Medical implant locking mechanism

A medical device system may include a replacement heart valve implant including an expandable anchor member reversibly actuatable between a delivery configuration and a deployed configuration, wherein the replacement heart valve implant includes at least one locking mechanism configured to lock the expandable anchor member in the deployed configuration, and at least one actuator element configured to releasably engage the at least one locking mechanism and actuate the expandable anchor member between the delivery configuration and the deployed configuration. The at least one actuator element may include external threads on a distal portion of each actuator element and a ramp disposed proximal of the external threads.

TECHNICAL FIELD

The present disclosure pertains to medical devices, and methods for manufacturing and/or using medical devices. More particularly, the present disclosure pertains to locking mechanisms for a medical implant and/or a replacement heart valve.

BACKGROUND

SUMMARY

In a first aspect, a medical device system may comprise a replacement heart valve implant including an expandable anchor member reversibly actuatable between a delivery configuration and a deployed configuration, wherein the replacement heart valve implant includes at least one locking mechanism configured to lock the expandable anchor member in the deployed configuration; and at least one actuator element configured to releasably engage the at least one locking mechanism and actuate the expandable anchor member between the delivery configuration and the deployed configuration. The at least one actuator element may include external threads on a distal portion of each actuator element and a ramp disposed proximal of the external threads.

In addition or alternatively, and in a second aspect, the at least one locking mechanism comprises a first locking portion secured to the expandable anchor member and a second locking portion secured to the expandable anchor member, the first locking portion and the second locking portion being longitudinally movable relative to each other in the delivery configuration.

In addition or alternatively, and in a third aspect, the first locking portion is non-releasably secured to a distal portion of the expandable anchor member, and the second locking portion is fixedly secured to a proximal portion of the expandable anchor member.

In addition or alternatively, and in a fourth aspect, the second locking portion is configured to slidably receive the first locking portion within a longitudinal channel extending through the second locking portion.

In addition or alternatively, and in a fifth aspect, the first locking portion is non-rotatable relative to the second locking portion when the first locking portion is at least partially disposed within the longitudinal channel.

In addition or alternatively, and in a sixth aspect, the first locking portion includes a longitudinally-oriented passageway extending at least partially through the first locking portion, the longitudinally-oriented passageway being configured to receive the distal portion of the at least one actuator element.

In addition or alternatively, and in a seventh aspect, the longitudinally-oriented passageway includes internal threads corresponding to the external threads.

In addition or alternatively, and in an eighth aspect, the second locking portion of each of the at least one locking mechanism includes at least one spring arm configured to deflect circumferentially relative to a central longitudinal axis of the expandable anchor member.

In addition or alternatively, and in a ninth aspect, the ramp is configured to deflect each of the at least one spring arm circumferentially as the ramp is longitudinally translated through the second locking portion.

In addition or alternatively, and in a tenth aspect, the first locking portion includes at least one aperture corresponding to each of the at least one spring arm, the at least one aperture extending through the first locking portion at a non-zero angle relative to the central longitudinal axis and being configured to receive a portion of its corresponding spring arm.

In addition or alternatively, and in an eleventh aspect, each of the at least one spring arm is configured to prevent distal movement of the first locking portion relative to the second locking portion after the at least one actuator element has been disengaged from the at least one locking mechanism.

In addition or alternatively, and in a twelfth aspect, a medical device system may comprise an outer sheath; a handle disposed at a proximal end of the outer sheath; a replacement heart valve implant including an expandable anchor member reversibly actuatable between a delivery configuration and a deployed configuration, wherein the replacement heart valve implant includes at least one locking element configured to lock the expandable anchor member in the deployed configuration; and at least one actuator element configured to releasably engage the at least one locking mechanism and actuate the expandable anchor member between the delivery configuration and the deployed configuration. The at least one actuator element may include external threads on a distal portion of each actuator element and a ramp disposed proximal of the external threads. The at least one actuator element may extend from the handle to the replacement heart valve implant, the replacement heart valve implant being disposed at a distal end of the outer sheath.

In addition or alternatively, and in a thirteenth aspect, the at least one actuator element is configured to reversibly actuate the expandable anchor member between the delivery configuration and the deployed configuration while the at least one actuator element is engaged with the at least one locking mechanism.

In addition or alternatively, and in a fourteenth aspect, the handle is configured to rotate each of the at least one actuator element relative to the at least one locking mechanism in the deployed configuration.

In addition or alternatively, and in a fifteenth aspect, rotation of the at least one actuator element relative to the at least one locking mechanism in the deployed configuration disengages the at least one actuator element from the at least one locking mechanism and releases the replacement heart valve implant.

In addition or alternatively, and in a sixteenth aspect, a medical device system may comprise an outer sheath; a handle disposed at a proximal end of the outer sheath; a replacement heart valve implant including an expandable anchor member reversibly actuatable between a delivery configuration and a deployed configuration, wherein the replacement heart valve implant includes a plurality of locking mechanisms configured to lock the expandable anchor member in the deployed configuration; and a plurality of actuator elements corresponding to the plurality of locking mechanisms, the plurality of actuator elements being configured to releasably engage the plurality of locking mechanisms and actuate the expandable anchor member between the delivery configuration and the deployed configuration. The plurality of actuator elements may include external threads proximate a distal end of each actuator element and a ramp disposed proximal of the external threads. The plurality of actuator elements may extend from the handle to the replacement heart valve implant, the replacement heart valve implant being disposed at a distal end of the outer sheath.

In addition or alternatively, and in a seventeenth aspect, the expandable anchor member is tubular and defines a lumen extending coaxially along a central longitudinal axis of the replacement heart valve implant.

In addition or alternatively, and in an eighteenth aspect, the handle is configured to rotate each of the plurality of actuator elements relative to the outer sheath in the deployed configuration.

In addition or alternatively, and in a nineteenth aspect, each of the plurality of actuator elements defines its own longitudinal actuator axis and is configured to rotate about its own longitudinal actuator axis.

In addition or alternatively, and in a twentieth aspect, the plurality of locking mechanisms each comprise:

a first locking portion secured to the expandable anchor member and having at least one valve leaflet attached to the first locking portion; and

a second locking portion secured to the expandable anchor member;

wherein the actuator element of the plurality of actuator elements corresponding to each of the plurality of locking mechanisms extends longitudinally through the second locking portion of its locking mechanism in the delivery configuration.

the first locking portion and the second locking portion being longitudinally movable relative to each other in the delivery configuration.

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 figures and the detailed description which follows more particularly exemplify these embodiments.

DETAILED DESCRIPTION

The following description should be read with reference to the drawings, which are not necessarily to scale, wherein like reference numerals indicate like elements throughout the several views. The detailed description and drawings are intended to illustrate but not limit the claimed invention. Those skilled in the art will recognize that the various elements described and/or shown may be arranged in various combinations and configurations without departing from the scope of the disclosure. The detailed description and drawings illustrate example embodiments of the claimed invention.

The recitation of numerical ranges by endpoints includes all numbers within that range, including the endpoints (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

Relative terms such as “proximal”, “distal”, “advance”, “retract”, variants thereof, and the like, may be generally considered with respect to the positioning, direction, and/or operation of various elements relative to a user/operator/manipulator of the device, wherein “proximal” and “retract” indicate or refer to closer to or toward the user and “distal” and “advance” indicate or refer to farther from or away from the user. In some instances, the terms “proximal” and “distal” may be arbitrarily assigned in an effort to facilitate understanding of the disclosure, and such instances will be readily apparent to the skilled artisan. Other relative terms, such as “upstream”, “downstream”, “inflow”, and “outflow” refer to a direction of fluid flow within a lumen, such as a body lumen, a blood vessel, or within a device.

The term “extent” may be understood to mean a greatest measurement of a stated or identified dimension. For example, “outer extent” may be understood to mean a maximum outer dimension, “radial extent” may be understood to mean a maximum radial dimension, “longitudinal extent” may be understood to mean a maximum longitudinal dimension, etc. Each instance of an “extent” may be different (e.g., axial, longitudinal, lateral, radial, circumferential, etc.) and will be apparent to the skilled person from the context of the individual usage. Generally, an “extent” may be considered a greatest possible dimension measured according to the intended usage. In some instances, an “extent” may generally be measured orthogonally within a plane and/or cross-section, but may be, as will be apparent from the particular context, measured differently—such as, but not limited to, angularly, radially, circumferentially (e.g., along an arc), etc.

Diseases and/or medical conditions that impact the cardiovascular system are prevalent throughout the world. Traditionally, treatment of the cardiovascular system was often conducted by directly accessing the impacted part of the system. For example, treatment of a blockage in one or more of the coronary arteries was traditionally treated using coronary artery bypass surgery. As can be readily appreciated, such therapies are rather invasive to the patient and require significant recovery times and/or treatments. More recently, less invasive therapies have been developed, for example, where a blocked coronary artery could be accessed and treated via a percutaneous catheter (e.g., angioplasty). Such therapies have gained wide acceptance among patients and clinicians.

Some relatively common medical conditions may include or be the result of inefficiency, ineffectiveness, or complete failure of one or more of the valves within the heart. For example, failure of the aortic valve or the mitral valve can have a serious effect on a human and could lead to serious health condition and/or death if not dealt with properly. Treatment of defective heart valves poses other challenges in that the treatment often requires the repair or outright replacement of the defective valve. Such therapies may be highly invasive to the patient. Disclosed herein are medical devices that may be used for delivering a medical device to a portion of the cardiovascular system in order to diagnose, treat, and/or repair the system. At least some of the medical devices disclosed herein may be used to deliver and implant a replacement heart valve (e.g., a replacement aortic valve, replacement mitral valve, etc.). In addition, the devices disclosed herein may deliver the replacement heart valve percutaneously and, thus, may be much less invasive to the patient. The devices disclosed herein may also provide other desirable features and/or benefits as described below.

The figures illustrate selected components and/or arrangements of a medical device system10, shown schematically inFIG. 1for example. It should be noted that in any given figure, some features of the medical device system10may not be shown, or may be shown schematically, for simplicity. Additional details regarding some of the components of the medical device system10may be illustrated in other figures in greater detail. A medical device system10may be used to deliver and/or deploy a variety of medical devices and/or implants to one or more locations within the anatomy. In at least some embodiments, the medical device system10may include a replacement heart valve delivery system (e.g., a replacement aortic valve delivery system) that can be used for percutaneous delivery of a medical or replacement heart valve implant16. This, however, is not intended to be limiting as the medical device system10may also be used for other interventions including valve repair, valvuloplasty, and the like, or other similar interventions.

FIG. 1illustrates the medical device system10including the medical or replacement heart valve implant16configured to be disposed within a native heart valve (e.g., a mitral valve, an aortic valve, etc.), wherein the medical or replacement heart valve implant16may be disposed within a lumen of the medical device system10in a delivery configuration for delivery to the native heart valve, where the medical or replacement heart valve implant16may be shifted to a deployed configuration. In some embodiments, the medical device system10may include an outer sheath12having a lumen extending from a proximal portion and/or proximal end of the outer sheath12to a distal end of the outer sheath12. The medical or replacement heart valve implant16may be disposed within the lumen of the outer sheath12proximate the distal end of the outer sheath12in the delivery configuration. In some embodiments, the medical device system10may include a handle18disposed proximate and/or at the proximal end of the outer sheath12.

The medical device system10may include an inner sheath or catheter14disposed within the lumen of the outer sheath12and/or slidable with respect to the outer sheath12within the lumen of the outer sheath12. In some embodiments, the handle18may be disposed proximate and/or at a proximal end of the inner sheath or catheter14. In some embodiments, the inner sheath or catheter14may be a tubular structure having one or more lumens extending therethrough, the inner sheath or catheter14may be a solid shaft, or the inner sheath or catheter14may be a combination thereof. In some embodiments, the medical device system10may include at least one actuator element15releasably connecting the medical or replacement heart valve implant16to the handle18. For example, the at least one actuator element15may extend from the handle18to the medical or replacement heart valve implant16, the medical or replacement heart valve implant16being disposed at a distal end of the lumen of the outer sheath12. The at least one actuator element15may extend distally from the inner sheath or catheter14to the medical or replacement heart valve implant16. In some embodiments, the at least one actuator element15may be slidably disposed within and/or may extend slidably through the inner sheath or catheter14.

The handle18and/or the at least one actuator element15may be configured to manipulate the position of the outer sheath12relative to the inner sheath or catheter14and/or aid in the deployment of the medical or replacement heart valve implant16. For example, the inner sheath or catheter14and/or the at least one actuator element15may be used to move the medical or replacement heart valve implant16with respect to the outer sheath12of the medical device system10. In some embodiments, the inner sheath or catheter14and/or the at least one actuator element15may be advanced distally within the lumen of the outer sheath12to push the medical or replacement heart valve implant16out the distal end of the outer sheath12and/or the medical device system10to deploy the medical or replacement heart valve implant16within the native heart valve. Alternatively, the inner sheath or catheter14and/or the at least one actuator element15may be held in a fixed position relative to the medical or replacement heart valve implant16and the outer sheath12may be withdrawn proximally relative to the inner sheath or catheter14, the at least one actuator element15, and/or the medical or replacement heart valve implant16to deploy the medical or replacement heart valve implant16within the native heart valve. Some examples of suitable but non-limiting materials for the medical device system10, the outer sheath12, the inner sheath or catheter14, the at least one actuator element15, the handle18, and/or components or elements thereof, are described below.

In some embodiments, the medical device system10may include a nose cone disposed at a distal end of a guidewire extension tube, wherein the guidewire extension tube may extend distally from the inner sheath or catheter14and/or the outer sheath12. In at least some embodiments, the nose cone may be designed to have an atraumatic shape and/or may include a ridge or ledge that is configured to abut a distal end of the outer sheath12during delivery of the medical or replacement heart valve implant16.

In use, the medical device system10may be advanced percutaneously through the vasculature to an area of interest or a target location. For example, the medical device system10may be advanced through the vasculature and across the aortic arch to a defective heart valve (e.g., aortic valve, mitral valve, etc.). Alternative approaches to treat a defective heart valve are also contemplated with the medical device system10. During delivery, the medical or replacement heart valve implant16may be generally disposed in an elongated and low profile “delivery” configuration within the lumen of the outer sheath12. Once positioned, the outer sheath12may be retracted relative to the medical or replacement heart valve implant16to expose the medical or replacement heart valve implant16. In at least some embodiments, the medical or replacement heart valve implant16may be disposed in an “everted” configuration or a partially-everted configuration while disposed within the lumen of the outer sheath12and/or immediately upon exposure after retracting the outer sheath12. In some embodiments, the medical or replacement heart valve implant16may be everted in the “delivery” configuration. The “everted” configuration may involve at least a portion of the valve leaflets (discussed below) of the medical implant16being disposed outside of the expandable anchor member (discussed below) of the medical implant16during delivery, thereby permitting a smaller radial profile of the medical implant16and the use of a smaller overall profile of the outer sheath12and/or the medical device system10. In some embodiments, the “delivery” configuration and the “everted” configuration may be substantially similar and/or may be used interchangeably herein.

The medical or replacement heart valve implant16may be actuated using the handle18and/or the at least one actuator element15in order to translate the medical or replacement heart valve implant16into a radially expanded and larger profile “deployed” configuration suitable for implantation within the anatomy at the area of interest or the target location. When the medical or replacement heart valve implant16is suitably deployed within the anatomy, the outer sheath12and/or the medical device system10can be removed from the vasculature, leaving the medical or replacement heart valve implant16in place in a “released” configuration to function as, for example, a suitable replacement for the native heart valve. In at least some interventions, the medical or replacement heart valve implant16may be deployed within the native heart valve (e.g., the native heart valve is left in place and not excised). Alternatively, the native heart valve may be removed and the medical or replacement heart valve implant16may be deployed in its place as a replacement.

Disposed within a first lumen of the inner sheath or catheter14may be the at least one actuator element15, which may be used to actuate and/or translate (e.g., expand and/or elongate) the medical or replacement heart valve implant16between the “delivery” configuration and the “deployed” configuration. In some embodiments, the at least one actuator element15may include or comprise a plurality of actuator elements15, two actuator elements15, three actuator elements15, four actuator elements15, or another suitable or desired number of actuator elements15. In some embodiments, each of the at least one actuator element15may be disposed within a separate lumen of the inner sheath or catheter14. For the purpose of illustration only, the medical device system10and the medical or replacement heart valve implant16are shown with three actuator elements15. In such an example, the three actuator elements15may require and/or be disposed within three separate lumens (e.g., a first lumen, a second lumen, and a third lumen) of the inner sheath or catheter14.

It is to be noted that in order to facilitate understanding, certain features of the disclosure may be described in the singular, even though those features may be plural or recurring within the disclosed embodiment(s). Each instance of the features may include and/or be encompassed by the singular disclosure(s), unless expressly stated to the contrary. For example, a reference to “the actuator element” may be equally referred to all instances and quantities beyond one of “the at least one actuator element”.

FIG. 2illustrates some selected components of the medical device system10and/or the medical or replacement heart valve implant16, shown in the “deployed” configuration. The medical or replacement heart valve implant16may include an expandable anchor member70that is reversibly actuatable between the elongated “delivery” configuration and the radially expanded and/or axially shortened “deployed” configuration. In some embodiments, the expandable anchor member70may be tubular and defines a lumen extending coaxially along a central longitudinal axis from a distal or inflow end of the expandable anchor member70and/or the medical or replacement heart valve implant16to a proximal or outflow end of the expandable anchor member70and/or the medical or replacement heart valve implant16.

In some embodiments, the expandable anchor member70may comprise an expandable stent structure and/or framework. In some embodiments, the expandable anchor member70may comprise a self-expanding braided and/or woven mesh structure made up of one or more filaments disposed and/or interwoven circumferentially about the lumen of the expandable anchor member70and/or the medical or replacement heart valve implant16. Non-self-expanding, mechanically-expandable, and/or assisted self-expanding expandable anchor members are also contemplated. In at least some embodiments, the expandable anchor member70may be formed as a unitary structure (e.g., formed from a single filament or strand of wire, cut from a single tubular member, etc.). In some embodiments, the expandable anchor member70may define a generally cylindrical outer surface in the deployed configuration. Other configurations are also possible—a cross-section defining a generally elliptical outer surface, for example. Some examples of suitable but non-limiting materials for the medical or replacement heart valve implant16, the expandable anchor member70, and/or components or elements thereof, are described below.

Also shown inFIG. 2, but omitted from the other figures in the interest of clarity, the replacement heart valve implant16may include a plurality of valve leaflets68disposed within the lumen of the medical or replacement heart valve implant16and/or the expandable anchor member70. In some embodiments, the plurality of valve leaflets68may be attached and/or secured to the expandable anchor member70at a plurality of locations within the lumen of the medical or replacement heart valve implant16and/or the expandable anchor member70. In some embodiments, the plurality of valve leaflets68may be attached and/or secured to the expandable anchor member70using sutures, adhesives, or other suitable means.

In some embodiments, the plurality of valve leaflets68may include or comprise two leaflets, three leaflets, four leaflets, etc. as desired. The plurality of valve leaflets68of the medical or replacement heart valve implant16may be configured to move between an open configuration permitting antegrade fluid flow through the medical or replacement heart valve implant16and/or the lumen of the medical or replacement heart valve implant16and/or the expandable anchor member70, and a closed configuration preventing retrograde fluid flow through the medical or replacement heart valve implant16and/or the lumen of the medical or replacement heart valve implant16and/or the expandable anchor member70. The plurality of valve leaflets68may each have a free edge, wherein the free edges of the plurality of valve leaflets68coapt within the medical or replacement heart valve implant16, the expandable anchor member70, and/or the lumen extending through the medical or replacement heart valve implant16and/or the expandable anchor member70in the closed configuration. Some examples of suitable but non-limiting materials for the plurality of valve leaflets68may include bovine pericardial, polymeric materials, or other suitably flexible biocompatible materials.

The plurality of valve leaflets68may include a valve leaflet commissure movable from a first longitudinal position within the lumen of the medical or replacement heart valve implant16and/or the expandable anchor member70relative to the proximal or downstream end in the delivery configuration to a second longitudinal position within the lumen of the medical or replacement heart valve implant16and/or the expandable anchor member70relative to the proximal or downstream end in the deployed configuration. In some embodiments, the plurality of valve leaflets68may include more than one valve leaflet commissure. For example, each adjacent pair of valve leaflets68may form and/or define one valve leaflet commissure. Therefore, the number of valve leaflet commissures may be directly related to the number of valve leaflets68(e.g., three valve leaflets68form and/or define three valve leaflet commissures, two valve leaflets68form and/or define two valve leaflet commissures, etc.).

In some embodiments, the medical or replacement heart valve implant16may include at least one locking mechanism58configured to lock the expandable anchor member70in the “deployed” configuration. In some embodiments, the at least one locking mechanism58may include or comprise a plurality of locking mechanisms58, two locking mechanisms58, three locking mechanisms58, etc. In some embodiments, each valve leaflet commissure may correspond to and/or include one corresponding locking mechanism58. Each locking mechanism58may include a first locking portion or a post member96secured to the expandable anchor member70and configured to engage with a second locking portion or a buckle member76secured to the expandable anchor member70, as will be described in more detail below.

In some embodiments, at least one actuator element15may be configured to releasably engage the at least one locking mechanism58and/or reversibly actuate the expandable anchor member70and/or the medical or replacement heart valve implant16between the “delivery” configuration and the “deployed” configuration and/or the “released” configuration while the at least one actuator element15is engaged with the at least one locking mechanism58. In some embodiments, one actuator element15may correspond to, engage with, and/or actuate one locking mechanism58. In some embodiments, one actuator element15may correspond to, engage with, and/or actuate more than one locking mechanism58. Other configurations are also contemplated.

In some embodiments, the first locking portion or post member96and the second locking portion or buckle member76may be longitudinally movable relative to each other along an inner surface of the expandable anchor member70in the “delivery” configuration and/or between the “delivery” configuration and the “deployed” configuration. In some embodiments, the first locking portion or post member96may be non-releasably secured to a distal portion and/or proximate the distal or upstream end of the expandable anchor member70along the inner surface of the expandable anchor member70. In some embodiments, the second locking portion or buckle member76may be fixedly secured to a proximal portion and/or proximate the proximal or downstream end of the expandable anchor member70against the inner surface of the expandable anchor member70. The second locking portion or buckle member76may be configured to slidably receive at least a portion of the first locking portion or post member96therein.

In some embodiments, the medical or replacement heart valve implant16may include a seal member20(shown partially cutaway) disposed on and/or around at least a portion of the outer surface of the expandable anchor member70. In some embodiments, the seal member20may be coupled and/or secured to the expandable anchor member70and/or the plurality of valve leaflets68. The seal member20may be sufficiently flexible and/or pliable to conform to and/or around native valve leaflets and/or the native heart valve in the deployed configuration, thereby sealing an exterior of the medical or replacement heart valve implant16and/or the expandable anchor member70within and/or against the native heart valve and/or the native valve leaflets and preventing leakage around the medical or replacement heart valve implant16and/or the expandable anchor member70.

In some embodiments, the seal member20may include a plurality of layers of polymeric material. Some suitable polymeric materials may include, but are not necessarily limited to, polycarbonate, polyurethane, polyamide, polyether block amide, polyethylene, polyethylene terephthalate, polypropylene, polyvinylchloride, polytetrafluoroethylene, polysulfone, and copolymers, blends, mixtures or combinations thereof. Other suitable polymeric materials are also contemplated, some of which are discussed below.

FIG. 3illustrates an example actuator element15. In some embodiments, each actuator element15may include a proximal end and a distal end. In use, the proximal end may be operatively connected to the handle18, and/or manipulated or otherwise actuated by a user using the handle18, to reversibly shift the medical or replacement heart valve implant16between the “delivery” configuration and the “deployed” configuration, and later the “released” configuration. In some embodiments, the actuator element15may be axially translatable and/or rotatable relative to the first locking portion or post member96and/or the second locking portion or buckle member76of the medical or replacement heart valve implant16.

In some embodiments, each actuator element15may include an elongated rod84having external threads86on a distal portion and/or adjacent a distal end, and a ramp88disposed on the distal portion proximal of the external threads86. In some embodiments, the actuator element15and/or the distal portion may be releasably connected and/or coupled to the post member96, as discussed below. In some embodiments, the distal portion, the external threads86, and/or the ramp88may be integrally formed with or as a part of the elongated rod84as a single monolithic structure.

Each of the at least one actuator element15(e.g., each of the plurality of actuator elements15, etc.) defines its own longitudinal actuator axis and is configured to rotate about its own longitudinal actuator axis. In some embodiments, the ramp88may extend transversely from and/or radially outward relative to the longitudinal actuator axis of the actuator element15such that the ramp88has a greater outer diameter or outer extent than the elongated rod84. In some embodiments, the distal portion may include more than one ramp88extending transversely from and/or radially outward relative to the longitudinal actuator axis of the actuator element15. In some embodiments, the actuator element15may include a second ramp extending opposite the ramp88, or a plurality of ramps spaced circumferentially around the longitudinal actuator axis of the actuator element15. In embodiments having a plurality of ramps88, the plurality of ramps88collectively defines the outer diameter or outer extent of the plurality of ramps88with respect to the elongated rod84.

In some embodiments, the distal portion of the actuator element15may be aligned with and/or releasably coupled to the first locking portion or post member96. In some embodiments, the distal portion may be rotatably received within a longitudinally-oriented passageway of the first locking portion or post member96, as discussed below. In some embodiments, the external threads86may be configured to engage with, be received by, and/or extend into internal threads formed within the first locking portion or post member96. The handle18may be configured to rotate each of the at least one actuator element15(e.g., each of the plurality of actuator elements15, etc.) relative to the outer sheath12, the medical or replacement heart valve implant16, the corresponding locking mechanism(s)58(e.g., the at least one locking mechanism58, etc.), and/or the first locking portion or post member96in the “deployed” configuration.

In some embodiments, each of the at least one actuator element15may be operatively connected to a central shaft extending distally from the handle18within the inner sheath or catheter14. The central shaft may be rotated by the handle18and/or a rotation mechanism disposed within the handle18. In some embodiments, each of the at least one actuator element15may extend distally from the handle18within the inner sheath or catheter14. Each of the at least one actuator element15may be operatively and individually engaged with a central lead screw disposed within the handle18. The central lead screw may be configured to rotate each of the at least one actuator element15. In at least some embodiments, the central lead screw may be configured to rotate each of the at least one actuator element15simultaneously.

In some embodiments, the actuator element15and/or the elongated rod84may be generally round, oblong, ovoid, rectangular, polygonal (i.e., two-sided, three-sided, four-sided, five-sided, six-sided, etc.) and/or combinations thereof in shape. Other shapes, both regular and irregular, are also contemplated. In some embodiments, the actuator element15may be formed from a single piece of wire, round stock, or other suitable material, as discussed herein. In some embodiments, the actuator element15may be formed by further processing the single piece of wire, round stock, or other suitable material, such as by machining, stamping, laser cutting, etc. Some suitable but non-limiting materials for the actuator element15, the elongated rod84, the distal portion, the external threads86, and/or the ramp88, for example metallic materials or polymeric materials, are described below.

FIGS. 4 and 4Aillustrate an example first locking portion or post member96. In some embodiments, the first locking portion or post member96may include an elongated member configured to engage with and/or releasably couple to the distal portion and/or the external threads86of the actuator element15. In some embodiments, the first locking portion or post member96may include a longitudinally-oriented passageway98extending at least partially through the first locking portion or post member96. In some embodiments, the longitudinally-oriented passageway98may extend completely through the first locking portion or post member96. In some embodiments, a longitudinal axis of the longitudinally-oriented passageway98and/or the first locking portion or post member96may be arranged generally parallel to the central longitudinal axis of the expandable anchor member70and/or the medical or replacement heart valve implant16.

The longitudinally-oriented passageway98may be configured to receive the distal portion of the at least one actuator element15and/or the external threads86therein. The longitudinally-oriented passageway98may include internal threads corresponding to the external threads86of the actuator element15. In some embodiments, the distal portion of the actuator element15may be rotatably disposed within the longitudinally-oriented passageway98and/or may be releasably coupled to the first locking portion or post member96by rotatably engaging the external threads86at, proximate, and/or on the distal portion of the actuator element15with the internal threads of the longitudinally-oriented passageway98, for example. In some embodiments, at least a portion of the distal portion and/or the external threads86of the at least one actuator element15may extend into the longitudinally-oriented passageway98when the at least one actuator element15is engaged with the first locking portion or post member96, for example in the elongated “delivery” configuration and/or the “everted” configuration. In some embodiments, the first locking portion or post member96may be disposed within the lumen of the medical or replacement heart valve implant16and/or the expandable anchor member70proximate the distal or inflow end of the medical or replacement heart valve implant16and/or the expandable anchor member70when the expandable anchor member70is in the elongated “delivery” configuration and/or the “everted” configuration. In some embodiments, at least a portion of the first locking portion or post member96may be disposed distal of the expandable anchor member70when the expandable anchor member70is in the elongated “delivery” configuration and/or the “everted” configuration.

In some embodiments, the first locking portion or post member96may include one or more laterally-extending bars97at a distal end of the first locking portion or post member96, the one or more laterally-extending bars97configured to engage with a proximal end of each of a pair of commissure posts72(e.g.,FIG. 2), thereby limiting and/or preventing relative movement therebetween. In at least some embodiments, the plurality of valve leaflets68may be secured to the pair of commissure posts72to define the valve leaflet commissure(s). For example, at least one of the plurality of valve leaflets68may be attached to the first locking portion or post member96via each pair of commissure posts72. In some embodiments, two adjacent valve leaflets68of the plurality of valve leaflets68may be attached to the first locking portion or post member96via each pair of commissure posts72.

In some embodiments, the first locking portion or post member96may include at least one aperture95extending generally transverse to the longitudinal axis of the longitudinally-oriented passageway98and/or the first locking portion or post member96. In some embodiments, the at least one aperture95may include or comprise a plurality of apertures95, two apertures95, three apertures95, etc. In some embodiments, the at least one aperture95may be disposed proximate a proximal end of the first locking portion or post member96. The at least one aperture95may each extend through the first locking portion or post member96at a non-zero angle relative to the central longitudinal axis of the expandable anchor member70and/or the medical or replacement heart valve implant16. In at least some embodiments, the at least one aperture95may extend transversely and/or laterally through a wall of the first locking portion or post member96into the longitudinally-oriented passageway98. In some embodiments, the at least one aperture95may be generally aligned with and/or parallel to the one or more laterally-extending bars97.

In some embodiments, the first locking portion or post member96may include a flat side99formed in and/or extending longitudinally along a length and/or an outer surface of the first locking portion or post member96. In some embodiments, the flat side99may extend along an entire length of the first locking portion or post member96. As will become apparent, the flat side99may serve as an alignment and/or anti-rotation feature with respect to the second locking portion or buckle member76. For example, the flat side99may prevent relative rotation between the first locking portion or post member96and the second locking portion or buckle member76when the first locking portion or post member96is engaged with the second locking portion or buckle member76.

In some embodiments, rotatable and/or threaded engagement of the external threads86with the internal threads of the longitudinally-oriented passageway98may permit the at least one actuator element15to axially translate the first locking portion or post member96relative to the second locking portion or buckle member76. Some suitable but non-limiting materials for the first locking portion or post member96, for example metallic materials or polymeric materials, are described below.

FIG. 5illustrates an example second locking portion or buckle member76. In some embodiments, the second locking portion or buckle member76may include a longitudinal channel74extending through a body portion75of the second locking portion or buckle member76. In some embodiments, the second locking portion or buckle member76may include a projecting portion73at a proximal end of the body portion75of the second locking portion or buckle member76, the projecting portion73being configured to releasably attach the medical or replacement heart valve implant16to the medical device system10and/or the inner sheath or catheter14. In at least some embodiments, the longitudinal channel74may have a keyed, directional, or non-round cross-sectional profile or shape configured to slidably receive the first locking portion or post member96. The first locking portion or post member96may have a cross-sectional profile or shape corresponding to the keyed, directional, or non-round cross-sectional profile or shape of the longitudinal channel74. For example, the longitudinal channel74and/or the projecting portion73may include a flat surface71corresponding to the flat side99of the first locking portion or post member96. As such, the first locking portion or post member96may be non-rotatable relative to the second locking portion or buckle member76when the first locking portion or post member96is engaged with and/or at least partially disposed within the longitudinal channel74of the second locking portion or buckle member76and/or when the flat side99of the first locking portion or post member96is aligned with and/or in facing engagement with the flat surface71of the second locking portion or buckle member76.

In some embodiments, the body portion75of the second locking portion or buckle member76of each of the at least one locking mechanism58may include at least one spring arm77configured to deflect laterally and/or circumferentially relative to the central longitudinal axis of the expandable anchor member70and/or the medical or replacement heart valve implant16. As will become more evident from the discussion below, the ramp88of the at least one actuator element15may be configured to deflect each of the at least one spring arm77laterally and/or circumferentially as the ramp88(and the first locking portion or post member96engaged thereto) is longitudinally translated through the longitudinal channel74of the body portion75of the second locking portion or buckle member76. In some embodiments, the at least one spring arm77may be biased or self-biased toward a neutral position aligned with the body portion75and/or may be biased or self-biased into the longitudinal channel74.

Briefly referencingFIG. 4above, the first locking portion or post member96includes at least one aperture95corresponding to each of the at least one spring arm77of the second locking portion or buckle member76. The at least one aperture95may be configured to receive a portion of its corresponding spring arm77after the at least one actuator element15has been disengaged from the at least one locking mechanism58and/or the first locking portion or post member96and the ramp88has been removed proximally from within the longitudinal channel74. Each of the at least one spring arm77is configured to limit or prevent distal movement and/or axial translation of the first locking portion or post member96relative to the second locking portion or buckle member76in the “deployed” configuration after the at least one actuator element15has been disengaged from the at least one locking mechanism58and/or the first locking portion or post member96, and the ramp88has been removed proximally from within the longitudinal channel74. Some suitable but non-limiting materials for the second locking portion or buckle member76, for example metallic materials or polymeric materials, are described below.

Returning toFIG. 2, in some embodiments, attachment between the medical or replacement heart valve implant16and the inner sheath or catheter14may be effected through the use of a coupler78. The coupler78may generally include a base (not shown) that may be attached to a distal end of the inner sheath or catheter14. Projecting distally from the base is a plurality of fingers79(e.g., two, three, four, etc.) that are each configured to engage with the medical or replacement heart valve implant16at the projecting portion73of the second locking portion or buckle member76of each of the at least one locking mechanism58. In some embodiments, each of the plurality of fingers79may extend from the base and/or the distal end of the inner sheath or catheter14to the medical or replacement heart valve implant16. In some embodiments, each finger79may include a collar80slidably disposed about the respective finger79and the projecting portion73of its respective second locking portion or buckle member76. A guide82may be disposed over each of the fingers79proximal of the collar80and may serve to keep the fingers79of the coupler78associated with their respective actuator element15extending adjacent to (and axially slidable relative to) the fingers79of the coupler78.

During delivery, the medical or replacement heart valve implant16may be secured at the distal end of the coupler78and/or the inner sheath or catheter14by two elongated tines of the finger79of the coupler78being matingly coupled with the projecting portion73of the second locking portion or buckle member76by the collar80, and by the at least one actuator element15being coupled to its corresponding first locking portion or post member96. When the medical or replacement heart valve implant16is advanced within the anatomy to the area of interest, the outer sheath12may be translated and/or actuated proximally to expose the medical or replacement heart valve implant16. Then, the at least one actuator element15can be actuated (e.g., proximally retracted) to axially shorten and/or radially expand the medical or replacement heart valve implant16and/or the expandable anchor member70from the “delivery” configuration toward the “deployed” configuration by proximally retracting and/or translating the at least one actuator element15to pull the first locking portion or post member96into engagement with the second locking portion or buckle member76, using the handle18for example. After verifying satisfactory placement of the medical or replacement heart valve implant16, such as by an appropriate imaging technique, the at least one actuator element15may each be rotated relative to and decoupled from the first locking portion or post member96, which allows the distal portion of the at least one actuator element15to be pulled proximally out of the second locking portion or buckle member76, where the ramp88subsequently engages the collar80and thereby retracts the collar80from the two elongated tines and the projecting portion73. Once the collar80has been retracted, the two elongated tines decouple from the projecting portion73, and the finger79of the coupler78may be withdrawn from the medical or replacement heart valve implant16thereby leaving the medical or replacement heart valve implant16(and/or the expandable anchor member70) in the anatomy at the area of interest in a “released” configuration.

FIGS. 6-12illustrate selected components of an example locking mechanism58configured to reversibly lock the medical or replacement heart valve implant16(and/or the expandable anchor member70) in the “deployed” configuration and/or the “released” configuration, and the general operation of those components. For simplicity and clarity purposes, only one actuator element15, first locking portion or post member96, second locking portion or buckle member76, etc. is shown and discussed (the whole medical or replacement heart valve implant16is not shown to facilitate understanding of the locking mechanism(s)58). However, it will be understood that the following discussion may apply equally to any and/or all of the components for which there are more than one within the medical or replacement heart valve implant16(i.e., the at least one actuator element15, the second locking portion or buckle member76, the first locking portion or post member96, etc.) and/or the medical device system10, unless explicitly stated to the contrary.

As seen inFIGS. 6-12, each of the at least one actuator element15extends through a guide82adjacent to and surrounding the finger79of the coupler78, through the collar80, through the second locking portion or buckle member76, and into engagement with the first locking portion or post member96. For example, the actuator element15of the at least one actuator element15(e.g., the plurality of actuator elements15) corresponding to each of the at least one locking mechanism58(e.g., the plurality of locking mechanisms58) extends longitudinally through the second locking portion or buckle member76of its respective locking mechanism58in the “delivery” configuration.

The at least one actuator element15may be axially and/or rotatably translatable through and/or relative to the guide82, the collar80, and/or the second locking portion or buckle member76. The at least one actuator element15may be rotatable within the longitudinally-oriented passageway98of the first locking portion or post member96. As discussed above, the distal portion of the at least one actuator element15may include external threads86configured to rotatably engage and/or extend into the longitudinally-oriented passageway98of the first locking portion or post member96.

The external threads86may releasably couple the distal portion of the at least one actuator element15to the first locking portion or post member96and form a configuration of these structures that can be utilized during delivery of the medical or replacement heart valve implant16. As can be appreciated, a proximal end of the first locking portion or post member96and a distal end of the second locking portion or buckle member76may be longitudinally separated and/or spaced apart (as seen inFIGS. 6-7, for example) and, accordingly, the medical or replacement heart valve implant16and/or the expandable anchor member70may be in an elongated and generally low-profile “delivery” configuration suitable for percutaneous translation through a patient's anatomy to the area of interest (e.g., the native heart valve). In at least some embodiments, the first locking portion or post member96and the second locking portion or buckle member76may be longitudinally moveable and/or translatable relative to each other in the “delivery” configuration.

When the medical or replacement heart valve implant16reaches the area of interest within the anatomy, a clinician can actuate (e.g., proximally retract) the at least one actuator element15, for example using the handle18, thereby moving and/or translating the proximal end of the first locking portion or post member96toward the distal end of the second locking portion or buckle member76and into the longitudinal channel74of the second locking portion or buckle member76in order to axially shorten and/or radially expand the expandable anchor member70and/or the medical or replacement heart valve implant16towards the “deployed” configuration. Ultimately, the at least one actuator element15can be retracted sufficiently far enough to translate the ramp88of the at least one actuator element15past the at least one spring arm77of the second locking portion or buckle member76as the ramp88passes through the longitudinal channel74of the second locking portion or buckle member76, thereby displacing and/or deflecting the at least one spring arm77laterally and/or circumferentially away from the longitudinal channel74of the second locking portion or buckle member76, wherein the medical or replacement heart valve implant16and/or the expandable anchor member70is at an axial and/or longitudinal position (along and/or relative to the central longitudinal axis of the expandable anchor member70) corresponding to the “deployed” configuration (as seen inFIGS. 8-9, for example), suitable for implantation within the anatomy at the area of interest.

In some embodiments, axial translation of the at least one actuator element15in a first (e.g., proximal) direction may actuate the expandable anchor member70from the “delivery” configuration toward the “deployed” configuration. As mentioned above, in some embodiments, the at least one actuator element15may include a ramp88extending laterally and/or radially outward from the elongated rod84. In some embodiments, the ramp88of the at least one actuator element15may be configured to prevent the at least one spring arm77of the second locking portion or buckle member76from engaging the at least one aperture95of the first locking portion or post member96prior to decoupling the at least one actuator element15from the first locking portion or post member96, as seen inFIGS. 8-9for example. At this point in the deployment process, proper positioning of the medical or replacement heart valve implant16at the area of interest may be verified using a suitable imaging technique.

In some embodiments and/or some procedures, it may be desirable to remove and/or reposition the medical or replacement heart valve implant16and/or expandable anchor member70. To do so, a clinician may urge and/or translate the at least one actuator element15in a second (e.g., distal) direction to extend and/or elongate the expandable anchor member70back towards the “delivery” configuration. Axial translation of the at least one actuator element15in the second (e.g., distal) direction relative to the at least one locking mechanism58(e.g., the first locking portion or post member96and/or the second locking portion or buckle member76) may slidably engage the ramp88of the at least one actuator element15with the at least one spring arm77of the second locking portion or buckle member76, thereby deflecting the at least one spring arm77of the second locking portion or buckle member76away from the longitudinal actuator axis of the at least one actuator element15and/or laterally or circumferentially relative to the central longitudinal axis of the expandable anchor member70, and permitting the first locking portion or post member96to pass back through and/or out of the longitudinal channel74of the second locking portion or buckle member76.

Alternatively, if a clinician is satisfied with the positioning of the medical or replacement heart valve implant16(e.g., after visualization of the medical or replacement heart valve implant16via a suitable imaging technique), the at least one actuator element15may be further actuated (e.g., rotated relative to the first locking portion or post member96) to decouple the external threads86and/or the at least one actuator element15from the internal threads of the first locking portion or post member96, as seen inFIGS. 10-11for example. Rotation of the at least one actuator element15relative to the at least one locking mechanism58(e.g., the first locking portion or post member96and/or the second locking portion or buckle member76), the expandable anchor member70, the medical or replacement heart valve implant16, etc. in the “deployed” configuration may disengage the at least one actuator element15from the at least one locking mechanism58(e.g., the first locking portion or post member96and/or the second locking portion or buckle member76) and release the medical or replacement heart valve implant16.

Once the at least one actuator element15has been disengaged and/or detached from the first locking portion or post member96, and the ramp88has been axially translated away from the at least one locking mechanism58(e.g., the first locking portion or post member96and/or the second locking portion or buckle member76), the at least one spring arm77of the second locking portion or buckle member76extends at least partially into the at least one aperture95of the first locking portion or post member96and locks the medical or replacement heart valve implant16and/or the expandable anchor member70in the “deployed” configuration, as seen inFIGS. 10-11for example, thereby limiting and/or preventing distal movement and/or axial translation of the first locking portion or post member96relative to the second locking portion or buckle member76.

Further actuation and/or retraction of the at least one actuator element15may cause the ramp88of the at least one actuator element15to engage the collar80and pull/slide the collar80proximally along the finger79while further withdrawing the at least one actuator element15from the first locking portion or post member96. In doing so, the two elongated tines of the finger79may be exposed, as seen inFIG. 10, and decoupled from the projecting portion73of the second locking portion or buckle member76, as seen inFIG. 12. Withdrawal of the at least one actuator element15completely from the first locking portion or post member96releases the expandable anchor member70from the at least one actuator element15and leaves the medical or replacement heart valve implant16disposed at the area of interest in the “released” configuration.

The materials that can be used for the various components of the medical device system10, the outer sheath12, the inner sheath or catheter14, the medical or replacement heart valve implant16, the handle18, etc. (and/or other systems disclosed herein) and the various elements thereof disclosed herein may include those commonly associated with medical devices. For simplicity purposes, the following discussion makes reference to the medical device system10, the outer sheath12, the inner sheath or catheter14, the medical or replacement heart valve implant16, the handle18, etc. However, this is not intended to limit the devices and methods described herein, as the discussion may be applied to other elements, members, components, or devices disclosed herein, such as, but not limited to, the actuator elements15, the seal member20, the valve leaflets68, the expandable anchor member70, the commissure posts72, the second locking portion or buckle members76, the collars80, the guides82, the first locking portion or post member96, etc., and/or elements or components thereof.

In some embodiments, the medical device system10, the outer sheath12, the inner sheath or catheter14, the medical or replacement heart valve implant16, the handle18, etc., and/or components thereof (such as, but not limited to, the actuator elements15, the seal member20, the valve leaflets68, the expandable anchor member70, the commissure posts72, the second locking portion or buckle members76, the collars80, the guides82, the first locking portion or post member96, etc.), may be made from a metal, metal alloy, polymer (some examples of which are disclosed below), a metal-polymer composite, ceramics, combinations thereof, and the like, or other suitable material. Some examples of suitable metals and metal alloys include stainless steel, such as 444V, 444L, and 314LV stainless steel; mild steel; nickel-titanium alloy such as linear-elastic and/or super-elastic nitinol; other nickel alloys such as nickel-chromium-molybdenum alloys (e.g., UNS: N06625 such as INCONEL® 625, UNS: N06022 such as HASTELLOY® C-22®, UNS: N10276 such as HASTELLOY® C276®, other HASTELLOY® alloys, and the like), nickel-copper alloys (e.g., UNS: N04400 such as MONEL® 400, NICKELVAC® 400, NICORROS® 400, and the like), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R44035 such as MP35-N® and the like), nickel-molybdenum alloys (e.g., UNS: N10665 such as HASTELLOY® ALLOY B2®), 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, and the like; cobalt-chromium alloys; cobalt-chromium-molybdenum alloys (e.g., UNS: R44003 such as ELGILOY®, PHYNOX®, and the like); platinum enriched stainless steel; titanium; platinum; palladium; gold; combinations thereof; and the like; or any other suitable material.

In at least some embodiments, portions or all of the medical device system10, the outer sheath12, the inner sheath or catheter14, the medical or replacement heart valve implant16, the handle18, etc., and/or components thereof, may also be doped with, made of, or otherwise include a radiopaque material. Radiopaque materials are understood to be materials capable of producing a relatively bright image on a fluoroscopy screen or another imaging technique during a medical procedure. This relatively bright image aids a user in determining the location of the medical device system10, the outer sheath12, the inner sheath or catheter14, the medical or replacement heart valve implant16, the handle18, etc. Some examples of radiopaque materials can include, but are not limited to, gold, platinum, palladium, tantalum, tungsten alloy, polymer material loaded with a radiopaque filler, and the like. Additionally, other radiopaque marker bands and/or coils may also be incorporated into the design of the medical device system10, the outer sheath12, the inner sheath or catheter14, the medical or replacement heart valve implant16, the handle18, etc. to achieve the same result.

In some embodiments, the medical device system10, the outer sheath12, the inner sheath or catheter14, the medical or replacement heart valve implant16, the handle18, etc. and/or other elements disclosed herein may include a fabric material disposed over or within the structure. The fabric material may be composed of a biocompatible material, such a polymeric material or biomaterial, adapted to promote tissue ingrowth. In some embodiments, the fabric material may include a bioabsorbable material. Some examples of suitable fabric materials include, but are not limited to, polyethylene glycol (PEG), nylon, polytetrafluoroethylene (PTFE, ePTFE), a polyolefinic material such as a polyethylene, a polypropylene, polyester, polyurethane, and/or blends or combinations thereof.

In some embodiments, the medical device system10, the outer sheath12, the inner sheath or catheter14, the medical or replacement heart valve implant16, the handle18, etc. may include and/or be formed from a textile material. Some examples of suitable textile materials may include synthetic yarns that may be flat, shaped, twisted, textured, pre-shrunk or un-shrunk. Synthetic biocompatible yarns suitable for use in the present invention include, but are not limited to, polyesters, including polyethylene terephthalate (PET) polyesters, polypropylenes, polyethylenes, polyurethanes, polyolefins, polyvinyls, polymethylacetates, polyamides, naphthalene dicarboxylene derivatives, natural silk, and polytetrafluoroethylenes. Moreover, at least one of the synthetic yarns may be a metallic yarn or a glass or ceramic yarn or fiber. Useful metallic yarns include those yarns made from or containing stainless steel, platinum, gold, titanium, tantalum or a Ni—Co—Cr-based alloy. The yarns may further include carbon, glass or ceramic fibers. Desirably, the yarns are made from thermoplastic materials including, but not limited to, polyesters, polypropylenes, polyethylenes, polyurethanes, polynaphthalenes, polytetrafluoroethylenes, and the like. The yarns may be of the multifilament, monofilament, or spun-types. The type and denier of the yarn chosen may be selected in a manner which forms a biocompatible and implantable prosthesis and, more particularly, a vascular structure having desirable properties.

It should be understood that this disclosure is, in many respects, only illustrative. Changes may be made to details, particularly in matters of shape, size, and arrangement of steps, without exceeding the scope of the invention. This may include, to the extent that it is appropriate, the use of any of the features of one example embodiment being used in other embodiments. The invention's scope is, of course, defined in the language in which the appended claims are expressed.