Impeller device and method for percutaneous ventricular assist device

Abstract

An impeller assembly for a percutaneously delivered pump to induce blood flow within a vascular system can be configured to reversibly transition in the vascular system from a deployment configuration to an operative configuration. The impeller can include an impeller shaft with an outer shaft surface including a helical channel formed in the outer shaft surface. The helical channel can be sized, shaped, or otherwise configured to receive a base portion of a blade frame to locate the blade frame with respect to the impeller shaft. The impeller can include the impeller blade, attached to the impeller shaft, where the impeller blade can comprise a blade frame and a polymer coating. The polymer coating is configured to encapsulate the blade frame and create a blade surface for contact with blood in the vascular system.

Description

IMPELLER DEVICE AND METHOD FOR PERCUTANEOUS VENTRICULAR ASSIST DEVICECLAIM OF PRIORITY(000.11 This application claims the benefit of priority to U.S. Patent Application Serial No. 63 / 538,328, filed on September 14, 2023, which is incorporated by reference herein in its entirety.TECHNICAL FIELD(0002 This document pertains generally, but not by way of limitation, to a percutaneous ventricular assist device (pVAD), such as to the impeller of a collapsible pVAD.BACKGROUND 000^1 A percutaneous ventricular assist device (pVAD) can be used to percutaneously introduce a pump through the vasculature into a left ventricle of a patient, such as to help move blood from the left ventricle into the aorta and provide temporary blood circulatory support for patients with weakened or failing hearts.Pfeffer (US8439859B2) mentions a catheter device that includes a drive shaft connected to a motor, and a rotor mounted on the drive shaft at the distal end section. The rotor has a frame structure, which is formed by a screwlike boundary frame and rotor struts extending radially inwards from the boundary frame.(0O05J McBride (US9364592B2) mentions an impeller that includes a hub and at least one blade supported by the hub. The impeller has a stored configuration in which the blade is compressed so that its distal end moves towards the hub, and a deployed configuration in which the blade extends away from the hub.|!)006| Scheckel (US9964115B2) mentions a fluid pump, in particular to a liquid pump having a rotor with at last one rotor blade for conveying the fluid, the rotor being variable with respect to its diameter between a first, compressed state and a second expanded state.OVERVIEW 00075 A percutaneous ventricular assist device (pVAD) is a minimally invasive device that can be at least partially inserted into a patient, such as into a blood vessel of a patient that can benefit from cardiac circulation assistance. The pVAD can include a collapsible pump with a collapsible impeller. As a percutaneous device, the pVAD impeller is small in size and rotates at high speeds to generate blood flow sufficient to perfuse the patient.

[0008] The collapsible impeller can be formed through an injection molding process to encapsulate an impeller structure, such as can include a flexible blade frame attached to a driveshaft, with an overmold material, such as a polymer material. High pressures applied to the impeller structure during the injection molding process can cause the blade frame to move with respect to the driveshaft, such as to produce collapsible impeller components that may not meet quality standards. 00O9] The present inventor has recognized, among other things, that a problem to be solved can include locating a blade frame with respect to a drive shaft to help inhibit or prevent motion of the blade frame during an overmolding operation. The present subject matter can help provide a solution to this problem, such as by providing a different approach that can attach the blade frame to the driveshaft before forming an overmold surface encapsulating the blade frame and at least a portion of the driveshaft.10010] An impeller assembly for a percutaneously delivered pump to induce blood flow within a vascular system can be configured to reversibly transition in the vascular system from a deployment configuration to an operative configuration. The impeller can include an impeller shaft with an outer shaft surface including a helical channel formed in the outer shaft surface. The helical channel can be sized, shaped, or otherwise configured to receive a base portion of a blade frame to locate the blade frame with respect to the impeller shaft. The impeller can include the impeller blade, attached to the impeller shaft, where the impeller blade can comprise a blade frame and a polymer coating. The polymer coating is configured to encapsulate the blade frame and create a blade surface for contact with blood in the vascular system.|00111 An overview of certain non-limiting aspects of the present subject matter is provided below.10012] Aspect 1 can include or use subject matter (such as an apparatus, a system, a device, a method, or a means for performing acts), such as an impeller assembly for a percutaneously delivered pump to induce blood flow within a vascular system. The impeller assembly can be configured to reversibly transition in the vascular system from a deployment configuration to an operative configuration. The impeller assembly can include an impeller shaft with an outer shaft surface, where the impeller shaft can include a helical channel formed in the outer shaft surface. The helical channel can be sized, shaped, or otherwise configure to receive a base portion of a blade frame to locate the blade frame with respect to the impeller shaft. An impeller blade can be attached to the impeller shaft. The impeller blade can include the blade frame and a polymer coating, such as configured to encapsulate the blade frame and create a blade surface for contact with blood in the vascular system.{0013] Aspect 2 can include or use or can optionally be combined with the subject matter of Aspect 1 to optionally include or use the impeller shaft, where the impeller shaft includes a circumferential channel formed in the outer shaft surface and configured to receive a fastener to secure the impeller blade to the impeller shaft.{0014] Aspect 3 can include or use or can optionally be combined with the subject matter of one or any combination of Aspects 1 or 2 to optionally include or use the fastener, where the fastener includes a set of one or more straps to locate or secure the blade frame with respect to the impeller shaft.|0015] Aspect 4 can include or use or can optionally be combined with the subject matter of one or any combination of Aspects 1 through 3 to optionally include or use the set of one or more straps, where the set of one or more straps includes an alternating set of one or more straps, the alternating locating an individual first one of the sets along a first lateral side of the impeller shaft and locating an individual second one of the sets along an opposing second lateral side of the impeller shaft.]0016] Aspect 5 can include or use or can optionally be combined with the subject matter of one or any combination of Aspects 1 through 4 to optionally include or use the polymer coating, where the polymer coating forms a leading edge, a body edge, a trailing edge, and a blade surface of the impeller blade, anda distance between the blade frame and at least one of the leading edge, the body edge, or the trailing edge is equal to or less than 5 millimeters. 0017| Aspect 6 can include or use or can optionally be combined with the subject matter of one or any combination of Aspects 1 through 5 to optionally include or use the blade frame, where the blade frame defines a blade surface plane coincident with a surface of the blade frame at a root end of the impeller blade and the impeller shaft defines a shaft surface plane tangent to the outer shaft surface at the root end of the impeller blade, such as the blade surface plane forms at an acute angle with respect to the shaft surface plane.(0018 Aspect 7 can include or use subject matter (such as an apparatus, a system, a device, a method, or a means for performing acts), such as an impeller assembly for a percutaneously delivered pump to induce blood flow within a vascular system. The impeller assembly can be configured to reversibly transition in the vascular system from a deployment configuration to an operative configuration. The impeller blade can include a leading edge, a body edge, a trailing edge, and a blade surface The impeller assembly can include an impeller shaft and an impeller blade attached to the impeller shaft. The impeller blade can include a blade frame and a polymer coating configured to encapsulate the blade frame and form the leading edge, the body edge, the trailing edge, and the blade surface, where a distance between the blade frame and at least one of the leading edge, the body edge, or the trailing edge is equal to or less than 5 millimeters.Aspect 8 can include or use or can optionally be combined with the subject matter of Aspect 7 to optionally include or use the impeller shaft where the impeller shaft includes an outer shaft surface and where a helical channel is formed in the outer shaft surface. 0O2O| Aspect 9 can include or use or can optionally be combined with the subject matter of one or any combination of Aspects 7 or 8 to optionally include or use the helical channel where the helical channel is configured to receive a base portion of the blade frame for locating the blade frame with respect to the impeller shaft.(0021 Aspect 10 can include or use or can optionally be combined with the subject matter of one or any combination of Aspects 7 through 11 to optionally include or use the impeller shaft where the impeller shaft includes an outer shaftsurface and wherein a circumferential channel is formed in the outer shaft surface.(0022 j Aspect 11 can include or use or can optionally be combined with the subject matter of one or any combination of Aspects 7 through 10 to optionally include or use the impeller blade where the impeller blade includes a blade surface plane coincident with a surface of the blade frame at a root end of the impeller blade and the impeller shaft includes a shaft surface plane tangent to an outer shaft surface at the root end of the impeller blade, such as wherein the blade surface plane forms at an acute angle with respect to the shaft surface plane.(0023J Aspect 12 can include or use subject matter (such as an apparatus, a system, a device, a method, or a means for performing acts), such as an impeller assembly for a percutaneously delivered pump to induce blood flow within a vascular system. The impeller assembly can be configured to reversibly transition in the vascular system from a deployment configuration to an operative configuration. The impeller assembly can include an impeller shaft and an impeller blade attached to the impeller shaft. The impeller blade can include a blade frame with a set of one or more straps to locate the blade frame with respect to the impeller shaft and a polymer coating configured to encapsulate the blade frame and create a blade surface for contact with blood in the vasculature system.(0024] Aspect 13 can include or use or can optionally be combined with the subject matter of Aspect 12 to optionally include or use the set of one or more straps where the set of one or more straps includes an alternating set of one or more straps, the alternating locating an individual first one of the sets along a first lateral side of the impeller shaft and locating an individual second one of the sets along an opposing second lateral side of the impeller shaft.(0025| Aspect 14 can include or use or can optionally be combined with the subject matter of one or any combination of Aspects 12 or 13 to optionally include or use the impeller shaft where the impeller shaft includes an outer shaft surface and a helical channel formed in the outer shaft surface and where the helical channel is configured to receive a base portion of the blade frame.(0026 | Aspect 15 can include or use or can optionally be combined with the subject matter of one or any combination of Aspects 12 through 14 to optionallyinclude or use the impeller shaft where the impeller shaft includes an outer shaft surface and a circumferential channel formed in the outer shaft surface.|0027] Aspect 16 can include or use or can optionally be combined with the subject matter of one or any combination of Aspects 12 through 15 to optionally include or use the polymer coating where the polymer coating can form a leading edge, a body edge, a trailing edge, and a blade surface of the impeller blade, and where a distance between the blade frame and at least one of the leading edge, the body edge, or the trailing edge is equal to or less than 5 millimeters.|0028] Aspect 17 can include or use or can optionally be combined with the subject matter of one or any combination of Aspects 12 through 16 to optionally include or use the impeller blade where the impeller blade includes a blade surface plane coincident with a surface of the blade frame at a root end of the impeller blade and the impeller shaft includes a shaft surface plane tangent to an outer shaft surface at the root end of the impeller blade, such as where the blade surface plane forms at an acute angle with respect to the shaft surface plane.|0029] This overview is intended to provide an overview of subject matter of the present patent application. It is not intended to provide an exclusive or exhaustive explanation of the invention. The detailed description is included to provide further information about the present patent application.BRIEF DESCRIPTION OF THE DRAWINGS|003(J] In the drawings, which are not necessarily drawn to scale, like numerals may describe similar components in different views. Like numerals having different letter suffixes may represent different instances of similar components. The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document. FIG. 1 shows an example of a percutaneous ventricular assist device (pVAD).10032] FIG. 2 shows an example of a molded impeller assembly.J0033] FIG. 3 shows an example of a blade frame.|0034J FIG. 4 shows an example of an impeller assembly. f!)035| FIG. 5 shows a second example of a molded impeller assembly.]OO30| FIG. 6 shows an example of a blade frame.(0037] FIG. 7 shows an example of a driveshaft.|0038] FIG. 8 shows an example of a blade frame located in a helical channel of a driveshaft.

[0039] FIG. 9A shows a first cross section of a driveshaft.

[0040] FIG. 9B shows a second cross section of a driveshaft.[00411 FIG. 10 shows an example of an impeller assembly with an overmold coating. 0042] FIG. 10A shows a second example of an impeller assembly with an overmold coating, a body edge, and a trailing edge.[ 00431 FIG. 11 shows flow diagram of an example of a method to form a molded impeller assembly.DETAILED DESCRIPTION

[0044] FIG. 1 shows an example of a percutaneous ventricular assist device (pVAD). A pVAD can be implanted in a patient, such as patient vasculature. The pVAD can assist blood flow in a patient, such as when the patient heart is unable to perfuse the patient. Using a pVAD, such as an expandable and collapsible pVAD, can help reduce or minimize trauma experienced by the patient, such as when inserting and removing the pVAD from the patient.[0045[ The pVAD can include a pump 102, a drive cable 104, and a motor 107. The pump 102 can include an impeller assembly 100. The drive cable 104 can include a distal cable end 103 and a proximal cable end 106. The pump 102 can attach to the distal cable end 103 of the drive cable 104. The motor 107 can attach to the proximal cable end 106 of the drive cable 104. The motor 107 can be configured to rotate the impeller assembly 100 via the drive cable 104.Rotation of the impeller assembly 100 can apply a force to blood in contact with the impeller assembly 100, such as to create blood flow in the patient vasculature and assist the patient heart in perfusing the patient body.

[0046] FIG. 2 shows a first example of an impeller assembly 100, such as a molded impeller assembly. The impeller assembly 100 can include at least one of a blade frame 110, a driveshaft 120, or an overmold coating 130.

[0047] FIG. 3 shows an example of a blade frame 110. The blade frame 110 can serve to reinforce the impeller assembly 100, such as to help reduce or minimize a possibility of failure of the impeller assembly 100 when the impellerassembly 100 is rotating within the pump 102. The blade frame 110 can be formed from a material, such as a shape memory material including a nickel titanium alloy (or nitinol). In an example, the blade frame 110 can be located on the driveshaft 120, such as with one or more straps 115. In an example, the blade frame 110 can be secured to the driveshaft 120, such as with one or more straps 115.(0048] The blade frame 110 can include an A portion 111 and a B portion 113. Each of the A portion 111 and the B portion 113 can include at least one of a base portion 112A, 112B, a body edge portion 114A, 114B, a leading edge portion 116A, 116B, a trailing edge portion 118A, 118B, or a mesh portion 119A, 119B. The blade frame 110 can include one or more straps 115, such as to connect the A portion 111 to the B portion 113.|0O49| FIG. 4 shows an example of an impeller assembly 100. The one or more straps 115 can locate the blade frame 110 on the driveshaft 120, such as before the overmold coating 130 is applied. The overmold coating 130 can encapsulate the blade frame 110 and at least a portion of the drive shaft 120, to form the impeller assembly 100. Alternating the one or more straps 115 on the driveshaft 120 can locate the blade frame 110 on the driveshaft 120.{0050} For example, as shown in FIG. 4, a first collection 170 of one or more straps 115 can include alternating straps 115, such as by locating an individual first strap 115 A along a first lateral side of the driveshaft 120 and locating an individual second strap 115B along an opposing second lateral side of the drive shaft 120.{0051 j A set of one or more straps 115 can include a plurality of straps 115 that share a common characteristic, such as a location of the strap 115 on the driveshaft 120. Alternating one or more sets of one or more straps 115 on the driveshaft 120 can locate the blade frame 110 on the driveshaft 120.{0052| For example, as shown in FIG. 4, a second collection 172 of one or more sets of one or more straps 115, such as a first set of one or more straps 115 (115C and 115D can constitute the first set of one or more straps 115) located along a first lateral side of the driveshaft 120 and a second set of one or more straps 115 (115E can constitute the second set of one or more straps 115) located along an opposing second lateral side of the driveshaft 120, can locate the blade frame 110 on the driveshaft 120.(0053] FIG. 5 shows a second example of an impeller assembly 100, such as an expandable and collapsible impeller assembly 100. The impeller assembly 100 can include at least one of a blade frame 180, a driveshaft 120, or an overmold coating 130. In an example, the blade frame 180 can be secured to the driveshaft 120, such as with one or more fasteners located in a circumferential channel 129, such as including one or more circumferential channels 129.(0054] FIG. 6 shows an example of a blade frame 180. The blade frame 180 can include at least one of a base portion 112, a body edge portion 114, a leading edge portion 116, a trailing edge portion 118, or a mesh portion 119. The base portion 112 can include a first face surface 190, a second face surface 192 opposite the first face surface 190 (not shown), and a base face surface 194 opposite the mesh portion 119 and located between the first and second face surfaces 192, 194. In an example, the base face surface 194 can be oriented perpendicularly to the first and second face surfaces 192, 194.(0055] FIG. 7 shows an example of a driveshaft 120. The driveshaft 120 can support the blade frame 180 and overmold coating 130, such as to form the expandable and collapsible impeller assembly 100. The driveshaft 120 can include a distal driveshaft end 122 and a proximal driveshaft end 124. The drive shaft 120 can include an outer shaft surface 126 and a helical channel 128, such as a helical channel 128 formed in the outer shaft surface 126. The helical channel 128 can be configured to receive and locate a blade frame 180 with respect to the driveshaft 120, such as at a connection interface. The connection interface can include a sliding connection interface, such as a dimension of the base portion 112 can slide into at least a portion of the helical channel 128 and include a fastener to retain the base portion 112 in the helical channel 128. The connection interface can include an interference (or friction) connection interface, such as a dimension of the base portion can be sized slightly larger than at least a portion of the helical channel 128 so that the base portion 112 can be retained in the helical channel 128 without a fastener. The helical channel 128 can extend around a diameter of the driveshaft 120, such as to form a continuous helical channel 128 around the driveshaft 120. The driveshaft 120 can include more than one helical channel 128, such as to locate more than one blade frame 180 on the driveshaft 120. The helical channel 128 can include a blade frame relief feature 123. The blade relief feature 123 can be configured toallow the base portion 112 to lay flat against the driveshaft 120, such as when the base portion 112 can be located in the helical channel 128. 0056| The driveshaft 120 can include a circumferential channel 129, such as a circumferential channel 129 formed in the outer shaft surface 126. The circumferential channel 129 can extend around a diameter of the drive shaft 120, such as to form a continuous groove around the driveshaft 120. The circumferential channel 129 can locate a fastener, such as a surgical suture, with respect to the driveshaft 120, such as to secure the blade frame 180 to the driveshaft 120. The driveshaft 120 can be formed from a material, such as a biocompatible material including at least one of a stainless-steel or a polymer material.(0057 | FIG. 8 shows an example of a blade frame 180, such as two blade frames 180, located on a driveshaft 120. The blade frame 180, such as the base portion 112 of the blade frame 180, can be located in the helical channel 128 of the driveshaft 120. Locating the base portion 112 in the helical channel 128 can help reduce or minimize motion of the blade frame 180 with respect to the driveshaft 120, such as during an overmold operation to form the overmold coating 130 on the blade frame 180 and at least a portion of the driveshaft 120. 0058 j FIG. 9A shows an example of a first cross-section of a driveshaft 120, such as a cross-section in a plane perpendicular to a longitudinal axis 193 of the driveshaft 120. The first cross-section can include the helical channel 128, such as two or more helical channels 128. The helical channel 128 can be configured to receive the base portion 112 of the blade frame 180, such as to locate the blade frame 180 with respect to the driveshaft 120.As shown in FIG. 9A, the helical channel 128 can include a rectangular cross-section. The rectangular cross-section can be defined by a first side surface 192, a second side surface 194 parallel to the first side surface 192, and a floor surface 196 located between and perpendicular to the first and second side surfaces 192, 194. A normal vector 195 can be defined with respect to the floor surface 196, such as the normal vector 195 can be perpendicular to the floor surface 196. A radial vector 197 can be defined with respect to the longitudinal axis 193 of the driveshaft 120, such as the radial vector 197 can extend perpendicularly from the longitudinal axis 193 through the outer shaft surface 126 and oriented perpendicular to the outer shaft surface 126. A shaftsurface plane 199 can be defined with respect to the radial vector 197. The shaft surface plane 199 can be perpendicular to the radial vector 197 at the outer shaft surface 126. The intersection of the radial vector 197 and the shaft surface plane 199 can be referred to as the root end of the impeller blade, such as when a base portion 112 of the blade frame 180 is located into the helical channel 128. The shaft surface plane 199 is shown as a dashed line orthogonal to the radial vector 197 in FIG. 9A.

[0060] Referring again to FIG. 9A, the helical channel 128 can be formed in the driveshaft 120. The normal vector 195 can align with the radial vector 197. By locating the blade frame 180 in the helical channel 128, the blade frame 180 can be oriented at different angles with respect to the driveshaft 120.{0061 | In a first example, the first face surface 190 of the blade frame 180 can be facing the floor surface 196, such as to contact the floor surface 196 of the helical channel 128. In this case, the blade frame 180 can be oriented parallel to the shaft surface plane 199 when located on the driveshaft 120.

[0062] In a second example, the base face surface 194 of the blade frame 180 can be facing the floor surface 196, such as contact the floor surface 196 of the helical channel 128. In this case, the blade frame 180 can be oriented perpendicular to the shaft surface plane 199 when located on the driveshaft 120. {0063] FIG. 9B shows an example of a second cross-section of a driveshaft 120. The helical channel 128 can be formed in the driveshaft 120. The normal vector 195 can form an angle 191 with respect to the radial vector 197. The angle 191 can vary, such as in a range from about 0 degrees to about 90 degrees. By varying the angle 191, the blade frame 180 can be oriented at an acute angle, such as in a range of about 0 degrees to about 90 degrees with respect to the shaft surface plane 199 when the blade frame 180 is located on the driveshaft 120.{0064] A cross-section of the helical channel 128, such as in a plane perpendicular to the longitudinal axis of the driveshaft 120, can assume a geometric shape. The geometric shape can include a regular geometric shape, such as a shape with channel sides of equal length. For example, a regular geometric shape can include at least one of a rectangular cross-section, a triangular cross-section, a semi-circular cross-section, or a shape that can be bilaterally symmetrical, such as bilaterally symmetrical about the normal vector195. The geometric shape can include an irregular geometric shape, such as a shape with sides of unequal length. For example, an irregular geometric shape can include at least one of a polygonal shape with unequal sides or a shape that can be bilaterally unsymmetrical, such as bilaterally unsymmetrical about the normal vector 195. 0O65| The driveshaft 120 can include a circumferential channel 129. The circumferential channel 129 can extend around a diameter of the drive shaft 120, such as to form a continuous channel around the driveshaft 120. A suture, such as a surgical suture, can be located in the circumferential channel 129, such as after the blade frame 180 has been located in the helical channel 128. Locating the suture in the circumferential channel 129 can help secure the blade frame 180 to the driveshaft 120, such as during an overmold operation to form the overmold coating 130 on the blade frame 180 and at least a portion of the driveshaft 120. In an example, the overmold coating 130 can be formed from at least one of a single shot overmold process or a multi-shot overmold process. |0966] FIG. 10 shows an example of an impeller assembly 100 with an overmold coating 130. The overmold coating 130 can encapsulate the blade frame 110 and at least a portion of the driveshaft 120. The overmold coating 130 can form an impeller surface, such as configured to apply a force to blood in contact with the rotating impeller assembly 100 and subsequently induce blood flow in the patient vasculature. The overmold coating 130 can include a biocompatible material, such as a polymer material. In an example, the polymer material can include a polyurethane material. 00671 The overmold coating 130 can include a leading edge 132. The leading edge 132 can be displaced from and oriented generally parallel to the leading edge portion 116 of the body frame 180. The distance between the leading edge 132 and the leading edge portion 116 can define the leading edge margin 142. The leading edge margin 142 can vary in a range, such as in a range of about 0.01 millimeter (mm) to about 5 mm. 0068] The overmold coating 130 can include a body edge 134. The body edge 134 can be displaced from and oriented generally parallel to the body edge portion 114 of the body frame 180. The distance between the body edge 134 and the body edge portion 114 can define the body edge margin 144. The body edgemargin 144 can vary in a range, such as in a range of about 0.01 millimeter (mm) to about 5 mm.(0069| The overmold coating 130 can include a trailing edge 136. The trailing edge 136 can be displaced from and generally parallel to the trailing edge portion 118 of the body frame 180. The distance between the body edge 134 and the trailing edge portion 118 can define the trailing edge margin 146. The trailing edge margin 146 can vary in a range, such as in a range of about 0.01 millimeter (mm) to about 5 mm. The body edge 134 and the trailing edge 136 can intersect, such as to form a trailing edge body radius 148. In an example, the trailing edge body radius 148 can include a radius of 0.01 mm or less, such as to form a comer as shown in FIG. 10.(00701 FIG. 10A shows a second example of an impeller assembly 100 with an overmold coating 130, a body edge 134, and a trailing edge 136. The trailing edge body radius 148 can define a radius, such as a radius between the body edge 134 and the trailing edge 136. In an example, the trailing edge body radius 148 can include a range, such as a range from about 0.01 mm to about 10 mm. In an example, the trailing edge body radius 148 can be selected to minimize force required to compress the impeller assembly 100 into a cannula, such as to transition the impeller assembly 100 from an operative (expanded) configuration to a deployment (compressed) configuration for retrieval of the impeller assembly 100 from patient vasculature.( 0071 ( FIG. 11 shows a flow diagram of an example method 1100 to form a molded impeller assembly 100 for use with a pump 102 of a percutaneous ventricular assist device (pVAD), such as shown in FIG. 1. The impeller assembly 100 can include an expandable and collapsible impeller assembly 100. (00721 At 1102, a channel can be formed in an outer shaft surface 126 of a driveshaft 120. The channel can include a helical channel 128, such as a continuous helical channel 128 that can extend around a diameter of the driveshaft 120. The channel can include a circumferential channel 129, such as a continuous circumferential channel 129 that can extend around a diameter of the driveshaft 120.(0O73( Forming a channel can include forming a helical channel 128 where a normal vector 195 forms an angle 191 with a radial vector 197. In an example, the normal vector 195 can be aligned with the radial vector 197, such as to forman angle 191 of about 0 degrees. In an example, the normal vector 195 can form an acute angle 191 with the radial vector 197, such as an acute angle 191 in a range of about 0 degrees to about 90 degrees.

[0074] At 1104, a blade frame 180 can be located in the helical channel 128 of the driveshaft 120. Locating a base portion 112 of the blade frame 180 in the helical channel 128 can help reduce or minimize motion of the blade frame 180 with respect to the driveshaft 120, such as during an overmold operation.

[0075] Locating a base portion 112 can include locating a face of the base portion 112 in the helical channel 128. In an example, a first face surface 190 of the base portion 112 can be located facing the floor surface 196, such as located against the floor surface 196 of the helical channel 128. In an example, a base face surface 194 can be located facing the floor surface 196, such as located against the floor surface 196 of the helical channel 128.

[0076] At 1106, the blade frame 180 can be secured to the driveshaft 120 with a fastener. The fastener can include any structure configured to secure a first body to a second body, such as at least one of a surgical suture, a strap, such as a strap 115, a staple, or a snap ring. The fastener can be located in the circumferential channel 129, such as after the blade frame 180 has been located in the helical channel 128. Locating the fastener in the circumferential channel 129 can help secure the blade frame 180 to the driveshaft 120, such as during an overmold operation to form the overmold coating 130 on the blade frame 180 and at least a portion of the driveshaft 120.

[0077] At 1108, the driveshaft 120 and the blade frame 180 can be overmolded, such as with a polymer overmold coating 130. The overmold coating 130 can encapsulate the blade frame 110 and at least a portion of the driveshaft 120, such as to form the impeller assembly 100.

[0078] Overmolding the blade frame 180 can include forming at least one of a leading edge margin 142, a body edge margin 144, or a trailing edge margin 146, on the impeller assembly 100. Overmolding the blade frame 180 can include forming a trailing edge body radius 148, such as between a body edge 134 and a trailing edge 136.[0079[ The above description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the invention can bepracticed. These embodiments are also referred to herein as “examples.” Such examples can include elements in addition to those shown or described.However, the present inventors also contemplate examples in which only those elements shown or described are provided. Moreover, the present inventors also contemplate examples using any combination or permutation of those elements shown or described (or one or more aspects thereof), either with respect to a particular example (or one or more aspects thereof), or with respect to other examples (or one or more aspects thereof) shown or described herein.J0O8O] In the event of inconsistent usages between this document and any documents so incorporated by reference, the usage in this document controls. JIMIS J | In this document, the terms “a” or “an” are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of “at least one” or “one or more.” In this document, the term “or” is used to refer to a nonexclusive or, such that “A or B” includes “A but not B,” “B but not A,” and “A and B,” unless otherwise indicated. In this document, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Also, in the following claims, the terms “including” and “comprising” are open-ended, that is, a system, device, article, composition, formulation, or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects.JIMI82 j Geometric terms, such as “parallel”, “perpendicular”, “round”, or “square”, are not intended to require absolute mathematical precision, unless the context indicates otherwise. Instead, such geometric terms allow for variations due to manufacturing or equivalent functions. For example, if an element is described as “round” or “generally round,” a component that is not precisely circular (e.g., one that is slightly oblong or is a many-sided polygon) is still encompassed by this description.J0083] Method examples described herein can be machine or computer- implemented at least in part. Some examples can include a computer-readable medium or machine-readable medium encoded with instructions operable to configure an electronic device to perform methods as described in the aboveexamples. An implementation of such methods can include code, such as microcode, assembly language code, a higher-level language code, or the like. Such code can include computer readable instructions for performing various methods. The code may form portions of computer program products. Further, in an example, the code can be tangibly stored on one or more volatile, non- transitory, or non-volatile tangible computer-readable media, such as during execution or at other times. Examples of these tangible computer-readable media can include, but are not limited to, hard disks, removable magnetic disks, removable optical disks (e.g., compact disks and digital video disks), magnetic cassettes, memory cards or sticks, random access memories (RAMs), read only memories (ROMs), and the like.|0084| The above description is intended to be illustrative, and not restrictive. For example, the above-described examples (or one or more aspects thereof) may be used in combination with each other. Other embodiments can be used, such as by one of ordinary skill in the art upon reviewing the above description. The Abstract is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features may be grouped together to streamline the disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter may lie in less than all features of a particular disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description as examples or embodiments, with each claim standing on its own as a separate embodiment, and it is contemplated that such embodiments can be combined with each other in various combinations or permutations. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

THE CLAIMED INVENTION IS:

1. An impeller assembly for a percutaneously delivered pump to induce blood flow within a vascular system, the impeller assembly configured to reversibly transition in the vascular system from a deployment configuration to an operative configuration, the impeller assembly comprising: an impeller shaft with an outer shaft surface, the impeller shaft including a helical channel formed in the outer shaft surface wherein the helical channel is sized, shaped, or otherwise configured to receive a base portion of a blade frame to locate the blade frame with respect to the impeller shaft; and an impeller blade, attached to the impeller shaft, the impeller blade comprising: the blade frame; and a polymer coating, configured to encapsulate the blade frame and create a blade surface for contact with blood in the vascular system.

2. The impeller assembly of claim 1, wherein the impeller shaft includes a circumferential channel formed in the outer shaft surface and configured to receive a fastener to secure the impeller blade to the impeller shaft.

3. The impeller assembly any one of claims 1 or 2, comprising a fastener, wherein the fastener includes a set of one or more straps to locate or secure the blade frame with respect to the impeller shaft.

4. The impeller assembly of claim 3, wherein the set of one or more straps includes an alternating set of one or more straps, the alternating locating an individual first one of the sets along a first lateral side of the impeller shaft and locating an individual second one of the sets along an opposing second lateral side of the impeller shaft.

5. The impeller assembly of any one of claims 1-4, wherein the polymer coating forms a leading edge, a body edge, a trailing edge, and a blade surface of the impeller blade, andwherein a distance between the blade frame and at least one of the leading edge, the body edge, or the trailing edge is equal to or less than 5 millimeters.

6. The impeller assembly of claims 1, wherein the blade frame defines a blade surface plane coincident with a surface of the blade frame at a root end of the impeller blade and the impeller shaft defines a shaft surface plane tangent to the outer shaft surface at the root end of the impeller blade, wherein the blade surface plane forms at an acute angle with respect to the shaft surface plane.

7. An impeller assembly with an impeller blade for a percutaneously delivered pump to induce blood flow within a vascular system, the impeller assembly configured to reversibly transition in the vascular system from a deployment configuration to an operative configuration, the impeller blade including a leading edge, a body edge, a trailing edge, and a blade surface, the impeller assembly comprising: an impeller shaft; and an impeller blade, attached to the impeller shaft, the impeller blade comprising: a blade frame, and a polymer coating configured to encapsulate the blade frame and form the leading edge, the body edge, the trailing edge, and the blade surface, wherein a distance between the blade frame and at least one of the leading edge, the body edge, or the trailing edge is equal to or less than 5 millimeters.

8. The impeller assembly of claim 7, wherein the impeller shaft includes an outer shaft surface and wherein a helical channel is formed in the outer shaft surface.

9. The impeller assembly of claim 8, wherein the helical channel is configured to receive a base portion of the blade frame for locating the blade frame with respect to the impeller shaft.

10. The impeller assembly of any one of claims 7-9, wherein the impeller shaft includes an outer shaft surface and wherein a circumferential channel is formed in the outer shaft surface.

11. The impeller assembly of any one of claims 7-10, wherein the impeller blade includes a blade surface plane coincident with a surface of the blade frame at a root end of the impeller blade and the impeller shaft includes a shaft surface plane tangent to an outer shaft surface at the root end of the impeller blade, wherein the blade surface plane forms at an acute angle with respect to the shaft surface plane.

12. An impeller assembly for a percutaneously delivered pump to induce blood flow within a vascular system, the impeller assembly configured to reversibly transition in the vascular system from a deployment configuration to an operative configuration, the impeller assembly comprising: an impeller shaft; and an impeller blade attached to the impeller shaft, comprising: a blade frame with a set of one or more straps to locate the blade frame with respect to the impeller shaft; and a polymer coating configured to encapsulate the blade frame and create a blade surface for contact with blood in the vascular system.

13. The impeller assembly of claim 12, wherein the set of one or more straps includes an alternating set of one or more straps, the alternating locating an individual first one of the sets along a first lateral side of the impeller shaft and locating an individual second one of the sets along an opposing second lateral side of the impeller shaft.

14. The impeller assembly of any one of claims 12 or 13, wherein the impeller shaft includes an outer shaft surface and a helical channel formed in theouter shaft surface, wherein the helical channel is configured to receive a base portion of the blade frame.

15. The impeller assembly of any one of claims 12-14, wherein the impeller shaft includes an outer shaft surface and a circumferential channel formed in the outer shaft surface wherein the circumferential channel is configured to receive a fastener to secure the blade frame to the impeller shaft.

16. The impeller assembly of any one of claims 12-15, wherein the polymer coating forms a leading edge, a body edge, a trailing edge, and a blade surface of the impeller blade, and wherein a distance between the blade frame and at least one of the leading edge, the body edge, or the trailing edge is equal to or less than 5 millimeters.

17. The impeller assembly of any one of claims 12-16, wherein the impeller blade includes a blade surface plane coincident with a surface of the blade frame at a root end of the impeller blade and the impeller shaft includes a shaft surface plane tangent to an outer shaft surface at the root end of the impeller blade, wherein the blade surface plane forms at an acute angle with respect to the shaft surface plane.

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