Linear cardiac assist pump

Abstract

Described herein is a linearly reciprocating pump to assist in circulating blood within a patient's body. Red blood cell damage can be avoided or minimized by such linear pumping motion. Linearly reciprocating motion can also generate a pulsatile pumping cycle that mimics the natural pumping cycle of the heart. The pump can be configured to reside in various body locations. For example, the pump can be mounted in the right ventricle, left ventricle, ascending aorta, descending aorta, thoracic aorta, or abdominal aorta. In some cases, the pump can be deployed in the venous circulation. In other cases, the pump can reside outside the patient.

Description

[[Technical Field]]

[0001] (Cross-Reference to Related Applications) This application claims the priority benefit of U.S. Provisional Application No. 63 / 152,126 filed on February 22, 2021, U.S. Provisional Application No. 63 / 176,817 filed on April 19, 2021, and U.S. Provisional Application No. 63 / 299,385 filed on January 13, 2022, each of which is incorporated herein by reference in its entirety.

[0002] The present application generally relates to a blood pumping device. The device may be a cardiac assist device or a cardiac assist pump of the type used to supplement or sustain blood flow on a short-term basis. Such devices are generally utilized in the treatment of patients suffering from impaired cardiac function or heart failure to stabilize the patient and gain time for implementing longer-term treatment. [[Background Art]]

[0003] Treatment and survival of patients suffering from severe cardiac trauma or heart failure is typically an urgent process. In most cases, treatment of patients suffering from traumatic heart failure requires immediate life-sustaining measures. Essentially, medical personnel must first assist or stabilize the failing heart to maintain systemic circulation until further diagnostic measures can be taken or treatment options are determined.

[0004] In some cases, it may be possible for a physician to stabilize such a patient through the careful administration of various medications, but the stabilization process often requires the application of an auxiliary blood pumping device. Generally, such auxiliary blood pumping devices, known in the art as “cardiac assist devices” or “cardiac assist pumps,” have had limited success despite the availability of various designs. These cardiac assist pumps generally utilize a small pumping device combined with a catheter support that is operationally coupled to an external pump drive and pump control system. The purpose is to insert the pump into the patient’s bloodstream at a critical point to complement or replace the pumping action of the patient’s heart. Various pump design approaches have been employed, but most cardiac assist pumps developed involve rotary pumps such as turbine impellers or equivalents.

[0005] Unfortunately, rotary pumps have proven problematic for several reasons. Perhaps the most significant limitation of such pumps stems from their undesirable high-speed operation. By design, such rotary pumps are required to operate at higher rotational speeds to provide sufficient pressure and blood flow. Another drawback is that the use of high-speed pumps such as turbines, even on a short-term basis, can cause damage to the patient's blood cells, which in turn endangers the patient's life. As a result, the operating time of cardiac assist pumps employing rotary turbine-type pumping devices is typically limited. In addition to the blood cell damage caused by high-speed rotary pump devices, problems also arise due to the constant, unchanging fluid characteristics of such rotary pumps. It has been found that the constant retraction of rotary pumps can interfere with the action of the heart valves and the pumping action of the heart.

[0006] Therefore, it would be beneficial to have an improved cardiac pump device that avoids excessive damage to blood cells and is compatible with the pulsatile blood flow and pumping characteristics of the human heart. [Overview of the project] [Means for solving the problem]

[0007] Described herein is a linearly reciprocating pump for assisting the circulation of blood within a patient's body. Red blood cell damage can be avoided or minimized by such linear pumping motion. Linear reciprocating motion can also generate pulsatile pumping cycles that result in pulsatile blood flow that is in harmony with the patient's heart's action. The pump may be configured to reside in various locations within the body. For example, the pump may be installed in the right ventricle, left ventricle, ascending aorta, descending aorta, thoracic aorta, or abdominal aorta. In some cases, the pump may be installed in the inferior vena cava. In other cases, the pump may be located outside the patient.

[0008] Generally, pumps for assisting blood circulation as described herein may include an expandable housing and a valve member disposed within the expandable housing, which moves linearly in a reciprocating motion therein. The valve member may be, for example, a flexible diaphragm or a valve cone. In addition, the valve member may include an inlet side facing the inlet of the expandable housing and an outlet side facing the outlet side of the expandable housing. The expandable housing may include an inner surface and an expandable configuration, which may define a chamber for collecting blood. The flexible diaphragm may have an extended configuration and a collapsible configuration, and may include a diaphragm body and a periphery. The valve cone may have an expanded configuration and a collapsible configuration, and may include a layer having multiple flaps that allow blood flow into the housing through the valve cone during the filling stroke, but prevent blood flow through the valve cone during the pump stroke. In some cases, the pump includes a non-expandable housing.

[0009] The valve member may be coupled to a support element having an extended configuration and a compressed configuration. The valve member may be structured such that the expansion of the support element deforms the valve member into its extended or extended configuration. In some modifications, the support element may be an expandable frame having a conical shape. The expandable frame may be coupled to an actuator which supports a valve cone or flexible diaphragm as it reciprocates linearly within the housing. In other modifications, the support element may be a tine support comprising a base and a plurality of tines coupled to an actuator which support a flexible diaphragm in an extended configuration during the pump stroke. The plurality of tines may be flexible and / or expandable and have an extended configuration and a compressed configuration.

[0010] The pump may include an actuator coupled to a valve member (e.g., a flexible diaphragm, a valve cone, or an umbrella structure), which may be configured to linearly reciprocate the valve member within an expandable housing to generate the filling and pumping strokes of the pumping cycle. The periphery of the valve member may be configured to maintain contact with the inner surface of the expandable housing during the pumping stroke. In some modifications, the contact may be maintained for the entire duration of the pumping stroke. In other modifications, the contact may be maintained for a portion of the pumping stroke, insofar as sufficient pressure is generated to move the desired amount of blood out of the housing during the pumping stroke. In further modifications, for example, when a high pumping speed is required, the valve member may be configured to have a small gap or clearance between its periphery and the inner surface of the housing. The clearance may help to avoid the generation of excessive friction within the pump. The clearance may also be sized so that the appropriate pressure is generated throughout the pumping stroke, while also avoiding crushing or damaging red blood cells during the pumping stroke. Here, the diameter of the valve member in their extended or expanded configuration may be at least about 95 percent of the diameter of the housing in their expanded configuration. For example, the valve member in their extended or expanded configuration may be at least about 95 percent, at least about 96 percent, at least about 97 percent, at least about 98 percent, or at least about 99 percent of the diameter of the housing in their expanded configuration. The pump may be driven by an external linear motor drive and linear motor controller mounted on the end of the catheter outside the patient. The linear motor drive may be operationally coupled to a linearly acting cardiac assist pump by a flexible cable or other flexible actuator. A movable sleeve or sheath may hold the expandable housing and valve member (e.g., a flexible diaphragm, valve cone, or umbrella structure) in the collapse configuration, allowing their insertion and advancement to a target location in the circulatory system.

[0011] More specifically, the expandable housing of the pump may include a support or scaffold, including a proximal end and a distal end. The scaffold may be made of a material including stainless steel, titanium, or an alloy thereof. With respect to the proximal and distal ends, they may or may not be tapered. Furthermore, the distal end of the scaffold may include an inlet for blood flow during the pump stroke. The proximal end of the scaffold may include an outlet for blood flow during the pump stroke.

[0012] In the expandable configuration, the chamber of the expandable housing may have a diameter ranging from approximately 12 mm to approximately 30 mm (including all values ​​and partial ranges within that range). The expandable housing may further include a covering. For example, the expandable housing may include a polymer layer, which may include, but is not limited to, an elastomer polymer such as silicone, polyester, polyurethane, fluoropolymer, or a combination thereof. Alternatively, the expandable housing may include a fabric layer bonded to the scaffold. For example, the fabric layer may include a woven material such as a material woven from buckram or polyester fibers. Films or sheets of nonwoven materials such as Mylar® plastic film may also be bonded to the expandable housing.

[0013] The pump may further include a cannula extending from the expandable housing. The cannula may extend from either the proximal or distal end of the expandable housing. The length of the cannula may vary depending on factors such as the intended location of pump placement or the patient's age or physique. For example, the cannula length may range from approximately 2.5 cm to 5.0 cm, 25 cm to 30 cm, or 35 cm to 40 cm. Some variations of the cannula may have lengths ranging from approximately 0.5 cm to 10 cm (including all values ​​and partial ranges within that range). In these variations, the length of the cannula may be approximately 0.5 cm, 1.0 cm, 1.5 cm, 2.0 cm, 2.5 cm, 3.0 cm, 3.5 cm, 4.0 cm, 4.5 cm, 5.0 cm, 5.5 cm, 6.0 cm, 6.5 cm, 7.0 cm, 7.5 cm, 8.0 cm, 8.5 cm, 9.0 cm, 9.5 cm, or 10 cm.

[0014] When the pump includes a valve cone within an expandable housing, the valve cone may include a single or multiple material layers bonded to the expandable frame. The multiple material layers may include a mesh layer, a flow control layer, or a combination thereof. In some cases, the mesh layer may be positioned between the flow control layer and the expandable frame. Woven fabric or elastomer polymer may be used to form the mesh layer. Exemplary elastomer polymers include, but are not limited to, silicone, polyester, polyurethane, fluoropolymer, or combinations thereof. The material layers may be bonded to the expandable frame in any preferred manner, for example, by stitching, suture, or sewn, by the use of adhesive, by heat sealing, or by welding. The expandable frame may include stainless steel, nickel, titanium, or alloys thereof. Generally, the valve cone has a conical shape, but any shape that can be crushed to allow advancement through a cannula may be used. When the valve cone is formed into a cone shape, the multiple material layers (e.g., mesh and flow control layers) and the expandable frame in their expandable configuration are formed into a cone shape. As mentioned above, the valve cone may have an inlet side facing the inlet of the expandable housing and an outlet side facing the outlet of the expandable housing.

[0015] The flow control layer of the valve cone (also referred to herein as the flow control cone) may also be formed from various polymers, such as the elastomer polymers described above, or from Mylar® plastic film. The flow control layer may include a plurality of flaps having both open and closed configurations. Generally, the flaps are in an open configuration during the filling stroke and in a closed configuration during the pump stroke. The flow control layer may be cut to produce a plurality of flaps, which can be of any preferred size and shape, allowing blood to flow into the housing during the filling stroke. For example, the flaps may have a semicircular, arcuate, circular, triangular, rhombic, square, or rectangular shape. Any preferred number of flaps in the flow control layer may also be employed. For example, a flow control layer containing 15 flaps may be useful. The valve cone may be configured such that a larger number of flaps are included when they are smaller in size, and a smaller number of flaps are included when they are larger in size. For example, three flaps may be employed when the flaps are larger in size. When the flaps are semicircular in shape, they may have radii ranging from approximately 0.50 mm to approximately 3.0 mm (including all values ​​and sub-ranges within that range).

[0016] Some valve members may also comprise a membrane coupled to a plurality of radially expandable and collapsible struts. The membrane may completely or partially cover the struts and may be formed from any suitable elastomer. Non-limiting examples of elastomers include silicone, polyester, polyurethane, fluoropolymer, or combinations thereof. Exemplary fluoropolymers may be polytetrafluoroethylene (PTFE) or expanded polytetrafluoroethylene (ePTFE). Here, the valve member may also have an open configuration and a collapsible configuration. For example, the valve member may have an umbrella structure. The struts may support the membrane and may include any suitable number of struts. The number of struts may range from 3 to 10 (including all values ​​and partial ranges thereof). Generally, a valve member including struts may have a collapsible configuration during the filling stroke and an open configuration during the pump stroke. In some cases, the valve member consists of an umbrella structure without an associated expandable frame.

[0017] The length of the struts included within the umbrella structure may vary depending on factors such as the expanded diameter of the housing, the size of the membrane, and the manner in which the struts are attached to the linear actuator, and may range from approximately 1.0 cm to approximately 3.0 cm (including all values ​​and partial ranges within this range). Struts with longer lengths may extend beyond the periphery of the membrane. In some cases, the struts include one or more bends along their length. One or more bends may be provided at any location along the strut. For example, one or more bends may be provided at the distal end (free end) of the strut and / or at the midpoint of the strut. The bends in the struts may form a bending angle of approximately 5 to approximately 15 degrees (including all values ​​and partial ranges within this range) with respect to the longitudinal axis of the umbrella structure.

[0018] A support column may have one or more divisions, and one or more divisions may have any preferred shape or geometric shape. The cross-sectional shape of the support column may be circular, oval, triangular, square, or rectangular. The support column may have different cross-sectional shapes along its length. For example, a support column may have one or more divisions with a circular cross-sectional shape and one or more divisions with a rectangular cross-sectional shape. In some cases, a support column may include three divisions, namely two end divisions and an intermediate division between them. The end divisions may have a circular cross-sectional shape, and the intermediate division may have a rectangular cross-sectional shape. The rectangular cross-sectional shape may provide an intermediate division with a flattened outline. In some variations, the different divisions of the support column may have different widths. For example, when a support column includes three divisions (two end divisions and one intermediate division), the intermediate division may be wider than the two end divisions. The distal end of the strut may be rounded to help prevent the strut from damaging the inner surface of the housing during the pump stroke. Radiopaque markers may also be provided at any suitable location along the length of one or more struts, for example, at the distal end of one or more struts (e.g., one-third of the strut, half of the strut, or the entire strut).

[0019] The umbrella structure may further include an anchor having a proximal end and a distal end. The proximal end may be configured to be attached to a linear actuator of a pump. The distal end may be configured to be attached to a plurality of supports. When the umbrella structure is in its extended configuration, the plurality of supports may gradually diverge radially outward from the distal end of the anchor, generating a certain support angle with respect to the longitudinal axis of the umbrella structure. The support angle may range from about 30 degrees to about 60 degrees (including all values ​​and subranges within this range).

[0020] The mesh layer may be used to support the flow control layer so that the flap is not pushed through the opening in the expandable frame when pressure is applied to the flap during the pump stroke. Thus, the mesh layer may help maintain the flap in a closed configuration during the pump stroke as blood moves out of the housing through the housing outlet. However, during the filling stroke, the mesh layer allows blood to flow from the housing inlet through the holes in the mesh and then through the flap, transitioning them to their open configuration so that blood can move towards the outlet side of the valve cone. In some cases, for example, when the opening of the expandable frame is smaller than the flap, the valve cone may not contain a mesh layer.

[0021] In addition to the periphery, the flow control layer may include a body. The body and periphery may be made from the same material or from different materials. In addition, the body and periphery may be separate components or formed integrally with each other. When provided as separate components, the body may be made from an elastomer polymer or Mylar® plastic film, and the periphery may be an O-ring. The peripheral edge of the flow control layer may be wound around the O-ring to form the periphery. The thickness of the periphery may exceed the thickness of the body. The body may have a thickness ranging from about 0.03 mm to about 0.05 mm. The periphery may have a thickness ranging from about 0.20 mm to about 1.5 mm. In some cases, the thicknesses of the periphery and the body may be equal.

[0022] Some variations of the valve member include a flexible diaphragm contained within an expandable housing. The flexible diaphragm may contain an elastomer polymer. Non-limiting embodiments of the elastomer polymer include silicone, polyester, polyurethane elastomer, fluoropolymer, or combinations thereof. Exemplary fluoropolymers may include polytetrafluoroethylene (PTFE) or expanded polytetrafluoroethylene (ePTFE). The body and periphery of the flexible diaphragm may contain the same material or different materials. In some cases, the diaphragm body and periphery are integrally formed. The thickness of the diaphragm body may range from about 0.03 mm to about 0.3 mm. With respect to the diaphragm periphery, its thickness may range from about 0.70 mm to about 1.5 mm. The thickness of the periphery may exceed the thickness of the diaphragm body, which may allow the flexible diaphragm to be in its compressed configuration during the filling stroke and in its extended configuration during the pump stroke of the pumping cycle. However, in some modifications, the periphery and the body may have the same thickness. The periphery of the flexible diaphragm may have a width ranging from about 1 mm to about 2 mm.

[0023] Furthermore, the flexible diaphragm may have any preferred shape or geometry capable of creating a seal between the periphery of the diaphragm and the inner surface of the expandable housing during the pump stroke. For example, the flexible diaphragm may have a conical shape when in an extended configuration. Multiple ribs extending from the central portion to the periphery of the diaphragm body may be employed to maintain the conical shape during the pump stroke. The multiple ribs may have a rib angle between a rib and an axis perpendicular to the actuator, ranging from about 30 to about 60 degrees. The multiple ribs may be equally spaced from each other. In some modifications, the multiple ribs may be unequally spaced from each other. Some modifications of the pump may also include a tine support comprising a base and multiple tines coupled to an actuator that support the flexible diaphragm in an extended configuration during the pump stroke. The multiple tines may be flexible and / or expandable and may have an extended configuration and a compressed configuration. In other modifications, the flexible diaphragm may be coupled to an expandable frame that is formed into a cone shape. The coupling to the expandable frame may be carried out in any preferred manner, for example, by sewing, stitching, or sewn, by using adhesive, by heat sealing, or by welding.

[0024] Some of the pumps described herein may include a valve member having an element that limits its expansion. For example, the valve member may include an expandable frame bonded to a polymer layer, where a plurality of control lines or tethers attach the valve member to the pump actuator. The plurality of tethers may have a relaxed state and a taut state, and may have a length that limits the expansion of the valve member so that it contacts the inner surface of the pump housing during the pump stroke of the pumping cycle without generating excessive friction, and creates a seal with it. The length of the tethers may also be adjusted so that a small gap is created between the valve member and the inner surface of the pump housing during the pump stroke. During the filling stroke, the valve member may collapse into a collapsed configuration, which in turn may move the plurality of tethers into a relaxed state. During the pump stroke, the valve member may expand into a taut configuration, which may transition the plurality of tethers from a relaxed state to a taut state.

[0025] In some cases, the expandable housing of the pump may include multiple openings or perforations. The number of openings used may range from approximately 2 to approximately 25. The openings may be equally spaced or unevenly spaced over a portion of the expandable housing. In addition, the multiple openings may have diameters ranging from approximately 0.10 mm to approximately 6.50 mm. When the expandable housing includes openings, a skirt may also be coupled to the expandable housing, surrounding the multiple openings.

[0026] Any component of a pump as described herein may be coated. For example, one or more of the cannula, expandable housing, expandable frame, valve cone, flexible diaphragm, and umbrella strut may be coated. Pump components may be coated completely or partially. The coating may provide increased lubricity and / or wetting properties to the coated part of the pump, or may provide the pump with antifouling, anti-proliferative, or antimicrobial properties.

[0027] The coating may generally comprise a polymeric material. Exemplary polymeric materials may include, but are not limited to, hydrophilic polymers, hydrophobic polymers, or mixtures of these two types of polymers. The coating may be a single layer on a pump component, or may comprise a plurality of layers. When a plurality of layers are employed, each layer may be made of the same polymer or different polymers. Coatings comprising polytetrafluoroethylene (PTFE) or expanded polytetrafluoroethylene (ePTFE) may be useful.

[0028] There are several variations in which the pump may be placed in a console external to the patient. A coaxial catheter coupled to the pump housing provides continuous and pulsatile blood flow between the patient and the external pump, and may have a diameter of about 10F to 18F. The coaxial catheter may comprise an inflow lumen and an outflow lumen. The inflow lumen may generally have a diameter greater than about 5F.

[0029] A method for pressure-feeding blood is further described herein. The method generally comprises advancing a pump to a target location within a patient's circulatory system, the pump including an expandable housing having an inner surface, an expanded configuration, and a collapsed configuration. The pump may further include a valve member that reciprocates linearly within the housing. An exemplary valve member may be a valve cone, a flexible diaphragm, or an umbrella structure comprising a plurality of material layers coupled to an expandable frame. The membranes of the valve cone, the flexible diaphragm, and the umbrella structure may comprise a body and a peripheral edge, the valve cone has an expanded configuration and a collapsed configuration, the flexible diaphragm has an extended configuration and a collapsed configuration, and the umbrella structure has expanded and collapsed configurations. Once at the target location, the expandable housing is expanded to the expanded configuration, and the valve cone, flexible diaphragm, or umbrella structure contained therein is linearly reciprocated to generate a filling stroke and a pumping stroke of a pumping cycle. During the pumping stroke, contact between the peripheral edge of the valve member and the inner surface of the expandable housing may be maintained such that a seal is created to prevent blood flow between the peripheral edge and the inner surface. Additionally, during the filling stroke, blood is drawn into the expandable housing. Depending on the variation of the pump used, blood may be drawn into the expandable housing from the left ventricle or the aorta. The pumping stroke generally pushes blood out of the expandable housing into a portion of the aorta, for example, the ascending aorta or the descending aorta. During the pumping cycle, flaps in the flow control layer of the valve cone close during the pumping stroke and open during the filling stroke. When a flexible diaphragm is employed, it may be collapsed to a collapsed configuration during the filling stroke and extended to an extended configuration during the pumping stroke. Similarly, when linearly reciprocated, the umbrella structure may collapse to the collapsed configuration during the filling stroke and expand to the expanded configuration during the pumping stroke.

[0030] The pump may be advanced and positioned in various parts of the patient's circulatory system. For example, the expandable housing of the pump may be advanced into the patient's left ventricle through arterial vessels, such as through the femoral artery, aorta, and aortic valve. If the pump further includes a cannula, the cannula may also be advanced into the patient's left ventricle through the aortic valve. Non-limiting embodiments of target locations for the expandable housing include the aortic arch, descending aorta, thoracic aorta, and abdominal aorta. In some cases, the expandable housing of the pump may be advanced in the descending aorta and specifically positioned to assist in renal perfusion of the patient. For example, the expandable housing may be positioned in the descending aorta near the renal artery to assist in renal perfusion.

[0031] In addition to arterial vessels, pumps may be advanced and positioned within the venous circulation. For example, the expandable housing of a pump may be advanced within the inferior vena cava to a location between the hepatic vein and the right atrium of the heart. When positioned in this location, the pump can draw blood toward the heart and increase circulation from the lower extremities and the liver. Pumps may be positioned at various locations between the hepatic vein and the right atrium. In some modifications, the expandable housing is positioned closer to the hepatic vein than to the right atrium. In one modification, for example, when the pump is positioned within the venous circulation, it may include a housing chamber (flow chamber) without an associated cannula.

[0032] As described above, the expandable housing may comprise a plurality of openings or perforations and a skirt coupled to the expandable housing. In this example, the blood exiting the openings may be directed retrogradely toward the patient's heart during the pump stroke by the skirt. The length of the skirt may be adjusted to achieve a predetermined amount of retrograde blood flow toward the patient's heart. The number of openings may also be adjusted to achieve a predetermined amount of retrograde blood flow toward the patient's heart. Alternatively, the diameter of the openings may be adjusted to achieve a predetermined amount of retrograde blood flow toward the patient's heart. Adjustment of any one or a combination of the above features may be used to ensure that approximately 60% of the blood from the pump stroke flows retrogradely toward the patient's heart, approximately 50% of the blood from the pump stroke flows retrogradely toward the patient's heart, or approximately 40% of the blood from the pump stroke flows retrogradely toward the patient's heart.

[0033] When the pump is located outside the patient, the method for pumping blood may include accessing the patient's circulatory system using a coaxial catheter and connecting the coaxial catheter to the pump housing. The housing may have an internal surface. A flexible diaphragm contained within the housing may comprise a diaphragm body and a periphery, and the flexible diaphragm may have an extended configuration and a collapsed configuration. Alternatively, a valve cone may be located within the housing and reciprocate linearly therein. The external pump may be located within or mounted on a console with a user interface.

[0034] Access to the circulatory system may be obtained from any suitable artery or vein, e.g., the femoral artery, subclavian artery, carotid artery, or jugular vein. Once access is obtained, the coaxial catheter may be advanced to a target location in the circulatory system, and a valve member, e.g., a valve cone, a flexible diaphragm, or an umbrella structure, may be linearly reciprocated within the expandable housing to generate the filling and pumping strokes of the pumping cycle. During the pumping stroke, contact between the periphery of the valve cone, flexible diaphragm, or umbrella structure and the inner surface of the expandable housing may be maintained to create a seal between them, preventing blood from flowing around the flexible diaphragm. The seal may help generate and maintain the force of the pumping stroke and minimize red blood cell damage that could occur due to blood flowing in the space between the periphery and the inner surface. The methods described herein may include advancing the coaxial catheter to various target locations within the patient. For example, the target location for the inflow lumen may be the patient's left ventricle, or the target location for the outflow lumen may be above the patient's aortic valve.

[0035] A coaxial catheter may comprise an inlet lumen and an outlet lumen. The inlet lumen may receive blood from the left ventricle, and the outlet lumen may return blood to the ascending aorta. Generally, a pump stroke may draw blood into the housing through the inlet lumen and push blood out of the housing through the outlet lumen. During the filling stroke, the flexible diaphragm may be compressed into a collapsed configuration. Correspondingly, the flexible diaphragm may be extended into an extended configuration during the pump stroke. When the valve cone is used, multiple flaps within the flow control layer may be opened during the filling stroke and closed during the pump stroke. A mesh layer may be provided in the flow control layer to support the flaps and prevent them from opening during the pump stroke.

[0036] Another method for pumping blood involves advancing a pump to a target location in the patient's aorta, such as the thoracic or abdominal aorta, wherein the pump has a filling stroke and a pumping stroke, drawing a filling volume of blood into the pump during the pumping stroke and pushing an exit volume of blood out of the pump during the pumping stroke, wherein the exit volume comprises a first portion of blood and a second portion of blood. The filling stroke may draw blood from the patient's left ventricle. In addition, the first portion of blood may be pumped retrogradely toward the patient's head, and the second portion of blood may be pumped antegradely. The second portion of blood may be about 60%, about 50%, or about 40% of the exit volume.

[0037] In some methods, an expandable housing having a cannula extending from the proximal end of the housing is advanced within a selected artery and positioned at a target location such as the patient's aorta and left ventricle. The selected artery may be the femoral artery. Once at the target location, the sheath surrounding the expandable housing may be withdrawn, thereby allowing the expandable housing to expand into its pumping configuration. An actuator may then be advanced into the housing, and a linear motor drive may be activated to induce reciprocating motion of a valve member (e.g., a valve cone or flexible diaphragm) coupled to it within the expandable housing in the forward and backward directions. During the reciprocating motion, forward movement may induce blood flow into the housing, and backward movement may impart pumping force to the blood within the housing. The result can be a highly efficient linear pulsatile pumping action that can match the pulsatile behavior of the human heart. The characteristics of the reciprocating motion of the pump described herein may be independently varied to provide optimized forward stroke, backward stroke, and motion profiles.

[0038] Systems for pumping blood are also described herein. These systems may generally include a pump comprising an expandable housing having an inner surface and an expansion configuration. A valve member, including a periphery, may be located within the expandable housing and may have an expansion or extension configuration and a compression configuration. The pump may also include an actuator coupled to the valve member, which linearly reciprocates the valve member within the housing, generating pump strokes and filling strokes for a pumping cycle. During the pump stroke, the periphery of the valve member may be configured to maintain contact with the inner surface of the housing. In some modifications, the contact may be maintained for the entire duration of the pump stroke. In other modifications, the contact may be maintained for a portion of the pump stroke, insofar as sufficient pressure is generated to move a desired amount of blood out of the housing during the pump stroke. In further modifications, for example, when a high pump speed is required, the valve member may be configured to have a small gap or clearance between its periphery and the inner surface of the housing. The gap may help to avoid the generation of excessive friction within the pump. The gap may also be sized so that the appropriate pressure is generated over the pump stroke while avoiding crushing or damaging red blood cells during the pump stroke. Here, the diameter of the valve member in their extended or expanded configuration may be at least about 95 percent of the diameter of the housing in their expanded configuration. For example, the valve member in their extended or expanded configuration may be at least about 95 percent, at least about 96 percent, at least about 97 percent, at least about 98 percent, or at least about 99 percent of the diameter of the housing in their expanded configuration.

[0039] In addition, the system may include a console located outside the patient, containing a controller configured to adjust the actuators. A user interface may be coupled to the controller and configured to manually set or adjust pump parameters and / or patient parameters, and / or display the pump and patient parameters. The user interface may be a display that forms part of the console housing the linear actuators. The console may be a permanent component of the system, or a mobile component when coupled to a wheeled cart or other rolling base.

[0040] Exemplary pump parameters include, but are not limited to, pump cycles per minute and pump cycle duration. When setting or adjusting the pump cycle duration, the duration of either the filling stroke or the pump stroke may be set or adjusted. Non-exclusive embodiments of patient parameters include age, height, weight, left ventricular pressure, left ventricular end-diastolic pressure, aortic pressure, and systemic blood pressure. The system may issue audible and / or visual alerts when any pump parameter or patient parameter exceeds or falls below a preset value, or exceeds or falls below a preset range.

[0041] During use, the pump of this system may advance to a target location in the patient's circulatory system. The pump may comprise an expandable housing, which includes an inner surface, an expansion configuration, and a collapse configuration, and a valve member having a periphery positioned within the expandable housing, as described above. Once at the target location, the expandable housing may expand from the collapse configuration to the expansion configuration. Pump parameters and / or patient parameters may be determined, and the valve member may reciprocate linearly within the expandable housing according to those parameters to generate filling strokes and pump strokes. During the pump stroke, contact between the periphery of the valve member and the inner surface of the expandable housing may be maintained. As mentioned above, the pump parameters may include pump cycles per minute, the duration of the pump cycle, or both. When setting or adjusting the duration of the pump cycle, the duration of either the filling stroke or the pump stroke may be set or adjusted, or both may be set or adjusted. When pump parameters are determined, they may be based on patient parameters such as age, height, weight, left ventricular pressure, left ventricular end-diastolic pressure, aortic pressure, or systemic blood pressure.

[0042] Pump and patient parameters may be displayed on the user interface. Parameters may be monitored continuously or intermittently, and the measured values ​​may be displayed continuously or intermittently on the user interface. The user interface may be a display that forms part of a console housing a linear actuator. The console may be a stationary component of the system, as mentioned above, or a movable component when coupled to a wheeled cart or other rolling base. Pump and patient parameters may be manually adjusted via buttons on the user interface. In some cases, the user interface display includes touch-sensitive buttons for manually adjusting parameters. In other cases, pump parameters may be automatically adjusted based on measured patient parameters.

[0043] The pump of this system may be advanced to a target location within an artery. When the artery is the aorta, the target location may be the ascending aorta, aortic arch, thoracic aorta, descending aorta, or abdominal aorta. The pump may also be advanced to a target location within a vein. The vein may be the inferior vena cava. When advanced within the inferior vena cava, the target location may be located between the hepatic vein and the right atrium. At this location, the pump may increase circulation from the liver or from the lower extremities. Another target location for the pump may be above or below the renal vein. Yet another target location may be within the aorta, either above or below the renal artery. Pumps positioned at these target locations may assist renal perfusion as part of the treatment of reduced renal perfusion resulting from cardiorenal syndrome or other causes due to acute or chronic heart failure. The present invention provides, for example, the following: (Item 1) A pump to assist blood circulation, An enclosure having an internal structure and an expandable configuration, A valve member having a periphery disposed within an expandable housing, wherein the valve member has an expandable or extending configuration and a compressive configuration, An actuator coupled to the valve member, wherein the actuator is configured to cause the valve member within the housing to reciprocate linearly, and Equipped with, The pump has a filling stroke and a pump stroke, and the periphery of the valve member is configured to maintain contact with the inner surface of the housing during the pump stroke. (Item 2) The pump according to item 1, wherein the valve member comprises a valve cone. (Item 3) The pump according to item 2, wherein the valve cone comprises multiple material layers coupled to an expandable frame. (Item 4) The pump according to item 3, wherein the plurality of material layers include a mesh layer. (Item 5) The aforementioned mesh layer includes a woven fabric, as described in item 4 of the pump. (Item 6) The pump according to item 4, wherein the mesh layer comprises an elastomer polymer. (Item 7) The pump according to item 6, wherein the elastomer polymer includes silicone, polyester, polyurethane, fluoropolymer, or a combination thereof. (Item 8) The pump according to item 3, wherein the plurality of material layers comprises a flow control layer, and the flow control layer comprises a plurality of flaps having an open configuration and a closed configuration. (Item 9) The pump according to item 8, wherein the flow control layer comprises 15 flaps. (Item 10) The pump according to item 8, wherein the plurality of flaps have a semicircular or arc shape. (Item 11) The pump according to item 8, wherein the plurality of flaps are in the open configuration during the filling stroke. (Item 12) The pump according to item 8, wherein the plurality of flaps are in the closed configuration during the pump stroke. (Item 13) The pump according to item 8, wherein the flow control layer comprises a body, and the periphery is formed by winding around the edge of the body. (Item 14) The pump according to item 13, wherein the thickness of the periphery exceeds the thickness of the main body. (Item 15) The aforementioned body is the pump described in item 13, having a thickness ranging from approximately 0.03 mm to approximately 0.05 mm. (Item 16) The pump described in item 1, wherein the aforementioned periphery has a thickness ranging from approximately 0.20 mm to approximately 1.5 mm. (Item 17) The pump according to item 3, wherein each of the multiple material layers has a conical shape. (Item 18) The pump according to item 3, wherein the expandable frame has a conical shape in its expanded configuration. (Item 19) The expandable frame is made of stainless steel, nickel, titanium, or an alloy thereof, as described in item 3 for the pump. (Item 20) The pump according to item 13, wherein the body and periphery of the flow control layer are made of the same material. (Item 21) The pump according to item 1, wherein the housing is expandable and includes a scaffold, the scaffold having a proximal end and a distal end. (Item 22) The aforementioned scaffolding includes stainless steel, titanium, or an alloy thereof, as described in item 21. (Item 23) The pump described in item 21, wherein the proximal and distal ends of the scaffolding are tapered. (Item 24) The pump according to item 21, wherein the distal end is provided with an inlet for blood flow during the filling stroke. (Item 25) The pump according to item 21, wherein the proximal end is provided with an outlet for blood flow during the pump stroke. (Item 26) The aforementioned housing is the pump described in item 1, having a diameter ranging from approximately 12 mm to approximately 30 mm in the expanded configuration. (Item 27) A pump as described in item 1, further equipped with a cannula. (Item 28) The cannula extends from the proximal end of the expandable housing, as described in item 27. (Item 29) The cannula extends from the distal end of the expandable housing, as described in item 27. (Item 30) The cannula is the pump described in item 27, having a length of approximately 2.5 cm to approximately 5.0 cm. (Item 31) The cannula is the pump described in item 27, having a length of approximately 25 cm to approximately 30 cm. (Item 32) The cannula is the pump described in item 27, having a length of approximately 35 cm to 40 cm. (Item 33) The pump according to item 1, further comprising a polymer layer in the housing. (Item 34) The pump according to item 33, wherein the polymer layer comprises an elastomer polymer. (Item 35) The pump according to item 34, wherein the elastomer polymer includes silicone, polyester, polyurethane, or a combination thereof. (Item 36) The pump according to item 21, wherein the housing further comprises a fabric layer that is coupled to the scaffolding. (Item 37) The aforementioned fabric layer comprises a woven material, as described in item 36. (Item 38) The pump according to item 1, wherein the valve member comprises a flexible diaphragm, and the flexible diaphragm comprises a diaphragm body. (Item 39) The flexible diaphragm comprises an elastomer polymer, as described in item 38. (Item 40) The pump according to item 39, wherein the elastomer polymer includes silicone, polyester, polyurethane elastomer, fluoropolymer, or a combination thereof. (Item 41) The pump according to item 38, wherein the diaphragm body and the periphery are made of the same material. (Item 42) The pump according to item 38, wherein the diaphragm body and the periphery are integrally formed. (Item 43) The pump according to item 42, wherein the thickness of the periphery exceeds the thickness of the diaphragm body. (Item 44) The pump described in item 38, wherein the diaphragm body has a thickness ranging from approximately 0.03 mm to approximately 0.3 mm. (Item 45) The pump according to item 38, wherein the aforementioned periphery has a thickness ranging from approximately 0.20 mm to approximately 1.5 mm. (Item 46) The pump according to item 38, wherein the flexible diaphragm is in the compressed configuration during the filling stroke. (Item 47) The pump according to item 38, wherein the flexible diaphragm is in the extended configuration during the pump stroke. (Item 48) The pump according to item 38, wherein the flexible diaphragm has a conical shape in the extended configuration. (Item 49) The pump according to item 48, wherein the flexible diaphragm comprises a plurality of ribs extending from the central portion of the diaphragm body to the periphery. (Item 50) The pump according to item 49, wherein the angle between the rib member having the plurality of ribs and the axis perpendicular to the actuator is approximately 30 degrees to approximately 60 degrees. (Item 51) The pump described in item 49, wherein the plurality of ribs are equally spaced apart from one another. (Item 52) The pump according to item 38, further comprising a plurality of tines coupled to the actuator supporting the flexible diaphragm in the extended configuration during the pump stroke. (Item 53) The pump according to item 52, wherein the plurality of tines are flexible and have an expansion configuration and a compression configuration. (Item 54) The aforementioned housing comprises a pump as described in item 1, having a plurality of openings. (Item 55) The aforementioned housing comprises approximately 2 to approximately 25 openings, the pump as described in item 54. (Item 56) The pump according to item 54, wherein the plurality of openings are equally spaced above a portion of the housing. (Item 57) The pump according to item 54, wherein the plurality of openings are provided in a pattern on a part of the housing. (Item 58) The pump according to item 54, further comprising a skirt coupled to the housing and surrounding the plurality of openings. (Item 59) The pump according to item 54, wherein the plurality of openings have a diameter ranging from approximately 0.10 mm to approximately 6.50 mm. (Item 60) The aforementioned housing is the pump described in item 1, which is located inside a console outside the patient. (Item 61) The pump according to item 60, wherein a coaxial catheter is coupled to the housing. (Item 62) The coaxial catheter comprises an inlet lumen and an outlet lumen, as described in item 61. (Item 63) The pump according to item 62, wherein the inlet lumen has a diameter greater than approximately 5F. (Item 64) A method of pumping blood, The pump is advanced to a target location within the patient's circulatory system, the pump is An expandable housing having an internal surface, an expansion configuration, and a crushing configuration, A valve member having a periphery disposed within the expandable housing, wherein the valve member has an extending or expanding configuration and a crushing configuration. To be equipped with, To expand the expandable housing from the compressed configuration to the expanded configuration at the target location, The valve member within the expandable housing is moved linearly back and forth to generate a filling stroke and a pump stroke, To maintain contact between the periphery of the valve member and the inner surface of the expandable housing during the pump stroke. Methods that include... (Item 65) The valve member comprises a valve cone, and the valve cone comprises a flow control layer, according to item 64. (Item 66) The method according to item 65, wherein the flow control layer comprises a plurality of flaps having an open configuration and a closed configuration. (Item 67) The method according to item 64, wherein the valve member comprises a flexible diaphragm, and the flexible diaphragm has an extended configuration and a compressed configuration. (Item 68) The pump stroke is used to draw blood into the expandable housing, as described in item 64. (Item 69) The method according to item 68, wherein the blood is drawn from the left ventricle into the expandable housing. (Item 70) The blood is drawn from the aorta into the expandable housing, according to the method of item 68. (Item 71) The pump stroke is the method according to item 64, wherein the pump stroke pushes blood out of the expandable housing. (Item 72) The method according to item 71, wherein the blood is pushed out of the expandable housing into a portion of the aorta. (Item 73) The method described in item 72, wherein the portion of the aorta is the ascending aorta. (Item 74) The method described in item 72, wherein the portion of the aorta is the descending aorta. (Item 75) The method according to item 66, further comprising opening the plurality of flaps to the open configuration during the filling stroke. (Item 76) The method according to item 66, further comprising closing the plurality of flaps to the closed configuration during the pump stroke. (Item 77) The method of item 67, further comprising crushing the flexible diaphragm into the crushed structure during the filling stroke. (Item 78) The method of item 67, further comprising extending the flexible diaphragm to the extended configuration during the pump stroke. (Item 79) The expandable housing is advanced into the patient's left ventricle through the aortic valve, according to the method of item 64. (Item 80) The pump further comprises a cannula, the cannula being advanced through the aortic valve into the patient's left ventricle, according to item 64. (Item 81) The method according to item 64, wherein the target location for the expandable housing is the aortic arch. (Item 82) The method according to item 64, wherein the target location for the expandable housing is the descending aorta. (Item 83) The method according to item 64, wherein the target location for the expandable housing is the thoracic aorta. (Item 84) The method according to item 64, wherein the target location for the expandable housing is the abdominal aorta. (Item 85) The method according to item 67, wherein the pump further comprises a plurality of tines that support the flexible diaphragm in the extended configuration during the pump stroke. (Item 86) The expandable enclosure is provided with a plurality of openings, as described in item 64. (Item 87) The method according to item 86, wherein the blood exiting from the opening is directed in a retrograde direction toward the patient's head during the pump stroke by a skirt attached to the housing. (Item 88) The method according to item 87, wherein the length of the skirt is adjusted to achieve a predetermined amount of retrograde blood flow toward the patient's head. (Item 89) The method according to item 87, wherein the number of openings is adjusted to achieve a predetermined amount of retrograde blood flow toward the patient's head. (Item 90) The method according to item 87, wherein the diameter of the opening is adjusted to achieve a predetermined amount of retrograde blood flow toward the patient's head. (Item 91) The method according to item 87, wherein approximately 60% of the blood from the pump stroke flows in a retrograde direction toward the patient's head. (Item 92) The method according to item 87, wherein approximately 50% of the blood from the pump stroke flows in a retrograde direction toward the patient's head. (Item 93) The method according to item 87, wherein approximately 40% of the blood from the pump stroke flows in a retrograde direction toward the patient's head. (Item 94) A method of pumping blood, Accessing the patient's circulatory system using a coaxial catheter extending from a pump located outside the patient, wherein the pump is A casing with an interior, A valve member having a periphery that is placed within an expandable housing, To be equipped with, The coaxial catheter is advanced to the target location within the circulatory system, The valve member within the expandable housing is moved linearly back and forth to generate a filling stroke and a pump stroke, To maintain contact between the periphery of the valve member and the inner surface of the housing during the pump stroke. Methods that include... (Item 95) The method according to item 94, wherein the valve member comprises a valve cone, and the valve cone comprises a flow control layer. (Item 96) The method according to item 95, wherein the flow control layer comprises a plurality of flaps having an open configuration and a closed configuration. (Item 97) The method according to item 94, wherein the valve member comprises a flexible diaphragm, and the flexible diaphragm has an extended configuration and a compressed configuration. (Item 98) The coaxial catheter according to item 94, comprising an inlet lumen and an outlet lumen. (Item 99) The method according to item 98, wherein the inlet lumen has a diameter greater than approximately 5F. (Item 100) The method according to item 98, wherein the inflow lumen receives blood from the left ventricle and the outflow lumen returns blood to the ascending aorta. (Item 101) The pump stroke is to draw blood into the housing through the inlet lumen, as described in item 98. (Item 102) The method according to item 98, wherein the pump stroke pushes blood out of the housing through the outflow lumen. (Item 103) The method according to item 96, further comprising opening the plurality of flaps to the open configuration during the filling stroke. (Item 104) The method according to item 96, further comprising closing the plurality of flaps to the closed configuration during the pump stroke. (Item 105) The method of item 97, further comprising crushing the flexible diaphragm into the crushed configuration during the filling stroke. (Item 106) The method according to item 97, further comprising extending the flexible diaphragm to the extended configuration during the pump stroke. (Item 107) The circulatory system is accessed from the femoral artery, subclavian artery, or carotid artery, as described in item 94. (Item 108) The method according to item 98, wherein the target location for the inflow lumen is the left ventricle of the patient. (Item 109) The method according to item 98, wherein the target location for the outflow lumen is above the patient's aortic valve. (Item 110) The method according to item 97, wherein the pump further comprises a plurality of tines that support the flexible diaphragm in the extended configuration during the pump stroke. (Item 111) The pump is located within a console equipped with a user interface, as described in item 94. (Item 112) A method of pumping blood, The pump is advanced to a target location within the patient's aorta, wherein the pump has a filling stroke and a pumping stroke. During the pump stroke, the filling volume of blood is drawn into the pump, The process involves pushing a volume of blood out of the pump during the pump stroke, wherein the volume of blood comprises a first portion of blood and a second portion of blood. Includes, A method wherein a first portion of the blood is pumped retrogradely toward the patient's head, and a second portion of the blood is pumped antegradely. (Item 113) The filling stroke is the method according to item 112, which draws blood from the patient's left ventricle. (Item 114) The method according to item 112, wherein the second portion of the blood is approximately 60% of the discharged volume. (Item 115) The method according to item 112, wherein the second portion of the blood is approximately 50% of the discharge volume. (Item 116) The method according to item 112, wherein the second portion of the blood is approximately 40% of the discharged volume. (Item 117) The method according to item 112, wherein the target location is the thoracic aorta. (Item 118) The method according to item 112, wherein the target location is the abdominal aorta. (Item 119) A pump to assist blood circulation, A chassis with an expandable configuration, A valve member comprising an expandable frame disposed within the housing and a polymer layer bonded to the expandable frame, wherein the valve member has an expandable configuration and a compressive configuration, An actuator coupled to the valve member, wherein the actuator is configured to cause the valve member within the housing to reciprocate linearly, A plurality of tethers for attaching the valve member to the actuator, wherein the plurality of tethers have a relaxed state and a tensioned state. A pump equipped with the following features. (Item 120) A system for pumping blood into a patient, A pump, wherein the pump is An expandable enclosure having an internal structure and an expandable configuration, A valve member having a periphery disposed within the expandable housing, wherein the valve member has an expandable or extending configuration and a compressive configuration, An actuator coupled to the valve member, wherein the actuator is configured to cause the valve member within the housing to reciprocate linearly, and A pump equipped with, A console located outside the patient, A controller contained within the console and configured to adjust the actuator, A user interface connected to the controller Equipped with, The pump has a filling stroke and a pumping stroke, and the periphery of the valve member is configured to maintain contact with the inner surface of the housing during the pumping stroke. (Item 121) The system described in item 120, wherein the user interface is configured to set or adjust pump parameters. (Item 122) The pump parameter is the pump cycles per minute, as described in item 121. (Item 123) The pump parameter is the duration of the pump stroke, as described in item 121. (Item 124) The system described in item 120, wherein the user interface is configured to set or adjust patient parameters. (Item 125) The patient parameters are age, height, weight, left ventricular pressure, left ventricular end-diastolic pressure, aortic pressure, or systemic blood pressure, as described in item 124. (Item 126) A method for pumping blood into a patient, The pump is advanced to a target location within the patient's circulatory system, the pump is An expandable housing having an internal surface, an expansion configuration, and a crushing configuration, A valve member having a periphery disposed within the expandable housing, wherein the valve member has an extending or expanding configuration and a crushing configuration. To be equipped with, To expand the expandable housing from the compressed configuration to the expanded configuration at the target location, Determining pump parameters or patient parameters, The valve member within the expandable housing is linearly reciprocated according to the pump parameters or patient parameters to generate a filling stroke and a pump stroke, To maintain contact between the periphery of the valve member and the inner surface of the expandable housing during the pump stroke. Methods that include... (Item 127) Determining the pump parameters is done according to the method described in item 126, based on the patient parameters. (Item 128) The pump parameter is the pump cycles per minute, as described in item 126. (Item 129) The method according to item 126, wherein the patient parameters are age, height, weight, left ventricular pressure, left ventricular end-diastolic pressure, aortic pressure, or systemic blood pressure. (Item 130) The method according to item 126, further comprising displaying the pump parameters or patient parameters on the user interface. (Item 131) The method according to item 130, further comprising manually adjusting the pump parameters or the patient parameters using the user interface. (Item 132) The method according to item 126, further comprising continuously monitoring the pump parameters or the patient parameters. (Item 133) The method according to item 126, wherein the pump parameters are automatically adjusted based on the patient parameters. (Item 134) The pump is advanced to a target location within an artery, as described in item 126. (Item 135) The method according to item 134, wherein the artery comprises a portion of the aorta. (Item 136) The method according to item 135, wherein the portion of the aorta is the ascending aorta, the aortic arch, the thoracic aorta, the descending aorta, or the abdominal aorta. (Item 137) The pump is advanced to a target location within a vein, according to the method of item 126. (Item 138) The method according to item 137, wherein the vein comprises a portion of the inferior vena cava. (Item 139) The aforementioned target location is permanently located between the hepatic vein and the right atrium, as described in item 138. (Item 140) The pump increases circulation from the liver or from the lower extremities, as described in item 139. (Item 141) A pump to assist blood circulation, An enclosure having an internal structure and an expandable configuration, A valve member comprising an umbrella structure disposed within an expandable housing, wherein the umbrella structure comprises a membrane having a periphery, a plurality of support columns having distal ends, and an anchor, and the umbrella structure has an expandable configuration and a compressed configuration, and A pump equipped with the following features. (Item 142) The pump according to item 141, further comprising an actuator coupled to the umbrella structure, the actuator configured to cause the umbrella structure to reciprocate linearly within the housing. (Item 143) The pump according to item 142, wherein the pump has a filling stroke and a pumping stroke, and the periphery of the membrane is configured to maintain contact with the inner surface of the housing during the pumping stroke. (Item 144) The pump according to item 141, wherein the membrane comprises an elastomer polymer. (Item 145) The pump according to item 144, wherein the elastomer polymer includes silicone, polyester, polyurethane, fluoropolymer, or a combination thereof. (Item 146) The pump according to item 145, wherein the fluoropolymer comprises polytetrafluoroethylene (PTFE) or expanded polytetrafluoroethylene (ePTFE). (Item 147) The pump according to item 141, wherein the plurality of supports comprises 6 to 10 supports. (Item 148) The pump according to item 141, wherein at least one of the plurality of support columns is provided with a bent portion. (Item 149) The pump described in item 148, wherein the bent portion has a bending angle ranging from approximately 5 degrees to approximately 15 degrees. (Item 150) The pump according to item 141, wherein each of the multiple support columns has a support angle ranging from approximately 30 degrees to approximately 60 degrees. (Item 151) The pump according to item 141, wherein the distal end of each of the plurality of support columns is provided with an opening. (Item 152) The pump according to item 141, wherein the distal end of each of the plurality of supports is circular or oval in shape. (Item 153) The pump according to item 141, wherein the plurality of support columns are configured to be inverted around the anchor. (Item 154) A pump to assist blood circulation, An enclosure having an internal structure and an expandable configuration, Actuator and A valve member comprising a cage structure disposed within an expandable housing, wherein the cage structure comprises a membrane having a periphery and a plurality of support columns, and the cage structure has an expansion configuration and a collapse configuration, and is configured to reciprocate linearly along the actuator, and A pump equipped with the following features. (Item 155) A pump to assist blood circulation, A housing comprising an inner surface, an extension configuration, and one or more ends having an expansion configuration, A valve member having a periphery disposed within an expandable housing, wherein the valve member has an expandable or extending configuration and a compressive configuration, An actuator coupled to the valve member, wherein the actuator is configured to cause the valve member within the housing to reciprocate linearly, and Equipped with, The pump has a filling stroke and a pump stroke, and the periphery of the valve member is configured to maintain contact with the inner surface of the housing during the pump stroke. [BRIEF DESCRIPTION OF THE DRAWINGS]

[0044] [Figure 1] Figure 1 depicts a perspective view of an exemplary pump and linear motor drive device.

[0045] [Figure 2] Figure 2 depicts the pump of Figure 1 being advanced into the left ventricle of the heart within the aorta.

[0046] [Figure 3] Figure 3 illustrates blood movement resulting from the pumping stroke of the pump of Figure 2.

[0047] [Figure 4] Figure 4 illustrates the filling stroke of the pump of Figure 2.

[0048] [Figure 5] Figure 5 depicts an enlarged cross-sectional view of the pump of Figure 1 prior to deployment within the heart.

[0049] [Figure 6] Figure 6 depicts an enlarged cross-sectional view of the pump of Figure 1 at an intermediate point during its configuration for a pumping operation.

[0050] [Figure 7] Figure 7 depicts an enlarged cross-sectional view of the pump of Figure 1 at the completion of its configuration for a pumping operation.

[0051] [Figure 8] Figure 8 depicts an enlarged cross-sectional view of the pump of Figure 1 during the filling stroke portion of its pumping operation.

[0052] [Figure 9] Figure 9 depicts an enlarged cross-sectional view of the pump of Figure 1 during the pumping stroke portion of its pumping operation.

[0053] [Figure 10] Figures 10A-10C depict side views of an exemplary enclosure comprising a scaffold and a barrier layer. The scaffold is shown in Figure 10A, and the barrier layer is shown in Figure 10B. In Figure 10C, the scaffold is shown coupled to the barrier layer.

[0054] [Figure 11] Figure 11 depicts a perspective view of an exemplary pump, including the housing of Figure 10C and a flexible diaphragm supported by multiple tines.

[0055] [Figure 12] Figures 12A and 12B depict enlarged views of a flexible diaphragm according to one modification. Figure 12A shows a top view of the flexible diaphragm, and Figure 12B shows a side cross-sectional view of the diaphragm of Figure 12A obtained along line AA.

[0056] [Figure 13] Figures 13A-13C depict enlarged views of multiple tines in one modification. Figure 13A shows a side view of multiple tines, Figure 13B shows a side cross-sectional view of the tines of Figure 13A obtained along line AA, and Figure 13C shows a front view of the tines of Figure 13A illustrating their spacing from one another.

[0057] [Figure 14] Figures 14A–14C depict enlarged views of another exemplary design relating to multiple tines. Figure 14A shows a side view of multiple tines, Figure 14B shows a side section view of the tines of Figure 14A obtained along line AA, and Figure 14C shows a front view of the tines of Figure 14A illustrating their spacing from one another.

[0058] [Figure 15] Figure 15 depicts a perspective view of another exemplary pump, which includes a conical flexible diaphragm.

[0059] [Figure 16]16A-16C depict enlarged views of the conical flexible diaphragm of Fig. 15. Fig. 16A shows a top view of the diaphragm of Fig. 15, Fig. 16B shows a side view of the diaphragm of Fig. 16A, and Fig. 16C shows a side cross-sectional view of the diaphragm of Fig. 16B.

[0060] [Figure 17] Fig. 17 illustrates seal formation between an exemplary conical flexible diaphragm and an inner surface of a housing.

[0061] [Figure 18A] Figs. 18A and 18B depict a pump according to another modification, wherein the housing lacks a cannula extending therefrom. Fig. 18A shows the pump positioned within the descending thoracic portion of the aorta. Fig. 18B shows the pump positioned within the descending abdominal portion of the aorta. [Figure 18B] Figs. 18A and 18B depict a pump according to another modification, wherein the housing lacks a cannula extending therefrom. Fig. 18A shows the pump positioned within the descending thoracic portion of the aorta. Fig. 18B shows the pump positioned within the descending abdominal portion of the aorta.

[0062] [Figure 19] Fig. 19 depicts an exemplary pump comprising a housing including a plurality of openings and a skirt coupled to the housing.

[0063] [Figure 20] Fig. 20 depicts an enlarged view of the housing of Fig. 19 with a cutout to show how the skirt and the plurality of openings cooperate with the flexible diaphragm to generate retrograde blood flow.

[0064] [Figure 21] Fig. 21 illustrates how blood flows during a pumping cycle, including retrograde and antegrade flow.

[0065] [Figure 22]Figures 22A–22C depict the pump, coupled to an external linear motor drive unit, and in another modified form. Figure 22A shows the pump located inside the patient and coupled to a linear motor drive unit in an external console; Figure 22B shows a close-up view of the pump housing inside the patient; and Figure 22C shows a close-up view of the distal end of the cannula inside the left ventricle.

[0066] [Figure 23] Figures 23A–23C depict an exemplary external pump, positioned within a bedside console and connected to the patient via a coaxial catheter. Figure 23A shows the coaxial catheter located within the patient and connected to a linear motor drive within the bedside console; Figure 23B shows close-up views of the inlet and outlet lumens of the coaxial catheter; and Figure 23C shows close-up views of the inlet and outlet of the coaxial catheter.

[0067] [Figure 24] Figures 24A-24C illustrate exemplary locations for mounting pressure sensors on a pump. Figure 24A shows a perspective view of the pump and pressure sensors, Figure 24B shows a close-up view of the two pressure sensors at the pump outlet, and Figure 24C shows a close-up view of the two pressure sensors at the pump inlet.

[0068] [Figure 25] Figures 25A–25C depict an exemplary valve member, including an expandable frame, a mesh cone, and a flow control cone. Figure 25A shows the mesh cone and flow control cone coupled to the expandable frame; Figure 25B shows an assembly diagram of the expandable frame, mesh cone, and flow control cone; and Figure 25C shows the mesh cone and flow control cone sewn to the expandable frame at multiple mounting points.

[0069] [Figure 26]Figures 26A-26C depict the expandable frame shown in Figures 25A and 25B. Figure 26A shows a perspective view of the expandable frame, Figure 26B shows a side view of the expandable frame, and Figure 26C shows a top view of the expandable frame.

[0070] [Figure 27] Figures 27A and 27B depict the mesh cones of Figures 25A–25C. Figure 27A shows a circular segment of the mesh, including a free edge, which can be wound into the conical shape shown in Figure 27B.

[0071] [Figure 28] Figures 28A-28C depict the flow-controlled cone of Figures 25A-25C. Figure 28A shows a circular segment of the material including multiple flaps and a free edge, Figure 28B shows the periphery extending circumferentially from the periphery of the material, and Figure 28C shows a circular segment of the material wound into a cone shape.

[0072] [Figure 29] Figures 29A and 29B depict another exemplary valve member, which includes multiple flaps.

[0073] [Figure 30A] Figures 30A-30D depict further variations of the valve member, including multiple supports and a membrane in an umbrella structure. [Figure 30B] Figures 30A-30D depict further variations of the valve member, including multiple supports and a membrane in an umbrella structure. [Figure 30C] Figures 30A-30D depict further variations of the valve member, including multiple supports and a membrane in an umbrella structure. [Figure 30D] Figures 30A-30D depict further variations of the valve member, including multiple supports and a membrane in an umbrella structure.

[0074] [Figure 31] Figure 31 depicts an exemplary valve member, including multiple tethers that limit its extension.

[0075] [Figure 32A] Figures 32A and 32B depict exemplary controller consoles and user interfaces. [Figure 32B] Figures 32A and 32B depict exemplary controller consoles and user interfaces.

[0076] [Figure 33] Figure 33 depicts an exemplary pump, including the housing chamber, lacking a cannula. The pump is shown positioned within the descending aorta above the renal artery.

[0077] [Figure 34] Figure 34 depicts another exemplary expandable frame supporting a flexible diaphragm.

[0078] [Figure 35A] Figures 35A-35B depict perspective and side views of an exemplary umbrella structure, including supports that are completely covered by a membrane. [Figure 35B] Figures 35A-35B depict perspective and side views of an exemplary umbrella structure, including supports that are completely covered by a membrane.

[0079] [Figure 35C] Figure 35C depicts a side view of another exemplary umbrella structure, including bends in multiple supports.

[0080] [Figure 36A] Figures 36A–36C illustrate further exemplary umbrella structures, including longer struts partially covered by the membrane. [Figure 36B] Figures 36A–36C illustrate further exemplary umbrella structures, including longer struts partially covered by the membrane. [Figure 36C] Figures 36A–36C illustrate further exemplary umbrella structures, including longer struts partially covered by the membrane.

[0081] [Figure 37] Figure 37 depicts a side view of another exemplary variant of the expandable enclosure in its expanded configuration.

[0082] [Figure 38] Figure 38 depicts another exemplary modification of the valve member, which includes a plurality of supports fixed to a linear actuator at one end and slidable across the linear actuator at the other end.

[0083] [Figure 39] Figures 39A-39B depict exemplary variations of the inverted umbrella structure.

[0084] [Figure 40] Figure 40 illustrates an exemplary variation of the distal end of the support in an umbrella structure.

[0085] [Figure 41] Figure 41 depicts another exemplary variation of the distal end of the support column.

[0086] [Figure 42A] Figures 42A–42C depict further exemplary umbrella structures in which the supports include bends and openings at their distal ends. Figure 42A is a side view of the umbrella structure, Figure 42B is an end view of the umbrella structure, and Figure 42C provides an assembled drawing of the umbrella structure. [Figure 42B] Figures 42A–42C depict further exemplary umbrella structures in which the supports include bends and openings at their distal ends. Figure 42A is a side view of the umbrella structure, Figure 42B is an end view of the umbrella structure, and Figure 42C provides an assembled drawing of the umbrella structure. [Figure 42C] Figures 42A–42C depict further exemplary umbrella structures in which the supports include bends and openings at their distal ends. Figure 42A is a side view of the umbrella structure, Figure 42B is an end view of the umbrella structure, and Figure 42C provides an assembled drawing of the umbrella structure.

[0087] [Figure 43] Figure 43 illustrates an exemplary cell shape formed by the support columns of the expandable enclosure.

[0088] [Figure 44] Figure 44 illustrates an exemplary rhombic cell shape formed by the support columns of the expandable enclosure.

[0089] [Figure 45] Figure 45 depicts an exemplary expandable enclosure including multiple parallel supports.

[0090] [Figure 46] Figures 46A-46B depict exemplary housings with enlarged ends.

[0091] [Figure 47] Figures 47A-47B depict another exemplary housing with an enlarged end.

[0092] [Figure 48] Figure 48 depicts a further exemplary valve member, including a hinge to assist in the collapse of the support column during the filling stroke of the pumping cycle. [Modes for carrying out the invention]

[0093] (Detailed explanation) Described herein are pumps for assisting blood circulation. Instead of a rotating impeller, the pump may include a linearly reciprocating member for moving blood, which can help avoid shear forces that cause red blood cell damage, pumping blood in a pulsatile manner and mimicking the heart's natural pumping cycle. The pump may generate pressure waves or back pulses during the pumping stroke to assist the associated heart action and can eliminate vascular collapse. Furthermore, the pump may be capable of providing adequate blood flow at operating speeds of 50 to 500 cycles per minute, which provides a much slower movement compared to a rotating impeller and can prevent red blood cell hemolysis. At slower pumping speeds, less heat is generated than with a rotating impeller, which can avoid the need to include a cooling device.

[0094] In some cases, a linearly reciprocating pump may be used to increase renal perfusion. The kidneys perform several vital functions, including maintaining overall fluid balance, regulating and filtering minerals from the blood, and filtering waste products from food, drugs, and toxic substances. Therefore, if blood flow through the kidneys is reduced, fluid may be retained and waste products may accumulate in the body to dangerous levels. Reduced renal perfusion can occur in patients with acute or chronic heart failure (e.g., cardiorenal syndrome), where lower cardiac output results in reduced renal blood flow, or where the patient suffers from medical conditions such as diabetes or hypertension that affect the small vessels within the kidneys. The pumps described herein may assist renal perfusion as part of the treatment of reduced renal perfusion resulting from cardiorenal syndrome or other causes due to acute or chronic heart failure. The renal perfusion pump may advance to a target location in the aorta, either above or below the renal arteries, to assist circulation to the renal arteries.

[0095] The linearly reciprocating member may include a valve, the seal of which is generated between it and the housing during the pump stroke of the pumping cycle, thereby generating the blood pressure necessary to move blood peripherally to, for example, the renal arteries. The pump stroke and length, and stroke speed of the linearly reciprocating member may be independently adjustable. Blood pressure and blood flow rate may be controlled by adjusting the stroke length and speed. Furthermore, adjustable anterior-posterior stroke speed ramping can avoid fluctuations in the pressure characteristics of the circulatory system. The pump may be installed in various parts of the patient's circulatory system, such as the left ventricle, right ventricle, and aorta. When the pump is installed in the descending aorta above or below the renal arteries, it may be used to assist renal perfusion. In some cases, it may be useful to have the pump outside the patient.

[0096] (pump) A pump for assisting blood circulation as described herein may include a housing and a linearly reciprocating member disposed within the housing, comprising a valve, for example, a flexible diaphragm, a valve cone, an umbrella structure, or an inverted umbrella structure. The housing may be expandable and include an inner surface, an expansion configuration, and a collapse configuration. A sheath, which may be arranged concentrically with respect to the housing, may maintain the housing in the collapse configuration during advancement to a target location. Upon reaching the target location, the sheath may retract to allow expansion of the housing into the expansion configuration. The diameter of the sheath may vary depending on the diameter of the pump housing, which may depend on factors such as whether the pump is located inside or outside the body, the utility of use, the patient's age, or physique. In modifications in which the pump is used inside the body, specifically in arteries, it may be beneficial for the sheath to be relatively small and flexible. For example, the diameter of the sheath may be approximately 9F, 10F, 11F, 12F, 13F, 14F, or any diameter between approximately 9F and 14F (including all values ​​and sub-ranges within that range). In addition, when the valve member is a flexible diaphragm, the flexible diaphragm may have an extended configuration and a compressed configuration, and may include a diaphragm body and a periphery. Similarly, when the valve member is a valve cone, the valve cone may have an expanded configuration and a compressed configuration, and may include layers having multiple flaps that allow blood flow into the housing during the filling stroke but prevent blood flow through the valve cone during the pump stroke. Bearings within the expandable housing may also be provided to prevent movement of the flexible diaphragm or valve cone within the housing.

[0097] The pump may also include an actuator coupled to a valve member (e.g., a flexible diaphragm, valve cone, umbrella structure, or inverted umbrella structure) via a support element, which may be configured to linearly reciprocate the valve member within the housing, generating the filling stroke and pump stroke of the pumping cycle. The periphery of the valve member may be configured to maintain contact with the inner surface of the housing during the pump stroke. However, the support elements may generally be sized and / or molded so that they do not contact the inner surface of the housing while they reciprocate linearly within the housing. The pump may be driven by an external linear motor drive and linear motor controller, which may be mounted on the proximal end of the catheter outside the patient. The linear motor drive may be operationally coupled to the pump by a cable or other actuator. Furthermore, the pump may be powered by an AC or DC source.

[0098] (Enclosure) Generally, the housing of a pump comprises a body, a proximal end, and a distal end. In addition, the housing may be expandable as described above and may include an expanded configuration and a collapse configuration. The housing may define a chamber for collecting blood and holding it until it is moved out by the pump stroke, and may comprise a support or scaffold and a covering. The housing may advance to a target location in the patient's circulatory system in the collapse configuration. Upon reaching the target location, the housing may then expand into an expanded configuration, providing a chamber for collecting blood to be pumped. The housing chamber may have a diameter ranging from about 12 mm to about 30 mm (including all sub-ranges thereof) in its expanded configuration. For example, the housing chamber may have a diameter of approximately 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, 25 mm, 26 mm, 27 mm, 28 mm, 29 mm, or 30 mm in its expanded configuration. The diameter may be selected based on factors such as the location where the housing will be permanently located, the patient's age, and other characteristics, such as whether a cannula, coaxial catheter, skirt, etc., will be used with the housing. Furthermore, the housing chamber may have a length ranging from approximately 2.5 cm to approximately 4.5 cm (including all values ​​and partial ranges within this range) in its expanded configuration. For example, the housing chamber may have a length of approximately 2.5 cm, 3.0 cm, 3.5 cm, 4.0 cm, or 4.5 cm in its expanded configuration. In some variations, as shown in Figure 37, the expandable housing 2100 may have a chamber diameter 2102 of approximately 20 mm and a chamber length 2104 of approximately 2.9 cm. The cannula length 2108 may be approximately 1.3 cm. The cannula of the pump device is described further below. Using these measurements, the total length of the pump, which resides in the heart below the aortic valve 2106, may be approximately 8.8 cm.

[0099] The support or scaffold may also include a proximal end and a distal end. The scaffold may be formed from braids, weaves, and / or coiled filaments and may be made from a variety of materials. For example, the scaffold material may include biocompatible polymers and metals including stainless steel, titanium, or alloys thereof. For example, the scaffold may include nickel-titanium alloy (nitinol). With respect to the proximal and distal ends of the scaffold, they may be tapered, obtuse-angled, or straight. Furthermore, the distal end of the scaffold may include an inlet for blood flow during pump strokes. The proximal end of the scaffold may include an outlet for blood flow during pump strokes. In one modification, the scaffold may be a self-expanding stent. In another modification, the scaffold comprises a plurality of supports, which may number from 10 to 24. For example, the scaffolding may include 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, or 24 posts.

[0100] The housing may further comprise a covering, coating, or layer configured to block blood flow. The covering, coating, or layer may be provided over the entire scaffold or over a section or portion of the scaffold. In one variation, the covering or layer may contain a polymer and thus form a polymer layer. The polymer layer may be overmolded over the scaffold so that the scaffold is embedded within the polymer layer. In some variations, the scaffold may be positioned within the center of the polymer layer, while in other variations, the scaffold may be positioned toward the inner or outer edge of the polymer layer. Embedding the scaffold with the polymer layer, or otherwise completely covering it, can provide a smooth inner surface to the expandable housing. The polymer layer may include, but is not limited to, an elastomer polymer such as silicone, polyester, polyurethane, or a combination thereof. Alternatively, the covering or layer may contain a fabric and thus form a fabric layer. In these variations, the expandable housing may include a fabric layer on the scaffold, which is typically bonded to the inner surface of the scaffold. The fabric layer may be bonded to the scaffolding by any preferred means, such as sewing the fabric layer to the scaffolding at one or more points (e.g., multiple points). The sewing points may be specifically selected so that the fabric layer forms a smooth surface (e.g., on the inside of the housing) so as not to interrupt the interface between the flexible diaphragm and the housing. In other modifications, the fabric layer may be bonded to the scaffolding using an adhesive such as an acrylic adhesive, a cyanoacrylate adhesive, or a silicone adhesive. Non-limiting embodiments of materials that can be used as the fabric layer include woven materials such as materials woven from buckram or polyester fibers. Films or sheets of nonwoven materials such as Mylar® plastic film may also be used.

[0101] In some cases, the pump housing (e.g., a covering or layer) may include multiple openings or perforations. The number of openings used may range from approximately 2 to approximately 25 (including all values ​​and subranges within that range). For example, an expandable housing may include 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 openings. The openings may be arranged in a pattern on a portion of the housing, either equally spaced or not equally spaced, and / or on a portion of the housing. In addition, the multiple openings may have diameters ranging from approximately 0.10 mm to approximately 6.50 mm (including all values ​​and subranges within that range). For example, the diameter may be approximately 0.10 mm, 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm, 3.5 mm, 4.0 mm, 4.5 mm, 5.0 mm, 5.5 mm, 6.0 mm, or 6.5 mm. Multiple openings within the expandable housing may have the same or different diameters. Furthermore, the multiple openings may have any preferred shape, such as circular, oval, or slot-like. In a modified example with slots, the slots may be linear, V-shaped, or arc-shaped in shape. In one modified example, the housing includes four openings uniformly spaced apart from the housing.

[0102] When the housing includes openings or perforations, the skirt may be coupled to the expandable housing in a manner that covers, surrounds, or otherwise superimposes on multiple openings to assist in generating retrograde blood flow directed toward the patient's head during the pump stroke of the pumping cycle. Retrograde blood flow can help provide proper perfusion to arteries branching from the aortic arch, such as the carotid and subclavian arteries. The ability to maintain proper perfusion of the subclavian arteries can prevent retrograde flow from the vertebrobasilar artery to the subclavian artery, a phenomenon known as "subclavian steal." A combination of the number of openings and the diameters of the openings may provide a certain amount of open surface area on the housing for retrograde blood flow. In addition, the skirt may be configured to adjust the amount of open surface area for retrograde flow by adjusting the number of openings that are patent (open) and closed. Generally, a larger open surface area may provide more retrograde blood flow toward the patient's head and heart, while a smaller open surface area may provide more antegrade blood flow toward the body. In some variations, a mechanism may be provided to lift, open, or gradually expand the skirt from the outer surface of the housing. For example, a tether may be configured to open and close the skirt relative to the housing, for example, by being attached to the skirt, for example, around the outer surface of the skirt, and a loop can be tightened and loosened. The amount of opening or closing may be adjusted, for example, using a rotatable dial located on a console outside the patient.

[0103] The skirt may have any preferred shape (e.g., cylindrical or frustoconical) that directs blood back towards the head and heart, and may be attached to the housing in various ways. In one variation, the skirt may be a separate component from the housing and may be attached to the housing by any preferred means, such as friction fitting or the use of adhesive. In another variation, the skirt may be integral with the housing (e.g., the two may be formed integrally by molding the two as a single component). The skirt may be made from the same material as the housing. For example, the skirt may comprise a mesh made from stainless steel, titanium, or an alloy thereof (e.g., nitinol) and a polymer or fabric layer. The length of the skirt may also vary, ranging from about 0.32 cm (0.125 inches) to about 1.90 cm (0.750 inches).

[0104] The housing may or may not be associated with a cannula, as will be further described below. Referring to Figure 33, the pump 1700 is shown positioned within the descending aorta 1702 above the renal artery 1704. The pump 1700 may include a valve member 1706 within the housing 1708 that reciprocates linearly to increase perfusion to the kidney 1710. In this modification, the housing 1708 may be cannula-less.

[0105] (Cannula) In some modifications, the pump may include a cannula comprising an extension body, a proximal end, a distal end, and a lumen extending through it. The cannula may be coupled to the housing as a separate component or formed integrally as its extension. Depending on the housing's configuration, the cannula may be coupled to or extend from the proximal or distal end of the housing. For example, when the housing is permanently located in the left ventricle, the cannula may extend from the proximal end of the housing so that it crosses the aortic valve and extends into the ascending aorta. In this modification, the cannula may have a smaller diameter than the housing in its extension configuration, thus assisting in the positioning of the pump across the aortic valve. In other modifications, the pump may include a cannula extending from the distal end of the housing. For example, when the housing is permanently located in the aorta, the cannula may extend from the distal end of the housing so that it crosses the aortic valve and extends into the left ventricle. In further modifications, the housing may not have a cannula extending from it. In these cases, the housing may reside in any portion of the aorta, for example, the thoracic aorta or abdominal aorta, or in a vein, for example, the inferior vena cava. The cannula may also be expandable and comprise an expansion configuration and a collapse configuration.

[0106] Like the housing, the cannula may have a covering, coating, or layer configured to block the flow of blood. When both the housing and the cannula include a covering, coating, or layer, the length of the covering, coating, or layer may range from approximately 4.0 cm to approximately 10 cm (including all values ​​and partial ranges within that range). For example, the covering, coating, or layer may have lengths of approximately 4.0 cm, 4.5 cm, approximately 5.0 cm, approximately 5.5 cm, approximately 6.0 cm, approximately 6.5 cm, approximately 7.0 cm, approximately 7.5 cm, approximately 8.0 cm, approximately 8.5 cm, approximately 9.0 cm, approximately 9.5 cm, or approximately 10 cm.

[0107] Cannulas of various lengths may be used. For example, short, medium, or long cannulas may be used. When short cannulas are used, the length of the cannula may range from approximately 2.5 cm to approximately 5.0 cm (including all values ​​and sub-ranges) in its expanded configuration. For example, the length of a short cannula may be approximately 2.5 cm, approximately 3.0 cm, approximately 3.5 cm, approximately 4.0 cm, approximately 4.5 cm, or approximately 5.0 cm in its expanded configuration. When medium-length cannulas are used, the length of the cannula may range from approximately 25 cm to approximately 30 cm (including all values ​​and sub-ranges) in its expanded configuration. For example, the length of a medium cannula may be approximately 25 cm, approximately 26 cm, approximately 27 cm, approximately 28 cm, approximately 29 cm, or approximately 30 cm in its expanded configuration. When a long cannula is used, the length of the cannula may range from 35 cm to approximately 40 cm (including all values ​​and sub-ranges) in its expanded configuration. For example, a long cannula may be approximately 35 cm, 36 cm, 37 cm, 38 cm, 39 cm, or 40 cm in its expanded configuration. In some variations, the pump may be equipped with short, medium, and long cannulas, and the user may select the appropriate cannula based on the desired use of the pump. It should be understood that in some cases, other cannula lengths may also be used. For example, the length of the cannula may range from approximately 0.5 cm to approximately 10 cm (including all values ​​and sub-ranges) in its expanded configuration. For example, the length of the cannula in its expanded configuration may be approximately 0.5 cm, 1.0 cm, 1.5 cm, 2.0 cm, 2.5 cm, 3.0 cm, 3.5 cm, 4.0 cm, 4.5 cm, 5.0 cm, 5.5 cm, 6.0 cm, 6.5 cm, 7.0 cm, 7.5 cm, 8.0 cm, 8.5 cm, 9.0 cm, 9.5 cm, or 10 cm. The diameter of the cannula may also range from approximately 5.0 mm to approximately 15 mm (including all values ​​and sub-ranges within that range) in its expanded configuration.For example, the cannula diameter may be approximately 5.0 mm, 6.0 mm, 7.0 mm, 8.0 mm, 9.0 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, or 15 mm.

[0108] In some modifications, the pump may include a housing chamber having a length of approximately 3.8 cm and a diameter of approximately 20 mm in its expanded configuration, and a cannula having a length of approximately 4.8 cm and a diameter of approximately 8.0 mm in its expanded configuration. In other modifications, the pump may include a housing chamber having a length of approximately 3.5 cm and a diameter of approximately 20 mm in its expanded configuration, and a cannula having a length of approximately 2.2 cm and a diameter of approximately 8.0 mm in its expanded configuration. In further modifications, the pump may include a housing chamber having a length of approximately 2.8 cm and a diameter of approximately 20 mm in its expanded configuration, and a cannula having a length of approximately 1.3 cm and a diameter of approximately 8.0 mm in its expanded configuration.

[0109] (Coaxial catheter) As mentioned above, in some modifications, the pump may be located outside the body, for example, in a console at the patient's bedside. In these modifications, the pump may further include a coaxial catheter. The first end of the coaxial catheter may be coupled to the pump housing via a connector or adapter, and the opposite (second) end of the coaxial catheter may be inserted into the patient so that blood flows between the patient and the housing. The coaxial catheter may have an outer diameter of about 10F to about 18F (including all values ​​and sub-ranges within that). For example, the outer diameter of the coaxial catheter may be about 10F, about 11F, about 12F, about 13F, about 14F, about 15F, about 16F, about 17F, or about 18F. The coaxial catheter may include an inflow lumen and an outflow lumen. In some modifications, the outflow lumen may be arranged concentrically with respect to the inflow lumen. In other modifications, the inflow and outflow lumen may extend parallel to each other within the coaxial catheter. The inlet lumen may generally have an inner diameter of approximately 7F to 14F.

[0110] The inlet and / or outlet lumens of the coaxial catheter may be washed, for example, with sterile saline or heparinized saline. Washing may be performed at any time, but is generally performed prior to the use of the coaxial catheter. The fluid for washing the coaxial catheter may be introduced into one or more of the catheter lumens by various types of connectors, for example, Y-connectors or two- or three-way connectors. Other types of catheter connectors and fittings may also be used. Washing around the coaxial catheter site may also be performed around the site of insertion into the body.

[0111] (valve cone) The linearly reciprocating members of the pump described herein may include valve members such as valve cones. The valve cone may be located within an expandable housing and may include multiple material layers coupled to a support member. The support member may be an expandable frame. However, in some modifications, a single layer of material may be coupled to the support member. As mentioned above, the valve cone may have an inlet side facing the inlet of the expandable housing and an outlet side facing the outlet of the expandable housing. The multiple material layers may include mesh layers, flow control layers, or a combination thereof. Any number of material layers may be used, as long as at least one flow control layer is included. The flow control layer generally includes multiple flaps that open when blood is drawn into the expandable housing during a filling stroke and close when blood is moved out of the expandable housing during a pump stroke. A mesh layer may be positioned between the flow control layer and the expandable frame and used to support the flow control layer so that the flap is not pushed or bent through the opening in the expandable frame when pressure is applied to the flap during the pump stroke. Thus, the mesh layer may help maintain the flap in a closed configuration during the pump stroke as blood moves out of the housing through the housing outlet. However, during the filling stroke, the mesh layer allows blood to flow from the housing inlet through the holes in the mesh and then through the flap, transitioning them to their open configuration so that blood can move towards the outlet side of the valve cone.

[0112] Woven fabrics or elastomer polymers may be used to form the mesh layer. Exemplary elastomer polymers include, but are not limited to, silicones, polyesters, polyurethanes, fluoropolymers, or combinations thereof. The thickness of the mesh layer may range from about 0.03 mm to about 0.05 mm (including all values ​​and partial ranges within this range). The size and shape of the mesh openings may also vary and may depend on the size and shape of the flaps in the flow control layer, given their supporting function as described above. In terms of shape, the mesh openings may be circular, triangular, square, rectangular, or rhombic, etc.

[0113] The material layers may be joined to the expandable frame in any preferred manner, for example, by stitching, suturing, or sewing, by the use of adhesive, by heat sealing, or by welding. The material layers may be joined to the expandable frame at multiple mounting points on the frame. The expandable frame has an expandable configuration and a collapsible configuration and may include stainless steel, nickel, titanium, or an alloy thereof (e.g., nitinol). In one variation, the expandable frame is made from a laser-cut nitinol tube. The expandable frame may have a first end that is coupled to the actuator of the pump and a molded second end that is coupled to the material layer of the valve cone. Generally, the shape of the valve cone corresponds to the shape of the expandable frame. The expandable frame typically has a conical shape, but any shape that can be collapsed to allow advancement through a cannula may be used. When the expandable frame is molded into a cone shape, multiple material layers (e.g., mesh and flow control layers) may also be molded into a cone shape.

[0114] The flow control layer of the valve cone may also be formed from various polymers, such as the elastomer polymers described above, or from Mylar® plastic film. The flow control layer may include a plurality of flaps having both open and closed configurations. Generally, the flaps are in an open configuration during the filling stroke and in a closed configuration during the pump stroke. The flow control layer may be cut to produce a plurality of flaps, which can be of any preferred size and shape, allowing blood to flow into the housing during the filling stroke. For example, the flaps may have a semicircular, arcuate, circular, triangular, rhombic, square, or rectangular shape. Any preferred number of flaps in the flow control layer may also be employed. The number of flaps may range from 2 to 20. For example, it may include 2 flaps, 3 flaps, 4 flaps, 5 flaps, 6 flaps, 7 flaps, 8 flaps, 9 flaps, 10 flaps, 11 flaps, 12 flaps, 13 flaps, 14 flaps, 15 flaps, 16 flaps, 17 flaps, 18 flaps, 19 flaps, or 20 flaps. In one variation, a flow control layer containing 15 flaps may be useful. The valve cone may be configured such that a larger number of flaps are included when they are smaller in size, and a smaller number of flaps are included when they are larger in size. When the flaps are semicircular in shape, they may have radii ranging from about 0.50 mm to about 3.0 mm (including all values ​​and partial ranges within that).

[0115] When a conical valve is formed into a cone shape, the flow control layer is also generally formed into a cone shape. Here, the material for the flow control layer may first be provided as a circle with a central cutout and a slit extending from the cutout to the periphery of the circle (see, for example, 28A). The slit provides a free edge so that the layer can later be wound to form a cone shape. Next, a flap may be formed by laser cutting or punching a flap shape into the flow control layer. The flap may have any preferred size and shape as described above. In one modification, the periphery is then generated around the periphery of the circle by winding the edge of the flow control layer over itself so as to generate thickness around the periphery, and then sewing, heat sealing, gluing, etc., the wound edge to maintain thickness in its area. In another modification, the edge may be wound around an O-ring to form the periphery. In further modifications, the periphery is a separate component from the flow control layer and includes an O-ring that is sewn, heat-sealed, glued, or joined to the edge of the flow control layer. After the periphery is formed, the free edge of the circular flow control layer is wound to form it into a cone. The periphery can serve to create a seal between the periphery of the flow control cone and the inner surface of the housing during the pump stroke. A cone-shaped mesh layer may be formed by the same process, except that it does not need to include a periphery.

[0116] In addition to the periphery, the flow control layer may include a body. The body and periphery may be made from the same material or from different materials. In addition, the body and periphery may be separate components or formed integrally with each other. When provided as separate components, the body may be made from an elastomer polymer or Mylar® plastic film, and the periphery may be an O-ring. The peripheral edge of the flow control layer may be wound around the O-ring to form the periphery. The thickness of the periphery may exceed the thickness of the body. The body may have a thickness ranging from about 0.03 mm to about 0.05 mm (including all values ​​and partial ranges within that range). The periphery may have a thickness ranging from about 0.20 mm to about 1.5 mm (including all values ​​and partial ranges within that range). For example, the periphery may have a thickness of approximately 0.20 mm, 0.30 mm, 0.40 mm, 0.50 mm, 0.60 mm, 0.70 mm, 0.80 mm, 0.90 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, or 1.5 mm.

[0117] (Flexible diaphragm) In some modifications, the linearly reciprocating member of the pump described herein may include a flexible diaphragm as a valve member. The flexible diaphragm may be contained within a housing. The flexible diaphragm may have a collapsed configuration and an extended configuration, and may reciprocate linearly within the housing. In the collapsed configuration, the flexible diaphragm may have a smaller diameter than when in the extended configuration to allow it to advance through the blood vessel. Once it reaches the target location in the patient, the flexible diaphragm may deform to its extended configuration, moving blood through it from the inlet of the housing, through the body of the housing, to the outlet of the housing, generating the pressure required to pump the blood. The flexible diaphragm may be coupled to a support member, which in turn is coupled to an actuator that causes the flexible diaphragm to reciprocate linearly within the housing. The support member may be an expandable frame (shown in Figure 34) or a tine support, which are formed into a cone shape, as will be further described below. The connection to the expandable frame may be carried out in any preferred manner, for example, by stitching, suturing, or sewing, by the use of adhesive, by heat sealing, or by welding. The flexible diaphragm may include a diaphragm body and a periphery. In some modifications, the flexible diaphragm may include an elastomer polymer. Non-limiting examples of the elastomer polymer include, but are not limited to, silicone, polyester, polyurethane elastomer, fluoropolymer, or combinations thereof. Some modifications of the flexible diaphragm include polytetrafluoroethylene (PTFE) as the elastomer polymer. The body and periphery of the flexible diaphragm may include the same material or different materials. In some cases, the diaphragm body and periphery are formed integrally.

[0118] The material and / or thickness of the diaphragm body and periphery may be selected so as to be flexible enough to allow the flexible diaphragm to bend during the filling stroke and allow blood to flow around it, but to prevent the flexible diaphragm from abducting or folding during the pump stroke. Furthermore, the material and / or thickness of the flexible diaphragm may be rigid enough to generate the pressure required to bring about the pump stroke and to prevent stretching of the diaphragm body. In one modification, the flexible diaphragm may maintain its shape during the pumping cycle by including a periphery that is thicker than the diaphragm body.

[0119] In some variations, the thickness of the diaphragm body may range from approximately 0.03 mm to approximately 0.3 mm (including all values ​​and subranges within this range). For example, the diaphragm thickness may be approximately 0.03 mm, approximately 0.04 mm, approximately 0.05 mm, approximately 0.06 mm, approximately 0.07 mm, approximately 0.08 mm, approximately 0.09 mm, approximately 0.10 mm, approximately 0.20 mm, or approximately 0.30 mm. With respect to the periphery of the diaphragm, its thickness may range from approximately 0.20 mm to approximately 1.5 mm (including all values ​​and subranges within this range). For example, the periphery thickness may be approximately 0.20 mm, 0.30 mm, 0.40 mm, 0.50 mm, 0.60 mm, 0.70 mm, 0.80 mm, 0.90 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, or 1.5 mm. In some modifications, the periphery thickness may range from approximately 0.5 mm to approximately 1.0 mm (including all values ​​and partial ranges within that range). The periphery thickness may exceed the thickness of the diaphragm body, which may help the flexible diaphragm maintain its shape during pumping cycles, as mentioned above. A larger periphery thickness may also help create a seal between the periphery and the inner surface of the housing during the pump stroke. However, in some modifications, the periphery and body may have equal thickness. The thickness ratio between the diaphragm body and the periphery may range from approximately 1:5 to approximately 1:20. The periphery of the flexible diaphragm may have a width ranging from approximately 1.0 mm to approximately 2.0 mm (including all values ​​and partial ranges within this range). In one modified example, the diaphragm body may have a thickness of approximately 0.05 mm, and the periphery may have a thickness of approximately 0.25 mm.

[0120] Furthermore, the flexible diaphragm may have any preferred shape or geometric shape that is capable of creating a seal between the periphery of the diaphragm and the inner surface of the housing during the pump stroke. For example, the flexible diaphragm may have a conical, frustoconical, or hemispherical shape when in an extended configuration. The flexible diaphragm may also have multiple ribs that can help provide further rigidity to the flexible diaphragm body. In one modification, the flexible diaphragm has a conical shape and multiple ribs that help maintain the conical shape during the pump stroke. The multiple ribs may be formed integrally with the diaphragm body, or they may be separate components that are joined to the diaphragm body, for example, by the use of adhesive, welding, etc. In some modifications, the multiple ribs may extend from the central portion of the diaphragm body to the periphery. The multiple ribs may have a rib angle between the longitudinal axis of one rib and an axis perpendicular to the actuator, ranging from about 30 degrees to about 60 degrees (including all values ​​and partial ranges within that range). For example, the rib angles may be approximately 30 degrees, 35 degrees, 40 degrees, 45 degrees, 50 degrees, 55 degrees, or 60 degrees. Multiple ribs may be equally spaced apart from one another. In some modifications, multiple ribs may be unequally spaced apart from one another.

[0121] (Actuator / Controller) Pumps described herein may typically include actuators coupled to valve members via support members. Valve members may be flexible diaphragms or valve cones. Actuators may generally be configured to linearly reciprocate a flexible diaphragm or valve cone within a housing to generate filling and pumping strokes of a pumping cycle. Exemplary actuators may include, but are not limited to, other actuators having flexibility to track and navigate blood vessels over cables, wires, rods, or guidewires, and rigidity required to reciprocate a flexible diaphragm during pumping and filling cycles. The linear reciprocating motion of the actuator may be generated by a linear motor drive and a linear motor controller. Linear motors are typically installed outside the patient, but in some modifications, linear motors may be provided as part of a pump implanted in the patient, for example, in a subcutaneous pocket, or installed in the patient's heart or blood vessels.

[0122] The linear motor controller may adjust various parameters of the pumping cycle. For example, the linear motor controller may adjust the speed of the linear reciprocating motion of the actuator and flexible diaphragm, and the length of the pumping and filling strokes. The speed of the linear reciprocating motion may be adjusted by increasing or decreasing the number of pumping cycles per minute. In some modifications, the number of pumping cycles per minute may be preset or adjusted to a speed corresponding to the patient's natural cardiac pumping cycle. In other modifications, patient parameters such as blood pressure (e.g., left ventricular pressure, left ventricular end-diastolic pressure, aortic pressure, and / or systemic blood pressure) may be preset to target values ​​or ranges, and the pumping cycle parameters may be adjusted to meet the preset blood pressure values ​​or ranges. The preset targets for blood pressure and pumping cycles per minute may be based on factors such as the patient's age, height, or weight, or a combination of all these factors. The type of heart failure the patient is diagnosed with (e.g., systolic heart failure, diastolic heart failure, right heart failure, left heart failure) may also be a factor when establishing the pumping cycles per minute and blood pressure targets.

[0123] In some variations, the adjustment or control of pump parameters or patient parameters (e.g., left ventricular pressure, left ventricular end-diastolic pressure, aortic pressure, and / or systemic blood pressure) may be performed manually, for example, by one or more control features or buttons provided on the user interface of an external console. In other variations, pump parameters may be adjusted automatically, for example, using a closed-loop system. The closed-loop system may comprise a processor and instructions stored in the processor's memory. During pump operation, the processor may store and / or process data from the pump and / or patient, execute instructions from memory, and automatically adjust pump parameters based on data received from one or more sensors provided with the pump. For example, the pumping cycle speed may be automatically adjusted (i.e., increased or decreased) to meet a preset blood pressure, as described above.

[0124] Various types of sensors may be employed to measure pump parameters (e.g., pump cycles per minute) and patient parameters (e.g., blood pressure and blood flow rate). Non-limiting embodiments of sensors include pressure sensors, flow sensors, temperature sensors, heart rate sensors, and cardiac rhythm sensors. Pressure sensors may be installed at various pump locations. In some variations, one or more pressure sensors may be mounted in or on the blood flow inlet or inlet / inlet ducts, or one or more pressure sensors may be mounted in or on the blood flow outlet, outlet / outlet ducts, or pump skirt. In other variations, two pressure sensors may be mounted in or on the inlet and outlet for redundancy in case one inlet and / or outlet pressure sensor fails. In further variations, one or more pressure sensors may be mounted near the blood flow inlet or inlet / inlet ducts, or one or more pressure sensors may be mounted near the blood flow outlet, outlet / outlet ducts, or pump skirt. The pressure sensors may be communicatively coupled to the controller, as described above, so that the controller can receive measurements from the pressure sensors, utilize those measurements, and modify the pump parameters. For example, in some modifications, the controller may be configured to have predetermined hypertension setpoints, hypotension setpoints, and / or predetermined target blood pressure ranges. The controller may further be configured to compare measurements received from one or more of the pressure sensors with the hypertension setpoints, hypotension setpoints, and / or predetermined desired blood pressure ranges, and to modify one or more of the pump parameters (e.g., reciprocating speed) accordingly. For example, when measurements from the pressure sensors indicate that the patient's measured blood pressure has fallen below the low setpoint and / or below the desired range, the controller may increase the linear reciprocating speed.When the reading from the pressure sensor indicates that the patient's measured blood pressure has risen above the hypertension setpoint and / or is above the desired range, the controller may reduce the velocity of the linear reciprocating motion, thereby reducing the flow and returning the blood pressure below the hypertension setpoint and / or within the target range.

[0125] (Tyne) Some modifications of the pump described herein may also include a tine support as a support member. The tine support may comprise a base and a plurality of tines configured to support a flexible diaphragm in an extended configuration during the pump stroke. In other modifications, the tine support may be coupled to the flexible diaphragm, as further described below in Figure 5-7. The plurality of tines may be flexible and / or expandable and may have an extended configuration and a compressed configuration. In the compressed configuration, the plurality of tines may have a smaller diameter than when in the extended configuration to allow advancement through the blood vessel. Once at the target location in the patient, the plurality of tines may expand to a larger diameter. Furthermore, the plurality of tines may have an extended configuration during the pump stroke of a linear pumping cycle and a compressed or partially compressed configuration during the filling stroke. The plurality of tines may be coupled to an actuator. In one modification, each of the plurality of tines may extend from a common hub or base to a free end. The hub may be configured to be coupled to an actuator. Furthermore, the free ends of the multiple tines may extend outward or bend when the multiple tines move from a compression configuration to an expansion configuration.

[0126] The number of tines contained within a group of tines may range from approximately 2 to approximately 8. For example, a group of tines may contain 2 (2) tines, 3 (3) tines, 4 (4) tines, 5 (5) tines, 6 (6) tines, 7 (7) tines, or 8 (8) tines. In one modified example, a group of tines may contain 6 (6) tines. The group of tines may be equally spaced apart from each other or not equally spaced apart. In terms of material, the group of tines may be made from metals such as stainless steel, titanium, or alloys thereof, or from biocompatible polymers such as fluoropolymers, polyamides, polyetheretherketone (PEEK), polyimide, polyolefins, polyurethanes, or combinations thereof.

[0127] In one modification, the tines may include a metal strip. The metal strip may extend from a common base at one end. At the other end, each tine of the tines has a free end. The free end may be attached to an outer cylinder, for example, a short cylinder, by welding, soldering, or gluing. The outer cylinder may provide an additional support area for the flexible diaphragm to abut during the pump stroke and help prevent movement of the flexible diaphragm between the tines during the pump stroke. In one modification, the length of each outer cylinder is about 1.0 mm. The tines may be fabricated from a metal cylinder that is laser-cut to form a strip.

[0128] Instead of strips, multiple tines may include multiple flexible first wires. Any preferred number of first wires may be used. For example, four (4) wires, six (6) wires, eight (8) wires, ten (10) wires, or twelve (12) wires may be used. Multiple holes corresponding to the number of first wires may be drilled in the base so that one end of the wire can be inserted into the holes. At the other end (free end) of the wire, an outer casing may be attached in the same manner as described above. The outer casing may include a central hole through which a second wire is threaded. After being threaded through all the outer casings, the ends of the second wire may be joined by soldering, welding, gluing, and the equivalent. The second wire may be made from a variety of materials, including, but not limited to, stainless steel, spring steel (piano wire), or nitinol. In some variations, each tine of the multiple tines may include two wires attached to the same outer casing at their free ends. Thus, when the multiple tines include six (6) tines, the number of wires would be twelve (12). The second wires may provide additional flexible diaphragm support during the pump stroke, provided by the outer casing, so that movement of the flexible diaphragm between the tines during the pump stroke is prevented or minimized.

[0129] (umbrella structure) In some modifications, a pump for assisting blood circulation may include a housing having an inner surface and an expansion configuration, and a valve member having an umbrella structure disposed within the expandable housing. The umbrella structure may include a membrane having a body and a periphery, a frame having a plurality of supports, and anchors, and may also have an expansion configuration and a compression configuration. An actuator coupled to the umbrella structure may be configured to cause the umbrella structure to reciprocate linearly within the housing. During the pump stroke and filling stroke of the pump, the periphery of the membrane may be configured to maintain contact with the inner surface of the housing. In some modifications, the contact may be maintained for the entire duration of the pump stroke. In other modifications, the contact may be maintained for a portion of the pump stroke, insofar as sufficient pressure is generated to move the desired amount of blood out of the housing during the pump stroke. In further modifications, for example, when a high pump speed is required, the umbrella structure may be configured to have a small gap or clearance between its periphery and the inner surface of the housing. The gap may help to avoid the generation of excessive friction within the pump. The gap may also be sized so that the appropriate pressure is generated over the pump stroke while avoiding crushing or damaging red blood cells during the pump stroke. Here, the diameter of the umbrella structure in the expansion configuration may be at least about 95 percent of the diameter of the housing in the expansion configuration. For example, the umbrella structure in the expansion configuration may be at least about 95 percent, at least about 96 percent, at least about 97 percent, at least about 98 percent, or at least about 99 percent of the diameter of the housing in the expansion configuration.

[0130] The membrane of the umbrella structure may be bonded to multiple struts and may completely or partially cover the struts. The membrane may contain an elastomer polymer. Non-limiting examples of elastomer polymers include silicone, polyester, polyurethane, fluoropolymer, or combinations thereof. Possible fluoropolymers to be employed include polytetrafluoroethylene (PTFE) or expanded polytetrafluoroethylene (ePTFE). In some modifications, the umbrella structure may comprise multiple struts and a PTFE or ePTFE membrane coated on the struts. The membrane may cover all or part of the struts as mentioned above. In some modifications, the membrane may cover the length of the struts ranging from about 0.5 cm to about 3.0 cm (including all values ​​and partial ranges within this). For example, the length of coverage may be about 0.5 cm, about 1.0 cm, about 1.5 cm, about 2.0 cm, about 2.5 cm, or about 3.0 cm. The body and periphery of the membrane may contain the same or different materials. In some cases, the body and periphery of the membrane are formed integrally. The thickness of the main body of the membrane may range from approximately 0.03 mm to approximately 0.3 mm. The thickness of the membrane's periphery may range from approximately 0.70 mm to approximately 1.5 mm. The thickness of the periphery may exceed the thickness of the main body of the membrane. However, in some modifications, the periphery and the main body may have equal thickness.

[0131] The umbrella structure may comprise a frame including any preferred number of struts. The number of struts may range from 3 to 10 (including all values ​​and subranges within that range). For example, the number of struts may be 3, 4, 5, 6, 7, 8, 9, or 10. In one variation, the umbrella structure comprises 6 struts. In another variation, the umbrella structure comprises 10 struts. Multiple struts may support the membrane, and the struts may be made from stainless steel, nickel, titanium, or an alloy thereof (e.g., nitinol). In one variation, the struts are made from laser-cut nitinol tubes.

[0132] The support columns may have any preferred shape or geometric shape. The support columns may have one or more divisions, one or more of which may have any preferred shape or geometric shape. The cross-sectional shape of the support columns may be circular, oval, triangular, square, or rectangular. The support columns may have different cross-sectional shapes along their length. For example, a support column may have one or more divisions with a first cross-sectional shape (e.g., circular) and one or more divisions with a second cross-sectional shape (e.g., rectangular). In some cases, the support column may include three divisions, namely two end divisions and an intermediate division between them. The end divisions may have a circular cross-sectional shape, and the intermediate division may have a rectangular cross-sectional shape. The rectangular cross-sectional shape may provide an intermediate division with a flattened outer shape. In some variations, the different divisions of the support column may have different widths. For example, when a support column has three sections (two end sections and one intermediate section), the intermediate section may be wider than one or both of the two end sections. In other variations, the different sections of the support column may have different thicknesses. For example, one or both end sections may be thicker than the intermediate section (the intermediate section is flatter than one or both end sections).

[0133] The distal end of the strut may be configured to be non-traumatic. In one modification, the non-traumatic distal end may be shaped to help prevent the strut from damaging the inner surface of the housing during the pump stroke. For example, the non-traumatic distal end may have a round or oval shape. In addition, or alternatively, one or more slits or cutouts may be provided along the length of the strut to increase the strut's flexibility, which may help prevent the strut from damaging the inner surface of the housing during the pump stroke. In some modifications, the distal end may include an opening that allows blood to flow through it. The opening may have various sizes and shapes, depending on the size and shape of the distal end. For example, the opening may be shaped to be circular, oval, square, rectangular, triangular, etc. In one modification, the opening at the distal end is rectangular in shape. In another modification, the opening at the distal end is circular in shape. Radiopaque markers may also be provided at any suitable location along the length of one or more struts, for example, at the distal end of one or more struts (e.g., one-third of a strut, half of a strut, or all of a strut). In some modifications, the umbrella structure may include a bend and an opening in one or more of the struts. In some modifications, the inclusion of both of these features may help minimize the risk of the struts puncturing the housing during the pump stroke.

[0134] The length of the struts may range from approximately 1.0 cm to approximately 3.0 cm (including all values ​​and sub-ranges within this range). For example, struts may have lengths of approximately 1.0 cm, 1.1 cm, 1.2 cm, 1.3 cm, 1.4 cm, 1.5 cm, 1.6 cm, 1.7 cm, 1.8 cm, 1.9 cm, 2.0 cm, 2.1 cm, 2.2 cm, 2.3 cm, 2.4 cm, 2.5 cm, 2.6 cm, 2.7 cm, 2.8 cm, 2.9 cm, or 3.0 cm. In some modifications, for example, in modifications with longer struts, the struts may extend beyond the periphery of the membrane. In other modifications, the struts may not extend beyond the periphery and instead may be completely covered by the membrane.

[0135] As mentioned above, in some variations, one or more of the struts may include one or more bends or curves along their length. One or more bends may be provided at any point along the strut. For example, one or more bends may be provided at the distal end (free end) of the strut and / or at the midpoint of the strut. The bends of the struts may have varying lengths. For example, the length of the bends may range from about 0.2 cm to about 1.0 cm (including all values ​​and sub-ranges within that range). For example, the bends may have lengths of about 0.2 cm, about 0.3 cm, about 0.4 cm, about 0.5 cm, about 0.6 cm, about 0.7 cm, about 0.8 cm, about 0.9 cm, or about 1.0 cm.

[0136] The bend in the support column may form a bending angle of approximately 5 to 15 degrees (including all values ​​and partial ranges) with respect to the longitudinal axis of the umbrella structure. For example, the bending angle may be approximately 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 degrees. In addition to the rounded, non-traumatic distal tip, the bend may be employed to prevent the support column from puncturing or otherwise damaging the inner surface of the housing during the pump stroke.

[0137] The umbrella structure may further include an anchor having a proximal end and a distal end. The proximal end of the anchor may be configured to attach a support column to a linear actuator of the pump. The distal end of the anchor may be configured to attach to multiple support columns. In some modifications, the anchor and support columns are formed integrally by laser cutting from a nitinol tube. The anchor length may range from about 0.5 cm to about 1.5 cm (including all values ​​and partial ranges within this range). For example, the anchor length may be about 0.5 cm, about 0.6 cm, about 0.7 cm, about 0.8 cm, about 0.9 cm, about 1.0 cm, or about 1.5 cm. In some cases, the umbrella structure may include components that facilitate the collapse of the support columns during the filling stroke of the pumping cycle. For example, the support columns may be attached to the proximal or distal end of the anchor via hinges, pivots, joints, or other swivel mechanisms that increase the flexibility of the support columns at that point. Exemplary types of hinges may include, but are not limited to, but will be sized according to the width and / or length of the posts, but may include butt hinges, non-recessed hinges, pivot hinges, and folding hinges. Flexible connectors may also be used to join the posts to the anchor. Flexible connectors may include polymers or polymers with fiber reinforcement. The polymers may include thermoplastic elastomers such as styrene-based block copolymers, thermoplastic polyolefins, thermoplastic polyurethanes, thermoplastic polyamides, or thermoplastic copolyesters. All or some of the posts may be attached to the anchor by a swivel mechanism or flexible connectors.

[0138] When the umbrella structure is in its extended configuration, multiple supports may extend radially from the distal end of the anchor, generating a certain support angle with respect to the longitudinal axis of the umbrella structure. The support angle may partially depend on the support length and may range from about 30 degrees to about 60 degrees (including all values ​​and partial ranges within this range). For example, the support angle may be about 30 degrees, about 35 degrees, about 40 degrees, about 45 degrees, about 50 degrees, about 55 degrees, or about 60 degrees.

[0139] Instead of extending radially from the anchor, the multiple supports may be configured to invert around the anchor (e.g., fold backward) to form a cone shape, for example. In such a configuration, the multiple supports may be attached to the proximal end of the anchor. In contrast, when the multiple supports extend radially from the anchor, the anchor may generally be attached to the distal end of the anchor. A membrane may also completely or partially cover the multiple inverted supports.

[0140] In some variations, for example, when longer struts are employed, the struts may form a cage structure. The struts of the cage may be fixed or anchored to a linear actuator at one end and slidable across the linear actuator at the other end. In this configuration, as shown in Figure 38, the cage expands to an expanded configuration during the pump stroke of the pumping cycle and collapses to a collapsed configuration during the filling stroke. Referring to Figure 38, the struts 2200 may include a proximal end 2202, a distal end 2204, and an intermediate section 2206. When the cage 2208 is in the expanded configuration (as shown in Figure 38), the intermediate section 2206 of the struts 2200 may be flat and may also form a flattened region of the cage 2208. The proximal end 2202 of the struts 2200 may be fixedly attached to a linear actuator (not shown). The distal end 2204 is not attached to the linear actuator and may therefore slide along the linear actuator during the reciprocating motion of the cage 2208. A membrane (not shown) may cover any preferred length of the support column 2200, which is coupled to the cage 2208 and allows a pump stroke to be generated.

[0141] Any component of a pump described herein may be coated. For example, one or more of the cannula, expandable housing, expandable frame, and flexible diaphragm may be coated. One or more tines or one or more struts may also be coated. Pump components may be coated completely or partially. The coating may provide increased lubricity and / or wetting properties to the coated part of the pump, or may provide antifouling, anti-proliferative, or antimicrobial properties to the coated pump component.

[0142] The coating thickness may vary depending on the pump component being coated. In some modifications, when the expandable housing includes a coating, the coating thickness may range from approximately 0.0025 cm to approximately 0.010 cm (approximately 0.001 inches to approximately 0.004 inches) (including all values ​​and subranges within this range). For example, the coating thickness may be approximately 0.0025 cm, approximately 0.003 cm, approximately 0.004 cm, approximately 0.005 cm, approximately 0.006 cm, approximately 0.007 cm, approximately 0.008 cm, approximately 0.009 cm, or approximately 0.010 cm. When the flexible diaphragm is coated, the coating thickness may range from approximately 0.0013 cm to approximately 0.0025 cm (approximately 0.0005 inches to approximately 0.001 inches) (including all values ​​and subranges within this range). For example, the coating thickness may be approximately 0.0013 cm, approximately 0.0015 cm, approximately 0.0020 cm, or approximately 0.0025 cm.

[0143] The coating may generally contain polymer materials. Exemplary polymer materials may include, but are not limited to, hydrophilic polymers, hydrophobic polymers, or mixtures of these two types of polymers. The coating may be a single layer on the pump component or may consist of multiple layers. When multiple layers are employed, each layer may be made from the same polymer or from different polymers.

[0144] Examples of hydrophilic polymers that can be used to form coatings include, but are not limited to, polyurethanes, polyvinylpyrrolidone, polyvinyl alcohol, polyethylene glycol and its copolymers, polypropylene glycol and its copolymers, polyoxyethylene and its copolymers, polyacrylic acid, polyacrylamide, carboxymethylcellulose, cellulose and its derivatives, dextran and other polysaccharides, starch, guar, xantham and other gums and thickeners, collagen, gelatin and other biological polymers.

[0145] Examples of hydrophobic polymers that can be used to form a coating include, but are not limited to, fluoropolymers such as polytetrafluoroethylene (PTFE) and extended polytetrafluoroethylene (ePTFE), polyvinyl chloride (PVC), polyvinyl acetate, poly(ethylene terephthalate), silicone, polyester, polyamide, polyurea, styrene-block copolymer, polymethyl methacrylate, acrylic-butadiene-styrene copolymer, polyethylene, polystyrene, polypropylene, natural and synthetic rubber, acrylonitrile rubber, and mixtures and copolymers of any of the above. In one variation, the coating includes polytetrafluoroethylene (PTFE) as the polymer material. In another variation, the coating includes extended polytetrafluoroethylene (ePTFE) as the polymer material.

[0146] (Pump system) Systems for pumping blood are also described herein. These systems may generally include a pump comprising an expandable housing having an inner surface and an extension configuration. A valve, including a periphery, may be located within the expandable housing and may have an extension or extending configuration and a compression configuration. The pump may also include an actuator coupled to the valve, which linearly reciprocates the valve within the housing, generating pump strokes and filling strokes for the pumping cycle. During the pump stroke, the periphery of the valve member may be configured to maintain contact with the inner surface of the housing. In some modifications, the contact may be maintained for the entire duration of the pump stroke. In other modifications, the contact may be maintained for a portion of the pump stroke, insofar as sufficient pressure is generated to move a desired amount of blood out of the housing during the pump stroke. In further modifications, for example, when a high pump speed is required, the valve member may be configured to have a small gap or clearance between its periphery and the inner surface of the housing. The gap may help to avoid the generation of excessive friction within the pump. The gap may also be sized so that the appropriate pressure is generated over the pump stroke while avoiding crushing or damaging red blood cells during the pump stroke. Here, the diameter of the valve member in their extended or expanded configuration may be at least about 95 percent of the diameter of the housing in their expanded configuration. For example, the valve member in their extended or expanded configuration may be at least about 95 percent, at least about 96 percent, at least about 97 percent, at least about 98 percent, or at least about 99 percent of the diameter of the housing in their expanded configuration.

[0147] In addition, the system may include a console located outside the patient, containing a controller configured to adjust actuators. A user interface may be coupled to the controller and configured to manually set or adjust pump parameters or patient parameters, and / or display pump and patient parameters. The user interface may be a display that forms part of the console housing the linear actuators. The console may be a permanent component of the system, or a mobile component when coupled to a wheeled cart or other rolling base.

[0148] Exemplary pump parameters include, but are not limited to, pump cycles per minute and pump cycle duration. When setting or adjusting the pump cycle duration, the duration of either the filling stroke or the pump stroke may be set or adjusted. Non-exclusive examples of patient parameters include age, height, weight, left ventricular pressure, left ventricular end-diastolic pressure, aortic pressure, and systemic blood pressure.

[0149] Referring to Figure 32A, an exemplary console 1600 is shown coupled to a movable base 1602. The controller 1600 may be detachably coupled to the movable base 1602 and may be lifted from the base 1602 if desired. In addition, the movable base 1602 may include a handle 1604 and a storage compartment 1606 for holding pump components. The console 1600 may include an area 1608 for accessing and connecting drive lines / cables. A user interface 1610, comprising a display 1612, may also be provided on the console 1600. The display 1612 may show various pump and patient parameters and may include a touchscreen and / or buttons (e.g., touch-sensitive buttons). For example, as shown in Figure 32B, pump parameters such as cycles per minute (CPM) (also referred to herein as pump cycles per minute), the total number of pump cycles, and pump start-up time may be displayed. Patient parameters such as blood flow, left ventricular pressure, aortic pressure, and blood pressure may also be displayed. A touch-sensitive button 1614 may be used to manually set or adjust the pump cycles per minute, for example, to increase or decrease them. Audible and / or visual alerts may be sounded when any pump parameter or patient parameter exceeds or falls above a preset value, or above or below a preset range of values.

[0150] During use, the pump of this system may advance to a target location in the patient's circulatory system. The pump may comprise an expandable housing, which includes an inner surface, an expansion configuration, and a collapse configuration, as described above, and a valve member having a periphery positioned within the expandable housing. Once at the target location, the expandable housing may expand from the collapse configuration to the expansion configuration. Pump parameters and / or patient parameters may be determined, and the valve member may reciprocate linearly within the expandable housing according to those parameters to generate filling strokes and pump strokes. During the pump stroke, contact between the periphery of the valve member and the inner surface of the expandable housing may be maintained. In some modifications, the valve member may not contact the inner surface of the housing as mentioned above, and a small gap or clearance may exist between the periphery and the inner surface of the housing. Also, as mentioned above, the pump parameters may include pump cycles per minute, the duration of the pump cycle, or both. When setting or adjusting the duration of the pump cycle, the duration of either the filling stroke or the pump stroke may be set or adjusted, or both may be set or adjusted. When pump parameters are determined, they may be based on patient parameters such as age, height, weight, left ventricular pressure, left ventricular end-diastolic pressure, aortic pressure, or systemic blood pressure.

[0151] Pump and patient parameters may be displayed on the user interface. Parameters may be monitored continuously or intermittently, and the measured values ​​may be displayed continuously or intermittently on the user interface. The user interface may be a display that forms part of a console housing a linear actuator. The console may be a stationary component of the system, as mentioned above, or a mobile component when coupled to a wheeled cart or other rolling base. Pump and patient parameters may be manually adjusted via buttons on the user interface. In some cases, the user interface display includes touch-sensitive buttons for manually adjusting parameters. In other cases, pump parameters may be automatically adjusted based on patient parameters. Automatic adjustment may be performed by a controller.

[0152] The pump of this system may advance to a target location within an artery. When the artery is the aorta, the target location may be the ascending aorta, aortic arch, thoracic aorta, descending aorta, or abdominal aorta. The pump may also advance to a target location within a vein. The vein may be the inferior vena cava. When advanced within the inferior vena cava, the target location may reside between the hepatic vein and the right atrium. At this location, the pump may increase circulation from the liver or from the lower extremities. Another target location for the pump may be above or below the renal vein.

[0153] When the pumps are positioned to cross the aortic valve, the length of the pump below the aortic valve (and within the left ventricle) may range from approximately 4.0 cm to approximately 10 cm (including all values ​​and partial ranges within this range). For example, the length of the pump below the aortic valve may be approximately 4.0 cm, 4.5 cm, 5.0 cm, 5.5 cm, 6.0 cm, 6.5 cm, 7.0 cm, 7.5 cm, 8.0 cm, 8.5 cm, 9.0 cm, or 10 cm. These lengths may include the length of the housing chamber and all or part of the associated cannula. The total pump length from the distal end of the device to the proximal end of the associated cannula may range from approximately 5.0 cm to approximately 14 cm (including all values ​​and partial ranges within this range). For example, the total pump length may be approximately 5.0 cm, 5.5 cm, 6.0 cm, 6.5 cm, 7.0 cm, 7.5 cm, 8.0 cm, 8.5 cm, 9.0 cm, 9.5 cm, 10 cm, 10.5 cm, 11 cm, 11.5 cm, 12 cm, 12.5 cm, 13 cm, 13.5 cm, or 14 cm.

[0154] (Additional illustrative variations) An exemplary pump is shown in Figure 1. As shown therein, the pump 10 includes an extendable outer sheath 11 having an inner end 12 supporting a bearing 13. An expandable housing 25 (shown in more detail in Figure 3) is received inside the outer sheath 11 and holds the bearing 13 in a fixed mounting. An inner sheath 16 extends from the bearing 13 through the inside of the outer sheath 11. A tine support 15, having a plurality of tines 20 for supporting a flexible diaphragm 30, is positioned inside the inner sheath 16 in a crushed configuration. An actuator (drive cable) 40 is coupled to the tine support 15 at one end by a fixed mounting, extends through the inside of the inner sheath 16, and is attached at the other end to a linear motor 19 in a linear motor drive unit 18.

[0155] Referring to Figures 5, 6, and 7, another modification of the pump is illustrated. In these figures, pump 100 is substantially identical to pump 10 in both structure and function, the difference being found in the configuration of the expandable housing. Compared with Figures 3 and 4, note that pump 10 utilizes an expandable housing 25 from which a cannula or extension portion 28 extends. Turning to Figure 5, note that pump 100 utilizes an expandable housing 60 from which a cannula or extension portion 28 does not exist. Apart from this difference in the structure of the expandable housing, pumps 10 and 100 are substantially identical.

[0156] More specifically, Figure 5 shows a cross-sectional view of the pulsatile pump portion (expandable housing and flexible diaphragm) of the pump 100. Figure 5 shows the expandable housing 60 in its collapsed configuration. The expandable housing 60 may advance from within the outer sheath 11 (as shown in Figure 4). The expandable housing 60 includes an inlet (scaffold portion) 63 adjacent to the end 62, which in turn supports the bearing 13 in fixed mounting. The expandable housing 60 further includes an outlet (scaffold portion) 64 and a chamber 61 within the expandable housing 60. The chamber 61 may be formed by overmolding a portion of the scaffold of the expandable housing 60 with a polymer layer, as described above, or by bonding a fabric layer to the scaffold. The pump 100 further includes an inner sheath 16 extending through the outlet 64 and the chamber 61 to the inner end of the bearing 13. A tine support 15 is received within the inner sheath 16 and includes a plurality of tines 20. The drive cable 40 extends through the inner sheath 16 and is coupled to the tine support 15. The flexible diaphragm 30 is also coupled to the tine support 15.

[0157] In the configuration shown in Figure 5, the pump 100 has begun to expand the expandable housing 60, while the tine support 15 remains trapped within the inner sheath 16 in the compression configuration. Therefore, the next step in configuring the pump 100 for operation requires removing the inner sheath 16, allowing the multiple tines 20 to expand and assume their operational expanded configuration.

[0158] Figure 6 shows a cross-sectional view of the pulsating pump portion of pump 100. As mentioned above, Figure 6 shows pump 100 at an intermediate point between the compact configuration of Figure 5 and the operational configuration of Figure 7. Pump 100 includes an expandable housing 60. The expandable housing 60 includes an inlet 63 adjacent to the end 62, which in turn supports the bearing 13 in a fixed mounting. The expandable housing 60 further includes an outlet 64 and a chamber 61. Pump 100 further includes an inner sheath 16 which is withdrawn to a certain point within the outlet 64, thereby freeing the tines 20 and diaphragm 30 from being trapped in the inner sheath 16. The expandable housing 60 further includes the chamber 61 and the end 62. A tine support 15 is received within the inner sheath 16 and includes a plurality of tines 20. A drive cable 40 extends through the inner sheath 16 and the outer sheath 11 and is coupled to the tine support 15. The flexible diaphragm 30 is also coupled to the tine support 15.

[0159] In the configuration shown in Figure 6, the pump 100 begins the expansion of the expandable housing 60 and the release of the tine support 15 from the inner sheath 16. Therefore, the next step in configuring the pump 100 for operation requires that the tines 20 and diaphragm 30 of the tine support 15 expand, allowing them to assume their operational configuration.

[0160] Figure 7 shows a cross-sectional view of the pulsatile pump portion of pump 100. As mentioned above, Figure 6 shows pump 100 in its operational configuration. The expandable housing 60 includes an inlet 63 adjacent to the end 62, which in turn supports the bearing 13 in fixed mounting. The expandable housing 60 further includes a mesh portion 64 and a chamber 61. Pump 100 further includes an inner sheath 16 which is withdrawn to a certain point in the outlet 64, thereby freeing the tines 20 and diaphragm 30 from being trapped in the inner sheath 16. The expandable housing 60 further includes the chamber 61 and the end 62. The tine support 15 extends partially into the bearing 13. The tine support 15 includes a plurality of tines 20 extending to the indicated position. The drive cable 40 extends through the inner sheath 16 and the outer sheath 11 and is coupled to the tine support 15. The flexible diaphragm 30 is also coupled to the tine support 15 and extends to its fully extended configuration, overlapping with the outer end of the tine 20.

[0161] In the configuration shown in Figure 7, the pump 100 completes the extension of the expandable housing 60, freeing the tine support 15 from the inner sheath 16, allowing the tines 20 and diaphragm 30 to assume their fully extended positions. Thus, the pump 100 is fully configured for operation.

[0162] In some modifications, the pump for assisting blood circulation includes an expandable housing as illustrated in Figures 10A-10C. Referring to Figure 10A, the expandable housing 200 has a cannula 202 extending therefrom. The cannula 202 may have a smaller diameter than the expandable housing 200, which may be useful when the cannula is to cross the aortic valve. In some modifications, the expandable housing 200 may include a scaffold 204, which may be an expandable stent. The scaffold 204 may include, but is not required, a tapered proximal end 208 and a tapered distal end 210. The distal end 210 may function as an inlet for blood into the expandable housing 200, and the proximal end 208 may function as an outlet for blood exiting the expandable housing 200. To block blood from flowing through the stent opening and to provide a smooth surface over which a flexible diaphragm can reciprocate, the expandable housing 200 may include a layer 206 that is bonded to and / or covers a scaffold (e.g., a stent) 204. Figure 10B depicts a polymer layer 206 that may be overmolded onto or otherwise attached to the scaffold 204. The polymer layer 206 may be overmolded onto the scaffold 204 such that the scaffold 204 is embedded within or otherwise completely surrounded by the polymer layer 206. Figure 10C shows the expandable housing 200 and cannula 202 with the polymer layer 206 bonded to the scaffold 204.

[0163] The expandable housing in Figure 10C may include a flexible diaphragm, which in some modifications may be supported by a plurality of tines, as shown in Figure 11. Referring to Figure 11, the flexible diaphragm 212 may be located in a chamber formed within the body of the expandable housing 200, and the flexible diaphragm 212 may have a compressed configuration and an expanded configuration (as depicted in Figure 11). The flexible diaphragm 212 may be coupled to the actuator 214 such that the linear movement of the actuator 214 results in a corresponding linear movement of the diaphragm 212. A plurality of tines 216, which may help support the flexible diaphragm 214 against blood pressure during a pump stroke, are also shown in their expanded configuration. The expandable housing 200, flexible diaphragm 212, and / or tines 216 may be configured to self-expand so that the expansion of the expandable housing 200, flexible diaphragm 212, and tines 216 can be achieved by relative motion between the expandable housing 200 and the flexible outer sheath 218, which can constrain the expandable housing 200, flexible diaphragm 212, and / or tines during advancement to a desired position within the body (e.g., retraction of the outer sheath 218 and / or advancement of the expandable housing 200 relative to the outer sheath 218).

[0164] Instead of multiple tines, the support member for coupling to the flexible diaphragm may be an expandable frame. Referring to Figure 34, the flexible diaphragm 1800 may be located within a chamber formed by an expandable housing 1802. The flexible diaphragm 1800 may have a compressed configuration and an expanded configuration (as shown in Figure 34). The flexible diaphragm 1800 may be coupled to the actuator 1804 such that the linear movement of the actuator 1804 results in a corresponding linear movement of the flexible diaphragm 1800. An expandable frame 1806, which may help support the flexible diaphragm 1800 against blood pressure during a pump stroke, is also shown in its expanded configuration. The expandable housing 1802, the flexible diaphragm 1800, and / or the expandable frame 1806 may be configured to self-expand.

[0165] Generally, a flexible diaphragm contained within an expandable housing moves blood through it from the inlet of the housing, through a chamber within the body of the expandable housing, to the outlet of the housing, generating pressure for pumping the blood. As shown in Figure 12A, the flexible diaphragm 300 in its extended configuration includes a diaphragm body 302 and a periphery 304 centered around the periphery of the body 302. The body 302 and periphery 304 of the flexible diaphragm 300 are formed integrally. However, in other modifications, they may be formed separately and joined together.

[0166] In some modifications, the diaphragm body 302 and the periphery 304 may have different thicknesses. For example, in some modifications, the thickness of the periphery 304 may exceed the thickness of the diaphragm body 302, as shown in the cross-sectional view provided in Figure 12B. A smaller thickness of the diaphragm body 302 may allow the flexible diaphragm to be in its compressed configuration during the filling stroke or part thereof and in an extended configuration during the pump stroke of the pumping cycle. A larger periphery thickness may provide greater rigidity around the diaphragm 300 relative to the diaphragm body 302 and may help create a seal between the periphery 304 and the inner surface of the expandable housing during the pump stroke.

[0167] Some variations of the pump may include a tine support comprising a base and a plurality of tines coupled to an actuator that support a flexible diaphragm in an extended configuration during the pump stroke. For example, as shown in Figures 13A-13C, the tine support 401 comprises a base 404 and a plurality of tines 400. The plurality of tines 400 may comprise six (6) flexible metal strips 402 having an extended configuration (as shown in Figure 13A) and a compressed configuration (see Figure 5). The metal strips 402 may have a compressed configuration during the advance of the expandable housing in the vessel to a target location, and may expand radially outward to an extended configuration at the target location. Although shown as having a rectangular cross-sectional shape, the plurality of tines 400 may have any preferred shape or geometric shape, e.g., circular, square, triangular, oval, etc. The metal strips 402 may extend from a common hub or base 404 at one end and have a free end 406 at the other end. As shown in the cross-sectional view of Figure 13B, the base 404 may include a bore 408 configured to connect a plurality of tines to the actuator. Although shown to include six (6) metal strips 402, more or fewer strips may be used. The metal strips 402 may be equally spaced apart from each other, as shown in Figure 13C. However, in some modifications, the metal strips 402 may be unequally spaced apart from each other. Also shown in Figures 13A-13C is an outer cylinder 412, which is a short cylinder attached to the free end 406 of the metal strip 402. The free end 406 may be attached to the outer cylinder 412 using any preferred means, such as welding, soldering, or gluing. The outer cylinder 412 may provide an additional support area for the flexible diaphragm to abut during the pump stroke and may help prevent the flexible diaphragm from moving between the tines during the pump stroke.

[0168] In some modifications, the multiple tines 500 may comprise multiple flexible first wires 502, as shown in Figures 14A-14C. Although each tine of the multiple tines in the figures is shown to include two first wires 502, they may include one wire or more than two wires. Multiple holes (not shown) corresponding to the number of first wires 502 may be formed (e.g., drilled) within the base 504 of the tine support 501 so that one end of the wires can be inserted into the holes. At the other end of the wires (free end 506), an outer cylinder 508 is attached in the same manner as described above. More specifically, in Figures 14A-14C, pairs of first wires 502 are attached to the same outer cylinder at their free ends 506 to form one of the multiple tines. Thus, when 12 (12) first wires are paired, 6 (6) tines are formed. Each outer cylinder 508 may include a central hole 510 through which a second wire 512 can be threaded. After being threaded through all the outer cylinders 508, the ends of the second wire 512 may be joined by soldering, welding, gluing, and / or equivalent. The second wire may provide additional flexible diaphragm support to the outer cylinders during the pump stroke so that movement of the flexible diaphragm between tines during the pump stroke can be prevented or minimized. As shown in the cross-sectional view of Figure 14B, the base 504 may include a bore 514 configured for coupling to an actuator. The first wires 502 may be equally spaced apart from each other, as shown in Figure 14C. However, the first wires 502 may also be configured to be unequally spaced apart from each other.

[0169] Other pump modifications may not include multiple tines supporting the flexible diaphragm. For example, as shown in Figure 15, a flexible conical diaphragm 600 is housed within an expandable housing 602. The flexible diaphragm 600 may have a compression configuration and an extension configuration, and when in the extension configuration, it may have a conical shape. As shown in Figures 16A (end view) and 16B (side view), the flexible diaphragm 600 may include a diaphragm body 604 and a periphery 606 centered around the periphery of the body 602. As depicted in Figures 16A-16B, the body 604 and periphery 606 of the flexible diaphragm 600 may be integrally formed and may be formed from the same material. However, in other modifications, they may be separate components and / or may be made of different materials.

[0170] In some modifications, the body 604 and the ribs 606 may have the same thickness, while in other modifications, the body 604 and the periphery 606 may have different thicknesses. For example, in some cases, it may be advantageous to use a diaphragm with a periphery 606 that is thicker than the body 604. Turning to Figure 17, which is shown therein is an enlarged cross-sectional view of a diaphragm 600 in an extended configuration, coupled to an actuator 612 and positioned within the chamber of the body of an expandable housing 614. The periphery 606 contacts the inner surface 612 of the expandable housing 614 so that a seal 610 can be formed between the expandable housing 614 and the diaphragm 600. Also, as can be seen in Figure 17, the periphery 606 of the diaphragm 600 is thicker than the diaphragm body 604. The greater thickness of the periphery 606 may help create a seal 610 between the periphery 606 and the inner surface 612 of the expandable housing during the pump stroke, while still allowing the diaphragm body 606 to have the necessary flexibility for compression during the filling stroke. In this modification, the conical shape of the diaphragm helps seal the diaphragm against the inner surface 612 and also helps prevent abduction of the diaphragm when pressure from the blood flow (in the direction of the arrow) pushes against it.

[0171] In some modifications, the flexible diaphragm may have one or more (e.g., multiple, two, three, four, five, six, or more) ribs. Referring to the cross-sectional view provided in Figure 16C, multiple ribs 608 may extend from the central portion 601 of the diaphragm body 604 to the periphery 606. Multiple ribs 608 may be employed to maintain the conical shape of the diaphragm body 604 during the pump stroke. Multiple ribs 608 may have a rib angle of approximately 60 degrees between the longitudinal axis of each rib and an axis perpendicular to the actuator. Although the multiple ribs 608 are shown as being equally spaced from one another, in some cases they may be unequally spaced from one another.

[0172] Instead of a flexible diaphragm, the pump may include a valve cone as a valve member that moves linearly in a reciprocating motion. In one modification, as shown in Figures 25A-25C, the valve cone 1200 may include an expandable frame 1202, a mesh cone 1204, and a flow control cone 1206. The flow control cone 1206 includes a plurality of arcuate flaps 1212. Other flap shapes may also be used. In addition, although the expandable frame 1202, the mesh cone 1204, and the flow control cone 1206 are shown as being formed into a cone shape, they may be formed to have different shapes. The expandable frame 1202 may be a stent-like structure having an expansion configuration and a collapse configuration at one end. In the expanded conical shape shown in the figure, the expandable frame 1202 contains a mesh cone 1204 and a flow control cone 1204 within the cone 1208 of the frame 1202. The flow control valve 1200 may generally be configured such that the mesh cone 1204 seats between the flow control cone 1206 and the expandable frame 1202. In this configuration, as shown in Figure 25B, a plurality of flaps 1212 open in the direction of arrow A when blood is drawn into the expandable housing through the mesh cone during the filling stroke, and close when blood is moved out of the expandable housing in the direction of arrow B during the pump stroke. The mesh cone 1204 is positioned between the flow control cone 1206 and the expandable frame 1202 and may provide support to the flap 1212 of the flow control cone 1206 so that the flap 1212 is not pushed or bent through the opening 1201 in the expandable frame 1202 when pressure is applied to the flap 1212 during the pump stroke. Thus, the mesh cone 1204 may help maintain the flap 1212 in a closed configuration during the pump stroke as blood moves out of the housing through the housing outlet. However, during the filling stroke, the mesh cone 1204 allows blood to flow from the housing inlet through the holes in the mesh and then through the flap 1212, transitioning them to their open configuration so that blood can move towards the outlet side of the valve cones.The mesh cone 1204 and the flow control cone 1206 may be sewn to the expandable frame 1202 at multiple mounting points 1210, as shown in Figure 25C. Other mechanisms for attaching the material layers to the expandable frame may also be employed.

[0173] The expandable frame 1202 is shown separately from the rest of the valve cone depicted in Figures 26A–26C. Figure 26A provides a perspective view of the expandable frame 1202, Figure 26B provides a side view of the frame 1202, and Figure 26C provides a top view of the frame 1202. As shown in the figures, the expandable frame 1202 may include a first end 1214 and a second end 1216. The first end 1214 may be coupled to an actuator for reciprocating the valve cone back and forth within the housing. The second end 1216 is generally expandable and forms a molded end, e.g., a conical shape 1208. The expandable frame 1202 may comprise a plurality of cells 1218, which may be rhombic. However, the cell shapes are not so limited, and they may have any preferred shape. In addition, the cells may have any preferred size. In one modification, the cell may be precisely sized smaller than the flap within the flow-controlled cone so that the flap is not pushed through the cell during the pump stroke.

[0174] In Figures 27A and 27B, the mesh cone 1204 is shown separately from the rest of the valve cone depicted in Figures 25A-25C. Referring to Figure 27A, the material for the mesh cone 1204 may first be provided as a circular layer 1220 with a central cutout 1222 and a slit 1224 extending from the cutout 1222 to the periphery 1226 of the circle. The slit 1224 provides a free edge so that the circular layer 1220 can subsequently be wound to form the mesh cone 1204. The conical shape of the mesh cone 1204 may be maintained by sewing, heat sealing, gluing, etc., of the mesh material. The height (H) of the mesh cone 1204 may be about 1.0 cm to about 2.0 cm (including all values ​​and partial ranges within that). For example, the height of the mesh cone may be approximately 1.0 cm, 1.1 cm, 1.2 cm, 1.3 cm, 1.4 cm, 1.5 cm, 1.6 cm, 1.7 cm, 1.8 cm, 1.9 cm, or 2.0 cm.

[0175] Figures 28A–28C depict the flow control cone 1206 separately from the rest of the valve cone depicted in Figures 25A–25C. Referring to Figure 28A, the material for the flow control cone 1206 may first be provided as a circular layer 1228 with a central cutout 1230 and a slit 1232 extending from the cutout 1230 to the periphery 1234 of the circle. The slit 1232 provides a free edge so that the circular layer 1228 can be wound to later form the flow control cone 1206. Next, the flap 1212 may be formed by laser cutting or punching the flap shape into the circular layer 1228. The flap 1212 is shown as an arc shape in the figure, but may have any preferred size and shape as described above. Referring to Figure 28B, the periphery 1236 may be formed around the circular layer 1228 by winding the edge of the layer over itself to generate thickness around the periphery 1234, and then sewing, heat sealing, gluing, etc., the wound edge to maintain thickness in its area. After the periphery 1236 is formed, the free edge of the slit 1232 is wound to form the circular layer 1228 into a flow control cone 1206. The periphery 1236 may help to create a seal between the flow control cone 1206 and the inner surface of the housing during the pump stroke. The conical flow control cone 1206 may be held in place by sewing, heat sealing, gluing, etc., a mesh material. The height (H) of the flow control cone 1204 may be approximately 1.0 cm to approximately 2.0 cm (including all values ​​and partial ranges within that). For example, the height of the flow-controlled cone may be approximately 1.0 cm, 1.1 cm, 1.2 cm, 1.3 cm, 1.4 cm, 1.5 cm, 1.6 cm, 1.7 cm, 1.8 cm, 1.9 cm, or 2.0 cm.

[0176] In some variations, the flow control cone may have one or more slits that extend radially outward from the central portion of the flow control cone but terminate ahead of the outer edge of the flow control cone, which can form multiple flaps. For example, the flow control cone may be cut to produce one or more slits, and thus multiple flaps. The multiple flaps may be of any preferred size and shape that allows blood to flow into the housing during the filling stroke. Generally, the flow control cone may be configured such that more flaps are included when they are smaller in size, and fewer flaps are included when they are larger in size. For example, three triangular flaps may be employed when the flaps are larger in size, as shown in Figures 29A and 29B. Figure 29A shows the side of the flow control cone that will face the outlet of the pump housing, and Figure 29B shows the side of the flow control cone that will face the inlet of the pump housing. Referring to the figure, the valve cone 1300 includes a flow control cone 1302, which is positioned within and covering the expandable frame 1304. Three slits 1306 in the flow control cone 1302 form three triangular flaps 1308 in the flow control cone 1302. The expandable frame 1304 supports the flow control cone 1302 so that the flaps are not pushed through the opening 1310 in the expandable frame 1304 when pressure is applied to the flaps 1308 during the pump stroke. However, during the filling stroke, the expandable frame 1304 allows blood to flow from the housing inlet, through the expandable frame opening 1310, and then through the flaps 1308, lifting them from the surface of the expandable frame 1304 so that the blood can move towards the outlet side of the flaps 1308.

[0177] In further modifications, the flow control cone may comprise a membrane and a plurality of struts arranged in an umbrella structure, and may have an open configuration and a collapsed configuration. For example, the membrane may be coupled to and supported by the struts. Any preferred number of struts may be included. For example, the number of struts may range from 3 to 10. For example, 3 struts, 4 struts, 5 struts, 6 struts, 7 struts, 8 struts, 9 struts, or 10 struts may be employed. Generally, a flow control cone comprising a membrane and a plurality of struts may have a collapsed configuration during the filling stroke (Figures 30A and 30B) and an open configuration during the pump stroke (Figures 30C and 30D). Referring specifically to Figures 30A-30D, the valve cone 1400 includes an expandable frame 1402 and a flow control cone 1404 disposed within the expandable frame 1402. As shown in detail in Figures 30B and 30C, the flow control cone 1404 may comprise an umbrella structure including a membrane 1406 having a periphery 1412 and a plurality of supports 1408. The membrane 1406 is coupled at one end to an expandable frame 1402 via a weld ring 1410. The periphery 1412 is a free edge that is not attached to the expandable frame 1402. During the filling stroke, the collapse of the membrane 1406 allows blood to flow from the housing inlet through the expandable frame opening 1414 and fill the housing pump. During the pump stroke, the expandable frame 1402 supports the membrane 1406 so that when pressure is applied to the membrane 1406, the membrane 1406 transitions to its open configuration, covering the expandable frame opening 1414, and thus preventing blood from flowing toward the outlet side of the housing and toward the inlet side. However, as mentioned above, in some modifications, the expandable frame 1402 may not be required, and the membrane 1406, including multiple support columns 1408, reciprocates linearly without the expandable frame 1402 to generate pump strokes and filling strokes.

[0178] An umbrella structure capable of linear reciprocating motion without an associated expandable frame is shown in Figures 35A–35C and 36A–36C. In the figures, the umbrella structure may include a membrane, a plurality of struts, and an anchor. The membrane may completely or partially cover the struts. Referring to Figure 35A, the umbrella structure 1900 is shown with a membrane 1902 that completely covers a plurality of struts 1904, and an anchor 1906 having a proximal end 1908 and a distal end 1910. As shown in the side view of Figure 35B, the struts 1904 may gradually widen radially outward to form a conical shape and also generate a strut angle (SA) of 40 degrees with respect to the longitudinal axis 1912 of the umbrella structure 1900. In the modification shown in Figure 35C, the strut angle (SA) is also 40 degrees, but the struts 1914 include a further bend 1916. The bending angle (BA) of the resulting support may be 30 degrees with respect to the longitudinal axis 1918 of the umbrella structure 1920. In further modifications, as shown in Figures 36A-36C, the umbrella structure 2000 also includes a membrane 2002, a plurality of support columns 2004 having a proximal end 2005 and a distal end 2006, and an anchor 2008 having a proximal end 2010 and a distal end 2012. In this modification, the support columns 2004 may have a ski-like shape, the distal end 2006 of the support column 2004 includes a bend, and the intermediate section 2007 is flattened and wider than the proximal end 2005 or the distal end of the support column 2004. The membrane 2002 may partially cover the plurality of support columns 2004. Some of the distal ends 2006 of the plurality of support columns may include a rounded tip 2014. The rounded tip 2014 may be equipped with a radiopaque marker. Referring to Figure 36C, a side view of the umbrella structure 2000 is provided, showing a support angle (SA) of 40 degrees with respect to the longitudinal axis 2016 of the umbrella structure 2000. In addition, each support 2004 includes a bend 2018 at the distal end 2006 of the support. The bend angle (BA) of the support formed therefrom may be 15 degrees with respect to the longitudinal axis 2016 of the umbrella structure 2000.

[0179] The umbrella structure may include components that facilitate the collapse of the support columns during the filling stroke of the pumping cycle. In some cases, the components may be a pivoting mechanism, such as a hinge, or a flexible connector that increases the flexibility of the support column at that point. The pivoting mechanism or flexible connector may attach the support column to the anchor at the proximal or distal end of the anchor. For example, as shown in Figure 48, the valve member 4000 may comprise an umbrella structure 4001 including a plurality of support columns 4002. The support columns 4002 may be attached to the proximal end 4003 of the anchor 4004 by a pivoting mechanism 4006.

[0180] Instead of extending radially from the anchor, the multiple supports may invert around the anchor (e.g., fold backward) to form a cone shape, for example. For example, as shown in Figure 39A, the umbrella structure 2300 includes multiple supports 2302 that are inverted around the anchor 2304. The anchor 2304 may include a proximal end 2306 and a distal end 2308. When the multiple supports 2302 are inverted, the actuator (not shown) may generally be attached to the proximal end 2306 of the anchor 2304. In contrast, when the multiple supports 2302 extend radially from the anchor 2304 and are not inverted, the actuator (not shown) may generally be attached to the distal end 2308 of the anchor 2304. The membrane 2310 may also cover the multiple supports 2302, as shown in Figure 39B. In the modified example shown in Figure 39B, the support is shown to be completely covered, but in some modifications, the membrane may only partially cover the support.

[0181] The distal end of the strut may be configured to be non-traumatic, as mentioned above. In one modification, the non-traumatic distal end may be shaped to help prevent the strut from damaging the inner surface of the housing during the pump stroke. For example, the non-traumatic distal end may have a rounded or oval shape, as shown in Figure 40. Referring to Figure 40, a plurality of struts 2400 are shown, including a distal end 2402 having an oval (e.g., paddle-like) shape. In addition, or alternatively, one or more slits or cutouts 2404 may be provided along the length of the strut to increase the strut flexibility, which may help prevent the strut from damaging the inner surface of the housing during the pump stroke.

[0182] In some modifications, the distal end of one or more struts may include an opening that allows blood to flow through it. The opening may have various sizes and shapes, depending on the size and shape of the distal end. The opening may be shaped to be circular, oval, square, rectangular, triangular, and equivalent. In one modification, the opening at the distal end is rectangular in shape. In another modification, the opening at the distal end is circular in shape. Referring to Figure 41, the valve member 2500 includes a plurality of struts 2502 having circular distal ends 2504, and a membrane 2508 extending beyond the distal end 2504, for example, about 1.0 mm to about 2.0 mm (including all values ​​and partial ranges within that). For example, the membrane may extend beyond approximately 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, or 2.0 mm at its distal tip. Each circular distal tip 2504 includes a circular opening 2506. While Figure 41B depicts all distal ends of the struts including openings, in some modifications, only a portion of the distal end may include an opening (e.g., at one-fifth of the strut, at one-quarter of the strut, at one-third of the strut, at half of the strut). Radiopaque markers 2510 may also be provided at any suitable location along the length of the strut, for example, at the distal end of one or more struts (e.g., one-third of the strut, half of the strut, or all of the strut). Instead of using radiopaque markers, a portion of the support column may be coated with a radiopaque material.

[0183] In other modifications, the umbrella structure may include a bend in one or more of the struts and an opening. In some modifications, the inclusion of both of these features may further help minimize the risk of the struts puncturing the housing during the pump stroke. Referring to Figures 42A-42C, the umbrella structure 2600 may include a membrane 2602, a plurality of struts 2604, and an anchor 2606. An actuator 2608 (e.g., a drive tube) causes the umbrella 2600 to reciprocate linearly, expanding the umbrella 2600 during the pump stroke and collapsing the umbrella 2600 during the filling stroke. The struts 2604 may include a bend 2614. The portion of the strut 2604 distal to the bend 2614 may form a distal tip 2610 of the strut 2604. The distal tip 2610 may include an opening 2612 that allows blood to flow through it. The shape of the opening 2612 corresponds to the shape of the distal tip 2610 in the modified example shown in Figure 42A, but this is not required, and other shapes may be used. It should be understood that the shape of the opening does not need to correspond to the shape of the distal tip 2610. For example, the shape of the distal tip may be oval, while the opening may be square. The umbrella structure 2600 may include 10 struts 2604, but as referred to herein, fewer or more struts may be employed in other modified examples. As shown in Figure 42B, the struts 2604 may be equally spaced around the outer circumference of the membrane 2602. Referring to Figure 42C, an assembly drawing of a modified example of the valve member 2618 including the umbrella structure 2600 is provided. In the modified example depicted therein, the valve member 2618 includes an umbrella structure 2600 comprising a membrane, a plurality of struts 2604, an anchor 2606, and an actuator 2608 (e.g., a drive pipe). The film may be formed from multiple layers, for example, by sealing an outer layer of material 2620 to an inner layer of material 2622, with an umbrella structure 2600 in between. The sealing of the outer and inner layers may be performed in various ways, for example, by heat, pressure, and / or by the use of adhesives. The ring 2616 may also be attached to the inner layer 2622 by heat sealing or pressure sealing, or by employing adhesives.The ring 2616 may further include a plurality of openings through which the support column 2604 can extend. The ring 2616 can thicken the membrane edge and facilitate contact between the membrane 2602 and the housing (not shown) during the pump stroke.

[0184] The inner layer, outer layer, and ring may be made from the same material or from different materials. In some modifications, one or more of the inner layer, outer layer, and ring may contain an elastomer polymer. Non-limiting examples of elastomer polymers include silicone, polyester, polyurethane, fluoropolymer, or combinations thereof. Possible fluoropolymers include polytetrafluoroethylene (PTFE) or expanded polytetrafluoroethylene (ePTFE). In one modification, the inner layer, outer layer, and ring are made from PTFE. In another modification, the inner layer, outer layer, and ring are made from ePTFE.

[0185] Other variations of the pump may include a valve member having elements that limit its expansion. For example, the valve member may include an expandable frame bonded to a polymer layer, where a plurality of control lines or tethers attach the valve member to the pump actuator. The plurality of tethers may have a relaxed state and a taut state, and may have a length that limits the expansion of the valve member so that it contacts the inner surface of the pump housing during the pump stroke of the pumping cycle without generating excessive friction, and creates a seal with it. The length of the tethers may also be adjusted so that a small gap is created between the valve member and the inner surface of the pump housing during the pump stroke. During the filling stroke, the valve member may collapse into a collapsed configuration, which in turn may move the plurality of tethers into a relaxed state. During the pump stroke, the valve member may expand into a taut configuration, which may transition the plurality of tethers from a relaxed state to a taut state.

[0186] For example, referring to Figure 31, an exemplary valve member is shown, which is located within an expandable housing 1500. The valve member includes a frame 1502, which may be a hollow hemispherical structure made from nitinol and coated with a thin polymer. The frame 1502 may have an expanded configuration and a collapsed configuration. When expanded, the element frame may have a diameter of about 20 mm. A number of control lines 1504 attach the open end 1508 of the frame 1502 to the pump actuator 1506. In addition, a check valve 1510 may be included in the pump. During the filling stroke, the hydraulic pressure of the blood may partially collapse the frame 1502, allowing blood to flow around it. At the start of the filling stroke, closing the check valve 1510 can ensure rapid collapse of the frame 1502. When the stroke reverses to the pump stroke of the pump cycle, the check valve 1510 may be opened, and the frame 1502 may expand to its expanded configuration. The control line 1504 can regulate the sealing pressure of the elements against the housing 1500 during the pump stroke, preventing the application of excessive pressure that could generate excessive friction. The check valves may also be equipped with alternative valve members as described herein to assist in their collapse and expansion.

[0187] In some modifications, the pump may include an expandable housing having multiple openings or perforations within its body, as mentioned above. The openings may be wall-penetrating openings within the body (e.g., through both the scaffold and the layers) so that blood from the chamber of the body of the expandable housing can flow directly from inside the chamber to the outside of the chamber without passing through the inlet or returning through the outlet. When openings are included, a skirt may be coupled to or extend from the outer surface of the expandable housing in a manner that surrounds, superimposes on, or otherwise covers the multiple openings in order to direct the blood flowing through the openings. For example, the skirt may be configured to generate retrograde blood flow directed toward the patient's heart during the pump stroke of the pumping cycle. Retrograde blood flow can help provide proper perfusion of arteries branching from the aortic arch, such as the carotid and subclavian arteries.

[0188] Turning to Figure 19, the pump 800 may include an expandable housing 802 having a plurality of openings 804, and a cylindrical skirt 806 coupled to the expandable housing 802 in a manner that separates it from the skirt. The skirt 806 may be coupled to the outer surface of the housing 802 and surround it circumferentially (or partially circumferentially), or it may rest on at least some of the plurality of openings 804. The skirt 806 may have a first diameter at its proximal end and a second larger diameter at its distal end, such that the skirt 806 may be coupled to the housing 802 at its proximal end, but then gradually widen or widen from the plurality of openings 804 formed within the housing 802, allowing retrograde flow of blood through them. The skirt 806 and the expandable housing 802 may be formed integrally as a single piece, or they may be separate components joined to each other by friction fitting, adhesive, welding, soldering, and / or equivalent. An outlet 808 may be provided at the proximal end 801 of the expandable housing 802 for antegrade blood flow into the body. The cannula 810 may be coupled to the expandable housing 802 and may extend from the distal end 820 of the housing through the aorta 816 and aortic valve 822 into the left ventricle 814. An inlet 812 may be provided at the distal end 824 of the cannula 810 for blood entry from the left ventricle 814. The cannula may have a variety of lengths. The variety of lengths may be used to adapt to factors such as the anatomical structure of different patients, the patient's physique or age, the desired location of pump placement, and / or points of access to the circulatory system. Any preferred length may be utilized, but the cannula may have short, intermediate, or long lengths as described above. In Figure 19, the cannula 810 has an intermediate length ranging from approximately 25 cm to approximately 30 cm.

[0189] Referring to Figure 20, an enlarged view of the pump 800 of Figure 19 is shown. A cutout is provided within the expandable housing 802 to further illustrate the structure and configuration of the skirt 806 related to the multiple openings 804. In Figure 20, the housing 802 includes the multiple openings 804 at its distal end 820. The skirt 806 is arranged concentrically with respect to the expandable housing 802 and rests on the multiple openings 804. In addition, the skirt 806 is configured such that a space 805 is provided between the multiple openings 804 and the skirt 806. During use, as the flexible diaphragm 803 moves toward the outlet 808, the blood in the expandable housing 802 is pushed toward the patient's feet through the outlet 808 of the expandable housing 802 in the direction of arrow 826. During the movement of the flexible diaphragm 803, a first portion of the blood is pushed through the multiple openings 804 as the flexible diaphragm passes beside them. The first portion of blood is pushed into space 805 and then directed by the skirt 806 to return towards the heart in the direction of arrow 828. As the flexible diaphragm 803 continues to move toward outlet 808, the portion of blood remaining within the expandable housing 802 (the second portion) is pushed through outlet 808 toward the feet and toward the rest of the body. The combination of the number of openings and the diameter of each opening may provide a certain amount of open surface area on the expandable housing for retrograde blood flow. In addition, the skirt may be configured to adjust the amount of open surface area for retrograde flow by adjusting the number of openings that are patent (open) and closed. Generally, a larger open surface area may provide more retrograde blood flow toward the patient's head, and a smaller open surface area may provide more antegrade blood flow toward the body.

[0190] Several modifications of the pump may be used to assist renal perfusion. In these modifications, the pump may include any combination of the structures described herein. For example, the pump may include a housing and a linearly reciprocating member disposed within the housing, comprising a valve, e.g., a flexible diaphragm, a valve cone, an umbrella structure, or an inverted umbrella structure. The housing may be expandable and may include an inner surface, an expanded configuration, and a collapsed configuration. A sheath, which may be positioned around the housing, may maintain the housing in the collapsed configuration during advancement to a target location. Upon reaching the target location, the sheath may retract to allow the housing to expand into the expanded configuration.

[0191] In some modifications, the renal perfusion pump is configured as shown in Figure 33. Referring to the figure, the pump 1700 is shown positioned within the descending aorta 1702 above the renal artery 1704. The pump 1700 may include a valve member 1706 within the housing 1708 that reciprocates linearly to increase perfusion to the kidney 1710. In this modification, the housing 1708 may lack a cannula. The housing 1708 may include a plurality of cells 1707 having a rhomboid shape, depending on the expansion of the housing 1708. However, it should be understood that the support can be configured to form wider or narrower rhomboid shapes, or other cell shapes. For example, instead of a rhomboid shape, the cells 2700 may be oval in shape, as shown in Figure 43. Other cell shapes may include circles, triangles, squares, rectangles, etc. In a modified version including a cannula 2802, the expandable housing 2800 may also include a rhomboid cell 2804, as shown in Figure 44. In a further modification, the support columns 2902 of the expandable housing 2900 may be linear and extend parallel to each other, as shown in Figure 45.

[0192] As described above, in its expanded configuration, the housing may have a diameter ranging from approximately 12 mm to approximately 30 mm (including all sub-ranges within that range). For example, in its expanded configuration, the housing may have a diameter of approximately 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, 25 mm, 26 mm, 27 mm, 28 mm, 29 mm, or 30 mm. Furthermore, the housing chamber of the renal perfusion pump may have a length ranging from approximately 2.5 cm to approximately 10 cm (including all values ​​and sub-ranges within that range) in its expanded configuration. For example, the enclosure chamber may have lengths of approximately 2.5 cm, 3.0 cm, 3.5 cm, 4.0 cm, 4.5 cm, 5.0 cm, 5.5 cm, 6.0 cm, 6.5 cm, 7.5 cm, 8.0 cm, 8.5 cm, 9.0 cm, 9.5 cm, or 10 cm in its expanded configuration.

[0193] Some variations of the expandable housing may also include one or more expanding ends having a larger diameter than that of the housing in its expanded state. In some cases, the diameter of the expanding end may be about 1.5 to about 2 times larger than the diameter of the expanded housing. One or more ends may be self-expandable. Expansion at one or more ends may help to anchor the housing in a blood vessel, such as the descending aorta. One or more ends may expand to anchor in a blood vessel having a diameter ranging from about 15 mm to about 25 mm (including all values ​​and partial ranges thereof). For example, one or more ends may expand to anchor in a blood vessel having a diameter of about 15 mm, about 16 mm, about 17 mm, about 18 mm, about 19 mm, about 20 mm, about 21 mm, about 22 mm, about 23 mm, about 24 mm, or about 25 mm. In some variations, the housing may include one expanding end. In other variations, the housing may include two expanding ends. Depending on the expansion, the ends may be configured to have the same or different shapes. For example, referring to Figures 46A, 46B, 47A, and 47B, the housings 2900, 3000 include two expanded ends, namely, first expanded ends 2902, 3002 and second expanded ends 2904, 3004. The first expanded ends 2902, 3002 have a rounded shape, while the second expandable ends 2904, 3004 have a taper 2906, 3006. The shapes of the expanded ends may vary and may depend, for example, on the orientation of the struts and / or the shape of the cells formed by the struts.

[0194] The housing may further comprise a covering, coating, or layer configured to block blood flow, as described above herein. The covering, coating, or layer may be provided on the entire housing or on a section or portion of the housing. In some variations, the covering, coating, or layer may be provided on a length of housing ranging from about 1.0 cm to about 6.0 cm (including all values ​​and partial ranges therewith). For example, the length of housing to be coated may be about 1.0 cm, about 1.5 cm, about 2.0 cm, about 2.5 cm, about 3.0 cm, about 3.5 cm, about 4.0 cm, about 4.5 cm, about 5.0 cm, about 5.5 cm, or about 6.0 cm. Referring to Figures 46B, 47A, and 47B, coatings 2908, 3008 may be provided on portions of housing 2900, 3000 between first expandable ends 2902, 3002 and second expandable ends 2904, 3004. As shown in Figure 47B, the valve member 3010 may reciprocate within the length of the housing that is coated.

[0195] When the valve member is a flexible diaphragm, the flexible diaphragm may have an extended configuration and a collapsible configuration, as mentioned above, and may include a diaphragm body and a periphery. Similarly, when the valve member is a valve cone, the valve cone may have an expanded configuration and a collapsible configuration, and may include a layer having a plurality of flaps that allow blood flow into the housing during the filling stroke but prevent blood flow through the valve cone during the pump stroke. Bearings in the expandable housing may also be provided to prevent movement of the flexible diaphragm or valve cone within the housing. When the valve member is an umbrella structure, the umbrella may include a membrane having a body and a periphery, a frame having a plurality of supports, and anchors, as described above, and may also have an expanded configuration and a collapsible configuration.

[0196] The distal end of the strut may be configured to be non-traumatic, as mentioned above. In one modification, the non-traumatic distal end may be shaped to help prevent the strut from damaging the inner surface of the housing during the pump stroke. For example, the non-traumatic distal end may have a round or oval shape. In addition, or alternatively, one or more slits or cutouts may be provided along the length of the strut to increase the strut's flexibility, which may help prevent the strut from damaging the inner surface of the housing during the pump stroke. In some modifications, the distal end may include an opening that allows blood to flow through it. The opening may have various sizes and shapes, depending on the size and shape of the distal end. The opening may be shaped to be circular, oval, square, rectangular, triangular, etc. In one modification, the opening at the distal end is rectangular in shape. In another modification, the opening at the distal end is circular in shape. Radiopaque markers may also be provided at any suitable location along the length of one or more struts, for example, at the distal end of one or more struts (e.g., one-third of a strut, half of a strut, or all of a strut). In some modifications, the umbrella structure may include a bend and an opening in one or more of the struts. The inclusion of both of these features may help minimize the risk of the struts puncturing the housing during the pump stroke.

[0197] The renal perfusion pump reciprocates linearly in the same manner as described above. In short, the renal perfusion pump may include an actuator coupled via a support element to a valve member (e.g., a flexible diaphragm, valve cone, or umbrella structure) which may be configured to cause the valve member within the housing to reciprocate linearly, generating the filling stroke and pump stroke of the pumping cycle. The periphery of the valve member may be configured to maintain contact with the inner surface of the housing during the pump stroke. However, the support elements may generally be sized and / or molded so that they do not contact the inner surface of the housing while they reciprocate linearly within the housing. The pump may be driven by an external linear motor drive and linear motor controller, which may be mounted on the proximal end of a catheter outside the patient. The linear motor drive may be operationally coupled to the pump by a cable or other actuator. Furthermore, the pump may be powered by an AC or DC source.

[0198] The pump described herein may be driven by an external linear motor drive and linear motor controller, which are mounted on the end of the catheter outside the patient. The linear motor drive may be operationally coupled to the pump by a flexible cable or other flexible actuator extending through the catheter. For example, as shown in Figure 22A, the pump 900 may be coupled to the linear motor drive 902 and linear motor controller 904 via the catheter 906. The linear motor drive 902 and linear motor controller 904 may be mounted outside the patient, within a console 908. The catheter 906 may be coupled to an expandable housing 910 of the pump 900, as shown in the close-up view of Figure 22B. Here, the expandable housing 910 includes a plurality of openings 914 and a skirt 912 arranged concentrically around the openings 914. A cannula 916 may extend from the expandable housing 910 so that the distal end 918 of the cannula 916 can be positioned within the left ventricle 920. As shown in the close-up view of Figure 22C, the inlet 922 may be provided at the distal end 918 of the cannula 916. The inlet 922 may draw blood from the left ventricle 920 into the expandable housing 910 for systemic pumping. The linear motor controller 904 may further be configured to control the pump 900. In some modifications, the linear motor controller 904 may be configured to control the pump 900 via sensor feedback, such as pressure sensor feedback. For example, as described above, one or more pressure sensors (not shown) may be mounted in or on the inlet 922 of the cannula 916, and one or more pressure sensors may be mounted in or on the outlet 924 of the expandable housing 910. In some modifications, two pressure sensors may be mounted in or on the inlet 922 and / or outlet 924 for redundancy. For example, referring to Figure 24A, the pump 1100 may include two pressure sensors 1102 on the distal end of the inner sheath 1103 at the pump outlet 1104, and two other pressure sensors 1106 may be located on the nose cap 1105 at the pump inlet 1108.Figures 24B and 24C show enlarged views of the pressure transducers at the pump outlet 1104 and pump inlet 1108. The controller 904 may be configured to have predetermined high and low blood pressure setpoints. When the measurement from the pressure transducer indicates that the blood pressure has fallen below the low setpoint, the controller 904 may increase the speed of the linear reciprocating motion, and / or when the measurement from the pressure transducer indicates that the blood pressure has risen above the high setpoint, the controller 904 may decrease the speed of the linear reciprocating motion, thereby reducing the flow and returning the blood pressure to within the target range.

[0199] Turning to Figures 23A-23C, in some modifications, the pump may be located outside the body, for example, in a console at the patient's bedside. A coaxial catheter may be connected to the pump at one end and inserted into the patient at the other end, so that blood flows between the patient and the external pump. The coaxial catheter may include an inlet lumen and an outlet lumen. As described with respect to Figure 22A, the external pump may be driven by a linear motor drive and a linear motor controller mounted on the end of the coaxial catheter outside the patient. The linear motor drive may be operationally coupled to the pump by any suitable connector or fitting, for example, a quick-connect coupler. For example, as shown in Figure 23A, the external pump 1000 may be coupled to the coaxial catheter 1006 via inlet and outlet tubes 1016. The pump 1000 may also be coupled to a linear motor drive 1002 and a linear motor controller 1004 in a console 1008. The console 1008 may also include a power source 1010, a battery 1012, and / or a user interface 1014. The coaxial catheter may include an inlet lumen 1018 and an outlet lumen 1020, as shown in the close-up view provided in Figure 23B. The distal end of the coaxial catheter 1006 is shown in the close-up view provided in Figure 23C, where blood is drawn from the left ventricle 1024 into the inlet lumen 1018 at the pump suction end and pushed out of the outlet lumen 1020 at the pump discharge end directly above the aortic valve 1022. The linear motor controller 1004 may further be configured to control the pump 1000 via pressure transducer feedback, as will be described in more detail herein. For example, one or more pressure transducers (not shown) may be mounted in or on the inlet lumen 1018, and another pressure transducer may be mounted in or on the outlet lumen 1020. In some variations, two pressure transducers may be mounted in or on the inlet and outlet lumens for redundancy. method

[0200] A method for pumping blood using a linear reciprocating pump is also described herein. In contrast to rotary pumps, utilizing a linear pump can help avoid shear forces that cause red blood cell damage, pump blood in a pulsatile manner, and mimic the natural pumping cycle of the heart. A linearly reciprocating member may be configured such that a seal is generated between it and the pump housing during the pump stroke of the pumping cycle, so that the pump generates sufficient blood pressure for the pump to move blood peripherally. The pump may be installed in various parts of the patient's circulatory system, such as the left ventricle, right ventricle, and aorta. However, in some cases, it may be useful to place the pump outside the patient. A linear reciprocating pump may be installed, for example, to assist heart failure resulting from myocardial infarction, hypertension, trauma, and cardiac malformations.

[0201] As a first step, the method may include accessing the patient's circulatory system. Access may generally be performed using the Seldinger technique, by which a guidewire is placed in the desired artery or vein, and the pump is advanced across the guidewire to the target location. Arterial access may be obtained, for example, from the femoral artery or carotid artery. Arterial access may be useful when the target location for the pump is the left ventricle or aorta. Venous access may be obtained, for example, from the femoral vein or internal jugular vein. Venous access may be useful when the target location for the pump is the right ventricle. The guidewire may be advanced slidingly through the lumen of the pump actuator, such as a drive line, cable, or rod, which linearly reciprocates a valve member, such as a valve cone or flexible diaphragm, within the expandable housing of the pump.

[0202] The method may also include advancing a pump to a target location within the patient's circulatory system, the pump comprising an expandable housing having an outer surface, an inner surface, an expansion configuration, and a collapse configuration. The pump may further include a valve member. In some modifications, the valve member may be a valve cone comprising a flow control layer and a mesh layer, coupled to the expandable frame. In other modifications, the valve member may be a flexible diaphragm comprising a diaphragm body and a periphery, disposed within the expandable housing, the flexible diaphragm having an expansion configuration and a collapse configuration. Once at the target location, the expandable housing may expand from the collapse configuration to the expansion configuration, and the valve cone or flexible diaphragm contained therein may reciprocate linearly to generate the filling stroke and pump stroke of the pumping cycle. When the pump further comprises a cannula, the cannula may be advanced into the patient's left ventricle through the aortic valve. Non-limiting embodiments of target locations for the expandable housing and flexible diaphragm include the aortic arch, descending aorta, thoracic aorta, and abdominal aorta.

[0203] In addition to arterial vessels, the pump may be advanced and positioned within the venous circulatory system. For example, the expandable housing of the pump may be advanced within the inferior vena cava to a location between the hepatic vein and the right atrium of the heart. When positioned in this location, the pump can draw blood toward the heart, increasing circulation from the lower extremities and the liver. The pump may be positioned at various locations between the hepatic vein and the right atrium. In some modifications, the expandable housing is positioned closer to the hepatic vein than to the right atrium.

[0204] The expandable housing and valve members (e.g., valve cone and flexible diaphragm) may be in their collapsed configurations within the outer and inner sheaths, respectively, during their advance within the vascular system. In some modifications, once the expandable housing is positioned at the target location, the outer sheath may be retracted, allowing the housing to expand from a collapsed configuration to an expanded configuration. In other modifications, the expandable housing may be advanced outward from the housing, for example, using a pusher, thereby allowing the housing to expand from a collapsed configuration to an expanded configuration. The inner sheath, which may be arranged concentrically around the valve cone or flexible diaphragm, may then be retracted, allowing the valve cone or diaphragm to expand from a collapsed configuration to an expanded or extended configuration. When the pump includes support members such as an expandable frame, removal of the inner sheath may also allow the frame to expand from a collapsed configuration to an expanded configuration. When the pump is equipped with support members such as tine supports, the removal of the inner sheath may also allow multiple tines to expand from a compression configuration to an expansion configuration.

[0205] The pump may reciprocate within the expandable housing under the force of a reciprocating actuator (e.g., a drive cable) to initiate a series of filling and pumping strokes. In a modification where the valve member is a flexible diaphragm, during each filling stroke of the pump, the flexible diaphragm may be compressed, allowing blood to flow past the diaphragm (with or without support tines) and fill the expandable housing. During each pumping stroke of the pump, the flexible diaphragm may return to its extended configuration, pushing blood out of the expandable housing. In a modification where the valve member is a valve cone including a flow control layer and a mesh layer, during each filling stroke of the pump, a flap in the flow control layer is open, and an opening in the mesh allows blood to flow through the valve cone and fill the expandable housing. During each pumping stroke of the pump, the flaps return to their closed configuration, supported by the mesh layer, and remain closed against the pressure of the blood as it is pushed out of the expandable housing. The reciprocating motion of the drive cable and pulsatile pump may be controlled by a programmable linear motor controller to provide desired blood flow and pressure characteristics. In some modifications, the linear motor controller may be configured to control the pump via sensor (e.g., pressure transducer) feedback, as described in more detail herein.

[0206] During the pump stroke, contact between the periphery of the valve cone or flexible diaphragm and the inner surface of the expandable housing may be maintained so as to create a seal to prevent blood flow between the periphery and the inner surface. In addition, during the pump stroke, blood may be drawn into the expandable housing. Depending on the modification of the pump used, blood may be drawn into the expandable housing from the left ventricle or aorta. The pump stroke may generally push blood out of the expandable housing into a portion of the aorta, for example, the ascending or descending aorta. When the expandable housing and flexible diaphragm are installed outside the patient, blood may be pushed into the ascending aorta directly above the aortic valve through a coaxial catheter connected to it. During the pumping cycle, the valve cone or flexible diaphragm may be collapsed into a collapsed configuration during the filling stroke and expanded into an expanded or extended configuration during the pump stroke.

[0207] The pump may be advanced and positioned at various points in the patient's circulatory system. In one modification, the pump may be advanced until the expandable housing and the pulsating portion of the pump (e.g., a flexible diaphragm with or without tines) are located in the left ventricle, and the cannula extending from the proximal end of the expandable housing extends through the aortic valve. In this modification, blood may flow through the proximal inlet of the expandable housing to fill the expandable housing during the filling stroke (backward movement of the flexible diaphragm toward the feet). The blood then exits through the distal outlet of the expandable housing to supply blood to the body during the pump stroke (forward movement of the flexible diaphragm toward the head).

[0208] For example, as shown in Figure 2, the pump 10 may be advanced into the left ventricle in its collapse configuration within the patient's aorta. The heart 50 includes the left ventricle 56, which is in fluid communication with the ascending aorta 52 and the descending aorta 51. The ascending aorta 52 further supports several arteries, such as artery 53 (brachiocephalic artery), 54 (left common carotid artery), and 55 (left subclavian artery). In Figure 2, the pump 10 is advanced into the left ventricle through the descending aorta 51 in the direction of arrow 35. As described above, the pump 10 may include an outer sheath 11 through which a drive cable 40 can pass. Also, as described above, the pump 10 may define an end 12 through which a bearing 13 can be supported. An expandable housing 25 (shown in more detail in Figure 3) may be unfolded from the outer sheath 11 and may also fix and support the bearing 13. The tine support 15, which includes multiple tines 20, may be coupled to the end of the drive cable 40 and may be captured within the outer sheath 11 in the manner described above in Figure 1.

[0209] Once the pump 10 is positioned within the left ventricle 56, it assumes the operating position shown in Figure 3. Here, the expandable housing 25 is expanded to its expandable configuration and is therefore shown to include a distal inlet (mesh portion) 26 and a proximal outlet (mesh portion) 27. The proximal outlet 27 is supplied at the end of a cannula (housing extension portion) 28 that extends from the expandable housing 25 through the aortic valve into the ascending aorta 52. In this configuration, blood is drawn from the left ventricle 56 into the expandable housing 25 during the filling stroke and moved out of the expandable housing 25 into the ascending aorta 52 and arteries 53, 54, and 55 in the direction of the arrows during the pump stroke.

[0210] The pumping action of pump 10 may be initiated by activating a linear motor 19 (shown in Figure 1) to start the reciprocating motion of the tine support 15 (and the multiple tines 20) by a continuous force pushing and pulling the flexible cable 40. The pumping action of pump 10 is described in more detail below in Figures 8 and 9. However, it is sufficient to note here that Figure 3 illustrates the operation of pump 10 during a pump stroke, which is generally characterized by the pulling force on the drive cable 40 and the movement of the tine support 15 in the direction indicated by the arrow 36. During this pump stroke, the diaphragm 30 extends in its fully open configuration and therefore provides driving force to the blood in the expandable housing 25, pushing the blood upward through the cannula (housing extension) 28 and outward through the proximal outlet (mesh portion) 27, generating outward blood flow to the patient's body through the ascending aorta 52 and through arteries such as arteries 53, 54, and 55. Referring to Figure 4, note that the pushing force on the drive cable 40 in the direction indicated by arrow 37 produces a filling stroke during which the diaphragm 30 is compressed and blood flows into the expandable housing 25 through the distal inlet 26.

[0211] As long as the cardiac assist pump 10 remains positioned within the left ventricle and aorta, and the expandable housing 25 remains configured for operation, the pumping action of the pump 10 continues as the linear motor 19 (shown in Figure 1) continues the reciprocating motion of the tine support (and multiple tines 20) by the continuous force pushing and pulling the flexible cable 40. Again, it should be understood that the pumping action of the pump 10 is described in more detail below in Figures 8 and 9. However, it is sufficient here to note that Figure 4 illustrates the operation of the pump 10 during the filling stroke, characterized by the pushing force on the drive cable 40 that moves the tine support 15 in the direction indicated by the arrow 37. Note that during this filling stroke, the diaphragm 30 is partially compressed and therefore imparts a reduced force to the blood in the expandable housing 25. As a result, the blood is able to flow inward through the distal inlet (mesh portion) 26 and fill the inside of the expandable housing 25. For illustrative purposes, let us temporarily return to Figure 3 and recall that the pulling force on the drive cable 40 in the direction indicated by arrow 36 produces a pump stroke during which the diaphragm 30 expands and blood flows outward from the expandable housing 25. Therefore, referring to Figures 3 and 4 simultaneously, the pumping action of the pump 10 can be illustrated by alternating the pump stroke shown in Figure 3 and the filling stroke shown in Figure 4.

[0212] Some variations of the pump do not include a cannula extending from the expandable housing. For example, pump 100 in Figures 5, 6, and 7 is substantially the same as pump 10 in Figures 3 and 4 in both structure and function, except for the absence of a cannula (extended portion) 28. In addition, as shown in Figures 18A and 18B, pump 700 does not include a cannula extending from either the proximal end 702 or the distal end 704 of the expandable housing 710, but is otherwise substantially the same as pump 100. Exemplary target locations for pumps 100 and 700 may be the thoracic aorta 706 (Figure 18A) or the abdominal aorta 708 (Figure 18B). In Figure 5, blood from one portion of the aorta is pumped to a second portion of the aorta as it enters the expandable housing 60 via an inlet 63 and exits through an outlet 64 of the expandable housing 60. Referring to Figure 18A, blood from one portion 716 of the thoracic aorta 706 is pumped to a second portion 718 of the thoracic aorta 706 as it enters the expandable housing 710 via the inlet 712 and exits through the outlet 714 of the expandable housing 710. In Figure 18B, blood from one portion 720 of the abdominal aorta 708 is pumped to a second portion 722 of the abdominal aorta 708 as it enters the expandable housing 710 via the inlet 712 and exits through the outlet 714 of the expandable housing 710.

[0213] In overview, Figures 5, 6, and 7 show sequential cross-sectional views of the pulsatile pump 100 illustrating the transition of the pulsatile pump portion between its compact configuration used during catheter insertion and its expanded configuration used during pumping. Thus, Figure 5 shows a cross-sectional view of the linear cardiac assisted tile pump 100 in its collapse configuration, while Figure 7 shows a cross-sectional view of the pump 100 in its expanded configuration. Figure 6 shows a cross-sectional view of the pump 100 at an intermediate point between the configurations shown in Figures 5 and 7.

[0214] Figures 8 and 9 show cross-sectional views of the pump 100 in operation. Figure 8 shows a cross-sectional view of the pump 100 during a filling stroke, while Figure 9 shows a cross-sectional view of the pump 100 during a pump stroke. A series of filling and pump strokes are repeated to produce a pulsating pumping action as a linear motor (linear motor 19 shown in Figure 1) reciprocates the drive cable 40, thereby reciprocating the pumping mechanism within the pump 100.

[0215] Referring specifically to Figure 8, the pump 100 includes an expandable housing 60 having a bearing 13 and an end 62 supporting an inlet (scaffold portion) 63. The expandable housing 60 further includes a chamber 61 and an outlet (scaffold portion) 64. The chamber may be formed by embedding (e.g., overmolding) a portion of the scaffold of the expandable housing 60 in a polymer layer, as described above, or by bonding a fabric layer to the scaffold. The tine support 15 is slidably received within the bearing 13 and may be coupled to the internal end of the drive cable 40. The tine support 15 supports a plurality of tines 20 and a flexible diaphragm 30. The tine support 15 may define a plurality of outwardly extending spline ribs between which spline grooves are formed. The spline grooves provide a blood flow path, thereby allowing blood to flow past the tine support 15.

[0216] As mentioned, Figure 8 shows the filling stroke of the pump 100 during operation. Therefore, the reciprocating force applied to the drive cable 40 moves the tine support 15 in the direction indicated by arrow 38. Because blood is present in the chamber 61, the movement of the tine support 15 in the direction indicated by arrow 38 creates a force on the rear side of the diaphragm 30, which in turn causes it to bend in the manner shown. The bending of the diaphragm 30 away from its outwardly extending position (seen in Figure 9) allows blood flow around the tine 20 and diaphragm 30 in the chamber 61. This provides filling of the chamber 61, and blood is drawn in through the inlet portion 63 and bearing 13. Once the tine support 15 has reached the end of its filling stroke, the drive mechanism described above applies a pulling force to the drive cable 40, initiating the pump stroke shown in Figure 9.

[0217] Referring specifically to Figure 9, the pump 100 includes an expandable housing 60 having a bearing 13 and an end 62 supporting an inlet (scaffolding portion) 63. The expandable housing 60 further includes a chamber 61 and an outlet (scaffolding portion) 64. A tine support 15 is slidably received within the bearing 13 and coupled to the internal end of the drive cable 40. The tine support 15 includes a plurality of tines 20 and a flexible diaphragm 30. The tine support 15 defines a plurality of outwardly extending spline ribs between which spline grooves are formed. The spline grooves provide a blood flow path, thereby allowing blood to flow past the tine support 15.

[0218] As mentioned, Figure 9 shows the pump stroke of the pump 100 during operation. Therefore, the reciprocating force applied to the drive cable 40 moves the tine support 15 in the direction indicated by arrow 39. Because blood is present in the chamber 61, the movement of the tine support 15 in the direction indicated by arrow 39 causes a force against the front of the diaphragm 30, which in turn pushes the diaphragm 30 against the tine 20 in the extended position shown. The extension of the diaphragm 30 to its outwardly extended position pushes blood from the chamber 61 to the front of the diaphragm 30 as the diaphragm 30 moves in the direction indicated by arrow 39. This in turn generates an outward blood flow from the chamber 61 through the outlet 64. Once the tine support 15 has reached the end of its pump stroke, the drive mechanism described above applies a pushing force to the drive cable 40, initiating the next filling stroke shown in Figure 8. As the drive mechanism described above moves back and forth, alternating pushing and pulling forces are generated on the cable 40, corresponding to the continuous filling and pumping strokes of the pump 100, which produce pulsating blood flow.

[0219] As described above, in some modifications, the expandable housing may comprise a plurality of openings and a skirt coupled to the expandable housing. In this example, the blood exiting the openings may be directed retrogradely toward the patient's heart during the pump stroke by the skirt. Retrograde blood flow can help provide proper perfusion of arteries branching from the aortic arch, such as the carotid and subclavian arteries. The ability to maintain proper perfusion of the subclavian arteries can prevent backflow from the vertebrobasilar artery to the subclavian artery, a phenomenon known as "subclavian steal." For example, referring to Figure 21, the pump 800 may draw blood from the left ventricle 814 through an inlet 812 provided at the distal end 824 of a cannula 810, which may extend from the expandable housing 802. From the inlet 812, the blood may flow in the direction of arrow 830 and fill the expandable housing 802. During the pump stroke, blood from the expandable housing 802 may generally move toward the outlet 808 in the direction of arrow 826. However, as the blood moves past the multiple openings 804, a first portion of the blood may be pushed through the openings 804 and then directed by the skirt 806 to return toward the heart in the direction of arrow 828, perfusing the vessels 818 branching from the aortic arch. The portion of blood that is not pushed out of the expandable housing through the multiple openings 804 and remains within the expandable housing 802 (a second portion) is pushed toward the feet and toward the rest of the body through the outlet 808.

[0220] The length of the skirt may be adjusted to achieve a predetermined amount of retrograde blood flow toward the patient's heart. Alternatively, the number of openings may be adjusted to achieve a predetermined amount of retrograde blood flow toward the patient's heart. The diameter of the openings may also be adjusted to achieve a predetermined amount of retrograde blood flow toward the patient's heart. The combination of the number of openings and the diameter of the openings may provide a certain amount of open surface area on the expandable housing for retrograde blood flow. Thus, adjustment of any one or a combination of the above features may be used to ensure that approximately 60% of the blood from the pump stroke flows retrograde toward the patient's heart, approximately 50% of the blood from the pump stroke flows retrograde toward the patient's heart, or approximately 40% of the blood from the pump stroke flows retrograde toward the patient's heart.

[0221] In some variations, the skirt may be configured to adjust the amount of open surface area for retrograde flow by adjusting the number of openings that are opened and closed. For example, a tether may be configured to open and close the skirt relative to the expandable housing, similar to how a rope can be tightened and loosened. The amount of opening or closing may be adjusted, for example, using a rotatable dial located on a console outside the patient. Generally, a larger open surface area may provide more retrograde blood flow toward the patient's head and heart, while a smaller open surface area may provide more antegrade blood flow toward the body.

[0222] Another method for pumping blood involves advancing a pump to a target location in the patient's aorta, such as the thoracic or abdominal aorta, wherein the pump has a filling stroke and a pumping stroke, drawing a filling volume of blood into the pump during the pumping stroke and pushing an exit volume of blood out of the pump during the pumping stroke, wherein the exit volume comprises a first portion of blood and a second portion of blood. The filling stroke may draw blood from the patient's left ventricle. In addition, the first portion of blood may be pumped retrogradely toward the patient's head, and the second portion of blood may be pumped antegradely. The second portion of blood may be about 60%, about 50%, or about 40% of the exit volume.

[0223] When the pump is located outside the patient, the method for pumping blood may include accessing the patient's circulatory system using a coaxial cable. The external pump may include the same valve members as the internal pump installed in the blood vessel or ventricle, e.g., a valve cone or flexible diaphragm, but the housing may not be expandable. A valve cone or flexible diaphragm contained within an expandable housing may comprise a body and a periphery. The flexible diaphragm may have an extended configuration and a collapsed configuration, and the valve cone may have an expanded configuration and a collapsed configuration. The external pump may be located within a console with a user interface. The coaxial catheter may comprise an inflow lumen and an outflow lumen. The coaxial catheter may be coupled to the external pump at one end, with the other end inserted and advanced into the patient.

[0224] Access to the circulatory system using a coaxial catheter may be obtained from any suitable artery or vein, such as the femoral artery, subclavian artery, carotid artery, or jugular vein. Once access is obtained, the coaxial catheter may be advanced to a target location in the circulatory system, and the flexible diaphragm may reciprocate linearly within the housing to generate the filling and pumping strokes of the pumping cycle. During the pumping stroke, contact between the periphery of the valve cone or flexible diaphragm and the inner surface of the housing may be maintained to create a seal between them, preventing blood from flowing around the valve cone or flexible diaphragm. The seal may help generate and maintain the force of the pumping stroke and minimize red blood cell damage that could occur due to blood flowing in the space between the periphery and the inner surface. The methods described herein may include advancing the coaxial catheter to various target locations within the patient. For example, the target location for the inflow lumen of the coaxial catheter may be the patient's left ventricle, and the target location for the outflow lumen of the coaxial catheter may be above the patient's aortic valve.

[0225] For example, as shown in Figure 23A, the external pump 1000 is connected to the coaxial catheter 1006 by inlet and outlet tubes 1016. The coaxial catheter 1006 includes an inlet lumen 1018 and an outlet lumen 1020, as shown in the close-up view provided in Figure 23B. Access to the circulatory system by the coaxial catheter 1006 is via the femoral artery 1026. Once access is obtained, the coaxial catheter 1006 is advanced into the left ventricle 1024. More specifically, as shown in the close-up view in Figure 23C, the distal end of the coaxial catheter 1006 is advanced until the inlet lumen 1018 is in the left ventricle and the outlet lumen 1020 is positioned above the aortic valve. In Figure 23C, blood is shown drawn from the left ventricle 1024 into the inlet lumen 1018 at the pump suction end and pushed out of the outlet lumen 1020 at the pump discharge end directly above the aortic valve 1022. The pump 1000 is also coupled to a linear motor drive unit 1002 and a linear motor controller 1004 in a console 1008. The console 1008 also includes a power source 1010, a battery 1012, and a user interface 1014. The linear motor controller 1004 may be configured to control the speed of the pump 1000 via pressure transducer feedback. For example, a pressure transducer (not shown) may be mounted in or on the inlet lumen 1018, and another pressure transducer may be mounted in or on the outlet lumen 1020. In some modifications, two pressure transducers may be mounted in or on the inlet and outlet lumen for redundancy in case one fails. The controller may be configured to have predetermined high and low blood pressure setpoints. When the measurement from the pressure transducer indicates that the blood pressure has fallen below the low setpoint, the controller 1004 will increase the speed of the linear reciprocating motion, and if it is too high (e.g., above the high setpoint), the controller 1004 will decelerate the speed of the linear reciprocating motion, thereby reducing the flow and lowering the blood pressure back to the target range.

[0226] The foregoing description uses specific names for explanatory purposes and to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that specific details are not required to practice the invention. Accordingly, the foregoing description of specific embodiments of the invention is presented for illustrative and explanatory purposes. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and as is obvious, many modifications and variations can be considered as possible in light of the teachings above. The embodiments are selected and described to illustrate the principles of the invention and its practical applications, thereby enabling those skilled in the art to utilize the invention and its various embodiments with various modifications to suit specific intended uses.

Claims

1. A pump for assisting blood circulation, wherein the pump is A housing with an internal structure and an expandable configuration, A valve member comprising an umbrella structure disposed within the housing, wherein the umbrella structure comprises a membrane having a periphery and a plurality of support columns, each of the plurality of support columns having a distal end, and Equipped with, A pump wherein the valve member is configured to reciprocate linearly within the housing during the filling stroke and pump stroke of the pumping cycle of the pump, the umbrella structure has an expanded configuration during the pump stroke to move blood outside the housing, and the umbrella structure has a collapsed configuration during the filling stroke to move blood beyond the periphery of the valve member.

2. The pump according to claim 1, further comprising an actuator coupled to the umbrella structure, wherein the actuator is configured to cause the umbrella structure to reciprocate linearly within the housing.

3. The pump according to claim 1, wherein the periphery of the membrane is configured to maintain contact with the inner surface of the housing during the pump stroke.

4. The pump according to claim 1, wherein the membrane comprises an elastomer polymer.

5. The pump according to claim 4, wherein the elastomer polymer includes silicone, polyester, polyurethane, fluoropolymer, or a combination thereof.

6. The pump according to claim 5, wherein the fluoropolymer comprises polytetrafluoroethylene (PTFE) or expanded polytetrafluoroethylene (ePTFE).

7. The pump according to claim 1, wherein the plurality of support columns include six to ten support columns.

8. The pump according to claim 1, wherein at least one of the plurality of support columns is provided with a bent portion.

9. The pump according to claim 8, wherein the bent portion has a bending angle in the range of about 5 degrees to about 15 degrees.

10. The pump according to claim 1, wherein the umbrella structure further comprises an anchor, and in the extended configuration of the umbrella structure, each of the plurality of support columns extends radially outward from the anchor such that it generates a support column angle in the range of about 30 degrees to about 60 degrees with respect to the longitudinal axis of the umbrella structure.

11. The pump according to claim 1, wherein the distal end of each of the plurality of support columns is provided with an opening.

12. The pump according to claim 1, wherein the distal end of each of the plurality of support columns has a circular or oval shape.

13. The pump according to claim 1, wherein the umbrella structure further comprises anchors attached to the proximal end of each of the plurality of support columns, each of the plurality of support columns is configured to be inverted so as to fold backward around the anchor, and the anchors are configured to attach each of the plurality of support columns to the actuator of the pump.

14. The pump according to claim 1, wherein the umbrella structure further comprises anchors attached to the proximal end of each of the plurality of support columns, the anchors being configured to attach each of the plurality of support columns to an actuator of the pump.

15. The pump according to claim 1, wherein at least a portion of the housing or the valve member includes a polymer coating.

16. The pump according to claim 15, wherein the polymer coating comprises polytetrafluoroethylene (PTFE) or expanded polytetrafluoroethylene (ePTFE).

17. The pump according to claim 1, wherein the membrane further comprises a body, and the thickness of the periphery is greater than the thickness of the body of the membrane.

18. The pump according to claim 1, wherein the plurality of support columns include stainless steel, nickel, titanium, or an alloy thereof.

19. The pump according to claim 1, wherein the periphery has a thickness in the range of about 0.20 mm to about 1.5 mm.

20. The pump according to claim 1, further comprising an extending portion extending from the proximal or distal end of the housing.

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