Cannula Assembly

Abstract

To provide a cannula assembly and a method of manufacturing the cannula assembly.SOLUTION: The cannula assembly includes a cannula and a pigtail extension coupled to the cannula. The pigtail extension includes a proximal section having a first stiffness and a distal section having a second stiffness, the first stiffness greater than the second stiffness. The proximal section of the pigtail extension is positioned between the cannula and at least a portion of the distal section.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Cross Reference to Related Applications This application claims the benefit of priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No. 61 / 992,825 filed on May 13, 2014, the entire content of which is incorporated herein by reference.

[0002] Technical Field The present disclosure relates to a cannula assembly. More specifically, the present disclosure relates to a cannula assembly that can be implemented with a blood pump assembly, such as an intravascular heart pump system. Background Art

[0003] Background To deliver blood from the heart to the arteries, a blood pump assembly such as an intracardiac or intravascular blood pump may be introduced into the heart. The blood pump assembly may be percutaneously introduced through the vascular system during a cardiac procedure. Specifically, via a catheter procedure, the blood pump assembly may be inserted through the femoral artery or axillary / subclavian artery, into the ascending aorta, across the valve, and into the left ventricle. The inserted blood pump assembly draws blood from the left ventricle through a cannula and pumps the blood out into the aorta.

[0004] The stability of the blood pump assembly within the ventricle affects the use and performance of the pump. Positioning the blood pump assembly too close to the apex of the ventricle can lead to suction and arrhythmia problems. Positioning the blood pump assembly too deep within the ventricle can result in the outlet being located on the aortic valve or within the ventricle. Improper positioning of the blood pump assembly consumes valuable time when the blood pump assembly needs to be repositioned. Since procedures requiring such embodiments affect the survivability and quality of life of the patient, time consumed in repositioning the blood pump assembly can be life-threatening. Summary of the Invention

[0005] overview The systems, methods, and devices disclosed herein provide a cannula assembly for an intravascular blood pump. The cannula assembly includes a cannula connected to a double-rigid pigtail extension. The double-rigid pigtail extension has a relatively rigid proximal portion and a relatively flexible distal portion. The intravascular blood pump may generate a thrust that compresses the cannula assembly against the patient's tissue. The rigid proximal portion is sufficiently rigid to resist substantially buckling under such compression (e.g., stiffness of 60, 70, 80, 90, 100, or higher on the Shore D scale). In contrast, the distal portion may be sufficiently flexible or pliable to exhibit a tendency to buckle against the patient's tissue (e.g., stiffness of 50, 40, 30, 20, or lower on the Shore D scale). This controlled buckling allows the proximal region of the pigtail extension to substantially maintain its original length so that it can act as a mechanical spacer. This spacing can facilitate the proper positioning of the intravascular blood pump relative to the patient's heart or vascular system. For example, a rigid proximal portion may prevent the blood inlet from being too close to the ventricular wall to avoid tissue aspiration. Furthermore, a rigid proximal portion may ensure that the blood pump outlet is positioned opposite the valve (e.g., the aortic valve) relative to the inlet. This allows blood to be pumped out of the ventricle, increasing cardiac output. At the same time, a relatively flexible distal portion may reduce trauma to the patient's tissues. For example, a more flexible material in the distal portion may reduce locally induced stress within the patient's tissues. Furthermore, deformation of the distal portion of the pigtail may increase the area over which forces transmitted to the tissue are distributed. As used herein, “intravascular” refers to a component that is positioned, in whole or in part, within the patient’s vascular system, within the patient’s heart, or both. Furthermore, as used herein, “dual rigidity” refers to a component having at least two sections with different rigidities.

[0006] In some embodiments, a kit is provided comprising a cannula and two or more pigtail extensions having relatively rigid proximal portions of varying lengths (e.g., 10 mm, 20 mm, 30 mm, 40 mm, 50 mm, 60 mm, or any other preferred length). Each pigtail extension in the kit has a proximal portion configured to connect to the distal end portion of the cannula. The connection may be detachable so that a physician can change the pigtail extension originally connected to the cannula assembly. This allows a physician to select a pigtail extension that provides appropriate spacing for positioning the intravascular blood pump to suit a particular patient. In some embodiments, a reasonable length of the rigid proximal portion is determined using imaging techniques (e.g., X-ray, MRI, CT scan, fluoroscopy, or ultrasound) or estimated using patient data (e.g., height, sex, age, or weight).

[0007] Various embodiments provide blood pump assemblies and methods for manufacturing and carrying out blood pump assemblies. Various embodiments provide a cannula assembly including a cannula and a pigtail extension connected to the cannula. The pigtail extension includes a proximal portion having first rigidity and a distal portion having second rigidity, the first being greater than the second. The proximal portion of the pigtail extension is positioned between the cannula and at least a portion of the distal portion.

[0008] In certain embodiments, the cannula assembly includes a pump connected to the cannula. The cannula is positioned between the pump and the pigtail extension. The cannula assembly may include an impeller blade rotatably connected to the pump motor. According to certain embodiments, the pump is connected to the cannula by a pump housing component that includes a plurality of blood drainage apertures. In certain embodiments, the pump housing component includes a circumferential wall extending around the rotation axis of the impeller blade. The circumferential wall includes a plurality of blood drainage apertures; each of the plurality of blood drainage apertures is surrounded by an aperture periphery. The aperture periphery extends across the circumferential wall from the inner surface to the outer surface. According to certain embodiments, the aperture periphery includes a rounded edge portion that is rounded between the inner and outer surfaces of the circumferential wall. The cannula component may include a blood inlet manifold. The blood inlet manifold may include a plurality of inlet openings. In certain embodiments, the proximal portion of the pigtail extension is made of nylon. In certain embodiments, the proximal portion of the pigtail extension is made of a polymer containing, not limited to, one or more of polyurethane or Pebax®. In certain embodiments, the distal portion of the pigtail extension is made of Pebax. In certain embodiments, the distal portion of the pigtail extension is made of a polymer containing, not limited to, polyurethane. The proximal portion of the pigtail extension may have a hardness or durometer value in the range of 60 to 100 Shore D. The distal portion of the pigtail extension may have a hardness or durometer value in the range of 20 to 50 Shore D. The stiffness of the proximal portion may be modified by the addition of other materials, such as glass fillers or metal or fiber braids.

[0009] Various embodiments provide a method for manufacturing a cannula assembly. The method includes the step of connecting a pigtail extension to a cannula. The pigtail extension includes a proximal portion having a first rigidity and a distal portion having a second rigidity less than the first rigidity. The proximal portion is positioned between the cannula and at least a portion of the distal portion. The method also includes the step of connecting a pump to the cannula. The cannula is positioned between the pump and the pigtail extension.

[0010] In certain embodiments, the impeller blades are rotatably connected to the pump motor. According to certain embodiments, the impeller blades are positioned at least partially within the pump housing component. According to certain embodiments, the pump is connected to the cannula by a pump housing component that includes a plurality of blood drainage apertures. The pigtail extension may be connected to the cannula via a blood inlet manifold. The blood inlet manifold may include a plurality of inlet openings. In certain embodiments, the proximal portion of the pigtail extension is made of nylon. In certain embodiments, the proximal portion of the pigtail extension is made of a polymer that non-limitingly includes one or more of polyurethane or Pebax. In certain embodiments, the distal portion of the pigtail extension is made of Pebax. In certain embodiments, the distal portion of the pigtail extension is made of a polymer that non-limitingly includes polyurethane.

[0011] [Invention 1001] Cannula and, It is connected to the cannula, A first rigid proximal portion, and Second rigid distal portion Includes, The first rigidity is greater than the second rigidity, The proximal portion is positioned between the cannula and at least a portion of the distal portion. Pigtail extension and A cannula assembly for an intravascular cardiac pump system, comprising the above features. [Invention 1002] The cannula assembly of the present invention 1001, wherein the proximal portion of the pigtail extension has a hardness in the range of approximately 60 to 100 Shore D. [Invention 1003] The cannula assembly according to the present invention 1001 or 1002, wherein the distal portion of the pigtail extension has a hardness in the range of approximately 20 to 50 Shore D. [Invention 1004] A cannula assembly according to any of the present invention 1001 to 1003, wherein the distal portion includes a curved portion. [Invention 1005] A cannula assembly according to any one of the present invention 1001 to 1004, wherein the curved portion is curved around an axis substantially perpendicular to the central axis of the cannula. [Invention 1006] A cannula assembly according to any of the present invention 1001 to 1005, wherein the curved portion is curved to more than approximately 180 degrees. [Invention 1007] A cannula assembly according to any one of the invention 1001 to 1006, wherein the proximal portion is sized such that it has a buckling load greater than the thrust generated by the blood pump assembly. [Invention 1008] A cannula assembly according to any one of the present invention 1001 to 1007, wherein the distal portion is sized such that it has a buckling load smaller than the thrust generated by the blood pump assembly. [Invention 1009] A cannula assembly according to any of the present invention 1001 to 1008, wherein the proximal portion of the pigtail extension has a length of more than approximately 10 mm. [Invention 1010] A cannula assembly according to any one of the present invention 1001 to 1009, wherein the pigtail extension is configured to be detachably connected to the cannula. [Invention 1011] A cannula assembly according to any of the present invention 1001 to 1010, wherein the distal portion of the pigtail extension is approximately 25% to 75% of the total length of the pigtail extension. [Invention 1012] A cannula assembly according to any of the present invention 1001 to 1011, further comprising a pump connected to the cannula, wherein the cannula is positioned between the pump and the pigtail extension. [Invention 1013] A cannula assembly according to any one of the invention 1001 to 1012, wherein the pump is connected to the cannula by a pump housing component that includes a plurality of blood drainage apertures. [Invention 1014] A cannula assembly according to any one of the present invention 1001 to 1013, wherein the cannula includes a blood inlet manifold. [Invention 1015] A cannula assembly according to any one of the present invention 1001 to 1014, wherein the proximal portion of the pigtail extension is made of nylon. [Invention 1016] A cannula assembly according to any of the present invention 1001 to 1015, wherein the proximal portion of the pigtail extension is composed of a polymer containing one or more of polyurethane and Pebax. [Invention 1017] A cannula assembly according to any one of the present invention 1001 to 1016, wherein the distal portion of the pigtail extension is made of Pebax. [Invention 1018] A cannula assembly according to any of the present invention 1001 to 1017, wherein the distal portion of the pigtail extension is made of polyurethane. [Invention 1019] A step of connecting a pigtail extension to a cannula, wherein the pigtail extension includes a proximal portion having first rigidity and a distal portion having second rigidity, and the proximal portion is positioned between the cannula and at least a portion of the distal portion; and a step of connecting a pump to the cannula, wherein the cannula is positioned between the pump and the pigtail extension A method of manufacturing a cannula assembly for an intravascular heart pump system, comprising:. [Invention 1020] The method of Invention 1019, wherein the proximal portion of the pigtail extension has a hardness in the range of 60 to 100 Shore D. [Invention 1021] The method of any one of Inventions 1019 or 1020, wherein the distal portion of the pigtail extension has a hardness in the range of 20 to 50 Shore D. [Invention 1022] The method of any one of Inventions 1019 to 1021, wherein the pump is connected to the cannula via a pump housing component comprising a plurality of blood discharge apertures. [Invention 1023] The method of any one of Inventions 1019 to 1022, wherein the pigtail extension is connected to the cannula via a blood inlet manifold. [Invention 1024] The method of any one of Inventions 1019 to 1023, wherein the pigtail extension is detachably connected to the cannula. [Invention 1025] a cannula; a first pigtail extension comprising a first proximal portion having a first stiffness and a first length, and a first distal portion having a second stiffness, wherein the first stiffness is greater than the second stiffness; a second pigtail extension comprising a second proximal portion having a third stiffness and a second length, and a second distal portion having a fourth stiffness, wherein the third stiffness is greater than the fourth stiffness comprising wherein the second length is greater than the first length, and the first pigtail extension and the second pigtail extension are each configured to be detachably connected to the cannula, a cannula assembly kit for an intravascular heart pump system. Those skilled in the art will likely recall variations and modifications after reviewing this disclosure. The disclosed features may be implemented in any combination and subcombinations (including multiple dependent and subcombinations) together with one or more other features described herein. The various features described or illustrated herein, including any of their components, may be combined or integrated into other systems. Furthermore, certain features may be omitted or not implemented at all. It should be understood that all combinations of the concepts described herein and any additional concepts described in more detail below are intended to be part of the invention disclosed herein (unless such concepts are contradictory). In particular, all combinations of the claims at the end of this disclosure are intended to be part of the invention disclosed herein. [Brief explanation of the drawing]

[0012] Those skilled in the art will understand that the accompanying drawings are for illustrative purposes only and are not intended to limit the scope of the subject matter described herein. The drawings are not necessarily to a uniform scale, and in some cases, different aspects of the subject matter disclosed herein may be exaggerated or enlarged in the drawings to aid in the understanding of different features. In the drawings, similar reference symbols generally refer to similar features (e.g., elements that are functionally and / or structurally similar). [Figure 1] A cannula assembly is shown according to an exemplary embodiment. [Figure 2] A side cross-sectional view of the pigtail extension is shown according to an exemplary embodiment. [Figure 3] Figure 2 shows an end view of the pigtail extension. [Figure 4] A method for manufacturing a cannula assembly according to a specific embodiment is illustrated.

[0013] The features and advantages of the concept of the present invention disclosed herein will become clearer upon reading the following description in conjunction with these drawings. [Modes for carrying out the invention]

[0014] Detailed explanation The following is a more detailed description of various concepts and embodiments of the present invention concerning systems and methods for providing cannula assemblies. The disclosed concepts are not limited to any particular form of embodiment, and it should be understood that the various concepts outlined above and described in more detail below may be implemented in any of the many possible methods. Examples of specific embodiments and applications are provided primarily for illustrative purposes.

[0015] The systems, methods, and devices disclosed herein provide a cannula assembly for an intravascular blood pump. The cannula assembly includes a cannula connected to a double-rigid pigtail extension. The double-rigid pigtail extension has a relatively rigid proximal portion and a relatively flexible distal portion. The intravascular blood pump may generate a thrust that compresses the cannula assembly against the patient's tissue. The rigid proximal portion is rigid enough to substantially resist buckling under such compression (e.g., stiffness of 60, 70, 80, 90, 100, or higher on the Shore D scale). In contrast, the distal portion may be flexible or pliable enough to exhibit a tendency to buckle against the patient's tissue (e.g., stiffness of 50, 40, 30, 20, or lower on the Shore D scale). This controlled buckling allows the proximal region of the pigtail extension to substantially maintain its original length so that it can act as a mechanical spacer. This spacing can facilitate the proper positioning of the intravascular blood pump relative to the patient's heart or vascular system. For example, a rigid proximal portion may prevent the blood inlet from being too close to the ventricular wall to avoid tissue aspiration. Furthermore, a rigid proximal portion may ensure that the blood pump outlet is positioned opposite the valve (e.g., the aortic valve) relative to the inlet. This allows blood to be pumped out of the ventricle, increasing cardiac output. At the same time, a relatively flexible distal portion may reduce trauma to the patient's tissues. For example, a more flexible material in the distal portion may reduce locally induced stress within the patient's tissues. Furthermore, deformation of the distal portion of the pigtail may increase the area over which forces transmitted to the tissue are distributed. As used herein, intravascular refers to a component that is positioned, in whole or in part, within the patient's vascular system, within the patient's heart, or both. Furthermore, as used herein, dual rigidity refers to a component having at least two sections with different rigidities.

[0016] Figure 1 shows a blood pump assembly according to an exemplary embodiment. The blood pump assembly 100 includes a blood pump 101, a housing component 102, an impeller blade 103 rotatably connected to the blood pump 101, a cannula 104, a blood inlet manifold 105, a pigtail extension 106, and a catheter 107. The blood pump 101 is connected to the cannula 104 at its distal end by the housing component 102. The blood pump 101 is also connected to the catheter 107. In some embodiments, the blood pump 101 includes a motor. In such cases, the catheter 107 may house wires that connect the pump 101 to one or more electrical controllers or other sensors in a communicative manner. In certain embodiments, the pump 101 is driven by a flexible shaft. In such cases, the drive portion of the motor may be located outside the patient's body, and the catheter 107 may house the flexible shaft. The catheter 107 may also house other components, such as a purging fluid conduit or other conduits configured to receive a guidewire or other components related to the procedure. The housing component 102 includes one or more apertures or openings 109 configured to eject or discharge blood drawn into the cannula 104 out of the blood pump assembly 100. In certain embodiments, the housing component 102 encloses the blood pump 101.

[0017] In certain embodiments, the blood pump 101 includes a micro-axial flow pump having a pumping capacity that is not limited to a range of 5 L / min to 2.5 L / min. In certain embodiments, the blood pump 101 includes a micro-axial flow pump having a diameter that is not limited to a range of 21 Fr to 10 Fr.

[0018] The cannula 104 may include an elongated, flexible hose portion, and may also include a shape memory coil, such as a nitinol coil. In certain embodiments, the cannula 104 is made of polyurethane material at least partially. In certain embodiments, the cannula 104 has a diameter that is not limited to the range of 12Fr to 9Fr. In certain embodiments, the cannula 104 includes a 45° bend. The cannula 104 includes a blood inlet manifold 105 connected to the cannula 104 at its proximal end to receive blood flow into the blood pump assembly 100. The blood inlet manifold 105 includes one or more blood inlet openings positioned within the inlet manifold 105. The blood inlet manifold 105 connects a pigtail extension 106 to the cannula 104.

[0019] The pigtail extension 106 assists in stabilizing and positioning the blood pump assembly 100 in the correct location within the left ventricle. In certain embodiments, the pigtail extension has an outer diameter that non-limitingly includes a range of 4Fr to 8Fr. In implementation, the blood pump assembly 100 is percutaneously inserted through the femoral artery or axillary / subclavian artery and into the left ventricle. When properly positioned, the blood pump assembly 100 delivers blood from the inlet area of ​​the blood inlet manifold 105 located inside the left ventricle, through the cannula 104, to the outlet opening of the housing component 102 positioned within the ascending aorta.

[0020] According to certain embodiments, the pigtail extension 106 can be configured from a straight configuration to a partially curved configuration. Figure 1 shows a curved configuration of the pigtail extension. The curve is around an axis substantially perpendicular to the central axis of the cannula. In some embodiments, the curve is greater than 180 degrees (e.g., 200, 220, 240, 260, 270, 300, 320 degrees, or any preferred angle). In some embodiments, the curve is less than 180 degrees (e.g., 90, 100, 120, 140, 160 degrees, or any preferred angle). Thus, the pigtail extension 106 may be made of a flexible material, at least partially. The pigtail extension 106 has dual rigidity. Specifically, the pigtail extension 106 includes a distal portion 107 and a proximal portion 108, the proximal portion 108 being made of a material having higher rigidity than the distal portion 107. The proximal portion 108 may be made of a different material and may have a different structure from the blood inlet manifold 105 and the cannula 104. In certain embodiments, the proximal portion 108 is sufficiently rigid to substantially prevent buckling of the proximal portion 108, thereby spacing the blood inlet opening of the blood inlet manifold 105 away from the ventricular apex. The rigidity of the proximal portion 108 also reduces the possibility of the blood outlet opening or drainage aperture 109 of the housing component 102 moving into the aortic valve or ventricle of the heart. The distal portion 107 of the pigtail extension 106 is more flexible than the proximal portion 108 to provide a non-traumatic tip for contacting the ventricular wall. This flexibility also allows for the insertion of a guidewire through the internal conduit 210 of the pigtail extension 106. In certain embodiments, the proximal 108 and distal 107 of the pigtail extension are made of different materials having different rigidities. In certain embodiments, the proximal 108 and distal 107 of the pigtail extension are made of the same material having different rigidities.

[0021] In some embodiments, the length of the proximal portion 108 of the pigtail extension is selected based on the size of the left ventricle of a particular patient. For example, a kit may be provided to a physician that includes two or more pigtail extensions having rigid proximal portions of varying lengths. Each pigtail extension in the kit may have a proximal end portion configured to connect to a cannula (for example, in a blood inlet manifold 105). In particular, the proximal end portion of the pigtail extension may be configured to connect to a cannula detachably. For example, the proximal end portion of the pigtail extension may include a snap connector, a crimp-fit, a screw connector, or any other suitable reversible or detachable connector. This allows the physician to change the pigtail extension that is originally connected to the cannula, while ensuring that the connection of the pigtail extension is secure enough to prevent it from coming loose in the patient's vascular system. In certain embodiments, this allows the kit to initially include a cannula having a “standard” sized pigtail, which is initially connected to the catheter 104, and which may be replaced with a larger or smaller pigtail as needed. The “standard” pigtail extension may be sized to fit the majority of patients (e.g., 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 95%), while larger or smaller sizes may fit the remaining patients. The physician may select a pigtail extension with an appropriate proximal length based on medical imaging. For example, the physician may determine the ventricular size using MRI, CT, X-ray, ultrasound, fluoroscopy, or any other preferred imaging method. In certain embodiments, this size is determined preoperatively. In some embodiments, the physician estimates the ventricular size using patient data (e.g., age, height, weight, sex).

[0022] Figure 2 shows a side section view of the pigtail extension 206 according to an exemplary embodiment. Figure 3 shows an end view of the pigtail extension 206 of Figure 2. The pigtail extension 206 includes a proximal section 208, a distal section 207 including a curved tip 212, and a conduit 210 for use with a guidewire. The pigtail extension 206 has dual rigidity because the proximal section 208 has greater rigidity than the distal section 207. In an exemplary embodiment, the distal section 207 and the proximal section 208 are composed of one or more layers of material provided to impart different rigidities to these two sections. In a particular embodiment, the proximal and distal sections have corresponding diameters. For example, the proximal section 208 may consist of a single layer of a first material having a first thickness and a first rigidity, and the distal section 207 may consist of two layers of material. In such cases, the two layers may comprise a first layer of the first material having a second thickness less than the first thickness, and a second layer of the second material having a third thickness (the sum of the second and third thicknesses corresponds to the first thickness) and a second stiffness. Thus, the distal portion 207 may have lower overall stiffness than the proximal portion 208 and may be configured to curl or buckle. The stiff proximal portion 208 is stiff enough to substantially resist buckling under such compression (e.g., hardness of 60, 70, 80, 90, 100 or higher on the Shore D scale). The distal portion 207 is sufficiently flexible or pliable to exhibit a tendency to buckle against patient tissue (e.g., hardness of 50, 40, 30, 20 or lower on the Shore D scale). In some embodiments, the distal portion may have greater stiffness by incorporating additional materials such as metal, fiber, braided metal or fiber, glass, or any other suitable material.

[0023] In some embodiments, the proximal portion may be more rigid than the distal portion by incorporating additional material, such as metal, fiber, braided metal or fiber, glass, or any other suitable material. The additional material may be added by injection molding, co-extrusion, bonding, thermal reflow, or any other suitable process. In some embodiments, the additional material forms a matrix or other suitable structure within the proximal portion. To reinforce the transition from the proximal to the distal portion, the additional material may extend partially from the proximal to the distal portion. In certain embodiments, the additional material may be placed between the first and second material layers of the rigid proximal portion. Incorporating additional material into the proximal portion allows for achieving a difference in rigidity between the proximal and distal portions using a single base material. Using a single base material for both the proximal and distal portions can help achieve melting in the transition region between the proximal and distal portions. This can facilitate joining the proximal to the distal portion during manufacturing.

[0024] Intravascular or intracardiac blood pumps may generate thrust that compresses the cannula assembly against the patient's tissue, and the stiffness of the proximal portion allows the proximal region to act as a mechanical spacer, maintaining its original length and ensuring proper positioning of the intravascular blood pump. Thus, the stiff proximal portion 208 can prevent the blood inlet from becoming too close to the ventricular wall to avoid tissue aspiration. The stiff distal portion 208 can ensure that the outlet of the blood pump (e.g., blood pump 101) is positioned opposite the valve (e.g., aortic valve) relative to the inlet. This allows blood to be pumped out of the ventricle, increasing cardiac output. At the same time, the relatively flexible distal region can reduce trauma to the patient's tissue. For example, softer material in the distal portion can reduce locally induced stress within the patient's tissue. Furthermore, deformation of the distal portion of the pigtail can increase the area over which forces are distributed to the tissue.

[0025] In certain embodiments, the pigtail extension 206 includes a curved tip 212. In some embodiments, the pigtail extension 206 can be configured from a straight configuration to a partially curved configuration. The curve of the curved tip is around an axis substantially perpendicular to the central axis of the cannula. In some embodiments, the curve is greater than 180 degrees (e.g., 200, 220, 240, 260, 270, 300, 320 degrees, or any preferred angle). In certain embodiments, the curve is less than 180 degrees (e.g., 90, 100, 120, 140, 160 degrees, or any preferred angle).

[0026] The pigtail extension 206 also includes a conduit 210 extending through its proximal and distal portions. The conduit 210 is sized to receive a guidewire through the pigtail extension 206. In certain embodiments, the proximal portion 208 of the pigtail extension 206 is made of nylon. In some embodiments, the proximal portion 208 of the pigtail extension 206 is made of a polymer that non-limitingly contains one or more of polyurethane or Pebax. In certain embodiments, the distal portion 207 of the pigtail extension 206 is made of Pebax. In certain embodiments, the distal portion 207 of the pigtail extension 208 is made of a polymer that non-limitingly contains polyurethane. The proximal portion 208 of the pigtail extension 206 may have a hardness or durometer value in the range of 60 to 100 Shore D. The distal portion 207 of the pigtail extension 208 may have a hardness or durometer value in the range of 20 to 50 Shore D. According to a particular embodiment, the distal portion 207 of the pigtail extension 206 includes 25 to 75% of the total length of the pigtail extension 206.

[0027] Figure 4 illustrates a method 400 for manufacturing a cannula assembly according to a particular embodiment. Method 400 may be performed to manufacture a cannula assembly 100 in any of the embodiments described above. In step 402, a dual-rigid pigtail extension, such as the pigtail extension 106 or 206 of Figures 1 and 2, is connected to the cannula. The pigtail extension includes a relatively rigid proximal portion and a relatively flexible distal portion. The pigtail extension may be removably connected to the cannula, or it may be permanently connected to the cannula. In step 404, a pump is connected to the cannula so that the cannula is positioned between the pump and the pigtail extension.

[0028] Where used herein, “approximately,” “about,” “substantially,” and similar terms are intended to have a broad meaning consistent with the common usage accepted by those skilled in the art in the field to which the subject matter of this disclosure belongs. It should be understood by those skilled in the art considering this disclosure that these terms allow for the description of certain features, but do not limit those features to the precise numerical ranges provided. Accordingly, these terms should be interpreted as indicating that any non-substantial or non-material modification or alteration to the subject matter is deemed to fall within the scope of this disclosure.

[0029] For the purposes of this disclosure, the term “connected” means that two members are connected to each other directly or indirectly. Such connections may be stationary or movable. Such connections may be realized by the two members, or by the two members and any additional intermediate members formed integrally with each other as a single unit, or by the two members, or by the two members and any additional intermediate members attached to each other. Such connections may be permanent or removable or detachable.

[0030] It should be noted that the orientation of various elements may differ according to other exemplary embodiments, and that such variations are intended to be covered by this disclosure. It is recognized that features of the disclosed embodiments may be incorporated into other disclosed embodiments.

[0031] Importantly, it should be noted that the structures and arrangements of the apparatus or its components shown in the various exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in this disclosure, it will be readily apparent to those skilled in the art that numerous modifications are possible without significantly departing from the novel teachings and merits of the disclosure (e.g., variations in the size, dimensions, structure, shape, and proportions of various elements, parameter values, mounting arrangements, material use, color, orientation, etc.). For example, elements shown as being formed as a single unit may be constructed as multiple parts or elements, the positions of elements may be reversed or otherwise modified, and the nature or number of separate elements or positions may be modified or changed. The order of any steps of a process or method may be changed or rearranged according to alternative embodiments. Other substitutions, modifications, changes, and omissions are also possible for the designs, operating conditions, and arrangements of the various exemplary embodiments without departing from the scope of this disclosure.

[0032] While various embodiments of the present invention have been described and illustrated herein, it is expected that those skilled in the art will readily conceive of various other mechanisms and / or structures for performing the functions described herein and / or obtaining one or more of the results and / or advantages described herein, and that each of such variations and / or modifications will fall within the scope of the embodiments of the invention described herein. More generally, it will be readily apparent to those skilled in the art that the parameters, dimensions, materials, and configurations described herein are intended to be illustrative unless otherwise noted, and that the actual parameters, dimensions, materials, and / or configurations will vary depending on the specific application in which the teachings of the present invention are used. Those skilled in the art will be able to recognize or verify numerous equivalents to the specific embodiments of the present invention described herein by routine experimentation alone. Therefore, it should be understood that the above embodiments are presented only as examples, and that embodiments of the invention may be made within the scope of the appended claims and their equivalents, beyond those specifically described and claimed. Embodiments of the invention of this disclosure relate to the individual features, systems, articles, materials, kits, and / or methods described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and / or methods is included within the scope of the inventions of this disclosure, provided that such features, systems, articles, materials, kits, and / or methods are not contradictory to each other.

[0033] Furthermore, at least one embodiment of the techniques described herein may be carried out in the manner provided above. The actions performed as part of the method may be ordered in any preferred manner unless otherwise specified. Thus, embodiments may be constructed such that the actions are performed in a different order than those exemplified, including performing some actions simultaneously, even if they are shown as sequential actions in the exemplary embodiments.

[0034] As used herein and in the claims, the indefinite articles “a” and “an” should be understood to mean “at least one” unless otherwise explicitly stated. As used herein and in the claims, “or” should be understood to have the same meaning as “and / as well as / or” as defined above. For example, when separating items in an enumeration, “or” or “and / as well as / or” should be interpreted as inclusive, meaning that it includes at least one, but also two or more of the elements or enumeration of elements, and optionally, additional items that are not enumerated. Only terms that are explicitly stated not to include, such as “only one of” or “exactly one of,” mean that it includes exactly one element of the elements or enumeration of elements. In general, the terms “or” as used herein should be interpreted as referring to something exclusive (i.e., “one or the other, but not both”) only when preceded by an exclusive term such as “either,” “one of,” “only one of,” or “strictly one of.”

[0035] When used herein and in the claims, the phrase “at least one” with respect to one or more elements means at least one element selected from any one or more elements in the element enumeration, but does not necessarily include at least one of each element specifically listed in the element enumeration, nor does it exclude any combination of elements in the element enumeration. This definition also makes it possible that there may be elements different from those specifically identified in the element enumeration to which the “at least one” phrase refers, whether or not they relate to those specifically identified elements. Therefore, as a non-restrictive example, “at least one of A and B” (or equivalently “at least one of A or B” or equivalently “at least one of A and / or B”) may, in one embodiment, refer to at least one A that has no B (and optionally includes elements other than B) and may include any two or more elements; in another embodiment, refer to at least one B that has no A (and optionally includes elements other than A) and may include any two or more elements; and in yet another embodiment, refer to at least one A that includes two or more elements and at least one B that includes any two or more elements (and may optionally include other elements), and so on.

[0036] In the claims and the above specification, all transitional phrases such as “equipped with,” “include,” “carry,” “have,” “contain,” “accompany,” “hold,” and “composed of” should be understood to be non-restrictive, meaning they include but are not limited to.

[0037] Unless otherwise stated, the claims should not be read as being limited to the order or elements described. It should be understood that various modifications in form and detail can be made by those skilled in the art without departing from the spirit and scope of the attached claims. All embodiments that fall within the spirit and scope of the following claims and their equivalents are claimed.

Claims

1. A blood pump and An impeller rotatably connected to the blood pump, A cannula having a proximal end and a distal end, wherein the proximal end of the cannula is connected to the blood pump, A catheter connected to the blood pump, wherein the blood pump is positioned between the catheter and the cannula. A first rigid proximal portion, and Second rigid distal portion Includes, The proximal portion comprises a single layer of a first material having a first thickness, and the distal portion comprises a first layer of the first material having a second thickness and a second layer of the second material having a third thickness. The first material and the second material are different materials. The first rigidity is greater than the second rigidity, The proximal portion is connected to the distal end of the cannula. Pigtail extension and An intravascular cardiac pump system equipped with this system.

2. The intravascular cardiac pump system according to claim 1, wherein the proximal portion of the pigtail extension has a hardness in the range of 60 to 100 Shore D.

3. The intravascular cardiac pump system according to claim 1 or 2, wherein the distal portion of the pigtail extension has a hardness in the range of 20 to 50 Shore D.

4. The intravascular cardiac pump system according to any one of claims 1 to 3, wherein the distal portion includes a curved portion.

5. The intravascular cardiac pump system according to claim 4, wherein the curved portion is curved around an axis perpendicular to the central axis of the cannula.

6. The intravascular cardiac pump system according to claim 4, wherein the curved portion is curved more than 180 degrees.

7. The intravascular cardiac pump system according to any one of claims 1 to 6, wherein the proximal portion of the pigtail extension has a length of more than 10 mm.

8. The intravascular cardiac pump system according to any one of claims 1 to 7, wherein the pigtail extension is configured to be detachably connected to the cannula.

9. The intravascular cardiac pump system according to any one of claims 1 to 8, wherein the distal portion of the pigtail extension is 25% to 75% of the total length of the pigtail extension.

10. The intravascular cardiac pump system according to claim 1, wherein the proximal portion has a hardness of at least 60 Shore D such that the proximal portion has a buckling load greater than the thrust generated by the intravascular cardiac pump system.

11. The intravascular cardiac pump system according to claim 1, wherein the distal portion has a hardness of 50 Shore D or less such that the distal portion has a buckling load smaller than the thrust generated by the intravascular cardiac pump system.

12. The intravascular cardiac pump system according to any one of claims 1 to 11, further comprising a pump housing component including a plurality of blood drainage apertures, wherein the blood pump is connected to the proximal end of the cannula by the pump housing component, and the impeller is positioned at least partially within the pump housing component.

13. The intravascular cardiac pump system according to claim 12, wherein the cannula includes a blood inlet manifold at the distal end of the cannula, and the proximal portion of the pigtail extension is connected to the blood inlet manifold.

14. The intravascular cardiac pump system according to any one of claims 1 to 13, wherein the blood pump includes a motor, and the catheter houses wires connecting the blood pump to one or more electric controllers or one or more sensors.

15. The intravascular cardiac pump system according to any one of claims 1 to 13, further comprising a flexible shaft for driving the blood pump, wherein the catheter accommodates the flexible shaft.

16. The intravascular cardiac pump system according to any one of claims 1 to 15, wherein the cannula includes an elongated flexible hose portion and a shape memory coil.

17. The intravascular cardiac pump system according to any one of claims 1 to 16, wherein the proximal portion of the pigtail extension is made of nylon.

18. The intravascular cardiac pump system according to any one of claims 1 to 17, wherein the proximal portion of the pigtail extension is composed of a polymer comprising one of polyurethane and Pebax®.

19. The intravascular cardiac pump system according to any one of claims 1 to 18, wherein the distal portion of the pigtail extension is made of Pebax (registered trademark).

20. The intravascular cardiac pump system according to any one of claims 1 to 19, wherein the distal portion of the pigtail extension is made of polyurethane.

21. The intravascular cardiac pump system according to claim 1, wherein the sum of the second thickness and the third thickness is equal to the first thickness.

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