanded configuration, as shown, sized so that the distal region will reside in the left ventricle while the proximal region will reside in the ascending aorta. A central region of the working portion extends to span the valve. The expanded outer configuration is generally cylindrical.

[0037]

[0091] 1C shows an example working portion in an expanded configuration in which the distal region of the working portion expands to a larger outer dimension than the proximal region of the working portion, with the outer dimension being significantly smaller (e.g., at least half the size) at the location of the valve and extending proximally.

[0038]

[0092] 1D shows an exemplary working portion in an expanded configuration in which the proximal region of the working portion (located within the ascending aorta) expands to a larger outer dimension than the distal region of the working portion, which is significantly smaller (e.g., at least half the size) at the location of the valve and extends distally.

[0039]

[0093] 1E shows an example working portion in an expanded configuration, with the proximal and distal regions configured to expand to dimensions greater than the central region, where the central region is disposed between the proximal and distal regions. The central region may have outer dimensions that are half or smaller than either or both of the distal and distal regions. The working portion of FIG. 1E may be considered to have a general dumbbell configuration when expanded.

[0040]

[0094] In an alternative embodiment, the working portion can have a generally uniform collapsed delivery profile and is configured to expand to a larger expanded profile that expands generally uniformly, "uniform" in this context may mean dimensions that vary by 10% or less.

[0041]

[0095] 2A and 2B show an exemplary fluid pumping portion having an impeller 26 radially disposed within the expandable member. Figures 2A and 2B illustrate the configuration of the pumping portion when expanded outside the body. The expandable member has a distal region 21, a central region 22, and a proximal region 23. The distal region 21 and the proximal region 23 have larger outer dimensions than the central region 22, and the expansion member may be considered to have a dumbbell configuration. In use, the central region 22, or at least a portion of the central region 22, may be positioned to straddle the valve. The proximal region 23 and the distal region 21 each have tapered end regions that taper from the larger outer dimensions of the more central regions. The impeller 26 is radially disposed within the proximal region 23, and a short portion of the impeller 26 may extend slightly into the central region 22. An elongated shaft 28, which may be a drive shaft or drive cable, is coupled to the impeller and, upon actuation, initiates rotation of the impeller 26 (e.g., by a motor). Centering struts 29 (four of which are shown) are located at the ends of the impeller 26 and extend around the shaft 28 to function to center the shaft 28. The struts 29 are coupled to the expandable member and extend around the shaft 28 to stabilize it. Two struts 29 at each end define apertures through which the shaft 29 extends. By centering the shaft 28, the struts 29 further center the impeller 26 within the expandable member and prevent the impeller blades from engaging the expandable member during rotation.

[0042]

[0096] The working portion 20 further includes a conduit 25 coupled to the expandable member. The conduit 25 extends from a location in the distal region 21 to a location in the proximal region 23, but does not extend to the distal or proximal ends of the expandable member. The conduit is operative and constructed of a material that creates a fluid lumen therein between the inflow region and the outflow region. Flow into the inflow region is marked with an "I," and flow out of the outflow region is marked with an "O." The expandable member includes multiple elongated members that simultaneously define multiple apertures, through which fluid flows in the inflow and outflow regions. Any of the conduits herein may be permeable. Alternatively, any of the conduits herein may be semi-permeable. Any of the conduits herein may be porous, yet still define a fluid lumen therethrough. In some embodiments, the conduit is a membrane or other relatively thin layered member. In this embodiment, a conduit 25 is coupled to the outer portion of the expandable member. The distal end of the working portion has a large open surface area that allows sufficient blood inflow even when the distal end of the working portion is pressed against (i.e., in contact with) the inner surface of a hollow anatomical structure, such as the left ventricle of the heart. The proximal region of the conduit 25 opens as an impeller shroud, thereby allowing efficient axial pump flow.

[0043]

[0097] Unless otherwise indicated, conduits of conduits herein may be secured to the expandable member such that the conduit resides radially inside and / or outside the expandable member when secured. For example, the conduit may extend radially within the expandable member such that the inner surface of the conduit resides radially within the expandable member when secured to the expandable member.

[0044]

[0098] Figure 2A is an example of a working portion in which the conduit has flared distal and proximal regions due to the configuration of the expandable member and depending on the extension of the conduit (axially) along the expandable member. Figure 2A also shows an example of a working portion with distal and proximal regions that have larger outer dimensions than the central region.

[0045]

[0099] In an alternative embodiment, the distal region of the conduit has a flared configuration, like a trumpet bell, thereby reducing the work energy required for fluid to enter the inlet region.

[0046]

[0100] The expandable member can be constructed of a variety of materials and in a variety of ways. For example, the expandable member can have a mesh configuration or can be formed by laser machining. The material can be deformable, such as Nitinol. The expandable member can be self-expanding or adapted to at least partially actively expand.

[0047]

[0101] The working portion of Figure 2A may be adapted to be collapsible to a low-profile delivery configuration. The expandable member and impeller may be adapted to be collapsible to a delivery configuration. The conduit, by virtue of being coupled to the expandable member, collapses along with the expandable member. Figure 2B shows a portion of the view of Figure 2A, showing components exaggerated for clarity.

[0048]

[0102] When the impeller is actuated and rotates, the rotation draws fluid into the inlet end, through the lumen defined by the conduit, and out the outlet end.

[0103] In some embodiments, the expandable member self-expands when released from within a containing tubular member, such as a delivery catheter, guide catheter, or access sheath. In some alternative embodiments, the expandable member is adapted to expand by active expansion, such as by actuation of a pull rod to move at least one of the distal and proximal ends of the expandable member toward one another.

[0049]

[0104] FIG. 3A shows an exemplary working portion 30 similar to the working portion shown in FIGS. 2A and 2B. Components that are the same as those in working portion 20 are not labeled for simplicity, but are also incorporated in this figure. Working portion 30 includes a conduit 31 having a distal region 32, a central region 34, and a proximal region 33. This embodiment differs from working portion 20 of FIG. 2A in that the distal region 32 of the conduit resides radially within the expandable member and is not directly attached to a portion of the distal region 32. For example, in the case of a working portion positioned to straddle the aorta, this placement near the distal end of the expandable member allows native cardiac ejection blood flow to reach the more distal end of the conduit (radially outward) and through the aortic valve, which is positioned adjacent to the conduit. A conduit 31 transitions from the exterior to the interior of the expansible member between the ends of the expansible member, and in this embodiment the conduit 31 transitions into a central region of the expansible member which has a reduced exterior dimension.

[0050]

[0105] FIG. 3B shows an exemplary working portion similar to those shown in FIGS. 2A and 3A. For brevity, similar parts are not again labeled, but are incorporated into this figure. In FIG. 3B, working portion 40 includes a conduit extending radially within the expandable member, the conduit having a distal region 41, a central region 42, and a proximal region 43. Within distal region 41, as shown, there is a region where the conduit simply lies radially within the expandable member and is not attached to the expandable member. For example, in applications where the working portion is positioned to straddle the aortic valve, such placement near the proximal end of the expandable member allows more native cardiac ejection blood flow, unimpeded by the conduit, to reach the distal end of the conduit (radially outward) and through the aortic valve adjacent to the conduit into the left and right main coronary arteries.

[0051]

[0106] The fluid transfer devices, systems, and methods herein may be used in and placed in a variety of locations within the body, and although specific examples may be presented herein, it should be understood that the working portions may be placed in areas within the body different from those specifically described herein.

[0052]

[0107] 4A and 4B show an example working portion of the working portion 40 of FIG. 3B. The working portion 40 is deployed in a deployed configuration, extending across the aorta with the aortic valve leaflets "VL." The distal region 21 of the expandable member is positioned within the left ventricle "LV," the central region 22 extends across the valve, and the proximal region 23 is positioned within the ascending aorta. The distal end of the proximal region 23 is also engaged with the leaflets as shown. The proximal region 23 is configured and sized relative to the valve opening to prevent it from passing through the valve to ensure the outflow opening remains within the ascending aorta. Furthermore, the distal region 21 is configured and sized to prevent it from passing through the aorta to ensure the blood inflow port remains within the left ventricle (see FIG. 4B). As can be seen, the working portion has a length between the blood inlet and outlet ports that ensures that the blood outlet port is located in the ascending aorta when the blood inlet port is positioned in the left ventricle.

[0053]

[0108] The present disclosure further includes a working portion having a plurality of impellers.

[0109] FIG. 5 shows a proximal impeller (with blades 201) connected to a first motor 202 and a distal impeller (with blades 20) connected to a second motor 202′. FIG. 5 shows an example working portion 200 of a medical device having a dual motor. Incorporating two motors into a fluid pump can double the available torque while maintaining the same maximum diameter as a single motor. This can help reduce the profile of the device. In the push-pull embodiment shown in FIG. 5, a proximal motor 202 draws blood through the working portion (which typically has an elongated, reinforced body 213, such as, but not limited to, a coiled or braided reinforced polymer), while a distal motor 202' pushes blood through the working portion. When used for left ventricular assist, an aortic valve would be located between a blood inflow port 207 and a blood outflow port 208. The elongated body 213 has an inflow aperture 207 on a radially outer portion of the body 213 and an outflow aperture 208 on a radially outer portion of the body 213. Arrows indicate the direction of blood flow through the apertures, with the right side of the page being the "distal" side.

[0054]

[0110] 6A-6C show an exemplary embodiment of the working portion 30, in which a proximal motor 302 draws blood through the working portion (which may have a reinforced body 313, e.g., a coiled or braided reinforced polymer), while a distal motor 302' pushes blood through the working portion via an expandable side lumen 311. The proximal motor 302 controls and causes rotation of the proximal impeller 301, and the distal motor 302 controls and causes rotation of the distal impeller 301'. Apertures 307 and 308 in the working portion are labeled. The expandable side lumen 311 can be enlarged using mechanical methods, such as, but not limited to, deploying an expandable generally braided structure or simply expanding the side lumen due to increased pressure generated by the distal impeller 301'. The working portion further has an inlet aperture 307 at the distal region. The side lumen 311 can be configured to expand on one side of the elongate body 313 to form a non-cylindrical profile at the outer portion of the catheter, or can expand to more completely surround the main reinforced catheter, as shown in the alternative cross-sectional view of FIG. 6C. At least a portion of space along the side of the reinforced body should remain exposed (e.g., one of the inlet ports 307) to allow blood entering the body 313 to assist inflow into the proximal motor 302 and impeller 301. When used for left ventricular assist, an aortic valve can be placed between the two sets of blood inflow and outflow ports 307, 308.

[0055]

[0111] Figures 7A-7E show another exemplary embodiment of a working section (400) with multiple impellers. In this pull-pull embodiment, each of the two impellers draws blood through the working section lumen and pushes it through a side-flow outlet hose, as indicated by the flow arrows. Aperture 407 is the inlet aperture, and aperture 408 is the outlet aperture. Because these impellers draw a relative vacuum to transport blood, the lumens must be reinforced to prevent or minimize collapse. Figures 7B-7E show cross-sectional views of the section shown in Figure 7A, with Figures 7B-7E below the cross-section. The embodiment of Figures 7A-7E shows a main lumen 413 within which the motor and impellers are coaxially located. The main lumen 413 may be coil-reinforced, braid-reinforced, or reinforced with other structures. Similar to the secondary lumen 311 of Figures 6A-6C, the secondary lumen 411 expands outward from the main lumen 413, such as by an expanding, braided, stented, or basket-like design. A blood inflow passage is located near the distal end of the working portion. As can be seen in cross-section view B-B of Figure 7C, which shows the crescent-shaped outer lumen 411 above the exit hole 408, the distal motor 402' and impeller 401' convey blood out at least through side holes 408 adjacent to or near the impeller 401'. The distal motor 402 and impeller 401 convey blood out of a side hole 408 adjacent to or near the proximal impeller 401 .

[0056]

[0112] 8A-8F show another exemplary embodiment of a working portion (500) having multiple impellers 500 and 501′, with arrows indicating flow direction. In this push-push embodiment, the working portion 500 has dual motors and impellers arranged in a push-push configuration, where each impeller pushes blood through the working portion's lumen (511 or 513) and through a side-outlet aperture or proximal-outlet aperture 508. Because the impellers generate pressure to transport blood, the lumens 511 and 513 do not necessarily need to be reinforced to prevent collapse; the outer lumen 511 can expand with fluid due to increased blood pressure generated by the pump. This embodiment shows a main lumen 513 within which the motor and impellers are coaxially positioned. The main lumen 513 may be, for example, coil-reinforced, braid-reinforced, or otherwise reinforced. The secondary lumen 511 can expand outward like any of the secondary lumens described above, or it can expand outward by distension with fluid due to increased blood pressure from the pump. A blood inflow passage is located near the distal end of the working portion. Both lumens 511 and 513 exit blood from the proximal portion of the working portion, such as through a side aperture 508, an open network, or similar exit passageway. The two impellers 501 and 501' can be driven by a single motor with a spindle exiting each end, or, as shown in FIG. 8F, two motors 502 and 502' oriented back-to-back and adjacent to each other effectively double the torque available to initiate blood pumping.

[0057]

[0113] FIG. 9 shows an exemplary embodiment of a medical device in which the working portion (600) has multiple impellers. The medical device has a remote motor 602 located at the proximal end of the elongated portion of the medical device. The remote motor 602 is coupled to a drive cable 603, which is coupled to the impellers 601 and 601′. The motor 602 drives the impellers. By remotely locating the motor, a larger motor can be used than would be desirable if it were fitted into a smaller insertable catheter shaft. Any of the embodiments herein having a motor within the catheter can be modified to have one or more remote motors. The working portion 600 can have a variety of inflow and outflow configurations and arrangements, such as catheter side holes 608 for each or either impeller, or end apertures 607 that allow for maximizing flow in the axial direction rather than the radial direction. The elongated body 604 extending between the impellers may be structurally reinforced, for example, by a wire coil sandwiched between layers of molten polymer, or by a generally braided structure. Coiled reinforcement designs generally have greater flexibility than braided reinforcement designs, and a high level of flexibility is generally desired in guiding the working portion into position. This embodiment, or any other suitable embodiment herein, may also have a remote motor with a catheter handle or associated handle / hub combination.

[0058]

[0114] 10 shows an exemplary embodiment of a medical device in which the working portion (1100) has multiple impellers. The working portion 1100 has a distal impeller 1101' coupled to a motor 1102'. The working portion 1100 further has a proximal impeller 1101, which is coupled to a remote motor 1102, which is operably connected via a drive cable 1103. The distal motor 1102' is located near the distal end of the working portion and drives the impeller 1101', which pushes blood through the lumen of the working portion, while the proximal remote motor 1102 drives the working portion. The working portion 1100 drives a cable-driven proximal impeller 1101 located closer to the proximal end of the working portion 1100. In use, as with the other working portions herein, the working portion 1100 can be positioned so that the body 1113 will traverse the valve (e.g., the aortic valve) at a location generally between the two impellers.

[0059]

[0115] 11 shows an exemplary embodiment of a medical device in which the working portion (1200) has multiple impellers. The working portion 1200 has a direct drive proximal motor 1202 coupled to a proximal impeller 1201. An external motor 1202' is operably connected to the distal impeller 1201' via a drive cable 1203. The drive cable 1203 may be configured in a lumen extending alongside and adjacent to the proximal internal motor 1202, and thus extends into the working portion lumen and is oriented to be generally centered within the lumen, such that the distal impeller 1201' is centered within the working portion lumen. Optional centering elements are not shown, such as, but not limited to, two or three pairs of struts attached between the outer wall 1213 of the working portion and the rotational bearing elements supporting the rotational drive cable 1203 to ensure stable centering of the impeller 1201′ within the working portion lumen. Exemplary centering struts that may be used are struts 29 of Figures 2A and 2B.

[0060]

[0116] FIG. 12 shows an exemplary embodiment of a medical device in which the working portion (1300) has multiple impellers. The medical device has remote motors 1302 and 1302′ operably connected to drive cables 1303 and 1303′, respectively. The drive cables 1303 and 1303′ are operably connected to the proximal impeller 1301 and the distal impeller 1301′, respectively, both of which are disposed within the working portion 1300. The drive cables 1303 and 1303′ are disposed adjacent to the proximal region 1310, with the drive cable 1303′ extending along the periphery of the working portion for a distance, thus extending toward the center of the lumen. A centering element, as described with reference to FIG. 11, may also be included. The drive cables may be in separate lumens within the proximal region 1310. The drive cable 1303' may reside within the outer lumen or may reside within one or more bearing elements, with the drive cable 1303' running along the periphery 1316 of the working portion.

[0061]

[0117] In any of the embodiments herein in which the medical device (1330) has multiple impellers, the device may be adapted to rotate the impellers at various speeds. FIG. 13A shows a medical device having a gear set 1340 coupled to both the inner drive member 1338 and the outer drive member 1336, which are operably connected to the distal impeller 1334 and the proximal impeller 1332, respectively. The device further includes a motor 1342 that initiates rotation of the inner drive member 1338. The inner drive member 1338 extends through the outer drive member 1336. Operation of the motor 1332 causes the two impellers to rotate at various speeds due to underdrive and overdrive ratios. The gear set 1340 may be adapted to drive either the proximal or distal impeller more quickly than the other. Any of the devices herein can have any of the gear sets herein for driving the impeller at various speeds.

[0062]

[0118] 13B shows a portion of an alternative embodiment of a dual impeller device (1350) also adapted to rotate different impellers at different speeds. A gear set 1356 is coupled to both the inner drive member 1351 and the outer drive member 1353, which are coupled to the distal impeller 1352 and the proximal impeller 1354, respectively. The device further includes a motor as in FIG. 13A. 13A and 13B show how the gear set can be adapted to drive the proximal impeller at a slower or faster speed than the distal impeller.

[0063]

[0119] In an alternative embodiment, a common drive cable or drive shaft can initiate rotation of two (or more) impellers, but the blade pitch (or angle of rotational curvature) of the two impellers can be different, with the distal or proximal impeller having a steeper or less steeper angle than the other impeller. This can create an effect similar to that of having a gear set. FIG. 13C shows a portion of a medical device (1360) having a common drive cable 1366 (not shown) coupled to a proximal impeller 1364 and a distal impeller 1362. The proximal impeller herein can have a higher or lower pitch than the distal impeller herein. Any of the working sections herein that include multiple impellers can be modified to have first and second impellers with different pitches.

[0064]

[0120] 14 shows an exemplary alternative embodiment of a fluid pump 1370 that can rotate the first and second impellers at different speeds. A first motor 1382 drives a cable 1376 coupled to the distal impeller 1372, while a second motor 1384 drives (via a gear set 1380) an outer drive member 1378 coupled to the proximal impeller 1374. The drive cable 1376 extends through the outer drive member 1378. The motors can be controlled and operated independently, thus allowing for separate control of the speeds of the two impellers. This system setup can be used with any of the systems herein that have multiple impellers.

[0065]

[0121] In use, the working portion herein can be positioned to span a sensitive structure, such as a valve (e.g., the aortic valve). It can be useful to avoid damaging the valve, and the working portion can be adapted and constructed to do so. Because the aorta (or other similar valves, for example) typically closes with three valves touching near its center, it can be advantageous for the outer portion of any of the working portions herein to have a non-circular configuration at the location where the working portion extends across or across the valve. For an ideal fit to the aorta, it may not be desirable to rotationally align a non-circular catheter body. Figures 15A, 15B, and 15C show example outer profile configurations for the working portion herein, which may be incorporated into any of the working portions herein. Figure 15D shows a circular outer profile configuration for comparison.

[0066]

[0122] In some embodiments, the working portion can have a conformal or semi-conformal outer structure in the area where it traverses the valve, such that the force of the valve pressing against the working portion causes the outer structure to at least partially deform, thereby at least partially reducing the reactionary force exerted on the valve by the outer structure, which can help prevent damage to the valve at the location where the working portion traverses the valve.

[0067]

[0123] It may also be advantageous to smooth the outer portion of any of the working portions to ensure that any friction on fragile structures, such as the valve leaflets, is minimally damaging to the structure. A stent-like or similar structure in this area of ​​the valve may create protruding spots (like a blunt cheese grater) that could potentially cause damage to the valve. Minimizing the height of such protrusions and / or minimizing the distance between them may be beneficial to prevent damage to sensitive anatomical structures. It may be possible to do so.

[0068]

[0124] FIG. 16 is a side view of the distal portion of an exemplary intravascular fluid pump having a working portion 1600 having a proximal impeller 1606 and a distal impeller 1616, both of which are operably connected to a drive cable 1612. In FIG. 16, the working portion 1600 is shown in an expanded configuration, but is adapted to be folded into a delivery configuration so that it can be delivered in a low profile. The impellers may be attached to the drive cable 1612. The drive cable 1612 is operably connected to an external motor (not shown) and extends through an elongated shaft 1610.

[0069]

[0125] The working portion 1600 further includes an expandable member 1602, which in this embodiment has a proximal end 1620 extending proximally from the proximal end of the proximal impeller 1606 and a distal end 1608 extending distally from the distal end of the distal impeller 1616. The expandable member 1602 is disposed radially outward of the impeller along the axial length of the impeller. The expandable member 1602 may be constructed in a manner similar to, and made from materials similar to, many types of expandable structures known in the medical arts so as to be collapsible and expandable. Examples of these approaches or methods are provided herein.

[0070]

[0126] The working portion 1600 further includes a conduit 1604 coupled to the expandable member 1602, which has a length L and extends axially between the impellers. The conduit 1604 forms and provides a fluid lumen between the two impellers. In use, fluid travels through the lumen provided by the conduit 1604. The conduits herein may be impermeable, or may be semi-permeable or even porous, so long as they are capable of defining a lumen. Also, unless otherwise specified, the conduits herein are flexible. The conduits herein extend completely (i.e., 360 degrees) around at least a portion of the working portion. Within the working portion 1600, the conduit extends completely around the expandable member 1602, but does not extend to the proximal or distal ends 1602, 1608 of the expandable member 1602. The structure of the expandable member creates at least one inlet aperture to allow inflow "I" and at least one outlet aperture to allow outflow "O." The conduit 1604 improves the dynamics of the pumping of the impeller compared to the dynamics that the working portion 1600 would have without the conduit.

[0071]

[0127] The expandable member 1602 can have a variety of configurations and can be made from a wide variety of materials, such as any type of expandable stent or stent-like device in the medical arts, or any other example provided herein. For example, and without limitation, the expandable member 1602 can have an open braided configuration, such as a 24-end braid. However, more or fewer braided wires can be used. An exemplary material for the expandable member is nitinol, although other materials can be used. The expandable member 1602 has an expanded configuration as shown, where the outermost dimension of the expandable member (measured perpendicularly relative to the longitudinal axis of the working portion) is greater than the outermost dimension of a central region 1622 of the expandable member that extends axially between the impellers, at least in the region where the expandable member is disposed radially outward of the impellers. The drive cable 1612 is coaxial with the longitudinal axis in this embodiment. In use, the central region can be positioned to span a valve, such as the aortic valve. In some embodiments, the expandable member 1602 is adapted and constructed to expand to an outermost dimension of 12-24F (4.0-8.0 mm) where the impellers reside axially within the expandable member, and to an outermost dimension of 10-20F (3.3-6.7 mm) in the central region 1622 between the impellers. The smaller outer dimension in the central region can reduce forces acting on the valve, thereby reducing or minimizing damage to the valve. The large dimensions of the expandable member can help axially stabilize the working portion during use. The expandable member 1602 has a general dumbbell configuration. The expandable member 1602 has an outer configuration that tapers where it transitions from the impeller region to the central region 1622 and also tapers at the distal and proximal ends of the expandable member 1602.

[0072]

[0128] The expandable member 1602 has a proximal end 1620 coupled to a shaft 1610 and a distal end 1608 coupled to a distal tip 1624. An impeller and drive cable 1612 rotates within the expandable member and conduit assembly. The drive cable 1612 is axially stabilized relative to the distal tip 1624 but is free to rotate relative to the distal tip 1624.

[0073]

[0129] In some embodiments, the expandable member 1602 can be collapsed by pulling tension across the expandable member. This can include a linear movement that stretches the expandable member 1602 axially (e.g., but not limited to, moving 5-20 mm) until the expandable member 1602 assumes a collapsed configuration with its collapsed outer dimensions. The expandable member 1602 can also be collapsed by pushing an outer shaft, such as a sheath, over the expandable member / conduit assembly, thereby collapsing the expandable member and conduit into the collapsed delivery configuration.

[0074]

[0130] Impellers 1606 and 1616 are also adapted and constructed to stretch or radially compress one or more blades to a reduced outermost dimension (measured perpendicular to the longitudinal axis of the working portion). For example, without limitation, any of the impellers herein can have one or more blades made from a plastic compound with spring properties, such as any of the impellers described in U.S. Pat. No. 7,393,181. The disclosure of U.S. Pat. No. 7,393,181 is incorporated herein by reference and may be incorporated into embodiments herein unless otherwise indicated by this disclosure. Alternatively, for example, one or more foldable impellers can comprise a superelastic wire frame with a polymer or other material acting as webbing that intersects the wire frame, such as a wire frame as described in U.S. Pat. No. 6,533,716, the disclosure of which is incorporated herein by reference.

[0075]

[0131] The inflow and / or outflow configuration of the working portion 1600 may be predominantly axial in nature.

[0132] Exemplary sheathing and unsheathing techniques and concepts for folding and expanding medical devices are known, such as those described and shown in U.S. Pat. No. 7,841,976 or U.S. Pat. No. 8,052,749, the disclosures of which are incorporated herein by reference.

[0076]

[0133] 17 is a side view showing the deployed configuration (outside the body) of the distal portion of an exemplary embodiment of a fluid transfer system. The exemplary system 1100 has a working portion 1104 and an elongated portion 1106 extending from the working portion 1104. The elongated portion 1106 may extend to a more proximal region of the system, not shown for simplicity; this more proximal region may include, for example, a motor. The working portion 1104 has a first expandable member 1108 and a second expandable member 1110 that are axially spaced apart along the longitudinal axis LA of the working portion 1104. Axially spaced apart in this context means that the entire first expandable member is axially spaced apart from the entire second expandable member along the longitudinal axis LA of the working portion 1104. The first portion of the first expandable member 1108 is axially spaced apart from the entire second expandable member along the longitudinal axis LA of the working portion 1104. An end 1122 of the second expansible member 1110 is axially spaced from a first end 1124 of the second expansible member 1110 .

[0077]

[0134] The first expandable member 1108 and the second expandable member 1110 each generally have a plurality of elongated segments arranged relative to one another to define a plurality of apertures 1130. Only one aperture of the plurality of apertures 1130 in the second expandable member 1110 is labeled with a reference number. The expandable members can have a wide variety of configurations and can be constructed in a wide variety of ways, such as, but not limited to, any of the configurations or constructions of U.S. Pat. No. 7,841,976 or the tubing of U.S. Pat. No. 6,533,716, which is described as a self-expanding metallic endoprosthetic material. For example, but not limited to, one or both of the expandable members can have a braided configuration or can be formed at least in part by laser cutting a tubular element.

[0078]

[0135] The working portion 1104 further includes a conduit 1112 coupled to the first and second expandable members 1108 and 1110 and extending axially between them in the deployed configuration. A central region 1113 of the conduit 1112 spans an axial distance 1132, where the working portion does not include the first and second expandable members 1108 and 1110. The central region 1113 may be considered to be axially between the expandable members. The distal end 1126 of the conduit 1112 does not extend distally as far as the distal end 1125 of the second expandable member 1110, and the proximal end 1128 of the conduit does not extend proximally as far as the proximal end 1121 of the first expandable member 1108.

[0079]

[0136] 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 such that the conduit physically contacts 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 such that as the expandable member expands or collapses, the conduit will also begin to transition to a different configuration and / or size. Thus, coupled in this context means that the conduit will move when the expandable member coupling the conduit transitions between the expanded and collapsed configurations.

[0080]

[0137] Any of the conduits herein may be deformable to some extent. For example, the conduit 1112 has an elongate member 1120 that may be made of one or more materials that allow the central region 1113 of the conduit to deform radially inward (toward the LA) to some extent, for example, in response to forces from the valve tissue (e.g., leaflets) or replacement valve in use when the working portion 1104 is deployed toward the configuration shown in FIG. 17 . In some embodiments, the conduit may be stretched rigidly between the expandable members. Alternatively, the conduit may be designed with slack to improve compliance. This may be desirable when the working portion is placed across a fragile structure, such as the aortic valve, allowing the valve to compress the conduit in a manner that minimizes point stresses within the valve. In some embodiments, the conduit may have a membrane attached to the proximal and distal expandable members. Exemplary materials that may be used for any of the conduits herein include, but are not limited to, polyurethane rubber, silicone rubber, acrylic rubber, expanded polytetrafluoroethylene, polyethylene, polyethylene terephthalate, including any combination thereof.

[0081]

[0138] Any of the conduits herein may have a diameter of, for example, 25.4 μm (1 thou) to 381 μm (15 thou), 38.1 μm (1.5 thou) to 381 μm ( It can have a thickness of 127 to 508 μm (5 to 20 thousandths of an inch (thou)), such as from 15 thousandths of an inch (thou), from 1.5 thousandths of an inch (thou) to 10 thousandths of an inch (thou), or from 2 thousandths of an inch (thou) to 10 thousandths of an inch (thou).

[0082]

[0139] Any of the conduits herein, or at least a portion of a conduit, may be impermeable to blood. In FIG. 17 , working portion 1104 has a lumen that extends from distal end 1126 of conduit 1112 to proximal end 1128 of conduit 1112. This lumen is defined by conduit 1112 in central region 1113, but in regions axially adjacent central region 1113, it may be considered to be defined by both the conduit and a portion of the expandable member. However, in this embodiment, it is the material of the conduit that causes the lumen to exist, and this material of the conduit also prevents blood from passing through the conduit.

[0083]

[0140] Any of the conduits herein secured to one or more expandable members, unless otherwise indicated, may be secured such that the conduit is disposed radially outward of the one or more expandable members, or radially inward of the one or more expandable members, or both, and the expandable members may be filled with the conduit material.

[0084]

[0141] The proximal and distal expandable members help maintain the conduit in an open configuration to create the lumen, while also creating an operating environment for the impellers, as described below. In the deployed configuration, each of the expandable members is maintained in a spaced-apart relationship relative to its respective impeller, allowing the impellers to rotate within the expandable member without contacting the expandable member. The working portion 1104 has a first impeller 1116 and a second impeller 1118, with the first impeller 1116 radially disposed within the first expandable member 1108 and the second impeller 1118 radially disposed within the second expandable member 1110. In this embodiment, the two impellers, although separate and distinct, are operably connected to a common drive feature (e.g., drive cable 1117) such that the two impellers rotate in unison when the drive feature is actuated. In this deployed configuration, impellers 1116 and 1118 are axially spaced apart along longitudinal axis LA just as expansible members 1108 and 1110 are axially spaced apart.

[0085]

[0142] Impellers 1116 and 1118 also reside axially within the ends of expandable members 1108 and 1110, respectively (in addition to being radially within expandable members 1108 and 1110). Impellers herein may be considered to reside axially within the expandable members even if the expandable members have struts (e.g., struts that are tapered in side view) that extend from a central region of the expandable member toward the longitudinal axis of the working portion. In FIG. 17, the second expandable member 1110 extends from a first end 1124 (proximal end) to a second end 1125 (distal end).

[0086]

[0143] 17, a distal portion of the impeller 1118 extends distally beyond the distal end 1126 of the conduit 1112, and a proximal portion of the impeller 1116 extends proximally beyond the proximal portion 1128 of the conduit 1112. In this illustration, a portion of each impeller resides axially within the conduit in this deployment configuration.

[0087]

[0144] 17, impellers 1116 and 1118 are operably connected to a common drive feature 1117, in which each of the impellers is coupled to a drive mechanism 1117 that extends through shaft 1119 and working portion 1104. Drive feature 1117 may be, for example, an elongated drive cable that, when rotated, also rotates the impellers. In this example, as shown, drive mechanism 1117 extends to distal tip 1114 and is fixed axially relative to distal tip 1114. However, the drive mechanism 1117 is also adapted to rotate relative to the distal tip 1114 upon actuation. Thus, in this embodiment, upon rotation of the drive mechanism 1117, the impeller and drive mechanism 1117 rotate in unison. Any number of known mechanisms may be used to rotate the drive function, such as mechanisms that use a motor (e.g., an external motor).

[0088]

[0145] The expandable member and conduit are not connected to the impeller and drive mechanism in a manner that allows for rotational movement. In this embodiment, the proximal end 1121 of the proximal expandable member 1108 is coupled to a shaft 1119, which may be the shaft of the elongated portion 1106 (e.g., an outer catheter shaft). The distal end 1122 of the proximal expandable member 1108 is coupled to a central tubular member 1133, through which the drive mechanism 1117 extends. The central tubular member 1133 extends distally from the proximal expandable member 1108 within the conduit 1112 and is further coupled to the proximal end 1124 of the distal expandable member 1110. Thus, the drive mechanism 1117 rotates within and relative to the central tubular member 1133. A 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 end 1114 as shown. A drive mechanism 1117 is adapted to rotate relative to the tip 1114 but is fixed axially relative to the tip 1114.

[0089]

[0146] The working portion 1104 is adapted and configured to collapse to a smaller profile than its deployed configuration (shown in FIG. 17 ). This allows the working portion 1104 to be delivered using a lower profile delivery device (smaller French size) than would be necessary if the working portion 1104 were not collapsible. Even if not specifically described herein, any expandable member and impeller may be adapted and configured to be collapsible to some degree to a smaller delivery configuration.

[0090]

[0147] The working portion herein can be collapsed into a collapsed delivery configuration using conventional techniques, such as those using an outer sheath that is movable relative to the working portion (e.g., by axially moving one or both of the sheath and the working portion). For example, but not limited to, any of the systems, devices, or methods shown in the following references can be used to facilitate collapsing the working portion herein: U.S. Patent No. 7,841,976 or U.S. Patent No. 8,052,749, the disclosures of which are incorporated herein by reference.

[0091]

[0148] Figures 18A-18E show an exemplary working portion similar in some respects to the working portion shown in Figure 17. Working portion 340 is similar to working portion 1104 in that it has two expandable members that are axially spaced apart when the working portion is expanded, and a conduit extending between the two expandable members. Figure 18A is a perspective view, Figure 18B is a side cross-sectional view, and Figures 18C and 18D are enlarged side cross-sectional views of the cross-section of the view of Figure 18B.

[0092]

[0149] The working portion 340 has a proximal impeller 341 and a distal impeller 342, which are coupled and operably connected to a drive cable, which defines a lumen therein. The lumen may be sized to accommodate a guidewire that may be used to deliver the working portion to a desired location. The drive cable, in this embodiment, has a first section 362 (e.g., wound material), a second section 348 (e.g., tubular member) that couples the proximal impeller 341, a third section 360 (e.g., wound material), and a fourth section 365 (e.g., tubular material) that couples the distal impeller 342. All of these drive cable sections have equal inner diameters, resulting in a lumen. The fourth section 365 has a constant inner diameter. These drive cable sections can be secured to one another using known attachment techniques. The distal end of the fourth section 365 extends to a distal region of the working portion, thereby allowing the working portion to be advanced, for example, over a guidewire, to position the working portion. In this embodiment, the second and fourth sections can have a higher stiffness than the first and third sections. For example, the second and fourth sections can be tubular, while the first and third sections can be a rolled material to reduce stiffness.

[0093]

[0150] Working portion 340 has proximal and distal expandable members 343 and 344, each extending radially outward of one of the impellers. The expandable members have distal and proximal ends that may extend axially beyond the distal and proximal ends of the impellers, as can be seen in FIGS. 18b-18D . A conduit 356 is coupled to the two expandable members, the conduit 356 having proximal and distal ends 353 and 352. Each of the two expandable members has a plurality of proximal and distal struts. The proximal struts in proximal expandable member 343 extend to and are secured to shaft section 345, which is coupled to bearing 361, through which a drive cable extends and is configured and sized to rotate. The distal struts of the proximal expandable member 343 extend to and are anchored to a proximal region (in this case, the proximal end) of the central tubular member 346, with the central tubular member 346 axially disposed between the expandable members. The proximal end of the central tubular member 346 is coupled to a bearing 349, as shown in FIG. 18C, through which the drive cable extends and rotates. The proximal struts of the distal expandable member 344 extend to and are anchored to a distal region (in this case, the distal end) of the central tubular member 346. Furthermore, a bearing 350 is coupled to the distal region of the central tubular member 346, as shown in FIG. 18D. The drive cable extends through and rotates relative to the bearing 350. The distal struts of the distal expandable member extend to and are fixed to shaft section 347 (see FIG. 18A ), which may be considered part of the distal end. Shaft section 347 is coupled to bearing 351 (see FIG. 18D ), through which the drive cable extends and rotates relative to bearing 351. The distal tip further includes bearing 366 (see FIG. 18D ), which may be a thrust bearing. Even if not explicitly included in this description, working portion 340 may be similar or equivalent to working portion 1104 in some respects.In this embodiment, conduit 356 extends at least as far as the end of the impeller, as opposed to working portion 1104. Either embodiment can be modified to extend the conduit to the positions described in other embodiments. In some embodiments, section 360 can be a tubular section instead of being coiled.

[0094]

[0151] Although specific example locations may be shown herein, the fluid pump may be usable in a wide variety of locations within the body. Some example locations for placement include near the aortic or pulmonary valve, such as spanning the valve and being located on one or both sides of the valve, and in the case of the aortic valve, optionally including a portion located within the ascending aorta. In some other embodiments, for example, the pump may be located further downstream in use, such as in the descending aorta.

[0095]

[0152] Figure 19 shows an example arrangement of the working portion 1104 from the system 100 of Figure 17. One difference shown in Figure 19 is that the conduit extends at least as far as the end of the impeller as in Figures 18A-18D. The working portion 1104 is shown in a deployed configuration, positioned in a straddling position. The working portion 1104 can be delivered, as shown, for example, but not limited to, via femoral artery access (a known access procedure). While not shown for simplicity, the system 100 can further include an outer sheath or shaft within which the working portion 1104 is positioned during delivery to a location near the aortic valve. The sheath or shaft can be moved proximally (toward the ascending aorta "AA" and away from the left ventricle "LV"), thereby deploying and expanding the working portion 1104. For example, the sheath can be retracted to allow the second expandable member 1110 to expand, and continued proximal movement allows the first expandable member 1108 to expand.

[0096]

[0153] In this embodiment, the second expandable member 1110 is expanded and positioned in a deployed configuration such that the distal end 1125 is within the left ventricle "LV," distal to the aortic valve leaflets "LV," and distal to the annulus. Furthermore, the proximal end 1124 is positioned distal to the leaflets "VL." However, in some embodiments, the proximal end 1124 may extend axially slightly within the leaflets VL. This embodiment is an example of a method in which at least half of the second expandable member 1110 resides within the left ventricle when measured along its length (measured along the longitudinal axis). Furthermore, as shown, this is also an example of a method in which the entire second expandable member 1110 resides within the left ventricle. This is also an example of a method in which at least half of the second impeller 1118 is positioned within the left ventricle, and even an embodiment in which the entire second impeller 1118 is positioned within the left ventricle.

[0097]

[0154] Continued retraction of the outer shaft or outer sheath (and / or distal movement of the working end 1104 relative to the outer sheath or outer shaft) continues to release the conduit 1112 until the central region 113 is released and deployed. The expansion of the expandable members 1108 and 1110 causes the conduit 1112 to assume a more open configuration, as shown in FIG. 19 . Thus, in this embodiment, the conduit 1112 does not have the same self-expanding properties as the expandable members, but deployment of the working end causes the conduit to assume a more open, deployed configuration. At least a portion of the central region 1113 of the conduit 1112 is located at the coaptation region with the aortic valve. In FIG. 18 , there is a short length of the central region 1113 that extends distally beyond the leaflet VL, but at least a portion of the central region 1113 resides axially within the leaflet.

[0098]

[0155] 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 placed in a deployed configuration (as shown) such that the proximal end 1121 resides within the ascending aorta AA and is proximal to the leaflet "LV." Additionally, although the distal end 1122 is positioned proximal to the leaflet VL, in some methods the distal end 1122 may extend axially slightly within the leaflet VL. This embodiment is an example of a method in which at least half of the first expandable member 1110 resides within the ascending aorta when measured along its length (measured along the longitudinal axis). Additionally, as shown, this is also an example of a method in which the entire first expandable member 1110 resides within the AA. This is also an example of a method in which at least half of the first impeller 1116 is disposed within the AA, and even an embodiment in which the entire first impeller 1116 is disposed within the AA.

[0099]

[0156] At any time during or after deployment of the working portion 1104, this position of the working portion may be accessed in any manner, such as under fluoroscopy. The position of the working portion can be adjusted at any time during or after deployment. For example, the working portion 1104 can be moved axially (distally or proximally) after the second expandable member 1110 is released but before the first expandable member 1108 is released, thereby repositioning the working portion. In addition, the working portion can be repositioned, for example, after the entire working portion has been released from the sheath and reached a desired final position.

[0100]

[0157] It should be understood that the positions of the components shown in FIG. 19 (relative to the anatomy) are to be considered exemplary final positions for the various components of the working portion 1104, even if repositioning occurs after initial deployment.

[0101]

[0158] One or more of the expandable members herein may be configured to and may be expanded in a variety of ways, such as by self-expanding, by mechanical actuation (e.g., by one or more axial forces exerted on the expandable member, by using a separate balloon radially disposed within the expandable member that expands to push the expandable member radially outward, etc.), or a combination thereof.

[0102]

[0159] As used herein, expansion generally refers to a reconfiguration to a larger profile having a larger outermost radial dimension (relative to the longitudinal axis), regardless of the specific manner in which one or more components are expanded. For example, a stent that self-expands and / or is subjected to an outward radial force may "expand," as the term is used herein. A device that unfolds or unfolds may assume a larger profile and may be considered to expand, as the term is used herein.

[0103]

[0160] The impellers may similarly be adapted and configured to expand in a variety of ways depending on their configuration. For example, when one or more impellers are released from the sheath, they may automatically return to or toward another larger-profile configuration due to the materials and / or configuration of the impeller's design (see, e.g., U.S. Pat. No. 6,533,716 or U.S. Pat. No. 7,393,181, both of which are incorporated herein by reference). Thus, in some embodiments, retracting the outer restraint allows both the expansible member and impellers to naturally return to their larger-profile deployed configurations without any other actuation.

[0104]

[0161] As shown in the embodiment of FIG. 19, the working portion has first and second spaced-apart impellers on either side of the aortic valve, each disposed within a separate expandable member. This contrasts with some designs in which the working portion has a single, elongated expandable member. Rather than a single, generally tubular expandable member spanning the entire valve, the working portion 1104 has a conduit 1112 extending between the expandable members 1108 and 1110. The conduit has greater flexibility and deformability than the expandable basket, thereby allowing for greater deformation of the working portion at the location of the aortic valve leaflets, as occurs when the expandable member extends across the leaflets. This can reduce damage to the leaflets after the working portion is deployed within the subject.

[0105]

[0162] Additionally, forces exerted on the central region of a single expandable member from the leaflets can translate axially to other regions of the expandable member, potentially causing undesired deformation of the expandable member at one or more impeller locations. This can cause the outer expandable member to contact the impeller, thereby undesirably interfering with the impeller's rotation. Designs with separate expandable members around each impeller This, and specifically the design in which each expandable member and each impeller is supported at both ends (i.e., distal and proximal), provides a high level of precision in positioning the impeller relative to the expandable member, and may allow two separate expandable members to more reliably maintain their deployed configuration compared to a single expandable member.

[0106]

[0163] As discussed above, it may be desirable to be able to reconfigure the working portion so that it can be delivered through a 9F sheath and achieve sufficient flow rates in use that are not possible with some current products during deployment and / or testing. For example, some products may be too large to be reconfigured for a sufficiently small delivery profile, while some compact designs may not be able to achieve the desired high flow rates. An illustrative advantage of the examples of Figures 16, 17, 18A-18D, and 19 is that, for example, the first and second impellers can work together to achieve the desired flow rate, and by having two axially spaced impellers, the entire working portion can be reconfigured to a smaller delivery profile than designs that use a single impeller to achieve the desired flow rate. Thus, these embodiments use multiple smaller, axially spaced, reconfigurable impellers to achieve both the desired small delivery profile and the desired high flow rate.

[0107]

[0164] Thus, embodiments herein can achieve a small delivery profile while maintaining a sufficiently high flow rate, while creating a more deformable and flexible central region of the working portion, exemplary benefits of which are described above (e.g., cooperative contact with vulnerable valve leaflets).

[0108]

[0165] 20A, 20B, and 20C show exemplary distal tip configurations and configurations for working portions that may be incorporated into any of the working portions herein or other working portions known in the art. Figures 20A-C show exemplary distal tip features that can help promote blood flow and promote proper positioning across the aortic valve when the tip is positioned to contact a flow-impeding structure, such as the apex of the left ventricle.

[0109]

[0166] 20A shows an example working portion 1502 comprising a distal tip 1504 with inflow and outflow apertures 1508, 1510, and a distal end 1506. The tip 1504 can have a pigtail configuration with sufficient strength to prevent it from collapsing when pressed against cardiac tissue, such as the tissue of the left ventricle. The tip 1504 may also have an inner wire with greater stiffness (greater stiffness than the outer material of the distal tip).

[0110]

[0167] 20B shows an example working portion 1512 having a distal end 1516 and an inflow portion 1514 proximally adjacent to the distal end 1516. The inflow portion 1514 has a plurality of elements 1518 defining a plurality of apertures that allow sufficient blood flow even when pressed against cardiac tissue, such as left ventricular tissue. The inflow portion 1514 may be configured as a stent or stent-like device made by braiding or braiding wire or by laser cutting a tubular member. The inflow portion 1514 may be constructed of a self-expanding material, such as nitinol, for example.

[0111]

[0168] 20C shows an example working portion 1520 having a tip 1524 with a first plurality of inlet openings 1526 having a first general configuration and a second plurality of inlet openings 1522 having a second general configuration different from the first general configuration, the openings configured to allow sufficient blood flow even when the tip is pressed against cardiac tissue.

[0112]

[0169] In any embodiment, multiple inlet openings or apertures can be molded into the design of the tip piece that is attached to the rest of the working portion by gluing, solvent bonding, ultrasonic welding, laser welding, or using similar processes. Additional holes can be added near the glued tip using, for example, but not limited to, core drilling or laser machining.

[0113]

[0170] 21A shows an exemplary position of the deployed working portion 1520, where the length of the working portion is such that proper positioning across the aortic valve is achieved by urging the working portion forward until it becomes engaged with tissue of the left ventricle (LV) as shown. In this position, the inflow inlets 1522 and 1526 are in the left ventricle, the outflow aperture 1528 is positioned in the ascending aorta, and the central region of the working portion extends along the aortic valve leaflet VL.

[0114]

[0171] 21B and 21C show alternative distal regions of the working portion that do not have a pigtail configuration as in 20A-20C and 21A. These tip regions can be incorporated into any suitable working portion herein or any other working portion known in the art. FIG. 21B shows an exemplary tip region having an expandable member 1612, such as a self-expanding stent-like structure, that can be formed like any of the expandable members herein. The expandable member 1612 has multiple elongated elements that define multiple inflow openings. These openings define a sufficiently open space to prevent blood flow restriction and minimize hemolysis while allowing sufficient blood flow, even when the member 1612 is pressed against a structure such as the wall of the left ventricle or even against the apex of the left ventricle. The member 1612 can have a variety of configurations (e.g., a length equal to the diameter or up to several times the diameter), such as, for example, a droplet shape or a circle shape. In this embodiment, member 1612 is at the distal most end of the working portion.

[0115]

[0172] 21C shows a portion of an exemplary working portion having a distal tip 1602 at its distal-most end with an entrance opening 1604 and one or more expandable members 1619. The expandable members 1619 are at the distal-most end of the working portion. The expandable tip, as shown in FIG. 21C, may be generally spherical, or optionally drop-shaped, so that the more proximal end has minimal or no features that may catch on chordae tendineae or similar structures in the heart, or on other structures near blood vessel bifurcations or other similarly hollow anatomical structures.

[0116]

[0173] The impellers herein, unless otherwise specified, are adapted to be folded from a deployed / expanded configuration to a folded configuration of smaller outer dimensions, which helps minimize the delivery profile for the entire working portion, and further helps expand to a larger outer dimension size that may help generate a desired flow rate.

[0117]

[0174] 22A and 22B show end views of an example impeller 1701 with blades 1720 in a collapsed configuration (FIG. 22A) and an expanded configuration (FIG. 22B). The impeller has a central member 1721, from which the blades 1720 extend radially. In the expanded configuration of FIG. 22B, the blades extend further radially outward relative to the central member 1721. The blades may be made from a material that self-expands to a larger outer dimension, such as, for example, a polymeric material (e.g., polyethylene, polypropylene, polyester, ABS, nylon, acetal, polyphenylene sulfide), silicone, or a superelastic wireform using polymer webbing.

[0118]

[0175] 23A-C show an example impeller 1801 including blades 1820 each having a weighting element 1822 therein. The weighting element 1822 may be a weighting element having a higher density (e.g., tungsten, stainless steel) or may be a region having a greater thickness than the rest of the blade. Thus, in the latter embodiment, the element 1822 may be a portion of the blade and not a separate component. The higher density or thickness causes the impeller blades to be pulled outward by centrifugal reaction, as can be seen by comparing the deployed configuration of FIG. 23 with the operating configuration during rotation seen in FIG. 23C.

[0119]

[0176] 24A and 24B show an impeller 1901 with blades 1922 in a folded configuration and an operating configuration, respectively. The impeller blades 1922 are configured to capture fluid flow such that the reaction force of blood pressing against the face of the blades causes the impeller blades to expand from a less expanded configuration to a more expanded configuration.

[0177] Some working sections herein can have multiple lumens, each of which is a fluid lumen through which fluid (e.g., blood) can flow. Dual-lumen working sections can be used, for example, with dual-motor designs. More than two lumens may be incorporated as well, and thus three or more motors may be incorporated as well. Figures 25A and 25B show an exemplary multi-lumen (lumens 1922 and 1924) working section in a collapsed configuration, a delivery configuration (Figure 25A), and an expanded configuration (Figure 25B). The collapsed profile can be reduced to reduce the delivery profile, yet the section can be expanded to a larger size to allow a desired high flow rate, such as 4-6 L / min. Exemplary techniques by which the lumen can be expanded include expanding the mesh basket structure, expanding the lumen due to increasing blood pressure, or a combination of both.

[0120]

[0178] 26A and 26B show an exemplary multi-lumen design for the working portion, showing the deployed and expanded configurations, respectively. Working portion 50 has an outer body 51 within which is embedded a matrix structure 52, such as a mesh structure. A septum 53 extends across the interior of the working portion and extends radially inward from outer body 51, thereby dividing lumens 54 and 55. Septum 53 and outer body 51 are flexible, stretching and becoming thinner as they expand from the smaller outer dimensions in the collapsed state to the larger outer dimensions in the deployed state (as shown). The materials selected provide these properties. The outer profile of this embodiment is circular.

[0121]

[0179] In some related embodiments, additional lumens may be included to accommodate, for example, motor wiring, a pressure measurement device, and / or a guidewire. Figures 27A-C illustrate an exemplary embodiment with such additional lumens. Figure 27A illustrates an exemplary working portion comprising an outer wall 60, a septum 61, a channel 62, a lumen 63 defined by the channel 62, a first fluid lumen 64, and a second fluid lumen 65. Lumen 63 and channel 62 are within septum 61. In Figure 26B, lumen 73 and channel 72 are located at the intersection between lumens 64 and 65. The working portion has wall 70, septum 71, and fluid lumens 74 and 75. Figure 26C illustrates channel 82 and lumen 83 located adjacent septum 81 at the periphery of wall 80.

[0122]

[0180] FIG. 28 shows an example concept where the working portion 90 has an expandable member 93, which has a plurality of elongated segments 92 (only one elongated segment is labeled). 9 further illustrates how wires and / or lumens 91 (only one lumen is labeled, but two or more lumens may be included for various purposes) can be incorporated into the expandable member (e.g., a braided structure). Here, the wires and / or lumens 91 follow the shape of the periphery of the expandable member in a curvilinear fashion from the proximal to the distal portion. Other working portion components (e.g., impellers, conduits) can, of course, also be incorporated into the expandable member 93. In this embodiment, expansion of the expandable member does not stretch the wires and / or lumens.

[0123]

[0181] The present disclosure next describes several exemplary magnetic coupling designs that may be incorporated into any suitable working portion and medical device herein. The magnetic coupling is part of a motor that can initiate rotation of one or more impellers herein. FIG. 29 shows an exemplary fluid transfer medical device 100 having a working portion 120, a magnetic coupling 105, a motor 108, a shaft 113, and one or more wires 109. An exemplary advantage of the embodiment of FIG. 29 is that the motor can be relatively easily reused for another procedure. A housing 114 houses the motor 108, a distal portion of the wire 109, the shaft 113, and the magnetic member 107. The working portion has an inlet end 101, a tip 104, an impeller 112, and an outlet opening 103. After use, the working portion 102 can be detached from the housing 114, and the housing 114 can be cut or separated at the optional cutting zone 111. This separates the motor, allowing it to be reused. This design also allows for a blood-free motor, which may be particularly useful in reusing this component in device reprocessing. Cut zone 111 may be configured to facilitate removal of motor 108 and associated wiring without damage.

[0124]

[0182] FIG. 30 shows an exemplary magnetic coupling for the motor and drive cable. This magnetic coupling configuration can be used near the proximal end of the medical device to provide clearance for indirect contact between the drive motor and the drive cable. This configuration allows for a sterile barrier to surround the non-sterile handle unit, with the drive motor in a manner that allows the sterile barrier to magnetically couple the drive motor to the sterile catheter shaft connector. This provides the advantage that the non-sterile handle and cable assembly can be used and reused as a multi-use assembly in multiple medical procedures without the need for cleaning, disinfection, and sterilization. In each procedure, a single-use catheter assembly with a working portion and a single-use sterile barrier may be used.

[0125]

[0183] 30 shows the proximal coupling 122 between a motor housing 128 and a catheter portion 123 of a medical device. The catheter portion 123 has any suitable working portion herein or other working portion known in the art. The motor housing 128 has a motor 126 coupled to a magnetic member 125. A sterile sleeve 127 can be advanced over the motor housing 128. The catheter portion 123 has a magnetic member 124 and a drive cable 121. Actuation of the motor rotates the drive cable via the magnetic coupling 122.

[0126]

[0184] If a magnetic coupling is used with any of the medical devices herein, a large torque lever may be required. Therefore, it may be advantageous to place a large coupler wheel at a 90 degree angle relative to the catheter shaft to allow for low-profile packaging (and therefore low-volume packaging). Figure 31 shows an embodiment of this, using a 90 degree gear set coupled to the drive cable. For simplicity, only a portion of the device is shown in Figure 31. A motor 133 is coupled to a first magnetic member 131. A drive cable 135 and A second magnetic member 132 is coupled to a 90 degree gear set 134 .

[0127]

[0185] In some embodiments, the working portion can have a generally straight tip to facilitate easy insertion into the body, where the tip is biased into a generally L- or J-shape to facilitate navigation and reduce potential trauma to intravascular or intervascular structures. This secondary distal configuration can be achieved by using a stiff, curved member inserted into the working portion lumen, such as a guidewire lumen. Alternatively, the secondary distal configuration can be achieved by a steerable catheter mechanism, such as one or more pullwires within the working portion wall near the distal tip. FIG. 32A shows an exemplary working portion 140 having a lumen region 141 and distal tip 142 in a generally straight configuration. FIG. 32B shows an elongated inner member 143, such as a guidewire, advanced through the working portion 140 and into the distal tip 142. In this embodiment, the initially straight tip 142 is permanently configured in a "J" configuration.

[0128]

[0186] 33A-33E show exemplary distal ends of working portions that may be incorporated into any suitable working portion herein or other working portions known in the art. In FIG. 33A, working portion 190 has conduit 191 and expandable member 192. Expandable member 192 has multiple elongated elements with tapered struts 193 extending proximally from elements 199. Struts 193 may be integral with elements 199 or may be coupled to elements 199. Struts 193 define entrance apertures 195 (only one entrance aperture is labeled) for blood flow into the working portion lumen. The distal end of the expandable member 192 has a first region 198 where at least one aperture has a first area, a second region 197 where at least one aperture has an intermediate aperture, and a third region 196 where at least one aperture has a third area, where the first area is greater than the intermediate area and the intermediate area is greater than the third area.

[0129]

[0187] Figure 33B is similar to Figure 33A, and the description of Figure 33A is incorporated by reference into the description of Figure 33B. However, working portion 220 has struts 222 extending radially outward and then radially inward. Working portion 220 further has elongated members 223 that may be coupled to the impeller, and interface elements 224.

[0130]

[0188] The working portion 230 of Figure 36C is similar to that of Figures 33A and 33B, the description of which is incorporated by reference into the description of Figure 33C. However, working portion 230 has a curved distal end 231 with a plurality of apertures 232 therein. Tip 231 has a distal end 233.

[0131]

[0189] The working portion 240 of Figure 33D is similar to that of Figures 33A-33C, and the description of Figures 33A-33C is incorporated by reference into the description of Figure 33D. However, the working portion 240 has struts 243 that taper and meet at the distal end of the working portion. The working portion 240 does not have separate tip portions extending distally of the struts as in Figures 33A-C. The working portion 240 further has a shaft 241 that is secured to a member 242.

[0132]

[0190] The working portion 250 in Figure 33E is similar to that in Figures 34A-D, and the description of Figures 34A-D is incorporated by reference into the description of Figure 33E. However, the working portion 250 has a distal extension portion 251 having a circular configuration, which may be spherical, toroidal, ovoid, etc. The distal extension portion 251 has a plurality of holes 253 therein and may be integrally formed with struts 254 via connector portions 252.

[0133]

[0191] Figure 34 shows an working portion similar to that shown in Figure 16. Working portion 265 has a proximal impeller 266 and a distal impeller 267, both coupled to a drive shaft 278 that extends into a distal bearing housing 272. A similar proximal bearing housing is present at the proximal end of the working portion. The working portion further has an expandable member, generally designated 270, and a conduit 268 secured to the expandable member and extending along substantially the entire length of the expandable member. The expandable member 270 has distal struts 271 extending to and secured to strut supports 273 secured to distal tips 273. The expandable member 270 further includes a proximal strut secured to the proximal strut support. All structures similar to those of FIG. 16 are incorporated by reference in this embodiment, even if not explicitly described. The expandable member 265 further includes a helical tension member 269 disposed along the periphery of the expandable member, the helical tension member 269 having a helical configuration when the expansion member is in the expanded configuration as shown. The helical tension member 269 is positioned and adapted to induce a rotation wrap when folded. The working portion 265 can be folded from the expanded configuration shown by simultaneously rotating one or both impellers at a relatively low speed to promote spiral folding of the impellers due to interaction with the expandable member. The helical tension member 269 (or the helically configured expandable member cells) functions as a tension member for the assembly.The helical tension member 269 is also configured so that when the expandable basket is pulled under tension along its length to collapse it (e.g., by stretching it over a long distance, such as approximately doubling its length), the tension member 269 is pulled into linear alignment, thereby rotating / twisting a desired segment of the expandable member during collapse, thereby causing the impeller blades to wrap radially inward as the expandable member and blades collapse. An exemplary configuration of such a tension member, when in its helical configuration, has a curved configuration that is approximately equal to the maximum length of the expandable member when collapsed. In an alternative embodiment, only a portion of the expandable member that surrounds the collapsible impeller is rotated when collapsed.

[0134]

[0192] There are alternative approaches for constructing the working portion such that it rotates the expandable member when folded by stretching (and thus by winding and folding the impeller blades). Any expandable member, even a dual-impeller design, can be constructed with such a structure. For example, when using an expandable member with multiple "cells" (e.g., a laser-cut elongated member) in the same sense as the term is commonly understood, the expandable member can have multiple specific cells that together define a specific configuration, such as a helical configuration, where the cells defining this configuration have different physical properties than other cells within the expandable member. In some embodiments, the expandable member can have a braided configuration, and the twisted region can comprise the entire group of wires or a significant portion (e.g., more than half) of the braided wires. Such a twisted braided configuration can be achieved, for example, during the braiding process, particularly over the length of the largest diameter portion of the braided configuration, by twisting the mandrel on which the wires are braided as it is pulled. This configuration may be completed during a second operation in the construction process, such as mechanically twisting the braided configuration prior to heat setting the wrapped profile on the shaped mandrel.

[0135]

[0193] FIG. 35 shows an alternative embodiment to any of the multi-impeller pump designs herein, in which an Archimedes pump-like There are two semi-rigid impellers 282 at the ends and a flexible helical wall 283 between impeller blades 285 that are configured with a helical pitch equal to the pitch of the blades for conveying blood. In another embodiment, there are multiple radial supports along the length of the flexible wall to prevent it from collapsing onto the impeller drive shaft 286, which is a common tendency when flexible tubing is twisted.

[0136]

[0194] By using any of the pigtail tips herein, the pigtail tip can have varying wall thicknesses to facilitate various entity properties, such as in an exemplary embodiment having a greater wall thickness in the most distal region of the pigtail and a relatively thinner wall thickness in a region disposed proximal to the most distal region.

[0137]

[0195] 36 shows an example pump console with a display 290 that may be used with any of the fluid pumps herein. The console has a speed display element, an impeller rotation indicator element, an estimated blood flow display 293, a sensor display 294 (e.g., blood pressure reading), a battery icon, and connections 295 for the fluid pump electronics and / or purge.

[0138]

[0196] In some embodiments, the catheter electrical connection and the fluid connection are integrated into a single connector configured to interface with the console, such as by magnetic attraction. In alternative embodiments, the electrical connection interfaces separately from the fluid connection. In such embodiments, the connections may be adjacent to each other to interface as an integrated mated connector. In some embodiments, the console is adapted to sense whether either or both connectors are properly and fully mated.

[0139]

[0197] In some embodiments, fluid entrainment, such as by injecting saline, is used to induce blood flow. Other exemplary fluids include dextrose solution or blood. Entrainment refers to the transport of fluid across the interface between two bulk fluids by shear-induced turbulent flux, but importantly, minimizes hemolysis of the blood that can occur due to turbulent flux.

[0140]

[0198] The present disclosure includes devices and methods for confirming proper positioning of the working portion herein. In some embodiments, for example, one or more ultrasonic crystals (e.g., piezoelectric crystals) are included in any of the working portions herein. The ultrasonic crystals can be used to indicate fluid movement, such as blood flow, and can also be used to detect movement of the aortic and / or mitral valves. Exemplary locations for such sensors include near the blood outlet port of the working portion and near the blood inlet port of the working portion. In one method of use, the direction and degree of turbulence of blood flow can be measured by the sensor and compared with reference data to determine whether the working portion is located at a valve (e.g., the aortic valve) between the blood inlet and outlet ports. If the sensing information does not indicate proper placement, the working portion can be moved until the sensor detects an indication of proper placement. In the ascending aorta, blood flows primarily from the aortic valve toward the descending aorta. Conversely, within the ventricle, flow direction changes frequently, i.e., is cyclical, as the ventricular cavities fill and then partially empty with each contraction of the ventricular muscle. The movement of the aortic valve leaflets can present a recognizable pattern that can be recognized when an ultrasonic crystal is passed through them. These methods can be used in conjunction with any of the methods herein.

[0141]

[0199] In some embodiments, the medical device, during placement and verification of the working portion, Furthermore, if desired, the catheter may have a miniature video camera (e.g., coupled to or proximal to the working portion) for direct viewing of anatomical structures during movement. In exemplary embodiments, one or more cameras are positioned proximal to the outflow port of the working portion, allowing the user to directly view the end of the working portion as it is navigated through the aortic valve. Visible markings positioned on the catheter shaft can further indicate proper placement of the catheter relative to a valve, such as the aortic valve (e.g., the working portion can be positioned so that the valve is between the blood inflow and outflow ports). In some embodiments, the video camera system is adapted to visualize throughout a blood-filled blood vessel, such as the aorta, using radiation of a wavelength that minimizes total optical loss through the blood. Exemplary wavelengths include those within the infrared spectrum. In some embodiments, radiation of this wavelength is at least partially reflected and backscattered by the cardiac vessel or catheter surface, thereby processing the detected signals by detecting all intensity signals of the reflected and backscattered radiation, selecting the intensity signal of radiation backscattered only by blood, and subtracting the selected intensity signal of radiation backscattered only by blood from all detected intensity signals of the reflected and backscattered radiation, thereby reconstructing an image of the cardiac vessel or catheter surface using the different intensity signals obtained by the subtraction.

[0142]

[0200] In any relevant embodiment herein, a ferrofluid may be used as a bearing or seal to prevent blood from entering the working part bearings and / or motor assembly. In some embodiments, during gas sterilization of the device, the ferrofluid is contained in a separate reservoir or channel and is released or injected into the magnetic field when it fills the space intended to function as a bearing and / or seal. In some embodiments, the reservoir containing the ferrofluid includes a membrane that dissolves on fluid contact, such as by rinsing the device with saline, or dissolves on blood contact, so that the ferrofluid is released into place when the membrane dissolves.

[0143]

[0201] In some embodiments, the drive motor in the handle may be cooled by a thermoelectric cooler (TEC), where heat from the hot end of the TEC is dissipated by cooling fins or by circulating fluid. Alternatively, the drive motor in the handle may be cooled by multiple cooling fins exposed to the air. The cooling fins may have air passed across them by an air-driven fan.

[0144]

[0202] In some embodiments, torque feedback can be used to determine whether blood inlet and outlet ports are located on either side of a valve, such as the aortic valve. One exemplary method for measuring torque feedback is by direct observation of position and flow when the working part is located across the valve, but also with the inlet / outlet fully within the left ventricle / ascending aorta, and determining torque boundaries as a function of impeller rotational speed. These boundaries can be used to determine whether the inlet and outlet are on either side of the aortic valve.

[0145]

[0203] In any of the related embodiments herein, the working portion can have one or more fluid exit holes between the distal impeller and the proximal impeller, such that the fluid exit holes can assist cardiac arteries in a system where the distal impeller section is in the left ventricle and the proximal impeller system is in the ascending aorta.

[0146]

[0204] The blood outlet end of the working portion herein can have a filter adapted to capture thrombus and / or necrotic debris.

[0205] In some embodiments, a first impeller (e.g., a distal or proximal impeller) may be fixedly affixed to the drive cable, and a second impeller (e.g., a distal or proximal impeller) may be configured to slide (e.g., proximally or distally) along the drive cable when the system is collapsed. However, the slidable impeller is configured to be mechanically engaged to the fixed impeller when the system is expanded. This mechanical engagement may be achieved by intermediate tubing with geared or slotted ends, such that the intermediate tubing transfers torque from the first impeller to the second impeller. In alternative embodiments, three or more impellers may be similarly configured, where one impeller is attached to the drive cable and the remaining impellers are mechanically engaged to the attached impeller.

[0147]

[0206] When any of the delivery, positioning, and use methods are used, any of the following additional steps, in any combination thereof, may also be performed: The following optional steps represent some of the clinical steps or processes that may be performed as part of a pVAD procedure.

[0148]

[0207] One exemplary process that can be implemented is a process for measuring activated clotting time (ACT) or partial thromboplastin time (PTT), which are useful for assessing anticoagulation. In any of the embodiments herein, an ACT or PTT sensor can be incorporated into or attached to the fluid pumping device, such as on a working portion on the fluid pumping device. ACT and / or PTT can be measured at any or all of the following times: before inserting the fluidic device, during use of the fluidic device (e.g., every 4-8 hours), after removing the fluid pump, and before removing the sheath. When hemolysis occurs, hemoglobin and hematocrit decrease, haptoglobin decreases, and plasma-free hemoglobin increases.

[0149]

[0208] Another exemplary step that may be performed is to verify that limb ischemia at the access site is not occurring due to an obstruction. In any of the embodiments herein, one or more sensors for blood flow may be located on the fluid pumping catheter or on the arterial or venous access sheath.

[0150]

[0209] Another exemplary step that may be performed is periodically assessing the arterial access site for bleeding or hematoma. In any of the embodiments herein, the arterial or venous access sheath may have one or more sensors adapted to detect bleeding or hematoma at the vascular access site.

[0151]

[0210] Another exemplary step that may be performed depending on the device used and the method of positioning the device is to verify that the working portion has been properly advanced and positioned to span the valve (see, for example, FIG. 18, which illustrates positioning across the aortic valve). For example, fluoroscopy may be used to confirm proper positioning of the working portion within the left ventricle and across the aortic valve. Furthermore, sensed pressure may be used to verify proper positioning. For example, evaluation of the ventricular waveform and the aortic waveform may be performed. Additionally, at high flow rates or when ventricular function is impaired, the patient's blood flow may not be pulsatile. Furthermore, the motor current signal may be used to determine proper positioning. For example, when the flow inlet and outlet of the working portion are within the left ventricle or an artery, or when ventricular function is impaired, the motor current signal becomes monotonic. For example, a process engine may monitor the motor current for atypical patterns that correlate to fluid recirculation from the flow outlet to the flow inlet of the pump. Additionally, the pump may be adapted to demonstrate the absence of suction within the ventricle.

[0152]

[0211] Another exemplary step that may be performed is assessing indicators of aortic valve damage. For example, one or more strain gauge sensors may be placed on the working portion in the region where the working portion extends to span a valve, such as the aortic valve.

[0153]

[0212] Another exemplary step that may be performed is sensing the blood flow rate delivered by the fluid pump. For example, one or more flow sensors may be part of the working portion, which may be located on the device directly adjacent to the working portion. For example, an ultrasonic quartz crystal sensor may be located on or within the device, such as on or within the working portion, and may be positioned to measure the flow of blood propelled by the working portion. Additionally or alternatively, a Doppler crystal may be used to measure the velocity of blood flowing through or out of the working portion.

[0154]

[0213] One other exemplary step that may be implemented is sensing the rotational speed of one or more impellers and correlating that rotational speed to blood flow rate.

[0214] Another exemplary step that may be performed is to verify, optionally frequently, that the patient is free of hemodynamic instability. For example, a blood pumping system may have multiple electrocardiogram leads for measuring the conduction of electrical signals indicative of cardiac function, such as heartbeat.

[0155]

[0215] Another exemplary step that may be performed is to perform continuous cardiac output monitoring, which may be useful for patients with cardiogenic shock. For example, a fluid pumping device, such as a working portion, may have one or more sensors, such as a thermodilution sensor, to indicate cardiac ejection fraction and / or cardiac index.

[0156]

[0216] In some uses, inotropes such as dobutamine or milrinone, and vasopressors such as dopamine and norepinephrine may be required even after a fluid pump is placed to maintain a cardiac index of at least 2 and a systolic blood pressure of 12 kPa (90 mmHg) or greater.

[0157]

[0217] If a patient requires signal decoding of a long-term pacemaker or implantable cardioverter-defibrillator, the fluid pump console can be switched off for a few seconds while the signal is established, for example, electrically isolating all possible electrical contacts within the fluid pump and within the patient, thereby eliminating the possibility of electrical interference between the fluid pump system and an active implantable electronic device such as a pacemaker or implantable cardioverter-defibrillator.

[0158]

[0218] Part of any of the methods herein is the demonstration of the absence of complications such as reperfusion, hypotension, fatal arrhythmias, etc.

[0219] In some embodiments, transthoracic echocardiography (TTE) may be performed, for example, to assess left ventricular size and function.

[0159]

[0220] In some embodiments, patient positioning is considered in ventilation and in the prevention of thrombosis / ulcers.

[0221] In some uses, the temperature of the motor and / or cable may be monitored to indicate blood infiltration / charring.

[0160]

[0222] In some embodiments, one or more strain sensors may be incorporated into any of the expandable members and used to assess the deployment of the expandable members. .

Claims

1. 1. An intravascular blood pump, comprising: an expandable member having a collapsed delivery configuration and an expanded deployment configuration, the expandable member having a proximal end and a distal end; an impeller radially and axially disposed within the expansible member; a conduit coupled to the expandable member, the conduit at least partially defining a blood flow lumen between a distal end of the conduit and a proximal end of the conduit; Equipped with the conduit being disposed only radially inward of the expandable member in a distal section of the expandable member; Intravascular blood pump.

2. 2. The blood pump of claim 1, wherein the proximal and distal sections of the expandable member each have an outermost dimension that is greater than an outermost dimension of a central region of the expandable member that is axially disposed between the proximal and distal sections.

3. The blood pump of claim 1 , wherein the distal end of the conduit has a flared configuration.

4. The blood pump of claim 3 , wherein the proximal end of the conduit does not have a flared configuration.

5. The blood pump of claim 1 , further comprising a drive cable operably connected to the impeller.

6. 6. The blood pump of claim 5, further comprising a plurality of distal centering struts coupled to the expandable member and extending around the drive shaft distal to the impeller, and a plurality of proximal centering struts coupled to the expandable member and extending around the drive shaft proximal to the impeller.

7. The blood pump of claim 1 , wherein the conduit is selected from one of an impermeable membrane and a semi-permeable membrane.

8. The blood pump of claim 1 , wherein the expandable member comprises a plurality of elongated elements defining a plurality of apertures.

9. The blood pump of claim 1 , wherein the conduit is radially disposed within the expandable member from the proximal end of the conduit to the distal end of the conduit.

10. 2. The blood pump of claim 1, wherein when the conduit is positioned only radially inside the expandable member, the conduit is radially spaced from the expandable member with a gap between the conduit and the expandable member.

11. 1. An intravascular blood pump, comprising: an expandable member having a collapsed delivery configuration and an expanded deployment configuration, the expandable member having a proximal end and a distal end; an impeller radially and axially disposed within the expansible member; a conduit attached to the expandable member, the conduit at least partially defining a blood flow lumen between a distal end of the conduit and a proximal end of the conduit; and Equipped with The conduit is disposed radially outward of the expansible member at a proximal region of the expansible member. and disposed only radially inward of the expandable member at a distal region of the expandable member. Intravascular blood pump.

12. 12. The blood pump of claim 11, wherein the proximal region and the distal region each have an outermost dimension that is greater than an outermost dimension of a central region of the expansible member that is axially disposed between the proximal and distal regions.

13. The blood pump of claim 11 , wherein the conduit is disposed radially inward of the expansible member in the central region.

14. The blood pump of claim 11 , wherein the distal end of the conduit has a flared configuration.

15. The blood pump of claim 11 , further comprising a drive cable operably connected to the impeller.

16. 12. The blood pump of claim 11, further comprising a plurality of distal centering struts coupled to the expandable member and extending around the drive shaft distal to the impeller, and a plurality of proximal centering struts coupled to the expandable member and extending around the drive shaft proximal to the impeller.

17. 12. The blood pump of claim 11, wherein the conduit is an impermeable membrane.

18. The blood pump of claim 11 , wherein the expandable member comprises a plurality of elongated elements defining a plurality of apertures.

19. 1. An intravascular blood pump, comprising: A deployable distal working portion, the deployable distal working portion, in a deployed configuration: a distal expandable member having a collapsed delivery configuration and a deployed configuration, the distal expandable member having a proximal end and a distal end; a distal impeller radially and axially disposed within the distal expansible member; a proximal expandable member having a collapsed delivery configuration and a deployed configuration, the proximal expandable member having a proximal end and a distal end, the distal end of the proximal expandable member being axially spaced from the proximal end of the distal expandable member; a proximal impeller radially and axially disposed within the proximal expansible member, the proximal impeller being proximally spaced from the distal impeller; a conduit coupled to the distal and proximal expandable members, the conduit extending axially between the proximal end of the distal expandable member and the distal end of the proximal expandable member, the conduit at least partially defining a blood flow lumen between the distal end of the conduit and the proximal end of the conduit; and a central region of the conduit extending an axial distance, the distal and proximal expandable members not extending axially into the central region; the distal end of the distal expandable member extends further distally than the distal end of the conduit, and the proximal end of the proximal expandable member extends further proximally than the proximal end of the conduit. a deployable distal working portion; an elongated portion extending proximally from the working portion; Equipped with Intravascular blood pump.

20. 20. The blood pump of claim 19, wherein the distal end of the proximal expandable member is coupled to the proximal end of a central tubular element, the proximal end of the distal expandable member is coupled to the distal end of the central tubular element, and the central tubular element is disposed within the lumen and extends between the proximal and distal expandable members.

21. 21. The blood pump of claim 20, wherein the central tubular element has the same outermost dimension in both the collapsed configuration and the deployed configuration.

22. 20. The blood pump of claim 19, wherein the proximal impeller and the distal impeller are driven by a common drive mechanism.

23. 23. The blood pump of claim 22, wherein the common drive mechanism comprises a common drive cable.

24. 24. The blood pump of claim 23, wherein the common drive cable is coupled to the proximal impeller and the distal impeller.

25. 24. The blood pump of claim 23, wherein the common drive cable has a first section coupled to a second section with the second section adjacent to the first section, the first and second sections having a common longitudinal axis and common outer dimensions measured perpendicular to the common longitudinal axis, the first section having a higher stiffness than the second section, and either the distal impeller or the proximal impeller being coupled to the first section.

26. 26. The blood pump of claim 25, wherein the first section can include a first tubular member and the second section can include a wound member.

27. 27. The blood pump of claim 26, wherein the drive cable further comprises a third section adjacent to the second section, the third section being coupled to the other of the distal impeller and the proximal impeller.

28. 23. The blood pump of claim 22, wherein the common drive mechanism defines a lumen, the lumen optionally being capable of being used as a guidewire lumen.

29. 20. The blood pump of claim 19, wherein the proximal impeller and the distal impeller are operably connected to a common motor.

30. 20. The blood pump of claim 19, wherein the distal expandable member is coupled to a distal bearing and a proximal bearing, and a drive mechanism extends through the distal bearing and the proximal bearing.

31. 20. The blood pump of claim 19, wherein the proximal expansible member is coupled to a distal bearing and a proximal bearing, and a drive mechanism extends through the distal bearing and the proximal bearing.

32. 20. The blood pump of claim 19, wherein the distal expandable member comprises a plurality of elongated segments arranged relative to one another to define a plurality of apertures, a portion of at least one of the plurality of apertures being distal to the distal end of the conduit, thereby defining at least one blood inlet aperture for allowing blood to enter the lumen.

33. 33. The blood pump of claim 32, wherein the proximal expandable member comprises a plurality of elongated segments arranged relative to one another to define a second plurality of apertures, a portion of at least one aperture of the second plurality of apertures being proximal to the proximal end of the conduit, thereby defining at least one exit aperture for allowing blood to exit the lumen.

34. 20. The blood pump of claim 19, wherein at least one of the distal and proximal expandable members has a plurality of elongated segments that are braided.

35. 20. The blood pump of claim 19, wherein the conduit is impermeable.

36. 20. The blood pump of claim 19, wherein the conduit is semi-permeable.

37. 20. The blood pump of claim 19, wherein the conduit can be made of a material in the central region axially between the distal and proximal expandable members such that the material is adapted to deform radially inward more easily than the expandable members in response to a radially inward force applied to the working portion.

38. 20. The blood pump of claim 19, wherein the conduit is coupled to the proximal expandable member at a location along the proximal expandable member such that a maximum diametric dimension is measured perpendicular to a longitudinal axis of the proximal expandable member, and the conduit is coupled to the distal expandable member at a location along the distal expandable member such that a maximum diametric dimension is measured perpendicular to a longitudinal axis of the distal expandable member.

39. 20. The blood pump of claim 19, wherein the conduit is radially disposed within the proximal expandable member at a location where the conduit is coupled to the proximal expandable member, and the conduit is radially disposed within the distal expandable member at a location where the conduit is coupled to the distal expandable member.

40. 40. The blood pump of claim 39, wherein the conduit is further disposed radially outward of the proximal expandable member at a location where the conduit is coupled to the proximal expandable member, and the conduit is further disposed radially outward of the distal expandable member at a location where the conduit is coupled to the distal expandable member.

41. 40. The blood pump of claim 39, wherein the proximal expandable member has a distal section tapering radially inward and distally, the distal expandable member has a proximal section tapering radially inward and proximally, the conduit can be positioned only radially outward of the proximal expandable member at a first location in the distal section and is not directly coupled to the proximal expandable member at the first location, and the conduit is positioned only radially outward of the distal expandable member at a second location in the proximal section and is not directly coupled to the distal expandable member at the second location.

42. 20. The blood pump of claim 19, wherein the distal end of the distal impeller does not extend further distally than the distal end of the conduit in the expanded configuration.

43. 20. The blood pump of claim 19, wherein the proximal end of the proximal impeller does not extend further proximally than the proximal end of the conduit in the expanded configuration.

44. 20. The blood pump of claim 19, wherein the conduit is flexible.

45. 20. The blood pump of claim 19, wherein the proximal impeller extends further proximally than the proximal end of the conduit in the deployed configuration.

46. 20. The blood pump of claim 19, wherein the distal impeller extends distally beyond the distal end of the conduit in the deployed configuration.

47. 20. The blood pump of claim 19, wherein in the deployed configuration, a first portion of the conduit is positioned only radially outward of the proximal expandable member, and a second portion of the conduit proximal to the first portion of the conduit is positioned radially inward of the proximal expandable member.

48. 48. The blood pump of claim 47, wherein the first portion of the conduit is distal to the distal end of the proximal impeller.

49. 20. The blood pump of claim 19, wherein a first portion of the conduit is disposed only radially outward of the distal expandable member, and a second portion of the conduit distal to the first portion of the conduit is disposed radially inward of the distal expandable member.

50. 50. The blood pump of claim 49, wherein the first portion of the conduit is proximal to the proximal end of the distal impeller.

51. 1. A method of deploying an intravascular blood pump to span an aortic valve, the method comprising: advancing the intravascular blood pump to a region of a heart valve, the intravascular blood pump comprising a distal expandable member, a distal impeller, a proximal expandable member, a proximal impeller, and a conduit; deploying each of the distal expandable member and the distal impeller from a collapsed delivery configuration to a deployed configuration, wherein the distal impeller is axially and radially disposed within the distal expandable member in the deployed configuration; deploying each of the proximal expandable member and the proximal impeller from a collapsed delivery configuration to a deployed configuration, wherein the proximal impeller is axially and radially disposed within the proximal expandable member in the deployed configuration, and the distal and proximal expandable members are axially spaced apart when in the deployed configuration, such that a proximal end of the distal expandable member is distal to a distal end of the proximal expandable member; positioning at least a portion of the distal expandable member within the left ventricle such that a distal end of the distal expandable member resides distal to an aortic valve leaflet; placing at least a portion of the proximal expandable member in the ascending aorta such that a proximal end of the proximal expandable member resides proximal to an aortic valve leaflet; positioning a central region of the conduit axially between the deployed distal expandable member and the deployed proximal expandable member at a coaptation region with the aortic valve such that the central region is positioned in coaptive contact with the aortic valve leaflets; simultaneously maintaining the distal expandable member, the proximal expandable member, and the central region of the conduit in their respective positions; actuating the distal impeller and the proximal impeller to rotate the distal impeller and the proximal impeller to move fluid from the left ventricle toward the ascending aorta; Contains method.

52. 52. The method of claim 51, wherein positioning at least a portion of the distal expandable member within the left ventricle comprises positioning the entire distal expandable member distal to an aortic valve leaflet.

53. 52. The method of claim 51, wherein positioning at least a portion of the proximal expandable member within the ascending aorta comprises positioning the entire proximal expandable member proximal to an aortic valve leaflet.

54. 52. The method of claim 51, wherein deploying comprises allowing the distal and proximal expandable members to self-expand.

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