Alignment tool for aligning a heart valve with a delivery system

Abstract

An alignment tool for loading a stent includes a plurality of arms, each arm having a shaft with an engagement region movable between a first angled configuration relative to the shaft and a second straight configuration, each engagement region having an inner surface shaped to mate with a stent holder. The alignment tool further includes a locking ring having a lumen configured to receive the plurality of arms, the locking ring configured to slide on the arms between a first retracted position in which the engagement region of each arm is exposed and biased to the angled configuration, and a second locked position in which the locking ring extends over at least a portion of the engagement region and compresses the engagement region into the straight configuration. The alignment tool may also include a spring configured to bias the locking ring into the locked position.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to medical devices, and more particularly to devices for aligning a heart valve during loading into a delivery system, and methods of using such medical devices. [Background technology]

[0002] A wide variety of medical devices have been developed for medical applications, including, for example, prosthetic heart valves for repairing or replacing diseased heart valves. The prosthetic heart valves must be precisely aligned when loaded into a delivery system. Each of the known medical devices and methods has certain advantages and disadvantages. There is a continuing need to provide alternative medical devices and alternative methods for manufacturing and using medical devices. Summary of the Invention

[0003] The present disclosure provides design, material, manufacturing method, and use alternatives for medical devices. An exemplary alignment tool for loading a stent includes a plurality of arms, each having a shaft with a first end including an engagement region and an opposite second end, wherein each engagement region is movable between a first angled configuration and a second straight configuration relative to the shaft, a locking ring having a lumen configured to receive the plurality of arms, the locking ring configured to slide over the arms between a first retracted position in which the engagement region of each arm is exposed and biased toward the angled configuration, and a second locked position in which the locking ring extends over at least a portion of the engagement region and compresses the engagement region into the straight configuration, and a spring configured to bias the locking ring into the locked position.

[0004] Alternatively or additionally to the above embodiments, each engagement region has a longitudinal slit extending from the free end of the engagement region toward the second end of the arm, the longitudinal slit allowing the engagement region to expand when in the angled configuration.

[0005] Alternatively or additionally to any of the above embodiments, each arm includes a cutout region on a side of the engagement region, the cutout regions of adjacent arms forming an opening when the adjacent arms are in a straight configuration, the opening being configured to receive a stent loop.

[0006] Alternatively or additionally to any of the above embodiments, the locking ring includes at least one magnifying lens configured to be positioned over the opening. Alternatively or additionally to any of the above embodiments, the locking ring is transparent.

[0007] Alternatively or additionally to any of the above embodiments, each arm has an enlarged portion at the second end of the shaft, the enlarged portion extending radially outward further than the diameter of the spring.

[0008] Alternatively or additionally to any of the above embodiments, each arm has a raised transverse rib spaced from the enlarged portion. Alternatively or additionally to any of the above embodiments, the locking ring includes a rear shoulder extending into the lumen, the rear shoulder configured to engage the transverse rib when the locking ring is in the second, locked position.

[0009] Alternatively or additionally to any of the above embodiments, the locking ring includes a forward shoulder extending into the lumen, the forward shoulder configured to slide along the arms and move the engagement regions of the arms from an angled configuration to a straight configuration.

[0010] Alternatively or additionally to any of the above embodiments, each of the plurality of arms is identical. Alternatively or additionally to any of the above embodiments, the locking ring has a front end disposed adjacent the engagement area of ​​the arm and an opposite rear end, the locking ring having an enlarged, flared rear end having a diameter greater than the diameter of the front end.

[0011] Alternatively or additionally to any of the above embodiments, each engagement region includes an inner surface shaped to mate with the stent holder. Alternatively or additionally to any of the above embodiments, at least at the second ends of the plurality of arms, a side edge of each arm abuts a side edge of an adjacent arm to define a channel extending through the plurality of arms.

[0012] Alternatively or additionally to any of the above embodiments, the side edges of each arm abut the side edges of adjacent arms along the length of each shaft in all areas except the engagement area of ​​each arm.

[0013] Another exemplary alignment tool for loading a stent onto a stent holder includes a plurality of arms, each having a shaft with a first end including an engagement region and an enlarged second end, wherein each engagement region is movable between a first angled configuration relative to the shaft and a second straight configuration, and wherein a side edge of each arm abuts a side edge of an adjacent arm at least at the enlarged second end to define a channel; a locking ring having a lumen configured to receive the shafts of the plurality of arms, the locking ring configured to slide on the arms between a first retracted position in which the engagement region of each arm is exposed and biased toward the angled configuration, and a second locked position in which the locking ring extends over at least a portion of the engagement region and compresses the engagement region into the straight configuration; and a spring configured to bias the locking ring into the locked position.

[0014] Alternatively or additionally to the above embodiments, each arm includes a notch region on a side of the engagement region, the notch regions of adjacent arms forming an opening when the adjacent arms are in a straight configuration, the opening being configured to receive a stent loop.

[0015] Alternatively or additionally to any of the above embodiments, each arm has a raised cross rib spaced from the enlarged portion, the raised cross ribs on all the arms collectively forming a raised ring.

[0016] Alternatively or additionally to any of the above embodiments, the locking ring includes a rear shoulder extending into the lumen, the rear shoulder configured to engage the raised ring when the locking ring is in the second, locked position.

[0017] Alternatively or additionally to any of the above embodiments, the locking ring includes a forward shoulder extending into the lumen, the forward shoulder configured to slide along the arms and move the engagement regions of the arms from an angled configuration to a straight configuration.

[0018] An exemplary method of loading a stent onto a stent holder using an alignment tool includes inserting a stent having a plurality of terminal loops into a stent holder having a plurality of pins on which the terminal loops are disposed, and placing the alignment tool over the stent holder, the alignment tool having a plurality of arms each having a shaft having a first end including an engagement region and an opposite second end, each engagement region being movable between a first angled configuration and a second straight configuration relative to the shaft, each engagement region having an inner surface shaped to mate with the stent holder, each arm including a notched region on a side of the engagement region, the notched regions of adjacent arms being shaped to receive the stent loops and pins. a locking ring having a lumen configured to receive the plurality of arms, the locking ring being configured to slide over the arms between a first retracted position in which an engagement region of each arm is exposed and biased into an angled configuration forming a mounting zone for receiving a stent holder, and a second, locked position in which the locking ring extends over at least a portion of the engagement region and compresses the engagement region into a straight configuration in which the stent holder is secured; and a spring configured to bias the locking ring into the locked position; and an alignment tool is placed over the stent holder with the locking ring in the first retracted position such that pins on the stent holder are received within the openings of the engagement regions. The method further includes the steps of releasing and moving the locking ring to a locked position, moving the engagement region of each arm to its straight configuration, advancing the stent to move one stent loop onto each pin, compressing the stent onto the stent holder, moving the locking ring on the alignment tool to a retracted position to release the stent holder, and removing the alignment tool from the stent holder and stent.

[0019] The above summary of some embodiments, aspects, and / or examples is not intended to describe each embodiment or every implementation of the present disclosure. The following figures and detailed description more particularly exemplify these embodiments. [Brief explanation of the drawings]

[0020] The present disclosure may be more fully understood from the following detailed description of various embodiments considered in conjunction with the accompanying drawings, in which: [Figure 1A] 1 shows the stent loop positioned adjacent to the pins on the stent holder prior to compression. [Figure 1B] FIG. 1B shows the stent holder and stent of FIG. 1A in a compressed state with the stent loops precisely aligned on the pins. [Figure 1C] 1B shows the stent holder and stent of FIG. 1A with the stent loop offset and compressed next to the pin. [Figure 2] FIG. 1 is a perspective view of an exemplary alignment tool in an open position. [Figure 3] FIG. 3 is a perspective view of the alignment tool of FIG. 2 in a closed position. [Figure 4] FIG. 3 is an exploded view of the alignment tool of FIG. 2. [Figure 5] 3 is a partial cutaway view of the alignment tool of FIG. 2 in an open position. [Figure 6] 3 is a partial cutaway view of the alignment tool of FIG. 2 in a closed position. [Figure 7] 3 is a partial cutaway view of the alignment tool of FIG. 2 in an open position. [Figure 8] 3 is a partial cutaway view of the alignment tool of FIG. 2 in a closed position. [Figure 9] FIG. 3 is an enlarged view of a portion of one arm of the alignment tool of FIG. 2. [Figure 10] 3 is a perspective view of the alignment tool of FIG. 2 with a stent holder inserted therein.

[0021] While aspects of the present disclosure are susceptible to various modifications and alternative forms, specifics of which have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit aspects of the present disclosure to the particular embodiments described. On the contrary, the invention covers all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0022] For the following defined terms, these definitions shall be applied, unless a different definition is given in the claims or elsewhere in this specification. All numerical values ​​are assumed to be modified herein by the term "about," whether explicitly stated or not. The term "about" in the context of numerical values ​​generally refers to a range of numbers that one of ordinary skill in the art would consider equivalent to the recited value (e.g., having the same function or result). In many cases, the term "about" may include numbers that are rounded to the nearest significant figure. Other uses of the term "about" (e.g., in contexts other than numerical values) can be assumed to have their ordinary and customary definition as understood from and consistent with the context of this specification, unless otherwise specified.

[0023] The recitation of numerical ranges by endpoints includes all numbers within that range, inclusive of the endpoints (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5.) While several suitable dimensions, ranges, and / or values ​​for various components, features, and / or specifications are disclosed, one of ordinary skill in the art inspired by this disclosure will understand that the desired dimensions, ranges, and / or values ​​may deviate from those expressly disclosed.

[0024] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term "or" is used generally in its sense including "and / or" unless the content clearly dictates otherwise. For ease of understanding, it should be noted that certain features of the present disclosure may be described in the singular even though those features may be multiple or repeated within a disclosed embodiment. Each instance of a feature may include and / or be encompassed by a singular disclosure unless expressly stated otherwise. For purposes of simplicity and clarity, not all elements of the present disclosure are necessarily shown in every figure or described in detail below. However, it will be understood that the following description may apply equally to any and / or all components present in more than one instance unless expressly stated otherwise. Moreover, for clarity, not every instance of some elements or features is shown in every figure.

[0025] Relative terms such as "proximal," "distal," "advance," "retract," and variations thereof may generally be considered with respect to the positioning, orientation, and / or movement of various elements relative to a user / operator / manipulator of the device, with "proximal" and "retract" indicating or referring to being closer to or toward the user, and "distal" and "advance" indicating or referring to being farther from or away from the user. In some cases, the terms "proximal" and "distal" may be assigned arbitrarily to facilitate understanding of the present disclosure, and such instances will be readily apparent to those skilled in the art. Other relative terms such as "upstream," "downstream," "inflow," and "outflow" refer to the direction of fluid flow within a body lumen, a lumen such as a blood vessel, or within a device.

[0026] The term "range" may be understood to mean the maximum measure of a stated or specified dimension, unless the range or dimension in question is preceded by or identified as "minimum," which may be understood to mean the minimum measure of the stated or specified dimension. For example, an "outer range" may be understood to mean the largest outer dimension, a "radial range" may be understood to mean the largest radial dimension, a "longitudinal range" may be understood to mean the largest longitudinal dimension, and so on. Each instance of "range" may be different (e.g., axially, longitudinally, laterally, radially, circumferentially, etc.) and will be apparent to one of ordinary skill in the art from the context of the particular usage. Generally, a "range" may be considered the largest possible dimension measured according to the intended application, while a "minimum range" may be considered the smallest possible dimension measured according to the intended application. In some cases, a "range" may generally be measured orthogonally in a plane and / or cross-section, but may also be measured differently, such as, but not limited to, angularly, radially, circumferentially (e.g., along an arc), etc., as will become apparent from the particular context.

[0027] The terms "monolithic" and "unitary" shall generally refer to one or more elements made from or consisting of a single structure or base unit / element. Monolithic and / or unitary elements shall exclude structures and / or features made by assembling or otherwise joining together multiple separate elements.

[0028] It should be noted that references herein to "an embodiment," "some embodiments," "other embodiments," etc., indicate that the described embodiment may include a particular feature, structure, or characteristic, but that not all embodiments necessarily include that particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in connection with an embodiment, it would be within the knowledge of one of ordinary skill in the art to effect that particular feature, structure, or characteristic in connection with other embodiments, whether or not explicitly described, unless expressly stated otherwise. That is, it is contemplated that various individual elements described below, even if not explicitly shown in specific combinations, can be combined or arranged with one another to form other or additional embodiments, or to complement and / or enhance the described embodiments, as will be understood by one of ordinary skill in the art.

[0029] For purposes of clarity, certain distinguishing numerical nomenclature (e.g., first, second, third, fourth, etc.) may be used throughout the description and / or claims to name and / or distinguish various description and / or claim features. It should be understood that the numerical nomenclature is not intended to be limiting and is merely exemplary. In some embodiments, variations and departures from previously used numerical nomenclature may be made for brevity and clarity. That is, a feature identified as a "first" element may later be referred to as a "second" element, a "third" element, etc., or may be omitted entirely, and / or a different feature may be referred to as the "first" element. The meaning and / or name in each instance will be apparent to one of ordinary skill in the art.

[0030] The following description should be read with reference to the drawings, which are not necessarily to scale, and similar elements in different drawings are numbered the same. The detailed description and drawings are intended to illustrate, but not limit, the present disclosure. Those skilled in the art will recognize that the various elements described and / or shown can be arranged in various combinations and configurations without departing from the scope of the present disclosure. The detailed description and drawings illustrate exemplary embodiments of the present disclosure. However, for clarity and ease of understanding, not all features and / or elements may be shown in every drawing, but the features and / or elements can be understood to be present regardless unless otherwise specified.

[0031] Current prosthetic heart valves, such as the replacement valve and expandable anchor described in U.S. Pat. No. 8,992,608, must be precisely loaded into a delivery catheter, such as those described in U.S. Pat. Nos. 10,245,145 and 10,682,228 (the disclosures of which are incorporated herein by reference). The prosthetic heart valve may include a looped stent portion that must be compressed and precisely aligned within the delivery catheter immediately prior to implantation. The loading step can be complex and difficult and generally occurs in a catheter lab. Components, including the pins on the stent holder and the loops on the stent, are small, making visually precise alignment difficult to achieve. The difficulties associated with the alignment step increase the risk of valve misloading, with adverse consequences in terms of loading time if misloading is identified and / or clinical outcomes related to suboptimal implant positioning if misloading is not identified. Only one misloading is generally tolerated; after a second misloading, the valve and delivery system must be discarded. The placement of prosthetic heart valves and associated stents is a critical part of the implantation procedure and improvement is desirable.

[0032] Applicants have developed an automated alignment tool that facilitates precise alignment of the stent portion of a prosthetic heart valve with a delivery system, allowing for a smoother preparation and expediting the installation process. Automated alignment of the valve with the delivery system assists individuals with installing the valve, reducing stress and anxiety in a pressurized catheterization lab environment. In some examples, the installed heart valve may be a transcatheter aortic valve replacement (TAVR), such as Boston Scientific's ACURATE™ aortic valve system.

[0033] Figures 1A-1C illustrate the loading of the stent portion of a heart valve onto a delivery device and some potential complications. The loop 5 of the stent portion at the distal end of the valve must be precisely aligned with the pin 7 on the stent holder 9, a component of the delivery system. Figure 1A shows the loop 5, which must be moved to align with the pin 7 on the stent holder 9 before the stent is compressed. The loop and pin are small and difficult to see. For example, the loop may be 1.5 mm and the pin may be 0.5 mm (0.060 in. and 0.020 in., respectively), approximately the size of a ballpoint pen tip, making precise alignment difficult. Figure 1B illustrates the precise alignment of the loop 5 onto the pin 7 and the compression of the stent. A potential complication that can lead to valve loading failure occurs when one of the three valve loops 5 is not aligned with one of the three pins 7 on the stent holder, as shown in Figure 1C. Then, when the valve is compressed by the loading tool 3, it is possible for the valve to be sheathed onto the stent holder 9 without all three loops properly engaging the three pins. Once the device is sheathed, any misalignment can be difficult to see. If this device were deployed in a clinical scenario, valve positioning and coaxial alignment could be compromised. The onus is on the individual loading the valve in the catheterization lab to identify any misalignment, and alignment can therefore be a significant source of stress and anxiety. Even if a problem is identified, the valve loading procedure must be restarted from the beginning, leading to a scenario in which the physician waits for the valve to be loaded and the TAVR procedure is extended.

[0034] As described in more detail below, FIG. 2 illustrates an exemplary alignment tool 100 including multiple arms 110 and a locking ring 150, with the arms 110 in an open position. Each arm 110 may have a first end defining an engagement region 112 and an opposite second end 114. The example illustrated in FIG. 2 includes three arms 110. The alignment tool 100 in FIG. 2 is shown with the locking ring 150 in a retracted position and the engagement regions 112 of the arms 110 in a biased open configuration. The side of each arm 110 within the engagement region 112 may include a cutout region 117 configured to receive a stent loop and a pin, as described in more detail below. FIG. 3 illustrates the alignment tool 100 with the arms 110 in a closed position. The locking ring 150 is in a forward, locked position, the engagement regions 112 of the arms 110 are in a straight configuration, and the cutout regions 117 of adjacent arms 110 form openings 119. In some examples, locking ring 150 may be transparent, which may make it easier for a user to see the alignment of the pins and stent loops within openings 119. In other examples, locking ring 150 may include at least one magnifying lens 155 configured to be positioned over openings 119 to aid in aligning the pins and stent loops. In some examples, a magnifying lens 155 may be positioned over each opening 119 to allow for easier viewing of each stent loop and pin. Alignment tool 100 may include a spring 180 configured to bias locking ring 150 toward the forward, locked position. In other examples, locking ring 150 may move along arms 110 with a friction fit to retain whatever position it is moved to.

[0035] Details of the arms 110 and locking ring 150 are shown in the exploded view of FIG. 4. Each arm 110 may have a shaft 116 having a first end including an engagement region 112 and an opposite second end 114. The engagement region 112 may be movable between a first angled configuration relative to the shaft 116, as shown in FIG. 2, and a second straight configuration, as shown in FIG. 3. The engagement region 112 may be joined to the shaft 116 by a flexible hinge 115. The engagement region 112 may be biased to the angled configuration in which the engagement region 112 extends radially outward from the longitudinal axis of the shaft 116. The engagement region 112 may be moved to a straight configuration in which the engagement region 112 is axially aligned with the shaft 116. Sliding the locking ring 150 over the engagement region 112 provides sufficient force to move the engagement region 112 to the straight configuration, as shown in FIG. 3.

[0036] Each arm 110 may have an enlarged portion 114 at the second end of the shaft 116, the enlarged portion 114 extending radially outward further than the diameter of the spring 180. The enlarged portion 114 of each arm 110 may include ridges or have a textured surface to aid in gripping it during use. Each arm 110 may be a single monolithic piece. In other examples, the engagement region 112 may be formed separately and joined to the shaft 116 in a biased angled configuration. In some examples, the inner surface of each arm 110 may be curved to form a channel 118 when the arms 110 are positioned adjacent to one another. The channel 118 may be sized to receive a portion of a stent holder (not shown). Each arm 110 may also include a raised transverse rib 113 spaced from the enlarged portion 114. In some examples, the structure of all of the multiple arms 110 may be identical. When the arms 110 are positioned adjacent to one another, the transverse ribs 113 on each arm 110 may collectively form a circumferential rib or ring 113. In the illustrated example, the alignment tool 100 includes three arms 110.

[0037] The locking ring 150 may define a lumen 152 configured to receive the arms 110 in sliding engagement, as shown in FIGS. 2 and 3 . In some examples, the locking ring 150 may be formed of two halves secured together over the arms 110, as shown in FIG. 4 . In other examples, the locking ring 150 may be a single monolithic element. The locking ring 150 may be configured to slide over the arms 110 between a first retracted position ( FIG. 2 ), in which the engagement region 112 of each arm 110 is exposed and biased into an angled configuration, and a second locked position ( FIG. 3 ), in which the locking ring 150 extends over at least a portion of the engagement region 112 and compresses the engagement region 112 into a straight configuration. The locking ring 150 may include a rear shoulder 154 and a front shoulder 156 extending into the lumen 152. In some examples, the locking ring 150 may include a recess 158 configured to receive a spring 180.

[0038] 5 and 6 illustrate the sliding movement of locking ring 150 over arms 110 to actuate engagement region 112 between an open configuration (FIG. 5) and a closed configuration (FIG. 6). One arm 110 and half of locking ring 150 are removed in the figures to show details of the internal structure. A channel 118 defined by the inner surface of arm 110 extends through alignment device 100, which is configured to receive a stent holder (not shown). In the open configuration, locking ring 150 is pushed toward enlarged portion 114 of arm 110, compressing spring 180 and moving front end 151 of locking ring 150 to a position rearward of hinge 115, allowing engagement region 112 to move to a biased, angled configuration, as shown in FIG. 5. In some examples, locking ring 150 may have a tapered or flared rear end 153 to aid in gripping and moving locking ring 150 rearward to the open configuration. The flared rear end 153 may have a diameter larger than the diameter of the front end 151 of the lock ring 150. Releasing the lock ring 150 allows the spring 180 to expand, thereby pushing the lock ring 150 forward until the rear shoulder 154 engages the rib 113, as shown in FIG. 6 . The rib 113 may prevent the lock ring 150 from slipping off the arm 110. As the lock ring 150 moves forward, the front shoulder 156 slides along the arm 110, pushing the engagement region 112 downward into a straight configuration in which the engagement region 112 is substantially aligned with the shaft 116. The enlarged portion 114 of the arm 110 may form a rear stop for the spring 180. In some examples, the enlarged portion 114 may include a recess that engages a portion of the spring 180.

[0039] When multiple arms 110 are positioned adjacent to one another with their side edges abutting and inside the locking ring 150, as shown in FIGS. 7 and 8, the side edges of each arm 110 may abut the side edges of adjacent arms 110 along the length of each shaft 116 in all areas except the engagement region 112 of each arm 110, as shown in FIG. 7. In FIGS. 7 and 8, half of the locking ring 150 has been removed to show details of the internal structure. The cutout regions 117 of adjacent arms 110 form openings 119 when the adjacent arms 110 are in a straight configuration, as shown in FIG. 8. The openings 119 may be configured to receive pins on a stent holder and stent loops on a stent portion of a heart valve. In some examples, the openings 119 may have chamfered lead-ins 120 to help guide the stent loops into the openings.

[0040] FIG. 9 is an enlarged view of the engagement region 112 of one arm 110, showing the notched region 117. In some examples, a retention region 121 is formed on the inner surface of the end of the arm 110. The retention region 121 may be shaped to match or fit the shape of the stent holder. The retention region 121 may include an inner protrusion 122 configured to engage a slot on the stent holder to prevent rotation of the stent holder relative to the alignment tool 100. The engagement region 112 may have a longitudinal slit 124 extending from the free end of the engagement region 112 toward the enlarged portion 114 of the arm 110. The longitudinal slit 124 may allow the engagement region 112 to expand when in the angled configuration. Moving the locking ring 150 to the forward locked position may compress the longitudinal slit 124, reducing the inner diameter of the engagement region 112 of the arm around the stent holder.

[0041] The alignment tool 100 may be used to assist a user in aligning terminal stent loops on a stent or prosthetic heart valve with pins on a stent holder. A method of using the alignment tool may include inserting a heart valve or stent having multiple terminal loops into a stent holder having multiple pins onto which the terminal loops are to be placed. Next, as shown in FIG. 10 , the alignment tool 100 described above can be placed over the stent holder 190. The alignment tool 100 may be placed over the stent holder 190 with the locking ring 150 in a first, retracted position so that the pins on the stent holder are received in the openings 119 in the engagement regions 112. The locking ring is released and allowed to move to a locked position, securing the stent holder 190 by moving the engagement regions 112 of each arm to their straight configuration. The stent may then be moved to align the stent loops aligned over the pins. The stent is then compressed onto the stent holder and the locking ring is moved to a retracted position on the alignment tool to release the stent holder. The alignment tool may then be removed from the stent holder and stent, and the stent loading process continues.

[0042] In some embodiments, one or more components of alignment tool 100 (and its variations, systems, or components disclosed herein) may be made from metals, metal alloys, ceramics, zirconia, polymers (some examples of which are disclosed below), metal-polymer composites, combinations thereof, or other suitable materials. Some examples of suitable metals and metal alloys include stainless steels such as 444V, 444L, and 314LV stainless steels; mild steel; nickel-titanium alloys such as linear elastic and / or superelastic nitinol; cobalt chromium alloys, titanium and its alloys, alumina, diamond-like coated (DLC) or titanium nitride coated metals, other nickel alloys such as nickel-chromium-molybdenum alloys (e.g., UNS: N06625, such as INCONEL® 625, HASTELLOY® C-22, etc.), and the like. and UNS:N06022 such as HASTELLOY® C276™, UNS:N10276 such as HASTELLOY® C276™, other HASTELLOY® alloys, etc.), nickel-copper alloys (e.g., UNS:N04400 such as MONEL® 400, NICKELVAC™ 400, NICORROS® 400, etc.), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS:R44035 such as MP35-N™), nickel-molybdenum alloys (e.g., HASTELLOY® ALLOY B2®, UNS: N10665), other nickel-chromium alloys, other nickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-iron alloys, other nickel-copper alloys, other nickel-tungsten or tungsten alloys, etc.; cobalt-chromium alloys; cobalt-chromium-molybdenum alloys (e.g., UNS: R44003, such as ELGILOY®, PHYNOX®); platinum strengthened stainless steel; titanium; platinum; palladium; gold; combinations thereof; the like; or any other suitable material.

[0043] As suggested herein, within the family of commercially available nickel-titanium or Nitinol alloys, there is a category referred to as "linear elastic" or "non-superelastic," which may be chemically similar to traditional shape memory and superelastic species but may exhibit distinct and useful mechanical properties. Linear elastic and / or non-superelastic Nitinol may be distinguished from superelastic Nitinol in that linear elastic and / or non-superelastic Nitinol does not exhibit a substantial "superelastic plateau" or "flag region" in its stress / strain curve as does superelastic Nitinol. Instead, in linear elastic and / or non-superelastic Nitinol, as recoverable strain increases, stress continues to increase in a substantially linear, or somewhat but not necessarily completely linear, relationship, or at least a relationship that is more linear than the superelastic plateau and / or flag region that may be seen in superelastic Nitinol, until plastic deformation begins. Therefore, for purposes of this disclosure, linear elastic and / or non-superelastic Nitinol may also be referred to as "substantially" linear elastic and / or non-superelastic Nitinol.

[0044] Additionally, in some cases, linear elastic and / or non-superelastic nitinol can be distinguished from superelastic nitinol in that linear elastic and / or non-superelastic nitinol can tolerate strains of up to about 2-5% while remaining substantially elastic (e.g., before plastic deformation), while superelastic nitinol can tolerate strains of up to about 8% before plastic deformation. Both of these materials can be distinguished from other linear elastic materials, such as stainless steel (which can also be distinguished based on its composition), which can only tolerate strains of about 0.2-0.44 percent before plastic deformation.

[0045] In some embodiments, linear elastic and / or non-superelastic nickel-titanium alloys are alloys that do not exhibit a martensite / austenite phase change detectable by differential scanning calorimetry (DSC) and dynamic metal thermal analysis (DMTA) analysis over a wide temperature range. For example, in some embodiments, linear elastic and / or non-superelastic nickel-titanium alloys may not exhibit a martensite / austenite phase change detectable by DSC and DMTA analysis over a range of about -60°C to about 120°C. Thus, the mechanical bending properties of such materials may be generally inert to the effects of temperature over this wide temperature range. In some embodiments, the mechanical bending properties of linear elastic and / or non-superelastic nickel-titanium alloys at ambient or room temperature are substantially the same as those at body temperature, e.g., in that they do not exhibit a superelastic plateau and / or flag region. For example, over a wide temperature range, linear elastic and / or non-superelastic nickel-titanium alloys maintain their linear elastic and / or non-superelastic properties and / or characteristics.

[0046] In some embodiments, the linear elastic and / or non-superelastic nickel-titanium alloy may range from about 50 to about 60 weight percent nickel, with the remainder essentially titanium. In some embodiments, the composition ranges from about 54 to about 57 weight percent nickel. One example of a suitable nickel-titanium alloy is FHP-NT alloy, commercially available from Furukawa Techno Material Co., Ltd., Kanagawa Prefecture, Japan. Other suitable materials include ULTANIUM™ (available from Neo-Metrics) and GUM METAL® (available from Toyota). In some other embodiments, a superelastic alloy, such as superelastic nitinol, may be used to achieve desired properties.

[0047] In some embodiments, one or more components of alignment tool 100 (and variations, systems, or components thereof disclosed herein) may be made from or include a polymer or other suitable material. Some examples of suitable polymers include polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), polyoxymethylene (POM, e.g., DELRIN® available from DuPont), polyether block esters, polyurethanes (e.g., Polyurethane 85A), polypropylene (PP), polyvinyl chloride (PVC), polyetheresters (e.g., ARNITEL® available from DSM Engineering Plastics), ether- or ester-based copolymers (e.g., butylene / poly(alkylene ether) phthalates and / or other polyester elastomers such as HYTREL® available from DuPont), polyamides (e.g., DURETHAN® or Elf® available from Bayer), and the like. CRISTAMID™ available from Atochem), elastomeric polyamides, block polyamide / ethers, polyether block amides (PEBA, e.g., available under the trade name PEBAX®), ethylene vinyl acetate copolymer (EVA), silicone, polyethylene (PE), Marlex® high density polyethylene, Marlex® low density polyethylene, linear low density polyethylene (e.g., REXELL®), polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polytrimethylene terephthalate, polyethylene naphthalate (PEN), polyether ether ketone (PEEK), polyimide (PI), polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene oxide (PPO), polyparaphenylene terephthalamide (e.g., KEVLAR®), polysulfone, nylon, nylon 12 (EMS AmericanSuitable materials for the sheath include, but are not limited to, GRILAMID® (available from Grillon), perfluoro(propyl vinyl ether) (PFA), ethylene vinyl alcohol, polyolefins, polystyrene, epoxies, polyvinylidene chloride (PVdC), poly(styrene-b-isobutylene-b-styrene) (e.g., SIBS and / or SIBS 50A), polycarbonates, ionomers, polyurethane-silicone copolymers (e.g., Elast-Eon™ from AorTech Biomaterials or ChronoSil™ from AdvanSource Biomaterials), biocompatible polymers, other suitable materials, or mixtures, combinations, copolymers, polymer / metal composites, and the like. In some embodiments, the sheath may be blended with a liquid crystal polymer (LCP). For example, the blend may contain up to about 6% LCP.

[0048] It will be understood that this disclosure is, in many respects, merely illustrative. Changes may be made in details, particularly in matters of shape, size, and arrangement of steps, without exceeding the scope of the disclosure. This may include, to the extent appropriate, the use of any of the features of one illustrative embodiment used in other embodiments. The scope of the disclosure is, of course, defined in the language in which the appended claims are expressed.

Claims

1. 1. An alignment tool for loading a stent, comprising: a plurality of arms, each having a shaft having a first end including an engagement region and an opposite second end, each engagement region movable between a first angled configuration and a second straight configuration relative to the shaft, each arm including a notched region on a side of the engagement region, the notched regions of adjacent arms forming openings when the adjacent arms are in the straight configuration, the openings configured to receive a stent loop; a locking ring having a lumen configured to receive the plurality of arms, the locking ring configured to slide over the arms between a first retracted position in which the engagement region of each arm is exposed and biased into the angled configuration, and a second locked position in which the locking ring extends over at least a portion of the engagement region and compresses the engagement region into the straight configuration; a spring configured to bias the locking ring to the locked position.

2. 2. The alignment tool of claim 1, wherein each engagement region has a longitudinal slit extending from a free end of the engagement region toward the second end of the arm, the longitudinal slit allowing the engagement region to expand when in the angled configuration.

3. The alignment tool of claim 1 , wherein the locking ring includes at least one magnifying lens configured to be positioned over the opening.

4. The alignment tool of claim 1 , wherein the locking ring is transparent.

5. The alignment tool of claim 1 , wherein each arm has an enlarged portion at the second end of the shaft, the enlarged portion extending radially outward further than a diameter of the spring.

6. The alignment tool of claim 5 , wherein each arm has a raised transverse rib spaced from the enlarged portion.

7. 7. The alignment tool of claim 6, wherein the locking ring includes a rearward shoulder extending into the lumen, the rearward shoulder configured to engage the transverse rib when the locking ring is in the second, locked position.

8. 8. The alignment tool of claim 7, wherein the locking ring includes a forward shoulder that extends into the lumen, the forward shoulder configured to slide along the arms and move the engagement regions of the arms from the angled configuration to the straight configuration.

9. 2. The alignment tool of claim 1, wherein the locking ring has a front end disposed adjacent the engagement region of the arm and an opposite rear end, the locking ring having an enlarged, flared rear end having a diameter greater than a diameter of the front end.

10. The alignment tool of claim 1 , wherein each engagement region includes an inner surface shaped to mate with a stent holder.

11. 11. An alignment tool according to any one of claims 1 to 10, wherein at least at the second ends of the plurality of arms, a side edge of each arm abuts a side edge of an adjacent arm to define a channel extending through the plurality of arms.

12. The alignment tool of claim 11 , wherein the side edge of each arm abuts the side edge of an adjacent arm along the length of each shaft in all areas except the engagement area of ​​each arm.

13. 1. A method of loading a stent onto a stent holder using an alignment tool, comprising: inserting the stent having a plurality of terminal loops into the stent holder having a plurality of pins on which the terminal loops are disposed; placing the alignment tool on the stent holder, the alignment tool comprising: a plurality of arms, each having a shaft having a first end including an engagement region and an opposite second end, each engagement region being movable between a first angled configuration and a second straight configuration relative to the shaft, each engagement region having an inner surface shaped to mate with the stent holder, each arm including a notched region on a side of the engagement region, the notched regions of adjacent arms forming openings configured to receive a stent loop and a pin; a locking ring having a lumen configured to receive the plurality of arms, the locking ring configured to slide over the arms between a first retracted position in which the engagement region of each arm is exposed and biased into the angled configuration forming a mounting zone for receiving the stent holder, and a second locked position in which the locking ring extends over at least a portion of the engagement region and compresses the engagement region into the straight configuration for securing the stent holder; a spring configured to bias the locking ring to the locked position; placing the alignment tool on the stent holder with the locking ring in the first retracted position such that the pins on the stent holder are received in the openings in the engagement region; Releasing the locking ring to allow it to move to the locked position and move the engagement region of each arm to its straight configuration; advancing the stent to move one stent loop over each pin; compressing the stent onto the stent holder; moving the locking ring on the alignment tool to the retracted position to release the stent holder; and removing the alignment tool from the stent holder and the stent.

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