Double-walled thermoformed cannula

Abstract

We provide a reinforced cannula for use in a blood pump assembly, configured to withstand the forces subjected to during insertion and operation of the blood pump. [Solution] A system and method for providing a reinforcing cannula for use in a blood pump assembly. The reinforcing cannula comprises one or more thermoformed reinforcing end portions. The thermoformed reinforcing end portions may have higher rigidity than the middle portion of the cannula, thereby allowing the middle portion of the cannula body to stretch and bend more easily than the cannula end portion when the cannula is subjected to applied stress, thereby reducing the stress and tension on the cannula end portion.

Description

Technical Field

[0001] Cross - reference to Related Applications This application claims priority to U.S. Patent Application No. 62 / 868,476, filed on June 28, 2019, which is hereby incorporated by reference in its entirety. Additionally, this application is related to U.S. Patent Application Publication No. 2017 / 0215918, titled "Thermoform Cannula with Variable Cannula Body Stiffness", and U.S. Patent No. 8,795,576, titled "Radiopaque Cannula Marker", both of which are hereby incorporated by reference in their entireties.

Background Art

[0002] Background Intravascular blood pump assemblies, such as assemblies with an intracardiac blood pump, may be introduced into the heart to deliver blood from the heart to the arteries. The intravascular blood pump can be introduced percutaneously through the vasculature during a cardiac procedure, such as by catheterization. Some blood pumps are designed to assist the left side of the heart, drawing blood from the left ventricle of the heart and discharging that blood into the aorta through a cannula. Some blood pumps that assist the left side of the heart are introduced into the left ventricle through the ascending aorta via the femoral artery by catheterization, passing over the aortic valve. Some systems are designed to assist the right side of the heart, and the blood pump is introduced through a vein and through the venous system (e.g., the vena cava) to the right side of the heart. The blood pump system can also be surgically implanted or inserted through the subclavian artery and / or the carotid artery. It can be difficult to advance the blood pump assembly through the patient's tortuous path or calcified anatomical structures while inserting the blood pump assembly through the blood vessels into the patient.

[0003] The complex situations involving pump introduction, resulting from these tortuous pathways, can, in some cases, cause damage to the blood pump assembly or to the patient. For example, in right heart procedures, damage can occur as the blood pump travels through the tortuous pathway within the right heart (e.g., spanning between the inferior vena cava and the pulmonary artery) toward the right heart. In some cases, the blood pump cannula bears a large portion of the load on the pump as it travels toward and within the heart. For example, the cannula of a right heart blood pump can be stretched or bent as a result of its placement. Similarly, the various interfaces between the cannula and the inflow and outflow components of the pump can also be stretched or bent, potentially causing damage to the blood pump. Known blood pump assemblies include the Impella® pump by Abiomed, Inc. The Impella® pump system generally consists of a catheter and, The Impella® pump includes a pump, a power supply to drive the pump rotor, a cannula for crossing the heart valves, and a non-traumatic extension. The Impella® pump assists the left or right heart. It can be introduced to patients. [Overview of the Initiative]

[0004] overview The systems, methods, and apparatus described herein provide reinforcing cannulas for use in blood pump assemblies, configured to withstand the forces subjected to the insertion and operation of the blood pump. In some aspects of the art, the reinforcing cannula is a double thermoformed cannula having at least one thermoformed reinforcing end portion that is more rigid than the middle portion of the cannula. This is a cannula. The thermoformed outer end reinforcement layer allows the cannula body to stretch more easily than the cannula end when the cannula is subjected to applied stress, thereby reducing the stress on the interface between the cannula end and the adjacent components of each cannula end. Therefore, the thermoformed reinforced end portion, also called the thermoformed outer end reinforcement layer, is a cannula It can function as a tension-relieving section for the purpose of [the object].

[0005] A thermoformed outer end reinforcement layer may be placed at the interface between the cannula and one of the other components of the blood pump assembly. For example, the thermoformed outer end reinforcement layer may be placed at the interface between the cannula and one of the other components of the blood pump assembly. The thermoformed outer end reinforcement layer may be located at the interface between the distal end and the distal component (e.g., the blood inflow cage), or at the interface between the proximal end of the cannula and the pump housing, or both. The thermoformed outer end reinforcement layer may help prevent the cannula from separating from other components of the blood pump assembly. The thermoformed outer end reinforcement layer may also improve the strength at the interface between the cannula and other components (e.g., the blood inflow cage located distal to the cannula).

[0006] The thermoformed outer end reinforcement layer may have a higher durometer hardness than the middle portion of the cannula's outer layer. In some configurations, the thermoformed outer end reinforcement layer has at least twice the rigidity of the middle portion of the cannula. In other configurations, the thermoformed outer end reinforcement layer The outer reinforcement layer has approximately 1.5 to 5.5 times the rigidity of the middle section of the cannula. In some configurations, the thermoformed outer reinforcement layer has approximately 2 to 5 times the rigidity of the middle section of the cannula. In further configurations, the thermoformed outer reinforcement layer has approximately 3 to 4 times the rigidity of the middle section of the cannula. In a specific configuration, the thermoformed outer reinforcement layer has approximately 3.5 times the rigidity of the middle section of the cannula.

[0007] In addition, one or more layers of the cannula body are also formed using a thermoforming process. It is possible. By incorporating a thermoformed layer into the middle section of the cannula, the cannula can be given further structural reinforcement along its length. Furthermore, one or more of the cannula bodies Thermoforming the layers may help improve the manufacturing yield of pump cannulas with short bonding areas.

[0008] According to some aspects of this technology, an intravascular blood pump system for insertion into the heart includes a pump having a rotor and one or more blades arranged within the pump housing for transporting fluid through the pump housing. The drive system also includes a motor. It is included together with the drive system. The motor may be an internal motor powered by wires, or an external motor having a drive cable connecting the pump and the motor. The blood pump system further has an elongated catheter through which the drive cable or wires will pass, connecting the pump to an external control system outside the patient's body. The cannula is located distal to the pump housing and connects to the distal end of the pump housing. As used herein, “distal” refers to the direction away from the blood pump operator toward the patient. Similarly, “proximal” refers to the direction away from the blood pump operator toward the patient. The cannula has length, a proximal end, a middle section, and a distal end. The distal end of the cannula is attached to the proximal end of an inflow cage extending distally from the cannula, and the distal end of the inflow cage is attached to a distal non-traumatic projection. The inflow cage separates the cannula from the distal non-traumatic projection, and blood flows through the inflow cage into the cannula.

[0009] The cannula consists of at least three concentric cylindrical layers, namely an inner layer, a reinforcing layer, and an outer layer. It can be constructed as follows: Each layer extends longitudinally along the length of the cannula, defining the body of the cannula from the distal end to the proximal end. The outer layer surrounds the reinforcing layer that surrounds the inner layer. The three concentric layers, especially the inner layer, form the lumen that extends along the length of the cannula. Further definition: The inner and outer layers of the cannula body can be thermoformed. In certain configurations, a thermoformed outer end reinforcement layer is placed on top of the outer layer of at least one of the distal and proximal ends of the cannula. The combination of the thermoformed outer end reinforcement layer and the thermoformed inner and outer layers provides structural stability to the cannula body and prevents shear forces from being applied during insertion into and movement of the cannula into the patient's vascular structure. The reinforced end layer—not the main body layer of the cannula—allows it to function as a tension-relieving section of the cannula.

[0010] In some configurations, the cannula consists of a thermoformed inner layer extending along the length of the cannula. The inner layer contains an inner material and has an inner diameter and an outer diameter. In some configurations, the outer diameter of the inner layer is approximately 1 Fr to 5 Fr. In other configurations, the outer diameter of the inner layer is approximately 2 Fr to 4 Fr. In certain configurations, the outer diameter of the inner layer is approximately 3 Fr. In certain configurations... In some configurations, the radial thickness of the inner layer is approximately 0 mm to 0.2 mm. In other configurations, the radial thickness of the inner layer is approximately 0.05 mm to 0.15 mm. In some configurations, the radial thickness of the inner layer is approximately 0.1 mm. In other configurations, the outer layer has a radial thickness of approximately 0 mm to 0.15 mm. In some specific configurations, the outer layer has a radial thickness of approximately 0.075 mm to 0.125 mm. In some specific configurations, the outer layer has a radial thickness of approximately 0.1 mm. The thickness of each layer By adjusting, a given total thickness of the cannula can be obtained. In certain implementations, the total radial thickness of the cannula is approximately 0 mm to 0.5 mm. In some implementations, the total radial thickness of the cannula is approximately 0.15 mm to 0.35 mm. In further implementations, the total radial thickness of the cannula is approximately 0.3 mm. In some implementations, the outer diameter of the middle portion of the cannula The diameter is approximately 17 Fr to 22 Fr. In certain implementations, the outer diameter of the middle section of the cannula is approximately 18 Fr to 21 Fr. In further implementations, the outer diameter of the middle section of the cannula is approximately 19.5 Fr.

[0011] In the case of a cannula with an outer layer of a fixed outer diameter, the amount of material at a given longitudinal point along the length of the cannula is determined during the manufacturing process by the radial thickness of the inner layer (e.g., outer diameter and / or This can be adjusted by adjusting the inner diameter. By adjusting the amount of material present at a longitudinal point along the length of the cannula, the stiffness of that point changes; points with more material become stiffer, and points with less material become stiffer. Therefore, in order to form a desired stiffness profile along the length of the cannula, the radial thickness of the inner layer can be adjusted so that a given point along the length of the cannula has an amount of material that gives the desired stiffness.

[0012] In addition, the cannula may be composed with a coil made of shape memory material, the coil may be positioned along the outer diameter of the inner layer. The cannula may further have a thermoformed outer layer that extends along the length of the cannula and is positioned on top of the inner layer and the coil. In certain implementations, the coil is embedded in the outer layer. In further implementations, the shape memory material included in the coil is at least one of nitinol or copper-aluminum alloy. The outer layer of the cannula includes an outer material. In certain implementations, the outer material includes polyurethane. In some implementations, the outer material includes Texin®, which is thermoplastic polyurethane (TPU). In some implementations, the inner material includes polyurethane. Other implementations In some configurations, the inner material includes Texin®. When polyurethane is used for the inner and / or outer layers, it may include polyether or polyester. In certain implementation configurations, the inner and outer materials are the same.

[0013] In some implementations, the inner layer extends longitudinally beyond the outer layer at at least one of the distal and proximal ends of the cannula body. These elongated portions of the inner layer are referred to as the distal medial projection and the proximal medial projection, respectively. In implementations with a distal medial projection, a continuous reinforcement profile along the length of the cannula can be formed by adding a thermoformed outer end reinforcement layer to the end of the outer layer. In certain implementations, at least one of the distal medial projection and the proximal medial projection has a length of approximately 1 cm to approximately 5 cm. In other implementations, at least one of the distal medial projection and the proximal medial projection has a length of approximately 2 cm. It has a length of several centimeters to approximately 4 centimeters. In certain implementation forms, the distal medial projection is present. At least one of the protruding portion and the proximal medial projection has a length of about 3 centimeters.

[0014] In addition, the cannula may further comprise a first thermoformed outer end reinforcing layer. In this implementation configuration, the first thermoformed outer end reinforcement layer is positioned at the proximal end of the cannula. It extends over and covers the outer layer. In other implementations, the first thermoformed outer end reinforcement layer is a crab The first thermoformed outer end reinforcing layer extends over the proximal portion of the proximal inner layer, which is longer than the outer layer, to form a continuous reinforcing profile along the length of the rühle. The first thermoformed outer end reinforcing layer contains reinforcing material. A reinforcing section can be formed between the cannula and the pump housing. The first thermoformed The outer end reinforcement layer may be configured to reduce the possibility of separation between the pump housing and the cannula due to forces applied to the cannula during percutaneous insertion of the intravascular blood pump system into the patient's body. When the blood pump assembly is in place within the patient's heart, the cannula may extend beyond the patient's aortic valve so that the distal end of the cannula is positioned in the left ventricle and the proximal end of the cannula is positioned in the aorta.

[0015] In certain implementation configurations, the cannula further includes a second thermoformed outer end reinforcement layer. In some embodiments, the second thermoformed outer end reinforcement layer is disposed over the outer layer at the distal end of the cannula. In other embodiments, the second thermoformed outer end reinforcement layer extends over the distal inner protrusion so as to form a continuous reinforcement profile along the length of the cannula. In such embodiments, the distal thermoformed outer end reinforcement layer comprises a reinforcing material. In some embodiments, the distal end of the cannula is connected to an inflow cage, and the distal thermoformed outer end reinforcement layer forms a second reinforcement section of the cannula at the interface between the cannula and the inflow cage. In embodiments having a distal thermoformed outer end reinforcement layer, the distal thermoformed outer end reinforcement layer can function as a stress relief section that reduces the likelihood of separation between the inflow cage and the cannula due to forces applied to the cannula during percutaneous insertion.

[0016] In some embodiments, the radial thickness of the reinforcement layer tapers. For example, the radial thickness of the proximal thermoformed outer end can be tapered such that the thickness decreases in the distal direction. In other embodiments, the radial thickness of the distal thermoformed outer end reinforcement layer can be tapered such that the thickness decreases in the distal direction. In certain embodiments, the radial thickness of both the thermoformed outer end reinforcement layers can be tapered such that the thickness decreases in the distal direction. In certain embodiments, the radial thickness of at least one of the thermoformed outer end reinforcement layers tapers from a thickness of about 1 millimeter to a minimum thickness close to 0. In other embodiments, the radial thickness of at least one of the thermoformed outer end reinforcement layers tapers from a thickness of about 0.7 millimeter to near 0. In further embodiments, the radial thickness of at least one of the thermoformed outer end reinforcement layers tapers from a thickness of about 0.4 millimeter to near 0.

[0017] ​​​​In some embodiments, the inner layer includes an inner material, the outer layer includes an outer material, and the thermoformed outer end reinforcement layer includes a reinforcement material. In certain embodiments, the inner material and the outer material include the same material. In some embodiments, at least one of the inner material and the outer material is polyurethane. In further embodiments, the inner material is polyester polyurethane. In other embodiments, the inner material is polyether urethane. In certain embodiments, at least one of the outer material and the reinforcement material is polyether polyurethane. In some embodiments, at least one of the inner material and the outer material is Texin®. The polymer may be selected based on its behavior during heat shrinkage. Further, the specific polymer selected for use in the cannula may be selected for its specific mechanical properties. For example, the polymer selected may have a stiffness such that when the cannula is subjected to stress, the cannula body bends more easily than the thermoformed outer end reinforcement layer. It may be selected based on its behavior during heat shrinkage. Further, the specific polymer selected for use in the cannula may be selected for its specific mechanical properties. For example, the polymer selected may have a stiffness such that when the cannula is subjected to stress, the cannula body bends more easily than the thermoformed outer end reinforcement layer.

[0018] In some embodiments, the reinforced portion of the cannula has a stiffness about 0.5 times to 3 times that of the middle portion of the cannula. In other embodiments, the reinforced portion of the cannula has a stiffness about 1 times to about 2.75 times that of the middle portion of the cannula. In further embodiments, the reinforced portion of the cannula has a stiffness about 1.5 times to about 2.5 times that of the middle portion of the cannula. In certain embodiments, the reinforced portion of the cannula has a stiffness less than 2.5 times that of the middle portion of the cannula. The stiffness ratio between the reinforced portion of the cannula and the middle portion of the cannula can be adjusted by incorporating one or more thermoformed outer end reinforcement layers of various stiffnesses. Additionally, the stiffness ratio can also be adjusted by incorporating materials having various stiffnesses included in the following ranges. The stiffness ratio between the reinforced portion of the cannula and the middle portion of the cannula can be advantageously selected to reduce the likelihood of torsion that would otherwise occur due to a large difference in stiffness between the reinforced portion of the cannula and the middle portion of the cannula. The stiffness ratio between the reinforced portion of the cannula and the middle portion of the cannula can be adjusted by incorporating one or more thermoformed outer end reinforcement layers of various stiffnesses. Additionally, the stiffness ratio can also be adjusted by incorporating materials having various stiffnesses included in the following ranges. The stiffness ratio between the reinforced portion of the cannula and the middle portion of the cannula can be advantageously selected to reduce the likelihood of torsion that would otherwise occur due to a large difference in stiffness between the reinforced portion of the cannula and the middle portion of the cannula.

[0019] The thermoformed outer end reinforcement layer may contain a material having higher rigidity than the material of the middle portion of the cannula. Furthermore, the shape of the thermoformed outer end reinforcement layer can be adjusted to achieve a desired rigidity ratio between the thermoformed outer end reinforcement layer and the middle portion. For example, the thermoformed outer end reinforcement layer may have a radial thickness of about 0 to about 0.3 mm. In further implementations, the radial thickness of the thermoformed outer end reinforcement layer is about 0.05 mm to about 0.15 mm. In certain implementations, the radial thickness of the thermoformed outer end reinforcement layer is about 0.075 mm to about 0.125 mm. In further implementations, the radial thickness of the thermoformed outer end reinforcement layer is less than about 0.1 mm. In addition, the thermoformed outer edge reinforcement layer can have various lengths. In certain mounting configurations, the length of the thermoformed outer edge reinforcement layer is approximately 1 cm to 3 cm. In other mounting configurations, the length of the thermoformed outer edge reinforcement layer is approximately 2 cm. In some mounting configurations, the length of the thermoformed outer edge reinforcement layer is approximately 3 mm to 9 mm. In certain mounting configurations, the length of the thermoformed outer edge reinforcement layer is approximately 5 mm to 7 mm. In other mounting configurations, the length of the thermoformed outer edge reinforcement layer is approximately 6 mm. Cannula shape and material At least one advantage of the variability of cannula stiffness is that along the length of the cannula One advantage is the ability to adjust the stiffness profile. For example, a given procedure may require a cannula of a specific stiffness based on the insertion angle of the procedure. The insertion angle of a procedure can vary based on the patient's anatomical structure and insertion site. Therefore, the shape and material of the cannula can be adjusted to provide a specific stiffness profile along the desired cannula length for a given procedure.

[0020] In certain mounting configurations, the inner material has an inner material hardness of approximately 45D to 65D. In other mounting configurations, the inner material has an inner material hardness of approximately 50D to 60D. In further mounting configurations, the inner material has an inner material hardness of approximately 55D. In some mounting configurations, the outer material has an outer material hardness of approximately 75A to 95A. In other mounting configurations, the outer material has an outer material hardness of approximately 80A to 90A. It has material hardness. In a further implementation configuration, the outer material has an outer material hardness of approximately 85A. In some implementation configurations, the hardness of the reinforcing material is approximately 1 to 3 grades higher than the hardness of the inner material. In specific implementation configurations, the hardness of the reinforcing material is approximately 2 grades higher than the hardness of the inner material. In a standard configuration, the reinforcing material has a reinforcing hardness of approximately 45D to 65D. In other configurations, the reinforcing material has a reinforcing hardness of approximately 50D to 60D. In further configurations, the reinforcing material has a reinforcing hardness of approximately 55D. In a specific configuration, the internal hardness and the reinforcing hardness are equal or They are approximately equal. The relative hardnesses of the inner material, outer material, and reinforcing material can be selected so that the thermoformed outer end reinforcing layer acts as a tension-relieving section when the cannula is subjected to stress.

[0021] In some implementations, the middle section of the cannula has a smaller outer diameter than one or both of the reinforcing sections. The outer diameter of the middle section of the cannula may be configured to extend over a certain range of diameters to obtain acceptable rigidity for the cannula body. In some implementations, the outer diameter of the reinforcing outer layer is larger than the average outer diameter of the middle section of the cannula. In certain implementations, the outer diameter of the middle section of the cannula is approximately 2Fr to approximately 7Fr, and the outer diameter of the reinforcing section of the cannula is approximately 3Fr to approximately 8Fr. In other implementations, the outer diameter of the middle section of the cannula is approximately 3Fr to approximately 6Fr, and the outer diameter of the reinforcing section of the cannula is approximately 4Fr to approximately 7Fr. Morphologically, the outer diameter of the middle section of the cannula is approximately 4Fr to 5Fr, while the outer diameter of the reinforced section of the cannula is approximately 5Fr to 6Fr.

[0022] In a particular implementation, the intermediate portion of the cannula is configured to have an inner layer, a coil, and an outer layer, and the reinforced portion of the cannula is an extension of the cannula from the intermediate portion, further including a thermoformed outer end reinforcement layer on one or both of the end regions of the cannula.

[0023] Methods for manufacturing cannulas having an inner layer and a reinforced end region are also being considered. In one implementation, the cannula is manufactured by the steps of: thermoforming the inner layer on a mandrel; arranging a shape memory coil across the outer diameter of the inner layer; and thermoforming the outer layer of the cannula on the inner layer and the coil of the cannula so as to extend along the length of the cannula. The outer end reinforcement layer is then thermoformed to extend over the outer layer of the cannula at the proximal end of the cannula. The thermoformed outer end reinforcement layer forms a reinforced section of the cannula between the cannula and the pump housing. The thermoformed outer end reinforcement layer may be configured to help prevent separation between the pump housing and the cannula during percutaneous insertion of the intravascular blood pump system into the patient's body. In addition, the reinforced section of the cannula is configured to increase the rigidity of the cannula at the interface between the cannula and the pump housing. In some implementations, the reinforced portion of the cannula has approximately 1.5 to 5.5 times the rigidity of the middle portion of the cannula. In other implementations, the reinforced portion of the cannula has approximately 2 to 5 times the rigidity of the middle portion of the cannula. In further implementations, the reinforced portion of the cannula has approximately 3 to 4 times the rigidity of the middle portion of the cannula. In a specific implementation, the reinforced portion of the cannula has approximately 3.5 times the rigidity of the middle portion of the cannula. Another implementation A method for manufacturing a cannula for use in a blood pump assembly comprises a pump housing of the pump assembly configured to at least partially enclose a rotor, and a cannula bonded to an inlet cage of the pump assembly. In such an implementation, the method further includes the steps of bonding the inlet cage to the distal end of the cannula and bonding the pump housing to the proximal end of the cannula. In a further implementation, at least one of the steps of bonding the inlet cage to the distal end of the cannula and bonding the pump housing to the proximal end of the cannula includes the steps of applying epoxy to the components to be bonded and thermally curing the epoxy.

[0024] In a particular implementation configuration, the process of thermoforming the inner layer involves placing the inner extruded sleeve on a mandrel and placing the first heat-shrinkable tube around the inner extruded sleeve. Next, the heat shrink tubing and the inner extrusion sleeve are heated to soften the sleeve and allow the heat shrink tubing to exert a compressive force on the sleeve in the direction of the mandrel. Then, the first heat shrink tubing is removed.

[0025] In other configurations, the process of thermoforming the outer layer involves placing an outer extruded sleeve containing the outer material on top of the inner layer and coil, followed by a second heat-shrinkable tube around the outer extruded sleeve. The process includes the step of positioning the tube. The heat shrink tube and the outer extruded sleeve are then subjected to the process of softening the sleeve and applying pressure to the second heat shrink tube relative to the sleeve in the direction of the inner layer and coil. The coil is heated to apply a compressive force and embed it into the outer material. Subsequently, the second The heat shrink tubing is removed. [Brief explanation of the drawing]

[0026] The other objectives and benefits mentioned above will become clear when the following detailed explanation is considered in conjunction with the attached drawings. In the drawings, similar reference numerals refer to the same parts throughout.

[0027] [Figure 1] This figure shows an exemplary blood pump assembly having a thermoformed outer end reinforcing layer at its proximal end, according to the aspect of the present disclosure. [Figure 2] This is an exemplary cross-sectional view showing a cannula for use in a blood pump assembly having a thermoformed outer end reinforcement layer, according to a aspect of the present disclosure. [Figure 3] This figure shows an exemplary blood pump assembly having two thermoformed outer end reinforcement layers according to a aspect of the present disclosure. [Figure 4] This figure shows an exemplary method for manufacturing a reinforced cannula according to the aspects of this disclosure. [Modes for carrying out the invention]

[0028] Detailed explanation To provide an overall understanding of the systems, methods, and apparatus disclosed herein, specific exemplary implementations are described. While the implementations and features described herein are specifically described in relation to use in connection with blood pump assemblies, it will be understood that the teachings may be adapted and applied to other pumps and other types of medical devices.

[0029] Figure 1 shows a pump 102 equipped with a motor 106 and a rotor 104, a pump housing 108, and a remote An exemplary blood pump having a catheter 110 with a proximal end 112, a cannula 114 having a proximal end 116, a distal end 118, an intermediate portion 120, a length 124, a thermoformed inner layer 126, a coil 128, an inner layer outer diameter 130, a thermoformed outer layer 132, a thermoformed outer end reinforcing layer 134, and a non-traumatic extension 136. The pump assembly 100 is shown. The rotor 104 of the pump 102 has at least one blade (not shown) for transporting fluid through the pump 102. The pump housing 108 surrounds at least one blade of the rotor 104. The proximal end 116 of the cannula 114 is connected to the pump housing 108, and the distal end 118 of the cannula 114 is connected to a blood inflow cage 122 which is itself connected to a flexible non-traumatic extension 136. The extension 136 allows the pump 102 to enter the patient When positioned, it helps stabilize the pump 102 by functioning as a rectifying region. It can stand upright. In some implementations, the extension 136 is a pigtail.

[0030] The cannula 114 may have the same structure as shown below with respect to Figure 2. In that regard, the cannula 114 of Figure 1 comprises a thermoformed inner layer 126 extending along the length 124 of the cannula 114, the inner layer 126 containing an inner material. In addition, the cannula 114 comprises a coil 128 containing a shape memory material, positioned on the thermoformed inner layer 126. The cannula 114 has a length 124 It further comprises a thermoformed outer layer 132 extending along it. The outer layer includes an outer material. Thermoformed The thermoformed outer end reinforcement layer 134 extends over the outer layer of the cannula 114 at the proximal end 116 of the cannula 114. The thermoformed outer end reinforcement layer 134 contains reinforcing material. Furthermore, the thermoformed outer end The reinforcing layer 134 provides further stability to the joint between the cannula 114 and the pump housing 108. provide.

[0031] In some configurations, the thermoformed outer end reinforcement layer 134 has at least twice the rigidity of the middle portion 120 of the cannula 114. In other configurations, the thermoformed outer end reinforcement layer 134 The cannula 114 has approximately 1.5 to 5.5 times the rigidity of the intermediate portion 120. In other configurations, the thermoformed outer end reinforcing layer 134 has approximately 2 to 5 times the rigidity of the intermediate portion 120 of the cannula 114. In a further implementation, the thermoformed outer end reinforcement layer 134 has approximately 3 to 4 times the rigidity of the intermediate portion 120 of the cannula 114. In a specific implementation, the thermoformed outer end reinforcement Layer 134 has approximately 3.5 times the rigidity of the intermediate portion 120 of the cannula 114.

[0032] As mentioned above, in certain mounting configurations, the inner material has a hardness of approximately 45D to 65D. In other mounting configurations, the inner material has a hardness of approximately 50D to 60D. In further mounting configurations, the inner material has a hardness of approximately 55D. In some mounting configurations, the outer material has a hardness of approximately 75A to 95A. It has hardness. In other mounting configurations, the outer material has a hardness of approximately 80A to 90A. In further mounting configurations, the outer material has a hardness of approximately 85A. In specific mounting configurations, the reinforcing material is It has a hardness of approximately 45D to 65D. In other mounting configurations, the reinforcing material has a hardness of approximately 50D to 60D. In further implementations, the reinforcing material has a hardness of approximately 55D. In specific implementations, The hardness of the inner material and the hardness of the reinforcing material are equal or approximately equal.

[0033] The stiffness ratio of the cannula's reinforced and intermediate sections can be adjusted to produce a desired stiffness profile along the length of the cannula. The stiffness ratio can be adjusted by incorporating one or more thermoformed outer end reinforcement layers of varying stiffnesses. The thermoformed outer end reinforcement layer may contain a material that has higher rigidity than the middle portion of the cannula. The rigidity ratio can be further adjusted by incorporating materials with various rigidities that fall within the above range. In addition, the shape of the thermoformed outer end reinforcement layer can also be adjusted to achieve a desired rigidity ratio. For example, thermoformed outer end reinforcement layer 134 The outer edge reinforcement layer 134 may have a radial thickness of approximately 0.05 mm to approximately 0.15 mm. In certain mounting configurations, the radial thickness of the thermoformed outer edge reinforcement layer 134 is less than approximately 0.1 mm. In addition, the thermoformed outer edge reinforcement layer 134 may have various lengths. In certain mounting configurations, the length of the thermoformed outer edge reinforcement layer 134 is approximately 1 cm to approximately 3 cm. In other mounting configurations, the length of the thermoformed outer edge reinforcement layer 134 is approximately 2 cm. In some mounting configurations, the length of the thermoformed outer edge reinforcement layer 134 is approximately 3 mm to approximately 9 mm. In certain mounting configurations, the thermoformed The length of the formed outer end reinforcement layer 134 is approximately 5 mm to 7 mm. In other mounting configurations, it is thermoformed. The length of the outer end reinforcing layer 134 is approximately 6 mm. Generally, different procedures requiring different insertion methods and angles may require cannulas with a specific stiffness profile along the length of the cannula. For example, femoral insertion of a blood pump assembly into an obese patient may suffer from torsion because the blood vessel is deeper relative to the insertion point than in a low-weight patient. In such cases, it may be desirable to increase the reinforcement of the distal and proximal ends of the cannula inserted in procedures on obese patients.

[0034] Figure 2 shows a blood pump having a thermoformed outer end reinforcement layer, similar to cannula 114 in Figure 1. Figure 2 shows an exemplary longitudinal section of a cannula 200 for use in assembly. The cannula 200 in Figure 2 consists of an inner layer 202, a coil 204, an outer layer 206, and a thermoformed outer end reinforcement layer 208. It has a proximal end 210, an intermediate portion 212, and a distal end 214. The inner layer 202 has an outer diameter 216. The inner layer 202 includes an inner material. Similarly, the outer layer 206 includes an outer material. In some configurations, the inner material is polyurethane. In some configurations, the outer material is polyurethane. In such cases, the polyurethane of the inner and / or outer material is poly It may contain ether or polyester. Coil 204 contains shape memory material and is placed on top of inner layer 202. The shape memory material is nitinol or copper-aluminum alloy. The thermoformed outer end reinforcement layer 208 extends over the outer layer 206 at the proximal end 210 of the cannula 200. The thermoformed outer end reinforcement layer 208 contains reinforcing material and forms a reinforced section where the cannula 200 is connected, for example, to a pump housing (e.g., the pump housing 108 in Figure 1) or near it.

[0035] In some configurations, the thermoformed outer end reinforcement layer 208 has approximately 1.5 to 5.5 times the rigidity of the middle portion 212 of the cannula 200. In other configurations, the thermoformed outer end reinforcement layer 208 has approximately 2 to 5 times the rigidity of the middle portion 212 of the cannula 200. In further configurations, the thermoformed outer end reinforcement layer 208 has approximately 3 to 4 times the rigidity of the middle portion 212 of the cannula 200. In certain implementations, the thermoformed outer end reinforcement layer 208 has approximately 3.5 times the rigidity of the middle portion 212 of the cannula 200. At least one advantage of the various rigidity ratios of the thermoformed outer end reinforcement layer 208 and the middle portion 212 is that it prevents the serpentine structure of the vascular structure traversed by the cannula during treatment. Depending on the procedure, a cannula with a specific stiffness profile can be selected.

[0036] To obtain the desired stiffness profile along the length of the cannula 200, these elements By changing the shape of one or both, the thermoformed outer end of the cannula 200 is reinforced. The stiffness ratio of layer 208 and the intermediate portion 212 can be adjusted. For example, the stiffness of the thermoformed outer end reinforcement layer 208 can be increased by increasing the radial thickness of the thermoformed outer end reinforcement layer 208. In addition, by decreasing the radius of the intermediate portion 212, The stiffness of the intermediate section 212 can also be made lower than that of the thermoformed outer end reinforcement layer 208. Furthermore, the stiffness ratio of the intermediate section 212 and the thermoformed outer end reinforcement layer 208 can be adjusted by changing the outer diameter 216 of the inner layer 202. For example, increasing the outer diameter 216 of the inner layer 202 while maintaining the same thickness of the inner layer 202 and the same outer diameter of the outer layer 206 will result in the material within the bending intermediate section 212 being... As the amount of material decreases, the rigidity of the intermediate section 212 decreases. Conversely, if the outer diameter 216 of the inner layer 202 is reduced while maintaining the same thickness of the inner layer 202 and the same outer diameter of the outer layer 206, the amount of material in the bending intermediate section 212 increases, thus increasing the rigidity of the intermediate section 212. In addition, the rigidity ratio between the intermediate section 212 and the thermoformed outer end reinforcing layer 208 can be adjusted by incorporating materials with various levels of rigidity. It can also be adjusted. The rigidity of the intermediate portion 212 of the cannula 200 and the thermoformed outer end reinforcing layer 208. At least one advantage of being able to adjust the ratio is that it is particularly suitable for a given treatment. The stiffness profile can be implemented along the length of the 200mm cannula.

[0037] Figure 3 shows a pump 302 equipped with a motor 306 and a rotor 304, a pump housing 308, and a remote A catheter 310 having a proximal end 312, and a thermoformed inner layer 326, a coil 328, an inner layer outer diameter 330, and a thermoformed outer layer 332. An exemplary blood pump having a cannula 314, a proximal thermoformed outer end reinforcement layer 334, a distal thermoformed outer end reinforcement layer 336, a non-traumatic extension 338, and an inflow cage 322. This shows Swertia japonica 300. Similar to the thermoformed outer edge reinforcement layer 134 in Figure 1, the proximal thermoformed The outer end reinforcing layer 334 extends over the outer layer of the cannula 314 at the proximal end 316 of the cannula 314 and contains reinforcing material. The proximal thermoformed outer end reinforcing layer 334 can provide further stability to the cannula 314 at or near the interface between the cannula 314 and the pump housing 308. Similarly, the distal thermoformed outer end reinforcing layer 336 also extends over the outer layer of the cannula 314 at the distal end 318 of the cannula 314 and contains the same reinforcing material as used for the proximal thermoformed outer end reinforcing layer 334. Includes direct or different reinforcing materials. The distal thermoformed outer end reinforcing layer 336 is cannula Further stability to the cannula 314 at or near the interface between the cannula 314 and the inflow cage 322 It can be provided.

[0038] The proximal thermoformed outer end reinforcement layer 334 has an outer diameter 342, and the intermediate portion 320 has an outer diameter 344. In some configurations, the outer diameter 344 of the intermediate portion 320 is smaller than the outer diameter 342 of the proximal thermoformed outer end reinforcement layer 334. Similarly, the distal thermoformed outer end reinforcement layer 336 also has an outer diameter 346. In some configurations, the outer diameter 344 of the intermediate portion 320 is smaller than the outer diameter 346 of the distal thermoformed outer end reinforcement layer 334.

[0039] In some implementations, the proximal thermoformed outer edge reinforcing layer 334 and the distal thermoformed At least one of the outer end reinforcing layers 336 is approximately 1.5 to 5.5 times the length of the middle portion 320 of the cannula 314. It has twice the rigidity. In other implementations, the proximal thermoformed outer end reinforcing layer 334 and the distal At least one of the thermoformed outer end reinforcing layers 336 has about 2 to 5 times the rigidity of the middle portion 320 of the cannula 314. In a further implementation, at least one of the proximal thermoformed outer end reinforcing layer 334 and the distal thermoformed outer end reinforcing layer 336 has about 3 to 4 times the rigidity of the middle portion 320 of the cannula 314. In a specific implementation, the proximal thermoformed outer end reinforcing At least one of layer 334 and the distal thermoformed outer end reinforcing layer 336 of the cannula 314 The intermediate section 320 has approximately 3.5 times the rigidity. As mentioned above, the rigidity ratio of the reinforced section and the intermediate section of the cannula can be adjusted to obtain a desired rigidity profile along the length of the cannula by changing the shape and material of the reinforced section and the intermediate section of the cannula. As already stated, different procedures requiring different insertion methods and insertion angles may require cannulas with different rigidity profiles.

[0040] Figure 4 shows an exemplary method 400 for manufacturing a cannula. The cannula is, for example, shown in Figure 1~ It may be any of the cannulas described above in relation to Figure 3. Method 400 first includes step 402 in which an inner layer including the inner material, inner diameter, and outer diameter is thermoformed on a mandrel. Subsequently, Step 404 includes arranging a shape memory coil across the outer diameter of the inner material. Then, Step 406 includes thermoforming an outer layer onto the coil and inner layer, the outer layer being the cannula It is configured to extend along its length. The outer layer includes the outer material.

[0041] Step 408 involves thermoforming the outer end reinforcement layer so that it extends over and covers the outer layer at the end of the cannula. This includes the following: The outer end reinforcement layer comprises a reinforcing material and forms a reinforced section of the cannula. For example, the reinforcing material may be applied to the proximal end of the cannula as shown in Figures 1 and 2 and configured to increase the rigidity of the cannula at or near the interface between the cannula and the part of the pump to which the proximal end of the cannula is joined (e.g., between the cannula and the pump housing). In such a case, this method may further include the step of joining the thermoformed outer end reinforcement layer to the pump housing of the blood pump assembly. Similarly, the reinforcing material may be as shown in Figure 3 As shown, it may be applied to the distal end of the cannula and configured to increase the rigidity of the cannula at or near the interface between the cannula and the pump portion to which the distal end of the cannula is joined (e.g., between the cannula and the inflow cage). In such a case, the method may further include the step of joining a thermoformed outer end reinforcing layer to the inflow cage of the blood pump assembly.

[0042] In some configurations, the thermoformed outer end reinforcement layer has approximately 1.5 to 5.5 times the rigidity of the middle section of the cannula in the blood pump assembly. In other configurations, the thermoformed outer end reinforcement layer has approximately 2 times the rigidity of the middle section of the cannula in the blood pump assembly. It has approximately five times the rigidity. In certain mounting configurations, the thermoformed outer edge reinforcement layer is used in blood pumps. The assembly has approximately 3 to 4 times the rigidity of the intermediate section of the cannula. In a further implementation, the thermoformed outer end reinforcement layer has approximately 3.5 times the rigidity of the intermediate section of the cannula of the blood pump assembly. The thermoformed outer end reinforcement layer is made of epoxy that hardens. By using this method, it can be joined to the pump housing or inlet cage.

[0043] As mentioned above, the process of thermoforming the inner layer involves placing the inner extruded sleeve containing the inner material onto the mandrel, and subsequently placing the first heat-shrinkable tube around the inner extruded sleeve. The process includes the following steps: The heat shrink tubing and inner extrusion sleeve are then heated to soften the sleeve and allow the heat shrink tubing to apply a compressive force to the sleeve in the direction of the mandrel. The first heat shrink tubing is then removed. Similarly, the process of thermoforming the outer layer is carried out. The process also includes the steps of placing an outer extruded sleeve, including the outer material, on top of the inner layer and coil, and subsequently placing a second heat-shrinkable tube around the outer extruded sleeve. The heat-shrink tubing and outer extrusion sleeve are heated to soften the sleeve and apply compressive force to the heat-shrink tubing relative to the sleeve in the direction of the inner layer and coil, thereby embedding the coil into the outer material. Subsequently, the second heat-shrink tubing is removed.

[0044] The above description is merely illustrative of the principles of this technology. Therefore, the apparatus and methods described herein can be implemented in forms other than those described, provided for illustrative purposes only, not limitation.

[0045] In addition, the features of the disclosure are (multiple) features of one or more other features described herein. They may be implemented as any combination or partial combination (including dependent and partial combinations of numbers). The various features described or illustrated above, including any of their components, may be combined or integrated into other systems. Furthermore, certain features may be omitted or not implemented without deviating from the spirit of this art.

Claims

1. A pump having a pump housing and rotor, and configured to be operated by a motor, An elongated catheter having a distal end connected to the motor or the pump housing, The pump housing has a proximal end that connects to the distal end, and at least one distal opening. A cannula having a distal end, having a longitudinal length, A thermoformed inner layer, extending along the longitudinal length of the cannula and including an inner material, A coil having a shape memory material and arranged across the outer diameter of the inner layer, A thermoformed outer layer, including an outer material, extends along the longitudinal length above the inner layer and the coil, and The proximal end of the cannula extends over the outer layer and includes the first reinforcing material A thermoformed first outer end reinforcing layer forming a first reinforcing portion of the cannula, wherein the first reinforcing portion of the cannula has at least twice the rigidity of the intermediate portion, and the intermediate portion is distal to the first reinforcing portion of the cannula. The cannula and An intravascular blood pump system, including one.

2. The system according to claim 1, wherein the first reinforcing portion of the cannula has at least four times the rigidity of the intermediate portion of the cannula.

3. A thermoformed second outer end reinforcing layer is positioned at the distal end of the cannula. Including, the second outer end reinforcing layer includes a second reinforcing material and the second reinforcement of the cannula A portion is formed, and the intermediate portion is located proximal to the second reinforcing portion of the cannula. The system described in item 1 or 2.

4. The system according to claim 3, wherein the first reinforcing material is the same as the second reinforcing material.

5. The system according to claim 3, wherein the distal end of the cannula is connected to the inflow cage.

6. The thickness of the first outer end reinforcing layer tapers distally, any one of claims 1 to 5 The system described.

7. The thickness of the second outer end reinforcing layer tapers distally, any one of claims 3 to 5 The system described.

8. The system according to any one of claims 1 to 7, wherein the inner material is polyester polyurethane.

9. At least one of the outer material or the first reinforcing material is polyetherpolyurethane The system according to any one of claims 1 to 7.

10. The system according to any one of claims 1 to 9, wherein the inner material has a hardness in the range of about 45D to 65D.

11. The outer material has a hardness in the range of approximately 75A to 95A, as described in any one of claims 1 to 10. The system.

12. The system according to any one of claims 1 to 11, wherein the first reinforcing material has a hardness in the range of about 55D to 75D.

13. The hardness of the inner material and the hardness of the first reinforcing material are equal or approximately equal. The system according to any one of claims 1 to 12.

14. The coil is embedded in the outer layer, according to any one of claims 1 to 13. Tem.

15. The system according to any one of claims 1 to 14, wherein the shape memory material comprises at least one of nitinol or a copper-aluminum alloy.

16. The outer diameter of the intermediate portion of the cannula is equal to the outer diameter of the first reinforcing portion of the cannula. Smaller than, The intermediate portion of the cannula includes the inner layer, the coil, and the outer layer, The first reinforcing portion of the cannula is the inner layer, the coil, the outer layer, and the front The first outer end reinforcing layer is included, The system according to any one of claims 1 to 15.

17. The system according to any one of claims 1 to 16, wherein the cannula is positioned within the patient's heart such that it extends beyond the aortic valve of the patient's heart, the distal end of the cannula is in the left ventricle of the patient's heart, and the proximal end of the cannula is in the aorta of the patient's heart.

18. A method for manufacturing a cannula, including the following steps: A step of thermoforming the inner layer of the cannula onto a mandrel, wherein the inner layer includes an inner material, an inner diameter, and an outer diameter; A step of arranging a shape memory coil across the outer diameter of the inner material; A step of thermoforming the outer layer of the cannula onto the inner layer and the coil, wherein the outer layer extends along the longitudinal length and includes an outer material; and To form the first reinforcing portion of the cannula, the proximal end of the cannula is used to form the anterior A process of thermoforming a first outer end reinforcing layer so as to cover and extend over the outer layer, the crab The process is as follows: the first reinforcing portion of the cannula has at least twice the rigidity of the intermediate portion of the cannula, and the intermediate portion is distal to the first reinforcing portion of the cannula.

19. The method according to claim 18, further comprising the step of joining the cannula to the pump housing and inflow cage of an intravascular blood pump, wherein the pump housing is configured to at least partially surround the rotor.

20. The method according to claim 19, wherein the distal end of the cannula is joined to the inflow cage and the proximal end of the cannula is joined to the pump housing.

21. The distal end of the cannula is joined to the inflow cage. Applying epoxy to the interface between the distal end of the cannula and the inflow cage, and The epoxy is then heat-cured. The method according to claim 20, including the method described in claim 20.

22. The proximal end of the cannula is joined to the pump housing. Applying epoxy to the interface between the proximal end of the cannula and the pump housing, and The epoxy is then heat-cured. The method according to claim 20, including the method described in claim 20.

23. The process of thermoforming the inner layer is as follows: Placing the inner extruded sleeve containing the inner material on the mandrel, The first heat-shrinkable tube is positioned around the inner extrusion sleeve. Heating the inner extruded sleeve and the heat shrink tube in order to soften the sleeve and to apply force to the sleeve in the direction of the mandrel by the heat shrinkage, Remove the first heat shrink tube. The method according to any one of claims 18 to 22, including the method described in any one of claims 18 to 22.

24. The process of thermoforming the outer layer is as follows: To place the outer extruded sleeve, which includes the outer material, on top of the inner layer and the coil, A second heat-shrinkable tube is placed around the outer extrusion sleeve. To soften the sleeve and to apply force to the sleeve in the direction of the inner layer and the coil by heat shrinkage, the sleeve and the heat shrink tube are heated to embed the coil into the outer material, and Remove the second heat shrink tube. The method according to any one of claims 18 to 23, including the method described in any one of claims 18 to 23.

25. The method according to any one of claims 18 to 24, wherein the first reinforcing portion of the cannula has at least four times the rigidity of the intermediate portion of the cannula.

26. To form the second reinforcing portion of the cannula, the distal end of the cannula The process further includes a step of thermoforming a second outer end reinforcing layer so as to cover and extend over the outer layer, Any of claims 18 to 25, wherein the intermediate portion is located proximal to the second reinforcing portion of the cannula. The method described in item 1.

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