Shape memory device and delivery system

Abstract

This invention provides a transcatheter device and delivery system with various shape memory enhancements to facilitate surgical manipulation and in-vivo propulsion. The device may include a metal stent feature trained to assume certain shapes upon direct heating or cooling. The device can be trained using multi-shape memory constructions. For some devices, an anchoring arm extends from the device and curls or bends at body temperature but straightens upon cooling. Similarly, the support structure of the device can be trained to radially self-grip as the temperature decreases. Various convertible elements within the delivery system can also be trained for selective disengagement. Cooling can be achieved by introducing a cold saline solution, by using a miniature Peltier cooler mounted on the convertible element itself, or by other means.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 610,875, filed December 15, 2023, the entire contents of which are incorporated herein by reference for all purposes. Background Technology

[0003] In vertebrates, the heart is a hollow muscular organ with four pumping chambers: the left and right atria and the left and right ventricles, each with its own one-way valve. Natural heart valves are identified as the aortic valve, mitral valve (or bicuspid), tricuspid valve, and pulmonary valve, each with flexible leaflets that interlock to prevent backflow.

[0004] Prostheses can be used to correct problems associated with damaged heart valves. For example, mechanical and tissue-based heart valve prostheses can be used to replace damaged natural heart valves. Recently, significant efforts have been made to develop replacement heart valves that can be delivered in a less invasive manner compared to open-heart surgery. Replacement valves can be designed for percutaneous delivery in so-called transcatheter procedures.

[0005] The development of transcatheter heart valves and their delivery systems can be challenging. Obtaining access for surgery in the heart or other anatomical locations may require percutaneous delivery devices through tortuous vascular systems.

[0006] Given the above, more advanced transcatheter devices and delivery systems are needed. Summary of the Invention

[0007] This summary is intended to provide examples and is not intended to limit the scope of the invention in any way. For example, any features included in the examples of this summary are not claimed by the claims unless those features are expressly stated in the claims. Furthermore, the features, components, steps, concepts, etc., described in the examples of this summary and in other parts of this disclosure can be combined in various ways. Various features and steps described in other parts of this disclosure may include those summarized herein.

[0008] In some embodiments, the transcatheter devices described herein (e.g., heart valves, implants, replacement devices, repair devices, therapeutic devices, etc.) may incorporate the shape memory effect, including elements capable of undergoing various shape memory changes. In some embodiments, the delivery systems described herein (e.g., transcatheter delivery systems, therapeutic device delivery systems, repair device delivery systems, implant delivery systems, replacement device delivery systems, heart valve delivery systems, etc.) incorporate the shape memory effect, including elements capable of undergoing various shape memory changes.

[0009] In some embodiments, the devices described herein (e.g., implants, transcatheter heart valves, therapeutic devices, repair devices, etc.) may include metallic stent features trained to take on certain shapes when the device is heated or cooled to one or more specific temperatures. In some embodiments, heating of the device can be accomplished by direct heating, such as heating by electrical stimulation, by conduction, or by heating with a fluid at a temperature higher than that of the device. In some embodiments, cooling of the device can be accomplished by direct cooling, such as by conduction, electrical manipulation, using a fluid at a temperature lower than that of the device, or applying cyclic thermal loads under a substantially constant stress field.

[0010] In some embodiments, the device may include an extension or arm (e.g., leaflet capturing arm, anchor, annular anchor, flange, ridge, etc.) extending from a portion of the device (e.g., end, middle, second end, side, etc.). In some embodiments, the extension or arm may be bent, flexed, or rolled up 180° at body temperature, but may also be relatively straight when cooled.

[0011] In some embodiments, the internal support of the device can be trained or shaped (e.g., configured to transform into a specific shape as the temperature rises and / or falls) to radially self-pressurize as the temperature decreases.

[0012] In some embodiments, the various components within the conveying system may also be trained or shaped to selectively engage and / or disengage at different temperatures. In some embodiments, the various components within the conveying system may also be trained or shaped to selectively engage at certain temperatures (e.g., when a certain temperature is reached, an element can move to engage with another element or component). In some embodiments, the various components within the conveying system may also be trained or shaped to disengage at certain temperatures (e.g., when a certain temperature is reached, an element can move out of engagement with another element or component, or disengage from another element or component).

[0013] In some embodiments, temperature changes can be achieved by introducing a fluid or solution (e.g., saline or others). In some embodiments, cooling can be achieved by introducing a cold fluid or solution. In some embodiments, heating can be achieved by introducing a warm or hot fluid or solution.

[0014] In some embodiments, temperature change can be achieved using a Peltier device (mounted on or near the convertible element) that alters the element's temperature until it is actuated (e.g., engaged, disengaged, moved, etc.). In some embodiments, cooling can be achieved using a Peltier device (mounted on or near the convertible element) that cools the element until it is actuated (e.g., engaged, disengaged, moved, etc.). In some embodiments, heating can be achieved using a Peltier device (mounted on or near the convertible element) that raises the element's temperature until it is actuated (e.g., engaged, disengaged, moved, etc.).

[0015] In some embodiments, the devices disclosed herein for replacing or repairing the function of defective natural heart valves (e.g., treatment devices, replacement devices, repair devices, implants, artificial heart valves, etc.) include a support structure (e.g., support stent, scaffold, laser-cut body, woven fabric, braid, etc.) comprising or made of a shape memory material adapted to transform into a first predetermined shape / construction upon cooling (e.g., shape-setting construction, device shape-setting construction, device set to remember construction, etc.) and transform into a second predetermined shape / construction upon heating, the second predetermined shape / construction (e.g., shape-setting construction, device shape-setting construction, device set to remember construction, etc.) being different from the first predetermined shape / construction.

[0016] In some embodiments, the device is configured to replace the function of a defective natural heart valve and includes a support structure configured as a support stent, the support stent comprising or made of a shape memory material adapted to transform into a first predetermined shape / construction upon cooling and into a second predetermined shape / construction upon heating. In some embodiments, the heart valve further includes a unidirectional valve structure housed within the lumen of the support stent. In some embodiments, a unidirectional valve structure includes multiple leaflets (e.g., 2, 3, 4, etc.) that can open to allow blood flow in a first direction and close to inhibit blood flow in a second direction, different from the first direction. In some embodiments, the unidirectional valve structure may be formed with leaflets made of pericardium.

[0017] In some embodiments, the support structure (e.g., it may be a component of any device described herein and / or can be used with any device described herein) may comprise metal struts forming multiple grid cells. In some embodiments, the first predetermined shape / construction has a reduced diameter (e.g., relative to a second predetermined shape / construction, relative to a relaxed state, relative to a relaxed room temperature state, relative to an implanted state, etc.). In some embodiments, the reduced diameter may facilitate or make it easier to load the device into a delivery sheath or delivery catheter (e.g., the pouch of the delivery sheath / catheter, the anterior region of the delivery sheath / catheter, etc.). In some embodiments, the reduced diameter may be less than 10 mm.

[0018] In some embodiments, the second predetermined shape / construction may have an expansion diameter (e.g., relative to the first predetermined shape / construction, relative to a reduced diameter state, relative to a relaxed state, relative to a relaxed room temperature state, relative to a cooled state, etc.). In some embodiments, the expansion diameter may be the size for implantation at the defective natural heart valve. In some embodiments, the expansion diameter may be at least 30 mm.

[0019] In some implementations, the shape of the shape memory material can be set to a plurality of predetermined shapes / structures by applying cyclic thermal loads under a substantially constant stress field.

[0020] In some implementations, the second predetermined shape / construction of the support stent is advantageously sized for implantation in a natural valve, such as an aortic valve, mitral valve, tricuspid valve, pulmonary valve, etc.

[0021] In some embodiments, the valve structure may be attached to a support structure. In some embodiments, the valve structure may be sutured to a support structure. In some embodiments, the valve structure may be sutured to a covering, fabric, material, component, etc., which is itself connected (e.g., sutured, adhered, fused, etc.) to the support structure.

[0022] In some embodiments, the device may include a fabric skirt that is positioned around a support structure to enhance the seal.

[0023] In some implementations, the device may have a proximal inflow end and a distal outflow end.

[0024] In some implementations, the support structure may include one or more (e.g., two, three, four, etc.) radially compressible frames.

[0025] In some embodiments, the support structure may include one or more extensions or arms (e.g., leaflet capturing arms, anchoring arms, anchoring extensions, anchors, etc.) extending from one or more frames. In some embodiments, one or more or each of the arms may be shape memory trained or configured into multiple shapes / constructions.

[0026] In some embodiments, one or more of the arms may be trained or configured by shape memory to switch or transform between a first shape / construction (e.g., an unfolding shape / construction, etc.) and a second shape / construction (e.g., a delivery shape / construction, etc.). In some embodiments, one or more of the arms may be trained or configured by shape memory to switch from the first shape / construction or transform into the second shape / construction when cooled to a first temperature below body temperature. In some embodiments, one or more of the arms may be trained or configured by shape memory to switch from the second shape / construction or transform into the first shape / construction when heated to a second temperature (e.g., body temperature, a temperature above body temperature, a temperature close to body temperature, etc.).

[0027] In some embodiments, one or more of the arms may be shape-memory trained or configured to switch or transform between a first shape / construction (e.g., an unfolding shape / construction, etc.) and a second shape / construction (e.g., a delivery shape / construction, etc.), in which one or more of the arms extend radially outward from a support structure and / or device, and in the second shape / construction, the arms are radially inward relative to their position in the unfolding shape. In some embodiments, one or more of the arms may be shape-memory trained or configured to switch or transform from the first shape / construction to the second shape / construction when cooled to a first temperature below body temperature, in which one or more of the arms extend radially outward from a support structure and / or device, and in the second shape / construction, the arms are radially inward relative to their position in the unfolding shape. In some implementations, one or more of the arms may be shape-memory trained or configured to transform from a second shape / construction or into a first shape / construction when heated to a second temperature (e.g., body temperature, a temperature above body temperature, a temperature close to body temperature, etc.), in which the arms are radially inward relative to their position in the unfolded shape, and in the first shape / construction, one or more of the arms extend radially outward from the support structure and / or device.

[0028] In some embodiments, the outflow end of the device and / or support structure may first exit from the delivery sheath (e.g., before the inflow end). In some embodiments, an arm / extension (e.g., a leaflet capturing arm, anchoring arm, anchoring extension, etc.) may extend distally from or relative to the outflow end. In some embodiments, the arm / extension may extend outward (e.g., radially outward, etc.) from or relative to the surface of the support structure. In some embodiments, the arm / extension may extend in a first direction relative to the outflow end and then transition to extending in a second direction relative to the outflow end, different from the first direction. In some embodiments, the arm / extension may extend in a first direction relative to the axis of the support structure and then transition to extending in a second direction relative to the axis, different from the first direction.

[0029] In some implementations, the arm / extension may be curled, bent, or flexed about 180° in a first shape / construction (e.g., to unfold into a shape / construction, etc.).

[0030] In some embodiments, the arm / extension may have a straight shape or an extended shape (e.g., a shape straighter than the first shape / construction) in a second shape / construction (e.g., a conveying shape / construction). In some embodiments, the arm / extension may be configured to extend in a distal direction relative to the outflow end or relative to the support structure.

[0031] In some implementations, a miniature electric cooler can be mounted on each leaflet capture arm to cool the arm below body temperature.

[0032] In some implementations, a miniature electric heater may be mounted on each leaflet capture arm to heat the arm to a desired temperature (e.g., to body temperature, to a temperature close to body temperature, to a temperature above body temperature, etc.).

[0033] In some embodiments, the device includes one or more frames. In some embodiments, the one or more frames are radially compressible. In some embodiments, the one or more frames are radially expandable. In some embodiments, the one or more frames may include and / or have pillars formed thereon, the pillars comprising and / or being made of shape memory material. In some embodiments, the one or more frames can be trained / set to radially tighten when the temperature decreases. In some embodiments, when subjected to a first temperature below body temperature, the one or more radially compressible frames can be trained / set to radially tighten or compress.

[0034] In some embodiments, the arm / extension (e.g., leaflet capturing arm, anchoring arm, anchoring extension, etc.) is integrally formed with at least one of one or more frames. In some embodiments, the one or more frames include an inner frame and an outer frame. In some embodiments, the arm / extension (e.g., leaflet capturing arm, anchoring arm, anchoring extension, etc.) may be integrally formed with the inner frame. In some embodiments, the arm / extension (e.g., leaflet capturing arm, anchoring arm, anchoring extension, etc.) may be integrally formed with the outer frame.

[0035] In some embodiments, the delivery system may include a control handle. In some embodiments, the delivery system may include a flexible access sheath or catheter with a lumen. In some embodiments, the delivery system may include a delivery catheter (which may supplement or replace the flexible access sheath / catheter). In some embodiments, the delivery system may include a device (e.g., a treatment device, replacement device, repair device, implant, artificial heart valve, etc.) and / or be coupled to said device, which may be the same as or similar to any device described herein or other known devices.

[0036] In some embodiments, the delivery catheter extends distally from the control handle. In some embodiments, the delivery catheter has an outer diameter sized to fit through a lumen into the sheath. In some embodiments, the delivery catheter forms a lumen through which it extends. In some embodiments, the delivery catheter has a distal pouch at its distal end region.

[0037] In some embodiments, the device includes a support structure or bracket made of or comprising a shape memory material, the shape memory material being adapted to transform into a first predetermined shape / structure upon cooling and into a second predetermined shape / structure upon heating.

[0038] In some embodiments, the device may include a one-way valve structure mounted within the lumen of a support structure or stent. In some embodiments, the device has a proximal inflow end and a distal outflow end. In some embodiments, the device is adapted to collapse radially and is loaded in the distal pocket or distal region of the delivery catheter with the inflow end facing forward.

[0039] In some embodiments, the support structure or bracket may have metal struts made of or including shape memory materials. In some embodiments, the support structure or bracket is trained or set to radially tighten when the temperature decreases. In some embodiments, the support structure or bracket may have one or more frames. In some embodiments, one or more frames are radially compressible. In some embodiments, one or more frames are radially expandable.

[0040] In some embodiments, the device and / or support structure may have arms / extensions extending therefrom (e.g., leaflet capturing arms, anchoring arms, anchoring extensions, anchors, etc.). In some embodiments, the arms / extensions extend radially outward relative to the support structure. In some embodiments, the arms / extensions extend from the outflow end or outflow end region of one of the frames. In some embodiments, the arms / extensions extend from a middle region of one of the frames. In some embodiments, the arms / extensions extend from the inflow end or inflow end region of one or more frames. In some embodiments, the arms / extensions extend from multiple different regions of one or more frames. In some embodiments, the arms / extensions extend distally relative to one or more of the frames.

[0041] In some embodiments, the arm / extension has a curved or coiled shape. In some embodiments, the arm / extension has a portion that extends distally and then turns, bends, or coils to extend proximally. In some embodiments, the arm / extension is configured to extend distally from the outlet end and coil in an unfolded shape about 180°.

[0042] In some embodiments, the arm / extension may extend radially outward and then move radially inward, for example, to capture tissue. In some embodiments, the arm / extension may be configured to extend in a first direction in a first configuration and in a second direction (different from the first direction) in a second configuration. Various configurations of the frame and arm / extension, as well as various combinations thereof, are possible.

[0043] In some embodiments, one, some, or all of the arms / extensions are shape-memory trained / set to transform into a first shape / construction at a first temperature. In some embodiments, one, some, or all of the arms / extensions are also shape-memory trained / set to transform into a second shape / construction at a second temperature, the second shape / construction being different from the first shape / construction, and the second temperature being different from the first temperature.

[0044] In some embodiments and at various locations within this disclosure, when a shape memory material is trained or configured to transform into a first preset shape / construction at a first temperature and trained or configured to transform into a second preset shape / construction at a second temperature, the material, apparatus, process, etc., may be referred to as "bidirectional," "dual-shape," or "multi-shape," such as "bidirectional shape memory material," "dual-shape memory material," "bidirectional shape memory device," "bidirectional shape memory component," "multi-shape memory material," etc. "Multi-shape" encompasses bidirectional but is not limited to bidirectional. In some embodiments, the material, apparatus, frame, extension, etc., may be movable into other configurations (e.g., by heating and / or cooling), but is trained / configured to transform from other configurations (e.g., intermediate shape / construction, third shape / construction, fourth shape / construction, end-user-induced shape / construction, etc.) into a first preset shape / construction upon reaching a first temperature, and to transform into a second shape / construction upon reaching a second temperature.

[0045] In some embodiments, one, some, or all of the arms / extensions can be trained / configured to transform from a first shape / construction or unfolded shape / construction to a second shape / construction or delivery shape / construction, in which the arms / extensions extend radially outward from or relative to the device, and in the second shape / construction or delivery shape / construction, the arms / extensions extend radially inward relative to the first shape / construction or unfolded shape / construction. In some embodiments, the transformation can be configured to occur upon cooling to a temperature below body temperature.

[0046] In some embodiments, in the conveying shape / construction, the arm / extension extends into a straight shape (e.g., relatively straighter than an unfolded shape / construction). In some embodiments, the arm / extension extends in a distal direction in the conveying configuration.

[0047] In some embodiments, one or more frames may be formed with struts made of or including shape memory material. In some embodiments, one or more frames are trained or configured to radially tighten or compress when the temperature decreases, such as when subjected to a temperature below body temperature, or when subjected to a temperature at least 20 degrees or more below body temperature.

[0048] In some embodiments, the arm / extension may be integrally formed with one or more frames. In some embodiments, the one or more frames include an inner frame and an outer frame. In some embodiments, the arm / extension is integrally formed with the inner frame. In some embodiments, the arm / extension is integrally formed with the outer frame.

[0049] In some embodiments, the arm / extension may be formed separately but coupled or connected to one or more frames. In some embodiments, the one or more frames include an inner frame and an outer frame. In some embodiments, the arm / extension is coupled to or connected to the inner frame. In some embodiments, the arm / extension is coupled to or connected to the outer frame.

[0050] In some embodiments, the delivery system (e.g., any delivery system disclosed herein) may include multiple flexible tethers. In some embodiments, each of the multiple tethers emerges from a retraction hub within a distal sac. In some embodiments, the multiple tethers wrap around one or more eyelets on a strut at the inflow end of one or more frames. In some embodiments, the flexible tethers are adapted to pull the device into the distal sac or distal region of the delivery conduit.

[0051] In some embodiments, a method of loading a device (e.g., a therapeutic device, a replacement device, a repair device, an implant, an artificial heart valve, etc.) into a delivery system includes providing or obtaining a delivery system (which may be the same as or similar to any delivery system disclosed herein and may incorporate some or all of the delivery system features disclosed herein). In some embodiments, the delivery system has a proximal control handle. In some embodiments, the delivery system has a flexible entry sheath having a lumen (e.g., an entry sheath lumen, a first lumen, etc.).

[0052] In some embodiments, the delivery system has a delivery conduit extending distally from or relative to a control handle. In some embodiments, the delivery conduit has an outer diameter sized to fit through a lumen into an access sheath. In some embodiments, the delivery conduit has a lumen extending therethrough (e.g., a delivery conduit lumen, a second lumen, etc.). In some embodiments, the delivery conduit has a distal pouch or distal device retention area at its distal end.

[0053] In some embodiments, the method includes providing or obtaining a device (e.g., a treatment device, replacement device, repair device, implant, artificial heart valve, etc.), which may be the same as or similar to any device disclosed herein and may incorporate some or all of the device features disclosed herein. In some embodiments, the device includes a support structure or scaffold made of multi-shape or bi-directional shape memory material.

[0054] In some embodiments, the material is constructed, trained, set, etc., to transform into a first preset shape / structure upon cooling and into a second preset shape / structure upon heating. In some embodiments, the material is constructed, trained, set, etc., to transform into a first preset shape / structure upon cooling to a first temperature and into a second preset shape / structure upon heating to a second temperature different from the first temperature.

[0055] In some embodiments, the device may optionally include a one-way valve structure mounted within the lumen of a support structure or stent. In some embodiments, the device has a proximal inflow end and a distal outflow end.

[0056] In some embodiments, the device is configured such that it can collapse radially and be loaded into the distal pouch or distal retention region in an inflow-end-forward manner.

[0057] In some embodiments, the method includes positioning the proximal end of the device (e.g., the inflow end, etc.) adjacent to the distal end of the distal pouch or distal retention region.

[0058] In some embodiments, when the proximal end of the device is positioned adjacent to the distal end of the distal pouch or the distal retention region, the support structure or bracket of the device is in a first shape / construction (e.g., unfolding construction, expansion construction, etc.).

[0059] In some embodiments, the method includes a cooling device to radially tighten or compress the support structure. In some embodiments, the method includes a cooling device to radially tighten or compress the support structure or bracket into a second shape / construction (e.g., a conveying structure, a loading structure, a collapse structure, a tightening structure, etc.).

[0060] In some embodiments, the device includes an arm / extension (which may be the same as or similar to any arm / extension disclosed anywhere herein). In some embodiments, the arm extends in a first shape / construction (e.g., unfolding construction, expansion construction, etc.) along a first direction. In some embodiments, in the first shape / construction, the arm / extension extends radially outward (or in a radially outward direction) relative to the outer wall of the support structure. In some embodiments, in the first shape / construction, the distal end of the arm / extension extends in a proximal direction (e.g., the first direction is the proximal direction). In some embodiments, in the first shape / construction, the distal end of the arm / extension extends in a distal direction (e.g., the first direction is the distal direction). In some embodiments, in the first shape / construction, the arm / extension extends in a distal direction and then bends back or rolls back in a proximal direction.

[0061] In some embodiments, the method includes a cooling device to change the arm / extension from a first shape / construction to a second shape / construction (e.g., a conveying structure, a loading structure, a collapsing structure, a tightening structure, etc.). In some embodiments, in the second shape / construction, the arm / extension extends in a second direction different from the first direction. In some embodiments, in the second shape / construction, the distal end of the arm / extension extends in a second direction different from the first direction. In some embodiments, in the second shape / construction, the arm / extension has a shape different from that in the first shape / construction (e.g., straight versus bent, etc.).

[0062] In some embodiments, the method includes a cooling device to cause (1) the support structure to be radially tightened or compressed, and (2) the arm / extension to be transformed into a different shape and / or pointed in a different direction (e.g., in a second shape / construction).

[0063] In some embodiments, the method includes loading the device into the distal pouch or distal retention region of the delivery catheter.

[0064] In some embodiments, the miniature electric cooler may be mounted on a support structure and / or one or more arms / extensions. In some embodiments, the cooling step includes energizing the miniature electric cooler.

[0065] In some implementations, the cooling step includes immersing the device in an ice bath or a cold saline solution.

[0066] In some implementations, the cooling step includes bringing a fluid with a temperature lower than that of the device into contact with or near the device.

[0067] In some embodiments, one or more frames may be formed with or include struts made of shape memory material. In some embodiments, one or more frames may be trained to radially tighten as the temperature decreases. In some embodiments, the cooling step includes cooling the struts to cause them to radially tighten.

[0068] In some embodiments, the delivery system may include multiple flexible tethers. In some embodiments, the tethers emerge from a retraction hub in the distal sac or distal capture region. In some embodiments, the tethers wrap around one or more eyelets on a support structure's strut (e.g., an eyelet at the inflow end of the support structure). In some embodiments, the loading step includes pulling the flexible tethers proximally to draw the device into the distal sac or distal holding region.

[0069] In some implementations, a funnel or other loading device with a narrow end can be fitted into the distal pouch to facilitate loading the device into the distal pouch or distal retention area.

[0070] In some embodiments, the delivery system may include an inner tubular member. In some embodiments, the inner tubular member is movable within a distal pouch or a distal holding region. In some embodiments, the inner tubular member includes a holding member at its distal end, said holding member being movable within a distal pouch or a distal holding region.

[0071] In some embodiments, the retaining member has an orifice for receiving and capturing a proximal strut at the proximal end or inflow end of one or more frames. In some embodiments, the loading step includes capturing the proximal strut in the orifice and pulling the inner tubular member proximally to pull the device into the distal pouch or distal retaining region.

[0072] In some embodiments, the delivery system includes a proximal control handle. In some embodiments, the delivery system includes a delivery conduit having a pouch (or distal retention region) along its distal portion. In some embodiments, the delivery conduit includes a curved section located proximal to the pouch. In some embodiments, the curved section has deformable filaments incorporated into its wall.

[0073] In some implementations, the expandable device (e.g., treatment device, replacement device, repair device, implant, artificial heart valve, etc.) is adapted to collapse radially and be positioned within a pocket to propel the vascular system through a subject (e.g., a living subject, a simulant, etc.).

[0074] In some embodiments, the delivery system may be configured such that energizing the deformable wire causes deflection of the delivery conduit. In some embodiments, the delivery system may be configured such that electrically heating the deformable wire causes deflection of the delivery conduit.

[0075] In some embodiments, the delivery system may be configured such that energizing the deformable wire causes bending in the curved section of the delivery conduit. In some embodiments, the delivery system may be configured such that electrically heating the curved section of the delivery conduit causes bending of the deformable wire.

[0076] In some implementations, the deformable wire is ideally made of nitinol.

[0077] In some implementations, the temperature of the filament is changed to produce a desired change in length.

[0078] In some implementations, the delivery system includes at least four deformable wires evenly distributed around the wall of the delivery conduit or around the wall of a curved section of the delivery conduit.

[0079] In some implementations, the delivery system includes an optional nose cone.

[0080] In some embodiments, the access sheath extends from the control handle to the nasal cone. In some embodiments, the delivery catheter extends from the control handle to the nasal cone. In some embodiments, the inner tubular member extends from the control handle to the nasal cone.

[0081] In some embodiments, the control handle has a fluid port communicating with an internal channel through an access sheath. In some embodiments, the control handle has a fluid port communicating with an internal channel through a delivery conduit. In some embodiments, the control handle has a fluid port communicating with an internal channel through an inner tubular member.

[0082] In some embodiments, the delivery system (e.g., inlet sheath, delivery catheter, etc.) includes concentric tubes with overlapping ends. In some embodiments, the concentric tubes are inside the inlet sheath. In some embodiments, the concentric tubes are inside the delivery catheter. Concentric tubes can be used in various types of catheters. In some embodiments, the first concentric tube has a coupling pin that snaps into an axially oriented retaining groove on the second tube. In some embodiments, the axially oriented retaining groove is defined by a pair of axially oriented lateral fingers formed of a shape memory material trained / set to be rigid at body temperature and more flexible when cooled.

[0083] In some embodiments, the internal channel terminates at the overlapping end of the tube. In some embodiments, an expandable device adapted for radial collapse is positioned within the pouch to propel through the vascular system.

[0084] In some implementations, introducing cold fluid into the fluid port makes the flank fingers more flexible, which helps to remove the engagement pin from the retaining groove and disengage the tube.

[0085] In some implementations, two engagement pins may be present on the diameter-opposite side of the first tube, and two retaining grooves may be present on the diameter-opposite side of the second tube.

[0086] In some embodiments, the first tube may be larger than the second tube. In some embodiments, the engagement pin extends radially inward from the first tube.

[0087] In some embodiments, the spacing between the flank fingers may be less than the diameter of the engaging pin. In some embodiments, the retaining groove may have a generally circular clearance hole at its inner end for receiving the engaging pin.

[0088] In some embodiments, the first tube in the concentric tubes has at least one curved tab that cantilevered across an opening in the sidewall of the first tube and extended into a similarly shaped opening in the sidewall of the second tube. In some embodiments, the at least one curved tab creates an interference between the two tubes, thereby preventing relative axial and rotational displacement between them.

[0089] In some embodiments, the bending tab is formed of a shape memory material trained to be in a martensitic state at body temperature, and the austenite transformation temperature is set above body temperature, causing the bending tab to straighten above the austenite transformation temperature. In some embodiments, heating the bending tab causes it to straighten and disengage from the opening, allowing relative axial and rotational displacement of the tube.

[0090] In some embodiments, two curved tabs may be present on the diameter-opposite side of the first tube, and two openings may be present on the diameter-opposite side of the second tube. In some embodiments, the first tube is larger than the second tube, and the curved tabs extend radially inward into the openings.

[0091] In some implementations, the bent tabs can be formed into an S-shape before heating.

[0092] In some implementations, the austenite transformation temperature can be about 110ºF.

[0093] In some embodiments, the control handle may have a fluid port communicating with an internal channel through a distal sheath. In some embodiments, the internal channel terminates at an overlapping end of the tube, wherein introducing hot fluid into the fluid port heats the bent tab. In some embodiments, the system includes electrical contacts positioned adjacent to the bent tab, wherein energizing the electrical contacts heats the bent tab.

[0094] In some implementations, the sidewalls of the pouch or distal retention region may be formed at least partially by a nitinol element or other shape memory element trained to contract in response to temperature changes.

[0095] In some embodiments, the nitinol element (or other shape memory element) may be in the form of a braided or woven tube. In some embodiments, the system includes electrical leads connected to the braided tube, such that the braided tube and the pouch tighten as electrical energy or heat is applied to the braided tube.

[0096] In some implementations, the braided tubing can be trained to shrink when cooled.

[0097] In some embodiments, the control handle may have a fluid port communicating with an internal channel terminating at the pouch. In some embodiments, introducing cold fluid into the fluid port will cool the braided tubing.

[0098] In some embodiments, the nitinol / shape memory element is in the form of one or more helically wound filaments. In some embodiments, the system may have electrical leads connected to the helically wound filaments, such that the filaments and the sac tighten as electrical energy or heat is applied to the filaments.

[0099] In some implementations, the filament can be trained to contract upon cooling. In some implementations, introducing cold fluid into the fluid port will cool the filament.

[0100] Any of the methods described above, as well as any methods using the systems, assemblies, devices, equipment, etc., described herein, can be performed on a living subject (e.g., a human or other animal) or a simulated object (e.g., a corpse, a corpse heart, an imagined person, a simulator, etc.). Through simulation, body parts may optionally be referred to as “simulated” (e.g., simulated heart, simulated tissue, etc.) and may optionally include computerized and / or physical representations.

[0101] Any of the aforementioned systems, assemblies, devices, equipment, components, etc., may be sterilized (e.g., using heat, radiation, ethylene oxide, hydrogen peroxide, etc.) to ensure their safe use in patients, and the methods described herein may include (e.g., using heat, radiation, ethylene oxide, hydrogen peroxide, etc.) sterilizing one or more of the systems, devices, equipment, components, etc. described herein (or additional methods may include or consist of said sterilization).

[0102] A further understanding of the nature and advantages of the invention will become apparent from the remainder of the specification and the accompanying drawings. Attached Figure Description

[0103] The features and advantages of the invention will become more readily apparent with reference to the specification, claims, and drawings, in which:

[0104] Figure 1 This is a perspective view of a device configured as a transcatheter heart valve, which can be modified according to the principles described herein;

[0105] Figure 2 It is formed Figure 1 A perspective view of a double-frame or double-support assembly, which is part of the device;

[0106] Figure 3 yes Figure 2 Exploded view of the double-frame assembly;

[0107] Figure 4 yes Figure 2A cross-sectional view of a dual-frame assembly having a miniature cooler or heater mounted on the underside of each leaflet capture arm;

[0108] Figure 5 It can be used Figure 4 A perspective view of an exemplary miniature cooler or heater of a dual-frame assembly;

[0109] Figure 6A This is a schematic cross-sectional view of the heart, showing the penultimate step in an exemplary mitral valve replacement surgery using a transcatheter valve delivery system;

[0110] Figure 6B This is an enlarged view of a transcatheter heart valve, showing the arm of the device extended;

[0111] Figures 7A-7C The sequence of using a funnel to tighten a transcatheter heart valve for fitting into the distal end of the delivery system is illustrated.

[0112] Figures 8A-8C The sequence of the staged tightening device for assembly into the distal end of the conveying system is schematically shown.

[0113] Figures 9A-9C The sequence of staged tightening of the transcatheter heart valve for fitting into the distal end of the delivery system is illustrated.

[0114] Figure 10 This is an exploded view of an exemplary conveyor system;

[0115] Figure 11A The overlapping ends of concentric tubes within a conveying system and the joining structure therebetween utilizing shape memory components are shown. Figure 11B The two tubes are shown after disassembly;

[0116] Figure 12A The overlapping ends of concentric tubes within the conveying system and the joining structure utilizing shape memory components are shown. Figure 12B This is an enlarged view of the joint structure;

[0117] Figure 12C yes Figure 12A A side view of the overlapping tube shows the junction structure connected by the electrode side. Figure 12D The engagement structure is shown after it has been activated for disassembly, and Figure 12E The two tubes are shown after disassembly;

[0118] Figure 13 This is an exploded side view of an exemplary conveying system having a proximal control handle and the ability to bend a distal region;

[0119] Figure 14yes Figure 13 An enlarged view of the curved section within the distal end of the conveyor system, as seen in the image. Figure 14A This is a cross-sectional view of the curved section, showing multiple shape memory tie rods within it, and Figure 14B This is a radial cross-sectional view of the curved section;

[0120] Figure 15 This is a schematic cross-sectional view of the heart, illustrating steps in an exemplary treatment procedure utilizing a transcatheter delivery system;

[0121] Figure 16A and 16B yes Figure 15 Side view before and after radial reduction of the distal pouch size in a transcatheter delivery system;

[0122] Figure 17 This is a cross-sectional view of the distal pouch, showing an example of a deformable structure used to tighten its radial cross-section, and Figure 17A This is a schematic diagram of the circuit used to initiate tightening;

[0123] Figure 18 This is a cross-sectional view of the distal pouch, showing a second example of a deformable structure used to tighten its radial cross-section, and Figure 18A This is a schematic diagram of the circuit used to initiate tightening; and

[0124] Figure 19A and 19B A deformable element that can be incorporated into a conveying system is shown. Detailed Implementation

[0125] The right and left ventricles are separated from the right and left atria by the tricuspid and mitral valves, respectively, i.e., atrioventricular valves. A septal wall extends between the right and left atria. This specification and accompanying drawings provide aspects and features of this disclosure in the context of several embodiments of therapeutic devices, replacement heart valves, delivery systems, methods, etc., configured as vascular systems for subjects (e.g., living subjects, simulants, etc.), such as for treating (e.g., replacing, repairing, etc.) the natural heart valves of subjects. Valve treatment in the mitral or tricuspid valve is the primary focus of the examples in this application; however, the characteristics of the delivery systems described herein can also be used for other valve locations, and therefore, unless explicitly limited, the claims should not be limited to mitral or tricuspid valve replacement only.

[0126] In some embodiments, the delivery system described herein can be used to percutaneously deliver a therapeutic device (e.g., a mitral valve replacement or repair device) via the femoral artery to the mitral valve to treat patients with moderate to severe mitral regurgitation (or to the tricuspid valve to treat moderate to severe tricuspid regurgitation). In some cases, for safety and / or other reasons, the disclosed device can be delivered from the atrial side of the atrioventricular valve or the atrioventricular valve annulus. For example, a transatrial approach can be performed through the atrial wall, which can be accessed, for example, through an incision across the chest. Atrial delivery can also be performed intravascularly, for example, from the pulmonary veins. Prosthetic valves can be delivered to the right atrium via the inferior vena cava or superior vena cava.

[0127] In some cases, left atrial delivery can be performed via a transdiaphragmatic approach. In the transdiaphragmatic approach, an incision is made in the atrial portion of the diaphragm wall to allow access from the right atrium to the left atrium (access can be made via one or more of various transcatheter methods, such as via the jugular vein, via the femoral artery, etc.).

[0128] In simple terms, the treatment device can be delivered via transvenous, transatrial, transjugular, and / or transfemoral methods, with minor or minimal modifications to the delivery process. Any method that travels through any vascular system can also be referred to as a transvascular method.

[0129] Exemplary transvascular methods can be found in U.S. Patents Nos. 10,004,599 and 10,813,757, the entire contents of which are incorporated herein by reference for all purposes, but similarly, various methods are possible.

[0130] Delivery systems can involve numerous actuators and components that cooperate to assist in the navigation and deployment of medical implants within the body. Delivery systems can be complex mechanical devices that can be costly to manufacture and difficult to operate. Therefore, there is a need for simplified and less complex delivery systems that can achieve the desired purpose. Various solutions to meet these needs are described below.

[0131] In some embodiments, this document discloses convertible elements of devices and / or delivery systems utilizing shape memory materials such as nitinol (NiTi). Shape memory materials are capable of returning to a previously defined shape or size upon appropriate heat treatment. This behavior is based on a substantially reversible phase transition that occurs when the material's temperature is above and below its transition (or transformation) temperature. For example, a cold sample of the material deforms, causing it to change its shape. However, after being heated above a certain characteristic temperature, the sample "remembers" its original shape and spontaneously returns to said original shape. Such materials also exhibit other attractive properties when subjected to mechanical stress, such as hyperelasticity (aka pseudoplasticity). Depending on temperature, the material can exist in several forms of internal arrangement.

[0132] Nickel-titanium alloys possess three stable, temperature-dependent microstructure phases: austenite, the R phase, and martensite. In the nomenclature, Rs, Rf, Ms, Mf, Rs', Rf', As, and Af denote the start or end temperatures of a specific transformation, where "s" indicates the start and "f" indicates the end. The specific temperature at which the transformation occurs depends on several factors, including the material's chemical composition (e.g., the nickel-to-titanium ratio, impurities, etc.) and how the material is heat-treated. In some cases, upon heating, the material can bypass the R phase and transform directly from martensite to austenite.

[0133] NiTi alloys transform from austenite to martensite when cooled from a temperature below the initial temperature Ms. Mf is the final temperature at which the transformation to martensite is completed during cooling. Similarly, during heating, As and Af are the temperatures at which the transformation from martensite to austenite begins and ends. U.S. Patents Nos. 6,837,901 and 7,524,329 provide additional background information on shape memory materials and are incorporated herein by reference.

[0134] The shape memory effect in medical devices is typically unidirectional, meaning that the spontaneous change from one structure to another occurs only at a single temperature (e.g., upon heating). (Stress is typically required to obtain the second structure at a temperature below the transition temperature.) However, as indicated herein, it is possible to obtain a bidirectional shape memory effect, in which the shape memory material transforms into a first predetermined shape / structure upon cooling and then into a second predetermined shape / structure upon heating.

[0135] The multi-shape memory effect (which is often described herein as a bidirectional shape memory effect for illustrative purposes) involves shape changes at multiple transition temperatures. For example, as a bidirectional shape memory effect, the multi-shape memory effect can involve shape changes below the second transition temperature during cooling and above the first transition temperature during heating.

[0136] Materials can remember multiple (e.g., two, three, etc.) different shapes. For example, a material can remember or be programmed to exhibit one shape at low temperatures and another at high temperatures. Materials that exhibit shape memory effects during heating and cooling are said to have bidirectional shape memory. The reason materials behave so differently in these cases is due to training or programming. Training means that shape memory can "learn" to behave in a certain way. Under normal conditions, a shape memory alloy "remembers" its low-temperature shape, but immediately "forgets" it once heated to recover its high-temperature shape. However, it can be "trained" to "remember," or leave some trace of the low-temperature deformed state in the high-temperature phase. One way to train a shape memory alloy (SMA) involves applying cyclic thermal loads under a constant stress field.

[0137] One method for achieving a bidirectional shape memory effect involves first establishing a standard shape. Then, "training" can be performed by cooling the material below its Af (making it twinned martensite) and then applying stress to change its shape—by applying cyclic thermal loading under a substantially constant stress field. The material is then heated back above its Af, making it austenitic. At this point, the geometry should revert to its original shape after the initial shape setting. This training is repeated multiple times as needed until the material, upon cooling (converting to the R phase or martensite), will transform into the "trained" shape / form without stress application.

[0138] In the standard setting of the first shape / construction and the training of the second shape / construction, the predetermined or preset shape / construction can be slightly adjusted over time; that is, the shape can drift or change slightly over time, especially under repeated heating and cooling. Various embodiments described herein refer to “first shape,” “first construction,” “second shape,” “second construction,” “predetermined shape,” “predetermined construction,” “preset shape,” “preset construction,” etc. These shapes / constructions do not need to be 100% rigid and immutable, but can have some slight drift while still being considered a specific shape / construction. For example, multiple transitions between a curved shape and a straightened shape may cause the degree of curvature of the curved shape to decrease slightly over time, or the degree of straightness of the straightened shape to decrease slightly over time, but these shapes are still two different predetermined or preset shapes and are still considered the same “first shape,” “second shape,” “predetermined shape,” “preset shape,” etc., when using these terms.

[0139] The convertible element can be both self-expanding and self-shrinking. The aforementioned convertible element utilizing the bidirectional shape memory effect can be both self-shrinking and self-expanding. In some embodiments, the convertible element can be configured to be self-expanding and / or self-shrinking. In some embodiments, the convertible element can include more than one shape memory material. In some embodiments, the transition temperature at which each shape memory material returns to its initial state can be different. Each shape memory material can exhibit a unidirectional shape memory effect. For example, the convertible element can be partially included in a first shape memory material and partially included in a second shape memory material, the first shape memory material expanding to its initial state at or above a first transition temperature, and the second shape memory material shrinking to its initial state at or above a second transition temperature. The first shape memory material and the second shape memory material can have different compositions and / or different processing histories.

[0140] The convertible element described herein can be formed from shape memory materials, such as Ni-Ti alloys (e.g., nitinol), Cu-Al-Ni alloys, or Cu-Zn-Al alloys. Shape memory alloys can exhibit unidirectional or bidirectional shape memory effects. Preferably, the convertible element can be composed of a Ni-Ti binary alloy. For example, the alloy may contain about 51 atomic percent Ni. The balance may be substantially Ti. Additionally, the binary alloy may contain very small concentrations of elements other than nickel or titanium, such as parts per million of copper. Optionally, the convertible element can be made of a ternary or quaternary Ni-Ti alloy containing one or more additional alloying elements, such as Al, Ag, Au, Cu, Fe, Ga, Hf, Ir, Nb, Pd, Pt, Rh, Ta, or W. In some embodiments, the convertible element may contain more than one shape memory alloy.

[0141] Figure 1 This is a perspective view of the device, which is configured as a transcatheter heart valve 20 that can be modified according to the principles described herein (although artificial heart valves are generally used for illustrative purposes herein, it should be understood that similar principles can be applied to other therapeutic devices (e.g., prosthetic devices, other implants, etc.).

[0142] Figure 2 This is a perspective view of the double-frame or double-support assembly 22, which is part of the forming device, and Figure 3 This is an exploded view. The device or heart valve 20 is shown in an expanded configuration, which occurs upon implantation. The device or heart valve 20 has an outer support or frame 24 surrounding and generally overlapping an inner support or frame 26, both of which are arranged around a central axis 28. Frames 24, 26 may be made of a biocompatible metal and are formed by multiple connected struts for tightening and expanding.

[0143] In some implementation schemes, such as Figure 2 As seen, the upper support 30 of the outer frame 24 extends higher than the upper support 32 of the inner frame 26, while the lower leaflet capturing arm 34 of the inner frame 26 curls downward and radially outward from the lower end 36 of the outer support in an unfolded shape by 180°. In some embodiments, the arm or extension 34 is shown or described as a leaflet capturing arm or anchoring arm for illustrative purposes, but various arms / extensions can be used for various purposes in various configurations (i.e., even though "leaflet capturing arm" is used as an example herein, it should be understood that other types of arms / extensions can also be used in various ways).

[0144] In some implementations, the arm 34 has a relaxed configuration when curled in this manner, a configuration that occurs after reaching body temperature. As will be seen below, although the arm 34 is integrally formed with the inner frame 26, the arm can be individually trained or programmed to change shape in a different manner than the rest of the inner frame upon cooling. Similarly, the supports of the inner frame 26, other than the arm 34, can be trained or programmed to change shape in a specific manner upon cooling.

[0145] Figure 1 An outer fabric cover 40 surrounding the outer frame 24 and an inner fabric panel 42 within the inner frame 26 are shown. The fabric cover 40 and panel 42 are preferably sewn to various locations on the respective frames 24, 26 and can be formed from a single piece or multiple pieces of fabric. A portion of a flexible leaflet 44 is seen through an opening 46 defined by the inner fabric panel 42. Multiple such leaflets 44 are attached, for example, by sewing to the fabric panel 42 and surrounding support structures to form a closure surface within an axial flow orifice defined by the valve 20.

[0146] Still Figure 1 As seen herein, each arm 34 of the inner frame 26 has a fabric tube 50 along most of its length and a rounded fabric bulb 52 at its apex. The device or transcatheter heart valve 20 is configured for implantation at one of the atrioventricular valves, namely the mitral or tricuspid valve. Not all devices described herein require implantation; that is, some devices can be used to administer treatment and will be removed rather than implanted indefinitely.

[0147] In the atrioventricular valves, blood flows from the left or right atrium into the left or right ventricle. Figure 1 In this context, valves are depicted with a conventional up-down orientation, where blood flows downwards. Blood depicted or described as flowing downwards typically flows downstream (even if the heart is not oriented up-down relative to the ground). The inflow or upstream direction is typically depicted and / or referred to as upwards, and the downstream or downstream direction is typically depicted and / or referred to as downwards.

[0148] In some implementations, arm 34 may be covered with fabric. Fabric tube 50 and fabric end 52 cover the originally sharp edges of the stent arm 34 and protect the heart valve tissue from excessive damage.

[0149] In some implementations, arm 34 is designed to extend into the ventricle and around the outside of the natural heart valve leaflet. Thus, arm 34 helps to anchor the heart valve 20 in place.

[0150] Figure 4This is a cross-sectional view of the dual-support assembly 22, modified using miniature Peltier coolers 60 mounted on the underside of each leaflet capturing arm 34. The miniature coolers 60 are positioned at the midpoint of a 180° bend in the arm 34 and are powered via filaments 62 extending upward between the dual frames 24, 26. Although not shown, the filaments 62 may pass through a conveying system on which actuators for energizing the coolers 60 are provided. The miniature coolers 60 used in this configuration are available from TEC Microsystems GmbH, Berlin, Germany. Similar miniature heaters, constructed in a similar manner but providing heat, may optionally be used, additionally or alternatively, in various embodiments described herein in a similar manner.

[0151] Figure 5 This is a perspective view of an exemplary microcooler 60 that can be used to modify the dual-support assembly 22. The cooler 60 may include a Peltier element. A Peltier element is an electrical component known in the art and has a cold side and a warm side when subjected to direct current. The temperature difference between the warm and cold sides can be controlled, and the cold and warm sides can be reversed by reversing the polarity. Typically, a Peltier element consists of a number of semiconductor components (also called pn junctions) mounted between two ceramic panels that act as electrical insulators. If current flows in one direction, heat is transferred from one side of the semiconductor components to the other. Reversing the flow direction / polarity similarly reverses the direction of heat transfer. In the present case, the cold ceramic panel will be mounted against the leaflet trapping arm 34. Due to the shape memory properties of the metal of the leaflet trapping arm 34, energizing the cooler 60 will cool the arm 34 and straighten it, as... Figure 4 The dashed outline in Figure 64 is shown.

[0152] Figure 6A This is a schematic cross-sectional view of the heart, illustrating the penultimate step in an exemplary mitral valve replacement surgery utilizing a transcatheter valve delivery system. Figure 6B This is an enlarged view of the transcatheter heart valve 20, showing the ability to straighten the leaflet capture arm 34. The delivery system includes an elongated sheath or catheter 70 having a flexible section 72 adjacent to its distal end. The transcatheter heart valve 20 is squeezed or otherwise tightened into a pocket or tube within the delivery system and is expelled to dilate within the target annulus.

[0153] Figure 6ADevice 20 is shown implanted at the natural mitral annulus MA, but the same procedure can also be performed at the natural tricuspid annulus TA shown on the left. As mentioned, leaflet capture arms 34 extend into the ventricle and are designed to curl beneath the mitral leaflet ML. In some embodiments, the leaflet capture arms 34 are straightened in a delivery shape within the delivery system and first ejected, then curled beneath the mitral leaflet ML. Due to the complex anatomy within the ventricle, including the chordae tendineae CT attached to the mitral leaflet ML, the deployment of the leaflet capture arms 34 can sometimes be hindered. Therefore, the ability to straighten the capture arms 34 again using an integrated cooler 66 is useful. Figure 6B As seen in the image, one of the arms 34 is shown in a dashed outline, indicating that it is extended. In the visualization, manipulation of each capture arm 34 can be achieved by selectively energizing the cooler 60.

[0154] When using the exemplary nitinol material, the final austenite temperature (Af) of the shape-set frame is approximately +15°C (59°F). One training protocol involves placing the anchoring arms in methanol at -35°C (-31°F) (converting to twinned martensite) and then straightening or unfolding them. The arms are then placed in warm water to allow the material to transform back into the austenitic phase. This operation is repeated approximately 45 times. As a result, when the arms are cooled to -35°C (-31°F), they tend to straighten or unfold, but when at body temperatures above +15°C (59°F), they return to their shape-set curled form. It should be understood that the bidirectional shape memory effect can be advantageously used to straighten the arms by cooling when needed and then bend them upon heating (such as to body temperature), thereby improving clinician control over valve deployment. This also allows for the straightening of one or more arms as needed in cases of misalignment (e.g., not properly positioned behind the natural leaflet).

[0155] Clamping a dual-frame nitinol stent can face many challenges, such as clamping damage, clamping force, and profile—current mechanical clamping mechanisms can introduce clamping asymmetry. This invention relates to “bidirectional” shape training of the nitinol frame to enable “self-clamping.” This technique can be used to partially clamp the frame. Currently, clamped frames are not cylindrical but more “conical,” which introduces higher clamping strain. A bidirectional effect with “cooling” can help clamp the valve into a cylindrical shape.

[0156] Figures 7A-7CThe schematic diagram illustrates the conventional sequence of tightening a transcatheter heart valve 80 into a valve delivery system 82. Although these figures are labeled "prior art," some elements, features, steps, etc., described or discussed below with respect to these figures may be inventive, but only in the context of other conventional ordering; that is, some descriptions of these figures or related to these figures may not be in the prior art.

[0157] In some embodiments, the valve delivery system may include a distal pouch 84 in the form of a tube for receiving the proximal end of the compressed heart valve 80. The pouch 84 is shown mounted on the distal end (unnumbered) of a flexible segment 86 of the delivery catheter to facilitate bending and reorientation of the pouch during the final stages of implantation. A larger sheath 88 may cover the entire heart valve 80 during delivery and then retract to expose the heart valve 80 and allow it to expand.

[0158] In some implementations, the heart valve 80 is packaged and supplied as a sterile component separate from the delivery system and is attached to the delivery system upon compression.

[0159] In some embodiments, the inner tubular member 90 has a conical retaining member 92 at its distal end, the conical retaining member being characterized by an orifice for receiving and capturing the proximal strut 94 on the heart valve 80.

[0160] In some embodiments, a small-diameter catheter or tube 96 extends through the tubular member 90 and through the heart valve 166 to engage with a nasal cone 98 for facilitating propulsion through the vascular system. Although not shown, a guidewire may extend through the tube 96 to similarly facilitate propulsion to the implantation site.

[0161] In some embodiments, the heart valve 80 is connected to the delivery system 82 using a temporary funnel 100, the temporary funnel having a narrow end that fits snugly within a pocket 84. By pushing or otherwise manipulating the heart valve 80 into the funnel 100, the internal self-expanding stent structure gradually tightens. Figure 7B As shown, the leaflet capturing arm 102 straightens when it contacts the wide end of the funnel 100. Finally, the proximal strut 94 on the heart valve 80 engages with and is captured by the orifice in the conical retaining member 92. At this point, the proximal retraction of the tubular member 90 pulls the heart valve the remaining distance into the delivery system until it reaches… Figure 7C The location is shown in the diagram. Only a portion of the heart valve 80 remains within the pouch 84, and the larger sheath 88 then advances distally to accommodate the entire heart valve. The advancement of the sheath pushes the temporary funnel 100 out of the pouch 84, and the pouch can be removed. The nasal cone 98 then also retracts proximally to form a seamless connection with the outer sheath 88.

[0162] Reducing the diameter of the heart valve 80 will facilitate loading the valve into the delivery sheath, but may require high loading forces to grip the valve stent. Similarly, extremely high bending forces are typically required when straightening the leaflet capture arm 102. Even trained technicians may find this difficult if this operation is performed just before a valve replacement surgery in a hospital. Furthermore, asymmetry may be introduced into the gripped valve, potentially affecting valve performance post-implantation. These challenges can be helped mitigate by using materials trained for bidirectional shape memory, allowing for staged gripping, as described below.

[0163] Figures 8A-8C The sequence of tightening the device 110 of this application into the conveying system 82 in two stages using the bidirectional shape memory effect is illustrated schematically. For consistency, the components of the conveying system 82 will retain the same numbering as previously used, but may have various modifications or differences. In some embodiments, the device 110 is held within the conveying system 82 by a holding member 92.

[0164] In some embodiments, the device or heart valve 110 includes one or more internal supports 112 formed by struts made of a material trained to tighten upon cooling. Similarly, the fabric-covered leaflet capture arms 114 are trained to straighten upon cooling. The dashed boxes indicate reduced temperatures, representing immersion in cold saline solution or cooling using solid elements such as Peltier coolers. The resulting shape changes are visible in… Figure 8B In this case, the diameter of the internal support 112 is reduced, while the leaflet capturing arm 114 is straightened.

[0165] In some embodiments, when the device or heart valve 110 presents this intermediate tightened shape, it enters a truncated conical temporary funnel 116, the narrow end of which fits within a tubular pouch 84. The tightened device 110 is further displaced into the funnel 116, causing the conical retaining member 92 to engage a proximal strut on the device. At this point, the device can be pulled into the pouch 84 while the outer sheath 88 is advanced to secure the fully tightened device 110 within the delivery system 82. In short, the bidirectional shape memory effect can be advantageously used to aid gripping by automatically reducing the diameter of the device upon cooling, thereby enabling the device to be pulled into the pouch or sheath. The reduction in the diameter of the inner support 112 facilitates loading the device into the delivery sheath and ultimately allows the diameter to be reduced to less than 10 mm.

[0166] Figures 9A-9C The diagram schematically illustrates the sequence in which the staged tightening devices 110, arranged in different configurations, are assembled within the conveying system 82. This sequence corresponds to the sequence described above regarding... Figures 8A-8CThe description is essentially the same, but the device or heart valve 110 is pre-connected to the delivery system 82.

[0167] In other words, the inner tubular member 90 within the delivery system 82 houses a shaft with a retraction hub 117 at its end. Multiple flexible tethers 118, such as sutures, extend through the delivery system and emerge from the distal end of the retraction hub 117. Each tether 118 wraps around and passes through an eyelet located at the proximal end of each atrial stent strut 119 in the device 110. The tether 118 wraps around the eyelet, and then two free length portions pass proximally back through a passage in the delivery system 82 to a proximal control handle (not shown). The tether 118 is secured to a movable element within the control handle such that tension can be applied to the movable element. In this way, the tether 118 can be pulled proximally to draw the eyelet, stent strut 119, and device / valve 110 into the pocket 84.

[0168] The compression sequence, as previously described, begins by lowering the temperature of the device or heart valve 110, which induces a shape memory effect, i.e., the stent 112 radially tightens and the leaflet capture arm 114 straightens. Once the heart valve 110 is partially compressed, as... Figure 9B As shown, the tether 118 is pulled from the proximal control handle to allow the heart valve 110 to retract through the truncated funnel 116 and enter the pocket 84. Again, as... Figure 9C As seen, the outer sheath 88 is pushed forward and connected to the nose cone 98.

[0169] The aforementioned device or heart valve 110 includes a tubular stent 112 made of a bidirectional shape memory material adapted to transform into a first predetermined shape / construction upon cooling and a second predetermined shape / construction upon heating. The first predetermined shape / construction is loaded into a delivery system when the device reaches body temperature, while the second predetermined shape / construction is achieved post-implantation. The stent 112 includes metal struts forming a plurality of grid cells, and the first predetermined shape / construction has a reduced diameter, which may be less than 10 mm. The second predetermined shape / construction has an expansion diameter sized for implantation within a defective natural heart valve, and preferably at least 30 mm.

[0170] Figure 10This is an exploded view of an exemplary delivery system 120 having a proximal control handle 122, with a distal sheath 124 extending from the proximal control handle to the nasal cone 126. The control handle 122 is characterized by a fluid port 128 into which cold saline solution can be introduced. The fluid port 128 is typically used to flush out air from the delivery system 120 before use. The fluid port 128 may be in fluid communication with various structures along the entire delivery system via one or more of various internal channels or passages. In this way, cold saline solution can be delivered to a specific location within the delivery system 120.

[0171] Shape memory effects can be incorporated into various convertible elements within the delivery system 120 itself. For example, it is often necessary to have multiple lumens that can be engaged and disengaged as needed (e.g., in the fixation and release of implants connected to the delivery system). Many current technologies require mechanisms that facilitate increased thickness, which conflicts with the general expectation of reducing the diameter of delivery catheters.

[0172] For example, Figure 11A The overlapping ends of the concentric tubes 130 and 132 within the conveying system 120 are shown, as well as the joint structure therebetween that has bidirectional shape memory properties. Figure 11B The two tubes are shown after disassembly. The end 134 of the smaller tube 132 fits snugly within the lumen of the larger tube 130. The end 134 has a pair of axially oriented retaining grooves 136 that receive an inwardly projecting pin 138 on the larger tube 130. It should be noted that although the pin 138 is shown on the larger tube 130 and the retaining groove 136 is shown on the smaller tube 132, their positions can be reversed.

[0173] refer to Figure 11B The retaining groove 136 is formed by a pair of axially oriented wing fingers 140. The fingers 140 are separated from the rest of the wall of the smaller tube 132 by a pair of axially released grooves 142. The wing fingers 140 are spaced apart by a distance less than the diameter of the pin 138, but each retaining groove 136 has a generally circular relief hole 144 at its inner end. Additionally, the distal end of each finger 140 tapers inward, such that pushing the two tubes 130, 132 together guides the pin 138 into the groove 136. The pin 138 propels the fingers 140 open until the pin reaches the circular relief hole 144, at which point the fingers 140 spring back to their original orientation. This provides a snap-fit ​​engagement between the two tubes 130, 132. Preferably, at least two diameter-opposite retaining grooves 138 are present to receive two similarly positioned pins 138.

[0174] The snap-fit ​​feature can be designed to prevent the engagement of the retaining groove 138 with the pin 138 on the larger tube 130 from disengaging under the relative axial forces expected to be experienced by the tube during operation. When designed with a shape memory effect, the smaller tube 132 can be rigid at body temperature. The aforementioned flushing mechanism and fluid port 128 can be used to inject very cold saline solution into the system, which will cool the smaller tube 132 to a more flexible martensitic state. Therefore, when in the martensitic state, the fingers 140 can open more easily, which reduces the force required to disengage from the pin 138 and allows the two tubes 130, 132 to separate easily.

[0175] In some implementation schemes, such as Figure 12A As described, the conveying system may have overlapping ends of concentric tubes 150 and 152 within the conveying system, and has a joint structure with shape memory properties. Figure 12B The enlarged view shows the outer tube 150 having a curved tab 154 that cantilevered across at least one opening 156 in the sidewall of the outer tube. The tab 154 is radially curved inward in a generally S-shape and extends into a similarly shaped rectangular opening 158 in the sidewall of the smaller tube 152. This creates an interference geometry between the two tubes 150, 152, thereby preventing relative axial and rotational displacement between them. In some embodiments, there are two such joint structures spanning the overlapping ends of the tubes 150, 152 with opposite diameters. Furthermore, although the curved tab 154 is shown on the larger outer tube 154 and the opening 158 is shown in the sidewall of the inner tube 152, their positions can be reversed.

[0176] The material of the tab 154 is trained to possess shape memory properties. The composition of the shape memory material allows it to exist in a martensitic state at body temperature, and the austenite transformation temperature can be set to a high temperature (~110ºF). By heating the tab 154, a bent shape can be straightened, such as... Figure 12D As seen, this removes the interference geometry and allows the two tubes 150 and 152 to detach. Heating can be achieved by introducing hot saline solution, for example, through the aforementioned flushing system and fluid port 128. Alternatively, as... Figure 12C As shown, electrical contacts 160 and 162 can be placed adjacent to the area to be heated. Therefore, energizing contacts 160 and 162 heats the area and causes the bent tab 154 to return to its straight, annealed shape, thereby eliminating interference geometry. Tab 154 can be made of so-called "muscle filaments".

[0177] Muscle filaments typically refer to a special type of filament that functions similarly to muscles in our bodies. They are made of nitinol (a nickel-titanium alloy) and are known for their ability to contract when an electric current is applied. Nitinol wire is made of equal parts nickel and titanium, making it significantly stronger than ordinary wire. The reason nitinol can expand and contract is due to its combined crystalline structure of nickel and titanium. Their different reactions at high and low temperatures make the wire soft when cooled but hard when heated.

[0178] The method used to train muscle filaments is similar to the current approach used to shape nitinol implants. This involves fixing nitinol filaments / sheets / tubes into the desired shape (corresponding to the "activation" current condition) and immersing them in a heat bath to "shape-set" the metal in the austenitic phase. Lowering the temperature below the Af temperature threshold initiates a phase transformation to martensite, making the nitinol weaker and more easily deformable (corresponding to the "deactivation" current condition), at which point the material has no strength. During the heat treatment process, the Af temperature can be manipulated by controlling the temperature and time, keeping it above ambient or body temperature. Without an applied current, the filaments are weak and in a neutral "deactivation" state, but applying current to the filaments heats them above the Af temperature, bringing them into the austenitic phase, and the filaments remember and transform into the shape they were shaped to.

[0179] Figure 13 This is an exploded side view of an exemplary transcatheter delivery system 220, which has a proximal control handle 222 and the ability to bend a distal sheath 224 terminating at a conical nasal cone 226. The specific delivery system 220 shown, as well as the device or heart valve 228, is similar to those described above. Figure 8A The described delivery system and device or heart valve. The device or heart valve 228 shown is in an expanded state, but it is delivered within a distal sheath 224 in a gripping configuration. The proximal strut on the device / heart valve 228 can be captured by a conical retaining member 229 and pulled within a tubular sheath (not shown). In some embodiments, a guidewire extends through the tubular delivery system to facilitate advance to the implantation site. The distal sheath 224 is characterized by a curved segment 230 adjacent to the distal end to allow manipulation of the distal end to properly position the device / heart valve within the target annulus.

[0180] In current delivery systems, flexural or deflection memory is a major problem. Once the deflection is activated, it is extremely difficult to straighten the sheath 224 (unidirectional deflection). Friction in the drawing mechanism and plastic deformation of the metal and / or polymer catheter components typically mean that once the tension in the drawing is removed by reversing the control knob, the system lacks sufficient elasticity to return to a straight or near-straight configuration. This complicates operation and causes numerous procedural problems. Some current delivery systems have two deflection planes (primary and secondary deflection planes) for drawing activation, controlled by separate "knobs" 232a, 232b on the handle 222, and significant crosstalk can exist between the two deflection planes. The mechanical knobs 232a, 232b activate the deflection and other delivery system mechanisms and require physical input that may approach the ergonomic limits of the physician. For example, in one currently available system, the EVOQUE transcatheter tricuspid valve replacement system from Edwards Lifesciences in Irvine, California, the main flexure in the distal flexure segment angles the replaced tricuspid valve in the anterior / posterior direction (relative to the tricuspid annulus). The EVOQUE system also features a proximal secondary flexure segment that angles the distal ends of the valve and catheter at 90º in the diaphragmatic / lateral direction. Of course, these flexures and filament directions can be positioned along the catheter and oriented to other locations for better navigation toward other valves such as the mitral valve.

[0181] therefore, Figure 14 This is an enlarged view of the curved section 230 of this application, and Figure 14A This is a cross-sectional view of the curved section, showing multiple shape memory wires within it. In some embodiments, the curved section has a flexible sheath 236 terminating in a solid ring 238. (As shown...) Figure 14B As seen, multiple filaments 240, distributed circumferentially, extend longitudinally within the sidewalls of a flexible sheath 236 and connect to a ring 238. Individual (or attached) power sources are then connected to each of the nitinol filaments 240, and the sheath 236 can flex in multiple planes when a charge is applied to heat certain filaments. Applying electricity to nitinol tends to heat a metal that can be trained to induce shape changes similar to those in muscle filaments. In this case, the shape change is the tightening or shortening of a particular filament due to heating, which tends to pull the sheath along said direction.

[0182] Once the circuit is deactivated and the system cools down, the bending caused by the energized wire drawing 240 should recover, but to facilitate straightening, the opposite wire can be activated. When using multiple NiTiNorm wires 240 as actuators, fine control of the sheath position is achieved by adjusting the current and thus heating the various wires. Figure 14BTwenty such filaments 240, evenly distributed around the sheath 236, are shown, providing very fine control, but only four, or more than twenty, can also be used. It should be understood that incorporating deformable filaments into the delivery catheter can offer significant advantages over conventional drawing. For example, precise steering can be provided, unwanted crosstalk can be eliminated, and actuator knobs can be removed from the catheter handle.

[0183] To enable simultaneous flexing at different axial locations, it may be necessary to place multiple independently energized nitinol wires at different axial locations. For example, if it is desired that only the distal end of the conduit flexes, this segment can be isolated by shielding the rest of the conduit from the flexural tension. This can be accomplished, for example, by placing mechanical tension isolation components such as compression coils or drawing thiopans around the unwanted flexing segment of the wire, or by electrical isolation, in which a dedicated circuit applies current only to the segment of the nitinol wire. Although not shown, these additional nuances are envisioned.

[0184] Figure 15 This is a cross-section of the heart, illustrating steps in an exemplary therapeutic procedure (e.g., mitral valve replacement, mitral valve repair, valve replacement, valve repair, etc.) utilizing a transcatheter delivery system 250. The delivery system 250 may have a distal portion or pocket 252 of a carrier device or heart valve, and structures for deploying the device / valve. Therefore, the pocket 252 is typically thicker than the rest of the elongated catheter or sheath, which can hinder the ability to manipulate within the vascular system and require a larger inlet. Therefore, this application discloses a mechanism for selectively reducing the radial cross-section of the pocket 252.

[0185] Figure 16A and 16B These are side views of the distal pouch 252 before and after radial size reduction. The sidewalls of the nitinol pouch 252 are constructed in various forms such that the pouch can contract or tighten upon application of energy such as electricity (to generate heat) or heat. Alternatively, as explained above, the nitinol can be trained to undergo bidirectional shape changes upon cooling, which can be initiated using a cold rinsing fluid or a Peltier element as described.

[0186] Figure 17 This is a cross-sectional view of the distal pouch, showing an example of a deformable structure used to tighten its radial cross-section, and Figure 17A This is a schematic diagram of the circuit used to initiate tightening. In this configuration, the sidewalls of the pouch are formed using a braided nitinol structure 260. Closing the switch applies electrical stimulation to the filaments within the braided structure 260, causing resistive heating and thus tightening into a changed shape 260', as shown. Figure 17AAs seen in the text.

[0187] Figure 18 This is a cross-sectional view of the distal pouch, showing a second example of a deformable structure used to tighten its radial cross-section, and Figure 18A This is a schematic diagram of the circuitry used to initiate heating and tightening. In this case, the outer tubular wall 270 of the sac is surrounded by one or more spirally wound nitinol wires 272. Figure 18A The circuit is shown to close to energize and heat the wire 272 and convert it to a tightened state 272', thus also tightening the tube 270'. In addition to the spirally wound wire 272, a laser-cut support pattern with a grid cell pattern such as a lattice, rhombus, V-shape, or other expansion / contraction support pattern can be used to tighten the device when energized.

[0188] Figure 19A and 19B This illustration shows a deformable nitinol (or other shape memory) element that can be incorporated into a delivery system. An outer elongated sheath 300 houses an inner tube 302, within which a suture 304 is positioned. A trained shape memory rod 306 is attached toward the proximal end of the inner tube 302. The rod 306 can be energized using a power button 308 and a wire 310 to cause the rod to curl into a shape. Figure 19B The shape 306' is visible in the image. The curling of the rod 306 will pull the tube 302 in the proximal direction, which will cause the suture 302 to be released.

[0189] The mechanism can be combined with, for example Figure 9A In the system shown, the device is attached to the delivery system using suture 118, and can then be released from the delivery system by releasing the suture. The suture loop 118 passes through an inlet hole on the atrium strut 119 of the device and folds back into the delivery system. Although not shown here, a pin (or pins) secures the folded-back suture to the delivery system. When the pin retracts, the end of the loop falls out of the delivery system, and the suture loop is now free to pull through the device hole, thus permanently disconnecting the device from the delivery system. This mechanism has a tube or rod at the proximal end within the handle, which is pulled back slightly to allow the suture loop to slide out. This retraction of the tube or rod releases the retaining pin, as... Figure 19A and 19BAs shown in the diagram. A wide variety of applications exist for actuating a lever or tube in a handle a short distance by pressing a button (sending current through a circuit) instead of rotating a knob or pulling a slider. This can be applied to other mechanisms in other delivery systems, such as the clasp actuator in devices like the PASCAL Precision System from Edwards Lifesciences in Irvine, California; for valve frame expansion; implant release; catheter deflection; and actuation of features or markers visible under echo or fluorescence fluoroscopy to aid navigation.

[0190] Any of the various systems, assemblies, devices, components, equipment, etc. disclosed herein can be sterilized (e.g., with heat, radiation, ethylene oxide, hydrogen peroxide, etc.) to ensure their safe use in patients, and the methods described herein may include (e.g., with heat, radiation, ethylene oxide, hydrogen peroxide, etc.) sterilizing the relevant systems, devices, components, equipment, etc. (or other methods may include or consist of said sterilization).

[0191] The techniques, methods, processes, operations, procedures, etc., described or suggested herein or in the references incorporated herein, as well as any methods using the systems, assemblies, devices, apparatuses, etc., described herein, may be performed on a living subject (e.g., a human, other animals, etc.) or on a simulated object (e.g., a cadaver, a cadaver's heart, a mannequin, a virtual human, etc.). When performed on a simulated object, body parts (e.g., a heart, tissue, valves, etc.) may be assumed to be simulated or may optionally be referred to as "simulated" (e.g., a simulated heart, simulated tissue, simulated valves, etc.), and may optionally include computerized and / or physical representations of body parts, tissues, etc. The term "simulated object" covers its use in cases involving cadavers, computer simulators, virtual humans (e.g., if they are simply demonstrated in the air on an imaginary heart), etc.

[0192] While the foregoing provides a complete description of preferred embodiments of the invention, various alternatives, modifications, and equivalents may be used. Furthermore, it will be apparent that certain other modifications may be practiced within the scope of the appended claims.

Claims

1. A device for treating congenital valves, the device comprising: A support structure made of multi-shape memory material, wherein the support structure is configured such that it automatically transforms into a first predetermined shape when cooled to a first temperature and automatically transforms into a second predetermined shape when heated.

2. The apparatus of claim 1, wherein the support structure comprises metal struts forming a plurality of grid cells, and wherein the first predetermined shape has a reduced diameter relative to the second predetermined shape.

3. The device of claim 2, wherein the reduced diameter of the support structure facilitates loading the device into the delivery sheath.

4. The apparatus of claim 3, wherein the reduced diameter is less than 10 mm.

5. The device of claim 3, wherein the second predetermined shape has an expansion diameter, the size of which is set for implantation into the natural heart valve.

6. The apparatus of claim 5, wherein the expansion diameter is at least 30 mm.

7. The device according to any one of claims 1 to 5, further comprising a unidirectional valve structure coupled to the support structure.

8. The device of claim 7, wherein the one-way valve structure is formed with leaflets made of pericardium.

9. The apparatus according to any one of claims 1 to 8, wherein the multi-shape memory material is a bidirectional shape memory material, wherein at least one of the first predetermined shape and the second predetermined shape is trained by applying a cyclic thermal load under a substantially constant stress field.

10. The device according to any one of claims 1 to 9, wherein the size of the second predetermined shape of the support structure is set for implantation in a natural aortic valve.

11. The device according to any one of claims 1 to 10, further comprising a valve structure sutured to the support structure.

12. The device according to any one of claims 1 to 11, further comprising a fabric skirt disposed around the support structure for enhancing the seal.

13. The device according to any one of claims 1 to 12, wherein the device has a proximal end and a distal end, and the support structure has one or more frames and one or more arms extending from at least one of the one or more frames.

14. The apparatus of claim 13, wherein each of the one or more arms is trained or configured by shape memory to change from an unfolded shape to a delivery shape when cooled to a temperature below body temperature, in which the one or more arms extend radially outward from the apparatus, and in which the one or more arms extend radially inward relative to the unfolded shape.

15. The device of claim 14, wherein the device is configured such that when the natural valve is processed, the distal end is first discharged from the delivery sheath, and the one or more arms extend distally from the distal end and bend rearward about 180° in the unfolded shape.

16. The apparatus according to any one of claims 14 to 15, wherein in the conveying shape, the one or more arms are extended into a straight shape and extend in a distal direction.

17. The device according to any one of claims 13 to 16, further comprising a micro-electric cooler mounted on each of the one or more arms to cool the arms below body temperature.

18. The apparatus according to any one of claims 13 to 17, wherein the one or more frames are formed with pillars made of shape memory material, and the one or more frames are trained or configured to radially tighten when the temperature decreases.

19. The device according to any one of claims 13 to 18, wherein the one or more arms are integrally formed with one of the one or more frames.

20. A system comprising: The conveying system includes: Control handle; and A delivery catheter extending distally relative to the control handle, the delivery catheter having a lumen extending therethrough and a distal pouch at its distal end; and The apparatus according to any one of claims 1 to 19.

21. The system of claim 20, further comprising a plurality of flexible tethers, each flexible tether circumferentially passing through an eyelet on a post at the proximal end of the support structure, the flexible tethers being configured to pull the device into the distal pouch.

22. The system according to any one of claims 20 to 21, wherein the delivery catheter includes a curved section proximal to the distal sac and has a deformable filament incorporated into its wall.

23. The system of claim 22, wherein the delivery system is configured such that energizing the deformable filament causes the bending section of the delivery conduit to deflect or bend.

24. The system according to any one of claims 22 to 23, wherein the temperature change of the filament produces a desired length change.

25. The system according to any one of claims 22 to 24, wherein at least four deformable wires are uniformly distributed around the wall.

26. The system according to any one of claims 20 to 25, wherein the delivery system includes a nose cone.

27. The system according to any one of claims 20 to 26, wherein the delivery system includes an entry sheath, and wherein the entry sheath and the delivery conduit are configured such that the delivery conduit can pass through the lumen of the entry sheath.

28. The system according to any one of claims 20 to 27, wherein the control handle has a fluid port communicating with an internal channel through an inlet sheath of the delivery system and at least one of the delivery conduits.

29. The system according to any one of claims 20 to 28, further comprising a concentric tube within the conveying system.

30. The system of claim 29, wherein the concentric tubes have overlapping ends.

31. The system according to any one of claims 29 to 30, wherein the first tube in the concentric tube has a coupling pin that engages with an axially oriented retaining groove on the second tube in the concentric tube.

32. The system of claim 31, wherein the engagement pin comprises a pair of axially oriented flank fingers formed of a shape memory material trained to be rigid at body temperature and more flexible when cooled.

33. The system of claim 32, wherein the lateral wing fingers are spaced apart by a distance less than the diameter of the engagement pin.

34. The system of claim 32, wherein the internal channel terminates at the overlapping end of the concentric tubes, wherein introducing cold fluid into the fluid port of the delivery system makes the flank fingers more flexible to facilitate removal of the engagement pin from the retaining groove and disengagement of the tube.

35. The system according to any one of claims 31 to 34, wherein two engagement pins are provided on the diameter-opposite side of the first tube, and two retaining grooves are provided on the diameter-opposite side of the second tube.

36. The system of claim 35, wherein the retaining groove has a generally circular relief hole at its inner end for receiving the engagement pin.

37. The system according to any one of claims 31 to 36, wherein the first tube is larger than the second tube, and the engagement pin extends radially inward from the first tube.

38. The system according to any one of claims 29 to 30, wherein the first tube has at least one curved tab that cantileverly crosses an opening in the sidewall of the first tube, extends into a similarly shaped opening in the sidewall of the second tube, and forms an interference between the two tubes to prevent relative axial and rotational displacement therebetween.

39. The system of claim 38, wherein the bending tab is formed of a shape memory material trained to be in a martensitic state at body temperature, and the austenite transformation temperature is set to a temperature higher than body temperature, and the bending tab straightens when the austenite transformation temperature is exceeded.

40. The system of claim 39, wherein heating the bent tab causes the bent tab to straighten and disengage from the opening to allow relative axial and rotational displacement of the tube.

41. The system of claim 40, wherein two curved tabs are present on the diameter-opposite side of the first tube, and two openings are present on the diameter-opposite side of the second tube.

42. The system according to any one of claims 40 to 41, wherein the first tube is larger than the second tube, and the curved tab extends radially inward into the opening.

43. The system according to any one of claims 40 to 42, wherein the curved tab is formed into an S-shape before heating.

44. The system according to any one of claims 39 to 43, wherein the austenite transformation temperature is about 110°F.

45. The system according to any one of claims 39 to 44, wherein the control handle has a fluid port communicating with an internal channel through at least one of the inlet sheath and the delivery conduit, and the internal channel terminating at an overlapping end of the conduit, wherein introducing hot fluid into the fluid port heats the curved tab.

46. ​​The system according to any one of claims 39 to 44, further comprising an electrical contact positioned adjacent to the curved tab, wherein energizing the electrical contact heats the curved tab.

47. The system according to any one of claims 20 to 46, wherein the sidewall of the distal pouch is at least partially formed of a shape memory element trained to contract or tighten in response to temperature changes.

48. The system of claim 47, wherein the shape memory element is in the form of a braided tube.

49. The system of claim 48, further comprising an electrical lead connected to the braided tube such that the braided tube and the pouch tighten upon application of electrical energy to the braided tube.

50. The system of claim 48, wherein the braided tube is trained to shrink upon cooling.

51. The system of claim 50, wherein the control handle has a fluid port communicating with an internal channel through the delivery conduit, the internal channel terminating at the pouch, wherein introducing cold fluid into the fluid port cools the braided tubing.

52. The system of claim 48, wherein the shape memory element is in the form of one or more helically wound filaments.

53. The system of claim 52, further comprising an electrical lead connected to the helical winding wire, such that the wire and the pouch tighten as electrical energy is applied to the wire.

54. The system of claim 52, wherein the filament is trained to shrink upon cooling.

55. The system of claim 53, wherein the control handle has a fluid port communicating with an internal channel through the delivery conduit, the internal channel terminating at the pouch, wherein introducing cold fluid into the fluid port cools the silk.

56. An artificial heart valve for replacing the function of a natural heart valve, said artificial heart valve comprising: The support bracket is made of a bidirectional shape memory material, which is adapted to transform into a first predetermined shape when cooled and into a second predetermined shape when heated; as well as A one-way valve structure is installed inside the lumen of the support bracket.

57. The artificial heart valve of claim 56, wherein the support stent comprises a metal strut forming a plurality of grid units, and wherein the first predetermined shape has a reduced diameter.

58. The artificial heart valve of claim 57, wherein the reduced diameter of the support stent facilitates loading the artificial heart valve into the delivery sheath.

59. The artificial heart valve according to any one of claims 56 to 58, wherein the second predetermined shape has an expansion diameter, the size of which is set for implantation into a defective natural heart valve.

60. The artificial heart valve according to any one of claims 56 to 59, wherein the second predetermined shape of the supporting stent is sized for implantation in a natural aortic valve.

61. The artificial heart valve according to any one of claims 56 to 60, further comprising a fabric skirt disposed around the support frame to enhance the seal.

62. The artificial heart valve according to any one of claims 56 to 61, wherein the artificial heart valve has a proximal inflow end and a distal outflow end, and the support stent has one or more frames and one or more arms extending from at least one of the one or more frames, each arm being shape memory trained to change from an unfolded shape to a delivery shape radially inward from the unfolded shape when cooled to a temperature below body temperature.

63. The artificial heart valve of claim 62, wherein in the delivery shape, the leaflet capturing arm is straightened from a curved shape to a straight shape.

64. The artificial heart valve according to any one of claims 62 to 63, further comprising a micro-electric cooler mounted on each of the one or more arms to cool the arms below body temperature.

65. The artificial heart valve according to any one of claims 62 to 64, wherein the one or more radially compressible frames are formed with struts made of shape memory material, and the one or more radially compressible frames are trained to radially tighten when the temperature decreases.

66. A conveying system comprising: Control handle; A flexible entry sheath, which has a lumen; A delivery catheter extends distally from the control handle and its outer diameter is set to fit through the lumen of the access sheath. The delivery catheter also forms a lumen extending therethrough and has a distal pouch that opens at its distal end. as well as An artificial heart valve includes a support structure and a one-way valve structure. The support structure is made of a bidirectional shape memory material adapted to transform into a first predetermined shape upon cooling and a second predetermined shape upon heating. The one-way valve structure is installed within the lumen of the support structure. The heart valve has a proximal inflow end and a distal outflow end, the ends being adapted to collapse radially and be loaded into the distal pocket with the inflow end facing forward.

67. The system of claim 66, wherein the support structure has metal struts made of shape memory material, and the support structure is trained to radially tighten as the temperature decreases.

68. The system of claim 66, wherein the support structure has one or more frames and one or more arms extending from at least one of the one or more frames, each arm being shape-memory trained to change from an unfolded shape to a delivery shape radially inward from the unfolded shape when cooled to a temperature below body temperature.

69. The system according to any one of claims 66 to 68, further comprising a plurality of flexible tethers surrounding one or more eyelets on a strut passing through the proximal end of the support structure, the flexible tethers being adapted to pull the heart valve into the distal pocket.

70. A conveying system comprising: Proximal control handle; Delivery catheter having a pouch along its distal end portion; The curved section, located close to the pouch along the delivery conduit, has deformable filaments incorporated into its sheath wall; as well as An expandable device adapted to collapse radially and positioned within the sac to propel through the vascular system; The deflection of the delivery conduit can be caused by energizing the deformable wire.

71. A conveying system comprising: A proximal control handle, a hollow distal sheath extending from the proximal control handle, the control handle having a fluid port communicating with an internal channel through the distal sheath; A delivery catheter, sized to slide through the sheath, having a pouch along its distal end portion; A concentric tube, within the sheath, having overlapping ends, wherein a first tube has a engagement pin that snaps into an axially oriented retaining groove on a second tube, the axially oriented retaining groove being defined by a pair of axially oriented lateral fingers formed of a shape memory material trained to be rigid at body temperature and more flexible when cooled, and wherein the internal channel terminates at the overlapping ends of the tubes; and Introducing cold fluid into the fluid port makes the side fingers more flexible, which helps to remove the engagement pin from the retaining groove and disengage the tube.

72. The system of claim 71, wherein two engagement pins are present on the diameter-opposite side of the first tube, and two retaining grooves are present on the diameter-opposite side of the second tube.

73. A conveying system comprising: A proximal control handle, with a hollow distal sheath extending from the proximal control handle; A delivery catheter, sized to slide through the sheath, having a pouch along its distal end portion; A concentric tube, within the sheath, having overlapping ends, wherein the first tube has at least one curved tab, the at least one curved tab cantilevered across an opening in the sidewall of the first tube, extending into a similarly shaped opening in the sidewall of the second tube, and forming an interference between the two tubes to prevent relative axial and rotational displacement therebetween, wherein the curved tab is formed of a shape memory material trained to be in a martensitic state at body temperature, and an austenitic transformation temperature set above body temperature, and the curved tab straightens above the austenitic transformation temperature; and Heating the bent tab will straighten it and disengage it from the opening, allowing for relative axial and rotational displacement of the tube.

74. The system of claim 73, wherein two curved tabs are present on the diameter-opposite side of the first tube, and two openings are present on the diameter-opposite side of the second tube.

75. A conveying system comprising: Proximal control handle; A delivery catheter having a pouch along its distal end portion, the sidewalls of which are at least partially formed of shape memory elements trained to contract or tighten in response to temperature changes; The curved section is located along the delivery conduit at a position immediately adjacent to the pouch; as well as An expandable device adapted to collapse radially and positioned within the sac to propel through the vascular system.

76. The system of claim 75, wherein the shape memory element is in the form of a braided tube.

77. The system of claim 76, further comprising an electrical lead connected to the braided tube such that the braided tube and the pouch tighten upon application of electrical energy to the braided tube.

78. The system of claim 75, wherein the nitinol element is in the form of one or more helically wound wires.

79. The system of claim 78, further comprising an electrical lead connected to the helical winding wire such that the wire and the pouch tighten as electrical energy is applied to the wire.

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