Patent Description:
Circulatory support devices may be disposed through a valve opening such as, for example, an aortic valve. In some cases, the size of the device may cause stress on the valve when the valve closes over the device. In the case of a motor failure, typical circulatory support devices may cause pressure differences between a left ventricle and an aorta. Additionally, typical circulatory support devices are prone to moving, resulting in a need for repositioning before treatment is continued.

<CIT> discloses a blood pump comprising a pump casing having a blood flow inlet and a blood flow outlet, and an impeller arranged in said pump casing so as to be rotatable about an axis of rotation, wherein the impeller has blades sized and shaped for conveying blood from the blood flow inlet to the blood flow outlet. The blood pump further comprises an outflow cannula having an upstream end portion, a downstream end portion and an intermediate portion extending between the upstream end portion and the downstream end portion. The upstream end portion of the outflow cannula is connected to the pump casing such that blood is conveyed from the blood flow outlet of the pump casing into and through the intermediate portion of the outflow cannula towards the downstream end portion of the outflow cannula, wherein the downstream end portion has a blood flow outlet through which blood can exit the outflow cannula. At least a portion of the intermediate portion of the outflow cannula has an outer diameter that is larger than an outer diameter of the pump casing.

In an Example <NUM>, a circulatory support device comprising: a flexible cannula having a fluid outlet at a proximal end; and a pump assembly disposed at a distal end of the flexible cannula, the pump assembly comprising: a pump housing having a fluid inlet defined therein; a motor disposed within a distal end of the housing; and an impeller, driven to rotate by the motor, and configured to push blood toward the fluid outlet.

In an Example <NUM>, the circulatory support device of Example <NUM>, further comprising a mesh skirt at least partially surrounding the pump housing, adjacent the fluid inlet.

In an Example <NUM>, the circulatory support device of either of Examples <NUM> or <NUM>, further comprising an expandable cage coupled to the distal end of the pump housing.

In an Example <NUM>, the circulatory support device of any of Examples <NUM>-<NUM>, further comprising an expandable cage coupled to the proximal end of the flexible cannula.

In an Example <NUM>, the circulatory support device of any of Examples <NUM>-<NUM>, further comprising: a first expandable cage coupled to the distal end of the pump housing and configured to be disposed within a left ventricle of a subject; and a second expandable cage coupled to the proximal end of the flexible cannula and configured to be disposed within the aorta.

In an Example <NUM>, the circulatory support device of any of Examples <NUM>-<NUM>, further comprising a helical tube coupled to a proximal end of the pump housing and extending through at least a portion of the flexible cannula, wherein one or more conductors are disposed within the helical tube.

In an Example <NUM>, the circulatory support device of any of Examples <NUM>-<NUM>, wherein at least a portion of the flexible cannula is configured to be disposed through an aortic valve opening and is configured to be compressible such that the aortic valve can close on the at least the portion of the flexible cannula.

In an Example <NUM>, a circulatory support device comprising: a flexible cannula having a fluid outlet at a proximal end; a pump assembly disposed at a distal end of the flexible cannula, the pump assembly comprising: a pump housing having a fluid inlet defined therein; a motor disposed within a distal end of the housing; and an impeller, driven to rotate by the motor, and configured to push blood toward the fluid outlet; and a first expandable cage coupled to a distal end of the pump housing; and a second expandable cage coupled to the proximal end of the flexible cannula.

In an Example <NUM>, the circulatory support device of either of Examples <NUM> or <NUM>, wherein the fluid inlet is disposed between the flexible cannula and the motor.

In an Example <NUM>, the circulatory support device of any of Examples <NUM>-<NUM>, wherein the first expandable cage is configured to be disposed in a left ventricle of a subject.

In an Example <NUM>, the circulatory support device of any of Examples <NUM>-<NUM>, wherein the second expandable cage is configured to be disposed in an aorta of a subject.

In an Example <NUM>, the circulatory support device of Example <NUM>, wherein the one or more conductors are configured to operably couple the motor to a control unit and extend from a distal end of the helical tube, along an outside of the pump housing, and into a distal end of the pump housing.

In an Example <NUM>, the circulatory support device of Example <NUM>, further comprising an expandable cage coupled to the distal end of the pump housing.

In an Example <NUM>, the circulatory support device of Example <NUM>, further comprising an expandable cage coupled to the proximal end of the flexible cannula.

In an Example <NUM>, the circulatory support device of Example <NUM>, further comprising: a first expandable cage coupled to the distal end of the pump housing and configured to be disposed within a left ventricle of a subject; and a second expandable cage coupled to the proximal end of the flexible cannula and configured to be disposed within the aorta.

In an Example <NUM>, the circulatory support device of Example <NUM>, further comprising a helical tube coupled to a proximal end of the pump housing and extending through at least a portion of the flexible cannula, wherein one or more conductors are disposed within the helical tube.

In an Example <NUM>, the circulatory support device of Example <NUM>, wherein at least a portion of the flexible cannula is configured to be disposed through an aortic valve opening and is configured to be compressible such that the aortic valve can close on the at least the portion of the flexible cannula.

In an Example <NUM>, the circulatory support device of Example <NUM>, wherein the fluid inlet is disposed between the flexible cannula and the motor.

In an Example <NUM>, the circulatory support device of Example <NUM>, wherein the first expandable cage is configured to be disposed in a left ventricle of a subject.

In an Example <NUM>, the circulatory support device of Example <NUM>, wherein the second expandable cage is configured to be disposed in an aorta of a subject.

In an Example <NUM>, a method of deploying a circulatory support device, the circulatory support device comprising a flexible cannula having a fluid outlet at a proximal end; a helical tube coupled to a proximal end of the pump housing and extending through at least a portion of the flexible cannula; a pump assembly disposed at a distal end of the flexible cannula, the pump assembly comprising a pump housing having a fluid inlet defined therein; a motor disposed within a distal end of the housing; and an impeller, driven to rotate by the motor, and configured to push blood toward the fluid outlet; and an expandable cage coupled to the distal end of the pump housing, the method comprising: navigating a delivery sheath to a deployment location, the delivery sheath comprising (<NUM>) an insertion manifold having a proximal opening and a distal opening, and (<NUM>) a delivery shaft extending from the distal opening; navigating the circulatory support device to the delivery sheath, wherein the circulatory support device is disposed within a protector tube; inserting the circulatory support device and protector tube into the proximal opening of the insertion manifold, wherein the insertion manifold includes a stop surface disposed therein and configured to engage a distal edge of the protector tube, thereby preventing the protector tube from being pushed into the delivery shaft; pushing the circulatory support device into the delivery shaft, wherein the protector tube is prevented from entering the delivery shaft by the stop surface; and pushing the circulatory support device out of a distal end of the delivery shaft, wherein, upon exiting the delivery shaft, an expandable cage expands and engages a cage location, thereby securing the circulatory support device in place.

In an Example <NUM>, the method of Example <NUM>, wherein navigating the delivery sheath to the deployment location comprises passing a guidewire through the delivery sheath and tracking at least one of the guidewire and the delivery sheath during navigation.

In an Example <NUM>, the method of Example <NUM>, wherein navigating the delivery sheath to the deployment location comprises positioning the distal end of the delivery shaft adjacent the cage location.

In an Example <NUM>, the method of Example <NUM>, wherein pushing the circulatory support device into the delivery shaft comprises pushing on the helical tube.

In an Example <NUM>, the method of Example <NUM>, wherein deploying the circulatory support device comprises positioning the circulatory support device in a deployment location without inserting a guidewire through the circulatory support device.

While multiple embodiments are disclosed, still other embodiments of the presently disclosed subject matter will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the disclosed subject matter.

While the disclosed subject matter is amenable to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail below. The intention, however, is not to limit the subject matter disclosed herein to the particular embodiments described. On the contrary, the disclosure is intended to cover all modifications, and alternatives falling within the scope of the subject matter disclosed herein, and as defined by the appended claims.

As used herein in association with values (e.g., terms of magnitude, measurement, and/or other degrees of qualitative and/or quantitative observations that are used herein with respect to characteristics (e.g., dimensions, measurements, attributes, components, etc.) and/or ranges thereof, of tangible things (e.g., products, inventory, etc.) and/or intangible things (e.g., data, electronic representations of currency, accounts, information, portions of things (e.g., percentages, fractions), calculations, data models, dynamic system models, algorithms, parameters, etc.), "about" and "approximately" may be used, interchangeably, to refer to a value, configuration, orientation, and/or other characteristic that is equal to (or the same as) the stated value, configuration, orientation, and/or other characteristic or equal to (or the same as) a value, configuration, orientation, and/or other characteristic that is reasonably close to the stated value, configuration, orientation, and/or other characteristic, but that may differ by a reasonably small amount such as will be understood, and readily ascertained, by individuals having ordinary skill in the relevant arts to be attributable to measurement error; differences in measurement and/or manufacturing equipment calibration; human error in reading and/or setting measurements; adjustments made to optimize performance and/or structural parameters in view of other measurements (e.g., measurements associated with other things); particular implementation scenarios; imprecise adjustment and/or manipulation of things, settings, and/or measurements by a person, a computing device, and/or a machine; system tolerances; control loops; machine-learning; foreseeable variations (e.g., statistically insignificant variations, chaotic variations, system and/or model instabilities, etc.); preferences; and/or the like.

Although the term "block" may be used herein to connote different elements illustratively employed, the term should not be interpreted as implying any requirement of, or particular order among or between, various blocks disclosed herein. Similarly, although illustrative methods may be represented by one or more drawings (e.g., flow diagrams, communication flows, etc.), the drawings should not be interpreted as implying any requirement of, or particular order among or between, various steps disclosed herein. However, certain embodiments may require certain steps and/or certain orders between certain steps, as may be explicitly described herein and/or as may be understood from the nature of the steps themselves (e.g., the performance of some steps may depend on the outcome of a previous step). Additionally, a "set," "subset," or "group" of items (e.g., inputs, algorithms, data values, etc.) may include one or more items, and, similarly, a subset or subgroup of items may include one or more items. A "plurality" means more than one.

Embodiments of the subject matter disclosed herein include bearing designs that may facilitate reducing heat formation by using lubrication, and reducing mechanical blood damage by preventing ingress of blood onto bearing surfaces. Bearing designs that include concave depressions and closed cavities facilitate preventing blood ingress onto bearing surfaces. Lubrication may be used to provide a fluid film at bearing surfaces to minimize wear. According to embodiments, any number of different types of lubricants may be used such as, for example, hydrophobic, water-insoluble lubricants (e.g., perfluoropolyether or poly-alpha-olefins classes of synthetic lubricants) may be used.

<FIG> depicts a side view of an illustrative percutaneous mechanical circulatory support device <NUM>, in accordance with embodiments of the subject matter disclosed herein. According to embodiments, the circulatory support device <NUM> may be a ventricular assist device configured to pump blood from a left ventricle of a subject into the subject's aorta. In embodiments, the circulatory support device <NUM> may be used to facilitate pumping blood from some other aspect of the subject's vasculature into an adjacent portion of the vasculature.

As shown in <FIG>, the circulatory support device <NUM> includes a flexible cannula <NUM> having a fluid outlet <NUM> at a proximal end <NUM> and coupled, at a distal end <NUM>, to a pump assembly <NUM>. According to embodiments, the flexible cannula <NUM>, or at least a portion thereof, may be configured to be disposed through a heart valve opening such as, for example, an aortic valve opening. In embodiments, the flexible cannula <NUM> may be configured to be compressible such that the heart valve can close on the cannula (or the portion thereof) without causing leaking through the valve. In this manner, for example, embodiments of the subject matter may be configured to prevent (or at least mitigate) pressure differences between the left ventricle and the aorta in the case of a motor failure of the device <NUM>.

As is further shown in <FIG>, the pump assembly <NUM> includes a pump housing <NUM> having a fluid inlet <NUM> defined therein. A motor (not shown in <FIG>) may be disposed within a distal portion <NUM> of the housing <NUM>. The motor may be configured to drive an impeller (not shown in <FIG>), disposed proximal to the motor, which may be configured to push blood toward the fluid outlet <NUM>. In embodiments, the circulatory support device <NUM> includes a mesh skirt <NUM> at least partially surrounding the pump housing <NUM>, adjacent the fluid inlet <NUM>. The mesh skirt <NUM> may be configured to facilitate blood flow into the fluid inlet <NUM> and/or to prevent larger particles from entering the fluid inlet <NUM>. As shown, the mesh skirt <NUM> may be configured in a conical shape, with an opening <NUM> facing distally.

A first expandable cage <NUM> may be coupled to the distal end <NUM> of the pump housing <NUM>. In embodiments, the first expandable cage <NUM> may be configured to be disposed in a first portion of a subject's vasculature such as, for example, within a left ventricle of a subject. As shown in <FIG>, a second expandable cage <NUM> may be coupled to (or adjacent) the proximal end <NUM> of the flexible cannula <NUM>. In embodiments, the second expandable cage <NUM> may be configured to be disposed within a second portion of the subject's vasculature such as, for example, the subject's aorta. In this manner, for example, the circulatory support device <NUM> may be used as a ventricular assist device, having an impeller disposed in the ventricle, pumping blood to a blood outlet disposed in the aorta. The first and/or second expandable cage <NUM>, <NUM> may facilitate keeping the device <NUM> in place, even during patient movement. According to embodiments, use of the design described herein for pumping the blood from the ventricle into the aorta, with an impeller disposed in the ventricle may facilitate allowing the aortic valve to close on the flexible cannula, thereby preventing back flow while simulating pumping of the heart.

As is further shown in <FIG>, the circulatory support device <NUM> includes a helical tube <NUM> coupled to a proximal end <NUM> of the pump housing <NUM> and extending through at least a portion of the flexible cannula <NUM>, wherein one or more conductors <NUM> are disposed within the helical tube <NUM>. That is, for example, the helical tube <NUM> provides a conduit therein for enclosing control and/or power conductors extending from a control unit to the motor, where the conductors facilitate controlling the motor. The helical tube <NUM> may be enclosed, in embodiments, by a catheter sleeve <NUM>. As is further shown, in embodiments, the one or more conductors <NUM> may be configured to extend from a distal end of the helical tube <NUM>, along an outside of the pump housing <NUM>, and into a distal end <NUM> of the pump housing <NUM>. A housing sleeve <NUM> may be disposed over at least a portion of the one or more conductors <NUM> for protection.

The illustrative circulatory support device <NUM> shown in <FIG> is not intended to suggest any limitation as to the scope of use or functionality of embodiments of the present disclosure. The illustrative circulatory support device <NUM> also should not be interpreted as having any dependency or requirement related to any single component or combination of components illustrated therein. Additionally, various components depicted in <FIG> may be, in embodiments, integrated with various ones of the other components depicted therein (and/or components not illustrated), all of which are considered to be within the ambit of the present disclosure.

<FIG> depicts a cross-sectional side view of an illustrative circulatory support device <NUM>, in accordance with embodiments of the subject matter disclosed herein. According to embodiments, the circulatory support device <NUM> may be, or be similar to, the circulatory support device <NUM> depicted in <FIG>. As shown in <FIG>, the circulatory support device <NUM> includes a flexible cannula <NUM> having a fluid outlet (not shown in <FIG>) at a proximal end thereof and coupled, at a distal end <NUM>, to a pump assembly <NUM>. As explained above, with regard to <FIG>, the flexible cannula <NUM>, or at least a portion thereof, may be configured to be disposed through a heart valve opening such as, for example, an aortic valve opening. In embodiments, the flexible cannula <NUM> may be configured to be compressible such that the heart valve can close on the cannula (or the portion thereof) without causing leaking through the valve. In this manner, for example, embodiments of the subject matter may be configured to prevent (or at least mitigate) pressure differences between the left ventricle and the aorta in the case of a motor failure of the device <NUM>.

As is further shown in <FIG>, the pump assembly <NUM> includes a pump housing <NUM> having a fluid inlet <NUM> defined therein. According to embodiments, the fluid inlet <NUM> may be disposed adjacent an impeller <NUM> that is also disposed within the pump housing <NUM>. A motor <NUM> may be disposed within a distal portion <NUM> of the housing <NUM>. The motor <NUM> may be configured to drive the impeller <NUM>, via a drive shaft <NUM>, and the impeller <NUM> and drive shaft <NUM> may be disposed proximal to the motor <NUM>, which may be configured to push fluid (e.g., blood) toward the fluid outlet. In embodiments, the distal portion <NUM> of the housing <NUM> may be laser welded to the motor <NUM>. In embodiments, the circulatory support device <NUM> includes a mesh skirt (such as, for example, the mesh skirt <NUM> depicted in <FIG>) at least partially surrounding the pump housing <NUM>, adjacent the fluid inlet <NUM>. The mesh skirt <NUM> may be configured to facilitate blood flow into the fluid inlet <NUM> and/or to prevent larger particles from entering the fluid inlet <NUM>.

An expandable cage <NUM> may be coupled to the distal end <NUM> of the pump housing <NUM>. In embodiments, the expandable cage <NUM> may be configured to be disposed in a first portion of a subject's vasculature such as, for example, within a left ventricle of a subject. Although not shown in <FIG>, as shown in <FIG>, a second expandable cage may be coupled to (or adjacent) the proximal end of the flexible cannula <NUM>. In embodiments, the second expandable cage may be configured to be disposed within a second portion of the subject's vasculature such as, for example, the subject's aorta. As is further shown in <FIG>, the circulatory support device <NUM> includes a helical tube <NUM> coupled to a proximal end <NUM> of the pump housing <NUM> and extending through at least a portion of the flexible cannula <NUM>, where one or more conductors <NUM> are disposed within the helical tube <NUM>. According to embodiments, the proximal end <NUM> of the pump housing <NUM> may be crimped onto the distal end <NUM> of the helical tube <NUM>, the two may be laser welded together. As is further shown, in embodiments, the one or more conductors <NUM> may be configured to extend from a distal end <NUM> of the helical tube <NUM>, along an outside of the pump housing <NUM>, and into the distal end <NUM> of the pump housing <NUM>. A housing sleeve (not shown) may be disposed over at least a portion of the one or more conductors <NUM> for protection.

Embodiments of the circulatory support device disclosed herein may be configured to be deployed without having to pass a guide wire through the housing of the circulatory support device, in contrast to typical circulatory support device delivery processes. Typically, a guide wire is disposed through the housing of a circulatory support device and the guide wire itself is tracked during delivery. For example, in many typical systems, the guide wire is loaded into the circulatory support device outlet, passed around the impeller and exits the fluid inlet of the device. In many instances, having the guide wire bent around and disposed through the circulatory support device may cause drag during delivery, scraping of the Teflon on the guide wire, and/or the like.

Embodiments of the subject matter disclosed herein may mitigate these issues by allowing a clinician to position and track the circulatory support device without routing a guidewire through the device (e.g., without routing the guidewire through the inlet and outlet of the device). That is, in embodiments, the guidewire is tracked to the left ventricle and, once positioned, the delivery sheath is tracked over the guidewire. Once the delivery sheath is in position, the guidewire is removed. Then, the circulatory device is pushed into the delivery sheath and tracked to position. The deployment process of circulatory support devices in accordance with embodiments of the subject matter disclosed herein may be simpler than typical deployment processes, may reduce drag during positioning, and may reduce the risk of damaging the device and/or the guidewire during deployment.

<FIG> depict an illustrative circulatory support device delivery system <NUM>, in different stages of a process of deploying a circulatory support device <NUM>, in accordance with embodiments of the subject matter disclosed herein. According to embodiments, the illustrative circulatory support device <NUM> may be, or be similar to, the circulatory support device <NUM> depicted in <FIG> and/or the circulatory support device <NUM> depicted in <FIG>.

As shown in <FIG>, the circulatory support device system <NUM> includes a circulatory support device <NUM> that is, initially, disposed in a circulatory support device protector tube <NUM>, and a delivery sheath <NUM>. The delivery sheath <NUM> may include an insertion manifold <NUM> having a proximal opening <NUM> and a delivery shaft <NUM> extending from a distal opening <NUM> of the insertion manifold <NUM>. The delivery sheath <NUM> may be configured to be positioned, using a guidewire inserted therethrough, such that a distal end <NUM> of the delivery shaft <NUM> is disposed adjacent a deployment location. In embodiments, the delivery sheath may be trackable by a tracking system and may include any number of features configured to facilitate its identification and tracking within the body of a subject. In embodiments, the delivery sheath is navigated (e.g., by tracking the delivery sheath <NUM> and/or guidewire) to a deployment location. At the deployment location, the distal end <NUM> of the delivery sheath <NUM> may be positioned at a first cage location - that is, a location at which a first expandable cage <NUM> is to be disposed (e.g., in the left ventricle). The circulatory support device <NUM> and protector tube <NUM> may be configured to be inserted into the subject's vasculature and navigated to the delivery sheath <NUM>.

The circulatory support device <NUM> and protector tube <NUM> may be configured to be inserted into the proximal opening <NUM> of the insertion manifold <NUM>. The insertion manifold <NUM> may include a stop surface <NUM> configured to engage a distal edge <NUM> of the protector tube <NUM>, thereby preventing the protector tube <NUM> from passing through the insertion manifold <NUM> into the delivery shaft <NUM>. According to embodiments, the delivery sheath <NUM> may include a tapered proximal end <NUM> configured to facilitate reception of the device <NUM>. In operation, as shown in <FIG>, the circulatory support device <NUM> and protector tube <NUM> may be inserted into the insertion manifold <NUM> by pushing on the helical tube of the device <NUM>. After the distal edge <NUM> of the protector tube <NUM> engages the stop surface <NUM>, the clinician may push on the helical tube to push the device <NUM> into the delivery shaft <NUM>, leaving the protector tube <NUM> behind.

The device <NUM> can then be pushed through the delivery shaft <NUM> until it exits the distal end <NUM> of the delivery sheath <NUM>, as shown in <FIG>. Upon exiting the distal end <NUM> of the delivery sheath <NUM>, the first expandable cage <NUM> may expand, as shown in <FIG>. In embodiments, as is further shown in <FIG>, the device <NUM> may include a mesh skirt <NUM> at least partially surrounding an inlet <NUM> of a pump housing <NUM>, and configured to be compressed until the mesh skirt <NUM> is pushed out of the delivery shaft <NUM>, at which time the mesh skirt <NUM> may be configured to expand.

The illustrative circulatory support device delivery system <NUM> shown in <FIG> is not intended to suggest any limitation as to the scope of use or functionality of embodiments of the present disclosure. The illustrative circulatory support device delivery system <NUM> also should not be interpreted as having any dependency or requirement related to any single component or combination of components illustrated therein. Additionally, various components depicted in <FIG> may be, in embodiments, integrated with various ones of the other components depicted therein (and/or components not illustrated), all of which are considered to be within the ambit of the present disclosure.

As described above, with reference to <FIG>, embodiments of the subject matter disclosed herein may facilitate an improved device deployment process. <FIG> is a flow diagram depicting an illustrative method <NUM> of deploying a circulatory support device, in accordance with embodiments of the subject matter disclosed herein. According to embodiments, the circulatory support device may be, or be similar to, the circulatory support device <NUM> depicted in <FIG>, the circulatory support device <NUM> depicted in <FIG>, and/or the circulatory support device <NUM> depicted in <FIG>.

That is, for example, embodiments of the circulatory support device may include a flexible cannula having a fluid outlet at a proximal end; and a pump assembly disposed at a distal end of the flexible cannula. The pump assembly may include a pump housing having a fluid inlet defined therein; a motor disposed within a distal end of the housing; and an impeller, driven to rotate by the motor, and configured to push blood toward the fluid outlet. The circulatory support device may further include a helical tube coupled to a proximal end of the pump housing and extending through at least a portion of the flexible cannula, where one or more conductors are disposed within the helical tube. Embodiments of the circulatory support device further include a mesh skirt at least partially surrounding the pump housing, adjacent the fluid inlet; an expandable cage coupled to the distal end of the pump housing; and/or the like.

According to embodiments, the method <NUM> may facilitate deploying a circulatory support device by positioning the circulatory support device in a deployment location without inserting a guidewire through the circulatory support device. As shown in <FIG>, embodiments of the method <NUM> include navigating a delivery sheath to a deployment location following a guidewire (block <NUM>). In embodiments, the delivery sheath includes (<NUM>) an insertion manifold having a proximal opening and a distal opening, and (<NUM>) a delivery shaft extending from the distal opening. According to embodiments, navigating the delivery sheath to the deployment location includes passing a guidewire through the delivery sheath and tracking at least one of the guidewire and the delivery sheath during navigation. In embodiments, navigating the delivery sheath to the deployment location includes positioning the distal end of the delivery shaft adjacent the cage location.

As is shown, embodiments of the method <NUM> further include navigating the circulatory support device to the delivery sheath (block <NUM>). In embodiments, during this step, the circulatory support device is disposed within a protector tube. Embodiments of the method <NUM> further include inserting the circulatory support device and protector tube into the proximal opening of the insertion manifold (block <NUM>). In embodiments, the insertion manifold includes a stop surface disposed therein and configured to engage a distal edge of the protector tube, thereby preventing the protector tube from being pushed into the delivery shaft.

Embodiments of the method <NUM> further include pushing the circulatory support device into the delivery shaft (block <NUM>). As indicated above, the protector tube may be prevented from entering the delivery shaft by the stop surface. In embodiments, pushing the circulatory support device into the delivery shaft may include pushing on the helical tube. The method <NUM> may further include pushing the circulatory support device out of a distal end of the delivery shaft (block <NUM>). According to embodiments, upon exiting the delivery shaft, one or more expandable cage may be configured to expand and engage a cage location, thereby securing the circulatory support device in place.

Claim 1:
A circulatory support device (<NUM>; <NUM>; <NUM>) comprising:
a flexible cannula (<NUM>; <NUM>) having a fluid outlet (<NUM>) at a proximal end (<NUM>); and
a pump assembly (<NUM>; <NUM>) disposed at a distal end (<NUM>) of the flexible cannula (<NUM>; <NUM>), the pump assembly (<NUM>) comprising:
a pump housing (<NUM>; <NUM>; <NUM>) having a fluid inlet (<NUM>) defined therein;
a motor (<NUM>) disposed within a distal portion (<NUM>; <NUM>) of the housing (<NUM>; <NUM>; <NUM>); and
an impeller (<NUM>), driven to rotate by the motor (<NUM>), and configured to push blood toward the fluid outlet (<NUM>).