Fluid Delivery to the Eye's Flow Channels

Abstract

A cannula adapter is disclosed for directing a catheter out of a cannula and dispensing fluid from a reservoir. The cannula adapter includes a first slidable member operable to connect to the catheter such that distal movement of the first slidable member causes the catheter to move in and out of the cannula. The cannula adapter includes a second slidable member operable to connect to the plunger and reservoir such that proximal and subsequent distal movement of the second slidable member operable to dispense fluid from the reservoir and out of the catheter.

Description

[Technical Field]

[0001] Incorporation by reference to priority application This application claims priority to U.S. Provisional Patent Application No. 63 / 023,162, filed May 11, 2020, the entire contents of which are hereby incorporated by reference. [Background technology]

[0002] Delivery of small amounts of viscoelastic agents to Schlemm's canal, collector channels, and the downstream episcleral venous network has been shown to reduce intraocular pressure in patients with open-angle glaucoma. Summary of the Invention [Means for solving the problem]

[0003] According to some embodiments, a device for delivering a fluid (e.g., a viscoelastic, surgical fluid, targeted drug, chemical, solution, therapeutic agent, or other liquid or gas) includes a housing (e.g., a proximal housing) having a fillable reservoir for storing the fluid and a connector configured to be fluidly coupled to a pre-filled fluid canister or vial (e.g., an ocular viscoelastic device or syringe). The device further includes a cannula having a proximal end, a distal end, and a lumen, the proximal end of the cannula coupled to the distal end of the housing, the distal end of the cannula configured to enter the patient's eye through a corneal incision, and the lumen of the cannula extending from the proximal end to the distal end of the cannula. The device also includes a catheter having a proximal end, a distal end, and a lumen, the proximal end of the catheter fluidly coupled to the reservoir, and the lumen extending from the proximal end of the catheter to the distal end of the catheter.

[0004] The fluid delivery device may also include a first actuator configured to, upon activation, advance the catheter along the lumen of the cannula and cause the catheter to exit the distal end of the cannula. The fluid delivery device may further include a second actuator configured to, upon activation, cause fluid stored in the reservoir to flow through the catheter and exit the distal end of the catheter. The catheter lumen is configured to allow fluid stored in the reservoir to flow through the catheter and into the patient's eye. The catheter is sized to extend out of the distal end of the cannula along the entire 360° circumference of the patient's Schlemm's canal upon activation of the first actuator.

[0005] In some embodiments, the distal end of the cannula comprises a scoop with a pointed tip. The distal end portion of the cannula may be pre-curved or angled. At least the distal portion of the catheter may be pre-formed to approximately follow or match the radius of curvature of Schlemm's canal.

[0006] In some embodiments, at least a distal portion of the catheter is flexible. In some embodiments, the cannula comprises a rigid material.

[0007] In some embodiments, the distal end of the cannula comprises one or more notches (e.g., one notch, two adjacent notches) and / or two or more anchors to form a cutting tip or surface. In some embodiments, the distal end of the cannula comprises a beveled tip.

[0008] The housing may further comprise a channel (e.g., a sliding channel). The first actuator may include a first sliding trigger adapted to move axially within the channel between a proximal position and a distal position, and the second actuator may include a second sliding trigger adapted to move axially within the channel between a proximal position and a distal position. When the first sliding trigger is in the proximal position, the distal end of the catheter is located between the proximal and distal ends of the cannula. When the first sliding trigger is in the distal position, the distal end of the catheter has advanced past the distal end of the cannula. Movement (e.g., axial movement) of the second sliding trigger between the proximal and distal positions may cause a predetermined amount of fluid to be dispensed through the distal end of the catheter. In some embodiments, the amount of axial movement of the second sliding trigger along the channel corresponds to the amount of fluid dispensed from the catheter.

[0009] In some configurations, the catheter is positioned and sized such that the distal end of the catheter is aligned with the distal end of the cannula when the first actuator is retracted to its proximal-most position within the channel, and the first and second actuators are configured to be actuable by one operator or user with one hand.

[0010] According to some embodiments, a device configured to deliver a fluid (e.g., a viscoelastic agent) to at least one ocular drainage pathway (e.g., Schlemm's canal, a collector channel, the episcleral venous system, the subretinal space, or the subscleral space) includes a housing with a proximal connector and a reservoir, the reservoir configured to store the fluid, and the proximal connector configured to be fluidly coupled to a drug-filled ocular viscoelastic agent device or other fluid source. The device further includes a cannula configured to be inserted into Schlemm's canal through a corneal incision, the cannula including a lumen. The device also includes a catheter having a proximal end, a distal end, and a lumen, the proximal end fluidly coupled to the reservoir, the distal end configured to advance past the distal end of the cannula, and the lumen configured to allow fluid stored in the reservoir to flow through the catheter and be dispensed through the distal end of the catheter.

[0011] The device further includes a first slidable trigger configured to be moved (e.g., by a finger or thumb) between an inactive position and an active position to cause the catheter to advance along the lumen of the cannula and past the distal end of the cannula. The device also includes a second slidable trigger configured to be moved between an inactive position and an active position to cause fluid stored in the reservoir to be dispensed through the lumen of the catheter and into Schlemm's canal.

[0012] According to some embodiments, a device configured to deliver fluid to at least one ocular drainage pathway includes a reservoir configured to store fluid, a cannula including a lumen and configured to enter a patient's eye through a corneal incision, and a catheter configured to advance along the cannula's lumen. The catheter includes a lumen configured to allow fluid stored in the reservoir to be dispensed through the catheter. The device also includes a first actuator and a second actuator, where actuation of the first actuator causes the catheter to advance along the cannula and actuation of the second actuator causes fluid to be dispensed from the reservoir through the catheter.

[0013] In some embodiments, the second actuator is configured to slide between an unactuated position and an actuated position to cause fluid to be dispensed, the amount of fluid dispensed being based at least in part on the distance between the unactuated position and the actuated position.

[0014] In some embodiments, the catheter includes a bulbous distal tip. At least a portion of the catheter may include a phosphorescent colorant. At least a portion of the catheter may include contrast marks spaced along the length of the catheter. At least the distal end of the cannula may be constructed of a shape memory material. In some embodiments, at least the distal end of the cannula includes notches to facilitate articulation of the distal end of the cannula.

[0015] According to some embodiments, a cannula adapter configured for use with a drug-filled ocular viscoelastic device to deliver a viscoelastic agent up to a full 360° circumference of Schlemm's canal in a single pass through a single entry point into Schlemm's canal includes a proximal housing having a sliding channel therein and a connector configured for axial back-and-forth movement within the sliding channel. The proximal end of the connector is configured to be fluidly coupled to the drug-filled ocular viscoelastic device. The adapter further includes an outer cannula having a proximal end coupled to the distal end of the housing, a distal end configured to be inserted into Schlemm's canal through a corneal incision, and an elongated cannula portion with a lumen extending from the proximal end to the distal end of the outer cannula. The adapter includes an inner catheter having a proximal end fluidly coupled to the distal end of the connector, a blunt or rounded distal end configured to advance along at least a portion of the circumference of Schlemm's canal, and an elongated catheter portion with a lumen extending from the proximal end of the inner catheter to the distal end of the inner catheter. The inner catheter is sized to fit within and advance along the lumen of the outer cannula. The lumen of the inner catheter is configured to deliver viscoelastic agent from the ocular viscoelastic agent device to Schlemm's canal. The inner catheter is sized to extend out of the distal end of the outer cannula along the entire 360° circumference of Schlemm's canal when the connector is advanced to its distal-most position within the sliding channel.

[0016] In some embodiments, the distal end of the outer cannula comprises a spatula with a pointed tip. In some embodiments, the distal end of the outer cannula is pre-curved. At least a distal portion of the inner catheter may be pre-formed to approximately follow the radius of curvature of Schlemm's canal. At least a distal portion of the inner catheter may be flexible. The outer cannula may comprise a rigid material. The inner catheter may be positioned and sized such that the distal end of the inner catheter will be aligned with the distal end of the outer cannula when the connector is retracted to its proximal-most position within the sliding channel.

[0017] In some embodiments, the cannula adapter further comprises a fluid adjustment adapter configured to attach to the proximal end of the drug-filled ocular viscoelastic device. The cannula adapter may further comprise a sliding trigger mechanically coupled to the connector and adapted for axial movement relative to the housing.

[0018] According to some embodiments, a cannula adapter configured for use with a drug-filled ocular viscoelastic device to deliver a viscoelastic agent to at least one ocular drainage tract includes a proximal housing having a sliding channel therein and a connector configured to move axially back and forth within the sliding channel. The proximal end of the connector is configured to be fluidly coupled to the drug-filled ocular viscoelastic device. The cannula adapter further includes an outer cannula having a proximal end coupled to the distal end of the housing, a distal end configured to be inserted through a corneal incision into Schlemm's canal, and an elongated cannula portion with a lumen extending from the proximal end to the distal end of the outer cannula. The cannula adapter also includes an inner catheter having a proximal end fluidly coupled to the distal end of the connector, a distal end configured to navigate along at least a portion of the circumference of Schlemm's canal, and an elongated catheter portion with a lumen extending from the proximal end to the distal end of the inner catheter. The lumen of the inner catheter is configured to deliver viscoelastic agent from the ocular viscoelastic agent device to Schlemm's canal.

[0019] According to some embodiments, a cannula adapter configured to deliver a viscoelastic agent to at least one ocular drainage tract comprises a proximal housing, the proximal housing comprising a rotatable dial and an actuator. The cannula adapter further comprises an outer cannula, the outer cannula having a proximal end mechanically coupled to the proximal housing, a distal end configured to be inserted through a corneal incision into Schlemm's canal, and an elongated cannula portion with a lumen extending from the proximal end to the distal end of the outer cannula. The cannula adapter also comprises an inner catheter, the inner catheter having a proximal end operably coupled to the rotatable dial, a distal end configured to advance along at least a portion of the circumference of Schlemm's canal, and an elongated catheter portion with a lumen extending from the proximal end of the inner catheter to the distal end of the inner catheter. The elongated catheter portion of the inner catheter is positioned to fit within and advance along the outer cannula. The adapter is configured such that rotation of the dial causes advancement of the inner catheter along the outer cannula and then around Schlemm's canal, up to a 360° circumference of Schlemm's canal. The proximal end of the inner catheter is fluidly coupled to a fluid dispensing mechanism. Operator actuation of the actuator allows fluid to be dispensed from a fluid reservoir in the fluid dispensing mechanism, through the inner catheter, and into Schlemm's canal.

[0020] In some embodiments, the actuator comprises a button adapted to be pressed by an operator's finger or thumb, and the dial adapted to be rotated by the operator's thumb or finger while the adapter is held in one of the operator's hands. The reservoir may be capable of being filled with any amount and any type of fluid.

[0021] The fluid dispensing mechanism may include a spring-driven system. The fluid dispensing mechanism may include a resilient or flexible tube adapted to be infused and expelled. In some embodiments, the fluid dispensing mechanism includes a peristaltic pump. The inner catheter may include a bulbous distal tip. At least a portion of the inner catheter may include a phosphorescent colorant. At least a portion of the inner catheter may include contrast marks spaced along the length of the inner catheter. At least a distal end of the outer cannula may be constructed of a shape memory material. At least a distal end of the outer cannula may include notches to facilitate articulated deformation of the distal end of the outer cannula. [Brief explanation of the drawings]

[0022] [Figure 1A] 1 illustrates a top view of an embodiment of a cannula adapter in an undeployed configuration. [Figure 1B] 1 illustrates a top view of an embodiment of a cannula adapter in a fully deployed configuration. [Figure 1C] 1B illustrates an example of how the cannula adapter of FIG. 1A can be attached to a standard ocular viscoelastic surgical device, such as an ocular viscoelastic syringe. [Figure 1D] 1B illustrates an example of how the cannula adapter of FIG. 1A can be attached to a standard ocular viscoelastic surgical device, such as an ocular viscoelastic syringe. [Figure 1E] 1B illustrates an example of a surgical implementation of access and insertion of the cannula adapter of FIG. 1A. [Figure 1F] 1B illustrates an example of a surgical implementation of access and insertion of the cannula adapter of FIG. 1A. [Figure 1G] 1B illustrates another example of a surgical implementation of access and insertion of the cannula adapter of FIG. 1A. [Figure 1H] 1B illustrates another example of a surgical implementation of access and insertion of the cannula adapter of FIG. 1A. [Figure 1I]1C illustrates a top view of a system comprising the cannula adapter of FIG. 1A combined with an additional adapter coupled to the proximal end of the standard ocular viscous agent surgical device of FIG. 1C to facilitate regulated fluid delivery. [Figure 2A] 10 illustrates a side view of another embodiment of a cannula adapter having a sliding trigger in an undeployed configuration. [Figure 2B] 10 illustrates a side view of another embodiment of a cannula adapter having a sliding trigger in a fully deployed configuration. [Figure 2C] 2B illustrates a side view of an adaptation of the embodiment of FIG. 2A with a coupler to facilitate pneumatic fluid delivery. [Figure 2D] 2D illustrates an example embodiment of a pneumatic system adapted for use with the cannula adapter of FIG. 2C. [Figure 2E] 2D illustrates an example embodiment of a pneumatic system adapted for use with the cannula adapter of FIG. 2C. [Figure 3A] 10 illustrates another embodiment of a cannula adapter that utilizes a compressed spring to maintain force on an ocular viscous agent device. [Figure 3B] 3B illustrates a schematic example of an operation method for the cannula adapter of FIG. 3A. [Figure 3C] 3B illustrates a schematic example of an operation method for the cannula adapter of FIG. 3A. [Figure 3D] 3B illustrates a schematic example of an operation method for the cannula adapter of FIG. 3A. [Figure 4A] 10A and 10B illustrate a schematic of a three-layer assembly that can be incorporated into any of the cannula adapter embodiments. [Figure 4B] 10A and 10B illustrate a schematic of a three-layer assembly that can be incorporated into any of the cannula adapter embodiments. [Figure 4C] 10A and 10B illustrate a schematic of a three-layer assembly that can be incorporated into any of the cannula adapter embodiments. [Figure 4D] FIG. 4D is a schematic, partially enlarged side view of the distal tip of the three-layer assembly of FIG. 4C. [Figure 4E]4A, 4B, and 4C illustrate an example of an operating mode for the three-layer assembly. [Figure 4F] 4A, 4B, and 4C illustrate an example of an operating mode for the three-layer assembly. [Figure 4G] 4A, 4B, and 4C illustrate an example of an operating mode for the three-layer assembly. [Figure 5A] 10A-10C schematically illustrate embodiments of an internal support mechanism that may be incorporated into any of the cannula adapter embodiments. [Figure 5B] 10A-10C schematically illustrate embodiments of an internal support mechanism that may be incorporated into any of the cannula adapter embodiments. [Figure 6A] 10A-10C schematically illustrate embodiments of an internal support mechanism that may be incorporated into any of the cannula adapter embodiments. [Figure 6B] 10A-10C schematically illustrate embodiments of an internal support mechanism that may be incorporated into any of the cannula adapter embodiments. [Figure 7A] 10A-10C schematically illustrate embodiments of an internal support mechanism that may be incorporated into any of the cannula adapter embodiments. [Figure 7B] 10A-10C schematically illustrate embodiments of an internal support mechanism that may be incorporated into any of the cannula adapter embodiments. [Figure 8A] 10A-10C schematically illustrate embodiments of an internal support mechanism that may be incorporated into any of the cannula adapter embodiments. [Figure 8B] 10A-10C schematically illustrate embodiments of an internal support mechanism that may be incorporated into any of the cannula adapter embodiments. [Figure 9A] 1A-1C are schematic illustrations of an external top view of an embodiment of a cannula adapter having a dial delivery system, illustrating an example mode of operation of the cannula adapter. [Figure 9B] 1A-1C are schematic illustrations of an external top view of an embodiment of a cannula adapter having a dial delivery system, illustrating an example mode of operation of the cannula adapter. [Figure 9C]9B is a schematic illustration of an internal top view showing an example of an operating mode of the cannula adapter of FIG. 9A. [Figure 9D] 9B is a schematic illustration of an internal top view showing an example of an operating mode of the cannula adapter of FIG. 9A. [Figure 9E] 9B is a schematic side view illustrating an example of an operating method for the cannula adapter of FIG. 9A. [Figure 9F] 9B is a schematic side view illustrating an example of an operating method for the cannula adapter of FIG. 9A. [Figure 10A] 10A-10C illustrate an example of a mode of operation for a cannula adapter having a spring-driven system with a refillable reservoir. [Figure 10B] 10A-10C illustrate an example of a mode of operation for a cannula adapter having a spring-driven system with a refillable reservoir. [Figure 10C] 10A-10C illustrate an example of a mode of operation for a cannula adapter having a spring-driven system with a refillable reservoir. [Figure 11A] 10A-10C illustrate schematic diagrams of exemplary modes of operation for a fillable cannula adapter having a threaded plunger fluid delivery system with reverse flow. [Figure 11B] 10A-10C illustrate schematic diagrams of exemplary modes of operation for a fillable cannula adapter having a threaded plunger fluid delivery system with reverse flow. [Figure 12A] 10A-10C schematically illustrate an example mode of operation of an embodiment of an injectable elastic tube fluid delivery mechanism. [Figure 12B] 10A-10C schematically illustrate an example mode of operation of an embodiment of an injectable elastic tube fluid delivery mechanism. [Figure 13A] 1A-1C schematically illustrate embodiments of peristaltic fluid delivery mechanisms. [Figure 13B] 1A-1C schematically illustrate embodiments of peristaltic fluid delivery mechanisms. [Figure 13C] 1A-1C schematically illustrate embodiments of peristaltic fluid delivery mechanisms. [Figure 14] 10 illustrates various examples of visualization-facilitating internal catheter shapes and features that may be incorporated into any of the cannula adapter embodiments. [Figure 15A]10A-10C schematically illustrate an example of the operation of a shape-set cannula that may be incorporated into any of the cannula adapter embodiments. [Figure 15B] 10A-10C schematically illustrate an example of the operation of a shape-set cannula that may be incorporated into any of the cannula adapter embodiments. [Figure 16] 10A and 10B schematically illustrate an embodiment of a cannula having a notched distal tip to facilitate multi-section deformation that may be incorporated into any of the cannula adapter embodiments. [Figure 17A] 10 illustrates a perspective view of another embodiment of a cannula adapter or fluid delivery device. [Figure 17B] 17B illustrates a perspective exploded view of the cannula adapter of FIG. 17A. [Figure 17C] 17B illustrates a cross-sectional view of the cannula adapter of FIG. 17A. [Figure 17D] 17B illustrates a cross-sectional view of the cannula adapter of FIG. 17A. [Figure 17E] 17D illustrates an enlarged cross-sectional view of the cannula adapter of FIG. 17A. [Figure 17F] 17B illustrates an enlarged cross-sectional view of the tip of the cannula adapter of FIG. 17A. [Figure 17G] 17B illustrates a perspective view of the cannula adapter of FIG. 17A without the locking pin. [Figure 17H] 17H illustrates a cross-sectional view of the cannula adapter of FIG. 17G. [Figure 18A] 1 illustrates a view of an outer cannula that may be incorporated into any of the cannula adapter embodiments. [Figure 18B] 1 illustrates a view of an outer cannula that may be incorporated into any of the cannula adapter embodiments. [Figure 18C] 1 illustrates a view of an inner catheter that may be incorporated into any of the cannula adapter embodiments. [Figure 18D] 1 illustrates a view of an inner catheter that may be incorporated into any of the cannula adapter embodiments. [Figure 18E] 1 illustrates a diagram of an example of a distal tip of a cannula of a fluid delivery device. [Figure 18F] 1 illustrates a diagram of an example of a distal tip of a cannula of a fluid delivery device. [Figure 18G] 1 illustrates a diagram of an example of a distal tip of a cannula of a fluid delivery device. [Figure 18H] 1 illustrates a diagram of an example of a distal tip of a cannula of a fluid delivery device. [Figure 19A] 10 illustrates an example mode of operation of another embodiment of a cannula adapter. [Figure 19B] 10 illustrates an example mode of operation of another embodiment of a cannula adapter. DETAILED DESCRIPTION OF THE INVENTION

[0023] Described and illustrated herein are various embodiments of systems, devices, and methods that facilitate the delivery of fluids (e.g., viscoelastic fluids, drugs, chemicals, solutions in liquid or fluid form) to (e.g., into) ocular channels or cavities (e.g., Schlemm's canal, collector channels, downstream episcleral venous network, ocular tissue canals, suprachoroidal space, subconjunctival space, subretinal space) within a mammalian eye (e.g., a human eye or the eye of another mammal, e.g., a monkey or horse). For example, the ocular channels or cavities may be adapted to facilitate drainage of aqueous humor to regulate (e.g., reduce) intraocular pressure. Regulation of intraocular pressure may treat or alleviate symptoms associated with glaucoma or other ocular diseases or conditions.

[0024] According to some embodiments, the systems, devices, and methods described and illustrated herein provide a simple, controlled, and potentially low-cost solution for delivery of viscoelastic agents or other fluids to and along up to 360° of Schlemm's canal and in a single pass or only a single pass through a single minimally invasive incision (e.g., a self-sealing corneal incision).

[0025] According to several embodiments, the systems, devices, and methods described and illustrated herein (i) have lower cost than existing treatment options; (ii) improved ease of use, being less complex than existing treatment options; (iii) are compatible with existing viscoelastic syringes or ocular viscoelastic surgical devices, eliminating the need for a pre-filling step; (iv) improved performance by decoupling dispensing from catheter movement, thereby allowing for precise dispensing location and volume of fluid at any point during the procedure; (v) are minimally invasive, requiring only a single incision; (vi) are configured to treat up to 360° of Schlemm's canal in a single pass; and (vii) do not require extensive training or experience to use. (viii) patient-dependent and / or position-dependent flexibility in the procedure; (ix) one-person operation providing independent control of fluid dispensing and catheter movement; (x) one-handed operation; (xi) components with a single pointed tip; (xii) increased trackability of the internal catheter position within Schlemm's canal; (xiii) accommodating any choice or operator discretion of viscoelastic or other fluid and varying amounts of viscoelastic or other fluid; (xiv) adjustable or fixed volume microbolus dispensing; and / or (xv) all-in-one integrated system replacing multiple separately inserted separate devices.

[0026] According to some embodiments, the systems and devices described herein provide improved performance compared to systems in which the amount of viscoelastic or other fluid is proportional to the return displacement of the delivery catheter, which often results in under-delivery of the viscoelastic or other fluid. Systems involving a fixed delivery volume ignore the logical presumption that the effective treatment volume is patient-dependent and location-dependent. Furthermore, limiting delivery to the return displacement prevents the operator (e.g., surgeon) from delivering fluid through potential obstacles during advancement of the delivery catheter through tissue, such as Schlemm's Canal.

[0027] 1A and 1B schematically illustrate top views of an embodiment of cannula adapter 100 in undeployed and deployed configurations, respectively. Cannula adapter 100 includes connector 105, housing 110, inner catheter 115, and outer cannula 120.

[0028] Connector 105 (e.g., a standard Luer connector) may be adapted to slide along a constrained axial range within housing 110 of cannula adapter 100. Connector 105 may also be constrained in azimuthal rotation. Inner catheter 115 may include a flexible lumen that is introduced through Schlemm's canal and fluidly coupled to the distal end of sliding connector 105. The lumen of inner catheter 115 may extend from the proximal end to the distal end of inner catheter 115. Inner catheter 115 may be adapted to fit within and extend through the lumen of outer cannula 120 such that the distal tip of inner catheter 115 and the distal tip of outer cannula 120 are aligned when sliding connector 105 is in a proximal-most position, such as the undeployed configuration shown in FIG. 1A .

[0029] The proximal end of outer cannula 120 can be coupled to a distal end portion of housing 110 (and to the distal end of sliding channel 122 of the housing within which connector 105 moves axially). When connector 105 is in its distal-most position (e.g., the fully deployed configuration shown in FIG. 1B when connector 105 is pushed forward until it terminates in sliding channel 122 within housing 110), the distal tip of inner catheter 115 can extend a predetermined distance past the distal tip of outer cannula 120. In some embodiments, the predetermined distance can be approximately equal to the circumference of Schlemm's canal (e.g., 360°). The length of the portion of inner catheter 115 extending out from the distal tip of outer cannula 120 when connector 105 is in its distal-most position within sliding channel 122 of housing 110 can be configured to have a length corresponding to an upper range of values ​​(e.g., the largest known value) or a length corresponding to an average or median value for the circumference of Schlemm's canal in a human or other mammal.

[0030] The distal portion of the inner catheter 115 (e.g., the portion extending past at least the distal tip) may be pre-formed (e.g., a shape set using a shape memory material such as a copper-aluminum-nickel alloy or a nickel-titanium alloy) to roughly follow the radius of curvature of Schlemm's canal (e.g., a predetermined median or average value), or may be made of a material that is sufficiently flexible to bend along the outer wall of Schlemm's canal (e.g., polyvinyl chloride, polyetheretherketone, polyethylene, polytetrafluoroethylene, thermoplastic polyurethane, polyamide, polyimide, polymethylmethacrylate (PMMA), acrylonitrile butadiene styrene, silicone and / or other sufficiently flexible materials).

[0031] 1A and 1B may be adapted for use with any standard "off-the-shelf" or commercially available ocular viscoelastic device (OVD) or other viscoelastic delivery device, such as the HEALON® viscoelastic syringe marketed by Johnson & Johnson. For example, a pre-filled ocular viscoelastic device (e.g., syringe) 125 can be inserted into the proximal end of the housing 110 and rotated to tightly lock with the sliding connector 105, as shown in FIG. 1C. As an example of use, an operator (e.g., a clinician or practitioner) can hold the housing 110 with one hand to extend the inner catheter 115 from the outer cannula 120 (e.g., by moving the sliding connector 105), use the other hand to move the syringe 125 forward (e.g., distally or toward the patient) relative to the housing 110 (e.g., by pressing the proximal stop 127 of the syringe 125), and then depress the syringe 125 (e.g., by pressing the proximal plunger actuator 128 of the syringe 125 as shown in FIG. 1D ) to deliver a desired amount of fluid 126 (e.g., a viscoelastic or other ocular viscoelastic device (OVD) fluid). The desired amount may be patient-specific or location-specific and may be determined by the operator as desired and / or required.

[0032] The outer cannula 120 can be inserted through a minimally invasive, temporary, and well-defined corneal incision. The corneal incision may be sized to self-seal without the need for sutures. FIG. 1E illustrates an example method of surgical insertion using a superior insertion approach. As illustrated, the distal portion 121 of the outer cannula 120 may be shaped (e.g., a spatula with a pointed tip) to facilitate penetration of the superior trabecular meshwork (TM) and guide the inner catheter 115 360° into Schlemm's canal (SC), as shown in FIG. 1F. Alternatively, the distal tip of the outer cannula 120 may be inserted using a nasal insertion approach through the nasal trabecular meshwork, as shown in FIGS. 1G and 1H.

[0033] In some embodiments, for example, when using a nasal insertion technique, the inner catheter 115 may be adapted to pass through the first 180° of Schlemm's canal and then advance through the remaining 180° of Schlemm's canal. For example, the distal portion 121 of the outer cannula 120 may be inserted into Schlemm's canal through the trabecular meshwork such that the inner catheter 115 advances from the insertion point through the first 180° of Schlemm's canal and into Schlemm's canal. The inner catheter 115 may then be retracted, and the distal tip 121 of the outer cannula 120 may be rotated or withdrawn from Schlemm's canal and reinserted in the opposite direction from the entry point such that the remaining 180° of Schlemm's canal is traversed by the inner catheter 115. The distal tip of the outer cannula 120 may be pre-curved or flexible enough to bend upon contact with the outer wall of Schlemm's canal. If pre-curved, the distal tip of the outer cannula 120 may have a different curve or bend configuration depending on whether a superior or nasal insertion technique is intended. In some embodiments, only a single 180° section is treated.

[0034] 1I, to facilitate precisely controlled delivery of viscoelastic or other fluids (e.g., drugs, chemicals, solutions, or other liquids) in some embodiments, a fluid control adapter 130 can be attached to the proximal end of a syringe 125. In such embodiments, the plunger handle of the syringe 125 may be removed. In the illustrated embodiment, the fluid control adapter 130 includes a dispenser mounting fixture 132 adapted to mount to the syringe 125, such as a conventional pneumatic adhesive dispenser (e.g., a pneumatic dispenser commercially available from Nordson EFD). The mounting fixture 132 may have a threaded throughbore for receiving a complementary threaded "bolt-type" plunger actuator 133 and a rotatable knob 134. Rotating the knob 134 (and thereby the plunger driver 133) clockwise depresses the internal plunger of the syringe 125, thus dispensing fluid 126 (e.g., a viscoelastic or other OVD fluid). The sensitivity of this dispensing can be adjusted by the pitch of the threads. The fluid regulating adapter 130 can be rigidly connected to the syringe 125, such that axial movement of the adapter 130 (e.g., caused by axial movement of the knob 134 resulting from rotation of the knob 134) can result in extension of the inner catheter 115. The rotatable knob 134 may optionally include a notched head.

[0035] 2A and 2B, cannula adapter 200 may be adapted or modified to include a sliding trigger 202 that is rigidly attached to inner sliding connector 105 (e.g., as a molded-in piece during manufacture) and that is axially slidable relative to housing 110. In that case, instead of pressing a proximal stop on syringe 125 (e.g., pressing proximal plunger actuator 128 of syringe 125 as shown in FIG. 1D ), the operator can extend inner catheter 115 simply by distal movement of the operator's finger or thumb (i.e., toward the patient). The outer surface of sliding trigger 135 may have surface features (e.g., ridges, grooves, etc.) that are adapted to promote grip or friction against the operator's finger or thumb.

[0036] 2C illustrates a further modification or adaptation of the cannula adapter 200 of FIGS. 2A and 2B that allows for single-handed actuation of the inner catheter 115 and dispensing of a viscoelastic or other fluid by an operator. The illustrated embodiment incorporates a pneumatic system 210 that may include the sliding trigger 202 introduced in FIGS. 2A and 2B to extend the inner catheter 115 and that is adapted to pressurize the viscoelastic syringe 125. The pneumatic system 210 is illustrated in expanded and more detailed detail in terms of its components and operation in FIGS. 2D and 2E.

[0037] Pneumatic system 210 can utilize a trigger 212 adapted to be actuated by an operator's finger (e.g., index finger). FIG. 2D illustrates pneumatic system 210 before trigger 212 is depressed, and FIG. 2E illustrates pneumatic system 210 after the trigger is depressed (e.g., pushed away from the patient to compress spring 218). When trigger 212 is depressed (e.g., moved to its actuated position), a miniature valve-release pressurized cartridge 216 (e.g., a PicoCylinder commercially available from Picocyl) can open (e.g., using an attachment similar to a conventional pneumatic adhesive dispenser) to apply pressure to a chamber 214 that is fluidly coupled to the proximal side of the syringe plunger. This arrangement or mechanism can advantageously enable regulated dispensing of a steady, pressurized supply of fluid 126 (e.g., a viscoelastic or other OVD fluid) from syringe 125. When trigger 212 is released, spring 218 can relax to an uncompressed configuration, forcing pressure cartridge 216 back to its nominal position, and chamber 214 can be vented via notch 220 to abruptly stop dispensing, for example, viscoelastic or other fluid. As shown in FIG. 2E , when trigger 142 is depressed, valve 222 in pressure cartridge 216 opens and spring 218 is compressed; when trigger 212 is released, valve 222 closes and spring 218 can be relaxed or extended (e.g., returned to its unactuated position).

[0038] The trigger 212 may include a notch 220 formed in a side of its body. Before the trigger 212 is depressed, the notch 220 may not be fluidly connected to the chamber 214. As the trigger 212 is depressed, the notch 220 may create a passageway between the chamber 214 and the environment. When the trigger 212 is fully compressed and the cartridge 216 opens to pressurize the chamber 214, the notch 220 may be isolated from the environment so that pressure within the chamber 214 is maintained. When the trigger 212 is released and returns to its unactuated position, the notch 220 may create a passageway between the chamber 214 and the environment to vent the chamber 214 to suddenly stop dispensing a viscoelastic or other fluid, for example, as described herein.

[0039] 3A-3D illustrate alternative embodiments of viscoelastic dispensing mechanisms incorporating valves and springs, which may be incorporated into any of the embodiments described herein. FIG. 3A shows a cannula adapter 300 that utilizes a compressed spring 304 to maintain force on a viscoelastic cartridge / plunger 306. As described herein, actuation of a sliding trigger 202 (e.g., sliding it toward the patient) can extend a catheter 115 from the distal end of an outer cannula 120. In the example illustrated in FIG. 3A, a connector 105 can include a dispense button 302 and a valve 308. The dispense button 302 can have an inactivated position and an activated position. When in the inactivated position (as shown in FIG. 3C), the body of the dispense button 302 can block a flow path within the connector 105, preventing, for example, fluid 126 from flowing from the viscoelastic cartridge 306 into the catheter 115. When in the actuated position (e.g., pressed downward to compress spring 310 as shown in FIG. 3D ), a lumen 320 formed within dispense button 302 can connect with the fluid path within connector 105 and between viscoelastic cartridge 306 and catheter 115. When dispense button 302 is released, spring 310 can force dispense button 302 to return to the unactuated position, blocking the fluid path between viscoelastic cartridge 306 and catheter 115.

[0040] In some embodiments, as shown in FIG. 3A, the viscoelastic cartridge 306 includes an optional diaphragm 330, and the connector 105 (e.g., the Luer connector shown in FIG. 1A) can include a hypodermic needle 312 to pierce the diaphragm 330.

[0041] The viscoelastic cartridge 306 may be housed within a single sliding assembly (as shown in FIG. 3A) or may have a separate attachment with a plunger spring 304 (as shown in FIGS. 3B-3D). Referring to FIGS. 3B-3D, which better illustrate the operation of the viscoelastic dispensing mechanism, the thumb slider / trigger 202 may be used to actuate the inner catheter 115 in and out of Schlemm's canal (as shown in FIGS. 3C and 3D), while the dispense button 302 is used to dispense fluid 126 (e.g., viscoelastic or other OVD fluid) from the viscoelastic cartridge 306 (as shown in FIG. 3D).

[0042] According to some embodiments, the cannula adapters described and illustrated herein may be comprised of multiple sliding layers, as illustrated schematically in Figures 4A-4C. The multiple sliding layers may include three layers: a needle assembly 420 including a sharp distal tip designed for penetration through the cornea; a cannula assembly 440 including a tip designed to pass through the anterior chamber and penetrate the trabecular meshwork; and an inner catheter assembly 460 having a blunt or rounded distal tip designed to pass through Schlemm's canal and lumen to deliver viscoelastic agents or other fluids. Figure 4A illustrates the needle assembly 420 of the cannula adapter 400 (shown in Figure 4E), Figure 4B illustrates the cannula assembly 440, and Figure 4C illustrates the inner catheter assembly 460.

[0043] The needle assembly 420 and cannula assembly 440 may include slots as illustrated. The needle assembly 420 may include a body 422, a lumen 404, an upper slot 426, a lower slot 428, and a needle 430. The needle 430 may be integral with the body 422. The slots 426, 428 may be formed on opposite sides of the body 422. In some embodiments, the locations of the slots 426, 428 may differ from the example illustrated in FIG. 4A . The cannula adapter 440 may include a body 442, a lumen 444, an upper slot 446, a cannula rider 448, and a tip 450. The tip 450 and cannula rider 448 may be integral with the body 442 such that movement of the cannula rider 448 can translate to movement of the body 442 and tip 450. The upper slot 446 may be formed on the body 442. The inner catheter assembly 460 can include a body 462, a catheter slider 464, and a catheter 115. The catheter slider 464 and catheter 115 can be integrated with the body such that movement of the catheter slider 464 can be translated into movement of the body 462 and catheter 115.

[0044] The operation and assembled arrangement of the three sliding layers of cannula adapter 400 is shown schematically in Figures 4E-4G. Cannula adapter 440 can be positioned within needle assembly 420 such that upper slot 446 of cannula adapter 440 overlaps at least a portion of upper slot 426 of needle assembly 420 and cannula slider 448 is positioned within lower slot 428 of needle assembly 420. Catheter assembly 460 can be positioned within cannula assembly 440 such that catheter slider 464 is positioned within upper slots 426, 446 of needle assembly 420 and cannula assembly 440, respectively.

[0045] The needle 430 can penetrate the patient's cornea as described herein. The cannula rider 448 can slide within the slot 428 of the needle assembly 420 to slide the cannula assembly 440 within the needle assembly 420. When the cannula rider 448 moves distally (e.g., toward the patient), the tip 450 of the cannula assembly 440 can move distally, for example, penetrating the upper trabecular meshwork (TM) portion of the patient. The slot 446 of the cannula adapter 440 can overlap at least a portion of the slot 426 of the needle assembly 420 to allow the catheter slider 464 to slide distally (e.g., toward the patient) and proximally (e.g., away from the patient) within the slots 426, 446. When the catheter slider 444 is moved distally (e.g., toward the patient), the catheter 115 can, for example, exit through the distal end of the tip 450 and, for example, enter Schlemm's canal and travel along Schlemm's canal. 4D shows an enlarged side view of the distal tip of catheter 115. As shown in FIG. 4D, catheter 115 can include a rounded tip 452 and a lumen 454 that allows viscoelastic or other fluids to flow therethrough.

[0046] The three sliding layer assemblies shown and described in Figures 4A-4G may advantageously eliminate the need for multiple separate surgical instruments, thereby simplifying the procedure.

[0047] 5A-8B illustrate the internal components of various embodiments of the cannula adapters described herein. A distinct challenge with larger catheter extensions is preventing internal bending of the inner catheter 115 as it is fed through the outer cannula 120. FIGS. 5A-8B show various internal support mechanisms (which may be used separately or one or more mechanisms may be combined together) designed to prevent bending and guide the inner catheter 115 along the outer cannula 120.

[0048] 5A and 5B illustrate side views (in undeployed and fully deployed configurations, respectively) of cannula adapter 500 comprising a collapsible helical support 152 having an inner diameter slightly larger than inner catheter 115 and an outer diameter confined by housing 110. Helical support 152 has a spring force close to zero yet is able to maintain radial stability.

[0049] 6A and 6B illustrate side views (in undeployed and fully deployed positions, respectively) of a cannula adapter 600 including a rigid support tube 154 having an inner diameter sized to fit over inner catheter 115 and an outer diameter sized to slide within outer cannula 120. Rigid support tube 154 may be formed of any suitable rigid material (e.g., 300 series stainless steel). In some embodiments, the use of rigid support tube 154 may cause the diameter of outer cannula 120 to increase.

[0050] 7A and 7B illustrate side views of a cannula adapter 700 including a wheel 701 and catheter feeders 702, 704. The catheter feeders 702, 704 can stabilize and prevent bending of the catheter 115 as it moves distally (e.g., toward the patient) or proximally (e.g., away from the patient). The wheel 701 can be coupled to the catheter feeder 702 such that rotation of the wheel 701 can translate to rotation of the catheter feeder 702. For example, as illustrated in FIG. 7B, counterclockwise rotation of the wheel 701 can cause clockwise rotation of the catheter feeder 702. Clockwise rotation of the catheter feeder 702 can move the catheter 115 distally (e.g., toward the patient). Similarly, clockwise rotation of the wheel 701 can cause counterclockwise rotation of the catheter feeder 702, which can move the catheter 115 proximally (e.g., away from the patient). In some embodiments, catheter feeders 702, 704 are coupled to one another such that rotation of one causes rotation of the other. For example, clockwise rotation of catheter feeder 702 can cause counterclockwise rotation of catheter feeder 704 (as illustrated in FIG. 7B). In some embodiments, movement of catheter 115 (e.g., distal or proximal) can cause rotation of catheter feeder 704. In some embodiments, catheter 115 can be retracted by simply pulling the assembly from syringe 125 (e.g., instead of rotating wheel 700 clockwise).

[0051] 8A and 8B illustrate side views (e.g., in undeployed and fully deployed configurations, respectively) of a telescoping tube 158 that provides support for the catheter 115 while collapsing upon actuation and that may be incorporated into any of the cannula adapter or fluid (e.g., viscoelastic) delivery device embodiments described or illustrated herein.

[0052] 9A-9F illustrate a feeding mechanism 900 that may be used to feed catheter 115 into outer cannula 120. Feeding mechanism 900 may be incorporated into any of the cannula adapter embodiments described or illustrated herein. Feeding mechanism 900 may include a thumb control dial 901 located near the distal end of housing 110 to facilitate one-handed operation by an operator.

[0053] Dial 901 can be rotated by the operator's thumb through interaction with a nub or protrusion 904 extending upward from dial 901. Alternatively, nub or protrusion 904 could comprise a dimple or indent. Dial 901 can be coupled to the proximal end of inner catheter 115 such that, for example, clockwise rotation of dial 901 advances inner catheter 115 in a controlled manner along outer cannula 120, then out of the outer cannula, and into and along Schlemm's canal, while counterclockwise rotation of dial 901 retracts inner catheter 115. Of course, these directions could be reversed as desired and / or required. The distal portion (e.g., inner loop) of inner catheter 115 that extends from the distal tip of outer cannula 120 when dial 901 is fully turned can have a length that corresponds to or corresponds (e.g., approximately equal) to the full 360° circumference of Schlemm's canal, as described herein. In some embodiments, a 360° rotation of dial 901 (illustrated in FIGS. 9B and 9D ) corresponds to 360° of movement of catheter 115 along Schlemm's canal. Additionally, the distal portion of inner catheter 115 can comprise a pre-defined shape (e.g., a shaped material having a defined radius of curvature that corresponds to the radius of curvature of Schlemm's canal) or a flexible material component as described herein.

[0054] Dial 901 can include a button 902 that can be depressed by an operator's thumb. When actuated (e.g., moving from an inactivated position to an activated position), button 902 can cause dispensing of a viscoelastic or other viscous surgical fluid. For example, when actuated, button 902 can cause (e.g., activate) a control valve to dispense the viscoelastic or other viscous surgical fluid. Dispensing of the viscoelastic or other viscous surgical fluid can occur at a constant rate, a variable rate based on the amount button 902 is depressed, or a predetermined bolus amount per button press. In some embodiments, actuation of button 902 can activate a pump, such as a positive displacement pump.

[0055] In some embodiments, delivery mechanism 900 may include indents or detents located at the clock times around dial 901. The indents or detents can provide the operator with an indirect indication of the azimuthal position of catheter 115 within Schlemm's canal without the need for actual visualization by imaging. For example, the detents at each clock time may provide tactile feedback (e.g., a pseudo stop position) to the operator or may generate an audible click to provide audible feedback to the operator. The operator can stop at a given clock time, dispense a predetermined volume of viscoelastic agent or other fluid, and then move on to the next clock time.

[0056] The catheter 115 may be made of one or more bonded materials, such as nylon / Pebax® polymer, polyimide, etc. The proximal end of the catheter 115 may be overmolded (e.g., insert molded) into the dial mechanism or bonded (e.g., with an adhesive) to the dial mechanism. The channel portion that feeds the catheter 115 into the outer cannula 120 may be a separate molded or metal component, or may be formed by the housing 110 of the cannula adapter 100. FIGS. 9E and 9F illustrate examples of how the dial 901 may be incorporated into or assembled with the housing 110. The inner catheter 115 may be connected to a fluid delivery system (not shown), such as a valve or syringe (e.g., as described herein), via a separate section of tubing 906 fluidly coupled to the catheter 115 (as shown in FIGS. 9E and 9F) or via a channel formed in a molded component. In some configurations, the valve may be integrated directly into the dial mechanism.

[0057] The cannula adapters described and illustrated herein may incorporate a variety of different viscoelastic agent dispensing mechanisms or systems. FIGS. 10A-10C illustrate an embodiment of a delivery system 1050 with the cannula adapter 900 of FIGS. 9A-9F. The delivery system 1050 may include a reservoir 1001, a spring 1002, a connector 1004, a stopper 1006, and a base member 168. The reservoir 1001 (or cartridge) may be removably coupled (e.g., by a friction fit, mating engaging components, latches and notches, etc.) to the housing 110 of the cannula adapter 900. The reservoir 1001 may include a spring 1002 that can be retracted into a compressed position (or configuration) prior to use, as shown in FIG. 10A. A stopper 1006 (e.g., a rubber stopper) may be located within and near the proximal end of the reservoir 1001 (e.g., the end opposite the supply mechanism 900). A connector 167 (e.g., a female Luer connector) can be located at the distal end of reservoir 1001 (e.g., the end proximal to delivery mechanism 900) to facilitate direct connection to any standard viscoelastic syringe or other viscosurgical device (e.g., pre-filled ocular viscoelastic device 125). In some embodiments (not shown), there can be a septum at the distal end of reservoir 1001 that can be pierced with a needle or dispensing cannula.

[0058] The reservoir 1001 may be filled with fluid 126 (e.g., viscoelastic or other ocular viscosurgical device (OVD) fluid) by depressing the plunger of a standard viscoelastic syringe 125. As the reservoir 1001 fills, the stopper 1006 may be forced back against the compressed spring 1002. To allow for further purging of air during this filling, the reservoir 1001 may be integrated with a vent valve or a breathable material, such as a porous plastic or porous polymer material. Once the desired amount of fluid 126 (e.g., viscoelastic or other fluid) has been added to the reservoir 1001, a delivery system 1050 may be connected to the housing 110 comprising the catheter 115. Once the delivery system 1050 is connected to the housing 110, the base member 1008 may be rotated to release the spring 1002, which applies a force to the stopper 1006. The spring 1002 may be coupled to the base member 1008 such that it can be manipulated to facilitate engagement (e.g., compression and relaxation) of the spring 1008 upon actuation of the base member 168. In some embodiments, rotation of the base member 1008 can cause compression or relaxation of the spring 1008. According to some embodiments, the delivery system 1050 of FIGS. 10A-10C can advantageously accommodate any selection of viscoelastic or other fluids and various amounts of viscoelastic or other fluids. The delivery system 1050 can ensure a consistent spring force is applied to the reservoir 1001 when filled.

[0059] 11A and 11B, a fillable cannula adapter 1100 is disclosed herein. The embodiment of the cannula adapter 1100 illustrated in FIGS. 11A and 11B utilizes a screw-drive (or threaded plunger) system that can be incorporated into the housing 110 of the cannula adapter 1100 or the housing of other embodiments of the cannula adapters described herein. The cannula adapter 1100 can include a threaded plunger 1112, a wheel 1110, a reservoir 1101, and a connector 1104 (e.g., a standard Luer connector or a check valve). The reservoir 1101 can be filled (e.g., primed) with fluid 126 from a syringe 125 (e.g., a standard viscoelastic syringe), and a cap or other sealing member can be placed on the rear end of the reservoir 1101 prior to operation. The wheel 1110 can be located and positioned such that it is accessible via a slot formed in the belly (e.g., bottom or underside) of the housing 110. The wheel 1110 can be conveniently positioned to be rotated by an operator's index or middle finger when the housing 110 is held in the operator's hand with the thumb over the dial 900. The threaded plunger 1112 can be operably and mechanically coupled to the wheel 1110 such that the threaded plunger 1112 is actuated by rotation of the wheel 1110. The threaded plunger 1112 and the wheel 1110 can include lumens that are fluidly coupled to tubing (e.g., flexible silicone tubing), which in turn is fluidly coupled to the lumen of the catheter 115. In some embodiments, the lumen of the threaded plunger 1112 can be directly coupled to the lumen of the catheter 115 without intermediate tubing. As the threaded plunger 1112 pushes against the reservoir 1101 , fluid 126 (eg, viscoelastic or other ocular viscosurgical device (OVD) fluid) is dispensed back through the plunger 1112 towards the catheter 115 .

[0060] 11A and 11B is coupled to the supply mechanism 900 described and illustrated in connection with FIGS. 9A-9F, the fluid delivery system of FIGS. 11A and 11B would theoretically be useful with any suitable supply system embodiment. According to some embodiments, the catheter 115 can be moved (e.g., by the supply mechanism 900) independently of the threaded plunger 1112, thereby allowing the operator to dispense fluid at any time. This independent movement capability may be implemented by connecting the plunger tube (e.g., tubing extending through the lumen of the wheel 1110 and plunger 1112) to the catheter 115 via flexible tubing with slack (e.g., silicone tubing). Alternatively, the connection between the plunger tube and the catheter 115 may be made using Pebax® polymer tubing or other more durable tubing, or rigid tubing with a spring-like configuration to allow independent movement of the catheter 115.

[0061] The connector 1104 (e.g., a female connector) can allow the operator to fill the reservoir 1101 using any standard viscoelastic syringe 125, as in the delivery system 1050 illustrated in FIGS. 10A-10C. The reservoir 1101 and the entire downstream system could be primed using the syringe 125. The reservoir 1101 and stopper 1106 (e.g., a rubber stopper) could be shaped to simplify the filling procedure and prevent unwanted air entrapment. The operator could then remove the viscoelastic syringe 125 and replace it with a plug or cap 1105. The plug or cap 1105 could be shaped to ergonomically form the remainder of the handle. The cap 1105 could also have an extension that protrudes into the reservoir 1101 when attached to expel any last traces of air from the connection. Alternatively, the device could include a valve that can be closed when priming is complete.

[0062] Wheel 1110 of housing 110 (e.g., exposed on the underside of housing 110) may include a pawl to provide an indication of the volume dispensed. For example, the pawl may produce an audible click or tactile feedback for each volume increment. The pawl may be user-configurable so that the operator can choose to have clicks every 2 μL or every 5 μL, for example. Of course, other volume indicators may be used as desired and / or required. In some embodiments, the underside (or underside) of housing 110 may include a plurality of spaced linear indicia indicating the total volume dispensed so far or the remaining volume left in the reservoir (e.g., reservoir 1101). This mechanism could be driven by a coupled screw or, for example, on a gear and pinion system with a coarser pitch to amplify the linear motion.

[0063] 11A and 11B can advantageously include a fluid delivery system configured for one-handed use that should be familiar to the operator. The fluid delivery system allows for dispensing of viscoelastic or other fluids at any time, as opposed to being coupled to the movement of the inner catheter, thereby allowing the operator to move the inner catheter through any barriers or obstructions encountered or encountered during movement along Schlemm's canal.

[0064] 12A and 12B illustrate an embodiment of a delivery system 1250 that may be incorporated into the cannula adapter described herein. The delivery system 1250 may advantageously enable regulated microbolus dispensing. The delivery system 1250 may include a resilient (e.g., flexible) tube 1210 that is charged by closing a distal end 1214 of the tube 1210 and opening a proximal end 1212 of the tube 1210 to a pressurized (e.g., spring-loaded) reservoir 1200. The reservoir 1200 may include a spring 1202 and a stopper 1204 having structural and operational features similar to those of the delivery system 1050 described in connection with FIGS. 10A-10C. 12A, the operator may toggle a switch (not shown) to close the proximal end 1212 and open the distal end 1214 to empty the flexible tube 1210 into the catheter 115. The length, diameter, and stiffness of the flexible tube 1210 may be varied to achieve a desired bolus volume.

[0065] Opening and closing the proximal end 1212 and the distal end 1214 can be facilitated by a controller directing the block 1220 to move between different positions. For example, the block 1220 can have a first position (shown in FIG. 12A ) and a second position (shown in FIG. 12B ). When the block 1220 is in the first position, the first opening 1222 of the block 1220 can fluidly connect the proximal end 1212 of the tube 1210 to the reservoir 1200, while the second opening 1224 can be offset from the distal end 1214 to fluidly isolate the distal end 1212 from the catheter 115. Thus, when the block 1220 is in the first position, fluid 126 (e.g., viscoelastic or other ocular viscosurgical device (OVD) fluid) stored in the reservoir 1200 can enter the tube 1210 through the proximal end 1212 and fill the tube 1210 up to the distal end 1214. When the block 1220 is in the second position, the first opening 1222 can be offset from the proximal end 1212 to fluidly isolate the reservoir 1200 from the proximal end 1212, while the second opening 1224 can fluidly connect the distal end 1214 to the catheter 115. Thus, when the block is in the second position, fluid stored in the tube 1200 (e.g., between the proximal end 1212 and the distal end 1214) can be released into the catheter 115 through the second opening 1224.

[0066] 13A-13C illustrate an embodiment of a peristaltic fluid delivery system 1300. The peristaltic fluid delivery system 1300 can include a resilient (or flexible) tube 1320 and a peristaltic pump 1310 (shown in FIGS. 13B and 13C ) that includes protrusions 1350 (e.g., roller or ball bearings) adapted to sequentially compress or squeeze the tube 1320 at spaced locations along its length to convey fluid between the reservoir 1300 containing the fluid 126 and the catheter 115. At least a portion of the tube 1320 and protrusions 1350 can be housed within a circular pump casing 1360. The peristaltic pump 1310 can be a rotary peristaltic pump (as shown) or a linear peristaltic pump.

[0067] In the illustrated embodiment, the tube 1320 can be disposed within a pump case 1360 around a protrusion 1350 (e.g., a ball bearing) on ​​a rotor 1352. The pump case 1360 can be actuated (e.g., pushed toward the rotor 1352) to pinch (e.g., compress) at least a portion of the tube 1320 with the protrusion 1350. While the pump case 1360 is actuated, rotation of the rotor 1352 forces the fluid 126 downstream along the tube 1320. As each of the pump elements 1350 disengages from the tube 1320, fluid flow is induced within its respective portion of the tube 1320. FIGS. 13B and 13C illustrate cross-sectional views of a peristaltic pump 1310. The peristaltic fluid delivery system 1300 can be primed (e.g., allowing the fluid 126 to enter the tube 1320) before the tube 1320 engages the pump element 1350. In some embodiments, the pump 1310 can be actuated by rotating the rotor 1352 after priming.

[0068] FIG. 14 illustrates various concepts related to catheter shapes and features that facilitate visualization or tracking of the catheter 115 as it advances along Schlemm's canal. A key challenge in viscous or other fluid delivery procedures is knowing where the tip of the inner catheter is so that it does not migrate to an unfavorable anatomical location (e.g., the suprachoroidal space when the target is Schlemm's canal). The top diagram shows a standard catheter lumen. The second diagram from the top shows that the distal end of the inner catheter can have a bulbous tip. This can be achieved by overmolding material onto an extruded lumen. Referring to the third diagram in the middle row, the catheter itself (e.g., catheter 115) can be formed using a polymer with a phosphorescent colorant so that it can be activated by microscope light or an ultraviolet / blue light source and then glow when the lights are dimmed. Alternatively, the operator can have an ultraviolet / blue light source attached to the surgical microscope that can be turned on during the procedure to make the phosphorescent catheter easier to see. In the embodiment illustrated in the fourth (second from the bottom) figure, the catheter has a bulbous distal tip that is colored with a phosphorescent colorant (e.g., a glow-in-the-dark material such as strontium aluminate). The bulbous tip may be overmolded onto the distal end of the extruded lumen. The final bottom figure shows that the catheter 115 may have contrast marks 1400 spaced along the length of the inner catheter to aid in visualization of the inner catheter (e.g., to indicate which portion of the inner catheter is visible through the trabecular meshwork). The distal tip may have more advanced contrast marks (e.g., longer or wider) to indicate the distal tip of the inner catheter. The cannula adapters described herein may be designed for use without a fiber optic cable to reduce cost.

[0069] 15A and 15B schematically illustrate the operation of an outer cannula 1500 that utilizes a shape memory material (e.g., nitinol or other shape memory alloy material) to form a shape-set distal tip 1520. The cannula's distal tip 1520 can be straight when constrained by an introducer needle 1510 (e.g., 304 stainless steel material, other 300 series stainless steel material, or other material), but curves to a set shape when no longer constrained (e.g., by the introducer needle). This set-shape configuration allows the outer cannula 1500 to slide within the rigid introducer needle 1510, but curve as it slides forward out of the introducer needle 1510 to enter Schlemm's canal.

[0070] 16 illustrates an embodiment of a distal end portion (e.g., distal tip) 120 of the outer cannula. As shown, the distal end portion (e.g., distal tip) may include a notch 1600 in the tubing to allow the cannula 120 to articulate in a particular direction. In some embodiments, the distal end portion (e.g., distal tip) is connected to a pull wire to allow an operator to adjust the articulation of the cannula 120 near the notched distal tip. In some embodiments, the tip of the outer cannula 120 may be configured to seat or be secured to the posterior wall of Schlemm's canal to prevent inadvertent tip movement, for example, during a viscous or other fluid delivery procedure.

[0071] 17A-17H, a cannula adapter or fluid delivery device embodiment 1700 is disclosed. The cannula adapter 1700 can include a housing 110, a first slider 1702, a second slider 1704, a channel 1703, a fluid delivery conduit 1716, a stopper 1790, and a distal end 1706. The distal end 1706 can include an opening sized to receive the cannula 120. The first slider 1702 can be mechanically and / or operably coupled to the reservoir 1780 and the plunger 1712. The second slider 1704 can include an insert 1740, which can be formed, for example, on the underside of the second slider 1704.

[0072] The fluid delivery conduit 1716 can comprise a proximal base 1709, a body 1708, and a tube 1714. The fluid delivery conduit 1716 can be disposed within the insert 1740 of the second slider 1704 (as shown in FIG. 17H ). In some embodiments, at least a portion of the body 1708 and the base 1709 is disposed within the insert 1740 of the second slider 1704. The tube 1714 of the fluid delivery conduit 1716 can be coupled to the catheter 115 in a manner that allows it to be manipulated such that distal and proximal movement of the fluid delivery conduit 1716 can move the catheter 115 distally or proximally. In some embodiments, the tube 1714 is directly connected to the catheter 115. In some embodiments, the tube 1714 is indirectly connected to the catheter 115 via an intermediate tube. The tube 1714 is fluidly coupled to the catheter 115.

[0073] 17D and 17E , the body 1708 of the fluid delivery conduit 1716 can include a bore 1720 that can receive a plunger 1712, which can slide within the bore 1720 of the body 1708. The plunger 1712 can include a lumen 1722 that can allow the fluid (e.g., viscoelastic fluid) to flow through the plunger 1712, enter the bore 1720 of the fluid delivery conduit 1716, and flow through the tube 1714 toward the catheter 115.

[0074] In operation, the first slider 1702 and the second slider 1704 can move together distally (e.g., toward the distal end 1706) along the channel 1703. As described herein, distal movement of the second slider 1704 can cause distal movement of the fluid delivery conduit 1716 (e.g., toward the distal end 1706), which in turn can cause the catheter 115 to move distally and out of the cannula 120. Referring to the example illustrated in FIG. 1F , an operator can enter a supratrabecular space (TM) portion with the distal portion 121 of the cannula 120 and slide the first slider 1702 and the second slider 1704 to guide the catheter 115 out of the cannula 120 and into Schlemm's canal (SC).

[0075] Once catheter 115 is extended out of cannula 120 (e.g., guided into Schlemm's canal (SC)), first slider 1702 can be used to dispense a fluid (e.g., a viscoelastic fluid) stored in reservoir 1780. To dispense the fluid stored in reservoir 1780, first slider 1702 may be moved proximally along channel 1703 (e.g., away from distal end 1706) and then moved distally along channel 1703 relative to second slider 1704 (e.g., toward distal end 1706). In some embodiments, second slider 1704 remains stationary (e.g., to ensure that catheter 115 does not move) while first slider 1702 is moved along channel 1703 to dispense a fluid (e.g., fluid 126) stored in reservoir 1780. When the first slider 1702 is moved proximally relative to the second slider 1704 along the channel 1703, the plunger 1712 can be moved proximally within the bore 1720 of the body 1708 of the fluid delivery conduit 1716. Proximal movement of the plunger 1712 within the bore 1720 (e.g., relative to the fluid delivery conduit 1716) can cause fluid stored in the reservoir 1780 to flow past the ball 1730 and gasket 1731, into the lumen 1722 of the plunger 1712, and into the bore 1720 of the fluid delivery conduit 1716. Once the fluid has flowed into the bore 1720 of the fluid delivery conduit 1716, the plunger 1712 can be moved distally along the channel 1703 to force the fluid out of the bore 1720 and into the tube 1714. In some embodiments, the bulb 1730 (and gasket 1731 ) can limit the amount of fluid that flows from the reservoir 1780 and into the lumen 1722 of the plunger 1712 .

[0076] In some embodiments, an operator (e.g., a clinician, surgeon, caregiver) can vary the amount of fluid dispensed by varying the distance the first slider 1702 moves along the channel 1703. For example, the more proximally (e.g., toward the operator) the first slider 1702 moves along the channel 1703, the more fluid is dispensed through the catheter 115, and vice versa. In some embodiments, the channel 1703 (or the first slider 1702) can include a tab that can provide tactile feedback as to how far the first slider 1702 is moved proximally (e.g., toward the operator) along the channel 1703 to indicate how much fluid would be dispensed if the first slider 1702 were moved distally back along the channel 1703.

[0077] Together, ball 1730 and gasket 1731 can function as a check valve for plunger 1712. Ball 1730 and gasket 1731 can allow fluid (e.g., fluid 126) to be dispensed from reservoir 1780 while preventing the fluid (e.g., fluid 126) from flowing backward (e.g., toward reservoir 1780) past ball 1730 and gasket 1731. Thus, once fluid has flowed past ball 1730 and gasket 1731, it cannot flow back into reservoir 1780. In some embodiments, other types of suitable valves may be used to provide one-way flow of fluid (e.g., fluid 126) from reservoir 1780 through plunger 1712.

[0078] In some implementations, a user may experience increased resistance when sliding the second slider 1704 back and forth to dispense fluid from the reservoir 1780 than when sliding both first sliders 1702 to move the catheter 115 out of the cannula 120. This resistance may be caused by greater friction between the second slider 1704 and the first slider 1702 (and channel 1703) than between the first slider 1702 and the channel 1703. This difference in resistance may provide tactile feedback that may, for example, allow a user to distinguish between a catheter-dispensing movement (e.g., sliding the first slider 1702) and a fluid-dispensing movement (e.g., sliding the second slider 1704).

[0079] In some embodiments, the second slider 1704 can include a groove 1705 through which the first slider 1702 can move (e.g., slide) distally or proximally. The first slider 1702 and the second slider 1704 can include ridges 1752 and grooves 1750 that can provide a better grip for the operator (e.g., a caregiver).

[0080] In some embodiments, cannula 120 can include a protrusion 1750 that can fixedly attach cannula 120 to an insert formed within distal end 1706 (as shown in the example illustrated in FIG. 17F). Thus, distal end 1706 can be rotated to change the orientation of cannula 120, and thus the orientation of distal portion 121 of cannula 120. This can advantageously allow an operator to change the orientation of cannula 120 by rotating distal end 1706 without having to change the orientation of cannula adapter 1700 (e.g., by rotating about an axis parallel to the length of the cannula adapter).

[0081] Cannula adapter 1700 can include a stopper 1790 that can be positioned within channel 1703. Stopper 1790 can prevent distal movement of first slider 1702 and second slider 1704, for example, during storage or operation. This can advantageously prevent catheter 115 from accidentally or inadvertently extending from cannula 120.

[0082] 17E , a gasket 1710 may be disposed within the base 1709 of the fluid delivery conduit 1716. The gasket 1710 may be dimensioned to fit snugly within the base 1709 and include an opening (e.g., a circular opening) to receive the plunger 1712. In some embodiments, the gasket 1710 may contact the outer surface of the plunger 1712 to generate sufficient resistance to cause smooth, controlled movement of the plunger 1712 within the bore 1720 of the body 1708.

[0083] 18A-18D illustrate various views of cannula 120 and catheter 115. As described herein, cannula 120 can include a distal portion 121 capable of penetrating a portion of the trabecular meshwork (TM) space with a tip 1800 and an end surface 1804. End surface 1804 can be formed at an angle (e.g., oblique) relative to an axis parallel to the body of cannula 120. Surface 1804 can facilitate penetration of a portion of the trabecular meshwork (TM), for example. In some embodiments, end surface 1804 can be perpendicular (or substantially perpendicular) to an axis parallel to the body of cannula 120. Tip 1800 can form a beveled distal tip to facilitate a cutting edge. The distal portion 121 may be curved to allow the catheter 115 to extend (e.g., exit) from the lumen 1802 of the cannula 120 at an angle, which may facilitate movement of the catheter 115 into and around Schlemm's Canal (SC). The catheter 115 may include a distal end 1810 having a tapered edge portion 1812. The tapered edge portion 1812 may facilitate and guide movement of the catheter 115 within the curved distal portion 121 and inside Schlemm's Canal (SC).

[0084] 18E-18H illustrate other examples of distal portion 121 of cannula 120. Distal portion 121 can include one or more notches 1852 that can be formed at tip 1800 of distal portion 121 to provide one or more cutting edges or surfaces. In some embodiments, notches 1852 can be formed at a distal edge of distal portion 121 (e.g., an edge away from a portion of cannula 120 proximal to distal portion 121). In some embodiments including multiple notches 1852, notches 1852 can be formed adjacent to one another (e.g., as shown in FIGS. 18G and 18H). Slits 1852 can include anchors 1854 that can abut a surface (e.g., the posterior wall of Schlemm's canal) and stabilize cannula 120 (e.g., prevent distal portion 121 of cannula 120 from moving around) during fluid dispensing through a catheter (e.g., catheter 115). In some embodiments, anchors 1854 can penetrate a tissue surface (e.g., the posterior wall of Schlemm's canal) during use. Distal portion 121 described herein and shown in Figures 18E-18H may be incorporated into any embodiment of cannula 120 described herein.

[0085] 19A and 19B illustrate an example mode of operation of the cannula adapter 1900. The cannula adapter 1900 can include a slider 202, a cannula 120, a dispensing mechanism 1902, and a reservoir 1904. An operator can slide the slider 202 distally (e.g., toward the patient), for example, to direct a catheter out of the cannula 120 and into Schlemm's canal. The operator can then actuate the reservoir 1904 to dispense fluid into and out of the catheter 115. In some embodiments, the dispensing mechanism 1902 can include a fixed plunger disposed within the reservoir 1904 that forces fluid out of the reservoir 1904 when the reservoir 1904 is rotated about an axis parallel to the length of the cannula adapter 1900. In some embodiments, the dispensing mechanism 1902 may include a plunger disposed within the reservoir 1904 and connected to a resilient member (e.g., a spring), which can push fluid out of the reservoir 1904 and toward the catheter 115, for example, when the proximal end of the reservoir 1904 is pushed distally (e.g., toward the patient).

[0086] In some implementations, Trypan blue or some other biocompatible dye (e.g., brilliant blue, indocyanine green, fluorescein) is introduced into the reservoir 164 prior to filling. Introducing the biocompatible dye may allow the operator to visualize the degree of dilation in Schlemm's canal and the downstream episcleral venous network.

[0087] Several additional components may be integrated with the above concepts. For example, a sealing component wrapped around the outside of the outer cannula 120 or introducer needle, such as a flexible / elastomeric overmolding or O-ring that fits inside or presses against the corneal incision during surgery to prevent aqueous humor leakage. Alternatively, a buffered saline solution (BSS) irrigation path through the outer cannula 120 may be used to provide chamber stability.

[0088] Although described primarily with respect to the delivery of viscoelastic agents within Schlemm's canal, the devices and methods described and illustrated herein could be used in connection with the delivery of viscoelastic agents or other fluids to other existing or created anatomical passageways, channels, spaces, lumens, or blood vessels, either associated with the eye (e.g., collector channels, downstream episcleral venous networks, ocular tissue canals, suprachoroidal space, subconjunctival space, subretinal space) or at sites outside the eye. Fluids other than viscoelastic agents (e.g., other liquids, medications, solutions, chemicals, etc.) may be used.

[0089] Conditional language, such as "can," "could," "might," or "may," among others, is otherwise understood in its commonly used context to convey that certain embodiments include certain features, elements, and / or steps, while other embodiments do not include certain features, elements, and / or steps, unless otherwise indicated. Thus, such conditional language generally does not imply that features, elements, and / or steps are in any way required for one or more embodiments, or that one or more embodiments necessarily include logic for determining whether those features, elements, and / or steps are included or performed in any particular embodiment, with or without user input or prompting.

[0090] Transitional language such as the phrase "at least one of X, Y, and Z" is otherwise understood in its commonly used context to convey that an item, item, etc. is either X, Y, or Z, unless otherwise indicated. Thus, such transitional language does not generally imply that a particular embodiment requires that at least one of X, at least one of Y, and at least one of Z, respectively, be present.

[0091] Several embodiments have been described in connection with the accompanying drawings. However, these figures are not drawn to scale. Distances, angles, and the like are merely illustrative and do not necessarily bear an exact relationship to the actual dimensions and layout of the illustrated devices. Components may be added, removed, and / or rearranged. Furthermore, any particular features, aspects, methods, properties, characteristics, qualities, attributes, elements, etc. disclosed herein in connection with various embodiments may be used in all other embodiments shown herein.

[0092] It should be emphasized that numerous variations and modifications may be made to the above-described embodiments, and that elements of the above-described embodiments are understood to be among other acceptable examples, and all such variations and modifications are intended to be included herein within the scope of this disclosure.

Claims

1. 1. A device for delivering a fluid, comprising: a housing including a connector configured to be fluidly coupled to a drug-filled ocular viscoelastic device; a fillable reservoir for storing a fluid; a cannula including a proximal end, a distal end, and a lumen, the proximal end of the cannula coupled to the distal end of the housing, the distal end of the cannula configured to enter a patient's eye through a corneal incision, the lumen of the cannula extending from the proximal end to the distal end of the cannula; a catheter including a proximal end, a distal end, and a lumen, the proximal end of the catheter being fluidly coupled to the reservoir, the lumen extending from the proximal end of the catheter to the distal end of the catheter; a first actuator configured, when actuated by a first manipulation by an operator, to advance the catheter along the lumen of the cannula and cause the catheter to exit through the distal end of the cannula; a second actuator configured, when actuated by a second manipulation by an operator, to cause fluid stored in the reservoir to flow through the catheter and exit through the distal end of the catheter; Including, the catheter lumen is configured to allow fluid stored in the reservoir to flow through the catheter and into the patient's eye; the catheter is sized to extend out of the distal end of the cannula along a full 360° circumference of Schlemm's canal of the patient upon actuation of a first actuator; the second actuator is movable relative to the first actuator such that dispensing of fluid stored in the reservoir is decoupled from movement of the catheter. Device.

2. The device of claim 1 , wherein the distal end of the cannula comprises a spatula having a sharp tip.

3. The device of claim 1 or 2, wherein the distal end of the cannula is pre-curved.

4. The device of any one of claims 1 to 3, wherein at least a distal portion of the catheter is pre-shaped to follow the curvature of Schlemm's canal.

5. The device of any one of claims 1 to 4, wherein at least a distal portion of the catheter is flexible.

6. The device of any one of claims 1 to 5, wherein the cannula comprises a rigid material.

7. The device of any one of claims 1 to 6, wherein the distal end of the cannula includes a notch and two or more anchors.

8. The device of claim 1 , wherein the first actuator and the second actuator are configured to be operable by one hand of the operator.

9. the housing further includes a channel; the first actuator includes a first sliding trigger adapted to move axially within the channel between a proximal position and a distal position; the second actuator includes a second sliding trigger adapted to move axially within the channel between a proximal position and a distal position; An apparatus according to any one of claims 1 to 8.

10. when the first sliding trigger is in the proximal position, the distal end of the catheter is located between the proximal and distal ends of the cannula; when the first sliding trigger is in the distal position, the distal end of the catheter advances past the distal end of the cannula; Movement of the second sliding trigger between the proximal and distal positions causes a predetermined amount of fluid to be dispensed through the distal end of the catheter.

10. The apparatus of claim 9.

11. 10. The device of claim 9, wherein an amount of axial movement of the second sliding trigger along the channel corresponds to an amount of fluid dispensed from the catheter.

12. 10. The device of claim 9, wherein the catheter is positioned and sized such that when the first actuator is retracted to its proximal-most position within the channel, the distal end of the catheter is aligned with the distal end of the cannula.

13. 1. A device for delivering a fluid, comprising: a housing including a proximal connector, the proximal connector configured to be fluidly coupled to a drug-filled ocular viscoelastic device; a reservoir configured to store a fluid; a cannula configured to be inserted through a corneal incision into Schlemm's canal, the cannula including a lumen; a catheter including a proximal end, a distal end, and a lumen, the proximal end fluidly coupled to the reservoir, the distal end configured to advance past the distal end of the cannula, and the lumen configured to allow fluid stored in the reservoir to flow through the catheter and be dispensed through the distal end of the catheter; a first slidable trigger configured to move between an inactivated position and an activated position when actuated by a first manipulation by an operator to cause the catheter to advance along the lumen of the cannula and past the distal end of the cannula; a second slidable trigger configured to move between an inactivated position and an activated position when actuated by a second manipulation by an operator to cause fluid stored in the reservoir to be dispensed through the lumen of the catheter and into Schlemm's canal; An apparatus comprising:

14. 1. A device for delivering a fluid, comprising: a reservoir configured to store a fluid; a cannula including a lumen configured to enter the patient's eye through a corneal incision; a catheter including a proximal end and a distal end, the catheter configured to advance along the lumen of the cannula, the catheter including a lumen configured to allow fluid stored in the reservoir to be dispensed through the catheter; a first actuator configured to be operable by an operator's operation; a second actuator configured to be operable by an operator's operation; Including, actuation of the first actuator by a first manipulation by the operator causes the catheter to advance along the cannula; actuation of the second actuator by a second operation by the operator causes the fluid to be dispensed from the reservoir through the catheter; actuation of the first actuator and actuation of the second actuator are operable independently of one another such that dispensing of fluid from the reservoir is decoupled from advancement of the catheter; Device.

15. the second actuator is configured to slide between an inactive position and an active position to cause the fluid to be dispensed; the amount of fluid dispensed is based at least in part on the distance between the inactive position and the active position; 15. The apparatus of claim 14.

16. 16. The apparatus of claim 14 or 15, wherein the distal end of the catheter includes a bulbous distal tip.

17. The apparatus of any one of claims 14 to 16, wherein at least a portion of the catheter includes a phosphorescent colorant.

18. 18. The apparatus of any one of claims 14 to 17, wherein at least a portion of the catheter includes contrast marks spaced along the length of the catheter.

19. The device of any one of claims 14 to 18, wherein at least the distal end of the cannula is constructed from a shape memory material.

20. 20. The device of any one of claims 14 to 19, wherein at least the distal end of the cannula includes notches to facilitate articulated deformation of the distal end of the cannula.

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