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 Art

[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 intervention ("PCI"). During such procedures, mechanical hemodynamic support is either prophylactically placed or immediately available in case of complications. In case of complications, hemodynamic support that continues to circulate blood throughout the body while the complications are being alleviated provides a great benefit to the patient.

[0003] In addition, pVADs can be used to reduce the load on the heart before performing PCI. As a result, since the pVAD takes on a significant portion of the pumping load, the amount of work required by the heart to pump blood is reduced. There is clinical evidence indicating that reducing the load on the heart during myocardial infarction has a beneficial effect on myocardial tissue viability over the long term.

Summary of the Invention

Problems to be Solved by the Invention

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

[0005] Furthermore, while small access sites can be treated with pressure alone, larger access sites require some form of access site closure device, or surgical incision and post-treatment suturing.

[0006] Furthermore, the current size of pVADs is too large for many patients worldwide, including children and those with smaller body structures. Therefore, improved systems, devices, and methods would be beneficial. [Means for solving the problem]

[0007] This disclosure describes blood pump systems, such as percutaneous ventricular assist devices, and methods of implantation and use thereof. An example of such a system described herein comprises an elongated flexible drive shaft defining a lumen, a pump impeller attached to the distal end of the drive shaft, and a pump housing. The pump impeller is expandable in response to receiving an expansion 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 positioned 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 of the following features: The pump impeller may comprise a tapered body having an outer surface and one or more protrusions extending from the outer surface. One or more protrusions may be expandable in response to receiving expansion fluid supplied to the impeller through a lumen. 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 pump impeller may comprise 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 comprise 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 delivery configuration with a small external shape and a radially expanded configuration. The blood pump system may also include a drive shaft housing extending proximal 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-type blood pump. An example of such a system described herein comprises a rotatable pump impeller mounted on a flexible drive shaft. The pump impeller is reconfigurable between (i) a small, contracted delivery configuration configured for transvascular advancement to a target location within the patient, and (ii) an inflated, radially expanded configuration. The pump impeller is configured to pump blood when rotated by the drive shaft in the inflated, radially expanded configuration.

[0010] Such a catheter-type blood pump system may optionally include at least one of the following features: The pump impeller may comprise a tapered body having an outer surface and one or more protrusions extending from the outer surface, the protrusions being inflatable. The pump impeller may comprise a tapered body having an outer surface and one or more non-inflatable fins or protrusions extending from the outer surface. The pump impeller may comprise a tapered body having an outer surface, the tapered body comprising one or more grooves extending along the outer surface. The catheter-type blood pump may also comprise a housing component. Such a housing component may comprise an elongated drive shaft housing defining a housing lumen, a pump housing positioned at the distal end 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 compact configuration when radially constrained within the sheath lumen of the delivery sheath device and (ii) a radially expanded configuration when not constrained by the delivery sheath device. The housing lumen may be configured to slidably receive the drive shaft and pump impeller when the pump impeller is in a compact delivery configuration with a contracted outer shape.

[0011] Another exemplary system described herein includes a blood pump comprising a rotatable pump impeller. The rotatable pump impeller is expandable from a small-proportion delivery configuration to a radially expanded configuration. The pump impeller is configured to pump blood when rotated while in the radially expanded configuration.

[0012] Such a blood pump may optionally include at least one of the following features: The pump impeller may comprise a tapered body having an outer surface and one or more protrusions extending from the outer surface. One or more protrusions may be inflatable. The pump impeller may comprise a tapered body having an outer surface, the tapered body comprising one or more grooves extending along the outer surface. The blood pump may also comprise a long, flexible drive shaft. The pump impeller may be attached to the distal end of the drive shaft. The pump impeller may rotate in response to the rotation of the drive shaft.

[0013] Another exemplary system described herein includes a blood pump system comprising an elongated delivery sheath device defining a sheath lumen, a housing component slidably positioned within the sheath lumen, and a rotatable internal catheter. The housing component comprises an elongated drive shaft housing defining a housing lumen, a pump housing positioned at the distal end 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 small external form when radially constrained within the sheath lumen and (ii) a radially expanded form when not constrained by the delivery sheath device. The rotatable internal catheter is slidably positioned within the housing lumen. The rotatable internal catheter comprises an elongated flexible drive shaft and an impeller positioned at the distal end of the drive shaft. The impeller is slidably positioned within the housing lumen when in a radially folded form. The impeller is radially expandable into an operational form within the pump housing.

[0014] Such a blood pump system may optionally include at least one of the following features: The impeller may be movable relative to the pump housing in response to the retraction or advancement of the drive shaft relative to the drive shaft housing. The drive shaft may define an expansion lumen. The impeller may be radially expandable in response to receiving expansion fluid supplied to the impeller through the expansion lumen. The internal catheter may also include a drive shaft hub attached to the proximal end portion of the drive shaft. The drive shaft hub may have a drive shaft hub seal coupled to the hub. The drive shaft hub seal may seal the proximal end of the expansion lumen. The blood pump system may also include a motor. The internal catheter may also include a drive shaft hub attached to the 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 so that expansion fluid can flow through the drive shaft hub into the expansion lumen while the drive shaft hub is coupled to the motor. A blood pump system may be configured to pump blood when (i) an impeller is positioned 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 outside 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. One or more openings of the delivery sheath device may be at least partially aligned with one or more openings of the drive shaft housing when the impeller is positioned within the pump housing. The blood pump system may be configured to pump blood by the rotation of the impeller without having mechanical bearings or bushings between the impeller and the pump housing while the impeller is positioned within the pump housing. The impeller may be configured to self-center relative to the pump housing when rotating within the pump housing.

[0015] Another exemplary system described herein includes a percutaneous ventricular assist device. Such a percutaneous ventricular assist device may comprise an elongated drive shaft housing defining a lumen, a pump housing attached to the distal end of the drive shaft housing, and a pump impeller attached to the distal end of the elongated drive shaft. The pump housing may be attached to the distal end of the drive shaft housing. The pump housing may be radially reconfigurable between (i) a small-sized delivery configuration configured for transvascular advancement to a target location in the patient and (ii) a radially expanded configuration. The pump impeller may be slidably positioned within the lumen when in the radially folded configuration. The pump impeller may be radially expandable to an operational configuration when the pump impeller is in the radially expanded configuration of the pump housing at the target location in the patient.

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

[0017] Another exemplary system described herein includes a mechanical hemodynamic assist device. The mechanical hemodynamic assist device comprises a pump housing configured to be placed in a patient and to allow blood flow from a pump housing inlet to a pump housing outlet, and a pump impeller that can be placed within the pump housing. The pump impeller is rotatable relative to the pump housing to produce blood flow from the pump housing inlet to the pump housing outlet. The pump impeller is configured to self-center relative to the pump housing when rotating relative to the pump housing.

[0018] Such mechanical hemodynamic assist devices may optionally include at least one of the following features: The pump impeller may be mounted on a flexible drive shaft. The pump impeller may be reconfigurable between (i) a small, contracted delivery configuration configured to advance transvascularly to a target location within the patient, and (ii) an inflated, radially expanded configuration configured to pump blood as the pump impeller rotates on the drive shaft. The pump housing may be reconfigurable between a small, contracted delivery configuration and a radially expanded, operable configuration. The pump impeller may be expandable from a small, contracted delivery configuration to a radially expanded, operable configuration configured to pump blood as the pump impeller rotates relative to the pump housing. The pump housing may be mounted on the distal end portion of the drive shaft housing. The drive shaft housing may allow a purge fluid or blood to flow between the pump housing and the pump impeller to provide a dynamic bearing between the pump housing and the pump impeller.

[0019] This disclosure also describes methods for implanting and operating blood pump systems, such as percutaneous ventricular assist devices and mechanical hemodynamic assist devices. In one example, such a method for implanting a percutaneous blood flow assist device at a target location in a patient involves advancing a long delivery sheath device through an incision in the patient. The delivery sheath device may define a sheath lumen, which houses a housing component slidably disposed within the sheath lumen. Such a housing component may comprise a long drive shaft housing defining the housing lumen, a pump housing located at the distal end of the drive shaft housing, and an inlet cannula extending distally from the pump housing. The method may also include: retracting the delivery sheath device relative to the housing components when the pump housing is in the target position to express the inlet cannula and pump housing out of the sheath lumen; inserting a rotatable internal catheter into the housing lumen of the drive shaft housing; advancing the internal catheter relative to the housing components to position the pump impeller within the pump housing; and supplying an expansion fluid while the pump impeller is within the pump housing to inflate the pump impeller into a radially expanded operational configuration. The pump housing and inlet cannula may be radially reconfigurable between (i) a smaller external form when radially constrained within the sheath lumen and (ii) a radially expanded form when not constrained by the delivery sheath device. The internal catheter may comprise a long, flexible drive shaft and a pump impeller positioned at the distal end of the drive shaft. The pump impeller may be in a radially folded configuration when within the housing lumen.

[0020] A method for implanting a percutaneous blood flow assist device at a target location within a patient may optionally include at least one 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 a drive shaft using a motor located outside the patient while the pump impeller is in a radially expanded, operable configuration and located within the pump housing. By rotating the drive shaft, the pump impeller may 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. One or more openings in the delivery sheath device may be at least partially aligned with one or more openings in the drive shaft housing when the pump impeller is positioned within the pump housing. In some embodiments of the method, blood flows distally toward the pump impeller through the delivery sheath device and one or more aligned openings in the drive shaft housing to provide a dynamic pressure bearing between the pump impeller and the pump housing. In certain embodiments, the motor and system controller are portable and can be moved with the patient so that the patient can walk freely while receiving circulatory assistance from the percutaneous blood flow assistance device. The target location may be the patient's aortic valve region.

[0021] In another example, a method for implanting a percutaneous blood flow assist device at a target location within a patient includes advancing a housing component into the patient's radial artery through a skin opening. The housing component may comprise an elongated drive shaft housing defining the housing lumen and a pump housing positioned at the distal end of the drive shaft housing. The pump housing may be radially reconfigurable between a smaller external form and a radially expanded form. The method may also include inserting a rotatable internal catheter into the housing lumen of the drive shaft housing while the pump housing is at the target location. The internal catheter may comprise an elongated flexible drive shaft and a pump impeller positioned at the distal end of the drive shaft. The pump impeller may be in a radially folded form when it is present within the housing lumen. The method also includes inflating the pump impeller to a radially expanded operational form by supplying an expansion fluid while the pump impeller is present within the pump housing.

[0022] A method for implanting a percutaneous blood flow assist device at a target location within a patient may optionally include at least one of the following features: The target location may be the patient's aortic valve region. The method may include rotating a drive shaft using a motor located outside the patient while the pump impeller is in a radially expanded, operable configuration and located within the pump housing. By rotating the drive shaft, the pump impeller may rotate relative to the pump housing. While rotating relative to the pump housing, the pump impeller may have a tendency to self-center relative to the pump housing. In some embodiments, inflating the pump impeller includes supplying an expansion fluid to the pump impeller through an expansion lumen of the drive shaft.

[0023] In another example, a method for implanting a percutaneous blood flow assistance device at a target location within a patient includes (i) advancing one or more components of the percutaneous blood flow assistance device into the patient's radial artery through a skin incision, and (ii) expanding the pump impeller of the percutaneous blood flow assistance device into an operable configuration in which it is radially expanded.

[0024] Such a method for implanting a percutaneous blood flow assistance device at a target location within a patient may optionally include one or more of at least the following features. The target location may be in the aortic valve region of the patient. The pump impeller may be attached to the distal end portion of an elongate flexible drive shaft. The method may also include rotating the pump impeller by rotating the drive shaft using a motor disposed external to the patient while the pump impeller is present in the aortic valve region and in a radially expanded operable configuration. In some embodiments, rotating the pump impeller causes blood to be pumped 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 the distal end portion of an elongate flexible drive shaft. Expanding the pump impeller may be accomplished by supplying expansion fluid to the pump impeller through an expansion lumen of the drive shaft.

[0025] While multiple embodiments are disclosed, still other embodiments of the present invention will be apparent to those of ordinary skill in the art from the following detailed description which illustrates and describes exemplary embodiments of the present 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] FIG. 1 is a schematic diagram showing an exemplary mechanical hemodynamic assistance system for providing hemodynamic assistance to a patient, according to an embodiment of the subject matter disclosed herein. [Figure 2] FIG. 2 is a schematic diagram showing another exemplary mechanical hemodynamic assistance system for providing hemodynamic assistance to a patient, according to an embodiment of the subject matter disclosed herein. [Figure 3] FIG. is a diagram showing an exemplary mechanical hemodynamic assist device disposed in a patient's heart in a blood extraction configuration according to an embodiment of the subject matter disclosed herein. [Figure 4A] FIG. is a diagram showing another exemplary mechanical hemodynamic assist device disposed in a patient's heart in a blood extrusion configuration according to an embodiment of the subject matter disclosed herein. [Figure 4B] FIG. is a diagram showing another exemplary mechanical hemodynamic assist device disposed in a patient's heart in a blood extrusion configuration according to an embodiment of the subject matter disclosed herein. [Figure 5A] FIG. is a diagram showing an exemplary outer sheath and housing component catheter of a mechanical hemodynamic assist system in a folded form according to an embodiment of the subject matter disclosed herein. [Figure 5B] FIG. is a diagram showing the sheath of the outer catheter of FIG. 5A according to an embodiment of the subject matter disclosed herein. [Figure 6] FIG. shows the housing component catheter of FIG. 5 in an expanded form. [Figure 7] FIG. is a diagram showing an exemplary rotatable inner catheter of a mechanical hemodynamic assist system in an expanded form according to an embodiment of the subject matter disclosed herein. [Figure 8A] FIG. is a diagram showing steps of assembling and / or implanting a mechanical hemodynamic assist system according to an embodiment of the subject matter disclosed herein. [Figure 8B] FIG. is a diagram showing steps of assembling and / or implanting a mechanical hemodynamic assist system according to an embodiment of the subject matter disclosed herein. [Figure 8C] FIG. is a diagram showing steps of assembling and / or implanting a mechanical hemodynamic assist system according to an embodiment of the subject matter disclosed herein. [Figure 8D] FIG. is a diagram showing steps of assembling and / or implanting a mechanical hemodynamic assist system according to an embodiment of the subject matter disclosed herein. [Figure 8E]This figure shows the steps for assembling and / or implanting a mechanical hemodynamic support system according to embodiments of the subject matter disclosed herein. [Figure 9A] This figure shows the steps for assembling and / or implanting a mechanical hemodynamic support system according to embodiments of the subject matter disclosed herein. [Figure 9B] This figure shows the steps for assembling and / or implanting a mechanical hemodynamic support system according to embodiments of the subject matter disclosed herein. [Figure 9C] This figure shows the steps for assembling and / or implanting a mechanical hemodynamic support system according to embodiments of the subject matter disclosed herein. [Figure 9D] This figure shows the steps for assembling and / or implanting a mechanical hemodynamic support system according to embodiments of the subject matter disclosed herein. [Figure 9E] This figure shows the steps for assembling and / or implanting a mechanical hemodynamic support system according to embodiments of the subject matter disclosed herein. [Figure 9F] This figure shows the steps for assembling and / or implanting a mechanical hemodynamic support system according to embodiments of the subject matter disclosed herein. [Figure 10A] This figure shows the assembled mechanical hemodynamic assist device of Figures 4A and 4B according to embodiments of the subject matter disclosed herein. [Figure 10B] This figure shows the assembled mechanical hemodynamic assist device of Figures 4A and 4B according to embodiments of the subject matter disclosed herein. [Figure 11] This figure shows the interaction between an exemplary pump impeller and an exemplary pump housing according to embodiments of the subject disclosed herein. [Figure 12A] This figure shows the interaction between a pump impeller of various shapes and a pump housing according to embodiments of the subject disclosed herein. [Figure 12B]This figure shows the interaction between a pump impeller of various shapes and a pump housing according to embodiments of the subject disclosed herein. [Figure 12C] This figure shows the interaction between a pump impeller of various shapes and a pump housing according to embodiments of the subject disclosed herein. [Figure 12D] This figure shows the interaction between a pump impeller of various shapes and a pump housing according to embodiments of the subject disclosed herein. [Figure 13A] This figure shows an exemplary pump impeller, an exemplary pump housing, and blood flow characteristics according to embodiments of the subject matter disclosed herein. [Figure 13B] This figure shows an exemplary pump impeller, an exemplary pump housing, and blood flow characteristics according to embodiments of the subject matter disclosed herein. [Figure 14A] This figure shows an exemplary pump impeller, an exemplary pump housing, and blood flow characteristics according to embodiments of the subject matter disclosed herein. [Figure 14B] This figure shows an exemplary pump impeller, an exemplary pump housing, and blood flow characteristics according to embodiments of the subject matter disclosed herein. [Figure 15A] This figure shows an exemplary pump impeller, an exemplary pump housing, and a small embedded motor according to embodiments of the subject matter disclosed herein. [Figure 15B] This figure shows an exemplary pump impeller, an exemplary pump housing, and a small embedded motor according to embodiments of the subject matter disclosed herein. [Figure 15C] This figure shows an exemplary pump impeller, an exemplary pump housing, and a small embedded motor according to embodiments of the subject matter disclosed herein. [Figure 16A] This figure shows an exemplary inflation needle used to inflate a particular pump impeller according to embodiments of the subject matter disclosed herein. [Figure 16B]This figure shows an exemplary inflation needle used to inflate a particular pump impeller according to embodiments of the subject matter disclosed herein. [Figure 17A] This figure shows the steps of extending the pump impeller and coupling the drive shaft to an external motor, according to embodiments of the subject matter disclosed herein. [Figure 17B] This figure shows the steps of extending the pump impeller and coupling the drive shaft to an external motor, according to embodiments of the subject matter disclosed herein. [Figure 17C] This figure shows the steps of extending the pump impeller and coupling the drive shaft to an external motor, according to embodiments of the subject matter disclosed herein. [Figure 18A] This figure shows the steps of coupling an impeller drive shaft to a motor and extending an exemplary pump impeller, according to embodiments of the subject disclosed herein. [Figure 18B] This figure shows the steps of coupling an impeller drive shaft to a motor and extending an exemplary pump impeller, according to embodiments of the subject disclosed herein. [Figure 18C] This figure shows the steps of coupling an impeller drive shaft to a motor and extending an exemplary pump impeller, according to embodiments of the subject disclosed herein. [Figure 19A] This figure shows an exemplary braided inlet cannula and pump housing according to an embodiment of the subject disclosed herein. [Figure 19B] This figure shows an exemplary braided inlet cannula and pump housing according to an embodiment of the subject disclosed herein. [Figure 20A] This figure shows an exemplary coil-supported inlet cannula and an unsupported pump housing according to an embodiment of the subject matter disclosed herein. [Figure 20B] This figure shows an exemplary coil-supported inlet cannula and an unsupported pump housing according to an embodiment of the subject matter disclosed herein. [Figure 21A] This figure shows an exemplary coil-supported inlet cannula and a longitudinally supported pump housing according to an embodiment of the subject disclosed herein. [Figure 21B] This figure shows an exemplary coil-supported inlet cannula and a longitudinally supported pump housing according to an embodiment of the subject disclosed herein. [Figure 22A] This figure shows an inlet cannula and pump housing supported by an exemplary braid having a constant diameter, according to an embodiment of the subject disclosed herein. [Figure 22B] This figure shows an exemplary balloon-type inlet cannula and pump housing according to embodiments of the subject matter disclosed herein. [Figure 23A] This figure shows an exemplary mechanical hemodynamic assist device comprising an aortic valve engaging skirt, according to embodiments of the subject matter disclosed herein. [Figure 23B] This figure shows an exemplary mechanical hemodynamic assist device comprising an aortic valve engaging skirt, according to embodiments of the subject matter disclosed herein. [Figure 24A] This figure shows an exemplary mechanical hemodynamic assist device comprising an aortic valve engaging petal, according to embodiments of the subject matter disclosed herein. [Figure 24B] This figure shows an exemplary mechanical hemodynamic assist device comprising an aortic valve engaging petal, according to embodiments of the subject matter disclosed herein. [Figure 25] This figure shows an exemplary method for immobilizing the mechanical hemodynamic assist device shown in Figure 3 within the anatomical structure of a patient, according to embodiments of the subject matter disclosed herein. [Figure 26] This figure shows another exemplary method and apparatus for immobilizing the mechanical hemodynamic assist device of Figure 3 within the anatomical structure of a patient, according to embodiments of the subject matter disclosed herein. [Figure 27] This figure shows another exemplary method and apparatus for immobilizing the mechanical hemodynamic assist device of Figure 3 within the anatomical structure of a patient, according to embodiments of the subject matter disclosed herein. [Figure 28A] This figure shows an exemplary pump housing and blood outlet port according to an embodiment of the subject disclosed herein. [Figure 28B] This figure shows an exemplary pump housing and blood outlet port according to an embodiment of the subject disclosed herein. [Figure 28C] This figure shows an exemplary pump housing and blood outlet port according to an embodiment of the subject disclosed herein. [Figure 28D] This figure shows an exemplary pump housing and blood outlet port according to an embodiment of the subject disclosed herein. [Figure 28E] This figure shows an exemplary pump housing and blood outlet port according to an embodiment of the subject disclosed herein. [Figure 28F] This figure shows an exemplary pump housing and blood outlet port according to an embodiment of the subject disclosed herein. [Figure 29A] This figure shows an exemplary pump housing and blood outlet port angle according to an embodiment of the subject disclosed herein. [Figure 29B] This figure shows an exemplary pump housing and blood outlet port angle according to an embodiment of the subject disclosed herein. [Figure 29C] This figure shows an exemplary pump housing and blood outlet port angle according to an embodiment of the subject disclosed herein. [Figure 30] This figure shows an exemplary catheter delivery sheath according to an embodiment of the subject disclosed herein. [Figure 31A] This figure shows an exemplary peel-off catheter delivery sheath according to an embodiment of the subject matter disclosed herein. [Figure 31B] This figure shows an exemplary peel-off catheter delivery sheath according to an embodiment of the subject matter disclosed herein. [Figure 31C] This figure shows an exemplary peel-off catheter delivery sheath according to an embodiment of the subject matter disclosed herein. [Figure 32] This figure shows an exemplary catheter delivery sheath having a blood perfusion hole, according to an embodiment of the subject disclosed herein. [Figure 33A] This figure shows an exemplary catheter delivery sheath having a proximal notch according to an embodiment of the subject disclosed herein. [Figure 33B] This figure shows an exemplary catheter delivery sheath having a proximal notch according to an embodiment of the subject disclosed herein. [Figure 34A] This figure shows exemplary housing components according to embodiments of the subject matter disclosed herein. [Figure 34B] This figure shows exemplary housing components according to embodiments of the subject matter disclosed herein. [Figure 34C] This figure shows exemplary housing components according to embodiments of the subject matter disclosed herein. [Figure 35] This figure shows an exemplary housing component having blood perfusion holes according to embodiments of the subject disclosed herein. [Figure 36] This figure shows an exemplary housing component having an open cell matrix according to an embodiment of the subject disclosed herein. [Figure 37A] This figure shows an exemplary housing component having a lumen for electrical connections, according to embodiments of the subject matter disclosed herein. [Figure 37B] This figure shows an exemplary housing component having a lumen for electrical connections, according to embodiments of the subject matter disclosed herein. [Figure 38A] This figure shows an exemplary drive shaft for a mechanical hemodynamic assist system according to an embodiment of the subject disclosed herein. [Figure 38B] This figure shows an exemplary drive shaft for a mechanical hemodynamic assist system according to an embodiment of the subject disclosed herein. [Figure 38C] This figure shows an exemplary drive shaft for a mechanical hemodynamic assist system according to an embodiment of the subject disclosed herein. [Figure 38D] This figure shows an exemplary drive shaft for a mechanical hemodynamic assist system according to an embodiment of the subject disclosed herein. [Figure 38E] This figure shows an exemplary drive shaft for a mechanical hemodynamic assist system according to an embodiment of the subject disclosed herein. [Figure 39A] Figures 38A to 38E further illustrate the drive shafts and their potential failure modes. [Figure 39B] Figures 38A to 38E further illustrate the drive shafts and their potential failure modes. [Figure 39C] Figures 38A to 38E further illustrate the drive shafts and their potential failure modes. [Figure 40A] This figure shows an exemplary drive shaft and drive shaft hub of a mechanical hemodynamic assist system according to embodiments of the subject matter disclosed herein. [Figure 40B] This figure shows an exemplary drive shaft and drive shaft hub of a mechanical hemodynamic assist system according to embodiments of the subject matter disclosed herein. [Figure 40C] This figure shows an exemplary drive shaft and drive shaft hub of a mechanical hemodynamic assist system according to embodiments of the subject matter disclosed herein. [Figure 40D] This figure shows an exemplary drive shaft and drive shaft hub of a mechanical hemodynamic assist system according to embodiments of the subject matter disclosed herein. [Figure 41A] This figure shows an exemplary expandable impeller for a mechanical hemodynamic assist device according to an embodiment of the subject disclosed herein. [Figure 41B] This figure shows an exemplary expandable impeller for a mechanical hemodynamic assist device according to an embodiment of the subject disclosed herein. [Figure 42A] This figure shows an expandable impeller supported by an exemplary braid for a mechanical hemodynamic assist device, according to an embodiment of the subject matter disclosed herein. [Figure 42B]This figure shows an expandable impeller supported by an exemplary braid for a mechanical hemodynamic assist device, according to an embodiment of the subject matter disclosed herein. [Figure 43A] This figure shows an exemplary triangular structure-supported expandable impeller of a mechanical hemodynamic assist device according to an embodiment of the subject disclosed herein. [Figure 43B] This figure shows an exemplary triangular structure-supported expandable impeller of a mechanical hemodynamic assist device according to an embodiment of the subject disclosed herein. [Figure 43C] This figure shows an exemplary triangular structure-supported expandable impeller of a mechanical hemodynamic assist device according to an embodiment of the subject disclosed herein. [Figure 44A] This figure shows an exemplary expandable impeller having a raised portion of a mechanical hemodynamic assist device according to an embodiment of the subject disclosed herein. [Figure 44B] This figure shows an exemplary expandable impeller having a raised portion of a mechanical hemodynamic assist device according to an embodiment of the subject disclosed herein. [Figure 44C] This figure shows an exemplary expandable impeller having a raised portion of a mechanical hemodynamic assist device according to an embodiment of the subject disclosed herein. [Figure 45A] This figure shows an exemplary expandable impeller having a spiral-shaped protrusion for a mechanical hemodynamic assist device, according to an embodiment of the subject disclosed herein. [Figure 45B] This figure shows an exemplary expandable impeller having a spiral-shaped protrusion for a mechanical hemodynamic assist device, according to an embodiment of the subject disclosed herein. [Figure 45C] This figure shows an exemplary expandable impeller having a spiral-shaped protrusion for a mechanical hemodynamic assist device, according to an embodiment of the subject disclosed herein. [Figure 46A] This figure shows an exemplary expandable impeller having a valley for a mechanical hemodynamic assist device, according to an embodiment of the subject matter disclosed herein. [Figure 46B] This figure shows an exemplary expandable impeller having a valley for a mechanical hemodynamic assist device, according to an embodiment of the subject matter disclosed herein. [Figure 46C] This figure shows an exemplary expandable impeller having a valley for a mechanical hemodynamic assist device, according to an embodiment of the subject matter disclosed herein. [Figure 46D] This figure shows an exemplary expandable impeller having a valley for a mechanical hemodynamic assist device, according to an embodiment of the subject matter disclosed herein. [Figure 47A] This figure shows an exemplary expandable impeller having spiral valleys for a mechanical hemodynamic assist device according to an embodiment of the subject disclosed herein. [Figure 47B] This figure shows an exemplary expandable impeller having spiral valleys for a mechanical hemodynamic assist device according to an embodiment of the subject disclosed herein. [Figure 47C] This figure shows an exemplary expandable impeller having spiral valleys for a mechanical hemodynamic assist device according to an embodiment of the subject disclosed herein. [Figure 48A] This figure shows an exemplary expandable impeller having a modified proximal surface shape of a mechanical hemodynamic assist device according to embodiments of the subject disclosed herein. [Figure 48B] This figure shows an exemplary expandable impeller having a modified proximal surface shape of a mechanical hemodynamic assist device according to embodiments of the subject disclosed herein. [Figure 49A] This figure shows an exemplary expandable impeller having a modified proximal surface shape of a mechanical hemodynamic assist device according to embodiments of the subject disclosed herein. [Figure 49B] This figure shows an exemplary expandable impeller having a modified proximal surface shape of a mechanical hemodynamic assist device according to embodiments of the subject disclosed herein. [Figure 50A]This figure shows an exemplary expandable impeller having a modified proximal surface shape of a mechanical hemodynamic assist device according to embodiments of the subject disclosed herein. [Figure 50B] This figure shows an exemplary expandable impeller having a modified proximal surface shape of a mechanical hemodynamic assist device according to embodiments of the subject disclosed herein. [Figure 51A] This figure shows an exemplary expandable impeller having a distal end modification for a blood extrusion configuration of a mechanical hemodynamic assist device, according to embodiments of the subject disclosed herein. [Figure 51B] This figure shows an exemplary expandable impeller having a distal end modification for a blood extrusion configuration of a mechanical hemodynamic assist device, according to embodiments of the subject disclosed herein. [Figure 52A] This figure shows another exemplary expandable impeller for a mechanical hemodynamic assist device according to embodiments of the subject matter disclosed herein. [Figure 52B] This figure shows another exemplary expandable impeller for a mechanical hemodynamic assist device according to embodiments of the subject matter disclosed herein. [Figure 52C] This figure shows another exemplary expandable impeller for a mechanical hemodynamic assist device according to embodiments of the subject matter disclosed herein. [Figure 52D] This figure shows another exemplary expandable impeller for a mechanical hemodynamic assist device according to embodiments of the subject matter disclosed herein. [Figure 53A] This figure shows another exemplary expandable impeller for a mechanical hemodynamic assist device according to embodiments of the subject matter disclosed herein. [Figure 53B] This figure shows another exemplary expandable impeller for a mechanical hemodynamic assist device according to embodiments of the subject matter disclosed herein. [Figure 53C] This figure shows another exemplary expandable impeller for a mechanical hemodynamic assist device according to embodiments of the subject matter disclosed herein. [Figure 54A]This figure shows another exemplary expandable impeller for a mechanical hemodynamic assist device according to embodiments of the subject matter disclosed herein. [Figure 54B] This figure shows another exemplary expandable impeller for a mechanical hemodynamic assist device according to embodiments of the subject matter disclosed herein. [Figure 54C] This figure shows another exemplary expandable impeller for a mechanical hemodynamic assist device according to embodiments of the subject matter disclosed herein. [Figure 55A] This figure shows another exemplary expandable impeller for a mechanical hemodynamic assist device according to embodiments of the subject matter disclosed herein. [Figure 55B] This figure shows another exemplary expandable impeller for a mechanical hemodynamic assist device according to embodiments of the subject matter disclosed herein. [Figure 55C] This figure shows another exemplary expandable impeller for a mechanical hemodynamic assist device according to embodiments of the subject matter disclosed herein. [Figure 55D] This figure shows another exemplary expandable impeller for a mechanical hemodynamic assist device according to embodiments of the subject matter disclosed herein. [Figure 56A] This figure shows the components and steps of an exemplary method for manufacturing an expandable impeller according to embodiments of the subject matter disclosed herein. [Figure 56B] This figure shows the components and steps of an exemplary method for manufacturing an expandable impeller according to embodiments of the subject matter disclosed herein. [Figure 56C] This figure shows the components and steps of an exemplary method for manufacturing an expandable impeller according to embodiments of the subject matter disclosed herein. [Figure 56D] This figure shows the components and steps of an exemplary method for manufacturing an expandable impeller according to embodiments of the subject matter disclosed herein. [Figure 56E] This figure shows the components and steps of an exemplary method for manufacturing an expandable impeller according to embodiments of the subject matter disclosed herein. [Figure 56F] This figure shows the components and steps of an exemplary method for manufacturing an expandable impeller according to embodiments of the subject matter disclosed herein. [Figure 57A] This figure shows components and steps of an exemplary method for manufacturing another expandable impeller according to embodiments of the subject matter disclosed herein. [Figure 57B] This figure shows components and steps of an exemplary method for manufacturing another expandable impeller according to embodiments of the subject matter disclosed herein. [Figure 57C] This figure shows an expandable impeller produced by the method shown in Figures 57A-57B, according to embodiments of the subject matter disclosed herein. [Figure 57D] This figure shows an expandable impeller produced by the method shown in Figures 57A-57B, according to embodiments of the subject matter disclosed herein. [Figure 58A] This figure shows components and steps of an exemplary method for manufacturing another expandable impeller according to embodiments of the subject matter disclosed herein. [Figure 58B] This figure shows components and steps of an exemplary method for manufacturing another expandable impeller according to embodiments of the subject matter disclosed herein. [Figure 58C] This figure shows components and steps of an exemplary method for manufacturing another expandable impeller according to embodiments of the subject matter disclosed herein. [Figure 58D] This figure shows an expandable impeller produced by the method shown in Figures 58A-58C, according to embodiments of the subject matter disclosed herein. [Figure 58E] This figure shows an expandable impeller produced by the method shown in Figures 58A-58C, according to embodiments of the subject matter disclosed herein. [Figure 59A] This figure shows components and steps of an exemplary method for manufacturing another expandable impeller according to embodiments of the subject matter disclosed herein. [Figure 59B]This figure shows components and steps of an exemplary method for manufacturing another expandable impeller according to embodiments of the subject matter disclosed herein. [Figure 59C] This figure shows an expandable impeller produced by the method shown in Figures 59A-59B, according to embodiments of the subject matter disclosed herein. [Figure 60A] This figure illustrates an exemplary method for using a pressurized balloon as a pressure transducer within a patient's cardiovascular system to provide measurements of the patient's systolic and diastolic blood pressure. [Figure 60B] This figure illustrates an exemplary method for using a pressurized balloon as a pressure transducer within a patient's cardiovascular system to provide measurements of the patient's systolic and diastolic blood pressure. [Figure 61] This figure shows various arterial and venous access sites and routes for delivering mechanical hemodynamic support devices to a patient's heart. [Modes for carrying out the invention]

[0027] While the present invention is open to various modifications and substitutions, specific embodiments are shown in the drawings as examples and are described in detail below. However, the present invention is not limited to the specific embodiments described. Rather, the present invention is intended to encompass all modifications, equivalents, and substitutions that fall within the scope of the present invention as defined by the appended claims.

[0028] Mechanical hemodynamic assist devices, such as percutaneous ventricular assist devices ("pVADs") according to embodiments of the present disclosure, can reduce the load on a patient's heart or assist the patient's heart for a period of time, for example, between myocardial infarction, cardiac shock, surgical or interventional procedures.

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

[0030] After the device has been advanced to a desired or target location, for example, within the patient's heart, the device expands radially from its entry form, also referred to as a small or folded form, to its functional pumping size, also referred to as an extended form or operational form. 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 rotation speed.

[0031] As used herein, the terms “proximal” and “distal” relate to the orientation of the device, not to the patient. For example, the proximal portion of a device described herein may be outside the patient for manipulation by a clinician operator while the distal portion of the device is inside the patient.

[0032] Depending on the context, the pump devices described herein may be said to have a blood "push-out" configuration or a blood "pull-out" configuration. In this disclosure, "push-out" is used to describe a pumping configuration that causes blood to flow from proximal to distal. In this disclosure, "pull-out" is used to describe a pumping configuration that causes blood to flow from distal to proximal.

[0033] Figure 1 schematically shows an exemplary mechanical hemodynamic assistance system 100 (or pVAD 100) that provides hemodynamic assistance to a patient P according to several embodiments of the subject matter disclosed herein. The system 100 comprises a mechanical hemodynamic assistance device 102 (also referred to herein as the “pump device” or “blood pump”) which may be at least partially located within the patient’s heart H. In the illustrated embodiment, the system 100 comprises an external motor 104 (located outside the patient P) coupled to the device 102 to drive the device 102 using a long, flexible drive shaft 106 that transmits torque. The proximal end of the drive shaft 106 is coupled to the motor 104, and the distal end of the drive shaft 106 is coupled to the pump device 102. In other words, the drive shaft 106 is partially outside the patient P and partially inside the patient P.

[0034] The motor 104 is controlled by a system controller 108, which controls the speed of the motor 104 and monitors its performance. 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 it may be an integrated system that also houses the motor 104.

[0035] Figure 2 shows another exemplary mechanical hemodynamic assist system 200 that provides 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 patient P) coupled to and driving a mechanical hemodynamic assist device 204 which is at least partially located inside the patient's heart H. The motor 202 is controlled by a system controller 206, which controls the speed of the motor 202 and monitors the performance of the motor 202. The controller 206 also provides an interface to the system 200 for a clinician operator to set up and operate the system 200.

[0036] Referring to Figures 1 and 2 in general terms, the motor used to drive the pump could be any motor capable of high-speed rotation, such as, but not limited to, a brushless motor, a brushed DC motor, or a pneumatically driven turbine.

[0037] Figure 3 shows an exemplary mechanical hemodynamic assist device 300 (or “pump device 300”) positioned in a patient’s heart H in a blood draw configuration, according to several embodiments of the subject matter disclosed herein. The pump device 300 may represent, for example, device 102 of system 100 (Figure 1) or device 204 of system 200 (Figure 2).

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

[0039] In the described embodiment, the distal tip portion of the pump device 300 defines one or more blood inlets 534 penetrating the side wall of the housing component of the pump device 300, and one or more end inlets 532 penetrating the distal tip of the housing component of the pump device 300. The pump device 300 draws blood from the ventricular LV through the inlets 532 / 534 and then delivers the blood to the aortic origin AOR at a higher pressure through one or more blood outlets 526 located at the aortic origin AOR. The multiple side wall blood inlets 534, when appropriately positioned within the anatomical structure, are located distal to the AV, thereby eliminating the possibility of blood from the aorta entering the inlet cannula and pump through the side wall blood inlets 534. The blood is then circulated throughout the patient's body by the patient's vascular system.

[0040] Figure 4A shows another exemplary mechanical hemodynamic assist device 400 (or “pump device 400”) positioned in a patient’s heart H in a blood pump configuration according to embodiments of the subject disclosed herein. Device 400 may represent, for example, device 102 of system 100 (Figure 1) or device 204 of system 200 (Figure 2). In the illustrated configuration, device 400 reaches the heart H by advancing device 400 into the left atrium LA via a transseptal pathway, crossing the mitral valve MV, and then crossing the aortic valve AV to the illustrated position. The distal tip portion of device 400 defines one or more blood outlets 402 located in the aortic origin AOR. One or more blood inlets 404 of device 400 may be located in the left ventricle LV and comprise one or more fenestrations or openings defined through the side wall of the inlet cannula 406 of device 400.

[0041] Figure 4B shows an exemplary mechanical hemodynamic assist device 400 positioned in a patient's heart H in a different blood extrusion configuration according to embodiments of the subject matter disclosed herein. Device 400 may represent, for example, device 102 of system 100 (Figure 1) or device 204 of system 200 (Figure 2). In the illustrated configuration, device 400 reaches the heart H by advancing device 400 through the patient's thoracic cavity into the left ventricle LV through the apex of the heart H and across the aortic valve AV to the illustrated position. The distal tip portion of device 400 defines one or more blood outlets 402 positioned in the aortic origin AOR. One or more blood inlets 404 of device 400 may be positioned in the left ventricle LV and comprise one or more fenestrations or openings defined through the side wall of the inlet cannula 406 of device 400.

[0042] Figure 5A shows an exemplary delivery sheath device 500 that can be used to deliver the housing components of the pump device described herein when the housing components of the pump device are in a radially folded state with a smaller outer shape. The delivery sheath 500 comprises a handle 512 and a sheath 502 extending distally from the handle 512. The sheath 502 can define a lumen in which the housing components of the pump device described herein can be slidably arranged while radially constrained by the sheath 502 to a radially folded state with a smaller outer shape.

[0043] The housing component 510 is also shown in Figure 5A. The housing component 510 is the first part of the two-part pump device described herein, and is further described below. The distal end portion of the housing component 510 is positioned within the lumen of the sheath 502 in a radially folded configuration with a smaller outer diameter. The housing component 510 is configured to receive a separate pump impeller and associated drive shaft, as described below.

[0044] Figure 5B shows a longitudinal cross-sectional view of the distal portion of the sheath 502, which houses the distal end portion of the housing component 510 in a form folded in the radial direction of its smaller outer shape. The distal end portion of the housing component 510 comprises an inlet cannula 504, a pump housing 508, and a drive shaft housing 511.

[0045] The sheath 502 of the delivery sheath device 500 holds the expandable inlet cannula 504 and pump housing 508 in a folded form during delivery to a target location within the patient. In the described embodiment, the distal tip portion of the sheath 502 is equipped with an intact bumper tip 506 to minimize injury to the patient's vascular system and / or heart as the device is advanced through the patient's anatomical structures.

[0046] The proximal end of the pump housing 508 is coupled to the distal end of the drive shaft housing 511. After the delivery sheath device 500 has been advanced to the target position, the sheath handle 512 may be pulled proximal by the clinician, thereby exposing the inlet cannula 504 and the pump housing 508, allowing these components to expand into their extended operating mode.

[0047] Figure 6 shows the delivery sheath device 500 and housing component 510 after the delivery sheath device 500 has been pulled proximal to expose the inlet cannula 504 and pump housing 508 of the housing component 510 from the lumen of the sheath 502. Once exposed from the sheath 502, the inlet cannula 504 and pump housing 508 can be expanded and reconfigured into their expanded forms, as shown in the figure. Housing component 510 is an example of the first part of a two-part pump device described herein.

[0048] In some embodiments, a clinician operator may stop the retraction of 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] The drive shaft housing hub 518 may be located at the proximal end of the drive shaft housing 511. The pump housing 508 may be located at the distal end of the drive shaft housing 511. The drive shaft housing 511 may include a multi-filar coil or braid embedded on or within the inner wall of the polymer tube constituting the drive shaft housing 511. In some embodiments, the inner wall of the drive shaft housing 511 includes a wear-resistant material to withstand contact with the rapidly rotating drive shaft.

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

[0051] The inlet cannula 504 may have radiopaque markers at its proximal end 528 and / or its distal end 530. The inlet cannula 504 may have one or more end inlets 532 and / or one or more lateral inlets 534 that allow blood flow into the inlet cannula 504. The inlet cannula 504 may have a flexible wall 536, with a support structure 538, such as a coil, embedded in the wall 536 or circumferentially arranged around the wall 536. The radiopaque marker at the proximal end 528 of the cannula 504 may be aligned with the aortic valve within the anatomical structure, thereby facilitating the placement of the pump housing 508 in the aortic origin / ascending aorta and the 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 facilitate efficient pumping, while also being flexible and pliable enough to ensure that the device can advance through the vascular system and reach the target vascular system without causing vascular damage, and can remain in place for extended periods and pump blood without damaging the targeted anatomical structures such as the heart, valves, or larger blood vessels.

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

[0054] The internal catheter 700 can be slidably positioned within the lumen defined by the housing component 510. As further described below, the internal 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 the delivery sheath device 500 being retracted.

[0055] The internal catheter 700 comprises a long, flexible drive shaft, in this example, including a proximal drive shaft portion 704a and a distal drive shaft portion 704b. In the described 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 described, the internal catheter 700 may also include a drive shaft hub 702 located at the proximal end of the proximal drive shaft portion 704a. An expandable pump impeller 708 is located at the distal end of the distal drive shaft portion 704b.

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

[0058] In some embodiments, such as the one described, 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 completely or partially radiopaque to facilitate identification under fluoroscopy.

[0059] Referring to both Figures 6 and 7 in general terms, after the delivery sheath device 500 (which houses the housing component 510 in a radially constrained form with a small outer diameter) is positioned at the target location within the patient, the delivery sheath device 500 can be pulled proximal to the housing component 510, allowing the housing component 510 to reconfigure into its expanded form. 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 inflated into its expanded form (illustrated), which is its working fluid pumping form. The inner catheter 700 can then be connected to a motor 104 (see, for example, Figure 1) and rotated to generate a fluid pressure gradient, thereby creating a flow of blood into the inlet cannula 504, into the pump housing 508, and out through the outlet 526 of the pump housing 508.

[0060] Figures 8A–8E illustrate an exemplary set of steps for delivering and assembling in vivo a blood draw-out mechanical hemodynamic assist device into a patient for use as part of a system 100 (e.g., Figure 1) according to embodiments of the subject disclosed herein. The illustrated exemplary blood draw-out two-part pump device 300 comprises a housing component 510 (e.g., see Figures 5A, 5B, and 6) and a separate internal catheter (e.g., see Figure 7). The housing component 510 can be delivered to a target location using a delivery sheath device 500 (e.g., see Figures 5A, 5B, and 6).

[0061] First, an access site, such as a radial access site, a femoral access site, or other access site, is created in the patient. In some embodiments, a guidewire is advanced into the patient's vascular system (e.g., across the aortic valve) to the target location. In some embodiments, such a guidewire is not used.

[0062] Next, as shown in Figure 8A, the delivery sheath device 500, which houses the distal portion of the housing component 510, is advanced through the access site (for example, using fluoroscopy or other image guidance in some embodiments) and tracked to the target location within the patient's anatomical structure.

[0063] Next, as shown in Figure 8B, the delivery sheath device 500 is retracted by pulling the sheath handle 512 proximal, thereby exposing the inlet cannula 504 and the pump housing 508. This is the first part of the two-part blood pump system. Once the inlet cannula 504 and the pump housing 508 are exposed from the delivery sheath device 500, they expand radially into their extended forms. The guidewire can then be fully retracted if used.

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

[0065] Next, as shown in Figure 8E, the impeller 708 is inflated and expanded within the pump housing 508. Subsequently, the rotatable inner catheter 700 and its impeller 708 can be rotated by a motor located outside the patient (see, for example, Figure 1) to provide blood flow and hemodynamic assistance to the patient.

[0066] Figures 9A–9F illustrate a series of steps for delivering and assembling in vivo a blood extraction mechanical hemodynamic assist device into a patient for use as part of a system 200 (e.g., Figure 2) comprising a blood pump having an internal motor located near the distal end of a catheter system, according to embodiments of the subject disclosed herein. The illustrated blood extraction 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, an impeller 708 extending distally from the motor 202, and a pump housing 508 and inlet cannula 504 similarly extending distally from the motor 202 and surrounding the impeller 708. The pumping unit 900 is delivered to a target location using a delivery sheath device 500.

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

[0068] Next, as shown in Figure 9B, the delivery sheath device 500 is 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 reduced form (impeller 708 contracted). In this system, driven by the miniature internal motor 202, the impeller 708 can be placed simultaneously with the housing 508. Once the inlet cannula 504 and pump housing 508 are exposed from the delivery sheath device 500, they radially expand into their extended form. Next, if used, the guide wire can be fully retracted, thereby opening a passage into the pumping unit 900 for inflating the impeller 708.

[0069] Next, the impeller inflation needle 1600, as depicted in Figure 9C, can be advanced into the pumping unit 900. That is, the inflation needle 1600 is inserted through the hub and lumen of the pumping unit 900 and advanced distally so that the distal tip 1602 of the inflation needle 1600 reaches the configuration shown in Figure 9D, where it is positioned inside the impeller 708.

[0070] Next, as shown in Figure 9E, the pressure of the inflation medium (e.g., saline solution) entering the impeller 708 through the opening at the distal tip 1602 of the inflation needle 1600 is applied to the hub 1606 of the inflation needle 1600, causing the impeller 708 to inflate and expand within the pump housing 508. Once the impeller 708 has expanded to its pumping shape, the inflation needle 1600 can be completely removed from the catheter system, as shown in Figure 9F. Subsequently, a small internal motor 202 can be activated to rotate the impeller 708 (e.g., Figure 2) to provide blood flow and hemodynamic assistance to the patient.

[0071] Figures 10A and 10B show a blood-extruding mechanical hemodynamic assist device 400 designed for use as part of system 100 (Figure 1), according to embodiments of the subject matter disclosed herein. In some cases, the pump device 400 can be placed in and operated within a patient in the configuration shown in Figure 4A. In other cases, the pump device 400 can be placed in and operated within a patient in the configuration shown in Figure 4B. In yet another case, the pump device 400 can be placed in and operated within a patient in a different configuration.

[0072] The pump device 400 comprises a housing component 510' and a rotatable internal catheter 700'. In a manner similar to the above description relating to the pump device 300, the delivery sheath device 500 is used to house the housing component 510' in a delivery form with a radially compressed external shape during advancement to a target location within the patient's anatomical structure. In some cases, advancement is performed on a pre-positioned guidewire.

[0073] If advancement is performed on a pre-positioned guidewire and the pump housing 408 is the most distal part of the housing component 510', the pump housing 408 may be designed to have a distal hole for the guidewire to pass through. Alternatively, the pump housing 408 may be folded in such a way that when it is folded and radially contracted, the guidewire can enter the contracted pump housing 408 through one of the pump housing exit ports 402, thereby utilizing advancement on the guidewire to facilitate catheter placement into an anatomical structure.

[0074] After advancing the delivery sheath device 500 and housing component 510', the clinician operator can pull the delivery sheath device 500 proximal to expose the pump housing 408 and inlet cannula 406. The pump housing 408 and inlet cannula 406 can then be radially expanded into the illustrated configuration. The guidewire can then be fully retracted if used. 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' retracted. While the impeller 708' is located within the pump housing 408, expansion fluid can be delivered to the impeller 708' through the lumen of the rotatable inner catheter 700' to inflate and expand the impeller 708' into the illustrated operational configuration (Figure 10B). Next, the rotatable internal catheter 700' and its impeller 708' can be rotated by a motor located outside the patient (e.g., Figure 1) to provide blood flow and hemodynamic assistance to the patient.

[0075] Figure 11 shows a specific interaction between the impeller 708 and the pump housing 508 of the pump device 300 (e.g., Figure 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 work together to act as a centrifugal pump. That is, the rotating impeller 708 applies centrifugal force to the blood, thereby striking the blood outward against the inner wall of the pump housing 508. As 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 largest diameter portion 1100 of the impeller 708. Outlets 526 defined by the pump housing 508 may be arranged radially around the largest diameter portion 1100 of the impeller 708. The outlets 526 allow the 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 generates a dynamic pressure bearing that causes the impeller 708 to self-center within the pump housing 508, rotating with the longitudinal axes of the impeller 708 and the pump housing 508 aligned. The anterograde blood flow 1102 originating from the cannula (illustrated elsewhere), represented by a large arrow, accounts for the majority of the blood flow, while the retrograde flow 1104, represented by a small arrow, accounts for only a small amount of blood flow. Therefore, the rotating impeller 708 may not require conventional mechanical bearings or bushings (conventional mechanical bearings or bushings are defined as physical solid components). In other words, in some embodiments, this is a bearingless two-part blood pump. Instead, the design of the impeller 708 within the pump housing 508 generates a dynamic bearing that works in cooperation with each other to self-center the impeller 708 within the pump housing 508 during its rotation.

[0077] Figures 12A and 12B schematically illustrate specific interactions between an impeller and a pump housing having various shapes according to embodiments of the subject matter disclosed herein. More specifically, Figures 12A and 12B show the interactions between components at two different alignment or spacing distances. In Figure 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 outlines. In Figure 12B, the impeller 1200B and the pump housing 1202B are further apart. However, the distance between the impeller 1200B and the pump housing 1202B is uniform across their surface outlines. This distance remains uniform because the angles of the impeller surface and the pump housing surface are equal in both cases.

[0078] A uniform distance between the impeller and the pump housing can promote efficient self-centering performance of the impeller within the pump housing, regardless of the relative longitudinal alignment or spacing distance of the impeller and the pump housing. However, if the interface surface between the impeller and the pump housing is curved, self-centering performance may benefit from a more precise longitudinal spacing. For example, as shown in Figure 12C, the impeller 1200C and pump housing 1202C are positioned longitudinally so that the distance between them is uniform, providing consistent self-centering performance. In contrast, as shown in Figure 12D, the impeller 1200D and pump housing 1202D are positioned further apart from each other, resulting in uneven distances between them. Such uneven distances can reduce self-centering performance and adversely affect blood flow, fluid pumping efficiency, and component durability. As a result, it may be preferable to construct an impeller and pump housing with linearly opposed geometries (Figures 12A and 12B) rather than curved surfaces (Figures 12C and 12D).

[0079] Figures 13A and 13B schematically illustrate various pump impellers and pump housings exhibiting different blood pumping blood flow characteristics according to embodiments of the subject matter disclosed herein. Figure 13A shows an impeller 1300A comprising an expandable tapered body 1302A and a plurality of impeller protrusions 1304A coupled to and extending outward 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 an intermediate surface 1312A, and (iii) a proximal portion 1314A having a rear surface 1316A. The plurality of protrusions 1304A extend radially outward from each of the front surface 1308A, the intermediate surface 1312A, and the rear surface 1316A.

[0080] Figure 13B shows a similar impeller 1300B with an expandable tapered body 1302B, where multiple impeller protrusions 1304B extend radially outward from the front surface 1308B and intermediate surface 1312B, but are absent from the rear surface 1316B. Impeller 1300A and its protrusions 1304A can advantageously provide relatively high antegrade blood flow, as indicated by arrow 1318A. In addition, impeller 1300A and its protrusions 1304A can advantageously provide relatively high retrograde flow, as indicated by arrow 1320A. Such retrograde flow is desirable and can act as a lubricant between the drive shaft and the drive shaft housing. Impeller 1300B and its protrusions 1304B offer similar advantages to antegrade flow 1318B while reducing retrograde flow 1320B, as indicated by a smaller arrow. The absence of the raised portion 1304B on the rear surface 1316B provides a more uniform and linear surface to the rear surface 1316B of the impeller 1300B, thereby bringing about the aforementioned advantages with respect to the impellers 1200A, 1200B and the pump housings 1202A, 1202B (Figures 12A and 12B).

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

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

[0083] Continuing to refer to Figure 14B, in this embodiment of the blood pump catheter system, the drive shaft housing 511 may be provided with a fenestration, window, or opening 3512. The sheath 502 of the delivery sheath device 500 may also be provided with a fenestration, window, or opening 3294. When the delivery sheath device 500 is retracted, the sheath window 3294 may be at least partially aligned with the window 3512 of the drive shaft housing 511. This alignment of windows 3294 / 3512 may allow blood to flow through the sheath 502 and the window opening of the drive shaft housing 511 to reach the drive shaft 704. This blood flow may provide a blood source for retrograde blood flow 1400 in the impeller 708, which may have several advantages. Two non-limiting examples of the advantages of the retrograde blood flow 1400 through the drive shaft housing 511 include improving the function of the hydrodynamic bearing generated between the impeller 708 and the pump housing 508, and reducing wear between components by acting like a lubricant between the drive shaft 704 and the drive shaft housing 511. This hydrodynamic bearing generated between the impeller 708 and the pump housing 508 can eliminate the need for conventional 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 exemplary blood extraction mechanical hemodynamic assist devices for use as part of a system 200 (e.g., Figure 2) comprising a blood pump having an internal motor located near the distal tip of a catheter system, according to embodiments of the subject disclosed herein. The illustrated blood extraction pump device is shown in its fully assembled state in Figure 15A. Figures 9A–9F (see above) illustrate the process of assembling this motorized blood pump configuration in vivo.

[0085] Figure 15B shows an enlarged view of the extended impeller 708 within the extended pump housing 508, as well as a small motor 202 located proximal to the impeller 708. In such a pump system with the small motor 202, several non-limiting considerations must be adapted to the pump assembly process. The impeller 708 may be connected to a short 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, so that when the motor 202 rotates, the drive shaft 1504 rotates relative to the motor stator 1502 and the pump housing 508.

[0086] The motor 202 has 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 the impeller 708 to inflate via the motor 202 and the drive shaft 1504. To maintain pressure when the impeller 708 inflates, 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 as element 1508 in Figure 15B. Figures 15B and 15C show the 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 position on the guidewire, and then, once the guidewire is removed from the system, may subsequently generate a pressure-resistant seal to allow the impeller 708 to maintain pressure.

[0087] Once the system is in the correct anatomical position, the inflation needle 1600 (e.g., Figures 9C-9E) can be advanced through the proximal seal 1510, thereby enabling inflation of the impeller 708. When the inflation needle 1600 is removed, the impeller 708 can 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 may 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 may also function as pressure relief valves to prevent over-inflation of the impeller 708.

[0089] The small motor 202 can be connected to a controller located outside the patient 206 (Figure 2) via a wire 1506 that can be embedded within the wall of the catheter shaft. Referring also to Figures 16A and 16B, additional illustrations of an exemplary inflation needle 1600 that may be used to inflate the impeller 708 through a small internal motor 202 are provided. The needle 1600 may comprise 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 the proximal seal 1510 at the proximal end of the small motor 202 without damaging the sealing membrane or impairing the function of the seal 1510.

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

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

[0092] Figure 17A shows a rotatable inner catheter 700 with the impeller 708 in a radially reduced form. Next, in Figures 17B and 17C, the impeller 708 is expanded to its pumping shape by applying pressure through the hub 702 of the rotatable inner catheter 700.

[0093] The impeller 708 can then connect the expanded, rotatable inner catheter 700 to the motor 1700 using a motor coupler 1702. The motor coupler 1702 may be a connector that mechanically connects the motor rotor 1704 to the catheter hub 702.

[0094] Figures 18A to 18C show possible sequences of steps for coupling a rotatable internal catheter 700 to an external motor 1800, which may be represented by, for example, a motor 104 (Figure 1), and subsequently expanding the impeller 708, according to embodiments of the subject matter disclosed herein. Figure 18A shows the rotatable internal catheter 700 with the impeller 708 in a radially contracted form. Next, as shown in Figure 18B, the hub 702 of the rotatable internal catheter 700 may be coupled to the motor 1800 via a motor coupler 1802. Once the rotatable internal catheter 700 is coupled to the motor 1800, the impeller 708 may be expanded by applying pressure through an expansion port 1804 located proximal to the motor rotor 1806. The pressure may pass through an expansion path 1808, which may be located within the hollow motor rotor 1806, as shown in Figure 18C.

[0095] Referring to Figures 17A-17C and 18A-18C in general, the rotating internal catheter system 700 is coupled to the motor 1700 / 1800, and once the impeller 708 is in its extended state, the motor rotor 1704 / 1806 can be activated while the motor stator 1706 / 1810 remains stationary, causing the motor rotor 1704 / 1806 to rotate. The rotating motor rotor 1704 / 1806 imparts rotational speed to the rotatable internal catheter system 700, thereby rotating the impeller 708 and generating blood flow.

[0096] Figures 18B and 18C show a motor system 1800 having a hollow motor rotor 1806 that allows pressure to be applied through the motor, but there are many other options for inflating the impeller 708 after the catheter is coupled to the motor, without the expansion path 1808 passing through the motor rotor. To give a non-limiting example, the hub 702 may be attached to a gear mechanism and offset from the motor 1800, so that the expansion path passes through the center of the gear instead of through the motor (not shown).

[0097] Figures 19A and 19B show exemplary configurations of the inlet cannula 504 and pump housing 508 located at the distal end of the housing component 510 in their extended state, according to embodiments of the subject matter disclosed herein.

[0098] During use, when the inlet cannula 504 is positioned across the AV, the AV valve leaflets can compress the outer surface of the inlet cannula 504, causing it to be compressed radially. Therefore, the inlet cannula 504 may require a radial strength, also known as hoop strength, sufficient to maintain its expanded diameter when it is positioned across the AV. The tendency of the inlet cannula 504 to maintain the desired expanded shape helps ensure proper pumping performance and the desired blood flow during use. Similarly, the pump housing 508, which houses the pump impeller 708 (illustrated elsewhere), may require a precise expanded shape to work in cooperation with the impeller 708 to ensure proper pumping performance and the desired blood flow.

[0099] In the described embodiment, the inlet cannula 504 is composed of a flexible wall 536, and an expandable braided support structure 1900 is 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 structure. This same braided support structure 1900 extends continuously to the pump housing 508 and supports the flexible wall 524 of the pump housing 508. The braided support structure 1900 may be located inside the flexible wall 536 / 524, may be embedded within the flexible wall 536 / 524, may be located outside the flexible wall 536 / 524, or may be any combination thereof.

[0100] When an expandable braided support structure 1900 is used as a support structure for the flexible wall 536 / 524, the inlet cannula 504 and pump housing 508 can be stretched longitudinally when folded and radially compressed, and then contracted longitudinally when they self-expand to their fully extended working shape. This braided support structure 1900 can provide the inlet cannula 504 with sufficient radial strength to withstand compression from the AV.

[0101] Figures 20A and 20B show another exemplary configuration of the inlet cannula 504 and pump housing 508 located at the distal end of the housing component 510 in their extended state, according to embodiments of the subject matter disclosed herein. The inlet cannula 504 may consist of a flexible wall 536 to which an expandable coil support structure 2000 is coupled.

[0102] The expandable coil support structure 2000 may consist of a single filar coil 2002 or a plurality of 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 on the distal side of the pump housing 508. The coil support structure 2000 may be located inside the flexible wall 536, embedded within the flexible wall 536, located outside the flexible wall 536, or any combination thereof. The coil support structure 2000 may provide the inlet cannula 504 with sufficient radial strength to withstand compression from the AV.

[0103] In the described embodiment, the pump housing 508 does not necessarily have to include a support structure within its flexible wall 524. The pump housing 508 can be expanded by the pumping action of the impeller 708 (illustrated elsewhere). As the impeller 708 rotates to generate blood flow, the pressure inside the pump housing 508 can increase relative to the pressure outside the pump housing 508. This increased internal pressure can expand the pump housing 508 to its optimal pumping configuration or shape.

[0104] Figures 21A and 21B show other possible configurations of the inlet cannula 504 and pump housing 508 in their extended state according to embodiments of the subject matter disclosed herein. The pump housing 508 may be reinforced by a longitudinal support structure 2100 to provide additional columnar strength. This longitudinal support structure 2100 may be within the flexible wall 524, embedded in the flexible wall 524, or bonded to the outside of the flexible wall 524. The additional columnar strength may assist in the delivery, operation and positioning, and retrieval of the device. In some embodiments, the same elongated elements of the longitudinal support structure 2100 in the area of ​​the pump housing 508 extend into the area of ​​the inlet cannula 504, as shown, and are braided or woven together. Alternatively, in some embodiments, the elongated elements of the longitudinal support structure 2100 in the area of ​​the pump housing 508 are separate from the elongated elements in the area of ​​the inlet cannula 504. In other embodiments, the elongated elements of the longitudinal support structure 2100 in the region of the pump housing 508 are separate from, but attached to, the elongated elements in the region of the inlet cannula 504.

[0105] Figure 22A shows another exemplary form of the inlet cannula 2200 and pump housing 2202 in their extended state according to embodiments of the subject matter disclosed herein. The inlet cannula 2200 and pump housing 2202 can be located in the distal end portion of several embodiments of the housing component 510. As illustrated, a possible form 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. In other embodiments described herein, the inlet cannula 504 and the pump housing 508 (illustrated elsewhere) have different diameters, with the pump housing 508 having a larger diameter and the inlet cannula 504 having a smaller diameter, which can make acceptance within the AV easier. However, if the patient is sufficiently large and the anatomical structure of the AV can accommodate a larger inlet cannula 2200, a larger inner diameter of the inlet cannula 2200 can reduce the pressure gradient within the inlet cannula 2200 and improve hemodynamics. In the configuration depicted in Figure 22A, the flexible walls of the inlet cannula 2200 and the pump housing 2202 are supported by a braided structure 2204 whose diameter continuously expands.

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

[0107] Referring generally to Figures 19A to 22B, according to embodiments of the subject matter disclosed herein, the support structures used to reinforce the inlet cannula and pump housing may consist of several different materials, components, or combinations thereof. The braids and coils may consist of a metallic structure, such as superelastic nitinol (but are not limited thereto). The braids and coils may also consist of a polymer material, such as aramid or nylon. The coil structure may also consist of a long tubular balloon structure that can expand itself to expand the inlet cannula and pump housing.

[0108] Figures 23A and 23B show another exemplary mechanical hemodynamic assist device 2300 (or “pump device 2300”) in a configuration that extends across the aortic valve AV. The pump device 2300 comprises a skirt 2302 attached to the connection between the pump housing 2304 and the inlet cannula 2306, according to embodiments of the subject disclosed herein.

[0109] The skirt 2302, once exposed (for example, from the delivery sheath device 500 described above), can self-expand by a self-expanding support structure 2308. The self-expanding support structure 2308 can be constructed, for example, from a superelastic nitinol wire. After the skirt 2302 has expanded, it can lean against the aortic valve AV, thereby preventing the device 2300 from moving excessively distally into the left ventricle. The skirt 2302 can also help stabilize the device when implanted within the patient's anatomical structure. In addition, the skirt 2302 can alleviate aortic regurgitation by preventing blood regurgitation through the aortic valve and increasing pressure on the aortic valve AV, thereby allowing the valve to close fully or completely during diastole.

[0110] Figures 24A and 24B show another exemplary mechanical hemodynamic assist device 2400 (or “Pump Device 2400”) in a configuration that extends across the aortic valve AV. The Pump Device 2400 comprises a petal 2402 attached to the connection between the pump housing 2404 and the inlet cannula 2406, according to embodiments of the subject disclosed herein.

[0111] Petal 2402, once exposed (e.g., from the delivery sheath device 500 described above), can self-expand by a self-expanding support structure 2408. The self-expanding support structure 2408 can be constructed, for example, from a superelastic nitinol wire. After petal 2402 expands, it can lean against the aortic valve AV, thereby preventing the device 2400 from moving excessively distally into the left ventricle. Petal 2302 can also help stabilize the device when implanted within the patient's anatomical structure. In addition, petal 2402 can alleviate aortic regurgitation by preventing blood regurgitation through the aortic valve AV and increasing pressure on the aortic valve AV, thereby allowing the valve to close fully or completely during diastole. In contrast to skirt 2302, leaning petal 2402 against AV may be less likely to interfere with the innate continuous blood flow provided by the patient's heart.

[0112] Figure 25 shows an exemplary system and method for fixing or securing the pump device 300 within the anatomical structure of a patient, according to embodiments of the subject matter disclosed herein. The method involves placing a balloon 2500 in an artery originating from the aortic arch, such as the aorta AO or descending aorta DAO. The balloon 2500 may be a separate device or a balloon attached to the drive shaft housing 511 and traversed through the anatomical structure simultaneously with the main pumping device 300.

[0113] When balloon 2500 inflates, it creates an apposition to the vessel wall, thereby fixing balloon 2500 within the anatomical structure. If balloon 2500 is attached to the drive shaft housing 511, when balloon 2500 is fixed within the anatomical structure, the pump device 300 is also fixed within the anatomical structure. If balloon 2500 is a separate device, when balloon 2500 inflates and is fixed within the anatomical structure, balloon 2500 compresses and presses the drive shaft housing 511 against the vessel wall, thereby fixing the pump device 300 within the anatomical structure.

[0114] In some embodiments, the balloon 2500 may, in its expanded state, have a spiral shape that defines an open central passage allowing blood perfusion through the balloon 2500, as shown in the figure. The balloon 2500 may be constructed of a semi-compliant material so that it can conform to the patient's vascular anatomy, thereby making the balloon 2500 more versatile in terms of placement.

[0115] Figure 26 shows another exemplary system and method for immobilizing the pump device 2400 (Figures 24A and 24B) within the patient's anatomical structure, according to embodiments of the subject matter disclosed herein. The petal 2402, once implanted, can prevent the pump device 2400 from moving distally within the patient's anatomical structure. However, the fluctuating thrust generated by the pumping action of the pump device 2400 may cause the pump device 2400 to move proximal away from its desired position within the anatomical structure. The overall device thrust will vary based on the flow rate. Consequently, it may be beneficial to add additional components or mechanisms to suppress the proximal movement of the device 2400 within the anatomical structure after implantation.

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

[0117] In some embodiments, the inlet shaft anchor 2600 may be constructed as an expandable structure, such as an open-cell stent (i.e., not covered by a membrane), thereby allowing perfusion through the artery. The inlet shaft anchor 2600 may be fixed in place along the drive shaft housing 511, or it may be movable along the drive shaft housing 511 and fixed on the drive shaft housing 511 after expansion. The inlet shaft anchor 2600 may be refoldable (e.g., into a delivery sheath device 500) to facilitate removal from subsequent anatomical structures.

[0118] Figure 27 shows yet another exemplary system and method for securing the pump device 300 within the anatomical structure of a patient, according to embodiments of the subject matter disclosed herein. In this embodiment, an expandable cage anchor 2700 is coupled to the drive shaft housing 511. When exposed from the delivery sheath device 500, the cage anchor 2700 self-expands, generating a force of adhesion to the vessel wall, thereby securing the drive shaft housing 511 within the anatomical structure. The expandable cage anchor 2700 may allow blood perfusion through the aorta and adjacent vessels.

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

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

[0121] Figures 28A, 28B, and 28C show an outlet port 526 having exemplary outlet port relief notches 2802. The outlet port relief notches 2802 are cut out from the flexible wall 524 of the pump housing 508. These outlet port relief notches 2802 are positioned around the outlet port 526 to create outlet port flaps 2804 between adjacent notches 2802 that can bend or flex outward when the pump housing 508 is pressurized. The outlet port flaps 2804 act as inclined or smooth transitions, allowing blood flowing out of the pump housing 508 to pass more gently and with less stress, thereby improving fluid dynamics.

[0122] Figures 28D, 28E, and 28F further adopt the concept of an outlet port relief notch 2802. In this embodiment, the exemplary outlet port 2810 consists mainly of a relief notch 2812 rather than a larger hole cut into the flexible wall 524 of the pump housing 508 (illustrated, e.g., in Figures 28A-28C). The hole at the center of the outlet port 2810 may be further reduced until it is no longer present. The relief notches 2812 may be much larger (e.g., longer) and large enough to merge with each other. This makes the outlet port flap 2814 much larger. The advantage of this embodiment of the outlet port 2810 is that it can now act as a one-way valve allowing blood to flow out of the pump housing 508 when the impeller 708 (illustrated elsewhere) is rotating and the pressure inside the pump housing 508 is higher than AO. Conversely, when the pump is not operating, the larger outlet port flaps 2814 can assemble together, thereby closing the outlet port and preventing blood from flowing back from the AO through the pump housing 508 and into the LV via the inlet cannula.

[0123] Figures 29A to 29C show cross-sectional views of a pump housing outlet port 526 according to embodiments of the subject disclosed herein. Figure 29A shows the pump housing 508A and its outlet port 526A, which is configured in an axial ring shape around the flexible wall 524 of the pump housing 508A, thereby having an angle of 90 degrees with respect to the tangent line 2904A from the central axis 2902A of the pump housing 508A. Figure 29B shows how the pump housing 508B and its outlet port 526B may be configured at any angle between 0 and 90 degrees (e.g., shown as 68 degrees) with respect to the axis of rotation 2902B. Figure 29C shows the pump housing 508C, whose outlet port 526C is located 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, resulting in a 0-degree angle with respect to the tangent line 2904C from the central axis 2902C of the pump housing 508C. Figures 29A to 29C show blood flows 2900A, 2900B, and 2900C through different outlet port angles. By adjusting the outlet port angle, the laminar flow dynamics of the blood as it passes through the outlet port can be improved, thereby reducing hemolysis.

[0124] Figure 30 shows another diagram of the delivery sheath device 500. The delivery sheath device 500 comprises a handle 512, a sheath 502, an optional radiopaque distal marker band 514, and an optional intact bumper tip 506. 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 of the sheath 502. In some embodiments, multiple radiopaque distal marker bands 514 can be located along the sheath 502. The intact bumper tip 506 may 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 stretch / low yield) film. In some embodiments, the sheath 502 can be purely polymer-based. In some embodiments, the sheath 502 can be polymer-based and may 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 in which a housing component (e.g., housing component 510) can be slidably housed in a delivery configuration with a small external shape that is radially compressed. After advancing the sheath 502 housing the housing component to a target location in the patient, e.g., the heart, the delivery sheath device 500 can then be retracted proximal (while maintaining the position of the housing component) to expose the distal end of the housing component from its restraint within the sheath 502. If it is desired to reposition or remove the pump device, the delivery sheath device 500 can be advanced distally to recapture the housing component within the sheath 502.

[0127] Figures 31A to 31C show that in some embodiments, the delivery sheath device 500 may be configured as a peelable or divisible sheath. In such cases, the delivery sheath device 500 can be advantageously removed from the patient after its function of advancing and implanting the housing components has been performed. Removing the delivery sheath device 500 in this manner may be advantageous because it allows for a slight reduction in the size of the patient's percutaneous opening after the removal of the delivery sheath device 500.

[0128] In Figure 31A, the sheath 502 has two sets of linearly arranged notches or perforations 3182. In Figure 31B, the sheath has two linearly arranged grooves 3186. Figure 31C shows that in some embodiments, the perforations 3182 or grooves 3186 are arranged approximately 180° opposite each other. In any case, the perforations 3182 or grooves 3186 constitute the sheath 502 by weakening regions that make the sheath 502 manually breakable or separable. The handle 512 can also be made from two separate parts or made to be separable into two parts.

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

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

[0131] Furthermore, with respect to Figures 14A and 14B, in some embodiments, the flow of blood into the drive shaft housing, which can pass through the opening 3294 of the sheath 502 and then through the opening of the drive shaft housing, facilitates the dynamic bearing function described with respect to Figures 11 to 13B.

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

[0133] Figures 33A and 33B show another optional feature that may be included as part of several embodiments of the delivery sheath device 500. In the embodiments depicted, the proximal portion of the sheath 502 includes a notched proximal portion 3302. The notched proximal portion 3302 is located along the proximal portion of the sheath 502 through the skin and subcutaneous puncture site at the vascular access site when the sheath 502 is in use. Thus, the size of the skin and subcutaneous puncture can be reduced, in some cases, compared to a sheath 502 without the notched proximal portion 3302. In some embodiments, as illustrated, one or more longitudinally extending stiffening rods 3390 can be provided to provide structural reinforcement to the notched proximal portion 3302 of the sheath 502.

[0134] Figures 34A to 34C show optional features that may be included as part of several embodiments of the housing component 510. In the depicted embodiments, the housing component 510 comprises a drive shaft housing hub 518, a drive shaft housing 511, a pump housing (not shown, see, for example, pump housing 508 in Figure 6), and an inlet cannula (not shown, see, for example, inlet cannula 504 in Figure 6).

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

[0136] In the described embodiment, the inner diameter of the drive shaft housing 511 includes an annular projection 3408. The annular projection 3408 causes the inner diameter of the lumen of the drive shaft housing 511 to narrow to a smaller opening diameter in a region compared to the rest of the drive shaft housing 511.

[0137] As shown in Figure 34C, the annular projection 3408 can interface with the annular protrusion 3468 on the impeller drive shaft (e.g., the impeller drive shaft 704). The outer diameter of the annular protrusion 3468 can be larger than the inner diameter of the annular projection 3408. Thus, the dimensional interference between the annular protrusion 3468 and the annular projection 3408 can serve to indicate the most distal longitudinal position of the impeller drive shaft relative to the housing component 510. This longitudinal 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] Figure 35 shows additional optional features that may be included as part of several embodiments of the housing component 510. In the embodiments depicted, the drive shaft housing 511 of the housing component 510 defines one or more openings, windows, or openings 3512. In the non-limiting examples depicted, the opening 3512 is a longitudinally elongated opening 3512. Openings 3512 of any suitable size and shape can be implemented in the drive shaft housing 511.

[0139] The opening 3512 can be at least partially aligned with, or otherwise cooperate with, the opening 3294 (Figure 32) defined by the sheath 502, so that blood can flow through the sheath 502 into the drive shaft housing 511. Such blood flow into the drive shaft housing 511 can (i) provide lubrication and cooling to reduce the heat generated from friction between the rotating impeller drive shaft and the stationary drive shaft housing 511, and (ii) can also facilitate the dynamic bearing function described with respect to Figures 11 to 13B.

[0140] Figure 36C shows additional optional features that may be included as part of several embodiments of the housing component 510. In the depicted embodiments, the drive shaft housing 511 of the housing component 510 comprises one or more open cell portions 3612. One or more open cell portions 3612 may be stent-like structures. That is, one or more open cell portions 3612 may be, for example, braided, woven, or laser-cut and expanded. One or more open cell portions 3612 have multiple open areas that allow lateral blood flow into the drive shaft housing 511 for the aforementioned lubrication, cooling, and hydrodynamic bearing advantages (in combination with the opening 3294 of the sheath 502 of the delivery sheath device 500 shown in Figure 32, or in combination with the stripped sheath device 500 shown in Figures 31A-31C). The open cell portion 3612 may allow for lateral blood flow while still protecting the rotary drive shaft (e.g., drive shaft 704) from damaging the patient's anatomical structures or becoming entangled with other devices used by the clinician.

[0141] Figures 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; for example, the motor 202 in Figure 15) that may be used in the pump system 200 shown in Figure 2. In this embodiment, the drive shaft housing 511 may include tubular lumens 3722 embedded within the wall of the drive shaft housing 511. These tubular lumens 3722 may accommodate the passage of wires 1506 (not shown; see Figure 15) that connect the motor 202, which is located inside the patient's body, to a controller 206 located outside the patient's body in order to supply power to the motor 202 and control the motor 202.

[0142] Figures 38A to 38E show examples of torque transmission drive shafts 3800 according to embodiments of the subject matter disclosed herein. The drive shaft 3800 may be used, for example, as a drive shaft 704 for a rotatable internal catheter of a pump device described herein.

[0143] In some embodiments, the drive shaft 3800 is constructed of a bidirectional helical hollow stranded wire coil 3802. The coil 3802 has high-performance torque transmission characteristics and facilitates flexibility and conformability through anatomical structures. As illustrated, the coil 3802 may or may not be enclosed by an outer cover 3804 (Figures 38A and 38B) or may be enclosed (Figures 38C-38E). The outer cover 3804 is constructed of polymer and can isolate the central lumen 3806 (Figure 38D) of the drive shaft 3800 from its external environment. As a result, the central lumen 3806 can be used as an expansion lumen for supplying expansion fluid to the pump impeller 708 (illustrated elsewhere). The outer cover 3804 can also enhance torque transmission and reduce longitudinal elongation of the drive shaft 3800.

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

[0145] The lumen support mandrel 3808 may suppress the transmission of expansion fluid through the central lumen 3806, so that the expansion fluid may be transmitted before the insertion of the mandrel 3808. In practice, the mandrel 3808 may, in some cases, act as a plunger in the central lumen 3806, thereby increasing the fluid pressure supplied to the pump impeller 708 (illustrated elsewhere). As a result, if the expansion fluid is initially supplied to the pump impeller 708 through the lumen 3806 of the drive shaft 3800, it may be beneficial to consider the pressure increase caused by the insertion of the mandrel 3808. Alternatively, a pressure relief valve (not shown) may be provided to maintain the desired pressure.

[0146] Figures 39A to 39C further illustrate the drive shaft 3800 and its potential failure modes. More specifically, Figure 39B shows one potential failure mode 3810 of the drive shaft 3800 that can occur when subjected to a high level of rotational resistance. Due to the presence of the central lumen 3806 (Figures 38B and 38D), the drive shaft 3800 may collapse on itself when subjected to a high level of torque, thereby impairing torque transmission at the collapsed point. This creates a stress concentration, where the drive shaft 3800 will begin to wrap around 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 collapse and separation of the drive shaft is very short. As a result, there may not be enough time to react to the collapsed drive shaft and stop its rotation.

[0147] Referring particularly to Figure 39C, one solution to mitigate this failure mode is to place a lumen support mandrel 3808 within the central lumen 3806 of the drive shaft 3800. The presence of the mandrel 3808 within the central lumen 3806 suppresses deformation of the drive shaft 3800, thereby suppressing the formation of stress concentration points and avoiding the failure mode. The mandrel 3808 may also provide additional benefits such as improved kink resistance, durability, and fatigue resistance.

[0148] Figures 40A to 40D show a drive shaft 704, a drive shaft hub 4002, and an expansion needle 4006 according to embodiments of the subject matter disclosed herein. The drive shaft 704 and the drive shaft hub 4002 may be, for example, part of system 100 (Figure 1). The drive shaft hub 4002 and the drive shaft 704 define a lumen that facilitates the transmission of expansion fluid from the expansion needle 4006 to the pump impeller 708 (illustrated elsewhere).

[0149] The drive shaft hub 4002 may be configured to maintain the pressure of the expansion fluid when the expansion needle 4006 is removed. More specifically, the drive shaft hub 4002 may have or include a drive shaft hub seal 4004, which may be a septum or a pressure-actuated seal.

[0150] Embodiments of the drive shaft hub 4002 including the pressure-operated drive shaft hub seal 4004 may be manually compressible and extendable. In some such embodiments, the drive shaft hub 4002 may comprise two parts that screw together, and these two parts are manually compressible and extendable by manually adjusting the degree to which the two parts are screwed together. In another exemplary embodiment, the drive shaft hub 4002 may comprise a detent mechanism that allows the drive shaft hub 4002 to be manually adjusted between a compressed form (Figure 40C) and an extended form (Figure 40A).

[0151] When the drive shaft hub 4002 is extended as shown in Figure 40A, the pressure-operated drive shaft hub seal 4004 is open or can be easily opened. When the drive shaft hub 4002 is compressed as shown in Figure 40C, the pressure-operated drive shaft hub seal 4004 is compressed, thereby closing the pressure-operated drive shaft hub seal 4004 and restricting the flow through it.

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

[0153] Referring again to Figures 40A to 40D, and in particular to Figure 40A, the expansion needle 4006 can be manually inserted and extended through the hub seal 4004 while the hub seal 4004 is open or in an openable state. While the expansion needle 4006 extends through the hub seal 4004, the hub seal 4004 compresses around the expansion needle 4006, thereby sealing it. The expansion fluid can then be delivered through the expansion needle 4006 to inflate the pump impeller coupled to the drive shaft 704 (e.g., the pump impeller 708). After the pump impeller reaches the appropriate pressure, the expansion needle 4006 can be slidably retracted proximally, and once the expansion needle 4006 is completely removed, the hub seal 4004 closes and maintains the seal. At this point, 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 into the system without depressurizing by pushing the mandrel 3808 through the seal 4004 and allowing the mandrel 3808 to follow through the drive shaft 704. The drive shaft hub 4002 may also include features that facilitate coupling to the motor. For example, Figure 40D shows that the hub 4002 may define coupling features such as three symmetrically arranged grooves 4008 on its outer circumference to facilitate coupling and torque transmission between the motor (illustrated elsewhere) and the drive shaft 704.

[0155] Figures 41A and 41B show exemplary expandable, inflatable, or balloon-type pump impellers 4100 according to embodiments of the subject matter disclosed herein. The impeller pump 4100 has a smooth surface without protruding external features such as grooves or ridges (for example, illustrated in several other impellers herein). A pump impeller 4100 having a smooth surface can enhance its self-centering ability. The impeller 4100 is attached to the distal end of the drive shaft 704 at both the distal and proximal constrictions of the impeller, thereby enabling uniform torque transmission between the drive shaft and the impeller from both the proximal and distal ends of the impeller.

[0156] Figures 42A and 42B show a self-expanding, or a hybrid of self-expanding and ballooning, pump impeller 4200 according to embodiments of the subject matter disclosed herein. The impeller 4200 may include a self-expanding support structure 4204 within the impeller 4200. When exposed, this support structure 4204 expands to give the impeller 4200 its fully expanded operating pumping shape. In the self-expanding impeller configuration, an expansion medium or expansion technique may not be required. The self-expanding impeller 4200 can be slidably followed through the internal lumen of the drive shaft housing 511 (illustrated elsewhere) in a folded state, and then, when the self-expanding impeller 4200 is advanced into the pump housing 508 (illustrated elsewhere), the self-expanding impeller 4200 expands on its own. To fold the self-expanding impeller 4200 again in order to remove the device, the impeller 4200 and the drive shaft 704 (illustrated elsewhere) can be retracted proximally through the drive shaft housing 511.

[0157] In this configuration, the impeller 4200 may also be a hybrid expandable impeller 4200, in which case the support structure 4204 facilitates the expansion of a portion of the impeller 4200, and the application of pressure into the balloon-type impeller 4200 may further contribute to the complete expansion of the impeller 4200. When expanded, the impeller can rotate around its axis 4202 to generate blood flow.

[0158] Figures 43A–43C show an exemplary expandable triangular pump impeller 4300 according to an embodiment of the subject disclosed herein. In this embodiment, the expansion of the impeller 4300 may be facilitated by a triangular support structure 4304. The support structure 4304 may have a three-filer configuration that expands within the membrane of the impeller 4300 when exposed. This expansion may be self-expandable or expandable by longitudinal compression along the rotation axis 4302 of the impeller. Figure 43B illustrates the expanded triangular impeller 4300 within a pump housing 508, showing the triangular corners of the impeller 4300 generated by the internal support structure 4304 and the small gap between 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 generate a flow by pushing blood through the outlet port 526 of the pump housing 508. Although this form of the impeller is illustrated as triangular, the impeller may also be planar with two filer support structures (not shown), or may have multiple filers to generate an impeller with any number of planes (not shown). In some embodiments, these internal filer support structures may spiral around the central axis 4302 of the impeller 4300 when expanded to generate a helical surface (not shown).

[0159] Figures 44A–44C show another exemplary expandable, inflatable, or balloon-type pump impeller 4400 according to embodiments of the subject matter disclosed herein. In this example, the impeller 4400 may have a plurality of protrusions 4406 arranged along the outer surface 4404 of the impeller 4400. In the depicted embodiment, the plurality of protrusions 4406 are longitudinally aligned along or parallel to the axis 4402 of the impeller 4400.

[0160] Many different possible forms exist for generating the ridge 4406. As some non-limiting examples, the ridge 4406 may be a solid, non-expandable ridge formed directly on the outer surface 4404 of the impeller 4400. The ridge 4406 may also be pressure-expandable and may expand when the balloon impeller 4400 is pressurized. The pressure-expandable ridge 4406 may be formed directly on the surface of the impeller 4400, or it may be a slender tubular balloon bonded onto the outer surface 4404 of the impeller 4400 and having an independent internal lumen within the ridge 4404.

[0161] These raised portions 4406 not only have surfaces 4404 that spin (rotate) in the tangential direction that propels the blood, but also angled surfaces of the raised portions 4406 that press against the blood, thereby further increasing the blood contact surface area of ​​the impeller 4400 and generating greater pressure on the blood. These raised portions 4406 can result in increased flow rate per rpm and reduced blood shear stress.

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

[0163] Figures 46A–46D show another exemplary expandable, inflatable, or balloon-type pump impeller 4600 according to embodiments of the subject matter disclosed herein. In contrast to the raised portion along the outer surface of the impeller (illustrated above), the impeller 4600 may have a plurality of valleys 4608 arranged along the outer surface 4604 of the impeller 4600. The valleys 4608 may also be referred to as grooves, channels, recesses, etc. The valleys 4608 may be arranged 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 on the outer surface 4604 of the impeller membrane 4604, or the valleys 4608 may be formed using a support structure 4606 located outside the surface 4604 of the impeller 4600. The support structure 4606 acts 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] Figures 47A–47C show another exemplary expandable, inflatable, or balloon-type pump impeller 4700 according to embodiments of the subject matter disclosed herein. In this example, the impeller 4700 is similar to the impeller 4600 (see Figures 46A–46D), but the multiple grooves 4506 arranged along the outer surface 4704 of the impeller 4700 may extend in a spiral configuration around the axis 4702 of the impeller 4700, rather than being longitudinally aligned along the axis 4602 of the impeller 4600. Having a spiral configuration may increase the blood flow rate per rpm and reduce blood shear stress.

[0165] Figures 48A and 48B show another exemplary expandable, inflatable, or balloon-type pump impeller 4800 according to embodiments of the subject matter disclosed herein. Similar to impeller 4100 (see Figures 41A and 41B), the distal impeller surface may have the same shape. However, the proximal surface 4804 may be flattened, resulting in a larger angle between the proximal surface 4804 and the axis of rotation 4802. Having a flattened proximal surface 4804 in impeller 4800 can reduce blood backflow through the pump housing caused by the proximal end of the impeller compared to the proximal surface of impeller 4100.

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

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

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

[0169] Figures 51A and 51B show another exemplary expandable, inflatable, or balloon-type pump impeller 5100 according to embodiments of the subject matter disclosed herein. When considering catheter-type blood pumps configured in a blood-extraction configuration (e.g., pump device 400, Figures 4 and 10), the impeller of the system may have some modifications compared to the impeller of a blood-extraction pump device. Since blood moves from proximal to distal, the design of the impeller may be optimized to pump blood in the said direction. Many of the examples of impellers disclosed are configured for a blood-extraction configuration, but if the impeller is flipped from proximal to distal, the design of the impeller will 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 form, 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 a distal tip protruding along the axis 5102. The distal tip of the impeller 5100 can be folded back into its interior as shown, creating a distal tip shaped like a cut tip or a more rounded distal tip. This tip outer shape 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 between them, 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 efficient entry of blood between the ridges 5202.

[0173] Continuing to refer to Figures 52A to 52D, in the non-limiting embodiments depicted, the ridge 5202 extends helically or spirally with respect to the longitudinal / rotation axis 5210 of the pump impeller 5200. More specifically, the ridge 5202 is offset from the longitudinal axis 5210 (if the ridge 5202 were extended, it would not converge on the rotation axis 5210 of the impeller 5200) and wraps around the surface of the pump impeller 5200 at a uniform angle. Alternatively, the ridge 5202 may wrap around the pump impeller 5200 at a fluctuating, non-uniform angle.

[0174] Figures 53A–53C show another exemplary expandable pump impeller 5300 according to embodiments of the subject matter disclosed herein. Pump impeller 5300 is similar to impeller 5200 shown in Figures 52A–52D, except that pump impeller 5300 comprises divided expandable protrusions 5302 spaced apart from each other by one or more gaps 5304 along the length of the protrusions. As the pressure increases within pump impeller 5300, pump impeller 5300 tends to round, thereby reducing the protruding height of the protrusions 5302. The gaps 5304 may not expand when pump impeller 5300 is pressurized, and the gaps 5304 thereafter act as tethers, providing hoop strength to maintain the expanded impeller shape and the integrity of the protrusions 5302.

[0175] Figures 54A to 54C show another exemplary expandable pump impeller 5400 according to embodiments of the subject matter disclosed herein. Pump impeller 5400 is similar to impeller 5200 shown in Figures 52A to 52D, except that pump impeller 5400 comprises a plurality of tapered, angled protrusions 5402 above the distal portion 5404 and the maximum diameter portion 5406. The proximal portion 5408 has a smooth surface and is relatively large so as to merge with the outermost dimensions of the protrusions 5402. Such a proximal portion 5408 may offer several advantages. One advantage is that there are no steps along the lateral outline of pump impeller 5400, and as a result, it may be relatively easy to construct a pump housing enclosed with smooth walls that conform to the rotating outline of impeller 5400. Another advantage is that the proximal portion 5408 may enhance the self-centering performance of pump impeller 5400. Another advantage is that the pump impeller 5400 defines a blood direction-reversing inclined section 5410. Such an inclined section 5410 can redirect the blood from an axial flow path to a radial flow path, thereby pushing the blood circumferentially out of the pump housing outlet.

[0176] Figures 55A to 55D show another exemplary expandable pump impeller 5500 according to embodiments of the subject matter disclosed herein. The pump impeller 5500 is similar to the impeller 5400 shown in Figures 54A to 54D, except that the pump impeller 5500 is inflatable and expandable as a whole, but comprises several non-expandable protrusions 5502, sometimes referred to as fins. The fins 5502 can be formed by fusing the balloon membranes of the pump impeller 5500 together, thereby making the fins 5502 non-expandable. However, the fins 5502 are nevertheless flexible and can be radially folded into a relatively small delivery profile.

[0177] In the extended form of the pump impeller 5500 (illustrated), the fins 5502 are supported by the fluid pressure used to inflate the pump impeller 5500. In addition, tension may be exerted on the back of each fin 5502 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 acting on them as they rotate and pump the blood. The pump impeller 5500 may also define a blood-direction deflection inclination 5508 to guide the blood through the pump housing outlet.

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

[0180] Figures 56A to 56F show the components and steps of a method for manufacturing the pump impeller 5500 of Figures 55A to 55D according to embodiments of the subject matter disclosed herein. First, a preform 5600 of a finless impeller is blown into an enlarged form, as shown in Figures 56A, 56C, and 56E. Next, as shown in Figures 56B and 56D, the enlarged preform 5600 is placed in a jig 5602 having an internal shape corresponding to the desired final shape of the pump impeller 5500. The preform 5600 can be pressurized and positioned within the jig 5602 with each part of the jig 5602 separated from each other. Next, each part of the jig 5602 can be tightened like an iris until those parts are in contact with each other. The preform 5600 and the jig 5602 can be heated to fuse the films together, thereby forming the fins 5502 (Figure 56F). Alternatively, the pump impeller 5500 may be formed by generating a film from co-extrusion with an adhesion layer in the inner diameter of the extrusion, thereby increasing the bonding strength of the fusion.

[0181] Figures 57A and 57B show components and steps of a method for manufacturing another exemplary pump impeller 5700 having an expandable ridge 5702, as shown in Figures 57C and 57D, according to embodiments of the subject matter disclosed herein. The method generally involves joining two film layers. The film layers include an outer layer 5704, shown in Figure 57A, which is formed into a desired outer impeller shape. The film layers also include an inner layer or mesh 5706, shown in Figure 57B. The inner mesh 5706 has a plurality of holes 5708, which can be generated by laser cutting. After the outer layer 5704 and the inner mesh 5706 are manufactured, the inner mesh 5706 can be placed inside the outer layer 5704, and the outer layer 5704 and the inner mesh 5706 can be fused together to produce the pump impeller 5700, as shown in Figures 57C and 57D. This construction of the pump impeller 5700 makes it less likely to round under pressure, thereby maintaining its shape (including the shape of the expandable ridge 5702). The strength of the fusion bond between the film layers can be increased by using co-extrusion with the adhesion layer on the fusion side of the layer.

[0182] Figures 58A and 58B illustrate the components and steps of a method for manufacturing another exemplary pump impeller 5800 having an expandable ridge 5802, as shown in Figures 58D and 58E, according to embodiments of the subject matter disclosed herein. First, an inner compliant or semi-compliant membrane 5804 is formed, as shown in Figure 58A. Figure 58A shows the unpressurized membrane 5804 as formed. Figure 58B shows the pressed membrane 5804, stretched and rounded. Figure 58C shows an outer layer 5806 constructed of a non-compliant material, the outer layer 5806 having a plurality of openings 5808 defining the periphery of the expandable ridge 5802. The outer layer 5806 is laminated on the membrane 5804. The outer layer 5806 acts as a cage to restrain the expansion of the membrane 5804 when pressurized. However, the opening 5808 does not restrict the expansion of the membrane 5804, thereby allowing the membrane 5804 to expand and stretch through the opening 5808 under pressure, thereby generating the raised portion 5802. As a result, as shown in Figures 58D and 58E, the pump impeller 5800 becomes a two-layer impeller with expandable raised portions 5802. The strength of the lamination bond between the membrane layers can be increased by using co-extrusion with the adhesion layer on the fusion side of the layers.

[0183] Figures 59A and 59B show components and steps of a method for manufacturing another exemplary pump impeller 5900 having an expandable ridge 5902 as shown in Figure 59C, according to embodiments of the subject matter disclosed herein. This method is similar to the method shown in Figures 58A to 58C, except that a single co-extrusion may be used to produce the impeller film 5904 as shown in Figure 59A. The outer layer of the co-extrusion may be non-compliant, and the inner layer may be compliant or semi-compliant. The opening 5906 in the outer layer may be produced, for example, by ablating the outer layer, so that the inner layer can expand through the opening 5906, as shown in Figure 59C, and an expandable ridge 5902 is produced.

[0184] Figures 60A and 60B illustrate an exemplary method of using a pressurized balloon within a patient's cardiovascular system as a pressure transducer to provide measurements of the patient's systolic and diastolic blood pressure. The method involves using a balloon pressure transducer system 6000, which comprises 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 cardiac diastole, the external pressure on the balloon 6002 will be small. As a result, the gauge 6006 will show a relatively low diastolic blood pressure 6008 (e.g., 80 mmHg), as shown in Figure 60A. During cardiac systole, the external pressure on the balloon 6002 will be large. As a result, the gauge 6006 will show a relatively high systolic blood pressure 6010 (e.g., 120 mmHg), as shown in Figure 60B.

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

[0186] Figure 61 shows various arterial and venous access sites and routes for delivering the mechanical hemodynamic assist devices described herein to a patient's heart. The most common access site is the femoral artery because it accepts larger devices, is easier to access, and is easier to seal afterward. If a patient has a femoral artery that is too small or too diseased to accept the device, an axillary artery access site may be used instead. With appropriate mechanical hemodynamic assist devices, such as the pumping devices described herein, the use of a radial access site via either a wrist or snuff box access site is now possible for the first time, which is beneficial because it is easier to access and the access site can be easily closed.

[0187] Venous access sites may be used to place mechanical hemodynamic support devices in the right ventricle to assist pulmonary circulation. Right ventricular support may be provided alone or in combination with left ventricular support to achieve complete cardiac support. In addition, if direct arterial access is not possible, venous access sites may be used, in which case mechanical hemodynamic support devices may be routed through the transcaval or atrial transseptal pathway to reach the arterial system and provide left ventricular support.

[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 specific features, the scope of the present invention also includes embodiments having different combinations of features and embodiments that do not necessarily include all of the described features. Thus, the scope of the present invention is intended to encompass all such substitutes, modifications, and variations within the claims, along with all their equivalents.

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

[0190] The expandable balloon-type pump impeller may be expanded using a standard balloon catheter inflation medium (e.g., a mixture of saline and contrast agent) via, for example, a luer adapter, or the pump impeller may also be expanded with a more viscous fluid or a more dense fluid. The impeller may also be expanded with a fluid that gels to help the impeller maintain its surface profile as it expands and spins. To contract the impeller filled with the gelled liquid, additional delivery of a chemical or enzyme that breaks down the gelled structure may be required. When the impeller is expanded with, for example, a mixture of saline and contrast agent, the impeller may be contracted using standard balloon contraction techniques (e.g., aspiration of the inflation medium).

[0191] In some embodiments, the impeller may have one or more radiopaque markers that assist the user in identifying the position of the impeller relative to the patient's anatomical structure 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 in a combination of both positions. Additionally, in some embodiments, the inflation medium used to expand the impeller may be radiopaque, thereby making the entire impeller 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, when the impeller is designed as a self-expanding impeller (as opposed to an impeller that can be expanded by fluid pressure), the drive shaft may not need to include an expansion lumen. Thus, in some such embodiments, the drive shaft may be designed as a solid cable and, accordingly, may not have a lumen for delivering an expansion medium to the impeller.

[0193] The torque transmission drive shaft may optionally include a structural reinforcement designed to transmit torque while maintaining flexibility. Some possible designs for the structural reinforcement include structures made of hypodermic tubing having a laser-cut pattern from the wall to increase flexibility. This may also be combined with a second layer of laser-cut hypodermic tubing having a mirrored (opposite) pattern with respect to the first hypodermic tubing to further increase torque transmission. The support may also be made of a multifilar coil, such as an HHS® (“Helical Hollow Strand”) coil, which may be a single-layer or double bi-directional coil, or a tri-directional coil concentrically arranged within each other. Multifilar coil reinforcement provides tough flexibility and torque transmission characteristics. The structural reinforcement may also be a combination of the support structures described above. A polymer membrane liner may be disposed either inside or outside the hollow shaft to seal the shaft and create an expansion lumen. The inside or outside of the coil may have a polymer membrane or polymer jacket that seals the shaft and creates an expansion lumen for inflating the balloon impeller.

[0194] In some embodiments, the structural torque transmission element may be made of a twisted stranded cable that can 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, a loose membrane may exist around the outside of the cable with a gap sufficient for fluid to pass between the membrane and the cable. During rotation, both the membrane and the cable may rotate at the same angular velocity.

[0195] Referring to the embodiments of the subject matter disclosed herein, which involve two catheter systems rotating relative to each other and system components implanted in a patient, coatings may be placed on the surfaces of the components forming the catheterized blood pump. Friction-reducing coatings, such as but not limited to silicone, hydrophilic or hydrophobic coatings, 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 thrombotic changes that form on the surface of the components. Bioactivity-enhancing or biocompatibility-improving coatings, such as but not limited to hydrogel or limus-based coatings, may be used to reduce the patient's response to the presence of foreign bodies in the body.

[0196] With regard to friction-reducing coatings in particular, these coatings can be applied to the outside of the sheath 500 to facilitate the sheath's movement through access sites and anatomical structures. Friction-reducing coatings can 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, thus facilitating the retraction of the sheath 500 and the exposure of the inlet cannula 504 and pump housing 508. Friction-reducing coatings between the sheath 500 and the housing component 510 can also facilitate the advancement of the sheath 500 over the housing component 510 to radially fold the pump housing 508 and inlet cannula 504 into the sheath 500 before removing the device. The inner lumen of the housing component 510 can also benefit from friction-reducing coatings, making it easier to follow pre-positioned guidewires and within anatomical structures. Having a friction-reducing coating on the inside of the drive shaft housing 511 may facilitate the 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 the resistance when spinning the rotatable inner catheter 700, which may lead to reduced fatigue and wear of the drive shaft and also result in an increased device lifespan.

[0197] Regarding thrombosis-reducing coatings in particular, because the device is located in the blood and pumps blood through its components, there may be areas within the device where blood flow stagnates. In these areas, it may be beneficial to apply a thrombosis-reducing coating to the surfaces of these components to reduce the likelihood of thrombus formation on the device or in the patient. One non-limiting example where this may be beneficial is the inside of the drive shaft housing 511, where blood or fluid perfusion through the drive shaft housing 511 may be minimal.

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

[0199] With respect to the two-part catheter system that rotates relative to each other as a whole, there may be a mechanism to ensure optimal longitudinal alignment between the housing component 510 and the rotatable inner catheter 700, as described in embodiments of the subject matter disclosed herein. The pump impeller and pump housing may have a precise longitudinal alignment mechanism. In a non-limiting example, the alignment mechanism may be controlled by adjusting the position between the hubs of the drive shaft and the drive shaft housing. The alignment mechanism may consist of two hubs that are locked in a stationary position and therefore cannot move freely, thus allowing for precise fine-tuning of their alignment. This fine-tuning may be performed using a lead screw mechanism, in which turning the screw moves the drive shaft distally or proximally relative to the drive shaft housing, thus adjusting the position of the impeller and pump housing. The alignment mechanism may also use a fine-tuning thumbwheel mechanism to precisely adjust the alignment between the components.

[0200] Another non-limiting example is the electronic control of the alignment mechanism to increase alignment accuracy. The electronic mechanism may allow for a worm gear coupled to a linear gear for improved accuracy and automatic position locking. The electronic alignment mechanism may allow for the optimization of component alignment 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] An electronic alignment mechanism can optimize the alignment of components and the tension of the drive shaft in real time as the impeller rotation speed increases or decreases. For example, as the rotation speed increases, the self-centering function of the pump impeller may tend to push the impeller distally or proximally within the pump housing. As the impeller rotation speed increases and the impeller attempts to move, the electronic alignment mechanism can adjust the drive shaft to move proximally or distally, thus maintaining the optimal impeller position within the pump housing. This real-time alignment adjustment can be performed automatically if the alignment mechanism is electrically operated and communicates with a controller system, allowing for correct alignment adjustments based on the impeller rotation speed.

[0202] The drive shaft housing and the drive shaft hub may have a home position into which they lock and a precision alignment mechanism engages. This home position may ensure that the impeller is aligned within the pump housing well enough, if not optimally, to safely pump blood. Then, as the device operates and rotates, the precision alignment mechanism may be used to optimize the arrangement of the components by moving the impeller proximal or distal within the pump housing.

[0203] Referring to catheter-type blood pumps as a whole, alternative embodiments of the system may exist, such as, but not limited to, multiple pumping units connected in series in a daisy-chain configuration, as described in embodiments of the subject matter disclosed herein. Multiple pumping units (inlet cannulas, pump housings, and impellers) can be connected in a daisy-chain configuration on a single device. An external catheter system may have multiple inlet cannulas and pump housings connected in series, and a drive shaft may have multiple impellers mounted in series around the shaft. Since all impellers mounted on a single drive shaft can rotate at the same angular velocity, if it is desired to adapt the fluid dynamics for each pumping unit, the flow can be adapted by using different impeller and pump housing geometries. By connecting multiple pumping units in a daisy-chain configuration on a single device, the system may be able to pump more blood with less damage to the blood by rotating the impellers at lower angular velocities. Each inlet cannula of the pumping unit can be located proximal to the outlet port of the distal pump housing, thereby reducing the back pressure that the distal pumping unit needs to work against. A non-limiting example of where the inlet cannula of the most distal pumping unit may be located is the left ventricle.

[0204] Daisy-chaining pumping units reduces back pressure on the distal pumping units, allowing the entire system to support higher fluid flow rates at lower rotational angular velocities. This configuration may result in a decrease in peak blood pressure at the outlet port of the most distal pump housing, although the proximal pumping units can continue to increase the outlet blood pressure until the desired blood pressure and perfusion are achieved.

[0205] The proximal inlet cannula and pump housing may be sized to reduce backflow through the inside of the vessel from the pump housing outlet port toward the inlet cannula. In addition, blocking of vascular backflow may be achieved by having a skirt or petal at the connection between each subsequent inlet cannula and the pump housing, which provides tight contact with the vessel wall and results in a reduction of backflow through the vessel.

[0206] Referring to the system controller as a whole, 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 be moved with the patient. The controller is the brain of the system. The system controller may be a critical device that communicates with and controls the motor used to rotate the impeller and pump blood. The controller may be capable of controlling cardiac output by adjusting the rotational speed (rpm) of the impeller. The controller should preferably monitor motor parameters to ensure smooth device operation. In addition, the controller may provide the user with feedback on the device's performance and the patient's vital signs.

[0207] Based on the motor current consumption, the impeller arrangement within the pump housing can be fine-tuned during operation to enable optimal fluid flow efficiency relative to rotational RPM. The controller can also inform the user of the pump flow rate and, by extension, the amount of circulatory assistance the patient is receiving from the pump. This can be done by calculating the device RPM-to-flow rate constant and calibrating the system with this constant.

[0208] During emergency procedures, patients may need to be immobilized. Therefore, the controller may be a standalone, essential device located next to the table where the patient is being treated. However, if the patient is receiving mechanical circulatory support for cardiac shock or other reasons requiring long-term circulatory support, a standalone system next to the patient's table is inconvenient as it prevents the patient from moving freely or getting out of bed. Therefore, a portable controller system and motor may be preferable.

[0209] When an upper body access site is used to position the device, the patient's legs may be able to walk freely if they can easily carry the motor and controller. When a radial access site is used, the patient's arms will have to be immobilized to prevent the device from shifting within the vascular system due to arm movement. For radial access sites, the patient may wear removable elbow and shoulder braces to immobilize their arms. The controller and motor can be secured to the patient's arms with straps, so the entire system can be housed on the patient's arms and made portable. Alternatively, when a radial access site is used, the device may be fixed within the vascular system, so the patient can move their arms without risking displacing the device. Methods for fixing the device within the vascular system are discussed and illustrated in the drawings.

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

[0211] The portable controller and motor system may be a single unit housing both components, or they may be separate units connected to each other. Some non-limiting examples where the motor and controller are separate include having an internally embedded motor and a controller located outside the patient. Another example may have an external motor attached to the patient's shoulder, such as an epaulet, and a controller attached to the patient's abdomen or housed in a backpack that the patient can carry. The portable controller system may include electronic devices necessary to power the motor, control the motor speed, and monitor patient and device performance.

[0212] The controller may monitor motor performance to determine whether the motor is operating efficiently or if it may have reached the end of its lifespan. By monitoring motor performance, the controller may also determine whether the alignment of the impeller and pump housing is nominal or whether the alignment is misaligned 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, which enable comprehensive real-time monitoring of the patient's vital signs and may adjust device performance for optimal patient health or inform the patient whether they should seek medical attention.

[0213] The portable controller may have monitoring device performance and data storage capacity for recording any patient's vital signs, which can assist clinicians by providing diagnostic data. This data can also help wean patients from mechanical circulatory support. The portable controller may have an alarm system that monitors and interprets the data and notifies the patient if any device parameter or patient vital sign deviates from nominal values, thus enabling proactive intervention rather than reactive response to any problem. The alarm system may be visual, auditory, tactile, or any combination thereof. The alarm system may also communicate wirelessly with the patient's clinician and emergency medical team in the event of a problem, thereby facilitating faster response times.

[0214] The controller may have the ability to adjust the magnitude of mechanical circulatory assistance provided by a catheter-based blood pump. The controller may adjust the flow rate (e.g., the rpm speed of the impeller) based on the patient's vital signs such as blood pH value, blood oxygen concentration, heart rate, blood pressure, etc. The portable controller may also have a function to gradually reduce the blood flow rate provided by the controller while monitoring the patient's vital signs, thereby enabling the patient to gradually wean from mechanical circulatory assistance while ensuring the patient is in a stable state.

[0215] The portable controller may also have adjustable parameters to enable the patient to adjust the flow rate of the blood pump. The flow rate adjustment may be limited to a specific preset range determined by the patient's clinician. By enabling the patient to change the flow rate, the patient can experience mechanical circulatory assistance that is personally adapted to their lifestyle. For example, the patient may increase the flow rate when walking or exercising and then reduce the flow rate when 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 house 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 to enable it to operate at 220 - 110 VAC or an adapter to enable it to operate at 12 - 24 VDC to supply power to the system and the motor. The low voltage DC adapter may make it possible to supply power to the controller from a mobile location such as a vehicle. In addition, a portable modular battery pack may be provided, which can be connected to the controller to supply power to the system over a long period when the patient is not around an external power source or when there is a power outage where the patient is located.

[0217] A general reference to the catheter-based blood pumps described herein reveals a variety of use scenarios in which the blood pump, according to embodiments of the subject matter disclosed herein, may assist a patient's vital signs and improve patient outcomes. The catheter-based blood pump may be used to provide mechanical circulatory support to patients who may require additional blood pumping capacity and / or volume. It may be used as either a long-term ventricular support device or a short-term device for performing protected PCI, but is not limited to these use scenarios. The present invention may provide patient access through either a conventional femoral access site or an upper body access site, such as a radial access site. Using a radial access site, the patient may be able to walk while the device remains in place and pumping blood, as long as the patient's arm is immobilized or the device is fixed within the ventricle / aorta. Radial access may also allow the use of the femoral artery for other incidental procedures, such as, but not limited to, percutaneous transluminal angioplasty / stent insertion and lower extremity revascularization.

[0218] Because a large-diameter access site is not required to place the device within the patient, many alternative access sites can be used to place the device. In addition to radial or femoral artery access sites, the access site may be the femoral vein or brachial vessel. The axillary artery may also be used as an access site for device placement. Furthermore, in the blood pumping configuration, the device can be placed via a transthoracic / transapical approach, as shown in Figure 4B, to pump blood from the left ventricle into the aorta.

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

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

[0221] [Table 1] The percutaneous ventricular assist devices described herein may operate at various speeds (for example, with respect to revolutions per minute ("rpm") of the pump impeller) to obtain desired operating pump flow performance. In some non-limiting exemplary embodiments, the pump impeller of the percutaneous ventricular assist device described herein may operate at speeds of 0 rpm to 10,000 rpm, or 5,000 rpm to 20,000 rpm, or 5,000 rpm to 30,000 rpm, or 5,000 rpm to 40,000 rpm, or 5,000 rpm to 50,000 rpm, or 10,000 rpm to 20,000 rpm, or 10,000 rpm to 30,000 rpm, or 10,000 rpm to 40,000 rpm, or 10,000 rpm to 50,000 rpm, or 10,000 rpm to 6 It can operate 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 above 60,000 rpm. Please understand that these pump impeller rpm ranges are merely illustrative and non-limiting, as the actual impeller rpm used during treatment ultimately depends on many different factors, including, but not limited to, impeller design, pump system size, patient parameters, and clinician's choice.

[0222] There are numerous further use scenarios for catheter-based blood pumps to assist a 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, improving oxygenated blood circulation. This use scenario may be useful, for example, for short-term support during pulmonary embolism. The device may also be placed in the carotid artery to increase cerebral perfusion, which may be desirable in transient ischemic attacks (ischemic strokes). The device may also be placed in the descending aorta to partially reduce the back pressure of blood on the heart and provide additional perfusion to the renal arteries and limbs. The device may be placed in the iliac artery to assist ischemic limbs. In general, whereever additional blood perfusion is useful or needed, the blood pump may be placed directly upstream of any specific organ.

[0223] Two separate devices may be used in a vertical line to simultaneously support two organ systems. In this example, one is positioned in the descending aorta to support the lower limbs, while the other is positioned 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 can be fabricated from MRI-compatible support material such as nitinol or PEEK, and the sheath, impeller, and casing can also be MRI-compatible, so that the entire implantable portion of the device is MRI-compatible. Therefore, it may be possible to provide hemodynamic support to the patient during MRI imaging using an externally extended drive shaft and drive shaft housing.

[0225] If a clinician is unsure whether mechanical circulatory support will be needed during an intervention such as protected PCI, the device described herein may be partially implanted. Partial implantation consists of positioning the housing component 510 within 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 folded state. At this stage, the clinician may continue the PCI procedure without activating the blood pump. If the patient ultimately does not require circulatory support during the procedure, the stationary external catheter system can be removed without needing to use the remainder of the pump assembly. If the patient does require circulatory support during the procedure, the rotatable internal catheter 700 can be immediately placed within the housing component 510 where it was already positioned, and the device can be activated, thereby dramatically reducing the delay between the time circulatory support is needed and the time it is provided. The partial implantation technique of the device can result in significant cost savings by eliminating the need for catheterization laboratory time to fully implant the device and by eliminating the need to use the rotatable internal catheter 700. If the components are available separately, clinicians can replenish their stock by replacing the housing component 510 and the sheath 500.

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

[0227] Similarly, although the actions are depicted in a specific order in the drawings, this should not be interpreted as requiring that such actions be performed in a specific or sequential order, or that all of the indicated actions be performed, in order to obtain the desired result.

[0228] A specific embodiment of the subject matter is described. Other embodiments are within the scope of the claims below. For example, the actions enumerated in the claims may be performed in a different order and still yield the desired results. As an example, the processes depicted in the accompanying drawings do not necessarily require the specific order or sequence shown to obtain the desired results.

Claims

1. A mechanical hemodynamic support device, A pump housing configured to be placed inside the patient and to allow blood flow from the pump housing inlet to the pump housing outlet, A pump impeller that can be positioned within the pump housing, wherein the pump impeller is rotatable relative to the pump housing to generate a flow of blood from the inlet to the outlet of the pump housing, and is configured to self-center relative to the pump housing when rotating relative to the pump housing, The pump housing is a mechanical hemodynamic assist device that defines one or more relief notches around the outlet of the pump housing.

2. The mechanical hemodynamic assist device according to claim 1, wherein the pump impeller is attached to a flexible drive shaft, and the pump impeller is reconfigurable between (i) a small, contracted delivery configuration configured to advance transvascularly 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.

3. The mechanical hemodynamic assist device according to claim 1 or 2, wherein the pump housing is reconfigurable between a delivery configuration with a small external size and an operable configuration that expands radially.

4. The mechanical hemodynamic assist device according to claim 3, wherein the pump impeller is expandable from a small external delivery configuration to a radially expanded operable configuration configured to pump blood when the pump impeller rotates relative to the pump housing.

5. The mechanical hemodynamic assist device according to claim 1, wherein the pump housing is attached to the distal end portion of the drive shaft housing, and the drive shaft housing allows purge fluid or blood to flow between the pump housing and the pump impeller, thereby providing a dynamic pressure bearing between the pump housing and the pump impeller.

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