Adjustable shunt system with shape memory actuator and related systems and methods

Abstract

The present technology provides adjustable shunt systems having an actuation assembly that can be selectively adjusted to change the level of therapy provided by the shunt. The actuation assembly can include a shape memory actuator having a plurality of leaflets or prongs that form a cone shape with openings at both ends of the cone. The actuation assembly can further include one or more membranes that individually cover or encase each of the prongs to form a lumen extending through the cone shape.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 477,104, filed December 23, 2022, and U.S. Provisional Patent Application No. 63 / 511,132, filed June 29, 2023, both of which are incorporated by reference in their entireties.

[0002] FIELD OF THE INVENTION The technology relates generally to implantable medical devices, and more particularly to adjustable shunt systems for fluidly connecting a first body region to a second body region. [Background technology]

[0003] Implantable shunt systems are widely used to treat various patient conditions by shunting fluid from a first body region / cavity to a second body region / cavity. Fluid flow through a shunt system is primarily controlled by the pressure gradient across the shunt lumen and the geometry (e.g., size) of the shunt lumen. One of the challenges with conventional shunt systems is selecting the appropriate shunt lumen geometry for a particular patient. A lumen that is too small may not provide sufficient therapy to the patient, while a lumen that is too large may create additional problems for the patient. Despite this, most conventional shunts cannot be adjusted once implanted. Therefore, once the system is implanted, the therapy provided by the shunt system cannot be adjusted or titrated to meet the patient's individual needs. Summary of the Invention [Means for solving the problem]

[0004] The present technology is directed to adjustable shunt systems for shunting fluid between a first body region and a second body region. In many of the embodiments described herein, the adjustable shunt system includes an actuation assembly that can be selectively manipulated after the system is implanted in a patient to change the level of therapy provided by the system, such as to tailor therapy to the patient's changing needs. The actuation assembly can include a shape-memory actuator having a plurality of leaflets or protrusions arranged relative to one another to form a generally annular structure having, for example, a generally conical, frustoconical, funnel, and / or hyperboloidal shape. The actuation assembly can further include one or more membranes that individually coat or cover individual protrusions of the plurality of protrusions to define a lumen extending through the shunt. As described throughout this detailed description, individually coating the protrusions is expected to provide several advantages over shunts having a lumen formed from a single membrane. As those skilled in the art will understand from the following detailed description, other aspects of the present technology may provide additional advantages. [Brief explanation of the drawings]

[0005] [Figure 1A] 1 shows an adjustable shunt system in a deployed configuration, constructed in accordance with selected embodiments of the art. [Figure 1B] 1 shows an adjustable shunt system in a deployed configuration, constructed in accordance with selected embodiments of the art. [Figure 2] 1 illustrates another adjustable shunt system in a deployed configuration, constructed in accordance with selected embodiments of the art. [Figure 3] 1 illustrates yet another adjustable shunt system in a deployed configuration, constructed in accordance with selected embodiments of the art. [Figure 4] 1 illustrates yet another adjustable shunt system in a deployed configuration, constructed in accordance with selected embodiments of the art. [Figure 5]1 illustrates an actuator for use with an adjustable shunt system constructed in accordance with selected embodiments of the art. [Figure 6] 1 illustrates another actuator for use with an adjustable shunt system, constructed in accordance with selected embodiments of the art. [Figure 7A] 1 illustrates aspects of an actuation assembly for use with an adjustable shunt system, constructed in accordance with selected embodiments of the art. [Figure 7B] 1 illustrates aspects of an actuation assembly for use with an adjustable shunt system, constructed in accordance with selected embodiments of the art. [Figure 8] 1 illustrates another adjustable shunt system constructed in accordance with selected embodiments of the art. DETAILED DESCRIPTION OF THE INVENTION

[0006] The terms used in the description provided below are intended to be interpreted in their broadest reasonable manner, even when used in conjunction with detailed descriptions of certain specific embodiments of the technology. Specific terms may even be emphasized below. However, any terms intended to be interpreted in a limiting manner will be clearly and specifically defined as such in this detailed description section. Furthermore, the technology may include other embodiments that are within the scope of the examples but are not described in detail with respect to FIGS. 1A-8.

[0007] Throughout this specification, a reference to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment of the technology. Thus, the appearances of the phrase "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Also, particular features or characteristics may be combined in any suitable manner in one or more embodiments.

[0008] As used herein, the use of relative terms such as "about," "approximately," and "substantially" refers to the stated value plus or minus 10 percent. For example, the use of the term "about 100" refers to a range of 90 to 110, inclusive. Where the context requires otherwise, and / or where relative terms are used in reference to things that do not include numerical values, these terms are to be given their ordinary meaning to those of ordinary skill in the art.

[0009] 1A illustrates an adjustable shunt system 100 ("system 100") in a deployed configuration, configured in accordance with selected embodiments of the technology. As described in detail below, system 100 may be configured to shunt fluid between a first body region and a second body region when implanted in a patient (not shown). For example, system 100 may be an interatrial shunt system configured to be implanted across a patient's septum to shunt blood from the patient's left atrium to the right atrium.

[0010] System 100 includes an anchoring or stabilizing feature or structure 110 ("anchor structure 110") configured to anchor system 100 to a patient's tissue and / or stabilize the position of system 100 in a desired anatomical location. In the illustrated embodiment, anchor structure 110 is a wire or filament structure (e.g., a braided or woven wire structure) having a generally circular geometry. A radially inner portion 111 of anchor structure 110 defines a central opening or passageway 113. As described in more detail below, actuating assembly 120 is coupled to anchor structure 110 and can be at least partially seated within opening 113 and / or extend from the periphery of radially inner portion 111. Actuating assembly 120 can define, or at least partially define, a lumen 102 extending through opening 113, as described in more detail below.

[0011] In the illustrated embodiment, the anchor structure 110 includes a first plurality of petals or appendages 112 and a second plurality of petals or appendages 114. In some embodiments, the wire forming pattern of the anchor structure 110 results in immediately adjacent ones of the first petals 112 not being formed by adjacent segments of the wire structure forming the anchor structure 110. Instead, the wire structure may alternate between forming first petals 112 on a first side of the system 100 and forming second petals 114 on a second side of the system 100 (e.g., a portion of the wire structure forming an individual first petal 112 at the 12:00 position may cross over to the other side of the anchor structure 110 to form an individual second petal at the 3:00 position, then cross back to form another individual first petal 112 at the 5:00 position, etc.). The first and second plurality of petals 112 and 114 are separated by a gap (not shown).

[0012] When the system 100 is deployed across a tissue structure (e.g., a septum (not shown)), the system 100 is configured to receive patient tissue between the first petal 112 and the second petal 114, e.g., in a gap. Additionally, the first and second petals 112, 114 may be at least partially biased toward one another such that the first and second petals 112, 114 at least partially compress the patient tissue received in the gap, securing the system 100 to the patient tissue. For example, when deployed across a septum, the first petal 112 may reside in the left atrium and the second petal 114 may reside in the right atrium, and the gap between the first and second petals 112, 114 may receive a portion of the patient's septum (e.g., at the fossa ovalis). The first petal 112 may be at least slightly biased toward the second petal 114 (and / or the second petal 114 may be at least slightly biased toward the first petal 112), such that the anchor structure 110 forms a slight clamping force against a portion of the septum within the gap 118. In some embodiments, the first petals 112 and second petals 114 are at least partially staggered such that each first petal 112 does not completely overlap each second petal 114. Without being bound by theory, this is expected to spread the clamping force over a wider area of ​​the septum.

[0013] The anchor structure 110 may be at least partially constructed of a self-expanding material so as to exhibit an elastic response upon deployment at body temperature after being subjected to stresses and strains induced by being folded within a delivery tool (e.g., a catheter, sheath, etc.) for delivery. For example, the anchor structure 110 may be at least partially constructed of nitinol having an austenite finish temperature below body temperature. Thus, the anchor structure 110 may automatically deploy (e.g., self-expand without additional input or manipulation by a clinician) from a folded delivery configuration (e.g., when positioned within a delivery tool such as a catheter or sheath) to an expanded, deployed configuration upon release from the delivery tool. In some embodiments, the self-expanding or superelastic properties of the anchor structure 110 may also enable the anchor structure 110 to resist plastic mechanical deformation upon deployment, thus providing the system 100 with a generally stable anchoring mechanism. In other embodiments, the anchor structure 110 may be constructed of a material that does not self-expand at body temperature. In one example, the anchor structure 110 may be constructed of nitinol having an austenite finish temperature above body temperature. In such an example, the anchor structure 110 may initially be released from a delivery tool in a preliminary position (e.g., a collapsed delivery configuration, an intermediate configuration, etc.) and then heated above the austenite finish temperature to transition the shape of the anchor structure 110 toward the deployed configuration. In a second example, the anchor structure 110 may be constructed from a material such as stainless steel (e.g., 316L), a titanium alloy (e.g., TiAl6V4), a cobalt-chromium alloy (e.g., L605), or a polymer (e.g., PEEK). Some implementations of the second example may be self-expanding based on the geometric configuration of the anchor structure 110. Other implementations may be manually expanded by an operator after initial deployment using a tool such as a catheter, suture, or balloon. Regardless of its material composition, in some embodiments, some or all of the anchor structure 110 may include an insulating or coating material. Examples of suitable materials include, but are not limited to, perylene, urethane, ePTFE, and the like.In some embodiments, anchor structure 110 can include multiple insulating / coating layers (e.g., alternating layers of perylene and urethane). The coating materials can be selected to (a) improve the biocompatibility of anchor structure 110, (b) improve the lubricity of anchor structure 110, and / or (c) improve the guidance properties of anchor structure 110, as described in more detail below. Further details regarding fixation features suitable for use with system 100 are provided in International Patent Application No. US2022 / 046584, the disclosure of which is incorporated herein by reference in its entirety.

[0014] Actuation assembly 120 includes an actuator 121 partially or completely covered by a membrane 130 that is fluidly impermeable, or at least substantially fluidly impermeable, to blood and / or other bodily fluids (the portion of actuator 121 covered by membrane 130 is shown in dashed lines in FIG. 1A ). Actuator 121 and membrane 130 together form a generally conical, frustoconical, funnel-shaped, cylindrical, or hyperboloidal shape with openings at both ends of the “cone.” In this manner, actuation assembly 120 at least partially defines lumen 102 extending through system 100, as described above. Thus, when system 100 is implanted in a patient (e.g., across the patient's septum), fluid can flow through system 100 via lumen 102 extending through actuation assembly 120. As described in more detail below, actuation assembly 120 is configured to alter one or more therapy parameters associated with the shunt (e.g., fluid resistance, lumen size, orifice size, flow rate, etc.) to control the therapy provided by system 100. For example, actuation assembly 120 can transition between multiple unique positions or configurations, each unique position or configuration providing a different fluid resistance through lumen 102.

[0015] As best shown in FIG. 1B , which illustrates system 100 with membrane 130 omitted to more clearly illustrate aspects of actuator 121, actuator 121 can be formed via one or more wires or wire-like structures. As shown, for example, actuator 121 can include multiple protrusions 122 (e.g., cusps, fingers, wings, struts, petals, lobes, etc.) formed via one or more wires or wire-like structures. Protrusions 122 can be formed to define desired cylindrical, conical, frusto-conical, funnel, and / or hyperboloid shapes. In some embodiments, multiple protrusions 122 are formed from a single or common wire structure. In other embodiments, individual protrusions of multiple protrusions 122 (or fewer than all of the multiple protrusions) can be formed by separate wire structures. Each protrusion 122 generally includes two struts 123 connected via tip 124, thereby generally forming a “U” or “V” shape. Each individual strut 123 is spaced from an individual strut 123 of an adjacent protrusion 122 by a gap 126. This at least partially mechanically separates adjacent protrusions 122, allowing each protrusion 122 to be individually covered by a discrete portion of membrane 130, as described in more detail below. Collectively, tips 124 form a generally circular central hole or opening 103 (opening 103 is approximated by a dashed line in FIG. 1B ) with respect to lumen 102. In alternative embodiments, tips 124 can form openings 103 of alternative shapes, such as, for example, generally square, generally pentagonal or hexagonal, elliptical, etc. When system 100 is implanted in a patient, fluid can flow through opening 103 as it enters or exits lumen 102. Although the illustrated embodiment shows the actuator 121 as having six protrusions 122, in other embodiments, the actuator 121 can have fewer or more protrusions, such as two, three, four, five, seven, eight, nine, or more protrusions.

[0016] In some embodiments, the struts 123 may include a slight curve or bend region 125. As described in detail below, the protrusions 122 may be configured to hinge or otherwise bend at the bend region 125 when the actuation assembly 120 is transitioned to different configurations to change the flow characteristics through the shunt. For example, to increase the size of the lumen 102 and / or opening 103, and therefore decrease the flow resistance through the system 100, the protrusions may deflect radially outward by decreasing the degree of curvature at the bend region 125. Conversely, to decrease the size of the lumen 102 and / or opening 103, and therefore increase the flow resistance through the system 100, the protrusions may deflect radially inward by increasing the degree of curvature at the bend region 125.

[0017] In some embodiments, the actuator 121 further includes a flange or waist region with multiple secondary projections 127 that can extend around or from the "base" of the projection 122 (additional details of actuators with flanges or secondary projections are described below with reference to FIGS. 5 and 6). The actuator flanges / secondary projections 127 can be positioned adjacent to and in a common plane with the first petal 112 and / or second petal 114 of the anchor structure 110 and can thus be coupled to the anchor structure 110 to secure the actuation assembly 120 thereto. For example, the actuation assembly 120 can be mechanically coupled to the anchor structure 110 (e.g., using sutures, crimps, adhesive, tape, micromolded fasteners, etc.) at multiple connection points 128 positioned proximate the tips of the first petal 112 and / or second petal 114. In other embodiments, actuation assembly 120 may be coupled to anchor structure 110 via other mechanisms and / or at other locations (e.g., proximate radially inner portion 111 of anchor structure 110, similar to the embodiment described below with reference to FIG. 4). Mechanically coupling actuation assembly 120 to anchor structure 110 is expected to stabilize actuation assembly 120 within opening 113.

[0018] To facilitate adjustment of actuation assembly 120, actuator 121 may be at least partially constructed of a shape memory material such as Nitinol. Accordingly, actuator 121 may be capable of transitioning between at least a first material phase or state (e.g., a martensite state, an R-phase, a combined martensite and R-phase state, etc.) and a second material phase or state (e.g., an austenite state, an R-phase state, a combined austenite and R-phase state, etc.). In the first material state, actuator 121 may have reduced (e.g., relatively less stiff) mechanical properties that make actuator 121 more readily deformable (e.g., plastically compressible, expandable, etc.) compared to when in the second material state. In the second material state, actuator 121 may have increased (e.g., relatively more stiff) mechanical properties compared to the first material state, and an increased preference for a particular preferred geometry (e.g., original geometry, manufactured geometry, machined geometry, heat-set geometry, etc.). If actuator 121 is deformed relative to its preferred geometry when in a first material state, heating actuator 121 above its transition temperature moves actuator 121 to and / or toward its preferred geometry as actuator 121 transitions to its second material state. In some embodiments, actuator 121 is fabricated to have a transition temperature higher than average body temperature so that actuator 121 remains in the first material state during and after implantation in a patient. For example, actuator 121 can have a transition temperature of about 38 degrees Celsius to about 80 degrees Celsius, or about 40 degrees Celsius to about 65 degrees Celsius, or about 40 degrees Celsius to about 55 degrees Celsius, or about 45 degrees Celsius to about 50 degrees Celsius.

[0019] 1A , in some embodiments, actuator 121 is configured such that its preferred / shape-memory geometry, which may also be referred to herein as the “reset configuration,” defines a minimum therapeutic dimension for lumen 102. (As used herein, the term “minimum therapeutic dimension” refers to the minimum dimension of lumen 102 when actuator 121 and lumen 102 occupy the intended therapeutic configuration; in some embodiments, the minimum therapeutic dimension may therefore be larger than the dimension of lumen 102 when actuator 121 is collapsed within the catheter and / or larger than the dimension of lumen 102 immediately after actuator 121 is deployed from the catheter but before it is expanded / reset to its preferred geometry.) Thus, when actuator 121 is in its preferred geometry, lumen 102 offers the highest therapeutic fluid resistance, such as by virtue of opening 103 having the smallest deployed diameter. Because actuator 121 has a transition temperature greater than body temperature and is therefore generally in a first material state at body temperature, actuator 121 can be mechanically deformed at body temperature to change the dimensions of lumen 102 and / or opening 103. This can be done, for example, by positioning a catheter carrying an expandable element (e.g., a non-compliant balloon) within lumen 102 and expanding the expandable member until actuator 121 is deformed (e.g., enlarged or expanded) to a desired position. More specifically, expanding the expandable element can mechanically deflect protrusions 122 radially outward (e.g., by decreasing the curvature at bend region 125), increasing the diameter of opening 103 and thereby decreasing resistance through lumen 102. The expandable element can then be collapsed and retracted, while actuator 121 can be configured to retain its deformed (e.g., enlarged or expanded) state due to material properties associated with the first material state.

[0020] To reduce the size of the lumen 102 and / or the opening 103, the actuator 121 can be heated above its transition temperature and transitioned to a second material state. By transitioning to the second material state, the actuator 121 is “reset” to its preferred geometry (e.g., “reset configuration”), which may be associated with the minimum deployed size of the lumen 102, as described above. For example, thermally resetting the actuator 121 can move the protrusions 122 radially inward (e.g., by bending or increasing the curvature at the bending region 125) to reduce the diameter of the opening 103. In some embodiments, the actuator 121 can be thermally reset via resistive heating. For example, part or all of the anchor structure 110 can form an inductor for generating electrical energy in response to exposure to an electromagnetic field. The anchor structure 110 can be electrically coupled to the actuator 121 such that electrical energy generated in the anchor structure 110 flows into the actuator 121 and resistively heats the actuator 121, e.g., above its transition temperature. Further details regarding incorporating shape memory actuators into RLC circuits and using anchor structures as inductors are described below with reference to Figures 3A and 3B and in International Patent Application Publication Nos. 2022 / 076601 and 2022 / 081980, the disclosures of which are incorporated herein by reference in their entireties.

[0021] Once reset to its preferred geometry and cooled below the transition temperature (e.g., by returning to body temperature), the user can optionally mechanically re-expand actuator 121 to the desired dimension. Thus, actuation assembly 120 can be repeatedly and selectively manipulated by the user to adjust the level of therapy provided by system 100. Additional examples and details for operating shape memory actuators for adjustable shunts are described in U.S. Patent Application Publication Nos. 2021 / 0085935 and 2022 / 0142652, the disclosures of which are incorporated herein by reference in their entireties.

[0022] 1A , as described above, the actuation assembly 120 includes a membrane 130 that covers (e.g., coats) the protrusions 122. The membrane 130 creates / defines the walls of the lumen 102, and thus defines a flow path through which fluid may travel through the system 100. Without such a membrane defining, or at least partially defining, a flow path through the shunt device, the dimensional changes to the lumen 102 and / or opening 103 described above have little effect on the flow characteristics through the system 100. Note that the individual protrusions 122 are covered by individual membranes 130 or individual membrane portions such that there is a mechanical separation 132 between adjacent protrusions 122. In embodiments in which the individual protrusions 122 are covered by individual membrane portions as opposed to individual membranes, the membrane 130 may be constructed from a single piece of material but may have notches or slits corresponding to the separation 132 between the individual protrusions 122. Therefore, as used herein, the term "individually covering" includes both covering individual protrusions 122 with separate individual films 130 and covering individual protrusions 122 with individual portions of a common film.

[0023] Individually coating each protrusion 122 is expected to be advantageous because it restricts movement of the protrusions 122 to a lesser extent than if the protrusions 122 were covered by a single, continuous membrane (e.g., where there is no mechanical separation or discontinuity between membrane portions covering adjacent protrusions 122). This is because the membrane 130 and the protrusions 122 do not need to move relative to one another as the actuation assembly 120 transitions between various configurations. As a result, the membrane 130 does not need to be constructed of a flexible or “stretchy” material and / or a material that is too large (relative to the actuation assembly 120) to accommodate movement of the protrusions 122 during actuation of the actuation assembly 120, as described above. Rather, the membrane 130 can move with the individual protrusions 122 as they are deflected radially outward or reset radially inward. Individually coating the protrusions 122 also allows the individual protrusions 122 to slide / move relative to one another without having to substantially stretch the membrane 130. Additionally, in many embodiments, individually covering the protrusions 122 eliminates or minimizes the constant radially inward force and / or hoop stress applied to the protrusions 122 by a single continuous membrane when the geometry of the lumen 102 and / or openings 103 is expanded beyond the reset configuration. Still further, in many embodiments, individually covering the protrusions 122 eliminates or minimizes the convolution or buckling areas present in a single continuous membrane covering the protrusions 122 when the geometry of the lumen 102 and / or openings 103 is in a relatively small or narrow configuration compared to the largest or widest possible configuration.

[0024] For at least the reasons discussed above, individually coating the protrusions 122 is expected to increase the variety of materials that can be used for the membrane 130. For example, the membrane 130 may be constructed from a generally more rigid but still biocompatible material, such as ePTFE. In other embodiments, the membrane 130 may be constructed, at least in part, from other suitable materials, such as PTFE, PET, silicone, urethane, nylon, or a combination of suitable materials. In some embodiments, the membrane 130 is constructed from ePTFE with a urethane coating. Because individually coating the protrusions 122 also reduces the amount that the membrane 130 is stretched, individually coating the protrusions 122 is also expected to provide advantages even when a generally stretchable or elastic material is used for the membrane 130. For example, individually coating the protrusions 122 is expected to reduce undesirable wrinkling, tenting, tearing, and / or other deformations that may result from repeatedly stretching the membrane 130.

[0025] FIG. 2 illustrates another adjustable shunt system 200 (“system 200”) in a deployed configuration, constructed in accordance with selected embodiments of the technology. System 200 may include certain features generally similar to those of system 100 of FIGS. 1A and 1B. For example, system 200 may include anchor structure 210, which may be generally similar or the same as anchor structure 110 of system 100. System 200 may also include an actuation assembly 220 having an actuator 221 and a membrane 230, defining a lumen 202 with an opening 203. Similar to system 100 described with reference to FIGS. 1A and 1B, actuator 221 may include a plurality of protrusions 222 constructed from a shape-memory material to facilitate adjustment of actuation assembly 220. Protrusions 222 are individually covered by membrane 230 or portions of membrane 230 to reduce the resistance offered by membrane 230 when actuator 121 is adjusted.

[0026] 1A and 1B, the protrusions 222 of the actuation assembly 120 at least partially overlap when the actuator 121 is in its preferred geometric / reset configuration (e.g., after the actuator 121 has been reset to its base configuration by heating the actuator 121 above its transition temperature). That is, each protrusion 222 at least partially overlaps an adjacent protrusion 222. In some embodiments, when the actuator 221 is in its preferred geometric / reset configuration, adjacent protrusions 222 may overlap by between about 0.1 mm and 2.5 mm, or between about 0.1 mm and about 2 mm, or between about 0.1 mm and about 1.5 mm, or between about 0.5 mm and about 1.5 mm, or between about 0.5 mm and about 1.0 mm, or between about 0.1 mm and about 1.0 mm, or between about 0.1 mm and about 0.5 mm. For example, in some embodiments, adjacent protrusions 222 overlap by about 0.1 mm, about 0.2 mm, about 0.3 mm, about 0.4 mm, about 0.5 mm, about 0.6 mm, about 0.7 mm, about 0.8 mm, about 0.9 mm, about 1.0 mm, about 1.1 mm, about 1.2 mm, about 1.3 mm, about 1.4 mm, about 1.5 mm, about 1.6 mm, about 1.7 mm, about 1.8 mm, about 1.9 mm, about 2.0 mm, about 2.1 mm, about 2.2 mm, about 2.3 mm, about 2.4 mm, or about 2.5 mm. The foregoing ranges and values ​​are provided by way of example only; in other embodiments, the protrusions 222 may overlap more or less. Furthermore, the amount of overlap is expected to vary along the length of the protrusions 222. For example, in the illustrated embodiment, there is more overlap near the base of the protrusions 222 than near the tip of the protrusions 222. In some embodiments, this may be reversed so that there is more overlap near the tips of the protrusions 222 than near the bases of the protrusions 222. In any event, unless the context clearly indicates otherwise, use of a particular dimension in the context of overlapping petals refers to the maximum amount of overlap between two adjacent protrusions 222 at any point along their length.

[0027] In some embodiments, the protrusions 222 are configured to overlap when the actuator 212 is in the reset (e.g., narrowest) configuration, but not overlap when the actuator 221 is in the expanded / extended (e.g., wider) configuration. In other embodiments, the protrusions 222 may be configured to overlap when the actuator is in the reset configuration and in some, but not all, of the possible expanded configurations. In still other embodiments, the protrusions 222 may be configured to overlap when the actuator is in the reset configuration and in all of the possible expanded configurations. In any event, one skilled in the art will understand that the amount of overlap between adjacent protrusions 222 will vary based on the configuration of the actuator 221.

[0028] Without being bound by theory, overlapping protrusions 222 may provide at least four advantages over non-overlapping protrusions. First, overlapping protrusions 222 may reduce the amount of fluid that can flow (e.g., leak) between adjacent protrusions 222. Instead, fluid is more likely to flow through opening 203 and lumen 202. Second, overlapping protrusions 222 may at least partially mechanically couple multiple protrusions 222, thereby providing stability to the overall shape of opening 203 during movement of actuator 221, particularly during mechanical expansion of actuator 221. For example, during balloon expansion of actuation assembly 220 to reduce fluid resistance through lumen 202, each protrusion 222 being pushed radially outward by the balloon applies a mechanical radially outward force to at least one adjacent protrusion 222 with which it overlaps. As a result, all of the protrusions 222 are expected to expand radially outward uniformly, even though the balloon does not directly contact each protrusion 222. Third, overlapping protrusions 222 may be easier to fold into a delivery configuration that can fit within a catheter. In other words, overlapping protrusions 222 may simplify the process of folding or otherwise collapsing system 200 so that it can fit within a catheter that can be percutaneously advanced to a target location within a patient for deployment. Fourth, overlapping protrusions 222 may make it easier to advance a percutaneous tool (e.g., a balloon, catheter, guidewire, etc.) through the corresponding openings 203 and lumens 202 because it reduces the likelihood that the tool will become trapped between adjacent protrusions. Of course, other advantages of overlapping protrusions may exist beyond those explicitly identified herein, and the technology is not limited by the aforementioned advantages.

[0029] FIG. 3 illustrates another adjustable shunt system 300 ("system 300") in a deployed configuration, constructed in accordance with selected embodiments of the technology. System 300 may include certain features generally similar to those of system 100 of FIGS. 1A and 1B and system 200 of FIG. 2. For example, system 300 may include an anchor structure 310 configured to stabilize system 300 across a target anatomical structure (e.g., the septum between the left and right atria). However, unlike systems 100 and 200 of FIGS. 1A-2, anchor structure 310 includes a first wire portion 310a and a second wire portion 310b. First wire portion 310a and second wire portion 310b may be constructed at least in part from a common material, such as Nitinol, configured to have superelastic properties at body temperature. However, the first wire portion 310a can further include a conductive cladding / coating (e.g., silver or copper cladding) surrounding the Nitinol core, while the second wire portion 310b does not include a conductive cladding. In alternative embodiments, the conductive portion of the material can be inside the Nitinol shell. In further variations, the conductive material can be combined with or interface with a material other than Nitinol to comprise a hybrid material structure. Thus, in such embodiments, the first wire portion 310a can have more favorable electrical properties to function as an inductor or antenna for wirelessly receiving energy transmissions (e.g., to resistively heat the actuator 321 and / or charge one or more active components of the system 300, such as sensors, other electronics, etc.), while the second wire portion 310b can function with more favorable mechanical properties (e.g., greater superelasticity) to mechanically stabilize the system 300. In some embodiments, the first wire portion 310a and / or the second wire portion 310b may interface with other components (e.g., capacitors, inductors, resistors, microcontrollers, etc.) to assist in the function of acting as an inductor or antenna. In some embodiments, the first wire portion 310a and the second wire portion 310b are part of the same wire.In other embodiments, the first wire portion 310a and the second wire portion 310b are part of different wires (e.g., the first wire portion 310a and the second wire portion 310b are separate wires, e.g., the first wire 310a and the second wire 310b). In some embodiments, the first wire portion 310a and the second wire portion 310b are not electrically connected (e.g., not electrically in series) such that current generated in the first wire portion 310a passes through the second wire portion 310b. Indeed, in some embodiments, the first wire portion 310a may form part of an electrical circuit with one or more system components (e.g., the actuator 321), and the second wire portion 310b may form an open circuit (e.g., an epoxy-filled potted cap structure (not shown)) that terminates at an electrically insulated end of the second wire portion 310b. Further details regarding the use of stabilisation / anchoring features as inductors are described in International Patent Application Publication No. 2022 / 081980, which has been previously incorporated herein by reference.

[0030] Actuation assembly 320 may also include certain features generally similar to those described with reference to actuation assemblies 120, 220 described with reference to FIGS. 1A-2. For example, actuation assembly 320 may include actuator 321 and membrane 330 that together define lumen 302 having opening 303. Actuator 321 may include a plurality of petals or protrusions 322 constructed from a shape memory material to facilitate adjustment of actuation assembly 320. Similar to system 200 described with reference to FIG. 2, adjacent protrusions 322 at least partially overlap. Also similar to systems 100 and 200 described with reference to FIGS. 1A-2, protrusions 322 are individually covered by membrane 330. As shown, membrane 330 includes a plurality of first membrane portions 332 (e.g., shirts) that cover corresponding individual protrusions 322. Membrane 330 also includes a "skirt" comprising one or more second membrane portions 334 that cover or otherwise at least partially encase the portion of actuator 321 that abuts anchor structure 310 (see, e.g., FIGS. 5 and 6). Additionally, unlike systems 100 and 200, actuation assembly 320 is coupled to a radially inner portion or "waist" 311 of anchor structure 310. For example, actuation assembly 320 is coupled to radially inner portion 311 via a plurality of connecting elements 328 (e.g., sutures, ties, tape, adhesive, crimps, molded fasteners, etc.).

[0031] The actuator 321 can be electrically coupled to the first wire portion 310a of the anchor structure 310. For example, the system 300 can include an electrical connector subassembly 340, in which an end of the first wire portion 310a is electrically coupled to an end of the actuator 321. In some embodiments, the electrical connector subassembly 340 includes a capacitor (not shown) electrically coupled between the first wire portion 310a and the actuator 321. For example, the end of the first wire portion 310a can be crimped, soldered, or otherwise coupled to a first terminal of the capacitor, and the end of the actuator 321 can be crimped, soldered, or otherwise coupled to a second terminal of the capacitor. The capacitor and the corresponding connection between the capacitor, first wire portion 310a, and the actuator 321 can be embedded in epoxy or other suitable material and positioned within a cap (e.g., a titanium cap), thereby forming a potted connection between the first wire portion 310a and the actuator 321. In some embodiments, the entire electrical connector subassembly 340 may be encapsulated, for example, in addition to or instead of embedding the capacitor in epoxy.

[0032] In some embodiments, the actuator 321 and first wire portion 310a are electrically disconnected from the second wire portion 310b of the anchor structure 310. That is, the electrical circuit formed by the first wire portion 310a and the actuator 321 does not include the first wire portion 310b. Instead, as described above, the second wire portion 310b may form an “open” circuit that terminates at an insulated end of the second wire portion 310b, such as a second epoxy-filled potted cap structure (not shown), distinct from the electrical connector subassembly 340. Excluding the second wire portion 310b from the electrical circuit that includes the actuator 321 may be advantageous because it may reduce the total resistance of the circuit within the anchor structure 310 and provide more efficient energy transfer to the actuator 321.

[0033] To activate the actuator 321, a user can generate an electromagnetic field surrounding and / or directed toward the first wire portion 310a (e.g., via a transmitting coil positioned at the distal end of the catheter extending proximate to the first wire portion 310a). Due to its inductive properties, the first wire portion 310a generates electrical energy in response to exposure to the electromagnetic field. The generated electrical energy can flow through the first wire portion 310a, through a capacitor (not shown) in the electrical connector subassembly 340, and into the actuator 321. The electrical energy flowing through the actuator 321 can resistively heat the actuator 321. Thus, the first wire portion 310a, the capacitor in the electrical connector subassembly 340, and the actuator 321 form an RLC circuit, with the first wire portion 310a acting as an inductor and the actuator 321 acting as a resistor. In some embodiments, the RLC circuit is configured to ensure that electrical energy flows in the same direction (e.g., clockwise through anchor structure 310 and actuator 321). Further details regarding the incorporation of shape memory actuators into RLC circuits are provided in International Patent Application Publication No. WO 2022 / 076601, which has been previously incorporated herein by reference.

[0034] 1A and 1B, heating actuator 321 above its transition temperature can "reset" actuator 321 to its preferred geometry, which can be associated with its minimum deployed dimension for lumen 302. Once reset to its preferred geometry and cooled below the transition temperature, a user can optionally mechanically expand actuator 321 to a desired dimension to achieve, for example, a desired fluid resistance and / or flow rate through lumen 302.

[0035] FIG. 4 illustrates yet another adjustable shunt system 400 ("system 400") in a deployed configuration, constructed in accordance with selected embodiments of the technology. System 400 may include certain features generally similar to those of systems 100-300 of FIGS. 1A-3. For example, system 400 may include an anchor structure 410, which may be generally similar to or the same as anchor structure 110 of system 100. System 400 may also include an actuation assembly 420 having an actuator 421 and a membrane 430 defining a lumen 402 having an opening 403. Similar to systems 100-300 described with reference to FIGS. 1A-3, actuator 421 may include a plurality of protrusions 422 constructed from a shape memory material to facilitate adjustment of actuation assembly 420.

[0036] However, compared to system 200 of FIG. 2 and system 300 of FIGS. 3A and 3B, adjacent protrusions 422 are separated by gaps 432. Also, compared to system 100 of FIGS. 1A and 1B, the gaps 432 between adjacent protrusions 422 are substantially larger. For example, the widest portion of the gaps 432 may be at least 0.5 mm, at least 1 mm, at least 1.5 mm, or at least 2 mm. Furthermore, compared to system 100 of FIGS. 1A and 1B, the protrusions 422 of system 400 may be formed by substantially parallel struts 423. As a result, the width of the gaps 432 decreases toward the tips 424 of the protrusions 422 compared to the width of the gaps at the bases 425 of the protrusions 422, while the width of the protrusions 422 remains substantially constant over their lengths. One possible advantage of actuator 421 is that it may allow relatively more flow through system 400 compared to actuators 321, 221, 121 described with reference to Figures 1A-3 when the struts are in a comparable angular configuration. A second possible advantage of actuator 421 is that its ability to deform the geometry of struts 423 may be less affected by tissue overgrowth compared to the other aforementioned configurations (e.g., any tissue overgrowth is more likely to be confined to individual protrusions 422 rather than growing between / across adjacent protrusions 422, which may inhibit movement of the protrusions 422).

[0037] While each of the actuators 121-421 is shown as having generally symmetrical projections / petals, in alternative embodiments, the actuator struts forming the projections / petals and / or the projections / petals themselves may not be symmetrically configured. For example, some embodiments may utilize one or more relatively large struts or projections and one or more relatively small struts or projections (e.g., at least one pair of asymmetric struts). Some embodiments may utilize alternatingly sized struts or projections and / or struts with different mechanical properties (e.g., resulting from different wire thicknesses) within different sections of the lumen opening. Such embodiments may make the actuator more resistant to unintended deformation, such as deformation induced through accidental contact with an adjustment tool (e.g., a balloon catheter) during removal of the tool from the body. In other variations, other aspects of the actuator, such as the spacing between struts, the strut coating material and / or thickness or density, the strut height, etc., may vary and / or be asymmetric.

[0038] Additionally, while each of the actuators 121-421 in FIGS. 1A-4 is shown as a separate component from the corresponding anchor structure 110-410, in some embodiments, the actuators 121-141 may be part of the same component as the anchor structure, such that a specific coupling mechanism (e.g., connection point 128 in FIGS. 1A and 1B) is not required. For example, in some embodiments, the actuators 121-421 and any of the corresponding anchor structures 110-410 may be formed from a common nitinol or other shape memory wire. In such embodiments, the portion of the common wire forming the actuators 121-141 may be heat treated to exhibit shape memory properties at body temperature (e.g., set to have a phase transition temperature higher than body temperature), and the portion of the common wire forming the anchor structure 110 may be heat treated to exhibit superelastic properties at body temperature (e.g., set to have a phase transition temperature lower than body temperature).

[0039] The systems described herein can have actuators other than those shown in FIGS. 1A-4 that allow petals / protrusions on the actuator to be individually covered by corresponding membranes or membrane portions. For example, FIG. 5 illustrates actuator 521 configured in accordance with selected embodiments of the present technology. Actuator 521 can function generally similarly to actuators 121, 221, 321, and 421 described with reference to FIGS. 1A-4 and, therefore, can be used in place of the aforementioned actuators with any of systems 100-400. For example, similar to the actuators described above, actuator 521 is formed from one or more wires or wire-like structures and includes multiple protrusions 522 that define a lumen when actuator 521 is coupled to an anchor structure (e.g., anchor structure 110 of system 100). Actuator 521 further includes multiple secondary protrusions 528. The secondary protrusion 528 occupies a different plane than the protrusion 522 and may be used to couple the actuator 521 to a corresponding anchor structure (not shown in FIG. 5), such as at connection point 128 (FIG. 1A) when the actuator 521 is used with the system 100 of FIGS. 1A and 1B. Thus, the secondary protrusion 528 may be designed to abut a portion of the anchor structure (e.g., the tip of the first petal 112 and / or the second petal 114 of the anchor structure 110 of FIGS. 1A and 1B) and be mechanically coupled thereto (e.g., via sutures, adhesive, crimps, molded fasteners, etc.) to stabilize the actuator 521 relative to the anchor structure. In some embodiments, the secondary protrusion 528 is configured to reside on the opposite side of the anatomical structure from the tip of the protrusion 522 when the actuator 521 is implanted in a patient as part of an adjustable shunt system. For example, in embodiments in which actuator 521 is used with an adjustable inter-atrial shunt system configured to be implanted across a patient's septum, secondary protrusion 528 may be positionable within the left atrium and the tip of protrusion 522 may be positionable within the right atrium, or vice versa.In some embodiments, the secondary protrusions 528 may be at least partially covered by a portion of the membrane that covers the corresponding protrusions 522, such as with the skirt 334 of the membrane 330 described with reference to FIG. 3 and / or described in more detail below with reference to FIGS. 7A and 7B.

[0040] FIG. 6 illustrates yet another actuator 621 configured in accordance with selected embodiments of the technology. Actuator 621 can function generally similarly to actuators 121, 221, 321, and 421 described with reference to FIGS. 1A-4 and, therefore, can be used in place of the aforementioned actuators with any of systems 100-400. Like the actuators described above, actuator 621 is formed from one or more wires or wire-like structures and includes a plurality of petals or protrusions 622 that define a lumen when actuator 621 is coupled to an anchor structure (e.g., anchor structure 110 of system 100). Actuator 621 further includes a plurality of loops 628. Loops 628 can be used to couple actuator 621 to a corresponding anchor structure (not shown in FIG. 6), such as at connecting element 328 (FIG. 3), when actuator 621 is used with system 300 of FIGS. 3A and 3B. Thus, loop 628 abuts a portion of the anchor structure (e.g., radially inner portion 111 of anchor structure 110 of FIGS. 1A and 1B) and may be mechanically coupled thereto (e.g., via sutures, adhesive, crimps, molded fasteners, etc.) to stabilize actuator 621 relative to the anchor structure. When actuator 621 is deformed relative to its preferred / shape-memory geometry (e.g., during balloon expansion that increases the dimensions of actuator 121 beyond its reset configuration), strain accumulates in loop 628 (as opposed to strain accumulating in a designed bending region within the actuator, such as with actuator 121 of FIGS. 1A and 1B). In some embodiments, loop 628 may be covered or covered by a portion of a membrane that covers the corresponding protrusion 622, such as with skirt 334 of membrane 330 described with reference to FIG. 3 and / or described in more detail below with reference to FIGS. 7A and 7B.

[0041] The systems described herein can have membranes other than those shown in FIGS. 1A-4. For example, FIG. 7A shows an actuation assembly 720 that can be used with any of the systems described herein. Similar to the actuation assemblies described herein, actuation assembly 720 includes an actuator 721 having multiple protrusions 722 and a membrane 730 that individually covers the multiple protrusions 722. FIG. 7A shows actuation assembly 720 during a manufacturing stage after protrusions 722 have been formed and covered by membrane 730, but before the remaining portions of the wire structure forming actuator 721 have been set into a desired shape for coupling to a corresponding anchor structure (e.g., before secondary protrusions, such as secondary protrusions 528 described with reference to actuator 521 in FIG. 5 or loops 628 described with reference to actuator 621 in FIG. 6, are formed within actuator 721). As shown, membrane 730 includes multiple individual membranes 730a-730e. Each individual membrane 730 includes a first membrane portion 732 (e.g., a shirt) and a second membrane portion 734 (e.g., a skirt). Figure 7B shows the flat pattern of a single membrane 730a, showing the first membrane portion 732 and the second membrane portion 734 separated by a waist W.

[0042] 7A and 7B together, the first membrane portion 732 of each membrane 730 covers a corresponding individual protrusion 722. Thus, the first membrane portion 732 may be comprised of two layers forming a pouch for receiving the protrusion 722. The second membrane portion 734 is configured to at least partially cover a portion of the actuator 721 configured to abut a corresponding anchor structure (e.g., a secondary protrusion for coupling to an anchor structure such as secondary protrusion 528 described with reference to actuator 521 in FIG. 5 or loop 628 described with reference to actuator 621 in FIG. 6) when the actuator 721 is fully formed. Note that in the illustrated embodiment, the second membrane portion 734 is comprised of a single layer and therefore does not completely cover the portion of the actuator 721 configured around the corresponding anchor structure. Without intending to be bound by theory, a membrane having a first portion (e.g., first membrane portion 732) that is a double layer and a second portion (e.g., second membrane portion 734) that is a single layer may be easier to place over the protrusions 722 because it defines a pouch with a slot or opening through which the protrusions 722 can be inserted. However, as mentioned above, in some embodiments, the membranes described herein may completely cover the protrusions and the portions of the actuators configured to abut the anchor structures.

[0043] FIG. 8 illustrates another embodiment of an adjustable shunt system 800 (“system 800”) configured in accordance with selected embodiments of the technology. System 800 may include certain features generally similar to those of systems 100-400 of FIGS. 1A-4 , described in detail above. For example, system 800 may include an anchor assembly 808 for anchoring system 800 in a desired anatomical location (e.g., across a patient's septum). System 800 may also include an actuating assembly 820 having a plurality of protrusions or petals 822 covered by one or more discontinuous membranes 830, as described in detail above with reference to FIGS. 1A-7 . Actuating assembly 820 may define a lumen 802 extending therethrough, for example, to shunt fluid between a first body region and a second body region when system 100 is implanted in a patient.

[0044] 1A-4 , anchor assembly 808 includes anchor structure 810 covered by (e.g., disposed within) anchor membrane 809 (“membrane 809”). In some embodiments, membrane 809 completely encases anchor structure 810, e.g., to prevent anchor structure 810 from being directly exposed to bodily fluids when system 800 is implanted. For example, membrane 809 can be a laminated structure including two sheets of material bonded together with anchor structure 810 positioned therebetween, a single piece of material folded to encase anchor structure 810, or have any other suitable configuration. Membrane 809 can be constructed of a biocompatible and / or anti-thrombogenic material. Exemplary materials include, but are not limited to, ePTFE, PTFE, PET, silicone, urethane, nylon, etc.

[0045] In some embodiments, membrane 809 covering anchor structure 810 is different from (e.g., not integral with) one or more membranes 830 covering protrusions 822 of actuation assembly 820. Thus, membrane 809 may optionally be constructed from a different material than membrane 830. In other embodiments, membrane 809 may be integral with one or more of membranes 830 covering protrusions 822.

[0046] System 800 may also optionally include a canister 840 coupled to anchor structure 810 or another portion of system 800. Canister 840 may be a sealed (e.g., hermetically sealed) container that houses various electronics and other components of system 800. For example, canister 840 may house one or more energy storage components (e.g., primary batteries, rechargeable batteries, capacitors, supercapacitors, etc.), one or more sensors or associated electronic circuitry (e.g., pressure sensors, flow sensors, etc.), one or more data storage elements (e.g., memory), one or more processors, one or more telemetry components, one or more microcontrollers, etc. Canister 840 may be constructed from a generally rigid material, such as titanium, steel, plastic, etc. Canister 840 may also be covered by a biocompatible membrane constructed, for example, from ePTFE or another suitable material. While shown with a single canister 840, in other embodiments, system 800 may have additional canisters, such as two, three, four, or more.

[0047] Those skilled in the art will appreciate from the disclosure herein that various components of the systems described above may be omitted without departing from the scope of the art. Similarly, additional components not expressly described above may be added to the systems without departing from the scope of the art. Furthermore, the features described herein may be incorporated into other types of implantable medical devices other than shunt systems. Exemplary other implantable medical devices include, but are not limited to, occlusion devices (e.g., septal occluders), septal sensor devices with transseptal access ports, stents (e.g., perfusion stents), valves, and the like. Thus, the art is not limited to the configurations expressly identified herein, but rather encompasses variations and modifications of the described systems. [Example]

[0048] Some aspects of this technology are described in the following examples.

[0049] 1. A shunt system for fluidly connecting a first body region and a second body region of a patient, the system comprising: an anchor structure configured to stabilize the shunt system across the target anatomical structure; an actuation assembly coupled to the anchor structure, the actuation assembly comprising: an actuator constructed from one or more shape memory wires, the actuator including a plurality of protrusions that together define a cylindrical or conical shape through which a lumen extends, the tips of the protrusions defining openings to the lumen; a membrane covering the plurality of protrusions, the membrane individually covering each of the plurality of protrusions; A shunt system, wherein the actuation assembly is selectively transitionable between at least two or more configurations, the at least two or more configurations being associated with different resistances to flow through the lumen.

[0050] 2. The system of example 1, wherein the at least two or more configurations include a reset position and one or more extended configurations.

[0051] 3. When the actuation assembly is in a reset position, the lumen has a first resistance; when the actuation assembly is in one of the one or more expanded configurations, the lumen has a second resistance; 3. The system of example 2, wherein the first resistance is greater than the second resistance.

[0052] 4. When the actuation assembly is in a reset position, the opening has a first diameter; when the actuation assembly is in one of the one or more expanded configurations, the opening has a second diameter; The system of example 2 or example 3, wherein the first diameter is smaller than the second diameter.

[0053] 5. The actuator is configured to transition between (a) a first material state having relatively less stiff mechanical properties and (b) a second material state having relatively more stiff mechanical properties in response to being heated above a transition temperature that is greater than body temperature; The system of any of Examples 2-4, wherein the actuation assembly is configured to return to the reset position in response to being heated above a transition temperature.

[0054] 6. The system of any of Examples 2-5, wherein adjacent protrusions of the plurality of protrusions at least partially overlap when the actuation assembly is in the reset position.

[0055] 7. The system of example 6, wherein adjacent protrusions overlap by about 0.1 mm to about 2.5 mm.

[0056] 8. The system of example 6, wherein adjacent protrusions overlap by about 0.5 mm to about 1.5 mm.

[0057] 9. The system of any of Examples 2-8, wherein adjacent protrusions of the plurality of protrusions at least partially overlap in both the reset position and the one or more extended positions.

[0058] 10. The system of any of Examples 1-6, wherein adjacent protrusions of the plurality of protrusions are separated by a gap.

[0059] 11. The system of example 10, wherein the gap is at least about 0.5 mm.

[0060] 12. The system of example 10, wherein the gap is at least about 1 mm.

[0061] 13. The system of any of Examples 1-12, wherein the membrane comprises a plurality of individual membranes, each individual membrane of the plurality of membranes covering a respective protrusion of the plurality of protrusions.

[0062] 14. The system of Example 13, wherein each individual membrane comprises a first membrane portion and a second membrane portion separated by a constriction, the first membrane portion covering an individual protrusion, and the second membrane portion extending over a portion of the anchor structure.

[0063] 15. The system of example 14, wherein the first membrane portion comprises two layers and the second membrane portion comprises a single layer.

[0064] 16. The system of example 14, wherein the first membrane portion comprises two layers and the second membrane portion comprises two layers.

[0065] 17. A system described in any one of Examples 1 to 12, wherein the membrane includes a single membrane having multiple membrane portions separated by gaps, and each of the multiple membrane portions covers each of the multiple protrusions.

[0066] 18. The system of any one of Examples 1-17, wherein the membrane is made of ePTFE.

[0067] 19. A system described in any of Examples 1-18, wherein the adjustable shunt system is an interatrial shunt system and the target anatomical structure is the cardiac septum between the left atrium and the right atrium.

[0068] 20. The system of any of Examples 1-19, wherein the membrane is a first membrane and the system further comprises a second membrane covering the anchor structure.

[0069] 21. The system of example 20, wherein the first membrane and the second membrane are discontinuous.

[0070] 22. The system of example 20 or example 21, wherein the second membrane is composed of a biocompatible and / or anti-thrombogenic material.

[0071] 23. The system of any of Examples 1-22, wherein the anchor structure is electrically coupled to the actuator via a capacitor.

[0072] 24. The system of example 23, wherein the anchor structure, the actuator, and the capacitor form an RLC circuit.

[0073] 25. A shunt system for fluidly connecting a first body region and a second body region of a patient, the system comprising: a plurality of petals each extending between a first end and a second end, the petals arranged in a cylindrical or conical shape to form a lumen therethrough, an opening to the lumen being defined by the first end of the petal; A shunt system in which each individual petal of the plurality of petals includes a corresponding individual membrane or individual membrane portion, such that at least first ends of adjacent petals can move relative to each other without stretching the individual membrane or individual membrane portion.

[0074] 26. The system of Example 25, wherein the petals are configured such that they can bend radially inward and / or radially outward without stretching the membrane or membrane portion.

[0075] 27. The system described in Example 26, wherein the opening size is adjustable by bending the petals radially inward and / or radially outward.

[0076] 28. A system described in any of Examples 25 to 27, wherein the membrane or membrane portion is rigid.

[0077] 29. A system described in any one of Examples 25 to 28, wherein adjacent petals among the plurality of petals overlap.

[0078] 30. A system described in any one of Examples 25 to 28, wherein adjacent petals of the plurality of petals are separated by a gap.

[0079] 31. A system described in any of Examples 25-30, wherein the plurality of petals includes a shape memory wire extending through the petals.

[0080] 32. An adjustable shunt system for fluidly connecting a first body region and a second body region of a patient, the system comprising: a plurality of membranes arranged in a conical or cylindrical configuration and forming a lumen therethrough; An adjustable shunt system, wherein each membrane has a periphery including a first edge extending at least partially along the length of the lumen, a second edge extending at least partially along the length of the lumen, and a tip connecting the first and second edges, wherein the width between the first and second edges is less than the circumference of the lumen.

[0081] 33. The system of example 32, wherein the width between the first edge and the second edge varies along the length of each membrane.

[0082] 34. The system of Example 32 or Example 33, wherein adjacent membranes of the plurality of membranes at least partially overlap.

[0083] 35. The system of example 32 or example 33, wherein adjacent membranes of the plurality of membranes are separated by a gap.

[0084] conclusion Embodiments of the present disclosure may include some or all of the following components:

[0085] The implant may include: a battery, supercapacitor, or other suitable power source; a microcontroller, FPGA, ASIC, or other programmable component or system capable of storing and executing software and / or firmware that drives the operation of the implant; memory, such as RAM or ROM, for storing data and / or software / firmware related to the implant and / or its operation; wireless communication hardware, such as an antenna system configured to transmit via Bluetooth, WiFi, or other protocols known in the art; energy harvesting means, for example, a coil or antenna capable of receiving and / or reading an externally provided signal that may be used to power the device, charge a battery, initiate readings from a sensor, or for other purposes. Embodiments may also include one or more sensors, such as a pressure sensor, an impedance sensor, an accelerometer, a force / strain sensor, a temperature sensor, a flow sensor, an optical sensor, a camera, a microphone or other acoustic sensor, an ultrasound sensor, an ECG or other cardiac rhythm sensor, an SpO2 or other sensor adapted to measure tissue and / or blood gas levels, a blood volume sensor, and other sensors known to those skilled in the art. Embodiments may include portions that are radiopaque and / or ultrasound reflective to facilitate image-guided implantation or image-guided procedures using techniques such as fluoroscopy, ultrasonography, or other imaging methods. System embodiments may include specialized delivery catheters / systems adapted to deliver the implant and / or perform the procedure. The systems may include components such as guidewires, sheaths, dilators, and multiple delivery catheters. Components may be exchanged via over-the-wire, rapid exchange, combination, or other techniques.

[0086] The above detailed description of embodiments of the technology is not intended to be exhaustive or to limit the technology to the precise form disclosed above. While specific embodiments and examples of the technology have been described above for illustrative purposes, those skilled in the art will recognize that various equivalent modifications are possible within the scope of the technology. For example, while steps are presented in a given order, alternative embodiments may perform steps in a different order. Various embodiments described herein can also be combined to provide further embodiments. For example, while the present disclosure has been generally described to describe devices that are described as being used to create a fluid communication pathway between the left and right atria, it should be understood that similar embodiments can be utilized for shunts between other ventricles of the heart or shunts in other regions of the body.

[0087] Unless the context clearly dictates otherwise, throughout the description and examples, words like "comprise," "comprising," and the like should be construed in an inclusive sense, i.e., "including, but not limited to," rather than an exclusive or exhaustive sense. As used herein, the terms "connected," "coupled," or any variation thereof, refer to any direct or indirect connection or coupling between two or more elements. The coupling between elements may be physical, logical, or a combination thereof. Additionally, the words "herein," "above," "below," and words of similar import, when used in this application, refer to this application as a whole and not to any particular portions of this application. Where the context permits, words in the above detailed description using the singular or plural may also include both the plural and the singular, respectively. As used herein, the phrase "and / or," such as "A and / or B," refers to A only, B only, or both A and B. Additionally, the term "comprising" is used throughout to mean the inclusion of at least the recited features, but not the exclusion of any more of the same features and / or other features of additional types. It will also be understood that, while specific embodiments have been described herein for illustrative purposes, various modifications may be made without departing from the technology. Furthermore, while advantages associated with some embodiments of the technology have been described in the context of these embodiments, other embodiments may also exhibit such advantages, and not all embodiments necessarily exhibit such advantages to fall within the scope of the technology. Thus, the present disclosure and related technology may encompass other embodiments not explicitly shown or described herein.

Claims

1. 1. A shunt system for fluidly connecting a first body region and a second body region of a patient, the system comprising: an anchor structure configured to stabilize the shunt system across a target anatomical structure; an actuation assembly coupled to the anchor structure, the actuation assembly comprising: an actuator constructed from one or more shape memory wires, said actuator including a plurality of protrusions that together define a cylindrical or conical shape through which a lumen extends, the tips of said protrusions defining openings to said lumen; a film covering the plurality of protrusions, the film individually covering each of the plurality of protrusions; A shunt system, wherein the actuation assembly is selectively transitionable between at least two or more configurations, the at least two or more configurations being associated with different resistances to flow through the lumen.

2. The system of claim 1 , wherein the at least two or more configurations include a reset position and one or more extended configurations.

3. When the actuation assembly is in the reset position, the lumen has a first resistance; the lumen has a second resistance when the actuation assembly is in one of the one or more expanded configurations; The system of claim 2 , wherein the first resistance is greater than the second resistance.

4. When the actuation assembly is in the reset position, the opening has a first diameter; the opening has a second diameter when the actuation assembly is in one of the one or more expanded configurations; The system of claim 2 , wherein the first diameter is smaller than the second diameter.

5. the actuator is configured to transition between (a) a first material state having relatively less stiff mechanical properties and (b) a second material state having relatively more stiff mechanical properties in response to being heated above a transition temperature that is greater than body temperature; The system of claim 2 , wherein the actuation assembly is configured to return to the reset position in response to being heated above the transition temperature.

6. The system of claim 2 , wherein adjacent protrusions of the plurality of protrusions at least partially overlap when the actuation assembly is in the reset position.

7. The system of claim 6 , wherein adjacent protrusions overlap by about 0.1 mm to about 2.5 mm.

8. The system of claim 6 , wherein adjacent protrusions overlap by about 0.5 mm to about 1.5 mm.

9. The system of claim 2 , wherein adjacent protrusions of the plurality of protrusions at least partially overlap in both the reset position and the one or more extended positions.

10. The system of claim 1 , wherein adjacent protrusions of the plurality of protrusions are separated by a gap.

11. The system of claim 10 , wherein the gap is at least about 0.5 mm.

12. The system of claim 10 , wherein the gap is at least about 1 mm.

13. The system of claim 1 , wherein the membrane comprises a plurality of individual membranes, each individual membrane of the plurality of membranes covering a respective protrusion of the plurality of protrusions.

14. 14. The system of claim 13, wherein each of the individual membranes includes a first membrane portion and a second membrane portion separated by a constriction, the first membrane portion covering an individual protrusion and the second membrane portion extending over a portion of the anchor structure.

15. The system of claim 14 , wherein the first membrane portion comprises two layers and the second membrane portion comprises a single layer.

16. The system of claim 14 , wherein the first membrane portion comprises two layers and the second membrane portion comprises two layers.

17. The system of claim 1 , wherein the membrane comprises a single membrane having multiple membrane portions separated by gaps, each membrane portion of the multiple membrane portions covering a respective protrusion of the multiple protrusions.

18. The system of claim 1 , wherein the membrane is constructed from ePTFE.

19. 10. The system of claim 1, wherein the adjustable shunt system is an interatrial shunt system and the target anatomy is the cardiac septum between the left and right atria.

20. The system of claim 1 , wherein the membrane is a first membrane, and the system further comprises a second membrane covering the anchor structure.

21. 21. The system of claim 20, wherein the first film and the second film are discontinuous.

22. 21. The system of claim 20, wherein the second membrane is constructed from a biocompatible and / or anti-thrombogenic material.

23. The system of claim 1 , wherein the anchor structure is electrically coupled to the actuator via a capacitor.

24. 24. The system of claim 23, wherein the anchor structure, the actuator, and the capacitor form an RLC circuit.

25. 1. A shunt system for fluidly connecting a first body region and a second body region of a patient, the system comprising: a plurality of petals each extending between a first end and a second end, the petals arranged in a cylindrical or conical shape to form a lumen therethrough, an opening to the lumen being defined by the first ends of the petals; A shunt system wherein each individual petal of the plurality of petals includes a corresponding individual membrane or individual membrane portion, such that at least the first ends of adjacent petals can move relative to each other without stretching the individual membranes or individual membrane portions.

26. 26. The system of claim 25, wherein the petals are configured such that the petals can bend radially inward and / or radially outward without stretching the membrane or membrane portion.

27. 27. The system of claim 26, wherein the opening size is adjustable by bending the petals radially inward and / or radially outward.

28. 26. The system of claim 25, wherein the membrane or membrane portion is rigid.

29. 26. The system of claim 25, wherein adjacent petals of the plurality of petals overlap.

30. 26. The system of claim 25, wherein adjacent petals of the plurality of petals are separated by a gap.

31. 26. The system of claim 25, wherein the plurality of petals includes a shape memory wire extending therethrough.

32. 1. An adjustable shunt system for fluidly connecting a first body region and a second body region of a patient, the system comprising: a plurality of membranes arranged in a conical or cylindrical configuration and forming a lumen therethrough; an adjustable shunt system, wherein each membrane has a periphery including a first edge extending at least partially along the length of the lumen, a second edge extending at least partially along the length of the lumen, and a tip connecting the first edge and the second edge, and wherein the width between the first edge and the second edge is less than the circumference of the lumen.

33. 33. The system of claim 32, wherein the width between the first edge and the second edge varies along the length of each membrane.

34. 33. The system of claim 32, wherein adjacent ones of the plurality of membranes at least partially overlap.

35. 33. The system of claim 32, wherein adjacent ones of the plurality of membranes are separated by a gap.

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