Expandable mechanical hemodynamic support systems, devices and methods

Abstract

Some embodiments of the percutaneous ventricular assist device have a two-part design including a housing component and a separately positionable and rotatable inner catheter component. The housing component can include an expandable pump housing. The inner catheter can include an expandable pump impeller and an associated flexible drive shaft. The drive shaft can be coupled to a motor located outside the patient. The motor can rotate the drive shaft to spin the pump impeller inside the pump housing, thereby pumping blood into the patient. In some embodiments, the pump impeller is inflatable or self-expandable. Two-part percutaneous ventricular assist devices with inflatable or self-expandable pump impellers are designed to have a very small delivery profile.

Description

[Technical field]

[0001] The present disclosure relates to mechanical hemodynamic support systems, devices and methods, such as expandable percutaneous ventricular assist devices and methods of use. [Background technology]

[0002] Mechanical hemodynamic support devices, such as percutaneous ventricular assist devices ("pVADs") and other devices, are currently used in interventional cardiology to perform protected percutaneous coronary interventions ("PCIs"). During such procedures, mechanical hemodynamic support is either placed prophylactically or is immediately available in the event of a complication. If a complication does occur, patients would greatly benefit from having hemodynamic support to keep blood circulating throughout the body while the complication is mitigated.

[0003] In addition, pVADs can be used to unload the heart before performing PCI. As a result, the amount of work required by the heart to pump blood is reduced, as the pVAD takes on a significant portion of the pumping load. There is clinical evidence that unloading the heart during myocardial infarction has long-term beneficial effects on the viability of myocardial tissue. Summary of the Invention [Problem to be solved by the invention]

[0004] Current pVADs require relatively large access sites to accommodate delivery. These devices are too large to be deployed through a radial access site. These large access site requirements necessitate vascular access via large vessels such as the femoral artery, axillary artery, or venous system. Large access sites require longer patient follow-up and are more susceptible to bleeding complications than radial access sites.

[0005] Additionally, small access sites can be treated with pressure alone, while larger access sites require some form of access site closure device or surgical incision and suturing after the procedure.

[0006] Additionally, the size of current pVADs is too large for many patients worldwide, including children and those with small anatomy, and thus improved systems, devices and methods would be beneficial. [Means for solving the problem]

[0007] The present disclosure describes blood pump systems, such as percutaneous ventricular assist devices, and methods of their placement and use. One example of such a system described herein includes an elongate flexible drive shaft defining a lumen, a pump impeller attached to a distal end portion of the drive shaft, and a pump housing. The pump impeller is expandable in response to receiving an inflation fluid supplied to the impeller through the lumen of the drive shaft. The system is configured to pump blood when (i) the pump impeller is disposed within the pump housing, (ii) the pump impeller is expanded, and (iii) the drive shaft is rotated.

[0008] Such a blood pump system may optionally include at least one or more of the following features: The pump impeller may include a tapered body having an outer surface and one or more ridges extending from the outer surface. The one or more ridges may be expandable in response to receiving inflation fluid supplied to the impeller through the lumen. The pump impeller may include a tapered body having an outer surface, the tapered body defining one or more grooves extending along the outer surface. The pump impeller may include a tapered body having an outer surface and one or more non-expandable fins extending from the outer surface. The pump housing may be reconfigurable between a low-profile delivery configuration and a radially expanded configuration. The pump housing may define one or more outlet openings. The pump housing may define one or more relief notches around each of the one or more outlet openings. The blood pump system may also include an inlet cannula extending from the pump housing. The inlet cannula may define one or more inlet openings. In some embodiments, the inlet cannula may be reconfigurable between a low profile delivery configuration and a radially expanded configuration. The blood pump system may also include a drive shaft housing extending proximally from the pump housing, the drive shaft housing defining a housing lumen configured to slidably receive the drive shaft and the pump impeller when the pump impeller is retracted.

[0009] Another exemplary system described herein is a catheter-based blood pump. One example of such a system described herein includes a rotatable pump impeller attached to a flexible drive shaft. The pump impeller is reconfigurable between (i) a contracted, low profile delivery configuration configured for transvascular advancement to a target location within a patient, and (ii) an expanded, radially expanded configuration. The pump impeller is configured to pump blood when rotated by the drive shaft in the expanded, radially expanded configuration.

[0010] Such a catheter blood pump system may optionally include at least one or more of the following features: The pump impeller may comprise a tapered body having an outer surface and one or more ridges extending from the outer surface, the plurality of ridges being expandable. The pump impeller may comprise a tapered body having an outer surface and one or more non-expandable fins or ridges extending from the outer surface. The pump impeller may comprise a tapered body having an outer surface, the tapered body defining one or more grooves extending along the outer surface. The catheter blood pump may also comprise a housing component. Such a housing component may comprise an elongate drive shaft housing defining a housing lumen, a pump housing disposed at a distal end portion of the drive shaft housing, and an inlet cannula extending from the pump housing. In some embodiments, the pump housing and inlet cannula are radially reconfigurable between (i) a low profile configuration when radially constrained within a sheath lumen of a delivery sheath device, and (ii) a radially expanded configuration when unconstrained by the delivery sheath device. The housing lumen can be configured to slidably receive the drive shaft and pump impeller when the pump impeller is in a contracted, low profile delivery configuration.

[0011] Another exemplary system described herein includes a blood pump with a rotatable pump impeller expandable from a low profile delivery configuration to a radially expanded configuration, the pump impeller configured to pump blood when rotated while in the radially expanded configuration.

[0012] Such a blood pump may optionally include at least one or more of the following features: The pump impeller may include a tapered body having an outer surface and one or more ridges extending from the outer surface. The one or more ridges may be expandable. The pump impeller may include a tapered body having an outer surface defining one or more grooves extending along the outer surface. The blood pump may also include an elongate flexible drive shaft. The pump impeller may be attached to a distal end portion of the drive shaft. The pump impeller may rotate in response to rotation of the drive shaft.

[0013] Another exemplary system described herein includes a blood pump system comprising an elongate delivery sheath device defining a sheath lumen, a housing component slidably positionable within the sheath lumen, and a rotatable inner catheter. The housing component comprises an elongate drive shaft housing defining a housing lumen, a pump housing disposed at a distal end portion of the drive shaft housing, and an inlet cannula extending from the pump housing. The pump housing and inlet cannula are radially reconfigurable between (i) a low profile configuration when radially constrained within the sheath lumen and (ii) a radially expanded configuration when unconstrained by the delivery sheath device. The rotatable inner catheter is slidably positionable within the housing lumen. The rotatable inner catheter comprises an elongate flexible drive shaft and an impeller disposed at a distal end of the drive shaft. The impeller is slidably positionable within the housing lumen when in a radially collapsed configuration. The impeller is radially expandable within the pump housing to an operable configuration.

[0014] Such a blood pump system may optionally include at least one or more of the following features: The impeller may be movable relative to the pump housing in response to retraction or advancement of the drive shaft relative to the drive shaft housing. The drive shaft may define an inflation lumen. The impeller may be radially expandable in response to receiving inflation fluid supplied to the impeller through the inflation lumen. The inner catheter may also include a drive shaft hub attached to a proximal end portion of the drive shaft. The drive shaft hub may have a drive shaft hub seal coupled with the hub. The drive shaft hub seal may seal a proximal end of the inflation lumen. The blood pump system may also include a motor. The inner catheter may also include a drive shaft hub attached to a proximal end portion of the drive shaft. The drive shaft hub may be configured to be coupled to the motor. The motor and drive shaft hub may be configured to allow inflation fluid to flow through the drive shaft hub and into the inflation lumen while the drive shaft hub is coupled to the motor. The blood pump system may be configured to pump blood when (i) the impeller is disposed within the pump housing at a target location within the patient, (ii) the impeller and pump housing are expanded, and (iii) the drive shaft is rotated by a motor located external to the patient. The inlet cannula may define one or more inlet openings. The pump housing may define one or more outlet openings. The delivery sheath device and the drive shaft housing may each define one or more openings. The one or more openings of the delivery sheath device may at least partially align with the one or more openings of the drive shaft housing when the impeller is disposed within the pump housing. The blood pump system may be configured to pump blood by rotation of the impeller while the impeller is disposed within the pump housing, without having a mechanical bearing or bushing between the impeller and the pump housing. The impeller may be configured to self-center with respect to the pump housing upon rotation within the pump housing.

[0015] Another exemplary system described herein includes a percutaneous ventricular assist device. Such a percutaneous ventricular assist device may include an elongate drive shaft housing defining a lumen, a pump housing attached to a distal end portion of the drive shaft housing, and a pump impeller attached to the distal end portion of the elongate drive shaft. The pump housing may be attached to the distal end portion of the drive shaft housing. The pump housing may be radially reconfigurable between (i) a low profile delivery configuration configured for transvascular advancement to a target location within a patient, and (ii) a radially expanded configuration. The pump impeller may be slidably positionable within the lumen when in a radially collapsed configuration. The pump impeller may be radially expandable to an operable configuration when the pump impeller is within the radially expanded configuration of the pump housing at a target location within a patient.

[0016] Such a percutaneous ventricular assist device may optionally include at least one or more of the following features: The pump impeller may be movable relative to the pump housing in response to retraction or advancement of the drive shaft relative to the drive shaft housing. The drive shaft may define an inflation lumen. The pump impeller may be radially expandable in response to receiving inflation fluid supplied to the pump impeller through the inflation lumen. The percutaneous ventricular assist device may be configured to pump blood by rotation of the pump impeller while the pump impeller is disposed within the pump housing, without having mechanical bearings or bushings between the pump impeller and the pump housing. The pump housing may be configured to self-expand into a radially expanded configuration.

[0017] Another exemplary system described herein includes a mechanical hemodynamic assist device comprising a pump housing configured for placement within a patient and for enabling blood flow from a pump housing inlet to a pump housing outlet, and a pump impeller positionable within the pump housing, the pump impeller rotatable relative to the pump housing to effect blood flow from the pump housing inlet to the pump housing outlet, the pump impeller configured to self-center with respect to the pump housing upon rotation relative to the pump housing.

[0018] Such a mechanical hemodynamic assist device may optionally include at least one or more of the following features: The pump impeller may be attached to a flexible drive shaft. The pump impeller may be reconfigurable between (i) a contracted, low profile delivery configuration configured for transvascular advancement to a target location within a patient, and (ii) an expanded, radially expanded configuration configured to pump blood when the pump impeller is rotated by the drive shaft. The pump housing may be reconfigurable between a low profile delivery configuration and a radially expanded operational configuration. The pump impeller may be expandable from a low profile delivery configuration to a radially expanded operational configuration configured to pump blood when the pump impeller is rotated relative to the pump housing. The pump housing may be attached to a distal end portion of the drive shaft housing. The drive shaft housing may allow purge fluid or blood to flow between the pump housing and the pump impeller to provide a hydrodynamic bearing between the pump housing and the pump impeller.

[0019] The present disclosure also describes methods of placing and operating blood pump systems, such as percutaneous ventricular assist devices and mechanical hemodynamic assist devices. In one example, such a method of placing a percutaneous blood flow assist device at a target location within a patient includes advancing an elongate delivery sheath device through an incision in the patient. The delivery sheath device may define a sheath lumen that houses a housing component slidably disposed within the sheath lumen. Such housing component may include an elongate drive shaft housing defining a housing lumen, a pump housing disposed at a distal end portion of the drive shaft housing, and an inlet cannula extending distally from the pump housing. The method may also include, when the pump housing is at the target location, retracting a delivery sheath device relative to the housing component to express the inlet cannula and the pump housing out of the sheath lumen, inserting a rotatable inner catheter into the housing lumen of the drive shaft housing, advancing the inner catheter relative to the housing component to position the pump impeller within the pump housing, and inflating the pump impeller to a radially expanded, operable configuration by supplying inflation fluid while the pump impeller resides within the pump housing. The pump housing and inlet cannula may be radially reconfigurable between (i) a low profile configuration when radially constrained within the sheath lumen and (ii) a radially expanded configuration when unconstrained by the delivery sheath device. The inner catheter may include an elongate flexible drive shaft and a pump impeller disposed at a distal end of the drive shaft. The pump impeller may be in a radially collapsed configuration when present within the housing lumen.

[0020] Such a method of placing a percutaneous blood flow assist device at a target location within a patient may optionally include at least one or more of the following features: The incision may provide access to the patient's femoral artery, and the delivery sheath device may be advanced through the femoral artery to the target location. The incision may provide access to the patient's radial artery, and the delivery sheath device may be advanced through the radial artery to the target location. The incision may provide access to the patient's thoracic cavity, and the delivery sheath device may be advanced through the thoracic cavity to the target location. The method may also include rotating the drive shaft with a motor located external to the patient while the pump impeller is in a radially expanded operable configuration and resides within the pump housing. Rotating the drive shaft may cause the pump impeller to rotate relative to the pump housing. The pump impeller may self-center relative to the pump housing while rotating relative to the pump housing. The delivery sheath device and the drive shaft housing may each define one or more openings. The one or more openings of the delivery sheath device may be at least partially aligned with the one or more openings of the drive shaft housing when the pump impeller is disposed within the pump housing. In some embodiments of the method, blood flows distally through the aligned one or more openings of the delivery sheath device and the drive shaft housing toward the pump impeller to provide a hydrodynamic bearing between the pump impeller and the pump housing. In certain embodiments, the motor and system controller are portable and capable of moving with the patient such that the patient is freely ambulatory while receiving circulatory assistance from the percutaneous blood flow assist device. The target location may be the aortic valve region of the patient.

[0021] In another example, a method of placing a percutaneous blood flow assist device at a target location within a patient includes advancing a housing component through a skin opening into the patient's radial artery. The housing component may include an elongate drive shaft housing defining a housing lumen and a pump housing disposed at a distal end portion of the drive shaft housing. The pump housing may be radially reconfigurable between a low profile configuration and a radially expanded configuration. The method may also include inserting a rotatable inner catheter into the housing lumen of the drive shaft housing while the pump housing is at the target location. The inner catheter may include an elongate flexible drive shaft and a pump impeller disposed at a distal end of the drive shaft. The pump impeller may be in a radially collapsed configuration when present within the housing lumen. The method also includes inflating the pump impeller to a radially expanded operable configuration by supplying an inflation fluid while the pump impeller is present within the pump housing.

[0022] Such a method of placing a percutaneous blood flow assist device at a target location within a patient may optionally include at least one or more of the following features: The target location may be an aortic valve region of the patient. The method may include rotating a drive shaft with a motor located external to the patient while the pump impeller is in a radially expanded operable configuration and is within the pump housing. Rotating the drive shaft may cause the pump impeller to rotate relative to the pump housing. The pump impeller may have a tendency to self-center relative to the pump housing while rotating relative to the pump housing. In some embodiments, inflating the pump impeller includes supplying an inflation fluid to the pump impeller through an inflation lumen of the drive shaft.

[0023] In another example, a method of placing a percutaneous blood flow assist device at a target location within a patient includes (i) advancing one or more components of the percutaneous blood flow assist device through a skin opening into the patient's radial artery, and (ii) expanding a pump impeller of the percutaneous blood flow assist device to a radially expanded, operable configuration at the target location.

[0024] Such a method of placing a percutaneous blood flow assist device at a target location within a patient may optionally include at least one or more of the following features: The target location may be the aortic valve region of the patient. The pump impeller may be attached to a distal end portion of an elongated flexible drive shaft. The method may also include rotating the pump impeller by rotating the drive shaft with a motor located external to the patient while the pump impeller is in the aortic valve region and in a radially expanded operable configuration. In some embodiments, rotating the pump impeller pumps blood from the patient's left ventricle across the aortic valve and into the patient's aorta. In certain embodiments, the pump impeller is attached to a distal end portion of an elongated flexible drive shaft. Expanding the pump impeller may be performed by supplying an inflation fluid to the pump impeller through an inflation lumen of the drive shaft.

[0025] While multiple embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive. [Brief description of the drawings]

[0026] [Figure 1] 1 is a schematic diagram illustrating an exemplary mechanical hemodynamic support system for providing hemodynamic support to a patient, according to an embodiment of the subject matter disclosed herein. [Diagram 2] 1 is a schematic diagram illustrating another exemplary mechanical hemodynamic support system for providing hemodynamic support to a patient, according to embodiments of the subject matter disclosed herein. [Diagram 3] 1A-1C show an exemplary mechanical hemodynamic assist device positioned in a patient's heart in a blood withdrawal configuration, according to embodiments of the subject matter disclosed herein. [Figure 4A] 1A-1C show another exemplary mechanical hemodynamic assist device positioned in a patient's heart in a blood pushing configuration, according to embodiments of the subject matter disclosed herein. [Figure 4B] 1A-1C show another exemplary mechanical hemodynamic assist device positioned in a patient's heart in a blood pushing configuration, according to embodiments of the subject matter disclosed herein. [Figure 5A] 1A-1C show an exemplary outer sheath and housing component catheter of a mechanical hemodynamic assist system in a collapsed configuration, in accordance with an embodiment of the subject matter disclosed herein. [Figure 5B] 5B illustrates a sheath of the outer catheter of FIG. 5A according to an embodiment of the presently disclosed subject matter. [Figure 6] FIG. 6 shows the housing component catheter of FIG. 5 in an expanded configuration. [Figure 7] 1A-1C show an exemplary rotatable inner catheter of a mechanical hemodynamic assist system in an expanded configuration, in accordance with an embodiment of the subject matter disclosed herein. [Figure 8A] 1A-1D illustrate steps for assembling and / or deploying a mechanical hemodynamic assist system according to an embodiment of the subject matter disclosed herein. [Figure 8B] 1A-1D illustrate steps for assembling and / or deploying a mechanical hemodynamic assist system according to an embodiment of the subject matter disclosed herein. [Figure 8C] 1A-1D illustrate steps for assembling and / or deploying a mechanical hemodynamic assist system according to an embodiment of the subject matter disclosed herein. [Figure 8D] 1A-1D illustrate steps for assembling and / or deploying a mechanical hemodynamic assist system according to an embodiment of the subject matter disclosed herein. [Figure 8E]1A-1D illustrate steps for assembling and / or deploying a mechanical hemodynamic assist system according to an embodiment of the subject matter disclosed herein. [Figure 9A] 1A-1D illustrate steps for assembling and / or deploying a mechanical hemodynamic assist system according to an embodiment of the subject matter disclosed herein. [Figure 9B] 1A-1D illustrate steps for assembling and / or deploying a mechanical hemodynamic assist system according to an embodiment of the subject matter disclosed herein. [Figure 9C] 1A-1D illustrate steps for assembling and / or deploying a mechanical hemodynamic assist system according to an embodiment of the subject matter disclosed herein. [Figure 9D] 1A-1D illustrate steps for assembling and / or deploying a mechanical hemodynamic assist system according to an embodiment of the subject matter disclosed herein. [Figure 9E] 1A-1D illustrate steps for assembling and / or deploying a mechanical hemodynamic assist system according to an embodiment of the subject matter disclosed herein. [Figure 9F] 1A-1D illustrate steps for assembling and / or deploying a mechanical hemodynamic assist system according to an embodiment of the subject matter disclosed herein. [Figure 10A] 4C shows the assembled mechanical hemodynamic assist device of FIGS. 4A and 4B according to an embodiment of the subject matter disclosed herein. [Figure 10B] 4C shows the assembled mechanical hemodynamic assist device of FIGS. 4A and 4B according to an embodiment of the subject matter disclosed herein. [Figure 11] 2A-2C illustrate interactions between an exemplary pump impeller and an exemplary pump housing, according to embodiments of the subject matter disclosed herein. [Figure 12A] 1A-1C illustrate interactions between pump impellers having various shapes and a pump housing according to embodiments of the subject matter disclosed herein. [Figure 12B]1A-1C illustrate interactions between pump impellers having various shapes and a pump housing according to embodiments of the subject matter disclosed herein. [Figure 12C] 1A-1C illustrate interactions between pump impellers having various shapes and a pump housing according to embodiments of the subject matter disclosed herein. [Figure 12D] 1A-1C illustrate interactions between pump impellers having various shapes and a pump housing according to embodiments of the subject matter disclosed herein. [Figure 13A] 1A-1C illustrate an exemplary pump impeller, an exemplary pump housing, and blood flow characteristics according to embodiments of the subject matter disclosed herein. [Figure 13B] 1A-1C illustrate an exemplary pump impeller, an exemplary pump housing, and blood flow characteristics according to embodiments of the subject matter disclosed herein. [Figure 14A] 1A-1C illustrate an exemplary pump impeller, an exemplary pump housing, and blood flow characteristics according to embodiments of the subject matter disclosed herein. [Figure 14B] 1A-1C illustrate an exemplary pump impeller, an exemplary pump housing, and blood flow characteristics according to embodiments of the subject matter disclosed herein. [Figure 15A] 1A-1C illustrate an example pump impeller, an example pump housing, and a miniature recessed motor according to embodiments of the subject matter disclosed herein. [Figure 15B] 1A-1C illustrate an example pump impeller, an example pump housing, and a miniature recessed motor according to embodiments of the subject matter disclosed herein. [Figure 15C] 1A-1C illustrate an example pump impeller, an example pump housing, and a miniature recessed motor according to embodiments of the subject matter disclosed herein. [Figure 16A] 1A-1C illustrate an exemplary expansion needle used to expand a particular pump impeller, according to embodiments of the subject matter disclosed herein. [Figure 16B]1A-1C illustrate an exemplary expansion needle used to expand a particular pump impeller, according to embodiments of the subject matter disclosed herein. [Figure 17A] 13A-13D illustrate steps of expanding the pump impeller and coupling the drive shaft to an external motor according to an embodiment of the subject matter disclosed herein. [Figure 17B] 13A-13D illustrate steps of expanding the pump impeller and coupling the drive shaft to an external motor according to an embodiment of the subject matter disclosed herein. [Figure 17C] 13A-13D illustrate steps of expanding the pump impeller and coupling the drive shaft to an external motor according to an embodiment of the subject matter disclosed herein. [Figure 18A] 1A-1C illustrate steps of coupling an impeller drive shaft to a motor and expanding an exemplary pump impeller in accordance with an embodiment of the subject matter disclosed herein. [Figure 18B] 1A-1C illustrate steps of coupling an impeller drive shaft to a motor and expanding an exemplary pump impeller in accordance with an embodiment of the subject matter disclosed herein. [Figure 18C] 1A-1C illustrate steps of coupling an impeller drive shaft to a motor and expanding an exemplary pump impeller in accordance with an embodiment of the subject matter disclosed herein. [Figure 19A] 1A-1C show an exemplary braid supported inlet cannula and pump housing according to an embodiment of the subject matter disclosed herein. [Figure 19B] 1A-1C show an exemplary braid supported inlet cannula and pump housing according to an embodiment of the subject matter disclosed herein. [Figure 20A] 1A-1C show an exemplary coil-supported inlet cannula and an unsupported pump housing, according to an embodiment of the subject matter disclosed herein. [Figure 20B] 1A-1C show an exemplary coil-supported inlet cannula and an unsupported pump housing, according to an embodiment of the subject matter disclosed herein. [Figure 21A] 1A-1C show an exemplary coil supported inlet cannula and longitudinally supported pump housing according to an embodiment of the subject matter disclosed herein. [Figure 21B] 1A-1C show an exemplary coil supported inlet cannula and longitudinally supported pump housing according to an embodiment of the subject matter disclosed herein. [Figure 22A] 1A-1C show an exemplary braid-supported inlet cannula and pump housing having a constant diameter, according to an embodiment of the subject matter disclosed herein. [Figure 22B] 1A-1C show an exemplary balloon inlet cannula and pump housing according to an embodiment of the subject matter disclosed herein. [Figure 23A] 1A-1C show an exemplary mechanical hemodynamic assist device with an aortic valve engaging skirt, in accordance with embodiments of the subject matter disclosed herein. [Figure 23B] 1A-1C show an exemplary mechanical hemodynamic assist device with an aortic valve engaging skirt, in accordance with embodiments of the subject matter disclosed herein. [Figure 24A] 1A-1C show an exemplary mechanical hemodynamic assist device with aortic valve engaging petals, in accordance with embodiments of the subject matter disclosed herein. [Figure 24B] 1A-1C show an exemplary mechanical hemodynamic assist device with aortic valve engaging petals, in accordance with embodiments of the subject matter disclosed herein. [Diagram 25] 4A-4C illustrate an exemplary method of anchoring the mechanical hemodynamic assistance device of FIG. 3 within a patient's anatomy, according to an embodiment of the subject matter disclosed herein. [Figure 26] 4 illustrates another exemplary method and apparatus for anchoring the mechanical hemodynamic assistance device of FIG. 3 within a patient's anatomy, according to embodiments of the subject matter disclosed herein. [Figure 27] 4 illustrates another exemplary method and apparatus for anchoring the mechanical hemodynamic assistance device of FIG. 3 within a patient's anatomy, according to embodiments of the subject matter disclosed herein. [Figure 28A] 1A-1C illustrate an exemplary pump housing and blood outlet port according to an embodiment of the subject matter disclosed herein. [Figure 28B] 1A-1C illustrate an exemplary pump housing and blood outlet port according to an embodiment of the subject matter disclosed herein. [Figure 28C] 1A-1C illustrate an exemplary pump housing and blood outlet port according to an embodiment of the subject matter disclosed herein. [Figure 28D] 1A-1C illustrate an exemplary pump housing and blood outlet port according to an embodiment of the subject matter disclosed herein. [Figure 28E] 1A-1C illustrate an exemplary pump housing and blood outlet port according to an embodiment of the subject matter disclosed herein. [Figure 28F] 1A-1C illustrate an exemplary pump housing and blood outlet port according to an embodiment of the subject matter disclosed herein. [Figure 29A] 1A-1C illustrate an exemplary pump housing and blood outlet port angle according to an embodiment of the subject matter disclosed herein. [Figure 29B] 1A-1C illustrate an exemplary pump housing and blood outlet port angle according to an embodiment of the subject matter disclosed herein. [Figure 29C] 1A-1C illustrate an exemplary pump housing and blood outlet port angle according to an embodiment of the subject matter disclosed herein. [Diagram 30] 1A-1C illustrate an exemplary catheter delivery sheath in accordance with an embodiment of the presently disclosed subject matter. [Figure 31A] 1A-1C illustrate an exemplary tear-away catheter delivery sheath in accordance with an embodiment of the presently disclosed subject matter. [Figure 31B] 1A-1C illustrate an exemplary tear-away catheter delivery sheath in accordance with an embodiment of the presently disclosed subject matter. [Figure 31C] 1A-1C illustrate an exemplary tear-away catheter delivery sheath in accordance with an embodiment of the presently disclosed subject matter. [Diagram 32] 1A-1C show an exemplary catheter delivery sheath having blood perfusion holes in accordance with embodiments of the subject matter disclosed herein. [Figure 33A] 1A-1C show an exemplary catheter delivery sheath having a proximal notch, in accordance with an embodiment of the subject matter disclosed herein. [Figure 33B] 1A-1C show an exemplary catheter delivery sheath having a proximal notch, in accordance with an embodiment of the subject matter disclosed herein. [Figure 34A] 1A-1C illustrate exemplary housing components according to embodiments of the subject matter disclosed herein. [Figure 34B] 1A-1C illustrate exemplary housing components according to embodiments of the subject matter disclosed herein. [Figure 33C] 1A-1C illustrate exemplary housing components according to embodiments of the subject matter disclosed herein. [Diagram 35] 1A-1C show an exemplary housing component having blood perfusion holes according to embodiments of the subject matter disclosed herein. [Diagram 36] FIG. 2 illustrates an exemplary housing component having an open cell matrix, according to an embodiment of the subject matter disclosed herein. [Figure 37A] 1A-1C illustrate an exemplary housing component having lumens for electrical connections according to embodiments of the subject matter disclosed herein. [Figure 37B] 1A-1C illustrate an exemplary housing component having lumens for electrical connections according to embodiments of the subject matter disclosed herein. [Figure 38A] 1 illustrates an exemplary drive shaft of a mechanical hemodynamic assist system, according to an embodiment of the subject matter disclosed herein. [Figure 38B] 1 illustrates an exemplary drive shaft of a mechanical hemodynamic assist system, according to an embodiment of the subject matter disclosed herein. [Figure 38C] 1 illustrates an exemplary drive shaft of a mechanical hemodynamic assist system, according to an embodiment of the subject matter disclosed herein. [Figure 38D] 1 illustrates an exemplary drive shaft of a mechanical hemodynamic assist system, according to an embodiment of the subject matter disclosed herein. [Figure 38E] 1 illustrates an exemplary drive shaft of a mechanical hemodynamic assist system, according to an embodiment of the subject matter disclosed herein. [Figure 39A] FIG. 38F further illustrates the drive shafts of FIGS. 38A-38E and their potential failure modes. [Figure 39B] FIG. 38F further illustrates the drive shafts of FIGS. 38A-38E and their potential failure modes. [Figure 39C] FIG. 38F further illustrates the drive shafts of FIGS. 38A-38E and their potential failure modes. [Figure 40A] 1A-1C illustrate an exemplary drive shaft and drive shaft hub of a mechanical hemodynamic assist system, in accordance with embodiments of the subject matter disclosed herein. [Figure 40B] 1A-1C illustrate an exemplary drive shaft and drive shaft hub of a mechanical hemodynamic assist system, in accordance with embodiments of the subject matter disclosed herein. [Figure 40C] 1A-1C illustrate an exemplary drive shaft and drive shaft hub of a mechanical hemodynamic assist system, in accordance with embodiments of the subject matter disclosed herein. [Figure 40D] 1A-1C illustrate an exemplary drive shaft and drive shaft hub of a mechanical hemodynamic assist system, in accordance with embodiments of the subject matter disclosed herein. [Figure 41A] 1A-1D illustrate an exemplary expandable impeller of a mechanical hemodynamic assist device, according to embodiments of the subject matter disclosed herein. [Figure 41B] 1A-1D illustrate an exemplary expandable impeller of a mechanical hemodynamic assist device, according to embodiments of the subject matter disclosed herein. [Figure 42A] 1A-1C show an exemplary braid-supported expandable impeller of a mechanical hemodynamic assist device, according to embodiments of the subject matter disclosed herein. [Figure 42B]1A-1C show an exemplary braid-supported expandable impeller of a mechanical hemodynamic assist device, according to embodiments of the subject matter disclosed herein. [Figure 43A] 1A-1C show an exemplary triangular structurally supported expandable impeller of a mechanical hemodynamic assist device according to embodiments of the subject matter disclosed herein. [Figure 43B] 1A-1C show an exemplary triangular structurally supported expandable impeller of a mechanical hemodynamic assist device according to embodiments of the subject matter disclosed herein. [Figure 43C] 1A-1C show an exemplary triangular structurally supported expandable impeller of a mechanical hemodynamic assist device according to embodiments of the subject matter disclosed herein. [Figure 44A] 1A-1C show an exemplary expandable impeller with ridges of a mechanical hemodynamic assist device according to embodiments of the subject matter disclosed herein. [Figure 44B] 1A-1C show an exemplary expandable impeller with ridges of a mechanical hemodynamic assist device according to embodiments of the subject matter disclosed herein. [Figure 44C] 1A-1C show an exemplary expandable impeller with ridges of a mechanical hemodynamic assist device according to embodiments of the subject matter disclosed herein. [Figure 45A] 1A-1C show an exemplary expandable impeller with spiral ridges of a mechanical hemodynamic assist device, according to embodiments of the subject matter disclosed herein. [Figure 45B] 1A-1C show an exemplary expandable impeller with spiral ridges of a mechanical hemodynamic assist device, according to embodiments of the subject matter disclosed herein. [Figure 45C] 1A-1C show an exemplary expandable impeller with spiral ridges of a mechanical hemodynamic assist device, according to embodiments of the subject matter disclosed herein. [Figure 46A] 1A-1C show an exemplary expandable impeller with valleys of a mechanical hemodynamic assist device, according to embodiments of the subject matter disclosed herein. [Figure 46B] 1A-1C show an exemplary expandable impeller with valleys of a mechanical hemodynamic assist device, according to embodiments of the subject matter disclosed herein. [Figure 46C] 1A-1C show an exemplary expandable impeller with valleys of a mechanical hemodynamic assist device, according to embodiments of the subject matter disclosed herein. [Figure 46D] 1A-1C show an exemplary expandable impeller with valleys of a mechanical hemodynamic assist device, according to embodiments of the subject matter disclosed herein. [Figure 47A] 1A-1C show an exemplary expandable impeller with spiral valleys of a mechanical hemodynamic assist device, according to embodiments of the subject matter disclosed herein. [Figure 47B] 1A-1C show an exemplary expandable impeller with spiral valleys of a mechanical hemodynamic assist device, according to embodiments of the subject matter disclosed herein. [Figure 47C] 1A-1C show an exemplary expandable impeller with spiral valleys of a mechanical hemodynamic assist device, according to embodiments of the subject matter disclosed herein. [Figure 48A] 1A-1C show an exemplary expandable impeller having variations in the proximal surface contour of a mechanical hemodynamic assist device, according to embodiments of the subject matter disclosed herein. [Figure 48B] 1A-1C show an exemplary expandable impeller having variations in the proximal surface contour of a mechanical hemodynamic assist device, according to embodiments of the subject matter disclosed herein. [Figure 49A] 1A-1C show an exemplary expandable impeller having variations in the proximal surface contour of a mechanical hemodynamic assist device, according to embodiments of the subject matter disclosed herein. [Figure 49B] 1A-1C show an exemplary expandable impeller having variations in the proximal surface contour of a mechanical hemodynamic assist device, according to embodiments of the subject matter disclosed herein. [Figure 50A]1A-1C show an exemplary expandable impeller having variations in the proximal surface contour of a mechanical hemodynamic assist device, according to embodiments of the subject matter disclosed herein. [Figure 50B] 1A-1C show an exemplary expandable impeller having variations in the proximal surface contour of a mechanical hemodynamic assist device, according to embodiments of the subject matter disclosed herein. [Figure 51A] 1A-1C show an exemplary expandable impeller with distal end modifications for a blood pushing configuration of a mechanical hemodynamic assist device according to embodiments of the subject matter disclosed herein. [Figure 51B] 1A-1C show an exemplary expandable impeller with distal end modifications for a blood pushing configuration of a mechanical hemodynamic assist device according to embodiments of the subject matter disclosed herein. [Figure 52A] 1A-1C show another exemplary expandable impeller of a mechanical hemodynamic assist device, in accordance with embodiments of the subject matter disclosed herein. [Figure 52B] 1A-1C show another exemplary expandable impeller of a mechanical hemodynamic assist device, in accordance with embodiments of the subject matter disclosed herein. [Figure 52C] 1A-1C show another exemplary expandable impeller of a mechanical hemodynamic assist device, in accordance with embodiments of the subject matter disclosed herein. [Fig. 52D] 1A-1C show another exemplary expandable impeller of a mechanical hemodynamic assist device, in accordance with embodiments of the subject matter disclosed herein. [Figure 53A] 1A-1C show another exemplary expandable impeller of a mechanical hemodynamic assist device, in accordance with embodiments of the subject matter disclosed herein. [Figure 53B] 1A-1C show another exemplary expandable impeller of a mechanical hemodynamic assist device, in accordance with embodiments of the subject matter disclosed herein. [Figure 53C] 1A-1C show another exemplary expandable impeller of a mechanical hemodynamic assist device, in accordance with embodiments of the subject matter disclosed herein. [Figure 54A]1A-1C show another exemplary expandable impeller of a mechanical hemodynamic assist device, in accordance with embodiments of the subject matter disclosed herein. [Figure 54B] 1A-1C show another exemplary expandable impeller of a mechanical hemodynamic assist device, in accordance with embodiments of the subject matter disclosed herein. [Fig. 54C] 1A-1C show another exemplary expandable impeller of a mechanical hemodynamic assist device, in accordance with embodiments of the subject matter disclosed herein. [Figure 55A] 1A-1C show another exemplary expandable impeller of a mechanical hemodynamic assist device, in accordance with embodiments of the subject matter disclosed herein. [Figure 55B] 1A-1C show another exemplary expandable impeller of a mechanical hemodynamic assist device, in accordance with embodiments of the subject matter disclosed herein. [Figure 55C] 1A-1C show another exemplary expandable impeller of a mechanical hemodynamic assist device, in accordance with embodiments of the subject matter disclosed herein. [Fig. 55D] 1A-1C show another exemplary expandable impeller of a mechanical hemodynamic assist device, in accordance with embodiments of the subject matter disclosed herein. [Figure 56A] 1 illustrates components and steps of an exemplary method for manufacturing an expandable impeller according to embodiments of the subject matter disclosed herein. [Figure 56B] 1 illustrates components and steps of an exemplary method for manufacturing an expandable impeller according to embodiments of the subject matter disclosed herein. [Figure 56C] 1 illustrates components and steps of an exemplary method for manufacturing an expandable impeller according to embodiments of the subject matter disclosed herein. [Figure 56D] 1 illustrates components and steps of an exemplary method for manufacturing an expandable impeller according to embodiments of the subject matter disclosed herein. [Figure 56E] 1 illustrates components and steps of an exemplary method for manufacturing an expandable impeller according to embodiments of the subject matter disclosed herein. [Fig. 56F] 1 illustrates components and steps of an exemplary method for manufacturing an expandable impeller according to embodiments of the subject matter disclosed herein. [Figure 57A] 13A-13D illustrate components and steps of an exemplary method for manufacturing another expandable impeller in accordance with embodiments of the subject matter disclosed herein. [Figure 57B] 13A-13D illustrate components and steps of an exemplary method for manufacturing another expandable impeller in accordance with embodiments of the subject matter disclosed herein. [Figure 57C] 57A-57B show an expandable impeller produced by the method shown in FIGS. 57A-57B, according to an embodiment of the subject matter disclosed herein. [Fig. 57D] 57A-57B show an expandable impeller produced by the method shown in FIGS. 57A-57B, according to an embodiment of the subject matter disclosed herein. [Figure 58A] 13A-13D illustrate components and steps of an exemplary method for manufacturing another expandable impeller in accordance with embodiments of the subject matter disclosed herein. [Figure 58B] 13A-13D illustrate components and steps of an exemplary method for manufacturing another expandable impeller in accordance with embodiments of the subject matter disclosed herein. [Figure 58C] 13A-13D illustrate components and steps of an exemplary method for manufacturing another expandable impeller in accordance with embodiments of the subject matter disclosed herein. [Fig. 58D] 58A-58C show an expandable impeller produced by the method shown in FIGS. 58A-58C according to an embodiment of the subject matter disclosed herein. [Figure 58E] 58A-58C show an expandable impeller produced by the method shown in FIGS. 58A-58C according to an embodiment of the subject matter disclosed herein. [Figure 59A] 13A-13D illustrate components and steps of an exemplary method for manufacturing another expandable impeller in accordance with embodiments of the subject matter disclosed herein. [Figure 59B]13A-13D illustrate components and steps of an exemplary method for manufacturing another expandable impeller in accordance with embodiments of the subject matter disclosed herein. [Figure 59C] 59A-59B show an expandable impeller produced by the method shown in FIGS. 59A-59B according to an embodiment of the subject matter disclosed herein. [Figure 60A] FIG. 1 illustrates an exemplary method of using a pressurized balloon within a patient's cardiovascular system to act as a pressure transducer, thereby providing measurements of the patient's systolic and diastolic blood pressure. [Figure 60B] FIG. 1 illustrates an exemplary method of using a pressurized balloon within a patient's cardiovascular system to act as a pressure transducer, thereby providing measurements of the patient's systolic and diastolic blood pressure. [Figure 61] 1A-1D illustrate various arterial and venous access sites and routes for delivering mechanical hemodynamic assist devices to a patient's heart. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] While the invention is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail below. It is not intended, however, that the invention be limited to the particular embodiments described. Rather, the invention is intended to cover all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the appended claims.

[0028] A mechanical hemodynamic assist device, such as a percutaneous ventricular assist device ("pVAD") according to embodiments of the present disclosure, can unload or support a patient's heart for a period of time, such as during a myocardial infarction, cardiogenic shock, surgical or interventional procedure, etc.

[0029] In some embodiments, the pVAD devices described herein have a sufficiently small profile to facilitate deployment through a sheath placed at a radial artery access site. Some such embodiments of the pVAD devices described herein have an innovative two-part design that allows for a very small delivery profile, such as required by a radial artery access site. The pVAD devices described herein can also be deployed through other vascular access sites, such as, but not limited to, the femoral artery, the axillary artery, and the venous system, to provide some non-limiting examples.

[0030] After the device is advanced to a desired or target location, for example within a patient's heart, the device is radially expanded from its entry profile, also referred to as a low profile or collapsed configuration, to its functional pumping size, also referred to as an expanded or operable configuration. Devices according to embodiments of the present disclosure can be configured to provide a variety of flow outputs based on factors such as, but not limited to, size, impeller design, and impeller rotational speed.

[0031] As used herein, the terms "proximal" and "distal" refer to the orientation of the device, not the patient. For example, a proximal portion of a device described herein may be external to the patient for manipulation by a clinician operator, while a distal portion of the device is within the patient.

[0032] In some cases, the pump devices described herein are said to have a blood "push" configuration or a blood "draw" configuration. In this disclosure, "push" is used to describe a pumping configuration that causes blood to flow in a proximal to distal direction. In this disclosure, "draw" is used to describe a pumping configuration that causes blood to flow in a distal to proximal direction.

[0033] FIG. 1 illustrates a schematic diagram of an exemplary mechanical hemodynamic assist system 100 (or pVAD 100) for providing hemodynamic assistance to a patient P, according to some embodiments of the subject matter disclosed herein. The system 100 includes a mechanical hemodynamic assist device 102 (also referred to herein as a "pump device" or "blood pump") that may be disposed at least partially within the patient's heart H. In the illustrated embodiment, the system 100 includes an external motor 104 (located outside the patient P) that is coupled to the device 102 to drive the device 102 with an elongated flexible drive shaft 106 that transmits torque. A proximal end of the drive shaft 106 is coupled to the motor 104, and a distal end of the drive shaft 106 is coupled to the pump device 102. In other words, the drive shaft 106 is partially external to the patient P and partially internal to the patient P.

[0034] The motor 104 is controlled by a system controller 108, which controls the speed of the motor 104 and monitors the performance of the motor 104. The controller 108 also provides an interface to the system 100 for a clinician operator to set up and operate the system 100. The system controller 108 may be a separate system (as shown) or may be an integrated system that also houses the motor 104.

[0035] 2 illustrates another exemplary mechanical hemodynamic assist system 200 for providing hemodynamic assistance to a patient P, according to embodiments of the subject matter disclosed herein. In this embodiment, the system 200 comprises an internal motor 202 (located inside the patient P) coupled to and driving a mechanical hemodynamic assist device 204 located at least partially within the patient's heart H. The motor 202 is controlled by a system controller 206, which controls the speed of and monitors the performance of the motor 202. The controller 206 also provides an interface for the system 200 for a clinician operator to set up and operate the system 200.

[0036] With general reference to Figures 1 and 2, the motor used to drive the pump can be any motor capable of high speed rotation, such as, but not limited to, a brushless motor, a brushed DC motor, or an air-driven turbine.

[0037] 3 illustrates an exemplary mechanical hemodynamic assistance device 300 (or "pump device 300") positioned in a blood-drawing configuration on a patient's heart H, in accordance with some embodiments of the subject matter disclosed herein. Pump device 300 may represent, for example, device 102 of system 100 (FIG. 1) or device 204 of system 200 (FIG. 2).

[0038] In the illustrated configuration, the pump device 300 reaches the heart H by advancing the pump device 300 through a patient's vascular access site and vasculature, with the housing components of the pump device 300 housed within a delivery sheath component 500 (or sheath 500) in a low-profile delivery configuration, as described further below. In the depicted example, the sheath 500 housing the housing components of the pump device 300 is advanced into the aorta AO and then advanced partially across the aortic valve AV to the position shown. At that position, the sheath 500 is then pulled proximally by the clinician to expose the housing components of the pump device 300. The housing components will expand as they are exposed from the sheath 500. A separate inner catheter comprising a pump impeller and a flexible drive shaft is then advanced by the clinician into the housing components to construct or assemble the two-part pump device 300 in vivo, as described further below.

[0039] In the depicted embodiment, the distal tip portion of the pump device 300 defines one or more blood inlets 534 that penetrate a sidewall of a housing component of the pump device 300 and one or more end inlets 532 that penetrate a distal tip of a housing component of the pump device 300. The pump device 300 draws blood from the ventricle LV through the inlets 532 / 534 and then delivers the blood at higher pressure to the aortic root AOR through one or more blood outlets 526 disposed in the aortic root AOR. The multiple sidewall blood inlets 534, when properly positioned within the anatomy, may be located distal to the AV, thereby eliminating the possibility of blood from the aorta entering the inlet cannula and pump through the sidewall blood inlets 534. The blood is then circulated throughout the patient's systemic circulation by the patient's vascular system.

[0040] FIG. 4A illustrates another exemplary mechanical hemodynamic assist device 400 (or “pump device 400”) disposed in a patient's heart H in a blood-pushing configuration, according to an embodiment of the subject matter disclosed herein. Device 400 may represent, for example, device 102 of system 100 ( FIG. 1 ) or device 204 of system 200 ( FIG. 2 ). In the illustrated configuration, device 400 reaches heart H by advancing device 400 through a transseptal route into left atrium LA, across mitral valve MV, and then across aortic valve AV to the illustrated position. A distal tip portion of device 400 defines one or more blood outlets 402 disposed at aortic root AOR. One or more blood inlets 404 of device 400 are disposed in left ventricle LV and may comprise one or more fenestrations or openings defined through a sidewall of inlet cannula 406 of device 400.

[0041] 4B illustrates an exemplary mechanical hemodynamic assist device 400 disposed in a patient's heart H in another blood pushing configuration, according to an embodiment of the subject matter disclosed herein. The device 400 may represent, for example, device 102 of system 100 (FIG. 1) or device 204 of system 200 (FIG. 2). In the illustrated configuration, the device 400 reaches the heart H by advancing the device 400 through the patient's thoracic cavity, through the apex of the heart H into the left ventricle LV, and across the aortic valve AV to the illustrated position. A distal tip portion of the device 400 defines one or more blood outlets 402 disposed at the aortic root AOR. One or more blood inlets 404 of the device 400 are disposed in the left ventricle LV and may comprise one or more fenestrations or openings defined through a sidewall of an inlet cannula 406 of the device 400.

[0042] 5A illustrates an exemplary delivery sheath device 500 that can be used to deliver a housing component of a pump device described herein with the housing component of the pump device in a low profile, radially collapsed configuration. The delivery sheath 500 includes a handle 512 and a sheath 502 extending distally from the handle 512. The sheath 502 can define a lumen within which a housing component of a pump device described herein can be slidably disposed while radially constrained by the sheath 502 in the low profile, radially collapsed configuration.

[0043] 5A. Housing component 510 is the first part of a two-part pump device described herein and further below. A distal end portion of housing component 510 is disposed within the lumen of sheath 502 in a low profile radially folded configuration. Housing component 510 is configured to receive a separate pump impeller and associated drive shaft, as described below.

[0044] 5B shows a longitudinal cross-sectional view of the distal portion of the sheath 502, which contains the distal end portion of the housing component 510 in its low profile radially folded configuration. The distal end portion of the housing component 510 includes the inlet cannula 504, the pump housing 508, and the drive shaft housing 511.

[0045] The sheath 502 of the delivery sheath device 500 holds the expandable inlet cannula 504 and the pump housing 508 in a collapsed configuration during delivery to a target location within a patient. In the depicted embodiment, the distal tip portion of the sheath 502 includes an atraumatic bumper tip 506 to limit injury to the patient's vasculature and / or heart as the device is advanced through the patient's anatomy.

[0046] The proximal end of the pump housing 508 is coupled to the distal end of the drive shaft housing 511. After advancing the delivery sheath device 500 to the target location, the sheath handle 512 can be pulled proximally by the clinician, thereby exposing the inlet cannula 504 and the pump housing 508 and allowing these components to expand to their expanded, operating configuration.

[0047] 6 shows the delivery sheath device 500 and the housing component 510 after the delivery sheath device 500 has been pulled proximally to cause the inlet cannula 504 and pump housing 508 of the housing component 510 to emerge from the lumen of the sheath 502. Upon emergence from the sheath 502, the inlet cannula 504 and pump housing 508 can expand and reconfigure to their expanded configuration, as shown. The housing component 510 is an example of a first part of a two-part pump device described herein.

[0048] In some embodiments, the clinician operator may stop retracting the delivery sheath device 500 based on an indication that the radiopaque distal marker band 514 on the distal portion of the sheath 502 has moved proximal to the radiopaque marker 513 located on the drive shaft housing 511.

[0049] A drive shaft housing hub 518 may be disposed at a proximal end of the drive shaft housing 511. The pump housing 508 may be disposed at a distal end of the drive shaft housing 511. The drive shaft housing 511 may comprise a multi-filar coil or braid embedded on or within the inner wall of the polymer tubing that makes up the drive shaft housing 511. In some embodiments, the inner wall of the drive shaft housing 511 comprises a wear-resistant material to withstand contact with the rapidly rotating drive shaft.

[0050] In some embodiments, the pump housing 508 is or comprises a volute. The pump housing 508 comprises a flexible wall 524 that defines one or more blood flow outlets 526.

[0051] The inlet cannula 504 may include radiopaque markers at its proximal end 528 and / or its distal end 530. The inlet cannula 504 may include one or more end inlets 532 and / or one or more side inlets 534 that allow blood to flow into the inlet cannula 504. The inlet cannula 504 may include a flexible wall 536 with a support structure 538, such as a coil, embedded within or circumferentially disposed around the wall 536. The radiopaque markers on the proximal end 528 of the cannula 504 may be aligned with the aortic valve in the anatomy, facilitating placement of the pump housing 508 within the aortic root / ascending aorta and placement of the inlet cannula 504 in the left ventricle.

[0052] The inlet cannula 504 and pump housing 508 may have sufficient structural support to maintain their shape and promote efficient pumping, while also being sufficiently supple and flexible to ensure that the device can navigate the vasculature and reach the target vasculature without causing vascular injury, and also be left in place and pump blood for extended periods of time without causing damage to the targeted anatomical structures, such as the heart, valves, or larger blood vessels.

[0053] 7 shows an exemplary rotatable inner catheter of a mechanical hemodynamic assist system 700 in an expanded configuration according to an embodiment of the subject matter disclosed herein. The inner catheter 700 is an example of a second part of a two-part pump system described herein. The inner catheter 700 may be part of a blood-withdrawing pump device, such as, for example, pump device 300 (FIG. 3), and may be positionable within housing component 510, as described further below. However, it is understood that other types of rotatable inner catheters having similar features may be part of a blood-pushing pump device, such as, for example, device 400 (FIG. 4).

[0054] The inner catheter 700 is slidably positionable within a lumen defined by the housing component 510. As described further below, the inner catheter 700 may be inserted into the lumen defined by the housing component 510 after the inlet cannula 504 and pump housing 508 of the housing component 510 have been positioned in the heart and aorta (or other target location) and radially expanded as a result of retracting the delivery sheath device 500.

[0055] The inner catheter 700 comprises an elongate flexible drive shaft, which in this example includes a proximal drive shaft portion 704a and a distal drive shaft portion 704b. In the depicted embodiment, the proximal drive shaft portion 704a has a larger diameter than the distal drive shaft portion 704b, although this is not required in all embodiments. The combination of the proximal drive shaft portion 704a and the distal drive shaft portion 704b may be referred to as the drive shaft 704.

[0056] As depicted, the inner catheter 700 may also include a drive shaft hub 702 disposed at a proximal end portion of the proximal drive shaft section 704a. An expandable pump impeller 708 is disposed at a distal end portion of the distal drive shaft section 704b.

[0057] In some embodiments, the expandable pump impeller 708 is inflatable and contractable. In some such embodiments, a lumen defined by the drive shaft hub 702 and the drive shaft 704 allows for delivery of an inflation fluid, such as saline, to the inflatable impeller 708 through an inflation lumen 706. The distal drive shaft portion 704b can define one or more sidewall openings 712 through which inflation fluid can flow between the lumen 706 and the interior of the inflatable impeller 708.

[0058] In some embodiments, such as the depicted embodiment, the drive shaft 704 extends through the pump impeller 708 to a drive shaft tip portion 710 that extends distally from the pump impeller 708. In some embodiments, the drive shaft tip portion 710 may be fully or partially radiopaque for ease of identification under fluoroscopy.

[0059] 6 and 7 , after the delivery sheath device 500 (which houses the housing component 510 in its low profile radially constrained configuration) is positioned at a target location within a patient, the delivery sheath device 500 can be pulled proximally relative to the housing component 510 to allow the housing component 510 to reconfigure to its expanded configuration. The inner catheter 700 can then be advanced through the drive shaft housing 511 until the impeller 708 is positioned within the pump housing 508. The impeller 708 can then be expanded to its operative fluid pumping configuration, the expanded configuration (as shown). The inner catheter 700 can then be connected to the motor 104 (see, e.g., FIG. 1 ) and rotated to create a fluid pressure gradient, thereby causing blood flow into the inlet cannula 504, into the pump housing 508, and out through the outlet 526 of the pump housing 508.

[0060] 8A-8E show an exemplary sequence of steps for delivering and assembling in vivo a blood-withdrawing mechanical hemodynamic-assist device within a patient for use as part of a system 100 (e.g., FIG. 1) according to an embodiment of the subject matter disclosed herein. The illustrated exemplary blood-withdrawing two-part pump device 300 comprises a housing component 510 (see, e.g., FIGS. 5A, 5B, and 6) and a separate inner catheter (see, e.g., FIG. 7). The housing component 510 can be delivered to a target location using a delivery sheath device 500 (see, e.g., FIGS. 5A, 5B, and 6).

[0061] First, an access site is created in the patient, such as a radial access site, femoral access site, or other. In some embodiments, a guidewire is advanced into the patient's vasculature (e.g., across the aortic valve) to the target location. In some embodiments, no such guidewire is used.

[0062] Next, as shown in FIG. 8A, the delivery sheath device 500, containing the distal portion of the housing component 510, is advanced through the access site (e.g., using fluoroscopy or other image guidance in some embodiments) and tracked to the target location within the patient's anatomy.

[0063] Next, as shown in FIG. 8B, the delivery sheath device 500 is retracted by pulling the sheath handle 512 proximally, thereby exposing the inlet cannula 504 and pump housing 508. This is the first part of the two-part blood pump system. Upon exposing the inlet cannula 504 and pump housing 508 from the delivery sheath device 500, the inlet cannula 504 and pump housing 508 radially expand to their expanded configuration. The guidewire, if used, may then be fully retracted.

[0064] The rotatable inner catheter 700 in its radially contracted configuration (with the impeller 708 retracted) may then be advanced into the housing component 510, as depicted in Figure 8C. That is, the rotatable inner catheter 700 is inserted into the hub and lumen of the housing component 510 and advanced distally to reach the configuration shown in Figure 8D, where the impeller 708, still in its contracted configuration, is disposed within the pump housing 508. The rotatable inner catheter 700 is the second part of the two-part blood pump system.

[0065] The impeller 708 is then inflated and expanded within the pump housing 508, as shown in FIG. 8E. The rotatable inner catheter 700 and its impeller 708 can then be rotated by a motor located external to the patient (see, e.g., FIG. 1) to provide blood flow and hemodynamic assistance to the patient.

[0066] 9A-9F show a sequence of steps for delivering and assembling in vivo a blood withdrawal mechanical hemodynamic assist device in a patient for use as part of a system 200 (e.g., FIG. 2) comprising a blood pump with an internal motor located near the distal tip of a catheter system according to an embodiment of the subject matter disclosed herein. The illustrated blood withdrawal pump device 300 comprises a pumping unit 900 and an impeller inflation needle 1600. The pumping unit 900 comprises a drive shaft housing, an internal motor 202 located near the distal end of the drive shaft housing and coupled to a short drive shaft, and an impeller 708 extending distally from the motor 202, as well as a pump housing 508 and an inlet cannula 504 which also extend distally from the motor 202 and surround the impeller 708. The pumping unit 900 is delivered to a target location using a delivery sheath device 500.

[0067] First, an access site is created in the patient, such as a radial access site, femoral access site, or other. In some embodiments, a guidewire is advanced into the patient's vasculature (e.g., across the aortic valve) to the target location. Next, as shown in FIG. 9A, a delivery sheath device 500 containing a distal portion of a pumping unit 900 is advanced through the access site (e.g., over a pre-placed guidewire in some embodiments) and followed to the target location in the patient's anatomy.

[0068] 9B, the delivery sheath device 500 is then retracted by pulling the sheath handle 512 proximally, thereby exposing the inlet cannula 504 and pump housing 508, as well as the impeller and miniature motor 202 in their radially contracted configuration (impeller 708 retracted). In this system driven by the miniature internal motor 202, the impeller 708 may be deployed simultaneously with the housing 508. As the inlet cannula 504 and pump housing 508 are exposed from the delivery sheath device 500, they radially expand to their expanded configuration. The guidewire, if used, may then be fully retracted, thereby opening a passageway in the pumping unit 900 for inflating the impeller 708.

[0069] The impeller expansion needle 1600 depicted in Figure 9C may then be advanced into the pumping unit 900. That is, the expansion needle 1600 is inserted through the hub and lumen of the pumping unit 900 and advanced distally to reach the configuration shown in Figure 9D where the distal tip 1602 of the expansion needle 1600 is disposed within the impeller 708.

[0070] The impeller 708 is then inflated and expanded within the pump housing 508 by applying pressure to the hub 1606 of the inflation needle 1600 with an inflation medium (e.g., saline) that passes through an opening in the distal tip 1602 of the inflation needle 1600 and into the impeller 708, as shown in Figure 9E. Once the impeller 708 has expanded to its pumping configuration, the inflation needle 1600 may be completely removed from the catheter system, as shown in Figure 9F. The miniature internal motor 202 may then be actuated to rotate the impeller 708 (e.g., Figure 2) to provide blood flow and hemodynamic assistance to the patient.

[0071] 10A and 10B show a blood pumping mechanical hemodynamic assist device 400 designed for use as part of system 100 (FIG. 1) according to an embodiment of the subject matter disclosed herein. In some cases, pump device 400 may be positioned and operated within a patient in the configuration shown in FIG. 4A. In other cases, pump device 400 may be positioned and operated within a patient in the configuration shown in FIG. 4B. In yet other cases, pump device 400 may be positioned and operated within a patient in other configurations relative to the patient.

[0072] Pump device 400 includes a housing component 510' and a rotatable inner catheter 700'. In a manner similar to that described above with respect to pump device 300, a delivery sheath device 500 is used to house housing component 510' in a radially compressed, low profile delivery configuration during advancement to a target location within the patient's anatomy. In some cases, advancement is performed over a pre-placed guidewire.

[0073] If advancement is performed over a pre-placed guidewire and the pump housing 408 is the distal-most portion of the housing component 510', the pump housing 408 may be designed to have a distal hole for the guidewire to pass through the pump housing 408. Alternatively, the pump housing 408 may be folded in such a way that when in its folded, radially contracted state, a guidewire can enter the contracted pump housing 408 through one of the pump housing exit ports 402, thereby facilitating catheter placement in the anatomy using advancement over the guidewire.

[0074] After advancing the delivery sheath device 500 and the housing component 510', the clinician operator can retract the delivery sheath device 500 proximally to expose the pump housing 408 and the inlet cannula 406. The pump housing 408 and the inlet cannula 406 can thereby be radially expanded to the configuration shown. The guidewire, if used, can then be fully retracted. The rotatable inner catheter 700' can then be inserted into the housing component 510' through the hub and lumen of the housing component 510' with its pump impeller 708' in a contracted state. When the impeller 708' is within the pump housing 408, inflation fluid can be delivered to the impeller 708' through the lumen of the rotatable inner catheter 700' to inflate and expand the impeller 708' to the operational configuration shown (FIG. 10B). The rotatable inner catheter 700' and its impeller 708' may then be rotated by a motor (eg, FIG. 1) located external to the patient to provide blood flow and hemodynamic assistance to the patient.

[0075] FIG. 11 illustrates a particular interaction between an impeller 708 and a pump housing 508 of a pump device 300 (e.g., FIG. 3) according to an embodiment of the subject matter disclosed herein. When the impeller 708 is driven to rotate, the impeller 708 and the pump housing 508 cooperate to act as a centrifugal pump. That is, the rotating impeller 708 exerts a centrifugal force on the blood, thereby slamming the blood outward against the inner wall of the pump housing 508. Because the centrifugal force increases along the tapered diameter of the impeller 708, the centrifugal force increases the pressure of the blood as it approaches the maximum diameter portion 1100 of the impeller 708. The outlets 526 defined by the pump housing 508 may be radially disposed about the maximum diameter portion 1100 of the impeller 708. The outlets 526 allow high pressure blood to exit the pump housing 508 and enter the aorta.

[0076] As the impeller 708 rotates within the pump housing 508, the blood surrounding the impeller 708 creates a dynamic bearing that causes the impeller 708 to self-center within the pump housing 508 and rotate with the longitudinal axes of the impeller 708 and pump housing 508 aligned. Antegrade blood flow 1102 originating from a cannula (shown elsewhere) represented by the large arrow constitutes the majority of the blood flow, while retrograde flow 1104 represented by the small arrow constitutes only a small amount of blood flow. Thus, the rotating impeller 708 may not require traditional mechanical bearings or bushings (which are defined as solid physical components). In other words, this is a bearingless two-part blood pump in some embodiments. Instead, the design of the impeller 708 within the pump housing 508 cooperate to create a hydrodynamic bearing that allows the impeller 708 to self-center within the pump housing 508 during rotation of the impeller 708.

[0077] 12A and 12B show schematic diagrams of specific interactions between impellers having various shapes and pump housings according to embodiments of the subject matter disclosed herein. More specifically, FIG. 12A and FIG. 12B show interactions between components at two different alignment or spacing distances. In FIG. 12A, the impeller 1200A and the pump housing 1202A are close together, and the distance between the impeller 1200A and the pump housing 1202A is uniform across their surface profiles. In FIG. 12B, the impeller 1200B and the pump housing 1202B are farther apart. However, the distance between the impeller 1200B and the pump housing 1202B is uniform across their surface profiles. This distance remains uniform because the angles of the impeller and pump housing surfaces are equal in both cases.

[0078] A uniform distance between the impeller and the pump housing may promote efficient self-centering performance of the impeller within the pump housing, regardless of the relative longitudinal alignment or spacing of the impeller and the pump housing. However, if the interface surfaces of the impeller and the pump housing are curved, the self-centering performance may benefit from more precise longitudinal spacing. For example, as shown in FIG. 12C, the impeller 1200C and the pump housing 1202C are longitudinally positioned to allow a uniform distance between them, thereby providing consistent self-centering performance. In contrast, as shown in FIG. 12D, the impeller 1200D and the pump housing 1202D are positioned farther away from each other, resulting in a non-uniform distance between them. Such non-uniform distances may reduce self-centering performance and adversely affect blood flow, fluid pumping efficiency, and component durability. As a result, it may be preferable to construct the impeller and pump housing with a linear opposed geometry (FIGS. 12A and 12B) rather than curved surfaces (FIGS. 12C and 12D).

[0079] 13A and 13B are schematic illustrations of various pump impellers and pump housings exhibiting different blood pumping flow characteristics according to embodiments of the subject matter disclosed herein. FIG. 13A illustrates an impeller 1300A comprising an expandable tapered body 1302A and a plurality of impeller ridges 1304A coupled to and extending outwardly from the tapered body 1302A. The tapered body 1302A includes (i) a distal portion 1306A having a front surface 1308A, (ii) a maximum diameter portion 1310A having a mid-surface 1312A, and (iii) a proximal portion 1314A having a rear surface 1316A. A plurality of ridges 1304A extend radially outwardly from each of the front surface 1308A, the mid-surface 1312A, and the rear surface 1316A.

[0080] FIG. 13B shows a similar impeller 1300B with an expandable tapered body 1302B, with multiple impeller ridges 1304B extending radially outward from the leading surface 1308B and the mid-surface 1312B, but absent from the trailing surface 1316B. The impeller 1300A and its ridges 1304A may advantageously provide a relatively high antegrade blood flow, as represented by arrow 1318A. In addition, the impeller 1300A and its ridges 1304A may advantageously provide a relatively high retrograde flow, as represented by arrow 1320A. Such retrograde flow may be desirable and act as a lubricant between the drive shaft and the drive shaft housing. The impeller 1300B and its ridges 1304B may provide a similar benefit to the antegrade flow 1318B, while reducing the retrograde flow 1320B, as represented by the smaller arrow. The absence of ridges 1304B on the rear face 1316B can also provide a more uniform and straighter surface for the rear face 1316B of the impeller 1300B, thereby providing the advantages described above with respect to the impellers 1200A, 1200B and pump housings 1202A, 1202B (Figures 12A and 12B).

[0081] 13A and 13B, in some embodiments, the impeller ridges 1304A, 1304B may extend parallel (non-helical) to the longitudinal / rotational axes 1322A, 1322B of the impellers 1300A, 1300B. Alternatively, as shown elsewhere, the expandable impeller ridges 1304A, 1304B may extend helically to the longitudinal / rotational axes 1322A, 1322B of the impellers 1300A, 1300B.

[0082] 14A and 14B show possible flow paths for retrograde blood flow 1400 generated by rotation of the impeller 708 within the pump housing 508, according to embodiments of the subject matter disclosed herein. FIG. 14A displays the operational alignment and relative orientation between the impeller 708 and the pump housing 508. Note that there are no bearings or bushings disposed between the impeller 708 and the pump housing 508 or between the impeller drive shaft 704 and the drive shaft housing 511.

[0083] 14B , in this version of the blood pump catheter system, the drive shaft housing 511 may include a fenestration, window, or opening 3512. The sheath 502 of the delivery sheath device 500 may also include a fenestration, window, or opening 3294. When the delivery sheath device 500 is retracted, the sheath window 3294 may at least partially align with the window 3512 of the drive shaft housing 511. The alignment of these windows 3294 / 3512 may allow blood to flow through the window openings of the sheath 502 and the drive shaft housing 511 to reach the drive shaft 704. This blood flow may provide a source of blood for retrograde blood flow 1400 in the impeller 708, which may have several advantages. Two non-limiting examples of advantages of retrograde blood flow 1400 through the drive shaft housing 511 may include improving the function of the dynamic pressure bearing created between the impeller 708 and the pump housing 508, and acting like a lubricant between the drive shaft 704 and the drive shaft housing 511 to reduce wear between the components. This dynamic pressure bearing created between the impeller 708 and the pump housing 508 may eliminate the need for traditional mechanical bearings or bushings between the impeller 708 and the pump housing 508 and / or between the impeller drive shaft 704 and the drive shaft housing 511.

[0084] Figures 15A-15C show an exemplary blood withdrawal mechanical hemodynamic assist device for use as part of a system 200 (e.g., Figure 2) comprising a blood pump with an internal motor located near the distal tip of a catheter system, according to an embodiment of the subject matter disclosed herein. The illustrated blood withdrawal pump device is shown in its fully assembled state in Figure 15A. Figures 9A-9F (see above) describe the process of assembling this motorized blood pump configuration in vivo.

[0085] 15B shows an expanded impeller 708 within the expanded pump housing 508, as well as a close-up of the miniature motor 202 located proximal to the impeller 708. In such a pump system with a miniature motor 202, several non-limiting considerations must be accommodated in the pump assembly process. The impeller 708 may be connected to a short length drive shaft 1504 that extends from the distal tip of the motor 202 to the distal end of the impeller 708. This short drive shaft 1504 may be connected to the distal tip of the motor rotor 1500, such that as the motor 202 rotates, the drive shaft 1504 rotates relative to the motor stator 1502 and pump housing 508.

[0086] The motor 202 may have a hollow rotor 1500, which may create an internal channel or lumen 1512 within the motor 202 and along its central axis. This central lumen 1512 may allow for expansion of the impeller 708 via the motor 202 and drive shaft 1504. In order for the impeller 708 to maintain pressure as it expands, the distal end of the drive shaft 1504 and / or the proximal end of the hollow motor rotor 1500 may have internal seals. The seal at the distal end of the drive shaft 1504 is shown in FIG. 15B as element 1508. FIGS. 15B and 15C show a seal 1510 at the proximal end of the hollow motor rotor 1500. These seals may allow the catheter system to be delivered to the correct anatomical location over a guidewire, and then may create a pressure-tight seal to allow the impeller 708 to maintain pressure once the guidewire is removed from the system.

[0087] Once the system is in the correct anatomical location, the inflation needle 1600 (e.g., FIGS. 9C-9E) may be advanced through the proximal seal 1510, thereby allowing inflation of the impeller 708. When the inflation needle 1600 is removed, the impeller 708 may maintain pressure due to the presence of the seal.

[0088] When the catheter system is ready to be removed from the patient, the inflation needle 1600 can be reinserted through the proximal seal 1510 and used to deflate the impeller 708. In some embodiments, the distal seal 1508 and the proximal seal 1510 can also function as pressure relief valves to prevent over-inflation of the impeller 708.

[0089] The miniature motor 202 may be connected to a controller external to the patient 206 (FIG. 2) through electrical wires 1506, which may be embedded within the wall of the catheter shaft. 16A and 16B, additional views of an exemplary inflation needle 1600 that may be used to inflate the impeller 708 through the miniature internal motor 202 are provided. The needle 1600 may include a sharp distal tip 1602, a surface ridge 1604, and a hub 1606. The sharp distal tip 1602 may function to allow the distal tip portion of the inflation needle 1600 to pass through a proximal seal 1510 at the proximal end of the miniature motor 202 without damaging the sealing membrane or compromising the function of the seal 1510.

[0090] The surface ridge 1604 may be an increase in diameter or a surface protrusion from the body of the expansion needle 1600. This surface ridge 1604 may function to prevent the expansion needle 1600 from tracking too far through the hollow motor rotor 1500, thereby preventing the sharp distal tip 1602 of the expansion needle 1600 from damaging the impeller 708.

[0091] 17A-17C show an exemplary sequence of steps for expanding an impeller 708 and then coupling a rotatable inner catheter 700 to an external motor 1700, which may be represented, for example, by motor 104 (FIG. 1), according to an embodiment of the subject matter disclosed herein. The external motor 1700 comprises a motor coupler 1702, a motor rotor 1704, and a motor stator 1706.

[0092] In Figure 17A, the rotatable inner catheter 700 is shown with the impeller 708 in its radially contracted configuration. Then, in Figures 17B and 17C, the impeller 708 is expanded to its pumping configuration by applying pressure through the hub 702 of the rotatable inner catheter 700.

[0093] The rotatable inner catheter 700, with its impeller 708 expanded, may then be connected to a motor 1700 using a motor coupler 1702. The motor coupler 1702 may be a connector that mechanically couples the motor rotor 1704 and the catheter hub 702.

[0094] 18A-18C illustrate a possible sequence of steps for coupling a rotatable inner catheter 700 to an external motor 1800, which may be represented by, for example, the motor 104 (FIG. 1), followed by expansion of the impeller 708, according to an embodiment of the subject matter disclosed herein. In FIG. 18A, the rotatable inner catheter 700 is shown with the impeller 708 in its radially contracted configuration. The hub 702 of the rotatable inner catheter 700 may then be coupled to the motor 1800 via a motor coupler 1802, as shown in FIG. 18B. Once the rotatable inner catheter 700 is coupled to the motor 1800, the impeller 708 may be expanded by applying pressure through an inflation port 1804 located proximal to the motor rotor 1806. The pressure may pass through an inflation passage 1808, which may be located within the hollow motor rotor 1806, as shown in FIG. 18C.

[0095] 17A-17C and 18A-18C, once the rotatable inner catheter system 700 is coupled to the motor 1700 / 1800 and the impeller 708 is in its expanded state, the motor rotor 1704 / 1806 may be actuated to rotate the motor rotor 1704 / 1806 while the motor stator 1706 / 1810 remains stationary. The rotating motor rotor 1704 / 1806 may impart a rotational speed to the rotatable inner catheter system 700, thereby rotating the impeller 708 and causing blood flow.

[0096] 18B and 18C show a motor system 1800 with a hollow motor rotor 1806 that allows pressure to be applied through the motor, there are many other options for inflating the impeller 708 after the catheter is coupled to the motor without the inflation path 1808 passing through the motor rotor. By way of non-limiting example, the hub 702 may be attached to a gearing system and offset from the motor 1800, allowing the inflation path to pass through the center of the gears instead of through the motor (not shown).

[0097] 19A and 19B show an exemplary configuration of an inlet cannula 504 and a pump housing 508 located at a distal end portion of a housing component 510 in their expanded state in accordance with an embodiment of the subject matter disclosed herein.

[0098] During use, when the inlet cannula 504 is positioned across the AV, the AV valve leaflets may bear against the outer surface of the inlet cannula 504, compressing it radially. Thus, the inlet cannula 504 may require sufficient radial strength, also known as hoop strength, to maintain its expanded diameter when it is positioned across the AV. The tendency of the inlet cannula 504 to maintain a desired expanded profile helps ensure proper pumping performance and desired blood flow during use. Similarly, the pump housing 508 may require a precise expanded profile to house the pump impeller 708 (shown elsewhere) and cooperate with the impeller 708 to ensure proper pumping performance and desired blood flow.

[0099] In the depicted embodiment, the inlet cannula 504 is constructed from a flexible wall 536 with an expandable braided support structure 1900 coupled to or within the flexible wall 536. The expandable braided support structure 1900 is constructed of one or more elongated elements 1902 that are braided or woven into a tubular construction. This same braided support structure 1900 continues to the pump housing 508 and supports the flexible wall 524 of the pump housing 508. The braided support structure 1900 may be disposed on the inside of the flexible wall 536 / 524, the braided support structure 1900 may be embedded within the flexible wall 536 / 524, the braided support structure 1900 may be disposed on the outside of the flexible wall 536 / 524, or any combination thereof.

[0100] When using the expandable braided support structure 1900 as the support structure for the flexible walls 536 / 524, the inlet cannula 504 and pump housing 508 can expand longitudinally when in a collapsed, radially constricted configuration and then contract longitudinally as they self-expand to their fully expanded, working configuration. This braided support structure 1900 can provide sufficient radial strength to the inlet cannula 504 to withstand compression from the AV.

[0101] 20A and 20B show another exemplary configuration of an inlet cannula 504 and a pump housing 508 in their expanded state located at a distal end portion of a housing component 510 in accordance with an embodiment of the subject matter disclosed herein. The inlet cannula 504 may be constructed of a flexible wall 536 having an expandable coil support structure 2000 coupled thereto.

[0102] The expandable coil support structure 2000 may be comprised of a single filar coil 2002 or may be comprised of multiple separate filars 2002. In some embodiments, the coil support structure 2000 may extend between the distal marker 530 and the proximal marker 528 and terminate distally of the pump housing 508. The coil support structure 2000 may be disposed inside the flexible wall 536, the coil support structure 2000 may be embedded within the flexible wall 536, the coil support structure 2000 may be disposed outside the flexible wall 536, or any combination thereof. The coil support structure 2000 may provide sufficient radial strength to the inlet cannula 504 to withstand compression from the AV.

[0103] In the depicted embodiment, the pump housing 508 may not include a support structure within its flexible walls 524. The pump housing 508 may expand due to the pumping action of the impeller 708 (shown elsewhere). As the impeller 708 rotates and creates a flow of blood, the pressure within the pump housing 508 may increase relative to the pressure outside the pump housing 508. This increased internal pressure may cause the pump housing 508 to expand to its optimal pumping configuration or geometry.

[0104] 21A and 21B show another possible configuration of the inlet cannula 504 and pump housing 508 in their expanded state according to an embodiment of the subject matter disclosed herein. The pump housing 508 can be reinforced by a longitudinal support structure 2100 to provide additional column strength. This longitudinal support structure 2100 can be within the flexible wall 524, embedded in the flexible wall 524, or bonded to the outside of the flexible wall 524. The additional column strength can aid in delivery, actuation and positioning, and retrieval of the device. In some embodiments, the same elongate elements of the longitudinal support structure 2100 in the region of the pump housing 508 extend into the region of the inlet cannula 504 and are braided or woven as shown. Alternatively, in some embodiments, the elongate elements of the longitudinal support structure 2100 in the region of the pump housing 508 are separate from the elongate elements in the region of the inlet cannula 504. In another embodiment, the elongate elements of the longitudinal support structure 2100 in the region of the pump housing 508 are separate from the elongate elements in the region of the inlet cannula 504 but are attached thereto.

[0105] 22A shows another exemplary configuration of the inlet cannula 2200 and pump housing 2202 in their expanded state according to embodiments of the subject matter disclosed herein. The inlet cannula 2200 and pump housing 2202 can be located at a distal end portion of some embodiments of the housing component 510. As shown, a possible configuration of the inlet cannula 2200 and pump housing 2202 is one in which the diameter of the inlet cannula 2200 and the diameter of the pump housing 2202 are the same diameter. In other configurations described herein, the inlet cannula 504 and pump housing 508 (shown elsewhere) have different diameters, with the pump housing 508 having a larger diameter and the inlet cannula 504 having a smaller diameter to allow easier acceptance within the AV. However, if the patient is sufficiently large and if the AV anatomy can accommodate a larger inlet cannula 2200, a larger inner diameter of the inlet cannula 2200 may reduce pressure gradients within the inlet cannula 2200 and improve hemodynamics. In the configuration depicted in FIG. 22A, the flexible walls of the inlet cannula 2200 and pump housing 2202 are supported by a braided structure 2204 that is continuously expanding in diameter.

[0106] Additionally, as shown in Figure 22B, in some embodiments, the inlet cannula and pump housing 2210 may be comprised of a helical balloon 2212 in a coiled stack configuration. The helical balloon pump housing 2210 may be a single helically stacked balloon (not shown) or may be comprised of multiple coiled balloons 2212 as shown in Figure 22B. This structure may be collapsed during delivery and then expanded using pressure to maintain a rigid shape.

[0107] 19A-22B, in accordance with an embodiment of the subject matter disclosed herein, the support structure used to reinforce the inlet cannula and pump housing can be comprised of a number of different materials, components, or combinations thereof. The braids and coils can be comprised of metallic structures, such as, but not limited to, superelastic Nitinol. The braids and coils may also be comprised of polymeric materials, such as aramid or nylon. The coil structures may also be comprised of long tubular balloon structures that can expand to expand the inlet cannula and pump housing.

[0108] 23A and 23B show another exemplary mechanical hemodynamic assist device 2300 (or "pump device 2300") in an expanded configuration across the aortic valve AV. The pump device 2300 includes a skirt 2302 attached to a connection between a pump housing 2304 and an inlet cannula 2306, according to an embodiment of the subject matter disclosed herein.

[0109] The skirt 2302, upon exposure (e.g., from the delivery sheath device 500 described above), may self-expand via the self-expanding support structure 2308. The self-expanding support structure 2308 may be constructed, for example, from a superelastic Nitinol wire. After the skirt 2302 is expanded, it may rest against the aortic valve AV, thereby preventing the device 2300 from moving too far distally into the left ventricle. The skirt 2302 may also help stabilize the device once placed within the patient's anatomy. Additionally, the skirt 2302 may alleviate aortic regurgitation by preventing blood backflow through the aortic valve and increasing pressure against the aortic valve AV, thereby allowing the valve to fully or completely close during diastole.

[0110] 24A and 24B show another exemplary mechanical hemodynamic assist device 2400 (or "pump device 2400") in an expanded configuration across the aortic valve AV. The pump device 2400 includes petals 2402 attached to a connection between a pump housing 2404 and an inlet cannula 2406, according to an embodiment of the subject matter disclosed herein.

[0111] The petals 2402 may self-expand via the self-expanding support structure 2408 upon exposure (e.g., from the delivery sheath device 500 described above). The self-expanding support structure 2408 may be constructed, for example, from a superelastic nitinol wire. After the petals 2402 are expanded, they may rest against the aortic valve AV, thereby preventing the device 2400 from moving too far distally into the left ventricle. The petals 2302 may also help stabilize the device once placed within the patient's anatomy. Additionally, the petals 2402 may alleviate aortic regurgitation by preventing blood backflow through the aortic valve AV and increasing pressure against the aortic valve AV, thereby allowing the valve to fully or completely close during diastole. In contrast to the skirt 2302, having the petals 2402 rest against the AV may be less disruptive to the natural continuous blood flow provided by the patient's heart.

[0112] 25 illustrates an exemplary system and method for anchoring or securing a pump device 300 in a patient's anatomy, according to embodiments of the subject matter disclosed herein. The method includes placing a balloon 2500 in an artery originating from the aortic arch, such as the aorta AO or the descending aorta DAO. The balloon 2500 can be a separate device or a balloon attached to the drive shaft housing 511 and tracked through the anatomy simultaneously with the main pumping device 300.

[0113] When the balloon 2500 is inflated, it creates an apposition against the vessel wall, thereby anchoring the balloon 2500 within the anatomy. If the balloon 2500 is attached to the drive shaft housing 511, then when the balloon 2500 is anchored within the anatomy, the pump device 300 is anchored within the anatomy. If the balloon 2500 is a separate device, then when the balloon 2500 is inflated and anchored within the anatomy, the balloon 2500 can press against the drive shaft housing 511 against the vessel wall, thereby anchoring the pump device 300 within the anatomy.

[0114] In some embodiments, the balloon 2500, in its expanded state, may have a spiral configuration that defines an open central passageway that allows blood perfusion through the balloon 2500, as shown. The balloon 2500 may be constructed of a semi-compliant material to allow the balloon 2500 to conform to the patient's vasculature, making the balloon 2500 more versatile with respect to placement locations.

[0115] FIG. 26 illustrates another exemplary system and method for anchoring a pump device 2400 (FIGS. 24A and 24B) within a patient's anatomy, according to embodiments of the subject matter disclosed herein. The petals 2402 may prevent the pump device 2400 from moving distally within the patient's anatomy once deployed. However, fluctuating thrust generated by the pumping action of the pump device 2400 may cause the pump device 2400 to move proximally away from a desired placement within the anatomy. The overall device thrust will vary based on the flow rate. As a result, it may be beneficial to add additional components or mechanisms that restrain the device 2400 from moving proximally within the anatomy once deployed.

[0116] An example of an additional anti-migration mechanism is an expandable ostium shaft anchor 2600, shown in FIG. 26. In some embodiments, the anchor 2600 may self-expand when exposed after being advanced through the brachiocephalic artery BA or left subclavian artery LSA, as shown. The anchor 2600 may expand to a diameter larger than the diameter of the artery. As a result, the expanded anchor 2600 cannot migrate proximally through the artery, thereby preventing proximal migration of the device 2400 within the patient.

[0117] In some embodiments, the ostium shaft anchor 2600 may be constructed in an expandable structure like an open cell stent (i.e., not covered by a membrane), thereby allowing perfusion through the artery. The ostium shaft anchor 2600 may be located in a fixed position along the drive shaft housing 511, or the ostium shaft anchor 2600 may be movable along the drive shaft housing 511 and securable on the drive shaft housing 511 after expansion. The ostium shaft anchor 2600 may be refoldable (e.g., within the delivery sheath device 500) to facilitate subsequent removal from the anatomy.

[0118] 27 illustrates yet another exemplary system and method for anchoring a pump device 300 within a patient's anatomy, according to embodiments of the subject matter disclosed herein. In this embodiment, an expandable cage anchor 2700 is coupled to a drive shaft housing 511. Upon self-expanding upon emergence from a delivery sheath device 500, the cage anchor 2700 creates an adhesive force against the vessel wall, thereby anchoring the drive shaft housing 511 within the anatomy. The expandable cage anchor 2700 may allow for perfusion of blood through the aorta and adjacent vessels.

[0119] Although not specifically shown, mechanical hemodynamic assist devices according to embodiments of the subject matter disclosed herein may include any combination of the fixation mechanisms shown in Figures 23, 24, 25, 26, and 27.

[0120] 28A-F show various possible configurations of a pump housing 508 and its exit port according to embodiments of the subject matter disclosed herein. A proximal portion of the pump housing 508 includes an exit port (e.g., exit port 526) through which high pressure blood exits the pump housing 508 and enters the AO. The exit port 526 acts like a nozzle when there is a large pressure gradient across the exit port 526. Therefore, it may be desirable to modify the standard exit port 526 to reduce the steepness of the pressure gradient and reduce stress (e.g., shear stress) on the blood.

[0121] 28A, 28B, and 28C show an outlet port 526 with exemplary outlet port relief notches 2802. The outlet port relief notches 2802 are cut out of the flexible wall 524 of the pump housing 508. These outlet port relief notches 2802 are disposed around the periphery of the outlet port 526 to create outlet port flaps 2804 between adjacent notches 2802 that may bend or flex outward when the pump housing 508 is pressurized. The outlet port flaps 2804 act as a ramp or smooth transition, allowing blood exiting the pump housing 508 to flow more gradually and with less stress, thereby improving flow dynamics.

[0122] 28D, 28E, and 28F further employ the concept of an outlet port relief notch 2802. In this configuration, the exemplary outlet port 2810 consists primarily of a relief notch 2812 rather than a larger hole cut into the flexible wall 524 of the pump housing 508 (e.g., as shown in Figs. 28A-28C). The hole in the center of the outlet port 2810 may be further reduced until it is nonexistent. The relief notch 2812 may be much larger (e.g., longer) and large enough to merge with one another. This allows the outlet port flap 2814 to be much larger. The advantage of this configuration of the outlet port 2810 is that the outlet port 2810 may now act as a one-way valve that allows blood to flow out of the pump housing 508 when the impeller 708 (shown elsewhere) is rotating and the pressure inside the pump housing 508 is higher than the AO. Conversely, when the pump is not operating, the larger outlet port flaps 2814 can converge together, thereby closing the outlet port and preventing blood from flowing back from the AO, through the pump housing 508, via the inlet cannula and into the LV.

[0123] 29A-29C show cross-sectional views of a pump housing outlet port 526 according to an embodiment of the subject matter disclosed herein. FIG. 29A shows a pump housing 508A and its outlet port 526A configured as an axial ring around the circumference of the flexible wall 524 of the pump housing 508A, thereby at a 90 degree angle to a tangent line 2904A from the central axis 2902A of the pump housing 508A. FIG. 29B shows how a pump housing 508B and its outlet port 526B can be configured at any angle between 0 and 90 degrees (e.g., shown at 68 degrees) to the axis of rotation 2902B. FIG. 29C shows a pump housing 508C with an outlet port 526C configured in a plane tangent to the central axis 2902C of the pump housing 508C and perpendicular to the flexible wall 524 of the pump housing 508C, such that the outlet port 526C is at a 0 degree angle to a tangent 2904C from the central axis 2902C of the pump housing 508C. FIGS. 29A-C show blood flow 2900A, 2900B, 2900C through different outlet port angles. Adjusting the outlet port angle can improve the laminar flow dynamics of blood as it passes through the outlet port, thereby reducing hemolysis.

[0124] 30 shows another view of the delivery sheath device 500. The delivery sheath device 500 comprises a handle 512, a sheath 502, a radiopaque distal marker band 514 (optional), and an atraumatic bumper tip 506 (optional). The handle 512 is located at the proximal end of the delivery sheath device 500 and remains external to the patient. The sheath 502 extends distally from the handle 512. The radiopaque distal marker band 514 can be located anywhere on the sheath 502, such as at the distal tip portion of the sheath 502. In some embodiments, multiple radiopaque distal marker bands 514 can be located along the sheath 502. The atraumatic bumper tip 506 can be located at the distal tip of the sheath 502.

[0125] The sheath 502 can be made of a thin, flexible, and non-compliant (low elongation / low yield) membrane. In some embodiments, the sheath 502 can be purely polymer-based. In some embodiments, the sheath 502 can be polymer-based and can include structural reinforcements in the form of metal or polymer members to increase parameters such as kink resistance and / or column strength.

[0126] As described above, the sheath 502 defines a lumen within which a housing component (e.g., housing component 510) may be slidably housed in a radially compressed, low profile delivery configuration. After the sheath 502 housing the housing component is advanced to a target location within a patient, e.g., the heart, the delivery sheath device 500 may then be retracted proximally (while maintaining the position of the housing component) to expose a distal end portion of the housing component from its constrained position within the sheath 502. Optionally, when it is desired to reposition or remove the pump device, the delivery sheath device 500 may be advanced distally to recapture the housing component within the sheath 502.

[0127] 31A-31C illustrate that in some embodiments, the delivery sheath device 500 can be configured as a tear-away or splittable sheath. In such cases, the delivery sheath device 500 can be advantageously removed from the patient after its function of advancing and deploying the housing components has been performed. Removing the delivery sheath device 500 in this manner can be advantageous because it can slightly reduce the size of the percutaneous opening in the patient after removal of the delivery sheath device 500.

[0128] In Fig. 31A, the sheath 502 includes two sets of linearly arranged notches or perforations 3182. In Fig. 31B, the sheath includes two linearly arranged grooves 3186. Fig. 31C shows that in some embodiments, the perforations 3182 or grooves 3186 are arranged approximately 180° opposite one another. In either case, the perforations 3182 or grooves 3186 configure the sheath 502 with weakened areas that make the sheath 502 manually breakable or splittable. The handle 512 can also be made from two separate pieces or made to be splittable into two pieces.

[0129] 32 illustrates another optional feature that may be included as part of some embodiments of the delivery sheath device 500. That is, as shown in the depicted embodiment, the sheath 502 may define one or more fenestrations, windows, or openings 3294. In the depicted non-limiting example, the openings 3294 are longitudinally elongated openings 3294. Any suitable size and shape of openings 3294 may be implemented in the delivery sheath device 500. The openings 3294 are not located in a proximal portion of the sheath 502 that is likely to be disposed outside the patient's body during use.

[0130] As described further herein, in some embodiments, opening 3294 can allow blood to flow laterally into sheath 502 and then into a housing component (e.g., housing component 510) that also includes an opening in its drive shaft housing (e.g., drive shaft housing 511). Such blood flowing into the housing component can advantageously provide lubrication and cooling, since heat can be generated from friction between the rotating impeller drive shaft and the stationary drive shaft housing.

[0131] Additionally, and with reference to Figures 14A and 14B, in some embodiments, the flow of blood into the drive shaft housing, which may pass through openings 3294 in the sheath 502 and then through openings in the drive shaft housing, facilitates the hydrodynamic bearing function described with reference to Figures 11-13B.

[0132] Additionally, in some cases, the opening 3294 can advantageously allow air to escape from the sheath 502 and / or drive shaft housing before and during insertion into the patient.

[0133] 33A and 33B illustrate another optional feature that may be included as part of some embodiments of the delivery sheath device 500. In the depicted embodiment, the proximal portion of the sheath 502 includes a notched proximal portion 3302. The notched proximal portion 3302 is located along a proximal portion of the sheath 502 where the sheath 502 passes through the skin and subcutaneous puncture at a vascular access site in use. Thus, the size of the skin and subcutaneous puncture may be reduced, in some cases, compared to a sheath 502 that does not include the notched proximal portion 3302. In some embodiments, as shown, one or more longitudinally extending stiffening rods 3390 may be included to provide structural reinforcement to the notched proximal portion 3302 of the sheath 502.

[0134] 34A-C show optional features that may be included as part of some embodiments of housing component 510. In the depicted embodiment, housing component 510 includes a drive shaft housing hub 518, a drive shaft housing 511, a pump housing (not shown, see e.g., pump housing 508 in FIG. 6), and an inlet cannula (not shown, see e.g., inlet cannula 504 in FIG. 6).

[0135] A drive shaft housing hub 518 is located at a proximal end portion of the housing component 510. A drive shaft hub seal 3404 configured to slidably receive and seal against an impeller drive shaft (e.g., drive shaft 704) is located within the drive shaft housing hub 518. A drive shaft housing 511 extends distally from the drive shaft housing hub 518. The drive shaft housing 511 defines a lumen configured to receive the impeller drive shaft (e.g., drive shaft 704). A pump housing (not shown) is attached to and extends distally from a distal end portion of the drive shaft housing 511. An inlet cannula (not shown) is attached to and extends distally from the pump housing.

[0136] In the depicted embodiment, the inner diameter of the drive shaft housing 511 includes an annular protrusion 3408. The annular protrusion 3408 creates an area where the inner diameter of the lumen of the drive shaft housing 511 is constricted to a smaller opening diameter as compared to other portions of the drive shaft housing 511.

[0137] 34C, the annular protrusion 3408 can interface with an annular protrusion 3468 on the impeller drive shaft (e.g., impeller drive shaft 704). The outer diameter of the annular protrusion 3468 can be larger than the inner diameter of the annular protrusion 3408. Thus, the dimensional interference between the annular protrusion 3468 and the annular protrusion 3408 can serve to indicate the distal-most longitudinal position of the impeller drive shaft relative to the housing component 510. This longitudinal position alignment can ensure that the pump impeller (e.g., pump impeller 708 and other pump impellers described herein) is properly positioned within the pump housing (e.g., pump housing 508).

[0138] 35 illustrates additional optional features that may be included as part of some embodiments of the housing component 510. In the depicted embodiment, the drive shaft housing 511 of the housing component 510 defines one or more fenestrations, windows, or openings 3512. In the depicted non-limiting example, the openings 3512 are longitudinally elongated openings 3512. Any suitable size and shape of openings 3512 may be implemented in the drive shaft housing 511.

[0139] The opening 3512 can be at least partially aligned with or otherwise cooperate with an opening 3294 (FIG. 32) defined by the sheath 502 to allow blood to flow through the sheath 502 and into the drive shaft housing 511. Such flow of blood into the drive shaft housing 511 can (i) provide lubrication and cooling to mitigate heat resulting from friction between the rotating impeller drive shaft and the stationary drive shaft housing 511, and (ii) facilitate the hydrodynamic bearing function described with respect to FIGS. 11-13B.

[0140] FIG. 36C illustrates additional optional features that may be included as part of some embodiments of the housing component 510. In the depicted embodiment, the drive shaft housing 511 of the housing component 510 comprises one or more open cell portions 3612. The one or more open cell portions 3612 may be a stent-like construct. That is, the one or more open cell portions 3612 may be braided, woven, or laser cut to expand, for example. The one or more open cell portions 3612 have a plurality of open areas that allow lateral blood flow into the drive shaft housing 511 for the lubrication, cooling, and hydrodynamic bearing benefits discussed above (in combination with the opening 3294 in the sheath 502 of the delivery sheath device 500 shown in FIG. 32, or in combination with the tear-away sheath device 500 shown in FIGS. 31A-31C). The open cell portion 3612 may allow lateral blood flow while still protecting the rotating drive shaft (e.g., drive shaft 704) from damaging the patient's anatomy or becoming entangled with another device being used by the clinician.

[0141] 37A and 37B show features that may be included as part of some embodiments of the housing component 510 when considering the requirements of a small internal motor 202 (not shown, e.g., motor 202 of FIG. 15) that may be used in the pump system 200 shown in FIG. 2. In this embodiment, the drive shaft housing 511 may include lumens 3722 embedded within the walls of the drive shaft housing 511. These lumens 3722 may accommodate the passage of electrical wires 1506 (not shown, see FIG. 15) connecting the motor 202 inside the patient's body to a controller 206 outside the patient's body to provide power to and control the motor 202.

[0142] 38A-E show an example of a torque transmitting drive shaft 3800 according to an embodiment of the subject matter disclosed herein. The drive shaft 3800 may be used, for example, as the drive shaft 704 of the rotatable inner catheter of the pump devices described herein.

[0143] In some embodiments, the drive shaft 3800 is constructed of a bidirectional helical hollow strand coil 3802. The coil 3802 has high performance torque transmission characteristics and promotes flexibility and tracking through the anatomy. As shown, the coil 3802 may be unencapsulated (FIGS. 38A and 38B) or encapsulated (FIGS. 38C-38E) by an outer cover 3804. The outer cover 3804 may be constructed of a polymer and may isolate a central lumen 3806 (FIG. 38D) of the drive shaft 3800 from its external environment. As a result, the central lumen 3806 may be used as an inflation lumen to provide inflation fluid to the pump impeller 708 (shown elsewhere). The outer cover 3804 may also enhance torque transmission and reduce longitudinal stretch of the drive shaft 3800.

[0144] 38E , in some embodiments, a luminal support mandrel 3808 may be removably inserted into the central lumen 3806 to further enhance torque transfer. The mandrel 3808 may have a variety of surface finishes or coatings to facilitate insertion of the drive shaft 3800 into the central lumen 3806 or to facilitate coupling between the drive shaft 3800 and the mandrel 3808 during rotation. The luminal support mandrel 3808 may rotate at the same angular velocity as the coil 3802, thereby reducing friction and wear between the components.

[0145] The lumen support mandrel 3808 may inhibit transmission of inflation fluid through the central lumen 3806 so that inflation fluid may be transmitted prior to insertion of the mandrel 3808. In effect, in some cases, the mandrel 3808 may act as a plunger within the central lumen 3806, thereby increasing the fluid pressure provided to the pump impeller 708 (shown elsewhere). As a result, it may be beneficial to account for the pressure increase caused by insertion of the mandrel 3808 when initially providing inflation fluid to the pump impeller 708 through the lumen 3806 of the drive shaft 3800. Alternatively, a pressure relief valve (not shown) may be provided to maintain the desired pressure.

[0146] 39A-39C further illustrate the drive shaft 3800 and its potential failure modes. More specifically, FIG. 39B illustrates one potential failure mode 3810 of the drive shaft 3800 that may occur when subjected to high levels of rotational resistance. Due to the presence of the central lumen 3806 (FIGS. 38B and 38D), the drive shaft 3800 may collapse upon itself when subjected to high levels of torque, thereby compromising torque transmission at the collapsed point. This creates a stress riser where the drive shaft 3800 will begin to wrap upon itself at the collapsed point rather than transmitting torque, and eventually the drive shaft 3800 will separate at the collapsed point 3810. When the drive shaft 3800 rotates at a high angular velocity, the time between such a collapse and separation of the drive shaft is very short. As a result, there may not be enough time to react to a collapsed drive shaft and stop the rotation of the drive shaft.

[0147] 39C, one solution to mitigate this failure mode is to place a luminal support mandrel 3808 within the central lumen 3806 of the drive shaft 3800. The presence of the mandrel 3808 within the central lumen 3806 reduces collapse of the drive shaft 3800, thereby reducing the formation of stress risers and avoiding the failure mode. The mandrel 3808 may also provide additional benefits such as improved kink resistance, durability, and fatigue resistance.

[0148] 40A-40D show a drive shaft 704, a drive shaft hub 4002, and an inflation needle 4006, according to an embodiment of the subject matter disclosed herein. The drive shaft 704 and the drive shaft hub 4002 can be part of system 100 (FIG. 1), for example. The drive shaft hub 4002 and the drive shaft 704 define a lumen that can facilitate communication of inflation fluid from the inflation needle 4006 to the pump impeller 708 (shown elsewhere).

[0149] The drive shaft hub 4002 can be configured to maintain the pressure of the inflation fluid when the inflation needle 4006 is removed. More specifically, the drive shaft hub 4002 can carry or include a drive shaft hub seal 4004, which can be a septum or a pressure activated seal.

[0150] An embodiment of the drive shaft hub 4002 including the pressure actuated drive shaft hub seal 4004 may be manually compressible and expandable. In some such embodiments, the drive shaft hub 4002 may include two portions that thread together and are manually compressible and expandable by manually adjusting the degree to which the two portions are threaded together. In another exemplary embodiment, the drive shaft hub 4002 may include a detent mechanism that allows the drive shaft hub 4002 to be manually adjusted between a compressed configuration (FIG. 40C) and an expanded configuration (FIG. 40A).

[0151] When the drive shaft hub 4002 is expanded, as shown in Fig. 40A, the pressure activated drive shaft hub seal 4004 is open or easily openable. When the drive shaft hub 4002 is compressed, as shown in Fig. 40C, the pressure activated drive shaft hub seal 4004 is compressed, which closes the pressure activated drive shaft hub seal 4004 and restricts flow therethrough.

[0152] In some embodiments, the drive shaft hub 4002 can carry multiple seals 4004. The drive shaft hub 4002 can also allow the drive shaft 704 to receive a mandrel 3808 (e.g., FIG. 38E) without loss of pressure.

[0153] 40A-40D, and in particular FIG. 40A, while the hub seal 4004 is in its open or releasable state, the inflation needle 4006 may be manually inserted and extended through the hub seal 4004. While the inflation needle 4006 extends through the hub seal 4004, the hub seal 4004 compresses around the inflation needle 4006, thereby sealing. An inflation fluid may then be delivered through the inflation needle 4006 to inflate a pump impeller coupled to the drive shaft 704 (e.g., pump impeller 708). After an appropriate pressure is reached within the pump impeller, the inflation needle 4006 may be slidably retracted proximally, and once the inflation needle 4006 is completely removed, the hub seal 4004 closes to maintain a seal. At this time, the pump impeller is pressurized (and expanded) and sealed.

[0154] If a drive shaft lumen support mandrel 3808 is to be used, the mandrel 3808 can be inserted without depressurizing the system by pushing the mandrel 3808 through the seal 4004 and following the mandrel 3808 through the drive shaft 704. The drive shaft hub 4002 can also include features to facilitate coupling to a motor. For example, FIG. 40D shows that the hub 4002 can define a coupling feature, such as three symmetrically positioned grooves 4008 on its periphery, to facilitate coupling and torque transfer between the motor (shown elsewhere) and the drive shaft 704.

[0155] 41A and 41B show an exemplary expandable, inflatable, or balloon pump impeller 4100 according to an embodiment of the subject matter disclosed herein. The impeller pump 4100 includes a smooth surface without any protruding exterior features such as grooves or ridges (e.g., as shown in some other impellers herein). A pump impeller 4100 with a smooth surface may enhance self-centering capabilities. The impeller 4100 may be attached to the distal end of the drive shaft 704 at both the distal and proximal waists of the impeller, thereby allowing for uniform torque transfer between the drive shaft and the impeller from both the proximal and distal ends of the impeller.

[0156] 42A and 42B show a self-expanding or hybrid self-expanding and balloon pump impeller 4200 according to an embodiment of the subject matter disclosed herein. The impeller 4200 may include a self-expanding support structure 4204 within the impeller 4200. When exposed, the support structure 4204 may expand to bring the impeller 4200 to its fully expanded operating pumping configuration. In the self-expanding impeller configuration, no expansion media or technology may be required. The self-expanding impeller 4200 may be slidably tracked through the inner lumen of the drive shaft housing 511 (shown elsewhere) in a collapsed state, and then the self-expanding impeller 4200 self-expands when advanced into the pump housing 508 (shown elsewhere). To re-collapse the self-expanding impeller 4200 for removal of the device, the impeller 4200 and drive shaft 704 (shown elsewhere) may be retracted proximally through the drive shaft housing 511.

[0157] In this form, the impeller 4200 may also be a hybrid expandable impeller 4200, where the support structure 4204 facilitates expansion of a portion of the impeller 4200, and application of pressure within the balloon impeller 4200 may further contribute to fully expanding the impeller 4200. Upon expansion, the impeller may rotate about its axis 4202 to cause blood flow.

[0158] 43A-C show an exemplary expandable triangular pump impeller 4300 according to an embodiment of the subject matter disclosed herein. In this configuration, the expansion of the impeller 4300 may be facilitated by a triangular support structure 4304. The support structure 4304 may have a three-filar form that expands within the membrane of the impeller 4300 when exposed. This expansion may be self-expandable or may be expandable by longitudinal compression along the impeller's axis of rotation 4302. FIG. 43B illustrates the expanded triangular impeller 4300 within the pump housing 508, showing the small gaps between the triangular corners of the impeller 4300 created by the internal support structure 4304 and the flexible wall 524 of the pump housing 508 and the outlet port 526 of the pump housing 508. As the impeller 4300 rotates about its axis 4302, it can create flow by pushing blood through the outlet port 526 of the pump housing 508. This form of impeller is shown to be triangular, but the impeller can also be planar with two filer support structures (not shown) or can have multiple filers to create an impeller in any number of planes (not shown). In some embodiments, these internal filer support structures can spiral around the central axis 4302 of the impeller 4300 when expanded to create a helical surface (not shown).

[0159] 44A-C show another exemplary expandable, inflatable, or balloon pump impeller 4400 according to embodiments of the subject matter disclosed herein. In this example, the impeller 4400 can have a number of ridges 4406 disposed along an outer surface 4404 of the impeller 4400. In the depicted embodiment, the multiple ridges 4406 are aligned longitudinally along or parallel to the axis 4402 of the impeller 4400.

[0160] There are many different possible configurations for creating the ridges 4406. As some non-limiting examples, the ridges 4406 can be solid, non-expanding ridges formed directly on the outer surface 4404 of the impeller 4400. The ridges 4406 can also be pressure expandable and expand when the balloon impeller 4400 is pressurized. The pressure expandable ridges 4406 can be formed directly on the surface of the impeller 4400 or can be a long, thin tubular balloon bonded onto the outer surface 4404 of the impeller 4400 with a separate internal lumen within the ridges 4404.

[0161] These ridges 4406 may further increase the blood contact surface area of ​​the impeller 4400 by having angled surfaces of the ridges 4406 that push against the blood, rather than just having a tangentially spinning surface 4404 that propels the blood, creating a greater push against the blood. These ridges 4406 may result in increased flow rate per rpm and reduced blood shear stress.

[0162] 45A-45C show another exemplary expandable, inflatable, or balloon pump impeller 4500 according to an embodiment of the subject matter disclosed herein. In this example, the impeller 4500 is similar to the impeller 4400 (see FIGS. 44A-44C), but instead of being aligned longitudinally along the axis 4402 of the impeller 4400, the plurality of ridges 4506 disposed about the outer surface 4504 of the impeller 4500 may be aligned in a spiral configuration along the axis 4502 of the impeller 4500. Having a spiral configuration may increase blood flow per rpm and reduce blood shear stress.

[0163] 46A-46D show another exemplary expandable, inflatable, or balloon pump impeller 4600 according to embodiments of the subject matter disclosed herein. In contrast to the ridges along the outer surface of the impeller (as shown above), the impeller 4600 may have a plurality of valley features 4608 disposed along the outer surface 4604 of the impeller 4600. The valleys 4608 may also be referred to as grooves, channels, recesses, and the like. The valleys 4608 may be disposed longitudinally and extend parallel to the axis 4602 of the impeller 4600. As some non-limiting examples of how the valleys 4608 may be generated, the valleys 4608 may be formed directly in the outer surface 4604 of the impeller membrane 4604, or the valleys 4608 may be formed using a support structure 4606 disposed outside the surface 4604 of the impeller 4600. The support structure 4606 may act as a cage around the impeller 4600, thereby preventing the impeller 4600 from fully expanding at the location of the support structure 4606 when fully inflated. This prevention of full expansion may create these valleys 4608. These valleys 4608 may result in increased flow rate per rpm and reduced blood shear stress.

[0164] 47A-47C show another exemplary expandable, inflatable, or balloon pump impeller 4700 according to an embodiment of the subject matter disclosed herein. In this example, the impeller 4700 is similar to the impeller 4600 (see FIGS. 46A-46D), but the valleys 4506 disposed along the outer surface 4704 of the impeller 4700 may extend along a spiral configuration around the axis 4702 of the impeller 4600, rather than being aligned longitudinally along the axis 4602 of the impeller 4600. Having a spiral configuration may increase blood flow per rpm and reduce blood shear stress.

[0165] 48A and 48B show another exemplary expandable, inflatable, or balloon pump impeller 4800 according to an embodiment of the subject matter disclosed herein. Similar to impeller 4100 (see FIGS. 41A and 41B), the distal impeller surface may have the same profile. However, the proximal surface 4804 may be flattened, resulting in a larger angle between the proximal surface 4804 and the axis of rotation 4802. With impeller 4800 having a flattened proximal surface 4804, blood backflow through the pump housing caused by the proximal end of the impeller may be reduced, as compared to the proximal surface of impeller 4100.

[0166] 49A and 49B show another exemplary expandable, inflatable, or balloon-type pump impeller 4900. Impeller 4900 is similar to impeller 4800 (shown above), but proximal surface 4904 may have a concave profile. This concave proximal surface 4904 may reduce blood reflux through the pump housing caused by the proximal end of impeller 4900, as compared to the proximal surface of impeller 4800.

[0167] 50A and 50B show another exemplary expandable, inflatable, or balloon-type pump impeller 5000. Impeller 5000 is similar to impeller 4800 (shown above), except that proximal surface 5004 may have a convex profile.

[0168] 48A-50B, the proximal surface of the impeller may be designed to reduce pumping action and minimize blood reflux through the pump housing. This may be desirable to reduce the time blood is in contact with the impeller as well as to reduce the risk of the impeller aspirating air through the device hub. In contrast, the proximal surface of the impeller may be designed to increase pumping action and / or maximize blood reflux through the pump housing. It may be desirable to specifically accommodate and / or increase blood reflux, as the reflux can be used as a lubricant or coolant to improve self-centering of the impeller within the pump housing and also to improve the interaction of the drive shaft with the drive shaft housing (e.g., to reduce friction, provide cooling, etc.). In some embodiments, a purge fluid (e.g., saline, dextrose, etc.) from outside the body can be introduced into the drive shaft housing to act as a lubricant or coolant to improve self-centering of the impeller within the pump housing and / or improve the interaction between the drive shaft and the drive shaft housing (e.g., reduce friction, provide cooling, etc.).

[0169] 51A and 51B show another exemplary expandable, inflatable, or balloon pump impeller 5100 according to an embodiment of the subject matter disclosed herein. When considering a catheter-based blood pump (e.g., pump device 400, FIGS. 4 and 10) configured in a blood-pushing configuration, the impeller of the system may have some modifications compared to the impeller of a blood-drawing pump device. Since blood moves in a proximal to distal direction, the impeller design may be optimized to pump blood in said direction. Many of the disclosed impeller examples are configured for a blood-drawing configuration, but if the impeller is flipped from proximal to distal, the impeller design would be optimized to increase blood flow in the proximal to distal direction with respect to the catheter.

[0170] In FIGS. 51A and 51B, the outer shape of the impeller 5100 is similar to that of the impeller 4100 (see FIG. 41). However, what is the distal end of the impeller 4100 here is the proximal end of the impeller 5100. The distal surface 5104 of the impeller 5100 is different from the proximal surface of the impeller 4100. In the blood extrusion mode, there may be no cannula extending distally from the end of the pump housing 408 (see FIG. 10), and thus the impeller 5100 can be configured without having a distal tip protruding along the axis 5102. The distal tip of the impeller 5100 can be folded back into itself as shown, creating a distal tip in the shape of a cut tip or a more rounded distal tip. This outer shape of the tip of the impeller 5100 can improve the interaction between the impeller 5100 and the closed distal form of the pump housing 408.

[0171] FIGS. 52A-52D show another exemplary expandable pump impeller 5200 according to an embodiment of the subject matter disclosed herein. The pump impeller 5200 includes a plurality of expandable ridges 5202 that provide improved fluid pumping dynamics. The ridges 5202 begin at the distal portion 5204 of the pump impeller 5200, pass through the maximum diameter portion 5206 of the impeller pump 5200, and end before the proximal portion 5208 of the impeller pump 5200. Such ridges 5202 provide a relatively large gap therebetween, and such a gap can act as a channel for blood to enter.

[0172] In some embodiments, the ridges 5202 can have a tapered width such that, as shown in FIG. 52D, the distal tip of the ridge 5202 has a width of X and the proximal portion of the ridge 5202 has a larger width of Y (where X < Y). This tapered width can also facilitate the efficient entry of blood between the ridges 5202.

[0173] 52A-52D, in the depicted non-limiting embodiment, the ridges 5202 extend in a helical or spiral manner relative to the longitudinal / rotational axis 5210 of the pump impeller 5200. More specifically, the ridges 5202 are offset from the longitudinal axis 5210 (if the ridges 5202 were extended, they would not converge on the rotational axis 5210 of the impeller 5200) and wrap around the surface of the pump impeller 5200 at a uniform angle. Alternatively, the ridges 5202 may wrap around the pump impeller 5200 at a varying, non-uniform angle.

[0174] 53A-53C show another exemplary expandable pump impeller 5300 according to an embodiment of the subject matter disclosed herein. The pump impeller 5300 is similar to the impeller 5200 shown in FIGS. 52A-52D, except that the pump impeller 5300 comprises segmented expandable ridges 5302 that are spaced apart from one another by one or more gaps 5304 along the length of the ridges. As pressure increases within the pump impeller 5300, the pump impeller 5300 tends to round off, thereby reducing the protruding height of the ridges 5302. The gaps 5304 may not expand when the pump impeller 5300 is pressurized, thereby acting as tethers to provide hoop strength to maintain the expanded impeller profile and integrity of the ridges 5302.

[0175] 54A-54C show another exemplary expandable pump impeller 5400 according to an embodiment of the subject matter disclosed herein. The pump impeller 5400 is similar to the impeller 5200 shown in FIGS. 52A-52D, except that the pump impeller 5400 includes a plurality of tapered and angled ridges 5402 on a distal portion 5404 and a maximum diameter portion 5406. The proximal portion 5408 has a smooth surface and is relatively large to merge with the outermost dimension of the ridges 5402. Such a proximal portion 5408 may provide several advantages. One advantage is that there are no steps along the side profile of the pump impeller 5400, and as a result, it may be relatively easy to construct a smooth-walled pump housing that matches the rotational profile of the impeller 5400. Another advantage is that the proximal portion 5408 may enhance the self-centering capabilities of the pump impeller 5400. Yet another advantage is that the pump impeller 5400 defines a blood redirecting ramp 5410. Such ramp 5410 may redirect blood from an axial flow path to a radial flow path, thereby forcing blood circumferentially out of the pump housing outlet.

[0176] 55A-55D show another exemplary expandable pump impeller 5500 according to an embodiment of the subject matter disclosed herein. The pump impeller 5500 is similar to the impeller 5400 shown in FIGS. 54A-54D, except that the pump impeller 5500 is generally inflatable and expandable, but includes a number of non-expandable ridges 5502, sometimes referred to as fins. The fins 5502 may be formed by fusing the balloon membranes of the pump impeller 5500 together, thereby rendering the fins 5502 non-expandable. However, the fins 5502 are nevertheless flexible, allowing the fins 5502 to be radially folded into a relatively small delivery profile.

[0177] In the expanded configuration of the pump impeller 5500 (as shown), the fins 5502 are supported by the fluid pressure used to inflate the pump impeller 5500. Additionally, the back of each fin 5502 may be in tension between the distal portion 5504 of the pump impeller 5500 and the maximum diameter portion 5506 of the pump impeller 5500.

[0178] If the fluid pressure within the pump impeller 5500 is sufficient, the fins 5502 can withstand the pressure of the blood on the fins 5502 as they rotate and pump blood. The pump impeller 5500 may also define a blood turning ramp 5508 to direct the blood through the pump housing outlet.

[0179] 55A-55C, in some embodiments, the fins 5502 may extend non-helically or along a straight path relative to the longitudinal / rotational axis 5510 of the pump impeller 5500. Alternatively, in some embodiments, the pump impeller 5500 may include fins 5512 that extend helically or along a curved path relative to the longitudinal / rotational axis 5510, as shown particularly in FIG.

[0180] 56A-56F show components and steps of a method for manufacturing the pump impeller 5500 of FIGS. 55A-55D according to an embodiment of the subject matter disclosed herein. First, a finless impeller preform 5600 is blown into an expanded form as shown in FIGS. 56A, 56C, and 56E. Next, the expanded preform 5600 is placed in a fixture 5602 with an internal geometry corresponding to the desired final geometry of the pump impeller 5500 as shown in FIGS. 56B and 56D. With the portions of the fixture 5602 separated from each other, the preform 5600 can be pressed and placed in the fixture 5602. The portions of the fixture 5602 can then be squeezed together like an iris until they contact each other. The preform 5600 and fixture 5602 can be heated to fuse the membranes together, thereby forming the fins 5502 (FIG. 56F). Alternatively, the pump impeller 5500 may be formed by producing a membrane from a co-extrusion with an adhesive layer at the inner diameter of the extrusion, which increases the bonding strength of the fusion bond.

[0181] 57A and 57B illustrate components and steps of a method for manufacturing another exemplary pump impeller 5700 with expandable ridges 5702, as shown in FIG. 57C and FIG. 57D, according to an embodiment of the subject matter disclosed herein. The method generally includes joining two membrane layers. The membrane layers include an outer layer 5704, as shown in FIG. 57A, which is formed into a desired outer impeller profile. The membrane layers also include an inner layer or mesh 5706, as shown in FIG. 57B. The inner mesh 5706 includes a plurality of holes 5708, which may be created by laser cutting. After creating the outer layer 5704 and the inner mesh 5706, the inner mesh 5706 may be placed within the outer layer 5704, and the outer layer 5704 and the inner mesh 5706 may be fused together to create the pump impeller 5700, as shown in FIG. 57C and FIG. 57D. Such construction of the pump impeller 5700 may make it less likely to round when pressurized, thereby maintaining its shape (including the shape of the expandable ridges 5702). The strength of the fusion bond between the membrane layers may be increased by using co-extrusion with a cling layer on the fusion side of the layers.

[0182] 58A and 58B illustrate components and steps of a method for manufacturing another exemplary pump impeller 5800 with expandable ridges 5802, as shown in FIG. 58D and FIG. 58E, according to an embodiment of the subject matter disclosed herein. First, an inner compliant or semi-compliant membrane 5804 is formed, as shown in FIG. 58A. FIG. 58A illustrates the as-formed, unpressurized membrane 5804. FIG. 58B illustrates the pressurized membrane 5804, stretched and rounded. FIG. 58C illustrates an outer layer 5806 constructed of a non-compliant material, the outer layer 5806 including a plurality of openings 5808 that define a base perimeter of the expandable ridges 5802. The outer layer 5806 is laminated onto the membrane 5804. The outer layer 5806 thus acts as a cage to restrain the expansion of the membrane 5804 when pressurized. However, the openings 5808 do not restrict the membrane 5804 from expanding, thereby allowing the membrane 5804 to expand and stretch through the openings 5808 when pressurized, creating the ridges 5802. As a result, as shown in Figures 58D and 58E, the pump impeller 5800 is a bi-layer impeller with expandable ridges 5802. The strength of the lamination bond between the membrane layers can be increased by using co-extrusion with a cling layer on the fused side of the layers.

[0183] 59A and 59B show components and steps of a method for manufacturing another exemplary pump impeller 5900 with expandable ridges 5902 as shown in FIG. 59C according to an embodiment of the subject matter disclosed herein. The method is similar to the method shown in FIGS. 58A-58C, except that a single co-extrusion may be used to generate the impeller membrane 5904 as shown in FIG. 59A. The outer layer of the co-extrusion may be non-compliant and the inner layer may be compliant or semi-compliant. An opening 5906 in the outer layer may be created, for example, by ablating the outer layer, so that the inner layer can expand through the opening 5906 to generate the expandable ridges 5902 as shown in FIG. 59C.

[0184] 60A and 60B illustrate an exemplary method of using a pressurized balloon within a patient's cardiovascular system to act as a pressure transducer, thereby providing measurements of the patient's systolic and diastolic blood pressure. The method includes using a balloon pressure transducer system 6000, which includes a balloon 6002, a pressure gauge inflation conduit 6004, and a pressure gauge 6006. After the balloon 6002 is placed in the left ventricle and inflated, the pressure gauge 6006 records the internal gauge pressure of the balloon 6002. During diastole, the balloon 6002 will have less external pressure applied to it. As a result, the gauge 6006 will indicate a relatively low diastolic pressure 6008 (e.g., 80 mmHg), as shown in FIG. 60A. During systole, the balloon 6002 will have more external pressure applied to it. As a result, the gauge 6006 will indicate a relatively high systolic pressure 6010 (e.g., 120 mmHg), as shown in FIG. 60B.

[0185] Any of the expandable, inflatable, or balloon-type pump impellers described herein may be used to perform the function of the balloon 6002 measuring blood pressure. More specifically, as the pump impeller expands and rotates to pump blood, the patient's QRS complex resulting from the patient's continuous heartbeat will cause periodic external pressure fluctuations on the pump impeller. With appropriate adjustment factors, the pumping action of the catheter blood pump can vary the external blood pressure experienced by the balloon-type impeller, while the internal pressure rhythm of the balloon-type impeller can be monitored to calculate an accurate blood pressure reading. A non-exhaustive list of adjustment factors to consider includes the pressure loss along the inner lumen of the drive shaft, the angular velocity of the impeller, the initial baseline inflation pressure of the impeller, and the initial diastolic and systolic arterial pressures of the patient prior to placement of the mechanical hemodynamic support device.

[0186] FIG. 61 illustrates various arterial and venous access sites and pathways for delivering the mechanical hemodynamic assist devices described herein to the patient's heart. The most common access site is the femoral artery because it can accommodate larger devices, is easy to access, and is easy to seal afterwards. If a patient has a femoral artery that is too small or too diseased to accommodate a device, an axillary artery access site may be used instead. A suitable mechanical hemodynamic assist device, such as the pumping device described herein, will for the first time allow the use of a radial access site, either via the wrist or snuff box access site, which is beneficial due to the ease of access and ease of closing the access site.

[0187] Venous access sites may be used to place mechanical hemodynamic assist devices in the right ventricle to assist the pulmonary circulation. Right ventricular circulatory assist may be provided alone or in conjunction with left ventricular circulatory assist to achieve complete cardiac circulatory assist. In addition, venous access sites may be used when direct arterial access is not possible, in which case mechanical hemodynamic assist devices may be tracked through a trans-caval or atrial transseptal route to reach the arterial system to provide left ventricular circulatory assist.

[0188] Various modifications and additions can be made to the exemplary embodiments discussed without departing from the scope of the present invention. For example, while the embodiments described above refer to certain features, the scope of the present invention also includes embodiments having different combinations of features and embodiments that do not include all of the described features. Thus, the scope of the present invention is intended to include all such alternatives, modifications, and variations that are within the scope of the claims, together with all equivalents thereof.

[0189] Optional Features and Additional Embodiments Referring generally to inflatable balloon pump impellers, some embodiments may utilize an impeller spinning at high rpm to assist in the expansion of the impeller. That is, as the pump impeller spins, it exerts a centrifugal force on the expansion fluid within the impeller. The impeller will tend to expand in response to the centrifugal force of the expansion fluid. As a result, additional expansion fluid will be drawn into the impeller causing it to fully expand. The centrifugal force may be sufficient to maintain the balloon in an inflated or expanded operating state. When centrifugal force is used in this manner, the rotatable inner catheter 700 need not be a completely sealed system in some instances.

[0190] The inflatable balloon pump impeller may be inflated with standard balloon catheter inflation media (e.g., a mixture of saline and contrast agent), for example, via a Luer adapter, or the pump impeller may be inflated with a more viscous or denser fluid. The impeller may also be inflated with a fluid that solidifies into a gelatinous form when expanded and spun to help the impeller maintain its surface configuration. In order to deflate an impeller filled with solidified liquid, further delivery of a chemical or enzyme that breaks down the gelatinous structure may be required. If the impeller is inflated with, for example, a mixture of saline and contrast agent, the impeller may be deflated with standard balloon deflation techniques (e.g., aspiration of the inflation media).

[0191] In some embodiments, the impeller may have one or more radiopaque markers to assist the user in locating the impeller relative to the patient's anatomy and relative to the pump housing to ensure proper placement. These radiopaque markers may be located either on the impeller membrane or on the drive shaft within the impeller, or a combination of both locations. Additionally, in some embodiments, the inflation medium used to expand the impeller may be radiopaque, allowing the entire impeller to be visible under fluoroscopy.

[0192] Referring generally to a rotatable drive shaft that drives a pump impeller according to embodiments of the subject matter disclosed herein, if the impeller is designed as a self-expanding impeller (as opposed to an impeller expandable by fluid pressure), the drive shaft may not need to include an inflation lumen. Thus, in some such embodiments, the drive shaft may be designed as a solid cable, without a lumen for delivering inflation media to the impeller.

[0193] The torque transmitting drive shaft may optionally include a structural reinforcement designed to transmit torque while remaining flexible. Some possible designs for the structural reinforcement include a structure made of hypotubes with a pattern laser cut from the wall to increase flexibility. This may also be combined with a second layer of laser cut hypotubes with a mirrored (opposite) pattern to the first hypotube to further increase torque transmission. The support may also be made of multifilar coils such as HHS® ("Helical Hollow Strand") coils, either in single or double bidirectional coils, or three-way coils concentrically placed inside each other. Multifilar coil reinforcement provides robust flexibility and torque transmission characteristics. The structural reinforcement may also be a combination of the aforementioned support structures. A polymeric film liner may be placed either inside the hollow shaft or outside the hollow shaft to seal the shaft and create an inflation lumen. The inside or outside of the coil may have a polymer membrane or jacket that seals the shaft and creates an inflation lumen for inflating the balloon impeller.

[0194] In some embodiments, the structural torque transmission element may be made of a twisted stranded cable that may be wound in a single layer, two opposing layers, or three opposing layers. In cable form, since there is no hollow opening inside the cable, there may be a loose membrane around the outside of the cable with enough clearance between the membrane and the cable for fluid to pass through. When rotating, both the membrane and the cable may rotate at the same angular velocity.

[0195] With general reference to the two catheter systems that rotate relative to each other and the system components that are implanted in the patient according to the embodiments of the subject matter disclosed herein, coatings may be disposed on the surfaces of the components that form the catheter blood pump. Friction-reducing coatings, such as, but not limited to, hydrophilic or hydrophobic coatings, such as silicone, may be applied to reduce wear on the components. Thrombotic reducing coatings, such as, but not limited to, heparin coatings, may be used to reduce the change in thrombus that forms on the surfaces of the components. Bioactive or biocompatible improving coatings, such as, but not limited to, hydrogel or limus drug-based coatings, may be used to reduce the patient's reaction to the presence of a foreign body in the body.

[0196] With particular reference to friction-reducing coatings, these coatings may be applied to the outside of the sheath 500 to facilitate tracking of the sheath through the access site and the anatomy. Friction-reducing coatings may also be applied to the inside of the sheath 500 or the outside of the housing component 510 (or both) to reduce friction between the two components and thus facilitate retraction of the sheath 500 and emergence of the inlet cannula 504 and pump housing 508. A friction-reducing coating between the sheath 500 and the housing component 510 may also facilitate re-advancing the sheath 500 over the housing component 510 to radially collapse the pump housing 508 and inlet cannula 504 into the sheath 500 prior to withdrawal of the device. The inner lumen of the housing component 510 may also benefit from a friction-reducing coating to make it easier to track over a pre-placed guidewire and into the anatomy. Having a friction-reducing coating on the inside of the drive shaft housing 511 may also facilitate advancement of the rotatable inner catheter 700 through the drive shaft housing 511 and into the pump housing 508. Coating the drive shaft 704 with a friction-reducing coating may reduce resistance when spinning the rotatable inner catheter 700, which may lead to reduced fatigue and wear on the drive shaft and may also result in increased lifespan of the device.

[0197] With particular regard to clot-reducing coatings, because the device sits in the blood and pumps blood through its components, there may be points within the device where blood flow is stagnant. In these points, it may be beneficial to apply a clot-reducing coating to the surfaces of these components to reduce the likelihood of clots forming on the device or in the patient. One non-limiting example where this may be beneficial is on the inside of the drive shaft housing 511 where there may be minimal blood or fluid perfusion through the drive shaft housing 511.

[0198] With particular regard to biocompatibility-enhancing coatings, if the device is used as a long-term ventricular assist device, it may be beneficial to coat the components to improve biocompatibility. These coatings could function by making the device less "recognizable" to the patient's body, thus reducing the chance of rejection. The coatings could also function by reducing cell proliferation, thus reducing the rate of endothelialization on the device, and increasing the usable life of the device. Notable components that may benefit from a biocompatibility-improving coating are the housing component 510 and the sheath 500, although any of the other components may also benefit from one of these coatings.

[0199] With general reference to a two-part catheter system that rotates relative to one another, there may be mechanisms to ensure optimal longitudinal alignment between the housing component 510 and the rotatable inner catheter 700 according to embodiments of the subject matter disclosed herein. The pump impeller and pump housing may have a precision longitudinal alignment mechanism. A non-limiting example may be that the alignment mechanism is controlled by adjusting the position between the drive shaft and the hub of the drive shaft housing. The alignment mechanism may consist of two hubs that are locked in a stationary position and are therefore not free to move, allowing for precise fine adjustment of their alignment. This fine adjustment may be performed using a lead screw type mechanism, where turning the screw moves the drive shaft distally or proximally relative to the drive shaft housing, thus adjusting the placement of the impeller and pump housing. The alignment mechanism may also use a fine adjustment thumbwheel type mechanism to precisely adjust the alignment between the components.

[0200] Another non-limiting example is for the alignment mechanism to be electronically controlled to increase the accuracy of the alignment. An electronic mechanism may allow for having a worm gear coupled to a straight gear for increased accuracy and automatic position locking. An electronic alignment mechanism may allow for the alignment of components to be optimized by taking into account the current draw of the main motor driver and adjusting the alignment of the components to minimize the current required to rotate the impeller at a given rotational speed.

[0201] The electronic alignment mechanism may allow component alignment and drive shaft tension to be optimized in real time as the impeller rotational speed increases or decreases. As an example, as rotational speed increases, the self-centering feature of the pump impeller may tend to push the impeller distally or proximally within the pump housing. As the impeller rotational speed increases and the impeller attempts to move, the electronic alignment mechanism may adjust to move the drive shaft proximally or distally, thus maintaining optimal impeller placement within the pump housing. This real-time alignment adjustment may be performed automatically if the alignment mechanism is motorized and in communication with the controller system to properly adjust the alignment based on the impeller rotational speed.

[0202] The drive shaft housing and drive shaft hub may have a home position where they lock into place and a precision alignment mechanism engages. This home position may ensure that the impeller is aligned well enough within the pump housing to safely pump blood, even if not optimally. Then, as the device is actuated and rotated, the precision alignment mechanism may be used to optimize component placement by moving the impeller proximally or distally within the pump housing.

[0203] With reference to catheter blood pumps in general, there may be alternative embodiments of the system, such as, but not limited to, multiple pumping units daisy-chained in series, according to embodiments of the subject matter disclosed herein. It is possible to daisy-chain multiple pumping units (inlet cannulas, pump housings, and impellers) on a single device. The outer catheter system may have multiple inlet cannulas and pump housings connected in series, and the drive shaft may have multiple impellers mounted in series around the shaft. Since all impellers mounted on a single drive shaft may all rotate at the same angular velocity, if it is desired to tailor the flow dynamics for each pumping unit, the flow can be tailored by using different impeller and pump housing geometries. Daisy-chaining multiple pumping units on a single device may allow the system to pump more blood with less damage to the blood by rotating the impellers at a lower angular velocity. Each inlet cannula of the pumping units may be located proximal to the outlet port of the distal pump housing, thereby reducing the backpressure that the distal pumping units must work against. A non-limiting example where the inlet cannula of the distal-most pumping unit may be located includes within the left ventricle.

[0204] Daisy-chaining the pumping units together reduces back pressure on the distal pumping unit, so the overall system may be able to support higher fluid flow rates at lower rotational angular velocities. This setup may result in a lower peak blood pressure at the distal-most pump housing outlet port, but the proximal pumping unit may continue to increase the outlet pressure until the desired blood pressure and perfusion is achieved.

[0205] The proximal inlet cannula and pump housing may be sized to reduce backflow inside the blood vessel from the pump housing outlet port toward the inlet cannula. Additionally, prevention of backflow in the blood vessel may be achieved by having each subsequent inlet cannula-to-pump housing connection have a skirt or petal that provides a seal against the blood vessel wall, resulting in reduced backflow through the blood vessel.

[0206] Referring generally to the system controller, there are several features that may be included in the controller according to embodiments of the subject matter disclosed herein. The system controller may be a fixed device or a portable system controller that can move with the patient. The controller is the brain of the system. The system controller may be the key device that communicates with and controls the motor used to rotate the impeller and pump blood. The controller may be able to adjust the rotational speed (rpm) of the impeller to control cardiac output. The controller should monitor motor parameters to ensure smooth device operation. Additionally, the controller may provide feedback to the user of the device's performance and the patient's vitals.

[0207] Based on the motor current draw, the impeller placement within the pump housing may be fine-tuned upon operation to allow optimal efficiency of fluid flow versus rotational rpm. The controller may also inform the user of the pump flow rate, and in turn, the amount of circulatory assistance the patient is receiving from the pump. This may be done by calculating a device rpm to flow rate constant and calibrating the system with said constant.

[0208] During emergency procedures, the patient may be immobilized. Thus, the controller may be a standalone, important piece of equipment next to the table where the patient is being treated. However, if the patient is on mechanical circulatory support for cardiogenic shock treatment or some other reason requiring long-term circulatory support, a standalone system next to the patient's table would be inconvenient as it would prevent the patient from moving freely or getting out of bed. Therefore, a portable controller system and motor may be preferred.

[0209] If an upper body access site is used to place the device, the patient's legs may be free to walk if they can easily carry the motor and controller. If a radial access site is used, the patient's arm will have to be immobilized to prevent arm movement from displacing the device within the vasculature. For a radial access site, the patient may wear a removable immobilization elbow and shoulder brace to immobilize the patient's arm. The controller and motor can be strapped to the patient's arm, thus allowing the entire system to be contained on the patient's arm and portable. Alternatively, if a radial access site is used, the device may be immobilized within the vasculature, thus allowing the patient to move the patient's arm without risking displacement of the device. Methods of immobilizing the device within the vasculature are discussed and depicted in the figures.

[0210] Instead, if an alternative upper body access site is used, such as an axillary or subclavian access site, to name a few non-limiting examples, the patient can continue to move their arm and torso without any risk of displacing the device within the vasculature. For an axillary or similar access site, the patient may have both the controller and motor strapped directly to the patient's shoulder like an epaulette, or may have some of the components strapped to the patient's chest or abdomen. The portable system may also be placed through an abdominal aorta ("AAA") access site, but an AAA access site requires a surgical incision. If an AAA access site is used, the portable system may be strapped to the patient's waistband, or even have parts of the system implanted inside the patient's abdominal cavity.

[0211] The portable controller and motor system may be a single unit all housed together, or they may be separate units connected to each other. Some non-limiting examples of separate motors and controllers may be to have an internally implanted motor and a controller external to the patient. Another example may be to have an external motor connected to the patient's shoulder like an epaulette and then have a controller attached to the patient's abdomen or in a backpack that the patient can carry. The portable controller system may include the electronics necessary to power the motor as well as to control the motor speed and monitor patient and device performance.

[0212] The controller may monitor motor performance to determine if the motor is operating efficiently or if the motor may have reached the end of its life. By monitoring motor performance, the controller may also be able to determine if the alignment of the impeller and pump housing is nominal or if it is out of alignment and requires adjustment. The portable controller may connect (wired or wirelessly) to additional external patient monitoring systems such as, but not limited to, pulse oximeters, EKG monitors, and blood pressure monitors that allow comprehensive real-time monitoring of patient vitals and may be able to adjust device performance for optimal patient health or inform the patient if they should seek medical attention.

[0213] The portable controller may have data storage capacity to record device performance and any patient vitals that are also being monitored, which may assist the clinician by providing diagnostic data. This data may also assist in weening the patient off mechanical circulatory support. The portable controller may have an alarm system that monitors and interprets the data and notifies the patient if any device parameters or patient vitals deviate from nominal, thus allowing the portable controller to intervene preemptively rather than reactively dealing with any issues. The alarm system may be visual, audible, tactile, or any combination thereof. The alarm system may also wirelessly communicate with the patient's clinician as well as emergency medical crews if any issues arise, thereby facilitating faster response times.

[0214] The controller may have the ability to adjust the amount of mechanical circulatory support provided by the catheter blood pump. The controller may adjust the flow rate (e.g., impeller rpm speed) based on patient vitals such as blood pH, blood oxygen level, heart rate, blood pressure, etc. The portable controller also has the ability to slowly reduce the blood flow rate it provides while monitoring the patient's vitals, thereby allowing the patient to be slowly weaned off mechanical circulatory support while ensuring the patient remains stable.

[0215] The portable controller may also have adjustable parameters to allow the patient to adjust the flow rate of the blood pump. The flow rate adjustment may be limited to certain pre-set ranges determined by the patient's clinician. Allowing the patient to vary the flow rate allows the patient to experience mechanical circulatory support that is personally adapted to their lifestyle. For example, the patient may increase the flow rate when the patient is walking or exercising, and then decrease the flow rate when the patient is resting, thereby potentially extending the life of the device and improving the patient's quality of life.

[0216] The portable controller requires a power source to operate the motor and any devices as well as the patient monitoring system. The portable controller may contain a battery to operate the system during periods when the controller is disconnected from an external power source. When connecting the portable controller to a power source, the portable controller may have a plug adapter that allows it to operate from 220-110 VAC, or an adapter that allows it to operate from 12-24 VDC to power the system and motor. A low voltage DC adapter may allow the controller to be powered from a mobile location such as a vehicle. Additionally, a portable modular battery pack may be provided that can be connected to the controller to power the system for an extended period of time while the patient is not around an external power source or in the event of a power outage at the patient's location.

[0217] With general reference to the catheter blood pumps described herein, there are many different use scenarios in which a blood pump according to embodiments of the subject matter disclosed herein may support a patient's vitals and improve patient outcomes. A catheter blood pump would be used to provide mechanical circulatory support to patients who may require additional blood pumping capabilities and / or capacity. It may be used either as a long-term ventricular assist device or a short-term device to perform protected PCI, but is not limited to these use scenarios. The present invention can gain access to the patient through either a traditional femoral access site, or an upper body access site, such as a radial access site. With a radial access site, the patient can be ambulatory with the device still in place and pumping blood, as long as the patient's arm is immobilized or the device is immobilized within the ventricle / aorta. Radial access may also allow the femoral artery to be used for other concomitant procedures, such as, but not limited to, percutaneous transluminal angioplasty / stent insertion and lower limb revascularization.

[0218] Since a large caliber access site is not required to place the device in the patient, many alternative access sites can be used to place the apparatus. In addition to the radial or femoral artery access sites, the access sites may be in the femoral vein or brachial vessels. The axillary artery may also be used as an access site for device placement. Additionally, in a blood pushing configuration, the device may be placed via a transthoracic / transapical approach to pump blood from the left ventricle into the aorta, as seen in FIG. 4B.

[0219] The device may be placed across the aortic valve to pump blood from the left ventricle into the aorta, as shown in Figure 3. In a blood-pushing configuration, the device may be placed in the right ventricle and across the semilunar valve to pump blood into the pulmonary artery. The blood-pushing configuration may also be placed into the left ventricle through a transseptal access route, as seen in Figure 4A.

[0220] To provide a general context, Table 1 (below) lists some exemplary size ranges for various components of some embodiments of the percutaneous ventricular assist devices described herein. However, it should be understood that these are non-limiting examples and that the components can be scaled to a variety of other desired sizes and size ranges, some smaller and some larger than those listed in Table 1.

[0221] [Table 1] The percutaneous ventricular assist devices described herein can be operated at a variety of speeds (e.g., in terms of revolutions per minute ("rpm") of the pump impeller) to obtain a desired operating pump flow performance. In some non-limiting exemplary embodiments, the pump impeller of the percutaneous ventricular assist devices described herein can be operated at a variety of speeds (e.g., in terms of revolutions per minute (rpm) of the pump impeller) to obtain a desired operating pump flow performance. In some non-limiting exemplary embodiments, the pump impeller of the percutaneous ventricular assist devices described herein can be operated at a variety of speeds (e.g., in terms of revolutions per minute (rpm) of the pump impeller) to obtain a desired operating pump flow performance. In some non-limiting exemplary embodiments, the pump impeller of the percutaneous ventricular assist devices described herein can be operated at a variety of speeds (e.g., in terms of revolutions per minute (rpm) of the pump impeller) to obtain a desired operating pump flow performance. The rotor may be operated in the range of 0,000 rpm, or 20,000 rpm to 30,000 rpm, or 20,000 rpm to 40,000 rpm, or 20,000 rpm to 50,000 rpm, or 20,000 rpm to 60,000 rpm, or 30,000 rpm to 40,000 rpm, or 30,000 rpm to 50,000 rpm, or 30,000 rpm to 60,000 rpm, or 40,000 rpm to 50,000 rpm, or 40,000 rpm to 60,000 rpm, or 50,000 rpm to 60,000 rpm, or over 60,000 rpm. It should be understood that these pump impeller rpm ranges are merely exemplary and non-limiting, as the actual impeller rpm used during a procedure will ultimately depend on many different factors, such as, but not limited to, impeller design, pump system size, patient parameters, clinician preference, etc.

[0222] There are many further use scenarios for catheter blood pumps to assist the patient's blood circulation. Some non-limiting examples of device use are listed herein. The device may be placed in the right ventricle to pump blood to the lungs to improve blood oxygenation circulation. This use scenario may be useful for short-term assistance during pulmonary embolism, for example. The device may be placed in the carotid artery to increase cerebral perfusion, which may be desirable during a transient ischemic attack (ischemic stroke). The device may also be placed in the descending aorta to partially offload blood back pressure to the heart and provide additional perfusion to the renal arteries and legs. The device may be placed in the iliac artery to help ischemic lower limbs. In general, the blood pump may be placed directly upstream of any particular organ when additional blood perfusion is useful or required.

[0223] Two separate devices may be used in tandem to support two organ systems simultaneously: in this example, one is placed in the descending aorta to support the lower extremities, while the other is placed in the carotid artery to maintain adequate blood pressure in the brain.

[0224] The devices described herein may optionally be MRI compatible. The drive shaft and drive shaft housing may be made of MRI compatible supporting structural materials such as Nitinol or PEEK, and the sheath, impeller, and casing may also be MRI compatible, making the entire implantable portion of the device MRI compatible. Thus, the drive shaft and drive shaft housing may be used to extend outside the body to provide hemodynamic support to the patient during MRI imaging.

[0225] If the clinician is uncertain whether mechanical circulatory support will be required during an intervention such as protected PCI, the device described herein may be partially implanted. Partial implantation consists of placing the housing component 510 in the patient and then expanding the inlet cannula 504 and pump housing 508 or leaving the inlet cannula 504 and pump housing 508 in their collapsed state. At this stage, the clinician may continue the PCI procedure without activating the blood pump. If the patient does not require circulatory support during the procedure after all, the stationary outer catheter system can be removed without the need to use the remainder of the pump assembly. If the patient does require circulatory support during the procedure, the rotatable inner catheter 700 can be immediately placed in the already placed housing component 510 and the device activated, thereby dramatically reducing the delay between when circulatory support is required and when it is provided. With the partial implantation technique of the device, significant cost savings can be realized by not requiring catheter lab time to fully implant the device as well as not having to use the rotatable inner catheter 700. If the components are available separately, the clinician can replenish their inventory by replacing the housing component 510 and the sheath 500.

[0226] Although the present specification contains many specific implementation details, these should not be construed as limitations on the scope of any invention or what may be claimed, but rather as descriptions of features that may be specific to certain embodiments of a particular invention. Certain features described herein in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable subcombination. Furthermore, even if features are described herein as acting in a particular combination and may initially be claimed as such, in some cases one or more features of a claimed combination may be deleted from the combination, and the claimed combination may be directed to a subcombination or a variation of the subcombination.

[0227] Similarly, although acts are depicted in the figures in a particular order, this should not be understood as requiring that such acts be performed in the particular order shown, or in sequential order, or that all of the shown acts be performed, to achieve desirable results.

[0228] Specific embodiments of the subject matter have been described. Other embodiments are within the scope of the following claims. For example, the actions recited in the claims can be performed in a different order and still achieve desirable results. As one example, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results.

Claims

1. 1. A percutaneous ventricular assist device comprising: an elongate flexible drive shaft defining a lumen; a pump impeller mounted on a distal end portion of the drive shaft, the pump impeller being expandable in response to receiving inflation fluid supplied to the impeller through the lumen; A pump housing, The percutaneous ventricular assist device is configured to pump blood when: (i) the pump impeller is disposed within the pump housing; (ii) the pump impeller is expanded; and (iii) the drive shaft is rotated.

2. The pump impeller is a tapered body having an outer surface; and one or more ridges extending from the outer surface.

3. The percutaneous ventricular assist device of claim 2 , wherein the one or more ridges are expandable in response to receiving the inflation fluid supplied to the impeller through the lumen.

4. 10. The percutaneous ventricular assist device of claim 1, wherein the pump impeller comprises a tapered body having an outer surface defining one or more grooves extending along the outer surface.

5. The pump impeller is a tapered body having an outer surface; and one or more non-expandable fins extending from the outer surface.

6. 6. The percutaneous ventricular assist device of claim 1, wherein the pump housing is reconfigurable between a low profile delivery configuration and a radially expanded configuration, the pump housing defining one or more outlet openings.

7. The percutaneous ventricular assist device of claim 6 , wherein the pump housing defines one or more relief notches around each of the one or more outlet openings.

8. The percutaneous ventricular assist device of any one of claims 1 to 5, comprising an inlet cannula extending from the pump housing, the inlet cannula defining one or more inlet openings.

9. The percutaneous ventricular assist device of claim 8 , wherein the inlet cannula is reconfigurable between a low profile delivery configuration and a radially expanded configuration.

10. 6. The percutaneous ventricular assist device of claim 1, further comprising a drive shaft housing extending proximally from the pump housing, the drive shaft housing defining a housing lumen configured to slidably receive the drive shaft and the pump impeller when the pump impeller is contracted.

11. 1. A catheter-based blood pump comprising a rotatable pump impeller attached to a flexible drive shaft, the pump impeller being reconfigurable between (i) a contracted, low profile delivery configuration configured for transvascular advancement to a target location within a patient, and (ii) an inflated, radially expanded configuration configured to pump blood when the pump impeller is rotated by the drive shaft.

12. The pump impeller is a tapered body having an outer surface; 12. The catheter blood pump of claim 11, further comprising: one or more ridges extending from said outer surface, said plurality of ridges being expandable.

13. The pump impeller is a tapered body having an outer surface; and one or more non-expandable fins or ridges extending from the outer surface.

14. 12. The catheter blood pump of claim 11, wherein the pump impeller comprises a tapered body having an outer surface, the tapered body defining one or more grooves extending along the outer surface.

15. Further comprising a housing component, the housing component comprising: an elongate drive shaft housing defining a housing lumen; a pump housing disposed at a distal end portion of the drive shaft housing; an inlet cannula extending from the pump housing; 15. The catheter blood pump of claim 11, wherein the pump housing and the inlet cannula are radially reconfigurable between (i) a low profile configuration when radially constrained within a sheath lumen of a delivery sheath device, and (ii) a radially expanded configuration when unconstrained by the delivery sheath device.

16. 16. The catheter blood pump of claim 15, wherein the housing lumen is configured to slidably receive the drive shaft and the pump impeller when the pump impeller is in the contracted, low profile delivery configuration.

17. 1. A blood pump comprising a rotatable pump impeller, the rotatable pump impeller being expandable from a low profile delivery configuration to a radially expanded configuration configured to pump blood when the pump impeller is rotated.

18. The pump impeller is a tapered body having an outer surface; 18. The blood pump of claim 17, further comprising: one or more ridges extending from the outer surface, the one or more ridges being expandable.

19. 20. The blood pump of claim 17, wherein the pump impeller comprises a tapered body having an outer surface, the tapered body defining one or more grooves extending along the outer surface.

20. 20. The blood pump of claim 17, further comprising an elongated flexible drive shaft, the pump impeller being attached to a distal end portion of the drive shaft, the pump impeller rotating in response to rotation of the drive shaft.

21. 1. A blood pump system comprising: an elongate delivery sheath device defining a sheath lumen; a housing component slidably positionable within the sheath lumen, an elongate drive shaft housing defining a housing lumen; a pump housing disposed at a distal end portion of the drive shaft housing; an inlet cannula extending from the pump housing; the pump housing and the inlet cannula are housing components that are radially reconfigurable between (i) a low profile configuration when radially constrained within the sheath lumen and (ii) a radially expanded configuration when unconstrained by the delivery sheath device; a rotatable inner catheter slidably positionable within the housing lumen, an elongated flexible drive shaft; an impeller disposed at a distal end of the drive shaft; an inner catheter, the impeller being slidably positionable within the housing lumen when in a radially folded configuration, the impeller being radially expandable within the pump housing to an operable configuration; and

22. 22. The blood pump system of claim 21, wherein the impeller is movable relative to the pump housing in response to retraction or advancement of the drive shaft relative to the drive shaft housing.

23. 23. The blood pump system of claim 21 or 22, wherein the drive shaft defines an inflation lumen, and the impeller is radially expandable in response to receiving inflation fluid supplied to the impeller through the inflation lumen.

24. The inner catheter comprises: a drive shaft hub attached to a proximal end portion of the drive shaft; 24. The blood pump system of claim 23, further comprising a drive shaft hub seal coupled to the hub, the drive shaft hub seal sealing a proximal end of the inflation lumen.

25. 24. The blood pump system of claim 23, further comprising a motor, the inner catheter further comprising a drive shaft hub attached to a proximal end portion of the drive shaft, the drive shaft hub configured to be coupled to the motor, and the motor and the drive shaft hub configured to allow inflation fluid to flow through the drive shaft hub and into the inflation lumen while the drive shaft hub is coupled to the motor.

26. 22. The blood pump system of claim 21, wherein the blood pump system is configured to pump blood when (i) the impeller is positioned within the pump housing at a target location within a patient, (ii) the impeller and the pump housing are expanded, and (iii) the drive shaft is rotated by a motor located outside the patient.

27. 22. The blood pump system of claim 21, wherein the inlet cannula defines one or more inlet openings and the pump housing defines one or more outlet openings.

28. 22. The blood pump system of claim 21, wherein the delivery sheath device and the drive shaft housing each define one or more openings, the one or more openings of the delivery sheath device at least partially aligning with the one or more openings of the drive shaft housing when the impeller is disposed within the pump housing.

29. 22. The blood pump system of claim 21, wherein the blood pump system is configured to pump blood by rotation of the impeller while the impeller is disposed within the pump housing without having any mechanical bearings or bushings between the impeller and the pump housing.

30. 22. The blood pump system of claim 21, wherein the impeller is configured to self-center relative to the pump housing upon rotation within the pump housing.

31. 1. A percutaneous ventricular assist device comprising: an elongate drive shaft housing defining a lumen; a pump housing attached to a distal end portion of the drive shaft housing, the pump housing being radially reconfigurable between (i) a low profile delivery configuration configured for transvascular advancement to a target location within a patient, and (ii) a radially expanded configuration; a pump impeller attached to a distal end portion of an elongate drive shaft, the pump impeller being slidably positionable within the lumen when in a radially collapsed configuration, the pump impeller being radially expandable to an operable configuration when the pump impeller is within the radially expanded configuration of the pump housing at the target location within the patient.

32. 32. The percutaneous ventricular assist device of claim 31, wherein the impeller is movable relative to the pump housing in response to retraction or advancement of the drive shaft relative to the drive shaft housing.

33. 33. The percutaneous ventricular assist device of claim 31 or 32, wherein the drive shaft defines an inflation lumen, and the pump impeller is radially expandable in response to receiving inflation fluid supplied to the pump impeller through the inflation lumen.

34. 32. The percutaneous ventricular assist device of claim 31, wherein the percutaneous ventricular assist device is configured to pump blood by rotation of the pump impeller while the pump impeller is disposed within the pump housing without having any mechanical bearings or bushings between the pump impeller and the pump housing.

35. 32. The percutaneous ventricular assist device of claim 31, wherein the pump housing is configured to self-expand into the radially expanded configuration.

36. 1. A mechanical hemodynamic assist device comprising: a pump housing configured to be disposed within a patient and to permit blood flow from a pump housing inlet to a pump housing outlet; a pump impeller positionable within the pump housing, the pump impeller rotatable relative to the pump housing to effect blood flow from the pump housing inlet to the pump housing outlet, the pump impeller configured to self-center with respect to the pump housing upon rotation relative to the pump housing.

37. 37. The mechanical hemodynamic assist device of claim 36, wherein the pump impeller is attached to a flexible drive shaft, the pump impeller being reconfigurable between (i) a contracted, low profile delivery configuration configured for transvascular advancement to a target location within a patient, and (ii) an inflated, radially expanded configuration configured to pump blood when the pump impeller is rotated by the drive shaft.

38. 38. The mechanical hemodynamic assist device of claim 36 or 37, wherein the pump housing is reconfigurable between a low profile delivery configuration and a radially expanded operational configuration.

39. 40. The mechanical hemodynamic assist device of claim 38, wherein the pump impeller is expandable from a low profile delivery configuration to a radially expanded operational configuration configured to pump blood upon rotation of the pump impeller relative to the pump housing.

40. 37. The mechanical hemodynamic assist device of claim 36, wherein the pump housing is attached to a distal end portion of a drive shaft housing, the drive shaft housing allowing purge fluid or blood to flow between the pump housing and the pump impeller to provide a hydrodynamic bearing between the pump housing and the pump impeller.

41. 1. A method for placing a percutaneous blood flow assist device at a target location within a patient, the method comprising: and advancing an elongate delivery sheath device through an incision in the patient, the delivery sheath device defining a sheath lumen, the sheath lumen housing a housing component slidably disposed within the sheath lumen, the housing component comprising: an elongate drive shaft housing defining a housing lumen; a pump housing disposed at a distal end portion of the drive shaft housing; an inlet cannula extending distally from the pump housing; advancing, wherein the pump housing and the inlet cannula are radially reconfigurable between (i) a low profile configuration when radially constrained within the sheath lumen, and (ii) a radially expanded configuration when unconstrained by the delivery sheath device; retracting the delivery sheath device relative to the housing component when the pump housing is at the target location to expose the inlet cannula and the pump housing out of the sheath lumen; Inserting a rotatable inner catheter into the housing lumen of the drive shaft housing, the inner catheter comprising: an elongated flexible drive shaft; a pump impeller disposed at a distal end of the drive shaft; inserting the pump impeller into the housing lumen, the pump impeller being in a radially folded configuration when present within the housing lumen; advancing the inner catheter relative to the housing component to position the pump impeller within the pump housing; and expanding the pump impeller to a radially expanded, operable configuration by supplying an inflation fluid while the pump impeller is within the pump housing.

42. 42. The method of claim 41, wherein the incision provides access to the patient's femoral artery and the delivery sheath device is advanced through the femoral artery to the target location.

43. 42. The method of claim 41, wherein the incision provides access to the patient's radial artery and the delivery sheath device is advanced through the radial artery to the target location.

44. 42. The method of claim 41, wherein the incision provides access to the patient's thoracic cavity and the delivery sheath device is advanced through the thoracic cavity to the target location.

45. 45. The method of any one of claims 41 to 44, further comprising rotating the drive shaft with a motor located external to the patient while the pump impeller is in the radially expanded operational configuration and within the pump housing.

46. 46. ​​The method of claim 45, wherein rotating the drive shaft causes the pump impeller to rotate relative to the pump housing, the pump impeller self-centering relative to the pump housing while rotating relative to the pump housing.

47. 47. The method of claim 46, wherein the delivery sheath device and the drive shaft housing each define one or more openings, the one or more openings of the delivery sheath device at least partially align with the one or more openings of the drive shaft housing when the pump impeller is disposed within the pump housing.

48. 48. The method of claim 47, wherein blood flows distally through the aligned one or more openings in the delivery sheath device and the drive shaft housing toward the pump impeller to provide a hydrodynamic bearing between the pump impeller and the pump housing.

49. 46. ​​The method of claim 45, wherein the motor and system controller are portable and capable of moving with the patient such that the patient is freely ambulatory while receiving circulatory assistance from the percutaneous blood flow assist device.

50. 42. The method of claim 41, wherein the target location is an aortic valve region of the patient.

51. 1. A method for placing a percutaneous blood flow assist device at a target location within a patient, the method comprising: advancing a housing component through a skin opening into a radial artery of a patient, the housing component comprising: an elongate drive shaft housing defining a housing lumen; a pump housing disposed at a distal end portion of the drive shaft housing, the pump housing being radially reconfigurable between a low profile configuration and a radially expanded configuration; inserting a rotatable inner catheter into the housing lumen of the drive shaft housing while the pump housing is at the target location, the inner catheter comprising: an elongated flexible drive shaft; a pump impeller disposed at a distal end of the drive shaft; inserting the pump impeller into the housing lumen, the pump impeller being in a radially folded configuration when present within the housing lumen; and expanding the pump impeller to a radially expanded, operable configuration by supplying an inflation fluid while the pump impeller is within the pump housing.

52. 52. The method of claim 51, wherein the target location is an aortic valve region of the patient.

53. 53. The method of claim 51 or 52, comprising rotating the drive shaft with a motor located external to the patient while the pump impeller is in the radially expanded operable configuration and is within the pump housing.

54. 54. The method of claim 53, wherein rotating the drive shaft causes the pump impeller to rotate relative to the pump housing, the pump impeller self-centering relative to the pump housing while rotating relative to the pump housing.

55. 52. The method of claim 51, wherein inflating the pump impeller comprises supplying the inflation fluid to the pump impeller through an inflation lumen of the drive shaft.

56. 1. A method for placing a percutaneous blood flow assist device at a target location within a patient, the method comprising: advancing one or more components of a percutaneous blood flow assist device through a skin opening and into the patient's radial artery; and expanding a pump impeller of the percutaneous blood flow assist device to a radially expanded, operable configuration at the target location.

57. 57. The method of claim 56, wherein the target location is an aortic valve region of the patient.

58. 58. The method of claim 57, wherein the pump impeller is attached to a distal end portion of an elongated flexible drive shaft, the method further comprising rotating the pump impeller while the pump impeller is in the aortic valve region and in the radially expanded operable configuration by rotating the drive shaft with a motor located external to the patient.

59. 59. The method of claim 58, wherein rotating the pump impeller pumps blood from the patient's left ventricle, across the aortic valve, and into the patient's aorta.

60. 60. The method of any one of claims 56-59, wherein the pump impeller is attached to a distal end portion of an elongate flexible drive shaft, and expanding the pump impeller comprises supplying inflation fluid to the pump impeller through an inflation lumen of the drive shaft.

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