Adjustable shunts with shape memory actuators and associated fluid control features and / or positioning features

Abstract

The present technology provides shape memory actuators and associated features that are expected to improve a seal the shape memory actuators can provide at a fluid aperture. For example, many of the embodiments described herein include adjustable shunts having one or more ramping features that interfere with the actuator as it transitions between a first (e.g., open) position and a second (e.g., closed) position to, for example, direct the shape memory actuator into the aperture to block the flow of fluid therethrough.

Description

ADJUSTABLE SHUNTS WITH SHAPE MEMORY ACTUATORS AND ASSOCIATED FLUID CONTROL FEATURESAND / OR POSITIONING FEATURESCROSS-REFERENCE TO RELATED APPLICATION(S)

[0001] The present application claims priority to U.S. Provisional Patent Application No. 63 / 594,861, filed October 31, 2023, and U.S. Provisional Patent Application No 63 / 551,412, filed February 8, 2024, each of which are incorporated by reference herein in their entireties.TECHNICAL FIELD

[0002] The present technology generally relates to implantable medical devices and, in particular, to adjustable shunts for controlling fluid flow between a first body region and a second body region of a patient.BACKGROUND

[0003] Implantable shunting systems are widely used to treat a variety of patient conditions by shunting fluid from a first body region / cavity to a second body region / cavity. For example, shunting systems have been proposed for treating glaucoma. The flow of fluid through the shunting systems is primarily controlled by the pressure gradient across the shunt and the physical characteristics of the flow path defined through the shunt (e g., the resistance of the shunt lumen). Conventional, early shunting systems (sometimes referred to as minimally invasive glaucoma shunts or “MIGS”) have shown clinical benefit; however, there is a need for improved shunting systems and techniques for addressing elevated intraocular pressure and risks associated with glaucoma, as well as other patient conditions. For example, there is a need for shunting systems capable of adjusting the therapy provided, including the flow rate / fluid resistance betw een the two fluidly-connected bodies. As another example, there is a need for a shunting system capable of being modified after manufacture (e g., in the clinic) to personalize the system for the patient and / or as part of the clinician's plan for the implant procedure.BRIEF DESCRIPTION OF THE DRAWINGS

[0004] Many aspects of the present technology can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale. Instead, emphasis is placed on illustrating clearly the principles of the present technology.Furthermore, components can be shown as transparent in certain views for clarity of illustration only and not to indicate that the component is necessarily transparent. Components may also be shown schematically.

[0005] FIG. 1A illustrates an adjustable shunting system configured in accordance with select embodiments of the present technology.

[0006] FIG. IB is an exploded perspective view of the adjustable shunting system of FIG. 1A.

[0007] FIGS. 2A-2D illustrate a shape memory actuator for selectively controlling a flow of fluid through an adjustable shunting system and configured in accordance with select embodiments of the present technology7.

[0008] FIGS. 3A and 3B are schematic, cross-sectional illustrations of various features of the shape memory actuator of FIGS. 2A and 2B and the adjustable shunting system of FIGS. 1 A and IB, and demonstrate a first ramping feature expected to provide improved fluid control and configured in accordance with select embodiments of the present technology.

[0009] FIGS. 4A and 4B are schematic, cross-sectional illustrations of various features of the shape memory actuator of FIGS. 2A and 2B and the adjustable shunting system of FIGS. 1 A and IB, and demonstrate a second ramping feature expected to provide improved fluid control and configured in accordance with select embodiments of the present technology.

[0010] FIGS. 5A and 5B are schematic, cross-sectional illustrations of various features of the shape memory actuator of FIGS. 2A and 2B and the adjustable shunting system of FIGS. 1 A and IB, and demonstrate a positional feature expected to provide improved positional control of the actuator and configured in accordance with select embodiments of the present technology.

[0011] FIGS. 6A-6C illustrate another embodiment of positional features configured in accordance with select embodiments of the present technology and that are expected to provide improved positional control of a shape memory actuator.

[0012] FIGS. 7A-7E illustrate additional embodiments of positional features configured in accordance with select embodiments of the present technology and that are expected to provide improved positional control of a shape memory actuator.

[0013] FIGS. 8-10 illustrate various plates configured in accordance with select embodiments of the present technology that include positional features expected to provide improved positional control of a shape memory actuator.

[0014] FIGS. 11A and 11B illustrate a plate and two actuators with complimentary draft angles coupled together in an assembled configuration and configured in accordance with select embodiments of the present technology.DETAILED DESCRIPTION

[0015] The present technology is generally directed to adjustable shunting systems, including adjustable shunting systems with improved flow control. For example, the adjustable shunting systems described herein can include a shunting element with at least one channel extending therethrough that permits fluid to flow through the system. The system can further include an actuator that can be selectively actuated to control the flow of fluid through an inlet or outlet aperture of the channel to titrate the level of therapy provided by the shunt. In some embodiments, the actuator can include a gating element having a distal end portion, which can also be referred to as a sealing element, moveable between a first (e.g., open) position in which the distal end portion provides a first resistance to fluid flow through the aperture (e.g., by not blocking the aperture), and a second (e.g., closed or partially closed) position in which the distal end portion provides a second resistance greater than the first resistance (e.g., by at least partially blocking the aperture).

[0016] The present technology provides several features expected to improve the flow control provided by the sealing assembly. For example, in some of the embodiments described herein, the adjustable shunts have one or more ramping features that interfere with the distal end portion of the gating element as it transitions between the first (e.g., open) position and the second (e.g., closed) position. In particular, in many embodiments described herein the actuator is configured to move the distal end portion of the gating element along an arc in a common plane (e g., in the x and / or y direction, or simply '‘horizontally’’). In contrast, the ramping feature can be sized and shaped to deflect the distal end portion of the gating element in the z direction (“vertically”). Without intending to be bound by theory, deflecting the distal end of the gating element in the z direction is expected to improve a seal that can be achieved at the aperture when the distal end of the gating element is in the second (e.g., closed) position, e.g., by directing a portion of the distal end toward the aperture. In some embodiments, the actuator may have a proj ection that is sized and shaped to fit at least partially inside of the aperture to further improve fluid control at the aperture.

[0017] In some embodiments, the adjustable shunts also have one or more positioning features, in addition to or in lieu of the ramping features. As described below, the positioningfeatures can (a) provide a defined track or arc for the distal end of the gating element to move along as it transitions between the first (e.g., open) position and the second (e.g., closed) position, and / or (b) provide positional stability at one or more of the first or second positions.

[0018] The terminology used in the description presented below is intended to be interpreted in its broadest reasonable manner, even though it is being used in conjunction with a detailed description of certain specific embodiments of the present technology. Certain terms may even be emphasized below; however, any terminology intended to be interpreted in any- restricted manner will be overtly and specifically defined as such in this Detailed Description section. Additionally, the present technology can include other embodiments that are within the scope of the examples and claims but are not described in detail with respect to FIGS. 1 A-l IB.

[0019] Reference throughout this specification to '‘one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present technology-. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features or characteristics may be combined in any suitable manner in one or more embodiments.

[0020] As used herein, the use of relative terminology', such as “about”, “approximately”, “substantially” and the like refer to the stated value plus or minus ten percent. For example, the use of the term “about 100” refers to a range of from 90 to 110. inclusive. In instances in which the context requires otherwise and / or relative terminology is used in reference to something that does not include a numerical value, the terms are given their ordinary- meaning to one skilled in the art.

[0021] Reference throughout this specification to the term “resistance” refers to fluid resistance unless the context clearly dictates otherwise. The terms “drainage rate” and “flowrate” are used interchangeably to describe the movement of fluid through a structure at a particular volumetric rate. The term “flow” is used herein to refer to the motion of fluid, in general.

[0022] The systems described herein can be designed for shunting fluid between a variety of body regions. For example, many of the embodiments described herein are designed to be implanted in a patient’s eye to shunt aqueous between the anterior chamber and a target outflow location (e.g., a subconjunctival bleb space), such as to treat glaucoma. However, althoughcertain embodiments are described in terms of shunting fluid from an anterior chamber of an eye, one of skill in the art will appreciate that the present technology can be readily adapted to shunt fluid from and / or between other portions of the eye or, more generally, from and / or between a first body region and a second, different body region of a patient. Moreover, while certain embodiments herein are described in the context of glaucoma treatment, any of the embodiments herein, including those referred to as “glaucoma shunts” or “glaucoma devices” may nevertheless be used and / or modified to treat other diseases or conditions, including other diseases or conditions of the eye or other body regions. For example, the systems described herein can be used to treat diseases characterized by increased pressure and / or fluid build-up including, but not limited to, heart failure (e.g., heart failure with preserved ejection fraction, heart failure with reduced ejection fraction, etc.), pulmonary failure, renal failure, hydrocephalus, and the like. Moreover, while generally described in terms of shunting aqueous, the systems described herein may be applied equally to shunting other fluid, such as blood or cerebrospinal fluid, between the first body region and the second body region.

[0023] FIGS. 1A and IB illustrate an adjustable shunting system 100 (“the system 100”) configured in accordance with select embodiments of the present technology. More specifically, FIG. 1A is a top view of the system 100 and FIG. IB is an exploded perspective view of the system 100. As described in greater detail below, the system 100 is configured to be adjustable in response to laser energy input to provide a titratable therapy for shunting fluid from a first body region to a second body region, such as shunting aqueous from an anterior chamber of a patient’s eye to a target outflow location.

[0024] Referring first to FIG. 1A, the system 100 includes a shunting element 102 and an actuation or control assembly 120. which is partially hidden from view by the shunting element 102 in FIG. 1 A. The shunting element 102 (which can also be referred to as a casing, membrane, elongated housing, or the like) extends between a first end portion 102a and a second end portion 102b. A plurality of flow channels 104 (not visible in FIG. 1 A — see FIG. IB) can extend through the shunting element 102 at least partially between the first end portion 102a and the second end portion 102b. As described in greater detail below, when the system 100 is implanted within a patient between a first body region and a second body region, fluid can flow from the first body region to the second body region via the flow channels 104. The shunting element 102 may optionally include one or more features to facilitate anchoring the system 100 to patient tissue, such as first and second suture holes 108a, 108b.

[0025] The shunting element 102 can be composed of a partially flexible and / or biocompatible material, such as silicone. polydimethylsiloxane (PDMS), polymethylmethacrylate (PMA), or the like. For example, the shunting element 102 may be composed of a material having a durometer of between about 60 and about 90, or between about 70 and 80, or about 75. Additional features of shunting elements suitable for use with the present technology are described in International Patent Application No. PCT / US2022 / 037747, the disclosure of which is incorporated by reference herein in its entirety and for all purposes.

[0026] The actuation assembly 120 can be positioned at or proximate the first end portion 102a of the shunting element 102. As described in greater detail below, the actuation assembly 120 can have one or more features that selectively control the flow of fluid through one or more of the flow channels extending through the shunting element 102. In this way, the actuation assembly 120 can be selectively manipulated by a clinician to adjust the resistance through the system 100, and thus the level of therapy provided by the system 100.

[0027] Referring next to FIG. IB, the shunting element 102 can include one or more components and / or layers that are stacked and sealed together to collectively form the shunting element 102. For example, the shunting element 102 can include a first (e.g., top) layer 110, a second (e.g., middle) layer 112, and a third (e.g., bottom) layer 114. Accordingly, in the illustrated embodiment the shunting element 102 includes three layers, although in other embodiments the shunting element 102 can include more or fewer layers, such as one, two. four, five, six, or more layers. In operation, the first layer 110, the second layer 112, and the third layer 114 are sealed together (e.g., glued, adhered, bonded, etc.) to form the shunting element 102. More specifically, a lower surface of the first layer 110 is sealed to an upper surface of the second layer 112, and a lower surface of the second layer 112 is sealed to an upper surface of the third layer 114. Sealing the layers prevents or at least reduces fluid from leaking through the system 100 between layers. Additional details regarding multi-layered shunting systems are described in International Patent Application No. PCT / US2022 / 037917, the disclosure of which is incorporated by reference herein in its entirety. In other embodiments, the shunting element 102 is formed from a single, contiguous structure, without the need for sealing a plurality of layers together.

[0028] Returning to the embodiment shown in FIG. IB, the first layer 110 includes an opening 111 that permits fluid to flow into the shunting element 102 (or, depending on the orientation of, and direction of flow through, the shunting element 102, fluid can flow out of theopening 111). In addition to permitting fluid to flow into the shunting element 102, the opening 111 enables a user to have an unobstructed view of at least a portion of the actuation assembly 120. For example, when the system 100 is assembled as shown in FIG. 1A, a portion of the actuation assembly 120 can be aligned with the opening 111. This enables a user to selectively actuate the actuation assembly by directing energy (e.g., laser energy) through the opening 111. Although shown as having a single opening 111, in some embodiments the first layer 110 may have two more openings.

[0029] The second layer 112 includes a chamber or cavity 116 at the first end portion 102a, with an opening to the chamber 116 facing toward the first layer 1 10. The second layer 112 therefore has a flexible membrane 113 forming the lower surface of the chamber 116. The membrane 113 is defined, at least in part, by a thinned portion / region of the second layer 112, as compared to a thickness of the second layer 112 elsewhere along the length of the second layer 112. For example, the second layer 112 (outside of the thinned portion of the membrane113) may have a thickness of between about 80 micron and about 200 micron, but the membrane113 at the chamber 116 may have a reduced thickness of between about 20 micron and about 80 micron, or between about 30 micron and about 70 micron, or between about 40 micron and about 60 micron, or about 50 micron. The foregoing ranges are provided by way of example only — in other embodiments, the second layer 1 12 and / or the thinned portion defining the membrane 113 can have thicknesses outside the foregoing ranges. The chamber 116 provides an empty space or cavity for receiving the actuation assembly 120. The chamber 116 also includes several openings (e.g., ports, apertures, etc.). For example, the chamber 116 includes a first aperture 117a. a second aperture 117b, and a third aperture 117c (collectively referred to as the apertures 117). The apertures 117 extend fully through the second layer 1 12 such that fluid can flow through the second layer 112 via the apertures 117.

[0030] The third layer 114 defines or at least partially defines the fl ow channels that extend through the shunting element 102. In the illustrated embodiment, for example, the third layer114 defines a first channel 104a, a second channel 104b, and a third channel 104c (collectively referred to as the channels 104). More specifically, a void space of the channels 104 can be formed within the third layer 1 14, with the second layer 112 forming a “top” of the channels 104 (e.g., the channels 104 become closed off once the second layer 112 is sealed to the third layer114). The third layer 114 also defines a first well 115a fluidly coupled to the first channel 104a at the first end portion 102a. a second well 115b fluidly coupled to the second channel 104b at the first end portion 102a, and a third well 115c fluidly coupled to the third channel 104c at thefirst end portion 102a. The first well 115a is aligned with, and therefore configured to receive fluid from, the first aperture 117a of the second layer 112. Likewise, the second well 115b is aligned with, and therefore configured to receive fluid from, the second aperture 1 17b of the second layer 112, and the third well 115c is aligned with, and therefore configured to receive fluid from, the third aperture 117c. In the illustrated embodiment, each of the wells 115 has a circular cross-sectional shape. In other embodiments, however, one or more of the wells 115 can have a different shape. For example, in some embodiments the first well 115a and / or the second well 115b has an oval shape and / or an elongated channel-like shape. In such embodiments, the elongated portion of the well 115 can extend generally normal to an axial length of the system 100, and may be at least partially curved.

[0031] Of note, at least the first well 115a and the second well 115b are bigger than the first aperture 117a and the second aperture 117b, respectively. For example, the first well 115a may have a first cross-sectional area that is greater than a second cross-sectional area of the first aperture 117a. In some embodiments, for example, the first cross-sectional area is between two to 50 times greater than, or between two to 25 times greater than, or between two to ten times greater than, the second cross-sectional area. Similarly, the first well 115a may have a first perimeter that is greater than a second perimeter of the first aperture 117a, such as between two to ten times greater than the second perimeter. The second well 115b may similarly have a greater cross-sectional area and / or perimeter than the second aperture 117b. As a result, some of the thinned portion defining the membrane 113 of the second layer 112 overlaps the first well 115a and the second well 115b. As described in greater detail below, this is expected to improve the seal that can be achieved by the first actuator 124a at the first aperture 117a and the second actuator 124b at the second aperture 1 17b.

[0032] The channels 104 can be designed to provide different fluid resistances. For example, each of the channels 104 may have a different cross-sectional dimension (e.g., cross- sectional area, diameter, circumference, perimeter, etc.) and / or length. For example, the first channel 104a may have a first cross-sectional area, the second channel 104b may have a second cross-sectional area greater than the first cross-sectional area, and the third channel 104c may have a third cross-sectional area greater than the first cross-sectional area but less than the second cross-sectional area. If the length of the channels 104 are the same in such embodiments, the first channel 104a has the highest fluid resistance, the second channel 104b has the lowest fluid resistance, and the third channel 104c has an intermediate fluid resistance. The foregoing is provided by way of example only — a person skilled in the art will appreciate that the channels104 can be designed with any combination of cross-sectional dimensions and lengths to achieve desired relative fluid resistances.

[0033] The actuation assembly 120 includes a first actuator 124a and a second actuator 124b (collectively referred to as the actuators 124). The first actuator 124a can be configured to selectively control the fluid resistance and / or flow of fluid through the first aperture 117a of the second layer 112 (and thus through the first channel 104a), and the second actuator 124b can be configured to selectively control the fluid resistance and / or the flow of fluid through the second aperture 117b of the second layer 112 (and thus through the second channel 104b). More specifically, the first actuator 124a can be selectively moveable between a first (e.g., open) position in which the first actuator 124a does not block or at least does not substantially block, and therefore permits fluid flow through, the first aperture 117a, and a second (e.g., closed or at least partially closed) position in which the first actuator 124a substantially blocks and / or seals, and therefore does not permit flow or at least clinically meaningful flow, through the first aperture 117a. That is, the first actuator 124a imparts a greater fluidic resistance through the first aperture 117a when the first actuator 124a is in the second position relative to when the first actuator 124a is in the first position. Likewise, the second actuator 124b can be selectively moveable between a first (e.g.. open) position in which the second actuator 124b does not block or at least does not substantially block, and therefore permits fluid flow through, the second aperture 117b, and a second (e.g., closed or at least partially closed) position in which the second actuator 124b substantially blocks and / or seals, and therefore does not permit flow or at least clinically meaningful flow, through the second aperture 117b. To facilitate movement between the first (e.g., open) positions and the second (e.g., closed) positions, each actuator 124 can include at least two actuation elements 123 composed of shape memory material. Additional details regarding shape memory' actuators having shape memory' actuation elements, including the operation thereof, are described below with reference to FIGS. 2 A and 2B. and in U.S. Patent No. 11.291,585, the disclosure of which is incorporated by reference herein in its entirety.

[0034] In some embodiments, the first actuator 124a and / or the second actuator 124b can further be selectively moveable between one or more intermediate positions between the first (e.g., open) position and the second (e.g., closed) position. The one or more intermediate positions can provide a different fluid resistance through the corresponding aperture 117. Alternatively, the system 100 can include additional apertures 117 (not shown) such that each actuator 124 is associated with controlling flow through two apertures. In such embodiments, each actuator 124 may be selectively moveable between (a) a first position in which the actuator124 blocks a first aperture but does not block a second aperture, (b) a second position in which the actuator 124 blocks the second aperture but does not block the first aperture, and (c) a third position in which the actuator 124 does not block the first aperture or the second aperture. In some embodiments the third position is associated with an intermediate position of the actuator 124 that is between the first position and the second position. In other embodiments, the third position is associated with an “end-of-range" position of the actuator 124 that is achieved by actuating only one of the actuation elements, and the intermediate position achieved by actuating both of the actuation elements blocks one of the two apertures. In yet other embodiments, each actuator 124 is associated with controlling flow through three apertures, with each of the three positions associated with blocking one of the three apertures.

[0035] The actuation assembly 120 can also include a plate, cartridge, or backbone 130 positionable within the chamber 116 and that is configured to hold and prime the actuators 124. For example, the plate 130 can include features configured to hold and '‘prime7’ the actuators 124 when the actuation assembly 120 is in an assembled configuration. For example, the plate 130 can include a first actuator chamber 134a with first anchoring element retention features (not shown) configured to receive the first actuator 124a, including corresponding anchoring elements of the first actuator 124a. The plate 130 can also include a second actuator chamber 134b configured to receive and prime the second actuator 124b (collectively referred to as the actuator chambers 134; the openings to the actuator chambers 133 are facing downwardly toward the actuators 124 in the orientation shown in FIG. IB). The actuator chambers 134 can be sized and shaped such that they at least partially deform (e.g., stretch, tension, compress, etc.) the actuators 124 when the actuators 124 are positioned therein. For example, in some embodiments positioning the anchoring elements of the actuators 124 within corresponding anchoring element retention features in the plate 130 can increase a length of the actuation elements (e.g., tension) relative to their preferred geometries. In other embodiments, positioning the anchoring elements of the actuators 124 within corresponding anchoring element retention features can decrease a length of the actuation elements (e g., compress) relative to their preferred geometries. In embodiments in which the actuators 124 are composed of a shape memory material as described below, this deformation primes the actuators 124 and permits them to be subsequently actuated. Additional details regarding loading and deforming shape memory actuators are described in U.S. Patent No. 1 1,291,585, previously incorporated by reference herein, and International Patent Application No. PCT / US2021 / 049140, the disclosure of which is incorporated by reference in its entirety and for all purposes. As described in greater detail below with referenceto FIGS. 3A-5B, the plate 130 can also include one or more features expected to improve positional control over a portion of the actuators 124.

[0036] The plate 130 can be composed of a material that has generally stiffer mechanical properties than the layers 110, 112. 114, and / or the actuators 124. For example, the plate 130 can be composed of superelastic Nitinol, stainless steel, titanium, glass, plastic, or other suitable materials. This is expected to enable the plate 130 to resist deformation when the actuators 124 are deformed and coupled to the plate 130, as described previously. This feature is also expected to enable the plate 130 to resist upward deflection of the actuators 124, which can assist in improving fluid flow control through the system 100.

[0037] FIGS. 2A and 2B illustrate a shape memory actuator 224 (“the actuator 224”) for selectively controlling fluid flow through an adjustable shunting system and configured in accordance with select embodiments of the present technology. More specifically, FIG. 2A is a perspective view of a first side 230a of the actuator 224, and FIG. 2B is a perspective view of a second side 230b of the actuator 224, rotated 180 degrees about its longitudinal axis relative to the view shown in FIG. 2A. As one skilled in the art will appreciate from the disclosure herein, the actuator 224 can be used with the adjustable shunting system 100 of FIGS. 1A and IB (e.g., instead of the actuators 124), or with other adjustable shunting systems similar to the system 100.

[0038] Referring collectively to FIGS. 2A and 2B, the actuator 224 includes gating element 226 that is a shaft or paddle that terminates at a free distal end portion 227 (also referred to simply as “the distal end 227”) configured to at least partially control (e.g., gate) flow through a corresponding aperture (e.g., the first aperture 117a or the second aperture 117b of the system 100, show in FIG. IB). The actuator 224 also includes a first actuation element 223a and a second actuation element 223b. The first actuation element 223a can be configured to rotate, pivot, slide, or otherwise move the gating element 226 along an arc in a first direction. For example, when actuated, the first actuation element 223a can be configured to move the gating element 226 from the second (e.g., closed) position to and / or toward the first (e.g., open) position. The second actuation element 223b can be configured to selectively rotate, pivot, slide, or otherwise move the gating element 226 along the same arc but in a second direction generally opposite the first direction. For example, when actuated, the second actuation element 123b can be configured to move the gating element 126 from the first (e.g., open) position to and / or toward the second (e.g., closed) position. The first and second actuation elements 223 generally cause movementof the gating element 226 within a single (e.g., horizontal) plane, e.g., along an arc that extends in the x- and / or y-directions.

[0039] In some embodiments, the first actuation element 223a and the second actuation element 223b (and the first actuator 124a and the second actuator 124b in their entireties) can be composed at least partially of a shape memory material or alloy (e.g., Nitinol). Accordingly, the first actuation element 223a and the second actuation element 223b can be transitionable at least between a first material phase or state (e.g., a martensitic state, a R-phase, a composite state between martensitic and R-phase, etc.) and a second material phase or state (e.g., an austenitic state, an R-phase state, a composite state between austenitic and R-phase, etc.). In the first material state, the first actuation element 223a and the second actuation element 223b may have reduced (e.g., relatively less stiff) mechanical properties that cause the actuation elements to be more easily deformable (e.g., compressible, expandable, etc.) relative to when the actuation elements are in the first material state. In the second material state, the first actuation element 223a and the second actuation element 223b may have increased (e.g., relatively more stiff) mechanical properties relative to the first material state, causing an increased preference toward a specific preferred geometry (e.g., original geometry, manufactured or fabricated geometry', heat set geometry, etc.).

[0040] The first actuation element 223a and the second actuation element 223b can be selectively and independently transitioned between the first material state and the second material state by applying energy (e.g., laser energy, electrical energy', etc.) to the first actuation element 223a or the second actuation element 223b to heat the corresponding actuation element above a transition temperature (e.g., above an austenite finish (Af) temperature, which is generally greater than body temperature). If the first actuation element 223a (or the second actuation element 223b) is deformed relative to its preferred geometry’ when heated above the transition temperature, the first actuation element 223 a (or the second actuation element 223b) will move to and / or toward its preferred geometry. In some embodiments, the first actuation element 223a and the second actuation element 223b are operably coupled such that, when the actuated actuation element (e.g., the first actuation element 223a) transitions toward its preferred geometry', the non-actuated actuation element (e.g., the second actuation element 223b) is further deformed relative to its preferred geometry’. In some embodiments, simultaneously heating both the first actuation element 223a and the second actuation element 223b above their transition temperatures can cause the actuator 224 to assume an intermediate position as both the first actuation element 223a and the second actuation element 223b attempt to assume their preferredgeometry and reach an equilibrium. Additional details regarding, and examples of, bi-directional shape memory actuators that can be used with the present technology are described in U.S. Patent Nos. 1 1,166,849 and 11,291,585, and International Patent Application No. PCT / US2023 / 071106, the disclosures of which are incorporated by reference herein in their entireties and for all purposes.

[0041] The actuator 224 further includes a first anchoring element 225a, a second anchoring element 225b, and a third anchoring element 225c (collectively referred to as the anchoring elements 225). The actuator 224 can be coupled to an adjustable shunting system such as the system 100 of FIGS. 1A and IB by placing the anchoring elements 225 in corresponding anchoring element retention features (e.g., within the plate 130 of the actuation assembly 120, shown in FIG. IB). In some embodiments, the act of placing the anchoring elements 225 in the anchoring element retention features deforms to the actuation elements 223 relative to their preferred geometry, thereby inducing strain in the actuation elements 223 and priming the actuator 224 for subsequent actuation.

[0042] As described above, the distal end portion 227 of the gating element 226 is configured to moveably interface with one or more apertures of an adjustable shunting system to at least partially control the flow of fluid through one or more flow pathways extending through the system. For example, when the actuator 224 is positioned within the first actuator chamber 123a of the system 100 shown in FIGS. 1A and IB, the distal end portion 227 of the gating element 226 is positioned proximate the first aperture 117a in the second layer 112 of the shunting element 102. As a result, the first actuator 224 can selectively move the distal end portion 227 between the first (e.g., open) position in which the gating element 226 does not block or substantially block flow through the first aperture 117a, and the second (e.g.. closed) position in which the gating element 226 blocks, or at least partially blocks, fluid flow through the first aperture 117a. In this way, the actuator 224 can control the flow of fluid through the first channel 104a.

[0043] The distal end 227 of the gating element 226 can have one or more features expected to improve the ability of the gating element 226 to form a substantial, or even a complete, seal at the corresponding aperture when in the second (e.g.. closed) position. For example, as shown in FIG. 2B, the distal end 227 of the gating element 226 includes a first layer or portion 228 (“the first portion 228”) and a second layer or portion 229 (“the second portion 229”) extending from the first portion 228. Because the second portion 229 extends from thefirst portion 228, the second portion 229 can also be referred to as a nub, bump, projection, protrusion, plateau feature, or the like. Regardless, the first portion 228 can occupy a first horizontal plane, and the second portion 229 can occupy a second horizontal plane parallel to the first horizontal plane. Of note, in some embodiments the other portions of the actuator 224 (e.g., the gating element 226, the actuation elements 223, and the anchor elements 225) can extend primarily or solely within the first horizontal plane. In such embodiments, the second portion 229 is the only part of the actuator 224 that extends within the second horizontal plane. As described in greater detail below with reference to FIGS. 3A-4B, this may improve the ability of the actuator 224 to form a partial or complete seal at an aperture when the actuator 224 is in the second (e.g., closed) position.

[0044] The shape of the second portion 229 can be designed to correspond to (e.g., fit within) the aperture that the actuator 224 is intended to gate. For example, in the illustrated embodiment the second portion 229 has a tapered cylindrical shape, which may correspond to a generally circular aperture. However, in other embodiments the second portion 229 can have a triangular, rectangular, oval-shaped, spherical, or other suitable shape, any of which may be at least partially tapered. Indeed, the tapering of the second portion 229 — in which the “base’' of the second portion 229 proximate the first portion 228 has a larger cross-sectional area than a “peak” of the second portion 229 away from the first portion 228 — may further improve a seal achievable at a target aperture by enabling some, but not all of, the second portion 229 to fit into (e.g., plug) the aperture.

[0045] The first portion 228 and the second portion 229 can be integrally formed. That is, the first portion 228 and the second portion 229 can be formed of a single, unitary structure (e g., with the rest of the actuator 224, including the gating element 226, the actuators 228, and the anchoring elements 225). In some embodiments, the actuator 224 can be manufactured using additive manufacturing techniques, such as physical vapor deposition. In some embodiments, the manufacturing technique inherently provides the slight tapering of the second portion 229, described above.

[0046] In some embodiments, the first portion 228 and the second portion 229 can be composed of different materials. For example, the first portion 228 can be composed of Nitinol or another nickel-titanium alloy, and the second portion 229 can be composed of copper, gold, silver, or another suitable metal or metal alloy. However, even in embodiments in which the first portion 228 and the second portion 229 are formed of different materials, the first portion 228and the second portion 229 can still be formed as a unitary structure, e.g., via physical vapor deposition, lithography, or other manufacturing techniques. In other embodiments, the first portion 228 and the second portion 229 are composed of the same material.

[0047] In addition to the second portion 229 having a taper, in some embodiments the entire actuator 224 can have a tapered shape or profile. In particular, the actuator 224 can have a taper or angle between the first side 230a (which can also be referred to as a first, or upper, surface 230a) shown in FIG. 2 A, and the second side 230b (which can also be referred to as a second, or supper, surface 230b) shown in FIG. 2B. That is, the taper can exist at each surface of the actuator that connects the first surface 230a and the second surface 230b. As described in greater detail below with reference to FIGS. 2C and 2D, the first surface 230a can be generally “wider"’ than the second surface 230b (e.g., the first surface 230a has a greater surface area than the second surface 230b), such that the actuator 224 is tapered inwardly as it transitions from the first surface 230a toward the second surface 230b. In other embodiments, the taper can be the opposite, such that the first surface 230a is generally narrower than the second surface 230b (e.g., the first surface 230a has a smaller surface area than the second surface 230b) and the actuator 224 is therefore tapered outwardly as it transition from the first surface 230a toward the second surface 230b.

[0048] FIG. 2C is a cross-sectional isometric view of the actuator 224 taken along the line indicated in FIG. 2B, and FIG. 2D is a front view of the actuator 224 taken along the line indicated in FIG. 2B. As best shown in the enlarged view of the distal end 227 of the actuator 224 in FIG. 2D, both the first portion 228 and the second portion 229 of the distal end 227 are tapered. More specifically, the first portion 228 is tapered at a first angle DI and the second surface 229 is tapered at a second angle D2 (the angles DI and D2 can also be referred to as “draft angles”). In the illustrated embodiment, the first angle DI and the second angle D2 are the same. In other embodiments, however, the first angle DI and the second angle D2 are different. Regardless, the first angle DI and the second angle D2 can each be between about 5 degrees and about 45 degrees, or between about 10 degrees and about 35 degrees, or between about 15 degrees and about 25 degrees.

[0049] Although the enlarged portion of FIG. 2D only shows the draft angles for the first portion 228 and the second portion 229, the entire actuator 224 can have a draft angle. For example, as illustrated by the cross-section of the first actuation element 223a and the second actuation element 223b in FIG. 2D, the first actuation element 223 a and the second actuationelement 223b can also be tapered and thus can also have corresponding draft angles. In some embodiments, the draft angles for the first actuation element 223 a and the second actuation element 223b can be the same as the first angle DI and / or the second angle D2 of the first portion 228 and the second portion 229 of the distal end 227. Indeed, in some embodiments the entire actuation element 224 has a consistent draft angle at each surface that connects the first side 230a (FIG. 2A) and the second side 230b (FIG. 2B). In some embodiments, this common draft angle may result from the actuator 224 being integrally formed by an additive manufacturing process that inherently produces the draft angle.

[0050] In some embodiments, the draft angle may dictate certain minimum and maximum dimensions for portions of the actuator 224. For example, if the actuator 224 has a particular height (the distance between the first side 230a and the second side 230b), then the “wider” side of the actuation elements 223 (e.g., the first side 230a in the illustrated embodiment) generally must have a width that is greater than a minimum threshold. If the width is less than the minimum threshold, the actuation elements 223 may not be manufacturable.

[0051] The draft angle may also provide several advantages. For example, the draft angle provides the tapering of the second portion 229 that can improve the seal achievable at a target aperture, as set forth above and described in more detail below with reference to FIGS. 3A-5B. As another example, the draft angle may provide a better “fit” between the actuator 224 and a corresponding plate or cartridge, such as described in greater detail below with reference to FIG. 11.

[0052] As also described in greater detail below, in some embodiments the actuator 224 can be used in combination with one or more features that increase a vertical motion (e.g., in the z-direction) of the distal end 227 of the gating element 226 as the distal end 227 is transitioned from the first (e.g., open) position to the second (e.g., closed) position. For example, the actuator 224 can be configured to interface with one or more mechanical ramping features that induce movement of the gating element 226 in the z-direction in response to the actuation elements 223a, 223b inducing movement of the gating element 226 in the x- and / or y- direction.

[0053] Moreover, the actuator 224 can be oriented such that the second portion 229 faces upwardly or downwardly when implanted in a patient, depending upon the embodiment (as used herein, the term “upward” refers to a direction toward a superficial surface of patient tissue when the shunt is implanted, and the term “downward” refers to a direction away from a superficial surface of patient tissue when the shunt is implanted). For example, in embodiments in whichthe actuator 224 is configured to seal an aperture that is positioned below the actuator 224 (e.g., away from a superficial surface of patient tissue), the first surface 230a faces up, e.g., away from the aperture, and the second surface 230b faces down, e.g., toward the aperture. In embodiments in which the actuator 224 is configured to seal an aperture that is positioned above the actuator 224 (e.g., toward a superficial surface of patient tissue), the second surface 230b of the actuator faces up, e.g., toward the aperture, and the first surface 230a faces down, e.g., away from the aperture.

[0054] FIGS. 3A and 3B illustrate a first example of using a ramping feature with the actuator 224 of FIGS. 2 A and 2B to improve a seal at the first aperture 1 17a of the system 100 of FIGS. 1A and IB. More specifically, FIG. 3A is a schematic, cross-sectional illustration of the plate 130, the distal end 227 of the gating element 226 of the actuator 224 (FIGS. 2A and 2B), the second layer 112 (at the membrane 113 that includes the first aperture 117a), and the third layer 114 (at the portion including the first well 115a). and illustrates the distal end 227 of the gating element 226 in the first (e.g., open) position. FIG. 3B is a schematic, cross-sectional illustration of the same components as shown in FIG. 3A, but illustrates the distal end 227 of the gating element 226 in the second (e.g.. closed) position. As one skilled in the art will appreciate, the schematic illustration of FIGS. 3A and 3B are intended to more clearly illustrate certain principles of the present technology, and thus are not necessarily drawn to scale and omit certain features of the actuator 224 and the system 100 for ease of illustration.

[0055] Referring both to FIGS. 3A and 3B, in the illustrated embodiment the plate 130 includes a ramping feature 336. The ramping feature 336 is shown as a wedge- or triangularshaped protrusion extending from a lower surface of the plate 130 that is configured to interact with the distal end 227 of the gating element 226. As described in detail below, the ramping feature 336 controls a vertical position of the distal end 227 of the gating element 226 as the gating element 226 is transitioned between the first (e.g., open) position and the second (e.g., closed) position. In other embodiments, however, the ramping feature 336 can have other suitable shapes that nevertheless control the vertical position of the distal end 227 of the gating element 226.

[0056] As shown in FIG. 3A, when the gating element 226 is in the first (e.g.. open) position, the distal end 227 of the gating element 226 is positioned away from the first aperture 117a such that the first portion 228 and the second portion 229 do not block fluid from flowing through the first aperture 117a. In contrast, when the gating element 226 is transitioned to thesecond (e.g., closed) position as shown in FIG. 3B, the distal end 227 of the gating element 226 is aligned with the first aperture 117a. Moreover, the ramping feature 336 contacts the first portion 228 of the distal end 227 of the gating element 226 and pushes the distal end 227 of the gating element 226 toward the second layer 112 and the first aperture 117a (e.g., pushes the distal end 227 “vertically downward" in the z-direction). Because the second portion 229 is sized and shaped to fit the first aperture 117a, the downward motion of the distal end 227 of the gating element 226 causes part of the second portion 229 to fit at least partially within the first aperture 117a. The second portion 229 accordingly plugs or at least partially plugs the first aperture 117a to inhibit (e.g., prevent) fluid flow therethrough. Without intending to be bound by theory, this is expected to improve the seal obtained at the first aperture 117a, which in turn is expected to improve the precision with which flow through the system 100 can be controlled. In some embodiments, the membrane 113 may also at least partially flex or bow into the first well 115a to accommodate the downward motion of the distal end 227 of the gating element 226 caused by the ramping feature 336, which may further improve the seal obtained at the first aperture 117a.

[0057] FIGS. 4 A and 4B illustrate a second example of using a ramping feature w ith the actuator 224 of FIGS. 2 A and 2B to improve a seal at the first aperture 117a of the system 100 of FIGS. 1A and IB. More specifically, FIG. 4A is a schematic, cross-sectional illustration of various portions of the actuator 224 of FIGS. 2A and 2B (including the distal end 227 of the gating element 226, the second anchoring element 225b, and the third anchoring element 225 c), the second layer 112 (at the membrane 113 that includes the first aperture 117a), and the third layer 114 (at the portion including the first well 115a). and illustrates the distal end 227 of the gating element 226 in the first (e.g., open) position. FIG. 4B is a schematic, cross-sectional illustration of the same components as shown in FIG. 4A, but illustrates the distal end 227 of the gating element 226 in the second (e.g., closed) position. FIGS. 4A and 4B also illustrate a ramping feature 436 that differs from the ramping feature 336 of FIGS. 3A and 3B. As one skilled in the art wall appreciate, the schematic illustration of FIGS. 4 A and 4B are intended to more clearly illustrate certain principles of the present technology7, and thus are not necessarily drawn to scale and omit certain features of the actuator 224 and the system 100 for ease of illustration.

[0058] Unlike the embodiment shown in FIGS. 3A and 3B, the ramping feature 436 in FIG. 4A and 4B is a ribbon-like structure having a shallow and inverted U- or V-shape. In particular, the ramping feature 436 includes respective end portions 436a positioned “under’’ or“beneath” the first and second anchoring elements 225b, 225c (e.g., positioned between the anchoring elements 225b, 225c and the second layer 112), and an intermediate portion 436b positioned “above” the distal end 227 of the gating element 226 (e.g., the distal end 227 of the gating element 226 is positioned between the intermediate portion 436b and the second layer 112). As a result, the ramping feature 436 includes two angled transition zones 436c between the end portions 436a and the intermediate portion 436b. The ramping feature 436 can be composed of a generally rigid or inflexible material, e.g., such that the ramping feature 436 can control a path of motion of the distal end 227 of the gating element 226, as described below.

[0059] In some embodiments, the ramping feature 436 can be integral with the plate 130 (FIGS. 1A and IB). For example, as described in greater detail below with reference to FIGS. 6A-6C, the plate 130 can be manufactured as a substantially planar or flat structure. An end portion of the plate can then be folded or bent between about 60 degrees and about 120 degrees (e.g.. about 90 degrees) to form the ramping feature 436. In other embodiments, the ramping feature 436 can be manufactured as a separate component than the plate 130 and subsequently secured thereto (e.g., via welding, gluing, chemical bonding, etc.).

[0060] In operation, the ramping feature 436 operates in a similar manner as the ramping feature 336 described above with reference to FIGS. 3A and 3B. For example, as the distal end 227 of the gating element 226 is transitioned from the first (e.g., open) position as shown in FIG. 4A toward the second (e.g.. closed) position as shown in FIG. 4B, the first portion 228 of the distal end 227 contacts and rides along one of the angled transition zones 436c. This pushes the distal end 227 of the gating element 226 toward the second layer 112 and the first aperture 117a (e.g., pushes the distal end 227 “vertically downward” in the z-direction). Because the second portion 229 is sized and shaped to fit the first aperture 117a, the downward motion of the distal end 227 causes part of the second portion 229 to fit within the first aperture 117a. The second portion 229 accordingly plugs or at least partially plugs the first aperture 117a to inhibit (e.g., prevent) fluid flow therethrough, similar to the embodiment described with reference to FIGS. 3A and 3B.

[0061] In addition to or in lieu of being used with a ramping feature to increase movement in the z-direction, the actuator 224 of FIGS. 2 A and 2B can also be designed for use with one or more features that increase a positional control or stability of the gating element 226. For example, the actuator 224 can be used in combination with one or more positioning features that bias the gating element 226 to remain in whichever of the first (e.g., open) position or the second(e.g., closed) position that it currently occupies, e.g., to reduce the likelihood that the gating element 226 is inadvertently dislodged from its desired position.

[0062] FIGS. 5A and 5B, for example, illustrate an example of using a positioning feature with the actuator 224 of FIGS. 2A and 2B to improve a positional control or stability- of the distal end 227 of the gating element 226 when used in the system 100 of FIGS. 1 A and I B. More specifically, FIG. 5 A is a schematic, cross-sectional illustration of the plate 130, the distal end 227 of the gating element 226 of the actuator 224 (FIGS. 2A and 2B), the second layer 112 (at the membrane 113 that includes the first aperture 117a), and the third layer 114 (at the portion including the first well 115a), and illustrates the distal end 227 of the gating element 226 in the first (e.g., open) position. FIG. 5B is a schematic, cross-sectional illustration of the same components as shown in FIG. 5A, but illustrates the distal end 227 of the gating element 226 in the second (e.g., closed) position. As one skilled in the art will appreciate, the schematic illustration of FIGS. 5A and 5B are intended to more clearly illustrate certain principles of the present technology, and thus are not necessarily drawn to scale and omit certain features of the actuator 224 and the system 100 for ease of illustration.

[0063] Referring collectively to FIGS. 5 A and 5B, the plate 130 includes a positioning feature 538, which can be a bump, protrusion, tab, or the like that extends from (e.g., downwardly from) the plate 130 toward the second layer 112. Of note, the positioning feature 538 is positioned along the path the distal end 227 of the gating element 226 traverses as the distal end 227 is transitioned between the first (e g., open) position shown in FIG. 5A and the second (e.g., closed) position shown in FIG. 5B (e.g., the positioning feature 538 is positioned between the first position and the second position). In some embodiments, the positioning feature 538 is designed to reduce unintentional drift of the gating element 226, e.g., by physically blocking the gating element 226 from moving between the first (e.g., open) position and the second (e.g., closed) position, absent an energy- input. That is, in order for the distal end 227 of the gating element 226 to pass the positioning feature 538, the distal end 227 must pass through a relatively higher energy-, less stable position than either of the first (e.g., open) position or the second (e.g., closed) position. This higher energy state can be achieved be intentionally actuating one of the actuators 223 (FIGS. 2A and 2B). However, the high energy- state is less likely to be achieved in the absence of an intentional actuation of one of the actuators 223. In this way, the positioning feature 538 biases the distal end 227 of the gating element 226 to retain its current position, absent an intentional actuation of the one of the actuation elements 223. The positioning feature 538 can therefore provide ‘"bistability” to the actuator 224 (e g., providing two stable positions).

[0064] FIGS. 6A-6C illustrate an example of another positioning feature 638 that can be used with the system 100 of FIGS. 1A and IB and / or the actuator 224 of FIGS. 2A and 2B. As shown in FIG. 6A, the positioning feature 638 can extend from a bridge feature 638, which in some embodiments can be structurally similar to the ramping feature 436 described above with reference to FIGS. 4A and 4B in that it extends “above’' the distal end 227 of the gating element 226 (FIGS. 2A and 2B). Unlike the ramping feature 436. however, the positioning feature 638 can function in a similar manner as described above with respect to the positioning feature 538 of FIGS. 5 A and 5B to control a position of the distal end 227 of the gating element 226. Relative to the embodiment described with reference to FIGS. 5A and 5B, however, the actuator 224 (FIGS. 2A and 2B) is rotated 180 degrees about its longitudinal axis such that the second portion 229 of the distal end 227 of the gating element 226 faces “upwardly”, e.g., toward the positioning feature 538. In such embodiments, the second portion 229 can be sized and shaped to interact with the positioning feature 638. For example, in the illustrated embodiment the second portion 229 includes a recess, divot, or groove 629a sized and shaped to receive the positioning feature 638 and / or a portion of the bridge 636. In some embodiments, this may impart additional positional control over the distal end 227 of the gating element 226.

[0065] The bridge 636 and the positioning feature 638 can form a uni tan’ structure that can be manufactured in a single plane as a substantially tw o-dimensional structure. For example, FIG. 6B illustrates a portion of a plate 630 (which in some embodiments can be the same as the plate 130 of FIGS. 1A and IB) that includes the bridge 636 and the positioning feature 638 existing in a common (e.g., horizontal) plane with the remainder of the plate 630. The plate 630 can have one or more folding or hinging features 631, which in the illustrated embodiment are notches in respective sides of the plate 630. After the plate 630 is manufactured, the plate 630 can be bent at the folding features 631 such that the bridge 636 and the positioning feature 638 extend in a second (e.g., horizontal) plane that is normal or substantially normal to the first plane in which the remainder of the plate 630 is positioned, as shown in FIG. 6C.

[0066] The present technology provides additional variation embodiments for providing positional control of the distal end 227 of the gating element 226. For example, FIGS. 7A-7E illustrate additional examples of improving the positional control of the distal end 227 of the gating element 226 via different mechanisms. Referring first to FIG. 7A, in some embodiments the distal end 227 of the gating element has two second portions or projections 729a, 729b, ith a slot therebetween. The slot between the two projections can be sized and shaped to ride along a corresponding bridge 736a as the distal end 227 is transitioned between the first (e.g., open)position and the second (e.g., closed) position. Without intending to be bound by theory, this may improve the positional stability of the gating element 226 by confining the distal end 227 to a predefined track or arc that aligns with the bridge 736a. In some embodiments, the bridge 736a is structurally similar to or the same as the bridge 636 of FIGS. 6A-6C and / or the ramping feature 438 of FIGS. 4A and 4B.

[0067] FIG. 7B illustrates a variation of the embodiment of FIG. 7A, in which a bridge 736b is co-planar with the other portions of its plate 730, instead of being oriented at an angle relative to the plate (not shown) as in FIG. 7A. As previously described, the second projections 729a, 729b can extend outwardly from, and exists in a separate plane than, the remainder of the gating element 226, such that the projections 729a, 729b are positioned along opposite sides of the bridge 736b. The bridge 736b can therefore define a track or arc for the distal end 227 of the gating element 226 to ride along as it moves between the first (e.g., open) position and the second (e.g.. closed) position.

[0068] FIG. 7C illustrates a variation of the embodiment of FIG. 7B in which a bridge 736c provides bistability in addition to providing a track for the gating element 226 to follow. For example, the bridge 736c includes a positioning feature 738c, which in the illustrated embodiment is a wide, central portion of the bridge 736c. The positioning feature 738c can function similarly to the positioning feature 538 of FIGS. 5A and 5B. For example, the positioning feature 738c reduces the likelihood that the distal end 227 of the gating element 226 will inadvertently transition between the first (e.g., open) position (illustrated) or the second (e.g., closed) position (not illustrated), e.g., by defining a higher energy intermediate state that the gating element 226 must pass through the transition between the first and second positions.

[0069] FIG. 7D illustrates yet another variation of the embodiments of FIGS. 7A-7C that provides both bistability and a track for the distal end 227 of the gating element 226. Unlike the embodiment shown in FIG. 7C, however, the distal end 227 includes a single projection 729 that is sized and shaped to fit within a slot 735 formed between a first bridge portion 736dl and a second bridge portion 736d2. In some embodiments, the first bridge portion 736dl and the second bridge portion 736d2 are formed as part of a common structure (e.g., as part of a plate), although in other embodiments the first bridge portion 736dl and the second bridge portion 736d2 are formed as separate components. Regardless, in addition to the slot 735 defining a track for the distal end 227 of the gating element 226, the slot 735 also includes a positioning feature 738d for providing bi stabi li ty. That is, similar to the positioning feature 738c of FIG. 7C and thepositioning feature 538 of FIGS. 5A and 5B, the positioning feature 738d reduces the likelihood that the distal end 227 of the gating element 226 will inadvertently transition between the first (e.g., open) position and the second (e.g., closed) position by defining a higher energy intermediate state that the gating element 226 must pass through the transition between the first and second positions. FIG. 7E shows a similar embodiment, but instead of the having a single projection 728. the distal end 227 of the gating element 226 has a first projection 729a and a second projection 729b, as described above with reference to FIGS. 7A-7C.

[0070] FIGS. 8-10 are perspective views of various plates configured in accordance with embodiments of the present technology that include features for providing positional control of a shape memory actuator. As one skilled in the art will appreciate from the following description, the plates described in FIGS. 8-10 can be used with the systems 100 of FIGS. 1 A and IB (instead of the plate 130). and / or with other similar adjustable shunting systems. The plates described in FIGS. 8-10 can also be designed for use with the actuator 224 of FIGS. 2A and 2B, and / or with other similar actuators.

[0071] FIG. 8, for example, illustrates a plate 830 having a first actuator chamber 834a sized and shaped to receive a first actuator (e.g., the actuator 224 of FIGS. 2A and 2B; not shown in FIG. 8) and a second actuator chamber 834b sized and shaped to receive a second actuator. Each actuator chamber includes a respective positioning feature 838a, 838b that is positioned to align with a distal end of the actuator when it is positioned within the corresponding actuator chamber 834. In particular, the first positioning feature 838a and the second positioning feature 838b are positioned along the path the gating element of the actuator (not shown) traverses when moving between the first (e.g., open) position and the second (e.g., closed) position. The first positioning feature 838a. which provides a ridge or bump along the path, can function similarly to the positioning feature 538 described with reference to FIGS. 5A and 5B and the positioning feature 638 described with reference to FIGS. 6A-6C. The second positioning feature 838b, which provides a slot between two opposing bumps or ridges, can function similarly to the positioning features 738d and 738e, described with reference to FIGS. 7D and 7E. That is, both positioning features 838 can provide positional control (e.g., bistability) to the gating element (not shown).

[0072] The positioning features 838 can be manufactured integrally with the plate 838. In some embodiments, the positioning features 838 can each comprise a plurality of individual ridges or teeth, with corresponding grooves or valleys therebetween. In some embodiments, theindividual ridges are tapered such that the portion of the ridge at the plate 830 is wider than the portion of the ridge at the peak. Although shown as positioning features, a similar construction of tapered ridges and grooves can be used to provide ramping features on the plate 830, similar to the ramping feature 336 described with reference to FIGS. 3A and 3B and / or the ramping feature 436 described with reference to FIGS. 4A and 4B.

[0073] FIG. 9 illustrates a plate 930 having a first actuator chamber 934a sized and shaped to receive a first actuator (e.g., the actuator 224 of FIGS. 2A and 2B: not shown in FIG. 9) and a second actuator chamber 934b sized and shaped to receive a second actuator. Each actuator chamber includes a respective slot 935a, 935b that is positioned to align with a distal end of the actuators when they are positioned within the actuator chambers 934a, 934b. In particular, the first slot 935a and the second slot 935b are positioned along the path the gating element of the actuator (not shown) traverses when moving between the first (e.g., open) position and the second (e.g., closed) position. Each slot 935a, 935b also has a corresponding positioning feature 938a, 938b, which is a narrow central portion of the slot 935a, 935b. The positioning features 938a, 938b function similarly to the positioning features 738d and 738e described with reference to FIGS. 7D and 7E, and therefore provide positional control (e.g., bistability) to the gating element (not shown). Accordingly, the plate 930 provides both a predefined track for the gating element (by virtue of the slots 935a, 935b) and bistability (by virtue of the positioning features 938a, 938b).

[0074] FIG. 10 illustrates another plate 1030 generally similar to the plate 930 shown in FIG. 9. Relative to the plate 930, however, the plate 1030 includes a first actuator chamber 1034a with a first slot 1035a that does not include a positioning feature. Similarly, the plate 1030 also includes a second actuator chamber 1034b with a second slot 1035b that also does not include a positioning feature. Accordingly, the plate 130 is designed to provide a track for the gating element (not shown) to follow (by virtue of the slots 1035a, 1035b), but does not provide bistability' like the plate 930 of FIG. 9.

[0075] In some embodiments, the plates can have a taper or draft angle that is complimentary to a draft angle of the actuators, described in detail above with reference FIGS. 2A-2D. For example, FIG. 11A is a perspective view of a plate 1130 with a first actuator 1124a and a second actuator 1124b (collectively, “the actuators 1124”) coupled thereto and configured in accordance with select embodiments of the present technology7. As one skilled in the art will appreciate from the following description, the plate 1130 and the actuators 1124 can be usedwith the system 100 of FIGS. 1A and IB (instead of the plate 130 and the actuators 124), and / or with other similar adjustable shunting systems. The actuators 1124 can be generally similar to or the same as the actuators 224 described with reference to FIGS. 2A-2D.

[0076] As shown, the plate 1130 and the actuators 1124 can have matching or complimentary draft angles. For example, as best shown in FIG. 1 I B, which is a front cross- sectional view of the plate 1130 and the actuators 1124 taken along the line indicated in FIG. 11 A, the actuators 1124 can each have a first draft angle DI and the plate 1130 can have a second draft angle D2. The first draft angle DI and the second draft angle D2 are the same or about the same. In other embodiments, however, the first draft angle DI and the second draft angle D2 can be different. Regardless, the first draft angle DI and the second draft angle D2 can each be between about 5 degrees and about 45 degrees, or between about 10 degrees and about 35 degrees, or between about 15 degrees and about 25 degrees.

[0077] In the illustrated embodiment, the plate 1130 and the actuators 1124 are arranged such that the first draft angle DI and the second draft angle D2 have a complimentary fit. That is, the second draft angle D2 for the plate 1130 tapers in a first direction and the first draft angle DI for the actuators 1124 tapers in a second direction, opposite of the first direction. Without intending to be bound by theory, tapering the plate 1130 and the actuators 224 in opposite directions but with the same or similar draft angle is expected to improve the “fit”, or the mating, between the plate 1130 and the actuators 1124. In other embodiments, however, the plate 1130 and the actuators 1 124 can taper in the same direction.

[0078] As one skilled in the art will appreciate from the foregoing, any of the above embodiments can be combined to form additional embodiments within the scope of the present technology. Indeed, although many of the foregoing embodiments describe features that provide either (a) increased movement of the gating element in the z-direction via one or more ramping features to improve sealing, or (b) increase positional control via tracks and / or positioning features, in some embodiments the foregoing features can be combined in a single embodiment. Accordingly, the present technology includes adjustable shunts and associated features that provide for both (a) increased movement of the gating element in the z-direction. and (b) increased positional control and / or stability.

[0079] The systems described herein can be designed for shunting fluid between a variety of body regions. As noted above, for example, in some embodiments the systems described herein are designed to be implanted in a patient’s eye to shunt aqueous between the anteriorchamber and a target outflow location (e.g., a subconjunctival bleb space), such as to treat glaucoma. Accordingly, in some embodiments the systems described herein can have dimensions compatible with being implanted in the patient’s eye. For example, the systems described herein (e.g., the system 100) may have a length of between about 4 mm and about 20 mm, such as between about 4 mm and 15 mm, or between about 4 mm and 12 mm, or between about 6 mm and 10 mm, or about 8 mm. In some embodiments, the layers (e.g., the first layer 110, the second layer 112. and / or third layer 114 — FIG. IB) can have a width or thickness less than about 500 microns, less than about 400 microns, less than about 300 microns, and / or less than about 200 microns. In some embodiments, the diameter of the fluidic channels and corresponding apertures (e.g., the channels 104) may be less than about 100 microns, less than about 75 microns, and / or less than about 50 microns, such as about 35 microns. The foregoing dimensions are provided by way of example only, and other dimensions outside the ranges provided above are possible and included within the scope of the present technology. Indeed, the dimensions of the systems described herein may be designed depending on the type of shunting system (e.g., glaucoma shunt vs. hydrocephalus shunt) and intended recipient (e.g., child vs. adult).Examples

[0080] Several aspects of the present technology7are set forth in the following examples:1. A shape memory actuator for use with an implantable adjustable shunting system, the shape memory actuator comprising: a gating element comprising an elongated paddle terminating at a distal end portion, wherein the distal end portion includes a first portion existing in a first plane that is co-planar with the elongated paddle, and a second portion extending from the first portion and existing in a second plane that is different than the first plane: a first shape memory- actuation element operably coupled to the gating element, wherein, in response to being actuated, the first shape memory actuation element is configured to move the gating element from a first position toward a second position; and a second shape memory actuation element operably coupled to the gating element,wherein, in response to being actuated, the second shape memory actuation element is configured to move the gating element from the second position toward the first position.2. The shape memory' actuator of example 1 wherein the first shape memory' actuation element and the second shape memory actuation element are co-planar with the elongated paddle.3. The shape memory' actuator of example 1 or example 2 wherein the second portion of the gating element is tapered.4. The shape memory actuator of any of examples 1-3 wherein the first portion and the second portion are manufactured as an integral structure.5. The shape memory actuator of any of examples 1-4 wherein the gating element, the first shape memory' actuation element, and the second shape memory actuation element each have a draft angle.6. The shape memory actuator of example 5 wherein the draft angles for each of the gating element, the first shape memory actuation element, and the second shape memory actuation element are the same.7. The shape memory actuator of any of examples 1-6 wherein the first portion is composed of a first material, and wherein the second portion is composed of a second material different than the first portion.8. The shape memory actuator of any of examples 1-6 wherein the first portion and the second portion of composed of the same material.9. An actuation assembly for use with an implantable adjustable shunting system, the actuation assembly comprising: a shape memory actuator, the shape memory' actuator including — an elongated paddle extending within a first plane,a protrusion extending from the elongated paddle and positioned within a second plane that is parallel to the first plane, and a shape memory actuation element operably coupled to the gating element and positioned within the first plane, wherein, in response to being actuated, the shape memory actuation element is configured to move the gating element within the first plane; and a plate, the plate including — a chamber sized and shaped to releasably receive at least a portion of the shape memory' actuator; and a positioning feature configured to physically interfere with the elongated paddle and / or the protrusion during movement of the shape memory actuator.10. The actuation assembly of example 9 wherein, when the gating element moves within the first plane, the positioning feature is configured to interfere with the elongated paddle and / or the protrusion to move the protrusion in a direction normal or substantially normal to the first plane and the second plane.11. The actuation assembly of example 9 wherein — the shape memory actuation element is configured to move the elongated paddle from a first position toward a second position within the first plane in response to being actuated; and the positioning feature is configured to physically interfere with the projection as the gating element moves from the first position toward the second position.12. The actuation assembly of example 11 wherein the positioning feature biases the elongated paddle toward its current position.13. The actuation assembly of any of examples 9-12 wherein the positioning feature includes a bump, projection, or tab.14. The actuation assembly of any of examples 9-12 wherein the positioning feature includes a slot.15. The actuation assembly of any of examples 9-14 wherein the plate further includes a bridge extending normal or at least substantially normal to a portion of the plate that includes the chamber, and wherein the bridge includes the positioning feature.16. The actuation assembly of any of examples 9-15 wherein the positioning feature is manufactured integrally with the other portions of the plate.17. The actuation assembly of any of examples 9-16 wherein the protrusion is a first protrusion, and wherein the shape memory actuator further includes a second protrusion extending from the elongated paddle, spaced apart from the first protrusion, and positioned within the second plane.18. An actuation assembly for use with an implantable adjustable shunting system, the actuation assembly comprising: an actuator having a first surface and a second surface opposite the first surface, wherein the actuator is tapered between the first surface and the second surface at a first draft angle; and a plate having one or more openings for receiving a portion of the actuator, wherein the plate is tapered at a second draft angle. wherein the first draft angle and the second draft angle are complimentary.19. The actuation assembly of example 18 wherein the actuator and the plate are tapered in opposite directions.20. The actuation assembly of example 18 or example 19 w herein the first draft angle and the second draft angle are the same or at least about the same.21. The actuation assembly of any of examples 18-20 wherein the first draft angle is between about 10 degrees and about 35 degrees, and wherein the second draft angle is between about 10 degrees and about 35 degrees.22. The actuation assembly of any of examples 18-20 wherein the first draft angle is between about 15 degrees and about 25 degrees, and wherein the second draft angle is between about 15 degrees and about 25 degrees.23. The actuation assembly of any of examples 18-22 wherein the actuator is composed of a first material, and wherein the plate is composed of a second material with a greater stiffness than the first material.Conclusion

[0081] The above detailed description of embodiments of the technology are not intended to be exhaustive or to limit the technology to the precise form disclosed above. Although specific embodiments of. and examples for, the technology are described above for illustrative purposes, various equivalent modifications are possible within the scope of the technology as those skilled in the relevant art will recognize. For example, any of the features of the intraocular shunts described herein may be combined with any of the features of the other intraocular shunts described herein and vice versa. Moreover, although steps are presented in a given order, alternative embodiments may perform steps in a different order. The various embodiments described herein may also be combined to provide further embodiments.

[0082] From the foregoing, it will be appreciated that specific embodiments of the technology have been described herein for purposes of illustration, but well-known structures and functions associated with intraocular shunts have not been shown or described in detail to avoid unnecessarily obscuring the description of the embodiments of the technology. Where the context permits, singular or plural terms may also include the plural or singular term, respectively.

[0083] Unless the context clearly requires otherwise, throughout the description and the examples, the w ords “comprise,” “comprising,” and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to.” As used herein, the terms “connected,” “coupled,” or any variant thereof, means any connection or coupling, either direct or indirect, between two or more elements; the coupling of connection betw een the elements can be physical, logical, or a combination thereof. Additionally, the w ords “herein,” “above,” “below ,” and words of similar import, when used in this application, shall 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 thesingular or plural number may also include the plural or singular number respectively. As used herein, the phrase "and / or" as in “A and / or B" refers to A alone, B alone, and A and B. Additionally, the term “comprising” is used throughout to mean including at least the recited feature(s) such that any greater number of the same feature and / or additional types of other features are not precluded. It will also be appreciated that specific embodiments have been described herein for purposes of illustration, but that various modifications may be made without deviating from the technology. Further, while advantages associated with some embodiments of the technology have been described in the context of those embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the technology. Accordingly, the disclosure and associated technology can encompass other embodiments not expressly shown or described herein.

Claims

CLAIMSI / 'W e claim:

1. A shape memory actuator for use with an implantable adjustable shunting system, the shape memory actuator comprising: a gating element comprising an elongated paddle terminating at a distal end portion, wherein the distal end portion includes a first portion existing in a first plane that is co-planar with the elongated paddle, and a second portion extending from the first portion and existing in a second plane that is different than the first plane: a first shape memory actuation element operably coupled to the gating element, wherein, in response to being actuated, the first shape memory actuation element is configured to move the gating element from a first position toward a second position; and a second shape memory actuation element operably coupled to the gating element, wherein, in response to being actuated, the second shape memory actuation element is configured to move the gating element from the second position toward the first position.

2. The shape memory actuator of claim 1 wherein the first shape memory actuation element and the second shape memory' actuation element are co-planar with the elongated paddle.

3. The shape memory' actuator of claim 1 wherein the second portion of the gating element is tapered.

4. The shape memory^ actuator of claim 1 wherein the first portion and the second portion are manufactured as an integral structure.

5. The shape memory actuator of claim 1 wherein the gating element, the first shape memory actuation element, and the second shape memory actuation element each have a draft angle.

6. The shape memory actuator of claim 5 wherein the draft angles for each of the gating element, the first shape memory actuation element, and the second shape memory actuation element are the same.

7. The shape memory actuator of claim 1 wherein the first portion is composed of a first material, and wherein the second portion is composed of a second material different than the first portion.

8. The shape memory actuator of claim 1 wherein the first portion and the second portion of composed of the same material.

9. An actuation assembly for use with an implantable adjustable shunting system, the actuation assembly comprising: a shape memory actuator, the shape memory actuator including — an elongated paddle extending within a first plane, a protrusion extending from the elongated paddle and positioned within a second plane that is parallel to the first plane, and a shape memory actuation element operably coupled to the gating element and positioned within the first plane, wherein, in response to being actuated, the shape memory actuation element is configured to move the gating element within the first plane; and a plate, the plate including — a chamber sized and shaped to releasably receive at least a portion of the shape memory' actuator; and a positioning feature configured to physically interfere with the elongated paddle and / or the protrusion during movement of the shape memory' actuator.

10. The actuation assembly of claim 9 wherein, when the gating element moves within the first plane, the positioning feature is configured to interfere with the elongated paddle and / or the protrusion to move the protrusion in a direction normal or substantially normal to the first plane and the second plane.

11. The actuation assembly of claim 9 wherein —the shape memory actuation element is configured to move the elongated paddle from a first position toward a second position within the first plane in response to being actuated; and the positioning feature is configured to physically interfere with the projection as the gating element moves from the first position toward the second position.

12. The actuation assembly of claim 11 wherein the positioning feature biases the elongated paddle toward its current position.

13. The actuation assembly of claim 9 wherein the positioning feature includes a bump, projection, or tab.

14. The actuation assembly of claim 9 wherein the positioning feature includes a slot.

15. The actuation assembly of claim 9 wherein the plate further includes a bridge extending normal or at least substantially normal to a portion of the plate that includes the chamber, and wherein the bridge includes the positioning feature.

16. The actuation assembly of claim 9 wherein the positioning feature is manufactured integrally with the other portions of the plate.

17. The actuation assembly of claim 9 wherein the protrusion is a first protrusion, and wherein the shape memory actuator further includes a second protrusion extending from the elongated paddle, spaced apart from the first protrusion, and positioned within the second plane.

18. An actuation assembly for use with an implantable adjustable shunting system, the actuation assembly comprising: an actuator having a first surface and a second surface opposite the first surface, wherein the actuator is tapered between the first surface and the second surface at a first draft angle; and a plate having one or more openings for receiving a portion of the actuator, wherein the plate is tapered at a second draft angle, wherein the first draft angle and the second draft angle are complimentary.

19. The actuation assembly of claim 18 wherein the actuator and the plate are tapered in opposite directions.

20. The actuation assembly of claim 18 wherein the first draft angle and the second draft angle are the same or at least about the same.

21. The actuation of claim 18 wherein the first draft angle is between about 10 degrees and about 35 degrees, and wherein the second draft angle is between about 10 degrees and about 35 degrees.

22. The actuation assembly of claim 18 wherein the first draft angle is between about 15 degrees and about 25 degrees, and wherein the second draft angle is between about 15 degrees and about 25 degrees.

23. The actuation assembly of claim 18 wherein the actuator is composed of a first material, and wherein the plate is composed of a second material with a greater stiffness than the first material.

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