IMPLANTABLE SHUNT HAVING A MULTILAYER FLUIDIC RESISTOR AND ASSOCIATED SYSTEMS AND METHODS - Patent application

Abstract

The present technology provides microfluidic shunt systems having multiple channels and associated methods of making the same. In some embodiments, the microfluidic shunt systems comprise multiple layers or drainage elements stacked and bonded together. In some embodiments, individual channels can be disposed within separate layers or drainage elements and / or can span multiple layers or drainage elements. In some embodiments, the shunt systems can be constructed from multiple layers or elements sealingly bonded together.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 63 / 224,075, filed July 21, 2021, the disclosure of which is incorporated by reference herein in its entirety.

[0002] The present technology relates generally to implantable medical devices, and more particularly to a multi-layer fluidic resistor for controlling fluid flow between a first body region and a second body region of a patient. [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. For example, shunt systems have been proposed to treat glaucoma. Fluid flow through the shunt system is primarily controlled by the pressure gradient across the shunt and the physical properties of the flow path defined through the shunt (e.g., the resistance of the shunt lumen). Conventional early shunt systems (sometimes referred to as minimally invasive glaucoma surgery devices or "MIGS" devices) have shown clinical benefits; however, improved shunt systems and techniques are needed to address the risks associated with elevated intraocular pressure and glaucoma. For example, there is a need for a shunt system that can tailor the therapy provided, including the flow rate between two fluidly connected bodies. As another example, there is a need for a shunt system that can be 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 implantation procedure. Summary of the Invention [Means for solving the problem]

[0004] Intraocular shunts for treating glaucoma are implanted in a patient's eye to drain aqueous humor from the patient's anterior chamber, thereby reducing intraocular pressure. Such shunts are necessarily small because of the target implantation site and because smaller intraocular shunts tend to be associated with fewer side effects, including less interference with the patient's vision, less tissue irritation, and the like. Indeed, a currently commercially available class of intraocular shunts known as Minimally Invasive Glaucoma Surgery ("MIGS") devices recognizes that it is beneficial for the shunt to be as small as possible while still providing effective treatment. As a result, most MIGS devices have cross-sectional dimensions (e.g., diameter, width, height, etc.) of less than about 1 mm or smaller.

[0005] In addition to being compact, it is also beneficial for a shunt to provide more than one flow path. Having multiple flow paths through a single shunt is advantageous because flow patency is maintained if one or more of the flow paths are blocked by cellular debris. In some embodiments, having multiple flow paths through a single shunt is also advantageous because flow through the shunt can be selectively diverted from or between specific channels to provide titratable fluid resistance and therefore titratable therapy. Naturally, adding more channels generally increases the overall size of the shunt. As a result, there is a conflict between minimizing the size of the shunt and providing multiple channels through the shunt to optimize therapy. Thus, there is a need to provide a shunt system that can accommodate multiple flow paths while retaining a relatively small footprint.

[0006] The present technology provides microfluidic shunt systems having multiple channels, and associated methods of making such systems. In some embodiments, the shunt system can be composed of multiple layers or elements sealingly bonded together. As described in detail throughout this Detailed Description, individual channels can be located in separate layers or elements and / or can span multiple layers or elements. As described below, this is expected to increase the number of channels that can fit within the shunt system while keeping the overall system size relatively small.

[0007] In some embodiments, the microfluidic shunt system is generally flat, such that it has a width-to-height ratio of 5:1 to 50:1. As a result, the microfluidic shunt system can be constructed from multiple separate flat layers stacked and bonded together, with each individual layer having a height of, for example, less than about 500 μm. As described in more detail below, the shunt can include multiple channels. Advantageously, in some embodiments, the individual channels are disposed in separate layers and / or the individual channels span multiple layers, such that the channels can be stacked vertically. As will become apparent from the description below, this is expected to increase the number of channels that can fit within the shunt system while keeping the overall system relatively small.

[0008] In some embodiments, an adjustable shunt system includes a drainage assembly having one or more drainage elements or cartridges that can be modularly "stacked" or otherwise aligned. Each of the drainage elements can include a drainage inlet, a drainage lumen portion, and a channel that fluidly couples the drainage inlet to the drainage lumen portion. Fluid can enter the drainage element via the fluid inlet and travel through the channel to the drainage lumen portion. The drainage elements can be stacked or otherwise oriented such that multiple drainage lumen portions of individual drainage elements are aligned to form a common drainage lumen. Thus, fluid entering the drainage elements via the fluid inlets can be collected in the common drainage lumen, which can direct the collected fluid to an outlet in a desired outflow region.

[0009] In some embodiments, each of the channels extending between the fluid inlet and the drainage lumen portion can have a length that imparts a particular fluid resistance. In at least some embodiments, for example, a first drainage element can have a first channel having a first length corresponding to a first fluid resistance, and a second drainage element can have a second channel having a second length that is greater than the first length, the second length corresponding to a second fluid resistance that is greater than the first fluid resistance. Thus, at a given pressure, the first drainage element can be associated with a first fluid flow rate, and the second drainage element can be associated with a second fluid flow rate that is less than the first fluid flow rate. Thus, an adjustable shunt system including a first drainage element and a second drainage element can be used to provide a titratable therapy based on, for example, the changed flow rate of the drainage elements.

[0010] In some embodiments, the technology can further include an actuation assembly for controlling the flow of fluid through the drainage assembly. The actuation assembly can include, for example, one or more actuators configured to control the flow of fluid through the drainage assembly. In particular, each actuator can include a control element corresponding to and configured to interface with one of the drainage elements. For example, each control element can be configured to interface with a corresponding drainage inlet of the drainage element(s). The actuator can also have a first actuation element and a second actuation element configured to move the control element between (i) a first position in which the control element does not substantially prevent or impede fluid flow through the corresponding fluid inlet (e.g., the drainage inlet is accessible) and (ii) a second position in which the control element substantially prevents or impedes fluid flow through the corresponding drainage inlet (e.g., the control element covers or blocks the drainage inlet). Thus, the actuation assembly can be used to control access to the drainage assembly, for example, to provide a titratable therapy.

[0011] As described in more detail below, it is expected that a drainage assembly having one or more drainage elements or cartridges configured according to the present technology may exhibit one or more advantageous properties that improve the operation of an adjustable shunt system. For example, the drainage assemblies described herein may be relatively compact while still having a channel of sufficient length to impart a desired fluid resistance. In addition, at least some of the drainage assemblies and / or drainage elements are expected to be easier and / or less expensive to manufacture compared to conventional drainage assemblies and drainage elements. In some embodiments, for example, the drainage elements may include one or more alignment features or openings configured to stack or otherwise align one or more first elements (e.g., first drainage inlet, first drainage lumen portion, etc.) of a first drainage element with one or more second elements (e.g., second drainage inlet, second drainage lumen portion, etc.) of a second drainage element. Of course, the present technology may also provide additional advantageous properties not explicitly described herein. [Brief description of the drawings]

[0012] Many aspects of the present technology can be better understood with reference to the following drawings. Components in the drawings are not necessarily drawn to scale. Instead, emphasis has been placed on clearly illustrating the principles of the present technology. Additionally, components may be shown as transparent in certain figures for clarity of illustration only, and are not intended to imply that the components shown are necessarily transparent. Components may also be shown in schematic form.

[0013] [Figure 1] 1 is a perspective view of a drainage assembly configured in accordance with selected embodiments of the present technology; FIG. [Figure 2A] 1 is a perspective view of a drainage assembly configured in accordance with selected embodiments of the present technology; FIG. [Figure 2B] FIG. 2B is a partially exploded view of the drainage assembly of FIG. 2A. [Figure 2C] FIG. 2B is an exploded view of the drainage assembly of FIG. 2A. [Figure 2D] FIG. 2B is a perspective view of a drainage element of the drainage assembly of FIG. 2A, with other aspects of the drainage assembly omitted for clarity. [Figure 3A] 1 illustrates a drainage element constructed in accordance with selected embodiments of the present technology. [Figure 3B] 1 illustrates a drainage element constructed in accordance with selected embodiments of the present technology. [Figure 4A] 1 illustrates a drainage element including one or more alignment openings and configured in accordance with selected embodiments of the present technology. [Figure 4B] 4B shows a plurality of drainage elements of FIG. 4A. [Figure 5A] 1 illustrates an actuation assembly configured in accordance with selected embodiments of the present technology. [Figure 5B] 1 illustrates an actuation assembly configured in accordance with selected embodiments of the present technology. [Figure 6A] 5C is a top view of a flow control system including the drainage assembly of FIG. 1 and the actuation assembly of FIGS. 5A and 5B, and configured in accordance with selected embodiments of the present technology. FIG. [Figure 6B] 5C is a top view of a flow control system including the drainage assembly of FIG. 1 and the actuation assembly of FIGS. 5A and 5B, and configured in accordance with selected embodiments of the present technology. FIG. [Figure 7A] 1 illustrates an actuator configured in accordance with selected embodiments of the present technology for controlling fluid flow within a shunt system. [Figure 7B] 1 illustrates an actuator configured in accordance with selected embodiments of the present technology for controlling fluid flow within a shunt system. [Figure 8A] 1 illustrates a shunt system configured in accordance with selected embodiments of the present technology. [Figure 8B] 8A illustrates a fluidic resistor network of a shunt system configured in accordance with selected embodiments of the present technology. [Figure 8C] FIG. 8C is a schematic diagram of the fluidic resistor network shown in FIG. 8B. [Figure 8D]FIG. 8B is an exploded isometric view of the shunt system shown in FIG. 8A. [Figure 9A] 1 illustrates another shunt system constructed in accordance with selected embodiments of the present technology. [Figure 9B] FIG. 9B is a schematic diagram of the fluidic resistor network of the shunt system shown in FIG. 9A. [Figure 9C] FIG. 9B is an exploded isometric view of the shunt system shown in FIG. 9A. [Figure 10A] 1 illustrates yet another shunt system constructed in accordance with selected embodiments of the present technology. [Figure 10B] FIG. 10B is a schematic diagram of a fluidic resistor network of the shunt system shown in FIG. 10A. [Figure 11] 1 is a cross-sectional view of a portion of a fluidic resistor network configured in accordance with an embodiment of the present technique. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The terminology used in the description presented below is intended to be interpreted in its broadest reasonable manner, even when used in conjunction with the detailed description of certain specific embodiments of the present technology. Certain terms may even be emphasized below, however, any terms intended to be interpreted in any limited manner are expressly and specifically defined as such in this detailed description section. Furthermore, the present technology may include other embodiments that are within the scope of the examples but are not described in detail with respect to Figures 1A-11.

[0015] Throughout this specification, references to "one embodiment" or "an embodiment" mean 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. Furthermore, particular features or characteristics may be combined in any suitable manner in one or more embodiments.

[0016] 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, 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.

[0017] References to the term "resistance" throughout this specification refer to fluid resistance unless the context clearly dictates otherwise. The terms "discharge rate" and "flow rate" are used interchangeably to describe the movement of a fluid through a structure at a particular volumetric flow rate. The term "flow" is used generally herein to refer to the movement of a fluid.

[0018] Although certain embodiments herein are described with respect to shunting fluid from the anterior chamber of the eye, those skilled in the art will understand that the technology may be readily adapted to shunt fluid from and / or between other portions of the eye (including the posterior chamber), or more generally, from a first body region and / or between a second body region. Additionally, although certain embodiments herein are described in the context of glaucoma treatment, any embodiment 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 may be used to treat diseases characterized by increased pressure and / or accumulation of fluid, 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, etc. Additionally, although generally described with respect to shunting water, the systems described herein may be equally applied to shunt other fluids, such as blood or cerebrospinal fluid, between a first body region and a second body region.

[0019] The following headings are provided for convenience only and are not to be used to interpret the scope of the claimed technology.

[0020] A. Shunt system with stackable channels and multilayer resistors FIG. 1 is a perspective view of a drainage or shunt assembly 100 ("assembly 100") configured in accordance with selected embodiments of the present technology. The assembly 100 can include an elongated carriage or housing element 102 having a first end 102a and a second end 102b opposite the first end 102a. The carriage element 102 can be at least partially hollow such that the carriage element 102 can include an interior 104 extending at least partially between the first end 102a and the second end 102b. In some embodiments, the carriage element 102 can include a slot or gap 106 extending longitudinally and / or radially through the carriage element 102 and extending at least partially between the first end and the second end 102a-b. The slot 106 can at least partially expose the interior 104 of the carriage element 102, such that, for example, one or more objects disposed within the interior 104 can contact, be coupled (e.g., fluidly coupled), or otherwise interface with an environment external to the carriage element 102 through the slot 106.

[0021] The assembly 100 may further include one or more drainage elements 110. The drainage element(s) 110 may be at least partially disposed within the interior 104 of the carriage element 102, for example at least partially between the first and second ends 102a-b, such that the carriage element 102 may carry, transport, and / or house the drainage element(s) 110. The drainage element(s) 110 may further include one or more fluid or drainage openings or inlets 112. In the illustrated embodiment, for example, the drainage element(s) 110 includes a first drainage inlet 112a, a second drainage inlet 112b, and a third drainage inlet 112c. The drainage inlets 112a-112c may be fluidly connected to a primary drainage lumen or collection chamber 114 ("lumen 114") by one or more fluid channels (not shown in FIG. 1) extending through the drainage element(s) 110, as shown in and described with reference to FIGS. 2C and 2D. Thus, fluid entering the assembly 100 via the drainage inlets 112a-112c is drained via the channels into the lumen 114 (FIGS. 2C and 2D). In some embodiments, one of the ends 102a,b may be blocked or sealed to reduce or prevent fluid in the lumen 114 from exiting the assembly 100 via the blocked end 102a,b. In the illustrated embodiment, for example, the second end 102b is blocked such that once fluid enters the lumen 114, fluid flow will flow toward the first end 102a of the carriage element 102, e.g., to exit the assembly 100.

[0022] In some embodiments, the assembly 100 can be coupled to an outflow tube or other fluid transport element (not shown) to transport fluid received within the lumen 114 via the fluid inlets 112a-112c to and / or toward a desired outflow location. For example, a proximal end of the outflow tube can be fluidly coupled to the lumen 114 at the first end 102a of the carriage element 102 such that the outflow tube receives fluid from the lumen 114, and a distal end of the outflow tube can be disposed at the desired outflow location. In other embodiments, the first end 102a of the assembly 100 can be configured to be at a desired outflow location such that an outlet of the lumen 114 at the first end 102a of the carriage element 102 is at the desired outflow location (e.g., eliminating the need for an outflow tube). Thus, fluid in a first body region can enter the assembly 100, pass through the fluid inlet(s) 112, and enter a second body region via the lumen 114 (and / or the outflow tube).

[0023] In some embodiments, the drainage element(s) 110 can form a fluid seal with the carriage element 102. In the illustrated embodiment, for example, an outer surface of the drainage element(s) 110 can form a fluid seal with an inner surface of the carriage element 102, for example, to reduce or prevent fluid from entering a space between the drainage element(s) 110 and the carriage element 102. This can reduce or prevent leakage or other uncontrolled fluid flow through the assembly 100, such that fluid can travel through the assembly 100 only via one or more predetermined flow paths (e.g., through the drainage inlet(s) 112 and corresponding channels (FIGS. 2C-2D) and lumen(s) 114).

[0024] In some embodiments, the drainage element(s) 110 can include an interface side or interface surface 113 that is generally or substantially flat or planar. The interface surface 113 can correspond to (e.g., sized, positioned, and / or aligned with) the slot 106 such that the interface surface 113 and the slot 106 can have a generally similar or same width W3. In some embodiments, the interface surface 113 can have a first width and the interior of the slot 106 can have a second width that is smaller or larger than the first width. Additionally, the drainage inlet(s) 112 can be positioned on the interface surface 113 and / or oriented toward the slot 106. Thus, the interface surface 113 can be used to align and / or position individual ones of the drainage element(s) 110 and / or the drainage inlet(s) 112 relative to each other and / or relative to the slot 106. As described in more detail below with reference to Figures 6A-7B, an actuation assembly (not shown in Figure 1) can be coupled to and / or interfaced with the interface surface 113 and configured to control the flow of fluid through the drainage inlet(s) 112.

[0025] Although the carriage element 102 is shown in FIG. 1 as having a circular shape, in other embodiments, the carriage element 102 can have an elliptical, triangular, square, rectangular, pentagonal, hexagonal, rectilinear, or any other suitable shape. The drainage element(s) 110 can be shaped to at least partially correspond to the shape of the carriage element 102. In the illustrated embodiment, for example, the carriage element 102 has a circular shape and the drainage element(s) 110 has an at least partially circular shape. However, in other embodiments, the drainage element(s) 112 can have an at least partially elliptical, at least partially triangular, at least partially square, at least partially rectangular, at least partially pentagonal, at least partially hexagonal, at least partially rectilinear, or any other suitable shape. In addition, although the drainage element(s) 110 is shown in FIG. 1 as including three fluid inlets 112a-c, in other embodiments, the drainage element(s) 110 can include more or fewer drainage inlets 112. In at least some embodiments, for example, the drainage element(s) 110 may include 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or any other suitable number of drainage inlets 112.

[0026] The carriage element 102 can be formed from a polymeric material such as polyimide or polyetheretherketone (PEEK), a metal such as stainless steel, nitinol, or titanium, combinations thereof (e.g., nitinol), and / or any other suitable material. The drainage element(s) 110 can be formed from a polymer (e.g., PEEK or polyimide), glass, metal, elastomer (e.g., silicone elastomer, thermoplastic elastomer (TPE), or urethane), combinations thereof, and / or any other suitable material.

[0027] In some embodiments, the carriage element 102 can have a length L from about 1 mm to about 20 mm, such as at least 1 mm, at least 2 mm, at least 3 mm, at least 4 mm, at least 5 mm, at least 6 mm, at least 7 mm, at least 8 mm, at least 9 mm, at least 10 mm, or any other suitable length. The carriage element 102 can have an outer width (e.g., diameter) W1 from about 450 μm to about 1.5 mm, such as at least 500 μm, at least 550 μm, at least 600 μm, at least 650 μm, at least 700 μm, at least 750 μm, at least 1 mm, and / or any other suitable outer width W1. The carriage element 102 (e.g., the interior 104) can have an inner width W2 of about 250 μm to about 650 μm, such as, for example, up to 300 μm, up to 350 μm, up to 400 μm, up to 450 μm, up to 500 μm, up to 550 μm, up to 600 μm, and / or any other suitable inner width W2. The drainage element(s) 110 can have an outer width that is generally similar or the same as the inner width W2 such that the drainage element(s) 110 can be disposed within the carriage element 102 as described above. In at least some embodiments, for example, the drainage element(s) 110 can have an outer width that is between 100% and about 80% of the inner width W2, such as at least 99%, 98%, 97%, 96%, 95%, 90%, and / or any other suitable percentage of the inner width W2.

[0028] FIG. 2A is a perspective view of a drainage assembly 200 ("assembly 200") configured in accordance with an embodiment of the present technology. FIG. 2B is a partially exploded view of the assembly 200 of FIG. 2A, FIG. 2C is an exploded view of the assembly 200 of FIG. 2A, and FIG. 2D is a perspective view of a drainage element 210 with other aspects of the assembly 200 omitted for clarity. The assembly 200 and / or its components may generally be similar or the same as the assembly 100 of FIG. 1. Thus, like numbers are used to indicate like components (e.g., drainage element(s) 110 vs. drainage element(s) 210), and the description of the assembly 200 is limited to features that differ from the assembly 100 of FIG. 1, and other aspects as necessary for the context.

[0029] 2A and 2B together, the assembly 200 can include multiple drainage elements 210 (which may also be referred to as cartridges, modular elements, stackable elements, layers, etc.). In the illustrated embodiment, for example, the assembly 200 includes a first drainage element 210a, a second drainage element 210b, a third drainage element 210c, and a fourth drainage element 210d. As best seen in FIG. 2B, the drainage elements 210a-d can be stacked, aligned, or stacked relative to one another (e.g., linearly, axially, sequentially, etc.). As shown in FIG. 2A, the drainage elements 210a-d can be disposed within a cavity or interior 204 defined by a carriage element 202 having a slot 206. Although the drainage element(s) 210 in the illustrated embodiment are shown as occupying only a portion of the interior 204 of the carriage element 202, in some embodiments, the drainage element(s) 210 occupy the entire or substantially the entire interior 204 having the slots 206 (e.g., to prevent fluid from entering the interior 204 without passing through the drainage elements 210). For example, the interior 204 can be filled (e.g., completely filled) or otherwise occupied by the drainage elements 210, for example, by adding additional drainage elements 210, increasing the thickness of the drainage elements 210, and / or decreasing the length L ( FIG. 1 ) of the carriage element 202. In other embodiments, plugs or other solid features without a fluid inlet (not shown) can be added to the unoccupied space shown in FIG. 2A to prevent fluid from entering the interior 204 without passing through the drainage elements.

[0030] In some embodiments, the drainage elements 210 may be fluidly sealed to one another when in a stacked configuration as shown in FIGS. 2A and 2B. Without being bound by theory, this is expected to prevent or at least reduce fluid leakage between adjacent drainage elements 210. In the illustrated embodiment, for example, a first fluid seal may be formed between the first drainage element and the second drainage element 210a-b, a second fluid seal may be formed between the second drainage element and the third drainage element 210b-c, and a third fluid seal may be formed between the third drainage element and the fourth drainage element 210c-d. In some embodiments, the individual drainage element(s) 210 may be pressed (e.g., compressed in the longitudinal direction indicated by arrow C in FIG. 2A) or otherwise held together by the carriage element 202 to form the fluid seal(s). For example, frictional forces between the drainage element(s) 210 and the carriage element 202 can maintain the position of the drainage elements 210 relative to one another, for example, to form a fluid seal(s) between individual ones of the drainage element(s) 210. In some embodiments, the fluid seal can be formed via adhesives, ultrasonic welding, heat fusion, heat reflow, and / or any other suitable process or technique. In some embodiments, one or more of the drainage elements 210 can be self-adhesive such that a self-adhesive drainage element can form (e.g., automatically form) a fluid seal when in contact with one or more of the other drainage elements. For example, one or more of the drainage elements 210 may be comprised of a self-bonding material that forms a bond or seal with adjacent drainage elements under certain conditions (e.g., in a vacuum).

[0031] Each of the drainage elements 210a-d can include one or more drainage inlets 212. In the illustrated embodiment, for example, the first drainage element 210a includes a first drainage inlet 212a (best seen in FIG. 2B), the second drainage element 210b includes a second drainage inlet 212b, the third drainage element 210c includes a third drainage inlet 212c, and the fourth drainage element 210d includes a fourth drainage inlet 212d. In some embodiments, the assembly 200 further includes an end cap or retention element 211. The end cap 211 can be disposed within the first end 202a and / or the second end 202b of the carriage element 202. The end cap 211 can be generally similar or the same as the drainage element(s) 210, but can lack (e.g., not include) a fluid inlet and / or a drainage lumen portion. In some embodiments, the end cap 211 can be configured to retain the drainage element(s) 210 within the carriage element 202 (e.g., within its interior 204). As such, the end cap 211 can reduce or prevent movement of the drainage element(s) 210 within the interior 204, can maintain the drainage element(s) 210 in compression, and / or can maintain fluid seal(s) between individual ones of the drainage element(s) 210. In some embodiments, the end cap 211 can form a fluid seal with the drainage element(s) 210, as described above. In the illustrated embodiment, for example, the end cap 211 can form a fifth fluid seal with the first drainage element 210a. In some embodiments, the end cap 211 can at least partially cover or block the drainage lumen portion(s) 214 (FIGS. 2C and 2D) such that the end cap 211 can reduce or prevent fluid flow through the first end 202a and / or the second end 202b. In the illustrated embodiment, for example, the end cap 221 can block or seal the first end 202a such that once fluid enters the lumen portion(s) 214 (FIGS. 2C and 2D), the fluid cannot exit the drainage assembly 200 via the first end 202a.Rather, in the illustrated embodiment, the fluid flow flows toward the second end 202b of the carriage element 202 and exits the drainage assembly (eg, via an outflow tube; not shown).

[0032] 2C, the drainage element(s) 210 can include one or more drainage lumens or fluid connections. In the illustrated embodiment, for example, the first drainage element 210a includes a first drainage lumen portion 214a, the second drainage element 210b includes a second drainage lumen portion 214b, the third drainage element 210c includes a third drainage lumen portion 214c, and the fourth drainage element 210d includes a fourth drainage lumen portion 214d ("drainage lumen portion(s) 214"). When the drainage element(s) 210 are disposed within the carriage element 202 (e.g., as shown in FIG. 2A ), each of the drainage lumen portion(s) 214 can be generally or substantially aligned, for example, such that the drainage lumen portions 214a-d are aligned and collectively form a single or common drainage lumen (e.g., drainage lumen 114 of FIG. 1 ). Thus, the multiple drainage lumen portions 214 can collectively form a drainage lumen for transporting fluid received from the fluid inlet 212 through the drainage assembly 200.

[0033] Each drainage element 210 further includes a flow path or channel 216 that fluidly couples the drainage inlet 212 to a corresponding drainage lumen portion 214. In the illustrated embodiment, for example, the first drainage element 210a includes a first channel 216a, the second drainage element 210b includes a second channel 216, the third drainage element 210c includes a third channel 216c, and the fourth drainage element includes a fourth channel 216d ("channel(s) 216"). Thus, the first channel 216a can fluidly couple the first drainage inlet 212a to the first drainage lumen portion 214a, the second channel 216b can fluidly couple the second drainage inlet 212b to the second drainage lumen portion 214b, and so on. As described below, the channels 216 provide fluidic resistance and therefore may be referred to herein as a "fluidic resistor network," a "network of fluidic resistors," a "parallel resistor," and the like.

[0034] In operation, the carriage element 202 can be positioned to reside in a first body region or cavity (e.g., the anterior chamber). Thus, fluid in the first body region can enter the assembly 200 via one of the drainage inlets 212 and pass through a corresponding channel 216 to a corresponding drainage lumen portion 214. The fluid then flows through a drainage lumen formed by the multiple drainage lumen portions into a second (e.g., outflow) body region (e.g., the subconjunctival eyelid cavity) and / or into an outflow duct that can transport the fluid to the second body region as described above. As described in more detail below with reference to FIG. 2D, each of the channels 216 can have a particular flow resistance such that the assembly 200 can provide a titratable treatment to the patient.

[0035] 2A-2C depict the assembly 200 as having four drainage elements 210, in other embodiments, the assembly 200 can include more or fewer drainage element(s) 210. In at least some embodiments, for example, the assembly 200 can include 1, 2, 3, 5, 6, 7, 8, 9, 10, or more drainage elements 210.

[0036] Figure 2D is an enlarged perspective view of the first drainage element 210a of Figure 2C. Although described with reference to the first drainage element 210a, the following description of Figure 2D applies equally to the second, third, and fourth drainage elements 210b-d of Figures 2A-2D. As shown, the first channel 216a has a length L, as measured by the distance that fluid travels through the first channel 216a between the first drainage inlet 212a and the first drainage lumen portion 214a. C1 It is noteworthy that the length L C1 can be greater than the height H of the first drainage element 210a, for example, due to the serpentine or linear shape of the first channel 216a. C1is selected / designed to provide a particular fluid resistance. For example, the length L of the first channel 216a C1 is the length L C1 As the resistance of the first channel 216a increases, the length L C1 may be proportional to the resistance (eg, fluid or flow resistance) of the first channel 216a, such that the resistance decreases as decreases (eg, assuming the cross-sectional area of ​​the channel 216a remains constant).

[0037] Each drainage element 210 can have channels 216 of different lengths and therefore different fluid resistances. For example, a first channel 216a can have a first length L C1 and the second channel 216b can have a first length L C1 A second length L corresponding to a second resistance that is shorter than the first resistance. C2 In such an embodiment, under a given pressure, the assembly 200 can provide a first flow rate when the fluid moves solely (or at least primarily) through the first channel 216a, and a second flow rate that is greater than the first flow rate when the fluid moves solely (or at least primarily) through the second channel 216b. The third channel 216c and the fourth channel 216d can also have different lengths, and thus different resistances, to provide additional treatment options. Thus, the relative levels of treatment provided by each drainage element 210 can be different, and the level of treatment provided by the assembly 200 can be adjusted by selectively allowing and / or blocking flow through various channels 216 and / or combinations of channels 216 (e.g., by selectively interfering or allowing flow through individual drainage inlets 212, as described below with respect to Figures 5A-7B). In other embodiments, the channels 216 can have the same or substantially similar geometric configurations such that they have the same or substantially similar fluid resistances and therefore provide similar flow rates (for a given pressure).

[0038] In some embodiments, the level of fluid flow through the drainage element 210a is controlled primarily by the resistance of the channel 216a. For example, the drainage inlet 212a and the drainage lumen portion 214a can be sized (e.g., having a length, width, diameter, circumference, etc.) such that the drainage inlet 212a and the drainage lumen portion 214a do not provide substantial resistance to fluid flow therethrough compared to the resistance provided by the channel 216a. Thus, in at least some embodiments, the length L of the channel 216a is C1 primarily determines the fluid resistance of the drainage element 210a.

[0039] As best seen in FIG. 2D, the first drainage element 210a can have a thickness T that provides sufficient stability to the drainage element to prevent or at least partially reduce deformability of the first drainage element 210a. For example, the thickness T can be about 50 μm to about 500 μm, such as at least 50 μm, at least 100 μm, at least 150 μm, at least 200 μm, at least 250 μm, at least 300 μm, at least 350 μm, at least 400 μm, and / or any other suitable thickness. The thickness T can be based at least in part on the material forming the first drainage element 210a. For example, the first drainage element 210a can have a first thickness T1 when the material is generally soft or compressible (e.g., a Young's modulus of about 0 gigapascals (GPa) to about 40 GPa, e.g., a Young's modulus less than 40 GPa), and a second thickness T2 that is less than the first thickness T1 when the material is generally hard or incompressible (e.g., a Young's modulus of about 100 GPa to about 500 GPa, e.g., a Young's modulus greater than 100 GPa). In at least some embodiments, the length L (FIG. 1) of the assembly 100, 200 can be generally similar or the same as the combined length or total length of the drainage element(s) 210 and the one or more end cap(s) 111, as measured by the sum of the thickness T of each of the drainage elements 210 and the thickness of the one or more end cap(s) 111.

[0040] In the embodiment shown in FIG. 2D, the first channel 216a is formed in the first surface 218a of the first drainage element 210a. By forming the channel 216 in the surface 218 of the drainage element 210, the channel 216 can be sealed (e.g., fluidically sealed) by a fluid seal formed between the individual drainage elements 210, as described above with reference to FIGS. 2A-2B. In some embodiments, the channel 216 can be formed internally in the drainage element 210, such that the embodiment shown in FIG. 2D represents a half or cross-section of the drainage element 210. In at least some embodiments, the channel(s) 216 can be formed by laser cutting, machining, or any other suitable process or technique to remove material from the surface(s) 218 ​​of the drainage element(s) 210. In at least some embodiments, the channel(s) 210 can be formed using a mold corresponding to the desired length and / or shape of the channel(s) 210, for example, as part of an additive manufacturing process.

[0041] 3A and 3B show additional drainage elements 310a-b configured in accordance with selected embodiments of the present technology. The drainage elements 310a-b and / or one or more components thereof may be generally similar or the same as the drainage element(s) 110 of FIG. 1 and / or the drainage element(s) 210 of FIG. 2A-2D. As such, like numbers are used to refer to like components (e.g., fluid inlet(s) 312 versus fluid inlet(s) 112 of FIG. 1, fluid inlet(s) 212 of FIG. 2A-2D), and the description of the drainage elements 310a-b is limited to features that differ from the drainage element(s) 110 of FIG. 1 and / or the drainage element(s) 210 of FIG. 2A-2D, as well as features necessary for the context. Additionally, any features of the drainage elements 310a-b may be combined with each other and / or with the drainage element(s) 110, 210 of Figures 1 and / or 2A-2D, respectively.

[0042] 3A, the drainage element 310a can include a protrusion or tab 311 extending from an interface surface 313a. The protrusion 311 can include a drainage inlet 312a such that the drainage inlet 312a opening is generally or substantially perpendicular to the interface surface 313a. In such an embodiment, the drainage inlet 312a can have a width W4 that is greater than a width W5 of the channel 316a. In at least some embodiments, for example, the width W4 of the drainage inlet 312a can be from about 40 μm to about 150 μm, e.g., at least 40 μm, at least 50 μm, at least 60 μm, at least 70 μm, at least 80 μm, at least 90 μm, at least 100 μm, or any other suitable width, and the width W5 of the channel 316a can be from about 5 μm to about 50 μm, e.g., up to 10 μm, up to 15 μm, up to 20 μm, up to 25 μm, up to 30 μm, up to 35 μm, up to 40 μm, or any other suitable width. Without being bound by theory, a drainage element including a drainage inlet having an opening having a width W4 that is perpendicular to the interface surface 313a and that is greater than a corresponding channel width W5 can allow fluid to enter the drainage inlet when the drainage inlet is positioned near a corresponding gating element configured to selectively control fluid flow through the inlet, as described in more detail below with reference to gating element 512 of Figures 5A-6B and gating element 702 of Figures 7A-7B. For example, this can reduce the distance D that the gating element must travel to move between a first (e.g., open) position that allows fluid to flow into the inlet 312 and a second (e.g., closed) position that prevents or at least partially reduces fluid from flowing into the inlet 312 (as described below with reference to Figures 6A-6B). In at least some embodiments, for example, the distance D can be from about 5 μm to about 50 μm, such as up to 10 μm, up to 15 μm, up to 20 μm, up to 25 μm, up to 30 μm, up to 35 μm, up to 40 μm, or up to any other suitable distance.

[0043] The channels in the drainage elements described herein can have any suitable shape that allows the length of the channel to be greater than the height of the drainage element. For example, FIG. 3B shows a drainage element 310b including a channel 316b having a curved or spiral shape. In other embodiments, the channel 316b can have a zigzag shape, a curved shape, a combination of one or more of any of the channel shapes described herein, or any other suitable shape. In the illustrated embodiment, the lumen portion 314b is concentric with the drainage element 310b or disposed along its longitudinal axis. In other embodiments, the lumen portion 314b can be disposed near the circumference of the drainage element 310b or in any other suitable location within the drainage element 310b. In the illustrated embodiment, the lumen portion 314 has a circular shape. In other embodiments, the lumen portion 314 can have an elliptical shape, a curved shape, a triangular shape, a square shape, a rectangular shape, a rectilinear shape, a pentagonal shape, a hexagonal shape, or any other suitable shape.

[0044] FIG. 4A illustrates another drainage element 410 configured in accordance with selected embodiments of the present technology. The drainage element 410 and / or one or more components thereof may be generally similar or the same as the drainage element(s) 110, 210, 310 of FIG. 1-3B, respectively. Thus, similar numbers are used to indicate similar components (e.g., drainage element 410 vs. drainage element(s) 110, 210, 310 of FIG. 1-3B, respectively), and the description of the drainage element 410 of FIG. 4 is limited to features that differ from the drainage element(s) 110, 210, 310 of FIG. 1-3B, respectively, and features necessary for the context. Additionally, any features of the drainage element 410 may be combined with the drainage element(s) 110, 210, 310 of FIG. 1-3B, respectively.

[0045] As shown in Figure 4A, the drainage element 410 can include one or more alignment openings 420. Each of the alignment openings 420 can be used to align or orient the drainage element 410 relative to one or more other drainage elements, to align or orient one or more first features of a first drainage element (e.g., first drainage inlet 412, first drainage lumen portion 414, first interfacing surface 413, etc.) with one or more second features of a second drainage element (e.g., second drainage inlet, second drainage lumen portion, second interfacing surface, etc.), and / or to align or orient the drainage element 410 relative to a carriage element (e.g., carriage element 202 of Figures 2A and 2B).

[0046] 4B illustrates a plurality of drainage elements 410a-d of FIG. Each of the drainage elements 410a-d may be aligned and / or oriented relative to one another by one or more alignment elements 422, for example, to reduce or prevent movement or rotation of a first drainage element 410a relative to one or more other drainage elements 410b-d. In the illustrated embodiment, for example, each of the drainage elements 410a-d includes a respective first alignment opening 420a1, 420b1, 420c1, 420d1 configured to receive a corresponding first alignment element 422a, and further includes a respective second alignment opening 420a2, 420b2, 420c2, 420d2 configured to receive a corresponding second alignment element 422b.

[0047] 4A and 4B together, in the illustrated embodiment, the alignment openings 420 have a circular shape, while in other embodiments, each of the alignment openings 420 can have an oval, a curvilinear shape, a triangle, a square, a rectangle, a rectilinear shape, a pentagon, a hexagon, or any other suitable shape. In some embodiments, the first alignment openings 420a1, 420b1, 420c1, 420d1 can have a first shape, and the second alignment openings 420a2, 420b2, 420c2, 420d2 can have a second shape that is different from the first shape. Each of the alignment elements 422 can have a size and / or shape corresponding to an individual corresponding one of the alignment openings 420. In at least some embodiments, for example, the first alignment element 422a can have a first size and / or shape corresponding to the size and / or shape of the first alignment openings 420a1, 420b1, 420c1, 420d1, and the second alignment element 422b can have a second size and / or shape corresponding to the size and / or shape of the second alignment openings 420a2, 420b2, 420c2, 420d2. Although each drainage element 410 in FIGS. 4A and 4B is shown as having two alignment openings 420, in other embodiments, each drainage element 410 can include more or fewer alignment openings 420. In at least some embodiments, for example, each drainage element 410 can include one, three, four, five, or more alignment openings 420. In some embodiments, the alignment openings 420 and alignment elements 422 can be used to align, stack, join, etc., two or more drainage elements 410 prior to insertion into a carriage assembly, such as assembly 200 of Figures 2A-2C.

[0048] 5A and 5B illustrate an actuation assembly 500 for selectively controlling fluid flow through a fluid inlet, as described herein and configured in accordance with selected embodiments of the present technology. For example, the actuation assembly 500 can be used as part of the drainage assemblies 100, 200 of FIGS. 1-2D, for example, to selectively control the flow of fluid into a drainage element. With reference collectively to FIGS. 5A and 5B, the actuation assembly 500 can include a housing or frame 502 that includes and / or defines a plurality of chambers or wells 504. In the illustrated embodiment, for example, the housing 502 includes a first well 504a, a second well 504b, and a third well 504c. Each of the wells 504 can include one or more actuators 510. In the illustrated embodiment, for example, the first well 504a includes a first actuator 510a, the second well 504b includes a second actuator 510b, and the third well 504c includes a third actuator 510c. Each of the actuators 510 can include a control or gating element 512 coupled to one or more first actuating elements 514 and one or more second actuating elements 516. Additionally, the first actuating element(s) 514 can be coupled to the housing 502, and the second actuating element(s) 516 can be coupled to a priming and / or anchoring element 518 ("priming element 518"). In at least some embodiments, the gating element 512, the first actuating element(s) 514, the second actuating element(s) 516, and / or the priming element 518 can be coplanar. The priming element 518 is described in more detail below with reference to FIG. 5B.

[0049] In the illustrated embodiment, the first actuator 510a includes three first actuation elements 514a. 1~3 (e.g., a strut) and three second actuation elements 516a 1~3 The second actuator 510b includes a first gate element 512a coupled to three first actuation elements 514b. 1~3 and three second actuation elements 516b 1~3a second gate element 512b coupled to the first actuator element 512c, and a third actuator 510c coupled to three first actuation elements 514c. 1~3 and three second actuating elements 516c 1~3 5 and a third gate element 512c coupled to the first and second actuating elements 514 and 516. Individual ones of the first actuating elements 514 and / or second actuating elements 516 can be disposed approximately parallel to one another when in their preferred geometries. In other embodiments, the actuating assembly 500 can include more or fewer wells 504, actuators 510, first actuating elements 514, and / or second actuating elements 516. In at least some embodiments, for example, the actuating assembly 500 can include one, two, four, five, six, seven, eight, nine, ten, or any other suitable number of chambers 504, actuators 510, first actuating elements 514, and / or second actuating elements 516 (e.g., to correspond to the number of drainage elements and / or fluid inlets on a corresponding drainage assembly). In at least some embodiments, each of the actuators 510 may include a first number of first actuating elements 514 and a second number of second actuating elements 516 that are the same as or different from the first number of first actuating elements 514.

[0050] The actuation assembly 500 can be configured to selectively control the flow of fluid into an adjustable shunt system, such as any of the systems previously described and / or incorporated by reference herein. In particular, the first actuator 510a can be configured to control the flow of fluid through a first fluid inlet (e.g., the first drain inlet 112a of FIG. 1), the second actuator 510b can be configured to control the flow of fluid through a second fluid inlet (e.g., the second drain inlet 112b of FIG. 1), and the third actuator 510c can be configured to control the flow of fluid through a third fluid inlet (e.g., the third drain inlet 112c of FIG. 1). Each of the protrusions or gate element(s) 512 can be configured to movably interface with a corresponding fluid inlet, e.g., to move between a first (e.g., "open") position in which the gate element 512 does not substantially prevent fluid from flowing through the corresponding fluid inlet (e.g., by not interfering with the corresponding fluid inlet) and a second (e.g., "closed") position in which the gate element 512 substantially prevents fluid from flowing through the corresponding fluid inlet (e.g., by blocking the corresponding fluid inlet). In some embodiments, the gate element(s) 512 can be configured to move to one or more intermediate positions between the first (e.g., open) position and the second (e.g., closed) position.

[0051] The first actuating element(s) 514 and the second actuating element(s) 516 can drive movement of the gate element(s) 512 between a first (e.g., open) position and a second (e.g., closed) position. The first actuating element(s) 514 and the second actuating element(s) 516 can be at least partially composed of a shape memory material or alloy (e.g., Nitinol). Thus, the first actuating element(s) 514 and the second actuating element 516 can be transitionable between at least a first material phase or state (e.g., a martensite state, an R-phase, a composite state between martensite and R-phase, etc.) and a second material phase or state (e.g., an austenite state, an R-phase state, a composite state between austenite and R-phase, etc.). In the first material state, the first actuating element(s) 514 and the second actuating element(s) 516 may have reduced (e.g., relatively less stiff) mechanical properties that render the actuating elements more easily deformable (e.g., compressible, expandable, etc.). In the second material state, the first actuating element(s) 514 and the second actuating element(s) 516 may have increased (e.g., relatively more stiff) mechanical properties relative to the first material state, resulting in an increased preference for a particular preferred geometry (e.g., original geometry, manufactured or assembled geometry, heat-set geometry, etc.). The first actuating element(s) 514 and the second actuating element(s) 516 may be configured to apply energy (e.g., laser energy, electrical energy, etc.) to the first actuating element(s) 514 or the second actuating element(s) 516 to bring the element to a transition temperature (e.g., an austenitic finish (A), which is generally higher than body temperature). f ) temperature. When heated above the transition temperature, first actuating element(s) 514 (or second actuating element(s) 516) moves to and / or toward its preferred geometric shape if first actuating element(s) 514 (or second actuating element(s) 516) deforms toward its preferred geometric shape.

[0052] The first actuating element(s) 514 and the second actuating element(s) 516 generally act in opposition. For example, the first actuating element(s) 514 can be actuated to move the corresponding gate element(s) 512 to and / or toward a first (e.g., closed) position, and the second actuating element(s) 516 can be actuated to move the corresponding gate element(s) 512 to and / or toward a second (e.g., open) position. Furthermore, the first actuating element(s) 514 and the second actuating element(s) 516 can move in concert such that as one moves toward its preferred geometric shape during a material phase transition, the other deforms toward its preferred geometric shape. This allows the actuating elements 514, 516 to be repeatedly actuated to repeatedly actuate the gate element(s) 512 between the first (e.g., open) position and the second (e.g., closed) position.

[0053] In the embodiment shown in FIG. 5A, the actuation elements 514, 516 are in their preferred (e.g., as-manufactured) geometric shapes and the gate element is in a first (e.g., open) position. Referring now to FIG. 5B, the priming element(s) 518 can be moved to contact and / or couple with the priming surface 506 of the housing 502. In some embodiments, coupling of the priming element(s) 518 to the priming surface 506 does not substantially move the gate element(s) 512 (e.g., the gate element(s) 512 can remain in the first position as shown in FIGS. 5A and 5B). In other embodiments, coupling of the priming element(s) 518 to the priming surface(s) 506 moves the gate element(s) 512 to an intermediate position between the first position and the second position. In any event, coupling of the priming element(s) 518 to the priming surface(s) 506 can deform / distort the second actuating element(s) 516 relative to their preferred geometry (FIG. 5A) such that the second actuating element(s) 516 are subjected to stress.

[0054] Once in the stressed configuration shown in FIG. 5B, the second actuating element(s) 516 can be actuated to move the gate element(s) 512 toward the second position. For example, applying energy to the second actuating element(s) 516 heats the second actuating element(s) above its transition temperature, which transitions the second actuating element(s) from a relatively less stiff first material state to a relatively more stiff second material state. This also moves the second actuating element(s) toward its preferred geometry and reduces stresses within the second actuating element. For example, the second actuating elements 516 can return toward their linear (e.g., non-distorted, non-stressed) configuration (i.e., their preferred geometry). However, because the second actuating elements 516 are coupled to the frame 502 via the priming element 518, the second actuating elements 516 do not return to the position shown in FIG. 5A. Rather, the second actuating element 516 moves at least partially away from the first actuating element 514 toward the frame 502. Because the gate element(s) 512 are coupled to the second actuating element(s) 516, as the second actuating element(s) 516 move toward their preferred geometry, the gate elements translate (e.g., slide) toward the second actuating element(s) 516 and the second (e.g., closed) position within the well. This movement deforms the first actuating element(s) 514. As previously discussed, this can repeatedly actuate the actuating elements 514, 516 to repeatedly cycle the gate element(s) 512 between the first (e.g., open) and second (e.g., closed) positions (not shown).

[0055] In the illustrated embodiment, each of the first and second actuating elements 514, 516 generally have a tapered or hourglass shape. The tapered or hourglass shaped actuating elements 514, 516 can have a relatively more consistent strain and / or stress distribution (e.g., across the length and / or width of the individual actuating elements 514, 516) when deformed to their preferred geometry. The relatively consistent strain across the actuating elements can allow for greater overall movement of the actuating elements and / or the gating elements to which they are coupled without forcing the material (e.g., the material forming the actuating elements) to a material limit. For example, a material limit can be a strain limit beyond which the material is no longer thermoelastically recoverable and, as a result, cannot reliably or consistently move between a first position and a second position. Thus, without being bound by theory, it is believed that actuating elements 514, 516 configured in accordance with embodiments of the present technology can improve the movement (e.g., consistency, linearity, etc.) of the gating element(s) 512 between a first position and a second position. In other embodiments, individual ones of the first actuating element(s) 514 and / or second actuating element(s) 516 can have a linear shape, a straight shape, a curved shape, a zigzag shape, a serpentine shape, or any other suitable shape.

[0056] In some embodiments, the gate element(s) 512 can include one or more ends. For example, as best seen in FIG. 5A, the first actuator 510a can include a first end 513a1 coupled to the first actuation element(s) 514a and a second end 513a2 coupled to the second actuation element(s) 516b. The first gate element 512a can include a first end 513a1 coupled to the first actuation element(s) 514a and a second end 513a2 coupled to the second actuation element(s) 516b. 1~25 and 6. In some embodiments, the first end 513a1 and the second end 513a2 can be on opposite sides of the gate element 512a and / or extend therefrom. In some embodiments, the first end 513a1 and / or the second end 513a2 can be generally or substantially perpendicular to the longitudinal axis of the gate element 512a and / or the housing 502. In some embodiments, the first actuating element(s) 514 and the second actuating element(s) 516 can selectively actuate the first end 513a1 and / or the second end 513a2 without or substantially without deforming or torquing the first end 513a1 and / or the second end 513a2 relative to each other or to the first gate element 512a. Thus, the movement of the gate element 512a between the first and second positions can be generally or substantially linear, e.g., generally or substantially perpendicular and / or transverse to the longitudinal axis of the housing 502.

[0057] In some embodiments, energy can be applied to one or more ends 513 to actuate individual ones of the first actuating element(s) 514 and / or second actuating element(s) 516. Energy applied to one or more ends 513 can spread into and thus heat the first actuating element(s) 514 and / or second actuating element(s) 516. In at least some embodiments, for example, energy can be applied to the first end 513a1 to actuate the first actuating element 514a. 1~3 and / or energy can be applied to the second end 513a2 to activate the second actuating element 516a. 1~3510c to move the first gate element 512a between the first and second positions, as described above. Energy may also be applied to the end(s) of the second actuator 510b and / or the third actuator 510c. Without being bound by theory, applying energy to one or more ends 513 is expected to simplify the actuation process due to the relatively large surface area (and thus the relatively large target) to which the energy may be applied. However, in some embodiments, energy may be applied directly to the first actuation element(s) 514 and / or the second actuation element(s) 516.

[0058] 5A and 5B together, in some embodiments, the actuation assembly 500 can be a single or continuous structure (e.g., cut from, printed as, or deposited as a single piece of material). For example, each of the actuators 510 can be patterned (e.g., cut, laser cut, formed, etc.) in a single piece of material (e.g., Nitinol), and the well(s) 504 can correspond to areas of the single piece of material that have been removed (e.g., during a subtractive manufacturing process) or where no material has been added (e.g., during an additive manufacturing process). Further details regarding shape memory actuators and the operation and manufacture of adjustable glaucoma shunts are described in U.S. Pat. No. 11,291,585, U.S. Pat. No. 11,166,849, and International Patent Application Nos. PCT / US 20 / 55144, PCT / US 20 / 55141, PCT / US 21 / 14774, PCT / US 21 / 18601, PCT / US 21 / 023238, and PCT / US 21 / 27742, the disclosures of which are incorporated by reference in their entireties for all purposes.

[0059] Figures 6A and 6B are top views of a flow control system 600 including the drainage assembly 100 of Figure 1 and the actuation assembly 500 of Figures 6A and 6B. Referring together to Figures 6A and 6B, as previously described, the actuation assembly 500 can be used to control the flow of fluid through the drainage inlet 112. In the illustrated embodiment, for example, the first gate element 512a is configured to control the flow of fluid through the third drainage inlet 112c, the second gate element 512b is configured to control the flow of fluid through the second drainage inlet 112b, and the third gate element 512c is configured to control the flow of fluid through the first drainage inlet 112a. As best seen in FIG. 6B, the actuation assembly 500 can be disposed within the slot 106 of the carriage element 102 and / or coupled to the drainage element(s) 110, e.g., coupled to the interface surface(s) 113 of the drainage element(s) 110. The flow control system 600 shown in FIGS. 6A and 6B includes the drainage assembly 100 of FIG. 1 and the actuation assembly 500 of FIGS. 5A and 5B, although in other embodiments, the flow control system 600 can include any combination of the actuation assemblies and / or drainage assemblies described herein and / or incorporated by reference herein.

[0060] 7A and 7B show another actuator 710 configured in accordance with selected embodiments of the present technology for controlling fluid flow in a shunt system. More specifically, FIG. 7A is an isometric view of the actuator 710 in an assembled or untensioned configuration, and FIG. 7B is a top view of the actuator 710 in an assembled or untensioned configuration. For clarity, the actuator 710 is shown in isolation. However, as one skilled in the art will appreciate, the actuator 710 can be used to selectively control fluid flow through an inlet of the assembly 100 and / or assembly 200 shown in FIGS. 1-2D (e.g., in place of the actuation assembly 500 shown in FIGS. 5A-6B).

[0061] The actuator 710 can include a first shape memory actuating element 714, a second shape memory actuating element 716, and a gate element 702 coupled to and disposed between the first shape memory actuating element 714 and the second shape memory actuating element 716. When the actuating elements 714, 716 are deformed toward their preferred (e.g., as-manufactured) geometric shapes, applying energy to the actuating elements 714, 716 (e.g., via respective targets 724a, 724b) induces a material phase change in the actuating elements that deforms the actuating elements toward their preferred geometric shapes, similar to the transitions previously described with respect to the actuating elements 514, 516 of Figures 5A and 5B. This transition imparts a rotational motion to the gate element 702. Thus, the gate element 702 can be moved between a first position in which it blocks the fluid inlet (e.g., the drain inlet(s) 212 shown in Figures 2A-2D) and a second position in which the gate element 702 does not interfere with the fluid inlet. The actuator 710 is described in further detail in U.S. patent application Ser. No. 17 / 175,332, previously incorporated by reference herein.

[0062] As will be appreciated by those skilled in the art, any of the actuation assemblies and / or actuators described above may be used with the assemblies 100 or 200 of Figures 1 and 2A-2D, respectively, to control the flow of fluid therethrough. Additionally, certain features described with respect to one assembly and / or drainage element may be added or combined with another assembly and / or drainage element. Thus, the present technology is not limited to the assemblies and / or drainage elements expressly identified herein.

[0063] 8A-8D illustrate a shunt system 800 ("system 800") configured in accordance with selected embodiments of the present technology. More specifically, FIG. 8A is a top view of system 800, FIG. 8B is a perspective view of a fluidic resistor network 820 extending through system 800 with other aspects of system 800 omitted for clarity, FIG. 8C is a schematic diagram of fluidic resistor network 820 shown in FIG. 8B, and FIG. 8D is an exploded isometric view of system 800. As described in more detail below, system 800 is configured to provide a titratable therapy for draining fluid from a first body region to a second body region, such as to drain aqueous humor from the anterior chamber of a patient's eye to aid in the treatment of glaucoma.

[0064] With reference to FIG. 8A, the system 800 includes an elongated housing or shunt element 801 that defines a network of fluidic resistors 820 (also referred to herein as “fluidic resistor network 820”) and houses one or more actuators 810 (shown as a first actuator 810a and a second actuator 810b). As will be described in more detail with reference to FIGS. 8B-8D, the network of fluidic resistors 820 can comprise a number of channels or lumens through which fluid can flow through the shunt element 801 when the system 800 is implanted within a patient. Also, as will be described in more detail with reference to FIGS. 8B-8D, the actuators 810 can selectively control the flow of fluid through the fluidic resistor network 820, such as by selectively interfering with and / or selectively not interfering with associated fluid flow ports. In some embodiments, the actuator is a shape memory actuator, such as those described above with reference to Figures 5A, 5B, 7A, and 7B, and / or those described in U.S. Patent Application Publication Nos. 2020 / 0229982 and 2021 / 0251806, the disclosures of which are incorporated by reference in their entireties and for all purposes.

[0065] 8B illustrates a network of fluidic resistors 820, with other aspects of the system 800 omitted for purposes of illustration and clarity. The network of fluidic resistors 820 can include a plurality of at least partially isolated channels or lumens. For example, in the illustrated embodiment, the network of fluidic resistors 820 includes a first channel 822 and a second channel 824, which merge to form a third channel 826. The first channel 822 includes a first end 822a and a second end 822b. The first end 822a is aligned (e.g., fluidly coupled) with a corresponding first fluid flow port 812 ("first port 812"), and the second end 822b is fluidly coupled to the third channel 826. As illustrated, the first channel 822 has a relatively linear or straight flow path. Thus, the first channel 822 and the third channel 826 can form a first flow path through the system 800.

[0066] The second channel 824 includes a first end 824a, a first spiral or portion or segment 824b, a second spiral portion or segment 824c, and a second end 824d. The first end 824a is fluidly aligned (e.g., fluidly coupled) with a corresponding second fluid flow port 814 ("second port 814"), and the second end 824d is fluidly coupled to the third channel 826. The first spiral portion 824b extends between and fluidly couples the first end 824a and the second spiral portion 824c. The second spiral portion 824c extends between and fluidly couples the first spiral portion 824b and the second end 824d. The second channel 824 may further include a bypass channel 815 fluidly coupled to a portion of the first spiral portion 824b. The bypass channel 815 can extend from a corresponding third fluid flow port 816 ("third port 816"). The second channel 824 thus defines two additional flow paths through the system 800: (1) a first flow path beginning at the second port 814, passing through the entire length of the second channel 824, and through the third channel 826, and (2) a second flow path beginning at the third port 816, passing through the bypass channel 815, passing through a portion of the second channel 824, and through the third channel 826.

[0067] Each of the channels and / or flow paths of the network of fluidic resistors 820 may be associated with a different fluidic resistance. For example, for a given cross-sectional area, the fluidic resistance provided by a channel is proportional to the length of the channel. That is, longer channels tend to have higher fluidic resistance and shorter channels tend to have lower fluidic resistance. Thus, in embodiments in which the first channel 822 and the second channel 824 have the same or substantially the same cross-sectional dimensions (e.g., diameter), the first channel 822 has a lower fluidic resistance than the second channel 824. This is because the second channel 824 has a greater length than the first channel 822 due to the first and second spiral portions 824b and 824c. Similarly, the fluid resistance of the flow path extending between the third port 816 and the third channel 826 is less than the fluid resistance of the flow path extending between the second port 814 and the third channel 826 because the length of the flow path between the third port 816 and the third channel 826 is less than the length of the flow path between the second port 814 and the third channel 826. In some embodiments, the third channel 826 has a cross-sectional dimension (e.g., diameter) that is substantially larger than the corresponding cross-sectional dimensions of the first channel 822 and the second channel 824, such that the third channel 826 has a negligible effect on the fluid resistance through the various flow paths. Similarly, the bypass channel 815 and the various ports may also have a negligible effect on the fluid resistance through the various flow paths. As one skilled in the art will appreciate, resistance is more sensitive to changes in cross-sectional area than length, and therefore the third channel 826, the bypass channel 815, and the various ports can be designed to have a negligible effect on the overall flow resistance simply by having a slightly larger cross-sectional area than the first channel 822 and the second channel 824. In such an embodiment, the length and cross-sectional area of ​​the first channel 822 and the second channel 824 can be designed to impart a desired fluidic resistance. Of course, in other embodiments, the third channel 826, the bypass channel 815, and / or the various ports can impart significant fluidic resistance to the various flow paths.

[0068] 8C is a schematic diagram of fluidic resistor network 820 further illustrating the relative fluidic resistance of various flow paths through fluidic resistor network 820. As shown, first channel 822, first spiral portion 824b, and second spiral portion 824c are the primary sources of resistance through network 820. That is, ports 812, 814, 816, bypass channel 815, and third channel 826 do not impart significant resistance through network 820. As a result, the network 820 provides three fluid flow paths through the system: a first flow path A between the first port 812 and the third channel 826 via the first channel 822; a second flow path B between the second port 814 and the third channel 826 via the first spiral portion 824b and the second spiral portion 824c; and a third flow path C between the third port 816 and the third channel 826 via the bypass channel 815 and the second spiral portion 824c. In the illustrated embodiment, the first flow path A has the lowest resistance, the second flow path B has the highest resistance, and the third flow path C has an intermediate resistance between the first and second resistances. As one skilled in the art will appreciate from the disclosure herein, the channels may be arranged to provide different relative resistances than those shown herein. Thus, the present technology is not limited to any particular configuration of channels unless otherwise stated. The fluidic resistor network may have more or fewer channels. Indeed, additional examples of fluidic resistor networks are described in Section C below.

[0069] System 800 is comprised of multiple layers of materials that are stacked and sealingly bonded (e.g., glued) together. For example, FIG. 8D is an exploded isometric view of system 800 showing multiple layers (shown as first layer 802, second layer 803, third layer 804, and fourth layer 805). First layer 802, second layer 803, third layer 804, and fourth layer 805 can be bonded together to form system 800 using any suitable manufacturing process, including welding, adhesives, chemical bonding, or other suitable techniques, as described in more detail in section B. When bonded, adjacent surfaces of first layer 802, second layer 803, third layer 804, and fourth layer 805 form a fluid- and gas-tight seal such that fluids or gases cannot leak between adjacent layers (other than through defined flow paths, such as fluidic resistor network 820). When assembled together, each of the layers 802-805 forms a plane that is parallel to the plane formed by each of the other layers 802-805 and to the longitudinal axis of the system 100. This is in contrast to the stackable drainage elements described above with reference to Figures 2A-4B, in which each stackable drainage element forms a plane perpendicular to the longitudinal axis of the corresponding system.

[0070] The layers 802-805 can be composed of the same or different materials. For example, in some embodiments, one or more of the first layer 802, the second layer 803, the third layer 804, and / or the fourth layer 805 can be composed of silicone, plastic, glass, a polymer, or another suitable material. As described in more detail below, the ability to fabricate individual layers from different materials is expected to be beneficial because different layers can be fabricated to have different material properties (e.g., different levels of stiffness) based on (e.g., optimized) the function of the layer.

[0071] Each of the layers 802-805 can be a flat layer having a width-to-height or width-to-thickness ratio of greater than about 10:1 or greater than about 50:1, such as from about 10:1 to about 100:1. The layers 802-805 can have the same or different heights / thicknesses. For example, in some embodiments, one or more of the first layer 802, the second layer 803, the third layer 804, and / or the fourth layer 805 have a thickness of about 10 μm to about 500 μm, or about 10 μm to about 100 μm, or about 10 μm to about 50 μm. In some embodiments, the first layer 802, the second layer 803, the third layer 804, and / or the fourth layer 805 can have a thickness of less than about 500 μm, less than about 250 μm, less than about 100 μm, less than about 50 μm, and / or less than about 25 μm. Without wishing to be bound by theory, fabricating layers 802-805 to have a relatively high width-to-thickness ratio (e.g., greater than 10:1) and a relatively small thickness (e.g., less than about 500 μm) advantageously results in the overall footprint of system 300 being relatively compact.

[0072] The fluidic resistor network 820 can occupy multiple layers of the system 800. In the illustrated embodiment, for example, the first channel 822 and the first spiral portion 824b of the second channel 824 are at least partially defined in the fourth layer 805, and the second spiral portion 824c of the second channel 824 and the third channel 826 are at least partially defined in the second layer 803. That is, the first channel 822 and the first spiral portion 824b are formed in a first plane parallel to the longitudinal axis of the system, and the second spiral portion 824c and the third channel 826 are formed in a second overlapping plane parallel to the first plane and the longitudinal axis of the system. As used herein, "at least partially defined," when used in the context of describing channels in a layer of material, includes embodiments in which at least 80%, at least 90%, or at least 95% of the void space of the channel is defined in the layer of material. In some embodiments, a layer that "at least partially defines" a channel does not completely enclose the channel itself. Rather, another layer may form the "top" or "bottom" surface of the channel, such that the channel is only enclosed when two adjacent layers are bonded together. An example of such an embodiment is described in more detail below with reference to Figure 11. In other embodiments, the channel, including the walls that define it, is formed all within a single layer.

[0073] The first layer 802 (e.g., the top layer) can include a first opening 811, a second opening 813, and a third opening 817. As described below, the first opening 811, the second opening 813, and the third opening 817 can allow fluid to enter the system 800 and therefore can be described as a first inlet, a second inlet, and a third inlet, respectively. The third layer 804 can also include various ports or openings that allow fluid to enter the fluidic resistor network 820 and / or flow between various channels of the fluidic resistor network 820. For example, the third layer 804 includes a first port 812 that provides fluid access to (e.g., aligned with) a first end 822a of the first channel 822, a second port 814 that provides fluid access to (e.g., aligned with) a first end 824a of the second channel 824, and a third port 816 that provides fluid access to (e.g., aligned with) a bypass channel 815. The first port 812, the second port 814, and the third port 816 are disposed in fluid communication with a first opening 811, a second opening 813, and a third opening 817, respectively, in the first layer 802. As described below, this allows fluid to enter the fluidic resistor network 820 via the first opening 811, the second opening 813, and the third opening 817.

[0074] The third layer 804 further includes various openings that function as portals or connectors between portions of the fluidic resistor network 820 disposed on different layers. For example, the third layer 804 includes a first connector 823 and a second connector 825. The first connector 823 and the second connector 825 can be through-holes, lumens, ports, etc. that extend between the upper and lower surfaces of the third layer 804. Thus, the connectors 823, 825 generally have axes perpendicular to the axes of the first channel 822, the second channel 824, and the third channel 826. The first connector 823 is disposed to extend between the second end 822b of the first channel 822 and the third channel 826 such that fluid flowing through the first channel 822 can enter the third channel 826 via the first connector 823. The second connector 825 is positioned to extend between the first spiral portion 824b of the second channel 824 and the second spiral portion 824c of the second channel 824 so that fluid flowing through the first spiral portion 824b can flow into the second spiral portion 824c.

[0075] Defining the fluidic resistor network 820 in multiple layers of the system 800 is expected to provide several advantages. For example, defining the fluidic resistor network 820 in multiple overlapping layers provides more volume in which the channels of the network 820 may be formed. As a result, a channel of a particular resistance may generally be longer and wider than a channel of the same resistance formed in a single layer of material (e.g., channel resistance is proportional to the channel length and inversely proportional to the channel diameter by a fourth power function, so a first channel that is longer and wider than a second channel may have the same overall resistance as the second channel). This is expected to be advantageous for at least two reasons: (1) utilizing relatively wide / tall channels reduces the possibility that cellular material or other debris will stick in the channel and thus block the channel, and (2) it is generally easier to manufacture wide channels than narrower channels, and any manufacturing variability in the diameter of the channel has less impact on the fluidic resistance when the channel is wider. The aforementioned advantages are particularly useful in embodiments in which the system 800 is small (e.g., embodiments in which the system 800 is a glaucoma shunt) and in embodiments in which it may not be feasible to define a fluid resistor network 820 with suitable properties in a single layer.

[0076] As discussed above, the system 800 may be selectively adjustable to provide titratable therapy. For example, as shown in FIG. 8D, the system 800 may include a first actuator 810a, a second actuator 810b, and an actuator housing 806. The actuator housing 806 may include a first actuator chamber 808a configured to receive the first actuator 810a, and a second actuator chamber 808b configured to receive the second actuator 810b. The actuator housing 806 may be constructed from a material having a higher durometer (e.g., being stiffer) than the layers 802-805 such that the actuator housing 806 resists deformation. The first actuator 810a may be configured to control the flow of fluid through the first port 812, and thus, the flow of fluid into the first channel 822. For example, the first actuator 810a may be movable between at least a first position in which the first actuator 810a blocks the first port 812 and a second position in which the first actuator 810a does not block the first port 812. Similarly, the second actuator 810b may be configured to control the flow of fluid through the second port 816, and thus the flow of fluid to the bypass channel 815, by moving between two or more positions. As mentioned above, the first actuator 810a and the second actuator 810b may be constructed from a shape memory material, such as Nitinol, and may operate in the same or similar manner as the actuators described above with reference to Figures 5A, 5B, 7A, and 7B, and / or the shape memory actuators described in U.S. Patent Application Publication Nos. 2020 / 0229982 and 2021 / 0251806, previously incorporated by reference herein. Although described as having two actuators 810a, 810b, one skilled in the art will appreciate that the system 800 can have more or fewer actuators, such as 0, 1, 3, 4, or more.Additionally, in some embodiments, the first port 812, the second port 814, and the third port 816 can each include a corresponding actuator for controlling the flow of fluid therethrough. In other embodiments, such as the configuration shown in FIG. 8D, at least one of the first port 812, the second port 814, and the third port 816 does not have a corresponding actuator, and thus at least one of the first port 812, the second port 814, or the third port 816 is normally open to allow fluid to enter the fluidic resistor network 820.

[0077] B. Manufacturing of multilayer resistors The present technology further includes systems and methods that are expected to improve the manufacturing process of microfluidic shunt systems. As previously described with respect to Figures 8A-8D, the present technology includes shunt systems comprised of multiple stackable layers (e.g., layers 802-805 of system 800). Layers 802-805 can be manufactured using the same or different processes. For example, one or more of first layer 802, second layer 803, third layer 804, and / or fourth layer 805 can be manufactured via photolithography, spin casting, injection molding, laser cutting, or other suitable techniques. In some embodiments, the manufacturing technique used is based on the desired properties of one or more of the layers. For example, the "external" facing layers (i.e., first layer 802 and fourth layer 805) may be manufactured in a manner that creates an atraumatic and / or biocompatible surface. The "inner" layers (ie, second layer 803 and third layer 804) may be manufactured in a manner that prioritizes other manufacturing characteristics (eg, precision, tolerances, etc.).

[0078] Once the individual layers 802-805 are fabricated, the layers 802-805 may be stacked and adhered in a desired orientation. For example, as best shown in FIG. 8D, the second (e.g., "lower") surface of the first layer 802 may be adhered to the first (e.g., "upper") surface of the second layer 803, which may be adhered to the first (e.g., "upper") surface of the third layer 804, which may be adhered to the first (e.g., "upper") surface of the fourth layer 805. As used herein, the terms "upper" and "lower" are used to designate the surfaces of the layers 802-805 shown in FIG. 8D. One of ordinary skill in the art will appreciate that depending on the orientation of the system 800, the "upper" surface may be disposed below the "lower" surface depending on the orientation of the system 800. Thus, the use of the terms "upper" and "lower" does not require a particular spatial orientation relative to ground, but is instead used for clarity of description. As discussed above in Section A, the individual layers 802-805 may be attached using any suitable technique, such as gluing, bonding, taping, welding, soldering, stapling, sewing, etc. Non-limiting examples include self-adhesive or self-bonding by plasma treatment, by polymerized precursor material (e.g., using uncured silicone to bond two adjacent layers of silicone together), and / or by ultrasonic bonding.

[0079] The shunt systems described herein can also have certain features that are expected to improve the manufacturability of the system. For example, Figures 9A-9C show a shunt system 900 ("system 900") configured in accordance with selected embodiments of the present technology. More specifically, Figure 9A is a top view of system 900, Figure 9B is a schematic diagram of the fluidic resistor network shown in Figure 9A, and Figure 9C is an exploded isometric view of system 900. Similar to system 800 described above, system 900 can be an adjustable shunt configured to drain fluid from a first body region to a second body region, such as draining aqueous humor from the anterior chamber of a patient's eye.

[0080] The system 900 may include certain features generally similar to certain features of the system 800 described with reference to Figures 8A-8D. For example, referring initially to Figure 9A, the system 900 includes an elongated housing or shunt element 901 that defines a network of fluidic resistors 920 (also referred to as "fluidic resistor network 920"). The fluidic resistor network 920 may include a plurality of channels or lumens extending through the shunt element 901. For example, the system 900 includes a first channel 922, a second channel 924 having a first (e.g., helical) portion or segment 924a and a second (e.g., serpentine) portion or segment 924b, and a third channel 926. The first channel 922, the second channel 924, and the third channel 926 may have a generally similar configuration as the first channel 822, the second channel 824, and the third channel 826 described with reference to Figures 8A-8D. For example, the first channel 922 can extend between or otherwise fluidly connect the first port 911 (e.g., the first inlet opening) and the third channel 926, while the second channel can extend between or otherwise fluidly connect the second port 913 (e.g., the second inlet opening) and the third channel 926. The first channel 922 can have a different resistance than the second channel 924 by having a different length and / or cross-section. For example, in the illustrated embodiment, the second channel 924, due to its spiral and serpentine shape, is substantially longer than the first channel 922 and therefore has a higher resistance than the first channel 922. The third channel 926 can have a resistance less than the resistance of either the first channel 922 or the second channel 924. The system 900 may further include a bypass channel 915 extending between or fluidly connecting a third port 917 (e.g., a third inlet opening) and an intermediate portion of the second channel 924, such that fluid entering the system 900 via the third port 917 bypasses the first (e.g., spiral) portion 924a of the second channel 924.

[0081] Similar to system 800, the shunt element 901 can also define one or more actuator chambers (shown as a first actuator chamber 908a and a second actuator chamber 908b) for holding one or more actuators 910 (for purposes of illustration and clarity, the actuator 910 is shown only in the second actuator chamber 908b in FIG. 9A ). An actuator (not shown) in the first actuator chamber 908a can be configured to selectively control the flow of fluid through the first port 911 and / or through another port or opening upstream of the first channel 922 (e.g., one or more intermediate ports or openings fluidly disposed between the first port 911 and the first channel 922). The actuator 910 in the second actuator chamber 908b may be configured to selectively control the flow of fluid through the third port 917 and / or through another port or opening upstream from the bypass channel 915 (e.g., one or more intermediate ports or openings fluidly disposed between the third port 917 and the bypass channel 915). In the illustrated embodiment, the second port 913 providing access to the second channel 924 does not include a corresponding actuator for selectively controlling the flow of fluid therethrough and thus remains open / unblocked. The actuator 910 may be similar or the same as the actuator 810 described with reference to FIGS. 8A-8D. For example, the actuator 910 may be a shape memory actuator such as those described with reference to FIGS. 5A, 5B, 7A, and 7B and / or those described in U.S. Patent Application Publication Nos. 2020 / 0229982 and 2021 / 0251806, the disclosures of which were previously incorporated herein by reference.

[0082] 9B is a schematic diagram of a fluidic resistor network 920 further illustrating the relative fluidic resistance of various flow paths through the fluidic resistor network 920. As shown, a first channel 922, a first portion 924a of a second channel 924, and a second portion 924b of a second channel 924 are the primary sources of resistance through the network 920. That is, ports 911, 913, and 917, bypass channel 915, and third channel 926 do not impart significant resistance through the network 920. As a result, the network 920 provides three fluid flow paths through the system: a first flow path D between the first port 911 and the third channel 926 via the first channel 922; a second flow path E between the second port 913 and the third channel 926 via the first portion 924a and the second portion 924b of the second channel 924; and a third flow path F between the third port 917 and the third channel 926 via the bypass channel 925 and the second portion 924b of the second channel 924. In the illustrated embodiment, the first flow path D has the lowest resistance, the second flow path E has the highest resistance, and the third flow path F has an intermediate resistance between the first and second resistances. As one skilled in the art will appreciate from the disclosure herein, the channels can be arranged to provide different relative resistances than those shown herein, and thus the present technology is not limited to any particular configuration of channels unless expressly stated otherwise. Indeed, additional examples of fluidic resistor networks are described in Section C below.

[0083] Similar to system 800 described above, system 900 may be constructed from multiple layers of material stacked and bonded together. For example, FIG. 9C is an exploded isometric view of system 900 showing a first layer 902, a second layer 903, and a third layer 904. First layer 902 includes a first port 911, a second port 913, and a third port 917, each of which may be a through hole extending between a first (e.g., upper) surface 951 and a second (e.g., lower) surface 952 of first layer 902. Unlike system 800, the majority of fluidic resistor network 220 (FIG. 9B) is defined within first layer 902. That is, first channel 922, second channel 924, and third channel 926 (not visible in FIG. 9C) are at least partially defined within the thickness of first layer 902. For example, the first layer 902 defines the void spaces of channels 922, 924, and 926. In such embodiments, the second layer 903 and / or the third layer 904 may provide at least a portion of the walls to the void spaces of channels 922, 924, and 926 defined in the first layer 902.

[0084] As discussed above, the system 900 includes certain features that are expected to improve the manufacturability of the multi-layer system 900. For example, the second surface 952 of the first layer 902 can have a first layer step 953 that divides the first layer 902 into a first region 954 having a first thickness and a second region 955 having a second thickness that is greater than the first thickness. For example, the first region 954 can have a thickness that is about 1 / 8 to about 3 / 4 of the thickness of the second region 955. The first surface 961 of the second layer 903 can also have a second layer step 963 that divides the second layer 903 into a first region 964 having a first thickness and a second region 965 having a second thickness that is less than the first thickness. For example, the second region 965 can have a thickness that is about 1 / 8 to about 3 / 4 of the thickness of the first region 964. The first region 964 of the second layer can include an actuator chamber 908. The first regions 954 , 964 have a total thickness that is equal to, or at least approximately equal to, the total thickness of the second regions 955 , 965 .

[0085] When the first layer 902 and the second layer 903 are bonded together, the first region 954 of the first layer 902 is aligned with (and bonded to) the first region 964 of the second layer 903. Similarly, the second region 955 of the first layer 902 is aligned with (and bonded to) the second region 965 of the second layer 903. As a result, when the first layer 902 is bonded to the second layer 903, the first layer step 953 abuts against the second layer step 963. Without being bound by theory, the inclusion of a layer of variable thickness is expected to improve the manufacturability of the system 900 because (1) the fluidic resistor network 920 can be coplanar or substantially coplanar with the actuator 910, while (2) allowing the fluidic resistor network 920 to be fabricated in a layer separate from the actuator housing 908. This is expected to be advantageous because the material properties best suited to form the fluidic resistor network 920 may be different than the material properties best suited to form the actuator housing 908. For example, in some embodiments, the first layer 902 (and thus the fluidic resistor network 920) is expected to be constructed from a relatively flexible material, such as silicone, while the second layer 903 (and thus the actuator housing 908) is expected to be constructed from a relatively inflexible material (such as superelastic Nitinol, stainless steel, or other medical grade rigid material). This is also expected to be advantageous because it may result in fewer layers of material having to be bonded together to form the system 900. However, in some embodiments, the fluidic resistor network 920 is fabricated from multiple layers of relatively flexible material, as described above with reference to FIGS. 8A-8D, in addition to having a lamination step as described with reference to FIG. 9C.

[0086] C. Additional Embodiments of Fluidic Resistor Networks As mentioned above, the present technology is not limited to the fluid resistor network described and illustrated with respect to Figures 8A-9C. Indeed, as one skilled in the art will appreciate from the disclosure herein, a number of different flow paths can be created through different layers of the shunt system to provide different titratable levels of therapy. For example, Figures 10A and 10B show another shunt system 1000 ("system 1000") configured, for example, in accordance with selected embodiments of the present technology and having a different fluid resistor network than systems 800 and 900 described with reference to Figures 8A-9C. More specifically, Figure 10A is a perspective view of system 1000, and Figure 10B is a schematic diagram of the fluid resistor network shown in Figure 10A. Similar to systems 100 and 200 described above, system 1000 can be an adjustable shunt configured to drain fluid from a first body region to a second body region, such as draining aqueous humor from the anterior chamber of a patient's eye.

[0087] Certain features of the system 1000 may be generally similar to corresponding features of the previously described systems 800 and 900. For example, the system 1000 includes an elongated housing or shunt element 1001 having a network of fluidic resistors 1020 (also referred to herein as "fluidic resistor network 1020"). Similar to the previously described fluidic resistor networks 820 and 920, the fluidic resistor network 1020 may be comprised of multiple channels or lumens extending through the shunt element 1001 to provide multiple flow paths for the evacuation of fluid therethrough. However, as will be described in more detail below with reference to FIG. 10B, the fluidic resistor network 1020 of the system 1000 differs from the previously described fluidic resistor networks 820 and 920. The system 1000 may further include one or more actuator chambers 1008 configured to accommodate corresponding actuators (not shown) for selectively controlling the flow of fluid through the fluidic resistor network 1020.

[0088] 10B, the fluidic resistor network 1020 includes a plurality of separate channel segments, namely, a first channel segment 1021, a second channel segment 1022, a third channel segment 1024, a fourth channel segment 1025, a fifth channel segment 1026, and a sixth channel segment 1027. The channel segments collectively define three different flow paths G-I through the fluidic resistor network 1020, each flow path having a different total resistance. Each of the three flow paths includes a first channel segment 1021 and a sixth channel segment 1027. That is, the first channel segment 1021 is a common inlet channel that collects fluid from the corresponding inlet port 1011, and the sixth channel segment 1027 is a common outlet channel that collects fluid from the second channel segment 1022 and the fifth channel segment 1026. In the illustrated embodiment, the first channel segment 1021 and the sixth channel segment 1027 impart significant resistance to the fluid path. However, the resistance imparted by the first channel segment 1021 and the sixth channel segment 1027 is the same for each flow path. In other embodiments, the first channel segment 1021 and / or the sixth channel segment 1027 do not impart significant resistance to the total resistance of the flow path.

[0089] The fluidic resistor network 1020 includes three parallel resistors, namely, a second channel segment 1022, a third channel segment 1024, and a fourth channel segment 1025. Each of the parallel resistors defines a different flow path, namely, a first flow path G through the second channel segment 1022, a second flow path H through the third channel segment 1024, and a third flow path I through the fourth channel segment 1025. One or more of the parallel resistors can be selectively gated by a corresponding actuator. For example, in the illustrated embodiment, the second channel segment 1022 is gated by a first actuator 1010a, and the fourth channel segment 1025 is gated by a second actuator 1010b. The first and second actuators 1010a, 1010b can be non-invasively actuated to selectively open or close the second channel segment 1022 and the fourth channel segment 1025, respectively. In the illustrated embodiment, the third channel segment 1024 remains open. The third channel segment 1024 and the fourth channel segment 1025 can merge into a fifth channel segment 1026. The second channel segment 1022 and the fifth channel segment can merge into a sixth channel segment 1027, which serves as a common outlet channel for each flow path GI, as described above. The resistance of each of the channel segments can be selected so that each flow path through the system 1000 has desired resistance characteristics. Furthermore, as described above in section A, different channel segments can be defined in different layers of the system 1000 to minimize the size of the system 1000 and / or improve the manufacturability of the system 1000.

[0090] 11 is a cross-sectional view of a portion of a fluidic resistor network 1100 that can be configured in accordance with selected embodiments of the present technology and implemented with any of the shunt systems described herein. More specifically, FIG. 11 is a cross-sectional view along an axial length of the fluidic resistor network 1100. As shown, the fluidic resistor network 1100 includes a first channel 1122 having a first (e.g., upper) wall 1122a and a second (e.g., lower) wall 1122b, and a second channel 1124 having a third (e.g., upper) wall 1124a and a fourth (e.g., lower) wall 1124b. Although only a cross-sectional view is shown in FIG. 11, the first channel 1122 and the second channel 1124 can have a shape generally similar to any of the channels described herein (e.g., linear, spiral, serpentine, etc.).

[0091] As shown, the void spaces of both the first channel 1122 and the second channel 1124 are substantially defined within the first layer 1102. However, the first layer 1102 does not completely surround either the first channel 1122 or the second channel 1124. Rather, the first channel 1122 is surrounded when the first layer 1102 is sealingly bonded to the second layer 1103 (e.g., the second layer 1103 includes the first wall 1122a of the first channel 1122), and the second channel 1124 is completely surrounded when the first layer 1102 is sealingly bonded to the third layer 1104 (e.g., the third layer 1104 includes the fourth wall 1124b). However, despite being defined within the same layer, the first channel 1122 and the second channel 1124 are not coplanar within the first layer 1102. More specifically, the "top" of the first channel 1122 (e.g., first wall 1122a), the "bottom" of the first channel 1122 (e.g., second wall 1122b), the "top" of the second channel 1124 (e.g., third wall 1124a), and the "bottom" of the second channel 1124 (e.g., fourth wall 1124b) each occupy a different plane (respectively labeled planes A-D) that extends parallel to the axial length of the system (e.g., planes A-D extend into the page along the dashed lines in the diagram shown in FIG. 11). Without wishing to be bound by theory, such a configuration may be easier to manufacture than a configuration that requires one or more channels to be formed entirely in a single layer, while still minimizing the overall height of the system.

[0092] The present technology can include other embodiments in which channels or portions of channels occupy different planes within one or more layers. For example, some embodiments include a shunt body having at least a first channel extending at least partially through the shunt body and a second channel extending at least partially through the shunt body. As described above with reference to FIG. 11, the first channel can have a first (e.g., upper) wall and a second (e.g., lower) wall, and the second channel can have a third (e.g., upper) wall and a fourth (e.g., lower) wall. Each of the first wall, second wall, third wall, and fourth wall can extend in different planes, each plane being parallel to the axial length of the shunt body. That is, the various walls can be at different "heights" within the shunt body. In some embodiments, this can be accomplished using the configuration shown in FIG. 11, in which a first channel 1122 and a second channel 1124 are defined in a first layer 1102. However, in other embodiments, the first channel and the second channel may be defined, or at least partially defined, in different layers and / or in two or more layers, such as in the embodiments described above with reference to Figures 8A-8D.

[0093] The fluidic resistor networks 1000 and 1100 are provided merely as additional examples of variations of the fluidic resistor networks described herein. As will be appreciated by those skilled in the art, the present technology can include other fluidic resistor networks than those explicitly described and illustrated herein. Indeed, additional examples of fluidic resistor networks that can be implemented using the present technology are described in U.S. Patent Application Publication No. 2022 / 0142818, the disclosure of which is incorporated herein by reference.

[0094] The present technology may provide additional advantages beyond those explicitly described herein. For example, the present technology may provide improved surface quality for the drainage assembly, the working assembly, and / or the shunt system, better mechanical properties of the drainage assembly, the working assembly, and / or the shunt system, and / or allow for greater selection of materials used to manufacture the drainage assembly, the working assembly, and / or the shunt system. EXAMPLES

[0095] Several aspects of the present technology are described in the following examples. Example 1. An implantable shunt for treating a patient, comprising: A first layer; a second layer sealingly bonded to the first layer; a network of fluidic resistors including at least a first channel having a first resistance and a second channel in parallel with the first channel and having a second resistance; a first channel is at least partially defined in the first layer; a second channel is at least partially defined in the second layer; An implantable shunt, wherein when the implantable shunt is implanted in a patient, the first channel and the second channel are each configured to drain fluid from a first body region to a second body region of the patient. Example 2. the first layer defines a first plane; the second layer defines a second plane; The implantable shunt of Example 1, wherein the first plane and the second plane are parallel. Example 3. An implantable shunt as described in Example 2, wherein the first plane and the second plane are parallel to a longitudinal axis of the implantable shunt. Example 4. An implantable shunt as described in Example 2, wherein the first plane and the second plane are perpendicular to a longitudinal axis of the implantable shunt. Example 5. An implantable shunt as described in any of Examples 1 to 4, wherein the first channel is fluidly parallel to the second channel such that the first channel defines a first flow path at least partially through the shunt and the second channel defines a second flow path at least partially through the shunt that is different from the first flow path. Example 6. An implantable shunt according to any of Examples 1 to 5, wherein the first resistance is different from the second resistance. Example 7. An implantable shunt according to any of Examples 1 to 6, wherein the second channel is longer than the first channel and the second resistance is greater than the first resistance. Example 8. An implantable shunt according to any of Examples 1 to 7, wherein at least one of the first channel or the second channel is helical and / or serpentine in shape. Example 9. The implantable shunt of Example 8, wherein both the first channel and the second channel are helical and / or serpentine in shape. Example 10. The implantable shunt of any of Examples 1 to 9, wherein the implantable shunt is an intraocular shunt and the first body region is the anterior chamber of the patient's eye. Example 11. An implantable shunt for treating a patient, comprising: A first layer; a second layer sealingly bonded to the first layer; a network of fluidic resistors including at least a first channel having a first resistance and a second channel in parallel with the first channel and having a second resistance; a first channel is at least partially defined in the first layer; the second channel includes a first portion at least partially defined in the first layer and a second portion at least partially defined in the second layer; An implantable shunt, wherein when the implantable shunt is implanted in a patient, the first channel and the second channel are each configured to drain fluid from a first body region to a second body region of the patient. Example 12. An implantable shunt as described in Example 11, wherein the first channel is fluidly parallel to the second channel such that the first channel defines a first flow path at least partially through the shunt, and the second channel defines a second flow path at least partially through the shunt that is different from the first flow path. Example 13. The implantable shunt of example 11 or 12, wherein the first resistance is different from the second resistance. Example 14. An implantable shunt according to any of Examples 11 to 13, wherein the second channel is longer than the first channel and the second resistance is greater than the first resistance. Example 15. An implantable shunt according to any of Examples 11 to 14, wherein the first channel is substantially straight and the second channel is helical and / or serpentine in shape. Example 16. An implantable shunt according to any of Examples 11 to 15, wherein the network of fluidic resistors further comprises a third channel. Example 17. The implantable shunt of Example 16, wherein the third channel is configured to receive fluid from both the first channel and the second channel. Example 18. The implantable shunt of example 16 or 17, wherein the third channel has a third resistance, the third resistance being less than the first resistance and the second resistance. Example 19. An implantable shunt according to any of Examples 16 to 18, wherein the third channel is at least partially defined within the first layer. Example 20. An implantable shunt according to any of Examples 16 to 18, wherein the third channel is defined at least partially within the second layer. Example 21. An implantable shunt described in any of Examples 11 to 20, wherein the fluid resistor network further includes a bypass channel, the bypass channel extending between the inflow port and a portion of the second channel between the first portion and the second portion. Example 22. the first layer defines a first plane; the second layer defines a second plane; 22. The implantable shunt of any of Examples 11 to 21, wherein the first plane and the second plane are parallel to a longitudinal axis of the implantable shunt. Example 23. An implantable shunt according to any of Examples 11 to 22, wherein the first layer and the second layer each have a thickness of less than about 100 microns. Example 24. An implantable shunt according to any of Examples 11 to 22, wherein the first layer and the second layer each have a thickness of less than about 50 microns. Example 25. An implantable shunt according to any of Examples 11 to 22, wherein the first layer and the second layer each have a thickness of less than about 25 microns. Example 26. The implantable shunt of any of Examples 11 to 25, further comprising a third layer. Example 27. The implantable shunt of Example 26, wherein the third layer is composed of a different material than the first layer and / or the second layer. Example 28. An implantable shunt as described in Example 26 or 27, wherein the third layer comprises an actuator housing configured to accommodate an actuator operable to selectively control fluid flow through the first channel and / or the second channel. Example 29. An implantable shunt as described in Example 26 or 27, wherein a third layer is disposed between the first layer and the second layer, the third layer including a connector fluidly coupling the first portion of the second channel and the second portion of the second channel. Example 30. The implantable shunt of any of Examples 11 to 29, wherein the implantable shunt is an intraocular shunt and the first body region is the anterior chamber of the patient's eye. Example 31. An implantable shunt for treating a patient, comprising: a first planar layer having a first thickness between 10 microns and 500 microns; a second planar layer having a second thickness between 10 microns and 500 microns, the second planar layer sealingly bonded to the first planar layer; a network of fluidic resistors including at least a first channel having a first resistance and a second channel in parallel with the first channel and having a second resistance; a first channel is at least partially defined in the first layer; a second channel is at least partially defined in the second layer; An implantable shunt, wherein the first channel and the second channel are each configured to drain fluid from a first body region to a second body region of a patient when the implantable shunt is implanted in the patient. Example 32. An implantable shunt as described in Example 31, wherein the first channel is fluidly parallel to the second channel such that the first channel defines a first flow path at least partially through the shunt, and the second channel defines a second flow path at least partially through the shunt that is different from the first flow path. Example 33. The implantable shunt of example 31 or 32, wherein the first resistance is different from the second resistance. Example 34. the first layer defines a first plane; the second layer defines a second plane; 34. The implantable shunt of any of Examples 31 to 33, wherein the first plane and the second plane are parallel to a longitudinal axis of the implantable shunt. Example 35. An implantable shunt according to any of Examples 31 to 34, wherein the first thickness is between 10 microns and 100 microns and the second thickness is between 10 microns and 100 microns. Example 36. An implantable shunt according to any of Examples 31 to 34, wherein the first thickness is between 10 microns and 50 microns and the second thickness is between 10 microns and 50 microns. Example 37. An implantable shunt according to any of Examples 31 to 36, wherein the first thickness and the second thickness are approximately the same. Example 38. An implantable shunt according to any of Examples 31 to 36, wherein the first thickness and the second thickness are different. Example 39. The implantable shunt of any of Examples 31 to 38, further comprising a third layer. Example 40. The implantable shunt of Example 39, wherein the third layer is composed of a different material than the first layer and / or the second layer. Example 41. An implantable shunt as described in Example 39 or 40, wherein the third layer comprises an actuator housing configured to accommodate an actuator operable to selectively control fluid flow through the first channel and / or the second channel. Example 42. The implantable shunt of any of Examples 31 to 41, wherein the implantable shunt is an intraocular shunt and the first body region is the anterior chamber of the patient's eye. Example 43. An implantable shunt for treating a patient, comprising: A shunt body; a first channel extending at least partially through the shunt body, the first channel having at least a first wall and a second wall that at least partially define a void space of the first channel; a second channel extending at least partially through the shunt body, the second channel having at least a third wall and a fourth wall at least partially defining a void space of the second channel; An implantable shunt, wherein the first wall, the second wall, the third wall, and the fourth wall each extend in a different plane parallel to the axial length of the shunt body. Example 44. An implantable shunt as described in Example 43, wherein the shunt body comprises a plurality of sealing bonding layers. Example 45. The implantable shunt of Example 44, wherein the void space of the first channel and the void space of the second channel are defined in separate layers. Example 46. The implantable shunt of Example 44, wherein the void space of the first channel and the void space of the second channel are defined in the same layer. Example 47. The shunt body is a first layer at least partially defining a void space of the first channel; and a second layer, the second layer comprising at least one of the first wall or the second wall. Example 48. The shunt body is a first layer at least partially defining a void space of the first channel and a void space of the second channel; a second layer sealingly coupled to the first side of the first layer, the second layer including the first wall or the second wall; and a third layer sealingly bonded to a second side of the first layer, the second layer comprising a third wall or a fourth wall. Example 49. A system for shunting a fluid, comprising: a carriage element including a slot and an at least partially hollow interior; a plurality of drainage elements disposed within an interior of the carriage element, each drainage element of the plurality of drainage elements comprising: The entrance and A drainage lumen portion; a plurality of drainage elements including a channel fluidly coupling the inlet and the drainage lumen portion; A system in which the individual drainage lumen portions of the individual drainage elements are at least partially aligned to form a common drainage lumen extending through at least a portion of the carriage element. Example 50. The system of example 49, wherein multiple drainage elements are linearly aligned within the carriage in a stacked configuration. Example 51. The system of example 49 or 50, wherein the channel has a serpentine shape, a spiral shape, a zigzag shape, a curved shape, or a straight shape. Example 52. A system described in any of Examples 49 to 51, wherein the drainage lumen has a rectangular, circular, elliptical, curvilinear, triangular, square, rectangular, rectilinear, pentagonal, or hexagonal shape. Example 53. A system described in any of Examples 49 to 52, wherein the carriage element has a circular, elliptical, triangular, square, rectangular, pentagonal, hexagonal, curved, or rectilinear shape, and each of the one or more drainage elements has a shape corresponding to the carriage element shape. Example 54. Each drainage element comprises: An interface surface; a protrusion extending from the interface surface; the projection includes an inlet; 54. The system of any of Examples 49 to 53, wherein the inlet opening is perpendicular to the interface surface. Example 55. A system described in any of Examples 49 to 54, wherein the one or more drainage elements include a first drainage element having a first drainage lumen portion and a second drainage element having a second drainage lumen portion, and the first drainage lumen portion and the second drainage lumen portion at least partially form a common drainage lumen. Example 56. A system described in any of Examples 49 to 55, wherein one or more drainage elements are bonded to each other via at least one of adhesive, ultrasonic welding, heat fusion, heat reflow, and / or one or more inherent adhesive properties of the drainage elements. Example 57. The one or more drainage elements include a first drainage element and a second drainage element, the first drainage element includes a first channel having a first length corresponding to a first fluid resistance; 57. A system described in any of Examples 49 to 56, wherein the second drainage element includes a second channel having a second length corresponding to a second fluid resistance. Example 58. The system of example 57, wherein the first length is greater than the second length, and the first length corresponds to a first fluid resistance greater than the second fluid resistance. Example 59. Each of the one or more drainage elements is one or more alignment elements; and one or more alignment openings configured to receive a corresponding one of the one or more alignment elements; A system described in any of Examples 49 to 58, wherein the one or more alignment elements and the one or more alignment openings are configured to linearly align multiple drainage elements in a stacked configuration. Example 60. The system of any of Examples 49 to 59, further comprising an actuation assembly having a plurality of actuators, each actuator of the plurality of actuators configured to selectively control the flow of fluid through a corresponding inlet. Example 61 A system described in any of Examples 49 to 60, wherein the channels have a length greater than the height of the corresponding drainage elements. Example 62. An actuation assembly for use with a shunt system, comprising: a housing containing one or more wells; For one or more individual wells, an actuator disposed within the well, a gate element having a central portion, a first end portion extending from a first side of the central portion and generally perpendicular to a longitudinal axis of the central portion, and a second end portion extending from a second side of the central portion and generally perpendicular to the longitudinal axis of the central portion; one or more first actuating elements extending between the first end and the housing; one or more second actuating elements extending between the second end and the housing; an actuator, wherein a plurality of first actuating elements are configured to slidably move the gate element in a first direction and a plurality of second actuating elements are configured to slidably move the gate element in a second direction. Example 63. The actuating assembly of example 62, wherein the one or more first actuating elements and the second actuating element are comprised of Nitinol. Example 64. The actuation assembly of example 62 or 63, further comprising a priming element coupled to the one or more second actuation elements and opposite the second end. Example 65. The actuation assembly of Example 64, wherein each of the one or more wells further comprises a priming surface, and wherein the one or more second actuation elements are configured to be deformed relative to a preferred geometric shape when the priming element is coupled to the priming surface. Example 66. An actuation assembly described in any of Examples 62 to 65, wherein at least one of the one or more first actuation elements and / or the one or more second actuation elements has an hourglass shape. Example 67. An actuation assembly described in any of Examples 62 to 66, wherein the respective surfaces of the gate element, the plurality of first actuation elements, and the plurality of second actuation elements are coplanar.

[0096] conclusion The above detailed description of the embodiments of the present technology is not intended to be exhaustive or to limit the present technology to the precise forms disclosed above. Although specific embodiments and examples of the present technology are described above for illustrative purposes, those skilled in the art will recognize that various equivalent modifications are possible within the scope of the present technology. For example, any of the features of the intraocular shunt described herein can be combined with any of the features of the other intraocular shunt described herein, and vice versa. Furthermore, although steps are presented in a given order, in alternative embodiments, steps may be performed in a different order. Various embodiments described herein may also be combined to provide further embodiments.

[0097] From the foregoing, it will be understood that, while specific embodiments of the present technology have been described herein for purposes of illustration, 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 present technology. Where the context permits, singular or plural terms may also include the plural or singular terms, respectively.

[0098] Unless the context clearly dictates otherwise, throughout the description and examples, words such as "comprise", "comprising", and the like, are to be construed in an inclusive sense, i.e., "including, but not limited to", and not in 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 of connections 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 each be in the plural or singular. As used herein, the phrase "and / or" appearing in "A and / or B" may refer to A only, B only, or both A and B. Additionally, the term "comprising" is used throughout to mean including at least the recited features, without excluding any more of the same features and / or other features of additional types. It will also be understood that, although certain embodiments have been described herein for purposes of illustration, various modifications may be made without departing from the technology. Furthermore, although 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

**Claim 1** An implantable shunt for treating a patient, said implantable shunt comprising: a first layer; a second layer hermetically bonded to said first layer; a network of fluid resistors including at least a first channel having a first resistance and a second channel parallel to said first channel and having a second resistance; said first channel being at least partially defined within said first layer; said second channel being at least partially defined within said second layer; an implantable shunt configured such that when said implantable shunt is implanted in said patient, said first channel and said second channel each discharge fluid from a first body region within said patient to a second body region. **Claim 2** said first layer defining a first plane; said second layer defining a second plane; The implantable shunt according to claim 1, wherein said first plane and said second plane are parallel. **Claim 3** The implantable shunt according to claim 2, wherein said first plane and said second plane are parallel to the longitudinal axis of said implantable shunt. **Claim 4** The implantable shunt according to claim 2, wherein said first plane and said second plane are perpendicular to the longitudinal axis of said implantable shunt. **Claim 5** The implantable shunt according to claim 1, wherein said first channel defines a first flow path passing at least partially through said shunt, and said second channel defines a second flow path passing at least partially through said shunt different from said first flow path, such that said first channel is in fluid parallel with said second channel. **Claim 6** The implantable shunt according to claim 1, wherein said first resistance is different from said second resistance. **Claim 7** The implantable shunt according to claim 1, wherein said second channel is longer than said first channel and said second resistance is greater than said first resistance. **Claim 8** The implantable shunt according to claim 1, wherein at least one of said first channel or said second channel is in a helical and / or serpentine shape. **Claim 9** The implantable shunt according to claim 8, wherein both said first channel and said second channel are in a helical and / or serpentine shape. **Claim 10** The implantable shunt according to claim 1, wherein the implantable shunt is an intraocular shunt and the first body region is the anterior chamber of the patient's eye.

11. An implantable shunt for treating a patient, the implantable shunt comprising: a first flat layer having a first thickness of 10 microns to 500 microns; a second flat layer having a second thickness of 10 microns to 500 microns, the second flat layer being sealingly bonded to the first flat layer; a network of fluid resistors including at least a first channel having a first resistance and a second channel having a second resistance, the second channel being in parallel with the first channel; the first channel being at least partially defined within the first layer; the second channel being at least partially defined within the second layer; the first channel and the second channel each being configured to drain fluid from a first body region within the patient to a second body region when the implantable shunt is implanted in the patient.

12. The implantable shunt according to claim 11, wherein the first channel defines a first flow path passing at least partially through the shunt, and the second channel defines a second flow path passing at least partially through the shunt different from the first flow path, and the first channel is in fluid parallel with the second channel.

13. The implantable shunt according to claim 11, wherein the first resistance is different from the second resistance.

14. the first layer defining a first plane; the second layer defining a second plane; The implantable shunt according to claim 11, wherein the first plane and the second plane are parallel to the longitudinal axis of the implantable shunt.

15. The implantable shunt according to claim 11, wherein the first thickness is 10 microns to 100 microns and the second thickness is 10 microns to 100 microns.

16. The implantable shunt according to claim 11, wherein the first thickness is 10 microns to 50 microns and the second thickness is 10 microns to 50 microns.

17. The implantable shunt according to claim 11, wherein the first thickness and the second thickness are substantially the same.

18. The implantable shunt according to claim 11, wherein the first thickness and the second thickness are different. **Claim 19** The implantable shunt according to claim 11, further comprising a third layer. **Claim 20** The implantable shunt according to claim 19, wherein the third layer is composed of a material different from that of the first layer and / or the second layer. **Claim 21** The implantable shunt according to claim 19, wherein the third layer includes an actuator housing configured to accommodate an actuator operable to selectively control the flow of fluid through the first channel and / or the second channel. **Claim 22** The implantable shunt according to claim 11, wherein the implantable shunt is an intraocular shunt and the first body region is the anterior chamber of the patient's eye.

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