Ventricular assist device

Abstract

Devices and methods including a left ventricular assist device including an impeller (50) and a frame (34) disposed about the impeller (50) are described. The frame (34) includes a strut junction (33) at a proximal end of the frame that is configured to be held in an open state during assembly of the left ventricular assist device to facilitate insertion of the impeller (50) into the frame (34). After insertion of the impeller (50) into the frame (34), a securing element (117) holds the strut junction in a closed state. A pump outlet tube (24) extends to a distal end of the frame (34) and defines one or more lateral blood inlet openings (108) configured to allow blood to flow from a left ventricle of a subject into the pump outlet tube (24). Other applications are also described.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to the following applications:

[0003] Tuval's U.S. Provisional Patent Application No. 63 / 158,708, entitled "Ventricular assist device," filed on March 9, 2021, and...

[0004] Tuval filed U.S. Provisional Patent Application No. 63 / 254,321, entitled "Ventricular assist device," on October 11, 2021.

[0005] These two U.S. provisional applications are incorporated herein by reference.

[0006] Field of the embodiments of the present invention

[0007] Some applications of this invention generally relate to medical devices. Specifically, some applications of this invention relate to ventricular assist devices and methods of using them.

[0008] background

[0009] Ventricular assist devices (VADs) are mechanical circulatory support devices designed to assist and unload the heart chambers to maintain or increase cardiac output. They are used in patients with heart failure and in patients at risk of cardiac deterioration during percutaneous coronary intervention. Most commonly, left ventricular assist devices (LVADs) are used in defective hearts to assist left ventricular function. In some cases, right ventricular assist devices (LVADs) are used to assist right ventricular function. These VADs are either designed for permanent implantation or are mounted on a catheter for temporary placement.

[0010] Overview of the Implementation Examples

[0011] According to some applications of the invention, a left ventricular assist device includes an impeller and a frame disposed around the impeller. The frame includes a strut joint located at a proximal end of the frame. The strut joint is configured to remain in an open state during assembly of the left ventricular assist device to facilitate insertion of the impeller into the frame. After the impeller is inserted into the frame, a retaining element holds the strut joint in a closed state. A pump outlet tube extends to a distal end of the frame and defines one or more lateral blood inlet openings configured to allow blood to flow from the left ventricle of a subject into the pump outlet tube.

[0012] For some applications (not shown), the pump outlet tube defines two to four lateral blood inlet openings. Typically, for such applications, each blood inlet opening defines an area greater than 20 mm² (e.g., greater than 30 mm²) and / or less than 60 mm² (e.g., less than 50 mm²), such as 20-60 mm² or 30-50 mm². Alternatively or additionally, the outlet tube defines a greater number of smaller blood inlet openings 108, such as more than 10 blood inlet openings, more than 50 blood inlet openings, more than 100 blood inlet openings, or more than 150 blood inlet openings, such as 50-100 blood inlet openings, 100-150 blood inlet openings, or 150-200 blood inlet openings. For some applications, the blood inlet openings are sized to (a) allow blood to flow from the subject's left ventricle into the tube, and (b) prevent structures from the subject's left ventricle from entering the frame. Typically, for such applications, the distal tapered portion of the pump outlet tube (which defines the blood inlet opening) is configured to reduce the risk of structures from the left ventricle (such as chordae tendineae, cardiac columns, and / or papillary muscles) entering the frame and potentially being damaged by the impeller and / or axial shaft and / or causing damage to the left ventricular assist device.

[0013] Typically, the portion of the pump outlet tube that defines the blood inlet opening (e.g., the distal tapered portion of the pump outlet tube) has a porosity greater than 40%, for example greater than 50%, or greater than 60% (where porosity is defined as the percentage of the area of ​​this portion that is porous for blood flow). Thus, on the one hand, the blood inlet opening is relatively small (to prevent left ventricular structures from entering the frame), but on the other hand, the porosity of the portion of the pump outlet tube that defines the blood inlet opening is relatively high to allow sufficient blood to flow into the pump outlet tube.

[0014] For some applications, each blood inlet opening has a circular or polygonal shape. For other applications, each blood inlet opening has a hexagonal shape. Typically, using openings with a hexagonal shape allows the portion of the pump outlet tube defining the blood inlet opening to have a relatively high porosity (e.g., as described above), while providing sufficient material between the blood inlet openings to prevent tearing and / or stretching of the material.

[0015] For some applications, the width of the gap between hexagonal (or other type of polygonal) orifices in the proximal region of the distal tapered portion of the pump outlet tube (which typically defines the blood inlet opening) is greater than the width of the gap between hexagonal (or other type of polygonal) orifices in the distal region of the distal tapered portion of the pump outlet tube. Typically, for such applications, the distance between opposite sides of each hexagon (or other type of polygon) in the proximal region of the distal tapered portion of the pump outlet tube is less than the distance between opposite sides of each hexagon (or other type of polygon) in the distal region of the distal tapered portion of the pump outlet tube. (Typically, such a distance also represents the diameter of the circle enclosed by the polygons of their respective defined dimensions.) Furthermore, typically, the distal tapered portion of the pump outlet tube has a higher porosity in the distal region than in the proximal region.

[0016] Typically, the pump outlet pipe is connected to the frame by heating. For some applications, in the proximal region of the distal tapered portion of the pump outlet pipe, the gap between the blood inlet orifices is wider and / or the blood inlet orifices are smaller and / or the porosity is lower than that in the distal region than in the proximal region, in order to prevent and / or reduce damage (e.g., tearing, thinning, and / or stretching) that may occur to the material defining the blood inlet orifices during the aforementioned heating process.

[0017] For some applications, ventricular assist devices include a liner that lines the inside of a frame housing the impeller. For some applications, the liner is positioned within the frame to provide a smooth inner surface (e.g., a smooth inner surface with a generally circular cross-sectional shape) through which blood is pumped by the impeller. Typically, by providing a smooth surface, the covering material reduces hemolysis caused by blood pumped by the impeller, relative to pumping blood between the impeller and the frame's supports. For some applications, the liner comprises polyurethane, polyester, and / or silicone. Alternatively or additionally, the liner comprises polyethylene terephthalate (PET) and / or polyether block amide.

[0018] Typically, in the overlapping area between the liner and the pump outlet pipe, the liner is shaped to form a smooth surface (e.g., as described above, to reduce hemolysis), and the pump outlet pipe is shaped to conform to the supports of the frame. Furthermore, the liner typically has a substantially circular cross-section. For some applications, in the overlapping area between the liner and the pump outlet pipe, the pump outlet pipe and the liner are joined together, for example, via vacuum, via adhesive, and / or using thermoforming processes, as described below.

[0019] For some applications, the pump outlet pipe and the liner are bonded to each other and / or to the frame in the following ways: For some applications, the liner is directly bonded to the inner surface of the frame before the pump outlet pipe is bonded to the outside of the frame. Note that by directly bonding the liner to the inner surface of the frame (rather than simply bonding the liner to the pump outlet pipe, thereby sandwiching the frame between the liner and the pump outlet pipe), any bubbles, wrinkles, and other smoothness discontinuities on the surface provided by the liner are typically avoided. For some applications, the frame is initially treated to enhance the bonding between the inner surfaces of the liner and the frame. For some applications, the frame treatment includes applying plasma treatment to the frame (e.g., to the inner surface of the frame), immersing the frame in a coupling agent having at least two functional groups (e.g., a silane solution) (the at least two functional groups being configured to bond with the materials used to manufacture the frame and the liner, respectively), and / or immersing the frame in a solution containing the material used to manufacture the liner (e.g., a polyurethane solution). For some applications, a solution containing the material used to manufacture the liner (e.g., a polyurethane solution) is then sprayed onto the central column portion of the cage. Once the inner surface of the frame has been treated, the liner is bonded to the inner surface of the central column portion of the frame (e.g., bonded to the inner surface of the central column portion of the frame). Typically, the liner (which is shaped as a tube) is placed on a mandrel, the frame is placed on the liner, and pressure is applied through a heat-shrinking process. Furthermore, the liner and frame assembly is typically heated in an oven.

[0020] After the liner has been attached to the frame, a portion of the pump outlet pipe is positioned around the outside of the frame. Typically, the frame is heated from the inside using a mandrel. Typically, as the frame is heated, the outer tube (usually made of silicone) applies pressure to the pump outlet pipe, causing it to be pushed radially inward so that it conforms to the shape of the frame's support. For some applications, at this stage, the mandrel, placed inside the liner and heating the liner, is shorter than the length of the liner. The mandrel is typically positioned inside the liner such that a margin is left outside the mandrel at each end of the liner. Typically, the liner acts as a shield to prevent the pump outlet pipe from overheating and from being damaged by the heating of the mandrel. Placing the liner on the mandrel in the manner described above prevents the mandrel from direct contact with the frame and / or the pump outlet pipe. For some applications, the combination of the frame, liner, and the portion of the pump outlet pipe positioned around the frame is then shaped to the desired shape and dimensions using shaping techniques known in the art.

[0021] Typically, a pump outlet pipe (or different types of pump inlet guards) includes a connecting portion (e.g., a tubular connecting portion, as shown) extending distally from the pump outlet pipe. For some applications, the connecting portion is coupled to a surface distal to the frame to anchor the distal end of the pump outlet pipe. For some applications, the connecting portion defines an orifice (e.g., toward the distal end of the connecting portion). For some applications, adhesive is applied between the connecting portion and the surface via the orifice. For some applications, the surface is threaded. Typically, a threaded surface allows the adhesive to diffuse gradually and uniformly between the connecting portion and the surface. Furthermore, the connecting portion is typically transparent, making the diffusion of the adhesive visible through it. Therefore, for some applications, adhesive application is terminated once the adhesive has sufficiently diffused between the connecting portion and the surface (e.g., once the surface is covered with adhesive).

[0022] For some applications, the ventricular assist device includes a protective braid at its distal end. In some applications, to reduce the risk of structures from the left ventricle (e.g., chordae tendineae, cardiac columns, and / or papillary muscles) entering the frame and potentially being damaged by the impeller and / or axial shaft and / or causing damage to the left ventricular assist device, the distal tapered portion of the frame is covered with a protective braid (from the inside or outside). Typically, within at least a portion of the cylindrical portion of the frame, the braid is embedded between the pump outlet tube and the liner, such that during frame roll-up, the braid rolls up together with the pump outlet tube and the liner, thereby preventing movement of the braid relative to the pump outlet tube and / or the liner.

[0023] Generally, in the specification and claims of this application, when the term "proximal" and related terms are used with respect to a device or a portion thereof, the term "proximal" and related terms should be interpreted as meaning that, when the device or a portion thereof is inserted into the body of a subject, the end of the device or a portion thereof is generally closer to the location through which the device is inserted into the body of the subject. When the term "distal" and related terms are used with respect to a device or a portion thereof, the term "distal" and related terms should be interpreted as meaning that, when the device or a portion thereof is inserted into the body of a subject, the end of the device or a portion thereof is generally farther from the location through which the device is inserted into the body of the subject.

[0024] The scope of this invention includes the use of the devices and methods described herein in anatomical locations other than the left ventricle and aorta. Therefore, ventricular assist devices and / or portions thereof are sometimes referred to herein (in the specification and claims) as blood pumps.

[0025] Therefore, according to some applications of the present invention, an apparatus is provided, the apparatus comprising:

[0026] Left ventricular assist device, the left ventricular assist device comprising:

[0027] An impeller is configured to be placed in the left ventricle of the subject and to pump blood from the subject's left ventricle to the subject's aorta by rotation;

[0028] A frame surrounding the impeller, the frame including multiple strut joints at the proximal end of the frame, the strut joints being configured to remain open during the assembly of the left ventricular assist device to facilitate the insertion of the impeller into the frame;

[0029] The fixing element is configured to hold the support joint in a closed state after the impeller is inserted into the frame; and

[0030] A pump outlet tube is configured to pass through the aortic valve of the subject, such that a proximal portion of the pump outlet tube is disposed within the subject's aorta and a distal portion of the pump outlet tube is disposed within the left ventricle of the subject. The distal portion of the pump outlet tube extends to the distal end of the frame and defines one or more lateral blood inlet openings, which are configured to allow blood to flow from the subject's left ventricle into the pump outlet tube.

[0031] In some applications, the fixing element includes a ring.

[0032] In some applications, the left ventricular assist device includes a portion located distal to the frame, and the pump outlet tube also includes a connecting portion that extends distally from the frame and connects to the distal portion of the left ventricular assist device.

[0033] In some applications, the distal portion of the pump outlet tube defines more than 10 blood inlet openings, which are sized to (a) allow blood to flow from the subject's left ventricle into the tube, and (b) prevent structures from the subject's left ventricle from entering the frame. In some applications, the distal portion of the pump outlet tube defines more than 50 blood inlet openings, which are sized to (a) allow blood to flow from the subject's left ventricle into the tube, and (b) prevent structures from the subject's left ventricle from entering the frame.

[0034] In some applications, left ventricular assist devices also include:

[0035] The proximal radial bearing is located within the proximal bearing housing at the proximal end of the frame.

[0036] A distal radial support member is disposed within a distal support member housing at the distal end of the frame;

[0037] An axial shaft is mounted on which the impeller is installed. The axial shaft passes through the proximal radial support and the distal radial support.

[0038] The fixing element is configured to keep the strut joint closed around the outer surface of the near-side support housing.

[0039] In some applications, the pump outlet pipe also includes a connection portion extending distally from the frame and connecting to the distal support housing. In some applications, the distal end of the frame is connected to the outer surface of the distal support housing. In some applications, the left ventricular assist device also includes a distal terminal element, which is connected to the distal support housing.

[0040] In some applications, the outer surface of the proximal support housing defines a groove shaped to receive the strut joint. In other applications, the strut joint defines a widened head, and the groove is shaped to correspond to the widened head of the strut joint.

[0041] In some applications, the proximal and distal radial supports are made of ceramic material, and the proximal and distal support housings are made of a second material that can be molded into the desired shape. In some applications, the proximal and distal support housings are made of metal and / or alloy. In some applications, the axial shaft comprises metal and / or alloy, and the area of ​​the axial shaft that contacts either the proximal or distal support during operation of the left ventricular assist device is covered with a ceramic sleeve.

[0042] According to some applications of the present invention, a method for manufacturing a left ventricular assist device is also provided, the method comprising:

[0043] A frame is formed such that the frame is closed at its distal end, and the joints of multiple struts at the proximal end of the frame remain open.

[0044] The pump outlet tube is connected to the frame such that the distal portion of the pump outlet tube extends to the distal end of the frame and defines one or more lateral blood inlet openings, the one or more lateral blood inlet openings being configured to allow blood to flow from the subject's left ventricle into the pump outlet tube, the pump outlet tube being configured to pass through the subject's aortic valve such that the proximal portion of the pump outlet tube is located within the subject's aorta and the distal portion of the pump outlet tube is located within the subject's left ventricle.

[0045] The impeller is inserted into the frame via the proximal end of the frame; the impeller is configured to pump blood through the pump outlet pipe by rotation; and

[0046] Subsequently, the strut joint at the proximal end of the frame is closed, and a fixing element is used to hold the strut joint in the closed state.

[0047] In some applications, the pump outlet pipe also includes a connecting portion configured to extend distally from the frame, and the method further includes connecting the connecting portion to a distal portion of the left ventricular assist device.

[0048] In some applications, the fixing element includes a ring, and using the fixing element to keep the strut joint in a closed state includes using a ring to keep the strut joint in a closed state.

[0049] In some applications, left ventricular assist devices also include:

[0050] A proximal radial support member is disposed within a proximal support member housing at the proximal end of the frame;

[0051] A distal radial support member is disposed within a distal support member housing at the distal end of the frame;

[0052] An axial shaft is mounted on which the impeller is installed. The axial shaft passes through the proximal radial support and the distal radial support.

[0053] Using fixing elements to keep the strut joint in a closed state includes keeping the strut joint closed around the outer surface of the proximal support housing.

[0054] In some applications, the pump outlet pipe also includes a connecting portion configured to extend distally from the frame, and the method further includes connecting the connecting portion to the distal support housing. In some applications, the method further includes connecting the distal end of the frame to the outer surface of the distal support housing. In some applications, the method further includes connecting a distal end element to the distal support housing.

[0055] In some applications, the outer surface of the proximal support housing defines a groove shaped to receive the strut joint, and keeping the strut joint closed around the outer surface of the proximal support housing includes retaining the strut joint within the groove defined by the outer surface of the proximal support housing. In some applications, the strut joint defines a widened head, and retaining the strut joint within the groove defined by the outer surface of the proximal support housing includes retaining the strut joint within a groove shaped to conform to the widened head of the strut joint.

[0056] In some applications, the proximal and distal radial supports are made of ceramic material, and the proximal and distal support housings are made of a second material that can be molded into the desired shape. In some applications, the proximal and distal support housings are made of metal and / or alloy. In some applications, the axial shaft comprises metal and / or alloy, and the method further includes covering the axial shaft with a ceramic sleeve in the area along the axial shaft that contacts either the proximal or distal support during operation of the left ventricular assist device.

[0057] According to some applications of the present invention, an apparatus is also provided, the apparatus comprising:

[0058] Left ventricular assist device, the left ventricular assist device comprising:

[0059] An impeller is configured to be placed in the left ventricle of the subject and to pump blood from the subject's left ventricle to the subject's aorta by rotation;

[0060] A frame, configured to surround the impeller; and

[0061] A pump outlet tube is configured to pass through the subject's aortic valve, such that the proximal portion of the tube is positioned within the subject's aorta, and the distal portion of the pump outlet tube is positioned within the subject's left ventricle.

[0062] The distal portion of the pump outlet tube extends to the distal end of the frame and defines more than 10 blood inlet openings, which are sized to (a) allow blood to flow from the subject's left ventricle into the tube, and (b) prevent structures from the subject's left ventricle from entering the frame.

[0063] The porosity of the defined blood inlet opening in the distal portion of the pump outlet tube is lower in the proximal region of the distal portion of the pump outlet tube than in the distal region of the distal portion of the pump outlet tube located distal to the proximal region.

[0064] In some applications, each blood inlet opening is shaped such that the width of the opening is less than 1 mm in at least one direction.

[0065] In some applications, the ratio of the porosity of the distal portion of the pump outlet pipe in the distal region to the porosity of the distal portion of the pump outlet pipe in the proximal region is greater than 4:3.

[0066] In some applications, the porosity of the distal portion of the pump outlet tubing varies between proximal and distal regions, resulting in varying hemodynamics at different regions of the distal portion of the pump outlet tubing. In some applications, the distal portion of the pump outlet tubing is tapered, and the porosity of the distal portion varies between proximal and distal regions, resulting in a shape variation of the distal tapered portion along its length.

[0067] In some applications, the pump outlet tube defines a large blood inlet opening along the distal region of the distal portion of the pump outlet tube. This large blood inlet opening is configured to be smaller than the blood inlet opening in the distal region of the distal tapered portion of the pump outlet tube, thereby reducing the risk of thrombosis.

[0068] In some applications, the distal portion of the pump outlet tube defines more than 50 blood inlet openings, which are sized to (a) allow blood to flow from the subject's left ventricle into the tube, and (b) prevent structures from the subject's left ventricle from entering the frame.

[0069] In some applications, the blood inlet openings are rectangular and shaped such that the length-to-width ratio of each blood inlet opening is between 1.1:1 and 4:1. In other applications, the blood inlet openings are rectangular and shaped such that the length-to-width ratio of each blood inlet opening is between 3:2 and 5:2.

[0070] In some applications, the distal portion of the pump outlet pipe has a porosity greater than 40%. In some applications, the distal portion of the pump outlet pipe has a porosity greater than 50%. In some applications, the distal portion of the pump outlet pipe has a porosity greater than 60%.

[0071] In some applications, the frame defines a central cylindrical portion and a distal conical portion, the distal portion of the pump outlet tube defining the blood inlet opening is conical and positioned above the distal conical portion of the frame, and a portion of the distal portion of the pump outlet tube near the pump outlet tube is connected to the central cylindrical portion of the frame.

[0072] In some applications, a portion of the distal section of the pump outlet tube is heated and connected to the central columnar section of the frame. The lower porosity in the proximal region of the distal section of the pump outlet tube, compared to the higher porosity in the proximal region of the distal section of the pump outlet tube, reduces potential damage to the material defining the blood inlet orifice in the proximal region of the distal section of the pump outlet tube during heating.

[0073] In some applications, the device also includes a liner attached to the inner surface of the central columnar portion of the frame, such that the liner provides a smooth inner surface to the central columnar portion of the frame.

[0074] In some applications, the proximal region of the distal portion of the pump outlet pipe extends along a length of 0.5 mm to 2 mm.

[0075] In some applications, the blood inlet opening has a polygonal shape. In other applications, the blood inlet opening has a hexagonal shape.

[0076] In some applications, the diameter of the circle surrounding each blood inlet opening is between 0.1 mm and 0.6 mm in the proximal region of the distal portion of the pump outlet tube. In some applications, the width of the gap between adjacent blood inlet openings is between 0.05 mm and 0.2 mm in the proximal region of the distal portion of the pump outlet tube.

[0077] In some applications, the diameter of the circle surrounding each blood inlet opening is between 0.2 mm and 0.8 mm in the distal region of the distal portion of the pump outlet tube. In some applications, the width of the gap between adjacent blood inlet openings is between 0.01 mm and 0.1 mm in the distal region of the distal portion of the pump outlet tube.

[0078] In some applications, the ratio of the diameter of the circle enclosed by each blood inlet opening in the distal region of the distal portion of the pump outlet tube to the diameter of the circle enclosed by each blood inlet opening in the proximal region of the distal portion of the pump outlet tube is greater than 7:6. In some applications, the ratio of the width of the gap between adjacent blood inlet openings in the proximal region of the proximal portion of the pump outlet tube to the width of the gap between adjacent blood inlet openings in the distal region of the distal portion of the pump outlet tube is greater than 3:2.

[0079] According to some applications of the present invention, a method is also provided, the method comprising:

[0080] The housing for the impeller of the blood pump is manufactured through the following steps:

[0081] The frame is treated to enhance the bond between the inner surface of the frame and the lining;

[0082] Subsequently, the liner is attached to the inner surface of the frame along at least a portion of the central columnar portion of the frame, the central columnar portion of the frame including a support column defining a generally columnar shape.

[0083] After attaching the liner to the inner surface of the frame along at least a portion of the central columnar section of the frame:

[0084] Place the mandrel inside the liner;

[0085] A portion of an elongated tube is positioned to surround at least a portion of a frame, the elongated tube including a proximal portion that defines at least one blood outlet opening;

[0086] When this portion of the elongated tube is configured to surround at least that portion of the frame, the liner, the frame, and that portion of the elongated tube are heated via a mandrel; and

[0087] When heating the liner, frame, and this portion of the elongated tube, pressure is applied from the outside of this portion of the elongated tube to connect this portion of the elongated tube to the frame.

[0088] In some applications, the pillars of the central column section of the frame define the cells, and the cells are constructed such that, in a non-radial constraint configuration of the frame, the width of each cell within the central column section of the frame, measured according to the circumference of the central column section of the frame, is less than 2 millimeters.

[0089] In some applications, applying pressure from the outside of the elongated tube portion when heating the liner, frame, and elongated tube portion includes aligning the elongated tube portion with the structure of the frame's supports.

[0090] In some applications, attaching the liner to the inner surface of the frame along at least a portion of the central columnar portion includes attaching the liner to the inner surface of the frame along at least a portion of the central columnar portion, such that the liner has a substantially circular cross-section. In some applications, attaching the liner to the inner surface of the frame along at least a portion of the central columnar portion includes attaching the liner to the inner surface of the frame along at least a portion of the central columnar portion, such that the liner provides a smooth inner surface to the portion of the frame to which the liner is attached.

[0091] In some applications, attaching the liner to the inner surface of the frame along at least a portion of the central columnar section of the frame includes preventing bubbles, wrinkles, and other discontinuities in the smoothness of the surface provided by the liner.

[0092] In some applications, treating the frame to enhance the bond between the frame's inner surface and the liner involves applying a plasma treatment to the frame.

[0093] In some applications, attaching the liner to the inner surface of the frame along at least a portion of the central columnar section of the frame includes:

[0094] Place the liner on the mandrel;

[0095] Place the frame on top of the lining; and

[0096] Pressure is applied through a thermal shrinkage process.

[0097] In some applications, treating the frame to enhance the bond between the frame's inner surface and the liner involves immersing the frame in a solution containing a material used to manufacture the liner. In some applications, the liner comprises polyurethane, and immersing the frame in the solution involves immersing the frame in a polyurethane solution.

[0098] In some applications, treating the frame to enhance the bond between the frame's inner surface and the liner includes spraying the inner surface of the central column portion of the frame with a solution containing a material used to manufacture the liner. In some applications, the liner comprises polyurethane, and spraying the inner surface of the central column portion of the frame includes spraying the inner surface of the central column portion of the frame with a polyurethane solution.

[0099] In some applications, after the liner is attached to the inner surface of the frame along at least that portion of the central columnar section of the frame, a mandrel shorter than the length of the liner is placed inside the liner. In some applications, placing the mandrel inside the liner after attaching the liner to the inner surface of the frame along at least that portion of the central columnar section of the frame includes placing the mandrel inside the liner such that a margin is left outside the mandrel at each end of the liner. In some applications, placing the mandrel inside the liner such that a margin is left outside the mandrel at each end of the liner includes preventing direct contact between the mandrel and the frame or pump outlet pipe, thereby preventing overheating of the pump outlet pipe and preventing damage to the pump outlet pipe due to heating of the mandrel.

[0100] In some applications, treating the frame to enhance the bond between the inner surface of the frame and the liner includes immersing the frame in a coupling agent having at least two functional groups configured to bond with the frame and the material used to manufacture the liner, respectively. In some applications, the liner comprises polyurethane, and immersing the frame in the coupling agent includes immersing the frame in a silane solution.

[0101] According to some applications of the present invention, a method is also provided, the method comprising:

[0102] The housing for the impeller of the blood pump is manufactured through the following steps:

[0103] The mandrel is placed inside the liner, with the central columnar portion of the frame surrounding the liner. This central columnar portion of the frame includes pillars that define the general columnar shape.

[0104] The mandrel is shorter than the length of the inner liner;

[0105] A portion of an elongated tube is positioned to surround at least a portion of a frame, the elongated tube including a proximal portion that defines at least one blood outlet opening;

[0106] When this portion of the elongated tube is configured to surround at least that portion of the frame, the liner, the frame, and that portion of the elongated tube are heated via a mandrel; and

[0107] When heating the liner, frame, and this portion of the elongated tube, pressure is applied from the outside of this portion of the elongated tube to connect this portion of the elongated tube to the frame.

[0108] In some applications, the pillars of the central column section of the frame define the cells, and the cells are constructed such that, in a non-radial constraint configuration of the frame, the width of each cell within the central column section of the frame, measured according to the circumference of the central column section of the frame, is less than 2 millimeters.

[0109] In some applications, applying pressure from the outside of the elongated tube portion when heating the liner, frame, and elongated tube portion includes aligning the elongated tube portion with the structure of the frame's supports.

[0110] In some applications, placing the mandrel inside the liner includes placing the mandrel inside the liner such that there is a margin outside the mandrel at each end of the liner. In some applications, placing the mandrel inside the liner such that there is a margin outside the mandrel at each end of the liner includes preventing the mandrel from coming into direct contact with the frame or pump outlet pipe, thereby preventing the pump outlet pipe from overheating and from being damaged by heating of the mandrel.

[0111] In some applications, the method also includes placing the mandrel inside the liner beforehand:

[0112] Treat the frame to enhance the bond between the inner surface of the frame and the lining; and

[0113] The liner is attached to the inner surface of the frame along at least a portion of the central column section of the frame.

[0114] In some applications, attaching the liner to the inner surface of the frame along at least a portion of the central columnar portion includes attaching the liner to the inner surface of the frame along at least a portion of the central columnar portion, such that the liner has a substantially circular cross-section. In some applications, attaching the liner to the inner surface of the frame along at least a portion of the central columnar portion includes attaching the liner to the inner surface of the frame along at least a portion of the central columnar portion, such that the liner provides a smooth inner surface to the portion of the frame to which the liner is attached.

[0115] In some applications, attaching the liner to the inner surface of the frame along at least a portion of the central columnar section of the frame includes preventing bubbles, wrinkles, and other discontinuities in the smoothness of the surface provided by the liner.

[0116] In some applications, treating the frame to enhance the bond between the frame's inner surface and the liner involves applying a plasma treatment to the frame.

[0117] In some applications, attaching the liner to the inner surface of the frame along at least a portion of the central columnar section of the frame includes:

[0118] Place the liner on the mandrel;

[0119] Place the frame on top of the lining; and

[0120] Pressure is applied through a thermal shrinkage process.

[0121] In some applications, treating the frame to enhance the bond between the frame's inner surface and the liner involves immersing the frame in a solution containing a material used to manufacture the liner. In some applications, the liner comprises polyurethane, and immersing the frame in the solution involves immersing the frame in a polyurethane solution.

[0122] In some applications, treating the frame to enhance the bond between the frame's inner surface and the liner includes spraying the inner surface of the central column portion of the frame with a solution containing a material used to manufacture the liner. In some applications, the liner comprises polyurethane, and spraying the inner surface of the central column portion of the frame includes spraying the inner surface of the central column portion of the frame with a polyurethane solution.

[0123] In some applications, treating the frame to enhance the bond between the inner surface of the frame and the liner includes immersing the frame in a coupling agent having at least two functional groups configured to bond with the frame and the material used to manufacture the liner, respectively. In some applications, where the liner comprises polyurethane, immersing the frame in the coupling agent includes immersing the frame in a silane solution.

[0124] According to some applications of the present invention, an apparatus is also provided, the apparatus comprising:

[0125] Left ventricular assist device, the left ventricular assist device comprising:

[0126] An impeller, configured to be placed in the left ventricle of the subject and configured to pump blood from the subject's left ventricle to the subject's aorta by rotation;

[0127] A frame, configured to surround the impeller, defining a distal conical portion;

[0128] The surface located on the far side of the frame; and

[0129] An entrance protection device is disposed on the distal conical portion of the frame. The entrance protection device:

[0130] A blood inlet opening is defined and sized to (a) allow blood to flow from the subject's left ventricle into the tube, and (b) prevent structures from the subject's left ventricle from entering the frame.

[0131] The distal connecting portion is configured to connect to a surface disposed on the distal side of the frame, and the distal connecting portion defines a hole configured to facilitate the application of adhesive between the distal connecting portion and the surface disposed on the distal side of the frame.

[0132] In some applications, the inlet protection device includes a distal portion of a pump outlet tube configured to pass through the subject's aortic valve, such that a proximal portion of the pump outlet tube is positioned within the subject's aorta and a distal portion of the pump outlet tube is positioned within the subject's left ventricle.

[0133] In some applications, the surface located on the distal side of the frame is ridged to enhance the bond between the surface and the connecting parts. In other applications, the surface located on the distal side of the frame is threaded to allow the adhesive to spread gradually and evenly between the connecting parts and the surface.

[0134] In some applications, the joint is tubular. In other applications, the joint is transparent, making the diffusion of the adhesive between the joint and the surface visible.

[0135] In some applications, left ventricular assist devices also include:

[0136] A proximal radial support member is disposed within a proximal support member housing at the proximal end of the frame;

[0137] A distal radial support member is disposed within a distal support member housing at the distal end of the frame;

[0138] An axial shaft is mounted on which the impeller is installed. The axial shaft passes through the proximal radial support and the distal radial support.

[0139] The surface connected to the distal connection portion includes at least a portion of the outer surface of the distal support housing.

[0140] In some applications, the distal end of the frame is coupled to another portion of the outer surface of the distal support housing. In some applications, the left ventricular assist device also includes a distal terminal element, which is coupled to another portion of the outer surface of the distal support housing.

[0141] In some applications, the proximal end of the frame is coupled to the outer surface of the proximal support housing. In some applications, the frame includes multiple strut joints at the proximal end of the frame, the strut joints being configured to remain open during assembly of the left ventricular assist device to facilitate insertion of the impeller into the frame, and the proximal end of the frame is coupled to the outer surface of the proximal support housing by a fixing element that holds the strut joints closed around the outer surface of the proximal support housing.

[0142] In some applications, the proximal and distal radial supports are made of ceramic material, and the proximal and distal support housings are made of a second material that can be molded into the desired shape. In some applications, the proximal and distal support housings are made of metal and / or alloy. In some applications, the axial shaft comprises metal and / or alloy, and the area of ​​the axial shaft that contacts either the proximal or distal support during operation of the left ventricular assist device is covered with a ceramic sleeve.

[0143] According to some applications of the present invention, an apparatus is also provided, the apparatus comprising:

[0144] Ventricular assist device, the ventricular assist device comprising:

[0145] A frame, comprising pillars defining a plurality of cells, is constructed such that, in a non-radial constraint configuration of the frame, the frame comprises a generally columnar central portion.

[0146] A pump outlet pipe, which defines one or more blood outlet openings, is provided on the outside of the frame and connected to the central part of the generally columnar part of the frame, such that this part of the pump outlet pipe is consistent with the strut structure of the frame.

[0147] The lining is attached to the inside of the central portion of the generally cylindrical frame to provide a smooth inner surface for the generally cylindrical portion of the frame.

[0148] An impeller, at least partially disposed within the generally cylindrical central portion of a frame, is configured to pump blood through a tube and discharge it from one or more blood outlet openings; and

[0149] A protective braid, positioned above the distal portion of the frame, is configured to prevent structures from the subject's left ventricle from entering the frame.

[0150] The proximal end of the protective braid is embedded between the pump outlet pipe and the liner, so that the braid curls together with the pump outlet pipe and the liner during frame curling, thereby preventing the braid from moving relative to the pump outlet pipe or the liner.

[0151] In some applications, the fabric is woven into the supports of the far side of the frame.

[0152] In some applications, the distal portion of the frame is tapered, and the protective braid extends to the end of the distal tapered portion of the frame.

[0153] In some applications, the braid is covered along the distal portion of the distal cone of the frame to prevent thrombus formation on the braid within the distal portion of the distal cone of the frame.

[0154] In some applications, the fabric within the distal portion of the distal conical section of the frame is opened to define large openings in order to prevent thrombus formation on the fabric within the distal portion of the distal conical section of the frame. In other applications, the fabric within the distal portion of the distal conical section of the frame is cut to define large openings in order to prevent thrombus formation on the fabric within the distal portion of the distal conical section of the frame.

[0155] In some applications, a braided fabric is covered along the distal portion of the distal tapered section of the frame, and the covered braided fabric is cut to define one or more large holes to prevent thrombus formation within the braided fabric within the distal portion of the distal tapered section of the frame. In some applications, holes are cut from the covered braided fabric around the entire circumference of the frame, such that the covered braided fabric defines holes extending around the entire circumference of the distal portion of the distal tapered section of the frame. In some applications, the holes are cut such that they extend to the distal end of the distal tapered section of the frame, resulting in a single hole extending around the entire circumference of the frame and extending to the distal end of the distal tapered section of the frame.

[0156] The invention will be more fully understood from the following detailed description of embodiments thereof, taken in conjunction with the accompanying drawings, in which: Brief description of the attached diagram

[0158] Figure 1A , Figure 1B and Figure 1C This is a schematic diagram of a ventricular assist device according to some applications of the present invention, wherein the distal end of the ventricular assist device is configured to be placed in the left ventricle of a subject;

[0159] Figure 2 This is a schematic diagram of a frame housing an impeller for a ventricular assist device according to some applications of the present invention;

[0160] Figure 3A , Figure 3B , Figure 3C , Figure 3D and Figure 3E This is a schematic diagram of the impeller or a portion thereof of a ventricular assist device according to some applications of the present invention;

[0161] Figure 4 This is a schematic diagram of an impeller disposed inside the frame of a ventricular assist device according to some applications of the present invention;

[0162] Figure 5A and Figure 5B This is a schematic diagram of the impeller and frame of a ventricular assist device in a non-radial constraint state and a radial constraint state, respectively, according to some applications of the present invention;

[0163] Figure 6A and Figure 6B This is a schematic diagram of a ventricular assist device according to some applications of the present invention, showing the impeller of the ventricular assist device at various stages of its motion cycle relative to the frame of the ventricular assist device.

[0164] Figure 7 This is a schematic diagram of the motor unit of a ventricular assist device according to some applications of the present invention;

[0165] Figure 8A and Figure 8B This is a schematic diagram of the motor unit of a ventricular assist device according to some applications of the present invention;

[0166] Figure 9A and Figure 9B This is a schematic diagram of a ventricular assist device according to some applications of the present invention, the ventricular assist device including an inner liner located on the inside of a frame housing an impeller;

[0167] Figure 10A , Figure 10B and Figure 10C This is a schematic diagram of a frame for a ventricular assist device according to some applications of the present invention, the frame of which includes a protective braid at its distal end;

[0168] Figure 11A , Figure 11B , Figure 11C and Figure 11D This is a schematic diagram of a pump outlet tube according to some applications of the present invention, the pump outlet tube defining a blood inlet opening at its distal end; and

[0169] Figure 12A and Figure 12B This is a schematic diagram of a pump outlet pipe according to some applications of the present invention, which defines a blood inlet opening at its distal end;

[0170] Figure 13A and Figure 13B This is a schematic diagram of a pump outlet pipe according to some applications of the present invention, which defines a blood inlet opening at its distal end;

[0171] Figure 14A and Figure 14B This is a schematic diagram of a frame for a ventricular assist device according to some applications of the present invention, the frame of which includes a protective braid at its proximal end; and

[0172] Figure 15 This is a schematic diagram of a pump outlet tube according to some applications of the present invention, which defines a blood outlet opening at its proximal end.

[0173] Detailed description of the embodiments

[0174] Now for reference Figure 1A , Figure 1B and Figure 1C These figures are schematic diagrams of a ventricular assist device 20 according to some applications of the present invention, wherein the distal end of the ventricular assist device is configured to be disposed in the left ventricle 22 of the subject. Figure 1A An overview of the ventricular assist device system, including console 21 and motor unit 23, is shown. Figure 1B A ventricular assist device inserted into the left ventricle of a subject is shown, and Figure 1C The pump head portion 27 of the ventricular assist device is shown in more detail. The ventricular assist device includes a pump outlet tube 24 that passes through the aortic valve 26 of the subject, such that the proximal end 28 of the pump outlet tube is positioned within the subject's aorta 30, and the distal end 32 of the pump outlet tube is positioned within the left ventricle 22. The pump outlet tube 24 (which is sometimes referred to herein as the "blood pump tube") is typically an elongated tube, with its axial length typically much larger than its diameter. The scope of the invention includes the use of the devices and methods described herein in anatomical locations other than the left ventricle and aorta. Therefore, the ventricular assist device and / or portions thereof are sometimes referred to herein (in the specification and claims) as a blood pump.

[0175] In some applications, ventricular assist devices (VADs) are used to assist left ventricular function in a subject during percutaneous coronary intervention (PCI). In this case, VADs are typically used for periods up to 6 hours (e.g., up to 10 hours), during which there is a risk of hemodynamic instability (e.g., during or immediately after PCI). Alternatively or additionally, VADs are used to assist left ventricular function in patients with cardiogenic shock for longer periods (e.g., 2-20 days, or 4-14 days), which can include any low cardiac output state (e.g., acute myocardial infarction, myocarditis, cardiomyopathy, postpartum, etc.). In some applications, VADs are used to assist left ventricular function in a subject for even longer periods (e.g., weeks or months), for example, in bridge-to-recovery therapy. For some of these applications, the ventricular assist device is permanently or semi-permanently implanted, and the impeller of the ventricular assist device is percutaneously powered, for example, by using an external antenna magnetically coupled to the impeller.

[0176] like Figure 1B As shown, Figure 1B The steps for deploying a ventricular assist device in the left ventricle are illustrated. Typically, the distal end of the ventricular assist device is guided into the left ventricle via a guide wire 10. During insertion of the distal end of the device into the left ventricle, a delivery catheter 143 is positioned over the distal end of the device. Once the distal end of the device is positioned in the left ventricle, the delivery catheter is typically retracted into the aorta, and the guide wire is withdrawn from the subject's body. Typically, the retraction of the delivery catheter causes the self-expanding portion of the distal end of the device to assume a non-radially constrained configuration, as described in further detail below. Typically, the ventricular assist device is inserted into the subject's body to provide acute treatment. For some applications, in order to withdraw the left ventricular device from the subject's body at the end of treatment, the delivery catheter is advanced over the distal end of the device, causing the self-expanding portion of the distal end of the device to assume a radially constrained configuration. Alternatively or additionally, the distal end of the device is retracted into the delivery catheter, causing the self-expanding portion of the distal end of the device to assume a radially constrained configuration.

[0177] For some applications (not shown), the ventricular assist device and / or delivery catheter 143 includes an ultrasound transducer at its distal end, and the ventricular assist device is advanced toward the ventricle of the subject under ultrasound guidance.

[0178] refer to Figure 1CThe diagram shows in more detail the pump head portion 27 of a ventricular assist device 20 according to some applications of the invention. Typically, an impeller 50 is disposed within the distal portion 102 of a pump outlet pipe 24 and is configured to pump blood from the left ventricle into the aorta by rotation. The pump outlet pipe typically defines one or more blood inlet openings 108 at its distal end, through which blood flows from the left ventricle into the pump outlet pipe during impeller operation. Figure 1C As shown, for some applications, the pump outlet pipe defines a single axially oriented blood inlet opening. Alternatively, the pump outlet pipe defines multiple lateral blood inlet openings (e.g., as...). Figure 1B As shown below, and described in further detail. For some applications, the proximal portion 106 of the pump outlet pipe defines one or more blood outlet openings 109 through which blood flows from the pump outlet pipe into the ascending aorta during impeller operation.

[0179] For some applications, this typically includes the console 21 of the computer processor 25 (such as...). Figure 1A (As shown) drives the impeller to rotate. For example, a computer processor can control motor 74 (such as...) Figure 7 As shown), motor 74 is installed in motor unit 23 (e.g. Figure 1A (as shown) inside, and via drive cable 130 (as shown) Figure 7 (As shown) drives the impeller to rotate. For some applications, the computer processor is configured to detect physiological parameters of the subject (e.g., left ventricular pressure, cardiac afterload, rate of change of left ventricular pressure, etc.) and control the rotation of the impeller in response, as described in further detail below. Typically, the operations performed by the computer processor described herein convert the physical state of the memory, which is a real physical artifact communicating with the computer processor, into different magnetic polarities, charges, etc., depending on the memory technology used. The computer processor 25 is typically a hardware device programmed with computer program instructions to produce a dedicated computer. For example, when programmed to perform the techniques described herein, the computer processor 25 typically acts as a dedicated ventricular assist computer processor and / or a dedicated blood pump computer processor.

[0180] For some applications, cleaning system 29 (in) Figure 1A As shown in the figure, a driving fluid (e.g., a glucose solution) passes through multiple parts of the ventricular assist device 20, for example, to cool multiple parts of the device, clean and / or lubricate the interface between the rotating parts and the fixed support, and / or to flush away debris from multiple parts of the device.

[0181] Typically, a frame 34 is disposed within the pump outlet tube 24, surrounding the impeller 50, along the distal portion 102 of the pump outlet tube 24. The frame is typically made of a shape memory alloy, such as nitinol. For some applications, the shape memory alloy of the frame is shaped such that at least a portion of the frame (and therefore the distal portion 102 of the tube 24) presents a generally circular, elliptical, or polygonal cross-sectional shape when no force is applied to the distal portion 102 of the tube 24. By presenting its generally circular, elliptical, or polygonal cross-sectional shape, the frame is configured to hold the distal portion of the pump outlet tube in an open state. Typically, during operation of the ventricular assist device, the distal portion of the pump outlet tube is configured to be placed within the subject's body such that the distal portion of the pump outlet tube is at least partially located within the left ventricle.

[0182] For some applications, along the proximal portion 106 of the pump outlet tube 24, the frame is not disposed within the pump outlet tube, and therefore the pump outlet tube is not supported by the frame 34 in the open position. The pump outlet tube 24 is typically made of a collapsible material that is impermeable to blood. For example, the pump outlet tube 24 may comprise polyurethane, polyester, and / or silicone. Alternatively or additionally, the pump outlet tube may be made of polyethylene terephthalate (PET) and / or polyether block amide (e.g., It is made of [material name missing]. For some applications (not shown), the pump outlet tubing is reinforced with a reinforcing structure (e.g., a braided reinforcement structure such as braided nitinol tubing). Typically, the proximal portion of the pump outlet tubing is configured such that it is at least partially situated within the subject's ascending aorta. For some applications, the proximal portion of the pump outlet tubing passes through the subject's aortic valve, entering the subject's ascending aorta from the subject's left ventricle, such as [example missing]. Figure 1B As shown.

[0183] As described above, the pump outlet tube typically defines one or more blood inlet openings 108 at its distal end, through which blood flows from the left ventricle into the pump outlet tube during impeller operation. For some applications, the proximal portion of the pump outlet tube defines one or more blood outlet openings 109, through which blood flows from the pump outlet tube into the ascending aorta during impeller operation. Typically, the pump outlet tube defines multiple blood outlet openings 109, for example, between two and eight blood outlet openings (e.g., between two and four blood outlet openings). During impeller operation, the pressure of the blood flow through the pump outlet tube typically keeps the proximal portion of the tube open. For some applications, such as in the event of impeller failure, the proximal portion of the pump outlet tube is configured to collapse inward in response to pressure outside the proximal portion of the pump outlet tube exceeding the pressure inside the proximal portion of the pump outlet tube. In this way, the proximal portion of the pump outlet tube acts as a safety valve, thereby preventing retrograde blood flow from the aorta into the left ventricle.

[0184] Refer again Figure 1C For some applications, frame 34 is shaped such that it defines a proximal conical portion 36, a central cylindrical portion 38, and a distal conical portion 40. Typically, the proximal conical portion is oriented proximally, for example, such that the narrow end of the cone is proximal to the wide end of the cone. More typically, the distal conical portion is oriented distally, for example, such that the narrow end of the cone is distal to the wide end of the cone. For some applications, pump outlet tube 24 extends to the end of cylindrical portion 38 (or slightly proximal or distal to that end), such that the distal end of pump outlet tube defines a single axially oriented blood inlet opening 108, as... Figure 1C As shown. For some applications, the lining 39 is laid on the frame within at least a portion of the frame 34 (e.g., along all or part of the central columnar portion of the frame). Figure 1C An embodiment of the pump head portion without liner 39 is shown, but several figures (e.g., Figure 4 , Figure 5A , Figures 6A-6B , Figures 9A-9B , Figures 10A-10C , Figure 11A , Figure 11C , Figure 13A and Figure 14A -Figure 14C) illustrates an embodiment of the pump head portion including the liner 39. Depending on the application, the liner partially or completely overlaps with the pump outlet pipe 24 on the liner-lined portion of the frame, as shown below. Figures 9A-9B As described in further detail.

[0185] Typically, the pump outlet tube 24 includes a tapered proximal portion 42 and a cylindrical central portion 44. The proximal tapered portion is typically oriented proximally, for example, such that the narrow end of the cone is proximal relative to the wide end of the cone. Typically, the blood outlet opening 109 is defined by the pump outlet tube 24 such that the opening extends at least partially along the proximal tapered segment of the tube 24. For some such applications, the blood outlet opening is teardrop-shaped, such as... Figure 1C As shown. Typically, the teardrop-shaped property of the blood outlet opening is combined with an opening that extends at least partially along the proximal conical segment of tube 24, such that blood flows out of the blood outlet opening at its location along a flow line substantially parallel to the longitudinal axis of tube 24.

[0186] For some applications (not shown), the diameter of the pump outlet pipe 24 varies along the length of its central portion, giving the central portion a truncated cone shape. For example, the central portion of the pump outlet pipe may widen from its proximal end to its distal end, or it may narrow from its proximal end to its distal end. For some applications, the central portion of the pump outlet pipe has a diameter between 5 mm and 7 mm at its proximal end, and between 8 mm and 12 mm at its distal end.

[0187] Refer again Figure 1C A typical ventricular assist device includes a distal end element 107 disposed distally relative to a frame 34, and the distal end element 107 includes an axial shaft receiving tube 126 and a distal end portion 120. Typically, the axial shaft receiving tube is configured to receive the distal portion of the axial shaft 92 of the pump head portion during axial reciprocating motion of the axial shaft (as described further in detail below) and / or during delivery of the ventricular assist device. (Typically, during delivery of the ventricular assist device, the frame remains in a radially constrained configuration, which typically results in the axial shaft being positioned differently relative to the frame relative to its arrangement during operation of the ventricular assist device). Typically, the distal end portion 120 is configured to have a curved shape when deployed into the left ventricle of a subject, for example, as... Figure 1C As shown. For some applications, the curvature of the distal end portion is configured to provide a non-invasive end to the ventricular assist device 20. Alternatively or additionally, the distal end portion is configured to separate the blood inlet opening 108 of the ventricular assist device from the wall of the left ventricle.

[0188] like Figure 1BAs shown in the enlarged portion, for some applications, the pump outlet pipe 24 extends to the end of the distal tapered portion 40 of the frame, and defines a plurality of lateral blood inlet openings 108, as described in further detail below. For such applications, the pump outlet pipe typically defines a distal tapered portion that faces distally, such that the narrow end of the tapered portion is distal relative to the wide end. For some such applications (not shown), the pump outlet pipe defines two to four lateral blood inlet openings (e.g., four lateral blood inlet openings, as shown). Typically, for such applications, each blood inlet opening defines an area greater than 20 square millimeters (e.g., greater than 30 square millimeters) and / or less than 60 square millimeters (e.g., less than 50 square millimeters), such as 20-60 square millimeters or 30-50 square millimeters. Alternatively or additionally, the outlet tube defines a greater number of smaller lateral blood inlet openings, for example, more than 10 blood inlet openings, more than 50 blood inlet openings, more than 200 blood inlet openings, or more than 400 blood inlet openings, for example, 50-100 blood inlet openings, 100-400 blood inlet openings, or 400-600 blood inlet openings. For some such applications, each blood inlet opening defines an area greater than 0.05 square millimeters (e.g., greater than 0.1 square millimeters) and / or less than 3 square millimeters (e.g., less than 1 square millimeter), for example, an area of ​​0.05 square millimeters to 3 square millimeters or 0.1 square millimeters to 1 square millimeter. Alternatively, each blood inlet opening defines an area greater than 0.1 square millimeters (e.g., greater than 0.3 square millimeters) and / or less than 5 square millimeters (e.g., less than 1 square millimeter), for example, an area of ​​0.1 square millimeters to 5 square millimeters or 0.3 square millimeters to 1 square millimeter.

[0189] Now for reference Figure 2 , Figure 2 This is a schematic diagram of a frame 34 housing the impeller of a ventricular assist device 20 according to some applications of the present invention. The frame 34 is typically made of a shape memory alloy such as nitinol, and the shape memory alloy is shaped such that the central portion of the frame (and therefore the tube 24) has a generally circular, elliptical, or polygonal cross-sectional shape when no force is applied to the pump outlet tube 24. By presenting its generally circular, elliptical, or polygonal cross-sectional shape, the frame is configured to keep the distal portion of the tube in the open state.

[0190] Typically, the frame is a support frame because it comprises pillars that sequentially define the cells. More typically, the frame is covered by the pump outlet pipe 24 and / or by the liner 39, as referenced below. Figures 9A-9BAs described below, for some applications, the impeller 50 undergoes axial reciprocating motion relative to the frame 34. Typically, during the impeller's motion relative to the frame, the portion of the impeller defining its maximum span is positioned within the central cylindrical portion 38 of the frame 34. In some cases, if the cell of the central cylindrical portion 38 of the frame 34 is too large, the pump outlet pipe 24 and / or liner 39 is stretched between the edges of the cell, causing the pump outlet pipe 24 and / or liner 39 to not define a circular cross-section. For some applications, if this occurs in the region where the portion defining the impeller's maximum span is located, this results in a non-constant clearance between the impeller blade edge and the pipe 24 (and / or liner) at that position during the impeller's rotation cycle. For some applications, this may lead to increased hemolysis compared to a situation where there is a constant clearance between the impeller blade edge and the pipe 24 (and / or liner) at that position during the impeller's rotation cycle.

[0191] refer to Figure 2 At least in part, taking into account the problems described in the previous paragraph, within the central columnar portion 38 of frame 34, the frame defines a large number of relatively small cells. Typically, when the frame is positioned in its non-radial constrained configuration, the maximum cell width CW (i.e., the distance, as measured around the circumference of columnar portion 38, from the inner edge of the post at the central joint on one side of the cell to the inner edge of the post at the central joint on the other side of the cell) of each cell within the columnar portion of the frame is less than 2 mm, for example, between 1.4 mm and 1.6 mm, or between 1.6 mm and 1.8 mm. Due to the relatively small size of the cells, liner 39 defines a substantially circular cross-section within the columnar portion of the frame.

[0192] Still referencing Figure 2 And starting from the distal end of the frame (on the right side of the figure), the frame typically defines the following portion: (a) a connecting portion 31, through which the frame is connected to the distal support housing 118H of the ventricular assist device (in Figure 5A(a) shown in the diagram, (b) the distal tapered portion 40, (c) the cylindrical portion 38, (d) the proximal tapered portion 36, and (e) the proximal strut joint 33. As shown, when the frame transitions from the proximal end of the frame toward the center of the frame (e.g., when the frame transitions from the proximal strut joint 33, through the proximal tapered portion 36, and to the central cylindrical portion 38), the struts 37 of the frame pass through joints 35, where two struts branch off from a single strut in a Y-shape. As described in further detail below, typically, the frame 34 is placed in the delivery conduit 143 in a radially constrained (i.e., coiled) configuration by being axially elongated within the frame. Furthermore, typically, the frame transmits its radial narrowing to the impeller, and the impeller becomes radially constrained by being axially elongated within the frame. For some applications, the struts of the frame configured as described above facilitate the transmission of axial elongation from the delivery conduit (or other means configured to coil the frame) to the frame, which in turn facilitates the transmission of axial elongation to the impeller. This is because the pairs of struts branching from each joint 35 are configured to pivot around the joint and move closer to each other, thus closing.

[0193] Still referencing Figure 2 During the assembly of the ventricular assist device, the initial distal connection portion 31 is initially connected to the distal support housing 118H, for example, via a snap-fit ​​mechanism. Figure 5A (As shown). For some applications, the proximal strut joint 33 remains open at this stage so that the impeller is placed within the frame via the proximal end of the frame. Typically, Figure 2 The structure of the frame 34 shown is for applications where the pump outlet pipe extends to the distal end of the frame 34 (e.g., as...). Figure 1B (As shown). In this case, the impeller cannot be inserted via the distal end of the frame because the distal end of the frame is covered by the pump outlet pipe 24. During the assembly of the ventricular assist device, the proximal strut joint is closed after the impeller is inserted via the proximal end of the frame. For some applications, the proximal strut joint surrounds the proximal support housing 116H (in... Figure 5A The outer closure (as shown in the image) is as follows (see reference below). Figures 5A-5B Further detailed description. Typically, the fixing element 117 (e.g., Figure 5A The ring shown in the diagram surrounds the outer side of the proximal support housing 116H, keeping the strut joint in its closed configuration.

[0194] Typically, when configured in its non-radial constraint configuration, the frame 34 has a total length greater than 25 mm (e.g., greater than 30 mm) and / or less than 50 mm (e.g., less than 45 mm), for example, 25 mm–50 mm or 30 mm–45 mm. Typically, when configured in its radial constraint configuration (within the delivery conduit 143), the length of the frame increases by 2 mm to 5 mm. Typically, when configured in its non-radial constraint configuration, the central columnar portion of the frame 34 has a length greater than 10 mm (e.g., greater than 12 mm) and / or less than 25 mm (e.g., less than 20 mm), for example, 10 mm–25 mm or 12 mm–20 mm. For some applications, the ratio of the length of the central columnar portion of the frame to the total length of the frame is greater than 1:4 and / or less than 1:2, for example, between 1:4 and 1:2.

[0195] Now for reference Figures 3A-3E , Figures 3A-3E This is a schematic diagram of an impeller 50 or a portion thereof according to some applications of the present invention. Typically, the impeller includes at least one outer helical elongated element 52 wound around a central axial spring 54, such that the helical structure defined by the helical elongated element is coaxial with the central axial spring. Typically, the impeller includes two or more helical elongated elements (e.g., three helical elongated elements, such as...). Figures 3A-3C (As shown). For some applications, the helical elongated element and the central axial spring are made of shape memory materials (e.g., shape memory alloys such as nitinol). Typically, each helical elongated element and the central axial spring is supported by a membrane 56 of material (e.g., an elastomer, such as polyurethane, and / or silicone) between them. For some applications, the membrane of the material includes nitinol sheets embedded therein, for example, to reinforce the membrane of the material. For illustrative purposes, the impeller in Figure 3A The text indicates that the material is not available. Figure 3B and Figure 3C Views of the impeller are shown, in which the material is supported between a helical elongated element and a spring. Figure 3D and Figure 3E They respectively showed the same as Figure 3B and Figure 3C The view shown is similar to that of the impeller, but some features of the impeller are different. Figure 3B and 3C The features shown are described in detail below.

[0196] Each helical elongated element, together with a membrane extending from the helical elongated element to the spring, defines a corresponding impeller blade, wherein the helical elongated element defines the outer edge of the blade, and the axial spring defines the axis of the impeller. Typically, the membrane of material extends along the spring and wraps around the spring. For some applications, the suture 53 (e.g., polyester suture, such as...) Figures 3A-3CThe suture (shown) is wound around a helical elongated element. Typically, the suture is configured to facilitate bonding between a film of material (typically an elastomer, such as polyurethane, or silicone) and a helical elongated element (typically a shape memory alloy, such as nitinol). For some applications, the suture (e.g., polyester suture, not shown) is wound around a spring 54. Typically, the suture is configured to facilitate bonding between a film of material (typically an elastomer, such as polyurethane, or silicone) and a spring (typically a shape memory alloy, such as nitinol).

[0197] Typically, the proximal ends of spring 54 and helical elongated element 52 extend from the proximal bushing (i.e., sleeve support) 64 of the impeller, such that the proximal ends of spring 54 and helical elongated element 52 are positioned at similar radial distances from the longitudinal axis of the impeller. Similarly, typically, the distal ends of spring 54 and helical elongated element 52 extend from the distal bushing 58 of the impeller, such that the distal ends of spring 54 and helical elongated element 52 are positioned at similar radial distances from the longitudinal axis of the impeller. The helical elongated element typically rises gradually from the proximal bushing before reaching its maximum span, and then gradually descends towards the distal bushing. Typically, the helical elongated element is symmetrical along its length, such that the rising portion of its length is symmetrical with respect to the falling portion of its length. Typically, the impeller defines a cavity 62 (e.g., Figure 3C As shown, the cavity typically extends through the impeller spring 54 and the proximal bushing 64 and the distal bushing 58 and is defined by the impeller spring 54 and the proximal bushing 64 and the distal bushing 58.

[0198] Now for reference Figure 4 This figure is a schematic diagram of an impeller 50 disposed within a frame 34 of a ventricular assist device 20 according to some applications of the present invention. For some applications, a liner 39 is laid on the frame within at least a portion of the frame 34 (e.g., all or part along the central columnar portion 38 of the frame). Depending on the application, the liner partially or completely overlaps with the pump outlet pipe 24 over the liner-laid portion of the frame, as referenced below. Figures 9A-9B As described in further detail.

[0199] like Figure 4As shown, typically, a gap G exists between the outer edge of the impeller 50 and the liner 39, even at the location of maximum impeller span. For some applications, it is desirable that the gap between the outer edge of the impeller blades and the liner 39 be relatively small so that the impeller can effectively pump blood from the subject's left ventricle into the subject's aorta. (Note that since the gap between the outer edge of the impeller 50 and the liner 39 is relatively small even at the location of maximum impeller span, and because of the shape of the impeller, the impeller functions as an axial flow impeller, in which the impeller pumps blood axially from the distal end to the proximal end of the pump outlet pipe 24.) It is also desirable that the gap between the outer edge of the impeller blades and the inner surface of the frame 34 be maintained throughout the rotation of the impeller within the frame 34, for example, to reduce the risk of hemolysis.

[0200] For some applications, when both impeller 50 and frame 34 are configured in a non-radial constrained configuration, and before impeller operation, at the position where the impeller span is at its maximum, the clearance G between the outer edge of the impeller and the liner 39 is greater than 0.05 mm (e.g., greater than 0.1 mm), and / or less than 1 mm (e.g., less than 0.4 mm), for example, 0.05 mm–1 mm, or 0.1 mm–0.4 mm. For some applications, when the impeller is configured in its non-radial constrained configuration and before impeller operation, at the position where the impeller outer diameter is at its maximum, the impeller outer diameter is greater than 7 mm (e.g., greater than 8 mm), and / or less than 10 mm (e.g., less than 9 mm), for example, 7 mm–10 mm, or 8 mm–9 mm. For some applications, when frame 34 is configured in its non-radial constraint configuration, the inner diameter of frame 34 (as measured from the inside of liner 39 on one side of the frame to the inside of liner on the opposite side of the frame) is greater than 7.5 mm (e.g., greater than 8.5 mm), and / or less than 10.5 mm (e.g., less than 9.5 mm), for example, 7.5 mm–10.5 mm, or 8.5 mm–9.5 mm. For some applications, when frame 34 is configured in its non-radial constraint configuration, the outer diameter of frame 34 is greater than 8 mm (e.g., greater than 9 mm), and / or less than 13 mm (e.g., less than 12 mm), for example, 8 mm–13 mm, or 9 mm–12 mm.

[0201] Typically, the axial shaft 92 passes through the impeller cavity 62 along the axis of the impeller 50. More typically, the axial shaft is rigid, such as a rigid tube. For some applications, the proximal bushing 64 of the impeller is coupled to the shaft such that the axial position of the proximal bushing relative to the shaft is fixed, and the distal bushing 58 of the impeller is slidable relative to the shaft. For example, the proximal bushing can be coupled, for example, via a snap-fit ​​mechanism, to a coupling element 65 disposed on the axial shaft (in... Figure 4(As shown in the diagram). Alternatively, the distal bushing 58 of the impeller is coupled to the shaft such that the axial position of the distal bushing relative to the shaft is fixed, and the proximal bushing 64 of the impeller is slidable relative to the shaft. The axial shaft itself is radially stabilized via the proximal radial support 116 and the distal radial support 118. Furthermore, the axial shaft radially stabilizes the impeller relative to the inner surface of the frame 34 by passing through the cavity 62 defined by the impeller, such that a relatively small gap (e.g., the gap as described above) is maintained even during impeller rotation, even between the outer edge of the impeller blades and the inner surface of the frame 34.

[0202] Refer again Figures 3A-3C For some applications, the impeller includes a plurality of elongated elements 67 extending radially from a central axial spring 54 to an outer helical elongated element 52. These elongated elements are typically flexible, but substantially non-stretchable along the axis defined by the elongated elements. More typically, each elongated element is configured not to exert a force on the helical elongated element unless a force is applied to the impeller causing the helical elongated element to move radially outward, thus (in the absence of elongated elements) the spacing between the helical elongated element and the central axial spring will be greater than the length of the elongated element. For example, the elongated elements may comprise ropes (e.g., polyester, and / or another polymer or a natural material containing fibers) and / or threads (e.g., nitinol thread, and / or threads made of different alloys or metals).

[0203] For some applications, the elongated element 67 holds the helical elongated element (which defines the outer edge of the impeller blades) within a given distance relative to the central axial spring. In this way, the elongated element is configured to prevent the outer edge of the impeller from being forced radially outward due to the forces applied to the impeller during impeller rotation. The elongated element is thus configured to maintain a gap between the outer edge of the impeller blades and the inner surface of the frame 34 during impeller rotation. Typically, more than one (e.g., more than two) and / or fewer than eight (e.g., fewer than four) elongated elements 67 are used in the impeller, wherein each elongated element is typically folded in half (i.e., extending radially from the central axial spring 54 to the outer helical elongated element 52 and then returning from the helical elongated element to the central axial spring). For some applications, multiple elongated elements are formed by a single rope or single line, wherein each elongated element extends from the spring to the corresponding helical elongated element and returns to the spring.

[0204] Now for reference Figure 3D and Figure 3E , Figure 3D and Figure 3EThis is a schematic diagram of impeller 50. According to some applications of the invention, the impeller includes a single integrated anti-over-expansion element 72 that defines a plurality of elongated elements 67. For some applications, the anti-over-expansion element 72 (which defines a plurality of elongated elements 67) is used as an alternative to the elongated elements 67, such as... Figures 3A-3C As shown. For some applications, element 72 defines a ring 73 and a plurality of elongated elements 67 extending radially from the ring. For some applications, instead of threading a rope and / or wire around the spring 54, the ring 73 of element 72 is positioned around the spring, for example, by positioning it around a tube 70, which is typically positioned longitudinally at the center of the spring. The ends of the respective elongated elements 67 are then coupled to the respective helical elongated elements 52. As mentioned above, the elongated elements 67 are typically flexible but substantially not stretchable along the axis defined by the elongated elements. More typically, each of the elongated elements 67 is configured to be substantially non-resistant to compression. More precisely, each elongated element 67 is configured to apply a tension force to the helical elongated elements 52, which prevents the helical elongated elements 52 from moving radially outward, such that (in the absence of elongated elements 67) the gap between the helical elongated elements 52 and the central axial spring 54 will be greater than the length of the elongated elements 67. When a force that would cause the helical elongated element 52 to move radially outward (in the absence of the elongated element 67) is applied to the impeller, the anti-extension element is configured to prevent the impeller from expanding radially. Typically, a corresponding elongated element 67 is disposed within each impeller blade and configured to prevent the impeller blade from expanding radially. For some applications, element 72 is made of polyester and / or another polymer or a fiber-containing natural material and / or nitinol (or a similar shape memory alloy).

[0205] Note that the scope of this application includes the use of a single integrated anti-impeller over-expansion element 72, whose impeller has the same characteristics as... Figures 3D-3E Different structures are shown. For example, a single integrated anti-impeller over-extension element 72 can be used with an impeller having an axial structure with a different construction than that of the spring 54. Typically, the axial structure defines a cavity therethrough, such that the impeller defines a cavity 62 therethrough.

[0206] For some applications, the following assembly techniques are used to manufacture the impeller while enhancing the bonding between the elastomeric material used to form the membrane 56 and at least one helical elongated element. Typically, the bonding of the elastomeric material to at least one helical elongated element is performed in a manner that does not result in protrusions from the effective edge of the impeller blades. Furthermore, typically, the bonding of the elastomeric material to at least one helical elongated element is performed by rounding the edge of the helical elongated element with the elastomeric material to provide a rounded outer edge to the impeller blades. The proximal bushing 64, the distal bushing 58, and the helical elongated element 52 are tube-cut from a shape memory material (e.g., nitinol). Typically, the tube cutting and the shape setting of the shape memory material are performed such that the helical elongated element and the bushing are defined by the cut and shape-set shape memory material tube. For some applications, the helical elongated element is subjected to plasma treatment before being coupled to the spring 54. Alternatively or additionally, the helical elongated element is coated with a coupling agent before being coupled to the spring 54. Typically, a coupling agent having at least two functional groups is selected, which are configured to bind to the helical elongated element and the elastomeric material, respectively. For example, a silane compound, such as n-(2-aminoethyl)-3-aminopropyltrimethoxysilane, can be used. This silane compound contains a first functional group (e.g., (OH)) configured to bind to the helical elongated element (typically made of an alloy such as nitinol), and the silane compound contains a second functional group (e.g., (NH2)) configured to bind to the elastomeric material. Typically, the functional groups in the coupling agent are effective only for a given time period (e.g., about one hour or less). Therefore, during this time period, a layer of elastomeric material is applied around the helical elongated element. Typically, this layer of elastomeric material is the same elastomeric material used in membrane 56 or a similar elastomeric material. For example, a polycarbonate-based thermoplastic polyurethane, such as Aromatic Carbothane. TM (e.g., Aromatic Carbothane) TM 75A) can be used in film 56, and the coating can be the same polycarbonate-based thermoplastic polyurethane, or a similar polycarbonate-based thermoplastic polyurethane, for example... (For example 90A).

[0207] As described above, the proximal bushing 64, distal bushing 58, and helical elongated element 52 are typically cut from a tube of shape memory material (e.g., nitinol). For some applications, a spring 54 is coupled to the helical elongated element 52 after a coating has been applied. Typically, the spring 54 is inserted into the cut and shaped tube such that it extends along the length of the tube at least from the proximal bushing to the distal bushing. For some applications, the spring is inserted into the cut and shaped tube when axially compressed, and the spring is configured to remain in place relative to the tube by applying radial forces to the proximal and distal bushings. Alternatively or additionally, multiple portions of the spring are welded to the proximal and distal bushings. For some applications, the spring is cut from a tube of shape memory material (e.g., nitinol). For some such applications, the spring is configured such that when the spring is set in a non-radial constraint configuration (where the spring is typically set in a non-radial constraint configuration during impeller operation), there is essentially no gap between the spring coil and its adjacent coil.

[0208] Typically, at this stage, as described above, an over-expansion prevention element 72 is placed between the spring and the helical elongated element to form an assembly comprising the coated helical elongated element 52, the spring 54, and the over-expansion prevention element 72.

[0209] For some applications, at this stage, the components of the coated spiral elongated element 52, spring 54, and anti-over-expansion element 72 are coated with another layer of elastomeric material. Typically, the elastomeric material being coated is the same as or similar to the elastomeric material used as the membrane 56. For example, polycarbonate-based thermoplastic polyurethanes, such as Aromatic Carbothane. TM (e.g., Aromatic Carbothane) TM 75A) can be used as film 56, and the coating material can be the same polycarbonate-based thermoplastic polyurethane, or a similar polycarbonate-based thermoplastic polyurethane, for example... (For example 90A). For some applications, a spray agent is applied to a helical elongated element to round it. Typically, when the helical elongated element has a circular cross-section, the elastomeric material forms a layer of substantially uniform thickness at the interface with the helical elongated element. For some applications, as described in the previous paragraph, the step of applying an elastomeric material coating layer to the helical elongated element at least partially rounds the helical elongated element.

[0210] For some applications, after spraying, the coated spiral elongated element 52, spring 54, and anti-over-expansion element 72 are immersed in the elastomer used to manufacture the membrane 56. For some applications, the material used to manufacture the membrane is an elastomer having a limiting elongation greater than 300%, for example, greater than 400%. Typically, the material has a relatively low molecular weight. For some applications, the material has a melt flow index (an indirect measure of molecular weight) of at least 4, for example, at least 4.3. For some applications, the material has a limiting tensile strength exceeding 6000 psi, for example, exceeding 7000 psi, or exceeding 7500 psi. For some applications, the material is a polycarbonate-based thermoplastic polyurethane, such as Carbothane. TM For some applications, Aromatic Carbothane TM (e.g., Aromatic Carbothane) TM 75A) is used. Typically, this material combines one or more of the following properties: no loss of outer diameter during immersion, fatigue resistance, resistance to deformities due to curling, and low loss of outer diameter during curling. The material is then cured, solidified, for example, by drying. Typically, at this stage, an impeller is positioned on a mandrel such that the mandrel passes through a cavity 62 defined by a bushing and a spring, thereby holding the cavity in place during drying. For some applications, the impeller is rotated as the material for making the membrane is dried, which typically helps to form a membrane of material with a substantially uniform thickness within each impeller blade. Once the material has dried, the mandrel is typically removed from the cavity 62.

[0211] Based on the above description of applying membrane 56 to the helical elongated element, the scope of the invention includes any technique, whether by spraying, immersion, or different coating methods, of applying additional layers of the same elastomeric material, different elastomeric materials, and / or intermediate materials to the helical elongated element before immersing it into the elastomeric material used to manufacture membrane 56. For some applications, the additional layer of elastomeric material is configured to round the helical elongated element and / or serve as an intermediary to enhance the bonding between the helical elongated element and the membrane 56 of the material. For some applications, an intermediary material (e.g., silane) is configured to act as an intermediary to enhance the bonding between the helical elongated element and the membrane 56 of the material.

[0212] Typically, impeller 50 is inserted into the left ventricle via a conduit, while impeller 50 is in a radially constrained configuration. In this configuration, both the helical elongated element 52 and the central axial spring 54 become axially elongated and radially constrained. Typically, the membrane 56 of a material (e.g., silicone and / or polyurethane) changes shape to correspond to the shape changes of the helical elongated element and the axially supporting spring (both of which support the membrane of the material). Typically, using a spring to support the inner edge of the membrane allows the membrane to change shape without breaking or collapsing because the spring provides a large surface area bound by the inner edge of the membrane. For some applications, using a spring to support the inner edge of the membrane reduces the diameter of the impeller that can be radially constrained compared to, for example, using a rigid shaft to support the inner edge of the membrane, because the diameter of the spring itself can be reduced by making the spring axially elongated.

[0213] As described above, for some applications, the proximal bushing 64 of the impeller 50 is coupled to the axial shaft 92 such that the axial position of the proximal bushing relative to the shaft is fixed, and the distal bushing 58 of the impeller is slidable relative to the shaft. For example, the proximal bushing can be coupled, for example, via a snap-fit ​​mechanism, to a connecting element 65 disposed on the axial shaft (in... Figure 4 (As shown in the diagram). For some applications, when the impeller is radially constrained for insertion into the ventricle or for removal from the subject's body, the impeller is axially elongated by sliding the distal bushing distally along the axial shaft. Alternatively (not shown), the distal bushing 58 of the impeller is coupled to the shaft such that the axial position of the distal bushing relative to the shaft is fixed, and the proximal bushing 64 of the impeller is slidable relative to the shaft. For some applications, when the impeller is radially constrained for insertion into the ventricle or for removal from the subject's body, the impeller is axially elongated by sliding the proximal bushing proximally along the axial shaft. (As shown in the diagram). Figures 3A-3E As shown, after being released from the subject's body, the impeller exhibits its non-radial constraint configuration (where the impeller is typically set to a non-radial constraint configuration during impeller operation).

[0214] Now for reference Figure 5A and Figure 5B These figures are schematic diagrams of the impeller 50 and frame 34 of a ventricular assist device 20 in its non-radial restraint and radial restraint states, respectively, according to some applications of the invention. During catheter insertion into the subject, the impeller and frame are typically configured in a radial restraint state, and during impeller operation within the left ventricle of the subject, the impeller and frame are configured in a non-radial restraint state.

[0215] like Figure 5BAs shown, the frame and impeller are typically held in a radially constrained configuration by the delivery duct 143. Typically, in a radially constrained configuration of the impeller, the total length of the impeller is greater than 15 mm (e.g., greater than 20 mm) and / or less than 30 mm (e.g., less than 25 mm), for example, 15-30 mm or 20-25 mm. Furthermore, typically, in a non-radially constrained configuration of the impeller, the impeller has a length greater than 8 mm (e.g., greater than 10 mm) and / or less than 18 mm (e.g., less than 15 mm), for example, 8 mm-18 mm or 10 mm-15 mm. Further, typically when the impeller and frame 34 are configured in a radially constrained configuration (e.g.... Figure 5B As shown), the impeller has an outer diameter of less than 2 mm (e.g., less than 1.6 mm), and the frame has an outer diameter of less than 2.5 mm (e.g., less than 2.1 mm).

[0216] As described above, typically, the axial shaft 92 passes through the axis of the impeller 50 via the impeller cavity 62. Typically, the proximal bushing 64 of the impeller is connected to the shaft via a connecting element 65, such that the axial position of the proximal bushing relative to the shaft is fixed, and the distal bushing 58 of the impeller is slidable relative to the shaft. (Alternatively, the distal bushing 58 of the impeller is connected to the shaft, such that the axial position of the distal bushing relative to the shaft is fixed, and the proximal bushing 64 of the impeller is slidable relative to the shaft.) The axial shaft itself is radially stabilized via a proximal radial support 116 and a distal radial support 118. Typically, the proximal support housing 116H is configured to surround and house the proximal support, and the distal support housing 118H is configured to surround and house the distal support. For some such applications, the radial supports and support housings are made of corresponding, different materials. For example, the radial support member can be made of a first material with relatively high hardness, such as ceramic (e.g., zirconium oxide), and the support member housing can be made of a second material that can be molded into the desired shape, such as a metal or alloy (e.g., stainless steel, cobalt chromium, and / or nickel titanate).

[0217] For some applications, the axial shaft 92 is made of metal or alloy, such as stainless steel. For some such applications, the area along the axial shaft that contacts either the proximal support 116 or the distal support 118 during operation of the ventricular assist device is covered with a ceramic sleeve 240 (e.g., a zirconia sleeve). In this way, the radial interface between the axial shaft and the proximal and distal supports is a ceramic-ceramic interface. As described further in detail herein, typically, the impeller and the axial shaft are configured to undergo axial reciprocating motion during operation of the ventricular assist device. Therefore, for some applications, at locations along the axial shaft corresponding to each of the proximal and distal supports, the axial shaft is covered by a ceramic sleeve along a length greater than 5 mm, for example, greater than 7 mm. In this way, during the axial reciprocating motion of the axial shaft, the area of ​​the axial shaft that contacts the radial supports is covered by the ceramic sleeve.

[0218] For some applications, the proximal support housing 116H and the distal support housing 118H perform additional functions. Referring first to the proximal support housing, as described above, for some applications, the proximal strut joint 33 of the frame 34 closes around the outer side of the proximal support housing. For some applications, the outer surface of the proximal support housing defines a groove shaped to receive the proximal strut joint. For example, as shown, the proximal strut joint has a widened head, and the groove defined by the outer surface of the proximal support housing is shaped to conform to the widened head of the proximal strut joint. Typically, a retaining element 117 (which typically includes a ring) holds the strut joint in its closed configuration around the outer side of the proximal support housing 116H. For some applications, additional portions of the ventricular assist device are coupled to the proximal support housing. For some applications, a drive cable 130 extends from outside the subject's body to the axial shaft 92 and is coupled to the axial shaft. Typically, the drive cable rotates within a first outer tube 140, which serves as a drive cable support tube and extends from outside the subject's body to the proximal support housing. For some applications, the first outer tube is disposed within a second outer tube 142, which also extends from outside the subject's body to the proximal support housing. For some applications, the first outer tube 140 and / or the second outer tube 142 are coupled to the proximal support housing (e.g., using adhesive). For example, the first outer tube 140 may be coupled to the inner surface of the proximal support housing, and the second outer tube 142 may be coupled to the outer surface of the proximal support housing.

[0219] Referring now to the distal support housing 118H, for some applications, the distal connecting portion 31 of the frame 34 is connected to the outer surface of the distal support housing 118H, for example, via a snap-fit ​​mechanism. For example, the outer surface of the proximal portion 119 of the distal support housing may include a snap-fit ​​mechanism to which the distal connecting portion 31 of the frame 34 is connected. For some applications, the distal support 118 is disposed within the proximal portion 119 of the distal support housing, such as... Figure 5A As shown. As described above, for some applications, the pump outlet tube 24 extends to the distal end of the frame 34 and defines a lateral blood inlet opening 108. For some such applications, a coupling portion 41 (e.g., a tubular coupling portion) extends distally from the pump outlet tube and is coupled to the distal support housing to anchor the distal end of the pump outlet tube. For some applications, the intermediate portion 123 of the distal support housing defines a ridged or threaded outer surface to which the coupling portion 41 of the pump outlet tube is coupled (e.g., by adhesive). For some applications, the outer surface is ridged to enhance the connection between the distal support housing and the coupling portion 41 of the pump outlet tube. For some applications, the outer surface is threaded to enhance the connection between the distal support housing and the coupling portion 41 of the pump outlet tube and to facilitate the application of adhesive between the outer surface and the coupling portion 41 of the pump outlet tube, as referenced below. Figure 12B Further detailed description. For some applications, the distal portion 121 of the distal support housing is configured to reinforce the area to which the distal end of the shaft 92 of the distal end element 107 moves (e.g., the axial shaft receiving tube 126 or a portion thereof). Typically, the distal end element 107 is coupled to the outer surface of the distal portion 121 of the distal support housing (e.g., via adhesive). For some applications, at least a portion of the outer surface of the distal portion 121 of the distal support housing is ridged and / or threaded to enhance the connection between the distal end element 107 and the distal support housing.

[0220] As described above, the axial shaft 92 is radially stabilized via a proximal radial support 116 and a distal radial support 118. Furthermore, the axial shaft, by passing through the cavity 62 defined by the impeller, radially stabilizes the impeller relative to the inner surface of the frame 34 and the liner 39, such that, as described above, even the relatively small gap (e.g., the gap described above) between the outer edge of the impeller blades and the liner 39 is maintained during impeller rotation. Typically, the impeller itself is not directly disposed within any radial support or thrust support. Instead, supports 116 and 118 act as radial supports relative to the axial shaft. Typically, the pump head portion 27 (and more generally, the ventricular assist device 20) does not include any thrust support configured to be disposed within the subject's body and configured to resist the thrust generated by the rotation of the impeller. For some applications, one or more thrust supports are disposed outside the subject's body (e.g., in situations such as...). Figure 1A , Figure 7 and Figures 8A-8B Within the motor unit 23 shown, resistance to the thrust generated by the rotation of the impeller is provided solely by one or more thrust supports disposed outside the subject's body. For some applications, mechanical and / or magnetic elements are configured to hold the impeller within a given axial position range. For example, a magnet (e.g., magnet 82, hereinafter referred to) disposed near the proximal end of the drive cable (e.g., outside the subject's body). Figure 7 (As described) can be configured to apply axial movement to the impeller and / or hold the impeller within a given axial position range.

[0221] Now for reference Figure 6A and Figure 6B These figures are schematic diagrams of a ventricular assist device 20 at various stages of its motion cycle relative to the frame 34 of the ventricular assist device, according to some applications of the invention. For some applications, when the impeller pumps blood through the tube 24 by rotation, an axial shaft 92 (on which the impeller is fixed) is driven to cause the impeller to reciprocate axially within the frame 34 by moving the axial shaft in an axial reciprocating motion, as shown below. Figure 7Further detailed description. Alternatively or additionally, the impeller and axial shaft are configured to reciprocate axially within the frame 34 in response to forces acting on the impeller, without requiring active drive of the axial shaft to move in a reciprocating manner. Typically, during a subject's cardiac cycle, the pressure gradient between the left ventricle and the aorta changes from approximately zero during ventricular systole (hereinafter referred to as "systole") to a relatively large pressure gradient (e.g., 50 mmHg–70 mmHg) during ventricular diastole (hereinafter referred to as "diastole"). For some applications, due to the increased pressure gradient resisted by the impeller pumping during diastole (and because the drive cable 130 is stretchable), the impeller is pushed distally relative to the frame 34 during diastole compared to its position relative to the frame 34 during systole. Consequently, the axial shaft moves forward because the impeller is connected to it. During systole, the impeller (and consequently the axial shaft) returns to its systolic position. In this way, the axial reciprocating motion of the impeller and the axial shaft is generated passively, that is, it is not necessary to actively drive the axial shaft and impeller to make them undergo this motion. Figure 6A and Figure 6B The impeller and axial shaft are shown at corresponding positions within the frame 34 during the aforementioned axial reciprocating motion cycle.

[0222] In some applications, the portion of the axial shaft in contact with the proximal support 116 and the distal support 118 changes continuously due to its axial reciprocating motion. In some such applications, assuming all else is equal, the frictional force exerted on the axial shaft by the supports is distributed over a larger area of ​​the axial shaft compared to when the axial shaft does not move relative to the supports, thereby reducing wear on the axial shaft. Alternatively or additionally, by reciprocating relative to the supports, the axial shaft removes any residue, such as blood residue, from the interface between the axial shaft and the supports.

[0223] For some applications, at the impeller's closest position during its motion cycle, the proximal end of the impeller is within the proximal conical segment of frame 34. For some applications, at the impeller's farthest position during its motion cycle, the distal end of the impeller is positioned at the distal end of the cylindrical segment of frame 34. Alternatively, even at the impeller's farthest position during its motion cycle, the distal end of the impeller is positioned proximal to the distal end of the cylindrical segment of frame 34. Typically, throughout the cardiac cycle, the segment with the largest impeller span is positioned within the cylindrical portion of frame 34. However, during at least a portion of the cardiac cycle, the proximal portion of the impeller is typically positioned within the proximal conical segment of the frame.

[0224] Refer again Figure 6A and Figure 6B Typically, the distal end element 107 is a single integrated element comprising both the axial shaft receiving tube 126 and the distal end portion 120. Typically, the axial shaft receiving tube is configured to receive the distal portion of the axial shaft 92 of the pump head portion during axial reciprocating motion of the axial shaft (as described further in detail below) and / or during delivery of the ventricular assist device. (Typically, during delivery of the ventricular assist device, the frame remains in a radially constrained configuration, which typically results in the axial shaft being positioned differently relative to the frame during delivery than it is during operation of the ventricular assist device). For some applications, the distal end portion 120 is configured to be flexible, such that it does not cause tissue damage to the subject even if it comes into contact with tissue (e.g., tissue of the left ventricle). For example, the distal end portion 120 or the entire distal end element may be made of silicone, polyethylene terephthalate (PET), and / or polyether block amide (e.g., The guide wire 10 is made of [material name missing]. For some applications, the distal end portion defines a cavity 122 passing through it. For some such applications, during insertion of the ventricular assist device into the left ventricle, the guide wire 10 [is used]. Figure 1B First, it is inserted into the left ventricle according to, for example, known techniques. Then, the distal portion of the ventricular assist device is guided into the left ventricle by advancing the distal portion of the guide wire, wherein the guide wire is disposed within the cavity 122. For some applications, a duckbill valve 390 (or a hemostatic valve of a different type) is disposed at the distal end of the cavity 122 of the distal portion 120.

[0225] Typically, during the insertion of the ventricular assist device into the ventricle of a subject, the delivery catheter 143 is positioned over the impeller 50 and frame 34, and the impeller and frame are maintained in their radially constrained configuration. For some applications, such as Figure 1B As shown, during insertion of the delivery catheter into the subject's ventricle, the distal distal element 107 extends distally from the delivery catheter. For some applications, the distal distal element has a protrusion 110 towards its proximal end. (Reference) Figure 5B (It shows the pump head portion disposed within the delivery catheter 143), and for some applications, during insertion of the ventricular assist device into the ventricle of a subject, the delivery catheter extends to the proximal side of the protrusion, such that the delivery catheter and the protrusion form a smooth, continuous surface. The distal side of the protrusion 110 is tapered, such that the vascular system is exposed to the tapered diameter variation and not exposed to any edges caused by the abrupt change in diameter at the interface between the delivery catheter and the distal terminal element.

[0226] For some applications, the distal distal element 107 defines a total curvature similar to a question mark or a tennis racket, wherein the distal distal element defines a straight proximal portion and a bulge on one side of the longitudinal axis of the straight proximal portion. Typically, as described above, the ventricular assist device is introduced into the ventricle of a subject via a guideline. The distal distal portion 120 defines a cavity 122 such that the distal distal portion is maintained in a straight configuration during the introduction of the ventricular assist device into the subject's ventricle (e.g., as in...). Figure 1B (As shown in the left view). For some applications, the distal end portion is configured to exhibit its curved shape when the guide wire is removed. It should be noted that... Figures 6A-6B The external shape of the distal distal portion (and some other figures) is shown to define a complete loop, wherein the distal end of the distal distal portion (within which the duckbill valve 390 is disposed) spans the more proximal portion of the distal distal portion. Typically, due to the guide wire inserted therethrough (during insertion of the ventricular assist device into the left ventricle), the distal distal portion remains partially straight, even after the guide wire is removed from the distal distal portion. Typically, the distal distal portion is partially straightened such that when the distal distal portion is positioned in the left ventricle, it does not define a complete loop in the absence of external force acting on it.

[0227] Refer again Figures 6A-6B For some applications, the axial shaft receiving tube 126 extends proximally from the distal end portion 120 of the distal end element 107. As described above, typically, the axial shaft undergoes axial reciprocating motion during impeller 50 operation. The axial shaft receiving tube 126 defines a cavity 127 configured to receive the axial shaft when it extends beyond the distal support 118. For some applications, the axial shaft receiving tube defines a stop 128 at its distal end, the stop being configured to prevent the axial shaft from being pushed beyond the stop. For some applications, the stop includes a rigid member inserted (e.g., embedded) into the distal end of the shaft receiving tube. Alternatively (not shown), the stop includes a shoulder between the cavity 127 of the axial shaft receiving tube and the cavity 122 of the distal end portion 120.

[0228] Typically, during normal impeller operation, the axial shaft does not contact the stop 128, even when the drive cable 130 (in) Figure 5AThis is also true when the ventricular assist device 20 is extended to its maximum extent (e.g., during diastole). However, during the retraction of the ventricular assist device 20 from the subject's ventricle, as the delivery catheter is advanced over the impeller 50 and frame 34, the stop 128 is configured to prevent the axial shaft from protruding into the distal portion. In some cases, there is a risk of the drive cable snapping during the advancement of the delivery catheter over the frame and impeller. Without the stop 128, in this situation, the axial shaft might protrude into the distal portion. The stop 128 prevents this from happening, even in the event of drive cable snapping.

[0229] It should be noted that at the proximal end of the frame 34, the proximal radial support 116 also acts as a stop by preventing the connecting element 65, and thus the proximal bushing 64 of the impeller 50, from moving beyond the proximal radial support. Typically, during normal operation of the impeller, the connecting element 65 does not contact the proximal radial support 116. However, the proximal radial support 116 is configured to prevent the connecting element 65, and thus the proximal bushing 64 of the impeller 50, from migrating proximal to the frame, for example, when the impeller and frame are held in a radially constrained (i.e., coiled) configuration within the delivery duct 143.

[0230] Typically, during the operation of the ventricular assist device and throughout the entire axial reciprocating cycle of the impeller, the impeller is positioned relatively very close to the distal end portion. For example, the distance from the impeller to the distal end portion can be within the farthest 50% of the tube 24, such as the farthest 30% (or the farthest 20%), throughout the entire axial reciprocating cycle of the impeller.

[0231] Now refer to Figure 7 This is a schematic exploded view of the motor unit 23 of a ventricular assist device 20 according to some applications of the present invention. For some applications, the console 21 ( Figure 1A The computer processor 25, which controls the rotation of the impeller 50, is also configured to control the reciprocating motion of the axial shaft. Typically, both types of motion are generated using the motor unit 23. The scope of the invention includes controlling reciprocating motion at any frequency. For some applications, an indication of a subject's cardiac cycle is detected (e.g., by detecting the subject's ECG), and the reciprocating motion of the axial shaft is synchronized with the subject's cardiac cycle.

[0232] Typically, motor unit 23 includes a motor 74 configured to apply rotational motion to impeller 50 via drive cable 130. As described further below, typically, the motor is magnetically coupled to the drive cable. For some applications, axial motion driver 76 is configured to drive the motor to move in an axial reciprocating motion (as indicated by double-headed arrow 79). Typically, due to the magnetic coupling between the motor and the drive cable, the motor applies reciprocating motion to the drive cable, which in turn applies that motion to the impeller. As described above and below, for some applications, the drive cable, impeller, and / or axial shaft undergo axial reciprocating motion passively, for example, due to periodic changes in pressure gradients resisted by the impeller pumping blood. Typically, for such applications, motor unit 23 does not include axial motion driver 76.

[0233] In some applications, the magnetic coupling between the motor and the drive cable is as follows: Figure 7 As shown. Figure 7 As shown, a set of drive magnets 77 are coupled to a motor via a drive magnet housing 78. For some applications, the drive magnet housing includes a ring 81 (e.g., a steel ring), and the drive magnets are adhered to the inner surface of the ring. For some applications, as shown, a gasket 85 is adhered to the inner surface of the ring 81 between two drive magnets. A driven magnet 82 is disposed between the drive magnets such that there is axial overlap between the drive magnets and the driven magnets. The driven magnet is coupled to a pin 131 that extends beyond the distal end of the driven magnet 82, wherein the pin is coupled to the proximal end of a drive cable 130. For example, the driven magnet may be cylindrical and define a hole through it, and the pin 131 may be adhered to the inner surface of the driven magnet defining the hole. For some applications, the driven magnet is cylindrical, and the magnet includes a north pole and a south pole that are separated from each other along the length of the cylinder by a line 83 that bisects the cylinder, as shown. For some applications, the driven magnet is housed within a cylindrical housing 87. Typically, pin 131 defines the guidewire cavity 133.

[0234] Note that in Figure 7 In the illustrated application, the driving magnet is disposed outside the driven magnet. However, the scope of this application includes configurations that reverse the driving and driven magnets (with necessary modifications). For example, the proximal end of the drive cable may be coupled to two or more driven magnets arranged around the driving magnet such that there is axial overlap between the driven and driving magnets.

[0235] As described above, typically, the cleaning system 29 (e.g.) Figure 1A(As shown) Used with ventricular assist device 20. Typically, motor unit 23 includes an inlet port 86 and an outlet port 88 for use with a cleaning system. In some applications, cleaning fluid is continuously or periodically pumped into the ventricular assist device via inlet port 86 and pumped out of the ventricular assist device via outlet port 88.

[0236] Typically, magnet 82 and pin 131 are held in an axially fixed position within motor unit 23. Typically, the proximal end of the drive cable is coupled to pin 131 and thus held in an axially fixed position by the pin. Typically, drive cable 130 extends from pin 131 to axial shaft 92, thereby at least partially fixing the axial position of the axial shaft, and consequently fixing the impeller 50. For some applications, the drive cable is somewhat stretchable. For example, the drive cable may be made of stretchable coiled wire. The drive cable typically allows the axial shaft (and consequently the impeller) to present a range of axial positions (due to more or less stretching of the drive cable), but limits the axial movement of the axial shaft and impeller to a certain range of motion (by holding the proximal end of the drive cable in an axially fixed position, and limiting the stretchability of the drive cable).

[0237] As described above, for some applications, the impeller 50 and axial shaft 92 are configured to reciprocate axially within the frame 34 in response to forces acting on the impeller, without requiring active drive of the axial shaft to move in a reciprocating manner. Typically, during a subject's cardiac cycle, the pressure gradient between the left ventricle and the aorta changes from approximately zero during systole to a relatively large gradient (e.g., 50 mmHg–70 mmHg) during diastole. For some applications, due to the increased pressure gradient resisted by the impeller pumping during diastole (and because the drive cable is stretchable), the impeller is pushed distally relative to the frame 34 during diastole compared to its position relative to the frame 34 during systole. Consequently, the axial shaft moves forward because the impeller is connected to it. During systole, the impeller (and consequently the axial shaft) returns to its systolic position. In this way, the axial reciprocating motion of the impeller and the axial shaft is generated passively, that is, it is not necessary to actively drive the axial shaft and impeller to make them undergo this motion.

[0238] Now refer to Figure 8A and Figure 8B These figures are schematic diagrams of motor unit 23 according to some applications of the present invention. Generally, as... Figure 8A and Figure 8B The motor unit 23 shown is similar to Figure 7 The motor unit shown, unless otherwise specified, is as follows: Figure 8A and Figure 8BThe motor unit 23 shown includes and Figure 7 The motor unit 23 shown is a similar component. For some applications, the motor unit includes a radiator 90 configured to dissipate heat generated by the motor. Alternatively or additionally, the motor unit includes a ventilation port 93 configured to further dissipate heat generated by the motor. For some applications, the motor unit includes vibration dampers 94 and 96 configured to dampen vibrations of the motor unit caused by the rotational and / or axial reciprocating motion of components of the ventricular assist device.

[0239] Now for reference Figure 9A and Figure 9B These figures are schematic diagrams of a ventricular assist device 20 according to some applications of the present invention, which includes a liner 39 lining the inside of a frame 34 housing an impeller 50. For some applications, the liner 39 is disposed inside the frame 34 to provide a smooth inner surface (e.g., a smooth inner surface having a generally circular cross-sectional shape) through which the impeller pumps blood. Typically, by providing a smooth surface, the covering material reduces hemolysis caused by blood pumped by the impeller, relative to pumping blood between the impeller and the struts of the frame 34. For some applications, the liner comprises polyurethane, polyester, and / or silicone. Alternatively or additionally, the liner comprises polyethylene terephthalate (PET) and / or polyether block amide.

[0240] Typically, the liner is disposed on the inner surface of at least a portion of the central columnar portion 38 of the frame 34. For some applications, the pump outlet pipe 24 also covers the central columnar portion 38 of the frame 34, for example, around the outer side of the frame, such that the pump outlet pipe 24 and the liner 39 overlap for at least 50% of the liner's length, for example, over the entire length of the columnar portion of the frame 34, such as... Figure 9A As shown. For some applications, there is only partial overlap between the pump outlet pipe 24 and the liner 39, for example, as Figure 9B As shown. For example, the pump outlet pipe 24 may overlap the liner along less than 50% (e.g., less than 25%) of the liner length. In some such applications, during insertion of the ventricular assist device 20 into the subject, the impeller is advanced distally within the frame 34 such that the impeller is not positioned within the overlapping area between the pump outlet pipe and the liner, thus eliminating a longitudinal position where the impeller, pump outlet pipe 24, frame 34, and liner 39 all overlap each other. Figure 9A and 9BAs shown, for some applications, a single axially oriented blood inlet opening 108 is defined at the distal end of the pump outlet pipe and / or liner. Alternatively, the liner is disposed on the inner surface of at least a portion of the central cylindrical portion 38 of the frame 34, and the pump outlet pipe extends to the distal end of the frame and defines a plurality of lateral blood inlet openings 108. For example, reference is made below. Figures 11A-13B This application will be described in further detail.

[0241] Typically, in the overlapping area between the liner 39 and the pump outlet pipe 24, the liner is shaped to form a smooth surface (e.g., to reduce hemolysis, as described above), and the pump outlet pipe 24 is shaped to conform to the struts of the frame 34 (e.g., as...). Figure 9A (As shown in the cross-section). Furthermore, the lining typically has a generally circular cross-section (e.g., due to the relatively small cell width within the central columnar portion of the frame, as referenced above). Figure 2 (as described below). For some applications, in the overlapping area between the liner 39 and the pump outlet pipe 24, the pump outlet pipe and the liner are joined together, for example, via vacuum, via adhesive and / or using a thermoforming process, as described below.

[0242] For some applications, the liner 39 and the pump outlet pipe 24 are made of different materials. For example, the liner may be made of polyurethane, while the pump outlet pipe may be made of polyether block amide. Fabrication. Typically, for this application, the material used to manufacture the liner has a higher thermoforming temperature than the material used to manufacture the pump outlet pipe. Optionally, the liner 39 and the pump outlet pipe 24 are made of the same material. For example, both the liner and the pump outlet pipe can be made of polyurethane or polyether block amide. Made.

[0243] For some applications, the pump outlet pipe and the liner are joined to each other and / or to the frame in the following ways. For some applications, the liner is directly joined to the inner surface of the frame before the pump outlet pipe is joined to the outside of the frame. Note that by joining the liner directly to the inner surface of the frame (rather than simply joining the liner to the pump outlet pipe, thereby sandwiching the frame between the liner and the pump outlet pipe), any bubbles, wrinkles, and other discontinuities in the smoothness of the surface provided by the liner are typically avoided. For some applications, techniques similar to those described above, used to enhance the bonding between the helical elongated elements of the elastomeric membrane and the impeller, are used to enhance the bonding between the inner surfaces of the liner and the frame. For some applications, the frame is initially treated to enhance the bonding between the inner surfaces of the liner and the frame. For some applications, the treatment of the frame includes applying plasma treatment to the frame (e.g., to the inner surface of the frame), immersing the frame in a coupling agent having at least two functional groups (e.g., a silane solution) configured to bond with the frame and the material used to manufacture the liner, respectively, and / or immersing the frame in a solution containing the material used to manufacture the liner (e.g., a polyurethane solution). For some applications, the liner is made of an elastomeric material (e.g., polyurethane), and the coupling agent is a silane solution, such as a solution of n-(2-aminoethyl)-3-aminopropyltrimethoxysilane, wherein the silane contains a first functional group (e.g., (OH)) configured to bond with the frame (which is typically made of an alloy, such as nitinol), and the silane contains a second functional group (e.g., (NH2)) configured to bond with the elastomeric material.

[0244] For some applications, a solution containing the material used to manufacture the liner (e.g., a polyurethane solution) is then sprayed onto the central column portion of the cage. Once the inner surface of the frame has been treated, the liner is bonded to the inner surface of the central column portion of the frame (e.g., bonded to the inner surface of the central column portion of the frame). Typically, the liner (which is shaped as a tube) is placed on a mandrel, the frame is placed on the liner, and pressure is applied through a heat-shrinking process. Furthermore, the liner and frame assembly is typically heated in an oven.

[0245] After the liner has been attached to the frame, a portion of the pump outlet pipe 24 is positioned to surround the outside of the frame. As mentioned above, for some applications, the liner 39 and the pump outlet pipe 24 are made of different materials. For example, the liner may be made of polyurethane, while the pump outlet pipe may be made of polyether block amide. Fabrication. Typically, for this application, the material used to manufacture the liner has a higher thermoforming temperature than the material used to manufacture the pump outlet pipe. For some applications, in order to mold the pump outlet pipe 24 to conform to the struts of the frame 34 without causing deformation of the liner, the frame is heated to a temperature higher than the thermoforming temperature of the pump outlet pipe 24 but lower than the thermoforming temperature of the liner 39.

[0246] Typically, a mandrel is used to heat the frame from the inside. Typically, when the frame is heated to the aforementioned temperature, the outer tube (typically made of silicone) applies pressure to the pump outlet pipe 24, causing the pump outlet pipe 24 to be radially pushed inward so that it conforms to the shape of the frame's support pillars, such as... Figure 9A The cross-section is shown. For some applications, at this stage, the mandrel placed inside the liner and heating the liner is shorter than the length of the liner. The mandrel is typically placed inside the liner such that a margin is left outside the mandrel at each end of the liner. Typically, the liner acts as a shield to prevent the pump outlet pipe from overheating and from being damaged by the heating of the mandrel. Placing the liner on the mandrel in the manner described above prevents the mandrel from direct contact with the frame and / or the pump outlet pipe. For some applications, the combination of the frame, the liner, and the portion of the pump outlet pipe 24 disposed around the frame is then shaped to the desired shape and size using shaping techniques known in the art.

[0247] Now for reference Figure 10A , Figure 10B and Figure 10C These figures are schematic diagrams of a portion of a ventricular assist device 20 according to some applications of the invention, which includes a protective braid 150 at its distal end. For some applications, the pump outlet tube 24 and the liner 39 extend to the end of the cylindrical portion 38 of the frame 34, such as... Figures 10A-10C As shown. For some applications, to reduce the risk of structures from the left ventricle (e.g., chordae tendineae, cardiac columns, and / or papillary muscles) entering the frame 34 and potentially being damaged by the impeller and / or axial shaft and / or causing damage to the left ventricular assist device, the distal tapered portion 40 of the frame is covered with a protective braid 150 (from the inside or outside). Typically, within at least a portion of the columnar portion of the frame, the braid is embedded between the pump outlet tube and the liner, such that during frame coiling, the braid coils together with the pump outlet tube and the liner, thereby preventing movement of the braid relative to the pump outlet tube and / or the liner. (In Figures 10A-10C The protective braided material embedded between the pump outlet pipe and the liner is not visible because it is covered by the pump outlet pipe.

[0248] For some applications, the protective braid 150 extends substantially to the distal end of the distal tapered portion of the frame, such as... Figure 10A As shown. For some such applications, along the distal portion 152 of the distal tapered section of the frame, the weave is covered with a blood-impermeable material 154 (e.g., polyurethane, polyester, silicone, polyethylene terephthalate (PET) and / or polyether block amides (e.g.)). )),like Figure 10AAs shown. Typically, most of the blood flowing into the blood inlet opening 108 defined by the pump outlet pipe originates from the side of the distal tapered portion of the frame, and relatively little axial flow exists via the distal end of the distal tapered portion of the frame. Therefore, in some cases, there is a risk of stagnation in this area. Furthermore, the holes defined by the braid are typically smaller within the distal portion 152 of the distal tapered portion of the frame due to the narrowing of the frame. Both of these factors can lead to thrombus formation on the braid within the distal portion 152 of the distal tapered portion of the frame. Therefore, for some applications, the braid is covered along the distal portion 152 of the distal tapered portion of the frame to prevent thrombus formation on the braid within this portion. Typically, the braid is covered (e.g., with a blood-impermeable elastomeric material, such as polyurethane). Alternatively, the pattern of the braid does not extend to the distal end of the distal tapered portion of the frame. Instead, within the distal portion 152 of the distal tapered portion of the frame, the braid is opened or cut, for example, defining large holes 156, such as... Figure 10B As shown.

[0249] For some applications (not shown), within the distal portion 152 of the distal tapered section of the frame, a fabric is covered (e.g., with a blood-impermeable elastomeric material, such as polyurethane), and then larger holes are cut from the covered fabric. Alternatively or additionally (also not shown), within the distal portion 152 of the distal tapered section of the frame, a fabric is covered with a blood-impermeable elastomeric material (e.g., polyurethane), and then holes are cut from the covered fabric around the entire circumference of the frame, such that the covered fabric defines holes extending around the entire circumference of the distal portion 152 of the distal tapered section of the frame. For some such applications, the aforementioned holes are cut such that they extend to the distal end of the distal tapered section of the frame, i.e., such that a single hole exists extending around the entire circumference of the frame and extending to the distal end of the distal tapered section of the frame.

[0250] In some applications, the weave extends substantially to the distal end of the distal tapered portion of the frame, and the weave is not even covered within the distal portion 152 of the distal tapered portion of the frame, such as... Figure 10C As shown. For some applications, the fabric is woven into the supports of the distal tapered portion of frame 34, as in... Figure 10C As shown in the enlarged view.

[0251] Now for reference Figures 11A-11DThese figures are schematic diagrams of a pump outlet tube 24 or a portion thereof according to some applications of the invention, the pump outlet tube being configured to define a lateral blood inlet opening 108 at its distal end. For some applications, the pump outlet tube extends substantially to the distal end of the distal tapered portion 40 of the frame 34. For such applications, the pump outlet tube typically defines a distal tapered portion 46, which is oriented distally, i.e., oriented such that the narrow end of the tapered portion is distal relative to the wide end of the tapered portion. Typically, the pump outlet tube includes a connecting portion 41 (e.g., a tubular connecting portion, as shown) extending distally from the pump outlet tube. As described above, the connecting portion is coupled to the distal support housing to anchor the distal end of the pump outlet tube.

[0252] For some applications (not shown), the pump outlet tube defines two to four lateral blood inlet openings. Typically, for such applications, each blood inlet opening defines an area greater than 20 mm² (e.g., greater than 30 mm²) and / or less than 60 mm² (e.g., less than 50 mm²), such as 20-60 mm² or 30-50 mm². Alternatively or additionally, the outlet tube defines a greater number of smaller blood inlet openings 108, such as more than 10 blood inlet openings, more than 50 blood inlet openings, more than 100 blood inlet openings, or more than 150 blood inlet openings, such as 50-100 blood inlet openings, 100-150 blood inlet openings, or 150-200 blood inlet openings. For some applications, the blood inlet openings are sized to (a) allow blood to flow from the subject's left ventricle into the tube, and (b) prevent structures from the subject's left ventricle from entering the frame. Typically, for such applications, the distal tapered portion 46 of the pump outlet pipe 24 is configured to reduce the risk of structures from the left ventricle (e.g., chordae tendineae, cardiac columns, and / or papillary muscles) entering the frame 34 and potentially being damaged by the impeller and / or axial shaft and / or causing damage to the left ventricular assist device. Therefore, for some applications, the blood inlet opening is shaped such that the width (or span) of the opening is less than 1 mm in at least one direction, for example, 0.1 mm–1 mm or 0.3 mm–0.8 mm. By defining such a small width (or span), typically, structures from the left ventricle (e.g., chordae tendineae, cardiac columns, and / or papillary muscles) are prevented from entering the frame 34. For some such applications, each blood inlet opening defines an area greater than 0.05 mm² (e.g., greater than 0.1 mm²) and / or less than 3 mm² (e.g., less than 1 mm²), for example, an area of ​​0.05 mm²–3 mm² or 0.1 mm²–1 mm². Alternatively, each blood inlet opening may be defined as having an area greater than 0.1 square millimeters (e.g., greater than 0.3 square millimeters) and / or less than 5 square millimeters (e.g., less than 1 square millimeter), such as an area of ​​0.1 square millimeters to 5 square millimeters or 0.3 square millimeters to 1 square millimeter.

[0253] Typically, the portion of the pump outlet tube that defines the blood inlet opening has a porosity greater than 40%, for example greater than 50%, or greater than 60% (where porosity is defined as the percentage of the area of ​​that portion that is porous for blood flow). Thus, on the one hand, the blood inlet opening is relatively small (to prevent left ventricular structures from entering the frame), but on the other hand, the porosity of the portion of the pump outlet tube that defines the blood inlet opening is relatively high to allow sufficient blood to flow into the pump outlet tube.

[0254] For some applications, each blood inlet opening has a circular or polygonal shape. For other applications, each blood inlet opening has a hexagonal shape, such as... Figures 11A-11D As shown. Typically, using an opening with a hexagonal shape allows the portion of the pump outlet tube defining the blood inlet opening to have a relatively high porosity (e.g., as described above), while providing sufficient material between the blood inlet openings to prevent tearing and / or stretching of the material. Figure 11B As shown, for some applications, the width W of the gap between adjacent hexagonal (or other polygonal) holes is greater than 0.01 mm (e.g., greater than 0.04 mm) and / or less than 0.1 mm (e.g., less than 0.08 mm), for example, 0.01 mm–0.1 mm, or 0.04 mm–0.08 mm. For some applications, the distance D between opposite sides of each hexagon (or other type of polygon) is greater than 0.2 mm (e.g., greater than 0.4 mm) and / or less than 0.8 mm (e.g., less than 0.6 mm), for example, 0.2 mm–0.8 mm, or 0.4 mm–0.6 mm. Figure 11B As shown, typically each polygon encloses a circle (such that any structure that cannot pass through such a circle cannot pass through the polygon). Typically, the diameter of the circle enclosed by the polygon is equal to the distance D, for example greater than 0.2 mm (e.g., greater than 0.4 mm) and / or less than 0.8 mm (e.g., less than 0.6 mm), such as 0.2 mm–0.8 mm, or 0.4 mm–0.6 mm.

[0255] Figure 11D A section of the distal tapered portion 46 of the pump outlet pipe 24 according to some applications of the present invention is shown. Figure 11D In the view shown, this section is unfolded and laid flat for illustrative purposes. (As shown...) Figure 11DAs shown, for some applications, the width W1 of the gap between hexagonal (or other type of polygonal) holes in the proximal region 46P of the distal tapered portion 46 of the pump outlet pipe 24 is greater than the width W of the gap between hexagonal (or other type of polygonal) holes in the distal region 46D of the distal tapered portion 46 of the pump outlet pipe. For some applications, the ratio of the width of the gap between adjacent blood inlet openings in the proximal region of the distal portion of the pump outlet pipe to the width of the gap between adjacent blood inlet openings in the distal region of the distal portion of the pump outlet pipe is greater than 3:2, for example, between 3:2 and 5:2. Typically, for such applications, the distance D1 between opposite sides of each hexagon (or other type of polygon) in the proximal region 46P of the distal tapered portion 46 of the pump outlet pipe 24 is less than the distance D between opposite sides of each hexagon (or other type of polygon) in the distal region 46D of the distal tapered portion 46 of the pump outlet pipe. (As mentioned above, typically, distances D and D1 also represent the diameters of the circles enclosed by polygons of corresponding sizes.) For some applications, the ratio of the diameter of the circle enclosed by each blood inlet opening in the distal region of the distal portion of the pump outlet tube to the diameter of the circle enclosed by each blood inlet opening in the proximal region of the distal portion of the pump outlet tube is greater than 7:6, for example, between 7:6 and 4:3. Furthermore, typically, the distal tapered portion of the pump outlet tube 24 has higher porosity in the distal region 46D of the distal tapered portion 46 of the pump outlet tube compared to the proximal region 46P of the distal tapered portion 46 of the pump outlet tube. For example, the ratio of porosity in the distal region 46D to that in the proximal region 46P is greater than 4:3 or greater than 3:2. For some applications, the proximal region extends along a length greater than 0.5 mm and / or less than 2 mm (e.g., less than 1.5 mm), for example, between 0.5 mm and 2 mm or between 0.5 mm and 1.5 mm. For some applications, the total length of the distal tapered portion is greater than 6 mm and / or less than 12 mm (e.g., less than 10 mm), for example, between 6 mm and 12 mm or 6 mm and 10 mm.

[0256] As referenced above Figures 9A-9B Typically, the pump outlet pipe is connected to the frame 34 via heating. For some applications, the gap between blood inlet orifices is wider in the proximal region 46P of the distal tapered portion 46 of the pump outlet pipe 24 than in the distal region 46D, and / or the blood inlet orifices are smaller and / or have lower porosity than in the distal region 46D, in order to prevent and / or reduce damage (e.g., tearing, thinning, and / or stretching) that may occur to the material defining the blood inlet orifices during the aforementioned heating process.

[0257] Typically, the width W of the gap between the hexagonal (or other type of polygonal) holes and the distance D between opposite sides of each hexagon (or other type of polygon) within the distal region 46D of the distal tapered portion 46 of the pump outlet pipe are as described above. For some applications, the width W1 of the gap between adjacent hexagonal (or other polygonal) holes within the proximal region 46P of the distal tapered portion 46 of the pump outlet pipe 24 is greater than 0.05 mm (e.g., greater than 0.07 mm) and / or less than 0.2 mm (e.g., less than 0.15 mm), for example, 0.05 mm–0.2 mm, or 0.07 mm–0.15 mm. For some applications, the distance D1 between opposite sides of each hexagon (or other type of polygon) within the proximal region 46P of the distal tapered portion 46 of the pump outlet pipe 24 is greater than 0.1 mm (e.g., greater than 0.3 mm) and / or less than 0.6 mm (e.g., less than 0.5 mm), for example, 0.1 mm–0.6 mm, or 0.3 mm–0.5 mm.

[0258] The scope of this disclosure includes lateral blood inlet openings of non-uniform size and / or shape (e.g., circular, rectangular, polygonal, and / or hexagonal lateral blood inlet openings) arranged in any configuration along the distal tapered portion 46 of the pump outlet pipe. Similarly, the scope of this disclosure includes the distal tapered portion 46 of the pump outlet pipe defining a lateral blood inlet opening, the lateral blood inlet opening being arranged such that the distal tapered portion has non-uniform porosity, the porosity varying between different regions of the distal tapered portion. For some applications, the shape and / or size of the lateral blood inlet opening, and / or the porosity of the distal tapered portion, are varied to result in varying hemodynamics at different regions of the distal tapered portion. Alternatively or additionally, the shape and / or size of the lateral blood inlet opening, and / or the porosity of the distal tapered portion, are varied to result in a variation in the shape of the distal tapered portion along its length.

[0259] Now for reference Figures 12A-12B This is a schematic diagram of a pump outlet pipe 24 or a portion thereof according to some applications of the invention, the pump outlet pipe being configured to define a lateral blood inlet opening 108 at its distal end. See reference... Figures 11A-11DAs described, for some applications, the pump outlet tube extends substantially to the distal end of the distal tapered portion 40 of the frame 34. For such applications, the pump outlet tube typically defines a distal tapered portion 46, which is oriented distally, i.e., oriented such that the narrow end of the cone is distal relative to the wide end of the cone. For some applications, the pump outlet tube defines more than 10 blood inlet openings, more than 50 blood inlet openings, more than 100 blood inlet openings, or more than 150 blood inlet openings, for example, 50-100 blood inlet openings, 100-150 blood inlet openings, or 150-200 blood inlet openings. For some applications, the blood inlet openings are sized to (a) allow blood to flow from the subject's left ventricle into the tube, and (b) prevent structures from the subject's left ventricle from entering the frame. Typically, for such applications, the distal tapered portion 46 of the pump outlet pipe 24 is configured to reduce the risk of structures from the left ventricle (e.g., chordae tendineae, cardiac columns, and / or papillary muscles) entering the frame 34 and potentially being damaged by the impeller and / or axial shaft and / or causing damage to the left ventricular assist device. Therefore, for some applications, the blood inlet openings are shaped such that the width (or span) of each opening is less than 1 mm in at least one direction, for example, 0.1 mm–1 mm or 0.3 mm–0.8 mm. By defining such a small width (or span), typically, structures from the left ventricle (e.g., chordae tendineae, cardiac columns, and / or papillary muscles) are prevented from entering the frame 34. For some such applications, each blood inlet opening defines an area greater than 0.05 mm² (e.g., greater than 0.1 mm²) and / or less than 3 mm² (e.g., less than 1 mm²), for example, an area of ​​0.05 mm²–3 mm² or 0.1 mm²–1 mm². Alternatively, each blood inlet opening may be defined as having an area greater than 0.1 square millimeters (e.g., greater than 0.3 square millimeters) and / or less than 5 square millimeters (e.g., less than 1 square millimeter), such as an area of ​​0.1 square millimeters to 5 square millimeters or 0.3 square millimeters to 1 square millimeter.

[0260] For some applications, the blood inlet opening is generally limited to a rectangular shape, such as... Figures 12A-12BAs shown. For some such applications, the length-to-width ratio of the blood inlet opening is between 1.1:1 and 4:1, for example, between 3:2 and 5:2. For some applications, by having a shape such that the blood inlet opening is configured to (a) prevent structures from the left ventricle (e.g., chordae tendineae, cardiac columns, and / or papillary muscles) from entering the frame 34, but (b) provide a portion of the pump outlet tube that defines the blood inlet opening with a relatively high porosity. Typically, the portion of the pump outlet tube that defines the blood inlet opening has a porosity greater than 40%, for example greater than 50%, or greater than 60% (where porosity is defined as the percentage of the area of ​​pores available for blood flow in that portion). Thus, on the one hand, the blood inlet opening is relatively small (to prevent structures from the left ventricle from entering the frame), but on the other hand, the portion of the pump outlet tube that defines the blood inlet opening has a relatively high porosity to allow sufficient blood to flow into the pump outlet tube.

[0261] Typically, the pump outlet pipe includes a connecting portion 41 (e.g., a tubular connecting portion, as shown) extending distally from the pump outlet pipe. As described above, the connecting portion is coupled to the distal support housing 118H to anchor the distal end of the pump outlet pipe. Also as described above, typically, the pump outlet pipe is coupled to the outer side of the central columnar portion of the frame. For some applications, the distal tapered portion 46 of the pump outlet pipe itself is not coupled to the distal tapered portion 40 of the frame. Instead, the distal tapered portion 46 of the pump outlet pipe remains in place relative to the distal tapered portion 40 of the frame because the connecting portion 41 is coupled to the distal support housing 118H, and the pump outlet pipe is coupled to the outer side of the central columnar portion of the frame. Alternatively, the distal tapered portion 46 of the pump outlet pipe is directly coupled to the distal tapered portion 40 of the frame (e.g., via heat shrink).

[0262] As described above, for some applications, the coupling portion 41 is coupled to the outer surface of portion 123 of the distal support housing 118H. For some applications, the coupling portion 41 defines a hole 111 (e.g., toward the distal end of the coupling portion), such as... Figure 12B As shown. For some applications, the adhesive is applied via a hole between the outer surfaces of the connecting portion 41 and the portion 123 of the distal support housing 118H. As described above, for some applications, the outer surface of the portion 123 of the distal support housing 118H is threaded. Typically, the threaded outer surface allows the adhesive to spread gradually and uniformly between the connecting portion 41 and the outer surfaces of the portion 123 of the distal support housing 118H. Furthermore, the connecting portion is typically transparent, making the diffusion of the adhesive visible through the connecting portion. Therefore, for some applications, the application of the adhesive is terminated once the adhesive has sufficiently diffused between the connecting portion 41 and the outer surfaces of the portion 123 of the distal support housing 118H (e.g., once the outer surface of the portion 123 has been covered by the adhesive).

[0263] Note that the above description of the method and apparatus for joining the distal tapered portion 46 of the pump outlet tube relative to other portions of the ventricular assist device applies to any embodiment of the distal tapered portion 46 of the pump outlet tube described herein, including references to Figures 11A-13B Any of the embodiments described. For some applications, similar techniques are used to fabricate protective braids 150 (such as...). Figures 10A-10C (As shown) is attached to the housing of the distal support component.

[0264] It should be noted that although the above description of the methods and apparatus for joining the connecting parts to the surface has been described with reference to the distal portion of the pump outlet pipe and the outer surface of the distal support housing, similar apparatus and methods can be applied to any type of inlet protection device (i.e., any element disposed above the distal tapered portion of the frame and defining a blood inlet opening, the blood inlet opening being sized to (a) allow blood to flow from the subject's left ventricle into the tube, and (b) prevent structures from the subject's left ventricle from entering the frame) and any surface disposed on the distal side of the frame.

[0265] Now for reference Figures 13A-13B These figures are schematic diagrams of a pump outlet pipe 24 or a portion thereof according to some applications of the present invention, the pump outlet pipe being configured to define a lateral blood inlet opening 108 at its distal end. Figures 13A-13B Pump outlet pipe 24 and Figures 12A-12B The pump outlet pipes shown are generally similar, except for the differences described below. (See reference...) Figure 10A As described, typically, most of the blood flow into the blood inlet opening 108 originates from the lateral portion of the distal conical portion of the frame, and relatively little axial flow exists via the distal end of the distal conical portion of the frame. Therefore, in some cases, there is a risk of stagnation in this region, which could lead to thrombus formation within the distal end of the distal conical portion of the frame. Furthermore, due to the lower blood flow, structures from the left ventricle (e.g., chordae tendineae, cardiac columns, and / or papillary muscles) are less likely to enter the frame 34 via this region. Therefore, for some applications, the pump outlet pipe 24 defines a large blood inlet opening 108L along the distal portion 158 of the distal conical portion 46 of the pump outlet pipe 24 (which typically covers the distal portion of the distal conical portion of the frame), compared to a smaller blood inlet opening along the distal portion 158 of the distal conical portion 46 of the pump outlet pipe 24, which reduces the risk of thrombus formation. (In some cases, the distal portion 158 corresponds to the distal region 46D, such as...) Figure 11D(As shown) Typically, the large blood inlet opening 108L has a trapezoidal or triangular shape. For some applications, the shape of the large blood inlet opening conforms to the shape of the frame struts within the distal portion of the frame. That is, the boundary 159 of the large blood inlet opening is positioned along the struts of the distal portion of the frame, and the opening itself is located above the opening defined by the struts. For some applications, there are 4 to 12 (e.g., 6 to 10) large blood inlet openings. Typically, each large blood inlet opening has an area of ​​1-7 square millimeters, for example 2-5 square millimeters or 3-4 square millimeters. For some applications, the ratio of the area of ​​the smallest blood inlet opening in the large blood inlet opening 108L to the largest blood inlet opening in the smaller blood inlet opening 108 is greater than 3:1, for example greater than 4:1. Typically, within the distal portion 158 of the distal tapered portion 46 of the pump outlet pipe 24, the pipe 24 has a porosity greater than 55%, for example greater than 65%.

[0266] Now for reference Figure 14A and Figure 14B , Figure 14A and Figure 14B This is a schematic diagram of a frame 34 of a ventricular assist device 20 according to some applications of the present invention, the frame including a protective braid 155 at its proximal end. For some applications, the protective braid is disposed above (or within) the proximal conical segment of the frame 34. For example, the protective braid may be in accordance with a reference... Figure 10C The protective braid is woven into the supports of the frame in a similar manner to that described herein. Typically, the protective braid is configured to function as a filter, for example, by preventing any element larger than a given size (e.g., a thrombus) from migrating proximally along the pump outlet tube 24. The protective braid is used in conjunction with any of the embodiments described herein. For example, the protective braid may be used with a single axially oriented blood inlet opening 108 (as described herein). Figure 14A The pump outlet tube (as shown) can be used together, or the protective braid can be used with the defined lateral blood inlet opening 108 (as shown). Figure 14B Used together with the pump outlet pipe (as shown).

[0267] Now for reference Figure 15The figure is a schematic diagram of a pump outlet pipe 24 according to some applications of the invention, which defines a blood outlet opening 109 at its proximal end. For some applications, the size and shape of the blood outlet opening are set to be similar to the shape and size of any embodiment of the lateral blood inlet opening 108 described herein. For some applications, by having a shape, the region of the pump outlet pipe defining the blood outlet opening is configured to (a) serve as a filter, for example, by preventing any element larger than a given size (e.g., a thrombus) from migrating proximally from the pump outlet pipe 24, and also (b) provide a portion of the pump outlet pipe defining the blood outlet opening with a relatively high porosity. Typically, the portion of the pump outlet pipe defining the blood inlet opening has a porosity greater than 40%, for example greater than 50%, or about 60% (where porosity is defined as the percentage of the area of ​​this portion that is porous for blood flow). Therefore, on the one hand, the blood outlet opening is relatively small (to prevent any element larger than a given size (e.g., a thrombus) from migrating proximally from the pump outlet tube 24), but on the other hand, the porosity of the portion of the pump outlet tube defining the blood outlet opening is relatively high, for example, to allow sufficient blood flow from the pump outlet tube. Figure 15 The blood outlet opening shown can be used in conjunction with any of the embodiments described herein. For example, as... Figure 15 The blood outlet opening shown can be used to define a single axially oriented blood inlet opening 108 (e.g.) Figure 15 (as shown) is part of the pump outlet pipe, or the blood outlet opening can be used as part of the pump outlet pipe defining the lateral blood inlet opening 108 (combination not shown).

[0268] Regarding references Figures 1A-15 All aspects of the described ventricular assist device 20 should be noted, although Figure 1A and Figure 1BA ventricular assist device 20 is shown in the left ventricle of a subject; however, for some applications, the ventricular assist device 20 is placed in the right ventricle of the subject, such that the device passes through the subject's pulmonary valve, and the technique described herein (with necessary modifications) is applied. For some applications, components of device 20 are adapted to different types of blood pumps. For example, aspects of the invention can be applied to pumps used to pump blood from the vena cava and / or right atrium into the right ventricle, from the vena cava and / or right atrium into the pulmonary artery, and / or from the renal vein into the vena cava. These aspects may include features of tube 24 (e.g., tube curvature), impeller 50, features of pump head portion 27, drive cable 130, etc. Alternatively or additionally, device 20 and / or a portion thereof (e.g., impeller 50, even without tube 24) are placed within different parts of the subject's body to assist in pumping blood from that part. For example, device 20 and / or a portion thereof (e.g., impeller 50, even without tube 24) may be placed in a blood vessel and may be used to pump blood through the blood vessel. For some applications, device 20 and / or a portion thereof (e.g., impeller 50, even without tube 24) (with necessary modifications) are configured for placement within the subclavian or jugular vein, at the junction of the vein and lymphatic vessels, and for increasing the flow rate of lymphatic fluid from the lymphatic vessels into the vein. Because the scope of the invention includes the use of the devices and methods described herein in anatomical locations other than the left ventricle and aorta, ventricular assist devices and / or portions thereof are sometimes referred to herein (in the specification and claims) as blood pumps.

[0269] The scope of this invention includes combining any device and method described herein with any device and method described in one or more of the following applications, all of which are incorporated herein by reference:

[0270] Tuval's US 17 / 609,589, is the U.S. national phase of PCT application No. PCT / IB2021 / 052857 (published as WO 21 / 205346) entitled "Ventricular assist device," filed April 6, 2021 by Tuval. This PCT application claims the following priority:

[0271] Tuval filed U.S. Provisional Patent Application No. 63 / 006,122 on April 7, 2020, entitled “Ventricular assist device”.

[0272] Tuval's U.S. Provisional Patent Application No. 63 / 114,136, entitled "Ventricular assist device," filed November 16, 2020; and

[0273] Tuval filed U.S. Provisional Patent Application No. 63 / 129,983 on December 23, 2020, entitled “Ventricular assist device”.

[0274] Tuval's US 2020 / 0237981, filed on January 23, 2020, entitled "Distal tip element for a ventricular assist device," claims the following priority:

[0275] Tuval filed U.S. Provisional Patent Application No. 62 / 796,138 entitled “Ventricular assist device” on January 24, 2019.

[0276] Tuval filed U.S. Provisional Patent Application No. 62 / 851,716 on May 23, 2019, entitled “Ventricular assist device”.

[0277] Tuval's U.S. Provisional Patent Application No. 62 / 870,821, filed July 5, 2019, entitled "Ventricular assist device"; and

[0278] Tuval filed U.S. Provisional Patent Application No. 62 / 896,026 on September 5, 2019, entitled “Ventricular assist device”.

[0279] Tuval's US 2019 / 0209758 is a continuation application to Tuval's international application PCT / IB2019 / 050186 (published as WO 19 / 138350) entitled "Ventricular assist device," filed on January 10, 2019. This international application claims the following priority:

[0280] Sohn filed U.S. Provisional Patent Application No. 62 / 615,538 entitled “Ventricular assist device” on January 10, 2018;

[0281] Sohn filed U.S. Provisional Patent Application No. 62 / 665,718 on May 2, 2018, entitled “Ventricular assist device”.

[0282] Tuval's U.S. Provisional Patent Application No. 62 / 681,868, filed June 7, 2018, entitled "Ventricular assist device"; and

[0283] Tuval filed U.S. Provisional Patent Application No. 62 / 727,605 on September 6, 2018, entitled “Ventricular assist device”.

[0284] Tuval's US 2019 / 0269840 is the U.S. national phase of Tuval's international patent application PCT / IL2017 / 051273 (published as WO 18 / 096531) entitled "Bloodpumps," filed November 21, 2017. This international patent application claims priority to Tuval's U.S. provisional patent application 62 / 425,814, filed November 23, 2016.

[0285] Tuval's US 2019 / 0175806 is a continuation application of Tuval's international application PCT / IL2017 / 051158 (published as WO 18 / 078615) entitled "Ventricular assist device," filed on October 23, 2017. This international application claims priority to Tuval's US 62 / 412,631, filed on October 25, 2016, and US 62 / 543,540, filed on August 10, 2016.

[0286] Tuval's US 2019 / 0239998 is the U.S. national phase of Tuval's international patent application PCT / IL2017 / 051092 (published as WO 18 / 061002), filed on September 28, 2017, entitled "Bloodvessel tube," which claims priority to Tuval's U.S. provisional patent application 62 / 401,403, filed on September 29, 2016.

[0287] Schwammenthal's US 2018 / 0169313 is the U.S. national phase of its international patent application PCT / IL2016 / 050525 (published as WO 16 / 185473) entitled "Blood pump," filed May 18, 2016. This international patent application claims priority to Schwammenthal's U.S. provisional patent application 62 / 162,881 entitled "Blood pump," filed May 18, 2015.

[0288] Schwammenthal's US 2017 / 0100527 is the U.S. national phase of its international patent application PCT / IL2015 / 050532 (published as WO 15 / 177793) entitled "Blood pump," filed May 19, 2015. This international patent application claims priority to Schwammenthal's U.S. provisional patent application 62 / 000,192 entitled "Blood pump," filed May 19, 2014.

[0289] Schwammenthal's US 10,039,874, which is the US national phase (published as WO14 / 141284) of Schwammenthal's international patent application PCT / IL2014 / 050289 entitled "Renal pump" filed on March 13, 2014, claims priority to (a) Schwammenthal's US Provisional Patent Application 61 / 779,803 entitled "Renal pump" filed on March 13, 2013, and (b) Schwammenthal's US Provisional Patent Application 61 / 914,475 entitled "Renal pump" filed on December 11, 2013;

[0290] U.S. Patent 9,764,113, entitled "Curved catheter," was granted to Tuval on September 19, 2017, claiming priority from Tuval's U.S. Provisional Patent Application 61 / 914,470, also entitled "Curved catheter," filed on December 11, 2013; and

[0291] Tuval's US 9,597,205 is the U.S. national phase of its international patent application PCT / IL2013 / 050495 (published as WO 13 / 183060) entitled "Prosthetic renal valve," filed June 6, 2013. This international patent application claims priority to Tuval's U.S. provisional patent application 61 / 656,244 entitled "Prosthetic renal valve," filed June 6, 2012.

[0292] Those skilled in the art will recognize that the present invention is not limited to what has been specifically shown and described above. Rather, the scope of protection of the present invention includes both combinations and sub-combinations of the various features described above, as well as variations and modifications of the invention that will arise in the mind of those skilled in the art upon reading the foregoing description and are not found in the prior art.

Claims

1. A device for left ventricular assist, comprising: Left ventricular assist device, the left ventricular assist device comprising: An impeller configured to be placed in the left ventricle of a subject and configured to pump blood from the subject's left ventricle to the subject's aorta by rotation; A frame surrounding the impeller, the frame including a plurality of strut joints at a proximal end of the frame, the strut joints being configured to remain in an open state during assembly of the left ventricular assist device to facilitate insertion of the impeller into the frame; A fixing element, configured to hold the support joint in a closed state after the impeller is inserted into the frame; and A pump outlet tube is configured to pass through the aortic valve of a subject, such that a proximal portion of the pump outlet tube is disposed within the aorta of the subject, and a distal portion of the pump outlet tube is disposed within the left ventricle of the subject. The distal portion of the pump outlet tube extends to the distal end of the frame and defines one or more lateral blood inlet openings configured to allow blood to flow from the left ventricle of the subject into the pump outlet tube.

2. The device according to claim 1, wherein, The fixing element includes a ring.

3. The device according to claim 1, wherein, The left ventricular assist device includes a portion located distal to the frame, and wherein the pump outlet tube further includes a connecting portion extending distally from the frame and connecting to the portion of the left ventricular assist device located distal to the frame.

4. The device according to any one of claims 1-3, wherein, The distal portion of the pump outlet tube defines more than 10 blood inlet openings, which are sized to (a) allow blood to flow from the subject's left ventricle into the pump outlet tube, and (b) prevent structures from the subject's left ventricle from entering the frame.

5. The device according to claim 4, wherein, The distal portion of the pump outlet tube defines more than 50 blood inlet openings, which are sized to (a) allow blood to flow from the subject's left ventricle into the pump outlet tube, and (b) prevent structures from the subject's left ventricle from entering the frame.

6. The device according to claim 1 or claim 2, wherein, The left ventricular assist device also includes: A proximal radial support member is disposed within a proximal support member housing at the proximal end of the frame; A distal radial support member is disposed within a distal support member housing at the distal end of the frame; An axial shaft is provided, on which the impeller is mounted, and the axial shaft passes through the proximal radial support and the distal radial support. The fixing element is configured to keep the strut joint closed around the outer surface of the proximal support housing.

7. The device according to claim 6, wherein, The pump outlet pipe also includes a connecting portion that extends distally from the frame and connects to the distal support housing.

8. The device according to claim 6, wherein, The distal end of the frame is connected to the outer surface of the distal support housing.

9. The device according to claim 6, wherein, The left ventricular assist device further includes a distal terminal element, wherein the distal terminal element is coupled to the distal support housing.

10. The device according to claim 6, wherein, The outer surface of the proximal support housing defines a groove, which is shaped to receive the strut joint.

11. The device according to claim 10, wherein, The strut joint defines a widened head, and the groove is shaped to correspond to the widened head of the strut joint.

12. The device according to claim 6, wherein, The proximal radial support and the distal radial support are made of ceramic material, and the proximal support housing and the distal support housing are made of a second material that can be molded into the desired shape.

13. The device according to claim 12, wherein, The proximal support housing and the distal support housing are made of metal and / or alloy.

14. The device according to claim 13, wherein, The axial shaft comprises metal and / or alloy, and wherein the area of ​​the axial shaft that contacts either the proximal radial support or the distal radial support during operation of the left ventricular assist device is covered with a ceramic sleeve.

15. A method for manufacturing a left ventricular assist device, the method comprising: A frame is formed such that the frame is closed at its distal end, and a plurality of strut joints at the proximal end of the frame remain open. A pump outlet tube is connected to the frame such that a distal portion of the pump outlet tube extends to a distal end of the frame, and the distal portion of the pump outlet tube defines one or more lateral blood inlet openings configured to allow blood to flow from the subject's left ventricle into the pump outlet tube, the pump outlet tube being configured to pass through the subject's aortic valve such that a proximal portion of the pump outlet tube is disposed within the subject's aorta, and a distal portion of the pump outlet tube is disposed within the subject's left ventricle. An impeller is inserted into the frame via the proximal end of the frame, the impeller being configured to pump blood through the pump outlet pipe by rotation; as well as Subsequently, the strut joint at the proximal end of the frame is closed, and the strut joint is held in the closed state using a fixing element.

16. The method according to claim 15, wherein, The fixing element includes a ring, and using the fixing element to hold the strut joint in a closed state includes using the ring to hold the strut joint in a closed state.

17. The method according to claim 15, wherein, The pump outlet pipe also includes a connecting portion configured to extend distally from the frame, wherein the method further includes connecting the connecting portion to a distal portion of the left ventricular assist device located on the frame.

18. The method according to claim 15 or claim 16, wherein, The left ventricular assist device also includes: A proximal radial support member is disposed within a proximal support member housing at the proximal end of the frame; A distal radial support member is disposed within a distal support member housing at the distal end of the frame; An axial shaft is provided, on which the impeller is mounted, and the axial shaft passes through the proximal radial support and the distal radial support. Holding the strut joint in a closed state using the fixing element includes holding the strut joint in a closed state by keeping the strut joint closed around the outer surface of the proximal support housing.

19. The method according to claim 18, wherein, The pump outlet pipe also includes a connecting portion configured to extend distally from the frame, wherein the method further includes connecting the connecting portion to the distal support housing.

20. The method of claim 18, further comprising attaching the distal end of the frame to the outer surface of the distal support housing.

21. The method of claim 18, further comprising coupling the distal end element to the distal support housing.

22. The method according to claim 18, wherein, The outer surface of the proximal support housing defines a groove shaped to receive the strut joint, and wherein keeping the strut joint closed around the outer surface of the proximal support housing includes keeping the strut joint within the groove defined by the outer surface of the proximal support housing.

23. The method according to claim 22, wherein, The strut joint defines a widened head, and wherein holding the strut joint within the groove defined by the outer surface of the proximal support housing includes holding the strut joint within the groove shaped to conform to the widened head of the strut joint.

24. The method according to claim 18, wherein, The proximal radial support and the distal radial support are made of ceramic material, and the proximal support housing and the distal support housing are made of a second material that can be molded into the desired shape.

25. The method according to claim 24, wherein, The proximal support housing and the distal support housing are made of metal and / or alloy.

26. The method of claim 25, wherein, The axial shaft comprises metal and / or alloy, and the method further comprises covering the axial shaft with a ceramic sleeve in the region along the axial shaft that contacts either the proximal radial support or the distal radial support during operation of the left ventricular assist device.

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